6.6-stable review patch. If anyone has any objections, please let me know.
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From: James Clark james.clark@arm.com
[ 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 irogers@google.com Signed-off-by: James Clark james.clark@arm.com Cc: Adrian Hunter adrian.hunter@intel.com Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: Athira Rajeev atrajeev@linux.vnet.ibm.com Cc: Ingo Molnar mingo@redhat.com Cc: Jiri Olsa jolsa@kernel.org Cc: Mark Rutland mark.rutland@arm.com Cc: Namhyung Kim namhyung@kernel.org Cc: Peter Zijlstra peterz@infradead.org Link: https://lore.kernel.org/r/20240507141210.195939-5-james.clark@arm.com Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/perf/util/symbol.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index 1976af974a371..ea24f21aafc3e 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -1935,6 +1935,10 @@ int dso__load(struct dso *dso, struct map *map) 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) {