<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/kernel/events, branch v6.1.2</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>perf: Fix possible memleak in pmu_dev_alloc()</title>
<updated>2022-12-31T12:31:56+00:00</updated>
<author>
<name>Chen Zhongjin</name>
<email>chenzhongjin@huawei.com</email>
</author>
<published>2022-11-11T10:36:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e9b4dc13d32c7be9a5a6418317477bcc821d164b'/>
<id>e9b4dc13d32c7be9a5a6418317477bcc821d164b</id>
<content type='text'>
[ Upstream commit e8d7a90c08ce963c592fb49845f2ccc606a2ac21 ]

In pmu_dev_alloc(), when dev_set_name() failed, it will goto free_dev
and call put_device(pmu-&gt;dev) to release it.
However pmu-&gt;dev-&gt;release is assigned after this, which makes warning
and memleak.
Call dev_set_name() after pmu-&gt;dev-&gt;release = pmu_dev_release to fix it.

  Device '(null)' does not have a release() function...
  WARNING: CPU: 2 PID: 441 at drivers/base/core.c:2332 device_release+0x1b9/0x240
  ...
  Call Trace:
    &lt;TASK&gt;
    kobject_put+0x17f/0x460
    put_device+0x20/0x30
    pmu_dev_alloc+0x152/0x400
    perf_pmu_register+0x96b/0xee0
    ...
  kmemleak: 1 new suspected memory leaks (see /sys/kernel/debug/kmemleak)
  unreferenced object 0xffff888014759000 (size 2048):
    comm "modprobe", pid 441, jiffies 4294931444 (age 38.332s)
    backtrace:
      [&lt;0000000005aed3b4&gt;] kmalloc_trace+0x27/0x110
      [&lt;000000006b38f9b8&gt;] pmu_dev_alloc+0x50/0x400
      [&lt;00000000735f17be&gt;] perf_pmu_register+0x96b/0xee0
      [&lt;00000000e38477f1&gt;] 0xffffffffc0ad8603
      [&lt;000000004e162216&gt;] do_one_initcall+0xd0/0x4e0
      ...

Fixes: abe43400579d ("perf: Sysfs enumeration")
Signed-off-by: Chen Zhongjin &lt;chenzhongjin@huawei.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lkml.kernel.org/r/20221111103653.91058-1-chenzhongjin@huawei.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit e8d7a90c08ce963c592fb49845f2ccc606a2ac21 ]

In pmu_dev_alloc(), when dev_set_name() failed, it will goto free_dev
and call put_device(pmu-&gt;dev) to release it.
However pmu-&gt;dev-&gt;release is assigned after this, which makes warning
and memleak.
Call dev_set_name() after pmu-&gt;dev-&gt;release = pmu_dev_release to fix it.

  Device '(null)' does not have a release() function...
  WARNING: CPU: 2 PID: 441 at drivers/base/core.c:2332 device_release+0x1b9/0x240
  ...
  Call Trace:
    &lt;TASK&gt;
    kobject_put+0x17f/0x460
    put_device+0x20/0x30
    pmu_dev_alloc+0x152/0x400
    perf_pmu_register+0x96b/0xee0
    ...
  kmemleak: 1 new suspected memory leaks (see /sys/kernel/debug/kmemleak)
  unreferenced object 0xffff888014759000 (size 2048):
    comm "modprobe", pid 441, jiffies 4294931444 (age 38.332s)
    backtrace:
      [&lt;0000000005aed3b4&gt;] kmalloc_trace+0x27/0x110
      [&lt;000000006b38f9b8&gt;] pmu_dev_alloc+0x50/0x400
      [&lt;00000000735f17be&gt;] perf_pmu_register+0x96b/0xee0
      [&lt;00000000e38477f1&gt;] 0xffffffffc0ad8603
      [&lt;000000004e162216&gt;] do_one_initcall+0xd0/0x4e0
      ...

