From 33941dbd14da4eac40a26ac5fd5f84e1842ffc3a Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Thu, 22 Jun 2023 21:31:07 -0700 Subject: [PATCH] perf unwind: Fix map reference counts The result of thread__find_map is the map in the passed in addr_location. Calling addr_location__exit puts that map and so copies need to do a map__get. Add in the corresponding map__puts. v2. Add missing map__put when dso is missing. Signed-off-by: Ian Rogers Acked-by: Namhyung Kim Cc: Mark Rutland Cc: Ivan Babrou 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/20230623043107.4077510-1-irogers@google.com Signed-off-by: Namhyung Kim --- tools/perf/util/unwind-libunwind-local.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/tools/perf/util/unwind-libunwind-local.c b/tools/perf/util/unwind-libunwind-local.c index 36bf5100bad2..ebfde537b99b 100644 --- a/tools/perf/util/unwind-libunwind-local.c +++ b/tools/perf/util/unwind-libunwind-local.c @@ -419,7 +419,8 @@ static struct map *find_map(unw_word_t ip, struct unwind_info *ui) struct map *ret; addr_location__init(&al); - ret = thread__find_map(ui->thread, PERF_RECORD_MISC_USER, ip, &al); + thread__find_map(ui->thread, PERF_RECORD_MISC_USER, ip, &al); + ret = map__get(al.map); addr_location__exit(&al); return ret; } @@ -440,8 +441,10 @@ find_proc_info(unw_addr_space_t as, unw_word_t ip, unw_proc_info_t *pi, return -EINVAL; dso = map__dso(map); - if (!dso) + if (!dso) { + map__put(map); return -EINVAL; + } pr_debug("unwind: find_proc_info dso %s\n", dso->name); @@ -476,11 +479,11 @@ find_proc_info(unw_addr_space_t as, unw_word_t ip, unw_proc_info_t *pi, memset(&di, 0, sizeof(di)); if (dwarf_find_debug_frame(0, &di, ip, base, symfile, start, map__end(map))) - return dwarf_search_unwind_table(as, ip, &di, pi, - need_unwind_info, arg); + ret = dwarf_search_unwind_table(as, ip, &di, pi, + need_unwind_info, arg); } #endif - + map__put(map); return ret; } @@ -534,12 +537,14 @@ static int access_dso_mem(struct unwind_info *ui, unw_word_t addr, dso = map__dso(map); - if (!dso) + if (!dso) { + map__put(map); return -1; + } size = dso__data_read_addr(dso, map, ui->machine, addr, (u8 *) data, sizeof(*data)); - + map__put(map); return !(size == sizeof(*data)); }