[PATCH v2 6/8] perf test: Add a signal handler around running a test

From: Ian Rogers
Date: Fri Oct 11 2024 - 18:05:33 EST


Add a signal handler around running a test. If a signal occurs during
the test a siglongjmp unwinds the stack and output is flushed. The
global run_test_jmp_buf is either unique per forked child or not
shared during sequential execution.

Tested-by: James Clark <james.clark@xxxxxxxxxx>
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/perf/tests/builtin-test.c | 28 +++++++++++++++++++++++++++-
1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
index 88ffc0feb51e..eca2e765beb5 100644
--- a/tools/perf/tests/builtin-test.c
+++ b/tools/perf/tests/builtin-test.c
@@ -8,6 +8,7 @@
#include <errno.h>
#include <poll.h>
#include <unistd.h>
+#include <setjmp.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
@@ -226,16 +227,41 @@ struct child_test {
int subtest;
};

+static jmp_buf run_test_jmp_buf;
+
+static void child_test_sig_handler(int sig)
+{
+ siglongjmp(run_test_jmp_buf, sig);
+}
+
static int run_test_child(struct child_process *process)
{
- struct child_test *child = container_of(process, struct child_test, process);
+ const int signals[] = {
+ SIGABRT, SIGBUS, SIGFPE, SIGILL, SIGINT, SIGPIPE, SIGQUIT, SIGSEGV, SIGTERM,
+ };
+ static struct child_test *child;
int err;

+ err = sigsetjmp(run_test_jmp_buf, 1);
+ if (err) {
+ fprintf(stderr, "\n---- unexpected signal (%d) ----\n", err);
+ err = err > 0 ? -err : -1;
+ goto err_out;
+ }
+
+ child = container_of(process, struct child_test, process);
+ for (size_t i = 0; i < ARRAY_SIZE(signals); i++)
+ signal(signals[i], child_test_sig_handler);
+
pr_debug("--- start ---\n");
pr_debug("test child forked, pid %d\n", getpid());
err = test_function(child->test, child->subtest)(child->test, child->subtest);
pr_debug("---- end(%d) ----\n", err);
+
+err_out:
fflush(NULL);
+ for (size_t i = 0; i < ARRAY_SIZE(signals); i++)
+ signal(signals[i], SIG_DFL);
return -err;
}

--
2.47.0.rc1.288.g06298d1525-goog