When a kthread calls call_usermodehelper() the steps are:
1. allocate current->mm
2. load_elf_binary()
3. populate current->thread.regs
While doing this, interrupts are not disabled. If there is a perf
interrupt in the middle of this process (i.e. step 1 has completed
but not yet reached to step 3) and if perf tries to read userspace
regs, kernel oops with following log:
Unable to handle kernel paging request for data at address 0x00000000
Faulting instruction address: 0xc0000000000da0fc
...
Call Trace:
perf_output_sample_regs+0x6c/0xd0
perf_output_sample+0x4e4/0x830
perf_event_output_forward+0x64/0x90
__perf_event_overflow+0x8c/0x1e0
record_and_restart+0x220/0x5c0
perf_event_interrupt+0x2d8/0x4d0
performance_monitor_exception+0x54/0x70
performance_monitor_common+0x158/0x160
--- interrupt: f01 at avtab_search_node+0x150/0x1a0
LR = avtab_search_node+0x100/0x1a0
...
load_elf_binary+0x6e8/0x15a0
search_binary_handler+0xe8/0x290
do_execveat_common.isra.14+0x5f4/0x840
call_usermodehelper_exec_async+0x170/0x210
ret_from_kernel_thread+0x5c/0x7c
Fix it by setting abi to PERF_SAMPLE_REGS_ABI_NONE when userspace
pt_regs are not set.
Fixes: ed4a4ef85c ("powerpc/perf: Add support for sampling interrupt register state")
Cc: stable@vger.kernel.org # v4.7+
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On Power9, trying to use data breakpoints throws the splat shown
below. This is because the check for a data breakpoint in DSISR is in
do_hash_page(), which is not called when in Radix mode.
Unable to handle kernel paging request for data at address 0xc000000000e19218
Faulting instruction address: 0xc0000000001155e8
cpu 0x0: Vector: 300 (Data Access) at [c0000000ef1e7b20]
pc: c0000000001155e8: find_pid_ns+0x48/0xe0
lr: c000000000116ac4: find_task_by_vpid+0x44/0x90
sp: c0000000ef1e7da0
msr: 9000000000009033
dar: c000000000e19218
dsisr: 400000
Move the check to handle_page_fault() so as to catch data breakpoints
in both Hash and Radix MMU modes.
We have to change the check in do_hash_page() against 0xa410 to use
0xa450, so as to include the value of (DSISR_DABRMATCH << 16).
There are two sites that call handle_page_fault() when in Radix, both
already pass DSISR in r4.
Fixes: caca285e5a ("powerpc/mm/radix: Use STD_MMU_64 to properly isolate hash related code")
Cc: stable@vger.kernel.org # v4.7+
Reported-by: Shriya R. Kulkarni <shriykul@in.ibm.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
[mpe: Fix the fall-through case on hash, we need to reload DSISR]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
ftrace_caller() depends on a modified regs->nip to detect if a certain
function has been livepatched. However, with KPROBES_ON_FTRACE, it is
possible for regs->nip to have been modified by the kprobes pre_handler
(jprobes, for instance). In this case, we do not want to invoke the
livepatch_handler so as not to consume the livepatch stack.
To distinguish between the two (kprobes and livepatch), we check if
there is an active kprobe on the current function. If there is, then we
know for sure that it must have modified the NIP as we don't support
livepatching a kprobe'd function. In this case, we simply skip the
livepatch_handler and branch to the new NIP. Otherwise, the
livepatch_handler is invoked.
Fixes: ead514d5fb ("powerpc/kprobes: Add support for KPROBES_ON_FTRACE")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
For DYNAMIC_FTRACE_WITH_REGS, we should be passing-in the original set
of registers in pt_regs, to capture the state _before_ ftrace_caller.
However, we are instead passing the stack pointer *after* allocating a
stack frame in ftrace_caller. Fix this by saving the proper value of r1
in pt_regs. Also, use SAVE_10GPRS() to simplify the code.
Fixes: 153086644f ("powerpc/ftrace: Add support for -mprofile-kernel ftrace ABI")
Cc: stable@vger.kernel.org # v4.6+
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This fixes a crash when function_graph and jprobes are used together.
This is essentially commit 237d28db03 ("ftrace/jprobes/x86: Fix
conflict between jprobes and function graph tracing"), but for powerpc.
