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  1. Mar 22, 2020
    • Chris Down's avatar
      mm, memcg: throttle allocators based on ancestral memory.high · e26733e0
      Chris Down authored 
      Prior to this commit, we only directly check the affected cgroup's
memory.high against its usage.  However, it's possible that we are being
reclaimed as a result of hitting an ancestor memory.high and should be
penalised based on that, instead.

This patch changes memory.high overage throttling to use the largest
overage in its ancestors when considering how many penalty jiffies to
charge.  This makes sure that we penalise poorly behaving cgroups in the
same way regardless of at what level of the hierarchy memory.high was
breached.

Fixes: 0e4b01df

 ("mm, memcg: throttle allocators when failing reclaim over memory.high")
Reported-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Signed-off-by: default avatarChris Down <chris@chrisdown.name>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: <stable@vger.kernel.org>	[5.4.x+]
Link: http://lkml.kernel.org/r/8cd132f84bd7e16cdb8fde3378cdbf05ba00d387.1584036142.git.chris@chrisdown.name


Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e26733e0
    • Chris Down's avatar
      mm, memcg: fix corruption on 64-bit divisor in memory.high throttling · d397a45f
      Chris Down authored 
      Commit 0e4b01df had a bunch of fixups to use the right division
method.  However, it seems that after all that it still wasn't right --
div_u64 takes a 32-bit divisor.

The headroom is still large (2^32 pages), so on mundane systems you
won't hit this, but this should definitely be fixed.

Fixes: 0e4b01df

 ("mm, memcg: throttle allocators when failing reclaim over memory.high")
Reported-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Signed-off-by: default avatarChris Down <chris@chrisdown.name>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: <stable@vger.kernel.org>	[5.4.x+]
Link: http://lkml.kernel.org/r/80780887060514967d414b3cd91f9a316a16ab98.1584036142.git.chris@chrisdown.name


Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      d397a45f
    • Qian Cai's avatar
      page-flags: fix a crash at SetPageError(THP_SWAP) · d72520ad
      Qian Cai authored 
      Commit bd4c82c2 ("mm, THP, swap: delay splitting THP after swapped
out") supported writing THP to a swap device but forgot to upgrade an
older commit df8c94d1 ("page-flags: define behavior of FS/IO-related
flags on compound pages") which could trigger a crash during THP
swapping out with DEBUG_VM_PGFLAGS=y,

  kernel BUG at include/linux/page-flags.h:317!

  page dumped because: VM_BUG_ON_PAGE(1 && PageCompound(page))
  page:fffff3b2ec3a8000 refcount:512 mapcount:0 mapping:000000009eb0338c index:0x7f6e58200 head:fffff3b2ec3a8000 order:9 compound_mapcount:0 compound_pincount:0
  anon flags: 0x45fffe0000d8454(uptodate|lru|workingset|owner_priv_1|writeback|head|reclaim|swapbacked)

  end_swap_bio_write()
    SetPageError(page)
      VM_BUG_ON_PAGE(1 && PageCompound(page))

  <IRQ>
  bio_endio+0x297/0x560
  dec_pending+0x218/0x430 [dm_mod]
  clone_endio+0xe4/0x2c0 [dm_mod]
  bio_endio+0x297/0x560
  blk_update_request+0x201/0x920
  scsi_end_request+0x6b/0x4b0
  scsi_io_completion+0x509/0x7e0
  scsi_finish_command+0x1ed/0x2a0
  scsi_softirq_done+0x1c9/0x1d0
  __blk_mqnterrupt+0xf/0x20
  </IRQ>

Fix by checking PF_NO_TAIL in those places instead.

Fixes: bd4c82c2

 ("mm, THP, swap: delay splitting THP after swapped out")
Signed-off-by: default avatarQian Cai <cai@lca.pw>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
Acked-by: default avatar"Huang, Ying" <ying.huang@intel.com>
Acked-by: default avatarRafael Aquini <aquini@redhat.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200310235846.1319-1-cai@lca.pw


Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      d72520ad
    • Baoquan He's avatar
      mm/hotplug: fix hot remove failure in SPARSEMEM|!VMEMMAP case · d41e2f3b
      Baoquan He authored 
      In section_deactivate(), pfn_to_page() doesn't work any more after
ms->section_mem_map is resetting to NULL in SPARSEMEM|!VMEMMAP case.  It
causes a hot remove failure:

  kernel BUG at mm/page_alloc.c:4806!
  invalid opcode: 0000 [#1] SMP PTI
  CPU: 3 PID: 8 Comm: kworker/u16:0 Tainted: G        W         5.5.0-next-20200205+ #340
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015
  Workqueue: kacpi_hotplug acpi_hotplug_work_fn
  RIP: 0010:free_pages+0x85/0xa0
  Call Trace:
   __remove_pages+0x99/0xc0
   arch_remove_memory+0x23/0x4d
   try_remove_memory+0xc8/0x130
   __remove_memory+0xa/0x11
   acpi_memory_device_remove+0x72/0x100
   acpi_bus_trim+0x55/0x90
   acpi_device_hotplug+0x2eb/0x3d0
   acpi_hotplug_work_fn+0x1a/0x30
   process_one_work+0x1a7/0x370
   worker_thread+0x30/0x380
   kthread+0x112/0x130
   ret_from_fork+0x35/0x40

Let's move the ->section_mem_map resetting after
depopulate_section_memmap() to fix it.

[akpm@linux-foundation.org: remove unneeded initialization, per David]
Fixes: ba72b4c8

 ("mm/sparsemem: support sub-section hotplug")
Signed-off-by: default avatarBaoquan He <bhe@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: default avatarPankaj Gupta <pankaj.gupta.linux@gmail.com>
Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200307084229.28251-2-bhe@redhat.com


Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      d41e2f3b
    • Chunguang Xu's avatar
      memcg: fix NULL pointer dereference in __mem_cgroup_usage_unregister_event · 7d36665a
      Chunguang Xu authored 
      An eventfd monitors multiple memory thresholds of the cgroup, closes them,
the kernel deletes all events related to this eventfd.  Before all events
are deleted, another eventfd monitors the memory threshold of this cgroup,
leading to a crash:

  BUG: kernel NULL pointer dereference, address: 0000000000000004
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0002) - not-present page
  PGD 800000033058e067 P4D 800000033058e067 PUD 3355ce067 PMD 0
  Oops: 0002 [#1] SMP PTI
  CPU: 2 PID: 14012 Comm: kworker/2:6 Kdump: loaded Not tainted 5.6.0-rc4 #3
  Hardware name: LENOVO 20AWS01K00/20AWS01K00, BIOS GLET70WW (2.24 ) 05/21/2014
  Workqueue: events memcg_event_remove
  RIP: 0010:__mem_cgroup_usage_unregister_event+0xb3/0x190
  RSP: 0018:ffffb47e01c4fe18 EFLAGS: 00010202
  RAX: 0000000000000001 RBX: ffff8bb223a8a000 RCX: 0000000000000001
  RDX: 0000000000000001 RSI: ffff8bb22fb83540 RDI: 0000000000000001
  RBP: ffffb47e01c4fe48 R08: 0000000000000000 R09: 0000000000000010
  R10: 000000000000000c R11: 071c71c71c71c71c R12: ffff8bb226aba880
  R13: ffff8bb223a8a480 R14: 0000000000000000 R15: 0000000000000000
  FS:  0000000000000000(0000) GS:ffff8bb242680000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000004 CR3: 000000032c29c003 CR4: 00000000001606e0
  Call Trace:
    memcg_event_remove+0x32/0x90
    process_one_work+0x172/0x380
    worker_thread+0x49/0x3f0
    kthread+0xf8/0x130
    ret_from_fork+0x35/0x40
  CR2: 0000000000000004

We can reproduce this problem in the following ways:

1. We create a new cgroup subdirectory and a new eventfd, and then we
   monitor multiple memory thresholds of the cgroup through this eventfd.

