<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/tools/perf/util, branch master</title>
<subtitle>Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git</subtitle>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/'/>
<entry>
<title>perf cap: Add __NR_capget to arch/x86 unistd</title>
<updated>2024-10-28T16:04:52+00:00</updated>
<author>
<name>Ian Rogers</name>
<email>irogers@google.com</email>
</author>
<published>2024-10-26T05:54:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=a5384c426744ebe41dafc6e5fa3acecc05e43462'/>
<id>a5384c426744ebe41dafc6e5fa3acecc05e43462</id>
<content type='text'>
As there are duplicated kernel headers in tools/include libc can pick
up the wrong definitions. This was causing the wrong system call for
capget in perf.

Reported-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Fixes: e25ebda78e230283 ("perf cap: Tidy up and improve capability testing")
Closes: https://lore.kernel.org/lkml/cc7d6bdf-1aeb-4179-9029-4baf50b59342@intel.com/
Signed-off-by: Ian Rogers &lt;irogers@google.com&gt;
Tested-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: https://lore.kernel.org/r/20241026055448.312247-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
As there are duplicated kernel headers in tools/include libc can pick
up the wrong definitions. This was causing the wrong system call for
capget in perf.

Reported-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Fixes: e25ebda78e230283 ("perf cap: Tidy up and improve capability testing")
Closes: https://lore.kernel.org/lkml/cc7d6bdf-1aeb-4179-9029-4baf50b59342@intel.com/
Signed-off-by: Ian Rogers &lt;irogers@google.com&gt;
Tested-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: https://lore.kernel.org/r/20241026055448.312247-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf python: Fix up the build on architectures without HAVE_KVM_STAT_SUPPORT</title>
<updated>2024-10-23T22:29:50+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2024-10-23T19:12:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=758f18158952a6287ac23679ec04c32d44ca5368'/>
<id>758f18158952a6287ac23679ec04c32d44ca5368</id>
<content type='text'>
Noticed while building on a raspbian arm 32-bit system.

There was also this other case, fixed by adding a missing util/stat.h
with the prototypes:

  /tmp/tmp.MbiSHoF3dj/perf-6.12.0-rc3/tools/perf/util/python.c:1396:6: error: no previous prototype for ‘perf_stat__set_no_csv_summary’ [-Werror=missing-prototypes]
   1396 | void perf_stat__set_no_csv_summary(int set __maybe_unused)
        |      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  /tmp/tmp.MbiSHoF3dj/perf-6.12.0-rc3/tools/perf/util/python.c:1400:6: error: no previous prototype for ‘perf_stat__set_big_num’ [-Werror=missing-prototypes]
   1400 | void perf_stat__set_big_num(int set __maybe_unused)
        |      ^~~~~~~~~~~~~~~~~~~~~~
  cc1: all warnings being treated as errors

In other architectures this must be building due to some lucky indirect
inclusion of that header.

Fixes: 9dabf4003423c8d3 ("perf python: Switch module to linking libraries from building source")
Reviewed-by: Ian Rogers &lt;irogers@google.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Link: https://lore.kernel.org/lkml/ZxllAtpmEw5fg9oy@x1
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Noticed while building on a raspbian arm 32-bit system.

There was also this other case, fixed by adding a missing util/stat.h
with the prototypes:

  /tmp/tmp.MbiSHoF3dj/perf-6.12.0-rc3/tools/perf/util/python.c:1396:6: error: no previous prototype for ‘perf_stat__set_no_csv_summary’ [-Werror=missing-prototypes]
   1396 | void perf_stat__set_no_csv_summary(int set __maybe_unused)
        |      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  /tmp/tmp.MbiSHoF3dj/perf-6.12.0-rc3/tools/perf/util/python.c:1400:6: error: no previous prototype for ‘perf_stat__set_big_num’ [-Werror=missing-prototypes]
   1400 | void perf_stat__set_big_num(int set __maybe_unused)
        |      ^~~~~~~~~~~~~~~~~~~~~~
  cc1: all warnings being treated as errors

In other architectures this must be building due to some lucky indirect
inclusion of that header.

Fixes: 9dabf4003423c8d3 ("perf python: Switch module to linking libraries from building source")
Reviewed-by: Ian Rogers &lt;irogers@google.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Link: https://lore.kernel.org/lkml/ZxllAtpmEw5fg9oy@x1
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf trace: Fix non-listed archs in the syscalltbl routines</title>
<updated>2024-10-23T14:34:56+00:00</updated>
<author>
<name>Jiri Slaby</name>
<email>jslaby@suse.cz</email>
</author>
<published>2024-10-22T20:22:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=5d35634ecc2d2c3938bd7dc23df0ad046da1b303'/>
<id>5d35634ecc2d2c3938bd7dc23df0ad046da1b303</id>
<content type='text'>
This fixes a build breakage on 32-bit arm, where the
syscalltbl__id_at_idx() function was missing.

Committer notes:

Generating a proper syscall table from a copy of
arch/arm/tools/syscall.tbl ends up being too big a patch for this rc
stage, I started doing it but while testing noticed some other problems
with using BPF to collect pointer args on arm7 (32-bit) will maybe
continue trying to make it work on the next cycle...

Fixes: 7a2fb5619cc1fb53 ("perf trace: Fix iteration of syscall ids in syscalltbl-&gt;entries")
Suggested-by: Howard Chu &lt;howardchu95@gmail.com&gt;
Signed-off-by: &lt;jslaby@suse.cz&gt;
Acked-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Howard Chu &lt;howardchu95@gmail.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Link: https://lore.kernel.org/lkml/3a592835-a14f-40be-8961-c0cee7720a94@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This fixes a build breakage on 32-bit arm, where the
syscalltbl__id_at_idx() function was missing.

Committer notes:

Generating a proper syscall table from a copy of
arch/arm/tools/syscall.tbl ends up being too big a patch for this rc
stage, I started doing it but while testing noticed some other problems
with using BPF to collect pointer args on arm7 (32-bit) will maybe
continue trying to make it work on the next cycle...

Fixes: 7a2fb5619cc1fb53 ("perf trace: Fix iteration of syscall ids in syscalltbl-&gt;entries")
Suggested-by: Howard Chu &lt;howardchu95@gmail.com&gt;
Signed-off-by: &lt;jslaby@suse.cz&gt;
Acked-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Howard Chu &lt;howardchu95@gmail.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Link: https://lore.kernel.org/lkml/3a592835-a14f-40be-8961-c0cee7720a94@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf trace augmented_raw_syscalls: Add more checks to pass the verifier</title>
<updated>2024-10-23T14:34:56+00:00</updated>
<author>
<name>Howard Chu</name>
<email>howardchu95@gmail.com</email>
</author>
<published>2024-10-11T02:14:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=395d38419f1853decab84acc16176b3fa5c96690'/>
<id>395d38419f1853decab84acc16176b3fa5c96690</id>
<content type='text'>
Add some more checks to pass the verifier in more kernels.

Signed-off-by: Howard Chu &lt;howardchu95@gmail.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alan Maguire &lt;alan.maguire@oracle.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: https://lore.kernel.org/r/20241011021403.4089793-3-howardchu95@gmail.com
[ Reduced the patch removing things that can be done later ]
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add some more checks to pass the verifier in more kernels.

Signed-off-by: Howard Chu &lt;howardchu95@gmail.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alan Maguire &lt;alan.maguire@oracle.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: https://lore.kernel.org/r/20241011021403.4089793-3-howardchu95@gmail.com
[ Reduced the patch removing things that can be done later ]
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf trace augmented_raw_syscalls: Add extra array index bounds checking to satisfy some BPF verifiers</title>
<updated>2024-10-23T14:34:56+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2024-10-15T20:03:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=ecabac70ff919580324b407818ee3e6c0004dcf8'/>
<id>ecabac70ff919580324b407818ee3e6c0004dcf8</id>
<content type='text'>
In a RHEL8 kernel (4.18.0-513.11.1.el8_9.x86_64), that, as enterprise
kernels go, have backports from modern kernels, the verifier complains
about lack of bounds check for the index into the array of syscall
arguments, on a BPF bytecode generated by clang 17, with:

