linux.git/tools/perf, branch v5.3-rc3

perf tools: Fix perf.data documentation units for memory size

2019-07-29T12:03:43+00:00

The perf.data-file-format documentation incorrectly says the
HEADER_TOTAL_MEM results are in bytes.  The results are in kilobytes
(perf reads the value from /proc/meminfo)

Signed-off-by: Vince Weaver 
Cc: Alexander Shishkin 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/alpine.DEB.2.21.1907251155500.22624@macbook-air
Signed-off-by: Arnaldo Carvalho de Melo

perf header: Fix use of unitialized value warning

2019-07-29T12:03:43+00:00

When building our local version of perf with MSAN (Memory Sanitizer) and
running the perf record command, MSAN throws a use of uninitialized
value warning in "tools/perf/util/util.c:333:6".

This warning stems from the "buf" variable being passed into "write".
It originated as the variable "ev" with the type union perf_event*
defined in the "perf_event__synthesize_attr" function in
"tools/perf/util/header.c".

In the "perf_event__synthesize_attr" function they allocate space with a malloc
call using ev, then go on to only assign some of the member variables before
passing "ev" on as a parameter to the "process" function therefore "ev"
contains uninitialized memory. Changing the malloc call to zalloc to initialize
all the members of "ev" which gets rid of the warning.

To reproduce this warning, build perf by running:
make -C tools/perf CLANG=1 CC=clang EXTRA_CFLAGS="-fsanitize=memory\
 -fsanitize-memory-track-origins"

(Additionally, llvm might have to be installed and clang might have to
be specified as the compiler - export CC=/usr/bin/clang)

then running:
tools/perf/perf record -o - ls / | tools/perf/perf --no-pager annotate\
 -i - --stdio

Please see the cover letter for why false positive warnings may be
generated.

Signed-off-by: Numfor Mbiziwo-Tiapo 
Cc: Alexander Shishkin 
Cc: Ian Rogers 
Cc: Jiri Olsa 
Cc: Mark Drayton 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Song Liu 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/r/20190724234500.253358-2-nums@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf header: Fix divide by zero error if f_header.attr_size==0

2019-07-29T12:03:43+00:00

So I have been having lots of trouble with hand-crafted perf.data files
causing segfaults and the like, so I have started fuzzing the perf tool.

First issue found:

If f_header.attr_size is 0 in the perf.data file, then perf will crash
with a divide-by-zero error.

Committer note:

Added a pr_err() to tell the user why the command failed.

Signed-off-by: Vince Weaver 
Cc: Alexander Shishkin 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/alpine.DEB.2.21.1907231100440.14532@macbook-air
Signed-off-by: Arnaldo Carvalho de Melo

tools perf beauty: Fix usbdevfs_ioctl table generator to handle _IOC()

2019-07-29T12:03:42+00:00

In addition to _IOW() and _IOR(), to handle this case:

  #define USBDEVFS_CONNINFO_EX(len)  _IOC(_IOC_READ, 'U', 32, len)

That will happen in the next sync of this header file.

Cc: Adrian Hunter 
Cc: Jiri Olsa 
Cc: Luis Cláudio Gonçalves 
Cc: Namhyung Kim 
Link: https://lkml.kernel.org/n/tip-3br5e4t64e4lp0goo84che3s@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

tools include UAPI: Sync x86's syscalls_64.tbl and generic unistd.h to pick up clone3 and pidfd_open

2019-07-26T15:31:28+00:00

  05a70a8ec287 ("unistd: protect clone3 via __ARCH_WANT_SYS_CLONE3")
  8f3220a80654 ("arch: wire-up clone3() syscall")
  7615d9e1780e ("arch: wire-up pidfd_open()")

Silencing the following tools/perf build warnings

  Warning: Kernel ABI header at 'tools/include/uapi/asm-generic/unistd.h' differs from latest version at 'include/uapi/asm-generic/unistd.h'
  diff -u tools/include/uapi/asm-generic/unistd.h include/uapi/asm-generic/unistd.h
  Warning: Kernel ABI header at 'tools/perf/arch/x86/entry/syscalls/syscall_64.tbl' differs from latest version at 'arch/x86/entry/syscalls/syscall_64.tbl'
  diff -u tools/perf/arch/x86/entry/syscalls/syscall_64.tbl arch/x86/entry/syscalls/syscall_64.tbl

Now 'perf trace -e pidfd*,clone*' will trace those syscalls as well as the
others with those prefixes.

  $ diff -u /tmp/build/perf/arch/x86/include/generated/asm/syscalls_64.c.before /tmp/build/perf/arch/x86/include/generated/asm/syscalls_64.c
  --- /tmp/build/perf/arch/x86/include/generated/asm/syscalls_64.c.before	2019-07-26 12:24:55.020944201 -0300
  +++ /tmp/build/perf/arch/x86/include/generated/asm/syscalls_64.c	2019-07-26 12:25:03.919047217 -0300
  @@ -344,5 +344,7 @@
        [431] = "fsconfig",
        [432] = "fsmount",
        [433] = "fspick",
  +     [434] = "pidfd_open",
  +     [435] = "clone3",
   };
  -#define SYSCALLTBL_x86_64_MAX_ID 433
  +#define SYSCALLTBL_x86_64_MAX_ID 435
  $

Cc: Adrian Hunter 
Cc: Brendan Gregg 
Cc: Christian Brauner 
Cc: Jiri Olsa 
Cc: Luis Cláudio Gonçalves 
Cc: Namhyung Kim 
Link: https://lkml.kernel.org/n/tip-0isnnqxtr1ihz6p8wzjiy47d@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

Merge tag 'perf-urgent-for-mingo-5.3-20190723' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

2019-07-23T21:41:33+00:00

Pull perf/urgent fixes from Arnaldo Carvalho de Melo:

perf.data:

  Alexey Budankov:

  - Fix loading of compressed data split across adjacent records

  Jiri Olsa:

  - Fix buffer size setting for processing CPU topology perf.data header.

perf stat:

  Jiri Olsa:

  - Fix segfault for event group in repeat mode

  Cong Wang:

  - Always separate "stalled cycles per insn" line, it was being appended to
    the "instructions" line.

perf script:

  Andi Kleen:

  - Fix --max-blocks man page description.

  - Improve man page description of metrics.

  - Fix off by one in brstackinsn IPC computation.

perf probe:

  Arnaldo Carvalho de Melo:

  - Avoid calling freeing routine multiple times for same pointer.

perf build:

  - Do not use -Wshadow on gcc < 4.8, avoiding too strict warnings
    treated as errors, breaking the build.

Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Ingo Molnar

perf probe: Avoid calling freeing routine multiple times for same pointer

2019-07-23T12:04:41+00:00

When perf_add_probe_events() we call cleanup_perf_probe_events() for the
pev pointer it receives, then, as part of handling this failure the main
'perf probe' goes on and calls cleanup_params() and that will again call
cleanup_perf_probe_events()for the same pointer, so just set nevents to
zero when handling the failure of perf_add_probe_events() to avoid the
double free.

Cc: Adrian Hunter 
Cc: Jiri Olsa 
Cc: Masami Hiramatsu 
Cc: Namhyung Kim 
Link: https://lkml.kernel.org/n/tip-x8qgma4g813z96dvtw9w219q@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Set pev->nargs to zero after freeing pev->args entries

2019-07-23T12:04:25+00:00

So that, when perf_add_probe_events() fails, like in:

  # perf probe icmp_rcv:64 "type=icmph->type"
  Failed to find 'icmph' in this function.
    Error: Failed to add events.
  Segmentation fault (core dumped)
  #

We don't segfault.

clear_perf_probe_event() was zeroing the whole pev, and since the switch
to zfree() for the members in the pev, that memset() was removed, which
left nargs with its original value, in the above case 1.

With the memset the same pev could be passed to clear_perf_probe_event()
multiple times, since all it would have would be zeroes, and free()
accepts zero, the loop would not happen and we would just memset it
again to zeroes.

Without it we got that segfault, so zero nargs to keep it like it was,
next cset will avoid calling clear_perf_probe_event() for the same pevs
in case of failure.

Cc: Adrian Hunter 
Cc: Jiri Olsa 
Cc: Masami Hiramatsu 
Cc: Namhyung Kim 
Fixes: d8f9da240495 ("perf tools: Use zfree() where applicable")
Link: https://lkml.kernel.org/n/tip-802f2jypnwqsvyavvivs8464@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf session: Fix loading of compressed data split across adjacent records

2019-07-23T12:04:03+00:00

Fix decompression failure found during the loading of compressed trace
collected on larger scale systems (>48 cores).

The error happened due to lack of decompression space for a mmaped
buffer data chunk split across adjacent PERF_RECORD_COMPRESSED records.

  $ perf report -i bt.16384.data --stats
  failed to decompress (B): 63869 -> 0 : Destination buffer is too small
  user stack dump failure
  Can't parse sample, err = -14
  0x2637e436 [0x4080]: failed to process type: 9
  Error:
  failed to process sample

  $ perf test 71
  71: Zstd perf.data compression/decompression              : Ok

Signed-off-by: Alexey Budankov 
Acked-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/4d839e1b-9c48-89c4-9702-a12217420611@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf stat: Always separate stalled cycles per insn

2019-07-23T12:03:46+00:00

The "stalled cycles per insn" is appended to "instructions" when the CPU
has this hardware counter directly. We should always make it a separate
line, which also aligns to the output when we hit the "if (total &&
avg)" branch.

Before:

  $ sudo perf stat --all-cpus --field-separator , --log-fd 1 -einstructions,cycles -- sleep 1
  4565048704,,instructions,64114578096,100.00,1.34,insn per cycle,,
  3396325133,,cycles,64146628546,100.00,,

After:

  $ sudo ./tools/perf/perf stat --all-cpus --field-separator , --log-fd 1 -einstructions,cycles -- sleep 1
  6721924,,instructions,24026790339,100.00,0.22,insn per cycle
  ,,,,,0.00,stalled cycles per insn
  30939953,,cycles,24025512526,100.00,,

Signed-off-by: Cong Wang 
Acked-by: Jiri Olsa 
Cc: Andi Kleen 
Link: http://lkml.kernel.org/r/20190517221039.8975-1-xiyou.wangcong@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo