<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/tools/perf/util, branch v4.19</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>perf tools: Stop fallbacking to kallsyms for vdso symbols lookup</title>
<updated>2018-10-17T18:56:15+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2018-10-16T20:08:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=edeb0c90df3581b821a764052d185df985f8b8dc'/>
<id>edeb0c90df3581b821a764052d185df985f8b8dc</id>
<content type='text'>
David reports that:

&lt;quote&gt;
Perf has this hack where it uses the kernel symbol map as a backup when
a symbol can't be found in the user's symbol table(s).

This causes problems because the tests driving this code path use
machine__kernel_ip(), and that is completely meaningless on Sparc.  On
sparc64 the kernel and user live in physically separate virtual address
spaces, rather than a shared one.  And the kernel lives at a virtual
address that overlaps common userspace addresses.  So this test passes
almost all the time when a user symbol lookup fails.

The consequence of this is that, if the unfound user virtual address in
the sample doesn't match up to a kernel symbol either, we trigger things
like this code in builtin-top.c:

	if (al.sym == NULL &amp;&amp; al.map != NULL) {
		const char *msg = "Kernel samples will not be resolved.\n";
		/*
		 * As we do lazy loading of symtabs we only will know if the
		 * specified vmlinux file is invalid when we actually have a
		 * hit in kernel space and then try to load it. So if we get
		 * here and there are _no_ symbols in the DSO backing the
		 * kernel map, bail out.
		 *
		 * We may never get here, for instance, if we use -K/
		 * --hide-kernel-symbols, even if the user specifies an
		 * invalid --vmlinux ;-)
		 */
		if (!machine-&gt;kptr_restrict_warned &amp;&amp; !top-&gt;vmlinux_warned &amp;&amp;
		    __map__is_kernel(al.map) &amp;&amp; map__has_symbols(al.map)) {
			if (symbol_conf.vmlinux_name) {
				char serr[256];
				dso__strerror_load(al.map-&gt;dso, serr, sizeof(serr));
				ui__warning("The %s file can't be used: %s\n%s",
					    symbol_conf.vmlinux_name, serr, msg);
			} else {
				ui__warning("A vmlinux file was not found.\n%s",
					    msg);
			}

			if (use_browser &lt;= 0)
				sleep(5);
			top-&gt;vmlinux_warned = true;
		}
	}

When I fire up a compilation on sparc, this triggers immediately.

I'm trying to figure out what the "backup to kernel map" code is
accomplishing.

I see some language in the current code and in the changes that have
happened in this area talking about vdso.  Does that really happen?

The vdso is mapped into userspace virtual addresses, not kernel ones.

More history.  This didn't cause problems on sparc some time ago,
because the kernel IP check used to be "ip &lt; 0" :-) Sparc kernel
addresses are not negative.  But now with machine__kernel_ip(), which
works using the symbol table determined kernel address range, it does
trigger.

What it all boils down to is that on architectures like sparc,
machine__kernel_ip() should always return false in this scenerio, and
therefore this kind of logic:

		if (cpumode == PERF_RECORD_MISC_USER &amp;&amp; machine &amp;&amp;
		    mg != &amp;machine-&gt;kmaps &amp;&amp;
		    machine__kernel_ip(machine, al-&gt;addr)) {

is basically invalid.  PERF_RECORD_MISC_USER implies no kernel address
can possibly match for the sample/event in question (no matter how
hard you try!) :-)
&lt;/&gt;

So, I thought something had changed and in the past we would somehow
find that address in the kallsyms, but I couldn't find anything to back
that up, the patch introducing this is over a decade old, lots of things
changed, so I was just thinking I was missing something.

I tried a gtod busy loop to generate vdso activity and added a 'perf
probe' at that branch, on x86_64 to see if it ever gets hit:

Made thread__find_map() noinline, as 'perf probe' in lines of inline
functions seems to not be working, only at function start. (Masami?)

  # perf probe -x ~/bin/perf -L thread__find_map:57
  &lt;thread__find_map@/home/acme/git/perf/tools/perf/util/event.c:57&gt;
     57                 if (cpumode == PERF_RECORD_MISC_USER &amp;&amp; machine &amp;&amp;
     58                     mg != &amp;machine-&gt;kmaps &amp;&amp;
     59                     machine__kernel_ip(machine, al-&gt;addr)) {
     60                         mg = &amp;machine-&gt;kmaps;
     61                         load_map = true;
     62                         goto try_again;
                        }
                } else {
                        /*
                         * Kernel maps might be changed when loading
                         * symbols so loading
                         * must be done prior to using kernel maps.
                         */
     69                 if (load_map)
     70                         map__load(al-&gt;map);
     71                 al-&gt;addr = al-&gt;map-&gt;map_ip(al-&gt;map, al-&gt;addr);

  # perf probe -x ~/bin/perf thread__find_map:60
  Added new event:
    probe_perf:thread__find_map (on thread__find_map:60 in /home/acme/bin/perf)

  You can now use it in all perf tools, such as:

	perf record -e probe_perf:thread__find_map -aR sleep 1

  #

  Then used this to see if, system wide, those probe points were being hit:

  # perf trace -e *perf:thread*/max-stack=8/
  ^C[root@jouet ~]#

  No hits when running 'perf top' and:

  # cat gtod.c
  #include &lt;sys/time.h&gt;

  int main(void)
  {
	struct timeval tv;

	while (1)
		gettimeofday(&amp;tv, 0);

	return 0;
  }
  [root@jouet c]# ./gtod
  ^C

  Pressed 'P' in 'perf top' and the [vdso] samples are there:

  62.84%  [vdso]                    [.] __vdso_gettimeofday
   8.13%  gtod                      [.] main
   7.51%  [vdso]                    [.] 0x0000000000000914
   5.78%  [vdso]                    [.] 0x0000000000000917
   5.43%  gtod                      [.] _init
   2.71%  [vdso]                    [.] 0x000000000000092d
   0.35%  [kernel]                  [k] native_io_delay
   0.33%  libc-2.26.so              [.] __memmove_avx_unaligned_erms
   0.20%  [vdso]                    [.] 0x000000000000091d
   0.17%  [i2c_i801]                [k] i801_access
   0.06%  firefox                   [.] free
   0.06%  libglib-2.0.so.0.5400.3   [.] g_source_iter_next
   0.05%  [vdso]                    [.] 0x0000000000000919
   0.05%  libpthread-2.26.so        [.] __pthread_mutex_lock
   0.05%  libpixman-1.so.0.34.0     [.] 0x000000000006d3a7
   0.04%  [kernel]                  [k] entry_SYSCALL_64_trampoline
   0.04%  libxul.so                 [.] style::dom_apis::query_selector_slow
   0.04%  [kernel]                  [k] module_get_kallsym
   0.04%  firefox                   [.] malloc
   0.04%  [vdso]                    [.] 0x0000000000000910

  I added a 'perf probe' to thread__find_map:69, and that surely got tons
  of hits, i.e. for every map found, just to make sure the 'perf probe'
  command was really working.

  In the process I noticed a bug, we're only have records for '[vdso]' for
  pre-existing commands, i.e. ones that are running when we start 'perf top',
  when we will generate the PERF_RECORD_MMAP by looking at /perf/PID/maps.

