[PATCH v1 3/8] perf daemon: Use sig_atomic_t to avoid UB

From: Ian Rogers
Date: Mon Oct 24 2022 - 14:57:48 EST


Use sig_atomic_t for a variable written to in a signal handler and
read elsewhere. This is undefined behavior as per:
https://wiki.sei.cmu.edu/confluence/display/c/SIG31-C.+Do+not+access+shared+objects+in+signal+handlers

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/perf/builtin-daemon.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/perf/builtin-daemon.c b/tools/perf/builtin-daemon.c
index 6cb3f6cc36d0..d05084952c09 100644
--- a/tools/perf/builtin-daemon.c
+++ b/tools/perf/builtin-daemon.c
@@ -9,6 +9,7 @@
#include <string.h>
#include <sys/file.h>
#include <signal.h>
+#include <stdatomic.h>
#include <stdlib.h>
#include <time.h>
#include <stdio.h>
@@ -105,7 +106,7 @@ static const char * const daemon_usage[] = {
NULL
};

-static bool done;
+static volatile sig_atomic_t done;

static void sig_handler(int sig __maybe_unused)
{
--
2.38.0.135.g90850a2211-goog