Gratian Crisan reported that vmalloc_fault() crashes when CONFIG_HUGETLBFS
is not set since the function inadvertently uses pXn_huge(), which always
return 0 in this case. ioremap() does not depend on CONFIG_HUGETLBFS.
Fix vmalloc_fault() to call pXd_large() instead.
Fixes: f4eafd8bcd ("x86/mm: Fix vmalloc_fault() to handle large pages properly")
Reported-by: Gratian Crisan <gratian.crisan@ni.com>
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20180313170347.3829-2-toshi.kani@hpe.com
Pull x86/pti updates from Thomas Gleixner:
"Yet another pile of melted spectrum related updates:
- Drop native vsyscall support finally as it causes more trouble than
benefit.
- Make microcode loading more robust. There were a few issues
especially related to late loading which are now surfacing because
late loading of the IB* microcodes addressing spectre issues has
become more widely used.
- Simplify and robustify the syscall handling in the entry code
- Prevent kprobes on the entry trampoline code which lead to kernel
crashes when the probe hits before CR3 is updated
- Don't check microcode versions when running on hypervisors as they
are considered as lying anyway.
- Fix the 32bit objtool build and a coment typo"
* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/kprobes: Fix kernel crash when probing .entry_trampoline code
x86/pti: Fix a comment typo
x86/microcode: Synchronize late microcode loading
x86/microcode: Request microcode on the BSP
x86/microcode/intel: Look into the patch cache first
x86/microcode: Do not upload microcode if CPUs are offline
x86/microcode/intel: Writeback and invalidate caches before updating microcode
x86/microcode/intel: Check microcode revision before updating sibling threads
x86/microcode: Get rid of struct apply_microcode_ctx
x86/spectre_v2: Don't check microcode versions when running under hypervisors
x86/vsyscall/64: Drop "native" vsyscalls
x86/entry/64/compat: Save one instruction in entry_INT80_compat()
x86/entry: Do not special-case clone(2) in compat entry
x86/syscalls: Use COMPAT_SYSCALL_DEFINEx() macros for x86-only compat syscalls
x86/syscalls: Use proper syscall definition for sys_ioperm()
x86/entry: Remove stale syscall prototype
x86/syscalls/32: Simplify $entry == $compat entries
objtool: Fix 32-bit build
Pull x86/pti fixes from Thomas Gleixner:
"Three fixes related to melted spectrum:
- Sync the cpu_entry_area page table to initial_page_table on 32 bit.
Otherwise suspend/resume fails because resume uses
initial_page_table and triggers a triple fault when accessing the
cpu entry area.
- Zero the SPEC_CTL MRS on XEN before suspend to address a
shortcoming in the hypervisor.
- Fix another switch table detection issue in objtool"
* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/cpu_entry_area: Sync cpu_entry_area to initial_page_table
objtool: Fix another switch table detection issue
x86/xen: Zero MSR_IA32_SPEC_CTRL before suspend
The separation of the cpu_entry_area from the fixmap missed the fact that
on 32bit non-PAE kernels the cpu_entry_area mapping might not be covered in
initial_page_table by the previous synchronizations.
This results in suspend/resume failures because 32bit utilizes initial page
table for resume. The absence of the cpu_entry_area mapping results in a
triple fault, aka. insta reboot.
With PAE enabled this works by chance because the PGD entry which covers
the fixmap and other parts incindentally provides the cpu_entry_area
mapping as well.
Synchronize the initial page table after setting up the cpu entry
area. Instead of adding yet another copy of the same code, move it to a
function and invoke it from the various places.
It needs to be investigated if the existing calls in setup_arch() and
setup_per_cpu_areas() can be replaced by the later invocation from
setup_cpu_entry_areas(), but that's beyond the scope of this fix.
Fixes: 92a0f81d89 ("x86/cpu_entry_area: Move it out of the fixmap")
Reported-by: Woody Suwalski <terraluna977@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Woody Suwalski <terraluna977@gmail.com>
Cc: William Grant <william.grant@canonical.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1802282137290.1392@nanos.tec.linutronix.de
Pull x86 fixes from Thomas Gleixner:
"Yet another pile of melted spectrum related changes:
- sanitize the array_index_nospec protection mechanism: Remove the
overengineered array_index_nospec_mask_check() magic and allow
const-qualified types as index to avoid temporary storage in a
non-const local variable.
- make the microcode loader more robust by properly propagating error
codes. Provide information about new feature bits after micro code
was updated so administrators can act upon.
- optimizations of the entry ASM code which reduce code footprint and
make the code simpler and faster.
- fix the {pmd,pud}_{set,clear}_flags() implementations to work
properly on paravirt kernels by removing the address translation
operations.
- revert the harmful vmexit_fill_RSB() optimization
- use IBRS around firmware calls
- teach objtool about retpolines and add annotations for indirect
jumps and calls.
- explicitly disable jumplabel patching in __init code and handle
patching failures properly instead of silently ignoring them.
- remove indirect paravirt calls for writing the speculation control
MSR as these calls are obviously proving the same attack vector
which is tried to be mitigated.
- a few small fixes which address build issues with recent compiler
and assembler versions"
* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (38 commits)
KVM/VMX: Optimize vmx_vcpu_run() and svm_vcpu_run() by marking the RDMSR path as unlikely()
KVM/x86: Remove indirect MSR op calls from SPEC_CTRL
objtool, retpolines: Integrate objtool with retpoline support more closely
x86/entry/64: Simplify ENCODE_FRAME_POINTER
extable: Make init_kernel_text() global
jump_label: Warn on failed jump_label patching attempt
jump_label: Explicitly disable jump labels in __init code
x86/entry/64: Open-code switch_to_thread_stack()
x86/entry/64: Move ASM_CLAC to interrupt_entry()
x86/entry/64: Remove 'interrupt' macro
x86/entry/64: Move the switch_to_thread_stack() call to interrupt_entry()
x86/entry/64: Move ENTER_IRQ_STACK from interrupt macro to interrupt_entry
x86/entry/64: Move PUSH_AND_CLEAR_REGS from interrupt macro to helper function
x86/speculation: Move firmware_restrict_branch_speculation_*() from C to CPP
objtool: Add module specific retpoline rules
objtool: Add retpoline validation
objtool: Use existing global variables for options
x86/mm/sme, objtool: Annotate indirect call in sme_encrypt_execute()
x86/boot, objtool: Annotate indirect jump in secondary_startup_64()
x86/paravirt, objtool: Annotate indirect calls
...
