<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/tools/perf/util, branch linux-3.18.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>perf symbols: Filter out hidden symbols from labels</title>
<updated>2019-03-23T07:18:57+00:00</updated>
<author>
<name>Jiri Olsa</name>
<email>jolsa@redhat.com</email>
</author>
<published>2019-01-28T13:35:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c8a52bb99462533c30bbf6e54830811700ec5c49'/>
<id>c8a52bb99462533c30bbf6e54830811700ec5c49</id>
<content type='text'>
[ Upstream commit 59a17706915fe5ea6f711e1f92d4fb706bce07fe ]

When perf is built with the annobin plugin (RHEL8 build) extra symbols
are added to its binary:

  # nm perf | grep annobin | head -10
  0000000000241100 t .annobin_annotate.c
  0000000000326490 t .annobin_annotate.c
  0000000000249255 t .annobin_annotate.c_end
  00000000003283a8 t .annobin_annotate.c_end
  00000000001bce18 t .annobin_annotate.c_end.hot
  00000000001bce18 t .annobin_annotate.c_end.hot
  00000000001bc3e2 t .annobin_annotate.c_end.unlikely
  00000000001bc400 t .annobin_annotate.c_end.unlikely
  00000000001bce18 t .annobin_annotate.c.hot
  00000000001bce18 t .annobin_annotate.c.hot
  ...

Those symbols have no use for report or annotation and should be
skipped.  Moreover they interfere with the DWARF unwind test on the PPC
arch, where they are mixed with checked symbols and then the test fails:

  # perf test dwarf -v
  59: Test dwarf unwind                                     :
  --- start ---
  test child forked, pid 8515
  unwind: .annobin_dwarf_unwind.c:ip = 0x10dba40dc (0x2740dc)
  ...
  got: .annobin_dwarf_unwind.c 0x10dba40dc, expecting test__arch_unwind_sample
  unwind: failed with 'no error'

The annobin symbols are defined as NOTYPE/LOCAL/HIDDEN:

  # readelf -s ./perf | grep annobin | head -1
    40: 00000000001bce4f     0 NOTYPE  LOCAL  HIDDEN    13 .annobin_init.c

They can still pass the check for the label symbol. Adding check for
HIDDEN and INTERNAL (as suggested by Nick below) visibility and filter
out such symbols.

&gt;   Just to be awkward, if you are going to ignore STV_HIDDEN
&gt;   symbols then you should probably also ignore STV_INTERNAL ones
&gt;   as well...  Annobin does not generate them, but you never know,
&gt;   one day some other tool might create some.

Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Michael Petlan &lt;mpetlan@redhat.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Nick Clifton &lt;nickc@redhat.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: http://lkml.kernel.org/r/20190128133526.GD15461@krava
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
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 59a17706915fe5ea6f711e1f92d4fb706bce07fe ]

When perf is built with the annobin plugin (RHEL8 build) extra symbols
are added to its binary:

  # nm perf | grep annobin | head -10
  0000000000241100 t .annobin_annotate.c
  0000000000326490 t .annobin_annotate.c
  0000000000249255 t .annobin_annotate.c_end
  00000000003283a8 t .annobin_annotate.c_end
  00000000001bce18 t .annobin_annotate.c_end.hot
  00000000001bce18 t .annobin_annotate.c_end.hot
  00000000001bc3e2 t .annobin_annotate.c_end.unlikely
  00000000001bc400 t .annobin_annotate.c_end.unlikely
  00000000001bce18 t .annobin_annotate.c.hot
  00000000001bce18 t .annobin_annotate.c.hot
  ...

Those symbols have no use for report or annotation and should be
skipped.  Moreover they interfere with the DWARF unwind test on the PPC
arch, where they are mixed with checked symbols and then the test fails:

  # perf test dwarf -v
  59: Test dwarf unwind                                     :
  --- start ---
  test child forked, pid 8515
  unwind: .annobin_dwarf_unwind.c:ip = 0x10dba40dc (0x2740dc)
  ...
  got: .annobin_dwarf_unwind.c 0x10dba40dc, expecting test__arch_unwind_sample
  unwind: failed with 'no error'

The annobin symbols are defined as NOTYPE/LOCAL/HIDDEN:

  # readelf -s ./perf | grep annobin | head -1
    40: 00000000001bce4f     0 NOTYPE  LOCAL  HIDDEN    13 .annobin_init.c

They can still pass the check for the label symbol. Adding check for
HIDDEN and INTERNAL (as suggested by Nick below) visibility and filter
out such symbols.

&gt;   Just to be awkward, if you are going to ignore STV_HIDDEN
&gt;   symbols then you should probably also ignore STV_INTERNAL ones
&gt;   as well...  Annobin does not generate them, but you never know,
&gt;   one day some other tool might create some.

Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Michael Petlan &lt;mpetlan@redhat.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Nick Clifton &lt;nickc@redhat.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: http://lkml.kernel.org/r/20190128133526.GD15461@krava
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf tools: Handle TOPOLOGY headers with no CPU</title>
<updated>2019-03-23T07:18:55+00:00</updated>
<author>
<name>Stephane Eranian</name>
<email>eranian@google.com</email>
</author>
<published>2019-01-19T08:12:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=aef2907d0f4ed01b789bf70650d207dbc6389b73'/>
<id>aef2907d0f4ed01b789bf70650d207dbc6389b73</id>
<content type='text'>
[ Upstream commit 1497e804d1a6e2bd9107ddf64b0310449f4673eb ]

This patch fixes an issue in cpumap.c when used with the TOPOLOGY
header. In some configurations, some NUMA nodes may have no CPU (empty
cpulist). Yet a cpumap map must be created otherwise perf abort with an
error. This patch handles this case by creating a dummy map.

  Before:

  $ perf record -o - -e cycles noploop 2 | perf script -i -
  0x6e8 [0x6c]: failed to process type: 80

  After:

  $ perf record -o - -e cycles noploop 2 | perf script -i -
  noploop for 2 seconds

Signed-off-by: Stephane Eranian &lt;eranian@google.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: http://lkml.kernel.org/r/1547885559-1657-1-git-send-email-eranian@google.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
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 1497e804d1a6e2bd9107ddf64b0310449f4673eb ]

This patch fixes an issue in cpumap.c when used with the TOPOLOGY
header. In some configurations, some NUMA nodes may have no CPU (empty
cpulist). Yet a cpumap map must be created otherwise perf abort with an
error. This patch handles this case by creating a dummy map.