Fixes: abe43400579d ("perf: Sysfs enumeration")
Signed-off-by: Chen Zhongjin &lt;chenzhongjin@huawei.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lkml.kernel.org/r/20221111103653.91058-1-chenzhongjin@huawei.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'perf_urgent_for_v6.1_rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2022-12-04T20:36:23+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-12-04T20:36:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0c3b5bcb484a659dd14466f92a073b57b2d3c1a5'/>
<id>0c3b5bcb484a659dd14466f92a073b57b2d3c1a5</id>
<content type='text'>
Pull perf fix from Borislav Petkov:

 - Fix a use-after-free case where the perf pending task callback would
   see an already freed event

* tag 'perf_urgent_for_v6.1_rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: Fix perf_pending_task() UaF
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull perf fix from Borislav Petkov:

 - Fix a use-after-free case where the perf pending task callback would
   see an already freed event

* tag 'perf_urgent_for_v6.1_rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: Fix perf_pending_task() UaF
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'net-6.1-rc8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net</title>
<updated>2022-11-29T17:52:10+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-11-29T17:52:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=01f856ae6d0ca5ad0505b79bf2d22d7ca439b2a1'/>
<id>01f856ae6d0ca5ad0505b79bf2d22d7ca439b2a1</id>
<content type='text'>
Pull networking fixes from Jakub Kicinski:
 "Including fixes from bpf, can and wifi.

  Current release - new code bugs:

   - eth: mlx5e:
      - use kvfree() in mlx5e_accel_fs_tcp_create()
      - MACsec, fix RX data path 16 RX security channel limit
      - MACsec, fix memory leak when MACsec device is deleted
      - MACsec, fix update Rx secure channel active field
      - MACsec, fix add Rx security association (SA) rule memory leak

  Previous releases - regressions:

   - wifi: cfg80211: don't allow multi-BSSID in S1G

   - stmmac: set MAC's flow control register to reflect current settings

   - eth: mlx5:
      - E-switch, fix duplicate lag creation
      - fix use-after-free when reverting termination table

  Previous releases - always broken:

   - ipv4: fix route deletion when nexthop info is not specified

   - bpf: fix a local storage BPF map bug where the value's spin lock
     field can get initialized incorrectly

   - tipc: re-fetch skb cb after tipc_msg_validate

   - wifi: wilc1000: fix Information Element parsing

   - packet: do not set TP_STATUS_CSUM_VALID on CHECKSUM_COMPLETE

   - sctp: fix memory leak in sctp_stream_outq_migrate()

   - can: can327: fix potential skb leak when netdev is down

   - can: add number of missing netdev freeing on error paths

   - aquantia: do not purge addresses when setting the number of rings

   - wwan: iosm:
      - fix incorrect skb length leading to truncated packet
      - fix crash in peek throughput test due to skb UAF"

* tag 'net-6.1-rc8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (79 commits)
  net: ethernet: renesas: ravb: Fix promiscuous mode after system resumed
  MAINTAINERS: Update maintainer list for chelsio drivers
  ionic: update MAINTAINERS entry
  sctp: fix memory leak in sctp_stream_outq_migrate()
  packet: do not set TP_STATUS_CSUM_VALID on CHECKSUM_COMPLETE
  net/mlx5: Lag, Fix for loop when checking lag
  Revert "net/mlx5e: MACsec, remove replay window size limitation in offload path"
  net: marvell: prestera: Fix a NULL vs IS_ERR() check in some functions
  net: tun: Fix use-after-free in tun_detach()
  net: mdiobus: fix unbalanced node reference count
  net: hsr: Fix potential use-after-free
  tipc: re-fetch skb cb after tipc_msg_validate
  mptcp: fix sleep in atomic at close time
  mptcp: don't orphan ssk in mptcp_close()
  dsa: lan9303: Correct stat name
  ipv4: Fix route deletion when nexthop info is not specified
  net: wwan: iosm: fix incorrect skb length
  net: wwan: iosm: fix crash in peek throughput test
  net: wwan: iosm: fix dma_alloc_coherent incompatible pointer type
  net: wwan: iosm: fix kernel test robot reported error
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull networking fixes from Jakub Kicinski:
 "Including fixes from bpf, can and wifi.