This is boot code and thus Spectre-safe: we run this _way_ before userspace
comes along to have a chance to poison our branch predictor.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This comment referred to a conditional call to kmemcheck_hide() that was
here until commit 4950276672 ("kmemcheck: remove annotations").
Now that kmemcheck has been removed, it doesn't make sense anymore.
Signed-off-by: Jann Horn <jannh@google.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180219175039.253089-1-jannh@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 fixes from Ingo Molnar:
"Misc fixes all across the map:
- /proc/kcore vsyscall related fixes
- LTO fix
- build warning fix
- CPU hotplug fix
- Kconfig NR_CPUS cleanups
- cpu_has() cleanups/robustification
- .gitignore fix
- memory-failure unmapping fix
- UV platform fix"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm, mm/hwpoison: Don't unconditionally unmap kernel 1:1 pages
x86/error_inject: Make just_return_func() globally visible
x86/platform/UV: Fix GAM Range Table entries less than 1GB
x86/build: Add arch/x86/tools/insn_decoder_test to .gitignore
x86/smpboot: Fix uncore_pci_remove() indexing bug when hot-removing a physical CPU
x86/mm/kcore: Add vsyscall page to /proc/kcore conditionally
vfs/proc/kcore, x86/mm/kcore: Fix SMAP fault when dumping vsyscall user page
x86/Kconfig: Further simplify the NR_CPUS config
x86/Kconfig: Simplify NR_CPUS config
x86/MCE: Fix build warning introduced by "x86: do not use print_symbol()"
x86/cpufeature: Update _static_cpu_has() to use all named variables
x86/cpufeature: Reindent _static_cpu_has()
Pull x86 PTI and Spectre related fixes and updates from Ingo Molnar:
"Here's the latest set of Spectre and PTI related fixes and updates:
Spectre:
- Add entry code register clearing to reduce the Spectre attack
surface
- Update the Spectre microcode blacklist
- Inline the KVM Spectre helpers to get close to v4.14 performance
again.
- Fix indirect_branch_prediction_barrier()
- Fix/improve Spectre related kernel messages
- Fix array_index_nospec_mask() asm constraint
- KVM: fix two MSR handling bugs
PTI:
- Fix a paranoid entry PTI CR3 handling bug
- Fix comments
objtool:
- Fix paranoid_entry() frame pointer warning
- Annotate WARN()-related UD2 as reachable
- Various fixes
- Add Add Peter Zijlstra as objtool co-maintainer
Misc:
- Various x86 entry code self-test fixes
- Improve/simplify entry code stack frame generation and handling
after recent heavy-handed PTI and Spectre changes. (There's two
more WIP improvements expected here.)
- Type fix for cache entries
There's also some low risk non-fix changes I've included in this
branch to reduce backporting conflicts:
- rename a confusing x86_cpu field name
- de-obfuscate the naming of single-TLB flushing primitives"
* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits)
x86/entry/64: Fix CR3 restore in paranoid_exit()
x86/cpu: Change type of x86_cache_size variable to unsigned int
x86/spectre: Fix an error message
x86/cpu: Rename cpu_data.x86_mask to cpu_data.x86_stepping
selftests/x86/mpx: Fix incorrect bounds with old _sigfault
x86/mm: Rename flush_tlb_single() and flush_tlb_one() to __flush_tlb_one_[user|kernel]()
x86/speculation: Add <asm/msr-index.h> dependency
nospec: Move array_index_nospec() parameter checking into separate macro
x86/speculation: Fix up array_index_nospec_mask() asm constraint
x86/debug: Use UD2 for WARN()
x86/debug, objtool: Annotate WARN()-related UD2 as reachable
objtool: Fix segfault in ignore_unreachable_insn()
selftests/x86: Disable tests requiring 32-bit support on pure 64-bit systems
selftests/x86: Do not rely on "int $0x80" in single_step_syscall.c
selftests/x86: Do not rely on "int $0x80" in test_mremap_vdso.c
selftests/x86: Fix build bug caused by the 5lvl test which has been moved to the VM directory
selftests/x86/pkeys: Remove unused functions
selftests/x86: Clean up and document sscanf() usage
selftests/x86: Fix vDSO selftest segfault for vsyscall=none
x86/entry/64: Remove the unused 'icebp' macro
...
flush_tlb_single() and flush_tlb_one() sound almost identical, but
they really mean "flush one user translation" and "flush one kernel
translation". Rename them to flush_tlb_one_user() and
flush_tlb_one_kernel() to make the semantics more obvious.
[ I was looking at some PTI-related code, and the flush-one-address code
is unnecessarily hard to understand because the names of the helpers are
uninformative. This came up during PTI review, but no one got around to
doing it. ]
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Linux-MM <linux-mm@kvack.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/3303b02e3c3d049dc5235d5651e0ae6d29a34354.1517414378.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The vsyscall page should be visible only if vsyscall=emulate/native when dumping /proc/kcore.
Signed-off-by: Jia Zhang <zhang.jia@linux.alibaba.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: jolsa@redhat.com
Link: http://lkml.kernel.org/r/1518446694-21124-3-git-send-email-zhang.jia@linux.alibaba.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit:
df04abfd18 ("fs/proc/kcore.c: Add bounce buffer for ktext data")
... introduced a bounce buffer to work around CONFIG_HARDENED_USERCOPY=y.
