From 78a175c4623f66722709494295a0f6754b46f858 Mon Sep 17 00:00:00 2001 From: James Clark Date: Fri, 30 Jun 2023 16:38:39 +0100 Subject: [PATCH] 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: 259dce914e93 ("perf symbol: Remove symbol_name_rb_node") Signed-off-by: James Clark Acked-by: Ian Rogers Cc: Mark Rutland Cc: Peter Zijlstra Cc: Adrian Hunter Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Alexander Shishkin Cc: Ingo Molnar Link: https://lore.kernel.org/r/20230630153840.858668-1-james.clark@arm.com Signed-off-by: Namhyung Kim --- tools/perf/util/symbol.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index bc79291b9f3b..f849f9ef68e6 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -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; }