  I.e. like this, for preexisting processes with a vdso map, again,
  tracing for all the system, only pre-existing processes get a [vdso] map
  (when having one):

  [root@jouet ~]# perf probe -x ~/bin/perf __machine__addnew_vdso
  Added new event:
  probe_perf:__machine__addnew_vdso (on __machine__addnew_vdso in /home/acme/bin/perf)

  You can now use it in all perf tools, such as:

	perf record -e probe_perf:__machine__addnew_vdso -aR sleep 1

  [root@jouet ~]# perf trace -e probe_perf:__machine__addnew_vdso/max-stack=8/
     0.000 probe_perf:__machine__addnew_vdso:(568eb3)
                                       __machine__addnew_vdso (/home/acme/bin/perf)
                                       map__new (/home/acme/bin/perf)
                                       machine__process_mmap2_event (/home/acme/bin/perf)
                                       machine__process_event (/home/acme/bin/perf)
                                       perf_event__process (/home/acme/bin/perf)
                                       perf_tool__process_synth_event (/home/acme/bin/perf)
                                       perf_event__synthesize_mmap_events (/home/acme/bin/perf)
                                       __event__synthesize_thread (/home/acme/bin/perf)

The kernel is generating a PERF_RECORD_MMAP for vDSOs, but somehow
'perf top' is not getting those records while 'perf record' is:

  # perf record ~acme/c/gtod
  ^C[ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.076 MB perf.data (1499 samples) ]

  # perf report -D | grep PERF_RECORD_MMAP2
  71293612401913 0x11b48 [0x70]: PERF_RECORD_MMAP2 25484/25484: [0x400000(0x1000) @ 0 fd:02 1137 541179306]: r-xp /home/acme/c/gtod
  71293612419012 0x11be0 [0x70]: PERF_RECORD_MMAP2 25484/25484: [0x7fa4a2783000(0x227000) @ 0 fd:00 3146370 854107250]: r-xp /usr/lib64/ld-2.26.so
  71293612432110 0x11c50 [0x60]: PERF_RECORD_MMAP2 25484/25484: [0x7ffcdb53a000(0x2000) @ 0 00:00 0 0]: r-xp [vdso]
  71293612509944 0x11cb0 [0x70]: PERF_RECORD_MMAP2 25484/25484: [0x7fa4a23cd000(0x3b6000) @ 0 fd:00 3149723 262067164]: r-xp /usr/lib64/libc-2.26.so
  #
  # perf script | grep vdso | head
      gtod 25484 71293.612768: 2485554 cycles:ppp:  7ffcdb53a914 [unknown] ([vdso])
      gtod 25484 71293.613576: 2149343 cycles:ppp:  7ffcdb53a917 [unknown] ([vdso])
      gtod 25484 71293.614274: 1814652 cycles:ppp:  7ffcdb53aca8 __vdso_gettimeofday+0x98 ([vdso])
      gtod 25484 71293.614862: 1669070 cycles:ppp:  7ffcdb53acc5 __vdso_gettimeofday+0xb5 ([vdso])
      gtod 25484 71293.615404: 1451589 cycles:ppp:  7ffcdb53acc5 __vdso_gettimeofday+0xb5 ([vdso])
      gtod 25484 71293.615999: 1269941 cycles:ppp:  7ffcdb53ace6 __vdso_gettimeofday+0xd6 ([vdso])
      gtod 25484 71293.616405: 1177946 cycles:ppp:  7ffcdb53a914 [unknown] ([vdso])
      gtod 25484 71293.616775: 1121290 cycles:ppp:  7ffcdb53ac47 __vdso_gettimeofday+0x37 ([vdso])
      gtod 25484 71293.617150: 1037721 cycles:ppp:  7ffcdb53ace6 __vdso_gettimeofday+0xd6 ([vdso])
      gtod 25484 71293.617478:  994526 cycles:ppp:  7ffcdb53ace6 __vdso_gettimeofday+0xd6 ([vdso])
  #

The patch is the obvious one and with it we also continue to resolve
vdso symbols for pre-existing processes in 'perf top' and for all
processes in 'perf record' + 'perf report/script'.

Suggested-by: David Miller &lt;davem@davemloft.net&gt;
Acked-by: David Miller &lt;davem@davemloft.net&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: https://lkml.kernel.org/n/tip-cs7skq9pp0kjypiju6o7trse@git.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>
David reports that:

&lt;quote&gt;
Perf has this hack where it uses the kernel symbol map as a backup when
a symbol can't be found in the user's symbol table(s).

This causes problems because the tests driving this code path use
machine__kernel_ip(), and that is completely meaningless on Sparc.  On
sparc64 the kernel and user live in physically separate virtual address
spaces, rather than a shared one.  And the kernel lives at a virtual
address that overlaps common userspace addresses.  So this test passes
almost all the time when a user symbol lookup fails.

The consequence of this is that, if the unfound user virtual address in
the sample doesn't match up to a kernel symbol either, we trigger things
like this code in builtin-top.c:

	if (al.sym == NULL &amp;&amp; al.map != NULL) {
		const char *msg = "Kernel samples will not be resolved.\n";
		/*
		 * As we do lazy loading of symtabs we only will know if the
		 * specified vmlinux file is invalid when we actually have a
		 * hit in kernel space and then try to load it. So if we get
		 * here and there are _no_ symbols in the DSO backing the
		 * kernel map, bail out.
		 *
		 * We may never get here, for instance, if we use -K/
		 * --hide-kernel-symbols, even if the user specifies an
		 * invalid --vmlinux ;-)
		 */
		if (!machine-&gt;kptr_restrict_warned &amp;&amp; !top-&gt;vmlinux_warned &amp;&amp;
		    __map__is_kernel(al.map) &amp;&amp; map__has_symbols(al.map)) {
			if (symbol_conf.vmlinux_name) {
				char serr[256];
				dso__strerror_load(al.map-&gt;dso, serr, sizeof(serr));
				ui__warning("The %s file can't be used: %s\n%s",
					    symbol_conf.vmlinux_name, serr, msg);
			} else {
				ui__warning("A vmlinux file was not found.\n%s",
					    msg);
			}

			if (use_browser &lt;= 0)
				sleep(5);
			top-&gt;vmlinux_warned = true;
		}
	}

When I fire up a compilation on sparc, this triggers immediately.

I'm trying to figure out what the "backup to kernel map" code is
accomplishing.

I see some language in the current code and in the changes that have
happened in this area talking about vdso.  Does that really happen?

The vdso is mapped into userspace virtual addresses, not kernel ones.

More history.  This didn't cause problems on sparc some time ago,
because the kernel IP check used to be "ip &lt; 0" :-) Sparc kernel
addresses are not negative.  But now with machine__kernel_ip(), which
works using the symbol table determined kernel address range, it does
trigger.

What it all boils down to is that on architectures like sparc,
machine__kernel_ip() should always return false in this scenerio, and
therefore this kind of logic:

		if (cpumode == PERF_RECORD_MISC_USER &amp;&amp; machine &amp;&amp;
		    mg != &amp;machine-&gt;kmaps &amp;&amp;
		    machine__kernel_ip(machine, al-&gt;addr)) {

is basically invalid.  PERF_RECORD_MISC_USER implies no kernel address
can possibly match for the sample/event in question (no matter how
hard you try!) :-)
&lt;/&gt;

So, I thought something had changed and in the past we would somehow
find that address in the kallsyms, but I couldn't find anything to back
that up, the patch introducing this is over a decade old, lots of things
changed, so I was just thinking I was missing something.

I tried a gtod busy loop to generate vdso activity and added a 'perf
probe' at that branch, on x86_64 to see if it ever gets hit:

Made thread__find_map() noinline, as 'perf probe' in lines of inline
functions seems to not be working, only at function start. (Masami?)

  # perf probe -x ~/bin/perf -L thread__find_map:57
  &lt;thread__find_map@/home/acme/git/perf/tools/perf/util/event.c:57&gt;
     57                 if (cpumode == PERF_RECORD_MISC_USER &amp;&amp; machine &amp;&amp;
     58                     mg != &amp;machine-&gt;kmaps &amp;&amp;
     59                     machine__kernel_ip(machine, al-&gt;addr)) {
     60                         mg = &amp;machine-&gt;kmaps;
     61                         load_map = true;
     62                         goto try_again;
                        }
                } else {
                        /*
                         * Kernel maps might be changed when loading
                         * symbols so loading
                         * must be done prior to using kernel maps.
                         */
     69                 if (load_map)
     70                         map__load(al-&gt;map);
     71                 al-&gt;addr = al-&gt;map-&gt;map_ip(al-&gt;map, al-&gt;addr);

  # perf probe -x ~/bin/perf thread__find_map:60
  Added new event:
    probe_perf:thread__find_map (on thread__find_map:60 in /home/acme/bin/perf)

  You can now use it in all perf tools, such as:

	perf record -e probe_perf:thread__find_map -aR sleep 1

  #

  Then used this to see if, system wide, those probe points were being hit:

  # perf trace -e *perf:thread*/max-stack=8/
  ^C[root@jouet ~]#

  No hits when running 'perf top' and:

  # cat gtod.c
  #include &lt;sys/time.h&gt;

  int main(void)
  {
	struct timeval tv;

	while (1)
		gettimeofday(&amp;tv, 0);

	return 0;
  }
  [root@jouet c]# ./gtod
  ^C

  Pressed 'P' in 'perf top' and the [vdso] samples are there:

  62.84%  [vdso]                    [.] __vdso_gettimeofday
   8.13%  gtod                      [.] main
   7.51%  [vdso]                    [.] 0x0000000000000914
   5.78%  [vdso]                    [.] 0x0000000000000917
   5.43%  gtod                      [.] _init
   2.71%  [vdso]                    [.] 0x000000000000092d
   0.35%  [kernel]                  [k] native_io_delay
   0.33%  libc-2.26.so              [.] __memmove_avx_unaligned_erms
   0.20%  [vdso]                    [.] 0x000000000000091d
   0.17%  [i2c_i801]                [k] i801_access
   0.06%  firefox                   [.] free
   0.06%  libglib-2.0.so.0.5400.3   [.] g_source_iter_next
   0.05%  [vdso]                    [.] 0x0000000000000919
   0.05%  libpthread-2.26.so        [.] __pthread_mutex_lock
   0.05%  libpixman-1.so.0.34.0     [.] 0x000000000006d3a7
   0.04%  [kernel]                  [k] entry_SYSCALL_64_trampoline
   0.04%  libxul.so                 [.] style::dom_apis::query_selector_slow
   0.04%  [kernel]                  [k] module_get_kallsym
   0.04%  firefox                   [.] malloc
   0.04%  [vdso]                    [.] 0x0000000000000910

  I added a 'perf probe' to thread__find_map:69, and that surely got tons
  of hits, i.e. for every map found, just to make sure the 'perf probe'
  command was really working.

  In the process I noticed a bug, we're only have records for '[vdso]' for
  pre-existing commands, i.e. ones that are running when we start 'perf top',
  when we will generate the PERF_RECORD_MMAP by looking at /perf/PID/maps.

  I.e. like this, for preexisting processes with a vdso map, again,
  tracing for all the system, only pre-existing processes get a [vdso] map
  (when having one):

  [root@jouet ~]# perf probe -x ~/bin/perf __machine__addnew_vdso
  Added new event:
  probe_perf:__machine__addnew_vdso (on __machine__addnew_vdso in /home/acme/bin/perf)

  You can now use it in all perf tools, such as:

	perf record -e probe_perf:__machine__addnew_vdso -aR sleep 1

  [root@jouet ~]# perf trace -e probe_perf:__machine__addnew_vdso/max-stack=8/
     0.000 probe_perf:__machine__addnew_vdso:(568eb3)
                                       __machine__addnew_vdso (/home/acme/bin/perf)
                                       map__new (/home/acme/bin/perf)
                                       machine__process_mmap2_event (/home/acme/bin/perf)
                                       machine__process_event (/home/acme/bin/perf)
                                       perf_event__process (/home/acme/bin/perf)
                                       perf_tool__process_synth_event (/home/acme/bin/perf)
                                       perf_event__synthesize_mmap_events (/home/acme/bin/perf)
                                       __event__synthesize_thread (/home/acme/bin/perf)

The kernel is generating a PERF_RECORD_MMAP for vDSOs, but somehow
'perf top' is not getting those records while 'perf record' is:

  # perf record ~acme/c/gtod
  ^C[ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.076 MB perf.data (1499 samples) ]

  # perf report -D | grep PERF_RECORD_MMAP2
  71293612401913 0x11b48 [0x70]: PERF_RECORD_MMAP2 25484/25484: [0x400000(0x1000) @ 0 fd:02 1137 541179306]: r-xp /home/acme/c/gtod
  71293612419012 0x11be0 [0x70]: PERF_RECORD_MMAP2 25484/25484: [0x7fa4a2783000(0x227000) @ 0 fd:00 3146370 854107250]: r-xp /usr/lib64/ld-2.26.so
  71293612432110 0x11c50 [0x60]: PERF_RECORD_MMAP2 25484/25484: [0x7ffcdb53a000(0x2000) @ 0 00:00 0 0]: r-xp [vdso]
  71293612509944 0x11cb0 [0x70]: PERF_RECORD_MMAP2 25484/25484: [0x7fa4a23cd000(0x3b6000) @ 0 fd:00 3149723 262067164]: r-xp /usr/lib64/libc-2.26.so
  #
  # perf script | grep vdso | head
      gtod 25484 71293.612768: 2485554 cycles:ppp:  7ffcdb53a914 [unknown] ([vdso])
      gtod 25484 71293.613576: 2149343 cycles:ppp:  7ffcdb53a917 [unknown] ([vdso])
      gtod 25484 71293.614274: 1814652 cycles:ppp:  7ffcdb53aca8 __vdso_gettimeofday+0x98 ([vdso])
      gtod 25484 71293.614862: 1669070 cycles:ppp:  7ffcdb53acc5 __vdso_gettimeofday+0xb5 ([vdso])
      gtod 25484 71293.615404: 1451589 cycles:ppp:  7ffcdb53acc5 __vdso_gettimeofday+0xb5 ([vdso])
      gtod 25484 71293.615999: 1269941 cycles:ppp:  7ffcdb53ace6 __vdso_gettimeofday+0xd6 ([vdso])
      gtod 25484 71293.616405: 1177946 cycles:ppp:  7ffcdb53a914 [unknown] ([vdso])
      gtod 25484 71293.616775: 1121290 cycles:ppp:  7ffcdb53ac47 __vdso_gettimeofday+0x37 ([vdso])
      gtod 25484 71293.617150: 1037721 cycles:ppp:  7ffcdb53ace6 __vdso_gettimeofday+0xd6 ([vdso])
      gtod 25484 71293.617478:  994526 cycles:ppp:  7ffcdb53ace6 __vdso_gettimeofday+0xd6 ([vdso])
  #

The patch is the obvious one and with it we also continue to resolve
vdso symbols for pre-existing processes in 'perf top' and for all
processes in 'perf record' + 'perf report/script'.

Suggested-by: David Miller &lt;davem@davemloft.net&gt;
Acked-by: David Miller &lt;davem@davemloft.net&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: https://lkml.kernel.org/n/tip-cs7skq9pp0kjypiju6o7trse@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf report: Don't crash on invalid inline debug information</title>
<updated>2018-10-16T17:52:21+00:00</updated>
<author>
<name>Milian Wolff</name>
<email>milian.wolff@kdab.com</email>
</author>
<published>2018-09-26T13:52:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=d4046e8e17b9f378cb861982ef71c63911b5dff3'/>
<id>d4046e8e17b9f378cb861982ef71c63911b5dff3</id>
<content type='text'>
When the function name for an inline frame is invalid, we must not try
to demangle this symbol, otherwise we crash with:

  #0  0x0000555555895c01 in bfd_demangle ()
  #1  0x0000555555823262 in demangle_sym (dso=0x555555d92b90, elf_name=0x0, kmodule=0) at util/symbol-elf.c:215
  #2  dso__demangle_sym (dso=dso@entry=0x555555d92b90, kmodule=&lt;optimized out&gt;, kmodule@entry=0, elf_name=elf_name@entry=0x0) at util/symbol-elf.c:400
  #3  0x00005555557fef4b in new_inline_sym (funcname=0x0, base_sym=0x555555d92b90, dso=0x555555d92b90) at util/srcline.c:89
  #4  inline_list__append_dso_a2l (dso=dso@entry=0x555555c7bb00, node=node@entry=0x555555e31810, sym=sym@entry=0x555555d92b90) at util/srcline.c:264
  #5  0x00005555557ff27f in addr2line (dso_name=dso_name@entry=0x555555d92430 "/home/milian/.debug/.build-id/f7/186d14bb94f3c6161c010926da66033d24fce5/elf", addr=addr@entry=2888, file=file@entry=0x0,
      line=line@entry=0x0, dso=dso@entry=0x555555c7bb00, unwind_inlines=unwind_inlines@entry=true, node=0x555555e31810, sym=0x555555d92b90) at util/srcline.c:313
  #6  0x00005555557ffe7c in addr2inlines (sym=0x555555d92b90, dso=0x555555c7bb00, addr=2888, dso_name=0x555555d92430 "/home/milian/.debug/.build-id/f7/186d14bb94f3c6161c010926da66033d24fce5/elf")
      at util/srcline.c:358

So instead handle the case where we get invalid function names for
inlined frames and use a fallback '??' function name instead.

While this crash was originally reported by Hadrien for rust code, I can
now also reproduce it with trivial C++ code. Indeed, it seems like
libbfd fails to interpret the debug information for the inline frame
symbol name:

  $ addr2line -e /home/milian/.debug/.build-id/f7/186d14bb94f3c6161c010926da66033d24fce5/elf -if b48
  main
  /usr/include/c++/8.2.1/complex:610
  ??
  /usr/include/c++/8.2.1/complex:618
  ??
  /usr/include/c++/8.2.1/complex:675
  ??
  /usr/include/c++/8.2.1/complex:685
  main
  /home/milian/projects/kdab/rnd/hotspot/tests/test-clients/cpp-inlining/main.cpp:39

I've reported this bug upstream and also attached a patch there which
should fix this issue:

https://sourceware.org/bugzilla/show_bug.cgi?id=23715

Reported-by: Hadrien Grasland &lt;grasland@lal.in2p3.fr&gt;
Signed-off-by: Milian Wolff &lt;milian.wolff@kdab.com&gt;
Cc: Jin Yao &lt;yao.jin@linux.intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Fixes: a64489c56c30 ("perf report: Find the inline stack for a given address")
[ The above 'Fixes:' cset is where originally the problem was
  introduced, i.e.  using a2l-&gt;funcname without checking if it is NULL,
  but this current patch fixes the current codebase, i.e. multiple csets
  were applied after a64489c56c30 before the problem was reported by Hadrien ]
Link: http://lkml.kernel.org/r/20180926135207.30263-3-milian.wolff@kdab.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>
When the function name for an inline frame is invalid, we must not try
to demangle this symbol, otherwise we crash with:

  #0  0x0000555555895c01 in bfd_demangle ()
  #1  0x0000555555823262 in demangle_sym (dso=0x555555d92b90, elf_name=0x0, kmodule=0) at util/symbol-elf.c:215
  #2  dso__demangle_sym (dso=dso@entry=0x555555d92b90, kmodule=&lt;optimized out&gt;, kmodule@entry=0, elf_name=elf_name@entry=0x0) at util/symbol-elf.c:400
  #3  0x00005555557fef4b in new_inline_sym (funcname=0x0, base_sym=0x555555d92b90, dso=0x555555d92b90) at util/srcline.c:89
  #4  inline_list__append_dso_a2l (dso=dso@entry=0x555555c7bb00, node=node@entry=0x555555e31810, sym=sym@entry=0x555555d92b90) at util/srcline.c:264
  #5  0x00005555557ff27f in addr2line (dso_name=dso_name@entry=0x555555d92430 "/home/milian/.debug/.build-id/f7/186d14bb94f3c6161c010926da66033d24fce5/elf", addr=addr@entry=2888, file=file@entry=0x0,
      line=line@entry=0x0, dso=dso@entry=0x555555c7bb00, unwind_inlines=unwind_inlines@entry=true, node=0x555555e31810, sym=0x555555d92b90) at util/srcline.c:313
  #6  0x00005555557ffe7c in addr2inlines (sym=0x555555d92b90, dso=0x555555c7bb00, addr=2888, dso_name=0x555555d92430 "/home/milian/.debug/.build-id/f7/186d14bb94f3c6161c010926da66033d24fce5/elf")
      at util/srcline.c:358

So instead handle the case where we get invalid function names for
inlined frames and use a fallback '??' function name instead.

While this crash was originally reported by Hadrien for rust code, I can
now also reproduce it with trivial C++ code. Indeed, it seems like
libbfd fails to interpret the debug information for the inline frame
symbol name:

  $ addr2line -e /home/milian/.debug/.build-id/f7/186d14bb94f3c6161c010926da66033d24fce5/elf -if b48
  main
  /usr/include/c++/8.2.1/complex:610
  ??
  /usr/include/c++/8.2.1/complex:618
  ??
  /usr/include/c++/8.2.1/complex:675
  ??
  /usr/include/c++/8.2.1/complex:685
  main
  /home/milian/projects/kdab/rnd/hotspot/tests/test-clients/cpp-inlining/main.cpp:39

I've reported this bug upstream and also attached a patch there which
should fix this issue:

https://sourceware.org/bugzilla/show_bug.cgi?id=23715

Reported-by: Hadrien Grasland &lt;grasland@lal.in2p3.fr&gt;
Signed-off-by: Milian Wolff &lt;milian.wolff@kdab.com&gt;
Cc: Jin Yao &lt;yao.jin@linux.intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Fixes: a64489c56c30 ("perf report: Find the inline stack for a given address")
[ The above 'Fixes:' cset is where originally the problem was
  introduced, i.e.  using a2l-&gt;funcname without checking if it is NULL,
  but this current patch fixes the current codebase, i.e. multiple csets
  were applied after a64489c56c30 before the problem was reported by Hadrien ]
Link: http://lkml.kernel.org/r/20180926135207.30263-3-milian.wolff@kdab.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf cpu_map: Align cpu map synthesized events properly.</title>
<updated>2018-10-16T15:30:03+00:00</updated>
<author>
<name>David Miller</name>
<email>davem@davemloft.net</email>
</author>
<published>2018-10-12T05:46:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0ed149cf5239cc6e7e65bf00f769e8f1e91076c0'/>
<id>0ed149cf5239cc6e7e65bf00f769e8f1e91076c0</id>
<content type='text'>
The size of the resulting cpu map can be smaller than a multiple of
sizeof(u64), resulting in SIGBUS on cpus like Sparc as the next event
will not be aligned properly.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Kan Liang &lt;kan.liang@intel.com&gt;
Fixes: 6c872901af07 ("perf cpu_map: Add cpu_map event synthesize function")
Link: http://lkml.kernel.org/r/20181011.224655.716771175766946817.davem@davemloft.net
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 size of the resulting cpu map can be smaller than a multiple of
sizeof(u64), resulting in SIGBUS on cpus like Sparc as the next event
will not be aligned properly.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Kan Liang &lt;kan.liang@intel.com&gt;
Fixes: 6c872901af07 ("perf cpu_map: Add cpu_map event synthesize function")
Link: http://lkml.kernel.org/r/20181011.224655.716771175766946817.davem@davemloft.net
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf evsel: Store ids for events with their own cpus perf_event__synthesize_event_update_cpus</title>
<updated>2018-10-16T11:18:52+00:00</updated>
<author>
<name>Jiri Olsa</name>
<email>jolsa@redhat.com</email>
</author>
<published>2018-10-03T21:20:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4ab8455f8bd83298bf7f67ab9357e3b1cc765c7d'/>
<id>4ab8455f8bd83298bf7f67ab9357e3b1cc765c7d</id>
<content type='text'>
John reported crash when recording on an event under PMU with cpumask defined:

  root@localhost:~# ./perf_debug_ record -e armv8_pmuv3_0/br_mis_pred/ sleep 1
  perf: Segmentation fault
  Obtained 9 stack frames.
  ./perf_debug_() [0x4c5ef8]
  [0xffff82ba267c]
  ./perf_debug_() [0x4bc5a8]
  ./perf_debug_() [0x419550]
  ./perf_debug_() [0x41a928]
  ./perf_debug_() [0x472f58]
  ./perf_debug_() [0x473210]
  ./perf_debug_() [0x4070f4]
  /lib/aarch64-linux-gnu/libc.so.6(__libc_start_main+0xe0) [0xffff8294c8a0]
  Segmentation fault (core dumped)

We synthesize an update event that needs to touch the evsel id array, which is
not defined at that time. Fixing this by forcing the id allocation for events
with their own cpus.

Reported-by: John Garry &lt;john.garry@huawei.com&gt;
Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Tested-by: John Garry &lt;john.garry@huawei.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: linux-arm-kernel@lists.infradead.org
Cc: linuxarm@huawei.com
Fixes: bfd8f72c2778 ("perf record: Synthesize unit/scale/... in event update")
Link: http://lkml.kernel.org/r/20181003212052.GA32371@krava
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>
John reported crash when recording on an event under PMU with cpumask defined:

  root@localhost:~# ./perf_debug_ record -e armv8_pmuv3_0/br_mis_pred/ sleep 1
  perf: Segmentation fault
  Obtained 9 stack frames.
  ./perf_debug_() [0x4c5ef8]
  [0xffff82ba267c]
  ./perf_debug_() [0x4bc5a8]
  ./perf_debug_() [0x419550]
  ./perf_debug_() [0x41a928]
  ./perf_debug_() [0x472f58]
  ./perf_debug_() [0x473210]
  ./perf_debug_() [0x4070f4]
  /lib/aarch64-linux-gnu/libc.so.6(__libc_start_main+0xe0) [0xffff8294c8a0]
  Segmentation fault (core dumped)

We synthesize an update event that needs to touch the evsel id array, which is
not defined at that time. Fixing this by forcing the id allocation for events
with their own cpus.

Reported-by: John Garry &lt;john.garry@huawei.com&gt;
Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Tested-by: John Garry &lt;john.garry@huawei.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: linux-arm-kernel@lists.infradead.org
Cc: linuxarm@huawei.com
Fixes: bfd8f72c2778 ("perf record: Synthesize unit/scale/... in event update")
Link: http://lkml.kernel.org/r/20181003212052.GA32371@krava
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Revert "perf tools: Fix PMU term format max value calculation"</title>
<updated>2018-10-09T13:48:55+00:00</updated>
<author>
<name>Jiri Olsa</name>
<email>jolsa@kernel.org</email>
</author>
<published>2018-10-03T07:20:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1b9caa10b31dda0866f4028e4bfb923fb6e4072f'/>
<id>1b9caa10b31dda0866f4028e4bfb923fb6e4072f</id>
<content type='text'>
This reverts commit ac0e2cd555373ae6f8f3a3ad3fbbf5b6d1e7aaaa.

Michael reported an issue with oversized terms values assignment
and I noticed there was actually a misunderstanding of the max
value check in the past.

The above commit's changelog says:

  If bit 21 is set, there is parsing issues as below.

    $ perf stat -a -e uncore_qpi_0/event=0x200002,umask=0x8/
    event syntax error: '..pi_0/event=0x200002,umask=0x8/'
                                      \___ value too big for format, maximum is 511

But there's no issue there, because the event value is distributed
along the value defined by the format. Even if the format defines
separated bit, the value is treated as a continual number, which
should follow the format definition.

In above case it's 9-bit value with last bit separated:
  $ cat uncore_qpi_0/format/event
  config:0-7,21

Hence the value 0x200002 is correctly reported as format violation,
because it exceeds 9 bits. It should have been 0x102 instead, which
sets the 9th bit - the bit 21 of the format.

  $ perf stat -vv -a -e uncore_qpi_0/event=0x102,umask=0x8/
  Using CPUID GenuineIntel-6-2D
  ...
  ------------------------------------------------------------
  perf_event_attr:
    type                             10
    size                             112
    config                           0x200802
    sample_type                      IDENTIFIER
  ...

Reported-by: Michael Petlan &lt;mpetlan@redhat.com&gt;
Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Fixes: ac0e2cd55537 ("perf tools: Fix PMU term format max value calculation")
Link: http://lkml.kernel.org/r/20181003072046.29276-1-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>
This reverts commit ac0e2cd555373ae6f8f3a3ad3fbbf5b6d1e7aaaa.

Michael reported an issue with oversized terms values assignment
and I noticed there was actually a misunderstanding of the max
value check in the past.

The above commit's changelog says:

  If bit 21 is set, there is parsing issues as below.

    $ perf stat -a -e uncore_qpi_0/event=0x200002,umask=0x8/
    event syntax error: '..pi_0/event=0x200002,umask=0x8/'
                                      \___ value too big for format, maximum is 511

But there's no issue there, because the event value is distributed
along the value defined by the format. Even if the format defines
separated bit, the value is treated as a continual number, which
should follow the format definition.

In above case it's 9-bit value with last bit separated:
  $ cat uncore_qpi_0/format/event
  config:0-7,21

Hence the value 0x200002 is correctly reported as format violation,
because it exceeds 9 bits. It should have been 0x102 instead, which
sets the 9th bit - the bit 21 of the format.

  $ perf stat -vv -a -e uncore_qpi_0/event=0x102,umask=0x8/
  Using CPUID GenuineIntel-6-2D
  ...
  ------------------------------------------------------------
  perf_event_attr:
    type                             10
    size                             112
    config                           0x200802
    sample_type                      IDENTIFIER
  ...

Reported-by: Michael Petlan &lt;mpetlan@redhat.com&gt;
Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Fixes: ac0e2cd55537 ("perf tools: Fix PMU term format max value calculation")
Link: http://lkml.kernel.org/r/20181003072046.29276-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf record: Use unmapped IP for inline callchain cursors</title>
<updated>2018-10-05T14:18:09+00:00</updated>
<author>
<name>Milian Wolff</name>
<email>milian.wolff@kdab.com</email>
</author>
<published>2018-09-26T13:52:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7a8a8fcf7b860e4b2d4edc787c844d41cad9dfcf'/>
<id>7a8a8fcf7b860e4b2d4edc787c844d41cad9dfcf</id>
<content type='text'>
Only use the mapped IP to find inline frames, but keep using the
unmapped IP for the callchain cursor. This ensures we properly show the
unmapped IP when displaying a frame we received via the
dso__parse_addr_inlines API for a module which does not contain
sufficient debug symbols to show the srcline.

This is another follow-up to commit 19610184693c ("perf script: Show
virtual addresses instead of offsets").

Signed-off-by: Milian Wolff &lt;milian.wolff@kdab.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Tested-by: Ravi Bangoria &lt;ravi.bangoria@linux.ibm.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Jin Yao &lt;yao.jin@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Sandipan Das &lt;sandipan@linux.ibm.com&gt;
Fixes: 19610184693c ("perf script: Show virtual addresses instead of offsets")
Link: http://lkml.kernel.org/r/20180926135207.30263-2-milian.wolff@kdab.com
Link: http://lkml.kernel.org/r/20181002073949.3297-1-milian.wolff@kdab.com
[ Squashed a fix from Milian for a problem reported by Ravi, fixed up space damage ]
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>
Only use the mapped IP to find inline frames, but keep using the
unmapped IP for the callchain cursor. This ensures we properly show the
unmapped IP when displaying a frame we received via the
dso__parse_addr_inlines API for a module which does not contain
sufficient debug symbols to show the srcline.

This is another follow-up to commit 19610184693c ("perf script: Show
virtual addresses instead of offsets").

Signed-off-by: Milian Wolff &lt;milian.wolff@kdab.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Tested-by: Ravi Bangoria &lt;ravi.bangoria@linux.ibm.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Jin Yao &lt;yao.jin@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Sandipan Das &lt;sandipan@linux.ibm.com&gt;
Fixes: 19610184693c ("perf script: Show virtual addresses instead of offsets")
Link: http://lkml.kernel.org/r/20180926135207.30263-2-milian.wolff@kdab.com
Link: http://lkml.kernel.org/r/20181002073949.3297-1-milian.wolff@kdab.com
[ Squashed a fix from Milian for a problem reported by Ravi, fixed up space damage ]
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf python: Use -Wno-redundant-decls to build with PYTHON=python3</title>
<updated>2018-10-05T14:11:55+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2018-09-18T19:08:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=05a2f54679861deb188750ba2a70187000b2c71f'/>
<id>05a2f54679861deb188750ba2a70187000b2c71f</id>
<content type='text'>
When building in ClearLinux using 'make PYTHON=python3' with gcc 8.2.1
it fails with:

    GEN      /tmp/build/perf/python/perf.so
  In file included from /usr/include/python3.7m/Python.h:126,
                   from /git/linux/tools/perf/util/python.c:2:
  /usr/include/python3.7m/import.h:58:24: error: redundant redeclaration of ‘_PyImport_AddModuleObject’ [-Werror=redundant-decls]
   PyAPI_FUNC(PyObject *) _PyImport_AddModuleObject(PyObject *, PyObject *);
                          ^~~~~~~~~~~~~~~~~~~~~~~~~
  /usr/include/python3.7m/import.h:47:24: note: previous declaration of ‘_PyImport_AddModuleObject’ was here
   PyAPI_FUNC(PyObject *) _PyImport_AddModuleObject(PyObject *name,
                          ^~~~~~~~~~~~~~~~~~~~~~~~~
  cc1: all warnings being treated as errors
  error: command 'gcc' failed with exit status 1

And indeed there is a redundant declaration in that Python.h file, one
with parameter names and the other without, so just add
-Wno-error=redundant-decls to the python setup instructions.

Now perf builds with gcc in ClearLinux with the following Dockerfile:

  # docker.io/acmel/linux-perf-tools-build-clearlinux:latest
  FROM docker.io/clearlinux:latest
  MAINTAINER Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
  RUN swupd update &amp;&amp; \
      swupd bundle-add sysadmin-basic-dev
  RUN mkdir -m 777 -p /git /tmp/build/perf /tmp/build/objtool /tmp/build/linux &amp;&amp; \
      groupadd -r perfbuilder &amp;&amp; \
      useradd -m -r -g perfbuilder perfbuilder &amp;&amp; \
      chown -R perfbuilder.perfbuilder /tmp/build/ /git/
  USER perfbuilder
  COPY rx_and_build.sh /
  ENV EXTRA_MAKE_ARGS=PYTHON=python3
  ENTRYPOINT ["/rx_and_build.sh"]

Now to figure out why the build fails with clang, that is present in the
above container as detected by the rx_and_build.sh script:

  clang version 6.0.1 (tags/RELEASE_601/final)
  Target: x86_64-unknown-linux-gnu
  Thread model: posix
  InstalledDir: /usr/sbin
  make: Entering directory '/git/linux/tools/perf'
    BUILD:   Doing 'make -j4' parallel build
    HOSTCC   /tmp/build/perf/fixdep.o
    HOSTLD   /tmp/build/perf/fixdep-in.o
    LINK     /tmp/build/perf/fixdep

  Auto-detecting system features:
  ...                         dwarf: [ OFF ]
  ...            dwarf_getlocations: [ OFF ]
  ...                         glibc: [ OFF ]
  ...                          gtk2: [ OFF ]
  ...                      libaudit: [ OFF ]
  ...                        libbfd: [ OFF ]
  ...                        libelf: [ OFF ]
  ...                       libnuma: [ OFF ]
  ...        numa_num_possible_cpus: [ OFF ]
  ...                       libperl: [ OFF ]
  ...                     libpython: [ OFF ]
  ...                      libslang: [ OFF ]
  ...                     libcrypto: [ OFF ]
  ...                     libunwind: [ OFF ]
  ...            libdw-dwarf-unwind: [ OFF ]
  ...                          zlib: [ OFF ]
  ...                          lzma: [ OFF ]
  ...                     get_cpuid: [ OFF ]
  ...                           bpf: [ OFF ]

  Makefile.config:331: *** No gnu/libc-version.h found, please install glibc-dev[el].  Stop.
  make[1]: *** [Makefile.perf:206: sub-make] Error 2
  make: *** [Makefile:70: all] Error 2
  make: Leaving directory '/git/linux/tools/perf'

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: Thiago Macieira &lt;thiago.macieira@intel.com&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: https://lkml.kernel.org/n/tip-c3khb9ac86s00qxzjrueomme@git.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>
When building in ClearLinux using 'make PYTHON=python3' with gcc 8.2.1
it fails with:

    GEN      /tmp/build/perf/python/perf.so
  In file included from /usr/include/python3.7m/Python.h:126,
                   from /git/linux/tools/perf/util/python.c:2:
  /usr/include/python3.7m/import.h:58:24: error: redundant redeclaration of ‘_PyImport_AddModuleObject’ [-Werror=redundant-decls]
   PyAPI_FUNC(PyObject *) _PyImport_AddModuleObject(PyObject *, PyObject *);
                          ^~~~~~~~~~~~~~~~~~~~~~~~~
  /usr/include/python3.7m/import.h:47:24: note: previous declaration of ‘_PyImport_AddModuleObject’ was here
   PyAPI_FUNC(PyObject *) _PyImport_AddModuleObject(PyObject *name,
                          ^~~~~~~~~~~~~~~~~~~~~~~~~
  cc1: all warnings being treated as errors
  error: command 'gcc' failed with exit status 1

And indeed there is a redundant declaration in that Python.h file, one
with parameter names and the other without, so just add
-Wno-error=redundant-decls to the python setup instructions.