  ; } else if (size &lt; 0 &amp;&amp; size &gt;= -6) { /* buffer */
  116: (b7) r1 = -6
  117: (2d) if r1 &gt; r6 goto pc-30
   R0=map_value(id=0,off=0,ks=4,vs=24688,imm=0) R1_w=inv-6 R2=map_value(id=0,off=16,ks=4,vs=8272,imm=0) R3=inv(id=0) R5=inv40 R6=inv(id=0,umin_value=18446744073709551610,var_off=(0xffffffff00000000; 0xffffffff)) R7=map_value(id=0,off=56,ks=4,vs=8272,imm=0) R8=invP6 R9=map_value(id=0,off=20,ks=4,vs=24,imm=0) R10=fp0 fp-8=mmmmmmmm fp-16=map_value fp-24=map_value fp-32=inv40 fp-40=ctx fp-48=map_value fp-56=inv1 fp-64=map_value fp-72=map_value fp-80=map_value
  ; index = -(size + 1);
  118: (a7) r6 ^= -1
  119: (67) r6 &lt;&lt;= 32
  120: (77) r6 &gt;&gt;= 32
  ; aug_size = args-&gt;args[index];
  121: (67) r6 &lt;&lt;= 3
  122: (79) r1 = *(u64 *)(r10 -24)
  123: (0f) r1 += r6
  last_idx 123 first_idx 116
  regs=40 stack=0 before 122: (79) r1 = *(u64 *)(r10 -24)
  regs=40 stack=0 before 121: (67) r6 &lt;&lt;= 3
  regs=40 stack=0 before 120: (77) r6 &gt;&gt;= 32
  regs=40 stack=0 before 119: (67) r6 &lt;&lt;= 32
  regs=40 stack=0 before 118: (a7) r6 ^= -1
  regs=40 stack=0 before 117: (2d) if r1 &gt; r6 goto pc-30
  regs=42 stack=0 before 116: (b7) r1 = -6
   R0_w=map_value(id=0,off=0,ks=4,vs=24688,imm=0) R1_w=inv1 R2_w=map_value(id=0,off=16,ks=4,vs=8272,imm=0) R3_w=inv(id=0) R5_w=inv40 R6_rw=invP(id=0,smin_value=-2147483648,smax_value=0) R7_w=map_value(id=0,off=56,ks=4,vs=8272,imm=0) R8_w=invP6 R9_w=map_value(id=0,off=20,ks=4,vs=24,imm=0) R10=fp0 fp-8=mmmmmmmm fp-16_w=map_value fp-24_r=map_value fp-32_w=inv40 fp-40=ctx fp-48=map_value fp-56_w=inv1 fp-64_w=map_value fp-72=map_value fp-80=map_value
  parent didn't have regs=40 stack=0 marks
  last_idx 110 first_idx 98
  regs=40 stack=0 before 110: (6d) if r1 s&gt; r6 goto pc+5
  regs=42 stack=0 before 109: (b7) r1 = 1
  regs=40 stack=0 before 108: (65) if r6 s&gt; 0x1000 goto pc+7
  regs=40 stack=0 before 98: (55) if r6 != 0x1 goto pc+9
   R0_w=map_value(id=0,off=0,ks=4,vs=24688,imm=0) R1_w=invP12 R2_w=map_value(id=0,off=16,ks=4,vs=8272,imm=0) R3_rw=inv(id=0) R5_w=inv24 R6_rw=invP(id=0,smin_value=-2147483648,smax_value=2147483647) R7_w=map_value(id=0,off=40,ks=4,vs=8272,imm=0) R8_rw=invP4 R9_w=map_value(id=0,off=12,ks=4,vs=24,imm=0) R10=fp0 fp-8=mmmmmmmm fp-16_rw=map_value fp-24_r=map_value fp-32_rw=invP24 fp-40_r=ctx fp-48_r=map_value fp-56_w=invP1 fp-64_rw=map_value fp-72_r=map_value fp-80_r=map_value
  parent already had regs=40 stack=0 marks
  124: (79) r6 = *(u64 *)(r1 +16)
   R0=map_value(id=0,off=0,ks=4,vs=24688,imm=0) R1_w=map_value(id=0,off=0,ks=4,vs=8272,umax_value=34359738360,var_off=(0x0; 0x7fffffff8),s32_max_value=2147483640,u32_max_value=-8) R2=map_value(id=0,off=16,ks=4,vs=8272,imm=0) R3=inv(id=0) R5=inv40 R6_w=invP(id=0,umax_value=34359738360,var_off=(0x0; 0x7fffffff8),s32_max_value=2147483640,u32_max_value=-8) R7=map_value(id=0,off=56,ks=4,vs=8272,imm=0) R8=invP6 R9=map_value(id=0,off=20,ks=4,vs=24,imm=0) R10=fp0 fp-8=mmmmmmmm fp-16=map_value fp-24=map_value fp-32=inv40 fp-40=ctx fp-48=map_value fp-56=inv1 fp-64=map_value fp-72=map_value fp-80=map_value
  R1 unbounded memory access, make sure to bounds check any such access
  processed 466 insns (limit 1000000) max_states_per_insn 2 total_states 20 peak_states 20 mark_read 3

If we add this line, as used in other BPF programs, to cap that index:

   index &amp;= 7;

The generated BPF program is considered safe by that version of the BPF
verifier, allowing perf to collect the syscall args in one more kernel
using the BPF based pointer contents collector.

With the above one-liner it works with that kernel:

  [root@dell-per740-01 ~]# uname -a
  Linux dell-per740-01.khw.eng.rdu2.dc.redhat.com 4.18.0-513.11.1.el8_9.x86_64 #1 SMP Thu Dec 7 03:06:13 EST 2023 x86_64 x86_64 x86_64 GNU/Linux
  [root@dell-per740-01 ~]# ~acme/bin/perf trace -e *sleep* sleep 1.234567890
       0.000 (1234.704 ms): sleep/3863610 nanosleep(rqtp: { .tv_sec: 1, .tv_nsec: 234567890 })                  = 0
  [root@dell-per740-01 ~]#

As well as with the one in Fedora 40:

  root@number:~# uname -a
  Linux number 6.11.3-200.fc40.x86_64 #1 SMP PREEMPT_DYNAMIC Thu Oct 10 22:31:19 UTC 2024 x86_64 GNU/Linux
  root@number:~# perf trace -e *sleep* sleep 1.234567890
       0.000 (1234.722 ms): sleep/14873 clock_nanosleep(rqtp: { .tv_sec: 1, .tv_nsec: 234567890 }, rmtp: 0x7ffe87311a40) = 0
  root@number:~#

Song Liu reported that this one-liner was being optimized out by clang
18, so I suggested and he tested that adding a compiler barrier before
it made clang v18 to keep it and the verifier in the kernel in Song's
case (Meta's 5.12 based kernel) also was happy with the resulting
bytecode.

I'll investigate using virtme-ng[1] to have all the perf BPF based
functionality thoroughly tested over multiple kernels and clang
versions.

[1] https://kernel-recipes.org/en/2024/virtme-ng/

Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alan Maguire &lt;alan.maguire@oracle.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Andrea Righi &lt;andrea.righi@linux.dev&gt;
Cc: Howard Chu &lt;howardchu95@gmail.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: James Clark &lt;james.clark@linaro.org&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Song Liu &lt;songliubraving@fb.com&gt;
Link: https://lore.kernel.org/lkml/Zw7JgJc0LOwSpuvx@x1
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In a RHEL8 kernel (4.18.0-513.11.1.el8_9.x86_64), that, as enterprise
kernels go, have backports from modern kernels, the verifier complains
about lack of bounds check for the index into the array of syscall
arguments, on a BPF bytecode generated by clang 17, with:

  ; } else if (size &lt; 0 &amp;&amp; size &gt;= -6) { /* buffer */
  116: (b7) r1 = -6
  117: (2d) if r1 &gt; r6 goto pc-30
   R0=map_value(id=0,off=0,ks=4,vs=24688,imm=0) R1_w=inv-6 R2=map_value(id=0,off=16,ks=4,vs=8272,imm=0) R3=inv(id=0) R5=inv40 R6=inv(id=0,umin_value=18446744073709551610,var_off=(0xffffffff00000000; 0xffffffff)) R7=map_value(id=0,off=56,ks=4,vs=8272,imm=0) R8=invP6 R9=map_value(id=0,off=20,ks=4,vs=24,imm=0) R10=fp0 fp-8=mmmmmmmm fp-16=map_value fp-24=map_value fp-32=inv40 fp-40=ctx fp-48=map_value fp-56=inv1 fp-64=map_value fp-72=map_value fp-80=map_value
  ; index = -(size + 1);
  118: (a7) r6 ^= -1
  119: (67) r6 &lt;&lt;= 32
  120: (77) r6 &gt;&gt;= 32
  ; aug_size = args-&gt;args[index];
  121: (67) r6 &lt;&lt;= 3
  122: (79) r1 = *(u64 *)(r10 -24)
  123: (0f) r1 += r6
  last_idx 123 first_idx 116
  regs=40 stack=0 before 122: (79) r1 = *(u64 *)(r10 -24)
  regs=40 stack=0 before 121: (67) r6 &lt;&lt;= 3
  regs=40 stack=0 before 120: (77) r6 &gt;&gt;= 32
  regs=40 stack=0 before 119: (67) r6 &lt;&lt;= 32
  regs=40 stack=0 before 118: (a7) r6 ^= -1
  regs=40 stack=0 before 117: (2d) if r1 &gt; r6 goto pc-30
  regs=42 stack=0 before 116: (b7) r1 = -6
   R0_w=map_value(id=0,off=0,ks=4,vs=24688,imm=0) R1_w=inv1 R2_w=map_value(id=0,off=16,ks=4,vs=8272,imm=0) R3_w=inv(id=0) R5_w=inv40 R6_rw=invP(id=0,smin_value=-2147483648,smax_value=0) R7_w=map_value(id=0,off=56,ks=4,vs=8272,imm=0) R8_w=invP6 R9_w=map_value(id=0,off=20,ks=4,vs=24,imm=0) R10=fp0 fp-8=mmmmmmmm fp-16_w=map_value fp-24_r=map_value fp-32_w=inv40 fp-40=ctx fp-48=map_value fp-56_w=inv1 fp-64_w=map_value fp-72=map_value fp-80=map_value
  parent didn't have regs=40 stack=0 marks
  last_idx 110 first_idx 98
  regs=40 stack=0 before 110: (6d) if r1 s&gt; r6 goto pc+5
  regs=42 stack=0 before 109: (b7) r1 = 1
  regs=40 stack=0 before 108: (65) if r6 s&gt; 0x1000 goto pc+7
  regs=40 stack=0 before 98: (55) if r6 != 0x1 goto pc+9
   R0_w=map_value(id=0,off=0,ks=4,vs=24688,imm=0) R1_w=invP12 R2_w=map_value(id=0,off=16,ks=4,vs=8272,imm=0) R3_rw=inv(id=0) R5_w=inv24 R6_rw=invP(id=0,smin_value=-2147483648,smax_value=2147483647) R7_w=map_value(id=0,off=40,ks=4,vs=8272,imm=0) R8_rw=invP4 R9_w=map_value(id=0,off=12,ks=4,vs=24,imm=0) R10=fp0 fp-8=mmmmmmmm fp-16_rw=map_value fp-24_r=map_value fp-32_rw=invP24 fp-40_r=ctx fp-48_r=map_value fp-56_w=invP1 fp-64_rw=map_value fp-72_r=map_value fp-80_r=map_value
  parent already had regs=40 stack=0 marks
  124: (79) r6 = *(u64 *)(r1 +16)
   R0=map_value(id=0,off=0,ks=4,vs=24688,imm=0) R1_w=map_value(id=0,off=0,ks=4,vs=8272,umax_value=34359738360,var_off=(0x0; 0x7fffffff8),s32_max_value=2147483640,u32_max_value=-8) R2=map_value(id=0,off=16,ks=4,vs=8272,imm=0) R3=inv(id=0) R5=inv40 R6_w=invP(id=0,umax_value=34359738360,var_off=(0x0; 0x7fffffff8),s32_max_value=2147483640,u32_max_value=-8) R7=map_value(id=0,off=56,ks=4,vs=8272,imm=0) R8=invP6 R9=map_value(id=0,off=20,ks=4,vs=24,imm=0) R10=fp0 fp-8=mmmmmmmm fp-16=map_value fp-24=map_value fp-32=inv40 fp-40=ctx fp-48=map_value fp-56=inv1 fp-64=map_value fp-72=map_value fp-80=map_value
  R1 unbounded memory access, make sure to bounds check any such access
  processed 466 insns (limit 1000000) max_states_per_insn 2 total_states 20 peak_states 20 mark_read 3

If we add this line, as used in other BPF programs, to cap that index:

   index &amp;= 7;

The generated BPF program is considered safe by that version of the BPF
verifier, allowing perf to collect the syscall args in one more kernel
using the BPF based pointer contents collector.

With the above one-liner it works with that kernel:

  [root@dell-per740-01 ~]# uname -a
  Linux dell-per740-01.khw.eng.rdu2.dc.redhat.com 4.18.0-513.11.1.el8_9.x86_64 #1 SMP Thu Dec 7 03:06:13 EST 2023 x86_64 x86_64 x86_64 GNU/Linux
  [root@dell-per740-01 ~]# ~acme/bin/perf trace -e *sleep* sleep 1.234567890
       0.000 (1234.704 ms): sleep/3863610 nanosleep(rqtp: { .tv_sec: 1, .tv_nsec: 234567890 })                  = 0
  [root@dell-per740-01 ~]#

As well as with the one in Fedora 40:

  root@number:~# uname -a
  Linux number 6.11.3-200.fc40.x86_64 #1 SMP PREEMPT_DYNAMIC Thu Oct 10 22:31:19 UTC 2024 x86_64 GNU/Linux
  root@number:~# perf trace -e *sleep* sleep 1.234567890
       0.000 (1234.722 ms): sleep/14873 clock_nanosleep(rqtp: { .tv_sec: 1, .tv_nsec: 234567890 }, rmtp: 0x7ffe87311a40) = 0
  root@number:~#

Song Liu reported that this one-liner was being optimized out by clang
18, so I suggested and he tested that adding a compiler barrier before
it made clang v18 to keep it and the verifier in the kernel in Song's
case (Meta's 5.12 based kernel) also was happy with the resulting
bytecode.