2.  closing this eventfd, and __mem_cgroup_usage_unregister_event ()
   will be called multiple times to delete all events related to this
   eventfd.

The first time __mem_cgroup_usage_unregister_event() is called, the
kernel will clear all items related to this eventfd in thresholds->
primary.

Since there is currently only one eventfd, thresholds-> primary becomes
empty, so the kernel will set thresholds-> primary and hresholds-> spare
to NULL.  If at this time, the user creates a new eventfd and monitor
the memory threshold of this cgroup, kernel will re-initialize
thresholds-> primary.

Then when __mem_cgroup_usage_unregister_event () is called for the
second time, because thresholds-> primary is not empty, the system will
access thresholds-> spare, but thresholds-> spare is NULL, which will
trigger a crash.

In general, the longer it takes to delete all events related to this
eventfd, the easier it is to trigger this problem.

The solution is to check whether the thresholds associated with the
eventfd has been cleared when deleting the event.  If so, we do nothing.

[akpm@linux-foundation.org: fix comment, per Kirill]
Fixes: 907860ed

 ("cgroups: make cftype.unregister_event() void-returning")
Signed-off-by: default avatarChunguang Xu <brookxu@tencent.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Acked-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/077a6f67-aefa-4591-efec-f2f3af2b0b02@gmail.com


Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      7d36665a
  3. Mar 21, 2020
    • Linus Torvalds's avatar
      Merge tag 'powerpc-5.6-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux · c63c50fc
      Linus Torvalds authored 
      Pull powerpc fixes from Michael Ellerman:
 "Two fixes for bugs introduced this cycle:

   - fix a crash when shutting down a KVM PR guest (our original style
     of KVM which doesn't use hypervisor mode)

   - fix for the recently added 32-bit KASAN_VMALLOC support

  Thanks to: Christophe Leroy, Greg Kurz, Sean Christopherson"

* tag 'powerpc-5.6-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  KVM: PPC: Fix kernel crash with PR KVM
  powerpc/kasan: Fix shadow memory protection with CONFIG_KASAN_VMALLOC
      c63c50fc
    • Linus Torvalds's avatar
      Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux · 5ad0ec0b
      Linus Torvalds authored 
      Pull arm64 fixes from Will Deacon:

 - Fix panic() when it occurs during secondary CPU startup

 - Fix "kpti=off" when KASLR is enabled

 - Fix howler in compat syscall table for vDSO clock_getres() fallback

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: compat: Fix syscall number of compat_clock_getres
  arm64: kpti: Fix "kpti=off" when KASLR is enabled
  arm64: smp: fix crash_smp_send_stop() behaviour
  arm64: smp: fix smp_send_stop() behaviour
      5ad0ec0b
    • Linus Torvalds's avatar
      Merge tag 'char-misc-5.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc · f014d2b8
      Linus Torvalds authored 
      Pull char/misc driver fixes from Greg KH:
 "Here are some small different driver fixes for 5.6-rc7:

   - binderfs fix, yet again

   - slimbus new device id added

   - hwtracing bugfixes for reported issues and a new device id

  All of these have been in linux-next with no reported issues"

* tag 'char-misc-5.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  intel_th: pci: Add Elkhart Lake CPU support
  intel_th: Fix user-visible error codes
  intel_th: msu: Fix the unexpected state warning
  stm class: sys-t: Fix the use of time_after()
  slimbus: ngd: add v2.1.0 compatible
  binderfs: use refcount for binder control devices too
      f014d2b8
    • Linus Torvalds's avatar
      Merge tag 'staging-5.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging · 3bd14829
      Linus Torvalds authored 
      Pull staging/IIO fixes from Greg KH:
 "Here are a number of small staging and IIO driver fixes for 5.6-rc7