  Current release - new code bugs:

   - eth: mlx5e:
      - use kvfree() in mlx5e_accel_fs_tcp_create()
      - MACsec, fix RX data path 16 RX security channel limit
      - MACsec, fix memory leak when MACsec device is deleted
      - MACsec, fix update Rx secure channel active field
      - MACsec, fix add Rx security association (SA) rule memory leak

  Previous releases - regressions:

   - wifi: cfg80211: don't allow multi-BSSID in S1G

   - stmmac: set MAC's flow control register to reflect current settings

   - eth: mlx5:
      - E-switch, fix duplicate lag creation
      - fix use-after-free when reverting termination table

  Previous releases - always broken:

   - ipv4: fix route deletion when nexthop info is not specified

   - bpf: fix a local storage BPF map bug where the value's spin lock
     field can get initialized incorrectly

   - tipc: re-fetch skb cb after tipc_msg_validate

   - wifi: wilc1000: fix Information Element parsing

   - packet: do not set TP_STATUS_CSUM_VALID on CHECKSUM_COMPLETE

   - sctp: fix memory leak in sctp_stream_outq_migrate()

   - can: can327: fix potential skb leak when netdev is down

   - can: add number of missing netdev freeing on error paths

   - aquantia: do not purge addresses when setting the number of rings

   - wwan: iosm:
      - fix incorrect skb length leading to truncated packet
      - fix crash in peek throughput test due to skb UAF"

* tag 'net-6.1-rc8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (79 commits)
  net: ethernet: renesas: ravb: Fix promiscuous mode after system resumed
  MAINTAINERS: Update maintainer list for chelsio drivers
  ionic: update MAINTAINERS entry
  sctp: fix memory leak in sctp_stream_outq_migrate()
  packet: do not set TP_STATUS_CSUM_VALID on CHECKSUM_COMPLETE
  net/mlx5: Lag, Fix for loop when checking lag
  Revert "net/mlx5e: MACsec, remove replay window size limitation in offload path"
  net: marvell: prestera: Fix a NULL vs IS_ERR() check in some functions
  net: tun: Fix use-after-free in tun_detach()
  net: mdiobus: fix unbalanced node reference count
  net: hsr: Fix potential use-after-free
  tipc: re-fetch skb cb after tipc_msg_validate
  mptcp: fix sleep in atomic at close time
  mptcp: don't orphan ssk in mptcp_close()
  dsa: lan9303: Correct stat name
  ipv4: Fix route deletion when nexthop info is not specified
  net: wwan: iosm: fix incorrect skb length
  net: wwan: iosm: fix crash in peek throughput test
  net: wwan: iosm: fix dma_alloc_coherent incompatible pointer type
  net: wwan: iosm: fix kernel test robot reported error
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>perf: Fix perf_pending_task() UaF</title>
<updated>2022-11-29T16:42:49+00:00</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2022-11-24T11:49:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=517e6a301f34613bff24a8e35b5455884f2d83d8'/>
<id>517e6a301f34613bff24a8e35b5455884f2d83d8</id>
<content type='text'>
Per syzbot it is possible for perf_pending_task() to run after the
event is free()'d. There are two related but distinct cases:

 - the task_work was already queued before destroying the event;
 - destroying the event itself queues the task_work.

The first cannot be solved using task_work_cancel() since
perf_release() itself might be called from a task_work (____fput),
which means the current-&gt;task_works list is already empty and
task_work_cancel() won't be able to find the perf_pending_task()
entry.

The simplest alternative is extending the perf_event lifetime to cover
the task_work.

The second is just silly, queueing a task_work while you know the
event is going away makes no sense and is easily avoided by
re-arranging how the event is marked STATE_DEAD and ensuring it goes
through STATE_OFF on the way down.

Reported-by: syzbot+9228d6098455bb209ec8@syzkaller.appspotmail.com
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Tested-by: Marco Elver &lt;elver@google.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Per syzbot it is possible for perf_pending_task() to run after the
event is free()'d. There are two related but distinct cases:

 - the task_work was already queued before destroying the event;
 - destroying the event itself queues the task_work.

The first cannot be solved using task_work_cancel() since
perf_release() itself might be called from a task_work (____fput),
which means the current-&gt;task_works list is already empty and
task_work_cancel() won't be able to find the perf_pending_task()
entry.

The simplest alternative is extending the perf_event lifetime to cover
the task_work.

The second is just silly, queueing a task_work while you know the
event is going away makes no sense and is easily avoided by
re-arranging how the event is marked STATE_DEAD and ensuring it goes
through STATE_OFF on the way down.

Reported-by: syzbot+9228d6098455bb209ec8@syzkaller.appspotmail.com
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Tested-by: Marco Elver &lt;elver@google.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf: Consider OS filter fail</title>
<updated>2022-11-24T09:12:23+00:00</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2022-11-19T02:45:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=030a976efae83f7b6593afb11a8254d42f9290fe'/>
<id>030a976efae83f7b6593afb11a8254d42f9290fe</id>
<content type='text'>
Some PMUs (notably the traditional hardware kind) have boundary issues
with the OS filter. Specifically, it is possible for
perf_event_attr::exclude_kernel=1 events to trigger in-kernel due to
SKID or errata.

This can upset the sigtrap logic some and trigger the WARN.

However, if this invalid sample is the first we must not loose the
SIGTRAP, OTOH if it is the second, it must not override the
pending_addr with a (possibly) invalid one.

Fixes: ca6c21327c6a ("perf: Fix missing SIGTRAPs")
Reported-by: Pengfei Xu &lt;pengfei.xu@intel.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Reviewed-by: Marco Elver &lt;elver@google.com&gt;
Tested-by: Pengfei Xu &lt;pengfei.xu@intel.com&gt;
Link: https://lkml.kernel.org/r/Y3hDYiXwRnJr8RYG@xpf.sh.intel.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Some PMUs (notably the traditional hardware kind) have boundary issues
with the OS filter. Specifically, it is possible for
perf_event_attr::exclude_kernel=1 events to trigger in-kernel due to
SKID or errata.

This can upset the sigtrap logic some and trigger the WARN.

However, if this invalid sample is the first we must not loose the
SIGTRAP, OTOH if it is the second, it must not override the
pending_addr with a (possibly) invalid one.

Fixes: ca6c21327c6a ("perf: Fix missing SIGTRAPs")
Reported-by: Pengfei Xu &lt;pengfei.xu@intel.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Reviewed-by: Marco Elver &lt;elver@google.com&gt;
Tested-by: Pengfei Xu &lt;pengfei.xu@intel.com&gt;
Link: https://lkml.kernel.org/r/Y3hDYiXwRnJr8RYG@xpf.sh.intel.com
</pre>
</div>
</content>
</entry>
<entry>
<title>perf: Fixup SIGTRAP and sample_flags interaction</title>
<updated>2022-11-24T09:12:23+00:00</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2022-11-21T14:57:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=af169b7759a9b9369b5106cd07a25c57ce60119e'/>
<id>af169b7759a9b9369b5106cd07a25c57ce60119e</id>
<content type='text'>
The perf_event_attr::sigtrap functionality relies on data-&gt;addr being
set. However commit 7b0846301531 ("perf: Use sample_flags for addr")
changed this to only initialize data-&gt;addr when not 0.

Fixes: 7b0846301531 ("perf: Use sample_flags for addr")
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lkml.kernel.org/r/Y3426b4OimE%2FI5po%40hirez.programming.kicks-ass.net
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The perf_event_attr::sigtrap functionality relies on data-&gt;addr being
set. However commit 7b0846301531 ("perf: Use sample_flags for addr")
changed this to only initialize data-&gt;addr when not 0.

Fixes: 7b0846301531 ("perf: Use sample_flags for addr")
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lkml.kernel.org/r/Y3426b4OimE%2FI5po%40hirez.programming.kicks-ass.net
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf, perf: Use subprog name when reporting subprog ksymbol</title>
<updated>2022-11-15T14:36:57+00:00</updated>
<author>
<name>Hou Tao</name>
<email>houtao1@huawei.com</email>
</author>
<published>2022-11-14T09:57:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=47df8a2f78bc34ff170d147d05b121f84e252b85'/>
<id>47df8a2f78bc34ff170d147d05b121f84e252b85</id>
<content type='text'>
Since commit bfea9a8574f3 ("bpf: Add name to struct bpf_ksym"), when
reporting subprog ksymbol to perf, prog name instead of subprog name is
used. The backtrace of bpf program with subprogs will be incorrect as
shown below:

  ffffffffc02deace bpf_prog_e44a3057dcb151f8_overwrite+0x66
  ffffffffc02de9f7 bpf_prog_e44a3057dcb151f8_overwrite+0x9f
  ffffffffa71d8d4e trace_call_bpf+0xce
  ffffffffa71c2938 perf_call_bpf_enter.isra.0+0x48

overwrite is the entry program and it invokes the overwrite_htab subprog
through bpf_loop, but in above backtrace, overwrite program just jumps
inside itself.

