As Namhyung reported(https://lkml.org/lkml/2014/4/1/89), current perf-probe -L option doesn't handle errors in line-range searching correctly. It causes a SEGV if an error occured in the line-range searching.
---- $ perf probe -x ./perf -v -L map__load Open Debuginfo file: /home/namhyung/project/linux/tools/perf/perf fname: util/map.c, lineno:153 New line range: 153 to 2147483647 path: (null) Segmentation fault (core dumped) ---- This is because line_range_inline_cb() ignores errors from find_line_range_by_line() which means that lr->path is already freed on the error path in find_line_range_by_line(). As a result, get_real_path() accesses the lr->path and it causes a NULL pointer exception. This fixes line_range_inline_cb() to handle the error correctly, and report it to the caller. Anyway, this just fixes a possible SEGV bug, Namhyung's patch is also required. Signed-off-by: Masami Hiramatsu <[email protected]> Reported-by: Namhyung Kim <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Jiri Olsa <[email protected]> --- tools/perf/util/probe-finder.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c index df02386..edcd2ff 100644 --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -1473,14 +1473,15 @@ static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf) static int line_range_inline_cb(Dwarf_Die *in_die, void *data) { - find_line_range_by_line(in_die, data); + int ret = find_line_range_by_line(in_die, data); /* * We have to check all instances of inlined function, because * some execution paths can be optimized out depends on the - * function argument of instances + * function argument of instances. However, if an error occurs, + * it should be handled by the caller. */ - return 0; + return ret < 0 ? ret : 0; } /* Search function definition from function name */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