  Nothing major here, just resolutions for some reported problems:
   - iio bugfixes for a number of different drivers
   - greybus loopback_test fixes
   - wfx driver fixes

  All of these have been in linux-next with no reported issues"

* tag 'staging-5.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: rtl8188eu: Add device id for MERCUSYS MW150US v2
  staging: greybus: loopback_test: fix potential path truncations
  staging: greybus: loopback_test: fix potential path truncation
  staging: greybus: loopback_test: fix poll-mask build breakage
  staging: wfx: fix RCU usage between hif_join() and ieee80211_bss_get_ie()
  staging: wfx: fix RCU usage in wfx_join_finalize()
  staging: wfx: make warning about pending frame less scary
  staging: wfx: fix lines ending with a comma instead of a semicolon
  staging: wfx: fix warning about freeing in-use mutex during device unregister
  staging/speakup: fix get_word non-space look-ahead
  iio: ping: set pa_laser_ping_cfg in of_ping_match
  iio: chemical: sps30: fix missing triggered buffer dependency
  iio: st_sensors: remap SMO8840 to LIS2DH12
  iio: light: vcnl4000: update sampling periods for vcnl4040
  iio: light: vcnl4000: update sampling periods for vcnl4200
  iio: accel: adxl372: Set iio_chan BE
  iio: magnetometer: ak8974: Fix negative raw values in sysfs
  iio: trigger: stm32-timer: disable master mode when stopping
  iio: adc: stm32-dfsdm: fix sleep in atomic context
  iio: adc: at91-sama5d2_adc: fix differential channels in triggered mode
      3bd14829
    • Linus Torvalds's avatar
      Merge tag 'usb-5.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb · b07c2e76
      Linus Torvalds authored 
      Pull USB fixes from Greg KH:
 "Here are some small USB fixes for 5.6-rc7. And there's a thunderbolt
  driver fix thrown in for good measure as well.

  These fixes are:
   - new device ids for usb-serial drivers
   - thunderbolt error code fix
   - xhci driver fixes
   - typec fixes
   - cdc-acm driver fixes
   - chipidea driver fix
   - more USB quirks added for devices that need them.

  All of these have been in linux-next with no reported issues"

* tag 'usb-5.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  USB: cdc-acm: fix rounding error in TIOCSSERIAL
  USB: cdc-acm: fix close_delay and closing_wait units in TIOCSSERIAL
  usb: quirks: add NO_LPM quirk for RTL8153 based ethernet adapters
  usb: chipidea: udc: fix sleeping function called from invalid context
  USB: serial: pl2303: add device-id for HP LD381
  USB: serial: option: add ME910G1 ECM composition 0x110b
  usb: host: xhci-plat: add a shutdown
  usb: typec: ucsi: displayport: Fix a potential race during registration
  usb: typec: ucsi: displayport: Fix NULL pointer dereference
  USB: Disable LPM on WD19's Realtek Hub
  usb: xhci: apply XHCI_SUSPEND_DELAY to AMD XHCI controller 1022:145c
  xhci: Do not open code __print_symbolic() in xhci trace events
  thunderbolt: Fix error code in tb_port_is_width_supported()
      b07c2e76
    • Linus Torvalds's avatar
      Merge tag 'tty-5.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty · fa91418b
      Linus Torvalds authored 
      Pull tty fixes from Greg KH:
 "Here are three small tty_io bugfixes for reported issues that Eric has
  resolved for 5.6-rc7

  All of these have been in linux-next with no reported issues"

* tag 'tty-5.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  tty: fix compat TIOCGSERIAL checking wrong function ptr
  tty: fix compat TIOCGSERIAL leaking uninitialized memory
  tty: drop outdated comments about release_tty() locking
      fa91418b
    • Linus Torvalds's avatar
      Merge tag 'sound-5.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound · 12bf19c9
      Linus Torvalds authored 
      Pull sound fixes from Takashi Iwai:
 "A few fixes covering the issues reported by syzkaller, a couple of
  fixes for the MIDI decoding bug, and a few usual HD-audio quirks.

