In order to simplify the page tracking infrastructure at EL2 in nVHE
protected mode, move the responsibility of refcounting pages that are
shared multiple times on the host. In order to do so, let's create a
red-black tree tracking all the PFNs that have been shared, along with
a refcount.
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211215161232.1480836-8-qperret@google.com

The create_hyp_mappings() function can currently be called at any point
in time. However, its behaviour in protected mode changes widely
depending on when it is being called. Prior to KVM init, it is used to
create the temporary page-table used to bring-up the hypervisor, and
later on it is transparently turned into a 'share' hypercall when the
kernel has lost control over the hypervisor stage-1. In order to prepare
the ground for also unsharing pages with the hypervisor during guest
teardown, introduce a kvm_share_hyp() function to make it clear in which
places a share hypercall should be expected, as we will soon need a
matching unshare hypercall in all those places.
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211215161232.1480836-7-qperret@google.com

Implement kvm_pgtable_hyp_unmap() which can be used to remove hypervisor
stage-1 mappings at EL2.
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211215161232.1480836-6-qperret@google.com

kvm_pgtable_hyp_unmap() relies on the ->page_count() function callback
being provided by the memory-management operations for the page-table.

Wire up this callback for the hypervisor stage-1 page-table.
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211215161232.1480836-5-qperret@google.com

In nVHE-protected mode, the hyp stage-1 page-table refcount is broken
due to the lack of refcount support in the early allocator. Fix-up the
refcount in the finalize walker, once the 'hyp_vmemmap' is up and running.
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211215161232.1480836-4-qperret@google.com

To prepare the ground for allowing hyp stage-1 mappings to be removed at
run-time, update the KVM page-table code to maintain a correct refcount
using the ->{get,put}_page() function callbacks.
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211215161232.1480836-3-qperret@google.com

In nVHE protected mode, the EL2 code uses a temporary allocator during
boot while re-creating its stage-1 page-table. Unfortunately, the
hyp_vmmemap is not ready to use at this stage, so refcounting pages
is not possible. That is not currently a problem because hyp stage-1
mappings are never removed, which implies refcounting of page-table
pages is unnecessary.

In preparation for allowing hypervisor stage-1 mappings to be removed,
provide stub implementations for {get,put}_page() in the early allocator.
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211215161232.1480836-2-qperret@google.com

* kvm-arm64/fpsimd-tracking:
  : .
  : Simplify the handling of both the FP/SIMD and SVE state by
  : removing the need for mapping the thread at EL2, and by
  : dropping the tracking of the host's SVE state which is
  : always invalid by construction.
  : .
  arm64/fpsimd: Document the use of TIF_FOREIGN_FPSTATE by KVM
  KVM: arm64: Stop mapping current thread_info at EL2
  KVM: arm64: Introduce flag shadowing TIF_FOREIGN_FPSTATE
  KVM: arm64: Remove unused __sve_save_state
  KVM: arm64: Get rid of host SVE tracking/saving
  KVM: arm64: Reorder vcpu flag definitions
Signed-off-by: Marc Zyngier <maz@kernel.org>

* kvm-arm64/vcpu-first-run:
  : Rework the "vcpu first run" sequence to be driven by KVM's
  : "PID change" callback, removing the need for extra state.
  KVM: arm64: Drop vcpu->arch.has_run_once for vcpu->pid
  KVM: arm64: Merge kvm_arch_vcpu_run_pid_change() and kvm_vcpu_first_run_init()
  KVM: arm64: Restructure the point where has_run_once is advertised
  KVM: arm64: Move kvm_arch_vcpu_run_pid_change() out of line
  KVM: arm64: Move SVE state mapping at HYP to finalize-time
Signed-off-by: Marc Zyngier <maz@kernel.org>

With the transition to kvm_arch_vcpu_run_pid_change() to handle
the "run once" activities, it becomes obvious that has_run_once
is now an exact shadow of vcpu->pid.

