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authorChristian Brauner <christian.brauner@ubuntu.com>2020-09-02 12:21:30 +0200
committerChristian Brauner <christian.brauner@ubuntu.com>2020-09-04 13:48:57 +0200
commitcd89597bbe5a0179b3f0f51604cb36a1ffd4e080 (patch)
treef9b20216145fa8b214c9198510d558f97709bf07
parent09d1de1a8e7b9fbf08e96e0aecf41f870e4433ee (diff)
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tests: add waitid() tests for non-blocking pidfds
Verify that the PIDFD_NONBLOCK flag works with pidfd_open() and that waitid() with a non-blocking pidfd returns EAGAIN: TAP version 13 1..3 # Starting 3 tests from 1 test cases. # RUN global.wait_simple ... # OK global.wait_simple ok 1 global.wait_simple # RUN global.wait_states ... # OK global.wait_states ok 2 global.wait_states # RUN global.wait_nonblock ... # OK global.wait_nonblock ok 3 global.wait_nonblock # PASSED: 3 / 3 tests passed. # Totals: pass:3 fail:0 xfail:0 xpass:0 skip:0 error:0 Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Cc: Shuah Khan <shuah@kernel.org> Cc: linux-kselftest@vger.kernel.org Link: https://lore.kernel.org/r/20200902102130.147672-5-christian.brauner@ubuntu.com
-rw-r--r--tools/testing/selftests/pidfd/pidfd.h4
-rw-r--r--tools/testing/selftests/pidfd/pidfd_wait.c91
2 files changed, 94 insertions, 1 deletions
diff --git a/tools/testing/selftests/pidfd/pidfd.h b/tools/testing/selftests/pidfd/pidfd.h
index a2c80914e3dc..01f8d3c0cf2c 100644
--- a/tools/testing/selftests/pidfd/pidfd.h
+++ b/tools/testing/selftests/pidfd/pidfd.h
@@ -46,6 +46,10 @@
#define __NR_pidfd_getfd -1
#endif
+#ifndef PIDFD_NONBLOCK
+#define PIDFD_NONBLOCK O_NONBLOCK
+#endif
+
/*
* The kernel reserves 300 pids via RESERVED_PIDS in kernel/pid.c
* That means, when it wraps around any pid < 300 will be skipped.
diff --git a/tools/testing/selftests/pidfd/pidfd_wait.c b/tools/testing/selftests/pidfd/pidfd_wait.c
index 075c716f6fb8..4063d6f31fa4 100644
--- a/tools/testing/selftests/pidfd/pidfd_wait.c
+++ b/tools/testing/selftests/pidfd/pidfd_wait.c
@@ -21,6 +21,11 @@
#define ptr_to_u64(ptr) ((__u64)((uintptr_t)(ptr)))
+/* Attempt to de-conflict with the selftests tree. */
+#ifndef SKIP
+#define SKIP(s, ...) XFAIL(s, ##__VA_ARGS__)
+#endif
+
static pid_t sys_clone3(struct clone_args *args)
{
return syscall(__NR_clone3, args, sizeof(struct clone_args));
@@ -65,7 +70,7 @@ TEST(wait_simple)
pidfd = -1;
pid = sys_clone3(&args);
- ASSERT_GE(pid, 1);
+ ASSERT_GE(pid, 0);
if (pid == 0)
exit(EXIT_SUCCESS);
@@ -133,4 +138,88 @@ TEST(wait_states)
EXPECT_EQ(close(pidfd), 0);
}
+TEST(wait_nonblock)
+{
+ int pidfd, status = 0;
+ unsigned int flags = 0;
+ pid_t parent_tid = -1;
+ struct clone_args args = {
+ .parent_tid = ptr_to_u64(&parent_tid),
+ .flags = CLONE_PARENT_SETTID,
+ .exit_signal = SIGCHLD,
+ };
+ int ret;
+ pid_t pid;
+ siginfo_t info = {
+ .si_signo = 0,
+ };
+
+ /*
+ * Callers need to see ECHILD with non-blocking pidfds when no child
+ * processes exists.
+ */
+ pidfd = sys_pidfd_open(getpid(), PIDFD_NONBLOCK);
+ EXPECT_GE(pidfd, 0) {
+ /* pidfd_open() doesn't support PIDFD_NONBLOCK. */
+ ASSERT_EQ(errno, EINVAL);
+ SKIP(return, "Skipping PIDFD_NONBLOCK test");
+ }
+
+ ret = sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL);
+ ASSERT_LT(ret, 0);
+ ASSERT_EQ(errno, ECHILD);
+ EXPECT_EQ(close(pidfd), 0);
+
+ pid = sys_clone3(&args);
+ ASSERT_GE(pid, 0);
+
+ if (pid == 0) {
+ kill(getpid(), SIGSTOP);
+ exit(EXIT_SUCCESS);
+ }
+
+ pidfd = sys_pidfd_open(pid, PIDFD_NONBLOCK);
+ EXPECT_GE(pidfd, 0) {
+ /* pidfd_open() doesn't support PIDFD_NONBLOCK. */
+ ASSERT_EQ(errno, EINVAL);
+ SKIP(return, "Skipping PIDFD_NONBLOCK test");
+ }
+
+ flags = fcntl(pidfd, F_GETFL, 0);
+ ASSERT_GT(flags, 0);
+ ASSERT_GT((flags & O_NONBLOCK), 0);
+
+ /*
+ * Callers need to see EAGAIN/EWOULDBLOCK with non-blocking pidfd when
+ * child processes exist but none have exited.
+ */
+ ret = sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL);
+ ASSERT_LT(ret, 0);
+ ASSERT_EQ(errno, EAGAIN);
+
+ /*
+ * Callers need to continue seeing 0 with non-blocking pidfd and
+ * WNOHANG raised explicitly when child processes exist but none have
+ * exited.
+ */
+ ret = sys_waitid(P_PIDFD, pidfd, &info, WEXITED | WNOHANG, NULL);
+ ASSERT_EQ(ret, 0);
+
+ ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WSTOPPED, NULL), 0);
+ ASSERT_EQ(info.si_signo, SIGCHLD);
+ ASSERT_EQ(info.si_code, CLD_STOPPED);
+ ASSERT_EQ(info.si_pid, parent_tid);
+
+ ASSERT_EQ(sys_pidfd_send_signal(pidfd, SIGCONT, NULL, 0), 0);
+
+ ASSERT_EQ(fcntl(pidfd, F_SETFL, (flags & ~O_NONBLOCK)), 0);
+
+ ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL), 0);
+ ASSERT_EQ(info.si_signo, SIGCHLD);
+ ASSERT_EQ(info.si_code, CLD_EXITED);
+ ASSERT_EQ(info.si_pid, parent_tid);
+
+ EXPECT_EQ(close(pidfd), 0);
+}
+
TEST_HARNESS_MAIN