linux.git/tools/perf/util/header.c, branch v5.3.2

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

perf tools: Fix proper buffer size for feature processing

2019-07-23T11:59:49+00:00

After Song Liu's segfault fix for pipe mode, Arnaldo reported following
error:

  # perf record -o - | perf script
  0x514 [0x1ac]: failed to process type: 80

It's caused by wrong buffer size setup in feature processing, which
makes cpu topology feature fail, because it's using buffer size to
recognize its header version.

Reported-by: Arnaldo Carvalho de Melo 
Signed-off-by: Jiri Olsa 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Alexander Shishkin 
Cc: David Carrillo-Cisneros 
Cc: Kan Liang 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Song Liu 
Fixes: e9def1b2e74e ("perf tools: Add feature header record to pipe-mode")
Link: http://lkml.kernel.org/r/20190715140426.32509-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Use zfree() where applicable

2019-07-09T13:13:27+00:00

In places where the equivalent was already being done, i.e.:

   free(a);
   a = NULL;

And in placs where struct members are being freed so that if we have
some erroneous reference to its struct, then accesses to freed members
will result in segfaults, which we can detect faster than use after free
to areas that may still have something seemingly valid.

Cc: Adrian Hunter 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Link: https://lkml.kernel.org/n/tip-jatyoofo5boc1bsvoig6bb6i@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

tools lib: Adopt zalloc()/zfree() from tools/perf

2019-07-09T13:13:26+00:00

Eroding a bit more the tools/perf/util/util.h hodpodge header.

Cc: Adrian Hunter 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Link: https://lkml.kernel.org/n/tip-natazosyn9rwjka25tvcnyi0@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

Merge remote-tracking branch 'tip/perf/core' into perf/urgent

2019-07-08T16:06:57+00:00

To pick up fixes.

Signed-off-by: Arnaldo Carvalho de Melo

perf header: Assign proper ff->ph in perf_event__synthesize_features()

2019-07-06T17:29:04+00:00

bpf/btf write_* functions need ff->ph->env.

With this missing, pipe-mode (perf record -o -)  would crash like:

Program terminated with signal SIGSEGV, Segmentation fault.

This patch assign proper ph value to ff.

Committer testing:

  (gdb) run record -o -
  Starting program: /root/bin/perf record -o -
  PERFILE2
  
  Thread 1 "perf" received signal SIGSEGV, Segmentation fault.
  __do_write_buf (size=4, buf=0x160, ff=0x7fffffff8f80) at util/header.c:126
  126		memcpy(ff->buf + ff->offset, buf, size);
  (gdb) bt
  #0  __do_write_buf (size=4, buf=0x160, ff=0x7fffffff8f80) at util/header.c:126
  #1  do_write (ff=ff@entry=0x7fffffff8f80, buf=buf@entry=0x160, size=4) at util/header.c:137
  #2  0x00000000004eddba in write_bpf_prog_info (ff=0x7fffffff8f80, evlist=) at util/header.c:912
  #3  0x00000000004f69d7 in perf_event__synthesize_features (tool=tool@entry=0x97cc00 , session=session@entry=0x7fffe9c6d010,
      evlist=0x7fffe9cae010, process=process@entry=0x4435d0 ) at util/header.c:3695
  #4  0x0000000000443c79 in record__synthesize (tail=tail@entry=false, rec=0x97cc00 ) at builtin-record.c:1214
  #5  0x0000000000444ec9 in __cmd_record (rec=0x97cc00 , argv=, argc=0) at builtin-record.c:1435
  #6  cmd_record (argc=0, argv=) at builtin-record.c:2450
  #7  0x00000000004ae3e9 in run_builtin (p=p@entry=0x98e058 , argc=argc@entry=3, argv=0x7fffffffd670) at perf.c:304
  #8  0x000000000042eded in handle_internal_command (argv=, argc=) at perf.c:356
  #9  run_argv (argcp=, argv=) at perf.c:400
  #10 main (argc=3, argv=) at perf.c:522
  (gdb)

After the patch the SEGSEGV is gone.

Reported-by: David Carrillo Cisneros 
Signed-off-by: Song Liu 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: kernel-team@fb.com
Cc: stable@vger.kernel.org # v5.1+
Fixes: 606f972b1361 ("perf bpf: Save bpf_prog_info information as headers to perf.data")
Link: http://lkml.kernel.org/r/20190620010453.4118689-1-songliubraving@fb.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Ditch rtrim(), use strim() from tools/lib

2019-07-02T01:50:33+00:00

Cleaning up a bit more tools/perf/util/ by using things we got from the
kernel and have in tools/lib/

Cc: Adrian Hunter 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Link: https://lkml.kernel.org/n/tip-7hluuoveryoicvkclshzjf1k@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf header: Use skip_spaces() in __write_cpudesc()

2019-06-26T00:34:31+00:00

No change in behaviour.

Cc: Stephane Eranian 
Cc: Adrian Hunter 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Link: https://lkml.kernel.org/n/tip-0dbfpi70aa66s6mtd8z6p391@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

tools perf: Move from sane_ctype.h obtained from git to the Linux's original

2019-06-26T00:02:47+00:00

We got the sane_ctype.h headers from git and kept using it so far, but
since that code originally came from the kernel sources to the git
sources, perhaps its better to just use the one in the kernel, so that
we can leverage tools/perf/check_headers.sh to be notified when our copy
gets out of sync, i.e. when fixes or goodies are added to the code we've
copied.

This will help with things like tools/lib/string.c where we want to have
more things in common with the kernel, such as strim(), skip_spaces(),
etc so as to go on removing the things that we have in tools/perf/util/
and instead using the code in the kernel, indirectly and removing things
like EXPORT_SYMBOL(), etc, getting notified when fixes and improvements
are made to the original code.

Hopefully this also should help with reducing the difference of code
hosted in tools/ to the one in the kernel proper.

Cc: Adrian Hunter 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Link: https://lkml.kernel.org/n/tip-7k9868l713wqtgo01xxygn12@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo