From: Arnaldo Carvalho de Melo acme@redhat.com
commit ebcb9464a2ae3a547e97de476575c82ece0e93e2 upstream.
It is possible to return a pointer to a local variable when looking up the architecture name for the running system and no normalization is done on that value, i.e. we may end up returning the uts.machine local variable.
While this doesn't happen on most arches, as normalization takes place, lets fix this by making that a static variable and optimize it a bit by not always running uname(), only the first time.
Noticed in fedora rawhide running with:
[perfbuilder@a5ff49d6e6e4 ~]$ gcc --version gcc (GCC) 10.0.1 20200216 (Red Hat 10.0.1-0.8)
Reported-by: Jiri Olsa jolsa@kernel.org Cc: Adrian Hunter adrian.hunter@intel.com Cc: Namhyung Kim namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Cc: Ben Hutchings ben@decadent.org.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- tools/perf/util/env.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/tools/perf/util/env.c +++ b/tools/perf/util/env.c @@ -326,11 +326,11 @@ static const char *normalize_arch(char *
const char *perf_env__arch(struct perf_env *env) { - struct utsname uts; char *arch_name;
if (!env || !env->arch) { /* Assume local operation */ - if (uname(&uts) < 0) + static struct utsname uts = { .machine[0] = '\0', }; + if (uts.machine[0] == '\0' && uname(&uts) < 0) return NULL; arch_name = uts.machine; } else