<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/tools/perf/util/annotate.c, branch v5.13.2</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>perf annotate: Add line number like in TUI and source location at EOL</title>
<updated>2021-04-20T11:40:20+00:00</updated>
<author>
<name>Martin Liška</name>
<email>mliska@suse.cz</email>
</author>
<published>2021-02-21T12:46:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f89a82a82b20261e5778132f5237971991bad8e6'/>
<id>f89a82a82b20261e5778132f5237971991bad8e6</id>
<content type='text'>
The patch changes the output format in 2 ways:
- line number is displayed for all source lines (matching TUI mode)
- source locations for the hottest lines are printed
   at the line end in order to preserve layout

Before:

     0.00 :   405ef1: inc    %r15
          :            tmpsd * (TD + tmpsd * TDD)));
     0.01 :   405ef4: vfmadd213sd 0x2b9b3(%rip),%xmm0,%xmm3        # 4318b0 &lt;_IO_stdin_used+0x8b0&gt;
          :            tmpsd * (TC +
  eff.c:1811    0.67 :   405efd: vfmadd213sd 0x2b9b2(%rip),%xmm0,%xmm3        # 4318b8 &lt;_IO_stdin_used+0x8b8&gt;
          :            TA + tmpsd * (TB +
     0.35 :   405f06: vfmadd213sd 0x2b9b1(%rip),%xmm0,%xmm3        # 4318c0 &lt;_IO_stdin_used+0x8c0&gt;
          :            dumbo =
  eff.c:1809    1.41 :   405f0f: vfmadd213sd 0x2b9b0(%rip),%xmm0,%xmm3        # 4318c8 &lt;_IO_stdin_used+0x8c8&gt;
          :            sumi -= sj * tmpsd * dij2i * dumbo;
  eff.c:1813    2.58 :   405f18: vmulsd %xmm3,%xmm0,%xmm0
     2.81 :   405f1c: vfnmadd213sd 0x30(%rsp),%xmm1,%xmm0
     3.78 :   405f23: vmovsd %xmm0,0x30(%rsp)
          :            for (k = 0; k &lt; lpears[i] + upears[i]; k++) {
  eff.c:1761    0.90 :   405f29: cmp    %r15d,%r12d

After:

     0.00 :   405ef1: inc    %r15
          : 1812   tmpsd * (TD + tmpsd * TDD)));
     0.01 :   405ef4: vfmadd213sd 0x2b9b3(%rip),%xmm0,%xmm3        # 4318b0 &lt;_IO_stdin_used+0x8b0&gt;
          : 1811   tmpsd * (TC +
     0.67 :   405efd: vfmadd213sd 0x2b9b2(%rip),%xmm0,%xmm3        # 4318b8 &lt;_IO_stdin_used+0x8b8&gt; // eff.c:1811
          : 1810   TA + tmpsd * (TB +
     0.35 :   405f06: vfmadd213sd 0x2b9b1(%rip),%xmm0,%xmm3        # 4318c0 &lt;_IO_stdin_used+0x8c0&gt;
          : 1809   dumbo =
     1.41 :   405f0f: vfmadd213sd 0x2b9b0(%rip),%xmm0,%xmm3        # 4318c8 &lt;_IO_stdin_used+0x8c8&gt; // eff.c:1809
          : 1813   sumi -= sj * tmpsd * dij2i * dumbo;
     2.58 :   405f18: vmulsd %xmm3,%xmm0,%xmm0 // eff.c:1813
     2.81 :   405f1c: vfnmadd213sd 0x30(%rsp),%xmm1,%xmm0
     3.78 :   405f23: vmovsd %xmm0,0x30(%rsp)
          : 1761   for (k = 0; k &lt; lpears[i] + upears[i]; k++) {

Where e.g. '// eff.c:1811' shares the same color as the percentantage
at the line beginning.

Signed-off-by: Martin Liška &lt;mliska@suse.cz&gt;
Link: http://lore.kernel.org/lkml/a0d53f31-f633-5013-c386-a4452391b081@suse.cz
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 patch changes the output format in 2 ways:
- line number is displayed for all source lines (matching TUI mode)
- source locations for the hottest lines are printed
   at the line end in order to preserve layout

Before:

     0.00 :   405ef1: inc    %r15
          :            tmpsd * (TD + tmpsd * TDD)));
     0.01 :   405ef4: vfmadd213sd 0x2b9b3(%rip),%xmm0,%xmm3        # 4318b0 &lt;_IO_stdin_used+0x8b0&gt;
          :            tmpsd * (TC +
  eff.c:1811    0.67 :   405efd: vfmadd213sd 0x2b9b2(%rip),%xmm0,%xmm3        # 4318b8 &lt;_IO_stdin_used+0x8b8&gt;
          :            TA + tmpsd * (TB +
     0.35 :   405f06: vfmadd213sd 0x2b9b1(%rip),%xmm0,%xmm3        # 4318c0 &lt;_IO_stdin_used+0x8c0&gt;
          :            dumbo =
  eff.c:1809    1.41 :   405f0f: vfmadd213sd 0x2b9b0(%rip),%xmm0,%xmm3        # 4318c8 &lt;_IO_stdin_used+0x8c8&gt;
          :            sumi -= sj * tmpsd * dij2i * dumbo;
  eff.c:1813    2.58 :   405f18: vmulsd %xmm3,%xmm0,%xmm0
     2.81 :   405f1c: vfnmadd213sd 0x30(%rsp),%xmm1,%xmm0
     3.78 :   405f23: vmovsd %xmm0,0x30(%rsp)
          :            for (k = 0; k &lt; lpears[i] + upears[i]; k++) {
  eff.c:1761    0.90 :   405f29: cmp    %r15d,%r12d

After:

     0.00 :   405ef1: inc    %r15
          : 1812   tmpsd * (TD + tmpsd * TDD)));
     0.01 :   405ef4: vfmadd213sd 0x2b9b3(%rip),%xmm0,%xmm3        # 4318b0 &lt;_IO_stdin_used+0x8b0&gt;
          : 1811   tmpsd * (TC +
     0.67 :   405efd: vfmadd213sd 0x2b9b2(%rip),%xmm0,%xmm3        # 4318b8 &lt;_IO_stdin_used+0x8b8&gt; // eff.c:1811
          : 1810   TA + tmpsd * (TB +
     0.35 :   405f06: vfmadd213sd 0x2b9b1(%rip),%xmm0,%xmm3        # 4318c0 &lt;_IO_stdin_used+0x8c0&gt;
          : 1809   dumbo =
     1.41 :   405f0f: vfmadd213sd 0x2b9b0(%rip),%xmm0,%xmm3        # 4318c8 &lt;_IO_stdin_used+0x8c8&gt; // eff.c:1809
          : 1813   sumi -= sj * tmpsd * dij2i * dumbo;
     2.58 :   405f18: vmulsd %xmm3,%xmm0,%xmm0 // eff.c:1813
     2.81 :   405f1c: vfnmadd213sd 0x30(%rsp),%xmm1,%xmm0
     3.78 :   405f23: vmovsd %xmm0,0x30(%rsp)
          : 1761   for (k = 0; k &lt; lpears[i] + upears[i]; k++) {

Where e.g. '// eff.c:1811' shares the same color as the percentantage
at the line beginning.

Signed-off-by: Martin Liška &lt;mliska@suse.cz&gt;
Link: http://lore.kernel.org/lkml/a0d53f31-f633-5013-c386-a4452391b081@suse.cz
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf annotate: Show full source location with 'l' hotkey</title>
<updated>2021-03-06T19:42:31+00:00</updated>
<author>
<name>Martin Liska</name>
<email>mliska@suse.cz</email>
</author>
<published>2021-02-15T11:34:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2777b81b379df772defd654bc4d3fa82dca17a4b'/>
<id>2777b81b379df772defd654bc4d3fa82dca17a4b</id>
<content type='text'>
Right now, when Line numbers are displayed, one can't easily find a
source file that the line corresponds to.

When a source line is selected and 'l' is pressed, full source file
location is displayed in perf UI footer line. The hotkey works only for
source code lines.

Signed-off-by: Martin Liška &lt;mliska@suse.cz&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Link: http://lore.kernel.org/lkml/25a6384f-d862-5dda-4fec-8f0555599c75@suse.cz
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>
Right now, when Line numbers are displayed, one can't easily find a
source file that the line corresponds to.

When a source line is selected and 'l' is pressed, full source file
location is displayed in perf UI footer line. The hotkey works only for
source code lines.

Signed-off-by: Martin Liška &lt;mliska@suse.cz&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Link: http://lore.kernel.org/lkml/25a6384f-d862-5dda-4fec-8f0555599c75@suse.cz
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf config: Add annotate.demangle{,_kernel}</title>
<updated>2021-03-06T19:42:31+00:00</updated>
<author>
<name>Martin Liska</name>
<email>mliska@suse.cz</email>
</author>
<published>2021-02-26T10:01:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=44e176501c557460de954572435baa4ae34d2a35'/>
<id>44e176501c557460de954572435baa4ae34d2a35</id>
<content type='text'>
Committer notes:

This allows setting this in from the command line:

  $ perf config annotate.demangle
  $ perf config annotate.demangle=yes
  $ perf config annotate.demangle
  annotate.demangle=yes
  $ cat ~/.perfconfig
  # this file is auto-generated.
  [report]
  	sort-order = srcline
  [annotate]
  	demangle = yes
  $
  $
  $ perf config annotate.demangle_kernel
  $ perf config annotate.demangle_kernel=yes
  $ perf config annotate.demangle_kernel
  annotate.demangle_kernel=yes
  $ cat ~/.perfconfig
  # this file is auto-generated.
  [report]
  	sort-order = srcline
  [annotate]
  	demangle = yes
  	demangle_kernel = yes
  $

Signed-off-by: Martin Liška &lt;mliska@suse.cz&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Link: https://lore.kernel.org/r/c96aabe7-791f-9503-295f-3147a9d19b60@suse.cz
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>
Committer notes:

This allows setting this in from the command line:

  $ perf config annotate.demangle
  $ perf config annotate.demangle=yes
  $ perf config annotate.demangle
  annotate.demangle=yes
  $ cat ~/.perfconfig
  # this file is auto-generated.
  [report]
  	sort-order = srcline
  [annotate]
  	demangle = yes
  $
  $
  $ perf config annotate.demangle_kernel
  $ perf config annotate.demangle_kernel=yes
  $ perf config annotate.demangle_kernel
  annotate.demangle_kernel=yes
  $ cat ~/.perfconfig
  # this file is auto-generated.
  [report]
  	sort-order = srcline
  [annotate]
  	demangle = yes
  	demangle_kernel = yes
  $

Signed-off-by: Martin Liška &lt;mliska@suse.cz&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Link: https://lore.kernel.org/r/c96aabe7-791f-9503-295f-3147a9d19b60@suse.cz
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf annotate: Fix jump parsing for C++ code.</title>
<updated>2021-02-11T21:23:53+00:00</updated>
<author>
<name>Martin Liška</name>
<email>mliska@suse.cz</email>
</author>
<published>2021-02-11T12:37:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1f0e6edcd968ff19211245f7da6039e983aa51e5'/>
<id>1f0e6edcd968ff19211245f7da6039e983aa51e5</id>
<content type='text'>
Considering the following testcase:

  int
  foo(int a, int b)
  {
     for (unsigned i = 0; i &lt; 1000000000; i++)
       a += b;
     return a;
  }

  int main()
  {
     foo (3, 4);
     return 0;
  }

'perf annotate' displays:

  86.52 │40055e: → ja   40056c &lt;foo(int, int)+0x26&gt;
  13.37 │400560:   mov  -0x18(%rbp),%eax
        │400563:   add  %eax,-0x14(%rbp)
        │400566:   addl $0x1,-0x4(%rbp)
   0.11 │40056a: → jmp  400557 &lt;foo(int, int)+0x11&gt;
        │40056c:   mov  -0x14(%rbp),%eax
        │40056f:   pop  %rbp

and the 'ja 40056c' does not link to the location in the function.  It's
caused by fact that comma is wrongly parsed, it's part of function
signature.

With my patch I see:

  86.52 │   ┌──ja   26
  13.37 │   │  mov  -0x18(%rbp),%eax
        │   │  add  %eax,-0x14(%rbp)
        │   │  addl $0x1,-0x4(%rbp)
   0.11 │   │↑ jmp  11
        │26:└─→mov  -0x14(%rbp),%eax

and 'o' output prints:

  86.52 │4005┌── ↓ ja   40056c &lt;foo(int, int)+0x26&gt;
  13.37 │4005│0:   mov  -0x18(%rbp),%eax
        │4005│3:   add  %eax,-0x14(%rbp)
        │4005│6:   addl $0x1,-0x4(%rbp)
   0.11 │4005│a: ↑ jmp  400557 &lt;foo(int, int)+0x11&gt;
        │4005└─→   mov  -0x14(%rbp),%eax

On the contrary, compiling the very same file with gcc -x c, the parsing
is fine because function arguments are not displayed:

  jmp  400543 &lt;foo+0x1d&gt;

Committer testing:

Before:

  $ cat cpp_args_annotate.c
  int
  foo(int a, int b)
  {
     for (unsigned i = 0; i &lt; 1000000000; i++)
       a += b;
     return a;
  }

  int main()
  {
     foo (3, 4);
     return 0;
  }
  $ gcc --version |&amp; head -1
  gcc (GCC) 10.2.1 20201125 (Red Hat 10.2.1-9)
  $ gcc -g cpp_args_annotate.c -o cpp_args_annotate
  $ perf record ./cpp_args_annotate
  [ perf record: Woken up 2 times to write data ]
  [ perf record: Captured and wrote 0.275 MB perf.data (7188 samples) ]
  $ perf annotate --stdio2 foo
  Samples: 7K of event 'cycles:u', 4000 Hz, Event count (approx.): 7468429289, [percent: local period]
  foo() /home/acme/c/cpp_args_annotate
  Percent
              0000000000401106 &lt;foo&gt;:
              foo():
              int
              foo(int a, int b)
              {
                push %rbp
                mov  %rsp,%rbp
                mov  %edi,-0x14(%rbp)
                mov  %esi,-0x18(%rbp)
              for (unsigned i = 0; i &lt; 1000000000; i++)
                movl $0x0,-0x4(%rbp)
              ↓ jmp  1d
              a += b;
   13.45  13:   mov  -0x18(%rbp),%eax
                add  %eax,-0x14(%rbp)
              for (unsigned i = 0; i &lt; 1000000000; i++)
                addl $0x1,-0x4(%rbp)
    0.09  1d:   cmpl $0x3b9ac9ff,-0x4(%rbp)
   86.46      ↑ jbe  13
              return a;
                mov  -0x14(%rbp),%eax
              }
                pop  %rbp
              ← retq
  $

I.e. works for C, now lets switch to C++:

  $ g++ -g cpp_args_annotate.c -o cpp_args_annotate
  $ perf record ./cpp_args_annotate
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.268 MB perf.data (6976 samples) ]
  $ perf annotate --stdio2 foo
  Samples: 6K of event 'cycles:u', 4000 Hz, Event count (approx.): 7380681761, [percent: local period]
  foo() /home/acme/c/cpp_args_annotate
  Percent
              0000000000401106 &lt;foo(int, int)&gt;:
              foo(int, int):
              int
              foo(int a, int b)
              {
                push %rbp
                mov  %rsp,%rbp
                mov  %edi,-0x14(%rbp)
                mov  %esi,-0x18(%rbp)
              for (unsigned i = 0; i &lt; 1000000000; i++)
                movl $0x0,-0x4(%rbp)
                cmpl $0x3b9ac9ff,-0x4(%rbp)
   86.53      → ja   40112c &lt;foo(int, int)+0x26&gt;
              a += b;
   13.32        mov  -0x18(%rbp),%eax
    0.00        add  %eax,-0x14(%rbp)
              for (unsigned i = 0; i &lt; 1000000000; i++)
                addl $0x1,-0x4(%rbp)
    0.15      → jmp  401117 &lt;foo(int, int)+0x11&gt;
              return a;
                mov  -0x14(%rbp),%eax
              }
                pop  %rbp
              ← retq
  $

Reproduced.

Now with this patch:

Reusing the C++ built binary, as we can see here:

  $ readelf -wi cpp_args_annotate | grep producer
    &lt;c&gt;   DW_AT_producer    : (indirect string, offset: 0x2e): GNU C++14 10.2.1 20201125 (Red Hat 10.2.1-9) -mtune=generic -march=x86-64 -g
  $

And furthermore:

  $ file cpp_args_annotate
  cpp_args_annotate: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, BuildID[sha1]=4fe3cab260204765605ec630d0dc7a7e93c361a9, for GNU/Linux 3.2.0, with debug_info, not stripped
  $ perf buildid-list -i cpp_args_annotate
  4fe3cab260204765605ec630d0dc7a7e93c361a9
  $ perf buildid-list | grep cpp_args_annotate
  4fe3cab260204765605ec630d0dc7a7e93c361a9 /home/acme/c/cpp_args_annotate
  $

It now works:

  $ perf annotate --stdio2 foo
  Samples: 6K of event 'cycles:u', 4000 Hz, Event count (approx.): 7380681761, [percent: local period]
  foo() /home/acme/c/cpp_args_annotate
  Percent
              0000000000401106 &lt;foo(int, int)&gt;:
              foo(int, int):
              int
              foo(int a, int b)
              {
                push %rbp
                mov  %rsp,%rbp
                mov  %edi,-0x14(%rbp)
                mov  %esi,-0x18(%rbp)
              for (unsigned i = 0; i &lt; 1000000000; i++)
                movl $0x0,-0x4(%rbp)
          11:   cmpl $0x3b9ac9ff,-0x4(%rbp)
   86.53      ↓ ja   26
              a += b;
   13.32        mov  -0x18(%rbp),%eax
    0.00        add  %eax,-0x14(%rbp)
              for (unsigned i = 0; i &lt; 1000000000; i++)
                addl $0x1,-0x4(%rbp)
    0.15      ↑ jmp  11
              return a;
          26:   mov  -0x14(%rbp),%eax
              }
                pop  %rbp
              ← retq
  $

Signed-off-by: Martin Liška &lt;mliska@suse.cz&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Jiri Slaby &lt;jslaby@suse.cz&gt;
Link: http://lore.kernel.org/lkml/13e1a405-edf9-e4c2-4327-a9b454353730@suse.cz
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>
Considering the following testcase:

  int
  foo(int a, int b)
  {
     for (unsigned i = 0; i &lt; 1000000000; i++)
       a += b;
     return a;
  }

  int main()
  {
     foo (3, 4);
     return 0;
  }

'perf annotate' displays:

  86.52 │40055e: → ja   40056c &lt;foo(int, int)+0x26&gt;
  13.37 │400560:   mov  -0x18(%rbp),%eax
        │400563:   add  %eax,-0x14(%rbp)
        │400566:   addl $0x1,-0x4(%rbp)
   0.11 │40056a: → jmp  400557 &lt;foo(int, int)+0x11&gt;
        │40056c:   mov  -0x14(%rbp),%eax
        │40056f:   pop  %rbp

and the 'ja 40056c' does not link to the location in the function.  It's
caused by fact that comma is wrongly parsed, it's part of function
signature.

With my patch I see:

  86.52 │   ┌──ja   26
  13.37 │   │  mov  -0x18(%rbp),%eax
        │   │  add  %eax,-0x14(%rbp)
        │   │  addl $0x1,-0x4(%rbp)
   0.11 │   │↑ jmp  11
        │26:└─→mov  -0x14(%rbp),%eax

and 'o' output prints:

  86.52 │4005┌── ↓ ja   40056c &lt;foo(int, int)+0x26&gt;
  13.37 │4005│0:   mov  -0x18(%rbp),%eax
        │4005│3:   add  %eax,-0x14(%rbp)
        │4005│6:   addl $0x1,-0x4(%rbp)
   0.11 │4005│a: ↑ jmp  400557 &lt;foo(int, int)+0x11&gt;
        │4005└─→   mov  -0x14(%rbp),%eax

On the contrary, compiling the very same file with gcc -x c, the parsing
is fine because function arguments are not displayed:

  jmp  400543 &lt;foo+0x1d&gt;

Committer testing:

Before:

  $ cat cpp_args_annotate.c
  int
  foo(int a, int b)
  {
     for (unsigned i = 0; i &lt; 1000000000; i++)
       a += b;
     return a;
  }

  int main()
  {
     foo (3, 4);
     return 0;
  }
  $ gcc --version |&amp; head -1
  gcc (GCC) 10.2.1 20201125 (Red Hat 10.2.1-9)
  $ gcc -g cpp_args_annotate.c -o cpp_args_annotate
  $ perf record ./cpp_args_annotate
  [ perf record: Woken up 2 times to write data ]
  [ perf record: Captured and wrote 0.275 MB perf.data (7188 samples) ]
  $ perf annotate --stdio2 foo
  Samples: 7K of event 'cycles:u', 4000 Hz, Event count (approx.): 7468429289, [percent: local period]
  foo() /home/acme/c/cpp_args_annotate
  Percent
              0000000000401106 &lt;foo&gt;:
              foo():
              int
              foo(int a, int b)
              {
                push %rbp
                mov  %rsp,%rbp
                mov  %edi,-0x14(%rbp)
                mov  %esi,-0x18(%rbp)
              for (unsigned i = 0; i &lt; 1000000000; i++)
                movl $0x0,-0x4(%rbp)
              ↓ jmp  1d
              a += b;
   13.45  13:   mov  -0x18(%rbp),%eax
                add  %eax,-0x14(%rbp)
              for (unsigned i = 0; i &lt; 1000000000; i++)
                addl $0x1,-0x4(%rbp)
    0.09  1d:   cmpl $0x3b9ac9ff,-0x4(%rbp)
   86.46      ↑ jbe  13
              return a;
                mov  -0x14(%rbp),%eax
              }
                pop  %rbp
              ← retq
  $

I.e. works for C, now lets switch to C++:

  $ g++ -g cpp_args_annotate.c -o cpp_args_annotate
  $ perf record ./cpp_args_annotate
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.268 MB perf.data (6976 samples) ]
  $ perf annotate --stdio2 foo
  Samples: 6K of event 'cycles:u', 4000 Hz, Event count (approx.): 7380681761, [percent: local period]
  foo() /home/acme/c/cpp_args_annotate
  Percent
              0000000000401106 &lt;foo(int, int)&gt;:
              foo(int, int):
              int
              foo(int a, int b)
              {
                push %rbp
                mov  %rsp,%rbp
                mov  %edi,-0x14(%rbp)
                mov  %esi,-0x18(%rbp)
              for (unsigned i = 0; i &lt; 1000000000; i++)
                movl $0x0,-0x4(%rbp)
                cmpl $0x3b9ac9ff,-0x4(%rbp)
   86.53      → ja   40112c &lt;foo(int, int)+0x26&gt;
              a += b;
   13.32        mov  -0x18(%rbp),%eax
    0.00        add  %eax,-0x14(%rbp)
              for (unsigned i = 0; i &lt; 1000000000; i++)
                addl $0x1,-0x4(%rbp)
    0.15      → jmp  401117 &lt;foo(int, int)+0x11&gt;
              return a;
                mov  -0x14(%rbp),%eax
              }
                pop  %rbp
              ← retq
  $

Reproduced.

Now with this patch:

Reusing the C++ built binary, as we can see here:

  $ readelf -wi cpp_args_annotate | grep producer
    &lt;c&gt;   DW_AT_producer    : (indirect string, offset: 0x2e): GNU C++14 10.2.1 20201125 (Red Hat 10.2.1-9) -mtune=generic -march=x86-64 -g
  $

And furthermore:

  $ file cpp_args_annotate
  cpp_args_annotate: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, BuildID[sha1]=4fe3cab260204765605ec630d0dc7a7e93c361a9, for GNU/Linux 3.2.0, with debug_info, not stripped
  $ perf buildid-list -i cpp_args_annotate
  4fe3cab260204765605ec630d0dc7a7e93c361a9
  $ perf buildid-list | grep cpp_args_annotate
  4fe3cab260204765605ec630d0dc7a7e93c361a9 /home/acme/c/cpp_args_annotate
  $

It now works:

  $ perf annotate --stdio2 foo
  Samples: 6K of event 'cycles:u', 4000 Hz, Event count (approx.): 7380681761, [percent: local period]
  foo() /home/acme/c/cpp_args_annotate
  Percent
              0000000000401106 &lt;foo(int, int)&gt;:
              foo(int, int):
              int
              foo(int a, int b)
              {
                push %rbp
                mov  %rsp,%rbp
                mov  %edi,-0x14(%rbp)
                mov  %esi,-0x18(%rbp)
              for (unsigned i = 0; i &lt; 1000000000; i++)
                movl $0x0,-0x4(%rbp)
          11:   cmpl $0x3b9ac9ff,-0x4(%rbp)
   86.53      ↓ ja   26
              a += b;
   13.32        mov  -0x18(%rbp),%eax
    0.00        add  %eax,-0x14(%rbp)
              for (unsigned i = 0; i &lt; 1000000000; i++)
                addl $0x1,-0x4(%rbp)
    0.15      ↑ jmp  11
              return a;
          26:   mov  -0x14(%rbp),%eax
              }
                pop  %rbp
              ← retq
  $

Signed-off-by: Martin Liška &lt;mliska@suse.cz&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Jiri Slaby &lt;jslaby@suse.cz&gt;
Link: http://lore.kernel.org/lkml/13e1a405-edf9-e4c2-4327-a9b454353730@suse.cz
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf annotate: Move bpf header inclusion to inside HAVE_LIBBPF_SUPPORT</title>
<updated>2020-11-04T12:42:41+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2020-10-20T18:48:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=20e88c6076fc50ebf0560e730349000ff2da94fd'/>
<id>20e88c6076fc50ebf0560e730349000ff2da94fd</id>
<content type='text'>
No need to include it otherwise.

Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
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>
No need to include it otherwise.

Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf annotate mips: Add perf arch instructions annotate handlers</title>
<updated>2020-11-04T12:42:40+00:00</updated>
<author>
<name>Dengcheng Zhu</name>
<email>dzhu@wavecomp.com</email>
</author>
<published>2020-10-19T07:21:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a701d28e2d997705ae4376753af6e35b20029cef'/>
<id>a701d28e2d997705ae4376753af6e35b20029cef</id>
<content type='text'>
Support the MIPS architecture using the ins_ops association method. With
this patch, perf-annotate can work well on MIPS.

Testing it with a perf.data file collected on a mips machine:

$./perf annotate -i perf.data

         :           Disassembly of section .text:
         :
         :           00000000000be6a0 &lt;get_next_seq&gt;:
         :           get_next_seq():
    0.00 :   be6a0:       lw      v0,0(a0)
    0.00 :   be6a4:       daddiu  sp,sp,-128
    0.00 :   be6a8:       ld      a7,72(a0)
    0.00 :   be6ac:       gssq    s5,s4,80(sp)
    0.00 :   be6b0:       gssq    s1,s0,48(sp)
    0.00 :   be6b4:       gssq    s8,gp,112(sp)
    0.00 :   be6b8:       gssq    s7,s6,96(sp)
    0.00 :   be6bc:       gssq    s3,s2,64(sp)
    0.00 :   be6c0:       sd      a3,0(sp)
    0.00 :   be6c4:       move    s0,a0
    0.00 :   be6c8:       sd      v0,32(sp)
    0.00 :   be6cc:       sd      a5,8(sp)
    0.00 :   be6d0:       sd      zero,8(a0)
    0.00 :   be6d4:       sd      a6,16(sp)
    0.00 :   be6d8:       ld      s2,48(a0)
    8.53 :   be6dc:       ld      s1,40(a0)
    9.42 :   be6e0:       ld      v1,32(a0)
    0.00 :   be6e4:       nop
    0.00 :   be6e8:       ld      s4,24(a0)
    0.00 :   be6ec:       ld      s5,16(a0)
    0.00 :   be6f0:       sd      a7,40(sp)
   10.11 :   be6f4:       ld      s6,64(a0)

...

