The counter backwards may be observed in the PMI handler when
counters-snapshotting some non-precise events in the freq mode.

For the non-precise events, it's possible the counters-snapshotting
records a positive value for an overflowed PEBS event. Then the HW
auto-reload mechanism reset the counter to 0 immediately. Because the
pebs_event_reset is cleared in the freq mode, which doesn't set the
PERF_X86_EVENT_AUTO_RELOAD.
In the PMI handler, 0 will be read rather than the positive value
recorded in the counters-snapshotting record.

The counters-snapshotting case has to be specially handled. Since the
event value has been updated when processing the counters-snapshotting
record, only needs to set the new period for the counter via
x86_pmu_set_period().

Fixes: e02e9b0374c3 ("perf/x86/intel: Support PEBS counters snapshotting")
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20250424134718.311934-6-kan.liang@linux.intel.com

The PEBS counters snapshotting group also requires a group flag in the
leader. The leader must be a X86 event.

Fixes: e02e9b0374c3 ("perf/x86/intel: Support PEBS counters snapshotting")
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20250424134718.311934-3-kan.liang@linux.intel.com

A warning in intel_pmu_lbr_counters_reorder() may be triggered by below
perf command.

perf record -e "{cpu-clock,cycles/call-graph="lbr"/}" -- sleep 1

It's because the group is mistakenly treated as a branch counter group.

The hw.flags of the leader are used to determine whether a group is a
branch counters group. However, the hw.flags is only available for a
hardware event. The field to store the flags is a union type. For a
software event, it's a hrtimer. The corresponding bit may be set if the
leader is a software event.

For a branch counter group and other groups that have a group flag
(e.g., topdown, PEBS counters snapshotting, and ACR), the leader must
be a X86 event. Check the X86 event before checking the flag.
The patch only fixes the issue for the branch counter group.
The following patch will fix the other groups.

There may be an alternative way to fix the issue by moving the hw.flags
out of the union type. It should work for now. But it's still possible
that the flags will be used by other types of events later. As long as
that type of event is used as a leader, a similar issue will be
triggered. So the alternative way is dropped.

Fixes: 33744916196b ("perf/x86/intel: Support branch counters logging")
Closes: https://lore.kernel.org/lkml/20250412091423.1839809-1-luogengkun@huaweicloud.com/
Reported-by: Luo Gengkun <luogengkun@huaweicloud.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20250424134718.311934-2-kan.liang@linux.intel.com

Perf doesn't work at perf stat for hardware events on certain x86 platforms:

$perf stat -- sleep 1
Performance counter stats for 'sleep 1':
16.44 msec task-clock # 0.016 CPUs utilized
2 context-switches # 121.691 /sec
0 cpu-migrations # 0.000 /sec
54 page-faults # 3.286 K/sec
<not supported> cycles
<not supported> instructions
<not supported> branches
<not supported> branch-misses

The reason is that the check in x86_pmu_hw_config() for sampling events is
unexpectedly applied to counting events as well.

It should only impact x86 platforms with limit_period used for non-PEBS
events. For Intel platforms, it should only impact some older platforms,
e.g., HSW, BDW and NHM.

Fixes: 88ec7eedbbd2 ("perf/x86: Fix low freqency setting issue")
Signed-off-by: Luo Gengkun <luogengkun@huaweicloud.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Link: https://lore.kernel.org/r/20250423064724.3716211-1-luogengkun@huaweicloud.com

Commit:

f4b07fd62d4d11d5 ("perf/core: Use POLLHUP for pinned events in error")

started to emit POLLHUP for pinned events in an error state.

But the POLLHUP is also used to signal events that the attached task is
terminated. To distinguish pinned per-task events in the error state
it would need to check if the task is live.

Change it to POLLERR to make it clear.

Suggested-by: Gabriel Marin <gmx@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250422223318.180343-1-namhyung@kernel.org

Pull btrfs fixes from David Sterba:

- subpage mode fixes:
- access correct object (folio) when looking up bit offset
- fix assertion condition for number of blocks per folio
- fix upper boundary of locking range in hole punch

- zoned fixes:
- fix potential deadlock caught by lockdep when zone reporting and
device freeze run in parallel
- fix zone write pointer mismatch and NULL pointer dereference when
metadata are converted from DUP to RAID1

- fix error handling when reloc inode creation fails

- in tree-checker, unify error code for header level check

- block layer: add helpers to read zone capacity

* tag 'for-6.15-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: zoned: skip reporting zone for new block group
block: introduce zone capacity helper
btrfs: tree-checker: adjust error code for header level check
btrfs: fix invalid inode pointer after failure to create reloc inode
btrfs: zoned: return EIO on RAID1 block group write pointer mismatch
btrfs: fix the ASSERT() inside GET_SUBPAGE_BITMAP()
btrfs: avoid page_lockend underflow in btrfs_punch_hole_lock_range()
btrfs: subpage: access correct object when reading bitmap start in subpage_calc_start_bit()

Pull integrity fix from Roberto Sassu:
"One performance fix to avoid unnecessarily taking the inode lock"

* tag 'integrity-6.15-rc3-fix' of https://github.com/linux-integrity/linux:
ima: process_measurement() needlessly takes inode_lock() on MAY_READ

There is a potential deadlock if we do report zones in an IO context, detailed
in below lockdep report. When one process do a report zones and another process
freezes the block device, the report zones side cannot allocate a tag because
the freeze is already started. This can thus result in new block group creation
to hang forever, blocking the write path.

Thankfully, a new block group should be created on empty zones. So, reporting
the zones is not necessary and we can set the write pointer = 0 and load the
zone capacity from the block layer using bdev_zone_capacity() helper.

======================================================
WARNING: possible circular locking dependency detected
6.14.0-rc1 #252 Not tainted
------------------------------------------------------
modprobe/1110 is trying to acquire lock:
ffff888100ac83e0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: __flush_work+0x38f/0xb60

but task is already holding lock:
ffff8881205b6f20 (&q->q_usage_counter(queue)#16){++++}-{0:0}, at: sd_remove+0x85/0x130

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #3 (&q->q_usage_counter(queue)#16){++++}-{0:0}:
blk_queue_enter+0x3d9/0x500
blk_mq_alloc_request+0x47d/0x8e0
scsi_execute_cmd+0x14f/0xb80
sd_zbc_do_report_zones+0x1c1/0x470
sd_zbc_report_zones+0x362/0xd60
blkdev_report_zones+0x1b1/0x2e0
btrfs_get_dev_zones+0x215/0x7e0 [btrfs]
btrfs_load_block_group_zone_info+0x6d2/0x2c10 [btrfs]
btrfs_make_block_group+0x36b/0x870 [btrfs]
btrfs_create_chunk+0x147d/0x2320 [btrfs]
btrfs_chunk_alloc+0x2ce/0xcf0 [btrfs]
start_transaction+0xce6/0x1620 [btrfs]
btrfs_uuid_scan_kthread+0x4ee/0x5b0 [btrfs]
kthread+0x39d/0x750
ret_from_fork+0x30/0x70
ret_from_fork_asm+0x1a/0x30

-> #2 (&fs_info->dev_replace.rwsem){++++}-{4:4}:
down_read+0x9b/0x470
btrfs_map_block+0x2ce/0x2ce0 [btrfs]
btrfs_submit_chunk+0x2d4/0x16c0 [btrfs]
btrfs_submit_bbio+0x16/0x30 [btrfs]
btree_write_cache_pages+0xb5a/0xf90 [btrfs]
do_writepages+0x17f/0x7b0
__writeback_single_inode+0x114/0xb00
writeback_sb_inodes+0x52b/0xe00
wb_writeback+0x1a7/0x800
wb_workfn+0x12a/0xbd0
process_one_work+0x85a/0x1460
worker_thread+0x5e2/0xfc0
kthread+0x39d/0x750
ret_from_fork+0x30/0x70
ret_from_fork_asm+0x1a/0x30

-> #1 (&fs_info->zoned_meta_io_lock){+.+.}-{4:4}:
__mutex_lock+0x1aa/0x1360
btree_write_cache_pages+0x252/0xf90 [btrfs]
do_writepages+0x17f/0x7b0
__writeback_single_inode+0x114/0xb00
writeback_sb_inodes+0x52b/0xe00
wb_writeback+0x1a7/0x800
wb_workfn+0x12a/0xbd0
process_one_work+0x85a/0x1460
worker_thread+0x5e2/0xfc0
kthread+0x39d/0x750
ret_from_fork+0x30/0x70
ret_from_fork_asm+0x1a/0x30

-> #0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}:
__lock_acquire+0x2f52/0x5ea0
lock_acquire+0x1b1/0x540
__flush_work+0x3ac/0xb60
wb_shutdown+0x15b/0x1f0
bdi_unregister+0x172/0x5b0
del_gendisk+0x841/0xa20
sd_remove+0x85/0x130
device_release_driver_internal+0x368/0x520
bus_remove_device+0x1f1/0x3f0
device_del+0x3bd/0x9c0
__scsi_remove_device+0x272/0x340
scsi_forget_host+0xf7/0x170
scsi_remove_host+0xd2/0x2a0
sdebug_driver_remove+0x52/0x2f0 [scsi_debug]
device_release_driver_internal+0x368/0x520
bus_remove_device+0x1f1/0x3f0
device_del+0x3bd/0x9c0
device_unregister+0x13/0xa0
sdebug_do_remove_host+0x1fb/0x290 [scsi_debug]
scsi_debug_exit+0x17/0x70 [scsi_debug]
__do_sys_delete_module.isra.0+0x321/0x520
do_syscall_64+0x93/0x180
entry_SYSCALL_64_after_hwframe+0x76/0x7e

other info that might help us debug this:

Chain exists of:
(work_completion)(&(&wb->dwork)->work) --> &fs_info->dev_replace.rwsem --> &q->q_usage_counter(queue)#16

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&q->q_usage_counter(queue)#16);
lock(&fs_info->dev_replace.rwsem);
lock(&q->q_usage_counter(queue)#16);
lock((work_completion)(&(&wb->dwork)->work));

*** DEADLOCK ***

5 locks held by modprobe/1110:
#0: ffff88811f7bc108 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0x8f/0x520
#1: ffff8881022ee0e0 (&shost->scan_mutex){+.+.}-{4:4}, at: scsi_remove_host+0x20/0x2a0
#2: ffff88811b4c4378 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0x8f/0x520
#3: ffff8881205b6f20 (&q->q_usage_counter(queue)#16){++++}-{0:0}, at: sd_remove+0x85/0x130
#4: ffffffffa3284360 (rcu_read_lock){....}-{1:3}, at: __flush_work+0xda/0xb60

stack backtrace:
CPU: 0 UID: 0 PID: 1110 Comm: modprobe Not tainted 6.14.0-rc1 #252
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-3.fc41 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x6a/0x90
print_circular_bug.cold+0x1e0/0x274
check_noncircular+0x306/0x3f0
? __pfx_check_noncircular+0x10/0x10
? mark_lock+0xf5/0x1650
? __pfx_check_irq_usage+0x10/0x10
? lockdep_lock+0xca/0x1c0
? __pfx_lockdep_lock+0x10/0x10
__lock_acquire+0x2f52/0x5ea0
? __pfx___lock_acquire+0x10/0x10
? __pfx_mark_lock+0x10/0x10
lock_acquire+0x1b1/0x540
? __flush_work+0x38f/0xb60
? __pfx_lock_acquire+0x10/0x10
? __pfx_lock_release+0x10/0x10
? mark_held_locks+0x94/0xe0
? __flush_work+0x38f/0xb60
__flush_work+0x3ac/0xb60
? __flush_work+0x38f/0xb60
? __pfx_mark_lock+0x10/0x10
? __pfx___flush_work+0x10/0x10
? __pfx_wq_barrier_func+0x10/0x10
? __pfx___might_resched+0x10/0x10
? mark_held_locks+0x94/0xe0
wb_shutdown+0x15b/0x1f0
bdi_unregister+0x172/0x5b0
? __pfx_bdi_unregister+0x10/0x10
? up_write+0x1ba/0x510
del_gendisk+0x841/0xa20
? __pfx_del_gendisk+0x10/0x10
? _raw_spin_unlock_irqrestore+0x35/0x60
? __pm_runtime_resume+0x79/0x110
sd_remove+0x85/0x130
device_release_driver_internal+0x368/0x520
? kobject_put+0x5d/0x4a0
bus_remove_device+0x1f1/0x3f0
device_del+0x3bd/0x9c0
? __pfx_device_del+0x10/0x10
__scsi_remove_device+0x272/0x340
scsi_forget_host+0xf7/0x170
scsi_remove_host+0xd2/0x2a0
sdebug_driver_remove+0x52/0x2f0 [scsi_debug]
? kernfs_remove_by_name_ns+0xc0/0xf0
device_release_driver_internal+0x368/0x520
? kobject_put+0x5d/0x4a0
bus_remove_device+0x1f1/0x3f0
device_del+0x3bd/0x9c0
? __pfx_device_del+0x10/0x10
? __pfx___mutex_unlock_slowpath+0x10/0x10
device_unregister+0x13/0xa0
sdebug_do_remove_host+0x1fb/0x290 [scsi_debug]
scsi_debug_exit+0x17/0x70 [scsi_debug]
__do_sys_delete_module.isra.0+0x321/0x520
? __pfx___do_sys_delete_module.isra.0+0x10/0x10
? __pfx_slab_free_after_rcu_debug+0x10/0x10
? kasan_save_stack+0x2c/0x50
? kasan_record_aux_stack+0xa3/0xb0
? __call_rcu_common.constprop.0+0xc4/0xfb0
? kmem_cache_free+0x3a0/0x590
? __x64_sys_close+0x78/0xd0
do_syscall_64+0x93/0x180
? lock_is_held_type+0xd5/0x130
? __call_rcu_common.constprop.0+0x3c0/0xfb0
? lockdep_hardirqs_on+0x78/0x100
? __call_rcu_common.constprop.0+0x3c0/0xfb0
? __pfx___call_rcu_common.constprop.0+0x10/0x10
? kmem_cache_free+0x3a0/0x590
? lockdep_hardirqs_on_prepare+0x16d/0x400
? do_syscall_64+0x9f/0x180
? lockdep_hardirqs_on+0x78/0x100
? do_syscall_64+0x9f/0x180
? __pfx___x64_sys_openat+0x10/0x10
? lockdep_hardirqs_on_prepare+0x16d/0x400
? do_syscall_64+0x9f/0x180
? lockdep_hardirqs_on+0x78/0x100
? do_syscall_64+0x9f/0x180
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f436712b68b
RSP: 002b:00007ffe9f1a8658 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
RAX: ffffffffffffffda RBX: 00005559b367fd80 RCX: 00007f436712b68b
RDX: 0000000000000000 RSI: 0000000000000800 RDI: 00005559b367fde8
RBP: 00007ffe9f1a8680 R08: 1999999999999999 R09: 0000000000000000
R10: 00007f43671a5fe0 R11: 0000000000000206 R12: 0000000000000000
R13: 00007ffe9f1a86b0 R14: 0000000000000000 R15: 0000000000000000
</TASK>

Reported-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
CC: <stable@vger.kernel.org> # 6.13+
Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Pull sched_ext fixes from Tejun Heo:

- Use kvzalloc() so that large exit_dump buffer allocations don't fail
easily

- Remove cpu.weight / cpu.idle unimplemented warnings which are more
annoying than helpful.

This makes SCX_OPS_HAS_CGROUP_WEIGHT unnecessary. Mark it for
deprecation

* tag 'sched_ext-for-6.15-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext:
sched_ext: Mark SCX_OPS_HAS_CGROUP_WEIGHT for deprecation
sched_ext: Remove cpu.weight / cpu.idle unimplemented warnings
sched_ext: Use kvzalloc for large exit_dump allocation

On IMA policy update, if a measure rule exists in the policy,
IMA_MEASURE is set for ima_policy_flags which makes the violation_check
variable always true. Coupled with a no-action on MAY_READ for a
FILE_CHECK call, we're always taking the inode_lock().

This becomes a performance problem for extremely heavy read-only workloads.
Therefore, prevent this only in the case there's no action to be taken.

Signed-off-by: Frederick Lawler <fred@cloudflare.com>
Acked-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

{bdev,disk}_zone_capacity() takes block_device or gendisk and sector position
and returns the zone capacity of the corresponding zone.

With that, move disk_nr_zones() and blk_zone_plug_bio() to consolidate them in
the same #ifdef block.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Pull cgroup fixes from Tejun Heo:

- Fix compilation in CONFIG_LOCKDEP && !CONFIG_PROVE_RCU configurations

- Allow "cpuset_v2_mode" mount option for "cpuset" filesystem type to
make life easier for android

* tag 'cgroup-for-6.15-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup/cpuset-v1: Add missing support for cpuset_v2_mode
cgroup: Fix compilation issue due to cgroup_mutex not being exported

SCX_OPS_HAS_CGROUP_WEIGHT was only used to suppress the missing cgroup
weight support warnings. Now that the warnings are removed, the flag doesn't
do anything. Mark it for deprecation and remove its usage from scx_flatcg.

v2: Actually include the scx_flatcg update.

Signed-off-by: Tejun Heo <tj@kernel.org>
Suggested-and-reviewed-by: Andrea Righi <arighi@nvidia.com>

The whole tree checker returns EUCLEAN, except the one check in
btrfs_verify_level_key(). This was inherited from the function that was
moved from disk-io.c in 2cac5af16537 ("btrfs: move
btrfs_verify_level_key into tree-checker.c") but this should be unified
with the rest.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

I had left the warning around but as a non-fatal error to get my gcc-15
builds going, but fixed up some of the most annoying warning cases so
that it wouldn't be *too* verbose.

Because I like the _concept_ of the warning, even if I detested the
implementation to shut it up.

It turns out the implementation to shut it up is even more broken than I
thought, and my "shut up most of the warnings" patch just caused fatal
errors on gcc-14 instead.

I had tested with clang, but when I upgrade my development environment,
I try to do it on all machines because I hate having different systems
to maintain, and hadn't realized that gcc-14 now had issues.

The ACPI case is literally why I wanted to have a *type* that doesn't
trigger the warning (see commit d5d45a7f2619: "gcc-15: make
'unterminated string initialization' just a warning"), instead of
marking individual places as "__nonstring".

But gcc-14 doesn't like that __nonstring location that shut gcc-15 up,
because it's on an array of char arrays, not on one single array:

drivers/acpi/tables.c:399:1: error: 'nonstring' attribute ignored on objects of type 'const char[][4]' [-Werror=attributes]
399 | static const char table_sigs[][ACPI_NAMESEG_SIZE] __initconst __nonstring = {
| ^~~~~~

and my attempts to nest it properly with a type had failed, because of
how gcc doesn't like marking the types as having attributes, only
symbols.

There may be some trick to it, but I was already annoyed by the bad
attribute design, now I'm just entirely fed up with it.

I wish gcc had a proper way to say "this type is a *byte* array, not a
string".

The obvious thing would be to distinguish between "char []" and an
explicitly signed "unsigned char []" (as opposed to an implicitly
unsigned char, which is typically an architecture-specific default, but
for the kernel is universal thanks to '-funsigned-char').

But any "we can typedef a 8-bit type to not become a string just because
it's an array" model would be fine.

But "__attribute__((nonstring))" is sadly not that sane model.

Reported-by: Chris Clayton <chris2553@googlemail.com>
Fixes: 4b4bd8c50f48 ("gcc-15: acpi: sprinkle random '__nonstring' crumbles around")
Fixes: d5d45a7f2619 ("gcc-15: make 'unterminated string initialization' just a warning")
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>