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2017-01-14Revert "driver core: Add deferred_probe attribute to devices in sysfs"Greg Kroah-Hartman4-34/+0
This reverts commit 6751667a29d6fd64afb9ce30567ad616b68ed789. Rob Herring objected to it, and a replacement for it will be added using debugfs in the future. Cc: Ben Hutchings <ben.hutchings@codethink.co.uk> Reported-by: Rob Herring <robh@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-14perf/x86: Reject non sampling events with precise_ipJiri Olsa1-0/+4
As Peter suggested [1] rejecting non sampling PEBS events, because they dont make any sense and could cause bugs in the NMI handler [2]. [1] http://lkml.kernel.org/r/20170103094059.GC3093@worktop [2] http://lkml.kernel.org/r/1482931866-6018-3-git-send-email-jolsa@kernel.org Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vince@deater.net> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/20170103142454.GA26251@krava Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14perf/x86/intel: Account interrupts for PEBS errorsJiri Olsa3-17/+37
It's possible to set up PEBS events to get only errors and not any data, like on SNB-X (model 45) and IVB-EP (model 62) via 2 perf commands running simultaneously: taskset -c 1 ./perf record -c 4 -e branches:pp -j any -C 10 This leads to a soft lock up, because the error path of the intel_pmu_drain_pebs_nhm() does not account event->hw.interrupt for error PEBS interrupts, so in case you're getting ONLY errors you don't have a way to stop the event when it's over the max_samples_per_tick limit: NMI watchdog: BUG: soft lockup - CPU#22 stuck for 22s! [perf_fuzzer:5816] ... RIP: 0010:[<ffffffff81159232>] [<ffffffff81159232>] smp_call_function_single+0xe2/0x140 ... Call Trace: ? trace_hardirqs_on_caller+0xf5/0x1b0 ? perf_cgroup_attach+0x70/0x70 perf_install_in_context+0x199/0x1b0 ? ctx_resched+0x90/0x90 SYSC_perf_event_open+0x641/0xf90 SyS_perf_event_open+0x9/0x10 do_syscall_64+0x6c/0x1f0 entry_SYSCALL64_slow_path+0x25/0x25 Add perf_event_account_interrupt() which does the interrupt and frequency checks and call it from intel_pmu_drain_pebs_nhm()'s error path. We keep the pending_kill and pending_wakeup logic only in the __perf_event_overflow() path, because they make sense only if there's any data to deliver. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vince@deater.net> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/1482931866-6018-2-git-send-email-jolsa@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14perf/core: Fix concurrent sys_perf_event_open() vs. 'move_group' racePeter Zijlstra1-4/+54
Di Shen reported a race between two concurrent sys_perf_event_open() calls where both try and move the same pre-existing software group into a hardware context. The problem is exactly that described in commit: f63a8daa5812 ("perf: Fix event->ctx locking") ... where, while we wait for a ctx->mutex acquisition, the event->ctx relation can have changed under us. That very same commit failed to recognise sys_perf_event_context() as an external access vector to the events and thereby didn't apply the established locking rules correctly. So while one sys_perf_event_open() call is stuck waiting on mutex_lock_double(), the other (which owns said locks) moves the group about. So by the time the former sys_perf_event_open() acquires the locks, the context we've acquired is stale (and possibly dead). Apply the established locking rules as per perf_event_ctx_lock_nested() to the mutex_lock_double() for the 'move_group' case. This obviously means we need to validate state after we acquire the locks. Reported-by: Di Shen (Keen Lab) Tested-by: John Dias <joaodias@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Min Chong <mchong@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Fixes: f63a8daa5812 ("perf: Fix event->ctx locking") Link: http://lkml.kernel.org/r/20170106131444.GZ3174@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14perf/core: Fix sys_perf_event_open() vs. hotplugPeter Zijlstra1-22/+48
There is problem with installing an event in a task that is 'stuck' on an offline CPU. Blocked tasks are not dis-assosciated from offlined CPUs, after all, a blocked task doesn't run and doesn't require a CPU etc.. Only on wakeup do we ammend the situation and place the task on a available CPU. If we hit such a task with perf_install_in_context() we'll loop until either that task wakes up or the CPU comes back online, if the task waking depends on the event being installed, we're stuck. While looking into this issue, I also spotted another problem, if we hit a task with perf_install_in_context() that is in the middle of being migrated, that is we observe the old CPU before sending the IPI, but run the IPI (on the old CPU) while the task is already running on the new CPU, things also go sideways. Rework things to rely on task_curr() -- outside of rq->lock -- which is rather tricky. Imagine the following scenario where we're trying to install the first event into our task 't': CPU0 CPU1 CPU2 (current == t) t->perf_event_ctxp[] = ctx; smp_mb(); cpu = task_cpu(t); switch(t, n); migrate(t, 2); switch(p, t); ctx = t->perf_event_ctxp[]; // must not be NULL smp_function_call(cpu, ..); generic_exec_single() func(); spin_lock(ctx->lock); if (task_curr(t)) // false add_event_to_ctx(); spin_unlock(ctx->lock); perf_event_context_sched_in(); spin_lock(ctx->lock); // sees event So its CPU0's store of t->perf_event_ctxp[] that must not go 'missing'. Because if CPU2's load of that variable were to observe NULL, it would not try to schedule the ctx and we'd have a task running without its counter, which would be 'bad'. As long as we observe !NULL, we'll acquire ctx->lock. If we acquire it first and not see the event yet, then CPU0 must observe task_curr() and retry. If the install happens first, then we must see the event on sched-in and all is well. I think we can translate the first part (until the 'must not be NULL') of the scenario to a litmus test like: C C-peterz { } P0(int *x, int *y) { int r1; WRITE_ONCE(*x, 1); smp_mb(); r1 = READ_ONCE(*y); } P1(int *y, int *z) { WRITE_ONCE(*y, 1); smp_store_release(z, 1); } P2(int *x, int *z) { int r1; int r2; r1 = smp_load_acquire(z); smp_mb(); r2 = READ_ONCE(*x); } exists (0:r1=0 /\ 2:r1=1 /\ 2:r2=0) Where: x is perf_event_ctxp[], y is our tasks's CPU, and z is our task being placed on the rq of CPU2. The P0 smp_mb() is the one added by this patch, ordering the store to perf_event_ctxp[] from find_get_context() and the load of task_cpu() in task_function_call(). The smp_store_release/smp_load_acquire model the RCpc locking of the rq->lock and the smp_mb() of P2 is the context switch switching from whatever CPU2 was running to our task 't'. This litmus test evaluates into: Test C-peterz Allowed States 7 0:r1=0; 2:r1=0; 2:r2=0; 0:r1=0; 2:r1=0; 2:r2=1; 0:r1=0; 2:r1=1; 2:r2=1; 0:r1=1; 2:r1=0; 2:r2=0; 0:r1=1; 2:r1=0; 2:r2=1; 0:r1=1; 2:r1=1; 2:r2=0; 0:r1=1; 2:r1=1; 2:r2=1; No Witnesses Positive: 0 Negative: 7 Condition exists (0:r1=0 /\ 2:r1=1 /\ 2:r2=0) Observation C-peterz Never 0 7 Hash=e427f41d9146b2a5445101d3e2fcaa34 And the strong and weak model agree. Reported-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Will Deacon <will.deacon@arm.com> Cc: jeremy.linton@arm.com Link: http://lkml.kernel.org/r/20161209135900.GU3174@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14x86/mpx: Use compatible types in comparison to fix sparse errorTobias Klauser1-1/+1
info->si_addr is of type void __user *, so it should be compared against something from the same address space. This fixes the following sparse error: arch/x86/mm/mpx.c:296:27: error: incompatible types in comparison expression (different address spaces) Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14x86/tsc: Add the Intel Denverton Processor to native_calibrate_tsc()Len Brown1-0/+1
The Intel Denverton microserver uses a 25 MHz TSC crystal, so we can derive its exact [*] TSC frequency using CPUID and some arithmetic, eg.: TSC: 1800 MHz (25000000 Hz * 216 / 3 / 1000000) [*] 'exact' is only as good as the crystal, which should be +/- 20ppm Signed-off-by: Len Brown <len.brown@intel.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/306899f94804aece6d8fa8b4223ede3b48dbb59c.1484287748.git.len.brown@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-13Merge branch 'for-linus-4.10' of ↵Linus Torvalds6-82/+117
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs fixes from Chris Mason: "These are all over the place. The tracepoint part of the pull fixes a crash and adds a little more information to two tracepoints, while the rest are good old fashioned fixes" * 'for-linus-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: btrfs: make tracepoint format strings more compact Btrfs: add truncated_len for ordered extent tracepoints Btrfs: add 'inode' for extent map tracepoint btrfs: fix crash when tracepoint arguments are freed by wq callbacks Btrfs: adjust outstanding_extents counter properly when dio write is split Btrfs: fix lockdep warning about log_mutex Btrfs: use down_read_nested to make lockdep silent btrfs: fix locking when we put back a delayed ref that's too new btrfs: fix error handling when run_delayed_extent_op fails btrfs: return the actual error value from from btrfs_uuid_tree_iterate
2017-01-13Merge tag 'ceph-for-4.10-rc4' of git://github.com/ceph/ceph-clientLinus Torvalds2-2/+7
Pull ceph fixes from Ilya Dryomov: "Two small fixups for the filesystem changes that went into this merge window" * tag 'ceph-for-4.10-rc4' of git://github.com/ceph/ceph-client: ceph: fix get_oldest_context() ceph: fix mds cluster availability check
2017-01-13Merge tag 'vfio-v4.10-rc4' of git://github.com/awilliam/linux-vfioLinus Torvalds3-10/+18
Pull VFIO fixes from Alex Williamson: - Cleanups and bug fixes for the mtty sample driver (Dan Carpenter) - Export and make use of has_capability() to fix incorrect use of ns_capable() for testing task capabilities (Jike Song) * tag 'vfio-v4.10-rc4' of git://github.com/awilliam/linux-vfio: vfio/type1: Remove pid_namespace.h include vfio iommu type1: fix the testing of capability for remote task capability: export has_capability vfio-mdev: remove some dead code vfio-mdev: buffer overflow in ioctl() vfio-mdev: return -EFAULT if copy_to_user() fails
2017-01-13Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds7-16/+80
Pull KVM fixes from Paolo Bonzini: - fix for module unload vs deferred jump labels (note: there might be other buggy modules!) - two NULL pointer dereferences from syzkaller - also syzkaller: fix emulation of fxsave/fxrstor/sgdt/sidt, problem made worse during this merge window, "just" kernel memory leak on releases - fix emulation of "mov ss" - somewhat serious on AMD, less so on Intel * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: x86: fix emulation of "MOV SS, null selector" KVM: x86: fix NULL deref in vcpu_scan_ioapic KVM: eventfd: fix NULL deref irqbypass consumer KVM: x86: Introduce segmented_write_std KVM: x86: flush pending lapic jump label updates on module unload jump_labels: API for flushing deferred jump label updates
2017-01-13Merge tag 'arm64-fixes' of ↵Linus Torvalds2-10/+28
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 fixes from Catalin Marinas: - Fix huge_ptep_set_access_flags() to return "changed" when any of the ptes in the contiguous range is changed, not just the last one - Fix the adr_l assembly macro to work in modules under KASLR * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: assembler: make adr_l work in modules under KASLR arm64: hugetlb: fix the wrong return value for huge_ptep_set_access_flags
2017-01-13block: don't try to discard from __blkdev_issue_zerooutChristoph Hellwig1-7/+6
Discard can return -EIO asynchronously if the alignment for the request isn't suitable for the driver, which makes a proper fallback to other methods in __blkdev_issue_zeroout impossible. Thus only issue a sync discard from blkdev_issue_zeroout an don't try discard at all from __blkdev_issue_zeroout as a non-invasive workaround. One more reason why abusing discard for zeroing must die.. Signed-off-by: Christoph Hellwig <hch@lst.de> Reported-by: Eryu Guan <eguan@redhat.com> Fixes: e73c23ff ("block: add async variant of blkdev_issue_zeroout") Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-13sd: remove __data_len hack for WRITE SAMEChristoph Hellwig1-16/+1
Now that we have the blk_rq_payload_bytes helper available to determine the actual I/O size we don't need to mess around with __data_len for WRITE SAME. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-13nvme: use blk_rq_payload_bytesChristoph Hellwig4-30/+15
The new blk_rq_payload_bytes generalizes the payload length hacks that nvme_map_len did before. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-13scsi: use blk_rq_payload_bytesChristoph Hellwig1-1/+1
Without that we'll pass a wrong payload size in cmd->sdb, which can lead to hangs with drivers that need the total transfer size. Signed-off-by: Christoph Hellwig <hch@lst.de> Reported-by: Chris Valean <v-chvale@microsoft.com> Reported-by: Dexuan Cui <decui@microsoft.com> Fixes: f9d03f96 ("block: improve handling of the magic discard payload") Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-13block: add blk_rq_payload_bytesChristoph Hellwig1-0/+13
Add a helper to calculate the actual data transfer size for special payload requests. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-13Merge tag 'scsi-fixes' of ↵Linus Torvalds7-6/+26
git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi Pull SCSI fixes from James Bottomley: "The major fix is the bfa firmware, since the latest 10Gb cards fail probing with the current firmware. The rest is a set of minor fixes: one missed Kconfig dependency causing randconfig failures, a missed error return on an error leg, a change for how multiqueue waits on a blocked device and a don't reset while in reset fix" * tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: scsi: bfa: Increase requested firmware version to 3.2.5.1 scsi: snic: Return error code on memory allocation failure scsi: fnic: Avoid sending reset to firmware when another reset is in progress scsi: qedi: fix build, depends on UIO scsi: scsi-mq: Wait for .queue_rq() if necessary
2017-01-13Merge branch 'for-linus' of ↵Linus Torvalds8-10/+20
git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input Pull input updates from Dmitry Torokhov: "Small driver fixups" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: Input: elants_i2c - avoid divide by 0 errors on bad touchscreen data Input: adxl34x - make it enumerable in ACPI environment Input: ALPS - fix TrackStick Y axis handling for SS5 hardware Input: synaptics-rmi4 - fix F03 build error when serio is module Input: xpad - use correct product id for x360w controllers Input: synaptics_i2c - change msleep to usleep_range for small msecs Input: i8042 - add Pegatron touchpad to noloop table Input: joydev - remove unused linux/miscdevice.h include
2017-01-13vfio/type1: Remove pid_namespace.h includeAlex Williamson1-1/+0
Using has_capability() rather than ns_capable(), we're no longer using this header. Cc: Jike Song <jike.song@intel.com> Cc: Kirti Wankhede <kwankhede@nvidia.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2017-01-13dmaengine: rcar-dmac: unmap slave resource when channel is freedNiklas Söderlund1-0/+8
The slave mapping should be removed together with other channel resources when the channel is freed. If it's not unmapped it will hang around forever after the channel is freed. Fixes: 9f878603dbdb7db3 ("dmaengine: rcar-dmac: add iommu support for slave transfers") Reported-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2017-01-12vfio iommu type1: fix the testing of capability for remote taskJike Song1-2/+1
Before the mdev enhancement type1 iommu used capable() to test the capability of current task; in the course of mdev development a new requirement, testing for another task other than current, was raised. ns_capable() was used for this purpose, however it still tests current, the only difference is, in a specified namespace. Fix it by using has_capability() instead, which tests the cap for specified task in init_user_ns, the same namespace as capable(). Cc: Gerd Hoffmann <kraxel@redhat.com> Signed-off-by: Jike Song <jike.song@intel.com> Reviewed-by: James Morris <james.l.morris@oracle.com> Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2017-01-12Merge tag 'sound-4.10-rc4' of ↵Linus Torvalds17-62/+151
git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound Pull sound fixes from Takashi Iwai: "This time we got a few more fixes than the previous rc's, and most of commits were about ASoC. The only significant change in the core side is the regression fix wrt the aux device list handling, and all the rest are driver-specific small / trivial fixes" * tag 'sound-4.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: ALSA: usb-audio: Add a quirk for Plantronics BT600 ASoC: rt5645: set sel_i2s_pre_div1 to 2 ASoC: dpcm: Avoid putting stream state to STOP when FE stream is paused ASoC: Intel: Skylake: Release FW ctx in cleanup ASoC: Intel: bytcr-rt5640: fix settings in internal clock mode ASoC: fsl_ssi: set fifo watermark to more reliable value ASoC: nau8825: fix invalid configuration in Pre-Scalar of FLL ASoC: nau8825: correct the function name of register ASoC: Intel: Skylake: Fix to fail safely if module not available in path ASoC: tlv320aic3x: Mark the RESET register as volatile ASoC: Fix binding and probing of auxiliary components ASoC: wm_adsp: Don't overrun firmware file buffer when reading region data ASoC: Intel: bytcr_rt5640: fallback mechanism if MCLK is not enabled ASoC: hdmi-codec: use unsigned type to structure members with bit-field ASoC: topology: kfree kcontrol->private_value before freeing kcontrol ASoC: rsnd: don't double free kctrl ASoC: dwc: Fix PIO mode initialization
2017-01-12i2c: piix4: Avoid race conditions with IMCRicardo Ribalda1-0/+22
On AMD's SB800 and upwards, the SMBus is shared with the Integrated Micro Controller (IMC). The platform provides a hardware semaphore to avoid race conditions among them. (Check page 288 of the SB800-Series Southbridges Register Reference Guide http://support.amd.com/TechDocs/45482.pdf) Without this patch, many access to the SMBus end with an invalid transaction or even with the bus stalled. Reported-by: Alexandre Desnoyers <alex@qtec.com> Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>: Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-01-12i2c: fix spelling mistake: "insufficent" -> "insufficient"Colin Ian King1-1/+1
Trivial fix to spelling mistake in WARN message, insufficient has an insufficient number of i's in the spelling. Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-01-12Merge tag 'xfs-for-linus-4.10-rc4-1' of ↵Linus Torvalds6-111/+43
git://git.kernel.org/pub/scm/fs/xfs/xfs-linux Pull xfs fixes from Darrick Wong: "As promised last week, here's some stability fixes from Christoph and Jan Kara: - fix free space request handling when low on disk space - remove redundant log failure error messages - free truncated dirty pages instead of letting them build up forever" * tag 'xfs-for-linus-4.10-rc4-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: xfs: Timely free truncated dirty pages xfs: don't print warnings when xfs_log_force fails xfs: don't rely on ->total in xfs_alloc_space_available xfs: adjust allocation length in xfs_alloc_space_available xfs: fix bogus minleft manipulations xfs: bump up reserved blocks in xfs_alloc_set_aside
2017-01-12i2c: print correct device invalid addressJohn Garry1-1/+1
In of_i2c_register_device(), when the check for device address validity fails we print the info.addr, which has not been assigned properly. Fix this by printing the actual invalid address. Signed-off-by: John Garry <john.garry@huawei.com> Reviewed-by: Vladimir Zapolskiy <vz@mleia.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Fixes: b4e2f6ac1281 ("i2c: apply DT flags when probing") Cc: stable@kernel.org
2017-01-12i2c: do not enable fall back to Host Notify by defaultDmitry Torokhov3-9/+17
Falling back unconditionally to HostNotify as primary client's interrupt breaks some drivers which alter their functionality depending on whether interrupt is present or not, so let's introduce a board flag telling I2C core explicitly if we want wired interrupt or HostNotify-based one: I2C_CLIENT_HOST_NOTIFY. For DT-based systems we introduce "host-notify" property that we convert to I2C_CLIENT_HOST_NOTIFY board flag. Tested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Acked-by: Pali Rohár <pali.rohar@gmail.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-01-12i2c: fix kernel memory disclosure in dev interfaceVlad Tsyrklevich1-1/+1
i2c_smbus_xfer() does not always fill an entire block, allowing kernel stack memory disclosure through the temp variable. Clear it before it's read to. Signed-off-by: Vlad Tsyrklevich <vlad@tsyrklevich.net> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Cc: stable@kernel.org
2017-01-12Merge tag 'rproc-v4.10-fixes' of git://github.com/andersson/remoteprocLinus Torvalds2-14/+19
Pull remoteproc fixes from Bjorn Andersson: "This fixes two regressions that have been reported to be introduced in v4.10-rc1. - correct an incorrect usage of the kref api - revert the change to make the resource table read-only. As the space each vdev resource is used as virtio device config space it must be shared with the remote" * tag 'rproc-v4.10-fixes' of git://github.com/andersson/remoteproc: Revert "remoteproc: Merge table_ptr and cached_table pointers" remoteproc: fix vdev reference management
2017-01-12Merge tag 'rpmsg-v4.10-fixes' of git://github.com/andersson/remoteprocLinus Torvalds1-2/+2
Pull rpmsg fixes from Bjorn Andersson: "This fixes a regression introduced in v4.10-rc1 that prohibits multiple channels with the same name but different endpoint addresses to be used" * tag 'rpmsg-v4.10-fixes' of git://github.com/andersson/remoteproc: rpmsg: virtio_rpmsg_bus: fix channel creation
2017-01-12Merge branch 'for-linus' of ↵Linus Torvalds4-0/+16
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid Pull HID fixes from Jiri Kosina: - device descriptor length validation fix to hid-cypress driver from Greg - introduction of a short delay into i2c-hid, which is not really mandated by the spec, but fixes Asus Touchpads - Petzl USB connectable flashlight quirk from myself * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid: HID: i2c-hid: Add sleep between POWER ON and RESET HID: hid-cypress: validate length of report HID: ignore Petzl USB headlamp
2017-01-12Merge branch 'scsi-target-for-v4.10' of ↵Linus Torvalds5-52/+142
git://git.kernel.org/pub/scm/linux/kernel/git/bvanassche/linux Pull scsi target fixes from Bart Van Assche: - a series of bug fixes for the XCOPY implementation from David Disseldorp - one bug fix for the ibmvscsis driver, a driver that is used for communication between partitions on IBM POWER systems. * 'scsi-target-for-v4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/bvanassche/linux: ibmvscsis: Fix srp_transfer_data fail return code target: support XCOPY requests without parameters target: check for XCOPY parameter truncation target: use XCOPY segment descriptor CSCD IDs target: check XCOPY segment descriptor CSCD IDs target: simplify XCOPY wwn->se_dev lookup helper target: return UNSUPPORTED TARGET/SEGMENT DESC TYPE CODE sense target: bounds check XCOPY total descriptor list length target: bounds check XCOPY segment descriptor list target: use XCOPY TOO MANY TARGET DESCRIPTORS sense target: add XCOPY target/segment desc sense codes
2017-01-12ceph: fix get_oldest_context()Geng, Jichao1-2/+2
For no snapshot case, we should use ci->truncate_{seq,size}. Fixes: 5f743e456606 ("ceph: record truncate size/seq for snap data writeback") Signed-off-by: Geng, Jichao <geng.jichao@h3c.com> Signed-off-by: Yan, Zheng <zyan@redhat.com>
2017-01-12ceph: fix mds cluster availability checkYan, Zheng1-0/+5
We should apply the check after getting the initial mdsmap. Fixes: e9e427f0a14f ("ceph: check availability of mds cluster on mount") Link: http://tracker.ceph.com/issues/18161 Signed-off-by: Yan, Zheng <zyan@redhat.com>
2017-01-12Merge tag 'md/4.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/mdLinus Torvalds6-261/+322
Pull md fixes from Shaohua Li: "Basically one fix for raid5 cache which is merged in this cycle, others are trival fixes" * tag 'md/4.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md: md/raid5: Use correct IS_ERR() variation on pointer check md: cleanup mddev flag clear for takeover md/r5cache: fix spelling mistake on "recoverying" md/r5cache: assign conf->log before r5l_load_log() md/r5cache: simplify handling of sh->log_start in recovery md/raid5-cache: removes unnecessary write-through mode judgments md/raid10: Refactor raid10_make_request md/raid1: Refactor raid1_make_request
2017-01-12arm64: assembler: make adr_l work in modules under KASLRArd Biesheuvel1-9/+27
When CONFIG_RANDOMIZE_MODULE_REGION_FULL=y, the offset between loaded modules and the core kernel may exceed 4 GB, putting symbols exported by the core kernel out of the reach of the ordinary adrp/add instruction pairs used to generate relative symbol references. So make the adr_l macro emit a movz/movk sequence instead when executing in module context. While at it, remove the pointless special case for the stack pointer. Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-01-12Merge tag 'usb-serial-4.10-rc4' of ↵Greg Kroah-Hartman2-39/+78
git://git.kernel.org/pub/scm/linux/kernel/git/johan/usb-serial into usb-linus Johan writes: USB-serial fixes for v4.10-rc4 These fixes address a number of issues in the ch341 driver and includes a partial revert of a change in how we set the line settings that went into 4.10-rc1 but which turned out to have undesired side effects. This included deasserting the modem-control lines when configuring the device, but also prevented a certain class of CH340 devices from working with the driver. Included are also two fixes for two minor information leaks in kl5kusb105 and ch341 due to failures to detect short control transfers. Signed-off-by: Johan Hovold <johan@kernel.org>
2017-01-12block: Rename blk_queue_zone_size and bdev_zone_sizeDamien Le Moal5-17/+17
All block device data fields and functions returning a number of 512B sectors are by convention named xxx_sectors while names in the form xxx_size are generally used for a number of bytes. The blk_queue_zone_size and bdev_zone_size functions were not following this convention so rename them. No functional change is introduced by this patch. Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Collapsed the two patches, they were nonsensically split and broke bisection. Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-12KVM: x86: fix emulation of "MOV SS, null selector"Paolo Bonzini1-10/+38
This is CVE-2017-2583. On Intel this causes a failed vmentry because SS's type is neither 3 nor 7 (even though the manual says this check is only done for usable SS, and the dmesg splat says that SS is unusable!). On AMD it's worse: svm.c is confused and sets CPL to 0 in the vmcb. The fix fabricates a data segment descriptor when SS is set to a null selector, so that CPL and SS.DPL are set correctly in the VMCS/vmcb. Furthermore, only allow setting SS to a NULL selector if SS.RPL < 3; this in turn ensures CPL < 3 because RPL must be equal to CPL. Thanks to Andy Lutomirski and Willy Tarreau for help in analyzing the bug and deciphering the manuals. Reported-by: Xiaohan Zhang <zhangxiaohan1@huawei.com> Fixes: 79d5b4c3cd809c770d4bf9812635647016c56011 Cc: stable@nongnu.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-01-12capability: export has_capabilityJike Song1-0/+1
has_capability() is sometimes needed by modules to test capability for specified task other than current, so export it. Cc: Kirti Wankhede <kwankhede@nvidia.com> Signed-off-by: Jike Song <jike.song@intel.com> Acked-by: Serge Hallyn <serge@hallyn.com> Acked-by: James Morris <james.l.morris@oracle.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2017-01-12KVM: x86: fix NULL deref in vcpu_scan_ioapicWanpeng Li1-0/+2
Reported by syzkaller: BUG: unable to handle kernel NULL pointer dereference at 00000000000001b0 IP: _raw_spin_lock+0xc/0x30 PGD 3e28eb067 PUD 3f0ac6067 PMD 0 Oops: 0002 [#1] SMP CPU: 0 PID: 2431 Comm: test Tainted: G OE 4.10.0-rc1+ #3 Call Trace: ? kvm_ioapic_scan_entry+0x3e/0x110 [kvm] kvm_arch_vcpu_ioctl_run+0x10a8/0x15f0 [kvm] ? pick_next_task_fair+0xe1/0x4e0 ? kvm_arch_vcpu_load+0xea/0x260 [kvm] kvm_vcpu_ioctl+0x33a/0x600 [kvm] ? hrtimer_try_to_cancel+0x29/0x130 ? do_nanosleep+0x97/0xf0 do_vfs_ioctl+0xa1/0x5d0 ? __hrtimer_init+0x90/0x90 ? do_nanosleep+0x5b/0xf0 SyS_ioctl+0x79/0x90 do_syscall_64+0x6e/0x180 entry_SYSCALL64_slow_path+0x25/0x25 RIP: _raw_spin_lock+0xc/0x30 RSP: ffffa43688973cc0 The syzkaller folks reported a NULL pointer dereference due to ENABLE_CAP succeeding even without an irqchip. The Hyper-V synthetic interrupt controller is activated, resulting in a wrong request to rescan the ioapic and a NULL pointer dereference. #include <sys/ioctl.h> #include <sys/mman.h> #include <sys/types.h> #include <linux/kvm.h> #include <pthread.h> #include <stddef.h> #include <stdint.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #ifndef KVM_CAP_HYPERV_SYNIC #define KVM_CAP_HYPERV_SYNIC 123 #endif void* thr(void* arg) { struct kvm_enable_cap cap; cap.flags = 0; cap.cap = KVM_CAP_HYPERV_SYNIC; ioctl((long)arg, KVM_ENABLE_CAP, &cap); return 0; } int main() { void *host_mem = mmap(0, 0x1000, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); int kvmfd = open("/dev/kvm", 0); int vmfd = ioctl(kvmfd, KVM_CREATE_VM, 0); struct kvm_userspace_memory_region memreg; memreg.slot = 0; memreg.flags = 0; memreg.guest_phys_addr = 0; memreg.memory_size = 0x1000; memreg.userspace_addr = (unsigned long)host_mem; host_mem[0] = 0xf4; ioctl(vmfd, KVM_SET_USER_MEMORY_REGION, &memreg); int cpufd = ioctl(vmfd, KVM_CREATE_VCPU, 0); struct kvm_sregs sregs; ioctl(cpufd, KVM_GET_SREGS, &sregs); sregs.cr0 = 0; sregs.cr4 = 0; sregs.efer = 0; sregs.cs.selector = 0; sregs.cs.base = 0; ioctl(cpufd, KVM_SET_SREGS, &sregs); struct kvm_regs regs = { .rflags = 2 }; ioctl(cpufd, KVM_SET_REGS, &regs); ioctl(vmfd, KVM_CREATE_IRQCHIP, 0); pthread_t th; pthread_create(&th, 0, thr, (void*)(long)cpufd); usleep(rand() % 10000); ioctl(cpufd, KVM_RUN, 0); pthread_join(th, 0); return 0; } This patch fixes it by failing ENABLE_CAP if without an irqchip. Reported-by: Dmitry Vyukov <dvyukov@google.com> Fixes: 5c919412fe61 (kvm/x86: Hyper-V synthetic interrupt controller) Cc: stable@vger.kernel.org # 4.5+ Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-01-12KVM: eventfd: fix NULL deref irqbypass consumerWanpeng Li1-2/+2
Reported syzkaller: BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 IP: irq_bypass_unregister_consumer+0x9d/0xb70 [irqbypass] PGD 0 Oops: 0002 [#1] SMP CPU: 1 PID: 125 Comm: kworker/1:1 Not tainted 4.9.0+ #1 Workqueue: kvm-irqfd-cleanup irqfd_shutdown [kvm] task: ffff9bbe0dfbb900 task.stack: ffffb61802014000 RIP: 0010:irq_bypass_unregister_consumer+0x9d/0xb70 [irqbypass] Call Trace: irqfd_shutdown+0x66/0xa0 [kvm] process_one_work+0x16b/0x480 worker_thread+0x4b/0x500 kthread+0x101/0x140 ? process_one_work+0x480/0x480 ? kthread_create_on_node+0x60/0x60 ret_from_fork+0x25/0x30 RIP: irq_bypass_unregister_consumer+0x9d/0xb70 [irqbypass] RSP: ffffb61802017e20 CR2: 0000000000000008 The syzkaller folks reported a NULL pointer dereference that due to unregister an consumer which fails registration before. The syzkaller creates two VMs w/ an equal eventfd occasionally. So the second VM fails to register an irqbypass consumer. It will make irqfd as inactive and queue an workqueue work to shutdown irqfd and unregister the irqbypass consumer when eventfd is closed. However, the second consumer has been initialized though it fails registration. So the token(same as the first VM's) is taken to unregister the consumer through the workqueue, the consumer of the first VM is found and unregistered, then NULL deref incurred in the path of deleting consumer from the consumers list. This patch fixes it by making irq_bypass_register/unregister_consumer() looks for the consumer entry based on consumer pointer itself instead of token matching. Reported-by: Dmitry Vyukov <dvyukov@google.com> Suggested-by: Alex Williamson <alex.williamson@redhat.com> Cc: stable@vger.kernel.org Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-01-12KVM: x86: Introduce segmented_write_stdSteve Rutherford1-4/+18
Introduces segemented_write_std. Switches from emulated reads/writes to standard read/writes in fxsave, fxrstor, sgdt, and sidt. This fixes CVE-2017-2584, a longstanding kernel memory leak. Since commit 283c95d0e389 ("KVM: x86: emulate FXSAVE and FXRSTOR", 2016-11-09), which is luckily not yet in any final release, this would also be an exploitable kernel memory *write*! Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: stable@vger.kernel.org Fixes: 96051572c819194c37a8367624b285be10297eca Fixes: 283c95d0e3891b64087706b344a4b545d04a6e62 Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Steve Rutherford <srutherford@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-01-12KVM: x86: flush pending lapic jump label updates on module unloadDavid Matlack3-0/+8
KVM's lapic emulation uses static_key_deferred (apic_{hw,sw}_disabled). These are implemented with delayed_work structs which can still be pending when the KVM module is unloaded. We've seen this cause kernel panics when the kvm_intel module is quickly reloaded. Use the new static_key_deferred_flush() API to flush pending updates on module unload. Signed-off-by: David Matlack <dmatlack@google.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-01-12jump_labels: API for flushing deferred jump label updatesDavid Matlack2-0/+12
Modules that use static_key_deferred need a way to synchronize with any delayed work that is still pending when the module is unloaded. Introduce static_key_deferred_flush() which flushes any pending jump label updates. Signed-off-by: David Matlack <dmatlack@google.com> Cc: stable@vger.kernel.org Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-01-12x86/entry: Fix the end of the stack for newly forked tasksJosh Poimboeuf2-23/+18
When unwinding a task, the end of the stack is always at the same offset right below the saved pt_regs, regardless of which syscall was used to enter the kernel. That convention allows the unwinder to verify that a stack is sane. However, newly forked tasks don't always follow that convention, as reported by the following unwinder warning seen by Dave Jones: WARNING: kernel stack frame pointer at ffffc90001443f30 in kworker/u8:8:30468 has bad value (null) The warning was due to the following call chain: (ftrace handler) call_usermodehelper_exec_async+0x5/0x140 ret_from_fork+0x22/0x30 The problem is that ret_from_fork() doesn't create a stack frame before calling other functions. Fix that by carefully using the frame pointer macros. In addition to conforming to the end of stack convention, this also makes related stack traces more sensible by making it clear to the user that ret_from_fork() was involved. Reported-by: Dave Jones <davej@codemonkey.org.uk> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> 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: Dmitry Vyukov <dvyukov@google.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/8854cdaab980e9700a81e9ebf0d4238e4bbb68ef.1483978430.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-12x86/unwind: Include __schedule() in stack tracesJosh Poimboeuf2-5/+10
In the following commit: 0100301bfdf5 ("sched/x86: Rewrite the switch_to() code") ... the layout of the 'inactive_task_frame' struct was designed to have a frame pointer header embedded in it, so that the unwinder could use the 'bp' and 'ret_addr' fields to report __schedule() on the stack (or ret_from_fork() for newly forked tasks which haven't actually run yet). Finish the job by changing get_frame_pointer() to return a pointer to inactive_task_frame's 'bp' field rather than 'bp' itself. This allows the unwinder to start one frame higher on the stack, so that it properly reports __schedule(). Reported-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Jones <davej@codemonkey.org.uk> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: H. Peter Anvin <hpa@zytor.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/598e9f7505ed0aba86e8b9590aa528c6c7ae8dcd.1483978430.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-12x86/unwind: Disable KASAN checks for non-current tasksJosh Poimboeuf2-3/+22
There are a handful of callers to save_stack_trace_tsk() and show_stack() which try to unwind the stack of a task other than current. In such cases, it's remotely possible that the task is running on one CPU while the unwinder is reading its stack from another CPU, causing the unwinder to see stack corruption. These cases seem to be mostly harmless. The unwinder has checks which prevent it from following bad pointers beyond the bounds of the stack. So it's not really a bug as long as the caller understands that unwinding another task will not always succeed. In such cases, it's possible that the unwinder may read a KASAN-poisoned region of the stack. Account for that by using READ_ONCE_NOCHECK() when reading the stack of another task. Use READ_ONCE() when reading the stack of the current task, since KASAN warnings can still be useful for finding bugs in that case. Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Jones <davej@codemonkey.org.uk> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/4c575eb288ba9f73d498dfe0acde2f58674598f1.1483978430.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-12x86/unwind: Silence warnings for non-current tasksJosh Poimboeuf1-0/+10
There are a handful of callers to save_stack_trace_tsk() and show_stack() which try to unwind the stack of a task other than current. In such cases, it's remotely possible that the task is running on one CPU while the unwinder is reading its stack from another CPU, causing the unwinder to see stack corruption. These cases seem to be mostly harmless. The unwinder has checks which prevent it from following bad pointers beyond the bounds of the stack. So it's not really a bug as long as the caller understands that unwinding another task will not always succeed. Since stack "corruption" on another task's stack isn't necessarily a bug, silence the warnings when unwinding tasks other than current. Reported-by: Dave Jones <davej@codemonkey.org.uk> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> 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: Dmitry Vyukov <dvyukov@google.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Miroslav Benes <mbenes@suse.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/00d8c50eea3446c1524a2a755397a3966629354c.1483978430.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>