[PATCH v1 4/8] perf ftrace: Use sig_atomic_t to avoid UB

From: Ian Rogers
Date: Mon Oct 24 2022 - 14:57:57 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-ftrace.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 7de07bb16d23..d7fe00f66b83 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -36,8 +36,8 @@

#define DEFAULT_TRACER "function_graph"

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

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