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  1. 05 8月, 2017 10 次提交
    • L
      Merge tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc · 65f4740e
      由 Linus Torvalds 提交于 
      Pull ARM SoC fixes from Arnd Bergmann:
 "This comes a bit later than I planned, and as a consequence is a
  larger than it should be.

  Most of the changes are devicetree fixes, across lots of platforms:
  Renesas, Samsung Exynos, Marvell EBU, TI OMAP, Rockchips, Amlogic
  Meson, Sigma Desings Tango, Allwinner SUNxi and TI Davinci.

  Also across many platforms, I applied an older series of simple
  randconfig build fixes. This includes making the CONFIG_MTD_XIP option
  compile again, which had been broken for many years and probably has
  not been missed, but it felt wrong to just remove it completely.

  The only other changes are:

   - We enable HWSPINLOCK in defconfig to get some Qualcomm boards to
     work out of the box.

   - A few regression fixes for Texas Instruments OMAP2+.

   - A boot regression fix for the Renesas regulator quirk.

   - A suspend/resume fix for Uniphier SoCs, fixing the resume of the
     system bus"

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (43 commits)
  ARM: dts: tango4: Request RGMII RX and TX clock delays
  bus: uniphier-system-bus: set up registers when resuming
  ARM64: dts: marvell: armada-37xx: Fix the number of GPIO on south bridge
  ARM: shmobile: rcar-gen2: Fix deadlock in regulator quirk
  arm64: defconfig: enable missing HWSPINLOCK
  ARM: pxa: select both FB and FB_W100 for eseries
  ARM: ixp4xx: fix ioport_unmap definition
  ARM: ep93xx: use ARM_PATCH_PHYS_VIRT correctly
  ARM: mmp: mark usb_dma_mask as __maybe_unused
  ARM: omap2: mark unused functions as __maybe_unused
  ARM: omap1: avoid unused variable warning
  ARM: sirf: mark sirfsoc_init_late as __maybe_unused
  ARM: ixp4xx: use normal prototype for {read,write}s{b,w,l}
  ARM: omap1/ams-delta: warn about failed regulator enable
  ARM: rpc: rename RAM_SIZE macro
  ARM: w90x900: normalize clk API
  ARM: ep93xx: normalize clk API
  ARM: dts: sun8i: a83t: Switch to CCU device tree binding macros
  arm64: allwinner: sun50i-a64: Correct emac register size
  ARM: dts: sunxi: h3/h5: Correct emac register size
  ...
      65f4740e
    • L
      Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux · b3c6858f
      由 Linus Torvalds 提交于 
      Pull arm64 fixes from Will Deacon:
 "Here are some more arm64 fixes for 4.13. The main one is the PTE race
  with the hardware walker, but there are a couple of other things too.

   - Report correct timer frequency to userspace when trapping
     CNTFRQ_EL0

   - Fix race with hardware page table updates when updating access
     flags

   - Silence clang overflow warning in VA_START and PAGE_OFFSET
     calculations"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: avoid overflow in VA_START and PAGE_OFFSET
  arm64: Fix potential race with hardware DBM in ptep_set_access_flags()
  arm64: Use arch_timer_get_rate when trapping CNTFRQ_EL0
      b3c6858f
    • L
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc · 0a23ea65
      由 Linus Torvalds 提交于 
      Pull sparc fixes from David Miller:

 - block interrupts properly across the entire MMU context change (both
   the hw MMU context change and the TSB table change) so that we don't
   get a perf event interrupt in the middle. From Rob Gardner.

 - be sure to register hugepages early enough, from Nitin Gupta.

 - UltraSPARC-III user copy exception handling would return garbage for
   the copied length in some circumstances.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc64: Fix exception handling in UltraSPARC-III memcpy.
  sbus: Convert to using %pOF instead of full_name
  sparc: defconfig: Cleanup from old Kconfig options
  sparc64: Register hugepages during arch init
  sparc64: Prevent perf from running during super critical sections
      0a23ea65
    • L
      Merge tag 'ceph-for-4.13-rc4' of git://github.com/ceph/ceph-client · c63716ab
      由 Linus Torvalds 提交于 
      Pull ceph fixes from Ilya Dryomov:
 "A bunch of fixes and follow-ups for -rc1 Luminous patches: issues with
  ->reencode_message() and last minute RADOS semantic changes in
  v12.1.2"