Jprobes breaks function_graph tracing since the jprobe hook needs to use
jprobe_return(), which never returns back to the hook, but instead to
the original jprobe'd function. The solution is to momentarily pause
function_graph tracing before invoking the jprobe hook and re-enable it
when returning back to the original jprobe'd function.
Fixes: 6794c78243 ("powerpc64: port of the function graph tracer")
Cc: stable@vger.kernel.org # v2.6.30+
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When trapped on WARN_ON(), report_bug() is expected to return
BUG_TRAP_TYPE_WARN so the caller will increment NIP by 4 and continue.
The __builtin_constant_p() path of the PPC's WARN_ON()
calls (indirectly) __WARN_FLAGS() which has BUGFLAG_WARNING set,
however the other branch does not which makes report_bug() report a
bug rather than a warning.
Fixes: f26dee1510 ("debug: Avoid setting BUGFLAG_WARNING twice")
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Architecturally we should apply a 0x400 offset for these. Not doing
it will break future HW implementations.
The offset of 0 is supposed to remain for "triggers" though not all
sources support both trigger and store EOI, and in P9 specifically,
some sources will treat 0 as a store EOI. But future chips will not.
So this makes us use the properly architected offset which should work
always.
Fixes: 243e25112d ("powerpc/xive: Native exploitation of the XIVE interrupt controller")
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Commit 4c3b89effc ("powerpc/powernv: Add sanity checks to
pnv_pci_get_{gpu|npu}_dev") introduced explicit warnings in
pnv_pci_get_npu_dev() when a PCIe device has no associated device-tree
node. However not all PCIe devices have an of_node and
pnv_pci_get_npu_dev() gets indirectly called at least once for every
PCIe device in the system. This results in spurious WARN_ON()'s so
remove it.
The same situation should not exist for pnv_pci_get_gpu_dev() as any
NPU based PCIe device requires a device-tree node.
Fixes: 4c3b89effc ("powerpc/powernv: Add sanity checks to pnv_pci_get_{gpu|npu}_dev")
Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The PPC_DT_CPU_FTRs is a bit misplaced in menuconfig, it shows up with
other general kernel options. It's really more at home in the "Platform
Support" section, so move it there.
Also enable it by default, for Book3s 64. It does mostly nothing unless
the device tree properties are found, and we will want it enabled
eventually in distro kernels, so turn it on to start getting more
testing.
Fixes: 5a61ef74f2 ("powerpc/64s: Support new device tree binding for discovering CPU features")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Supporting 512TB requires us to do a order 3 allocation for level 1 page
table (pgd). This results in page allocation failures with certain workloads.
For now limit 4k linux page size config to 64TB.
Fixes: f6eedbba7a ("powerpc/mm/hash: Increase VA range to 128TB")
Reported-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Fix error path if we can't copy user structure on CXL_IOCTL_START_WORK
ioctl. We shouldn't unlock the context status mutex as it was not
locked (yet).
Fixes: 0712dc7e73 ("cxl: Fix issues when unmapping contexts")
Cc: stable@vger.kernel.org # v3.19+
Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Reviewed-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Commit 8d911904f3 ('powerpc/perf: Add restrictions to PMC5 in power9 DD1')
was added to restrict the use of PMC5 in Power9 DD1. Intention was to disable
the use of PMC5 using raw event code. But instead of updating the
power9_isa207_pmu structure (used on DD1), the commit incorrectly updated the
power9_pmu structure. Fix it.
Fixes: 8d911904f3 ("powerpc/perf: Add restrictions to PMC5 in power9 DD1")
Reported-by: Shriya <shriyak@linux.vnet.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Tested-by: Shriya <shriyak@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In commit 8c27226119 ("powerpc/numa: Enable USE_PERCPU_NUMA_NODE_ID"), we
switched to the generic implementation of cpu_to_node(), which uses a percpu
variable to hold the NUMA node for each CPU.
Unfortunately we neglected to notice that we use cpu_to_node() in the allocation
of our percpu areas, leading to a chicken and egg problem. In practice what
happens is when we are setting up the percpu areas, cpu_to_node() reports that
all CPUs are on node 0, so we allocate all percpu areas on node 0.
