linux-stable.git/tools/perf/util/map.c, branch v5.16.2

Revert "perf map: Fix dso->nsinfo refcounting"

2021-07-30T21:26:22+00:00

This makes 'perf top' abort in some cases, and the right fix will
involve surgery that is too much to do at this stage, so revert for now
and fix it in the next merge window.

This reverts commit 2d6b74baa7147251c30a46c4996e8cc224aa2dc5.

Cc: Riccardo Mancini 
Cc: Ian Rogers 
Cc: Jiri Olsa 
Cc: Krister Johansen 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Signed-off-by: Arnaldo Carvalho de Melo

perf map: Fix dso->nsinfo refcounting

2021-07-15T20:25:27+00:00

ASan reports a memory leak of nsinfo during the execution of

  # perf test "31: Lookup mmap thread"

The leak is caused by a refcounted variable being replaced without
dropping the refcount.

This patch makes sure that the refcnt of nsinfo is decreased whenever a
refcounted variable is replaced with a new value.

Signed-off-by: Riccardo Mancini 
Fixes: bf2e710b3cb8445c ("perf maps: Lookup maps in both intitial mountns and inner mountns.")
Cc: Ian Rogers 
Cc: Jiri Olsa 
Cc: Krister Johansen 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lore.kernel.org/lkml/55223bc8821b34ccb01f92ef1401c02b6a32e61f.1626343282.git.rickyman7@gmail.com
[ Split from a larger patch ]
Signed-off-by: Arnaldo Carvalho de Melo

perf map: Fix error return code in maps__clone()

2021-04-23T19:03:09+00:00

Although 'err' has been initialized to -ENOMEM, but it will be reassigned
by the "err = unwind__prepare_access(...)" statement in the for loop. So
that, the value of 'err' is unknown when map__clone() failed.

Fixes: 6c502584438bda63 ("perf unwind: Call unwind__prepare_access for forked thread")
Reported-by: Hulk Robot 
Signed-off-by: Zhen Lei 
Cc: Alexander Shishkin 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: zhen lei 
Link: http://lore.kernel.org/lkml/20210415092744.3793-1-thunder.leizhen@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo

perf map: Tighten snprintf() string precision to pass gcc check on some 32-bit arches

2021-03-06T19:54:32+00:00

Noticed on a debian:experimental mips and mipsel cross build build
environment:

  perfbuilder@ec265a086e9b:~$ mips-linux-gnu-gcc --version | head -1
  mips-linux-gnu-gcc (Debian 10.2.1-3) 10.2.1 20201224
  perfbuilder@ec265a086e9b:~$

    CC       /tmp/build/perf/util/map.o
  util/map.c: In function 'map__new':
  util/map.c:109:5: error: '%s' directive output may be truncated writing between 1 and 2147483645 bytes into a region of size 4096 [-Werror=format-truncation=]
    109 |    "%s/platforms/%s/arch-%s/usr/lib/%s",
        |     ^~
  In file included from /usr/mips-linux-gnu/include/stdio.h:867,
                   from util/symbol.h:11,
                   from util/map.c:2:
  /usr/mips-linux-gnu/include/bits/stdio2.h:67:10: note: '__builtin___snprintf_chk' output 32 or more bytes (assuming 4294967321) into a destination of size 4096
     67 |   return __builtin___snprintf_chk (__s, __n, __USE_FORTIFY_LEVEL - 1,
        |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     68 |        __bos (__s), __fmt, __va_arg_pack ());
        |        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  cc1: all warnings being treated as errors

Since we have the lenghts for what lands in that place, use it to give
the compiler more info and make it happy.

Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Store build id when available in PERF_RECORD_MMAP2 metadata events

2020-12-28T13:01:55+00:00

When processing a PERF_RECORD_MMAP2 metadata event, check on the build
id misc bit: PERF_RECORD_MISC_MMAP_BUILD_ID and if it is set, store the
build id in mmap's dso object.

Also adding the build id data to struct perf_record_mmap2 event
definition.

Signed-off-by: Jiri Olsa 
Acked-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Alexei Budankov 
Cc: Andi Kleen 
Cc: Ian Rogers 
Cc: Mark Rutland 
Cc: Michael Petlan 
Cc: Peter Zijlstra 
Cc: Song Liu 
Cc: Stephane Eranian 
Link: http://lore.kernel.org/lkml/20201214105457.543111-8-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Pass build_id object to build_id__sprintf()

2020-10-14T11:46:22+00:00

Passing build_id object to build_id__sprintf function, so it can operate
with the proper size of build id.

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

  a50e350e97c43b4708d09bcd85ebfff7

instead of:

  a50e350e97c43b4708d09bcd85ebfff700000000

Signed-off-by: Jiri Olsa 
Acked-by: Ian Rogers 
Link: https://lore.kernel.org/r/20201013192441.1299447-5-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Use build_id object in dso

2020-10-14T11:44:47+00:00

Replace build_id byte array with struct build_id object and all the code
that references it.