However, accessing the vsyscall user page will cause an SMAP fault.
Replace memcpy() with copy_from_user() to fix this bug works, but adding
a common way to handle this sort of user page may be useful for future.
Currently, only vsyscall page requires KCORE_USER.
Signed-off-by: Jia Zhang <zhang.jia@linux.alibaba.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: jolsa@redhat.com
Link: http://lkml.kernel.org/r/1518446694-21124-2-git-send-email-zhang.jia@linux.alibaba.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
ARM:
- Include icache invalidation optimizations, improving VM startup time
- Support for forwarded level-triggered interrupts, improving
performance for timers and passthrough platform devices
- A small fix for power-management notifiers, and some cosmetic changes
PPC:
- Add MMIO emulation for vector loads and stores
- Allow HPT guests to run on a radix host on POWER9 v2.2 CPUs without
requiring the complex thread synchronization of older CPU versions
- Improve the handling of escalation interrupts with the XIVE interrupt
controller
- Support decrement register migration
- Various cleanups and bugfixes.
s390:
- Cornelia Huck passed maintainership to Janosch Frank
- Exitless interrupts for emulated devices
- Cleanup of cpuflag handling
- kvm_stat counter improvements
- VSIE improvements
- mm cleanup
x86:
- Hypervisor part of SEV
- UMIP, RDPID, and MSR_SMI_COUNT emulation
- Paravirtualized TLB shootdown using the new KVM_VCPU_PREEMPTED bit
- Allow guests to see TOPOEXT, GFNI, VAES, VPCLMULQDQ, and more AVX512
features
- Show vcpu id in its anonymous inode name
- Many fixes and cleanups
- Per-VCPU MSR bitmaps (already merged through x86/pti branch)
- Stable KVM clock when nesting on Hyper-V (merged through x86/hyperv)
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Merge tag 'kvm-4.16-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Radim Krčmář:
"ARM:
- icache invalidation optimizations, improving VM startup time
- support for forwarded level-triggered interrupts, improving
performance for timers and passthrough platform devices
- a small fix for power-management notifiers, and some cosmetic
changes
PPC:
- add MMIO emulation for vector loads and stores
- allow HPT guests to run on a radix host on POWER9 v2.2 CPUs without
requiring the complex thread synchronization of older CPU versions
- improve the handling of escalation interrupts with the XIVE
interrupt controller
- support decrement register migration
- various cleanups and bugfixes.
s390:
- Cornelia Huck passed maintainership to Janosch Frank
- exitless interrupts for emulated devices
- cleanup of cpuflag handling
- kvm_stat counter improvements
- VSIE improvements
- mm cleanup
x86:
- hypervisor part of SEV
- UMIP, RDPID, and MSR_SMI_COUNT emulation
- paravirtualized TLB shootdown using the new KVM_VCPU_PREEMPTED bit
- allow guests to see TOPOEXT, GFNI, VAES, VPCLMULQDQ, and more
AVX512 features
- show vcpu id in its anonymous inode name
- many fixes and cleanups
- per-VCPU MSR bitmaps (already merged through x86/pti branch)
- stable KVM clock when nesting on Hyper-V (merged through
x86/hyperv)"
* tag 'kvm-4.16-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (197 commits)
KVM: PPC: Book3S: Add MMIO emulation for VMX instructions
KVM: PPC: Book3S HV: Branch inside feature section
KVM: PPC: Book3S HV: Make HPT resizing work on POWER9
KVM: PPC: Book3S HV: Fix handling of secondary HPTEG in HPT resizing code
KVM: PPC: Book3S PR: Fix broken select due to misspelling
KVM: x86: don't forget vcpu_put() in kvm_arch_vcpu_ioctl_set_sregs()
KVM: PPC: Book3S PR: Fix svcpu copying with preemption enabled
KVM: PPC: Book3S HV: Drop locks before reading guest memory
kvm: x86: remove efer_reload entry in kvm_vcpu_stat
KVM: x86: AMD Processor Topology Information
x86/kvm/vmx: do not use vm-exit instruction length for fast MMIO when running nested
kvm: embed vcpu id to dentry of vcpu anon inode
kvm: Map PFN-type memory regions as writable (if possible)
x86/kvm: Make it compile on 32bit and with HYPYERVISOR_GUEST=n
KVM: arm/arm64: Fixup userspace irqchip static key optimization
KVM: arm/arm64: Fix userspace_irqchip_in_use counting
KVM: arm/arm64: Fix incorrect timer_is_pending logic
MAINTAINERS: update KVM/s390 maintainers
MAINTAINERS: add Halil as additional vfio-ccw maintainer
MAINTAINERS: add David as a reviewer for KVM/s390
...
* Require struct page by default for filesystem DAX to remove a number of
surprising failure cases. This includes failures with direct I/O, gdb and
fork(2).
* Add support for the new Platform Capabilities Structure added to the NFIT in
ACPI 6.2a. This new table tells us whether the platform supports flushing
of CPU and memory controller caches on unexpected power loss events.
* Revamp vmem_altmap and dev_pagemap handling to clean up code and better
support future future PCI P2P uses.
* Deprecate the ND_IOCTL_SMART_THRESHOLD command whose payload has become
out-of-sync with recent versions of the NVDIMM_FAMILY_INTEL spec, and
instead rely on the generic ND_CMD_CALL approach used by the two other IOCTL
families, NVDIMM_FAMILY_{HPE,MSFT}.
* Enhance nfit_test so we can test some of the new things added in version 1.6
of the DSM specification. This includes testing firmware download and
simulating the Last Shutdown State (LSS) status.
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Merge tag 'libnvdimm-for-4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull libnvdimm updates from Ross Zwisler:
- Require struct page by default for filesystem DAX to remove a number
of surprising failure cases. This includes failures with direct I/O,
gdb and fork(2).
- Add support for the new Platform Capabilities Structure added to the
NFIT in ACPI 6.2a. This new table tells us whether the platform
supports flushing of CPU and memory controller caches on unexpected
power loss events.