* tag 'ceph-for-4.13-rc4' of git://github.com/ceph/ceph-client:
  libceph: make RECOVERY_DELETES feature create a new interval
  libceph: upmap semantic changes
  crush: assume weight_set != null imples weight_set_size > 0
  libceph: fallback for when there isn't a pool-specific choose_arg
  libceph: don't call ->reencode_message() more than once per message
  libceph: make encode_request_*() work with r_mempool requests
      c63716ab
    • L
      Merge tag 'sound-4.13-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound · a64c40e7
      由 Linus Torvalds 提交于 
      Pull sound fixes from Takashi Iwai:
 "Now we hit the usual ASoC-fix-flood in the middle of release.

  Most of the changes are trivial and device-specific, while one
  significant change is the fix for unbalanced of_graph_*() refcounts.
  This involved a change in the graph API itself that had been a bit
  messy"

* tag 'sound-4.13-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda - Fix speaker output from VAIO VPCL14M1R
  device property: Fix usecount for of_graph_get_port_parent()
  ASoC: rt5665: fix wrong register for bclk ratio control
  ASoC: Intel: Use MCLK instead of BLCK as the sysclock for RT5514 codec on kabylake platform
  ASoC: Intel: Enabling ASRC for RT5663 codec on kabylake platform
  ASoC: codecs: msm8916-analog: fix DIG_CLK_CTL_RXD3_CLK_EN define
  ASoC: Intel: Skylake: Fix missing sentinels in sst_acpi_mach
  ASoC: sh: hac: add missing "int ret"
  ASoC: samsung: odroid: Fix EPLL frequency values
  ASoC: sgtl5000: Use snd_soc_kcontrol_codec()
  ASoC: rt5665: fix GPIO6 pin function define
  ASoC: ux500: Restore platform DAI assignments
  ASoC: fix pcm-creation regression
  ASoC: do not close shared backend dailink
  ASoC: pxa: SND_PXA2XX_SOC should depend on HAS_DMA
  ASoC: Intel: Skylake: Fix default dma_buffer_size
  ASoC: rt5663: Update the HW default values based on the shipping version
  ASoC: imx-ssi: add check on platform_get_irq return value
      a64c40e7
    • L
      Merge tag 'iommu-fixes-v4.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu · 83b89ea4
      由 Linus Torvalds 提交于 
      Pull IOMMU fixes from Joerg Roedel:

 - fix a scheduling-while-atomic bug in the AMD IOMMU driver. It was
   found after the checker was enabled earlier.

 - a fix for the virtual APIC code in the AMD IOMMU driver which
   delivers device interrupts directly into KVM guests for assigned
   devices.

 - fixes for the recently merged lock-less page-table code for ARM. The
   redundant TLB syncs got reverted and locks added again around the TLB
   sync code.

 - fix for error handling in arm_smmu_add_device()

 - address sanitization fix for arm io-pgtable code

* tag 'iommu-fixes-v4.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/amd: Fix schedule-while-atomic BUG in initialization code
  iommu/amd: Enable ga_log_intr when enabling guest_mode
  iommu/io-pgtable: Sanitise map/unmap addresses
  iommu/arm-smmu: Fix the error path in arm_smmu_add_device
  Revert "iommu/io-pgtable: Avoid redundant TLB syncs"
  iommu/mtk: Avoid redundant TLB syncs locally
  iommu/arm-smmu: Reintroduce locking around TLB sync operations
      83b89ea4
    • L
      Merge tag 'mmc-v4.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc · 8145f373
      由 Linus Torvalds 提交于 
      Pull MMC fixes from Ulf Hansson:
 "A couple of mmc fixes intended for v4.13-rc4.

