While looking at an objtool UACCESS warning, it suddenly occurred to me
that it is entirely possible to have an OPTPROBE right in the middle of
an UACCESS region.
In this case we must of course clear FLAGS.AC while running the KPROBE.
Luckily the trampoline already saves/restores [ER]FLAGS, so all we need
to do is inject a CLAC. Unfortunately we cannot use ALTERNATIVE() in the
trampoline text, so we have to frob that manually.
Fixes: ca0bbc70f147 ("sched/x86_64: Don't save flags on context switch")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lkml.kernel.org/r/20200305092130.GU2596@hirez.programming.kicks-ass.net
When booting x86 images in qemu, the following warning is seen randomly
if DEBUG_LOCKDEP is enabled.
WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:1119
lockdep_register_key+0xc0/0x100
static_obj() returns true if an address is between _stext and _end.
On x86, this includes the brk memory space. Problem is that this memory
block is not static on x86; its unused portions are released after init
and can be allocated. This results in the observed warning if a lockdep
object is allocated from this memory.
Solve the problem by implementing arch_is_kernel_initmem_freed() for
x86 and have it return true if an address is within the released memory
range.
The same problem was solved for s390 with commit
7a5da02de8 ("locking/lockdep: check for freed initmem in static_obj()"),
which introduced arch_is_kernel_initmem_freed().
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200131021159.9178-1-linux@roeck-us.net
Straightforward, except for compat_save_altstack_ex() stuck in those.
Replace that thing with an analogue that would use unsafe_put_user()
instead of put_user_ex() (called unsafe_compat_save_altstack()) and
be done with that...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Just do copyin into a local struct and be done with that - we are
on a shallow stack here.
[reworked by tglx, removing the macro horrors while we are touching that]
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Just do a copyin of what we want into a local variable and
be done with that. We are guaranteed to be on shallow stack
here...
Note that conditional expression for range passed to access_ok()
in mainline had been pointless all along - the only difference
between vm86plus_struct and vm86_struct is that the former has
one extra field in the end and when we get to copyin of that
field (conditional upon 'plus' argument), we use copy_from_user().
Moreover, all fields starting with ->int_revectored are copied
that way, so we only need that check (be it done by access_ok()
or by user_access_begin()) only on the beginning of the structure -
the fields that used to be covered by that get_user_try() block.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
... and consolidate the definition of sigframe_ia32->extramask - it's
always a 1-element array of 32bit unsigned.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
... to find whether there are northbridges present on the
system. Convert the last forgotten user and therefore, unexport
amd_nb_misc_ids[] too.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Michal Kubecek <mkubecek@suse.cz>
Cc: Yazen Ghannam <yazen.ghannam@amd.com>
Link: https://lkml.kernel.org/r/20200316150725.925-1-bp@alien8.de
- Map EFI runtime service data as encrypted when SEV is enabled otherwise
e.g. SMBIOS data cannot be properly decoded by dmidecode.
- Remove the warning in the vector management code which triggered when a
managed interrupt affinity changed outside of a CPU hotplug
operation. The warning was correct until the recent core code change
that introduced a CPU isolation feature which needs to migrate managed
interrupts away from online CPUs under certain conditions to achieve the
isolation.
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Merge tag 'x86-urgent-2020-03-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
"Two fixes for x86:
- Map EFI runtime service data as encrypted when SEV is enabled.
Otherwise e.g. SMBIOS data cannot be properly decoded by dmidecode.
- Remove the warning in the vector management code which triggered
when a managed interrupt affinity changed outside of a CPU hotplug
operation.
The warning was correct until the recent core code change that
introduced a CPU isolation feature which needs to migrate managed
interrupts away from online CPUs under certain conditions to
achieve the isolation"
* tag 'x86-urgent-2020-03-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/vector: Remove warning on managed interrupt migration
x86/ioremap: Map EFI runtime services data as encrypted for SEV
- Shut down the per CPU thermal throttling poll work properly when a CPU
goes offline. The missing shutdown caused the poll work to be migrated
to a unbound worker which triggered warnings about the usage of
smp_processor_id() in preemptible context
- Fix the PPIN feature initialization which missed to enable the
functionality when PPIN_CTL was enabled but the MSR locked against
updates.
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Merge tag 'ras-urgent-2020-03-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RAS fixes from Thomas Gleixner:
"Two RAS related fixes:
- Shut down the per CPU thermal throttling poll work properly when a
CPU goes offline.
The missing shutdown caused the poll work to be migrated to a
unbound worker which triggered warnings about the usage of
smp_processor_id() in preemptible context
- Fix the PPIN feature initialization which missed to enable the
functionality when PPIN_CTL was enabled but the MSR locked against
updates"
* tag 'ras-urgent-2020-03-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mce: Fix logic and comments around MSR_PPIN_CTL
x86/mce/therm_throt: Undo thermal polling properly on CPU offline
The value in "new" is constructed from "old" such that all bits defined
as reserved by the ACPI spec[1] are left untouched. But if those bits
do not happen to be all zero, "new < 3" will not evaluate to true.
The firmware of the laptop(s) Medion MD63490 / Akoya P15648 comes with
garbage inside the "FACS" ACPI table. The starting value is
old=0x4944454d, therefore new=0x4944454e, which is >= 3. Mask off
the reserved bits.
[1] https://uefi.org/sites/default/files/resources/ACPI_6_2.pdf
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206553
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Jan Engelhardt <jengelh@inai.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
BGRT is for displaying seamless OEM logo from booting to login screen;
however, this mechanism does not always work well on all configurations
and the OEM logo can be displayed multiple times. This looks worse than
without BGRT enabled.
This patch adds a kernel parameter to disable BGRT in boot time. This is
easier than re-compiling a kernel with CONFIG_ACPI_BGRT disabled.
Signed-off-by: Alex Hung <alex.hung@canonical.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
g++ insists that function declaration must start with extern "C"
(which asmlinkage expands to).
gcc doesn't care.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The vector management code assumes that managed interrupts cannot be
migrated away from an online CPU. free_moved_vector() has a WARN_ON_ONCE()
which triggers when a managed interrupt vector association on a online CPU
is cleared. The CPU offline code uses a different mechanism which cannot
trigger this.
This assumption is not longer correct because the new CPU isolation feature
which affects the placement of managed interrupts must be able to move a
managed interrupt away from an online CPU.
There are two reasons why this can happen:
1) When the interrupt is activated the affinity mask which was
established in irq_create_affinity_masks() is handed in to
the vector allocation code. This mask contains all CPUs to which
the interrupt can be made affine to, but this does not take the
CPU isolation 'managed_irq' mask into account.
When the interrupt is finally requested by the device driver then the
affinity is checked again and the CPU isolation 'managed_irq' mask is
taken into account, which moves the interrupt to a non-isolated CPU if
possible.
2) The interrupt can be affine to an isolated CPU because the
non-isolated CPUs in the calculated affinity mask are not online.
Once a non-isolated CPU which is in the mask comes online the
interrupt is migrated to this non-isolated CPU
In both cases the regular online migration mechanism is used which triggers
the WARN_ON_ONCE() in free_moved_vector().
Case #1 could have been addressed by taking the isolation mask into
account, but that would require a massive code change in the activation
logic and the eventual migration event was accepted as a reasonable
tradeoff when the isolation feature was developed. But even if #1 would be
addressed, #2 would still trigger it.
Of course the warning in free_moved_vector() was overlooked at that time
and the above two cases which have been discussed during patch review have
obviously never been tested before the final submission.
So keep it simple and remove the warning.
[ tglx: Rewrote changelog and added a comment to free_moved_vector() ]
Fixes: 11ea68f553 ("genirq, sched/isolation: Isolate from handling managed interrupts")
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lkml.kernel.org/r/20200312205830.81796-1-peterx@redhat.com
Every time a new architecture defines the IMA architecture specific
functions - arch_ima_get_secureboot() and arch_ima_get_policy(), the IMA
include file needs to be updated. To avoid this "noise", this patch
defines a new IMA Kconfig IMA_SECURE_AND_OR_TRUSTED_BOOT option, allowing
the different architectures to select it.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Philipp Rudo <prudo@linux.ibm.com> (s390)
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Family 19h CPUs are Zen-based and still share most architectural
features with Family 17h CPUs, and therefore still need to call
init_amd_zn() e.g., to set the RECLAIM_DISTANCE override.
init_amd_zn() also sets X86_FEATURE_ZEN, which today is only used
in amd_set_core_ssb_state(), which isn't called on some late
model Family 17h CPUs, nor on any Family 19h CPUs:
X86_FEATURE_AMD_SSBD replaces X86_FEATURE_LS_CFG_SSBD on those
later model CPUs, where the SSBD mitigation is done via the
SPEC_CTRL MSR instead of the LS_CFG MSR.
Family 19h CPUs also don't have the erratum where the CPB feature
bit isn't set, but that code can stay unchanged and run safely
on Family 19h.
Signed-off-by: Kim Phillips <kim.phillips@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200311191451.13221-1-kim.phillips@amd.com
The "Intel 64 and IA-32 Architectures Software Developer’s Manual Volume 4:
Model-Specific Registers" has the following table for the values from
freq_desc_byt:
000B: 083.3 MHz
001B: 100.0 MHz
010B: 133.3 MHz
011B: 116.7 MHz
100B: 080.0 MHz
Notice how for e.g the 83.3 MHz value there are 3 significant digits, which
translates to an accuracy of a 1000 ppm, where as a typical crystal
oscillator is 20 - 100 ppm, so the accuracy of the frequency format used in
the Software Developer’s Manual is not really helpful.
As far as we know Bay Trail SoCs use a 25 MHz crystal and Cherry Trail
uses a 19.2 MHz crystal, the crystal is the source clock for a root PLL
which outputs 1600 and 100 MHz. It is unclear if the root PLL outputs are
used directly by the CPU clock PLL or if there is another PLL in between.
This does not matter though, we can model the chain of PLLs as a single PLL
with a quotient equal to the quotients of all PLLs in the chain multiplied.
So we can create a simplified model of the CPU clock setup using a
reference clock of 100 MHz plus a quotient which gets us as close to the
frequency from the SDM as possible.
For the 83.3 MHz example from above this would give 100 MHz * 5 / 6 = 83
and 1/3 MHz, which matches exactly what has been measured on actual
hardware.
Use a simplified PLL model with a reference clock of 100 MHz for all Bay
and Cherry Trail models.
This has been tested on the following models:
CPU freq before: CPU freq after:
Intel N2840 2165.800 MHz 2166.667 MHz
Intel Z3736 1332.800 MHz 1333.333 MHz
Intel Z3775 1466.300 MHz 1466.667 MHz
Intel Z8350 1440.000 MHz 1440.000 MHz
Intel Z8750 1600.000 MHz 1600.000 MHz
This fixes the time drifting by about 1 second per hour (20 - 30 seconds
per day) on (some) devices which rely on the tsc_msr.c code to determine
the TSC frequency.
Reported-by: Vipul Kumar <vipulk0511@gmail.com>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200223140610.59612-3-hdegoede@redhat.com
According to the "Intel 64 and IA-32 Architectures Software Developer's
Manual Volume 4: Model-Specific Registers" on Cherry Trail (Airmont)
devices the 4 lowest bits of the MSR_FSB_FREQ mask indicate the bus freq
unlike on e.g. Bay Trail where only the lowest 3 bits are used.
This is also the reason why MAX_NUM_FREQS is defined as 9, since Cherry
Trail SoCs have 9 possible frequencies, so the lo value from the MSR needs
to be masked with 0x0f, not with 0x07 otherwise the 9th frequency will get
interpreted as the 1st.
Bump MAX_NUM_FREQS to 16 to avoid any possibility of addressing the array
out of bounds and makes the mask part of the cpufreq struct so it can be
set it per model.
While at it also log an error when the index points to an uninitialized
part of the freqs lookup-table.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200223140610.59612-2-hdegoede@redhat.com
Use named struct initializers for the freq_desc struct-s initialization
and change the "u8 msr_plat" to a "bool use_msr_plat" to make its meaning
more clear instead of relying on a comment to explain it.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200223140610.59612-1-hdegoede@redhat.com
We have had a hard coded limit of 32 machine check records since the
dawn of time. But as numbers of cores increase, it is possible for
more than 32 errors to be reported before a user process reads from
/dev/mcelog. In this case the additional errors are lost.
Keep 32 as the minimum. But tune the maximum value up based on the
number of processors.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200218184408.GA23048@agluck-desk2.amr.corp.intel.com
Sathyanarayanan reported that the PCI-E AER error injection mechanism
can result in a NULL pointer dereference in apic_ack_edge():
BUG: unable to handle kernel NULL pointer dereference at 0000000000000078
RIP: 0010:apic_ack_edge+0x1e/0x40
Call Trace:
handle_edge_irq+0x7d/0x1e0
generic_handle_irq+0x27/0x30
aer_inject_write+0x53a/0x720
It crashes in irq_complete_move() which dereferences get_irq_regs() which
is obviously NULL when this is called from non interrupt context.
Of course the pointer could be checked, but that just papers over the real
issue. Invoking the low level interrupt handling mechanism from random code
can wreckage the fragile interrupt affinity mechanism of x86 as interrupts
can only be moved in interrupt context or with special care when a CPU goes
offline and the move has to be enforced.
In the best case this triggers the warning in the MSI affinity setter, but
if the call happens on the correct CPU it just corrupts state and might
prevent further interrupt delivery for the affected device.
Mark the APIC interrupts as unsuitable for being invoked in random contexts.
This prevents the AER injection from proliferating the wreckage, but that's
less broken than the current state of affairs and more correct than just
papering over the problem by sprinkling random checks all over the place
and silently corrupting state.
Reported-by: sathyanarayanan.kuppuswamy@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200306130623.684591280@linutronix.de
code32_start is meant for 16-bit real-mode bootloaders to inform the
kernel where the 32-bit protected mode code starts. Nothing in the
protected mode kernel except the EFI stub uses it.
efi_main() currently returns boot_params, with code32_start set inside it
to tell efi_stub_entry() where startup_32 is located. Since it was invoked
by efi_stub_entry() in the first place, boot_params is already known.
Return the address of startup_32 instead.
This will allow a 64-bit kernel to live above 4Gb, for example, and it's
cleaner as well.
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200301230436.2246909-5-nivedita@alum.mit.edu
Link: https://lore.kernel.org/r/20200308080859.21568-13-ardb@kernel.org
Pull x86 fixes from Ingo Molnar:
"Misc fixes: a pkeys fix for a bug that triggers with weird BIOS
settings, and two Xen PV fixes: a paravirt interface fix, and
pagetable dumping fix"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm: Fix dump_pagetables with Xen PV
x86/ioperm: Add new paravirt function update_io_bitmap()
x86/pkeys: Manually set X86_FEATURE_OSPKE to preserve existing changes
as too large frame sizes on some configurations. On the
ARM side, the compiler was messing up shadow stacks between
EL1 and EL2 code, which is easily fixed with __always_inline.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Paolo Bonzini:
"More bugfixes, including a few remaining "make W=1" issues such as too
large frame sizes on some configurations.
On the ARM side, the compiler was messing up shadow stacks between EL1
and EL2 code, which is easily fixed with __always_inline"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: VMX: check descriptor table exits on instruction emulation
kvm: x86: Limit the number of "kvm: disabled by bios" messages
KVM: x86: avoid useless copy of cpufreq policy
KVM: allow disabling -Werror
KVM: x86: allow compiling as non-module with W=1
KVM: Pre-allocate 1 cpumask variable per cpu for both pv tlb and pv ipis
KVM: Introduce pv check helpers
KVM: let declaration of kvm_get_running_vcpus match implementation
KVM: SVM: allocate AVIC data structures based on kvm_amd module parameter
arm64: Ask the compiler to __always_inline functions used by KVM at HYP
KVM: arm64: Define our own swab32() to avoid a uapi static inline
KVM: arm64: Ask the compiler to __always_inline functions used at HYP
kvm: arm/arm64: Fold VHE entry/exit work into kvm_vcpu_run_vhe()
KVM: arm/arm64: Fix up includes for trace.h
Commit 111e7b15cf ("x86/ioperm: Extend IOPL config to control ioperm()
as well") reworked the iopl syscall to use I/O bitmaps.
Unfortunately this broke Xen PV domains using that syscall as there is
currently no I/O bitmap support in PV domains.
Add I/O bitmap support via a new paravirt function update_io_bitmap which
Xen PV domains can use to update their I/O bitmaps via a hypercall.
Fixes: 111e7b15cf ("x86/ioperm: Extend IOPL config to control ioperm() as well")
Reported-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Cc: <stable@vger.kernel.org> # 5.5
Link: https://lkml.kernel.org/r/20200218154712.25490-1-jgross@suse.com
Nick Desaulniers Reported:
When building with:
$ make CC=clang arch/x86/ CFLAGS=-Wframe-larger-than=1000
The following warning is observed:
arch/x86/kernel/kvm.c:494:13: warning: stack frame size of 1064 bytes in
function 'kvm_send_ipi_mask_allbutself' [-Wframe-larger-than=]
static void kvm_send_ipi_mask_allbutself(const struct cpumask *mask, int
vector)
^
Debugging with:
https://github.com/ClangBuiltLinux/frame-larger-than
via:
$ python3 frame_larger_than.py arch/x86/kernel/kvm.o \
kvm_send_ipi_mask_allbutself
points to the stack allocated `struct cpumask newmask` in
`kvm_send_ipi_mask_allbutself`. The size of a `struct cpumask` is
potentially large, as it's CONFIG_NR_CPUS divided by BITS_PER_LONG for
the target architecture. CONFIG_NR_CPUS for X86_64 can be as high as
8192, making a single instance of a `struct cpumask` 1024 B.
This patch fixes it by pre-allocate 1 cpumask variable per cpu and use it for
both pv tlb and pv ipis..
Reported-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Introduce some pv check helpers for consistency.
Suggested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
There are two implemented bits in the PPIN_CTL MSR:
Bit 0: LockOut (R/WO)
Set 1 to prevent further writes to MSR_PPIN_CTL.
Bit 1: Enable_PPIN (R/W)
If 1, enables MSR_PPIN to be accessible using RDMSR.
If 0, an attempt to read MSR_PPIN will cause #GP.
So there are four defined values:
0: PPIN is disabled, PPIN_CTL may be updated
1: PPIN is disabled. PPIN_CTL is locked against updates
2: PPIN is enabled. PPIN_CTL may be updated
3: PPIN is enabled. PPIN_CTL is locked against updates
Code would only enable the X86_FEATURE_INTEL_PPIN feature for case "2".
When it should have done so for both case "2" and case "3".
Fix the final test to just check for the enable bit. Also fix some of
the other comments in this function.
Fixes: 3f5a7896a5 ("x86/mce: Include the PPIN in MCE records when available")
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20200226011737.9958-1-tony.luck@intel.com
Explicitly set X86_FEATURE_OSPKE via set_cpu_cap() instead of calling
get_cpu_cap() to pull the feature bit from CPUID after enabling CR4.PKE.
Invoking get_cpu_cap() effectively wipes out any {set,clear}_cpu_cap()
changes that were made between this_cpu->c_init() and setup_pku(), as
all non-synthetic feature words are reinitialized from the CPU's CPUID
values.
Blasting away capability updates manifests most visibility when running
on a VMX capable CPU, but with VMX disabled by BIOS. To indicate that
VMX is disabled, init_ia32_feat_ctl() clears X86_FEATURE_VMX, using
clear_cpu_cap() instead of setup_clear_cpu_cap() so that KVM can report
which CPU is misconfigured (KVM needs to probe every CPU anyways).
Restoring X86_FEATURE_VMX from CPUID causes KVM to think VMX is enabled,
ultimately leading to an unexpected #GP when KVM attempts to do VMXON.
Arguably, init_ia32_feat_ctl() should use setup_clear_cpu_cap() and let
KVM figure out a different way to report the misconfigured CPU, but VMX
is not the only feature bit that is affected, i.e. there is precedent
that tweaking feature bits via {set,clear}_cpu_cap() after ->c_init()
is expected to work. Most notably, x86_init_rdrand()'s clearing of
X86_FEATURE_RDRAND when RDRAND malfunctions is also overwritten.
Fixes: 0697694564 ("x86/mm/pkeys: Actually enable Memory Protection Keys in the CPU")
Reported-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Tested-by: Jacob Keller <jacob.e.keller@intel.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200226231615.13664-1-sean.j.christopherson@intel.com
#BP is not longer using IST and using ist_enter() and ist_exit() makes it
harder to change ist_enter() and ist_exit()'s behavior. Instead open-code
the very small amount of required logic.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200225220217.150607679@linutronix.de
That function returns immediately after conditionally reenabling interrupts which
is more than pointless and requires the ASM code to disable interrupts again.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20191023123117.871608831@linutronix.de
Link: https://lkml.kernel.org/r/20200225220216.518575042@linutronix.de
Remove the pointless difference between 32 and 64 bit to make further
unifications simpler.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200225220216.428188397@linutronix.de
do_machine_check() can be raised in almost any context including the most
fragile ones. Prevent kprobes and tracing.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200225220216.315548935@linutronix.de
This time, the set of changes for the EFI subsystem is much larger than
usual. The main reasons are:
- Get things cleaned up before EFI support for RISC-V arrives, which will
increase the size of the validation matrix, and therefore the threshold to
making drastic changes,
- After years of defunct maintainership, the GRUB project has finally started
to consider changes from the distros regarding UEFI boot, some of which are
highly specific to the way x86 does UEFI secure boot and measured boot,
based on knowledge of both shim internals and the layout of bootparams and
the x86 setup header. Having this maintenance burden on other architectures
(which don't need shim in the first place) is hard to justify, so instead,
we are introducing a generic Linux/UEFI boot protocol.
Summary of changes:
- Boot time GDT handling changes (Arvind)
- Simplify handling of EFI properties table on arm64
- Generic EFI stub cleanups, to improve command line handling, file I/O,
memory allocation, etc.
- Introduce a generic initrd loading method based on calling back into
the firmware, instead of relying on the x86 EFI handover protocol or
device tree.
- Introduce a mixed mode boot method that does not rely on the x86 EFI
handover protocol either, and could potentially be adopted by other
architectures (if another one ever surfaces where one execution mode
is a superset of another)
- Clean up the contents of struct efi, and move out everything that
doesn't need to be stored there.
- Incorporate support for UEFI spec v2.8A changes that permit firmware
implementations to return EFI_UNSUPPORTED from UEFI runtime services at
OS runtime, and expose a mask of which ones are supported or unsupported
via a configuration table.
- Various documentation updates and minor code cleanups (Heinrich)
- Partial fix for the lack of by-VA cache maintenance in the decompressor
on 32-bit ARM. Note that these patches were deliberately put at the
beginning so they can be used as a stable branch that will be shared with
a PR containing the complete fix, which I will send to the ARM tree.
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Merge tag 'efi-next' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi into efi/core
Pull EFI updates for v5.7 from Ard Biesheuvel:
This time, the set of changes for the EFI subsystem is much larger than
usual. The main reasons are:
- Get things cleaned up before EFI support for RISC-V arrives, which will
increase the size of the validation matrix, and therefore the threshold to
making drastic changes,
- After years of defunct maintainership, the GRUB project has finally started
to consider changes from the distros regarding UEFI boot, some of which are
highly specific to the way x86 does UEFI secure boot and measured boot,
based on knowledge of both shim internals and the layout of bootparams and
the x86 setup header. Having this maintenance burden on other architectures
(which don't need shim in the first place) is hard to justify, so instead,
we are introducing a generic Linux/UEFI boot protocol.
Summary of changes:
- Boot time GDT handling changes (Arvind)
- Simplify handling of EFI properties table on arm64
- Generic EFI stub cleanups, to improve command line handling, file I/O,
memory allocation, etc.
- Introduce a generic initrd loading method based on calling back into
the firmware, instead of relying on the x86 EFI handover protocol or
device tree.
- Introduce a mixed mode boot method that does not rely on the x86 EFI
handover protocol either, and could potentially be adopted by other
architectures (if another one ever surfaces where one execution mode
is a superset of another)
- Clean up the contents of struct efi, and move out everything that
doesn't need to be stored there.
- Incorporate support for UEFI spec v2.8A changes that permit firmware
implementations to return EFI_UNSUPPORTED from UEFI runtime services at
OS runtime, and expose a mask of which ones are supported or unsupported
via a configuration table.
- Various documentation updates and minor code cleanups (Heinrich)
- Partial fix for the lack of by-VA cache maintenance in the decompressor
on 32-bit ARM. Note that these patches were deliberately put at the
beginning so they can be used as a stable branch that will be shared with
a PR containing the complete fix, which I will send to the ARM tree.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Chris Wilson reported splats from running the thermal throttling
workqueue callback on offlined CPUs. The problem is that that callback
should not even run on offlined CPUs but it happens nevertheless because
the offlining callback thermal_throttle_offline() does not symmetrically
undo the setup work done in its onlining counterpart. IOW,
1. The thermal interrupt vector should be masked out before ...
2. ... cancelling any pending work synchronously so that no new work is
enqueued anymore.
Do those things and fix the issue properly.
[ bp: Write commit message. ]
Fixes: f6656208f0 ("x86/mce/therm_throt: Optimize notifications of thermal throttle")
Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
Tested-by: Pandruvada, Srinivas <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/158120068234.18291.7938335950259651295@skylake-alporthouse-com
Now that .eh_frame sections for the files in setup.elf and realmode.elf
are not generated anymore, the linker scripts don't need the special
output section name /DISCARD/ any more.
Remove the one in the main kernel linker script as well, since there are
no .eh_frame sections already, and fix up a comment referencing .eh_frame.
Update the comment in asm/dwarf2.h referring to .eh_frame so it continues
to make sense, as well as being more specific.
[ bp: Touch up commit message. ]
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Link: https://lkml.kernel.org/r/20200224232129.597160-3-nivedita@alum.mit.edu
Alex Shi reported the pkey macros above arch_set_user_pkey_access()
to be unused. They are unused, and even refer to a nonexistent
CONFIG option.
But, they might have served a good use, which was to ensure that
the code does not try to set values that would not fit in the
PKRU register. As it stands, a too-large 'pkey' value would
be likely to silently overflow the u32 new_pkru_bits.
Add a check to look for overflows. Also add a comment to remind
any future developer to closely examine the types used to store
pkey values if arch_max_pkey() ever changes.
This boots and passes the x86 pkey selftests.
Reported-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200122165346.AD4DA150@viggo.jf.intel.com
Replace the EFI runtime services check with one that tells us whether
EFI GetVariable() is implemented by the firmware.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Instead of going through the EFI system table each time, just copy the
runtime services table pointer into struct efi directly. This is the
last use of the system table pointer in struct efi, allowing us to
drop it in a future patch, along with a fair amount of quirky handling
of the translated address.
Note that usually, the runtime services pointer changes value during
the call to SetVirtualAddressMap(), so grab the updated value as soon
as that call returns. (Mixed mode uses a 1:1 mapping, and kexec boot
enters with the updated address in the system table, so in those cases,
we don't need to do anything here)
Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
There is some code that exposes physical addresses of certain parts of
the EFI firmware implementation via sysfs nodes. These nodes are only
used on x86, and are of dubious value to begin with, so let's move
their handling into the x86 arch code.
Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Since commit 33b85447fa ("efi/x86: Drop two near identical versions
of efi_runtime_init()"), we no longer map the EFI runtime services table
before calling SetVirtualAddressMap(), which means we don't need the 1:1
mapped physical address of this table, and so there is no point in passing
the address via EFI setup data on kexec boot.
Note that the kexec tools will still look for this address in sysfs, so
we still need to provide it.
Tested-by: Tony Luck <tony.luck@intel.com> # arch/ia64
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
- Populate the per CPU MCA bank descriptor pointer only after it has been
completely set up to prevent a use-after-free in case that one of the
subsequent initialization step fails
- Implement a proper release function for the sysfs entries of MCA
threshold controls instead of freeing the memory right in the CPU
teardown code, which leads to another use-after-free when the
associated sysfs file is opened and accessed.
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Merge tag 'ras-urgent-2020-02-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RAS fixes from Thomas Gleixner:
"Two fixes for the AMD MCE driver:
- Populate the per CPU MCA bank descriptor pointer only after it has
been completely set up to prevent a use-after-free in case that one
of the subsequent initialization step fails
- Implement a proper release function for the sysfs entries of MCA
threshold controls instead of freeing the memory right in the CPU
teardown code, which leads to another use-after-free when the
associated sysfs file is opened and accessed"
* tag 'ras-urgent-2020-02-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mce/amd: Fix kobject lifetime
x86/mce/amd: Publish the bank pointer only after setup has succeeded
- Remove the __force_oder definiton from the kaslr boot code as it is
already defined in the page table code which makes GCC 10 builds fail
because it changed the default to -fno-common.
- Address the AMD erratum 1054 concerning the IRPERF capability and
enable the Instructions Retired fixed counter on machines which are not
affected by the erratum.
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Merge tag 'x86-urgent-2020-02-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
"Two fixes for x86:
- Remove the __force_oder definiton from the kaslr boot code as it is
already defined in the page table code which makes GCC 10 builds
fail because it changed the default to -fno-common.
- Address the AMD erratum 1054 concerning the IRPERF capability and
enable the Instructions Retired fixed counter on machines which are
not affected by the erratum"
* tag 'x86-urgent-2020-02-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/cpu/amd: Enable the fixed Instructions Retired counter IRPERF
x86/boot/compressed: Don't declare __force_order in kaslr_64.c
A split-lock occurs when an atomic instruction operates on data that spans
two cache lines. In order to maintain atomicity the core takes a global bus
lock.
This is typically >1000 cycles slower than an atomic operation within a
cache line. It also disrupts performance on other cores (which must wait
for the bus lock to be released before their memory operations can
complete). For real-time systems this may mean missing deadlines. For other
systems it may just be very annoying.
Some CPUs have the capability to raise an #AC trap when a split lock is
attempted.
Provide a command line option to give the user choices on how to handle
this:
split_lock_detect=
off - not enabled (no traps for split locks)
warn - warn once when an application does a
split lock, but allow it to continue
running.
fatal - Send SIGBUS to applications that cause split lock
On systems that support split lock detection the default is "warn". Note
that if the kernel hits a split lock in any mode other than "off" it will
OOPs.
One implementation wrinkle is that the MSR to control the split lock
detection is per-core, not per thread. This might result in some short
lived races on HT systems in "warn" mode if Linux tries to enable on one
thread while disabling on the other. Race analysis by Sean Christopherson:
- Toggling of split-lock is only done in "warn" mode. Worst case
scenario of a race is that a misbehaving task will generate multiple
#AC exceptions on the same instruction. And this race will only occur
if both siblings are running tasks that generate split-lock #ACs, e.g.
a race where sibling threads are writing different values will only
occur if CPUx is disabling split-lock after an #AC and CPUy is
re-enabling split-lock after *its* previous task generated an #AC.
- Transitioning between off/warn/fatal modes at runtime isn't supported
and disabling is tracked per task, so hardware will always reach a steady
state that matches the configured mode. I.e. split-lock is guaranteed to
be enabled in hardware once all _TIF_SLD threads have been scheduled out.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Co-developed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20200126200535.GB30377@agluck-desk2.amr.corp.intel.com
Commit
aaf248848d ("perf/x86/msr: Add AMD IRPERF (Instructions Retired)
performance counter")
added support for access to the free-running counter via 'perf -e
msr/irperf/', but when exercised, it always returns a 0 count:
BEFORE:
$ perf stat -e instructions,msr/irperf/ true
Performance counter stats for 'true':
624,833 instructions
0 msr/irperf/
Simply set its enable bit - HWCR bit 30 - to make it start counting.
Enablement is restricted to all machines advertising IRPERF capability,
except those susceptible to an erratum that makes the IRPERF return
bad values.
That erratum occurs in Family 17h models 00-1fh [1], but not in F17h
models 20h and above [2].
AFTER (on a family 17h model 31h machine):
$ perf stat -e instructions,msr/irperf/ true
Performance counter stats for 'true':
621,690 instructions
622,490 msr/irperf/
[1] Revision Guide for AMD Family 17h Models 00h-0Fh Processors
[2] Revision Guide for AMD Family 17h Models 30h-3Fh Processors
The revision guides are available from the bugzilla Link below.
[ bp: Massage commit message. ]
Fixes: aaf248848d ("perf/x86/msr: Add AMD IRPERF (Instructions Retired) performance counter")
Signed-off-by: Kim Phillips <kim.phillips@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537
Link: http://lkml.kernel.org/r/20200214201805.13830-1-kim.phillips@amd.com
A user has reported that they are seeing spurious corrected errors on
their hardware.
Intel Errata HSD131, HSM142, HSW131, and BDM48 report that "spurious
corrected errors may be logged in the IA32_MC0_STATUS register with
the valid field (bit 63) set, the uncorrected error field (bit 61) not
set, a Model Specific Error Code (bits [31:16]) of 0x000F, and an MCA
Error Code (bits [15:0]) of 0x0005." The Errata PDFs are linked in the
bugzilla below.
Block these spurious errors from the console and logs.
[ bp: Move the intel_filter_mce() header declarations into the already
existing CONFIG_X86_MCE_INTEL ifdeffery. ]
Co-developed-by: Alexander Krupp <centos@akr.yagii.de>
Signed-off-by: Alexander Krupp <centos@akr.yagii.de>
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206587
Link: https://lkml.kernel.org/r/20200219131611.36816-1-prarit@redhat.com
All architectures which use the generic VDSO code have their own storage
for the VDSO clock mode. That's pointless and just requires duplicate code.
X86 abuses the function which retrieves the architecture specific clock
mode storage to mark the clocksource as used in the VDSO. That's silly
because this is invoked on every tick when the VDSO data is updated.
Move this functionality to the clocksource::enable() callback so it gets
invoked once when the clocksource is installed. This allows to make the
clock mode storage generic.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Michael Kelley <mikelley@microsoft.com> (Hyper-V parts)
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> (VDSO parts)
Acked-by: Juergen Gross <jgross@suse.com> (Xen parts)
Link: https://lkml.kernel.org/r/20200207124402.934519777@linutronix.de
Fix a couple of typos in code comments.
[ bp: While at it: s/IRQ's/IRQs/. ]
Signed-off-by: Martin Molnar <martin.molnar.programming@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lkml.kernel.org/r/0819a044-c360-44a4-f0b6-3f5bafe2d35c@gmail.com
Accessing the MCA thresholding controls in sysfs concurrently with CPU
hotplug can lead to a couple of KASAN-reported issues:
BUG: KASAN: use-after-free in sysfs_file_ops+0x155/0x180
Read of size 8 at addr ffff888367578940 by task grep/4019
and
BUG: KASAN: use-after-free in show_error_count+0x15c/0x180
Read of size 2 at addr ffff888368a05514 by task grep/4454
for example. Both result from the fact that the threshold block
creation/teardown code frees the descriptor memory itself instead of
defining proper ->release function and leaving it to the driver core to
take care of that, after all sysfs accesses have completed.
Do that and get rid of the custom freeing code, fixing the above UAFs in
the process.
[ bp: write commit message. ]
Fixes: 9526866439 ("[PATCH] x86_64: mce_amd support for family 0x10 processors")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20200214082801.13836-1-bp@alien8.de
threshold_create_bank() creates a bank descriptor per MCA error
thresholding counter which can be controlled over sysfs. It publishes
the pointer to that bank in a per-CPU variable and then goes on to
create additional thresholding blocks if the bank has such.
However, that creation of additional blocks in
allocate_threshold_blocks() can fail, leading to a use-after-free
through the per-CPU pointer.
Therefore, publish that pointer only after all blocks have been setup
successfully.
Fixes: 019f34fccf ("x86, MCE, AMD: Move shared bank to node descriptor")
Reported-by: Saar Amar <Saar.Amar@microsoft.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200128140846.phctkvx5btiexvbx@kili.mountain
An XSAVES component's alignment/offset is meaningful only when the
feature is enabled. Return zero and WARN_ONCE on checking alignment of
disabled features.
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lkml.kernel.org/r/20200109211452.27369-4-yu-cheng.yu@intel.com
In setup_xstate_comp(), each XSAVES component offset starts from the
end of its preceding component plus alignment. A disabled feature does
not take space and its offset should be set to the end of its preceding
one with no alignment. However, in this case, alignment is incorrectly
added to the offset, which can cause the next component to have a wrong
offset.
This problem has not been visible because currently there is no xfeature
requiring alignment.
Fix it by tracking the next starting offset only from enabled
xfeatures. To make it clear, also change the function name to
setup_xstate_comp_offsets().
[ bp: Fix a typo in the comment above it, while at it. ]
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lkml.kernel.org/r/20200109211452.27369-3-yu-cheng.yu@intel.com
The IMA arch code attempts to inspect the "SetupMode" EFI variable
by populating a variable called efi_SetupMode_name with the string
"SecureBoot" and passing that to the EFI GetVariable service, which
obviously does not yield the expected result.
Given that the string is only referenced a single time, let's get
rid of the intermediate variable, and pass the correct string as
an immediate argument. While at it, do the same for "SecureBoot".
Fixes: 399574c64e ("x86/ima: retry detecting secure boot mode")
Fixes: 980ef4d22a ("x86/ima: check EFI SetupMode too")
Cc: Matthew Garrett <mjg59@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Cc: stable@vger.kernel.org # v5.3
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
The function setup_xstate_features() uses CPUID to find each xfeature's
standard-format offset and size. Since XSAVES always uses the compacted
format, supervisor xstates are *NEVER* in the standard-format and their
offsets are left as -1's. However, they are still being tracked as
last_good_offset.
Fix it by tracking only user xstate offsets.
[ bp: Use xfeature_is_supervisor() and save an indentation level. Drop
now unused xfeature_is_user(). ]
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lkml.kernel.org/r/20200109211452.27369-2-yu-cheng.yu@intel.com
- Ensure that the PIT is set up when the local APIC is disable or
configured in legacy mode. This is caused by an ordering issue
introduced in the recent changes which skip PIT initialization when the
TSC and APIC frequencies are already known.
- Handle malformed SRAT tables during early ACPI parsing which caused an
infinite loop anda boot hang.
- Fix a long standing race in the affinity setting code which affects PCI
devices with non-maskable MSI interrupts. The problem is caused by the
non-atomic writes of the MSI address (destination APIC id) and data
(vector) fields which the device uses to construct the MSI message. The
non-atomic writes are mandated by PCI.
If both fields change and the device raises an interrupt after writing
address and before writing data, then the MSI block constructs a
inconsistent message which causes interrupts to be lost and subsequent
malfunction of the device.
The fix is to redirect the interrupt to the new vector on the current
CPU first and then switch it over to the new target CPU. This allows to
observe an eventually raised interrupt in the transitional stage (old
CPU, new vector) to be observed in the APIC IRR and retriggered on the
new target CPU and the new vector. The potential spurious interrupts
caused by this are harmless and can in the worst case expose a buggy
driver (all handlers have to be able to deal with spurious interrupts as
they can and do happen for various reasons).
- Add the missing suspend/resume mechanism for the HYPERV hypercall page
which prevents resume hibernation on HYPERV guests. This change got
lost before the merge window.
- Mask the IOAPIC before disabling the local APIC to prevent potentially
stale IOAPIC remote IRR bits which cause stale interrupt lines after
resume.
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Merge tag 'x86-urgent-2020-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
"A set of fixes for X86:
- Ensure that the PIT is set up when the local APIC is disable or
configured in legacy mode. This is caused by an ordering issue
introduced in the recent changes which skip PIT initialization when
the TSC and APIC frequencies are already known.
- Handle malformed SRAT tables during early ACPI parsing which caused
an infinite loop anda boot hang.
- Fix a long standing race in the affinity setting code which affects
PCI devices with non-maskable MSI interrupts. The problem is caused
by the non-atomic writes of the MSI address (destination APIC id)
and data (vector) fields which the device uses to construct the MSI
message. The non-atomic writes are mandated by PCI.
If both fields change and the device raises an interrupt after
writing address and before writing data, then the MSI block
constructs a inconsistent message which causes interrupts to be
lost and subsequent malfunction of the device.
The fix is to redirect the interrupt to the new vector on the
current CPU first and then switch it over to the new target CPU.
This allows to observe an eventually raised interrupt in the
transitional stage (old CPU, new vector) to be observed in the APIC
IRR and retriggered on the new target CPU and the new vector.
The potential spurious interrupts caused by this are harmless and
can in the worst case expose a buggy driver (all handlers have to
be able to deal with spurious interrupts as they can and do happen
for various reasons).
- Add the missing suspend/resume mechanism for the HYPERV hypercall
page which prevents resume hibernation on HYPERV guests. This
change got lost before the merge window.
- Mask the IOAPIC before disabling the local APIC to prevent
potentially stale IOAPIC remote IRR bits which cause stale
interrupt lines after resume"
* tag 'x86-urgent-2020-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/apic: Mask IOAPIC entries when disabling the local APIC
x86/hyperv: Suspend/resume the hypercall page for hibernation
x86/apic/msi: Plug non-maskable MSI affinity race
x86/boot: Handle malformed SRAT tables during early ACPI parsing
x86/timer: Don't skip PIT setup when APIC is disabled or in legacy mode
Pull vfs file system parameter updates from Al Viro:
"Saner fs_parser.c guts and data structures. The system-wide registry
of syntax types (string/enum/int32/oct32/.../etc.) is gone and so is
the horror switch() in fs_parse() that would have to grow another case
every time something got added to that system-wide registry.
New syntax types can be added by filesystems easily now, and their
namespace is that of functions - not of system-wide enum members. IOW,
they can be shared or kept private and if some turn out to be widely
useful, we can make them common library helpers, etc., without having
to do anything whatsoever to fs_parse() itself.
And we already get that kind of requests - the thing that finally
pushed me into doing that was "oh, and let's add one for timeouts -
things like 15s or 2h". If some filesystem really wants that, let them
do it. Without somebody having to play gatekeeper for the variants
blessed by direct support in fs_parse(), TYVM.
Quite a bit of boilerplate is gone. And IMO the data structures make a
lot more sense now. -200LoC, while we are at it"
* 'merge.nfs-fs_parse.1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (25 commits)
tmpfs: switch to use of invalfc()
cgroup1: switch to use of errorfc() et.al.
procfs: switch to use of invalfc()
hugetlbfs: switch to use of invalfc()
cramfs: switch to use of errofc() et.al.
gfs2: switch to use of errorfc() et.al.
fuse: switch to use errorfc() et.al.
ceph: use errorfc() and friends instead of spelling the prefix out
prefix-handling analogues of errorf() and friends
turn fs_param_is_... into functions
fs_parse: handle optional arguments sanely
fs_parse: fold fs_parameter_desc/fs_parameter_spec
fs_parser: remove fs_parameter_description name field
add prefix to fs_context->log
ceph_parse_param(), ceph_parse_mon_ips(): switch to passing fc_log
new primitive: __fs_parse()
switch rbd and libceph to p_log-based primitives
struct p_log, variants of warnf() et.al. taking that one instead
teach logfc() to handle prefices, give it saner calling conventions
get rid of cg_invalf()
...
Unused now.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
When a system suspends, the local APIC is disabled in the suspend sequence,
but the IOAPIC is left in the current state. This means unmasked interrupt
lines stay unmasked. This is usually the case for IOAPIC pin 9 to which the
ACPI interrupt is connected.
That means that in suspended state the IOAPIC can respond to an external
interrupt, e.g. the wakeup via keyboard/RTC/ACPI, but the interrupt message
cannot be handled by the disabled local APIC. As a consequence the Remote
IRR bit is set, but the local APIC does not send an EOI to acknowledge
it. This causes the affected interrupt line to become stale and the stale
Remote IRR bit will cause a hang when __synchronize_hardirq() is invoked
for that interrupt line.
To prevent this, mask all IOAPIC entries before disabling the local
APIC. The resume code already has the unmask operation inside.
[ tglx: Massaged changelog ]
Signed-off-by: Tony W Wang-oc <TonyWWang-oc@zhaoxin.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/1579076539-7267-1-git-send-email-TonyWWang-oc@zhaoxin.com
* fix register corruption
* ENOTSUPP/EOPNOTSUPP mixed
* reset cleanups/fixes
* selftests
x86:
* Bug fixes and cleanups
* AMD support for APIC virtualization even in combination with
in-kernel PIT or IOAPIC.
MIPS:
* Compilation fix.
Generic:
* Fix refcount overflow for zero page.
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Merge tag 'kvm-5.6-2' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull more KVM updates from Paolo Bonzini:
"s390:
- fix register corruption
- ENOTSUPP/EOPNOTSUPP mixed
- reset cleanups/fixes
- selftests
x86:
- Bug fixes and cleanups
- AMD support for APIC virtualization even in combination with
in-kernel PIT or IOAPIC.
MIPS:
- Compilation fix.
Generic:
- Fix refcount overflow for zero page"
* tag 'kvm-5.6-2' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (42 commits)
KVM: vmx: delete meaningless vmx_decache_cr0_guest_bits() declaration
KVM: x86: Mark CR4.UMIP as reserved based on associated CPUID bit
x86: vmxfeatures: rename features for consistency with KVM and manual
KVM: SVM: relax conditions for allowing MSR_IA32_SPEC_CTRL accesses
KVM: x86: Fix perfctr WRMSR for running counters
x86/kvm/hyper-v: don't allow to turn on unsupported VMX controls for nested guests
x86/kvm/hyper-v: move VMX controls sanitization out of nested_enable_evmcs()
kvm: mmu: Separate generating and setting mmio ptes
kvm: mmu: Replace unsigned with unsigned int for PTE access
KVM: nVMX: Remove stale comment from nested_vmx_load_cr3()
KVM: MIPS: Fold comparecount_func() into comparecount_wakeup()
KVM: MIPS: Fix a build error due to referencing not-yet-defined function
x86/kvm: do not setup pv tlb flush when not paravirtualized
KVM: fix overflow of zero page refcount with ksm running
KVM: x86: Take a u64 when checking for a valid dr7 value
KVM: x86: use raw clock values consistently
KVM: x86: reorganize pvclock_gtod_data members
KVM: nVMX: delete meaningless nested_vmx_run() declaration
KVM: SVM: allow AVIC without split irqchip
kvm: ioapic: Lazy update IOAPIC EOI
...
kvm_setup_pv_tlb_flush will waste memory and print a misguiding message
when KVM paravirtualization is not available.
Intel SDM says that the when cpuid is used with EAX higher than the
maximum supported value for basic of extended function, the data for the
highest supported basic function will be returned.
So, in some systems, kvm_arch_para_features will return bogus data,
causing kvm_setup_pv_tlb_flush to detect support for pv tlb flush.
Testing for kvm_para_available will work as it checks for the hypervisor
signature.
Besides, when the "nopv" command line parameter is used, it should not
continue as well, as kvm_guest_init will no be called in that case.
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Evan tracked down a subtle race between the update of the MSI message and
the device raising an interrupt internally on PCI devices which do not
support MSI masking. The update of the MSI message is non-atomic and
consists of either 2 or 3 sequential 32bit wide writes to the PCI config
space.
- Write address low 32bits
- Write address high 32bits (If supported by device)
- Write data
When an interrupt is migrated then both address and data might change, so
the kernel attempts to mask the MSI interrupt first. But for MSI masking is
optional, so there exist devices which do not provide it. That means that
if the device raises an interrupt internally between the writes then a MSI
message is sent built from half updated state.
On x86 this can lead to spurious interrupts on the wrong interrupt
vector when the affinity setting changes both address and data. As a
consequence the device interrupt can be lost causing the device to
become stuck or malfunctioning.
Evan tried to handle that by disabling MSI accross an MSI message
update. That's not feasible because disabling MSI has issues on its own:
If MSI is disabled the PCI device is routing an interrupt to the legacy
INTx mechanism. The INTx delivery can be disabled, but the disablement is
not working on all devices.
Some devices lose interrupts when both MSI and INTx delivery are disabled.
Another way to solve this would be to enforce the allocation of the same
vector on all CPUs in the system for this kind of screwed devices. That
could be done, but it would bring back the vector space exhaustion problems
which got solved a few years ago.
Fortunately the high address (if supported by the device) is only relevant
when X2APIC is enabled which implies interrupt remapping. In the interrupt
remapping case the affinity setting is happening at the interrupt remapping
unit and the PCI MSI message is programmed only once when the PCI device is
initialized.
That makes it possible to solve it with a two step update:
1) Target the MSI msg to the new vector on the current target CPU
2) Target the MSI msg to the new vector on the new target CPU
In both cases writing the MSI message is only changing a single 32bit word
which prevents the issue of inconsistency.
After writing the final destination it is necessary to check whether the
device issued an interrupt while the intermediate state #1 (new vector,
current CPU) was in effect.
This is possible because the affinity change is always happening on the
current target CPU. The code runs with interrupts disabled, so the
interrupt can be detected by checking the IRR of the local APIC. If the
vector is pending in the IRR then the interrupt is retriggered on the new
target CPU by sending an IPI for the associated vector on the target CPU.
This can cause spurious interrupts on both the local and the new target
CPU.
1) If the new vector is not in use on the local CPU and the device
affected by the affinity change raised an interrupt during the
transitional state (step #1 above) then interrupt entry code will
ignore that spurious interrupt. The vector is marked so that the
'No irq handler for vector' warning is supressed once.
2) If the new vector is in use already on the local CPU then the IRR check
might see an pending interrupt from the device which is using this
vector. The IPI to the new target CPU will then invoke the handler of
the device, which got the affinity change, even if that device did not
issue an interrupt
3) If the new vector is in use already on the local CPU and the device
affected by the affinity change raised an interrupt during the
transitional state (step #1 above) then the handler of the device which
uses that vector on the local CPU will be invoked.
expose issues in device driver interrupt handlers which are not prepared to
handle a spurious interrupt correctly. This not a regression, it's just
exposing something which was already broken as spurious interrupts can
happen for a lot of reasons and all driver handlers need to be able to deal
with them.
Reported-by: Evan Green <evgreen@chromium.org>
Debugged-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Evan Green <evgreen@chromium.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/87imkr4s7n.fsf@nanos.tec.linutronix.de
Pull x86 fixes from Ingo Molnar:
"Misc fixes:
- three fixes and a cleanup for the resctrl code
- a HyperV fix
- a fix to /proc/kcore contents in live debugging sessions
- a fix for the x86 decoder opcode map"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/decoder: Add TEST opcode to Group3-2
x86/resctrl: Clean up unused function parameter in mkdir path
x86/resctrl: Fix a deadlock due to inaccurate reference
x86/resctrl: Fix use-after-free due to inaccurate refcount of rdtgroup
x86/resctrl: Fix use-after-free when deleting resource groups
x86/hyper-v: Add "polling" bit to hv_synic_sint
x86/crash: Define arch_crash_save_vmcoreinfo() if CONFIG_CRASH_CORE=y
Unfortunately, GCC 9.1 is expected to be be released without support for
MPX. This means that there was only a relatively small window where
folks could have ever used MPX. It failed to gain wide adoption in the
industry, and Linux was the only mainstream OS to ever support it widely.
Support for the feature may also disappear on future processors.
This set completes the process that we started during the 5.4 merge window.
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Merge tag 'mpx-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/daveh/x86-mpx
Pull x86 MPX removal from Dave Hansen:
"MPX requires recompiling applications, which requires compiler
support. Unfortunately, GCC 9.1 is expected to be be released without
support for MPX. This means that there was only a relatively small
window where folks could have ever used MPX. It failed to gain wide
adoption in the industry, and Linux was the only mainstream OS to ever
support it widely.
Support for the feature may also disappear on future processors.
This set completes the process that we started during the 5.4 merge
window when the MPX prctl()s were removed. XSAVE support is left in
place, which allows MPX-using KVM guests to continue to function"
* tag 'mpx-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/daveh/x86-mpx:
x86/mpx: remove MPX from arch/x86
mm: remove arch_bprm_mm_init() hook
x86/mpx: remove bounds exception code
x86/mpx: remove build infrastructure
x86/alternatives: add missing insn.h include
Here are the big set of tty and serial driver updates for 5.6-rc1
Included in here are:
- dummy_con cleanups (touches lots of arch code)
- sysrq logic cleanups (touches lots of serial drivers)
- samsung driver fixes (wasn't really being built)
- conmakeshash move to tty subdir out of scripts
- lots of small tty/serial driver updates
All of these have been in linux-next for a while with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial driver updates from Greg KH:
"Here are the big set of tty and serial driver updates for 5.6-rc1
Included in here are:
- dummy_con cleanups (touches lots of arch code)
- sysrq logic cleanups (touches lots of serial drivers)
- samsung driver fixes (wasn't really being built)
- conmakeshash move to tty subdir out of scripts
- lots of small tty/serial driver updates
All of these have been in linux-next for a while with no reported
issues"
* tag 'tty-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (140 commits)
tty: n_hdlc: Use flexible-array member and struct_size() helper
tty: baudrate: SPARC supports few more baud rates
tty: baudrate: Synchronise baud_table[] and baud_bits[]
tty: serial: meson_uart: Add support for kernel debugger
serial: imx: fix a race condition in receive path
serial: 8250_bcm2835aux: Document struct bcm2835aux_data
serial: 8250_bcm2835aux: Use generic remapping code
serial: 8250_bcm2835aux: Allocate uart_8250_port on stack
serial: 8250_bcm2835aux: Suppress register_port error on -EPROBE_DEFER
serial: 8250_bcm2835aux: Suppress clk_get error on -EPROBE_DEFER
serial: 8250_bcm2835aux: Fix line mismatch on driver unbind
serial_core: Remove unused member in uart_port
vt: Correct comment documenting do_take_over_console()
vt: Delete comment referencing non-existent unbind_con_driver()
arch/xtensa/setup: Drop dummy_con initialization
arch/x86/setup: Drop dummy_con initialization
arch/unicore32/setup: Drop dummy_con initialization
arch/sparc/setup: Drop dummy_con initialization
arch/sh/setup: Drop dummy_con initialization
arch/s390/setup: Drop dummy_con initialization
...
Tony reported a boot regression caused by the recent workaround for systems
which have a disabled (clock gate off) PIT.
On his machine the kernel fails to initialize the PIT because
apic_needs_pit() does not take into account whether the local APIC
interrupt delivery mode will actually allow to setup and use the local
APIC timer. This should be easy to reproduce with acpi=off on the
command line which also disables HPET.
Due to the way the PIT/HPET and APIC setup ordering works (APIC setup can
require working PIT/HPET) the information is not available at the point
where apic_needs_pit() makes this decision.
To address this, split out the interrupt mode selection from
apic_intr_mode_init(), invoke the selection before making the decision
whether PIT is required or not, and add the missing checks into
apic_needs_pit().
Fixes: c8c4076723 ("x86/timer: Skip PIT initialization on modern chipsets")
Reported-by: Anthony Buckley <tony.buckley000@gmail.com>
Tested-by: Anthony Buckley <tony.buckley000@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Daniel Drake <drake@endlessm.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206125
Link: https://lore.kernel.org/r/87sgk6tmk2.fsf@nanos.tec.linutronix.de
Pull x86 mtrr updates from Ingo Molnar:
"Two changes: restrict /proc/mtrr to CAP_SYS_ADMIN, plus a cleanup"
* 'x86-mtrr-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mtrr: Require CAP_SYS_ADMIN for all access
x86/mtrr: Get rid of mtrr_seq_show() forward declaration
Pull x86 FPU updates from Ingo Molnar:
"Three changes: fix a race that can result in FPU corruption, plus two
cleanups"
* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/fpu: Deactivate FPU state after failure during state load
x86/fpu/xstate: Make xfeature_is_supervisor()/xfeature_is_user() return bool
x86/fpu/xstate: Fix small issues
Pull x86 cpu-features updates from Ingo Molnar:
"The biggest change in this cycle was a large series from Sean
Christopherson to clean up the handling of VMX features. This both
fixes bugs/inconsistencies and makes the code more coherent and
future-proof.
There are also two cleanups and a minor TSX syslog messages
enhancement"
* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
x86/cpu: Remove redundant cpu_detect_cache_sizes() call
x86/cpu: Print "VMX disabled" error message iff KVM is enabled
KVM: VMX: Allow KVM_INTEL when building for Centaur and/or Zhaoxin CPUs
perf/x86: Provide stubs of KVM helpers for non-Intel CPUs
KVM: VMX: Use VMX_FEATURE_* flags to define VMCS control bits
KVM: VMX: Check for full VMX support when verifying CPU compatibility
KVM: VMX: Use VMX feature flag to query BIOS enabling
KVM: VMX: Drop initialization of IA32_FEAT_CTL MSR
x86/cpufeatures: Add flag to track whether MSR IA32_FEAT_CTL is configured
x86/cpu: Set synthetic VMX cpufeatures during init_ia32_feat_ctl()
x86/cpu: Print VMX flags in /proc/cpuinfo using VMX_FEATURES_*
x86/cpu: Detect VMX features on Intel, Centaur and Zhaoxin CPUs
x86/vmx: Introduce VMX_FEATURES_*
x86/cpu: Clear VMX feature flag if VMX is not fully enabled
x86/zhaoxin: Use common IA32_FEAT_CTL MSR initialization
x86/centaur: Use common IA32_FEAT_CTL MSR initialization
x86/mce: WARN once if IA32_FEAT_CTL MSR is left unlocked
x86/intel: Initialize IA32_FEAT_CTL MSR at boot
tools/x86: Sync msr-index.h from kernel sources
selftests, kvm: Replace manual MSR defs with common msr-index.h
...
On some platforms such as the Dell XPS 13 laptop the firmware disables turbo
when the machine is disconnected from AC, and viceversa it enables it again
when it's reconnected. In these cases a _PPC ACPI notification is issued.
The scheduler needs to know freq_max for frequency-invariant calculations.
To account for turbo availability to come and go, record freq_max at boot as
if turbo was available and store it in a helper variable. Use a setter
function to swap between freq_base and freq_max every time turbo goes off or on.
Signed-off-by: Giovanni Gherdovich <ggherdovich@suse.cz>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lkml.kernel.org/r/20200122151617.531-7-ggherdovich@suse.cz
The scheduler needs the ratio freq_curr/freq_max for frequency-invariant
accounting. On all ATOM CPUs prior to Goldmont, set freq_max to the 1-core
turbo ratio.
We intended to perform tests validating that this patch doesn't regress in
terms of energy efficiency, given that this is the primary concern on Atom
processors. Alas, we found out that turbostat doesn't support reading RAPL
interfaces on our test machine (Airmont), and we don't have external equipment
to measure power consumption; all we have is the performance results of the
benchmarks we ran.
Test machine:
Platform : Dell Wyse 3040 Thin Client[1]
CPU Model : Intel Atom x5-Z8350 (aka Cherry Trail, aka Airmont)
Fam/Mod/Ste : 6:76:4
Topology : 1 socket, 4 cores / 4 threads
Memory : 2G
Storage : onboard flash, XFS filesystem
[1] https://www.dell.com/en-us/work/shop/wyse-endpoints-and-software/wyse-3040-thin-client/spd/wyse-3040-thin-client
Base frequency and available turbo levels (MHz):
Min Operating Freq 266 |***
Low Freq Mode 800 |********
Base Freq 2400 |************************
4 Cores 2800 |****************************
3 Cores 2800 |****************************
2 Cores 3200 |********************************
1 Core 3200 |********************************
Tested kernels:
Baseline : v5.4-rc1, intel_pstate passive, schedutil
Comparison #1 : v5.4-rc1, intel_pstate active , powersave
Comparison #2 : v5.4-rc1, this patch, intel_pstate passive, schedutil
tbench, hackbench and kernbench performed the same under all three kernels;
dbench ran faster with intel_pstate/powersave and the git unit tests were a
lot faster with intel_pstate/powersave and invariant schedutil wrt the
baseline. Not that any of this is terrbily interesting anyway, one doesn't buy
an Atom system to go fast. Power consumption regressions aren't expected but
we lack the equipment to make that measurement. Turbostat seems to think that
reading RAPL on this machine isn't a good idea and we're trusting that
decision.
comparison ratio of performance with baseline; 1.00 means neutral,
lower is better:
I_PSTATE FREQ-INV
----------------------------------------
dbench 0.90 ~
kernbench 0.98 0.97
gitsource 0.63 0.43
Signed-off-by: Giovanni Gherdovich <ggherdovich@suse.cz>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lkml.kernel.org/r/20200122151617.531-6-ggherdovich@suse.cz
The scheduler needs the ratio freq_curr/freq_max for frequency-invariant
accounting. On GOLDMONT (aka Apollo Lake), GOLDMONT_D (aka Denverton) and
GOLDMONT_PLUS CPUs (aka Gemini Lake) set freq_max to the highest frequency
reported by the CPU.
The encoding of turbo ratios for GOLDMONT* is identical to the one for
SKYLAKE_X, but we treat the Atom case apart because we want to set freq_max to
a higher value, thus the ratio freq_curr/freq_max to be lower, leading to more
conservative frequency selections (favoring power efficiency).
Signed-off-by: Giovanni Gherdovich <ggherdovich@suse.cz>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lkml.kernel.org/r/20200122151617.531-5-ggherdovich@suse.cz
The scheduler needs the ratio freq_curr/freq_max for frequency-invariant
accounting. On Xeon Phi CPUs set freq_max to the second-highest frequency
reported by the CPU.
Xeon Phi CPUs such as Knights Landing and Knights Mill typically have either
one or two turbo frequencies; in the former case that's 100 MHz above the base
frequency, in the latter case the two levels are 100 MHz and 200 MHz above
base frequency.
We set freq_max to the second-highest frequency reported by the CPU. This
could be the base frequency (if only one turbo level is available) or the first
turbo level (if two levels are available). The rationale is to compromise
between power efficiency or performance -- going straight to max turbo would
favor efficiency and blindly using base freq would favor performance.
For reference, this is how MSR_TURBO_RATIO_LIMIT must be parsed on a Xeon Phi
to get the available frequencies (taken from a comment in turbostat's sources):
[0] -- Reserved
[7:1] -- Base value of number of active cores of bucket 1.
[15:8] -- Base value of freq ratio of bucket 1.
[20:16] -- +ve delta of number of active cores of bucket 2.
i.e. active cores of bucket 2 =
active cores of bucket 1 + delta
[23:21] -- Negative delta of freq ratio of bucket 2.
i.e. freq ratio of bucket 2 =
freq ratio of bucket 1 - delta
[28:24]-- +ve delta of number of active cores of bucket 3.
[31:29]-- -ve delta of freq ratio of bucket 3.
[36:32]-- +ve delta of number of active cores of bucket 4.
[39:37]-- -ve delta of freq ratio of bucket 4.
[44:40]-- +ve delta of number of active cores of bucket 5.
[47:45]-- -ve delta of freq ratio of bucket 5.
[52:48]-- +ve delta of number of active cores of bucket 6.
[55:53]-- -ve delta of freq ratio of bucket 6.
[60:56]-- +ve delta of number of active cores of bucket 7.
[63:61]-- -ve delta of freq ratio of bucket 7.
1. PERFORMANCE EVALUATION: TBENCH +5%
2. NEUTRAL BENCHMARKS (ALL OTHERS)
3. TEST SETUP
1. PERFORMANCE EVALUATION: TBENCH +5%
-------------------------------------
A performance evaluation was conducted on a Knights Mill machine (see "Test
Setup" below), were the frequency-invariance patch (on schedutil) is compared
to both non-invariant schedutil and active intel_pstate with powersave: all
three tested kernels behave the same performance-wise and with regard to power
consumption (performance per watt). The only notable difference is tbench:
comparison ratio of performance with baseline; 1.00 means neutral,
higher is better:
I_PSTATE FREQ-INV
----------------------------------------
tbench 1.04 1.05
performance-per-watt ratios with baseline; 1.00 means neutral, higher is better:
I_PSTATE FREQ-INV
----------------------------------------
tbench 1.03 1.04
which essentially means that frequency-invariant schedutil is 5% better than
baseline, the same as intel_pstate+powersave.
As the results above are averaged over the varying parameter, here the detailed
table.
Varying parameter : number of clients
Unit : MB/sec (higher is better)
5.2.0 vanilla (BASELINE) 5.2.0 intel_pstate 5.2.0 freq-inv
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Hmean 1 49.06 +- 2.12% ( ) 51.66 +- 1.52% ( 5.30%) 52.87 +- 0.88% ( 7.76%)
Hmean 2 93.82 +- 0.45% ( ) 103.24 +- 0.70% ( 10.05%) 105.90 +- 0.70% ( 12.88%)
Hmean 4 192.46 +- 1.15% ( ) 215.95 +- 0.60% ( 12.21%) 215.78 +- 1.43% ( 12.12%)
Hmean 8 406.74 +- 2.58% ( ) 438.58 +- 0.36% ( 7.83%) 437.61 +- 0.97% ( 7.59%)
Hmean 16 857.70 +- 1.22% ( ) 890.26 +- 0.72% ( 3.80%) 889.11 +- 0.73% ( 3.66%)
Hmean 32 1760.10 +- 0.92% ( ) 1791.70 +- 0.44% ( 1.79%) 1787.95 +- 0.44% ( 1.58%)
Hmean 64 3183.50 +- 0.34% ( ) 3183.19 +- 0.36% ( -0.01%) 3187.53 +- 0.36% ( 0.13%)
Hmean 128 4830.96 +- 0.31% ( ) 4846.53 +- 0.30% ( 0.32%) 4855.86 +- 0.30% ( 0.52%)
Hmean 256 5467.98 +- 0.38% ( ) 5793.80 +- 0.28% ( 5.96%) 5821.94 +- 0.17% ( 6.47%)
Hmean 512 5398.10 +- 0.06% ( ) 5745.56 +- 0.08% ( 6.44%) 5503.68 +- 0.07% ( 1.96%)
Hmean 1024 5290.43 +- 0.63% ( ) 5221.07 +- 0.47% ( -1.31%) 5277.22 +- 0.80% ( -0.25%)
Hmean 1088 5139.71 +- 0.57% ( ) 5236.02 +- 0.71% ( 1.87%) 5190.57 +- 0.41% ( 0.99%)
2. NEUTRAL BENCHMARKS (ALL OTHERS)
----------------------------------
* pgbench (both read/write and read-only)
* NASA Parallel Benchmarks (NPB), MPI or OpenMP for message-passing
* hackbench
* netperf
* dbench
* kernbench
* gitsource (git unit test suite)
3. TEST SETUP
-------------
Test machine:
CPU Model : Intel Xeon Phi CPU 7255 @ 1.10GHz (a.k.a. Knights Mill)
Fam/Mod/Ste : 6:133:0
Topology : 1 socket, 68 cores / 272 threads
Memory : 96G
Storage : rotary, XFS filesystem
Max EFFICiency, BASE frequency and available turbo levels (MHz):
EFFIC 1000 |**********
BASE 1100 |***********
68C 1100 |***********
30C 1200 |************
Tested kernels:
Baseline : v5.2, intel_pstate passive, schedutil
Comparison #1 : v5.2, intel_pstate active , powersave
Comparison #2 : v5.2, this patch, intel_pstate passive, schedutil
Signed-off-by: Giovanni Gherdovich <ggherdovich@suse.cz>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lkml.kernel.org/r/20200122151617.531-4-ggherdovich@suse.cz
Implement arch_scale_freq_capacity() for 'modern' x86. This function
is used by the scheduler to correctly account usage in the face of
DVFS.
The present patch addresses Intel processors specifically and has positive
performance and performance-per-watt implications for the schedutil cpufreq
governor, bringing it closer to, if not on-par with, the powersave governor
from the intel_pstate driver/framework.
Large performance gains are obtained when the machine is lightly loaded and
no regression are observed at saturation. The benchmarks with the largest
gains are kernel compilation, tbench (the networking version of dbench) and
shell-intensive workloads.
1. FREQUENCY INVARIANCE: MOTIVATION
* Without it, a task looks larger if the CPU runs slower
2. PECULIARITIES OF X86
* freq invariance accounting requires knowing the ratio freq_curr/freq_max
2.1 CURRENT FREQUENCY
* Use delta_APERF / delta_MPERF * freq_base (a.k.a "BusyMHz")
2.2 MAX FREQUENCY
* It varies with time (turbo). As an approximation, we set it to a
constant, i.e. 4-cores turbo frequency.
3. EFFECTS ON THE SCHEDUTIL FREQUENCY GOVERNOR
* The invariant schedutil's formula has no feedback loop and reacts faster
to utilization changes
4. KNOWN LIMITATIONS
* In some cases tasks can't reach max util despite how hard they try
5. PERFORMANCE TESTING
5.1 MACHINES
* Skylake, Broadwell, Haswell
5.2 SETUP
* baseline Linux v5.2 w/ non-invariant schedutil. Tested freq_max = 1-2-3-4-8-12
active cores turbo w/ invariant schedutil, and intel_pstate/powersave
5.3 BENCHMARK RESULTS
5.3.1 NEUTRAL BENCHMARKS
* NAS Parallel Benchmark (HPC), hackbench
5.3.2 NON-NEUTRAL BENCHMARKS
* tbench (10-30% better), kernbench (10-15% better),
shell-intensive-scripts (30-50% better)
* no regressions
5.3.3 SELECTION OF DETAILED RESULTS
5.3.4 POWER CONSUMPTION, PERFORMANCE-PER-WATT
* dbench (5% worse on one machine), kernbench (3% worse),
tbench (5-10% better), shell-intensive-scripts (10-40% better)
6. MICROARCH'ES ADDRESSED HERE
* Xeon Core before Scalable Performance processors line (Xeon Gold/Platinum
etc have different MSRs semantic for querying turbo levels)
7. REFERENCES
* MMTests performance testing framework, github.com/gormanm/mmtests
+-------------------------------------------------------------------------+
| 1. FREQUENCY INVARIANCE: MOTIVATION
+-------------------------------------------------------------------------+
For example; suppose a CPU has two frequencies: 500 and 1000 Mhz. When
running a task that would consume 1/3rd of a CPU at 1000 MHz, it would
appear to consume 2/3rd (or 66.6%) when running at 500 MHz, giving the
false impression this CPU is almost at capacity, even though it can go
faster [*]. In a nutshell, without frequency scale-invariance tasks look
larger just because the CPU is running slower.
[*] (footnote: this assumes a linear frequency/performance relation; which
everybody knows to be false, but given realities its the best approximation
we can make.)
+-------------------------------------------------------------------------+
| 2. PECULIARITIES OF X86
+-------------------------------------------------------------------------+
Accounting for frequency changes in PELT signals requires the computation of
the ratio freq_curr / freq_max. On x86 neither of those terms is readily
available.
2.1 CURRENT FREQUENCY
====================
Since modern x86 has hardware control over the actual frequency we run
at (because amongst other things, Turbo-Mode), we cannot simply use
the frequency as requested through cpufreq.
Instead we use the APERF/MPERF MSRs to compute the effective frequency
over the recent past. Also, because reading MSRs is expensive, don't
do so every time we need the value, but amortize the cost by doing it
every tick.
2.2 MAX FREQUENCY
=================
Obtaining freq_max is also non-trivial because at any time the hardware can
provide a frequency boost to a selected subset of cores if the package has
enough power to spare (eg: Turbo Boost). This means that the maximum frequency
available to a given core changes with time.
The approach taken in this change is to arbitrarily set freq_max to a constant
value at boot. The value chosen is the "4-cores (4C) turbo frequency" on most
microarchitectures, after evaluating the following candidates:
* 1-core (1C) turbo frequency (the fastest turbo state available)
* around base frequency (a.k.a. max P-state)
* something in between, such as 4C turbo
To interpret these options, consider that this is the denominator in
freq_curr/freq_max, and that ratio will be used to scale PELT signals such as
util_avg and load_avg. A large denominator will undershoot (util_avg looks a
bit smaller than it really is), viceversa with a smaller denominator PELT
signals will tend to overshoot. Given that PELT drives frequency selection
in the schedutil governor, we will have:
freq_max set to | effect on DVFS
--------------------+------------------
1C turbo | power efficiency (lower freq choices)
base freq | performance (higher util_avg, higher freq requests)
4C turbo | a bit of both
4C turbo proves to be a good compromise in a number of benchmarks (see below).
+-------------------------------------------------------------------------+
| 3. EFFECTS ON THE SCHEDUTIL FREQUENCY GOVERNOR
+-------------------------------------------------------------------------+
Once an architecture implements a frequency scale-invariant utilization (the
PELT signal util_avg), schedutil switches its frequency selection formula from
freq_next = 1.25 * freq_curr * util [non-invariant util signal]
to
freq_next = 1.25 * freq_max * util [invariant util signal]
where, in the second formula, freq_max is set to the 1C turbo frequency (max
turbo). The advantage of the second formula, whose usage we unlock with this
patch, is that freq_next doesn't depend on the current frequency in an
iterative fashion, but can jump to any frequency in a single update. This
absence of feedback in the formula makes it quicker to react to utilization
changes and more robust against pathological instabilities.
Compare it to the update formula of intel_pstate/powersave:
freq_next = 1.25 * freq_max * Busy%
where again freq_max is 1C turbo and Busy% is the percentage of time not spent
idling (calculated with delta_MPERF / delta_TSC); essentially the same as
invariant schedutil, and largely responsible for intel_pstate/powersave good
reputation. The non-invariant schedutil formula is derived from the invariant
one by approximating util_inv with util_raw * freq_curr / freq_max, but this
has limitations.
Testing shows improved performances due to better frequency selections when
the machine is lightly loaded, and essentially no change in behaviour at
saturation / overutilization.
+-------------------------------------------------------------------------+
| 4. KNOWN LIMITATIONS
+-------------------------------------------------------------------------+
It's been shown that it is possible to create pathological scenarios where a
CPU-bound task cannot reach max utilization, if the normalizing factor
freq_max is fixed to a constant value (see [Lelli-2018]).
If freq_max is set to 4C turbo as we do here, one needs to peg at least 5
cores in a package doing some busywork, and observe that none of those task
will ever reach max util (1024) because they're all running at less than the
4C turbo frequency.
While this concern still applies, we believe the performance benefit of
frequency scale-invariant PELT signals outweights the cost of this limitation.
[Lelli-2018]
https://lore.kernel.org/lkml/20180517150418.GF22493@localhost.localdomain/
+-------------------------------------------------------------------------+
| 5. PERFORMANCE TESTING
+-------------------------------------------------------------------------+
5.1 MACHINES
============
We tested the patch on three machines, with Skylake, Broadwell and Haswell
CPUs. The details are below, together with the available turbo ratios as
reported by the appropriate MSRs.
* 8x-SKYLAKE-UMA:
Single socket E3-1240 v5, Skylake 4 cores/8 threads
Max EFFiciency, BASE frequency and available turbo levels (MHz):
EFFIC 800 |********
BASE 3500 |***********************************
4C 3700 |*************************************
3C 3800 |**************************************
2C 3900 |***************************************
1C 3900 |***************************************
* 80x-BROADWELL-NUMA:
Two sockets E5-2698 v4, 2x Broadwell 20 cores/40 threads
Max EFFiciency, BASE frequency and available turbo levels (MHz):
EFFIC 1200 |************
BASE 2200 |**********************
8C 2900 |*****************************
7C 3000 |******************************
6C 3100 |*******************************
5C 3200 |********************************
4C 3300 |*********************************
3C 3400 |**********************************
2C 3600 |************************************
1C 3600 |************************************
* 48x-HASWELL-NUMA
Two sockets E5-2670 v3, 2x Haswell 12 cores/24 threads
Max EFFiciency, BASE frequency and available turbo levels (MHz):
EFFIC 1200 |************
BASE 2300 |***********************
12C 2600 |**************************
11C 2600 |**************************
10C 2600 |**************************
9C 2600 |**************************
8C 2600 |**************************
7C 2600 |**************************
6C 2600 |**************************
5C 2700 |***************************
4C 2800 |****************************
3C 2900 |*****************************
2C 3100 |*******************************
1C 3100 |*******************************
5.2 SETUP
=========
* The baseline is Linux v5.2 with schedutil (non-invariant) and the intel_pstate
driver in passive mode.
* The rationale for choosing the various freq_max values to test have been to
try all the 1-2-3-4C turbo levels (note that 1C and 2C turbo are identical
on all machines), plus one more value closer to base_freq but still in the
turbo range (8C turbo for both 80x-BROADWELL-NUMA and 48x-HASWELL-NUMA).
* In addition we've run all tests with intel_pstate/powersave for comparison.
* The filesystem is always XFS, the userspace is openSUSE Leap 15.1.
* 8x-SKYLAKE-UMA is capable of HWP (Hardware-Managed P-States), so the runs
with active intel_pstate on this machine use that.
This gives, in terms of combinations tested on each machine:
* 8x-SKYLAKE-UMA
* Baseline: Linux v5.2, non-invariant schedutil, intel_pstate passive
* intel_pstate active + powersave + HWP
* invariant schedutil, freq_max = 1C turbo
* invariant schedutil, freq_max = 3C turbo
* invariant schedutil, freq_max = 4C turbo
* both 80x-BROADWELL-NUMA and 48x-HASWELL-NUMA
* [same as 8x-SKYLAKE-UMA, but no HWP capable]
* invariant schedutil, freq_max = 8C turbo
(which on 48x-HASWELL-NUMA is the same as 12C turbo, or "all cores turbo")
5.3 BENCHMARK RESULTS
=====================
5.3.1 NEUTRAL BENCHMARKS
------------------------
Tests that didn't show any measurable difference in performance on any of the
test machines between non-invariant schedutil and our patch are:
* NAS Parallel Benchmarks (NPB) using either MPI or openMP for IPC, any
computational kernel
* flexible I/O (FIO)
* hackbench (using threads or processes, and using pipes or sockets)
5.3.2 NON-NEUTRAL BENCHMARKS
----------------------------
What follow are summary tables where each benchmark result is given a score.
* A tilde (~) means a neutral result, i.e. no difference from baseline.
* Scores are computed with the ratio result_new / result_baseline, so a tilde
means a score of 1.00.
* The results in the score ratio are the geometric means of results running
the benchmark with different parameters (eg: for kernbench: using 1, 2, 4,
... number of processes; for pgbench: varying the number of clients, and so
on).
* The first three tables show higher-is-better kind of tests (i.e. measured in
operations/second), the subsequent three show lower-is-better kind of tests
(i.e. the workload is fixed and we measure elapsed time, think kernbench).
* "gitsource" is a name we made up for the test consisting in running the
entire unit tests suite of the Git SCM and measuring how long it takes. We
take it as a typical example of shell-intensive serialized workload.
* In the "I_PSTATE" column we have the results for intel_pstate/powersave. Other
columns show invariant schedutil for different values of freq_max. 4C turbo
is circled as it's the value we've chosen for the final implementation.
80x-BROADWELL-NUMA (comparison ratio; higher is better)
+------+
I_PSTATE 1C 3C | 4C | 8C
pgbench-ro 1.14 ~ ~ | 1.11 | 1.14
pgbench-rw ~ ~ ~ | ~ | ~
netperf-udp 1.06 ~ 1.06 | 1.05 | 1.07
netperf-tcp ~ 1.03 ~ | 1.01 | 1.02
tbench4 1.57 1.18 1.22 | 1.30 | 1.56
+------+
8x-SKYLAKE-UMA (comparison ratio; higher is better)
+------+
I_PSTATE/HWP 1C 3C | 4C |
pgbench-ro ~ ~ ~ | ~ |
pgbench-rw ~ ~ ~ | ~ |
netperf-udp ~ ~ ~ | ~ |
netperf-tcp ~ ~ ~ | ~ |
tbench4 1.30 1.14 1.14 | 1.16 |
+------+
48x-HASWELL-NUMA (comparison ratio; higher is better)
+------+
I_PSTATE 1C 3C | 4C | 12C
pgbench-ro 1.15 ~ ~ | 1.06 | 1.16
pgbench-rw ~ ~ ~ | ~ | ~
netperf-udp 1.05 0.97 1.04 | 1.04 | 1.02
netperf-tcp 0.96 1.01 1.01 | 1.01 | 1.01
tbench4 1.50 1.05 1.13 | 1.13 | 1.25
+------+
In the table above we see that active intel_pstate is slightly better than our
4C-turbo patch (both in reference to the baseline non-invariant schedutil) on
read-only pgbench and much better on tbench. Both cases are notable in which
it shows that lowering our freq_max (to 8C-turbo and 12C-turbo on
80x-BROADWELL-NUMA and 48x-HASWELL-NUMA respectively) helps invariant
schedutil to get closer.
If we ignore active intel_pstate and focus on the comparison with baseline
alone, there are several instances of double-digit performance improvement.
80x-BROADWELL-NUMA (comparison ratio; lower is better)
+------+
I_PSTATE 1C 3C | 4C | 8C
dbench4 1.23 0.95 0.95 | 0.95 | 0.95
kernbench 0.93 0.83 0.83 | 0.83 | 0.82
gitsource 0.98 0.49 0.49 | 0.49 | 0.48
+------+
8x-SKYLAKE-UMA (comparison ratio; lower is better)
+------+
I_PSTATE/HWP 1C 3C | 4C |
dbench4 ~ ~ ~ | ~ |
kernbench ~ ~ ~ | ~ |
gitsource 0.92 0.55 0.55 | 0.55 |
+------+
48x-HASWELL-NUMA (comparison ratio; lower is better)
+------+
I_PSTATE 1C 3C | 4C | 8C
dbench4 ~ ~ ~ | ~ | ~
kernbench 0.94 0.90 0.89 | 0.90 | 0.90
gitsource 0.97 0.69 0.69 | 0.69 | 0.69
+------+
dbench is not very remarkable here, unless we notice how poorly active
intel_pstate is performing on 80x-BROADWELL-NUMA: 23% regression versus
non-invariant schedutil. We repeated that run getting consistent results. Out
of scope for the patch at hand, but deserving future investigation. Other than
that, we previously ran this campaign with Linux v5.0 and saw the patch doing
better on dbench a the time. We haven't checked closely and can only speculate
at this point.
On the NUMA boxes kernbench gets 10-15% improvements on average; we'll see in
the detailed tables that the gains concentrate on low process counts (lightly
loaded machines).
The test we call "gitsource" (running the git unit test suite, a long-running
single-threaded shell script) appears rather spectacular in this table (gains
of 30-50% depending on the machine). It is to be noted, however, that
gitsource has no adjustable parameters (such as the number of jobs in
kernbench, which we average over in order to get a single-number summary
score) and is exactly the kind of low-parallelism workload that benefits the
most from this patch. When looking at the detailed tables of kernbench or
tbench4, at low process or client counts one can see similar numbers.
5.3.3 SELECTION OF DETAILED RESULTS
-----------------------------------
Machine : 48x-HASWELL-NUMA
Benchmark : tbench4 (i.e. dbench4 over the network, actually loopback)
Varying parameter : number of clients
Unit : MB/sec (higher is better)
5.2.0 vanilla (BASELINE) 5.2.0 intel_pstate 5.2.0 1C-turbo
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Hmean 1 126.73 +- 0.31% ( ) 315.91 +- 0.66% ( 149.28%) 125.03 +- 0.76% ( -1.34%)
Hmean 2 258.04 +- 0.62% ( ) 614.16 +- 0.51% ( 138.01%) 269.58 +- 1.45% ( 4.47%)
Hmean 4 514.30 +- 0.67% ( ) 1146.58 +- 0.54% ( 122.94%) 533.84 +- 1.99% ( 3.80%)
Hmean 8 1111.38 +- 2.52% ( ) 2159.78 +- 0.38% ( 94.33%) 1359.92 +- 1.56% ( 22.36%)
Hmean 16 2286.47 +- 1.36% ( ) 3338.29 +- 0.21% ( 46.00%) 2720.20 +- 0.52% ( 18.97%)
Hmean 32 4704.84 +- 0.35% ( ) 4759.03 +- 0.43% ( 1.15%) 4774.48 +- 0.30% ( 1.48%)
Hmean 64 7578.04 +- 0.27% ( ) 7533.70 +- 0.43% ( -0.59%) 7462.17 +- 0.65% ( -1.53%)
Hmean 128 6998.52 +- 0.16% ( ) 6987.59 +- 0.12% ( -0.16%) 6909.17 +- 0.14% ( -1.28%)
Hmean 192 6901.35 +- 0.25% ( ) 6913.16 +- 0.10% ( 0.17%) 6855.47 +- 0.21% ( -0.66%)
5.2.0 3C-turbo 5.2.0 4C-turbo 5.2.0 12C-turbo
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Hmean 1 128.43 +- 0.28% ( 1.34%) 130.64 +- 3.81% ( 3.09%) 153.71 +- 5.89% ( 21.30%)
Hmean 2 311.70 +- 6.15% ( 20.79%) 281.66 +- 3.40% ( 9.15%) 305.08 +- 5.70% ( 18.23%)
Hmean 4 641.98 +- 2.32% ( 24.83%) 623.88 +- 5.28% ( 21.31%) 906.84 +- 4.65% ( 76.32%)
Hmean 8 1633.31 +- 1.56% ( 46.96%) 1714.16 +- 0.93% ( 54.24%) 2095.74 +- 0.47% ( 88.57%)
Hmean 16 3047.24 +- 0.42% ( 33.27%) 3155.02 +- 0.30% ( 37.99%) 3634.58 +- 0.15% ( 58.96%)
Hmean 32 4734.31 +- 0.60% ( 0.63%) 4804.38 +- 0.23% ( 2.12%) 4674.62 +- 0.27% ( -0.64%)
Hmean 64 7699.74 +- 0.35% ( 1.61%) 7499.72 +- 0.34% ( -1.03%) 7659.03 +- 0.25% ( 1.07%)
Hmean 128 6935.18 +- 0.15% ( -0.91%) 6942.54 +- 0.10% ( -0.80%) 7004.85 +- 0.12% ( 0.09%)
Hmean 192 6901.62 +- 0.12% ( 0.00%) 6856.93 +- 0.10% ( -0.64%) 6978.74 +- 0.10% ( 1.12%)
This is one of the cases where the patch still can't surpass active
intel_pstate, not even when freq_max is as low as 12C-turbo. Otherwise, gains are
visible up to 16 clients and the saturated scenario is the same as baseline.
The scores in the summary table from the previous sections are ratios of
geometric means of the results over different clients, as seen in this table.
Machine : 80x-BROADWELL-NUMA
Benchmark : kernbench (kernel compilation)
Varying parameter : number of jobs
Unit : seconds (lower is better)
5.2.0 vanilla (BASELINE) 5.2.0 intel_pstate 5.2.0 1C-turbo
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Amean 2 379.68 +- 0.06% ( ) 330.20 +- 0.43% ( 13.03%) 285.93 +- 0.07% ( 24.69%)
Amean 4 200.15 +- 0.24% ( ) 175.89 +- 0.22% ( 12.12%) 153.78 +- 0.25% ( 23.17%)
Amean 8 106.20 +- 0.31% ( ) 95.54 +- 0.23% ( 10.03%) 86.74 +- 0.10% ( 18.32%)
Amean 16 56.96 +- 1.31% ( ) 53.25 +- 1.22% ( 6.50%) 48.34 +- 1.73% ( 15.13%)
Amean 32 34.80 +- 2.46% ( ) 33.81 +- 0.77% ( 2.83%) 30.28 +- 1.59% ( 12.99%)
Amean 64 26.11 +- 1.63% ( ) 25.04 +- 1.07% ( 4.10%) 22.41 +- 2.37% ( 14.16%)
Amean 128 24.80 +- 1.36% ( ) 23.57 +- 1.23% ( 4.93%) 21.44 +- 1.37% ( 13.55%)
Amean 160 24.85 +- 0.56% ( ) 23.85 +- 1.17% ( 4.06%) 21.25 +- 1.12% ( 14.49%)
5.2.0 3C-turbo 5.2.0 4C-turbo 5.2.0 8C-turbo
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Amean 2 284.08 +- 0.13% ( 25.18%) 283.96 +- 0.51% ( 25.21%) 285.05 +- 0.21% ( 24.92%)
Amean 4 153.18 +- 0.22% ( 23.47%) 154.70 +- 1.64% ( 22.71%) 153.64 +- 0.30% ( 23.24%)
Amean 8 87.06 +- 0.28% ( 18.02%) 86.77 +- 0.46% ( 18.29%) 86.78 +- 0.22% ( 18.28%)
Amean 16 48.03 +- 0.93% ( 15.68%) 47.75 +- 1.99% ( 16.17%) 47.52 +- 1.61% ( 16.57%)
Amean 32 30.23 +- 1.20% ( 13.14%) 30.08 +- 1.67% ( 13.57%) 30.07 +- 1.67% ( 13.60%)
Amean 64 22.59 +- 2.02% ( 13.50%) 22.63 +- 0.81% ( 13.32%) 22.42 +- 0.76% ( 14.12%)
Amean 128 21.37 +- 0.67% ( 13.82%) 21.31 +- 1.15% ( 14.07%) 21.17 +- 1.93% ( 14.63%)
Amean 160 21.68 +- 0.57% ( 12.76%) 21.18 +- 1.74% ( 14.77%) 21.22 +- 1.00% ( 14.61%)
The patch outperform active intel_pstate (and baseline) by a considerable
margin; the summary table from the previous section says 4C turbo and active
intel_pstate are 0.83 and 0.93 against baseline respectively, so 4C turbo is
0.83/0.93=0.89 against intel_pstate (~10% better on average). There is no
noticeable difference with regard to the value of freq_max.
Machine : 8x-SKYLAKE-UMA
Benchmark : gitsource (time to run the git unit test suite)
Varying parameter : none
Unit : seconds (lower is better)
5.2.0 vanilla 5.2.0 intel_pstate/hwp 5.2.0 1C-turbo
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Amean 858.85 +- 1.16% ( ) 791.94 +- 0.21% ( 7.79%) 474.95 ( 44.70%)
5.2.0 3C-turbo 5.2.0 4C-turbo
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Amean 475.26 +- 0.20% ( 44.66%) 474.34 +- 0.13% ( 44.77%)
In this test, which is of interest as representing shell-intensive
(i.e. fork-intensive) serialized workloads, invariant schedutil outperforms
intel_pstate/powersave by a whopping 40% margin.
5.3.4 POWER CONSUMPTION, PERFORMANCE-PER-WATT
---------------------------------------------
The following table shows average power consumption in watt for each
benchmark. Data comes from turbostat (package average), which in turn is read
from the RAPL interface on CPUs. We know the patch affects CPU frequencies so
it's reasonable to ignore other power consumers (such as memory or I/O). Also,
we don't have a power meter available in the lab so RAPL is the best we have.
turbostat sampled average power every 10 seconds for the entire duration of
each benchmark. We took all those values and averaged them (i.e. with don't
have detail on a per-parameter granularity, only on whole benchmarks).