- Revamp vmem_altmap and dev_pagemap handling to clean up code and
better support future future PCI P2P uses.
- Deprecate the ND_IOCTL_SMART_THRESHOLD command whose payload has
become out-of-sync with recent versions of the NVDIMM_FAMILY_INTEL
spec, and instead rely on the generic ND_CMD_CALL approach used by
the two other IOCTL families, NVDIMM_FAMILY_{HPE,MSFT}.
- Enhance nfit_test so we can test some of the new things added in
version 1.6 of the DSM specification. This includes testing firmware
download and simulating the Last Shutdown State (LSS) status.
* tag 'libnvdimm-for-4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (37 commits)
libnvdimm, namespace: remove redundant initialization of 'nd_mapping'
acpi, nfit: fix register dimm error handling
libnvdimm, namespace: make min namespace size 4K
tools/testing/nvdimm: force nfit_test to depend on instrumented modules
libnvdimm/nfit_test: adding support for unit testing enable LSS status
libnvdimm/nfit_test: add firmware download emulation
nfit-test: Add platform cap support from ACPI 6.2a to test
libnvdimm: expose platform persistence attribute for nd_region
acpi: nfit: add persistent memory control flag for nd_region
acpi: nfit: Add support for detect platform CPU cache flush on power loss
device-dax: Fix trailing semicolon
libnvdimm, btt: fix uninitialized err_lock
dax: require 'struct page' by default for filesystem dax
ext2: auto disable dax instead of failing mount
ext4: auto disable dax instead of failing mount
mm, dax: introduce pfn_t_special()
mm: Fix devm_memremap_pages() collision handling
mm: Fix memory size alignment in devm_memremap_pages_release()
memremap: merge find_dev_pagemap into get_dev_pagemap
memremap: change devm_memremap_pages interface to use struct dev_pagemap
...
There are two places where core serialization is needed by membarrier:
1) When returning from the membarrier IPI,
2) After scheduler updates curr to a thread with a different mm, before
going back to user-space, since the curr->mm is used by membarrier to
check whether it needs to send an IPI to that CPU.
x86-32 uses IRET as return from interrupt, and both IRET and SYSEXIT to go
back to user-space. The IRET instruction is core serializing, but not
SYSEXIT.
x86-64 uses IRET as return from interrupt, which takes care of the IPI.
However, it can return to user-space through either SYSRETL (compat
code), SYSRETQ, or IRET. Given that SYSRET{L,Q} is not core serializing,
we rely instead on write_cr3() performed by switch_mm() to provide core
serialization after changing the current mm, and deal with the special
case of kthread -> uthread (temporarily keeping current mm into
active_mm) by adding a sync_core() in that specific case.
Use the new sync_core_before_usermode() to guarantee this.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrea Parri <parri.andrea@gmail.com>
Cc: Andrew Hunter <ahh@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Avi Kivity <avi@scylladb.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Dave Watson <davejwatson@fb.com>
Cc: David Sehr <sehr@google.com>
Cc: Greg Hackmann <ghackmann@google.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Maged Michael <maged.michael@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-api@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Link: http://lkml.kernel.org/r/20180129202020.8515-10-mathieu.desnoyers@efficios.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Document the membarrier requirement on having a full memory barrier in
__schedule() after coming from user-space, before storing to rq->curr.
It is provided by smp_mb__after_spinlock() in __schedule().
Document that membarrier requires a full barrier on transition from
kernel thread to userspace thread. We currently have an implicit barrier
from atomic_dec_and_test() in mmdrop() that ensures this.
The x86 switch_mm_irqs_off() full barrier is currently provided by many
cpumask update operations as well as write_cr3(). Document that
write_cr3() provides this barrier.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrea Parri <parri.andrea@gmail.com>
Cc: Andrew Hunter <ahh@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Avi Kivity <avi@scylladb.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Dave Watson <davejwatson@fb.com>
Cc: David Sehr <sehr@google.com>
Cc: Greg Hackmann <ghackmann@google.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Maged Michael <maged.michael@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-api@vger.kernel.org
Link: http://lkml.kernel.org/r/20180129202020.8515-4-mathieu.desnoyers@efficios.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull spectre/meltdown updates from Thomas Gleixner:
"The next round of updates related to melted spectrum:
- The initial set of spectre V1 mitigations:
- Array index speculation blocker and its usage for syscall,
fdtable and the n180211 driver.
- Speculation barrier and its usage in user access functions
- Make indirect calls in KVM speculation safe
- Blacklisting of known to be broken microcodes so IPBP/IBSR are not
touched.
- The initial IBPB support and its usage in context switch
- The exposure of the new speculation MSRs to KVM guests.
- A fix for a regression in x86/32 related to the cpu entry area
- Proper whitelisting for known to be safe CPUs from the mitigations.
- objtool fixes to deal proper with retpolines and alternatives
- Exclude __init functions from retpolines which speeds up the boot
process.
- Removal of the syscall64 fast path and related cleanups and
simplifications
- Removal of the unpatched paravirt mode which is yet another source
of indirect unproteced calls.
- A new and undisputed version of the module mismatch warning
- A couple of cleanup and correctness fixes all over the place
Yet another step towards full mitigation. There are a few things still
missing like the RBS underflow mitigation for Skylake and other small
details, but that's being worked on.
