linux/tools/lib
Adrian Hunter a668cc07f9 perf tools: Fix segfault accessing sample_id xyarray
perf_evsel::sample_id is an xyarray which can cause a segfault when
accessed beyond its size. e.g.

  # perf record -e intel_pt// -C 1 sleep 1
  Segmentation fault (core dumped)
  #

That is happening because a dummy event is opened to capture text poke
events accross all CPUs, however the mmap logic is allocating according
to the number of user_requested_cpus.

In general, perf sometimes uses the evsel cpus to open events, and
sometimes the evlist user_requested_cpus. However, it is not necessary
to determine which case is which because the opened event file
descriptors are also in an xyarray, the size of whch can be used
to correctly allocate the size of the sample_id xyarray, because there
is one ID per file descriptor.

Note, in the affected code path, perf_evsel fd array is subsequently
used to get the file descriptor for the mmap, so it makes sense for the
xyarrays to be the same size there.

Fixes: d1a177595b ("libperf: Adopt perf_evlist__mmap()/munmap() from tools/perf")
Fixes: 246eba8e90 ("perf tools: Add support for PERF_RECORD_TEXT_POKE")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: stable@vger.kernel.org # 5.5+
Link: https://lore.kernel.org/r/20220413114232.26914-1-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-04-13 22:23:02 -03:00
..
api Kbuild updates for v5.18 2022-03-31 11:59:03 -07:00
bpf Kbuild updates for v5.18 2022-03-31 11:59:03 -07:00
perf perf tools: Fix segfault accessing sample_id xyarray 2022-04-13 22:23:02 -03:00
subcmd Kbuild updates for v5.18 2022-03-31 11:59:03 -07:00
symbol libsymbols kallsyms: Move hex2u64 out of header 2020-05-05 16:35:32 -03:00
traceevent libtraceevent: Add __rel_loc relative location attribute support 2021-12-06 15:37:22 -05:00
argv_split.c tools lib: Move argv_{split,free} from tools/perf/util/ 2019-07-01 22:50:40 -03:00
bitmap.c tools lib: Adopt bitmap_intersects() operation from the kernel sources 2021-06-30 15:28:00 -03:00
ctype.c tools perf: Move from sane_ctype.h obtained from git to the Linux's original 2019-06-25 21:02:47 -03:00
find_bit.c tools: sync tools/bitmap with mother linux 2022-01-15 08:47:31 -08:00
hweight.c
list_sort.c tools lib: Adopt list_sort() from the kernel sources 2021-10-20 10:30:59 -03:00
rbtree.c tools/: replace HTTP links with HTTPS ones 2020-08-07 11:33:21 -07:00
slab.c tools: Move gfp.h and slab.h from radix-tree to lib 2022-02-20 08:44:37 +02:00
str_error_r.c objtool, perf: Fix GCC 8 -Wrestrict error 2018-03-19 13:51:54 -03:00
string.c tools lib: Adopt memchr_inv() from kernel 2020-11-27 08:34:52 -03:00
vsprintf.c perf script: Pad DSO name for --call-trace 2019-05-28 18:37:44 -03:00
zalloc.c tools lib: Adopt zalloc()/zfree() from tools/perf 2019-07-09 10:13:26 -03:00