The original patch link:
https://lore.kernel.org/patchwork/patch/1180480/

Signed-off-by: Dengcheng Zhu &lt;dzhu@wavecomp.com&gt;
Cc: Dengcheng Zhu &lt;dzhu@wavecomp.com&gt;
Cc: Jiaxun Yang &lt;jiaxun.yang@flygoat.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Xuefeng Li &lt;lixuefeng@loongson.cn&gt;
Cc: linux-mips@vger.kernel.org
[ fanpeng@loongson.cn: Add missing "bgtzl", "bltzl", "bgezl", "blezl", "beql" and "bnel" for pre-R6processors ]
Signed-off-by: Peng Fan &lt;fanpeng@loongson.cn&gt;
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>
Support the MIPS architecture using the ins_ops association method. With
this patch, perf-annotate can work well on MIPS.

Testing it with a perf.data file collected on a mips machine:

$./perf annotate -i perf.data

         :           Disassembly of section .text:
         :
         :           00000000000be6a0 &lt;get_next_seq&gt;:
         :           get_next_seq():
    0.00 :   be6a0:       lw      v0,0(a0)
    0.00 :   be6a4:       daddiu  sp,sp,-128
    0.00 :   be6a8:       ld      a7,72(a0)
    0.00 :   be6ac:       gssq    s5,s4,80(sp)
    0.00 :   be6b0:       gssq    s1,s0,48(sp)
    0.00 :   be6b4:       gssq    s8,gp,112(sp)
    0.00 :   be6b8:       gssq    s7,s6,96(sp)
    0.00 :   be6bc:       gssq    s3,s2,64(sp)
    0.00 :   be6c0:       sd      a3,0(sp)
    0.00 :   be6c4:       move    s0,a0
    0.00 :   be6c8:       sd      v0,32(sp)
    0.00 :   be6cc:       sd      a5,8(sp)
    0.00 :   be6d0:       sd      zero,8(a0)
    0.00 :   be6d4:       sd      a6,16(sp)
    0.00 :   be6d8:       ld      s2,48(a0)
    8.53 :   be6dc:       ld      s1,40(a0)
    9.42 :   be6e0:       ld      v1,32(a0)
    0.00 :   be6e4:       nop
    0.00 :   be6e8:       ld      s4,24(a0)
    0.00 :   be6ec:       ld      s5,16(a0)
    0.00 :   be6f0:       sd      a7,40(sp)
   10.11 :   be6f4:       ld      s6,64(a0)

...

The original patch link:
https://lore.kernel.org/patchwork/patch/1180480/

Signed-off-by: Dengcheng Zhu &lt;dzhu@wavecomp.com&gt;
Cc: Dengcheng Zhu &lt;dzhu@wavecomp.com&gt;
Cc: Jiaxun Yang &lt;jiaxun.yang@flygoat.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Xuefeng Li &lt;lixuefeng@loongson.cn&gt;
Cc: linux-mips@vger.kernel.org
[ fanpeng@loongson.cn: Add missing "bgtzl", "bltzl", "bgezl", "blezl", "beql" and "bnel" for pre-R6processors ]
Signed-off-by: Peng Fan &lt;fanpeng@loongson.cn&gt;
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf tools: Pass build_id object to build_id__sprintf()</title>
<updated>2020-10-14T11:46:22+00:00</updated>
<author>
<name>Jiri Olsa</name>
<email>jolsa@kernel.org</email>
</author>
<published>2020-10-13T19:24:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bf5411695a31f7bf07c3e9bad27b442c9224f2a9'/>
<id>bf5411695a31f7bf07c3e9bad27b442c9224f2a9</id>
<content type='text'>
Passing build_id object to build_id__sprintf function, so it can operate
with the proper size of build id.

This will create proper md5 build id readable names,
like following:

  a50e350e97c43b4708d09bcd85ebfff7

instead of:

  a50e350e97c43b4708d09bcd85ebfff700000000

Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Acked-by: Ian Rogers &lt;irogers@google.com&gt;
Link: https://lore.kernel.org/r/20201013192441.1299447-5-jolsa@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>
Passing build_id object to build_id__sprintf function, so it can operate
with the proper size of build id.

This will create proper md5 build id readable names,
like following:

  a50e350e97c43b4708d09bcd85ebfff7

instead of:

  a50e350e97c43b4708d09bcd85ebfff700000000

Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Acked-by: Ian Rogers &lt;irogers@google.com&gt;
Link: https://lore.kernel.org/r/20201013192441.1299447-5-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf tools: Use build_id object in dso</title>
<updated>2020-10-14T11:44:47+00:00</updated>
<author>
<name>Jiri Olsa</name>
<email>jolsa@kernel.org</email>
</author>
<published>2020-10-13T19:24:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0aba7f036a56675b7fdc536757b4c49fc76a2208'/>
<id>0aba7f036a56675b7fdc536757b4c49fc76a2208</id>
<content type='text'>
Replace build_id byte array with struct build_id object and all the code
that references it.

The objective is to carry size together with build id array, so it's
better to keep both together.

This is preparatory change for following patches, and there's no
functional change.

Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Acked-by: Ian Rogers &lt;irogers@google.com&gt;
Link: https://lore.kernel.org/r/20201013192441.1299447-2-jolsa@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>
Replace build_id byte array with struct build_id object and all the code
that references it.

The objective is to carry size together with build id array, so it's
better to keep both together.

This is preparatory change for following patches, and there's no
functional change.

Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Acked-by: Ian Rogers &lt;irogers@google.com&gt;
Link: https://lore.kernel.org/r/20201013192441.1299447-2-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf annotate: Allow configuring the 'disassembler_style' knob via 'perf config'</title>
<updated>2020-09-04T19:07:23+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2020-09-04T16:10:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bbe544682ee25a41f20a59fc7c29f790d502b3ce'/>
<id>bbe544682ee25a41f20a59fc7c29f790d502b3ce</id>
<content type='text'>
  # perf annotate --stdio2 acpi_processor_ffh_cstate_enter &gt; default
  # perf config annotate.disassembler_style=intel
  # perf config annotate.disassembler_style
  annotate.disassembler_style=intel
  # perf annotate --stdio2 acpi_processor_ffh_cstate_enter &gt; intel
  # diff -u default intel
  --- default	2020-09-04 13:09:26.019205732 -0300
  +++ intel	2020-09-04 13:09:52.823795081 -0300
  @@ -1,42 +1,42 @@
   Samples: 1K of event 'cycles', 4000 Hz, Event count (approx.): 990065316, [percent: local period]
   acpi_processor_ffh_cstate_enter() /lib/modules/5.9.0-rc3/build/vmlinux
  -Percent     → callq   __fentry__
  -              mov     cpu_number,%edx
  -              mov     %edx,%edx
  -              mov     cpu_cstate_entry,%rax
  -              add     -0x7dbe9700(,%rdx,8),%rax
  -              movzbl  0x9(%rdi),%edx
  -              mov     0x4(%rax,%rdx,8),%edi
  -              mov     (%rax,%rdx,8),%esi
  -            → jmpq    137ccc6
  -        2d: → jmpq    137ccd8
  +Percent     → call    __fentry__
  +              mov     edx,DWORD PTR gs:[rip+0x7e541d74]
  +              mov     edx,edx
  +              mov     rax,QWORD PTR [rip+0x152b8fb]
  +              add     rax,QWORD PTR [rdx*8-0x7dbe9700]
  +              movzx   edx,BYTE PTR [rdi+0x9]
  +              mov     edi,DWORD PTR [rax+rdx*8+0x4]
  +              mov     esi,DWORD PTR [rax+rdx*8]
  +            → jmp     137ccc6
  +        2d: → jmp     137ccd8
                 mfence
  -              mov     %gs:0x17bc0,%rax
  -              clflush (%rax)
  +              mov     rax,QWORD PTR gs:0x17bc0
  +              clflush BYTE PTR [rax]
                 mfence
  -              xor     %edx,%edx
  -              mov     %rdx,%rcx
  -              mov     %gs:0x17bc0,%rax
  -  0.00        monitor %rax,%ecx,%edx
  -              mov     (%rax),%rax
  -              test    $0x8,%al
  +              xor     edx,edx
  +              mov     rcx,rdx
  +              mov     rax,QWORD PTR gs:0x17bc0
  +  0.00        monitor
  +              mov     rax,QWORD PTR [rax]
  +              test    al,0x8
               ↓ jne     71
  -            ↓ jmpq    68
  -              verw    0x538b08(%rip)        # ffffffff82008150 &lt;ds.0&gt;
  -        68:   mov     %rsi,%rax
  -              mov     %rdi,%rcx
  -100.00        mwait   %eax,%ecx
  -        71:   mov     %gs:0x17bc0,%rax
  -              lock    andb    $0xdf,0x2(%rax)
  -              lock    addl    $0x0,-0x4(%rsp)
  -              mov     (%rax),%rax
  -              test    $0x8,%al
  +            ↓ jmp     68
  +              verw    WORD PTR [rip+0x538b08]        # ffffffff82008150 &lt;ds.0&gt;
  +        68:   mov     rax,rsi
  +              mov     rcx,rdi
  +100.00        mwait
  +        71:   mov     rax,QWORD PTR gs:0x17bc0
  +              lock    and     BYTE PTR [rax+0x2],0xdf
  +              lock    add     DWORD PTR [rsp-0x4],0x0
  +              mov     rax,QWORD PTR [rax]
  +              test    al,0x8
               ↓ je      97
  -              andl    $0x7fffffff,__preempt_count
  -        97: ← retq
  -              mov     %gs:0x17bc0,%rax
  -              lock    orb     $0x20,0x2(%rax)
  -              mov     (%rax),%rax
  -              test    $0x8,%al
  +              and     DWORD PTR gs:[rip+0x7e548509],0x7fffffff
  +        97:   ret
  +              mov     rax,QWORD PTR gs:0x17bc0
  +              lock    or      BYTE PTR [rax+0x2],0x20
  +              mov     rax,QWORD PTR [rax]
  +              test    al,0x8
               ↑ jne     71
  -            ↑ jmpq    2d
  +            ↑ jmp     2d
  #

Requested-by: Matt P. Dziubinski &lt;matdzb@gmail.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
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>
  # perf annotate --stdio2 acpi_processor_ffh_cstate_enter &gt; default
  # perf config annotate.disassembler_style=intel
  # perf config annotate.disassembler_style
  annotate.disassembler_style=intel
  # perf annotate --stdio2 acpi_processor_ffh_cstate_enter &gt; intel
  # diff -u default intel
  --- default	2020-09-04 13:09:26.019205732 -0300
  +++ intel	2020-09-04 13:09:52.823795081 -0300
  @@ -1,42 +1,42 @@
   Samples: 1K of event 'cycles', 4000 Hz, Event count (approx.): 990065316, [percent: local period]
   acpi_processor_ffh_cstate_enter() /lib/modules/5.9.0-rc3/build/vmlinux
  -Percent     → callq   __fentry__
  -              mov     cpu_number,%edx
  -              mov     %edx,%edx
  -              mov     cpu_cstate_entry,%rax
  -              add     -0x7dbe9700(,%rdx,8),%rax
  -              movzbl  0x9(%rdi),%edx
  -              mov     0x4(%rax,%rdx,8),%edi
  -              mov     (%rax,%rdx,8),%esi
  -            → jmpq    137ccc6
  -        2d: → jmpq    137ccd8
  +Percent     → call    __fentry__
  +              mov     edx,DWORD PTR gs:[rip+0x7e541d74]
  +              mov     edx,edx
  +              mov     rax,QWORD PTR [rip+0x152b8fb]
  +              add     rax,QWORD PTR [rdx*8-0x7dbe9700]
  +              movzx   edx,BYTE PTR [rdi+0x9]
  +              mov     edi,DWORD PTR [rax+rdx*8+0x4]
  +              mov     esi,DWORD PTR [rax+rdx*8]
  +            → jmp     137ccc6
  +        2d: → jmp     137ccd8
                 mfence
  -              mov     %gs:0x17bc0,%rax
  -              clflush (%rax)
  +              mov     rax,QWORD PTR gs:0x17bc0
  +              clflush BYTE PTR [rax]
                 mfence
  -              xor     %edx,%edx
  -              mov     %rdx,%rcx
  -              mov     %gs:0x17bc0,%rax
  -  0.00        monitor %rax,%ecx,%edx
  -              mov     (%rax),%rax
  -              test    $0x8,%al
  +              xor     edx,edx
  +              mov     rcx,rdx
  +              mov     rax,QWORD PTR gs:0x17bc0
  +  0.00        monitor
  +              mov     rax,QWORD PTR [rax]
  +              test    al,0x8
               ↓ jne     71
  -            ↓ jmpq    68
  -              verw    0x538b08(%rip)        # ffffffff82008150 &lt;ds.0&gt;
  -        68:   mov     %rsi,%rax
  -              mov     %rdi,%rcx
  -100.00        mwait   %eax,%ecx
  -        71:   mov     %gs:0x17bc0,%rax
  -              lock    andb    $0xdf,0x2(%rax)
  -              lock    addl    $0x0,-0x4(%rsp)
  -              mov     (%rax),%rax
  -              test    $0x8,%al
  +            ↓ jmp     68
  +              verw    WORD PTR [rip+0x538b08]        # ffffffff82008150 &lt;ds.0&gt;
  +        68:   mov     rax,rsi
  +              mov     rcx,rdi
  +100.00        mwait
  +        71:   mov     rax,QWORD PTR gs:0x17bc0
  +              lock    and     BYTE PTR [rax+0x2],0xdf
  +              lock    add     DWORD PTR [rsp-0x4],0x0
  +              mov     rax,QWORD PTR [rax]
  +              test    al,0x8
               ↓ je      97
  -              andl    $0x7fffffff,__preempt_count
  -        97: ← retq
  -              mov     %gs:0x17bc0,%rax
  -              lock    orb     $0x20,0x2(%rax)
  -              mov     (%rax),%rax
  -              test    $0x8,%al
  +              and     DWORD PTR gs:[rip+0x7e548509],0x7fffffff
  +        97:   ret
  +              mov     rax,QWORD PTR gs:0x17bc0
  +              lock    or      BYTE PTR [rax+0x2],0x20
  +              mov     rax,QWORD PTR [rax]
  +              test    al,0x8
               ↑ jne     71
  -            ↑ jmpq    2d
  +            ↑ jmp     2d
  #

Requested-by: Matt P. Dziubinski &lt;matdzb@gmail.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf annotate: Fix non-null terminated buffer returned by readlink()</title>
<updated>2020-07-09T15:36:50+00:00</updated>
<author>
<name>Numfor Mbiziwo-Tiapo</name>
<email>nums@google.com</email>
</author>
<published>2019-07-29T20:57:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b39730a6633d630b2a7bc61e597a0c671eb753b4'/>
<id>b39730a6633d630b2a7bc61e597a0c671eb753b4</id>
<content type='text'>
Our local MSAN (Memory Sanitizer) build of perf throws a warning that
comes from the "dso__disassemble_filename" function in
"tools/perf/util/annotate.c" when running perf record.

The warning stems from the call to readlink, in which "build_id_path"
was being read into "linkname". Since readlink does not null terminate,
an uninitialized memory access would later occur when "linkname" is
passed into the strstr function. This is simply fixed by
null-terminating "linkname" after the call to readlink.

To reproduce this warning, build perf by running:

  $ make -C tools/perf CLANG=1 CC=clang EXTRA_CFLAGS="-fsanitize=memory -fsanitize-memory-track-origins"

(Additionally, llvm might have to be installed and clang might have to
be specified as the compiler - export CC=/usr/bin/clang)

Then running:

  tools/perf/perf record -o - ls / | tools/perf/perf --no-pager annotate -i - --stdio

Please see the cover letter for why false positive warnings may be
generated.

Signed-off-by: Numfor Mbiziwo-Tiapo &lt;nums@google.com&gt;
Acked-by: Ian Rogers &lt;irogers@google.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Mark Drayton &lt;mbd@fb.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;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Link: http://lore.kernel.org/lkml/20190729205750.193289-1-nums@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>
Our local MSAN (Memory Sanitizer) build of perf throws a warning that
comes from the "dso__disassemble_filename" function in
"tools/perf/util/annotate.c" when running perf record.

The warning stems from the call to readlink, in which "build_id_path"
was being read into "linkname". Since readlink does not null terminate,
an uninitialized memory access would later occur when "linkname" is
passed into the strstr function. This is simply fixed by
null-terminating "linkname" after the call to readlink.

To reproduce this warning, build perf by running:

  $ make -C tools/perf CLANG=1 CC=clang EXTRA_CFLAGS="-fsanitize=memory -fsanitize-memory-track-origins"

(Additionally, llvm might have to be installed and clang might have to
be specified as the compiler - export CC=/usr/bin/clang)

Then running:

  tools/perf/perf record -o - ls / | tools/perf/perf --no-pager annotate -i - --stdio

Please see the cover letter for why false positive warnings may be
generated.

Signed-off-by: Numfor Mbiziwo-Tiapo &lt;nums@google.com&gt;
Acked-by: Ian Rogers &lt;irogers@google.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Mark Drayton &lt;mbd@fb.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;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Link: http://lore.kernel.org/lkml/20190729205750.193289-1-nums@google.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