  Before:

  $ perf record -o - -e cycles noploop 2 | perf script -i -
  0x6e8 [0x6c]: failed to process type: 80

  After:

  $ perf record -o - -e cycles noploop 2 | perf script -i -
  noploop for 2 seconds

Signed-off-by: Stephane Eranian &lt;eranian@google.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: http://lkml.kernel.org/r/1547885559-1657-1-git-send-email-eranian@google.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf unwind: Take pgoff into account when reporting elf to libdwfl</title>
<updated>2019-02-06T16:34:52+00:00</updated>
<author>
<name>Milian Wolff</name>
<email>milian.wolff@kdab.com</email>
</author>
<published>2018-10-29T14:16:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1330478d468cbbfefa2cb7d6cbdc8c3cc61d5a37'/>
<id>1330478d468cbbfefa2cb7d6cbdc8c3cc61d5a37</id>
<content type='text'>
[ Upstream commit 1fe627da30331024f453faef04d500079b901107 ]

libdwfl parses an ELF file itself and creates mappings for the
individual sections. perf on the other hand sees raw mmap events which
represent individual sections. When we encounter an address pointing
into a mapping with pgoff != 0, we must take that into account and
report the file at the non-offset base address.

This fixes unwinding with libdwfl in some cases. E.g. for a file like:

```

using namespace std;

mutex g_mutex;

double worker()
{
    lock_guard&lt;mutex&gt; guard(g_mutex);
    uniform_real_distribution&lt;double&gt; uniform(-1E5, 1E5);
    default_random_engine engine;
    double s = 0;
    for (int i = 0; i &lt; 1000; ++i) {
        s += norm(complex&lt;double&gt;(uniform(engine), uniform(engine)));
    }
    cout &lt;&lt; s &lt;&lt; endl;
    return s;
}

int main()
{
    vector&lt;std::future&lt;double&gt;&gt; results;
    for (int i = 0; i &lt; 10000; ++i) {
        results.push_back(async(launch::async, worker));
    }
    return 0;
}
```

Compile it with `g++ -g -O2 -lpthread cpp-locking.cpp  -o cpp-locking`,
then record it with `perf record --call-graph dwarf -e
sched:sched_switch`.

When you analyze it with `perf script` and libunwind, you should see:

```
cpp-locking 20038 [005] 54830.236589: sched:sched_switch: prev_comm=cpp-locking prev_pid=20038 prev_prio=120 prev_state=T ==&gt; next_comm=swapper/5 next_pid=0 next_prio=120
        ffffffffb166fec5 __sched_text_start+0x545 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb166fec5 __sched_text_start+0x545 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb1670208 schedule+0x28 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb16737cc rwsem_down_read_failed+0xec (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb1665e04 call_rwsem_down_read_failed+0x14 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb1672a03 down_read+0x13 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb106bd85 __do_page_fault+0x445 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb18015f5 page_fault+0x45 (/lib/modules/4.14.78-1-lts/build/vmlinux)
            7f38e4252591 new_heap+0x101 (/usr/lib/libc-2.28.so)
            7f38e4252d0b arena_get2.part.4+0x2fb (/usr/lib/libc-2.28.so)
            7f38e4255b1c tcache_init.part.6+0xec (/usr/lib/libc-2.28.so)
            7f38e42569e5 __GI___libc_malloc+0x115 (inlined)
            7f38e4241790 __GI__IO_file_doallocate+0x90 (inlined)
            7f38e424fbbf __GI__IO_doallocbuf+0x4f (inlined)
            7f38e424ee47 __GI__IO_file_overflow+0x197 (inlined)
            7f38e424df36 _IO_new_file_xsputn+0x116 (inlined)
            7f38e4242bfb __GI__IO_fwrite+0xdb (inlined)
            7f38e463fa6d std::basic_streambuf&lt;char, std::char_traits&lt;char&gt; &gt;::sputn(char const*, long)+0x1cd (inlined)
            7f38e463fa6d std::ostreambuf_iterator&lt;char, std::char_traits&lt;char&gt; &gt;::_M_put(char const*, long)+0x1cd (inlined)
            7f38e463fa6d std::ostreambuf_iterator&lt;char, std::char_traits&lt;char&gt; &gt; std::__write&lt;char&gt;(std::ostreambuf_iterator&lt;char, std::char_traits&lt;char&gt; &gt;, char const*, int)+0x1cd (inlined)
            7f38e463fa6d std::ostreambuf_iterator&lt;char, std::char_traits&lt;char&gt; &gt; std::num_put&lt;char, std::ostreambuf_iterator&lt;char, std::char_traits&lt;char&gt; &gt; &gt;::_M_insert_float&lt;double&gt;(std::ostreambuf_iterator&lt;c&gt;
            7f38e464bd70 std::num_put&lt;char, std::ostreambuf_iterator&lt;char, std::char_traits&lt;char&gt; &gt; &gt;::put(std::ostreambuf_iterator&lt;char, std::char_traits&lt;char&gt; &gt;, std::ios_base&amp;, char, double) const+0x90 (inl&gt;
            7f38e464bd70 std::ostream&amp; std::ostream::_M_insert&lt;double&gt;(double)+0x90 (/usr/lib/libstdc++.so.6.0.25)
            563b9cb502f7 std::ostream::operator&lt;&lt;(double)+0xb7 (inlined)
            563b9cb502f7 worker()+0xb7 (/ssd/milian/projects/kdab/rnd/hotspot/build/tests/test-clients/cpp-locking/cpp-locking)
            563b9cb506fb double std::__invoke_impl&lt;double, double (*)()&gt;(std::__invoke_other, double (*&amp;&amp;)())+0x2b (inlined)
            563b9cb506fb std::__invoke_result&lt;double (*)()&gt;::type std::__invoke&lt;double (*)()&gt;(double (*&amp;&amp;)())+0x2b (inlined)
            563b9cb506fb decltype (__invoke((_S_declval&lt;0ul&gt;)())) std::thread::_Invoker&lt;std::tuple&lt;double (*)()&gt; &gt;::_M_invoke&lt;0ul&gt;(std::_Index_tuple&lt;0ul&gt;)+0x2b (inlined)
            563b9cb506fb std::thread::_Invoker&lt;std::tuple&lt;double (*)()&gt; &gt;::operator()()+0x2b (inlined)
            563b9cb506fb std::__future_base::_Task_setter&lt;std::unique_ptr&lt;std::__future_base::_Result&lt;double&gt;, std::__future_base::_Result_base::_Deleter&gt;, std::thread::_Invoker&lt;std::tuple&lt;double (*)()&gt; &gt;, dou&gt;
            563b9cb506fb std::_Function_handler&lt;std::unique_ptr&lt;std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter&gt; (), std::__future_base::_Task_setter&lt;std::unique_ptr&lt;std::__future_&gt;
            563b9cb507e8 std::function&lt;std::unique_ptr&lt;std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter&gt; ()&gt;::operator()() const+0x28 (inlined)
            563b9cb507e8 std::__future_base::_State_baseV2::_M_do_set(std::function&lt;std::unique_ptr&lt;std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter&gt; ()&gt;*, bool*)+0x28 (/ssd/milian/&gt;
            7f38e46d24fe __pthread_once_slow+0xbe (/usr/lib/libpthread-2.28.so)
            563b9cb51149 __gthread_once+0xe9 (inlined)
            563b9cb51149 void std::call_once&lt;void (std::__future_base::_State_baseV2::*)(std::function&lt;std::unique_ptr&lt;std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter&gt; ()&gt;*, bool*)&gt;
            563b9cb51149 std::__future_base::_State_baseV2::_M_set_result(std::function&lt;std::unique_ptr&lt;std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter&gt; ()&gt;, bool)+0xe9 (inlined)
            563b9cb51149 std::__future_base::_Async_state_impl&lt;std::thread::_Invoker&lt;std::tuple&lt;double (*)()&gt; &gt;, double&gt;::_Async_state_impl(std::thread::_Invoker&lt;std::tuple&lt;double (*)()&gt; &gt;&amp;&amp;)::{lambda()#1}::op&gt;
            563b9cb51149 void std::__invoke_impl&lt;void, std::__future_base::_Async_state_impl&lt;std::thread::_Invoker&lt;std::tuple&lt;double (*)()&gt; &gt;, double&gt;::_Async_state_impl(std::thread::_Invoker&lt;std::tuple&lt;double&gt;
            563b9cb51149 std::__invoke_result&lt;std::__future_base::_Async_state_impl&lt;std::thread::_Invoker&lt;std::tuple&lt;double (*)()&gt; &gt;, double&gt;::_Async_state_impl(std::thread::_Invoker&lt;std::tuple&lt;double (*)()&gt; &gt;&gt;
            563b9cb51149 decltype (__invoke((_S_declval&lt;0ul&gt;)())) std::thread::_Invoker&lt;std::tuple&lt;std::__future_base::_Async_state_impl&lt;std::thread::_Invoker&lt;std::tuple&lt;double (*)()&gt; &gt;, double&gt;::_Async_state_&gt;
            563b9cb51149 std::thread::_Invoker&lt;std::tuple&lt;std::__future_base::_Async_state_impl&lt;std::thread::_Invoker&lt;std::tuple&lt;double (*)()&gt; &gt;, double&gt;::_Async_state_impl(std::thread::_Invoker&lt;std::tuple&lt;dou&gt;
            563b9cb51149 std::thread::_State_impl&lt;std::thread::_Invoker&lt;std::tuple&lt;std::__future_base::_Async_state_impl&lt;std::thread::_Invoker&lt;std::tuple&lt;double (*)()&gt; &gt;, double&gt;::_Async_state_impl(std::thread&gt;
            7f38e45f0062 execute_native_thread_routine+0x12 (/usr/lib/libstdc++.so.6.0.25)
            7f38e46caa9c start_thread+0xfc (/usr/lib/libpthread-2.28.so)
            7f38e42ccb22 __GI___clone+0x42 (inlined)
```