Now perf builds with gcc in ClearLinux with the following Dockerfile:

  # docker.io/acmel/linux-perf-tools-build-clearlinux:latest
  FROM docker.io/clearlinux:latest
  MAINTAINER Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
  RUN swupd update &amp;&amp; \
      swupd bundle-add sysadmin-basic-dev
  RUN mkdir -m 777 -p /git /tmp/build/perf /tmp/build/objtool /tmp/build/linux &amp;&amp; \
      groupadd -r perfbuilder &amp;&amp; \
      useradd -m -r -g perfbuilder perfbuilder &amp;&amp; \
      chown -R perfbuilder.perfbuilder /tmp/build/ /git/
  USER perfbuilder
  COPY rx_and_build.sh /
  ENV EXTRA_MAKE_ARGS=PYTHON=python3
  ENTRYPOINT ["/rx_and_build.sh"]

Now to figure out why the build fails with clang, that is present in the
above container as detected by the rx_and_build.sh script:

  clang version 6.0.1 (tags/RELEASE_601/final)
  Target: x86_64-unknown-linux-gnu
  Thread model: posix
  InstalledDir: /usr/sbin
  make: Entering directory '/git/linux/tools/perf'
    BUILD:   Doing 'make -j4' parallel build
    HOSTCC   /tmp/build/perf/fixdep.o
    HOSTLD   /tmp/build/perf/fixdep-in.o
    LINK     /tmp/build/perf/fixdep

  Auto-detecting system features:
  ...                         dwarf: [ OFF ]
  ...            dwarf_getlocations: [ OFF ]
  ...                         glibc: [ OFF ]
  ...                          gtk2: [ OFF ]
  ...                      libaudit: [ OFF ]
  ...                        libbfd: [ OFF ]
  ...                        libelf: [ OFF ]
  ...                       libnuma: [ OFF ]
  ...        numa_num_possible_cpus: [ OFF ]
  ...                       libperl: [ OFF ]
  ...                     libpython: [ OFF ]
  ...                      libslang: [ OFF ]
  ...                     libcrypto: [ OFF ]
  ...                     libunwind: [ OFF ]
  ...            libdw-dwarf-unwind: [ OFF ]
  ...                          zlib: [ OFF ]
  ...                          lzma: [ OFF ]
  ...                     get_cpuid: [ OFF ]
  ...                           bpf: [ OFF ]

  Makefile.config:331: *** No gnu/libc-version.h found, please install glibc-dev[el].  Stop.
  make[1]: *** [Makefile.perf:206: sub-make] Error 2
  make: *** [Makefile:70: all] Error 2
  make: Leaving directory '/git/linux/tools/perf'

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: Thiago Macieira &lt;thiago.macieira@intel.com&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: https://lkml.kernel.org/n/tip-c3khb9ac86s00qxzjrueomme@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf report: Don't try to map ip to invalid map</title>
<updated>2018-09-27T19:05:43+00:00</updated>
<author>
<name>Milian Wolff</name>
<email>milian.wolff@kdab.com</email>
</author>
<published>2018-09-26T13:52:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ff4ce2885af8f9e8e99864d78dbeb4673f089c76'/>
<id>ff4ce2885af8f9e8e99864d78dbeb4673f089c76</id>
<content type='text'>
Fixes a crash when the report encounters an address that could not be
associated with an mmaped region:

  #0  0x00005555557bdc4a in callchain_srcline (ip=&lt;error reading variable: Cannot access memory at address 0x38&gt;, sym=0x0, map=0x0) at util/machine.c:2329
  #1  unwind_entry (entry=entry@entry=0x7fffffff9180, arg=arg@entry=0x7ffff5642498) at util/machine.c:2329
  #2  0x00005555558370af in entry (arg=0x7ffff5642498, cb=0x5555557bdb50 &lt;unwind_entry&gt;, thread=&lt;optimized out&gt;, ip=18446744073709551615) at util/unwind-libunwind-local.c:586
  #3  get_entries (ui=ui@entry=0x7fffffff9620, cb=0x5555557bdb50 &lt;unwind_entry&gt;, arg=0x7ffff5642498, max_stack=&lt;optimized out&gt;) at util/unwind-libunwind-local.c:703
  #4  0x0000555555837192 in _unwind__get_entries (cb=&lt;optimized out&gt;, arg=&lt;optimized out&gt;, thread=&lt;optimized out&gt;, data=&lt;optimized out&gt;, max_stack=&lt;optimized out&gt;) at util/unwind-libunwind-local.c:725
  #5  0x00005555557c310f in thread__resolve_callchain_unwind (max_stack=127, sample=0x7fffffff9830, evsel=0x555555c7b3b0, cursor=0x7ffff5642498, thread=0x555555c7f6f0) at util/machine.c:2351
  #6  thread__resolve_callchain (thread=0x555555c7f6f0, cursor=0x7ffff5642498, evsel=0x555555c7b3b0, sample=0x7fffffff9830, parent=0x7fffffff97b8, root_al=0x7fffffff9750, max_stack=127) at util/machine.c:2378
  #7  0x00005555557ba4ee in sample__resolve_callchain (sample=&lt;optimized out&gt;, cursor=&lt;optimized out&gt;, parent=parent@entry=0x7fffffff97b8, evsel=&lt;optimized out&gt;, al=al@entry=0x7fffffff9750,
      max_stack=&lt;optimized out&gt;) at util/callchain.c:1085

Signed-off-by: Milian Wolff &lt;milian.wolff@kdab.com&gt;
Tested-by: Sandipan Das &lt;sandipan@linux.ibm.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Jin Yao &lt;yao.jin@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Fixes: 2a9d5050dc84 ("perf script: Show correct offsets for DWARF-based unwinding")
Link: http://lkml.kernel.org/r/20180926135207.30263-1-milian.wolff@kdab.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>
Fixes a crash when the report encounters an address that could not be
associated with an mmaped region:

  #0  0x00005555557bdc4a in callchain_srcline (ip=&lt;error reading variable: Cannot access memory at address 0x38&gt;, sym=0x0, map=0x0) at util/machine.c:2329
  #1  unwind_entry (entry=entry@entry=0x7fffffff9180, arg=arg@entry=0x7ffff5642498) at util/machine.c:2329
  #2  0x00005555558370af in entry (arg=0x7ffff5642498, cb=0x5555557bdb50 &lt;unwind_entry&gt;, thread=&lt;optimized out&gt;, ip=18446744073709551615) at util/unwind-libunwind-local.c:586
  #3  get_entries (ui=ui@entry=0x7fffffff9620, cb=0x5555557bdb50 &lt;unwind_entry&gt;, arg=0x7ffff5642498, max_stack=&lt;optimized out&gt;) at util/unwind-libunwind-local.c:703
  #4  0x0000555555837192 in _unwind__get_entries (cb=&lt;optimized out&gt;, arg=&lt;optimized out&gt;, thread=&lt;optimized out&gt;, data=&lt;optimized out&gt;, max_stack=&lt;optimized out&gt;) at util/unwind-libunwind-local.c:725
  #5  0x00005555557c310f in thread__resolve_callchain_unwind (max_stack=127, sample=0x7fffffff9830, evsel=0x555555c7b3b0, cursor=0x7ffff5642498, thread=0x555555c7f6f0) at util/machine.c:2351
  #6  thread__resolve_callchain (thread=0x555555c7f6f0, cursor=0x7ffff5642498, evsel=0x555555c7b3b0, sample=0x7fffffff9830, parent=0x7fffffff97b8, root_al=0x7fffffff9750, max_stack=127) at util/machine.c:2378
  #7  0x00005555557ba4ee in sample__resolve_callchain (sample=&lt;optimized out&gt;, cursor=&lt;optimized out&gt;, parent=parent@entry=0x7fffffff97b8, evsel=&lt;optimized out&gt;, al=al@entry=0x7fffffff9750,
      max_stack=&lt;optimized out&gt;) at util/callchain.c:1085

Signed-off-by: Milian Wolff &lt;milian.wolff@kdab.com&gt;
Tested-by: Sandipan Das &lt;sandipan@linux.ibm.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Jin Yao &lt;yao.jin@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Fixes: 2a9d5050dc84 ("perf script: Show correct offsets for DWARF-based unwinding")
Link: http://lkml.kernel.org/r/20180926135207.30263-1-milian.wolff@kdab.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf tools: Fix maps__find_symbol_by_name()</title>
<updated>2018-09-11T17:12:51+00:00</updated>
<author>
<name>Adrian Hunter</name>
<email>adrian.hunter@intel.com</email>
</author>
<published>2018-09-07T08:51:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=03db8b583d1c3c84963e08e2abf6c79081da5c31'/>
<id>03db8b583d1c3c84963e08e2abf6c79081da5c31</id>
<content type='text'>
Commit 1c5aae7710bb ("perf machine: Create maps for x86 PTI entry
trampolines") revealed a problem with maps__find_symbol_by_name() that
resulted in probes not being found e.g.

	$ sudo perf probe xsk_mmap
	xsk_mmap is out of .text, skip it.
	Probe point 'xsk_mmap' not found.
	   Error: Failed to add events.

maps__find_symbol_by_name() can optionally return the map of the found
symbol. It can get the map wrong because, in fact, the symbol is found
on the map's dso, not allowing for the possibility that the dso has more
than one map. Fix by always checking the map contains the symbol.

Reported-by: Björn Töpel &lt;bjorn.topel@intel.com&gt;
Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Tested-by: Björn Töpel &lt;bjorn.topel@intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: stable@vger.kernel.org
Fixes: 1c5aae7710bb ("perf machine: Create maps for x86 PTI entry trampolines")
Link: http://lkml.kernel.org/r/20180907085116.25782-1-adrian.hunter@intel.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>
Commit 1c5aae7710bb ("perf machine: Create maps for x86 PTI entry
trampolines") revealed a problem with maps__find_symbol_by_name() that
resulted in probes not being found e.g.

	$ sudo perf probe xsk_mmap
	xsk_mmap is out of .text, skip it.
	Probe point 'xsk_mmap' not found.
	   Error: Failed to add events.

maps__find_symbol_by_name() can optionally return the map of the found
symbol. It can get the map wrong because, in fact, the symbol is found
on the map's dso, not allowing for the possibility that the dso has more
than one map. Fix by always checking the map contains the symbol.

Reported-by: Björn Töpel &lt;bjorn.topel@intel.com&gt;
Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Tested-by: Björn Töpel &lt;bjorn.topel@intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: stable@vger.kernel.org
Fixes: 1c5aae7710bb ("perf machine: Create maps for x86 PTI entry trampolines")
Link: http://lkml.kernel.org/r/20180907085116.25782-1-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf annotate: Fix parsing aarch64 branch instructions after objdump update</title>
<updated>2018-08-30T18:51:54+00:00</updated>
<author>
<name>Kim Phillips</name>
<email>kim.phillips@arm.com</email>
</author>
<published>2018-08-27T17:53:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4e67b2a5df5d3f341776d12ee575e00ca3ef92de'/>
<id>4e67b2a5df5d3f341776d12ee575e00ca3ef92de</id>
<content type='text'>
Starting with binutils 2.28, aarch64 objdump adds comments to the
disassembly output to show the alternative names of a condition code
[1].

It is assumed that commas in objdump comments could occur in other
arches now or in the future, so this fix is arch-independent.

The fix could have been done with arm64 specific jump__parse and
jump__scnprintf functions, but the jump__scnprintf instruction would
have to have its comment character be a literal, since the scnprintf
functions cannot receive a struct arch easily.

This inconvenience also applies to the generic jump__scnprintf, which is
why we add a raw_comment pointer to struct ins_operands, so the __parse
function assigns it to be re-used by its corresponding __scnprintf
function.

Example differences in 'perf annotate --stdio2' output on an aarch64
perf.data file:

BEFORE: → b.cs   ffff200008133d1c &lt;unwind_frame+0x18c&gt;  // b.hs, dffff7ecc47b
AFTER : ↓ b.cs   18c

BEFORE: → b.cc   ffff200008d8d9cc &lt;get_alloc_profile+0x31c&gt;  // b.lo, b.ul, dffff727295b
AFTER : ↓ b.cc   31c

The branch target labels 18c and 31c also now appear in the output:

BEFORE:        add    x26, x29, #0x80
AFTER : 18c:   add    x26, x29, #0x80

BEFORE:        add    x21, x21, #0x8
AFTER : 31c:   add    x21, x21, #0x8

The Fixes: tag below is added so stable branches will get the update; it
doesn't necessarily mean that commit was broken at the time, rather it
didn't withstand the aarch64 objdump update.

Tested no difference in output for sample x86_64, power arch perf.data files.

[1] https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=commit;h=bb7eff5206e4795ac79c177a80fe9f4630aaf730

Signed-off-by: Kim Phillips &lt;kim.phillips@arm.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Anton Blanchard &lt;anton@samba.org&gt;
Cc: Christian Borntraeger &lt;borntraeger@de.ibm.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Ravi Bangoria &lt;ravi.bangoria@linux.vnet.ibm.com&gt;
Cc: Robin Murphy &lt;robin.murphy@arm.com&gt;
Cc: Taeung Song &lt;treeze.taeung@gmail.com&gt;
Cc: linux-arm-kernel@lists.infradead.org
Fixes: b13bbeee5ee6 ("perf annotate: Fix branch instruction with multiple operands")
Link: http://lkml.kernel.org/r/20180827125340.a2f7e291901d17cea05daba4@arm.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>
Starting with binutils 2.28, aarch64 objdump adds comments to the
disassembly output to show the alternative names of a condition code
[1].

It is assumed that commas in objdump comments could occur in other
arches now or in the future, so this fix is arch-independent.

The fix could have been done with arm64 specific jump__parse and
jump__scnprintf functions, but the jump__scnprintf instruction would
have to have its comment character be a literal, since the scnprintf
functions cannot receive a struct arch easily.

This inconvenience also applies to the generic jump__scnprintf, which is
why we add a raw_comment pointer to struct ins_operands, so the __parse
function assigns it to be re-used by its corresponding __scnprintf
function.

Example differences in 'perf annotate --stdio2' output on an aarch64
perf.data file:

BEFORE: → b.cs   ffff200008133d1c &lt;unwind_frame+0x18c&gt;  // b.hs, dffff7ecc47b
AFTER : ↓ b.cs   18c

BEFORE: → b.cc   ffff200008d8d9cc &lt;get_alloc_profile+0x31c&gt;  // b.lo, b.ul, dffff727295b
AFTER : ↓ b.cc   31c

The branch target labels 18c and 31c also now appear in the output:

BEFORE:        add    x26, x29, #0x80
AFTER : 18c:   add    x26, x29, #0x80

BEFORE:        add    x21, x21, #0x8
AFTER : 31c:   add    x21, x21, #0x8

The Fixes: tag below is added so stable branches will get the update; it
doesn't necessarily mean that commit was broken at the time, rather it
didn't withstand the aarch64 objdump update.

Tested no difference in output for sample x86_64, power arch perf.data files.

[1] https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=commit;h=bb7eff5206e4795ac79c177a80fe9f4630aaf730

Signed-off-by: Kim Phillips &lt;kim.phillips@arm.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Anton Blanchard &lt;anton@samba.org&gt;
Cc: Christian Borntraeger &lt;borntraeger@de.ibm.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Ravi Bangoria &lt;ravi.bangoria@linux.vnet.ibm.com&gt;
Cc: Robin Murphy &lt;robin.murphy@arm.com&gt;
Cc: Taeung Song &lt;treeze.taeung@gmail.com&gt;
Cc: linux-arm-kernel@lists.infradead.org
Fixes: b13bbeee5ee6 ("perf annotate: Fix branch instruction with multiple operands")
Link: http://lkml.kernel.org/r/20180827125340.a2f7e291901d17cea05daba4@arm.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