  Some of them are about ALSA core stuff, but they are small fixes just
  for corner cases, and nothing thrilling"

* tag 'sound-5.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda/realtek - Enable the headset of Acer N50-600 with ALC662
  ALSA: hda/realtek - Enable headset mic of Acer X2660G with ALC662
  ALSA: seq: oss: Fix running status after receiving sysex
  ALSA: seq: virmidi: Fix running status after receiving sysex
  ALSA: pcm: oss: Remove WARNING from snd_pcm_plug_alloc() checks
  ALSA: hda/realtek: Fix pop noise on ALC225
  ALSA: line6: Fix endless MIDI read loop
  ALSA: pcm: oss: Avoid plugin buffer overflow
      12bf19c9
    • Linus Torvalds's avatar
      Merge tag 'drm-fixes-2020-03-20' of git://anongit.freedesktop.org/drm/drm · 69d3e5a5
      Linus Torvalds authored 
      Pull drm fixes from Dave Airlie:
 "Hope you are well hiding out above the garage. A few amdgpu changes
  but nothing too major. I've had a wisdom tooth out this week so
  haven't been to on top of things, but all seems good.

  core:
   - fix lease warning

  i915:
   - Track active elements during dequeue
   - Fix failure to handle all MCR ranges
   - Revert unnecessary workaround

  amdgpu:
   - Pageflip fix
   - VCN clockgating fixes
   - GPR debugfs fix for umr
   - GPU reset fix
   - eDP fix for MBP
   - DCN2.x fix

  dw-hdmi:
   - fix AVI frame colorimetry

  komeda:
   - fix compiler warning

  bochs:
   - downgrade a binding failure to a warning"

* tag 'drm-fixes-2020-03-20' of git://anongit.freedesktop.org/drm/drm:
  drm/amd/display: Fix pageflip event race condition for DCN.
  drm/amdgpu: fix typo for vcn2.5/jpeg2.5 idle check
  drm/amdgpu: fix typo for vcn2/jpeg2 idle check
  drm/amdgpu: fix typo for vcn1 idle check
  drm/lease: fix WARNING in idr_destroy
  drm/i915: Handle all MCR ranges
  Revert "drm/i915/tgl: Add extra hdc flush workaround"
  drm/i915/execlists: Track active elements during dequeue
  drm/bochs: downgrade pci_request_region failure from error to warning
  drm/amd/display: Add link_rate quirk for Apple 15" MBP 2017
  drm/amdgpu: add fbdev suspend/resume on gpu reset
  drm/amd/amdgpu: Fix GPR read from debugfs (v2)
  drm/amd/display: fix typos for dcn20_funcs and dcn21_funcs struct
  drm/komeda: mark PM functions as __maybe_unused
  drm/bridge: dw-hdmi: fix AVI frame colorimetry
      69d3e5a5
  5. Mar 20, 2020
    • Dave Airlie's avatar
      Merge tag 'drm-intel-fixes-2020-03-19' of... · 5366b96b
      Dave Airlie authored 
      Merge tag 'drm-intel-fixes-2020-03-19' of git://anongit.freedesktop.org/drm/drm-intel

 into drm-fixes

drm/i915 fixes for v5.6-rc7:
- Track active elements during dequeue
- Fix failure to handle all MCR ranges
- Revert unnecessary workaround

Signed-off-by: default avatarDave Airlie <airlied@redhat.com>

From: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/877dzgepvu.fsf@intel.com
      5366b96b
    • Dave Airlie's avatar
      Merge tag 'amd-drm-fixes-5.6-2020-03-19' of... · 362b86a3
      Dave Airlie authored 
      Merge tag 'amd-drm-fixes-5.6-2020-03-19' of git://people.freedesktop.org/~agd5f/linux

 into drm-fixes

amd-drm-fixes-5.6-2020-03-19:

amdgpu:
- Pageflip fix
- VCN clockgating fixes
- GPR debugfs fix for umr
- GPU reset fix
- eDP fix for MBP
- DCN2.x fix

Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
From: Alex Deucher <alexdeucher@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200319204054.1036478-1-alexander.deucher@amd.com
      362b86a3
    • Greg Kurz's avatar
      KVM: PPC: Fix kernel crash with PR KVM · 1d0c32ec
      Greg Kurz authored 
      With PR KVM, shutting down a VM causes the host kernel to crash:

[  314.219284] BUG: Unable to handle kernel data access on read at 0xc00800000176c638
[  314.219299] Faulting instruction address: 0xc008000000d4ddb0
cpu 0x0: Vector: 300 (Data Access) at [c00000036da077a0]
    pc: c008000000d4ddb0: kvmppc_mmu_pte_flush_all+0x68/0xd0 [kvm_pr]
    lr: c008000000d4dd94: kvmppc_mmu_pte_flush_all+0x4c/0xd0 [kvm_pr]
    sp: c00000036da07a30
   msr: 900000010280b033
   dar: c00800000176c638
 dsisr: 40000000
  current = 0xc00000036d4c0000
  paca    = 0xc000000001a00000   irqmask: 0x03   irq_happened: 0x01
    pid   = 1992, comm = qemu-system-ppc
Linux version 5.6.0-master-gku+ (greg@palmb) (gcc version 7.5.0 (Ubuntu 7.5.0-3ubuntu1~18.04)) #17 SMP Wed Mar 18 13:49:29 CET 2020
enter ? for help
[c00000036da07ab0] c008000000d4fbe0 kvmppc_mmu_destroy_pr+0x28/0x60 [kvm_pr]
[c00000036da07ae0] c0080000009eab8c kvmppc_mmu_destroy+0x34/0x50 [kvm]
[c00000036da07b00] c0080000009e50c0 kvm_arch_vcpu_destroy+0x108/0x140 [kvm]
[c00000036da07b30] c0080000009d1b50 kvm_vcpu_destroy+0x28/0x80 [kvm]
[c00000036da07b60] c0080000009e4434 kvm_arch_destroy_vm+0xbc/0x190 [kvm]
[c00000036da07ba0] c0080000009d9c2c kvm_put_kvm+0x1d4/0x3f0 [kvm]
[c00000036da07c00] c0080000009da760 kvm_vm_release+0x38/0x60 [kvm]
[c00000036da07c30] c000000000420be0 __fput+0xe0/0x310
[c00000036da07c90] c0000000001747a0 task_work_run+0x150/0x1c0
[c00000036da07cf0] c00000000014896c do_exit+0x44c/0xd00
[c00000036da07dc0] c0000000001492f4 do_group_exit+0x64/0xd0
[c00000036da07e00] c000000000149384 sys_exit_group+0x24/0x30
[c00000036da07e20] c00000000000b9d0 system_call+0x5c/0x68

This is caused by a use-after-free in kvmppc_mmu_pte_flush_all()
which dereferences vcpu->arch.book3s which was previously freed by
kvmppc_core_vcpu_free_pr(). This happens because kvmppc_mmu_destroy()
is called after kvmppc_core_vcpu_free() since commit ff030fdf
("KVM: PPC: Move kvm_vcpu_init() invocation to common code").

The kvmppc_mmu_destroy() helper calls one of the following depending
on the KVM backend:

- kvmppc_mmu_destroy_hv() which does nothing (Book3s HV)

- kvmppc_mmu_destroy_pr() which undoes the effects of
  kvmppc_mmu_init() (Book3s PR 32-bit)

- kvmppc_mmu_destroy_pr() which undoes the effects of
  kvmppc_mmu_init() (Book3s PR 64-bit)

- kvmppc_mmu_destroy_e500() which does nothing (BookE e500/e500mc)

It turns out that this is only relevant to PR KVM actually. And both
32 and 64 backends need vcpu->arch.book3s to be valid when calling
kvmppc_mmu_destroy_pr(). So instead of calling kvmppc_mmu_destroy()
from kvm_arch_vcpu_destroy(), call kvmppc_mmu_destroy_pr() at the
beginning of kvmppc_core_vcpu_free_pr(). This is consistent with
kvmppc_mmu_init() being the last call in kvmppc_core_vcpu_create_pr().