Before this patch, using libdwfl, you would see:

```
cpp-locking 20038 [005] 54830.236589: sched:sched_switch: prev_comm=cpp-locking prev_pid=20038 prev_prio=120 prev_state=T ==&gt; next_comm=swapper/5 next_pid=0 next_prio=120
        ffffffffb166fec5 __sched_text_start+0x545 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb166fec5 __sched_text_start+0x545 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb1670208 schedule+0x28 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb16737cc rwsem_down_read_failed+0xec (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb1665e04 call_rwsem_down_read_failed+0x14 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb1672a03 down_read+0x13 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb106bd85 __do_page_fault+0x445 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb18015f5 page_fault+0x45 (/lib/modules/4.14.78-1-lts/build/vmlinux)
            7f38e4252591 new_heap+0x101 (/usr/lib/libc-2.28.so)
        a041161e77950c5c [unknown] ([unknown])
```

With this patch applied, we get a bit further in unwinding:

```
cpp-locking 20038 [005] 54830.236589: sched:sched_switch: prev_comm=cpp-locking prev_pid=20038 prev_prio=120 prev_state=T ==&gt; next_comm=swapper/5 next_pid=0 next_prio=120
        ffffffffb166fec5 __sched_text_start+0x545 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb166fec5 __sched_text_start+0x545 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb1670208 schedule+0x28 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb16737cc rwsem_down_read_failed+0xec (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb1665e04 call_rwsem_down_read_failed+0x14 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb1672a03 down_read+0x13 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb106bd85 __do_page_fault+0x445 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb18015f5 page_fault+0x45 (/lib/modules/4.14.78-1-lts/build/vmlinux)
            7f38e4252591 new_heap+0x101 (/usr/lib/libc-2.28.so)
            7f38e4252d0b arena_get2.part.4+0x2fb (/usr/lib/libc-2.28.so)
            7f38e4255b1c tcache_init.part.6+0xec (/usr/lib/libc-2.28.so)
            7f38e42569e5 __GI___libc_malloc+0x115 (inlined)
            7f38e4241790 __GI__IO_file_doallocate+0x90 (inlined)
            7f38e424fbbf __GI__IO_doallocbuf+0x4f (inlined)
            7f38e424ee47 __GI__IO_file_overflow+0x197 (inlined)
            7f38e424df36 _IO_new_file_xsputn+0x116 (inlined)
            7f38e4242bfb __GI__IO_fwrite+0xdb (inlined)
            7f38e463fa6d std::basic_streambuf&lt;char, std::char_traits&lt;char&gt; &gt;::sputn(char const*, long)+0x1cd (inlined)
            7f38e463fa6d std::ostreambuf_iterator&lt;char, std::char_traits&lt;char&gt; &gt;::_M_put(char const*, long)+0x1cd (inlined)
            7f38e463fa6d std::ostreambuf_iterator&lt;char, std::char_traits&lt;char&gt; &gt; std::__write&lt;char&gt;(std::ostreambuf_iterator&lt;char, std::char_traits&lt;char&gt; &gt;, char const*, int)+0x1cd (inlined)
            7f38e463fa6d std::ostreambuf_iterator&lt;char, std::char_traits&lt;char&gt; &gt; std::num_put&lt;char, std::ostreambuf_iterator&lt;char, std::char_traits&lt;char&gt; &gt; &gt;::_M_insert_float&lt;double&gt;(std::ostreambuf_iterator&lt;c&gt;
            7f38e464bd70 std::num_put&lt;char, std::ostreambuf_iterator&lt;char, std::char_traits&lt;char&gt; &gt; &gt;::put(std::ostreambuf_iterator&lt;char, std::char_traits&lt;char&gt; &gt;, std::ios_base&amp;, char, double) const+0x90 (inl&gt;
            7f38e464bd70 std::ostream&amp; std::ostream::_M_insert&lt;double&gt;(double)+0x90 (/usr/lib/libstdc++.so.6.0.25)
            563b9cb502f7 std::ostream::operator&lt;&lt;(double)+0xb7 (inlined)
            563b9cb502f7 worker()+0xb7 (/ssd/milian/projects/kdab/rnd/hotspot/build/tests/test-clients/cpp-locking/cpp-locking)
        6eab825c1ee3e4ff [unknown] ([unknown])
```