  MMC core:
   - Fix NULL pointer dereference for block I/O during hotplug

  MMC host:
   - sdhci-of-at91: Fix card detect for non-removable cards"

* tag 'mmc-v4.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc:
  mmc: block: bypass the queue even if usage is present for hotplug
  mmc: sdhci-of-at91: force card detect value for non removable devices
      8145f373
    • L
      Merge tag 'drm-fixes-for-v4.13-rc4' of git://people.freedesktop.org/~airlied/linux · 47d47585
      由 Linus Torvalds 提交于 
      Pull drm fixes from Dave Airlie:
 "Either my email ate everything or everyone is on holidays, either way
  all I can find is some lonely AMD fixes"

[ Europe might be on vacation, and the Pacific NW is too hot for work. ]

* tag 'drm-fixes-for-v4.13-rc4' of git://people.freedesktop.org/~airlied/linux:
  drm/amdgpu: Use list_del_init in amdgpu_mn_unregister
  drm/amdgpu: Fix undue fallthroughs in golden registers initialization
  drm/amdgpu: fix header on gfx9 clear state
      47d47585
    • L
      Merge tag 'powerpc-4.13-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux · 841fe953
      由 Linus Torvalds 提交于 
      Pull powerpc fixes from Michael Ellerman:
 "Fixes for recently merged code:
   - a fix for the _PAGE_DEVMAP support, which was breaking KVM on
     Power9 radix
   - avoid a (harmless) lockdep warning in the early SMP code
   - return failure for some uses of dma_set_mask() rather than falling
     back to 32-bits
   - fix stack setup in watchdog soft_nmi_common() to use emergency
     stack
   - fix of_irq_to_resource() error check in of_fsl_spi_probe()

  Two fixes going to stable:
   - fix saving of Transactional Memory SPRs in core dump
   - fix __check_irq_replay missing decrementer interrupt

  And two misc:
   - fix 64-bit boot wrapper build with non-biarch compiler
   - work around a POWER9 PMU hang after state-loss idle

  Thanks to: Alistair Popple, Aneesh Kumar K.V, Cyril Bur, Gustavo
  Romero, Jose Ricardo Ziviani, Laurent Vivier, Nicholas Piggin, Oliver
  O'Halloran, Sergei Shtylyov, Suraj Jitindar Singh, Thomas Gleixner"

* tag 'powerpc-4.13-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64: Fix __check_irq_replay missing decrementer interrupt
  powerpc/perf: POWER9 PMU stops after idle workaround
  powerpc/83xx/mpc832x_rdb: fix of_irq_to_resource() error check
  powerpc/64s: Fix stack setup in watchdog soft_nmi_common()
  powerpc/powernv/pci: Return failure for some uses of dma_set_mask()
  powerpc/boot: Fix 64-bit boot wrapper build with non-biarch compiler
  powerpc/smp: Call smp_ops->setup_cpu() directly on the boot CPU
  powerpc/tm: Fix saving of TM SPRs in core dump
  powerpc/mm: Fix pmd/pte_devmap() on non-leaf entries
      841fe953
    • D
      sparc64: Fix exception handling in UltraSPARC-III memcpy. · 0ede1c40
      由 David S. Miller 提交于 
      Mikael Pettersson reported that some test programs in the strace-4.18
testsuite cause an OOPS.

After some debugging it turns out that garbage values are returned
when an exception occurs, causing the fixup memset() to be run with
bogus arguments.

The problem is that two of the exception handler stubs write the
successfully copied length into the wrong register.

Fixes: ee841d0a ("sparc64: Convert U3copy_{from,to}_user to accurate exception reporting.")
Reported-by: NMikael Pettersson <mikpelinux@gmail.com>
Tested-by: NMikael Pettersson <mikpelinux@gmail.com>
Reviewed-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      0ede1c40
  3. 04 8月, 2017 21 次提交
  5. 03 8月, 2017 9 次提交
    • S
      mmc: block: bypass the queue even if usage is present for hotplug · 7c84b8b4
      由 Shawn Lin 提交于 
      The commit 304419d8 ("mmc: core: Allocate per-request data using the
block layer core") refactored mechanism of queue handling caused
mmc_init_request() can be called just after mmc_cleanup_queue() caused null
pointer dereference.

Another commit bbdc74dc ("mmc: block: Prevent new req entering queue
after its cleanup") tried to fix the problem. However it actually miss one
corner case.

