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authorArnaldo Carvalho de Melo <acme@redhat.com>2011-02-21 13:23:57 -0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2011-02-21 22:21:27 -0300
commitfbee632d0ca9f4073a3fefb9a843eac8af036b0f (patch)
tree8fcc1304b6503f3ad00e94b256f08002cb008e90 /tools
parenta3d1ee10d1bf4520af3d44c1aa6cd46956ec4fd7 (diff)
perf probe: Fix error propagation leading to segfault
There are two hunks in this patch that stops probe processing as soon as one error is found, breaking out of loops, the other fix an error propagation that should return a negative error number but instead was returning the result of "ret < 0", which is 1 and thus made several error checks fail because they test agains < 0. The problem could be triggered by asking for a variable that was optimized out, fact that should stop the whole probe processing but instead was segfaulting while installing broken probes: [root@emilia ~]# probe perf_mmap:55 user_lock_limit Failed to find the location of user_lock_limit at this address. Perhaps, it has been optimized out. Failed to find 'user_lock_limit' in this function. Add new events: probe:perf_mmap (on perf_mmap:55 with user_lock_limit) probe:perf_mmap_1 (on perf_mmap:55 with user_lock_limit) Segmentation fault (core dumped) [root@emilia ~]# perf probe -l probe:perf_mmap (on perf_mmap:55@git/linux/kernel/perf_event.c with user_lock_limit) probe:perf_mmap_1 (on perf_mmap:55@git/linux/kernel/perf_event.c with user_lock_limit) [root@emilia ~]# After the fix: [root@emilia ~]# probe perf_mmap:55 user_lock_limit Failed to find the location of user_lock_limit at this address. Perhaps, it has been optimized out. Failed to find 'user_lock_limit' in this function. Error: Failed to add events. (-2) [root@emilia ~]# Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Tom Zanussi <tzanussi@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools')
-rw-r--r--tools/perf/util/probe-event.c5
-rw-r--r--tools/perf/util/probe-finder.c4
2 files changed, 7 insertions, 2 deletions
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 0e3ea132110..369ddc64bbb 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -1832,9 +1832,12 @@ int add_perf_probe_events(struct perf_probe_event *pevs, int npevs,
}
/* Loop 2: add all events */
- for (i = 0; i < npevs && ret >= 0; i++)
+ for (i = 0; i < npevs && ret >= 0; i++) {
ret = __add_probe_trace_events(pkgs[i].pev, pkgs[i].tevs,
pkgs[i].ntevs, force_add);
+ if (ret < 0)
+ break;
+ }
end:
/* Loop 3: cleanup and free trace events */
for (i = 0; i < npevs; i++) {
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index fe461f6559f..eecbdca5c0d 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -1262,7 +1262,7 @@ static int probe_point_line_walker(const char *fname, int lineno,
ret = call_probe_finder(NULL, pf);
/* Continue if no error, because the line will be in inline function */
- return ret < 0 ?: 0;
+ return ret < 0 ? ret : 0;
}
/* Find probe point from its line number */
@@ -1484,6 +1484,8 @@ static int find_probes(int fd, struct probe_finder *pf)
pf->lno = pp->line;
ret = find_probe_point_by_line(pf);
}
+ if (ret != DWARF_CB_OK)
+ break;
}
off = noff;
}