<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/kernel, branch v6.18-rc2</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>Merge tag 'sched_urgent_for_v6.18_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2025-10-19T14:59:43+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-10-19T14:59:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=d9043c79ba68a089f95bb4344ab0232c3585f9f1'/>
<id>d9043c79ba68a089f95bb4344ab0232c3585f9f1</id>
<content type='text'>
Pull scheduler fixes from Borislav Petkov:

 - Make sure the check for lost pelt idle time is done unconditionally
   to have correct lost idle time accounting

 - Stop the deadline server task before a CPU goes offline

* tag 'sched_urgent_for_v6.18_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Fix pelt lost idle time detection
  sched/deadline: Stop dl_server before CPU goes offline
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull scheduler fixes from Borislav Petkov:

 - Make sure the check for lost pelt idle time is done unconditionally
   to have correct lost idle time accounting

 - Stop the deadline server task before a CPU goes offline

* tag 'sched_urgent_for_v6.18_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Fix pelt lost idle time detection
  sched/deadline: Stop dl_server before CPU goes offline
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'perf_urgent_for_v6.18_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2025-10-19T14:54:08+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-10-19T14:54:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=343b4b44a10f6e383bd829ba130024cfde2a08d4'/>
<id>343b4b44a10f6e383bd829ba130024cfde2a08d4</id>
<content type='text'>
Pull perf fixes from Borislav Petkov:

 - Make sure perf reporting works correctly in setups using
   overlayfs or FUSE

 - Move the uprobe optimization to a better location logically

* tag 'perf_urgent_for_v6.18_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Fix MMAP2 event device with backing files
  perf/core: Fix MMAP event path names with backing files
  perf/core: Fix address filter match with backing files
  uprobe: Move arch_uprobe_optimize right after handlers execution
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull perf fixes from Borislav Petkov:

 - Make sure perf reporting works correctly in setups using
   overlayfs or FUSE

 - Move the uprobe optimization to a better location logically

* tag 'perf_urgent_for_v6.18_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Fix MMAP2 event device with backing files
  perf/core: Fix MMAP event path names with backing files
  perf/core: Fix address filter match with backing files
  uprobe: Move arch_uprobe_optimize right after handlers execution
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Fix memory leak in __lookup_instance error path</title>
<updated>2025-10-16T17:45:17+00:00</updated>
<author>
<name>Shardul Bankar</name>
<email>shardulsb08@gmail.com</email>
</author>
<published>2025-10-16T06:33:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=f6fddc6df3fc0cffce329b87927db4eb5989728d'/>
<id>f6fddc6df3fc0cffce329b87927db4eb5989728d</id>
<content type='text'>
When __lookup_instance() allocates a func_instance structure but fails
to allocate the must_write_set array, it returns an error without freeing
the previously allocated func_instance. This causes a memory leak of 192
bytes (sizeof(struct func_instance)) each time this error path is triggered.

Fix by freeing 'result' on must_write_set allocation failure.

Fixes: b3698c356ad9 ("bpf: callchain sensitive stack liveness tracking using CFG")
Reported-by: BPF Runtime Fuzzer (BRF)
Signed-off-by: Shardul Bankar &lt;shardulsb08@gmail.com&gt;
Signed-off-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
Acked-by: Eduard Zingerman &lt;eddyz87@gmail.com&gt;
Link: https://patch.msgid.link/20251016063330.4107547-1-shardulsb08@gmail.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When __lookup_instance() allocates a func_instance structure but fails
to allocate the must_write_set array, it returns an error without freeing
the previously allocated func_instance. This causes a memory leak of 192
bytes (sizeof(struct func_instance)) each time this error path is triggered.

Fix by freeing 'result' on must_write_set allocation failure.

Fixes: b3698c356ad9 ("bpf: callchain sensitive stack liveness tracking using CFG")
Reported-by: BPF Runtime Fuzzer (BRF)
Signed-off-by: Shardul Bankar &lt;shardulsb08@gmail.com&gt;
Signed-off-by: Martin KaFai Lau &lt;martin.lau@kernel.org&gt;
Acked-by: Eduard Zingerman &lt;eddyz87@gmail.com&gt;
Link: https://patch.msgid.link/20251016063330.4107547-1-shardulsb08@gmail.com
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Replace bpf_map_kmalloc_node() with kmalloc_nolock() to allocate bpf_async_cb structures.</title>
<updated>2025-10-15T10:22:22+00:00</updated>
<author>
<name>Alexei Starovoitov</name>
<email>ast@kernel.org</email>
</author>
<published>2025-10-15T00:07:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=5fb750e8a9ae123b2034771b864b8a21dbef65cd'/>
<id>5fb750e8a9ae123b2034771b864b8a21dbef65cd</id>
<content type='text'>
The following kmemleak splat:

[    8.105530] kmemleak: Trying to color unknown object at 0xff11000100e918c0 as Black
[    8.106521] Call Trace:
[    8.106521]  &lt;TASK&gt;
[    8.106521]  dump_stack_lvl+0x4b/0x70
[    8.106521]  kvfree_call_rcu+0xcb/0x3b0
[    8.106521]  ? hrtimer_cancel+0x21/0x40
[    8.106521]  bpf_obj_free_fields+0x193/0x200
[    8.106521]  htab_map_update_elem+0x29c/0x410
[    8.106521]  bpf_prog_cfc8cd0f42c04044_overwrite_cb+0x47/0x4b
[    8.106521]  bpf_prog_8c30cd7c4db2e963_overwrite_timer+0x65/0x86
[    8.106521]  bpf_prog_test_run_syscall+0xe1/0x2a0

happens due to the combination of features and fixes, but mainly due to
commit 6d78b4473cdb ("bpf: Tell memcg to use allow_spinning=false path in bpf_timer_init()")
It's using __GFP_HIGH, which instructs slub/kmemleak internals to skip
kmemleak_alloc_recursive() on allocation, so subsequent kfree_rcu()-&gt;
kvfree_call_rcu()-&gt;kmemleak_ignore() complains with the above splat.

To fix this imbalance, replace bpf_map_kmalloc_node() with
kmalloc_nolock() and kfree_rcu() with call_rcu() + kfree_nolock() to
make sure that the objects allocated with kmalloc_nolock() are freed
with kfree_nolock() rather than the implicit kfree() that kfree_rcu()
uses internally.

Note, the kmalloc_nolock() happens under bpf_spin_lock_irqsave(), so
it will always fail in PREEMPT_RT. This is not an issue at the moment,
since bpf_timers are disabled in PREEMPT_RT. In the future
bpf_spin_lock will be replaced with state machine similar to
bpf_task_work.

Fixes: 6d78b4473cdb ("bpf: Tell memcg to use allow_spinning=false path in bpf_timer_init()")
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Reviewed-by: Shakeel Butt &lt;shakeel.butt@linux.dev&gt;
Acked-by: Harry Yoo &lt;harry.yoo@oracle.com&gt;
Acked-by: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: linux-mm@kvack.org
Link: https://lore.kernel.org/bpf/20251015000700.28988-1-alexei.starovoitov@gmail.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The following kmemleak splat:

[    8.105530] kmemleak: Trying to color unknown object at 0xff11000100e918c0 as Black
[    8.106521] Call Trace:
[    8.106521]  &lt;TASK&gt;
[    8.106521]  dump_stack_lvl+0x4b/0x70
[    8.106521]  kvfree_call_rcu+0xcb/0x3b0
[    8.106521]  ? hrtimer_cancel+0x21/0x40
[    8.106521]  bpf_obj_free_fields+0x193/0x200
[    8.106521]  htab_map_update_elem+0x29c/0x410
[    8.106521]  bpf_prog_cfc8cd0f42c04044_overwrite_cb+0x47/0x4b
[    8.106521]  bpf_prog_8c30cd7c4db2e963_overwrite_timer+0x65/0x86
[    8.106521]  bpf_prog_test_run_syscall+0xe1/0x2a0

happens due to the combination of features and fixes, but mainly due to
commit 6d78b4473cdb ("bpf: Tell memcg to use allow_spinning=false path in bpf_timer_init()")
It's using __GFP_HIGH, which instructs slub/kmemleak internals to skip
kmemleak_alloc_recursive() on allocation, so subsequent kfree_rcu()-&gt;
kvfree_call_rcu()-&gt;kmemleak_ignore() complains with the above splat.

To fix this imbalance, replace bpf_map_kmalloc_node() with
kmalloc_nolock() and kfree_rcu() with call_rcu() + kfree_nolock() to
make sure that the objects allocated with kmalloc_nolock() are freed
with kfree_nolock() rather than the implicit kfree() that kfree_rcu()
uses internally.

Note, the kmalloc_nolock() happens under bpf_spin_lock_irqsave(), so
it will always fail in PREEMPT_RT. This is not an issue at the moment,
since bpf_timers are disabled in PREEMPT_RT. In the future
bpf_spin_lock will be replaced with state machine similar to
bpf_task_work.

Fixes: 6d78b4473cdb ("bpf: Tell memcg to use allow_spinning=false path in bpf_timer_init()")
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Reviewed-by: Shakeel Butt &lt;shakeel.butt@linux.dev&gt;
Acked-by: Harry Yoo &lt;harry.yoo@oracle.com&gt;
Acked-by: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: linux-mm@kvack.org
Link: https://lore.kernel.org/bpf/20251015000700.28988-1-alexei.starovoitov@gmail.com
</pre>
</div>
</content>
</entry>
<entry>
<title>sched/fair: Fix pelt lost idle time detection</title>
<updated>2025-10-14T11:43:08+00:00</updated>
<author>
<name>Vincent Guittot</name>
<email>vincent.guittot@linaro.org</email>
</author>
<published>2025-10-08T13:12:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=17e3e88ed0b6318fde0d1c14df1a804711cab1b5'/>
<id>17e3e88ed0b6318fde0d1c14df1a804711cab1b5</id>
<content type='text'>
The check for some lost idle pelt time should be always done when
pick_next_task_fair() fails to pick a task and not only when we call it
from the fair fast-path.

The case happens when the last running task on rq is a RT or DL task. When
the latter goes to sleep and the /Sum of util_sum of the rq is at the max
value, we don't account the lost of idle time whereas we should.

Fixes: 67692435c411 ("sched: Rework pick_next_task() slow-path")
Signed-off-by: Vincent Guittot &lt;vincent.guittot@linaro.org&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The check for some lost idle pelt time should be always done when
pick_next_task_fair() fails to pick a task and not only when we call it
from the fair fast-path.

The case happens when the last running task on rq is a RT or DL task. When
the latter goes to sleep and the /Sum of util_sum of the rq is at the max
value, we don't account the lost of idle time whereas we should.

Fixes: 67692435c411 ("sched: Rework pick_next_task() slow-path")
Signed-off-by: Vincent Guittot &lt;vincent.guittot@linaro.org&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>sched/deadline: Stop dl_server before CPU goes offline</title>
<updated>2025-10-14T11:43:08+00:00</updated>
<author>
<name>Peter Zijlstra (Intel)</name>
<email>peterz@infradead.org</email>
</author>
<published>2025-10-09T18:47:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ee6e44dfe6e50b4a5df853d933a96bdff5309e6e'/>
<id>ee6e44dfe6e50b4a5df853d933a96bdff5309e6e</id>
<content type='text'>
IBM CI tool reported kernel warning[1] when running a CPU removal
operation through drmgr[2]. i.e "drmgr -c cpu -r -q 1"

WARNING: CPU: 0 PID: 0 at kernel/sched/cpudeadline.c:219 cpudl_set+0x58/0x170
NIP [c0000000002b6ed8] cpudl_set+0x58/0x170
LR [c0000000002b7cb8] dl_server_timer+0x168/0x2a0
Call Trace:
[c000000002c2f8c0] init_stack+0x78c0/0x8000 (unreliable)
[c0000000002b7cb8] dl_server_timer+0x168/0x2a0
[c00000000034df84] __hrtimer_run_queues+0x1a4/0x390
[c00000000034f624] hrtimer_interrupt+0x124/0x300
[c00000000002a230] timer_interrupt+0x140/0x320

Git bisects to: commit 4ae8d9aa9f9d ("sched/deadline: Fix dl_server getting stuck")

This happens since:
- dl_server hrtimer gets enqueued close to cpu offline, when
  kthread_park enqueues a fair task.
- CPU goes offline and drmgr removes it from cpu_present_mask.
- hrtimer fires and warning is hit.

Fix it by stopping the dl_server before CPU is marked dead.

[1]: https://lore.kernel.org/all/8218e149-7718-4432-9312-f97297c352b9@linux.ibm.com/
[2]: https://github.com/ibm-power-utilities/powerpc-utils/tree/next/src/drmgr

[sshegde: wrote the changelog and tested it]
Fixes: 4ae8d9aa9f9d ("sched/deadline: Fix dl_server getting stuck")
Closes: https://lore.kernel.org/all/8218e149-7718-4432-9312-f97297c352b9@linux.ibm.com
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Reported-by: Venkat Rao Bagalkote &lt;venkat88@linux.ibm.com&gt;
Signed-off-by: Shrikanth Hegde &lt;sshegde@linux.ibm.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Tested-by: Marek Szyprowski &lt;m.szyprowski@samsung.com&gt;
Tested-by: Shrikanth Hegde &lt;sshegde@linux.ibm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
IBM CI tool reported kernel warning[1] when running a CPU removal
operation through drmgr[2]. i.e "drmgr -c cpu -r -q 1"

WARNING: CPU: 0 PID: 0 at kernel/sched/cpudeadline.c:219 cpudl_set+0x58/0x170
NIP [c0000000002b6ed8] cpudl_set+0x58/0x170
LR [c0000000002b7cb8] dl_server_timer+0x168/0x2a0
Call Trace:
[c000000002c2f8c0] init_stack+0x78c0/0x8000 (unreliable)
[c0000000002b7cb8] dl_server_timer+0x168/0x2a0
[c00000000034df84] __hrtimer_run_queues+0x1a4/0x390
[c00000000034f624] hrtimer_interrupt+0x124/0x300
[c00000000002a230] timer_interrupt+0x140/0x320

Git bisects to: commit 4ae8d9aa9f9d ("sched/deadline: Fix dl_server getting stuck")

This happens since:
- dl_server hrtimer gets enqueued close to cpu offline, when
  kthread_park enqueues a fair task.
- CPU goes offline and drmgr removes it from cpu_present_mask.
- hrtimer fires and warning is hit.

Fix it by stopping the dl_server before CPU is marked dead.

[1]: https://lore.kernel.org/all/8218e149-7718-4432-9312-f97297c352b9@linux.ibm.com/
[2]: https://github.com/ibm-power-utilities/powerpc-utils/tree/next/src/drmgr

[sshegde: wrote the changelog and tested it]
Fixes: 4ae8d9aa9f9d ("sched/deadline: Fix dl_server getting stuck")
Closes: https://lore.kernel.org/all/8218e149-7718-4432-9312-f97297c352b9@linux.ibm.com
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Reported-by: Venkat Rao Bagalkote &lt;venkat88@linux.ibm.com&gt;
Signed-off-by: Shrikanth Hegde &lt;sshegde@linux.ibm.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Tested-by: Marek Szyprowski &lt;m.szyprowski@samsung.com&gt;
Tested-by: Shrikanth Hegde &lt;sshegde@linux.ibm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf/core: Fix MMAP2 event device with backing files</title>
<updated>2025-10-14T08:38:10+00:00</updated>
<author>
<name>Adrian Hunter</name>
<email>adrian.hunter@intel.com</email>
</author>
<published>2025-10-13T07:22:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=fa4f4bae893fbce8a3edfff1ab7ece0c01dc1328'/>
<id>fa4f4bae893fbce8a3edfff1ab7ece0c01dc1328</id>
<content type='text'>
Some file systems like FUSE-based ones or overlayfs may record the backing
file in struct vm_area_struct vm_file, instead of the user file that the
user mmapped.

That causes perf to misreport the device major/minor numbers of the file
system of the file, and the generation of the file, and potentially other
inode details.  There is an existing helper file_user_inode() for that
situation.

Use file_user_inode() instead of file_inode() to get the inode for MMAP2
events.

Example:

  Setup:

    # cd /root
    # mkdir test ; cd test ; mkdir lower upper work merged
    # cp `which cat` lower
    # mount -t overlay overlay -olowerdir=lower,upperdir=upper,workdir=work merged
    # perf record -e cycles:u -- /root/test/merged/cat /proc/self/maps
    ...
    55b2c91d0000-55b2c926b000 r-xp 00018000 00:1a 3419                       /root/test/merged/cat
    ...
    [ perf record: Woken up 1 times to write data ]
    [ perf record: Captured and wrote 0.004 MB perf.data (5 samples) ]
    #
    # stat /root/test/merged/cat
      File: /root/test/merged/cat
      Size: 1127792         Blocks: 2208       IO Block: 4096   regular file
    Device: 0,26    Inode: 3419        Links: 1
    Access: (0755/-rwxr-xr-x)  Uid: (    0/    root)   Gid: (    0/    root)
    Access: 2025-09-08 12:23:59.453309624 +0000
    Modify: 2025-09-08 12:23:59.454309624 +0000
    Change: 2025-09-08 12:23:59.454309624 +0000
     Birth: 2025-09-08 12:23:59.453309624 +0000

  Before:

    Device reported 00:02 differs from stat output and /proc/self/maps

    # perf script --show-mmap-events | grep /root/test/merged/cat
             cat     377 [-01]   243.078558: PERF_RECORD_MMAP2 377/377: [0x55b2c91d0000(0x9b000) @ 0x18000 00:02 3419 2068525940]: r-xp /root/test/merged/cat

  After:

    Device reported 00:1a is the same as stat output and /proc/self/maps

    # perf script --show-mmap-events | grep /root/test/merged/cat
             cat     362 [-01]   127.755167: PERF_RECORD_MMAP2 362/362: [0x55ba6e781000(0x9b000) @ 0x18000 00:1a 3419 0]: r-xp /root/test/merged/cat

With respect to stable kernels, overlayfs mmap function ovl_mmap() was
added in v4.19 but file_user_inode() was not added until v6.8 and never
back-ported to stable kernels.  FMODE_BACKING that it depends on was added
in v6.5.  This issue has gone largely unnoticed, so back-porting before
v6.8 is probably not worth it, so put 6.8 as the stable kernel prerequisite
version, although in practice the next long term kernel is 6.12.

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Acked-by: Amir Goldstein &lt;amir73il@gmail.com&gt;
Cc: stable@vger.kernel.org # 6.8
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Some file systems like FUSE-based ones or overlayfs may record the backing
file in struct vm_area_struct vm_file, instead of the user file that the
user mmapped.

That causes perf to misreport the device major/minor numbers of the file
system of the file, and the generation of the file, and potentially other
inode details.  There is an existing helper file_user_inode() for that
situation.

Use file_user_inode() instead of file_inode() to get the inode for MMAP2
events.

Example:

  Setup:

    # cd /root
    # mkdir test ; cd test ; mkdir lower upper work merged
    # cp `which cat` lower
    # mount -t overlay overlay -olowerdir=lower,upperdir=upper,workdir=work merged
    # perf record -e cycles:u -- /root/test/merged/cat /proc/self/maps
    ...
    55b2c91d0000-55b2c926b000 r-xp 00018000 00:1a 3419                       /root/test/merged/cat
    ...
    [ perf record: Woken up 1 times to write data ]
    [ perf record: Captured and wrote 0.004 MB perf.data (5 samples) ]
    #
    # stat /root/test/merged/cat
      File: /root/test/merged/cat
      Size: 1127792         Blocks: 2208       IO Block: 4096   regular file
    Device: 0,26    Inode: 3419        Links: 1
    Access: (0755/-rwxr-xr-x)  Uid: (    0/    root)   Gid: (    0/    root)
    Access: 2025-09-08 12:23:59.453309624 +0000
    Modify: 2025-09-08 12:23:59.454309624 +0000
    Change: 2025-09-08 12:23:59.454309624 +0000
     Birth: 2025-09-08 12:23:59.453309624 +0000

