From 9ec45f857a01b761756eb1687b3b057ad83371a6 Mon Sep 17 00:00:00 2001 From: James Clark Date: Tue, 7 May 2024 15:12:08 +0100 Subject: perf symbols: Fix ownership of string in dso__load_vmlinux() [ Upstream commit 25626e19ae6df34f336f235b6b3dbd1b566d2738 ] The linked commit updated dso__load_vmlinux() to call dso__set_long_name() before loading the symbols. Loading the symbols may not succeed but dso__set_long_name() takes ownership of the string. The two callers of this function free the string themselves on failure cases, resulting in the following error: $ perf record -- ls $ perf report free(): double free detected in tcache 2 Fix it by always taking ownership of the string, even on failure. This means the string is either freed at the very first early exit condition, or later when the dso is deleted or the long name is replaced. Now no special return value is needed to signify that the caller needs to free the string. Fixes: e59fea47f83e8a9a ("perf symbols: Fix DSO kernel load and symbol process to correctly map DSO to its long_name, type and adjust_symbols") Reviewed-by: Ian Rogers Signed-off-by: James Clark Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Athira Rajeev Cc: Ingo Molnar Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20240507141210.195939-5-james.clark@arm.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin --- tools/perf/util/symbol.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'tools/perf') diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index 1976af974a37..ea24f21aafc3 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -1935,6 +1935,10 @@ out: return ret; } +/* + * Always takes ownership of vmlinux when vmlinux_allocated == true, even if + * it returns an error. + */ int dso__load_vmlinux(struct dso *dso, struct map *map, const char *vmlinux, bool vmlinux_allocated) { @@ -1953,8 +1957,11 @@ int dso__load_vmlinux(struct dso *dso, struct map *map, else symtab_type = DSO_BINARY_TYPE__VMLINUX; - if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type)) + if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type)) { + if (vmlinux_allocated) + free((char *) vmlinux); return -1; + } /* * dso__load_sym() may copy 'dso' which will result in the copies having @@ -1997,7 +2004,6 @@ int dso__load_vmlinux_path(struct dso *dso, struct map *map) err = dso__load_vmlinux(dso, map, filename, true); if (err > 0) goto out; - free(filename); } out: return err; @@ -2149,7 +2155,6 @@ static int dso__load_kernel_sym(struct dso *dso, struct map *map) err = dso__load_vmlinux(dso, map, filename, true); if (err > 0) return err; - free(filename); } if (!symbol_conf.ignore_vmlinux && vmlinux_path != NULL) { -- cgit v1.2.3