linux-stable.git/tools/perf, branch v5.0.4

perf intel-pt: Fix divide by zero when TSC is not available

2019-03-23T19:11:38+00:00

commit 076333870c2f5bdd9b6d31e7ca1909cf0c84cbfa upstream.

When TSC is not available, "timeless" decoding is used but a divide by
zero occurs if perf_time_to_tsc() is called.

Ensure the divisor is not zero.

Signed-off-by: Adrian Hunter 
Cc: Jiri Olsa 
Cc: stable@vger.kernel.org # v4.9+
Link: https://lkml.kernel.org/n/tip-1i4j0wqoc8vlbkcizqqxpsf4@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf intel-pt: Fix overlap calculation for padding

2019-03-23T19:11:37+00:00

commit 5a99d99e3310a565b0cf63f785b347be9ee0da45 upstream.

Auxtrace records might have up to 7 bytes of padding appended. Adjust
the overlap accordingly.

Signed-off-by: Adrian Hunter 
Cc: Jiri Olsa 
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20190206103947.15750-3-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf auxtrace: Define auxtrace record alignment

2019-03-23T19:11:37+00:00

commit c3fcadf0bb765faf45d6d562246e1d08885466df upstream.

Define auxtrace record alignment so that it can be referenced elsewhere.

Note this is preparation for patch "perf intel-pt: Fix overlap calculation
for padding"

Signed-off-by: Adrian Hunter 
Cc: Jiri Olsa 
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20190206103947.15750-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf tools: Fix split_kallsyms_for_kcore() for trampoline symbols

2019-03-23T19:11:37+00:00

commit d6d457451eb94fa747dc202765592eb8885a7352 upstream.

Kallsyms symbols do not have a size, so the size becomes the distance to
the next symbol.

Consequently the recently added trampoline symbols end up with large
sizes because the trampolines are some distance from one another and the
main kernel map.

However, symbols that end outside their map can disrupt the symbol tree
because, after mapping, it can appear incorrectly that they overlap
other symbols.

Add logic to truncate symbol size to the end of the corresponding map.

Signed-off-by: Adrian Hunter 
Acked-by: Jiri Olsa 
Cc: stable@vger.kernel.org
Fixes: d83212d5dd67 ("kallsyms, x86: Export addresses of PTI entry trampolines")
Link: http://lkml.kernel.org/r/20190109091835.5570-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf intel-pt: Fix CYC timestamp calculation after OVF

2019-03-23T19:11:37+00:00

commit 03997612904866abe7cdcc992784ef65cb3a4b81 upstream.

CYC packet timestamp calculation depends upon CBR which was being
cleared upon overflow (OVF). That can cause errors due to failing to
synchronize with sideband events. Even if a CBR change has been lost,
the old CBR is still a better estimate than zero. So remove the clearing
of CBR.

Signed-off-by: Adrian Hunter 
Cc: Jiri Olsa 
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20190206103947.15750-4-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf script python: Add Python3 support to tests/attr.py

2019-02-05T13:31:08+00:00

Support both Python 2 and Python 3 in tests/attr.py

The use of "except as" syntax implies the minimum supported Python2 version is
now v2.6

Committer testing:

  $ make -C tools/perf PYTHON3=python install-bin

Before:

  # perf test attr
  16: Setup struct perf_event_attr                          : FAILED!
  48: Synthesize attr update                                : Ok
  [root@quaco ~]# perf test -v attr
  16: Setup struct perf_event_attr                          :
  --- start ---
  test child forked, pid 3121
    File "/home/acme/libexec/perf-core/tests/attr.py", line 324
      except Unsup, obj:
                ^
  SyntaxError: invalid syntax
  test child finished with -1
  ---- end ----
  Setup struct perf_event_attr: FAILED!
  48: Synthesize attr update                                :
  --- start ---
  test child forked, pid 3124
  test child finished with 0
  ---- end ----
  Synthesize attr update: Ok
  #

After:

   # perf test attr
  16: Setup struct perf_event_attr                          : Ok
  48: Synthesize attr update                                : Ok
  #

Signed-off-by: Tony Jones 
Acked-by: Jiri Olsa 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Jonathan Corbet 
Cc: Ravi Bangoria 
Cc: Seeteena Thoufeek 
Link: http://lkml.kernel.org/r/20190124005229.16146-7-tonyj@suse.de
Signed-off-by: Arnaldo Carvalho de Melo

perf trace: Support multiple "vfs_getname" probes

2019-02-04T18:50:38+00:00

With a suitably defined "probe:vfs_getname" probe, 'perf trace' can
"beautify" its output, so syscalls like open() or openat() can print the
"filename" argument instead of just its hex address, like:

  $ perf trace -e open -- touch /dev/null
  [...]
       0.590 ( 0.014 ms): touch/18063 open(filename: /dev/null, flags: CREAT|NOCTTY|NONBLOCK|WRONLY, mode: IRUGO|IWUGO) = 3
  [...]