  Before:

    Device reported 00:02 differs from stat output and /proc/self/maps

    # perf script --show-mmap-events | grep /root/test/merged/cat
             cat     377 [-01]   243.078558: PERF_RECORD_MMAP2 377/377: [0x55b2c91d0000(0x9b000) @ 0x18000 00:02 3419 2068525940]: r-xp /root/test/merged/cat

  After:

    Device reported 00:1a is the same as stat output and /proc/self/maps

    # perf script --show-mmap-events | grep /root/test/merged/cat
             cat     362 [-01]   127.755167: PERF_RECORD_MMAP2 362/362: [0x55ba6e781000(0x9b000) @ 0x18000 00:1a 3419 0]: r-xp /root/test/merged/cat

With respect to stable kernels, overlayfs mmap function ovl_mmap() was
added in v4.19 but file_user_inode() was not added until v6.8 and never
back-ported to stable kernels.  FMODE_BACKING that it depends on was added
in v6.5.  This issue has gone largely unnoticed, so back-porting before
v6.8 is probably not worth it, so put 6.8 as the stable kernel prerequisite
version, although in practice the next long term kernel is 6.12.

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Acked-by: Amir Goldstein &lt;amir73il@gmail.com&gt;
Cc: stable@vger.kernel.org # 6.8
</pre>
</div>
</content>
</entry>
<entry>
<title>perf/core: Fix MMAP event path names with backing files</title>
<updated>2025-10-14T08:38:09+00:00</updated>
<author>
<name>Adrian Hunter</name>
<email>adrian.hunter@intel.com</email>
</author>
<published>2025-10-13T07:22:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=8818f507a9391019a3ec7c57b1a32e4b386e48a5'/>
<id>8818f507a9391019a3ec7c57b1a32e4b386e48a5</id>
<content type='text'>
Some file systems like FUSE-based ones or overlayfs may record the backing
file in struct vm_area_struct vm_file, instead of the user file that the
user mmapped.

Since commit def3ae83da02f ("fs: store real path instead of fake path in
backing file f_path"), file_path() no longer returns the user file path
when applied to a backing file.  There is an existing helper
file_user_path() for that situation.

Use file_user_path() instead of file_path() to get the path for MMAP
and MMAP2 events.

Example:

  Setup:

    # cd /root
    # mkdir test ; cd test ; mkdir lower upper work merged
    # cp `which cat` lower
    # mount -t overlay overlay -olowerdir=lower,upperdir=upper,workdir=work merged
    # perf record -e intel_pt//u -- /root/test/merged/cat /proc/self/maps
    ...
    55b0ba399000-55b0ba434000 r-xp 00018000 00:1a 3419                       /root/test/merged/cat
    ...
    [ perf record: Woken up 1 times to write data ]
    [ perf record: Captured and wrote 0.060 MB perf.data ]
    #

  Before:

    File name is wrong (/cat), so decoding fails:

    # perf script --no-itrace --show-mmap-events
             cat     367 [016]   100.491492: PERF_RECORD_MMAP2 367/367: [0x55b0ba399000(0x9b000) @ 0x18000 00:02 3419 489959280]: r-xp /cat
    ...
    # perf script --itrace=e | wc -l
    Warning:
    19 instruction trace errors
    19
    #

  After:

    File name is correct (/root/test/merged/cat), so decoding is ok:

    # perf script --no-itrace --show-mmap-events
                 cat     364 [016]    72.153006: PERF_RECORD_MMAP2 364/364: [0x55ce4003d000(0x9b000) @ 0x18000 00:02 3419 3132534314]: r-xp /root/test/merged/cat
    # perf script --itrace=e
    # perf script --itrace=e | wc -l
    0
    #

Fixes: def3ae83da02f ("fs: store real path instead of fake path in backing file f_path")
Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Acked-by: Amir Goldstein &lt;amir73il@gmail.com&gt;
Cc: stable@vger.kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Some file systems like FUSE-based ones or overlayfs may record the backing
file in struct vm_area_struct vm_file, instead of the user file that the
user mmapped.

Since commit def3ae83da02f ("fs: store real path instead of fake path in
backing file f_path"), file_path() no longer returns the user file path
when applied to a backing file.  There is an existing helper
file_user_path() for that situation.

Use file_user_path() instead of file_path() to get the path for MMAP
and MMAP2 events.

Example:

  Setup:

    # cd /root
    # mkdir test ; cd test ; mkdir lower upper work merged
    # cp `which cat` lower
    # mount -t overlay overlay -olowerdir=lower,upperdir=upper,workdir=work merged
    # perf record -e intel_pt//u -- /root/test/merged/cat /proc/self/maps
    ...
    55b0ba399000-55b0ba434000 r-xp 00018000 00:1a 3419                       /root/test/merged/cat
    ...
    [ perf record: Woken up 1 times to write data ]
    [ perf record: Captured and wrote 0.060 MB perf.data ]
    #

  Before:

    File name is wrong (/cat), so decoding fails:

    # perf script --no-itrace --show-mmap-events
             cat     367 [016]   100.491492: PERF_RECORD_MMAP2 367/367: [0x55b0ba399000(0x9b000) @ 0x18000 00:02 3419 489959280]: r-xp /cat
    ...
    # perf script --itrace=e | wc -l
    Warning:
    19 instruction trace errors
    19
    #

  After:

    File name is correct (/root/test/merged/cat), so decoding is ok:

    # perf script --no-itrace --show-mmap-events
                 cat     364 [016]    72.153006: PERF_RECORD_MMAP2 364/364: [0x55ce4003d000(0x9b000) @ 0x18000 00:02 3419 3132534314]: r-xp /root/test/merged/cat
    # perf script --itrace=e
    # perf script --itrace=e | wc -l
    0
    #

Fixes: def3ae83da02f ("fs: store real path instead of fake path in backing file f_path")
Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Acked-by: Amir Goldstein &lt;amir73il@gmail.com&gt;
Cc: stable@vger.kernel.org
</pre>
</div>
</content>
</entry>
<entry>
<title>perf/core: Fix address filter match with backing files</title>
<updated>2025-10-14T08:38:09+00:00</updated>
<author>
<name>Adrian Hunter</name>
<email>adrian.hunter@intel.com</email>
</author>
<published>2025-10-13T07:22:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ebfc8542ad62d066771e46c8aa30f5624b89cad8'/>
<id>ebfc8542ad62d066771e46c8aa30f5624b89cad8</id>
<content type='text'>
It was reported that Intel PT address filters do not work in Docker
containers.  That relates to the use of overlayfs.

overlayfs records the backing file in struct vm_area_struct vm_file,
instead of the user file that the user mmapped.  In order for an address
filter to match, it must compare to the user file inode.  There is an
existing helper file_user_inode() for that situation.

Use file_user_inode() instead of file_inode() to get the inode for address
filter matching.

Example:

  Setup:

    # cd /root
    # mkdir test ; cd test ; mkdir lower upper work merged
    # cp `which cat` lower
    # mount -t overlay overlay -olowerdir=lower,upperdir=upper,workdir=work merged
    # perf record --buildid-mmap -e intel_pt//u --filter 'filter * @ /root/test/merged/cat' -- /root/test/merged/cat /proc/self/maps
    ...
    55d61d246000-55d61d2e1000 r-xp 00018000 00:1a 3418                       /root/test/merged/cat
    ...
    [ perf record: Woken up 1 times to write data ]
    [ perf record: Captured and wrote 0.015 MB perf.data ]
    # perf buildid-cache --add /root/test/merged/cat

  Before:

    Address filter does not match so there are no control flow packets

    # perf script --itrace=e
    # perf script --itrace=b | wc -l
    0
    # perf script -D | grep 'TIP.PGE' | wc -l
    0
    #

  After:

    Address filter does match so there are control flow packets

    # perf script --itrace=e
    # perf script --itrace=b | wc -l
    235
    # perf script -D | grep 'TIP.PGE' | wc -l
    57
    #

With respect to stable kernels, overlayfs mmap function ovl_mmap() was
added in v4.19 but file_user_inode() was not added until v6.8 and never
back-ported to stable kernels.  FMODE_BACKING that it depends on was added
in v6.5.  This issue has gone largely unnoticed, so back-porting before
v6.8 is probably not worth it, so put 6.8 as the stable kernel prerequisite
version, although in practice the next long term kernel is 6.12.

Closes: https://lore.kernel.org/linux-perf-users/aBCwoq7w8ohBRQCh@fremen.lan
Reported-by: Edd Barrett &lt;edd@theunixzoo.co.uk&gt;
Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Acked-by: Amir Goldstein &lt;amir73il@gmail.com&gt;
Cc: stable@vger.kernel.org # 6.8
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
It was reported that Intel PT address filters do not work in Docker
containers.  That relates to the use of overlayfs.

overlayfs records the backing file in struct vm_area_struct vm_file,
instead of the user file that the user mmapped.  In order for an address
filter to match, it must compare to the user file inode.  There is an
existing helper file_user_inode() for that situation.

Use file_user_inode() instead of file_inode() to get the inode for address
filter matching.

Example:

  Setup:

    # cd /root
    # mkdir test ; cd test ; mkdir lower upper work merged
    # cp `which cat` lower
    # mount -t overlay overlay -olowerdir=lower,upperdir=upper,workdir=work merged
    # perf record --buildid-mmap -e intel_pt//u --filter 'filter * @ /root/test/merged/cat' -- /root/test/merged/cat /proc/self/maps
    ...
    55d61d246000-55d61d2e1000 r-xp 00018000 00:1a 3418                       /root/test/merged/cat
    ...
    [ perf record: Woken up 1 times to write data ]
    [ perf record: Captured and wrote 0.015 MB perf.data ]
    # perf buildid-cache --add /root/test/merged/cat

  Before:

    Address filter does not match so there are no control flow packets

    # perf script --itrace=e
    # perf script --itrace=b | wc -l
    0
    # perf script -D | grep 'TIP.PGE' | wc -l
    0
    #

  After:

    Address filter does match so there are control flow packets

    # perf script --itrace=e
    # perf script --itrace=b | wc -l
    235
    # perf script -D | grep 'TIP.PGE' | wc -l
    57
    #

With respect to stable kernels, overlayfs mmap function ovl_mmap() was
added in v4.19 but file_user_inode() was not added until v6.8 and never
back-ported to stable kernels.  FMODE_BACKING that it depends on was added
in v6.5.  This issue has gone largely unnoticed, so back-porting before
v6.8 is probably not worth it, so put 6.8 as the stable kernel prerequisite
version, although in practice the next long term kernel is 6.12.

Closes: https://lore.kernel.org/linux-perf-users/aBCwoq7w8ohBRQCh@fremen.lan
Reported-by: Edd Barrett &lt;edd@theunixzoo.co.uk&gt;
Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Acked-by: Amir Goldstein &lt;amir73il@gmail.com&gt;
Cc: stable@vger.kernel.org # 6.8
</pre>
</div>
</content>
</entry>
<entry>
<title>uprobe: Move arch_uprobe_optimize right after handlers execution</title>
<updated>2025-10-14T08:38:09+00:00</updated>
<author>
<name>Jiri Olsa</name>
<email>jolsa@kernel.org</email>
</author>
<published>2025-10-01T13:24:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=62685ab071de7c39499212bff19f1b5bc0148bc7'/>
<id>62685ab071de7c39499212bff19f1b5bc0148bc7</id>
<content type='text'>
It's less confusing to optimize uprobe right after handlers execution
and before we do the check for changed ip register to avoid situations
where changed ip register would skip uprobe optimization.

Suggested-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Reviewed-by: Masami Hiramatsu (Google) &lt;mhiramat@kernel.org&gt;
Acked-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Oleg Nesterov &lt;oleg@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
It's less confusing to optimize uprobe right after handlers execution
and before we do the check for changed ip register to avoid situations
where changed ip register would skip uprobe optimization.

Suggested-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Reviewed-by: Masami Hiramatsu (Google) &lt;mhiramat@kernel.org&gt;
Acked-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Oleg Nesterov &lt;oleg@redhat.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