I'll investigate using virtme-ng[1] to have all the perf BPF based
functionality thoroughly tested over multiple kernels and clang
versions.

[1] https://kernel-recipes.org/en/2024/virtme-ng/

Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alan Maguire &lt;alan.maguire@oracle.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Andrea Righi &lt;andrea.righi@linux.dev&gt;
Cc: Howard Chu &lt;howardchu95@gmail.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: James Clark &lt;james.clark@linaro.org&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Song Liu &lt;songliubraving@fb.com&gt;
Link: https://lore.kernel.org/lkml/Zw7JgJc0LOwSpuvx@x1
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'perf-tools-fixes-for-v6.12-1-2024-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools</title>
<updated>2024-10-08T17:43:22+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-10-08T17:43:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=b2760b839044132c29234b648aa4f6a2877de234'/>
<id>b2760b839044132c29234b648aa4f6a2877de234</id>
<content type='text'>
Pull perf tools fixes from Arnaldo Carvalho de Melo:

 - Fix an assert() to handle captured and unprocessed ARM CoreSight CPU
   traces

 - Fix static build compilation error when libdw isn't installed or is
   too old

 - Add missing include when building with
   !HAVE_DWARF_GETLOCATIONS_SUPPORT

 - Add missing refcount put on 32-bit DSOs

 - Fix disassembly of user space binaries by setting the binary_type of
   DSO when loading

 - Update headers with the kernel sources, including asound.h, sched.h,
   fcntl, msr-index.h, irq_vectors.h, socket.h, list_sort.c and arm64's
   cputype.h

* tag 'perf-tools-fixes-for-v6.12-1-2024-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools:
  perf cs-etm: Fix the assert() to handle captured and unprocessed cpu trace
  perf build: Fix build feature-dwarf_getlocations fail for old libdw
  perf build: Fix static compilation error when libdw is not installed
  perf dwarf-aux: Fix build with !HAVE_DWARF_GETLOCATIONS_SUPPORT
  tools headers arm64: Sync arm64's cputype.h with the kernel sources
  perf tools: Cope with differences for lib/list_sort.c copy from the kernel
  tools check_headers.sh: Add check variant that excludes some hunks
  perf beauty: Update copy of linux/socket.h with the kernel sources
  tools headers UAPI: Sync the linux/in.h with the kernel sources
  perf trace beauty: Update the arch/x86/include/asm/irq_vectors.h copy with the kernel sources
  tools arch x86: Sync the msr-index.h copy with the kernel sources
  tools include UAPI: Sync linux/fcntl.h copy with the kernel sources
  tools include UAPI: Sync linux/sched.h copy with the kernel sources
  tools include UAPI: Sync sound/asound.h copy with the kernel sources
  perf vdso: Missed put on 32-bit dsos
  perf symbol: Set binary_type of dso when loading
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull perf tools fixes from Arnaldo Carvalho de Melo:

 - Fix an assert() to handle captured and unprocessed ARM CoreSight CPU
   traces

 - Fix static build compilation error when libdw isn't installed or is
   too old

 - Add missing include when building with
   !HAVE_DWARF_GETLOCATIONS_SUPPORT

 - Add missing refcount put on 32-bit DSOs

 - Fix disassembly of user space binaries by setting the binary_type of
   DSO when loading

 - Update headers with the kernel sources, including asound.h, sched.h,
   fcntl, msr-index.h, irq_vectors.h, socket.h, list_sort.c and arm64's
   cputype.h

* tag 'perf-tools-fixes-for-v6.12-1-2024-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools:
  perf cs-etm: Fix the assert() to handle captured and unprocessed cpu trace
  perf build: Fix build feature-dwarf_getlocations fail for old libdw
  perf build: Fix static compilation error when libdw is not installed
  perf dwarf-aux: Fix build with !HAVE_DWARF_GETLOCATIONS_SUPPORT
  tools headers arm64: Sync arm64's cputype.h with the kernel sources
  perf tools: Cope with differences for lib/list_sort.c copy from the kernel
  tools check_headers.sh: Add check variant that excludes some hunks
  perf beauty: Update copy of linux/socket.h with the kernel sources
  tools headers UAPI: Sync the linux/in.h with the kernel sources
  perf trace beauty: Update the arch/x86/include/asm/irq_vectors.h copy with the kernel sources
  tools arch x86: Sync the msr-index.h copy with the kernel sources
  tools include UAPI: Sync linux/fcntl.h copy with the kernel sources
  tools include UAPI: Sync linux/sched.h copy with the kernel sources
  tools include UAPI: Sync sound/asound.h copy with the kernel sources
  perf vdso: Missed put on 32-bit dsos
  perf symbol: Set binary_type of dso when loading
</pre>
</div>
</content>
</entry>
<entry>
<title>move asm/unaligned.h to linux/unaligned.h</title>
<updated>2024-10-02T21:23:23+00:00</updated>
<author>
<name>Al Viro</name>
<email>viro@zeniv.linux.org.uk</email>
</author>
<published>2024-10-01T19:35:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=5f60d5f6bbc12e782fac78110b0ee62698f3b576'/>
<id>5f60d5f6bbc12e782fac78110b0ee62698f3b576</id>
<content type='text'>
asm/unaligned.h is always an include of asm-generic/unaligned.h;
might as well move that thing to linux/unaligned.h and include
that - there's nothing arch-specific in that header.

auto-generated by the following:

for i in `git grep -l -w asm/unaligned.h`; do
	sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i
done
for i in `git grep -l -w asm-generic/unaligned.h`; do
	sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i
done
git mv include/asm-generic/unaligned.h include/linux/unaligned.h
git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h
sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild
sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
asm/unaligned.h is always an include of asm-generic/unaligned.h;
might as well move that thing to linux/unaligned.h and include
that - there's nothing arch-specific in that header.

auto-generated by the following:

for i in `git grep -l -w asm/unaligned.h`; do
	sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i
done
for i in `git grep -l -w asm-generic/unaligned.h`; do
	sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i
done
git mv include/asm-generic/unaligned.h include/linux/unaligned.h
git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h
sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild
sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h
</pre>
</div>
</content>
</entry>
<entry>
<title>perf cs-etm: Fix the assert() to handle captured and unprocessed cpu trace</title>
<updated>2024-10-02T21:21:49+00:00</updated>
<author>
<name>Ilkka Koskinen</name>
<email>ilkka@os.amperecomputing.com</email>
</author>
<published>2024-09-24T23:39:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=e934a35e3cc1fe0bfb1bc771e64f3ba6e70c40e2'/>
<id>e934a35e3cc1fe0bfb1bc771e64f3ba6e70c40e2</id>
<content type='text'>
If one builds perf with DEBUG=1, captures data on multiple CPUs and
finally runs 'perf report -C &lt;cpu&gt;' for only one of the cpus, assert()
aborts the program. This happens because there are empty queues with
format set.

This patch changes the condition to abort only if a queue is not empty
and if the format is unset.

  $ make -C tools/perf DEBUG=1 CORESIGHT=1 CSLIBS=/usr/lib CSINCLUDES=/usr/include install
  $ perf record -o kcore --kcore -e cs_etm/timestamp/k -s -C 0-1 dd if=/dev/zero of=/dev/null bs=1M count=1
  $ perf report --input kcore/data --vmlinux=/home/ikoskine/projects/linux/vmlinux -C 1
  Aborted (core dumped)

Fixes: 57880a7966be510c ("perf: cs-etm: Allocate queues for all CPUs")
Reviewed-by: James Clark &lt;james.clark@linaro.org&gt;
Signed-off-by: Ilkka Koskinen &lt;ilkka@os.amperecomputing.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: James Clark &lt;james.clark@linaro.org&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: John Garry &lt;john.g.garry@oracle.com&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Leo Yan &lt;leo.yan@linux.dev&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Mike Leach &lt;mike.leach@linaro.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Suzuki Poulouse &lt;suzuki.poulose@arm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Link: https://lore.kernel.org/r/20240924233930.5193-1-ilkka@os.amperecomputing.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If one builds perf with DEBUG=1, captures data on multiple CPUs and
finally runs 'perf report -C &lt;cpu&gt;' for only one of the cpus, assert()
aborts the program. This happens because there are empty queues with
format set.

This patch changes the condition to abort only if a queue is not empty
and if the format is unset.

  $ make -C tools/perf DEBUG=1 CORESIGHT=1 CSLIBS=/usr/lib CSINCLUDES=/usr/include install
  $ perf record -o kcore --kcore -e cs_etm/timestamp/k -s -C 0-1 dd if=/dev/zero of=/dev/null bs=1M count=1
  $ perf report --input kcore/data --vmlinux=/home/ikoskine/projects/linux/vmlinux -C 1
  Aborted (core dumped)

Fixes: 57880a7966be510c ("perf: cs-etm: Allocate queues for all CPUs")
Reviewed-by: James Clark &lt;james.clark@linaro.org&gt;
Signed-off-by: Ilkka Koskinen &lt;ilkka@os.amperecomputing.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: James Clark &lt;james.clark@linaro.org&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: John Garry &lt;john.g.garry@oracle.com&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Leo Yan &lt;leo.yan@linux.dev&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Mike Leach &lt;mike.leach@linaro.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Suzuki Poulouse &lt;suzuki.poulose@arm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Link: https://lore.kernel.org/r/20240924233930.5193-1-ilkka@os.amperecomputing.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf dwarf-aux: Fix build with !HAVE_DWARF_GETLOCATIONS_SUPPORT</title>
<updated>2024-10-02T21:21:49+00:00</updated>
<author>
<name>James Clark</name>
<email>james.clark@linaro.org</email>
</author>
<published>2024-10-01T12:36:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=008979cc6911987152eb7485943c85b9c92c1e9b'/>
<id>008979cc6911987152eb7485943c85b9c92c1e9b</id>
<content type='text'>
The linked fixes commit added an #include "dwarf-aux.h" to disasm.h
which gets picked up in a lot of places. Without
HAVE_DWARF_GETLOCATIONS_SUPPORT the stubs return an errno, so include
errno.h to fix the following build error:

  In file included from util/disasm.h:8,
                 from util/annotate.h:16,
                 from builtin-top.c:23:
  util/dwarf-aux.h: In function 'die_get_var_range':
  util/dwarf-aux.h:183:10: error: 'ENOTSUP' undeclared (first use in this function)
    183 |  return -ENOTSUP;
        |          ^~~~~~~

Fixes: 782959ac248ac3cb ("perf annotate: Add "update_insn_state" callback function to handle arch specific instruction tracking")
Signed-off-by: James Clark &lt;james.clark@linaro.org&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Athira Rajeev &lt;atrajeev@linux.vnet.ibm.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Kajol Jain &lt;kjain@linux.ibm.com&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: https://lore.kernel.org/r/20241001123625.1063153-1-james.clark@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The linked fixes commit added an #include "dwarf-aux.h" to disasm.h
which gets picked up in a lot of places. Without
HAVE_DWARF_GETLOCATIONS_SUPPORT the stubs return an errno, so include
errno.h to fix the following build error:

  In file included from util/disasm.h:8,
                 from util/annotate.h:16,
                 from builtin-top.c:23:
  util/dwarf-aux.h: In function 'die_get_var_range':
  util/dwarf-aux.h:183:10: error: 'ENOTSUP' undeclared (first use in this function)
    183 |  return -ENOTSUP;
        |          ^~~~~~~

Fixes: 782959ac248ac3cb ("perf annotate: Add "update_insn_state" callback function to handle arch specific instruction tracking")
Signed-off-by: James Clark &lt;james.clark@linaro.org&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Athira Rajeev &lt;atrajeev@linux.vnet.ibm.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Kajol Jain &lt;kjain@linux.ibm.com&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: https://lore.kernel.org/r/20241001123625.1063153-1-james.clark@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf vdso: Missed put on 32-bit dsos</title>
<updated>2024-09-27T18:38:52+00:00</updated>
<author>
<name>Ian Rogers</name>
<email>irogers@google.com</email>
</author>
<published>2024-09-12T18:27:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=424aafb61a0b98d7d242f447fdb84bb8b323e8a8'/>
<id>424aafb61a0b98d7d242f447fdb84bb8b323e8a8</id>
<content type='text'>
If the dso type doesn't match then NULL is returned but the dso should
be put first.

Fixes: f649ed80f3cabbf1 ("perf dsos: Tidy reference counting and locking")
Signed-off-by: Ian Rogers &lt;irogers@google.com&gt;
Acked-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: https://lore.kernel.org/r/20240912182757.762369-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
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If the dso type doesn't match then NULL is returned but the dso should
be put first.

Fixes: f649ed80f3cabbf1 ("perf dsos: Tidy reference counting and locking")
Signed-off-by: Ian Rogers &lt;irogers@google.com&gt;
Acked-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: https://lore.kernel.org/r/20240912182757.762369-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
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