Arnaldo, this fixes the SEGV bug which you reported. But I've found that perf probe sometimes loses the location of variables with recent DWARF implementation. I need to check and fix that too.
Anyway, this patch should be applied for fixing critical bug. Thank you, (2014/05/29 19:52), 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). > > commit 3d918a12a1b3088ac16ff37fa52760639d6e2403 > > Signed-off-by: Masami Hiramatsu <[email protected]> > Reported-by: Arnaldo Carvalho de Melo <[email protected]> > Cc: Peter Zijlstra <[email protected]> > Cc: Paul Mackerras <[email protected]> > Cc: Ingo Molnar <[email protected]> > Cc: Namhyung Kim <[email protected]> > Cc: Jiri Olsa <[email protected]> > --- > 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: [email protected] -- 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/
