Commit 78a175c4 authored by James Clark's avatar James Clark Committed by Namhyung Kim
Browse files

perf symbol: Fix uninitialized return value in symbols__find_by_name() 



found_idx and s aren't initialized, so if no symbol is found then the
assert at the end will index off the end of the array causing a
segfault. The function also doesn't return NULL when the symbol isn't
found even if the assert passes. Fix it by initializing the values and
only setting them when something is found.

Fixes the following test failure:

  $ perf test 1
  1: vmlinux symtab matches kallsyms     : FAILED!

Fixes: 259dce91 ("perf symbol: Remove symbol_name_rb_node")
Signed-off-by: default avatarJames Clark <james.clark@arm.com>
Acked-by: default avatarIan Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Link: https://lore.kernel.org/r/20230630153840.858668-1-james.clark@arm.com


Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
parent 2aefb4cc

tools/perf/util/symbol.c

+9 −7
Original line number Diff line number Diff line
@@ -495,7 +495,10 @@ static struct symbol *symbols__find_by_name(struct symbol *symbols[], 
					    size_t *found_idx)

{

	size_t i, lower = 0, upper = symbols_len;

	struct symbol *s;

	struct symbol *s = NULL;



	if (found_idx)

		*found_idx = SIZE_MAX;



	if (!symbols_len)

		return NULL;
@@ -504,8 +507,7 @@ static struct symbol *symbols__find_by_name(struct symbol *symbols[], 
		int cmp;



		i = (lower + upper) / 2;

		s = symbols[i];

		cmp = symbol__match_symbol_name(s->name, name, includes);

		cmp = symbol__match_symbol_name(symbols[i]->name, name, includes);



		if (cmp > 0)

			upper = i;
@@ -514,10 +516,11 @@ static struct symbol *symbols__find_by_name(struct symbol *symbols[], 
		else {

			if (found_idx)

				*found_idx = i;

			s = symbols[i];

			break;

		}

	}

	if (includes != SYMBOL_TAG_INCLUDE__DEFAULT_ONLY) {

	if (s && includes != SYMBOL_TAG_INCLUDE__DEFAULT_ONLY) {

		/* return first symbol that has same name (if any) */

		for (; i > 0; i--) {

			struct symbol *tmp = symbols[i - 1];
@@ -525,13 +528,12 @@ static struct symbol *symbols__find_by_name(struct symbol *symbols[], 
			if (!arch__compare_symbol_names(tmp->name, s->name)) {

				if (found_idx)

					*found_idx = i - 1;

				s = tmp;

			} else

				break;



			s = tmp;

		}

	}

	assert(!found_idx || s == symbols[*found_idx]);

	assert(!found_idx || !s || s == symbols[*found_idx]);

	return s;

}