This is visible in the dmesg output, as all pcpu allocs being in group 0:
pcpu-alloc: [0] 00 01 02 03 [0] 04 05 06 07
pcpu-alloc: [0] 08 09 10 11 [0] 12 13 14 15
pcpu-alloc: [0] 16 17 18 19 [0] 20 21 22 23
pcpu-alloc: [0] 24 25 26 27 [0] 28 29 30 31
pcpu-alloc: [0] 32 33 34 35 [0] 36 37 38 39
pcpu-alloc: [0] 40 41 42 43 [0] 44 45 46 47
To fix it we need an early_cpu_to_node() which can run prior to percpu being
setup. We already have the numa_cpu_lookup_table we can use, so just plumb it
in. With the patch dmesg output shows two groups, 0 and 1:
pcpu-alloc: [0] 00 01 02 03 [0] 04 05 06 07
pcpu-alloc: [0] 08 09 10 11 [0] 12 13 14 15
pcpu-alloc: [0] 16 17 18 19 [0] 20 21 22 23
pcpu-alloc: [1] 24 25 26 27 [1] 28 29 30 31
pcpu-alloc: [1] 32 33 34 35 [1] 36 37 38 39
pcpu-alloc: [1] 40 41 42 43 [1] 44 45 46 47
We can also check the data_offset in the paca of various CPUs, with the fix we
see:
CPU 0: data_offset = 0x0ffe8b0000
CPU 24: data_offset = 0x1ffe5b0000
And we can see from dmesg that CPU 24 has an allocation on node 1:
node 0: [mem 0x0000000000000000-0x0000000fffffffff]
node 1: [mem 0x0000001000000000-0x0000001fffffffff]
Cc: stable@vger.kernel.org # v3.16+
Fixes: 8c27226119 ("powerpc/numa: Enable USE_PERCPU_NUMA_NODE_ID")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
During an eeh call to cxl_remove can result in double free_irq of
psl,slice interrupts. This can happen if perst_reloads_same_image == 1
and call to cxl_configure_adapter() fails during slot_reset
callback. In such a case we see a kernel oops with following back-trace:
Oops: Kernel access of bad area, sig: 11 [#1]
Call Trace:
free_irq+0x88/0xd0 (unreliable)
cxl_unmap_irq+0x20/0x40 [cxl]
cxl_native_release_psl_irq+0x78/0xd8 [cxl]
pci_deconfigure_afu+0xac/0x110 [cxl]
cxl_remove+0x104/0x210 [cxl]
pci_device_remove+0x6c/0x110
device_release_driver_internal+0x204/0x2e0
pci_stop_bus_device+0xa0/0xd0
pci_stop_and_remove_bus_device+0x28/0x40
pci_hp_remove_devices+0xb0/0x150
pci_hp_remove_devices+0x68/0x150
eeh_handle_normal_event+0x140/0x580
eeh_handle_event+0x174/0x360
eeh_event_handler+0x1e8/0x1f0
This patch fixes the issue of double free_irq by checking that
variables that hold the virqs (err_hwirq, serr_hwirq, psl_virq) are
not '0' before un-mapping and resetting these variables to '0' when
they are un-mapped.
Cc: stable@vger.kernel.org
Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently tsk->thread.load_tm is not initialized in the task creation
and can contain garbage on a new task.
This is an undesired behaviour, since it affects the timing to enable
and disable the transactional memory laziness (disabling and enabling
the MSR TM bit, which affects TM reclaim and recheckpoint in the
scheduling process).
Fixes: 5d176f751e ("powerpc: tm: Enable transactional memory (TM) lazily for userspace")
Cc: stable@vger.kernel.org # v4.9+
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently tsk->thread->load_vec and load_fp are not initialized during
task creation, which can lead to garbage values in these variables (non-zero
values).
These variables will be checked later in restore_math() to validate if the
FP and vector registers are being utilized. Since these values might be
non-zero, the restore_math() will continue to save the FP and vectors even if
they were never utilized by the userspace application. load_fp and load_vec
counters will then overflow (they wrap at 255) and the FP and Altivec will be
finally disabled, but before that condition is reached (counter overflow)
several context switches will have restored FP and vector registers without
need, causing a performance degradation.
Fixes: 70fe3d980f ("powerpc: Restore FPU/VEC/VSX if previously used")
Cc: stable@vger.kernel.org # v4.6+
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Gustavo Romero <gusbromero@gmail.com>
Acked-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
We are running low on CPU feature bits, so we only want to use them when
it's really necessary.