Replace vcpu->arch.has_run_once with a new vcpu_has_run_once()
helper that directly checks for vcpu->pid, and get rid of the
now unused field.
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>

The kvm_arch_vcpu_run_pid_change() helper gets called on each PID
change. The kvm_vcpu_first_run_init() helper gets run on the...
first run(!) of a vcpu.

As it turns out, the first run of a vcpu also triggers a PID change
event (vcpu->pid is initially NULL).

Use this property to merge these two helpers and get rid of another
arm64-specific oddity.
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>

Restructure kvm_vcpu_first_run_init() to set the has_run_once
flag after having completed all the "run once" activities.

This includes moving the flip of the userspace irqchip static key
to a point where nothing can fail.
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>

Having kvm_arch_vcpu_run_pid_change() inline doesn't bring anything
to the table. Move it next to kvm_vcpu_first_run_init(), which will
be convenient for what is next to come.
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>

We currently map the SVE state to HYP on detection of a PID change.
Although this matches what we do for FPSIMD, this is pretty pointless
for SVE, as the buffer is per-vcpu and has nothing to do with the
thread that is being run.

Move the mapping of the SVE state to finalize-time, which is where
we allocate the state memory, and thus the most logical place to
do this.
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>

Pull vhost,virtio,vdpa bugfixes from Michael Tsirkin:
 "Misc fixes all over the place.

  Revert of virtio used length validation series: the approach taken
  does not seem to work, breaking too many guests in the process. We'll
  need to do length validation using some other approach"

[ This merge also ends up reverting commit f7a36b03 ("vsock/virtio:
  suppress used length validation"), which came in through the
  networking tree in the meantime, and was part of that whole used
  length validation series   - Linus ]

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  vdpa_sim: avoid putting an uninitialized iova_domain
  vhost-vdpa: clean irqs before reseting vdpa device
  virtio-blk: modify the value type of num in virtio_queue_rq()
  vhost/vsock: cleanup removing `len` variable
  vhost/vsock: fix incorrect used length reported to the guest
  Revert "virtio_ring: validate used buffer length"
  Revert "virtio-net: don't let virtio core to validate used length"
  Revert "virtio-blk: don't let virtio core to validate used length"
  Revert "virtio-scsi: don't let virtio core to validate used buffer length"

Pull x86 build fix from Thomas Gleixner:
 "A single fix for a missing __init annotation of prepare_command_line()"

* tag 'x86-urgent-2021-11-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot: Mark prepare_command_line() __init

Pull scheduler fix from Thomas Gleixner:
 "A single scheduler fix to ensure that there is no stale KASAN shadow
  state left on the idle task's stack when a CPU is brought up after it
  was brought down before"

* tag 'sched-urgent-2021-11-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/scs: Reset task stack state in bringup_cpu()

Pull perf fix from Thomas Gleixner:
 "A single fix for perf to prevent it from sending SIGTRAP to another
  task from a trace point event as it's not possible to deliver a
  synchronous signal to a different task from there"

* tag 'perf-urgent-2021-11-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: Ignore sigtrap for tracepoints destined for other tasks

Pull locking fixes from Thomas Gleixner:
 "Two regression fixes for reader writer semaphores:

   - Plug a race in the lock handoff which is caused by inconsistency of
     the reader and writer path and can lead to corruption of the
     underlying counter.

   - down_read_trylock() is suboptimal when the lock is contended and
     multiple readers trylock concurrently. That's due to the initial
     value being read non-atomically which results in at least two
     compare exchange loops. Making the initial readout atomic reduces
     this significantly. Whith 40 readers by 11% in a benchmark which
     enforces contention on mmap_sem"

* tag 'locking-urgent-2021-11-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/rwsem: Optimize down_read_trylock() under highly contended case
  locking/rwsem: Make handoff bit handling more consistent

Pull another tracing fix from Steven Rostedt:
 "Fix the fix of pid filtering

  The setting of the pid filtering flag tested the "trace only this pid"
  case twice, and ignored the "trace everything but this pid" case.