Fixing it by using subprog name when reporting subprog ksymbol. After
the fix, the output of perf script will be correct as shown below:

  ffffffffc031aad2 bpf_prog_37c0bec7d7c764a4_overwrite_htab+0x66
  ffffffffc031a9e7 bpf_prog_c7eb827ef4f23e71_overwrite+0x9f
  ffffffffa3dd8d4e trace_call_bpf+0xce
  ffffffffa3dc2938 perf_call_bpf_enter.isra.0+0x48

Fixes: bfea9a8574f3 ("bpf: Add name to struct bpf_ksym")
Signed-off-by: Hou Tao &lt;houtao1@huawei.com&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20221114095733.158588-1-houtao@huaweicloud.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Since commit bfea9a8574f3 ("bpf: Add name to struct bpf_ksym"), when
reporting subprog ksymbol to perf, prog name instead of subprog name is
used. The backtrace of bpf program with subprogs will be incorrect as
shown below:

  ffffffffc02deace bpf_prog_e44a3057dcb151f8_overwrite+0x66
  ffffffffc02de9f7 bpf_prog_e44a3057dcb151f8_overwrite+0x9f
  ffffffffa71d8d4e trace_call_bpf+0xce
  ffffffffa71c2938 perf_call_bpf_enter.isra.0+0x48

overwrite is the entry program and it invokes the overwrite_htab subprog
through bpf_loop, but in above backtrace, overwrite program just jumps
inside itself.

Fixing it by using subprog name when reporting subprog ksymbol. After
the fix, the output of perf script will be correct as shown below:

  ffffffffc031aad2 bpf_prog_37c0bec7d7c764a4_overwrite_htab+0x66
  ffffffffc031a9e7 bpf_prog_c7eb827ef4f23e71_overwrite+0x9f
  ffffffffa3dd8d4e trace_call_bpf+0xce
  ffffffffa3dc2938 perf_call_bpf_enter.isra.0+0x48

Fixes: bfea9a8574f3 ("bpf: Add name to struct bpf_ksym")
Signed-off-by: Hou Tao &lt;houtao1@huawei.com&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Link: https://lore.kernel.org/bpf/20221114095733.158588-1-houtao@huaweicloud.com
</pre>
</div>
</content>
</entry>
<entry>
<title>perf: Improve missing SIGTRAP checking</title>
<updated>2022-11-08T09:39:27+00:00</updated>
<author>
<name>Marco Elver</name>
<email>elver@google.com</email>
</author>
<published>2022-10-31T09:35:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bb88f9695460bec25aa30ba9072595025cf6c8af'/>
<id>bb88f9695460bec25aa30ba9072595025cf6c8af</id>
<content type='text'>
To catch missing SIGTRAP we employ a WARN in __perf_event_overflow(),
which fires if pending_sigtrap was already set: returning to user space
without consuming pending_sigtrap, and then having the event fire again
would re-enter the kernel and trigger the WARN.

This, however, seemed to miss the case where some events not associated
with progress in the user space task can fire and the interrupt handler
runs before the IRQ work meant to consume pending_sigtrap (and generate
the SIGTRAP).

syzbot gifted us this stack trace:

 | WARNING: CPU: 0 PID: 3607 at kernel/events/core.c:9313 __perf_event_overflow
 | Modules linked in:
 | CPU: 0 PID: 3607 Comm: syz-executor100 Not tainted 6.1.0-rc2-syzkaller-00073-g88619e77b33d #0
 | Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022
 | RIP: 0010:__perf_event_overflow+0x498/0x540 kernel/events/core.c:9313
 | &lt;...&gt;
 | Call Trace:
 |  &lt;TASK&gt;
 |  perf_swevent_hrtimer+0x34f/0x3c0 kernel/events/core.c:10729
 |  __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 |  __hrtimer_run_queues+0x1c6/0xfb0 kernel/time/hrtimer.c:1749
 |  hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
 |  local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1096 [inline]
 |  __sysvec_apic_timer_interrupt+0x17c/0x640 arch/x86/kernel/apic/apic.c:1113
 |  sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1107
 |  asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649
 | &lt;...&gt;
 |  &lt;/TASK&gt;

In this case, syzbot produced a program with event type
PERF_TYPE_SOFTWARE and config PERF_COUNT_SW_CPU_CLOCK. The hrtimer
manages to fire again before the IRQ work got a chance to run, all while
never having returned to user space.

Improve the WARN to check for real progress in user space: approximate
this by storing a 32-bit hash of the current IP into pending_sigtrap,
and if an event fires while pending_sigtrap still matches the previous
IP, we assume no progress (false negatives are possible given we could
return to user space and trigger again on the same IP).

Fixes: ca6c21327c6a ("perf: Fix missing SIGTRAPs")
Reported-by: syzbot+b8ded3e2e2c6adde4990@syzkaller.appspotmail.com
Signed-off-by: Marco Elver &lt;elver@google.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lkml.kernel.org/r/20221031093513.3032814-1-elver@google.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
To catch missing SIGTRAP we employ a WARN in __perf_event_overflow(),
which fires if pending_sigtrap was already set: returning to user space
without consuming pending_sigtrap, and then having the event fire again
would re-enter the kernel and trigger the WARN.

This, however, seemed to miss the case where some events not associated
with progress in the user space task can fire and the interrupt handler
runs before the IRQ work meant to consume pending_sigtrap (and generate
the SIGTRAP).

syzbot gifted us this stack trace:

 | WARNING: CPU: 0 PID: 3607 at kernel/events/core.c:9313 __perf_event_overflow
 | Modules linked in:
 | CPU: 0 PID: 3607 Comm: syz-executor100 Not tainted 6.1.0-rc2-syzkaller-00073-g88619e77b33d #0
 | Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022
 | RIP: 0010:__perf_event_overflow+0x498/0x540 kernel/events/core.c:9313
 | &lt;...&gt;
 | Call Trace:
 |  &lt;TASK&gt;
 |  perf_swevent_hrtimer+0x34f/0x3c0 kernel/events/core.c:10729
 |  __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 |  __hrtimer_run_queues+0x1c6/0xfb0 kernel/time/hrtimer.c:1749
 |  hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
 |  local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1096 [inline]
 |  __sysvec_apic_timer_interrupt+0x17c/0x640 arch/x86/kernel/apic/apic.c:1113
 |  sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1107
 |  asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649
 | &lt;...&gt;
 |  &lt;/TASK&gt;

In this case, syzbot produced a program with event type
PERF_TYPE_SOFTWARE and config PERF_COUNT_SW_CPU_CLOCK. The hrtimer
manages to fire again before the IRQ work got a chance to run, all while
never having returned to user space.

Improve the WARN to check for real progress in user space: approximate
this by storing a 32-bit hash of the current IP into pending_sigtrap,
and if an event fires while pending_sigtrap still matches the previous
IP, we assume no progress (false negatives are possible given we could
return to user space and trigger again on the same IP).

Fixes: ca6c21327c6a ("perf: Fix missing SIGTRAPs")
Reported-by: syzbot+b8ded3e2e2c6adde4990@syzkaller.appspotmail.com
Signed-off-by: Marco Elver &lt;elver@google.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lkml.kernel.org/r/20221031093513.3032814-1-elver@google.com
</pre>
</div>
</content>
</entry>
<entry>
<title>perf/hw_breakpoint: test: Skip the test if dependencies unmet</title>
<updated>2022-11-02T11:22:05+00:00</updated>
<author>
<name>David Gow</name>
<email>davidgow@google.com</email>
</author>
<published>2022-10-26T14:10:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4b18cb3f74dcfc183c2434e17bfce09ce6302e37'/>
<id>4b18cb3f74dcfc183c2434e17bfce09ce6302e37</id>
<content type='text'>
Running the test currently fails on non-SMP systems, despite being
enabled by default. This means that running the test with:

 ./tools/testing/kunit/kunit.py run --arch x86_64 hw_breakpoint

results in every hw_breakpoint test failing with:

 # test_one_cpu: failed to initialize: -22
 not ok 1 - test_one_cpu

Instead, use kunit_skip(), which will mark the test as skipped, and give
a more comprehensible message:

 ok 1 - test_one_cpu # SKIP not enough cpus

This makes it more obvious that the test is not suited to the test
environment, and so wasn't run, rather than having run and failed.