Note that the backtrace is still stopping too early, when compared to
the nice results obtained via libunwind. It's unclear so far what the
reason for that is.

Committer note:

Further comment by Milian on the thread started on the Link: tag below:

 ---
The remaining issue is due to a bug in elfutils:

https://sourceware.org/ml/elfutils-devel/2018-q4/msg00089.html

With both patches applied, libunwind and elfutils produce the same output for
the above scenario.
 ---

Signed-off-by: Milian Wolff &lt;milian.wolff@kdab.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Link: http://lkml.kernel.org/r/20181029141644.3907-1-milian.wolff@kdab.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
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 1fe627da30331024f453faef04d500079b901107 ]

libdwfl parses an ELF file itself and creates mappings for the
individual sections. perf on the other hand sees raw mmap events which
represent individual sections. When we encounter an address pointing
into a mapping with pgoff != 0, we must take that into account and
report the file at the non-offset base address.

This fixes unwinding with libdwfl in some cases. E.g. for a file like:

```

using namespace std;

mutex g_mutex;

double worker()
{
    lock_guard&lt;mutex&gt; guard(g_mutex);
    uniform_real_distribution&lt;double&gt; uniform(-1E5, 1E5);
    default_random_engine engine;
    double s = 0;
    for (int i = 0; i &lt; 1000; ++i) {
        s += norm(complex&lt;double&gt;(uniform(engine), uniform(engine)));
    }
    cout &lt;&lt; s &lt;&lt; endl;
    return s;
}

int main()
{
    vector&lt;std::future&lt;double&gt;&gt; results;
    for (int i = 0; i &lt; 10000; ++i) {
        results.push_back(async(launch::async, worker));
    }
    return 0;
}
```

Compile it with `g++ -g -O2 -lpthread cpp-locking.cpp  -o cpp-locking`,
then record it with `perf record --call-graph dwarf -e
sched:sched_switch`.

When you analyze it with `perf script` and libunwind, you should see:

```
cpp-locking 20038 [005] 54830.236589: sched:sched_switch: prev_comm=cpp-locking prev_pid=20038 prev_prio=120 prev_state=T ==&gt; next_comm=swapper/5 next_pid=0 next_prio=120
        ffffffffb166fec5 __sched_text_start+0x545 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb166fec5 __sched_text_start+0x545 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb1670208 schedule+0x28 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb16737cc rwsem_down_read_failed+0xec (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb1665e04 call_rwsem_down_read_failed+0x14 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb1672a03 down_read+0x13 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb106bd85 __do_page_fault+0x445 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb18015f5 page_fault+0x45 (/lib/modules/4.14.78-1-lts/build/vmlinux)
            7f38e4252591 new_heap+0x101 (/usr/lib/libc-2.28.so)
            7f38e4252d0b arena_get2.part.4+0x2fb (/usr/lib/libc-2.28.so)
            7f38e4255b1c tcache_init.part.6+0xec (/usr/lib/libc-2.28.so)
            7f38e42569e5 __GI___libc_malloc+0x115 (inlined)
            7f38e4241790 __GI__IO_file_doallocate+0x90 (inlined)
            7f38e424fbbf __GI__IO_doallocbuf+0x4f (inlined)
            7f38e424ee47 __GI__IO_file_overflow+0x197 (inlined)
            7f38e424df36 _IO_new_file_xsputn+0x116 (inlined)
            7f38e4242bfb __GI__IO_fwrite+0xdb (inlined)
            7f38e463fa6d std::basic_streambuf&lt;char, std::char_traits&lt;char&gt; &gt;::sputn(char const*, long)+0x1cd (inlined)
            7f38e463fa6d std::ostreambuf_iterator&lt;char, std::char_traits&lt;char&gt; &gt;::_M_put(char const*, long)+0x1cd (inlined)
            7f38e463fa6d std::ostreambuf_iterator&lt;char, std::char_traits&lt;char&gt; &gt; std::__write&lt;char&gt;(std::ostreambuf_iterator&lt;char, std::char_traits&lt;char&gt; &gt;, char const*, int)+0x1cd (inlined)
            7f38e463fa6d std::ostreambuf_iterator&lt;char, std::char_traits&lt;char&gt; &gt; std::num_put&lt;char, std::ostreambuf_iterator&lt;char, std::char_traits&lt;char&gt; &gt; &gt;::_M_insert_float&lt;double&gt;(std::ostreambuf_iterator&lt;c&gt;
            7f38e464bd70 std::num_put&lt;char, std::ostreambuf_iterator&lt;char, std::char_traits&lt;char&gt; &gt; &gt;::put(std::ostreambuf_iterator&lt;char, std::char_traits&lt;char&gt; &gt;, std::ios_base&amp;, char, double) const+0x90 (inl&gt;
            7f38e464bd70 std::ostream&amp; std::ostream::_M_insert&lt;double&gt;(double)+0x90 (/usr/lib/libstdc++.so.6.0.25)
            563b9cb502f7 std::ostream::operator&lt;&lt;(double)+0xb7 (inlined)
            563b9cb502f7 worker()+0xb7 (/ssd/milian/projects/kdab/rnd/hotspot/build/tests/test-clients/cpp-locking/cpp-locking)
            563b9cb506fb double std::__invoke_impl&lt;double, double (*)()&gt;(std::__invoke_other, double (*&amp;&amp;)())+0x2b (inlined)
            563b9cb506fb std::__invoke_result&lt;double (*)()&gt;::type std::__invoke&lt;double (*)()&gt;(double (*&amp;&amp;)())+0x2b (inlined)
            563b9cb506fb decltype (__invoke((_S_declval&lt;0ul&gt;)())) std::thread::_Invoker&lt;std::tuple&lt;double (*)()&gt; &gt;::_M_invoke&lt;0ul&gt;(std::_Index_tuple&lt;0ul&gt;)+0x2b (inlined)
            563b9cb506fb std::thread::_Invoker&lt;std::tuple&lt;double (*)()&gt; &gt;::operator()()+0x2b (inlined)
            563b9cb506fb std::__future_base::_Task_setter&lt;std::unique_ptr&lt;std::__future_base::_Result&lt;double&gt;, std::__future_base::_Result_base::_Deleter&gt;, std::thread::_Invoker&lt;std::tuple&lt;double (*)()&gt; &gt;, dou&gt;
            563b9cb506fb std::_Function_handler&lt;std::unique_ptr&lt;std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter&gt; (), std::__future_base::_Task_setter&lt;std::unique_ptr&lt;std::__future_&gt;
            563b9cb507e8 std::function&lt;std::unique_ptr&lt;std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter&gt; ()&gt;::operator()() const+0x28 (inlined)
            563b9cb507e8 std::__future_base::_State_baseV2::_M_do_set(std::function&lt;std::unique_ptr&lt;std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter&gt; ()&gt;*, bool*)+0x28 (/ssd/milian/&gt;
            7f38e46d24fe __pthread_once_slow+0xbe (/usr/lib/libpthread-2.28.so)
            563b9cb51149 __gthread_once+0xe9 (inlined)
            563b9cb51149 void std::call_once&lt;void (std::__future_base::_State_baseV2::*)(std::function&lt;std::unique_ptr&lt;std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter&gt; ()&gt;*, bool*)&gt;
            563b9cb51149 std::__future_base::_State_baseV2::_M_set_result(std::function&lt;std::unique_ptr&lt;std::__future_base::_Result_base, std::__future_base::_Result_base::_Deleter&gt; ()&gt;, bool)+0xe9 (inlined)
            563b9cb51149 std::__future_base::_Async_state_impl&lt;std::thread::_Invoker&lt;std::tuple&lt;double (*)()&gt; &gt;, double&gt;::_Async_state_impl(std::thread::_Invoker&lt;std::tuple&lt;double (*)()&gt; &gt;&amp;&amp;)::{lambda()#1}::op&gt;
            563b9cb51149 void std::__invoke_impl&lt;void, std::__future_base::_Async_state_impl&lt;std::thread::_Invoker&lt;std::tuple&lt;double (*)()&gt; &gt;, double&gt;::_Async_state_impl(std::thread::_Invoker&lt;std::tuple&lt;double&gt;
            563b9cb51149 std::__invoke_result&lt;std::__future_base::_Async_state_impl&lt;std::thread::_Invoker&lt;std::tuple&lt;double (*)()&gt; &gt;, double&gt;::_Async_state_impl(std::thread::_Invoker&lt;std::tuple&lt;double (*)()&gt; &gt;&gt;
            563b9cb51149 decltype (__invoke((_S_declval&lt;0ul&gt;)())) std::thread::_Invoker&lt;std::tuple&lt;std::__future_base::_Async_state_impl&lt;std::thread::_Invoker&lt;std::tuple&lt;double (*)()&gt; &gt;, double&gt;::_Async_state_&gt;
            563b9cb51149 std::thread::_Invoker&lt;std::tuple&lt;std::__future_base::_Async_state_impl&lt;std::thread::_Invoker&lt;std::tuple&lt;double (*)()&gt; &gt;, double&gt;::_Async_state_impl(std::thread::_Invoker&lt;std::tuple&lt;dou&gt;
            563b9cb51149 std::thread::_State_impl&lt;std::thread::_Invoker&lt;std::tuple&lt;std::__future_base::_Async_state_impl&lt;std::thread::_Invoker&lt;std::tuple&lt;double (*)()&gt; &gt;, double&gt;::_Async_state_impl(std::thread&gt;
            7f38e45f0062 execute_native_thread_routine+0x12 (/usr/lib/libstdc++.so.6.0.25)
            7f38e46caa9c start_thread+0xfc (/usr/lib/libpthread-2.28.so)
            7f38e42ccb22 __GI___clone+0x42 (inlined)
```

Before this patch, using libdwfl, you would see:

```
cpp-locking 20038 [005] 54830.236589: sched:sched_switch: prev_comm=cpp-locking prev_pid=20038 prev_prio=120 prev_state=T ==&gt; next_comm=swapper/5 next_pid=0 next_prio=120
        ffffffffb166fec5 __sched_text_start+0x545 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb166fec5 __sched_text_start+0x545 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb1670208 schedule+0x28 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb16737cc rwsem_down_read_failed+0xec (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb1665e04 call_rwsem_down_read_failed+0x14 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb1672a03 down_read+0x13 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb106bd85 __do_page_fault+0x445 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb18015f5 page_fault+0x45 (/lib/modules/4.14.78-1-lts/build/vmlinux)
            7f38e4252591 new_heap+0x101 (/usr/lib/libc-2.28.so)
        a041161e77950c5c [unknown] ([unknown])
```

With this patch applied, we get a bit further in unwinding:

```
cpp-locking 20038 [005] 54830.236589: sched:sched_switch: prev_comm=cpp-locking prev_pid=20038 prev_prio=120 prev_state=T ==&gt; next_comm=swapper/5 next_pid=0 next_prio=120
        ffffffffb166fec5 __sched_text_start+0x545 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb166fec5 __sched_text_start+0x545 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb1670208 schedule+0x28 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb16737cc rwsem_down_read_failed+0xec (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb1665e04 call_rwsem_down_read_failed+0x14 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb1672a03 down_read+0x13 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb106bd85 __do_page_fault+0x445 (/lib/modules/4.14.78-1-lts/build/vmlinux)
        ffffffffb18015f5 page_fault+0x45 (/lib/modules/4.14.78-1-lts/build/vmlinux)
            7f38e4252591 new_heap+0x101 (/usr/lib/libc-2.28.so)
            7f38e4252d0b arena_get2.part.4+0x2fb (/usr/lib/libc-2.28.so)
            7f38e4255b1c tcache_init.part.6+0xec (/usr/lib/libc-2.28.so)
            7f38e42569e5 __GI___libc_malloc+0x115 (inlined)
            7f38e4241790 __GI__IO_file_doallocate+0x90 (inlined)
            7f38e424fbbf __GI__IO_doallocbuf+0x4f (inlined)
            7f38e424ee47 __GI__IO_file_overflow+0x197 (inlined)
            7f38e424df36 _IO_new_file_xsputn+0x116 (inlined)
            7f38e4242bfb __GI__IO_fwrite+0xdb (inlined)
            7f38e463fa6d std::basic_streambuf&lt;char, std::char_traits&lt;char&gt; &gt;::sputn(char const*, long)+0x1cd (inlined)
            7f38e463fa6d std::ostreambuf_iterator&lt;char, std::char_traits&lt;char&gt; &gt;::_M_put(char const*, long)+0x1cd (inlined)
            7f38e463fa6d std::ostreambuf_iterator&lt;char, std::char_traits&lt;char&gt; &gt; std::__write&lt;char&gt;(std::ostreambuf_iterator&lt;char, std::char_traits&lt;char&gt; &gt;, char const*, int)+0x1cd (inlined)
            7f38e463fa6d std::ostreambuf_iterator&lt;char, std::char_traits&lt;char&gt; &gt; std::num_put&lt;char, std::ostreambuf_iterator&lt;char, std::char_traits&lt;char&gt; &gt; &gt;::_M_insert_float&lt;double&gt;(std::ostreambuf_iterator&lt;c&gt;
            7f38e464bd70 std::num_put&lt;char, std::ostreambuf_iterator&lt;char, std::char_traits&lt;char&gt; &gt; &gt;::put(std::ostreambuf_iterator&lt;char, std::char_traits&lt;char&gt; &gt;, std::ios_base&amp;, char, double) const+0x90 (inl&gt;
            7f38e464bd70 std::ostream&amp; std::ostream::_M_insert&lt;double&gt;(double)+0x90 (/usr/lib/libstdc++.so.6.0.25)
            563b9cb502f7 std::ostream::operator&lt;&lt;(double)+0xb7 (inlined)
            563b9cb502f7 worker()+0xb7 (/ssd/milian/projects/kdab/rnd/hotspot/build/tests/test-clients/cpp-locking/cpp-locking)
        6eab825c1ee3e4ff [unknown] ([unknown])
```

Note that the backtrace is still stopping too early, when compared to
the nice results obtained via libunwind. It's unclear so far what the
reason for that is.

Committer note:

Further comment by Milian on the thread started on the Link: tag below:

 ---
The remaining issue is due to a bug in elfutils:

https://sourceware.org/ml/elfutils-devel/2018-q4/msg00089.html

With both patches applied, libunwind and elfutils produce the same output for
the above scenario.
 ---

Signed-off-by: Milian Wolff &lt;milian.wolff@kdab.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Link: http://lkml.kernel.org/r/20181029141644.3907-1-milian.wolff@kdab.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf unwind: Unwind with libdw doesn't take symfs into account</title>
<updated>2019-02-06T16:34:52+00:00</updated>
<author>
<name>Martin Vuille</name>
<email>jpmv27@aim.com</email>
</author>
<published>2018-02-11T21:24:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0ebdf0080949db2b9ddd02ee8c969954736c9f86'/>
<id>0ebdf0080949db2b9ddd02ee8c969954736c9f86</id>
<content type='text'>
[ Upstream commit 3d20c6246690219881786de10d2dda93f616d0ac ]

Path passed to libdw for unwinding doesn't include symfs path
if specified, so unwinding fails because ELF file is not found.

Similar to unwinding with libunwind, pass symsrc_filename instead
of long_name. If there is no symsrc_filename, fallback to long_name.

Signed-off-by: Martin Vuille &lt;jpmv27@aim.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: http://lkml.kernel.org/r/20180211212420.18388-1-jpmv27@aim.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
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 3d20c6246690219881786de10d2dda93f616d0ac ]

Path passed to libdw for unwinding doesn't include symfs path
if specified, so unwinding fails because ELF file is not found.

Similar to unwinding with libunwind, pass symsrc_filename instead
of long_name. If there is no symsrc_filename, fallback to long_name.

Signed-off-by: Martin Vuille &lt;jpmv27@aim.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: http://lkml.kernel.org/r/20180211212420.18388-1-jpmv27@aim.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf parse-events: Fix unchecked usage of strncpy()</title>
<updated>2019-01-26T08:44:28+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2018-12-06T16:52:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4f7d2b60ce73ca8ac519cfcd9a79274d7239a5e8'/>
<id>4f7d2b60ce73ca8ac519cfcd9a79274d7239a5e8</id>
<content type='text'>
[ Upstream commit bd8d57fb7e25e9fcf67a9eef5fa13aabe2016e07 ]

The strncpy() function may leave the destination string buffer
unterminated, better use strlcpy() that we have a __weak fallback
implementation for systems without it.

This fixes this warning on an Alpine Linux Edge system with gcc 8.2:

  util/parse-events.c: In function 'print_symbol_events':
  util/parse-events.c:2465:4: error: 'strncpy' specified bound 100 equals destination size [-Werror=stringop-truncation]
      strncpy(name, syms-&gt;symbol, MAX_NAME_LEN);
      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  In function 'print_symbol_events.constprop',
      inlined from 'print_events' at util/parse-events.c:2508:2:
  util/parse-events.c:2465:4: error: 'strncpy' specified bound 100 equals destination size [-Werror=stringop-truncation]
      strncpy(name, syms-&gt;symbol, MAX_NAME_LEN);
      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  In function 'print_symbol_events.constprop',
      inlined from 'print_events' at util/parse-events.c:2511:2:
  util/parse-events.c:2465:4: error: 'strncpy' specified bound 100 equals destination size [-Werror=stringop-truncation]
      strncpy(name, syms-&gt;symbol, MAX_NAME_LEN);
      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  cc1: all warnings being treated as errors

Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Fixes: 947b4ad1d198 ("perf list: Fix max event string size")
Link: https://lkml.kernel.org/n/tip-b663e33bm6x8hrkie4uxh7u2@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
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 bd8d57fb7e25e9fcf67a9eef5fa13aabe2016e07 ]

The strncpy() function may leave the destination string buffer
unterminated, better use strlcpy() that we have a __weak fallback
implementation for systems without it.