For the same reason, if kvmppc_core_vcpu_create_pr() returns an
error then this means that kvmppc_mmu_init() was either not called
or failed, in which case kvmppc_mmu_destroy() should not be called.
Drop the line in the error path of kvm_arch_vcpu_create().

Fixes: ff030fdf

 ("KVM: PPC: Move kvm_vcpu_init() invocation to common code")
Signed-off-by: default avatarGreg Kurz <groug@kaod.org>
Reviewed-by: default avatarSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/158455341029.178873.15248663726399374882.stgit@bahia.lan
      1d0c32ec
    • Mario Kleiner's avatar
      drm/amd/display: Fix pageflip event race condition for DCN. · eb916a5a
      Mario Kleiner authored 
      Commit '16f17eda ("drm/amd/display: Send vblank and user
events at vsartup for DCN")' introduces a new way of pageflip
completion handling for DCN, and some trouble.

The current implementation introduces a race condition, which
can cause pageflip completion events to be sent out one vblank
too early, thereby confusing userspace and causing flicker:

prepare_flip_isr():

1. Pageflip programming takes the ddev->event_lock.
2. Sets acrtc->pflip_status == AMDGPU_FLIP_SUBMITTED
3. Releases ddev->event_lock.

--> Deadline for surface address regs double-buffering passes on
    target pipe.

4. dc_commit_updates_for_stream() MMIO programs the new pageflip
   into hw, but too late for current vblank.

=> pflip_status == AMDGPU_FLIP_SUBMITTED, but flip won't complete
   in current vblank due to missing the double-buffering deadline
   by a tiny bit.

5. VSTARTUP trigger point in vblank is reached, VSTARTUP irq fires,
   dm_dcn_crtc_high_irq() gets called.

6. Detects pflip_status == AMDGPU_FLIP_SUBMITTED and assumes the
   pageflip has been completed/will complete in this vblank and
   sends out pageflip completion event to userspace and resets
   pflip_status = AMDGPU_FLIP_NONE.

=> Flip completion event sent out one vblank too early.

This behaviour has been observed during my testing with measurement
hardware a couple of time.

The commit message says that the extra flip event code was added to
dm_dcn_crtc_high_irq() to prevent missing to send out pageflip events
in case the pflip irq doesn't fire, because the "DCH HUBP" component
is clock gated and doesn't fire pflip irqs in that state. Also that
this clock gating may happen if no planes are active. This suggests
that the problem addressed by that commit can't happen if planes
are active.

The proposed solution is therefore to only execute the extra pflip
completion code iff the count of active planes is zero and otherwise
leave pflip completion handling to the pflip irq handler, for a
more race-free experience.

Note that i don't know if this fixes the problem the original commit
tried to address, as i don't know what the test scenario was. It
does fix the observed too early pageflip events though and points
out the problem introduced.

Fixes: 16f17eda

 ("drm/amd/display: Send vblank and user events at vsartup for DCN")
Reviewed-by: default avatarNicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: default avatarMario Kleiner <mario.kleiner.de@gmail.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
      eb916a5a
    • Linus Torvalds's avatar
      Merge tag 'mmc-v5.6-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc · 6c90b86a
      Linus Torvalds authored 
      Pull MMC fixes from Ulf Hansson:

 - rtsx_pci: Fix support for some various speed modes

 - sdhci-of-at91: Fix support for GPIO card detect on SAMA5D2

 - sdhci-cadence: Fix support for DDR52 speed mode for eMMC on UniPhier

 - sdhci-acpi: Fix broken WP support on Acer Aspire Switch 10

 - sdhci-acpi: Workaround FW bug for suspend on Lenovo Miix 320

* tag 'mmc-v5.6-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc:
  mmc: rtsx_pci: Fix support for speed-modes that relies on tuning
  mmc: sdhci-of-at91: fix cd-gpios for SAMA5D2
  mmc: sdhci-cadence: set SDHCI_QUIRK2_PRESET_VALUE_BROKEN for UniPhier
  mmc: sdhci-acpi: Disable write protect detection on Acer Aspire Switch 10 (SW5-012)
  mmc: sdhci-acpi: Switch signal voltage back to 3.3V on suspend on external microSD on Lenovo Miix 320
      6c90b86a
    • Vincenzo Frascino's avatar
      arm64: compat: Fix syscall number of compat_clock_getres · 3568b889
      Vincenzo Frascino authored 
      The syscall number of compat_clock_getres was erroneously set to 247
(__NR_io_cancel!) instead of 264. This causes the vDSO fallback of
clock_getres() to land on the wrong syscall for compat tasks.

Fix the numbering.

Cc: <stable@vger.kernel.org>
Fixes: 53c489e1

 ("arm64: compat: Add missing syscall numbers")
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Reviewed-by: default avatarNick Desaulniers <ndesaulniers@google.com>
Signed-off-by: default avatarVincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: default avatarWill Deacon <will@kernel.org>
      3568b889
    • Linus Torvalds's avatar
      Merge tag '5.6-rc6-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6 · cd607737
      Linus Torvalds authored 
      Pull cifs fixes from Steve French:
 "Three small smb3 fixes, two for stable"

* tag '5.6-rc6-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  CIFS: fiemap: do not return EINVAL if get nothing
  CIFS: Increment num_remote_opens stats counter even in case of smb2_query_dir_first
  cifs: potential unintitliazed error code in cifs_getattr()
      cd607737
    • Linus Torvalds's avatar
      Merge tag 'kbuild-fixes-v5.6-3' of... · 207f75c4
      Linus Torvalds authored 
      Merge tag 'kbuild-fixes-v5.6-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - fix __uint128_t capability test in Kconfig when GCC that defaults to
   32-bit is used to build the 64-bit kernel

 - suppress new noisy Clang warnings -Wpointer-to-enum-cast

 - move the namespace field in Module.symvers for the backward
   compatibility reason for the depmod tool

 - use available compression for initramdisk when INTRAMFS_SOURCE is
   defined, which was the original behavior

 - fix modpost to handle correct large section numbers when it refers to
   modversion CRCs and module namespaces

 - fix comments and documents

* tag 'kbuild-fixes-v5.6-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  scripts/kallsyms: fix wrong kallsyms_relative_base
  modpost: Get proper section index by get_secindex() instead of st_shndx
  initramfs: restore default compression behavior
  modpost: move the namespace field in Module.symvers last
  kbuild: Disable -Wpointer-to-enum-cast
  kbuild: doc: fix references to other documents
  int128: fix __uint128_t compiler test in Kconfig
  kconfig: introduce m32-flag and m64-flag
  kbuild: Fix inconsistent comment
      207f75c4
    • Corentin Labbe's avatar
      rtc: max8907: add missing select REGMAP_IRQ · 5d892919
      Corentin Labbe authored 
      I have hit the following build error:

  armv7a-hardfloat-linux-gnueabi-ld: drivers/rtc/rtc-max8907.o: in function `max8907_rtc_probe':
  rtc-max8907.c:(.text+0x400): undefined reference to `regmap_irq_get_virq'

max8907 should select REGMAP_IRQ

Fixes: 94c01ab6

 ("rtc: add MAX8907 RTC driver")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: default avatarCorentin Labbe <clabbe@baylibre.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      5d892919
  7. Mar 19, 2020
  9. Mar 18, 2020