  The 5.15 kernel does things a little differently due to the new sparse
  pid mask introduced in 5.16, and as the bug was discovered running the
  5.15 kernel, and the first fix was initially done for that kernel,
  that fix handled both cases (only pid and all but pid), but the
  forward port to 5.16 created this bug"

* tag 'trace-v5.16-rc2-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Test the 'Do not trace this pid' case in create event

Pull iommu fixes from Joerg Roedel:

 - Intel VT-d fixes:
     - Remove unused PASID_DISABLED
     - Fix RCU locking
     - Fix for the unmap_pages call-back

 - Rockchip RK3568 address mask fix

 - AMD IOMMUv2 log message clarification

* tag 'iommu-fixes-v5.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/vt-d: Fix unmap_pages support
  iommu/vt-d: Fix an unbalanced rcu_read_lock/rcu_read_unlock()
  iommu/rockchip: Fix PAGE_DESC_HI_MASKs for RK3568
  iommu/amd: Clarify AMD IOMMUv2 initialization messages
  iommu/vt-d: Remove unused PASID_DISABLED

Pull ksmbd fixes from Steve French:
 "Five ksmbd server fixes, four of them for stable:

   - memleak fix

   - fix for default data stream on filesystems that don't support xattr

   - error logging fix

   - session setup fix

   - minor doc cleanup"

* tag '5.16-rc2-ksmbd-fixes' of git://git.samba.org/ksmbd:
  ksmbd: fix memleak in get_file_stream_info()
  ksmbd: contain default data stream even if xattr is empty
  ksmbd: downgrade addition info error msg to debug in smb2_get_info_sec()
  docs: filesystem: cifs: ksmbd: Fix small layout issues
  ksmbd: Fix an error handling path in 'smb2_sess_setup()'

Use the architecture independent Kconfig option PAGE_SIZE_LESS_THAN_64KB
to indicate that VMXNET3 requires a page size smaller than 64kB.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

NTFS_RW code allocates page size dependent arrays on the stack. This
results in build failures if the page size is 64k or larger.

  fs/ntfs/aops.c: In function 'ntfs_write_mst_block':
  fs/ntfs/aops.c:1311:1: error:
	the frame size of 2240 bytes is larger than 2048 bytes

Since commit f22969a6 ("powerpc/64s: Default to 64K pages for 64 bit
book3s") this affects ppc:allmodconfig builds, but other architectures
supporting page sizes of 64k or larger are also affected.

Increasing the maximum frame size for affected architectures just to
silence this error does not really help.  The frame size would have to
be set to a really large value for 256k pages.  Also, a large frame size
could potentially result in stack overruns in this code and elsewhere
and is therefore not desirable.  Make NTFS_RW dependent on page sizes
smaller than 64k instead.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Cc: Anton Altaparmakov <anton@tuxera.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

NTFS_RW and VMXNET3 require a page size smaller than 64kB.  Add generic
Kconfig option for use outside architecture code to avoid architecture
specific Kconfig options in that code.
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Cc: Anton Altaparmakov <anton@tuxera.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When creating a new event (via a module, kprobe, eprobe, etc), the
descriptors that are created must add flags for pid filtering if an
instance has pid filtering enabled, as the flags are used at the time the
event is executed to know if pid filtering should be done or not.

The "Only trace this pid" case was added, but a cut and paste error made
that case checked twice, instead of checking the "Trace all but this pid"
case.

Link: https://lore.kernel.org/all/202111280401.qC0z99JB-lkp@intel.com/

Fixes: 6cb20650 ("tracing: Check pid filtering when creating events")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Pull xfs fixes from Darrick Wong:
 "Fixes for a resource leak and a build robot complaint about totally
  dead code:

   - Fix buffer resource leak that could lead to livelock on corrupt fs.

   - Remove unused function xfs_inew_wait to shut up the build robots"

* tag 'xfs-5.16-fixes-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: remove xfs_inew_wait
  xfs: Fix the free logic of state in xfs_attr_node_hasname

Pull iomap fixes from Darrick Wong:
 "A single iomap bug fix and a cleanup for 5.16-rc2.

  The bug fix changes how iomap deals with reading from an inline data
  region -- whereas the current code (incorrectly) lets the iomap read
  iter try for more bytes after reading the inline region (which zeroes
  the rest of the page!) and hopes the next iteration terminates, we
  surveyed the inlinedata implementations and realized that all
  inlinedata implementations also require that the inlinedata region end
  at EOF, so we can simply terminate the read.

  The second patch documents these assumptions in the code so that
  they're not subtle implications anymore, and cleans up some of the
  grosser parts of that function.

  Summary:

   - Fix an accounting problem where unaligned inline data reads can run
     off the end of the read iomap iterator. iomap has historically
     required that inline data mappings only exist at the end of a file,
     though this wasn't documented anywhere.

   - Document iomap_read_inline_data and change its return type to be
     appropriate for the information that it's actually returning"

* tag 'iomap-5.16-fixes-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  iomap: iomap_read_inline_data cleanup
  iomap: Fix inline extent handling in iomap_readpage

Pull tracing fixes from Steven Rostedt:
 "Two fixes to event pid filtering:

   - Make sure newly created events reflect the current state of pid
     filtering

   - Take pid filtering into account when recording trigger events.
     (Also clean up the if statement to be cleaner)"

* tag 'trace-v5.16-rc2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix pid filtering when triggers are attached
  tracing: Check pid filtering when creating events

Pull more io_uring fixes from Jens Axboe:
 "The locking fixup that was applied earlier this rc has both a deadlock
  and IRQ safety issue, let's get that ironed out before -rc3. This
  contains:

   - Link traversal locking fix (Pavel)

   - Cancelation fix (Pavel)

   - Relocate cond_resched() for huge buffer chain freeing, avoiding a
     softlockup warning (Ye)

   - Fix timespec validation (Ye)"

* tag 'io_uring-5.16-2021-11-27' of git://git.kernel.dk/linux-block:
  io_uring: Fix undefined-behaviour in io_issue_sqe
  io_uring: fix soft lockup when call __io_remove_buffers
  io_uring: fix link traversal locking
  io_uring: fail cancellation for EXITING tasks

Pull more block fixes from Jens Axboe:
 "Turns out that the flushing out of pending fixes before the
  Thanksgiving break didn't quite work out in terms of timing, so here's
  a followup set of fixes:

   - rq_qos_done() should be called regardless of whether or not we're
     the final put of the request, it's not related to the freeing of
     the state. This fixes an IO stall with wbt that a few users have
     reported, a regression in this release.

   - Only define zram_wb_devops if it's used, fixing a compilation
     warning for some compilers"

* tag 'block-5.16-2021-11-27' of git://git.kernel.dk/linux-block:
  zram: only make zram_wb_devops for CONFIG_ZRAM_WRITEBACK
  block: call rq_qos_done() before ref check in batch completions

Pull SCSI fixes from James Bottomley:
 "Twelve fixes, eleven in drivers (target, qla2xx, scsi_debug, mpt3sas,
  ufs). The core fix is a minor correction to the previous state update
  fix for the iscsi daemons"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: scsi_debug: Zero clear zones at reset write pointer
  scsi: core: sysfs: Fix setting device state to SDEV_RUNNING
  scsi: scsi_debug: Sanity check block descriptor length in resp_mode_select()
  scsi: target: configfs: Delete unnecessary checks for NULL
  scsi: target: core: Use RCU helpers for INQUIRY t10_alua_tg_pt_gp
  scsi: mpt3sas: Fix incorrect system timestamp
  scsi: mpt3sas: Fix system going into read-only mode
  scsi: mpt3sas: Fix kernel panic during drive powercycle test
  scsi: ufs: ufs-mediatek: Add put_device() after of_find_device_by_node()
  scsi: scsi_debug: Fix type in min_t to avoid stack OOB
  scsi: qla2xxx: edif: Fix off by one bug in qla_edif_app_getfcinfo()
  scsi: ufs: ufshpb: Fix warning in ufshpb_set_hpb_read_to_upiu()

Pull NFS client fixes from Trond Myklebust:
 "Highlights include:

  Stable fixes:

   - NFSv42: Fix pagecache invalidation after COPY/CLONE

  Bugfixes:

   - NFSv42: Don't fail clone() just because the server failed to return
     post-op attributes

   - SUNRPC: use different lockdep keys for INET6 and LOCAL

   - NFSv4.1: handle NFS4ERR_NOSPC from CREATE_SESSION

   - SUNRPC: fix header include guard in trace header"

* tag 'nfs-for-5.16-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  SUNRPC: use different lock keys for INET6 and LOCAL
  sunrpc: fix header include guard in trace header
  NFSv4.1: handle NFS4ERR_NOSPC by CREATE_SESSION
  NFSv42: Fix pagecache invalidation after COPY/CLONE
  NFS: Add a tracepoint to show the results of nfs_set_cache_invalid()
  NFSv42: Don't fail clone() unless the OP_CLONE operation failed

Pull erofs fix from Gao Xiang:
 "Fix an ABBA deadlock introduced by XArray conversion"

* tag 'erofs-for-5.16-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs:
  erofs: fix deadlock when shrink erofs slab

Pull powerpc fixes from Michael Ellerman:
 "Fix KVM using a Power9 instruction on earlier CPUs, which could lead
  to the host SLB being incorrectly invalidated and a subsequent host
  crash.

  Fix kernel hardlockup on vmap stack overflow on 32-bit.

  Thanks to Christophe Leroy, Nicholas Piggin, and Fabiano Rosas"

* tag 'powerpc-5.16-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/32: Fix hardlockup on vmap stack overflow
  KVM: PPC: Book3S HV: Prevent POWER7/8 TLB flush flushing SLB

Pull MIPS fixes from Thomas Bogendoerfer:

 - build fix for ZSTD enabled configs

 - fix for preempt warning

 - fix for loongson FTLB detection

 - fix for page table level selection

* tag 'mips-fixes_5.16_2' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  MIPS: use 3-level pgtable for 64KB page size on MIPS_VA_BITS_48
  MIPS: loongson64: fix FTLB configuration
  MIPS: Fix using smp_processor_id() in preemptible in show_cpuinfo()
  MIPS: boot/compressed/: add __ashldi3 to target for ZSTD compression

We got issue as follows:
================================================================================
UBSAN: Undefined behaviour in ./include/linux/ktime.h:42:14
signed integer overflow:
-4966321760114568020 * 1000000000 cannot be represented in type 'long long int'
CPU: 1 PID: 2186 Comm: syz-executor.2 Not tainted 4.19.90+ #12
Hardware name: linux,dummy-virt (DT)
Call trace:
 dump_backtrace+0x0/0x3f0 arch/arm64/kernel/time.c:78
 show_stack+0x28/0x38 arch/arm64/kernel/traps.c:158
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x170/0x1dc lib/dump_stack.c:118
 ubsan_epilogue+0x18/0xb4 lib/ubsan.c:161
 handle_overflow+0x188/0x1dc lib/ubsan.c:192
 __ubsan_handle_mul_overflow+0x34/0x44 lib/ubsan.c:213
 ktime_set include/linux/ktime.h:42 [inline]
 timespec64_to_ktime include/linux/ktime.h:78 [inline]
 io_timeout fs/io_uring.c:5153 [inline]
 io_issue_sqe+0x42c8/0x4550 fs/io_uring.c:5599
 __io_queue_sqe+0x1b0/0xbc0 fs/io_uring.c:5988
 io_queue_sqe+0x1ac/0x248 fs/io_uring.c:6067
 io_submit_sqe fs/io_uring.c:6137 [inline]
 io_submit_sqes+0xed8/0x1c88 fs/io_uring.c:6331
 __do_sys_io_uring_enter fs/io_uring.c:8170 [inline]
 __se_sys_io_uring_enter fs/io_uring.c:8129 [inline]
 __arm64_sys_io_uring_enter+0x490/0x980 fs/io_uring.c:8129
 invoke_syscall arch/arm64/kernel/syscall.c:53 [inline]
 el0_svc_common+0x374/0x570 arch/arm64/kernel/syscall.c:121
 el0_svc_handler+0x190/0x260 arch/arm64/kernel/syscall.c:190
 el0_svc+0x10/0x218 arch/arm64/kernel/entry.S:1017
================================================================================

As ktime_set only judge 'secs' if big than KTIME_SEC_MAX, but if we pass
negative value maybe lead to overflow.
To address this issue, we must check if 'sec' is negative.
Signed-off-by: Ye Bin <yebin10@huawei.com>
Link: https://lore.kernel.org/r/20211118015907.844807-1-yebin10@huawei.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

I got issue as follows:
[ 567.094140] __io_remove_buffers: [1]start ctx=0xffff8881067bf000 bgid=65533 buf=0xffff8881fefe1680
[  594.360799] watchdog: BUG: soft lockup - CPU#2 stuck for 26s! [kworker/u32:5:108]
[  594.364987] Modules linked in:
[  594.365405] irq event stamp: 604180238
[  594.365906] hardirqs last  enabled at (604180237): [<ffffffff93fec9bd>] _raw_spin_unlock_irqrestore+0x2d/0x50
[  594.367181] hardirqs last disabled at (604180238): [<ffffffff93fbbadb>] sysvec_apic_timer_interrupt+0xb/0xc0
[  594.368420] softirqs last  enabled at (569080666): [<ffffffff94200654>] __do_softirq+0x654/0xa9e
[  594.369551] softirqs last disabled at (569080575): [<ffffffff913e1d6a>] irq_exit_rcu+0x1ca/0x250
[  594.370692] CPU: 2 PID: 108 Comm: kworker/u32:5 Tainted: G            L    5.15.0-next-20211112+ #88
[  594.371891] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014
[  594.373604] Workqueue: events_unbound io_ring_exit_work
[  594.374303] RIP: 0010:_raw_spin_unlock_irqrestore+0x33/0x50
[  594.375037] Code: 48 83 c7 18 53 48 89 f3 48 8b 74 24 10 e8 55 f5 55 fd 48 89 ef e8 ed a7 56 fd 80 e7 02 74 06 e8 43 13 7b fd fb bf 01 00 00 00 <e8> f8 78 474
[  594.377433] RSP: 0018:ffff888101587a70 EFLAGS: 00000202
[  594.378120] RAX: 0000000024030f0d RBX: 0000000000000246 RCX: 1ffffffff2f09106
[  594.379053] RDX: 0000000000000000 RSI: ffffffff9449f0e0 RDI: 0000000000000001
[  594.379991] RBP: ffffffff9586cdc0 R08: 0000000000000001 R09: fffffbfff2effcab
[  594.380923] R10: ffffffff977fe557 R11: fffffbfff2effcaa R12: ffff8881b8f3def0
[  594.381858] R13: 0000000000000246 R14: ffff888153a8b070 R15: 0000000000000000
[  594.382787] FS:  0000000000000000(0000) GS:ffff888399c00000(0000) knlGS:0000000000000000
[  594.383851] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  594.384602] CR2: 00007fcbe71d2000 CR3: 00000000b4216000 CR4: 00000000000006e0
[  594.385540] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  594.386474] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  594.387403] Call Trace:
[  594.387738]  <TASK>
[  594.388042]  find_and_remove_object+0x118/0x160
[  594.389321]  delete_object_full+0xc/0x20
[  594.389852]  kfree+0x193/0x470
[  594.390275]  __io_remove_buffers.part.0+0xed/0x147
[  594.390931]  io_ring_ctx_free+0x342/0x6a2
[  594.392159]  io_ring_exit_work+0x41e/0x486
[  594.396419]  process_one_work+0x906/0x15a0
[  594.399185]  worker_thread+0x8b/0xd80
[  594.400259]  kthread+0x3bf/0x4a0
[  594.401847]  ret_from_fork+0x22/0x30
[  594.402343]  </TASK>