CPU_FTR_SUBCORE is only used in one place, and only in C, so we don't
need it in order to make asm patching work. It can only be set on
"Power8" CPUs, which in practice means POWER8, POWER8E and POWER8NVL.
There are no plans to implement it on future CPUs, but if there ever
were we could retrofit it then.
Although KVM uses subcores, it never looks at the CPU feature, it either
looks at the ISA level or the threads_per_subcore value.
So drop the CPU feature and do a PVR check instead. Drop the device tree
"subcore" feature as we no longer support doing anything with it, and we
will drop it from skiboot too.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When adding or removing memory, the aa_index (affinity value) for the
memblock must also be converted to match the endianness of the rest
of the 'ibm,dynamic-memory' property. Otherwise, subsequent retrieval
of the attribute will likely lead to non-existent nodes, followed by
using the default node in the code inappropriately.
Fixes: 5f97b2a0d1 ("powerpc/pseries: Implement memory hotplug add in the kernel")
Cc: stable@vger.kernel.org # v4.1+
Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
If a process dumps core while it has SPU contexts active then we have
code to also dump information about the SPU contexts.
Unfortunately it's been broken for 3 1/2 years, and we didn't notice. In
commit 7b1f4020d0 ("spufs: get rid of dump_emit() wrappers") the nread
variable was removed and rc used instead. That means when the loop exits
successfully, rc has the number of bytes read, but it's then used as the
return value for the function, which should return 0 on success.
So fix it by setting rc = 0 before returning in the success case.
Fixes: 7b1f4020d0 ("spufs: get rid of dump_emit() wrappers")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Provide a dt_cpu_ftrs= cmdline option to disable the dt_cpu_ftrs CPU
feature discovery, and fall back to the "cputable" based version.
Also allow control of advertising unknown features to userspace and
with this parameter, and remove the clunky CONFIG option.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Add explicit early check of bootargs in dt_cpu_ftrs_init()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Providing "scv" support to userspace requires kernel support, so it
must be advertised as independently to the base ISA 3 instruction set.
The darn instruction relies on firmware enablement, so it has been
decided to split this out from the core ISA 3 feature as well.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Commit ac29c64089 ("powerpc/mm: Replace _PAGE_USER with
_PAGE_PRIVILEGED") swapped _PAGE_USER for _PAGE_PRIVILEGED, and
introduced check_pte_access() which denied kernel access to
non-_PAGE_PRIVILEGED pages.
However, it didn't add _PAGE_PRIVILEGED to the hash fault handler
for spufs' kernel accesses, so the DMAs required to establish SPE
memory no longer work.
This change adds _PAGE_PRIVILEGED to the hash fault handler for
kernel accesses.
Fixes: ac29c64089 ("powerpc/mm: Replace _PAGE_USER with _PAGE_PRIVILEGED")
Cc: stable@vger.kernel.org # v4.7+
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Reported-by: Sombat Tragolgosol <sombat3960@gmail.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently if you disable CONFIG_PPC_RADIX_MMU you'll crash on boot on
a P9. This is because we still set MMU_FTR_TYPE_RADIX via
ibm,pa-features and MMU_FTR_TYPE_RADIX is what's used for code patching
in much of the asm code (ie. slb_miss_realmode)
This patch fixes the problem by stopping MMU_FTR_TYPE_RADIX from being
set from ibm.pa-features.
We may eventually end up removing the CONFIG_PPC_RADIX_MMU option
completely but until then this fixes the issue.
Fixes: 17a3dd2f5f ("powerpc/mm/radix: Use firmware feature to enable Radix MMU")
Cc: stable@vger.kernel.org # v4.7+
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
opal_npu_destroy_context() should be called with the NPU PHB, not the
PCIe PHB.
Fixes: 1ab66d1fba ("powerpc/powernv: Introduce address translation services for Nvlink2")
Signed-off-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The tm-resched-dscr test has started failing sometimes, depending on
what compiler it's built with, eg:
test: tm_resched_dscr
Check DSCR TM context switch: tm-resched-dscr: tm-resched-dscr.c:76: test_body: Assertion `rv' failed.