This fixes this warning on an Alpine Linux Edge system with gcc 8.2:

  util/parse-events.c: In function 'print_symbol_events':
  util/parse-events.c:2465:4: error: 'strncpy' specified bound 100 equals destination size [-Werror=stringop-truncation]
      strncpy(name, syms-&gt;symbol, MAX_NAME_LEN);
      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  In function 'print_symbol_events.constprop',
      inlined from 'print_events' at util/parse-events.c:2508:2:
  util/parse-events.c:2465:4: error: 'strncpy' specified bound 100 equals destination size [-Werror=stringop-truncation]
      strncpy(name, syms-&gt;symbol, MAX_NAME_LEN);
      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  In function 'print_symbol_events.constprop',
      inlined from 'print_events' at util/parse-events.c:2511:2:
  util/parse-events.c:2465:4: error: 'strncpy' specified bound 100 equals destination size [-Werror=stringop-truncation]
      strncpy(name, syms-&gt;symbol, MAX_NAME_LEN);
      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  cc1: all warnings being treated as errors

Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Fixes: 947b4ad1d198 ("perf list: Fix max event string size")
Link: https://lkml.kernel.org/n/tip-b663e33bm6x8hrkie4uxh7u2@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf svghelper: Fix unchecked usage of strncpy()</title>
<updated>2019-01-26T08:44:28+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2018-12-06T14:29:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7b20a6d4059ad2941519fd33df3b06252f586614'/>
<id>7b20a6d4059ad2941519fd33df3b06252f586614</id>
<content type='text'>
[ Upstream commit 2f5302533f306d5ee87bd375aef9ca35b91762cb ]

The strncpy() function may leave the destination string buffer
unterminated, better use strlcpy() that we have a __weak fallback
implementation for systems without it.

In this specific case this would only happen if fgets() was buggy, as
its man page states that it should read one less byte than the size of
the destination buffer, so that it can put the nul byte at the end of
it, so it would never copy 255 non-nul chars, as fgets reads into the
orig buffer at most 254 non-nul chars and terminates it. But lets just
switch to strlcpy to keep the original intent and silence the gcc 8.2
warning.

This fixes this warning on an Alpine Linux Edge system with gcc 8.2:

  In function 'cpu_model',
      inlined from 'svg_cpu_box' at util/svghelper.c:378:2:
  util/svghelper.c:337:5: error: 'strncpy' output may be truncated copying 255 bytes from a string of length 255 [-Werror=stringop-truncation]
       strncpy(cpu_m, &amp;buf[13], 255);
       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Arjan van de Ven &lt;arjan@linux.intel.com&gt;
Fixes: f48d55ce7871 ("perf: Add a SVG helper library file")
Link: https://lkml.kernel.org/n/tip-xzkoo0gyr56gej39ltivuh9g@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
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 2f5302533f306d5ee87bd375aef9ca35b91762cb ]

The strncpy() function may leave the destination string buffer
unterminated, better use strlcpy() that we have a __weak fallback
implementation for systems without it.

In this specific case this would only happen if fgets() was buggy, as
its man page states that it should read one less byte than the size of
the destination buffer, so that it can put the nul byte at the end of
it, so it would never copy 255 non-nul chars, as fgets reads into the
orig buffer at most 254 non-nul chars and terminates it. But lets just
switch to strlcpy to keep the original intent and silence the gcc 8.2
warning.

This fixes this warning on an Alpine Linux Edge system with gcc 8.2:

  In function 'cpu_model',
      inlined from 'svg_cpu_box' at util/svghelper.c:378:2:
  util/svghelper.c:337:5: error: 'strncpy' output may be truncated copying 255 bytes from a string of length 255 [-Werror=stringop-truncation]
       strncpy(cpu_m, &amp;buf[13], 255);
       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Arjan van de Ven &lt;arjan@linux.intel.com&gt;
Fixes: f48d55ce7871 ("perf: Add a SVG helper library file")
Link: https://lkml.kernel.org/n/tip-xzkoo0gyr56gej39ltivuh9g@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf tools: Cleanup trace-event-info 'tdata' leak</title>
<updated>2018-11-22T06:32:42+00:00</updated>
<author>
<name>Sanskriti Sharma</name>
<email>sansharm@redhat.com</email>
</author>
<published>2018-10-02T14:29:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=dac6480460793316bc9cd911ce2ff1250a5a1acb'/>
<id>dac6480460793316bc9cd911ce2ff1250a5a1acb</id>
<content type='text'>
[ Upstream commit faedbf3fd19f2511a39397f76359e4cc6ee93072 ]

Free tracing_data structure in tracing_data_get() error paths.

Fixes the following coverity complaint:

  Error: RESOURCE_LEAK (CWE-772):
  leaked_storage: Variable "tdata" going out of scope leaks the storage

Signed-off-by: Sanskriti Sharma &lt;sansharm@redhat.com&gt;
Reviewed-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Joe Lawrence &lt;joe.lawrence@redhat.com&gt;
Link: http://lkml.kernel.org/r/1538490554-8161-3-git-send-email-sansharm@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit faedbf3fd19f2511a39397f76359e4cc6ee93072 ]

Free tracing_data structure in tracing_data_get() error paths.

Fixes the following coverity complaint:

  Error: RESOURCE_LEAK (CWE-772):
  leaked_storage: Variable "tdata" going out of scope leaks the storage

Signed-off-by: Sanskriti Sharma &lt;sansharm@redhat.com&gt;
Reviewed-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Joe Lawrence &lt;joe.lawrence@redhat.com&gt;
Link: http://lkml.kernel.org/r/1538490554-8161-3-git-send-email-sansharm@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf tools: Free temporary 'sys' string in read_event_files()</title>
<updated>2018-11-22T06:32:42+00:00</updated>
<author>
<name>Sanskriti Sharma</name>
<email>sansharm@redhat.com</email>
</author>
<published>2018-10-02T14:29:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3f237bd15d2e71348a9f5c34a987a8424b8c6c39'/>
<id>3f237bd15d2e71348a9f5c34a987a8424b8c6c39</id>
<content type='text'>
[ Upstream commit 1e44224fb0528b4c0cc176bde2bb31e9127eb14b ]

For each system in a given pevent, read_event_files() reads in a
temporary 'sys' string.  Be sure to free this string before moving onto
to the next system and/or leaving read_event_files().