That said, I'm taking a belated christmas vacation for a week and hope
that everything is magically solved when I'm back on Feb 12th"
* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits)
KVM/SVM: Allow direct access to MSR_IA32_SPEC_CTRL
KVM/VMX: Allow direct access to MSR_IA32_SPEC_CTRL
KVM/VMX: Emulate MSR_IA32_ARCH_CAPABILITIES
KVM/x86: Add IBPB support
KVM/x86: Update the reverse_cpuid list to include CPUID_7_EDX
x86/speculation: Fix typo IBRS_ATT, which should be IBRS_ALL
x86/pti: Mark constant arrays as __initconst
x86/spectre: Simplify spectre_v2 command line parsing
x86/retpoline: Avoid retpolines for built-in __init functions
x86/kvm: Update spectre-v1 mitigation
KVM: VMX: make MSR bitmaps per-VCPU
x86/paravirt: Remove 'noreplace-paravirt' cmdline option
x86/speculation: Use Indirect Branch Prediction Barrier in context switch
x86/cpuid: Fix up "virtual" IBRS/IBPB/STIBP feature bits on Intel
x86/spectre: Fix spelling mistake: "vunerable"-> "vulnerable"
x86/spectre: Report get_user mitigation for spectre_v1
nl80211: Sanitize array index in parse_txq_params
vfs, fdtable: Prevent bounds-check bypass via speculative execution
x86/syscall: Sanitize syscall table de-references under speculation
x86/get_user: Use pointer masking to limit speculation
...
Pull printk updates from Petr Mladek:
- Add a console_msg_format command line option:
The value "default" keeps the old "[time stamp] text\n" format. The
value "syslog" allows to see the syslog-like "<log
level>[timestamp] text" format.
This feature was requested by people doing regression tests, for
example, 0day robot. They want to have both filtered and full logs
at hands.
- Reduce the risk of softlockup:
Pass the console owner in a busy loop.
This is a new approach to the old problem. It was first proposed by
Steven Rostedt on Kernel Summit 2017. It marks a context in which
the console_lock owner calls console drivers and could not sleep.
On the other side, printk() callers could detect this state and use
a busy wait instead of a simple console_trylock(). Finally, the
console_lock owner checks if there is a busy waiter at the end of
the special context and eventually passes the console_lock to the
waiter.
The hand-off works surprisingly well and helps in many situations.
Well, there is still a possibility of the softlockup, for example,
when the flood of messages stops and the last owner still has too
much to flush.
There is increasing number of people having problems with
printk-related softlockups. We might eventually need to get better
solution. Anyway, this looks like a good start and promising
direction.
- Do not allow to schedule in console_unlock() called from printk():
This reverts an older controversial commit. The reschedule helped
to avoid softlockups. But it also slowed down the console output.
This patch is obsoleted by the new console waiter logic described
above. In fact, the reschedule made the hand-off less effective.
- Deprecate "%pf" and "%pF" format specifier:
It was needed on ia64, ppc64 and parisc64 to dereference function
descriptors and show the real function address. It is done
transparently by "%ps" and "pS" format specifier now.
Sergey Senozhatsky found that all the function descriptors were in
a special elf section and could be easily detected.
- Remove printk_symbol() API:
It has been obsoleted by "%pS" format specifier, and this change
helped to remove few continuous lines and a less intuitive old API.
- Remove redundant memsets:
Sergey removed unnecessary memset when processing printk.devkmsg
command line option.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: (27 commits)
printk: drop redundant devkmsg_log_str memsets
printk: Never set console_may_schedule in console_trylock()
printk: Hide console waiter logic into helpers
printk: Add console owner and waiter logic to load balance console writes
kallsyms: remove print_symbol() function
checkpatch: add pF/pf deprecation warning
symbol lookup: introduce dereference_symbol_descriptor()
parisc64: Add .opd based function descriptor dereference
powerpc64: Add .opd based function descriptor dereference
ia64: Add .opd based function descriptor dereference
sections: split dereference_function_descriptor()
openrisc: Fix conflicting types for _exext and _stext
lib: do not use print_symbol()
irq debug: do not use print_symbol()
sysfs: do not use print_symbol()
drivers: do not use print_symbol()
x86: do not use print_symbol()
unicore32: do not use print_symbol()
sh: do not use print_symbol()
mn10300: do not use print_symbol()
...
This pull requests contains a consolidation of the generic no-IOMMU code,
a well as the glue code for swiotlb. All the code is based on the x86
implementation with hooks to allow all architectures that aren't cache
coherent to use it. The x86 conversion itself has been deferred because
the x86 maintainers were a little busy in the last months.
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Merge tag 'dma-mapping-4.16' of git://git.infradead.org/users/hch/dma-mapping
Pull dma mapping updates from Christoph Hellwig:
"Except for a runtime warning fix from Christian this is all about
consolidation of the generic no-IOMMU code, a well as the glue code
for swiotlb.
All the code is based on the x86 implementation with hooks to allow
all architectures that aren't cache coherent to use it.
The x86 conversion itself has been deferred because the x86
maintainers were a little busy in the last months"
* tag 'dma-mapping-4.16' of git://git.infradead.org/users/hch/dma-mapping: (57 commits)
MAINTAINERS: add the iommu list for swiotlb and xen-swiotlb
arm64: use swiotlb_alloc and swiotlb_free
arm64: replace ZONE_DMA with ZONE_DMA32
mips: use swiotlb_{alloc,free}
mips/netlogic: remove swiotlb support
tile: use generic swiotlb_ops
tile: replace ZONE_DMA with ZONE_DMA32
unicore32: use generic swiotlb_ops
ia64: remove an ifdef around the content of pci-dma.c
ia64: clean up swiotlb support
ia64: use generic swiotlb_ops
ia64: replace ZONE_DMA with ZONE_DMA32
swiotlb: remove various exports
swiotlb: refactor coherent buffer allocation
swiotlb: refactor coherent buffer freeing
swiotlb: wire up ->dma_supported in swiotlb_dma_ops
swiotlb: add common swiotlb_map_ops
swiotlb: rename swiotlb_free to swiotlb_exit
x86: rename swiotlb_dma_ops
powerpc: rename swiotlb_dma_ops
...
Flush indirect branches when switching into a process that marked itself
non dumpable. This protects high value processes like gpg better,
without having too high performance overhead.
If done naïvely, we could switch to a kernel idle thread and then back
to the original process, such as:
process A -> idle -> process A
In such scenario, we do not have to do IBPB here even though the process
is non-dumpable, as we are switching back to the same process after a
hiatus.
To avoid the redundant IBPB, which is expensive, we track the last mm
user context ID. The cost is to have an extra u64 mm context id to track
the last mm we were using before switching to the init_mm used by idle.
Avoiding the extra IBPB is probably worth the extra memory for this
common scenario.
For those cases where tlb_defer_switch_to_init_mm() returns true (non
PCID), lazy tlb will defer switch to init_mm, so we will not be changing
the mm for the process A -> idle -> process A switch. So IBPB will be
skipped for this case.
Thanks to the reviewers and Andy Lutomirski for the suggestion of
using ctx_id which got rid of the problem of mm pointer recycling.
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: ak@linux.intel.com
Cc: karahmed@amazon.de
Cc: arjan@linux.intel.com
Cc: torvalds@linux-foundation.org
Cc: linux@dominikbrodowski.net
Cc: peterz@infradead.org
Cc: bp@alien8.de
Cc: luto@kernel.org
Cc: pbonzini@redhat.com
Cc: gregkh@linux-foundation.org
Link: https://lkml.kernel.org/r/1517263487-3708-1-git-send-email-dwmw@amazon.co.uk
On a 5-level kernel, if a non-init mm has a top-level entry, it needs to
match init_mm's, but the vmalloc_fault() code skipped over the BUG_ON()
that would have checked it.
While we're at it, get rid of the rather confusing 4-level folded "pgd"
logic.
Cleans-up: b50858ce3e ("x86/mm/vmalloc: Add 5-level paging support")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Neil Berrington <neil.berrington@datacore.com>
Link: https://lkml.kernel.org/r/2ae598f8c279b0a29baf75df207e6f2fdddc0a1b.1516914529.git.luto@kernel.org
Neil Berrington reported a double-fault on a VM with 768GB of RAM that uses
large amounts of vmalloc space with PTI enabled.
The cause is that load_new_mm_cr3() was never fixed to take the 5-level pgd
folding code into account, so, on a 4-level kernel, the pgd synchronization
logic compiles away to exactly nothing.
Interestingly, the problem doesn't trigger with nopti. I assume this is
because the kernel is mapped with global pages if we boot with nopti. The
sequence of operations when we create a new task is that we first load its
mm while still running on the old stack (which crashes if the old stack is
unmapped in the new mm unless the TLB saves us), then we call
prepare_switch_to(), and then we switch to the new stack.
prepare_switch_to() pokes the new stack directly, which will populate the
mapping through vmalloc_fault(). I assume that we're getting lucky on
non-PTI systems -- the old stack's TLB entry stays alive long enough to
make it all the way through prepare_switch_to() and switch_to() so that we
make it to a valid stack.
Fixes: b50858ce3e ("x86/mm/vmalloc: Add 5-level paging support")
Reported-and-tested-by: Neil Berrington <neil.berrington@datacore.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: stable@vger.kernel.org
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Link: https://lkml.kernel.org/r/346541c56caed61abbe693d7d2742b4a380c5001.1516914529.git.luto@kernel.org
Commit bacf6b499e ("x86/mm: Use a struct to reduce parameters for SME
PGD mapping") moved some parameters into a structure.
The structure was large enough to trigger the stack protection canary in
sme_encrypt_kernel which doesn't work this early, causing reboots.
Mark sme_encrypt_kernel appropriately to not use the canary.
Fixes: bacf6b499e ("x86/mm: Use a struct to reduce parameters for SME PGD mapping")
Signed-off-by: Laura Abbott <labbott@redhat.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull x86 fixes from Ingo Molnar:
"Misc fixes:
- A rather involved set of memory hardware encryption fixes to
support the early loading of microcode files via the initrd. These
are larger than what we normally take at such a late -rc stage, but
there are two mitigating factors: 1) much of the changes are
limited to the SME code itself 2) being able to early load
microcode has increased importance in the post-Meltdown/Spectre
era.
- An IRQ vector allocator fix
- An Intel RDT driver use-after-free fix
- An APIC driver bug fix/revert to make certain older systems boot
again
- A pkeys ABI fix
- TSC calibration fixes
- A kdump fix"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/apic/vector: Fix off by one in error path
x86/intel_rdt/cqm: Prevent use after free
x86/mm: Encrypt the initrd earlier for BSP microcode update
x86/mm: Prepare sme_encrypt_kernel() for PAGE aligned encryption
x86/mm: Centralize PMD flags in sme_encrypt_kernel()
x86/mm: Use a struct to reduce parameters for SME PGD mapping
x86/mm: Clean up register saving in the __enc_copy() assembly code
x86/idt: Mark IDT tables __initconst
Revert "x86/apic: Remove init_bsp_APIC()"
x86/mm/pkeys: Fix fill_sig_info_pkey
x86/tsc: Print tsc_khz, when it differs from cpu_khz
x86/tsc: Fix erroneous TSC rate on Skylake Xeon
x86/tsc: Future-proof native_calibrate_tsc()
kdump: Write the correct address of mem_section into vmcoreinfo
Pull x86 pti bits and fixes from Thomas Gleixner:
"This last update contains:
- An objtool fix to prevent a segfault with the gold linker by
changing the invocation order. That's not just for gold, it's a
general robustness improvement.
- An improved error message for objtool which spares tearing hairs.
- Make KASAN fail loudly if there is not enough memory instead of
oopsing at some random place later
- RSB fill on context switch to prevent RSB underflow and speculation
through other units.
- Make the retpoline/RSB functionality work reliably for both Intel
and AMD
- Add retpoline to the module version magic so mismatch can be
detected
- A small (non-fix) update for cpufeatures which prevents cpu feature
clashing for the upcoming extra mitigation bits to ease
backporting"
* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
module: Add retpoline tag to VERMAGIC
x86/cpufeature: Move processor tracing out of scattered features
objtool: Improve error message for bad file argument
objtool: Fix seg fault with gold linker
x86/retpoline: Add LFENCE to the retpoline/RSB filling RSB macros
x86/retpoline: Fill RSB on context switch for affected CPUs
x86/kasan: Panic if there is not enough memory to boot
Check whether the PAT memory type of a pfn cannot be overridden by
MTRR UC memory type, i.e. the PAT memory type is UC, UC- or WC. This
function will be used by KVM to distinguish MMIO pfns and give them
UC memory type in the EPT page tables (on Intel processors, EPT
memory types work like MTRRs).
Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
Reviewed-by: Xiao Guangrong <xiaoguangrong@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Currently the BSP microcode update code examines the initrd very early
in the boot process. If SME is active, the initrd is treated as being
encrypted but it has not been encrypted (in place) yet. Update the
early boot code that encrypts the kernel to also encrypt the initrd so
that early BSP microcode updates work.
Tested-by: Gabriel Craciunescu <nix.or.die@gmail.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180110192634.6026.10452.stgit@tlendack-t1.amdoffice.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In preparation for encrypting more than just the kernel, the encryption
support in sme_encrypt_kernel() needs to support 4KB page aligned
encryption instead of just 2MB large page aligned encryption.
Update the routines that populate the PGD to support non-2MB aligned
addresses. This is done by creating PTE page tables for the start
and end portion of the address range that fall outside of the 2MB
alignment. This results in, at most, two extra pages to hold the
PTE entries for each mapping of a range.
Tested-by: Gabriel Craciunescu <nix.or.die@gmail.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180110192626.6026.75387.stgit@tlendack-t1.amdoffice.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In preparation for encrypting more than just the kernel during early
boot processing, centralize the use of the PMD flag settings based
on the type of mapping desired. When 4KB aligned encryption is added,
this will allow either PTE flags or large page PMD flags to be used
without requiring the caller to adjust.
Tested-by: Gabriel Craciunescu <nix.or.die@gmail.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180110192615.6026.14767.stgit@tlendack-t1.amdoffice.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In preparation for follow-on patches, combine the PGD mapping parameters
into a struct to reduce the number of function arguments and allow for
direct updating of the next pagetable mapping area pointer.
Tested-by: Gabriel Craciunescu <nix.or.die@gmail.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180110192605.6026.96206.stgit@tlendack-t1.amdoffice.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Clean up the use of PUSH and POP and when registers are saved in the
__enc_copy() assembly function in order to improve the readability of the code.
Move parameter register saving into general purpose registers earlier
in the code and move all the pushes to the beginning of the function
with corresponding pops at the end.
We do this to prepare fixes.
Tested-by: Gabriel Craciunescu <nix.or.die@gmail.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180110192556.6026.74187.stgit@tlendack-t1.amdoffice.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Currently KASAN doesn't panic in case it don't have enough memory
to boot. Instead, it crashes in some random place:
kernel BUG at arch/x86/mm/physaddr.c:27!
RIP: 0010:__phys_addr+0x268/0x276
Call Trace:
kasan_populate_shadow+0x3f2/0x497
kasan_init+0x12e/0x2b2
setup_arch+0x2825/0x2a2c
start_kernel+0xc8/0x15f4
x86_64_start_reservations+0x2a/0x2c
x86_64_start_kernel+0x72/0x75
secondary_startup_64+0xa5/0xb0
Use memblock_virt_alloc_try_nid() for allocations without failure
fallback. It will panic with an out of memory message.
Reported-by: kernel test robot <xiaolong.ye@intel.com>
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Cc: kasan-dev@googlegroups.com
Cc: Alexander Potapenko <glider@google.com>
Cc: lkp@01.org
Link: https://lkml.kernel.org/r/20180110153602.18919-1-aryabinin@virtuozzo.com
Mark the C exception handler functions that are directly called through
exception tables visible. LTO needs to know they are accessed from assembler.
[ tglx: Mopped up the wrecked argument alignment. Sigh.... ]
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20171222001821.2157-6-andi@firstfloor.org
Pull x86 pti updates from Thomas Gleixner:
"This contains:
- a PTI bugfix to avoid setting reserved CR3 bits when PCID is
disabled. This seems to cause issues on a virtual machine at least
and is incorrect according to the AMD manual.
- a PTI bugfix which disables the perf BTS facility if PTI is
enabled. The BTS AUX buffer is not globally visible and causes the
CPU to fault when the mapping disappears on switching CR3 to user
space. A full fix which restores BTS on PTI is non trivial and will
be worked on.
- PTI bugfixes for EFI and trusted boot which make sure that the user
space visible page table entries have the NX bit cleared
- removal of dead code in the PTI pagetable setup functions
- add PTI documentation
- add a selftest for vsyscall to verify that the kernel actually
implements what it advertises.
- a sysfs interface to expose vulnerability and mitigation
information so there is a coherent way for users to retrieve the
status.
- the initial spectre_v2 mitigations, aka retpoline:
+ The necessary ASM thunk and compiler support
+ The ASM variants of retpoline and the conversion of affected ASM
code
+ Make LFENCE serializing on AMD so it can be used as speculation
trap
+ The RSB fill after vmexit
- initial objtool support for retpoline
As I said in the status mail this is the most of the set of patches
which should go into 4.15 except two straight forward patches still on
hold:
- the retpoline add on of LFENCE which waits for ACKs
- the RSB fill after context switch
Both should be ready to go early next week and with that we'll have
covered the major holes of spectre_v2 and go back to normality"
* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (28 commits)
x86,perf: Disable intel_bts when PTI
security/Kconfig: Correct the Documentation reference for PTI
x86/pti: Fix !PCID and sanitize defines
selftests/x86: Add test_vsyscall
x86/retpoline: Fill return stack buffer on vmexit
x86/retpoline/irq32: Convert assembler indirect jumps
x86/retpoline/checksum32: Convert assembler indirect jumps
x86/retpoline/xen: Convert Xen hypercall indirect jumps
x86/retpoline/hyperv: Convert assembler indirect jumps
x86/retpoline/ftrace: Convert ftrace assembler indirect jumps
x86/retpoline/entry: Convert entry assembler indirect jumps
x86/retpoline/crypto: Convert crypto assembler indirect jumps
x86/spectre: Add boot time option to select Spectre v2 mitigation
x86/retpoline: Add initial retpoline support
objtool: Allow alternatives to be ignored
objtool: Detect jumps to retpoline thunks
x86/pti: Make unpoison of pgd for trusted boot work for real
x86/alternatives: Fix optimize_nops() checking
sysfs/cpu: Fix typos in vulnerability documentation
x86/cpu/AMD: Use LFENCE_RDTSC in preference to MFENCE_RDTSC
...
SEGV_PKUERR is a signal specific si_code which happens to have the same
numeric value as several others: BUS_MCEERR_AR, ILL_ILLTRP, FPE_FLTOVF,
TRAP_HWBKPT, CLD_TRAPPED, POLL_ERR, SEGV_THREAD_ID, as such it is not safe
to just test the si_code the signal number must also be tested to prevent a
false positive in fill_sig_info_pkey.
This error was by inspection, and BUS_MCEERR_AR appears to be a real
candidate for confusion. So pass in si_signo and check for SIG_SEGV to
verify that it is actually a SEGV_PKUERR
Fixes: 019132ff3d ("x86/mm/pkeys: Fill in pkey field in siginfo")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180112203135.4669-2-ebiederm@xmission.com
phys_to_dma, dma_to_phys and dma_capable are helpers published by
architecture code for use of swiotlb and xen-swiotlb only. Drivers are
not supposed to use these directly, but use the DMA API instead.
Move these to a new asm/dma-direct.h helper, included by a
linux/dma-direct.h wrapper that provides the default linear mapping
unless the architecture wants to override it.
In the MIPS case the existing dma-coherent.h is reused for now as
untangling it will take a bit of work.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Robin Murphy <robin.murphy@arm.com>
No functional changes, just untangling the call chain and document
why the altmap is passed around the hotplug code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
We can just pass this on instead of having to do a radix tree lookup
without proper locking a few levels into the callchain.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
We can just pass this on instead of having to do a radix tree lookup
without proper locking 2 levels into the callchain.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
We can just pass this on instead of having to do a radix tree lookup
without proper locking a few levels into the callchain.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
We can just pass this on instead of having to do a radix tree lookup
without proper locking 2 levels into the callchain.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Only x86_64 and sh export this symbol, and it is not used by any
modular code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
The following code contains dead logic:
162 if (pgd_none(*pgd)) {
163 unsigned long new_p4d_page = __get_free_page(gfp);
164 if (!new_p4d_page)
165 return NULL;
166
167 if (pgd_none(*pgd)) {
168 set_pgd(pgd, __pgd(_KERNPG_TABLE | __pa(new_p4d_page)));
169 new_p4d_page = 0;
170 }
171 if (new_p4d_page)
172 free_page(new_p4d_page);
173 }
There can't be any difference between two pgd_none(*pgd) at L162 and L167,
so it's always false at L171.
Dave Hansen explained:
Yes, the double-test was part of an optimization where we attempted to
avoid using a global spinlock in the fork() path. We would check for
unallocated mid-level page tables without the lock. The lock was only
taken when we needed to *make* an entry to avoid collisions.
Now that it is all single-threaded, there is no chance of a collision,
no need for a lock, and no need for the re-check.
As all these functions are only called during init, mark them __init as
well.
Fixes: 03f4424f34 ("x86/mm/pti: Add functions to clone kernel PMDs")
Signed-off-by: Jike Song <albcamus@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Jiri Koshina <jikos@kernel.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Kees Cook <keescook@google.com>
Cc: Andi Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Greg KH <gregkh@linux-foundation.org>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Paul Turner <pjt@google.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180108160341.3461-1-albcamus@gmail.com
Pull more x86 pti fixes from Thomas Gleixner:
"Another small stash of fixes for fallout from the PTI work:
- Fix the modules vs. KASAN breakage which was caused by making
MODULES_END depend of the fixmap size. That was done when the cpu
entry area moved into the fixmap, but now that we have a separate
map space for that this is causing more issues than it solves.
- Use the proper cache flush methods for the debugstore buffers as
they are mapped/unmapped during runtime and not statically mapped
at boot time like the rest of the cpu entry area.
- Make the map layout of the cpu_entry_area consistent for 4 and 5
level paging and fix the KASLR vaddr_end wreckage.
- Use PER_CPU_EXPORT for per cpu variable and while at it unbreak
nvidia gfx drivers by dropping the GPL export. The subject line of
the commit tells it the other way around, but I noticed that too
late.
- Fix the ASM alternative macros so they can be used in the middle of
an inline asm block.
- Rename the BUG_CPU_INSECURE flag to BUG_CPU_MELTDOWN so the attack
vector is properly identified. The Spectre mitigations will come
with their own bug bits later"
* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/pti: Rename BUG_CPU_INSECURE to BUG_CPU_MELTDOWN
x86/alternatives: Add missing '\n' at end of ALTERNATIVE inline asm
x86/tlb: Drop the _GPL from the cpu_tlbstate export
x86/events/intel/ds: Use the proper cache flush method for mapping ds buffers
x86/kaslr: Fix the vaddr_end mess
x86/mm: Map cpu_entry_area at the same place on 4/5 level
x86/mm: Set MODULES_END to 0xffffffffff000000
Use the name associated with the particular attack which needs page table
isolation for mitigation.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: David Woodhouse <dwmw@amazon.co.uk>
Cc: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Cc: Jiri Koshina <jikos@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Lutomirski <luto@amacapital.net>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Turner <pjt@google.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Greg KH <gregkh@linux-foundation.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kees Cook <keescook@google.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1801051525300.1724@nanos
