[BUGFIX PATCH -tip 3/5] perf probe: Fix event namelist to duplicatestring

From: Masami Hiramatsu
Date: Mon Dec 07 2009 - 11:56:49 EST


Fix event namelist to duplicate string. Without duplicating,
adding multiple probes causes stack overwrite bug, because
it reuses a buffer on stack while the buffer is already
added in the namelist. String duplication solves this bug
because only contents of the buffer is copied to the namelist.

Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---

tools/perf/util/probe-event.c | 4 +++-
1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index cd7fbda..de0d913 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -413,12 +413,13 @@ static struct strlist *get_perf_event_names(int fd)

rawlist = get_trace_kprobe_event_rawlist(fd);

- sl = strlist__new(false, NULL);
+ sl = strlist__new(true, NULL);
for (i = 0; i < strlist__nr_entries(rawlist); i++) {
ent = strlist__entry(rawlist, i);
parse_trace_kprobe_event(ent->s, &group, &event, NULL);
strlist__add(sl, event);
free(group);
+ free(event);
}

strlist__delete(rawlist);
@@ -480,5 +481,6 @@ void add_trace_kprobe_events(struct probe_point *probes, int nr_probes)
strlist__add(namelist, event);
}
}
+ strlist__delete(namelist);
close(fd);
}


--
Masami Hiramatsu

Software Engineer
Hitachi Computer Products (America), Inc.
Software Solutions Division

e-mail: mhiramat@xxxxxxxxxx
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