Commit 0c188a07 authored May 29, 2014 by Masami Hiramatsu Committed by Jiri Olsa Jun 04, 2014

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 3d918a12

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Tested-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>
Link: http://lkml.kernel.org/r/20140529105232.28251.30447.stgit@ltc230.yrl.intra.hitachi.co.jp


Signed-off-by: Jiri Olsa <jolsa@kernel.org>

parent b69cf536

tools/perf/util/probe-finder.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -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);