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

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

Signed-off-by: Jiri Olsa 
Acked-by: Ian Rogers 
Link: https://lore.kernel.org/r/20201013192441.1299447-2-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf inject: Do not load map/dso when injecting build-id

2020-10-13T14:01:37+00:00

No need to load symbols in a DSO when injecting build-id.  I guess the
reason was to check the DSO is a special file like anon files.  Use some
helper functions in map.c to check them before reading build-id.  Also
pass sample event's cpumode to a new build-id event.

It brought a speedup in the benchmark of 25 -> 21 msec on my laptop.
Also the memory usage (Max RSS) went down by ~200 KB.

  # Running 'internals/inject-build-id' benchmark:
    Average build-id injection took: 21.389 msec (+- 0.138 msec)
    Average time per event: 2.097 usec (+- 0.014 usec)
    Average memory usage: 8225 KB (+- 0 KB)

Committer notes:

Before:

  $ perf stat -r5 perf bench internals inject-build-id > /dev/null

   Performance counter stats for 'perf bench internals inject-build-id' (5 runs):

            4,020.56 msec task-clock:u              #    1.271 CPUs utilized            ( +-  0.74% )
                   0      context-switches:u        #    0.000 K/sec
                   0      cpu-migrations:u          #    0.000 K/sec
             123,354      page-faults:u             #    0.031 M/sec                    ( +-  0.81% )
       7,119,951,568      cycles:u                  #    1.771 GHz                      ( +-  1.74% )  (83.27%)
         230,086,969      stalled-cycles-frontend:u #    3.23% frontend cycles idle     ( +-  1.97% )  (83.41%)
       1,168,298,765      stalled-cycles-backend:u  #   16.41% backend cycles idle      ( +-  1.13% )  (83.44%)
      11,173,083,669      instructions:u            #    1.57  insn per cycle
                                                    #    0.10  stalled cycles per insn  ( +-  1.58% )  (83.31%)
       2,413,908,936      branches:u                #  600.392 M/sec                    ( +-  1.69% )  (83.26%)
          46,576,289      branch-misses:u           #    1.93% of all branches          ( +-  2.20% )  (83.31%)

              3.1638 +- 0.0309 seconds time elapsed  ( +-  0.98% )

  $

After:

  $ perf stat -r5 perf bench internals inject-build-id > /dev/null

   Performance counter stats for 'perf bench internals inject-build-id' (5 runs):

            2,379.94 msec task-clock:u              #    1.473 CPUs utilized            ( +-  0.18% )
                   0      context-switches:u        #    0.000 K/sec
                   0      cpu-migrations:u          #    0.000 K/sec
              62,584      page-faults:u             #    0.026 M/sec                    ( +-  0.07% )
       2,372,389,668      cycles:u                  #    0.997 GHz                      ( +-  0.29% )  (83.14%)
         106,937,862      stalled-cycles-frontend:u #    4.51% frontend cycles idle     ( +-  4.89% )  (83.20%)
         581,697,915      stalled-cycles-backend:u  #   24.52% backend cycles idle      ( +-  0.71% )  (83.47%)
       3,659,692,199      instructions:u            #    1.54  insn per cycle
                                                    #    0.16  stalled cycles per insn  ( +-  0.10% )  (83.63%)
         791,372,961      branches:u                #  332.518 M/sec                    ( +-  0.27% )  (83.39%)
          10,648,083      branch-misses:u           #    1.35% of all branches          ( +-  0.22% )  (83.16%)

             1.61570 +- 0.00172 seconds time elapsed  ( +-  0.11% )

  $

Signed-off-by: Namhyung Kim 
Original-patch-by: Stephane Eranian 
Tested-by: Arnaldo Carvalho de Melo 
Acked-by: Jiri Olsa 
Link: https://lore.kernel.org/r/20201012070214.2074921-5-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Add bpf image check to mapis_kmodule

2020-09-03T19:04:46+00:00

When validating kcore modules the do_validate_kcore_modules function
checks on every kernel module dso against modules record. The
__map__is_kmodule check is used to get only kernel module dso objects
through.

Currently the bpf images are slipping through the check and making the
validation to fail, so report falls back from kcore usage to kallsyms.

Adding __map__is_bpf_image check for bpf image and adding it to
__map__is_kmodule check.

Fixes: 3c29d4483e85 ("perf annotate: Add basic support for bpf_image")
Signed-off-by: Jiri Olsa 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Ian Rogers 
Cc: Michael Petlan 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: http://lore.kernel.org/lkml/20200826213017.818788-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Rename 'enum dso_kernel_type' to 'enum dso_space_type'

2020-08-13T12:53:21+00:00

Rename enum dso_kernel_type to enum dso_space_type, which seems like
better fit.

Committer notes:

This is used with 'struct dso'->kernel, which once was a boolean, so
DSO_SPACE__USER is zero, !zero means some sort of kernel space, be it
the host kernel space or a guest kernel space.

Signed-off-by: Jiri Olsa 
Cc: Adrian Hunter 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Signed-off-by: Arnaldo Carvalho de Melo