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| author | Adrian Hunter <adrian.hunter@intel.com> | 2015-05-19 16:05:45 +0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2015-05-27 18:21:43 +0300 |
| commit | 554e92ed8fcdbcad736ef906c393847d44d52692 (patch) | |
| tree | a614aa7e175aad3f5e36540e03bbd7e9c1df5dcd | |
| parent | 05b41775e2edd69a83f592e3534930c934d4038e (diff) | |
| download | linux-554e92ed8fcdbcad736ef906c393847d44d52692.tar.xz | |
perf session: Fix perf_session__peek_event()
perf_session__peek_event() generally leverages there being a single mmap
of the perf.data file, however on 32-bit platforms when there is more
that 32MiB of data, then there are multiple mmaps, so
perf_session__peek_event() reads from the file.
In that case a couple of bugs were exposed (note how the seg. fault
appears with >32M of data):
$ perf record --per-thread -e intel_bts// ../rtit-tests/loopy 1000000
[ perf record: Woken up 13 times to write data ]
[ perf record: Captured and wrote 24.568 MB perf.data ]
$ perf script > /dev/null
$ perf record --per-thread -e intel_bts// ../rtit-tests/loopy 10000000
[ perf record: Woken up 136 times to write data ]
[ perf record: Captured and wrote 270.794 MB perf.data ]
$ perf script > /dev/null
Segmentation fault (core dumped)
The wrong address was being passed to the readn() function and the
buffer size was not being checked.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Link: http://lkml.kernel.org/r/1432040746-1755-5-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| -rw-r--r-- | tools/perf/util/session.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index e722107f932a..39fe09d5a87e 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -1182,7 +1182,7 @@ int perf_session__peek_event(struct perf_session *session, off_t file_offset, return -1; if (lseek(fd, file_offset, SEEK_SET) == (off_t)-1 || - readn(fd, &buf, hdr_sz) != (ssize_t)hdr_sz) + readn(fd, buf, hdr_sz) != (ssize_t)hdr_sz) return -1; event = (union perf_event *)buf; @@ -1190,12 +1190,12 @@ int perf_session__peek_event(struct perf_session *session, off_t file_offset, if (session->header.needs_swap) perf_event_header__bswap(&event->header); - if (event->header.size < hdr_sz) + if (event->header.size < hdr_sz || event->header.size > buf_sz) return -1; rest = event->header.size - hdr_sz; - if (readn(fd, &buf, rest) != (ssize_t)rest) + if (readn(fd, buf, rest) != (ssize_t)rest) return -1; if (session->header.needs_swap) |