From 0c188a07b6a399e3df66534c29fef0a2082aaf57 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Thu, 29 May 2014 19:52:32 +0900 Subject: [PATCH] perf probe: Fix a segfault if asked for variable it doesn't find Fix a segfault bug by asking for variable it doesn't find. Since the convert_variable() didn't handle error code returned from convert_variable_location(), it just passed an incomplete variable field and then a segfault was occurred when formatting the field. This fixes that bug by handling success code correctly in convert_variable(). Other callers of convert_variable_location() are correctly checking the return code. This bug was introduced by following commit. But another hidden erroneous error handling has been there previously (-ENOMEM case). commit 3d918a12a1b3088ac16ff37fa52760639d6e2403 Signed-off-by: Masami Hiramatsu Reported-by: Arnaldo Carvalho de Melo Tested-by: Arnaldo Carvalho de Melo Cc: Peter Zijlstra Cc: Paul Mackerras Cc: Ingo Molnar Cc: Namhyung Kim Link: http://lkml.kernel.org/r/20140529105232.28251.30447.stgit@ltc230.yrl.intra.hitachi.co.jp Signed-off-by: Jiri Olsa --- tools/perf/util/probe-finder.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c index 562762117639..9d8eb26f0533 100644 --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -511,12 +511,12 @@ static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf) ret = convert_variable_location(vr_die, pf->addr, pf->fb_ops, &pf->sp_die, pf->tvar); - if (ret == -ENOENT) + if (ret == -ENOENT || ret == -EINVAL) pr_err("Failed to find the location of %s at this address.\n" " Perhaps, it has been optimized out.\n", pf->pvar->var); else if (ret == -ENOTSUP) pr_err("Sorry, we don't support this variable location yet.\n"); - else if (pf->pvar->field) { + else if (ret == 0 && pf->pvar->field) { ret = convert_variable_fields(vr_die, pf->pvar->var, pf->pvar->field, &pf->tvar->ref, &die_mem); -- GitLab