We could still reproduce the issue mentioned with these steps:
(1) insert a SD card and mount it
(2) hotplug it, so it will leave md->usage still be counted
(3) reboot the system which will sync data and umount the card

[Unable to handle kernel NULL pointer dereference at virtual address
00000000
[user pgtable: 4k pages, 48-bit VAs, pgd = ffff80007bab3000
[[0000000000000000] *pgd=000000007a828003, *pud=0000000078dce003,
*pmd=000000007aab6003, *pte=0000000000000000
[Internal error: Oops: 96000007 [#1] PREEMPT SMP
[Modules linked in:
[CPU: 3 PID: 3507 Comm: umount Tainted: G        W
4.13.0-rc1-next-20170720-00012-g9d9bf45 #33
[Hardware name: Firefly-RK3399 Board (DT)
[task: ffff80007a1de200 task.stack: ffff80007a01c000
[PC is at mmc_init_request+0x14/0xc4
[LR is at alloc_request_size+0x4c/0x74
[pc : [<ffff0000087d7150>] lr : [<ffff000008378fe0>] pstate: 600001c5
[sp : ffff80007a01f8f0

....

[[<ffff0000087d7150>] mmc_init_request+0x14/0xc4
[[<ffff000008378fe0>] alloc_request_size+0x4c/0x74
[[<ffff00000817ac28>] mempool_create_node+0xb8/0x17c
[[<ffff00000837aadc>] blk_init_rl+0x9c/0x120
[[<ffff000008396580>] blkg_alloc+0x110/0x234
[[<ffff000008396ac8>] blkg_create+0x424/0x468
[[<ffff00000839877c>] blkg_lookup_create+0xd8/0x14c
[[<ffff0000083796bc>] generic_make_request_checks+0x368/0x3b0
[[<ffff00000837b050>] generic_make_request+0x1c/0x240

So mmc_blk_put wouldn't calling blk_cleanup_queue which actually the
QUEUE_FLAG_DYING and QUEUE_FLAG_BYPASS should stay. Block core expect
blk_queue_bypass_{start, end} internally to bypass/drain the queue before
actually dying the queue, so it didn't expose API to set the queue bypass.
I think we should set QUEUE_FLAG_BYPASS whenever queue is removed, although
the md->usage is still counted, as no dispatch queue could be found then.

Fixes: 304419d8 ("mmc: core: Allocate per-request data using the block layer core")
Signed-off-by: NShawn Lin <shawn.lin@rock-chips.com>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
      7c84b8b4
    • L
      mmc: sdhci-of-at91: force card detect value for non removable devices · 7a1e3f14
      由 Ludovic Desroches 提交于 
      When the device is non removable, the card detect signal is often used
for another purpose i.e. muxed to another SoC peripheral or used as a
GPIO. It could lead to wrong behaviors depending the default value of
this signal if not muxed to the SDHCI controller.

Fixes: bb5f8ea4 ("mmc: sdhci-of-at91: introduce driver for the Atmel SDMMC")
Signed-off-by: NLudovic Desroches <ludovic.desroches@microchip.com>
Acked-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
      7a1e3f14
    • L
      Merge tag 'nfs-for-4.13-4' of git://git.linux-nfs.org/projects/anna/linux-nfs · 19ec50a4
      由 Linus Torvalds 提交于 
      Pull NFS client fixes from Anna Schumaker:
 "Two fixes from Trond this time, now that he's back from his vacation.
  The first is a stable fix for the EXCHANGE_ID issue on the mailing
  list, and the other fixes a double-free situation that he found at the
  same time.

  Stable fix:
   - Fix EXCHANGE_ID corrupt verifier issue

  Other fix:
   - Fix double frees in nfs4_test_session_trunk()"

* tag 'nfs-for-4.13-4' of git://git.linux-nfs.org/projects/anna/linux-nfs:
  NFSv4: Fix double frees in nfs4_test_session_trunk()
  NFSv4: Fix EXCHANGE_ID corrupt verifier issue
      19ec50a4
    • A
      isdn/i4l: fix buffer overflow · 9f5af546
      由 Annie Cherkaev 提交于 
      This fixes a potential buffer overflow in isdn_net.c caused by an
unbounded strcpy.

[ ISDN seems to be effectively unmaintained, and the I4L driver in
  particular is long deprecated, but in case somebody uses this..
    - Linus ]
Signed-off-by: NJiten Thakkar <jitenmt@gmail.com>
Signed-off-by: NAnnie Cherkaev <annie.cherk@gmail.com>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      9f5af546
    • J
      ocfs2: don't clear SGID when inheriting ACLs · 19ec8e48
      由 Jan Kara 提交于 
      When new directory 'DIR1' is created in a directory 'DIR0' with SGID bit
set, DIR1 is expected to have SGID bit set (and owning group equal to
the owning group of 'DIR0').  However when 'DIR0' also has some default
ACLs that 'DIR1' inherits, setting these ACLs will result in SGID bit on
'DIR1' to get cleared if user is not member of the owning group.

Fix the problem by moving posix_acl_update_mode() out of ocfs2_set_acl()
into ocfs2_iop_set_acl().  That way the function will not be called when
inheriting ACLs which is what we want as it prevents SGID bit clearing
and the mode has been properly set by posix_acl_create() anyway.  Also
posix_acl_chmod() that is calling ocfs2_set_acl() takes care of updating
mode itself.

Fixes: 07393101 ("posix_acl: Clear SGID bit when setting file permissions")
Link: http://lkml.kernel.org/r/20170801141252.19675-3-jack@suse.czSigned-off-by: NJan Kara <jack@suse.cz>
Cc: Mark Fasheh <mfasheh@versity.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <jiangqi903@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      19ec8e48
    • K
      mm: allow page_cache_get_speculative in interrupt context · 1ee1c3f5
      由 Kan Liang 提交于 
      Kernel panic when calling the IRQ-safe __get_user_pages_fast in NMI
handler.

The bug was introduced by commit 2947ba05 ("x86/mm/gup: Switch GUP
to the generic get_user_page_fast() implementation").

The original x86 __get_user_page_fast used plain get_page() or
page_ref_add().  However, the generic __get_user_page_fast uses
page_cache_get_speculative(), which has VM_BUG_ON(in_interrupt()).

There is no reason to prevent page_cache_get_speculative from using in
interrupt context.  According to the author, putting a BUG_ON there is
just because the code is not verifying correctness of interrupt races.
I did some tests in interrupt context.  There is no issue found.

Removing VM_BUG_ON(in_interrupt()) for page_cache_get_speculative().

Link: http://lkml.kernel.org/r/1501609146-59730-1-git-send-email-kan.liang@intel.com
Fixes: 2947ba05 ("x86/mm/gup: Switch GUP to the generic get_user_page_fast() implementation")
Signed-off-by: NKan Liang <kan.liang@intel.com>
Cc: Jens Axboe <axboe@fb.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Ying Huang <ying.huang@intel.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      1ee1c3f5
    • M
      userfaultfd: non-cooperative: flush event_wqh at release time · 5a18b64e
      由 Mike Rapoport 提交于 
      There may still be threads waiting on event_wqh at the time the
userfault file descriptor is closed.  Flush the events wait-queue to
prevent waiting threads from hanging.

Link: http://lkml.kernel.org/r/1501398127-30419-1-git-send-email-rppt@linux.vnet.ibm.com
Fixes: 9cd75c3c ("userfaultfd: non-cooperative: add ability to report
non-PF events from uffd descriptor")
Signed-off-by: NMike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Pavel Emelyanov <xemul@virtuozzo.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      5a18b64e
    • K
      ipc: add missing container_of()s for randstruct · ade9f91b
      由 Kees Cook 提交于 
      When building with the randstruct gcc plugin, the layout of the IPC
structs will be randomized, which requires any sub-structure accesses to
use container_of().  The proc display handlers were missing the needed
container_of()s since the iterator is passing in the top-level struct
kern_ipc_perm.

This would lead to crashes when running the "lsipc" program after the
system had IPC registered (e.g. after starting up Gnome):

  general protection fault: 0000 [#1] PREEMPT SMP
  ...
  RIP: 0010:shm_add_rss_swap.isra.1+0x13/0xa0
  ...
  Call Trace:
    sysvipc_shm_proc_show+0x5e/0x150
    sysvipc_proc_show+0x1a/0x30
    seq_read+0x2e9/0x3f0
  ...

Link: http://lkml.kernel.org/r/20170730205950.GA55841@beast
Fixes: 3859a271 ("randstruct: Mark various structs for randomization")
Signed-off-by: NKees Cook <keescook@chromium.org>
Reported-by: NDominik Brodowski <linux@dominikbrodowski.net>
Acked-by: NDavidlohr Bueso <dave@stgolabs.net>
Acked-by: NManfred Spraul <manfred@colorfullife.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      ade9f91b
    • D
      cpuset: fix a deadlock due to incomplete patching of cpusets_enabled() · 89affbf5
      由 Dima Zavin 提交于 
      In codepaths that use the begin/retry interface for reading
mems_allowed_seq with irqs disabled, there exists a race condition that
stalls the patch process after only modifying a subset of the
static_branch call sites.

This problem manifested itself as a deadlock in the slub allocator,
inside get_any_partial.  The loop reads mems_allowed_seq value (via
read_mems_allowed_begin), performs the defrag operation, and then
verifies the consistency of mem_allowed via the read_mems_allowed_retry
and the cookie returned by xxx_begin.

The issue here is that both begin and retry first check if cpusets are
enabled via cpusets_enabled() static branch.  This branch can be
rewritted dynamically (via cpuset_inc) if a new cpuset is created.  The
x86 jump label code fully synchronizes across all CPUs for every entry
it rewrites.  If it rewrites only one of the callsites (specifically the
one in read_mems_allowed_retry) and then waits for the
smp_call_function(do_sync_core) to complete while a CPU is inside the
begin/retry section with IRQs off and the mems_allowed value is changed,
we can hang.

This is because begin() will always return 0 (since it wasn't patched
yet) while retry() will test the 0 against the actual value of the seq
counter.

The fix is to use two different static keys: one for begin
(pre_enable_key) and one for retry (enable_key).  In cpuset_inc(), we
first bump the pre_enable key to ensure that cpuset_mems_allowed_begin()
always return a valid seqcount if are enabling cpusets.  Similarly, when
disabling cpusets via cpuset_dec(), we first ensure that callers of
cpuset_mems_allowed_retry() will start ignoring the seqcount value
before we let cpuset_mems_allowed_begin() return 0.

The relevant stack traces of the two stuck threads:

  CPU: 1 PID: 1415 Comm: mkdir Tainted: G L  4.9.36-00104-g540c51286237 #4
  Hardware name: Default string Default string/Hardware, BIOS 4.29.1-20170526215256 05/26/2017
  task: ffff8817f9c28000 task.stack: ffffc9000ffa4000
  RIP: smp_call_function_many+0x1f9/0x260
  Call Trace:
    smp_call_function+0x3b/0x70
    on_each_cpu+0x2f/0x90
    text_poke_bp+0x87/0xd0
    arch_jump_label_transform+0x93/0x100
    __jump_label_update+0x77/0x90
    jump_label_update+0xaa/0xc0
    static_key_slow_inc+0x9e/0xb0
    cpuset_css_online+0x70/0x2e0
    online_css+0x2c/0xa0
    cgroup_apply_control_enable+0x27f/0x3d0
    cgroup_mkdir+0x2b7/0x420
    kernfs_iop_mkdir+0x5a/0x80
    vfs_mkdir+0xf6/0x1a0
    SyS_mkdir+0xb7/0xe0
    entry_SYSCALL_64_fastpath+0x18/0xad

  ...

  CPU: 2 PID: 1 Comm: init Tainted: G L  4.9.36-00104-g540c51286237 #4
  Hardware name: Default string Default string/Hardware, BIOS 4.29.1-20170526215256 05/26/2017
  task: ffff8818087c0000 task.stack: ffffc90000030000
  RIP: int3+0x39/0x70
  Call Trace:
    <#DB> ? ___slab_alloc+0x28b/0x5a0
    <EOE> ? copy_process.part.40+0xf7/0x1de0
    __slab_alloc.isra.80+0x54/0x90
    copy_process.part.40+0xf7/0x1de0
    copy_process.part.40+0xf7/0x1de0
    kmem_cache_alloc_node+0x8a/0x280
    copy_process.part.40+0xf7/0x1de0
    _do_fork+0xe7/0x6c0
    _raw_spin_unlock_irq+0x2d/0x60
    trace_hardirqs_on_caller+0x136/0x1d0
    entry_SYSCALL_64_fastpath+0x5/0xad
    do_syscall_64+0x27/0x350
    SyS_clone+0x19/0x20
    do_syscall_64+0x60/0x350
    entry_SYSCALL64_slow_path+0x25/0x25

Link: http://lkml.kernel.org/r/20170731040113.14197-1-dmitriyz@waymo.com
Fixes: 46e700ab ("mm, page_alloc: remove unnecessary taking of a seqlock when cpusets are disabled")
Signed-off-by: NDima Zavin <dmitriyz@waymo.com>
Reported-by: NCliff Spradlin <cspradlin@waymo.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christopher Lameter <cl@linux.com>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      89affbf5