Messages in this thread Patch in this message | | | Subject | [PATCH -tip/urgent ] [BUGFIX] perf/probe: Fix a segfault if asked for variable it doesn't find | From | Masami Hiramatsu <> | Date | Thu, 29 May 2014 19:52:32 +0900 |
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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 occured 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 previuosly (-ENOMEM case).
commit 3d918a12a1b3088ac16ff37fa52760639d6e2403
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> --- 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 5627621..9d8eb26 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);
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