80x-BROADWELL-NUMA (power consumption, watts)
+--------+
BASELINE I_PSTATE 1C 3C | 4C | 8C
pgbench-ro 130.01 142.77 131.11 132.45 | 134.65 | 136.84
pgbench-rw 68.30 60.83 71.45 71.70 | 71.65 | 72.54
dbench4 90.25 59.06 101.43 99.89 | 101.10 | 102.94
netperf-udp 65.70 69.81 66.02 68.03 | 68.27 | 68.95
netperf-tcp 88.08 87.96 88.97 88.89 | 88.85 | 88.20
tbench4 142.32 176.73 153.02 163.91 | 165.58 | 176.07
kernbench 92.94 101.95 114.91 115.47 | 115.52 | 115.10
gitsource 40.92 41.87 75.14 75.20 | 75.40 | 75.70
+--------+
8x-SKYLAKE-UMA (power consumption, watts)
+--------+
BASELINE I_PSTATE/HWP 1C 3C | 4C |
pgbench-ro 46.49 46.68 46.56 46.59 | 46.52 |
pgbench-rw 29.34 31.38 30.98 31.00 | 31.00 |
dbench4 27.28 27.37 27.49 27.41 | 27.38 |
netperf-udp 22.33 22.41 22.36 22.35 | 22.36 |
netperf-tcp 27.29 27.29 27.30 27.31 | 27.33 |
tbench4 41.13 45.61 43.10 43.33 | 43.56 |
kernbench 42.56 42.63 43.01 43.01 | 43.01 |
gitsource 13.32 13.69 17.33 17.30 | 17.35 |
+--------+
48x-HASWELL-NUMA (power consumption, watts)
+--------+
BASELINE I_PSTATE 1C 3C | 4C | 12C
pgbench-ro 128.84 136.04 129.87 132.43 | 132.30 | 134.86
pgbench-rw 37.68 37.92 37.17 37.74 | 37.73 | 37.31
dbench4 28.56 28.73 28.60 28.73 | 28.70 | 28.79
netperf-udp 56.70 60.44 56.79 57.42 | 57.54 | 57.52
netperf-tcp 75.49 75.27 75.87 76.02 | 76.01 | 75.95
tbench4 115.44 139.51 119.53 123.07 | 123.97 | 130.22
kernbench 83.23 91.55 95.58 95.69 | 95.72 | 96.04
gitsource 36.79 36.99 39.99 40.34 | 40.35 | 40.23
+--------+
A lower power consumption isn't necessarily better, it depends on what is done
with that energy. Here are tables with the ratio of performance-per-watt on
each machine and benchmark. Higher is always better; a tilde (~) means a
neutral ratio (i.e. 1.00).
80x-BROADWELL-NUMA (performance-per-watt ratios; higher is better)
+------+
I_PSTATE 1C 3C | 4C | 8C
pgbench-ro 1.04 1.06 0.94 | 1.07 | 1.08
pgbench-rw 1.10 0.97 0.96 | 0.96 | 0.97
dbench4 1.24 0.94 0.95 | 0.94 | 0.92
netperf-udp ~ 1.02 1.02 | ~ | 1.02
netperf-tcp ~ 1.02 ~ | ~ | 1.02
tbench4 1.26 1.10 1.06 | 1.12 | 1.26
kernbench 0.98 0.97 0.97 | 0.97 | 0.98
gitsource ~ 1.11 1.11 | 1.11 | 1.13
+------+
8x-SKYLAKE-UMA (performance-per-watt ratios; higher is better)
+------+
I_PSTATE/HWP 1C 3C | 4C |
pgbench-ro ~ ~ ~ | ~ |
pgbench-rw 0.95 0.97 0.96 | 0.96 |
dbench4 ~ ~ ~ | ~ |
netperf-udp ~ ~ ~ | ~ |
netperf-tcp ~ ~ ~ | ~ |
tbench4 1.17 1.09 1.08 | 1.10 |
kernbench ~ ~ ~ | ~ |
gitsource 1.06 1.40 1.40 | 1.40 |
+------+
48x-HASWELL-NUMA (performance-per-watt ratios; higher is better)
+------+
I_PSTATE 1C 3C | 4C | 12C
pgbench-ro 1.09 ~ 1.09 | 1.03 | 1.11
pgbench-rw ~ 0.86 ~ | ~ | 0.86
dbench4 ~ 1.02 1.02 | 1.02 | ~
netperf-udp ~ 0.97 1.03 | 1.02 | ~
netperf-tcp 0.96 ~ ~ | ~ | ~
tbench4 1.24 ~ 1.06 | 1.05 | 1.11
kernbench 0.97 0.97 0.98 | 0.97 | 0.96
gitsource 1.03 1.33 1.32 | 1.32 | 1.33
+------+
These results are overall pleasing: in plenty of cases we observe
performance-per-watt improvements. The few regressions (read/write pgbench and
dbench on the Broadwell machine) are of small magnitude. kernbench loses a few
percentage points (it has a 10-15% performance improvement, but apparently the
increase in power consumption is larger than that). tbench4 and gitsource, which
benefit the most from the patch, keep a positive score in this table which is
a welcome surprise; that suggests that in those particular workloads the
non-invariant schedutil (and active intel_pstate, too) makes some rather
suboptimal frequency selections.
+-------------------------------------------------------------------------+
| 6. MICROARCH'ES ADDRESSED HERE
+-------------------------------------------------------------------------+
The patch addresses Xeon Core processors that use MSR_PLATFORM_INFO and
MSR_TURBO_RATIO_LIMIT to advertise their base frequency and turbo frequencies
respectively. This excludes the recent Xeon Scalable Performance processors
line (Xeon Gold, Platinum etc) whose MSRs have to be parsed differently.
Subsequent patches will address:
* Xeon Scalable Performance processors and Atom Goldmont/Goldmont Plus
* Xeon Phi (Knights Landing, Knights Mill)
* Atom Silvermont
+-------------------------------------------------------------------------+
| 7. REFERENCES
+-------------------------------------------------------------------------+
Tests have been run with the help of the MMTests performance testing
framework, see github.com/gormanm/mmtests. The configuration file names for
the benchmark used are:
db-pgbench-timed-ro-small-xfs
db-pgbench-timed-rw-small-xfs
io-dbench4-async-xfs
network-netperf-unbound
network-tbench
scheduler-unbound
workload-kerndevel-xfs
workload-shellscripts-xfs
hpc-nas-c-class-mpi-full-xfs
hpc-nas-c-class-omp-full
All those benchmarks are generally available on the web:
pgbench: https://www.postgresql.org/docs/10/pgbench.html
netperf: https://hewlettpackard.github.io/netperf/
dbench/tbench: https://dbench.samba.org/
gitsource: git unit test suite, github.com/git/git
NAS Parallel Benchmarks: https://www.nas.nasa.gov/publications/npb.html
hackbench: https://people.redhat.com/mingo/cfs-scheduler/tools/hackbench.c
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Giovanni Gherdovich <ggherdovich@suse.cz>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Doug Smythies <dsmythies@telus.net>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lkml.kernel.org/r/20200122151617.531-2-ggherdovich@suse.cz
Pull misc x86 updates from Ingo Molnar:
"Misc changes:
- Enhance #GP fault printouts by distinguishing between canonical and
non-canonical address faults, and also add KASAN fault decoding.
- Fix/enhance the x86 NMI handler by putting the duration check into
a direct function call instead of an irq_work which we know to be
broken in some cases.
- Clean up do_general_protection() a bit"
* 'x86-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/nmi: Remove irq_work from the long duration NMI handler
x86/traps: Cleanup do_general_protection()
x86/kasan: Print original address on #GP
x86/dumpstack: Introduce die_addr() for die() with #GP fault address
x86/traps: Print address on #GP
x86/insn-eval: Add support for 64-bit kernel mode
Pull x86 cleanups from Ingo Molnar:
"Misc cleanups all around the map"
* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/CPU/AMD: Remove amd_get_topology_early()
x86/tsc: Remove redundant assignment
x86/crash: Use resource_size()
x86/cpu: Add a missing prototype for arch_smt_update()
x86/nospec: Remove unused RSB_FILL_LOOPS
x86/vdso: Provide missing include file
x86/Kconfig: Correct spelling and punctuation
Documentation/x86/boot: Fix typo
x86/boot: Fix a comment's incorrect file reference
x86/process: Remove set but not used variables prev and next
x86/Kconfig: Fix Kconfig indentation
Pull x86 resource control updates from Ingo Molnar:
"The main change in this tree is the extension of the resctrl procfs
ABI with a new file that helps tooling to navigate from tasks back to
resctrl groups: /proc/{pid}/cpu_resctrl_groups.
Also fix static key usage for certain feature combinations and
simplify the task exit resctrl case"
* 'x86-cache-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/resctrl: Add task resctrl information display
x86/resctrl: Check monitoring static key in the MBM overflow handler
x86/resctrl: Do not reconfigure exiting tasks
Pull x86 boot update from Ingo Molnar:
"Two minor changes: fix an atypical binutils combination build bug, and
also fix a VRAM size check for simplefb"
* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/sysfb: Fix check for bad VRAM size
x86/boot: Discard .eh_frame sections
Pull x86 asm updates from Ingo Molnar:
"Misc updates:
- Remove last remaining calls to exception_enter/exception_exit() and
simplify the entry code some more.
- Remove force_iret()
- Add support for "Fast Short Rep Mov", which is available starting
with Ice Lake Intel CPUs - and make the x86 assembly version of
memmove() use REP MOV for all sizes when FSRM is available.
- Micro-optimize/simplify the 32-bit boot code a bit.
- Use a more future-proof SYSRET instruction mnemonic"
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/boot: Simplify calculation of output address
x86/entry/64: Add instruction suffix to SYSRET
x86: Remove force_iret()
x86/cpufeatures: Add support for fast short REP; MOVSB
x86/context-tracking: Remove exception_enter/exit() from KVM_PV_REASON_PAGE_NOT_PRESENT async page fault
x86/context-tracking: Remove exception_enter/exit() from do_page_fault()
Pull x86 apic fix from Ingo Molnar:
"A single commit that simplifies the code and gets rid of a compiler
warning"
* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/apic/uv: Avoid unused variable warning
Pull perf updates from Ingo Molnar:
"Kernel side changes:
- Ftrace is one of the last W^X violators (after this only KLP is
left). These patches move it over to the generic text_poke()
interface and thereby get rid of this oddity. This requires a
surprising amount of surgery, by Peter Zijlstra.
- x86/AMD PMUs: add support for 'Large Increment per Cycle Events' to
count certain types of events that have a special, quirky hw ABI
(by Kim Phillips)
- kprobes fixes by Masami Hiramatsu
Lots of tooling updates as well, the following subcommands were
updated: annotate/report/top, c2c, clang, record, report/top TUI,
sched timehist, tests; plus updates were done to the gtk ui, libperf,
headers and the parser"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (57 commits)
perf/x86/amd: Add support for Large Increment per Cycle Events
perf/x86/amd: Constrain Large Increment per Cycle events
perf/x86/intel/rapl: Add Comet Lake support
tracing: Initialize ret in syscall_enter_define_fields()
perf header: Use last modification time for timestamp
perf c2c: Fix return type for histogram sorting comparision functions
perf beauty sockaddr: Fix augmented syscall format warning
perf/ui/gtk: Fix gtk2 build
perf ui gtk: Add missing zalloc object
perf tools: Use %define api.pure full instead of %pure-parser
libperf: Setup initial evlist::all_cpus value
perf report: Fix no libunwind compiled warning break s390 issue
perf tools: Support --prefix/--prefix-strip
perf report: Clarify in help that --children is default
tools build: Fix test-clang.cpp with Clang 8+
perf clang: Fix build with Clang 9
kprobes: Fix optimize_kprobe()/unoptimize_kprobe() cancellation logic
tools lib: Fix builds when glibc contains strlcpy()
perf report/top: Make 'e' visible in the help and make it toggle showing callchains
perf report/top: Do not offer annotation for symbols without samples
...
Pull EFI updates from Ingo Molnar:
"The main changes in this cycle were:
- Cleanup of the GOP [graphics output] handling code in the EFI stub
- Complete refactoring of the mixed mode handling in the x86 EFI stub
- Overhaul of the x86 EFI boot/runtime code
- Increase robustness for mixed mode code
- Add the ability to disable DMA at the root port level in the EFI
stub
- Get rid of RWX mappings in the EFI memory map and page tables,
where possible
- Move the support code for the old EFI memory mapping style into its
only user, the SGI UV1+ support code.
- plus misc fixes, updates, smaller cleanups.
... and due to interactions with the RWX changes, another round of PAT
cleanups make a guest appearance via the EFI tree - with no side
effects intended"
* 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (75 commits)
efi/x86: Disable instrumentation in the EFI runtime handling code
efi/libstub/x86: Fix EFI server boot failure
efi/x86: Disallow efi=old_map in mixed mode
x86/boot/compressed: Relax sed symbol type regex for LLVM ld.lld
efi/x86: avoid KASAN false positives when accessing the 1: 1 mapping
efi: Fix handling of multiple efi_fake_mem= entries
efi: Fix efi_memmap_alloc() leaks
efi: Add tracking for dynamically allocated memmaps
efi: Add a flags parameter to efi_memory_map
efi: Fix comment for efi_mem_type() wrt absent physical addresses
efi/arm: Defer probe of PCIe backed efifb on DT systems
efi/x86: Limit EFI old memory map to SGI UV machines
efi/x86: Avoid RWX mappings for all of DRAM
efi/x86: Don't map the entire kernel text RW for mixed mode
x86/mm: Fix NX bit clearing issue in kernel_map_pages_in_pgd
efi/libstub/x86: Fix unused-variable warning
efi/libstub/x86: Use mandatory 16-byte stack alignment in mixed mode
efi/libstub/x86: Use const attribute for efi_is_64bit()
efi: Allow disabling PCI busmastering on bridges during boot
efi/x86: Allow translating 64-bit arguments for mixed mode calls
...
Pull objtool updates from Ingo Molnar:
"The main changes are to move the ORC unwind table sorting from early
init to build-time - this speeds up booting.
No change in functionality intended"
* 'core-objtool-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/unwind/orc: Fix !CONFIG_MODULES build warning
x86/unwind/orc: Remove boot-time ORC unwind tables sorting
scripts/sorttable: Implement build-time ORC unwind table sorting
scripts/sorttable: Rename 'sortextable' to 'sorttable'
scripts/sortextable: Refactor the do_func() function
scripts/sortextable: Remove dead code
scripts/sortextable: Clean up the code to meet the kernel coding style better
scripts/sortextable: Rewrite error/success handling
Pull header cleanup from Ingo Molnar:
"This is a treewide cleanup, mostly (but not exclusively) with x86
impact, which breaks implicit dependencies on the asm/realtime.h
header and finally removes it from asm/acpi.h"
* 'core-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/ACPI/sleep: Move acpi_get_wakeup_address() into sleep.c, remove <asm/realmode.h> from <asm/acpi.h>
ACPI/sleep: Convert acpi_wakeup_address into a function
x86/ACPI/sleep: Remove an unnecessary include of asm/realmode.h
ASoC: Intel: Skylake: Explicitly include linux/io.h for virt_to_phys()
vmw_balloon: Explicitly include linux/io.h for virt_to_phys()
virt: vbox: Explicitly include linux/io.h to pick up various defs
efi/capsule-loader: Explicitly include linux/io.h for page_to_phys()
perf/x86/intel: Explicitly include asm/io.h to use virt_to_phys()
x86/kprobes: Explicitly include vmalloc.h for set_vm_flush_reset_perms()
x86/ftrace: Explicitly include vmalloc.h for set_vm_flush_reset_perms()
x86/boot: Explicitly include realmode.h to handle RM reservations
x86/efi: Explicitly include realmode.h to handle RM trampoline quirk
x86/platform/intel/quark: Explicitly include linux/io.h for virt_to_phys()
x86/setup: Enhance the comments
x86/setup: Clean up the header portion of setup.c
and improvements:
- Update the cached HLE state when the TSX state is changed via the new
control register. This ensures feature bit consistency.
- Exclude the new Zhaoxin CPUs from Spectre V2 and SWAPGS vulnerabilities.
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Merge tag 'x86-pti-2020-01-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 pti updates from Thomas Gleixner:
"The performance deterioration departement provides a few non-scary
fixes and improvements:
- Update the cached HLE state when the TSX state is changed via the
new control register. This ensures feature bit consistency.
- Exclude the new Zhaoxin CPUs from Spectre V2 and SWAPGS
vulnerabilities"
* tag 'x86-pti-2020-01-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/speculation/swapgs: Exclude Zhaoxin CPUs from SWAPGS vulnerability
x86/speculation/spectre_v2: Exclude Zhaoxin CPUs from SPECTRE_V2
x86/cpu: Update cached HLE state on write to TSX_CTRL_CPUID_CLEAR
- Time namespace support:
If a container migrates from one host to another then it expects that
clocks based on MONOTONIC and BOOTTIME are not subject to
disruption. Due to different boot time and non-suspended runtime these
clocks can differ significantly on two hosts, in the worst case time
goes backwards which is a violation of the POSIX requirements.
The time namespace addresses this problem. It allows to set offsets for
clock MONOTONIC and BOOTTIME once after creation and before tasks are
associated with the namespace. These offsets are taken into account by
timers and timekeeping including the VDSO.
Offsets for wall clock based clocks (REALTIME/TAI) are not provided by
this mechanism. While in theory possible, the overhead and code
complexity would be immense and not justified by the esoteric potential
use cases which were discussed at Plumbers '18.
The overhead for tasks in the root namespace (host time offsets = 0) is
in the noise and great effort was made to ensure that especially in the
VDSO. If time namespace is disabled in the kernel configuration the
code is compiled out.
Kudos to Andrei Vagin and Dmitry Sofanov who implemented this feature
and kept on for more than a year addressing review comments, finding
better solutions. A pleasant experience.
- Overhaul of the alarmtimer device dependency handling to ensure that
the init/suspend/resume ordering is correct.
- A new clocksource/event driver for Microchip PIT64
- Suspend/resume support for the Hyper-V clocksource
- The usual pile of fixes, updates and improvements mostly in the
driver code.
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Merge tag 'timers-core-2020-01-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Thomas Gleixner:
"The timekeeping and timers departement provides:
- Time namespace support:
If a container migrates from one host to another then it expects
that clocks based on MONOTONIC and BOOTTIME are not subject to
disruption. Due to different boot time and non-suspended runtime
these clocks can differ significantly on two hosts, in the worst
case time goes backwards which is a violation of the POSIX
requirements.
The time namespace addresses this problem. It allows to set offsets
for clock MONOTONIC and BOOTTIME once after creation and before
tasks are associated with the namespace. These offsets are taken
into account by timers and timekeeping including the VDSO.
Offsets for wall clock based clocks (REALTIME/TAI) are not provided
by this mechanism. While in theory possible, the overhead and code
complexity would be immense and not justified by the esoteric
potential use cases which were discussed at Plumbers '18.
The overhead for tasks in the root namespace (ie where host time
offsets = 0) is in the noise and great effort was made to ensure
that especially in the VDSO. If time namespace is disabled in the
kernel configuration the code is compiled out.
Kudos to Andrei Vagin and Dmitry Sofanov who implemented this
feature and kept on for more than a year addressing review
comments, finding better solutions. A pleasant experience.
- Overhaul of the alarmtimer device dependency handling to ensure
that the init/suspend/resume ordering is correct.
- A new clocksource/event driver for Microchip PIT64
- Suspend/resume support for the Hyper-V clocksource
- The usual pile of fixes, updates and improvements mostly in the
driver code"
* tag 'timers-core-2020-01-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits)
alarmtimer: Make alarmtimer_get_rtcdev() a stub when CONFIG_RTC_CLASS=n
alarmtimer: Use wakeup source from alarmtimer platform device
alarmtimer: Make alarmtimer platform device child of RTC device
alarmtimer: Update alarmtimer_get_rtcdev() docs to reflect reality
hrtimer: Add missing sparse annotation for __run_timer()
lib/vdso: Only read hrtimer_res when needed in __cvdso_clock_getres()
MIPS: vdso: Define BUILD_VDSO32 when building a 32bit kernel
clocksource/drivers/hyper-v: Set TSC clocksource as default w/ InvariantTSC
clocksource/drivers/hyper-v: Untangle stimers and timesync from clocksources
clocksource/drivers/timer-microchip-pit64b: Fix sparse warning
clocksource/drivers/exynos_mct: Rename Exynos to lowercase
clocksource/drivers/timer-ti-dm: Fix uninitialized pointer access
clocksource/drivers/timer-ti-dm: Switch to platform_get_irq
clocksource/drivers/timer-ti-dm: Convert to devm_platform_ioremap_resource
clocksource/drivers/em_sti: Fix variable declaration in em_sti_probe
clocksource/drivers/em_sti: Convert to devm_platform_ioremap_resource
clocksource/drivers/bcm2835_timer: Fix memory leak of timer
clocksource/drivers/cadence-ttc: Use ttc driver as platform driver
clocksource/drivers/timer-microchip-pit64b: Add Microchip PIT64B support
clocksource/drivers/hyper-v: Reserve PAGE_SIZE space for tsc page
...
- remove ioremap_nocache given that is is equivalent to
ioremap everywhere
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Merge tag 'ioremap-5.6' of git://git.infradead.org/users/hch/ioremap
Pull ioremap updates from Christoph Hellwig:
"Remove the ioremap_nocache API (plus wrappers) that are always
identical to ioremap"
* tag 'ioremap-5.6' of git://git.infradead.org/users/hch/ioremap:
remove ioremap_nocache and devm_ioremap_nocache
MIPS: define ioremap_nocache to ioremap
Pull RAS updates from Borislav Petkov:
- Misc fixes to the MCE code all over the place, by Jan H. Schönherr.
- Initial support for AMD F19h and other cleanups to amd64_edac, by
Yazen Ghannam.
- Other small cleanups.
* 'ras-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
EDAC/mce_amd: Make fam_ops static global
EDAC/amd64: Drop some family checks for newer systems
EDAC/amd64: Add family ops for Family 19h Models 00h-0Fh
x86/amd_nb: Add Family 19h PCI IDs
EDAC/mce_amd: Always load on SMCA systems
x86/MCE/AMD, EDAC/mce_amd: Add new Load Store unit McaType
x86/mce: Fix use of uninitialized MCE message string
x86/mce: Fix mce=nobootlog
x86/mce: Take action on UCNA/Deferred errors again
x86/mce: Remove mce_inject_log() in favor of mce_log()
x86/mce: Pass MCE message to mce_panic() on failed kernel recovery
x86/mce/therm_throt: Mark throttle_active_work() as __maybe_unused
... and fold its function body into its single call site.
No functional changes:
# arch/x86/kernel/cpu/amd.o:
text data bss dec hex filename
5994 385 1 6380 18ec amd.o.before
5994 385 1 6380 18ec amd.o.after
md5:
99ec6daa095b502297884e949c520f90 amd.o.before.asm
99ec6daa095b502297884e949c520f90 amd.o.after.asm
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200123165811.5288-1-bp@alien8.de
From: Dave Hansen <dave.hansen@linux.intel.com>
MPX is being removed from the kernel due to a lack of support
in the toolchain going forward (gcc).
This removes all the remaining (dead at this point) MPX handling
code remaining in the tree. The only remaining code is the XSAVE
support for MPX state which is currently needd for KVM to handle
VMs which might use MPX.
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: x86@kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
From: Dave Hansen <dave.hansen@linux.intel.com>
MPX is being removed from the kernel due to a lack of support
in the toolchain going forward (gcc).
Remove the other user-visible ABI: signal handling. This code
should basically have been inactive after the prctl()s were
removed, but there may be some small ABI remnants from this code.
Remove it.
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: x86@kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
From: Dave Hansen <dave.hansen@linux.intel.com>
While testing my MPX removal series, Borislav noted compilation
failure with an allnoconfig build.
Turned out to be a missing include of insn.h in alternative.c.
With MPX, it got it implicitly from:
asm/mmu_context.h -> asm/mpx.h -> asm/insn.h
Fixes: c3d6324f84 ("x86/alternatives: Teach text_poke_bp() to emulate instructions")
Reported-by: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: x86@kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Previously, the assignment to the local variable 'now' took place
before the for loop. The loop is unconditional so it will be entered
at least once. The variable 'now' is reassigned in the loop and is not
used before reassigning. Therefore, the assignment before the loop is
unnecessary and can be removed.
No code changed:
# arch/x86/kernel/tsc_sync.o:
text data bss dec hex filename
3569 198 44 3811 ee3 tsc_sync.o.before
3569 198 44 3811 ee3 tsc_sync.o.after
md5:
36216de29b208edbcd34fed9fe7f7b69 tsc_sync.o.before.asm
36216de29b208edbcd34fed9fe7f7b69 tsc_sync.o.after.asm
[ bp: Massage commit message. ]
Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200118171143.25178-1-mateusznosek0@gmail.com
Commit
334b0f4e9b ("x86/resctrl: Fix a deadlock due to inaccurate reference")
changed the argument to rdtgroup_kn_lock_live()/rdtgroup_kn_unlock()
within mkdir_rdt_prepare(). That change resulted in an unused function
parameter to mkdir_rdt_prepare().
Clean up the unused function parameter in mkdir_rdt_prepare() and its
callers rdtgroup_mkdir_mon() and rdtgroup_mkdir_ctrl_mon().
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/1578500886-21771-5-git-send-email-xiaochen.shen@intel.com
There is a race condition which results in a deadlock when rmdir and
mkdir execute concurrently:
$ ls /sys/fs/resctrl/c1/mon_groups/m1/
cpus cpus_list mon_data tasks
Thread 1: rmdir /sys/fs/resctrl/c1
Thread 2: mkdir /sys/fs/resctrl/c1/mon_groups/m1
3 locks held by mkdir/48649:
#0: (sb_writers#17){.+.+}, at: [<ffffffffb4ca2aa0>] mnt_want_write+0x20/0x50
#1: (&type->i_mutex_dir_key#8/1){+.+.}, at: [<ffffffffb4c8c13b>] filename_create+0x7b/0x170
#2: (rdtgroup_mutex){+.+.}, at: [<ffffffffb4a4389d>] rdtgroup_kn_lock_live+0x3d/0x70
4 locks held by rmdir/48652:
#0: (sb_writers#17){.+.+}, at: [<ffffffffb4ca2aa0>] mnt_want_write+0x20/0x50
#1: (&type->i_mutex_dir_key#8/1){+.+.}, at: [<ffffffffb4c8c3cf>] do_rmdir+0x13f/0x1e0
#2: (&type->i_mutex_dir_key#8){++++}, at: [<ffffffffb4c86d5d>] vfs_rmdir+0x4d/0x120
#3: (rdtgroup_mutex){+.+.}, at: [<ffffffffb4a4389d>] rdtgroup_kn_lock_live+0x3d/0x70
Thread 1 is deleting control group "c1". Holding rdtgroup_mutex,
kernfs_remove() removes all kernfs nodes under directory "c1"
recursively, then waits for sub kernfs node "mon_groups" to drop active
reference.
Thread 2 is trying to create a subdirectory "m1" in the "mon_groups"
directory. The wrapper kernfs_iop_mkdir() takes an active reference to
the "mon_groups" directory but the code drops the active reference to
the parent directory "c1" instead.
As a result, Thread 1 is blocked on waiting for active reference to drop
and never release rdtgroup_mutex, while Thread 2 is also blocked on
trying to get rdtgroup_mutex.
Thread 1 (rdtgroup_rmdir) Thread 2 (rdtgroup_mkdir)
(rmdir /sys/fs/resctrl/c1) (mkdir /sys/fs/resctrl/c1/mon_groups/m1)
------------------------- -------------------------
kernfs_iop_mkdir
/*
* kn: "m1", parent_kn: "mon_groups",
* prgrp_kn: parent_kn->parent: "c1",
*
* "mon_groups", parent_kn->active++: 1
*/
kernfs_get_active(parent_kn)
kernfs_iop_rmdir
/* "c1", kn->active++ */
kernfs_get_active(kn)
rdtgroup_kn_lock_live
atomic_inc(&rdtgrp->waitcount)
/* "c1", kn->active-- */
kernfs_break_active_protection(kn)
mutex_lock
rdtgroup_rmdir_ctrl
free_all_child_rdtgrp
sentry->flags = RDT_DELETED
rdtgroup_ctrl_remove
rdtgrp->flags = RDT_DELETED
kernfs_get(kn)
kernfs_remove(rdtgrp->kn)
__kernfs_remove
/* "mon_groups", sub_kn */
atomic_add(KN_DEACTIVATED_BIAS, &sub_kn->active)
kernfs_drain(sub_kn)
/*
* sub_kn->active == KN_DEACTIVATED_BIAS + 1,
* waiting on sub_kn->active to drop, but it
* never drops in Thread 2 which is blocked
* on getting rdtgroup_mutex.
*/
Thread 1 hangs here ---->
wait_event(sub_kn->active == KN_DEACTIVATED_BIAS)
...
rdtgroup_mkdir
rdtgroup_mkdir_mon(parent_kn, prgrp_kn)
mkdir_rdt_prepare(parent_kn, prgrp_kn)
rdtgroup_kn_lock_live(prgrp_kn)
atomic_inc(&rdtgrp->waitcount)
/*
* "c1", prgrp_kn->active--
*
* The active reference on "c1" is
* dropped, but not matching the
* actual active reference taken
* on "mon_groups", thus causing
* Thread 1 to wait forever while
* holding rdtgroup_mutex.
*/
kernfs_break_active_protection(
prgrp_kn)
/*
* Trying to get rdtgroup_mutex
* which is held by Thread 1.
*/
Thread 2 hangs here ----> mutex_lock
...
The problem is that the creation of a subdirectory in the "mon_groups"
directory incorrectly releases the active protection of its parent
directory instead of itself before it starts waiting for rdtgroup_mutex.
This is triggered by the rdtgroup_mkdir() flow calling
rdtgroup_kn_lock_live()/rdtgroup_kn_unlock() with kernfs node of the
parent control group ("c1") as argument. It should be called with kernfs
node "mon_groups" instead. What is currently missing is that the
kn->priv of "mon_groups" is NULL instead of pointing to the rdtgrp.
Fix it by pointing kn->priv to rdtgrp when "mon_groups" is created. Then
it could be passed to rdtgroup_kn_lock_live()/rdtgroup_kn_unlock()
instead. And then it operates on the same rdtgroup structure but handles
the active reference of kernfs node "mon_groups" to prevent deadlock.
The same changes are also made to the "mon_data" directories.
This results in some unused function parameters that will be cleaned up
in follow-up patch as the focus here is on the fix only in support of
backporting efforts.
Fixes: c7d9aac613 ("x86/intel_rdt/cqm: Add mkdir support for RDT monitoring")
Suggested-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1578500886-21771-4-git-send-email-xiaochen.shen@intel.com
There is a race condition in the following scenario which results in an
use-after-free issue when reading a monitoring file and deleting the
parent ctrl_mon group concurrently:
Thread 1 calls atomic_inc() to take refcount of rdtgrp and then calls
kernfs_break_active_protection() to drop the active reference of kernfs
node in rdtgroup_kn_lock_live().
In Thread 2, kernfs_remove() is a blocking routine. It waits on all sub
kernfs nodes to drop the active reference when removing all subtree
kernfs nodes recursively. Thread 2 could block on kernfs_remove() until
Thread 1 calls kernfs_break_active_protection(). Only after
kernfs_remove() completes the refcount of rdtgrp could be trusted.
Before Thread 1 calls atomic_inc() and kernfs_break_active_protection(),
Thread 2 could call kfree() when the refcount of rdtgrp (sentry) is 0
instead of 1 due to the race.
In Thread 1, in rdtgroup_kn_unlock(), referring to earlier rdtgrp memory
(rdtgrp->waitcount) which was already freed in Thread 2 results in
use-after-free issue.
Thread 1 (rdtgroup_mondata_show) Thread 2 (rdtgroup_rmdir)
-------------------------------- -------------------------
rdtgroup_kn_lock_live
/*
* kn active protection until
* kernfs_break_active_protection(kn)
*/
rdtgrp = kernfs_to_rdtgroup(kn)
rdtgroup_kn_lock_live
atomic_inc(&rdtgrp->waitcount)
mutex_lock
rdtgroup_rmdir_ctrl
free_all_child_rdtgrp
/*
* sentry->waitcount should be 1
* but is 0 now due to the race.
*/
kfree(sentry)*[1]
/*
* Only after kernfs_remove()
* completes, the refcount of
* rdtgrp could be trusted.
*/
atomic_inc(&rdtgrp->waitcount)
/* kn->active-- */
kernfs_break_active_protection(kn)
rdtgroup_ctrl_remove
rdtgrp->flags = RDT_DELETED
/*
* Blocking routine, wait for
* all sub kernfs nodes to drop
* active reference in
* kernfs_break_active_protection.
*/
kernfs_remove(rdtgrp->kn)
rdtgroup_kn_unlock
mutex_unlock
atomic_dec_and_test(
&rdtgrp->waitcount)
&& (flags & RDT_DELETED)
kernfs_unbreak_active_protection(kn)
kfree(rdtgrp)
mutex_lock
mon_event_read
rdtgroup_kn_unlock
mutex_unlock
/*
* Use-after-free: refer to earlier rdtgrp
* memory which was freed in [1].
*/
atomic_dec_and_test(&rdtgrp->waitcount)
&& (flags & RDT_DELETED)
/* kn->active++ */
kernfs_unbreak_active_protection(kn)
kfree(rdtgrp)
Fix it by moving free_all_child_rdtgrp() to after kernfs_remove() in
rdtgroup_rmdir_ctrl() to ensure it has the accurate refcount of rdtgrp.
Fixes: f3cbeacaa0 ("x86/intel_rdt/cqm: Add rmdir support")
Suggested-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1578500886-21771-3-git-send-email-xiaochen.shen@intel.com
A resource group (rdtgrp) contains a reference count (rdtgrp->waitcount)
that indicates how many waiters expect this rdtgrp to exist. Waiters
could be waiting on rdtgroup_mutex or some work sitting on a task's
workqueue for when the task returns from kernel mode or exits.
The deletion of a rdtgrp is intended to have two phases:
(1) while holding rdtgroup_mutex the necessary cleanup is done and
rdtgrp->flags is set to RDT_DELETED,
(2) after releasing the rdtgroup_mutex, the rdtgrp structure is freed
only if there are no waiters and its flag is set to RDT_DELETED. Upon
gaining access to rdtgroup_mutex or rdtgrp, a waiter is required to check
for the RDT_DELETED flag.
When unmounting the resctrl file system or deleting ctrl_mon groups,
all of the subdirectories are removed and the data structure of rdtgrp
is forcibly freed without checking rdtgrp->waitcount. If at this point
there was a waiter on rdtgrp then a use-after-free issue occurs when the
waiter starts running and accesses the rdtgrp structure it was waiting
on.
See kfree() calls in [1], [2] and [3] in these two call paths in
following scenarios:
(1) rdt_kill_sb() -> rmdir_all_sub() -> free_all_child_rdtgrp()
(2) rdtgroup_rmdir() -> rdtgroup_rmdir_ctrl() -> free_all_child_rdtgrp()
There are several scenarios that result in use-after-free issue in
following:
Scenario 1:
-----------
In Thread 1, rdtgroup_tasks_write() adds a task_work callback
move_myself(). If move_myself() is scheduled to execute after Thread 2
rdt_kill_sb() is finished, referring to earlier rdtgrp memory
(rdtgrp->waitcount) which was already freed in Thread 2 results in
use-after-free issue.
Thread 1 (rdtgroup_tasks_write) Thread 2 (rdt_kill_sb)
------------------------------- ----------------------
rdtgroup_kn_lock_live
atomic_inc(&rdtgrp->waitcount)
mutex_lock
rdtgroup_move_task
__rdtgroup_move_task
/*
* Take an extra refcount, so rdtgrp cannot be freed
* before the call back move_myself has been invoked
*/
atomic_inc(&rdtgrp->waitcount)
/* Callback move_myself will be scheduled for later */
task_work_add(move_myself)
rdtgroup_kn_unlock
mutex_unlock
atomic_dec_and_test(&rdtgrp->waitcount)
&& (flags & RDT_DELETED)
mutex_lock
rmdir_all_sub
/*
* sentry and rdtgrp are freed
* without checking refcount
*/
free_all_child_rdtgrp
kfree(sentry)*[1]
kfree(rdtgrp)*[2]
mutex_unlock
/*
* Callback is scheduled to execute
* after rdt_kill_sb is finished
*/
move_myself
/*
* Use-after-free: refer to earlier rdtgrp
* memory which was freed in [1] or [2].
*/
atomic_dec_and_test(&rdtgrp->waitcount)
&& (flags & RDT_DELETED)
kfree(rdtgrp)
Scenario 2:
-----------
In Thread 1, rdtgroup_tasks_write() adds a task_work callback
move_myself(). If move_myself() is scheduled to execute after Thread 2
rdtgroup_rmdir() is finished, referring to earlier rdtgrp memory
(rdtgrp->waitcount) which was already freed in Thread 2 results in
use-after-free issue.
Thread 1 (rdtgroup_tasks_write) Thread 2 (rdtgroup_rmdir)
------------------------------- -------------------------
rdtgroup_kn_lock_live
atomic_inc(&rdtgrp->waitcount)
mutex_lock
rdtgroup_move_task
__rdtgroup_move_task
/*
* Take an extra refcount, so rdtgrp cannot be freed
* before the call back move_myself has been invoked
*/
atomic_inc(&rdtgrp->waitcount)
/* Callback move_myself will be scheduled for later */
task_work_add(move_myself)
rdtgroup_kn_unlock
mutex_unlock
atomic_dec_and_test(&rdtgrp->waitcount)
&& (flags & RDT_DELETED)
rdtgroup_kn_lock_live
atomic_inc(&rdtgrp->waitcount)
mutex_lock
rdtgroup_rmdir_ctrl
free_all_child_rdtgrp
/*
* sentry is freed without
* checking refcount
*/
kfree(sentry)*[3]
rdtgroup_ctrl_remove
rdtgrp->flags = RDT_DELETED
rdtgroup_kn_unlock
mutex_unlock
atomic_dec_and_test(
&rdtgrp->waitcount)
&& (flags & RDT_DELETED)
kfree(rdtgrp)
/*
* Callback is scheduled to execute
* after rdt_kill_sb is finished
*/
move_myself
/*
* Use-after-free: refer to earlier rdtgrp
* memory which was freed in [3].
*/
atomic_dec_and_test(&rdtgrp->waitcount)
&& (flags & RDT_DELETED)
kfree(rdtgrp)
If CONFIG_DEBUG_SLAB=y, Slab corruption on kmalloc-2k can be observed
like following. Note that "0x6b" is POISON_FREE after kfree(). The
corrupted bits "0x6a", "0x64" at offset 0x424 correspond to
waitcount member of struct rdtgroup which was freed:
Slab corruption (Not tainted): kmalloc-2k start=ffff9504c5b0d000, len=2048
420: 6b 6b 6b 6b 6a 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkjkkkkkkkkkkk
Single bit error detected. Probably bad RAM.
Run memtest86+ or a similar memory test tool.
Next obj: start=ffff9504c5b0d800, len=2048
000: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
010: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Slab corruption (Not tainted): kmalloc-2k start=ffff9504c58ab800, len=2048
420: 6b 6b 6b 6b 64 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkdkkkkkkkkkkk
Prev obj: start=ffff9504c58ab000, len=2048
000: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
010: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Fix this by taking reference count (waitcount) of rdtgrp into account in
the two call paths that currently do not do so. Instead of always
freeing the resource group it will only be freed if there are no waiters
on it. If there are waiters, the resource group will have its flags set
to RDT_DELETED.
It will be left to the waiter to free the resource group when it starts
running and finding that it was the last waiter and the resource group
has been removed (rdtgrp->flags & RDT_DELETED) since. (1) rdt_kill_sb()
-> rmdir_all_sub() -> free_all_child_rdtgrp() (2) rdtgroup_rmdir() ->
rdtgroup_rmdir_ctrl() -> free_all_child_rdtgrp()
Fixes: f3cbeacaa0 ("x86/intel_rdt/cqm: Add rmdir support")
Fixes: 60cf5e101f ("x86/intel_rdt: Add mkdir to resctrl file system")
Suggested-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1578500886-21771-2-git-send-email-xiaochen.shen@intel.com
Both functions call init_intel_cacheinfo() which computes L2 and L3 cache
sizes from CPUID(4). But then they also call cpu_detect_cache_sizes() a
bit later which computes ->x86_tlbsize and L2 size from CPUID(80000006).
However, the latter call is not needed because
- on these CPUs, CPUID(80000006).EBX for ->x86_tlbsize is reserved
- CPUID(80000006).ECX for the L2 size has the same result as CPUID(4)
Therefore, remove the latter call to simplify the code.
[ bp: Rewrite commit message. ]
Signed-off-by: Tony W Wang-oc <TonyWWang-oc@zhaoxin.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/1579075257-6985-1-git-send-email-TonyWWang-oc@zhaoxin.com
Monitoring tools that want to find out which resctrl control and monitor
groups a task belongs to must currently read the "tasks" file in every
group until they locate the process ID.
Add an additional file /proc/{pid}/cpu_resctrl_groups to provide this
information:
1) res:
mon:
resctrl is not available.
2) res:/
mon:
Task is part of the root resctrl control group, and it is not associated
to any monitor group.
3) res:/
mon:mon0
Task is part of the root resctrl control group and monitor group mon0.
4) res:group0
mon:
Task is part of resctrl control group group0, and it is not associated
to any monitor group.
5) res:group0
mon:mon1
Task is part of resctrl control group group0 and monitor group mon1.
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Jinshi Chen <jinshi.chen@intel.com>
Link: https://lkml.kernel.org/r/20200115092851.14761-1-yu.c.chen@intel.com
When checking whether the reported lfb_size makes sense, the height
* stride result is page-aligned before seeing whether it exceeds the
reported size.
This doesn't work if height * stride is not an exact number of pages.
For example, as reported in the kernel bugzilla below, an 800x600x32 EFI
framebuffer gets skipped because of this.
Move the PAGE_ALIGN to after the check vs size.
Reported-by: Christopher Head <chead@chead.ca>
Tested-by: Christopher Head <chead@chead.ca>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206051
Link: https://lkml.kernel.org/r/20200107230410.2291947-1-nivedita@alum.mit.edu
We carry a quirk in the x86 EFI code to switch back to an older
method of mapping the EFI runtime services memory regions, because
it was deemed risky at the time to implement a new method without
providing a fallback to the old method in case problems arose.
Such problems did arise, but they appear to be limited to SGI UV1
machines, and so these are the only ones for which the fallback gets
enabled automatically (via a DMI quirk). The fallback can be enabled
manually as well, by passing efi=old_map, but there is very little
evidence that suggests that this is something that is being relied
upon in the field.
Given that UV1 support is not enabled by default by the distros
(Ubuntu, Fedora), there is no point in carrying this fallback code
all the time if there are no other users. So let's move it into the
UV support code, and document that efi=old_map now requires this
support code to be enabled.
Note that efi=old_map has been used in the past on other SGI UV
machines to work around kernel regressions in production, so we
keep the option to enable it by hand, but only if the kernel was
built with UV support.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200113172245.27925-8-ardb@kernel.org
Pull x86 fixes from Ingo Molnar:
"Misc fixes:
- a resctrl fix for uninitialized objects found by debugobjects
- a resctrl memory leak fix
- fix the unintended re-enabling of the of SME and SEV CPU flags if
memory encryption was disabled at bootup via the MSR space"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/CPU/AMD: Ensure clearing of SME/SEV features is maintained
x86/resctrl: Fix potential memory leak
x86/resctrl: Fix an imbalance in domain_remove_cpu()
Currently, there are three static keys in the resctrl file system:
rdt_mon_enable_key and rdt_alloc_enable_key indicate if the monitoring
feature and the allocation feature are enabled, respectively. The
rdt_enable_key is enabled when either the monitoring feature or the
allocation feature is enabled.
If no monitoring feature is present (either hardware doesn't support a
monitoring feature or the feature is disabled by the kernel command line
option "rdt="), rdt_enable_key is still enabled but rdt_mon_enable_key
is disabled.
MBM is a monitoring feature. The MBM overflow handler intends to
check if the monitoring feature is not enabled for fast return.
So check the rdt_mon_enable_key in it instead of the rdt_enable_key as
former is the more accurate check.
[ bp: Massage commit message. ]
Fixes: e33026831b ("x86/intel_rdt/mbm: Handle counter overflow")
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/1576094705-13660-1-git-send-email-xiaochen.shen@intel.com
New Zhaoxin family 7 CPUs are not affected by the SWAPGS vulnerability. So
mark these CPUs in the cpu vulnerability whitelist accordingly.
Signed-off-by: Tony W Wang-oc <TonyWWang-oc@zhaoxin.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/1579227872-26972-3-git-send-email-TonyWWang-oc@zhaoxin.com
New Zhaoxin family 7 CPUs are not affected by SPECTRE_V2. So define a
separate cpu_vuln_whitelist bit NO_SPECTRE_V2 and add these CPUs to the cpu
vulnerability whitelist.
Signed-off-by: Tony W Wang-oc <TonyWWang-oc@zhaoxin.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/1579227872-26972-2-git-send-email-TonyWWang-oc@zhaoxin.com
/proc/cpuinfo currently reports Hardware Lock Elision (HLE) feature to
be present on boot cpu even if it was disabled during the bootup. This
is because cpuinfo_x86->x86_capability HLE bit is not updated after TSX
state is changed via the new MSR IA32_TSX_CTRL.
Update the cached HLE bit also since it is expected to change after an
update to CPUID_CLEAR bit in MSR IA32_TSX_CTRL.
Fixes: 95c5824f75 ("x86/cpu: Add a "tsx=" cmdline option with TSX disabled by default")
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Neelima Krishnan <neelima.krishnan@intel.com>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/2529b99546294c893dfa1c89e2b3e46da3369a59.1578685425.git.pawan.kumar.gupta@linux.intel.com
When CONFIG_PROC_FS is disabled, the compiler warns about an unused
variable:
arch/x86/kernel/apic/x2apic_uv_x.c: In function 'uv_setup_proc_files':
arch/x86/kernel/apic/x2apic_uv_x.c:1546:8: error: unused variable 'name' [-Werror=unused-variable]
char *name = hubless ? "hubless" : "hubbed";
Simplify the code so this variable is no longer needed.
Fixes: 8785968bce ("x86/platform/uv: Add UV Hubbed/Hubless Proc FS Files")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191212140419.315264-1-arnd@arndb.de
If the SME and SEV features are present via CPUID, but memory encryption
support is not enabled (MSR 0xC001_0010[23]), the feature flags are cleared
using clear_cpu_cap(). However, if get_cpu_cap() is later called, these
feature flags will be reset back to present, which is not desired.
Change from using clear_cpu_cap() to setup_clear_cpu_cap() so that the
clearing of the flags is maintained.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org> # 4.16.x-
Link: https://lkml.kernel.org/r/226de90a703c3c0be5a49565047905ac4e94e8f3.1579125915.git.thomas.lendacky@amd.com
Add the new PCI Device 18h IDs for AMD Family 19h systems. Note that
Family 19h systems will not have a new PCI root device ID.
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200110015651.14887-4-Yazen.Ghannam@amd.com
Add support for a new version of the Load Store unit bank type as
indicated by its McaType value, which will be present in future SMCA
systems.
Add the new (HWID, MCATYPE) tuple. Reuse the same name, since this is
logically the same to the user.
Also, add the new error descriptions to edac_mce_amd.
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200110015651.14887-2-Yazen.Ghannam@amd.com
Don't print an error message about VMX being disabled by BIOS if KVM,
the sole user of VMX, is disabled. E.g. if KVM is disabled and the MSR
is unlocked, the kernel will intentionally disable VMX when locking
feature control and then complain that "BIOS" disabled VMX.
Fixes: ef4d3bf198 ("x86/cpu: Clear VMX feature flag if VMX is not fully enabled")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200114202545.20296-1-sean.j.christopherson@intel.com
It is relatively easy to trigger the following boot splat on an Ice Lake
client platform. The call stack is like:
kernel BUG at kernel/timer/timer.c:1152!
Call Trace:
__queue_delayed_work
queue_delayed_work_on
therm_throt_process
intel_thermal_interrupt
...
The reason is that a CPU's thermal interrupt is enabled prior to
executing its hotplug onlining callback which will initialize the
throttling workqueues.
Such a race can lead to therm_throt_process() accessing an uninitialized
therm_work, leading to the above BUG at a very early bootup stage.
Therefore, unmask the thermal interrupt vector only after having setup
the workqueues completely.
[ bp: Heavily massage commit message and correct comment formatting. ]
Fixes: f6656208f0 ("x86/mce/therm_throt: Optimize notifications of thermal throttle")
Signed-off-by: Chuansheng Liu <chuansheng.liu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20200107004116.59353-1-chuansheng.liu@intel.com
con_init in tty/vt.c will now set conswitchp to dummy_con if it's unset.
Drop it from arch setup code.
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20191218214506.49252-24-nivedita@alum.mit.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
VDSO support for time namespaces needs to set up a page with the same
layout as VVAR. That timens page will be placed on position of VVAR page
inside namespace. That page has vdso_data->seq set to 1 to enforce
the slow path and vdso_data->clock_mode set to VCLOCK_TIMENS to enforce
the time namespace handling path.
To prepare the time namespace page the kernel needs to know the vdso_data
offset. Provide arch_get_vdso_data() helper for locating vdso_data on VVAR
page.
Co-developed-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191112012724.250792-22-dima@arista.com
Add a new feature flag, X86_FEATURE_MSR_IA32_FEAT_CTL, to track whether
IA32_FEAT_CTL has been initialized. This will allow KVM, and any future
subsystems that depend on IA32_FEAT_CTL, to rely purely on cpufeatures
to query platform support, e.g. allows a future patch to remove KVM's
manual IA32_FEAT_CTL MSR checks.
Various features (on platforms that support IA32_FEAT_CTL) are dependent
on IA32_FEAT_CTL being configured and locked, e.g. VMX and LMCE. The
MSR is always configured during boot, but only if the CPU vendor is
recognized by the kernel. Because CPUID doesn't incorporate the current
IA32_FEAT_CTL value in its reporting of relevant features, it's possible
for a feature to be reported as supported in cpufeatures but not truly
enabled, e.g. if the CPU supports VMX but the kernel doesn't recognize
the CPU.
As a result, without the flag, KVM would see VMX as supported even if
IA32_FEAT_CTL hasn't been initialized, and so would need to manually
read the MSR and check the various enabling bits to avoid taking an
unexpected #GP on VMXON.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20191221044513.21680-14-sean.j.christopherson@intel.com
Set the synthetic VMX cpufeatures, which need to be kept to preserve
/proc/cpuinfo's ABI, in the common IA32_FEAT_CTL initialization code.
Remove the vendor code that manually sets the synthetic flags.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20191221044513.21680-13-sean.j.christopherson@intel.com
Add support for generating VMX feature names in capflags.c and use the
resulting x86_vmx_flags to print the VMX flags in /proc/cpuinfo. Don't
print VMX flags if no bits are set in word 0, which holds Pin Controls.
Pin Control's INTR and NMI exiting are fundamental pillars of VMX, if
they are not supported then the CPU is broken, it does not actually
support VMX, or the kernel wasn't built with support for the target CPU.
Print the features in a dedicated "vmx flags" line to avoid polluting
the common "flags" and to avoid having to prefix all flags with "vmx_",
which results in horrendously long names.
Keep synthetic VMX flags in cpufeatures to preserve /proc/cpuinfo's ABI
for those flags. This means that "flags" and "vmx flags" will have
duplicate entries for tpr_shadow (virtual_tpr), vnmi, ept, flexpriority,
vpid and ept_ad, but caps the pollution of "flags" at those six VMX
features. The vendor-specific code that populates the synthetic flags
will be consolidated in a future patch to further minimize the lasting
damage.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20191221044513.21680-12-sean.j.christopherson@intel.com
Add an entry in struct cpuinfo_x86 to track VMX capabilities and fill
the capabilities during IA32_FEAT_CTL MSR initialization.
Make the VMX capabilities dependent on IA32_FEAT_CTL and
X86_FEATURE_NAMES so as to avoid unnecessary overhead on CPUs that can't
possibly support VMX, or when /proc/cpuinfo is not available.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20191221044513.21680-11-sean.j.christopherson@intel.com
Now that IA32_FEAT_CTL is always configured and locked for CPUs that are
known to support VMX[*], clear the VMX capability flag if the MSR is
unsupported or BIOS disabled VMX, i.e. locked IA32_FEAT_CTL and didn't
set the appropriate VMX enable bit.
[*] Because init_ia32_feat_ctl() is called from vendors ->c_init(), it's
still possible for IA32_FEAT_CTL to be left unlocked when VMX is
supported by the CPU. This is not fatal, and will be addressed in a
future patch.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20191221044513.21680-9-sean.j.christopherson@intel.com
Use the recently added IA32_FEAT_CTL MSR initialization sequence to
opportunistically enable VMX support when running on a Zhaoxin CPU.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20191221044513.21680-8-sean.j.christopherson@intel.com
Use the recently added IA32_FEAT_CTL MSR initialization sequence to
opportunistically enable VMX support when running on a Centaur CPU.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20191221044513.21680-7-sean.j.christopherson@intel.com
Opportunistically initialize IA32_FEAT_CTL to enable VMX when the MSR is
left unlocked by BIOS. Configuring feature control at boot time paves
the way for similar enabling of other features, e.g. Software Guard
Extensions (SGX).
Temporarily leave equivalent KVM code in place in order to avoid
introducing a regression on Centaur and Zhaoxin CPUs, e.g. removing
KVM's code would leave the MSR unlocked on those CPUs and would break
existing functionality if people are loading kvm_intel on Centaur and/or
Zhaoxin. Defer enablement of the boot-time configuration on Centaur and
Zhaoxin to future patches to aid bisection.
Note, Local Machine Check Exceptions (LMCE) are also supported by the
kernel and enabled via feature control, but the kernel currently uses
LMCE if and only if the feature is explicitly enabled by BIOS. Keep
the current behavior to avoid introducing bugs, future patches can opt
in to opportunistic enabling if it's deemed desirable to do so.
Always lock IA32_FEAT_CTL if it exists, even if the CPU doesn't support
VMX, so that other existing and future kernel code that queries the MSR
can assume it's locked.
Start from a clean slate when constructing the value to write to
IA32_FEAT_CTL, i.e. ignore whatever value BIOS left in the MSR so as not
to enable random features or fault on the WRMSR.
Suggested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20191221044513.21680-5-sean.j.christopherson@intel.com
As pointed out by Boris, the defines for bits in IA32_FEATURE_CONTROL
are quite a mouthful, especially the VMX bits which must differentiate
between enabling VMX inside and outside SMX (TXT) operation. Rename the
MSR and its bit defines to abbreviate FEATURE_CONTROL as FEAT_CTL to
make them a little friendlier on the eyes.
Arguably, the MSR itself should keep the full IA32_FEATURE_CONTROL name
to match Intel's SDM, but a future patch will add a dedicated Kconfig,
file and functions for the MSR. Using the full name for those assets is
rather unwieldy, so bite the bullet and use IA32_FEAT_CTL so that its
nomenclature is consistent throughout the kernel.
Opportunistically, fix a few other annoyances with the defines:
- Relocate the bit defines so that they immediately follow the MSR
define, e.g. aren't mistaken as belonging to MISC_FEATURE_CONTROL.
- Add whitespace around the block of feature control defines to make
it clear they're all related.
- Use BIT() instead of manually encoding the bit shift.
- Use "VMX" instead of "VMXON" to match the SDM.
- Append "_ENABLED" to the LMCE (Local Machine Check Exception) bit to
be consistent with the kernel's verbiage used for all other feature
control bits. Note, the SDM refers to the LMCE bit as LMCE_ON,
likely to differentiate it from IA32_MCG_EXT_CTL.LMCE_EN. Ignore
the (literal) one-off usage of _ON, the SDM is simply "wrong".
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20191221044513.21680-2-sean.j.christopherson@intel.com
When writing a pid to file "tasks", a callback function move_myself() is
queued to this task to be called when the task returns from kernel mode
or exits. The purpose of move_myself() is to activate the newly assigned
closid and/or rmid associated with this task. This activation is done by
calling resctrl_sched_in() from move_myself(), the same function that is
called when switching to this task.
If this work is successfully queued but then the task enters PF_EXITING
status (e.g., receiving signal SIGKILL, SIGTERM) prior to the
execution of the callback move_myself(), move_myself() still calls
resctrl_sched_in() since the task status is not currently considered.
When a task is exiting, the data structure of the task itself will
be freed soon. Calling resctrl_sched_in() to write the register that
controls the task's resources is unnecessary and it implies extra
performance overhead.
Add check on task status in move_myself() and return immediately if the
task is PF_EXITING.
[ bp: Massage. ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lkml.kernel.org/r/1578500026-21152-1-git-send-email-xiaochen.shen@intel.com
The function mce_severity() is not required to update its msg argument.
In fact, mce_severity_amd() does not, which makes mce_no_way_out()
return uninitialized data, which may be used later for printing.
Assuming that implementations of mce_severity() either always or never
update the msg argument (which is currently the case), it is sufficient
to initialize the temporary variable in mce_no_way_out().
While at it, avoid printing a useless "Unknown".
Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200103150722.20313-4-jschoenh@amazon.de
Since commit
8b38937b7a ("x86/mce: Do not enter deferred errors into the generic
pool twice")
the mce=nobootlog option has become mostly ineffective (after being only
slightly ineffective before), as the code is taking actions on MCEs left
over from boot when they have a usable address.
Move the check for MCP_DONTLOG a bit outward to make it effective again.
Also, since commit
011d826111 ("RAS: Add a Corrected Errors Collector")
the two branches of the remaining "if" at the bottom of machine_check_poll()
do same. Unify them.
Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200103150722.20313-3-jschoenh@amazon.de
Commit
fa92c58694 ("x86, mce: Support memory error recovery for both UCNA
and Deferred error in machine_check_poll")
added handling of UCNA and Deferred errors by adding them to the ring
for SRAO errors.
Later, commit
fd4cf79fcc ("x86/mce: Remove the MCE ring for Action Optional errors")
switched storage from the SRAO ring to the unified pool that is still
in use today. In order to only act on the intended errors, a filter
for MCE_AO_SEVERITY is used -- effectively removing handling of
UCNA/Deferred errors again.
Extend the severity filter to include UCNA/Deferred errors again.
Also, generalize the naming of the notifier from SRAO to UC to capture
the extended scope.
Note, that this change may cause a message like the following to appear,
as the same address may be reported as SRAO and as UCNA:
Memory failure: 0x5fe3284: already hardware poisoned
Technically, this is a return to previous behavior.
Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20200103150722.20313-2-jschoenh@amazon.de
First, printk() is NMI-context safe now since the safe printk() has been
implemented and it already has an irq_work to make NMI-context safe.
Second, this NMI irq_work actually does not work if a NMI handler causes
panic by watchdog timeout. It has no chance to run in such case, while
the safe printk() will flush its per-cpu buffers before panicking.
While at it, repurpose the irq_work callback into a function which
concentrates the NMI duration checking and makes the code easier to
follow.
[ bp: Massage. ]
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200111125427.15662-1-changbin.du@gmail.com
Use resource_size() rather than a verbose computation on
the end and start fields.
The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)
<smpl>
@@ struct resource ptr; @@
- (ptr.end - ptr.start + 1)
+ resource_size(&ptr)
</smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/1577900990-8588-10-git-send-email-Julia.Lawall@inria.fr
force_iret() was originally intended to prevent the return to user mode with
the SYSRET or SYSEXIT instructions, in cases where the register state could
have been changed to be incompatible with those instructions. The entry code
has been significantly reworked since then, and register state is validated
before SYSRET or SYSEXIT are used. force_iret() no longer serves its original
purpose and can be eliminated.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lkml.kernel.org/r/20191219115812.102620-1-brgerst@gmail.com
In __fpu__restore_sig(), fpu_fpregs_owner_ctx needs to be reset if the
FPU state was not fully restored. Otherwise the following may happen (on
the same CPU):
Task A Task B fpu_fpregs_owner_ctx
*active* A.fpu
__fpu__restore_sig()
ctx switch load B.fpu
*active* B.fpu
fpregs_lock()
copy_user_to_fpregs_zeroing()
copy_kernel_to_xregs() *modify*
copy_user_to_xregs() *fails*
fpregs_unlock()
ctx switch skip loading B.fpu,
*active* B.fpu
In the success case, fpu_fpregs_owner_ctx is set to the current task.
In the failure case, the FPU state might have been modified by loading
the init state.
In this case, fpu_fpregs_owner_ctx needs to be reset in order to ensure
that the FPU state of the following task is loaded from saved state (and
not skipped because it was the previous state).
Reset fpu_fpregs_owner_ctx after a failure during restore occurred, to
ensure that the FPU state for the next task is always loaded.
The problem was debugged-by Yu-cheng Yu <yu-cheng.yu@intel.com>.
[ bp: Massage commit message. ]
Fixes: 5f409e20b7 ("x86/fpu: Defer FPU state load until return to userspace")
Reported-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191220195906.plk6kpmsrikvbcfn@linutronix.de
To fix follwowing warning due to ORC sort moved to build time:
arch/x86/kernel/unwind_orc.c:210:12: warning: ‘orc_sort_cmp’ defined but not used [-Wunused-function]
arch/x86/kernel/unwind_orc.c:190:13: warning: ‘orc_sort_swap’ defined but not used [-Wunused-function]
Signed-off-by: Shile Zhang <shile.zhang@linux.alibaba.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/c9c81536-2afc-c8aa-c5f8-c7618ecd4f54@linux.alibaba.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This is a leftover. Page faults, just like most other exceptions,
are protected inside user_exit() / user_enter() calls in x86 entry code
when we fault from userspace. So this pair of calls is now superfluous.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jim Mattson <jmattson@google.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wanpeng Li <wanpengli@tencent.com>
Link: https://lkml.kernel.org/r/20191227163612.10039-3-frederic@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Have both xfeature_is_supervisor()/xfeature_is_user() return bool
because they are used only in boolean context.
Suggested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191212210855.19260-3-yu-cheng.yu@intel.com
ioremap has provided non-cached semantics by default since the Linux 2.6
days, so remove the additional ioremap_nocache interface.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
set_cache_qos_cfg() is leaking memory when the given level is not
RDT_RESOURCE_L3 or RDT_RESOURCE_L2. At the moment, this function is
called with only valid levels but move the allocation after the valid
level checks in order to make it more robust and future proof.
[ bp: Massage commit message. ]
Fixes: 99adde9b37 ("x86/intel_rdt: Enable L2 CDP in MSR IA32_L2_QOS_CFG")
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20200102165844.133133-1-shakeelb@google.com
Hoist the user_mode() case up because it is less code and can be dealt
with up-front like the other special cases UMIP and vm86.
This saves an indentation level for the kernel-mode #GP case and allows
to "unfold" the code more so that it is more readable.
No functional changes.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Jann Horn <jannh@google.com>
Cc: x86@kernel.org
Make #GP exceptions caused by out-of-bounds KASAN shadow accesses easier
to understand by computing the address of the original access and
printing that. More details are in the comments in the patch.
This turns an error like this:
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault, probably for non-canonical address
0xe017577ddf75b7dd: 0000 [#1] PREEMPT SMP KASAN PTI
into this:
general protection fault, probably for non-canonical address
0xe017577ddf75b7dd: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: maybe wild-memory-access in range
[0x00badbeefbadbee8-0x00badbeefbadbeef]
The hook is placed in architecture-independent code, but is currently
only wired up to the X86 exception handler because I'm not sufficiently
familiar with the address space layout and exception handling mechanisms
on other architectures.
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: kasan-dev@googlegroups.com
Cc: linux-mm <linux-mm@kvack.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191218231150.12139-4-jannh@google.com
Split __die() into __die_header() and __die_body(). This allows inserting
extra information below the header line that initiates the bug report.
Introduce a new function die_addr() that behaves like die(), but is for
faults only and uses __die_header() and __die_body() so that a future
commit can print extra information after the header line.
[ bp: Comment the KASAN-specific usage of gp_addr. ]
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: kasan-dev@googlegroups.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191218231150.12139-3-jannh@google.com
A frequent cause of #GP exceptions are memory accesses to non-canonical
addresses. Unlike #PF, #GP doesn't report a fault address in CR2, so the
kernel doesn't currently print the fault address for a #GP.
Luckily, the necessary infrastructure for decoding x86 instructions and
computing the memory address being accessed is already present. Hook
it up to the #GP handler so that the address operand of the faulting
instruction can be figured out and printed.
Distinguish two cases:
a) (Part of) the memory range being accessed lies in the non-canonical
address range; in this case, it is likely that the decoded address
is actually the one that caused the #GP.
b) The entire memory range of the decoded operand lies in canonical
address space; the #GP may or may not be related in some way to the
computed address. Print it, but with hedging language in the message.
While it is already possible to compute the faulting address manually by
disassembling the opcode dump and evaluating the instruction against the
register dump, this should make it slightly easier to identify crashes
at a glance.
Note that the operand length which comes from the instruction decoder
and is used to determine whether the access straddles into non-canonical
address space, is currently somewhat unreliable; but it should be good
enough, considering that Linux on x86-64 never maps the page directly
before the start of the non-canonical range anyway, and therefore the
case where a memory range begins in that page and potentially straddles
into the non-canonical range should be fairly uncommon.
In the case the address is still computed wrongly, it only influences
whether the error message claims that the access is canonical.
[ bp: Remove ambiguous "we", massage, reflow comments and spacing. ]
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Tested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: kasan-dev@googlegroups.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191218231150.12139-2-jannh@google.com
A system that supports resource monitoring may have multiple resources
while not all of these resources are capable of monitoring. Monitoring
related state is initialized only for resources that are capable of
monitoring and correspondingly this state should subsequently only be
removed from these resources that are capable of monitoring.
domain_add_cpu() calls domain_setup_mon_state() only when r->mon_capable
is true where it will initialize d->mbm_over. However,
domain_remove_cpu() calls cancel_delayed_work(&d->mbm_over) without
checking r->mon_capable resulting in an attempt to cancel d->mbm_over on
all resources, even those that never initialized d->mbm_over because
they are not capable of monitoring. Hence, it triggers a debugobjects
warning when offlining CPUs because those timer debugobjects are never
initialized:
ODEBUG: assert_init not available (active state 0) object type:
timer_list hint: 0x0
WARNING: CPU: 143 PID: 789 at lib/debugobjects.c:484
debug_print_object
Hardware name: HP Synergy 680 Gen9/Synergy 680 Gen9 Compute Module, BIOS I40 05/23/2018
RIP: 0010:debug_print_object
Call Trace:
debug_object_assert_init
del_timer
try_to_grab_pending
cancel_delayed_work
resctrl_offline_cpu
cpuhp_invoke_callback
cpuhp_thread_fun
smpboot_thread_fn
kthread
ret_from_fork
Fixes: e33026831b ("x86/intel_rdt/mbm: Handle counter overflow")
Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Reinette Chatre <reinette.chatre@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: john.stultz@linaro.org
Cc: sboyd@kernel.org
Cc: <stable@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: tj@kernel.org
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191211033042.2188-1-cai@lca.pw
Commit:
285a54efe3 ("x86/alternatives: Sync bp_patching update for avoiding NULL pointer exception")
added an additional text_poke_sync() IPI to text_poke_bp_batch() to
handle the rare case where another CPU is still inside an INT3 handler
while we clear the global state.
Instead of spraying IPIs around, count the active INT3 handlers and
wait for them to go away before proceeding to clear/reuse the data.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
On x86 kernels configured with CONFIG_PROC_KCORE=y and
CONFIG_KEXEC_CORE=n, the vmcoreinfo note in /proc/kcore is incomplete.
Specifically, it is missing arch-specific information like the KASLR
offset and whether 5-level page tables are enabled. This breaks
applications like drgn [1] and crash [2], which need this information
for live debugging via /proc/kcore.
This happens because:
1. CONFIG_PROC_KCORE selects CONFIG_CRASH_CORE.
2. kernel/crash_core.c (compiled if CONFIG_CRASH_CORE=y) calls
arch_crash_save_vmcoreinfo() to get the arch-specific parts of
vmcoreinfo. If it is not defined, then it uses a no-op fallback.
3. x86 defines arch_crash_save_vmcoreinfo() in
arch/x86/kernel/machine_kexec_*.c, which is only compiled if
CONFIG_KEXEC_CORE=y.
Therefore, an x86 kernel with CONFIG_CRASH_CORE=y and
CONFIG_KEXEC_CORE=n uses the no-op fallback and gets incomplete
vmcoreinfo data. This isn't relevant to kdump, which requires
CONFIG_KEXEC_CORE. It only affects applications which read vmcoreinfo at
runtime, like the ones mentioned above.
Fix it by moving arch_crash_save_vmcoreinfo() into two new
arch/x86/kernel/crash_core_*.c files, which are gated behind
CONFIG_CRASH_CORE.
1: 73dd7def12/libdrgn/program.c (L385)
2: 60a42d7092
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kairui Song <kasong@redhat.com>
Cc: Lianbo Jiang <lijiang@redhat.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/0589961254102cca23e3618b96541b89f2b249e2.1576858905.git.osandov@fb.com
Pull x86 RAS fixes from Borislav Petkov:
"Three urgent RAS fixes for the AMD side of things:
- initialize struct mce.bank so that calculated error severity on AMD
SMCA machines is correct
- do not send IPIs early during bank initialization, when interrupts
are disabled
- a fix for when only a subset of MCA banks are enabled, which led to
boot hangs on some new AMD CPUs"
* 'ras-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mce: Fix possibly incorrect severity calculation on AMD
x86/MCE/AMD: Allow Reserved types to be overwritten in smca_banks[]
x86/MCE/AMD: Do not use rdmsr_safe_on_cpu() in smca_configure()
Pull timer fixes from Ingo Molnar:
"Add HPET quirks for the Intel 'Coffee Lake H' and 'Ice Lake' platforms"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/intel: Disable HPET on Intel Ice Lake platforms
x86/intel: Disable HPET on Intel Coffee Lake H platforms
The mutex in mce_inject_log() became unnecessary with commit
5de97c9f6d ("x86/mce: Factor out and deprecate the /dev/mcelog driver"),
though the original reason for its presence only vanished with commit
7298f08ea8 ("x86/mcelog: Get rid of RCU remnants").
Drop the mutex. And as that makes mce_inject_log() identical to mce_log(),
get rid of the former in favor of the latter.
Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191210000733.17979-7-jschoenh@amazon.de
In commit
b2f9d678e2 ("x86/mce: Check for faults tagged in EXTABLE_CLASS_FAULT exception table entries")
another call to mce_panic() was introduced. Pass the message of the
handled MCE to that instance of mce_panic() as well, as there doesn't
seem to be a reason not to.
Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191210000733.17979-6-jschoenh@amazon.de
throttle_active_work() is only called if CONFIG_SYSFS is set, otherwise
we get a harmless warning:
arch/x86/kernel/cpu/mce/therm_throt.c:238:13: error: 'throttle_active_work' \
defined but not used [-Werror=unused-function]
Mark the function as __maybe_unused to avoid the warning.
Fixes: f6656208f0 ("x86/mce/therm_throt: Optimize notifications of thermal throttle")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: bberg@redhat.com
Cc: ckellner@redhat.com
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: hdegoede@redhat.com
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191210203925.3119091-1-arnd@arndb.de
The function mce_severity_amd_smca() requires m->bank to be initialized
for correct operation. Fix the one case, where mce_severity() is called
without doing so.
Fixes: 6bda529ec4 ("x86/mce: Grade uncorrected errors for SMCA-enabled systems")
Fixes: d28af26faa ("x86/MCE: Initialize mce.bank in the case of a fatal error in mce_no_way_out()")
Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: <stable@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Cc: Yazen Ghannam <Yazen.Ghannam@amd.com>
Link: https://lkml.kernel.org/r/20191210000733.17979-4-jschoenh@amazon.de
Each logical CPU in Scalable MCA systems controls a unique set of MCA
banks in the system. These banks are not shared between CPUs. The bank
types and ordering will be the same across CPUs on currently available
systems.
However, some CPUs may see a bank as Reserved/Read-as-Zero (RAZ) while
other CPUs do not. In this case, the bank seen as Reserved on one CPU is
assumed to be the same type as the bank seen as a known type on another
CPU.
In general, this occurs when the hardware represented by the MCA bank
is disabled, e.g. disabled memory controllers on certain models, etc.
The MCA bank is disabled in the hardware, so there is no possibility of
getting an MCA/MCE from it even if it is assumed to have a known type.
For example:
Full system:
Bank | Type seen on CPU0 | Type seen on CPU1
------------------------------------------------
0 | LS | LS
1 | UMC | UMC
2 | CS | CS
System with hardware disabled:
Bank | Type seen on CPU0 | Type seen on CPU1
------------------------------------------------
0 | LS | LS
1 | UMC | RAZ
2 | CS | CS
For this reason, there is a single, global struct smca_banks[] that is
initialized at boot time. This array is initialized on each CPU as it
comes online. However, the array will not be updated if an entry already
exists.
This works as expected when the first CPU (usually CPU0) has all
possible MCA banks enabled. But if the first CPU has a subset, then it
will save a "Reserved" type in smca_banks[]. Successive CPUs will then
not be able to update smca_banks[] even if they encounter a known bank
type.
This may result in unexpected behavior. Depending on the system
configuration, a user may observe issues enumerating the MCA
thresholding sysfs interface. The issues may be as trivial as sysfs
entries not being available, or as severe as system hangs.
For example:
Bank | Type seen on CPU0 | Type seen on CPU1
------------------------------------------------
0 | LS | LS
1 | RAZ | UMC
2 | CS | CS
Extend the smca_banks[] entry check to return if the entry is a
non-reserved type. Otherwise, continue so that CPUs that encounter a
known bank type can update smca_banks[].
Fixes: 68627a697c ("x86/mce/AMD, EDAC/mce_amd: Enumerate Reserved SMCA bank type")
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: <stable@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191121141508.141273-1-Yazen.Ghannam@amd.com
... because interrupts are disabled that early and sending IPIs can
deadlock:
BUG: sleeping function called from invalid context at kernel/sched/completion.c:99
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 0, name: swapper/1
no locks held by swapper/1/0.
irq event stamp: 0
hardirqs last enabled at (0): [<0000000000000000>] 0x0
hardirqs last disabled at (0): [<ffffffff8106dda9>] copy_process+0x8b9/0x1ca0
softirqs last enabled at (0): [<ffffffff8106dda9>] copy_process+0x8b9/0x1ca0
softirqs last disabled at (0): [<0000000000000000>] 0x0
Preemption disabled at:
[<ffffffff8104703b>] start_secondary+0x3b/0x190
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.5.0-rc2+ #1
Hardware name: GIGABYTE MZ01-CE1-00/MZ01-CE1-00, BIOS F02 08/29/2018
Call Trace:
dump_stack
___might_sleep.cold.92
wait_for_completion
? generic_exec_single
rdmsr_safe_on_cpu
? wrmsr_on_cpus
mce_amd_feature_init
mcheck_cpu_init
identify_cpu
identify_secondary_cpu
smp_store_cpu_info
start_secondary
secondary_startup_64
The function smca_configure() is called only on the current CPU anyway,
therefore replace rdmsr_safe_on_cpu() with atomic rdmsr_safe() and avoid
the IPI.
[ bp: Update commit message. ]
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Yazen Ghannam <yazen.ghannam@amd.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: <stable@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/157252708836.3876.4604398213417262402.stgit@buzz
Remove two unused variables:
arch/x86/kernel/process.c: In function ‘__switch_to_xtra’:
arch/x86/kernel/process.c:618:31: warning: variable ‘next’ set but not used [-Wunused-but-set-variable]
618 | struct thread_struct *prev, *next;
| ^~~~
arch/x86/kernel/process.c:618:24: warning: variable ‘prev’ set but not used [-Wunused-but-set-variable]
618 | struct thread_struct *prev, *next;
|
They are never used and so can be removed.
Signed-off-by: yu kuai <yukuai3@huawei.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Cc: yi.zhang@huawei.com
Cc: zhengbin13@huawei.com
Link: https://lkml.kernel.org/r/20191213121253.10072-1-yukuai3@huawei.com
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Merge tag 'sizeof_field-v5.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull FIELD_SIZEOF conversion from Kees Cook:
"A mostly mechanical treewide conversion from FIELD_SIZEOF() to
sizeof_field(). This avoids the redundancy of having 2 macros
(actually 3) doing the same thing, and consolidates on sizeof_field().
While "field" is not an accurate name, it is the common name used in
the kernel, and doesn't result in any unintended innuendo.
As there are still users of FIELD_SIZEOF() in -next, I will clean up
those during this coming development cycle and send the final old
macro removal patch at that time"
* tag 'sizeof_field-v5.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
treewide: Use sizeof_field() macro
MIPS: OCTEON: Replace SIZEOF_FIELD() macro
Now that the orc_unwind and orc_unwind_ip tables are sorted at build time,
remove the boot time sorting pass.
No change in functionality.
[ mingo: Rewrote the changelog and code comments. ]
Signed-off-by: Shile Zhang <shile.zhang@linux.alibaba.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kbuild@vger.kernel.org
Link: https://lkml.kernel.org/r/20191204004633.88660-8-shile.zhang@linux.alibaba.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
- Removal of code I accidentally applied when doing a minor fix up
to a patch, and then using "git commit -a --amend", which pulled
in some other changes I was playing with.
- Remove an used variable in trace_events_inject code
- Fix to function graph tracer when it traces a ftrace direct function.
It will now ignore tracing a function that has a ftrace direct
tramploine attached. This is needed for eBPF to use the ftrace direct
code.
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Merge tag 'trace-v5.5-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
- Remove code I accidentally applied when doing a minor fix up to a
patch, and then using "git commit -a --amend", which pulled in some
other changes I was playing with.
- Remove an used variable in trace_events_inject code
- Fix function graph tracer when it traces a ftrace direct function.
It will now ignore tracing a function that has a ftrace direct
tramploine attached. This is needed for eBPF to use the ftrace direct
code.
* tag 'trace-v5.5-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
ftrace: Fix function_graph tracer interaction with BPF trampoline
tracing: remove set but not used variable 'buffer'
module: Remove accidental change of module_enable_x()
Depending on type of BPF programs served by BPF trampoline it can call original
function. In such case the trampoline will skip one stack frame while
returning. That will confuse function_graph tracer and will cause crashes with
bad RIP. Teach graph tracer to skip functions that have BPF trampoline attached.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Move the definition of acpi_get_wakeup_address() into sleep.c to break
linux/acpi.h's dependency (by way of asm/acpi.h) on asm/realmode.h.
Everyone and their mother includes linux/acpi.h, i.e. modifying
realmode.h results in a full kernel rebuild, which makes the already
inscrutable real mode boot code even more difficult to understand and is
positively rage inducing when trying to make changes to x86's boot flow.
No functional change intended.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Link: https://lkml.kernel.org/r/20191126165417.22423-13-sean.j.christopherson@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
None of the declarations in x86's acpi/sleep.h are in any way dependent
on the real mode boot code. Remove sleep.h's include of asm/realmode.h
to limit the dependencies on realmode.h to code that actually interacts
with the boot code.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lkml.kernel.org/r/20191126165417.22423-11-sean.j.christopherson@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The inclusion of linux/vmalloc.h, which is required for its definition
of set_vm_flush_reset_perms(), is somehow dependent on asm/realmode.h
being included by asm/acpi.h. Explicitly include linux/vmalloc.h so
that a future patch can drop the realmode.h include from asm/acpi.h
without breaking the build.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lkml.kernel.org/r/20191126165417.22423-5-sean.j.christopherson@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The inclusion of linux/vmalloc.h, which is required for its definition
of set_vm_flush_reset_perms(), is somehow dependent on asm/realmode.h
being included by asm/acpi.h. Explicitly include linux/vmalloc.h so
that a future patch can drop the realmode.h include from asm/acpi.h
without breaking the build.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lkml.kernel.org/r/20191126165417.22423-4-sean.j.christopherson@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Explicitly include asm/realmode.h, which provides reserve_real_mode(),
instead of picking it up by an indirect include of asm/acpi.h. acpi.h
will soon stop including realmode.h so that changing realmode.h doesn't
require a full kernel rebuild.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Link: https://lkml.kernel.org/r/20191126165417.22423-3-sean.j.christopherson@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
- Untangle the somewhat incestous way of how VMALLOC_START is used all across the
kernel, but is, on x86, defined deep inside one of the lowest level page table headers.
It doesn't help that vmalloc.h only includes a single asm header:
#include <asm/page.h> /* pgprot_t */
So there was no existing cross-arch way to decouple address layout
definitions from page.h details. I used this:
#ifndef VMALLOC_START
# include <asm/vmalloc.h>
#endif
This way every architecture that wants to simplify page.h can do so.
- Also on x86 we had a couple of LDT related inline functions that used
the late-stage address space layout positions - but these could be
uninlined without real trouble - the end result is cleaner this way as
well.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
pat.h is a file whose main purpose is to provide the memtype_*() APIs.
PAT is the low level hardware mechanism - but the high level abstraction
is memtype.
So name the header <memtype.h> as well - this goes hand in hand with memtype.c
and memtype_interval.c.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Update various comments, fix outright mistakes and meaningless descriptions.
Also harmonize the style across the file, both in form and in language.
Cc: linux-kernel@vger.kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In 20 years we accumulated 89 #include lines in setup.c,
but we only need 30 of them (!) ...
Get rid of the excessive ones, and while at it, sort the
remaining ones alphabetically.
Also get rid of the incomplete changelogs at the header of the file,
and explain better what this file does.
Cc: linux-kernel@vger.kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Replace all the occurrences of FIELD_SIZEOF() with sizeof_field() except
at places where these are defined. Later patches will remove the unused
definition of FIELD_SIZEOF().
This patch is generated using following script:
EXCLUDE_FILES="include/linux/stddef.h|include/linux/kernel.h"
git grep -l -e "\bFIELD_SIZEOF\b" | while read file;
do
if [[ "$file" =~ $EXCLUDE_FILES ]]; then
continue
fi
sed -i -e 's/\bFIELD_SIZEOF\b/sizeof_field/g' $file;
done
Signed-off-by: Pankaj Bharadiya <pankaj.laxminarayan.bharadiya@intel.com>
Link: https://lore.kernel.org/r/20190924105839.110713-3-pankaj.laxminarayan.bharadiya@intel.com
Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: David Miller <davem@davemloft.net> # for net
Zhang Xiaoxu noted that physical address locations for MTRR were visible
to non-root users, which could be considered an information leak.
In discussing[1] the options for solving this, it sounded like just
moving the capable check into open() was the first step.
If this breaks userspace, then we will have a test case for the more
conservative approaches discussed in the thread. In summary:
- MTRR should check capabilities at open time (or retain the
checks on the opener's permissions for later checks).
- changing the DAC permissions might break something that expects to
open mtrr when not uid 0.
- if we leave the DAC permissions alone and just move the capable check
to the opener, we should get the desired protection. (i.e. check
against CAP_SYS_ADMIN not just the wider uid 0.)
- if that still breaks things, as in userspace expects to be able to
read other parts of the file as non-uid-0 and non-CAP_SYS_ADMIN, then
we need to censor the contents using the opener's permissions. For
example, as done in other /proc cases, like commit
51d7b12041 ("/proc/iomem: only expose physical resource addresses to privileged users").
[1] https://lore.kernel.org/lkml/201911110934.AC5BA313@keescook/
Reported-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: James Morris <jamorris@linux.microsoft.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-security-module@vger.kernel.org
Cc: Matthew Garrett <mjg59@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: x86-ml <x86@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/201911181308.63F06502A1@keescook
Pull x86 fixes from Ingo Molnar:
"Various fixes:
- Fix the PAT performance regression that downgraded write-combining
device memory regions to uncached.
- There's been a number of bugs in 32-bit double fault handling -
hopefully all fixed now.
- Fix an LDT crash
- Fix an FPU over-optimization that broke with GCC9 code
optimizations.
- Misc cleanups"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm/pat: Fix off-by-one bugs in interval tree search
x86/ioperm: Save an indentation level in tss_update_io_bitmap()
x86/fpu: Don't cache access to fpu_fpregs_owner_ctx
x86/entry/32: Remove unused 'restore_all_notrace' local label
x86/ptrace: Document FSBASE and GSBASE ABI oddities
x86/ptrace: Remove set_segment_reg() implementations for current
x86/traps: die() instead of panicking on a double fault
x86/doublefault/32: Rewrite the x86_32 #DF handler and unify with 64-bit
x86/doublefault/32: Move #DF stack and TSS to cpu_entry_area
x86/doublefault/32: Rename doublefault.c to doublefault_32.c
x86/traps: Disentangle the 32-bit and 64-bit doublefault code
lkdtm: Add a DOUBLE_FAULT crash type on x86
selftests/x86/single_step_syscall: Check SYSENTER directly
x86/mm/32: Sync only to VMALLOC_END in vmalloc_sync_all()
Pull RAS fix from Borislav Petkov:
"One urgent fix for the thermal throttling machinery: the recent change
reworking the thermal notifications forgot to mask out read-only and
reserved bits in the thermal status MSRs, leading to exceptions while
writing those MSRs.
The fix takes care of masking out those bits first"
* 'ras-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mce/therm_throt: Mask out read-only and reserved MSR bits
- improve dma-debug scalability (Eric Dumazet)
- tiny dma-debug cleanup (Dan Carpenter)
- check for vmap memory in dma_map_single (Kees Cook)
- check for dma_addr_t overflows in dma-direct when using
DMA offsets (Nicolas Saenz Julienne)
- switch the x86 sta2x11 SOC to use more generic DMA code
(Nicolas Saenz Julienne)
- fix arm-nommu dma-ranges handling (Vladimir Murzin)
- use __initdata in CMA (Shyam Saini)
- replace the bus dma mask with a limit (Nicolas Saenz Julienne)
- merge the remapping helpers into the main dma-direct flow (me)
- switch xtensa to the generic dma remap handling (me)
- various cleanups around dma_capable (me)
- remove unused dev arguments to various dma-noncoherent helpers (me)
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Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux; tag 'dma-mapping-5.5' of git://git.infradead.org/users/hch/dma-mapping
Pull dma-mapping updates from Christoph Hellwig:
- improve dma-debug scalability (Eric Dumazet)
- tiny dma-debug cleanup (Dan Carpenter)
- check for vmap memory in dma_map_single (Kees Cook)
- check for dma_addr_t overflows in dma-direct when using DMA offsets
(Nicolas Saenz Julienne)
- switch the x86 sta2x11 SOC to use more generic DMA code (Nicolas
Saenz Julienne)
- fix arm-nommu dma-ranges handling (Vladimir Murzin)
- use __initdata in CMA (Shyam Saini)
- replace the bus dma mask with a limit (Nicolas Saenz Julienne)
- merge the remapping helpers into the main dma-direct flow (me)
- switch xtensa to the generic dma remap handling (me)
- various cleanups around dma_capable (me)
- remove unused dev arguments to various dma-noncoherent helpers (me)
* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux:
* tag 'dma-mapping-5.5' of git://git.infradead.org/users/hch/dma-mapping: (22 commits)
dma-mapping: treat dev->bus_dma_mask as a DMA limit
dma-direct: exclude dma_direct_map_resource from the min_low_pfn check
dma-direct: don't check swiotlb=force in dma_direct_map_resource
dma-debug: clean up put_hash_bucket()
powerpc: remove support for NULL dev in __phys_to_dma / __dma_to_phys
dma-direct: avoid a forward declaration for phys_to_dma
dma-direct: unify the dma_capable definitions
dma-mapping: drop the dev argument to arch_sync_dma_for_*
x86/PCI: sta2x11: use default DMA address translation
dma-direct: check for overflows on 32 bit DMA addresses
dma-debug: increase HASH_SIZE
dma-debug: reorder struct dma_debug_entry fields
xtensa: use the generic uncached segment support
dma-mapping: merge the generic remapping helpers into dma-direct
dma-direct: provide mmap and get_sgtable method overrides
dma-direct: remove the dma_handle argument to __dma_direct_alloc_pages
dma-direct: remove __dma_direct_free_pages
usb: core: Remove redundant vmap checks
kernel: dma-contiguous: mark CMA parameters __initdata/__initconst
dma-debug: add a schedule point in debug_dma_dump_mappings()
...
- PERAMAENT flag to ftrace_ops when attaching a callback to a function
As /proc/sys/kernel/ftrace_enabled when set to zero will disable all
attached callbacks in ftrace, this has a detrimental impact on live
kernel tracing, as it disables all that it patched. If a ftrace_ops
is registered to ftrace with the PERMANENT flag set, it will prevent
ftrace_enabled from being disabled, and if ftrace_enabled is already
disabled, it will prevent a ftrace_ops with PREMANENT flag set from
being registered.
- New register_ftrace_direct(). As eBPF would like to register its own
trampolines to be called by the ftrace nop locations directly,
without going through the ftrace trampoline, this function has been
added. This allows for eBPF trampolines to live along side of
ftrace, perf, kprobe and live patching. It also utilizes the ftrace
enabled_functions file that keeps track of functions that have been
modified in the kernel, to allow for security auditing.
- Allow for kernel internal use of ftrace instances. Subsystems in
the kernel can now create and destroy their own tracing instances
which allows them to have their own tracing buffer, and be able
to record events without worrying about other users from writing over
their data.
- New seq_buf_hex_dump() that lets users use the hex_dump() in their
seq_buf usage.
- Notifications now added to tracing_max_latency to allow user space
to know when a new max latency is hit by one of the latency tracers.
- Wider spread use of generic compare operations for use of bsearch and
friends.
- More synthetic event fields may be defined (32 up from 16)
- Use of xarray for architectures with sparse system calls, for the
system call trace events.
This along with small clean ups and fixes.
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Merge tag 'trace-v5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
"New tracing features:
- New PERMANENT flag to ftrace_ops when attaching a callback to a
function.
As /proc/sys/kernel/ftrace_enabled when set to zero will disable
all attached callbacks in ftrace, this has a detrimental impact on
live kernel tracing, as it disables all that it patched. If a
ftrace_ops is registered to ftrace with the PERMANENT flag set, it
will prevent ftrace_enabled from being disabled, and if
ftrace_enabled is already disabled, it will prevent a ftrace_ops
with PREMANENT flag set from being registered.
- New register_ftrace_direct().
As eBPF would like to register its own trampolines to be called by
the ftrace nop locations directly, without going through the ftrace
trampoline, this function has been added. This allows for eBPF
trampolines to live along side of ftrace, perf, kprobe and live
patching. It also utilizes the ftrace enabled_functions file that
keeps track of functions that have been modified in the kernel, to
allow for security auditing.
- Allow for kernel internal use of ftrace instances.
Subsystems in the kernel can now create and destroy their own
tracing instances which allows them to have their own tracing
buffer, and be able to record events without worrying about other
users from writing over their data.
- New seq_buf_hex_dump() that lets users use the hex_dump() in their
seq_buf usage.
- Notifications now added to tracing_max_latency to allow user space
to know when a new max latency is hit by one of the latency
tracers.
- Wider spread use of generic compare operations for use of bsearch
and friends.
- More synthetic event fields may be defined (32 up from 16)
- Use of xarray for architectures with sparse system calls, for the
system call trace events.
This along with small clean ups and fixes"
* tag 'trace-v5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (51 commits)
tracing: Enable syscall optimization for MIPS
tracing: Use xarray for syscall trace events
tracing: Sample module to demonstrate kernel access to Ftrace instances.
tracing: Adding new functions for kernel access to Ftrace instances
tracing: Fix Kconfig indentation
ring-buffer: Fix typos in function ring_buffer_producer
ftrace: Use BIT() macro
ftrace: Return ENOTSUPP when DYNAMIC_FTRACE_WITH_DIRECT_CALLS is not configured
ftrace: Rename ftrace_graph_stub to ftrace_stub_graph
ftrace: Add a helper function to modify_ftrace_direct() to allow arch optimization
ftrace: Add helper find_direct_entry() to consolidate code
ftrace: Add another check for match in register_ftrace_direct()
ftrace: Fix accounting bug with direct->count in register_ftrace_direct()
ftrace/selftests: Fix spelling mistake "wakeing" -> "waking"
tracing: Increase SYNTH_FIELDS_MAX for synthetic_events
ftrace/samples: Add a sample module that implements modify_ftrace_direct()
ftrace: Add modify_ftrace_direct()
tracing: Add missing "inline" in stub function of latency_fsnotify()
tracing: Remove stray tab in TRACE_EVAL_MAP_FILE's help text
tracing: Use seq_buf_hex_dump() to dump buffers
...