!! child died by signal 6
When it fails we see that the compiler doesn't initialise rv to 1 before
entering the inline asm block. Although that's counter intuitive, it
is allowed because we tell the compiler that the inline asm will write
to rv (using "=r"), meaning the original value is irrelevant.
Marking it as a read/write parameter would presumably work, but it seems
simpler to fix it by setting the initial value of rv in the inline asm.
Fixes: 96d0161086 ("powerpc: Correct DSCR during TM context switch")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Michael Neuling <mikey@neuling.org>
virt_addr_valid() is supposed to tell you if it's OK to call virt_to_page() on
an address. What this means in practice is that it should only return true for
addresses in the linear mapping which are backed by a valid PFN.
We are failing to properly check that the address is in the linear mapping,
because virt_to_pfn() will return a valid looking PFN for more or less any
address. That bug is actually caused by __pa(), used in virt_to_pfn().
eg: __pa(0xc000000000010000) = 0x10000 # Good
__pa(0xd000000000010000) = 0x10000 # Bad!
__pa(0x0000000000010000) = 0x10000 # Bad!
This started happening after commit bdbc29c19b ("powerpc: Work around gcc
miscompilation of __pa() on 64-bit") (Aug 2013), where we changed the definition
of __pa() to work around a GCC bug. Prior to that we subtracted PAGE_OFFSET from
the value passed to __pa(), meaning __pa() of a 0xd or 0x0 address would give
you something bogus back.
Until we can verify if that GCC bug is no longer an issue, or come up with
another solution, this commit does the minimal fix to make virt_addr_valid()
work, by explicitly checking that the address is in the linear mapping region.
Fixes: bdbc29c19b ("powerpc: Work around gcc miscompilation of __pa() on 64-bit")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Paul Mackerras <paulus@ozlabs.org>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Tested-by: Breno Leitao <breno.leitao@gmail.com>
The page table dump code doesn't know about huge pages, so currently
it crashes (or walks random memory, usually leading to a crash), if it
finds a huge page. On Book3S we only see huge pages in the Linux page
tables when we're using the P9 Radix MMU.
Teaching the code to properly handle huge pages is a bit more involved,
so for now just prevent the crash.
Cc: stable@vger.kernel.org # v4.10+
Fixes: 8eb07b1870 ("powerpc/mm: Dump linux pagetables")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Commit 22d8b3dec2 ("powerpc/kprobes: Emulate instructions on kprobe
handler re-entry") enabled emulating instructions on kprobe re-entry,
rather than single-stepping always. However, we didn't update the single
stepping code to only be run if the emulation fails. Also, we missed
re-enabling preemption if the instruction emulation was successful. Fix
those issues.
Fixes: 22d8b3dec2 ("powerpc/kprobes: Emulate instructions on kprobe handler re-entry")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Commit 17ed4c8f81 ("powerpc/powernv: Recover correct PACA on wakeup
from a stop on P9 DD1") promises to set the NAPSTATELOST bit in paca
after recovering the correct paca for the thread waking up from stop1
on DD1, so that the GPRs can be correctly restored on the stop exit
path. However, it loads the value 1 into r3, but stores the value in
r0 into NAPSTATELOST(r13).
Fix this by correctly set the NAPSTATELOST bit in paca after
recovering the paca on POWER9 DD1.
Fixes: 17ed4c8f81 ("powerpc/powernv: Recover correct PACA on wakeup from a stop on P9 DD1")
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Test that the VMX checkpointed register state is maintained when a VMX
unavailable exception is taken during a transaction.
Thanks to Breno Leitao <brenohl@br.ibm.com> and
Gustavo Bueno Romero <gromero@br.ibm.com> for the original test this
is based heavily on.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Reviewed-by: Cyril Bur <cyrilbur@gmail.com>
[mpe: Add to .gitignore, always build it 64-bit to fix build errors]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In commit dc3106690b ("powerpc: tm: Always use fp_state and vr_state
to store live registers"), a section of code was removed that copied
the current state to checkpointed state. That code should not have been
removed.
When an FP (Floating Point) unavailable is taken inside a transaction,
we need to abort the transaction. This is because at the time of the
tbegin, the FP state is bogus so the state stored in the checkpointed
registers is incorrect. To fix this, we treclaim (to get the
checkpointed GPRs) and then copy the thread_struct FP live state into
the checkpointed state. We then trecheckpoint so that the FP state is
correctly restored into the CPU.
The copying of the FP registers from live to checkpointed is what was
missing.
This simplifies the logic slightly from the original patch.
tm_reclaim_thread() will now always write the checkpointed FP
state. Either the checkpointed FP state will be written as part of
the actual treclaim (in tm.S), or it'll be a copy of the live
state. Which one we use is based on MSR[FP] from userspace.
Similarly for VMX.
Fixes: dc3106690b ("powerpc: tm: Always use fp_state and vr_state to store live registers")
Cc: stable@vger.kernel.org # 4.9+
Signed-off-by: Michael Neuling <mikey@neuling.org>
Reviewed-by: cyrilbur@gmail.com
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On powerpc we can build the kernel with two different ABIs for mcount(), which
is used by ftrace. Kernels built with one ABI do not know how to load modules
built with the other ABI. The new style ABI is called "mprofile-kernel", for
want of a better name.
Currently if we build a module using the old style ABI, and the kernel with
mprofile-kernel, when we load the module we'll oops something like:
# insmod autofs4-no-mprofile-kernel.ko
ftrace-powerpc: Unexpected instruction f8810028 around bl _mcount
------------[ cut here ]------------
WARNING: CPU: 6 PID: 3759 at ../kernel/trace/ftrace.c:2024 ftrace_bug+0x2b8/0x3c0
CPU: 6 PID: 3759 Comm: insmod Not tainted 4.11.0-rc3-gcc-5.4.1-00017-g5a61ef74f269 #11
...
NIP [c0000000001eaa48] ftrace_bug+0x2b8/0x3c0
LR [c0000000001eaff8] ftrace_process_locs+0x4a8/0x590
Call Trace:
alloc_pages_current+0xc4/0x1d0 (unreliable)
ftrace_process_locs+0x4a8/0x590
load_module+0x1c8c/0x28f0
SyS_finit_module+0x110/0x140
system_call+0x38/0xfc
...
ftrace failed to modify
[<d000000002a31024>] 0xd000000002a31024
actual: 35:65:00:48
We can avoid this by including in the vermagic whether the kernel/module was
built with mprofile-kernel. Which results in:
# insmod autofs4-pg.ko
autofs4: version magic
'4.11.0-rc3-gcc-5.4.1-00017-g5a61ef74f269 SMP mod_unload modversions '
should be
'4.11.0-rc3-gcc-5.4.1-00017-g5a61ef74f269-dirty SMP mod_unload modversions mprofile-kernel'
insmod: ERROR: could not insert module autofs4-pg.ko: Invalid module format
Fixes: 8c50b72a3b ("powerpc/ftrace: Add Kconfig & Make glue for mprofile-kernel")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Acked-by: Jessica Yu <jeyu@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Pull some more input subsystem updates from Dmitry Torokhov:
"An updated xpad driver with a few more recognized device IDs, and a
new psxpad-spi driver, allowing connecting Playstation 1 and 2 joypads
via SPI bus"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: cros_ec_keyb - remove extraneous 'const'
Input: add support for PlayStation 1/2 joypads connected via SPI
Input: xpad - add USB IDs for Mad Catz Brawlstick and Razer Sabertooth
Input: xpad - sync supported devices with xboxdrv
Input: xpad - sort supported devices by USB ID
Pull UML fixes from Richard Weinberger:
"No new stuff, just fixes"
* 'for-linus-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
um: Add missing NR_CPUS include
um: Fix to call read_initrd after init_bootmem
um: Include kbuild.h instead of duplicating its macros
um: Fix PTRACE_POKEUSER on x86_64
um: Set number of CPUs
um: Fix _print_addr()
Merge misc fixes from Andrew Morton:
"15 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
mm, docs: update memory.stat description with workingset* entries
mm: vmscan: scan until it finds eligible pages
mm, thp: copying user pages must schedule on collapse
dax: fix PMD data corruption when fault races with write
dax: fix data corruption when fault races with write
ext4: return to starting transaction in ext4_dax_huge_fault()
mm: fix data corruption due to stale mmap reads
dax: prevent invalidation of mapped DAX entries
Tigran has moved
mm, vmalloc: fix vmalloc users tracking properly
mm/khugepaged: add missed tracepoint for collapse_huge_page_swapin
gcov: support GCC 7.1
mm, vmstat: Remove spurious WARN() during zoneinfo print
time: delete current_fs_time()
hwpoison, memcg: forcibly uncharge LRU pages
Commit 4b4cea91691d ("mm: vmscan: fix IO/refault regression in cache
workingset transition") introduced three new entries in memory stat
file:
- workingset_refault
- workingset_activate
- workingset_nodereclaim
This commit adds a corresponding description to the cgroup v2 docs.
Link: http://lkml.kernel.org/r/1494530293-31236-1-git-send-email-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We have encountered need_resched warnings in __collapse_huge_page_copy()
while doing {clear,copy}_user_highpage() over HPAGE_PMD_NR source pages.
mm->mmap_sem is held for write, but the iteration is well bounded.
Reschedule as needed.
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1705101426380.109808@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is based on a patch from Jan Kara that fixed the equivalent race in
the DAX PTE fault path.
Currently DAX PMD read fault can race with write(2) in the following
way:
CPU1 - write(2) CPU2 - read fault
dax_iomap_pmd_fault()
->iomap_begin() - sees hole
dax_iomap_rw()
iomap_apply()
->iomap_begin - allocates blocks
dax_iomap_actor()
invalidate_inode_pages2_range()
- there's nothing to invalidate
grab_mapping_entry()
- we add huge zero page to the radix tree
and map it to page tables
The result is that hole page is mapped into page tables (and thus zeros
are seen in mmap) while file has data written in that place.
Fix the problem by locking exception entry before mapping blocks for the
fault. That way we are sure invalidate_inode_pages2_range() call for
racing write will either block on entry lock waiting for the fault to
finish (and unmap stale page tables after that) or read fault will see
already allocated blocks by write(2).
Fixes: 9f141d6ef6 ("dax: Call ->iomap_begin without entry lock during dax fault")
Link: http://lkml.kernel.org/r/20170510172700.18991-1-ross.zwisler@linux.intel.com
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently DAX read fault can race with write(2) in the following way:
CPU1 - write(2) CPU2 - read fault
dax_iomap_pte_fault()
->iomap_begin() - sees hole
dax_iomap_rw()
iomap_apply()
->iomap_begin - allocates blocks
dax_iomap_actor()
invalidate_inode_pages2_range()
- there's nothing to invalidate
grab_mapping_entry()
- we add zero page in the radix tree
and map it to page tables
The result is that hole page is mapped into page tables (and thus zeros
are seen in mmap) while file has data written in that place.
Fix the problem by locking exception entry before mapping blocks for the
fault. That way we are sure invalidate_inode_pages2_range() call for
racing write will either block on entry lock waiting for the fault to
finish (and unmap stale page tables after that) or read fault will see
already allocated blocks by write(2).
Fixes: 9f141d6ef6
Link: http://lkml.kernel.org/r/20170510085419.27601-5-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
DAX will return to locking exceptional entry before mapping blocks for a
page fault to fix possible races with concurrent writes. To avoid lock
inversion between exceptional entry lock and transaction start, start
the transaction already in ext4_dax_huge_fault().
Fixes: 9f141d6ef6
Link: http://lkml.kernel.org/r/20170510085419.27601-4-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, we didn't invalidate page tables during invalidate_inode_pages2()
for DAX. That could result in e.g. 2MiB zero page being mapped into
page tables while there were already underlying blocks allocated and
thus data seen through mmap were different from data seen by read(2).
The following sequence reproduces the problem:
- open an mmap over a 2MiB hole
- read from a 2MiB hole, faulting in a 2MiB zero page
- write to the hole with write(3p). The write succeeds but we
incorrectly leave the 2MiB zero page mapping intact.
- via the mmap, read the data that was just written. Since the zero
page mapping is still intact we read back zeroes instead of the new
data.
Fix the problem by unconditionally calling invalidate_inode_pages2_range()
in dax_iomap_actor() for new block allocations and by properly
invalidating page tables in invalidate_inode_pages2_range() for DAX
mappings.
Fixes: c6dcf52c23
Link: http://lkml.kernel.org/r/20170510085419.27601-3-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm,dax: Fix data corruption due to mmap inconsistency",
v4.
This series fixes data corruption that can happen for DAX mounts when
page faults race with write(2) and as a result page tables get out of
sync with block mappings in the filesystem and thus data seen through
mmap is different from data seen through read(2).
The series passes testing with t_mmap_stale test program from Ross and
also other mmap related tests on DAX filesystem.
This patch (of 4):
dax_invalidate_mapping_entry() currently removes DAX exceptional entries
only if they are clean and unlocked. This is done via:
invalidate_mapping_pages()
invalidate_exceptional_entry()
dax_invalidate_mapping_entry()
However, for page cache pages removed in invalidate_mapping_pages()
there is an additional criteria which is that the page must not be
mapped. This is noted in the comments above invalidate_mapping_pages()
and is checked in invalidate_inode_page().
For DAX entries this means that we can can end up in a situation where a
DAX exceptional entry, either a huge zero page or a regular DAX entry,
could end up mapped but without an associated radix tree entry. This is
inconsistent with the rest of the DAX code and with what happens in the
page cache case.
We aren't able to unmap the DAX exceptional entry because according to
its comments invalidate_mapping_pages() isn't allowed to block, and
unmap_mapping_range() takes a write lock on the mapping->i_mmap_rwsem.
Since we essentially never have unmapped DAX entries to evict from the
radix tree, just remove dax_invalidate_mapping_entry().
Fixes: c6dcf52c23 ("mm: Invalidate DAX radix tree entries only if appropriate")
Link: http://lkml.kernel.org/r/20170510085419.27601-2-jack@suse.cz
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Reported-by: Jan Kara <jack@suse.cz>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@vger.kernel.org> [4.10+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 1f5307b1e0 ("mm, vmalloc: properly track vmalloc users") has
pulled asm/pgtable.h include dependency to linux/vmalloc.h and that
turned out to be a bad idea for some architectures. E.g. m68k fails
with
In file included from arch/m68k/include/asm/pgtable_mm.h:145:0,
from arch/m68k/include/asm/pgtable.h:4,
from include/linux/vmalloc.h:9,
from arch/m68k/kernel/module.c:9:
arch/m68k/include/asm/mcf_pgtable.h: In function 'nocache_page':
>> arch/m68k/include/asm/mcf_pgtable.h:339:43: error: 'init_mm' undeclared (first use in this function)
#define pgd_offset_k(address) pgd_offset(&init_mm, address)
as spotted by kernel build bot. nios2 fails for other reason
In file included from include/asm-generic/io.h:767:0,
from arch/nios2/include/asm/io.h:61,
from include/linux/io.h:25,
from arch/nios2/include/asm/pgtable.h:18,
from include/linux/mm.h:70,
from include/linux/pid_namespace.h:6,
from include/linux/ptrace.h:9,
from arch/nios2/include/uapi/asm/elf.h:23,
from arch/nios2/include/asm/elf.h:22,
from include/linux/elf.h:4,
from include/linux/module.h:15,
from init/main.c:16:
include/linux/vmalloc.h: In function '__vmalloc_node_flags':
include/linux/vmalloc.h:99:40: error: 'PAGE_KERNEL' undeclared (first use in this function); did you mean 'GFP_KERNEL'?
which is due to the newly added #include <asm/pgtable.h>, which on nios2
includes <linux/io.h> and thus <asm/io.h> and <asm-generic/io.h> which
again includes <linux/vmalloc.h>.
Tweaking that around just turns out a bigger headache than necessary.
This patch reverts 1f5307b1e0 and reimplements the original fix in a
different way. __vmalloc_node_flags can stay static inline which will
cover vmalloc* functions. We only have one external user
(kvmalloc_node) and we can export __vmalloc_node_flags_caller and
provide the caller directly. This is much simpler and it doesn't really
need any games with header files.
[akpm@linux-foundation.org: coding-style fixes]
[mhocko@kernel.org: revert old comment]
Link: http://lkml.kernel.org/r/20170509211054.GB16325@dhcp22.suse.cz
Fixes: 1f5307b1e0 ("mm, vmalloc: properly track vmalloc users")
Link: http://lkml.kernel.org/r/20170509153702.GR6481@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: Tobias Klauser <tklauser@distanz.ch>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
One return case of `__collapse_huge_page_swapin()` does not invoke
tracepoint while every other return case does. This commit adds a
tracepoint invocation for the case.
Link: http://lkml.kernel.org/r/20170507101813.30187-1-sj38.park@gmail.com
Signed-off-by: SeongJae Park <sj38.park@gmail.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
