linux-stable.git/tools/perf, branch v4.19.2

perf tests: Fix record+probe_libc_inet_pton.sh without ping's debuginfo

2018-11-13T19:08:28+00:00

[ Upstream commit 1632936480a53d85ef3012cd9f290e247251cbb9 ]

When we don't have the iputils-debuginfo package installed, i.e. when we
don't have the DWARF information needed to resolve ping's samples, we
end up failing this 'perf test' entry:

  # perf test ping
  62: probe libc's inet_pton & backtrace it with ping       : Ok
  # rpm -e iputils-debuginfo
  # perf test ping
  62: probe libc's inet_pton & backtrace it with ping       : FAILED!
  #

Fix it to accept "[unknown]" where the symbol + offset, when resolved,
is expected.

I think this will fail in the other arches as well, but since I can't
test now, I'm leaving s390x and ppc cases as-is.

Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: David Ahern 
Cc: Hendrik Brueckner 
Cc: Jiri Olsa 
Cc: Kim Phillips 
Cc: Michael Petlan 
Cc: Namhyung Kim 
Cc: Naveen N. Rao 
Cc: Peter Zijlstra 
Cc: Ravi Bangoria 
Cc: Sandipan Das 
Cc: Sukadev Bhattiprolu 
Cc: Thomas Richter 
Cc: Wang Nan 
Fixes: 7903a7086723 ("perf script: Show symbol offsets by default")
Link: https://lkml.kernel.org/n/tip-hnizqwqrs03vcq1b74yao0f6@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

perf strbuf: Match va_{add,copy} with va_end

2018-11-13T19:08:22+00:00

[ Upstream commit ce49d8436cffa9b7a6a5f110879d53e89dbc6746 ]

Ensure that all code paths in strbuf_addv() call va_end() on the
ap_saved copy that was made.

Fixes the following coverity complaint:

  Error: VARARGS (CWE-237): [#def683]
  tools/perf/util/strbuf.c:106: missing_va_end: va_end was not called
  for "ap_saved".

Signed-off-by: Sanskriti Sharma 
Reviewed-by: Jiri Olsa 
Cc: Joe Lawrence 
Link: http://lkml.kernel.org/r/1538490554-8161-2-git-send-email-sansharm@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

perf tools: Free 'printk' string in parse_ftrace_printk()

2018-11-13T19:08:22+00:00

[ Upstream commit 9c8a182e5a73e01afd11742a2ab887bf338fdafd ]

parse_ftrace_printk() tokenizes and parses a line, calling strdup() each
iteration.  Add code to free this temporary format string duplicate.

Fixes the following coverity complaints:

  Error: RESOURCE_LEAK (CWE-772):
  tools/perf/util/trace-event-parse.c:158: overwrite_var: Overwriting
  "printk" in "printk = strdup(fmt + 1)" leaks the storage that "printk"
  points to.

  tools/perf/util/trace-event-parse.c:162: leaked_storage: Variable
  "printk" going out of scope leaks the storage it points to.

Signed-off-by: Sanskriti Sharma 
Reviewed-by: Jiri Olsa 
Cc: Joe Lawrence 
Link: http://lkml.kernel.org/r/1538490554-8161-4-git-send-email-sansharm@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

perf tools: Cleanup trace-event-info 'tdata' leak

2018-11-13T19:08:22+00:00

[ 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 
Reviewed-by: Jiri Olsa 
Cc: Joe Lawrence 
Link: http://lkml.kernel.org/r/1538490554-8161-3-git-send-email-sansharm@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

perf tools: Free temporary 'sys' string in read_event_files()

2018-11-13T19:08:22+00:00

[ 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 
Reviewed-by: Jiri Olsa 
Cc: Joe Lawrence 
Link: http://lkml.kernel.org/r/1538490554-8161-6-git-send-email-sansharm@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

perf tools: Stop fallbacking to kallsyms for vdso symbols lookup

2018-10-17T18:56:15+00:00

David reports that:


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 && 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->kptr_restrict_warned && !top->vmlinux_warned &&
		    __map__is_kernel(al.map) && map__has_symbols(al.map)) {
			if (symbol_conf.vmlinux_name) {
				char serr[256];
				dso__strerror_load(al.map->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 <= 0)
				sleep(5);
			top->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 < 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 && machine &&
		    mg != &machine->kmaps &&
		    machine__kernel_ip(machine, al->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!) :-)


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
  
     57                 if (cpumode == PERF_RECORD_MISC_USER && machine &&
     58                     mg != &machine->kmaps &&
     59                     machine__kernel_ip(machine, al->addr)) {
     60                         mg = &machine->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->map);
     71                 al->addr = al->map->map_ip(al->map, al->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 

  int main(void)
  {
	struct timeval tv;

	while (1)
		gettimeofday(&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 
Acked-by: David Miller 
Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: https://lkml.kernel.org/n/tip-cs7skq9pp0kjypiju6o7trse@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Pass build flags to traceevent build

2018-10-16T17:57:59+00:00

So the extra user build flags are propagated to libtraceevent.

Signed-off-by: Jiri Olsa 
Cc: "Herton R. Krzesinski" 
Cc: Steven Rostedt (VMware) 
Cc: Tzvetomir Stoyanov (VMware) 
Cc: Yordan Karadzhov (VMware) 
Link: http://lkml.kernel.org/r/20181016150614.21260-3-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf report: Don't crash on invalid inline debug information

2018-10-16T17:52:21+00:00

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=, 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 
Signed-off-by: Milian Wolff 
Cc: Jin Yao 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
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->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

perf cpu_map: Align cpu map synthesized events properly.

2018-10-16T15:30:03+00:00

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 
Cc: Jiri Olsa 
Cc: Kan Liang 
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

perf tools: Fix use of alternatives to find JDIR

2018-10-16T15:06:47+00:00

When a build is run from something like a cron job, the user's $PATH is
rather minimal, of note, not including /usr/sbin in my own case. Because
of that, an automated rpm package build ultimately fails to find
libperf-jvmti.so, because somewhere within the build, this happens...

  /bin/sh: alternatives: command not found
  /bin/sh: alternatives: command not found
  Makefile.config:849: No openjdk development package found, please install
  JDK package, e.g. openjdk-8-jdk, java-1.8.0-openjdk-devel

...and while the build continues, libperf-jvmti.so isn't built, and
things fall down when rpm tries to find all the %files specified. Exact
same system builds everything just fine when the job is launched from a
login shell instead of a cron job, since alternatives is in $PATH, so
openjdk is actually found.

The test required to get into this section of code actually specifies
the full path, as does a block just above it, so let's do that here too.

Signed-off-by: Jarod Wilson 
Acked-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: William Cohen 
Fixes: d4dfdf00d43e ("perf jvmti: Plug compilation into perf build")
Link: http://lkml.kernel.org/r/20180906221812.11167-1-jarod@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo