[PATCH v1 2/8] perf record: Use sig_atomic_t for signal handlers

From: Ian Rogers
Date: Mon Oct 24 2022 - 15:06:10 EST


This removes undefined behavior as described in:
https://wiki.sei.cmu.edu/confluence/display/c/SIG31-C.+Do+not+access+shared+objects+in+signal+handlers

Suggested-by: Leo Yan <leo.yan@xxxxxxxxxx>
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/perf/builtin-record.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index e128b855ddde..5332b9c05f28 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -61,6 +61,7 @@
#include <locale.h>
#include <poll.h>
#include <pthread.h>
+#include <stdatomic.h>
#include <unistd.h>
#ifndef HAVE_GETTID
#include <syscall.h>
@@ -646,10 +647,10 @@ static int record__pushfn(struct mmap *map, void *to, void *bf, size_t size)
return record__write(rec, map, bf, size);
}

-static volatile int signr = -1;
-static volatile int child_finished;
+static volatile sig_atomic_t signr = -1;
+static volatile sig_atomic_t child_finished;
#ifdef HAVE_EVENTFD_SUPPORT
-static volatile int done_fd = -1;
+static volatile sig_atomic_t done_fd = -1;
#endif

static void sig_handler(int sig)
@@ -1926,7 +1927,7 @@ static void record__read_lost_samples(struct record *rec)

}

-static volatile int workload_exec_errno;
+static volatile sig_atomic_t workload_exec_errno;

/*
* evlist__prepare_workload will send a SIGUSR1
--
2.38.0.135.g90850a2211-goog