Signed-off-by: David Gow &lt;davidgow@google.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Reviewed-by: Daniel Latypov &lt;dlatypov@google.com&gt;
Acked-by: Marco Elver &lt;elver@google.com&gt;
Link: https://lore.kernel.org/r/20221026141040.1609203-1-davidgow@google.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Running the test currently fails on non-SMP systems, despite being
enabled by default. This means that running the test with:

 ./tools/testing/kunit/kunit.py run --arch x86_64 hw_breakpoint

results in every hw_breakpoint test failing with:

 # test_one_cpu: failed to initialize: -22
 not ok 1 - test_one_cpu

Instead, use kunit_skip(), which will mark the test as skipped, and give
a more comprehensible message:

 ok 1 - test_one_cpu # SKIP not enough cpus

This makes it more obvious that the test is not suited to the test
environment, and so wasn't run, rather than having run and failed.

Signed-off-by: David Gow &lt;davidgow@google.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Reviewed-by: Daniel Latypov &lt;dlatypov@google.com&gt;
Acked-by: Marco Elver &lt;elver@google.com&gt;
Link: https://lore.kernel.org/r/20221026141040.1609203-1-davidgow@google.com
</pre>
</div>
</content>
</entry>
<entry>
<title>perf: Fix missing raw data on tracepoint events</title>
<updated>2022-10-27T08:27:30+00:00</updated>
<author>
<name>James Clark</name>
<email>james.clark@arm.com</email>
</author>
<published>2022-10-12T14:38:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4b66ff46f2e18b1d32e18c881799ef911606f3be'/>
<id>4b66ff46f2e18b1d32e18c881799ef911606f3be</id>
<content type='text'>
Since commit 838d9bb62d13 ("perf: Use sample_flags for raw_data")
raw data is not being output on tracepoints due to the PERF_SAMPLE_RAW
field not being set. Fix this by setting it for tracepoint events.

This fixes the following test failure:

  perf test "sched_switch" -vvv

   35: Track with sched_switch
  --- start ---
  test child forked, pid 1828
  ...
  Using CPUID 0x00000000410fd400
  sched_switch: cpu: 2 prev_tid -14687 next_tid 0
  sched_switch: cpu: 2 prev_tid -14687 next_tid 0
  Missing sched_switch events
  4613 events recorded
  test child finished with -1
  ---- end ----
  Track with sched_switch: FAILED!

Fixes: 838d9bb62d13 ("perf: Use sample_flags for raw_data")
Signed-off-by: James Clark &lt;james.clark@arm.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Acked-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Tested-by: SeongJae Park &lt;sj@kernel.org&gt;
Tested-by: Athira Rajeev &lt;atrajeev@linux.vnet.ibm.com&gt;
Link: https://lore.kernel.org/r/20221012143857.48198-1-james.clark@arm.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Since commit 838d9bb62d13 ("perf: Use sample_flags for raw_data")
raw data is not being output on tracepoints due to the PERF_SAMPLE_RAW
field not being set. Fix this by setting it for tracepoint events.

This fixes the following test failure:

  perf test "sched_switch" -vvv

   35: Track with sched_switch
  --- start ---
  test child forked, pid 1828
  ...
  Using CPUID 0x00000000410fd400
  sched_switch: cpu: 2 prev_tid -14687 next_tid 0
  sched_switch: cpu: 2 prev_tid -14687 next_tid 0
  Missing sched_switch events
  4613 events recorded
  test child finished with -1
  ---- end ----
  Track with sched_switch: FAILED!

Fixes: 838d9bb62d13 ("perf: Use sample_flags for raw_data")
Signed-off-by: James Clark &lt;james.clark@arm.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Acked-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Tested-by: SeongJae Park &lt;sj@kernel.org&gt;
Tested-by: Athira Rajeev &lt;atrajeev@linux.vnet.ibm.com&gt;
Link: https://lore.kernel.org/r/20221012143857.48198-1-james.clark@arm.com
</pre>
</div>
</content>
</entry>
</feed>