Fixes the following coverity complaints:

  Error: RESOURCE_LEAK (CWE-772):

  tools/perf/util/trace-event-read.c:343: overwrite_var: Overwriting
  "sys" in "sys = read_string()" leaks the storage that "sys" points to.

  tools/perf/util/trace-event-read.c:353: leaked_storage: Variable "sys"
  going out of scope leaks the storage it points to.

Signed-off-by: Sanskriti Sharma &lt;sansharm@redhat.com&gt;
Reviewed-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Joe Lawrence &lt;joe.lawrence@redhat.com&gt;
Link: http://lkml.kernel.org/r/1538490554-8161-6-git-send-email-sansharm@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 1e44224fb0528b4c0cc176bde2bb31e9127eb14b ]

For each system in a given pevent, read_event_files() reads in a
temporary 'sys' string.  Be sure to free this string before moving onto
to the next system and/or leaving read_event_files().

Fixes the following coverity complaints:

  Error: RESOURCE_LEAK (CWE-772):

  tools/perf/util/trace-event-read.c:343: overwrite_var: Overwriting
  "sys" in "sys = read_string()" leaks the storage that "sys" points to.

  tools/perf/util/trace-event-read.c:353: leaked_storage: Variable "sys"
  going out of scope leaks the storage it points to.

Signed-off-by: Sanskriti Sharma &lt;sansharm@redhat.com&gt;
Reviewed-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Joe Lawrence &lt;joe.lawrence@redhat.com&gt;
Link: http://lkml.kernel.org/r/1538490554-8161-6-git-send-email-sansharm@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf bench numa: Fix to show proper convergence stats</title>
<updated>2018-11-10T15:39:18+00:00</updated>
<author>
<name>Srikar Dronamraju</name>
<email>srikar@linux.vnet.ibm.com</email>
</author>
<published>2015-06-24T11:10:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7c852f4aa687dbc71567c06aa22e87f1122dd6d2'/>
<id>7c852f4aa687dbc71567c06aa22e87f1122dd6d2</id>
<content type='text'>
[ Upstream commit 2b42b09b88c831ba4da2d669581dde371c38c2af ]

With commit: e1e455f4f4d3 (perf tools: Work around lack of sched_getcpu
in glibc &lt; 2.6), perf_bench numa mem with -c or -m option is not able to
correctly calculate convergence.

With the above commit, sched_getcpu always seems to return -1. The
intention of commit e1e455f was to add a sched_getcpu in glibc &lt; 2.6.
Hence keep the sched_getcpu definition under an ifdef.

This regression happened occurred between v4.0 and v4.1

Signed-off-by: Srikar Dronamraju &lt;srikar@linux.vnet.ibm.com&gt;
Acked-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Masami Hiramatsu &lt;masami.hiramatsu.pt@hitachi.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Vinson Lee &lt;vlee@twitter.com&gt;
Fixes:  e1e455f4f4d3 ("perf tools: Work around lack of sched_getcpu in glibc &lt; 2.6")
Link: http://lkml.kernel.org/r/20150624111004.GA5220@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
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 2b42b09b88c831ba4da2d669581dde371c38c2af ]

With commit: e1e455f4f4d3 (perf tools: Work around lack of sched_getcpu
in glibc &lt; 2.6), perf_bench numa mem with -c or -m option is not able to
correctly calculate convergence.

With the above commit, sched_getcpu always seems to return -1. The
intention of commit e1e455f was to add a sched_getcpu in glibc &lt; 2.6.
Hence keep the sched_getcpu definition under an ifdef.

This regression happened occurred between v4.0 and v4.1

Signed-off-by: Srikar Dronamraju &lt;srikar@linux.vnet.ibm.com&gt;
Acked-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Masami Hiramatsu &lt;masami.hiramatsu.pt@hitachi.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Vinson Lee &lt;vlee@twitter.com&gt;
Fixes:  e1e455f4f4d3 ("perf tools: Work around lack of sched_getcpu in glibc &lt; 2.6")
Link: http://lkml.kernel.org/r/20150624111004.GA5220@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf tools: Fix segfault for symbol annotation on TUI</title>
<updated>2018-11-10T15:39:17+00:00</updated>
<author>
<name>Namhyung Kim</name>
<email>namhyung@kernel.org</email>
</author>
<published>2015-01-14T11:18:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=12c2155a4178686dd3b6783f074f4146956a2af2'/>
<id>12c2155a4178686dd3b6783f074f4146956a2af2</id>
<content type='text'>
[ Upstream commit 813ccd15452ed34e97aa526ffc70d6d8e6c466c5 ]

Currently the symbol structure is allocated with symbol_conf.priv_size
to carry sideband information like annotation, map browser on TUI and
sort-by-name tree node.  So retrieving these information from symbol
needs to care about the details of such placement.

However the annotation code just assumes that the symbol is placed after
the struct annotation.  But actually there's other info between them.
So accessing those struct will lead to an undefined behavior (usually a
crash) after they write their info to the same location.

To reproduce the problem, please follow the steps below:

  1. run perf report (TUI of course) with -v option
  2. open map browser (by pressing right arrow key for any entry)
  3. search any function (by pressing '/' key and input whatever..)
  4. return to the hist browser (by pressing 'q' or left arrow key)
  5. open annotation window for the same entry (by pressing 'a' key)

Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Masami Hiramatsu &lt;masami.hiramatsu.pt@hitachi.com&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Link: http://lkml.kernel.org/r/1421234288-22758-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
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 813ccd15452ed34e97aa526ffc70d6d8e6c466c5 ]

Currently the symbol structure is allocated with symbol_conf.priv_size
to carry sideband information like annotation, map browser on TUI and
sort-by-name tree node.  So retrieving these information from symbol
needs to care about the details of such placement.

However the annotation code just assumes that the symbol is placed after
the struct annotation.  But actually there's other info between them.
So accessing those struct will lead to an undefined behavior (usually a
crash) after they write their info to the same location.

To reproduce the problem, please follow the steps below:

  1. run perf report (TUI of course) with -v option
  2. open map browser (by pressing right arrow key for any entry)
  3. search any function (by pressing '/' key and input whatever..)
  4. return to the hist browser (by pressing 'q' or left arrow key)
  5. open annotation window for the same entry (by pressing 'a' key)

Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Masami Hiramatsu &lt;masami.hiramatsu.pt@hitachi.com&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Link: http://lkml.kernel.org/r/1421234288-22758-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