The output without such beautifier looks like:

     0.529 ( 0.011 ms): touch/18075 open(filename: 0xc78cf288, flags: CREAT|NOCTTY|NONBLOCK|WRONLY, mode: IRUGO|IWUGO) = 3

However, when the vfs_getname probe expands to multiple probes and it is
not the first one that is hit, the beautifier fails, as following:

     0.326 ( 0.010 ms): touch/18072 open(filename: , flags: CREAT|NOCTTY|NONBLOCK|WRONLY, mode: IRUGO|IWUGO) = 3

Fix it by hooking into all the expanded probes (inlines), now, for instance:

  [root@quaco ~]# perf probe -l
    probe:vfs_getname    (on getname_flags:73@fs/namei.c with pathname)
    probe:vfs_getname_1  (on getname_flags:73@fs/namei.c with pathname)
  [root@quaco ~]# perf trace -e open* sleep 1
       0.010 ( 0.005 ms): sleep/5588 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: RDONLY|CLOEXEC)   = 3
       0.029 ( 0.006 ms): sleep/5588 openat(dfd: CWD, filename: /lib64/libc.so.6, flags: RDONLY|CLOEXEC)   = 3
       0.194 ( 0.008 ms): sleep/5588 openat(dfd: CWD, filename: /usr/lib/locale/locale-archive, flags: RDONLY|CLOEXEC) = 3
  [root@quaco ~]#

Works, further verified with:

  [root@quaco ~]# perf test vfs
  65: Use vfs_getname probe to get syscall args filenames   : Ok
  66: Add vfs_getname probe to get syscall args filenames   : Ok
  67: Check open filename arg using perf trace + vfs_getname: Ok
  [root@quaco ~]#

Reported-by: Michael Petlan 
Tested-by: Michael Petlan 
Cc: Adrian Hunter 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Link: https://lkml.kernel.org/n/tip-mv8kolk17xla1smvmp3qabv1@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Filter out hidden symbols from labels

2019-02-04T18:50:38+00:00

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.

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

Signed-off-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Masami Hiramatsu 
Cc: Michael Petlan 
Cc: Namhyung Kim 
Cc: Nick Clifton 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/20190128133526.GD15461@krava
Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Add fallback definitions for GELF_ST_VISIBILITY()

2019-02-04T18:50:37+00:00

Those aren't present in Alpine Linux 3.4 to edge, so provide fallback
defines to get the next patch building there keeping the build
bisectable.

Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Jiri Olsa 
Cc: Masami Hiramatsu 
Cc: Michael Petlan 
Cc: Namhyung Kim 
Cc: Nick Clifton 
Cc: Peter Zijlstra 
Link: https://lkml.kernel.org/n/tip-03cg3gya2ju4ba2x6ibb9fuz@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf clang: Do not use 'return std::move(something)'

2019-02-04T14:32:34+00:00

It prevents copy elision, generating this warning when building with
fedora:rawhide's clang:

  clang version 7.0.1 (Fedora 7.0.1-2.fc30)
  Target: x86_64-unknown-linux-gnu
  Thread model: posix
  InstalledDir: /usr/bin
  Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-redhat-linux/9
  Found candidate GCC installation: /usr/lib/gcc/x86_64-redhat-linux/9
  Selected GCC installation: /usr/bin/../lib/gcc/x86_64-redhat-linux/9
  Candidate multilib: .;@m64
  Candidate multilib: 32;@m32
  Selected multilib: .;@m64

  $ make -C tools/perf CC=clang LIBCLANGLLVM=1
  
  util/c++/clang.cpp: In function 'std::unique_ptr > perf::getBPFObjectFromModule(llvm::Module*)':
  util/c++/clang.cpp:163:18: error: moving a local object in a return statement prevents copy elision [-Werror=pessimizing-move]
    163 |  return std::move(Buffer);
        |         ~~~~~~~~~^~~~~~~~
  util/c++/clang.cpp:163:18: note: remove 'std::move' call
  cc1plus: all warnings being treated as errors
  

References:

  http://www.cplusplus.com/forum/general/186411/#msg908572
  https://en.cppreference.com/w/cpp/language/return#Notes
  https://en.cppreference.com/w/cpp/language/copy_elision

Cc: Adrian Hunter 
Cc: Jiri Olsa 
Cc: Luis Cláudio Gonçalves 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: https://lkml.kernel.org/n/tip-lehqf5x5q96l0o8myhb6blz6@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo