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@google.com>
---
 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