* [PATCH v2 2/2] tests: test CLONE3_CLEAR_SIGHAND
2019-10-11 10:25 [PATCH v2 1/2] clone3: add CLONE3_CLEAR_SIGHAND Christian Brauner
@ 2019-10-11 10:25 ` Christian Brauner
0 siblings, 0 replies; 2+ messages in thread
From: Christian Brauner @ 2019-10-11 10:25 UTC (permalink / raw)
To: linux-kernel, Oleg Nesterov, Florian Weimer, libc-alpha
Cc: Ingo Molnar, Peter Zijlstra, Juri Lelli, Vincent Guittot,
Dietmar Eggemann, Steven Rostedt, Ben Segall, Mel Gorman,
Shuah Khan, Andrew Morton, Michal Hocko, Elena Reshetova,
Thomas Gleixner, Roman Gushchin, Andrea Arcangeli, Al Viro,
Aleksa Sarai, Dmitry V. Levin, linux-kselftest,
Christian Brauner, linux-api
Test that CLONE3_CLEAR_SIGHAND resets signal handlers to SIG_DFL for the
child process and that CLONE3_CLEAR_SIGHAND and CLONE_SIGHAND are
mutually exclusive.
Cc: Florian Weimer <fweimer@redhat.com>
Cc: libc-alpha@sourceware.org
Cc: linux-api@vger.kernel.org
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
---
/* v1 */
Link: https://lore.kernel.org/r/20191010133518.5420-2-christian.brauner@ubuntu.com
/* v2 */
- Christian Brauner <christian.brauner@ubuntu.com>:
- remove unused variable
- reuse variable in child process instead od declaring a new one
- move check for mutual exclusivity of CLONE_SIGHAND and
CLONE3_CLEAR_SIGHAND to top of test before setting up signal
handlers
- rename variables
---
MAINTAINERS | 1 +
tools/testing/selftests/Makefile | 1 +
tools/testing/selftests/clone3/.gitignore | 1 +
tools/testing/selftests/clone3/Makefile | 7 +
.../selftests/clone3/clone3_clear_sighand.c | 172 ++++++++++++++++++
5 files changed, 182 insertions(+)
create mode 100644 tools/testing/selftests/clone3/.gitignore
create mode 100644 tools/testing/selftests/clone3/Makefile
create mode 100644 tools/testing/selftests/clone3/clone3_clear_sighand.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 55199ef7fa74..582275d85607 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12828,6 +12828,7 @@ S: Maintained
T: git git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux.git
F: samples/pidfd/
F: tools/testing/selftests/pidfd/
+F: tools/testing/selftests/clone3/
K: (?i)pidfd
K: (?i)clone3
K: \b(clone_args|kernel_clone_args)\b
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index c3feccb99ff5..6bf7aeb47650 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -4,6 +4,7 @@ TARGETS += bpf
TARGETS += breakpoints
TARGETS += capabilities
TARGETS += cgroup
+TARGETS += clone3
TARGETS += cpufreq
TARGETS += cpu-hotplug
TARGETS += drivers/dma-buf
diff --git a/tools/testing/selftests/clone3/.gitignore b/tools/testing/selftests/clone3/.gitignore
new file mode 100644
index 000000000000..6c9f98097774
--- /dev/null
+++ b/tools/testing/selftests/clone3/.gitignore
@@ -0,0 +1 @@
+clone3_clear_sighand
diff --git a/tools/testing/selftests/clone3/Makefile b/tools/testing/selftests/clone3/Makefile
new file mode 100644
index 000000000000..3ecd56ebc99d
--- /dev/null
+++ b/tools/testing/selftests/clone3/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0-only
+CFLAGS += -g -I../../../../usr/include/
+
+TEST_GEN_PROGS := clone3_clear_sighand
+
+include ../lib.mk
+
diff --git a/tools/testing/selftests/clone3/clone3_clear_sighand.c b/tools/testing/selftests/clone3/clone3_clear_sighand.c
new file mode 100644
index 000000000000..1a3adc206e74
--- /dev/null
+++ b/tools/testing/selftests/clone3/clone3_clear_sighand.c
@@ -0,0 +1,172 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <linux/sched.h>
+#include <linux/types.h>
+#include <sys/syscall.h>
+#include <sys/wait.h>
+
+#include "../kselftest.h"
+
+#ifndef CLONE3_CLEAR_SIGHAND
+#define CLONE3_CLEAR_SIGHAND 0x100000000ULL
+#endif
+
+#ifndef __NR_clone3
+#define __NR_clone3 -1
+struct clone_args {
+ __aligned_u64 flags;
+ __aligned_u64 pidfd;
+ __aligned_u64 child_tid;
+ __aligned_u64 parent_tid;
+ __aligned_u64 exit_signal;
+ __aligned_u64 stack;
+ __aligned_u64 stack_size;
+ __aligned_u64 tls;
+};
+#endif
+
+static pid_t sys_clone3(struct clone_args *args, size_t size)
+{
+ return syscall(__NR_clone3, args, size);
+}
+
+static void test_clone3_supported(void)
+{
+ pid_t pid;
+ struct clone_args args = {};
+
+ if (__NR_clone3 < 0)
+ ksft_exit_skip("clone3() syscall is not supported\n");
+
+ /* Set to something that will always cause EINVAL. */
+ args.exit_signal = -1;
+ pid = sys_clone3(&args, sizeof(args));
+ if (!pid)
+ exit(EXIT_SUCCESS);
+
+ if (pid > 0) {
+ wait(NULL);
+ ksft_exit_fail_msg(
+ "Managed to create child process with invalid exit_signal\n");
+ }
+
+ if (errno == ENOSYS)
+ ksft_exit_skip("clone3() syscall is not supported\n");
+
+ ksft_print_msg("clone3() syscall supported\n");
+}
+
+static void nop_handler(int signo)
+{
+}
+
+static int wait_for_pid(pid_t pid)
+{
+ int status, ret;
+
+again:
+ ret = waitpid(pid, &status, 0);
+ if (ret == -1) {
+ if (errno == EINTR)
+ goto again;
+
+ return -1;
+ }
+
+ if (!WIFEXITED(status))
+ return -1;
+
+ return WEXITSTATUS(status);
+}
+
+static void test_clone3_clear_sighand(void)
+{
+ int ret;
+ pid_t pid;
+ struct clone_args args = {};
+ struct sigaction act;
+
+ /*
+ * Check that CLONE3_CLEAR_SIGHAND and CLONE_SIGHAND are mutually
+ * exclusive.
+ */
+ args.flags |= CLONE3_CLEAR_SIGHAND | CLONE_SIGHAND;
+ args.exit_signal = SIGCHLD;
+ pid = sys_clone3(&args, sizeof(args));
+ if (pid > 0)
+ ksft_exit_fail_msg(
+ "clone3(CLONE3_CLEAR_SIGHAND | CLONE_SIGHAND) succeeded\n");
+
+ act.sa_handler = nop_handler;
+ ret = sigemptyset(&act.sa_mask);
+ if (ret < 0)
+ ksft_exit_fail_msg("%s - sigemptyset() failed\n",
+ strerror(errno));
+
+ act.sa_flags = 0;
+
+ /* Register signal handler for SIGUSR1 */
+ ret = sigaction(SIGUSR1, &act, NULL);
+ if (ret < 0)
+ ksft_exit_fail_msg(
+ "%s - sigaction(SIGUSR1, &act, NULL) failed\n",
+ strerror(errno));
+
+ /* Register signal handler for SIGUSR2 */
+ ret = sigaction(SIGUSR2, &act, NULL);
+ if (ret < 0)
+ ksft_exit_fail_msg(
+ "%s - sigaction(SIGUSR2, &act, NULL) failed\n",
+ strerror(errno));
+
+ /* Check that CLONE3_CLEAR_SIGHAND works. */
+ args.flags = CLONE3_CLEAR_SIGHAND;
+ pid = sys_clone3(&args, sizeof(args));
+ if (pid < 0)
+ ksft_exit_fail_msg("%s - clone3(CLONE3_CLEAR_SIGHAND) failed\n",
+ strerror(errno));
+
+ if (pid == 0) {
+ ret = sigaction(SIGUSR1, NULL, &act);
+ if (ret < 0)
+ exit(EXIT_FAILURE);
+
+ if (act.sa_handler != SIG_DFL)
+ exit(EXIT_FAILURE);
+
+ ret = sigaction(SIGUSR2, NULL, &act);
+ if (ret < 0)
+ exit(EXIT_FAILURE);
+
+ if (act.sa_handler != SIG_DFL)
+ exit(EXIT_FAILURE);
+
+ exit(EXIT_SUCCESS);
+ }
+
+ ret = wait_for_pid(pid);
+ if (ret)
+ ksft_exit_fail_msg(
+ "Failed to clear signal handler for child process\n");
+
+ ksft_test_result_pass("Cleared signal handlers for child process\n");
+}
+
+int main(int argc, char **argv)
+{
+ ksft_print_header();
+ ksft_set_plan(1);
+
+ test_clone3_supported();
+ test_clone3_clear_sighand();
+
+ return ksft_exit_pass();
+}
--
2.23.0
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