Message from syslogd@localhost at Nov 13 09:09:54 ...
kernel:watchdog: BUG: soft lockup - CPU#2 stuck for 26s! [kworker/u32:5:108]
[  596.793660] __io_remove_buffers: [2099199]start ctx=0xffff8881067bf000 bgid=65533 buf=0xffff8881fefe1680

We can reproduce this issue by follow syzkaller log:
r0 = syz_io_uring_setup(0x401, &(0x7f0000000300), &(0x7f0000003000/0x2000)=nil, &(0x7f0000ff8000/0x4000)=nil, &(0x7f0000000280)=<r1=>0x0, &(0x7f0000000380)=<r2=>0x0)
sendmsg$ETHTOOL_MSG_FEATURES_SET(0xffffffffffffffff, &(0x7f0000003080)={0x0, 0x0, &(0x7f0000003040)={&(0x7f0000000040)=ANY=[], 0x18}}, 0x0)
syz_io_uring_submit(r1, r2, &(0x7f0000000240)=@IORING_OP_PROVIDE_BUFFERS={0x1f, 0x5, 0x0, 0x401, 0x1, 0x0, 0x100, 0x0, 0x1, {0xfffd}}, 0x0)
io_uring_enter(r0, 0x3a2d, 0x0, 0x0, 0x0, 0x0)

The reason above issue  is 'buf->list' has 2,100,000 nodes, occupied cpu lead
to soft lockup.
To solve this issue, we need add schedule point when do while loop in
'__io_remove_buffers'.
After add  schedule point we do regression, get follow data.
[  240.141864] __io_remove_buffers: [1]start ctx=0xffff888170603000 bgid=65533 buf=0xffff8881116fcb00
[  268.408260] __io_remove_buffers: [1]start ctx=0xffff8881b92d2000 bgid=65533 buf=0xffff888130c83180
[  275.899234] __io_remove_buffers: [2099199]start ctx=0xffff888170603000 bgid=65533 buf=0xffff8881116fcb00
[  296.741404] __io_remove_buffers: [1]start ctx=0xffff8881b659c000 bgid=65533 buf=0xffff8881010fe380
[  305.090059] __io_remove_buffers: [2099199]start ctx=0xffff8881b92d2000 bgid=65533 buf=0xffff888130c83180
[  325.415746] __io_remove_buffers: [1]start ctx=0xffff8881b92d1000 bgid=65533 buf=0xffff8881a17d8f00
[  333.160318] __io_remove_buffers: [2099199]start ctx=0xffff8881b659c000 bgid=65533 buf=0xffff8881010fe380
...

Fixes:8bab4c09("io_uring: allow conditional reschedule for intensive iterators")
Signed-off-by: Ye Bin <yebin10@huawei.com>
Link: https://lore.kernel.org/r/20211122024737.2198530-1-yebin10@huawei.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

If a event is filtered by pid and a trigger that requires processing of
the event to happen is a attached to the event, the discard portion does
not take the pid filtering into account, and the event will then be
recorded when it should not have been.

Cc: stable@vger.kernel.org
Fixes: 3fdaf80f ("tracing: Implement event pid filtering")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>