Commit-ID: 554e92ed8fcdbcad736ef906c393847d44d52692 Gitweb: http://git.kernel.org/tip/554e92ed8fcdbcad736ef906c393847d44d52692 Author: Adrian Hunter <adrian.hunter@xxxxxxxxx> AuthorDate: Tue, 19 May 2015 16:05:45 +0300 Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> CommitDate: Wed, 27 May 2015 12:21:43 -0300 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@xxxxxxxxx> Cc: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: Namhyung Kim <namhyung@xxxxxxxxx> Link: http://lkml.kernel.org/r/1432040746-1755-5-git-send-email-adrian.hunter@xxxxxxxxx Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> --- tools/perf/util/session.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index e722107..39fe09d 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) -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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