Messages in this thread | | | Date | Fri, 30 May 2014 15:32:26 +0900 | From | Masami Hiramatsu <> | Subject | Re: [PATCH -tip/urgent ] [BUGFIX] perf/probe: Fix a segfault if asked for variable it doesn't find |
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(2014/05/30 15:03), Namhyung Kim wrote: > Hi Masami, > > On Thu, 29 May 2014 19:52:32 +0900, Masami Hiramatsu wrote: >> 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). > > And -ERANGE too.. :)
Right, Anyway, I've added ret==0 sanity check. That error should be handled too. :-)
Thank you,
> > Thanks, > Namhyung > >> >> 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); >
-- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Research Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com
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