diff options
Diffstat (limited to 'tools/testing/selftests/pidfd/pidfd_wait.c')
| -rw-r--r-- | tools/testing/selftests/pidfd/pidfd_wait.c | 224 |
1 files changed, 224 insertions, 0 deletions
diff --git a/tools/testing/selftests/pidfd/pidfd_wait.c b/tools/testing/selftests/pidfd/pidfd_wait.c new file mode 100644 index 000000000..17999e082 --- /dev/null +++ b/tools/testing/selftests/pidfd/pidfd_wait.c @@ -0,0 +1,224 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#define _GNU_SOURCE +#include <errno.h> +#include <linux/sched.h> +#include <linux/types.h> +#include <signal.h> +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <sched.h> +#include <string.h> +#include <sys/resource.h> +#include <sys/time.h> +#include <sys/types.h> +#include <sys/wait.h> +#include <unistd.h> + +#include "pidfd.h" +#include "../kselftest_harness.h" + +#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)); +} + +static int sys_waitid(int which, pid_t pid, siginfo_t *info, int options, + struct rusage *ru) +{ + return syscall(__NR_waitid, which, pid, info, options, ru); +} + +TEST(wait_simple) +{ + int pidfd = -1; + pid_t parent_tid = -1; + struct clone_args args = { + .parent_tid = ptr_to_u64(&parent_tid), + .pidfd = ptr_to_u64(&pidfd), + .flags = CLONE_PIDFD | CLONE_PARENT_SETTID, + .exit_signal = SIGCHLD, + }; + pid_t pid; + siginfo_t info = { + .si_signo = 0, + }; + + pidfd = open("/proc/self", O_DIRECTORY | O_RDONLY | O_CLOEXEC); + ASSERT_GE(pidfd, 0); + + pid = sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL); + ASSERT_NE(pid, 0); + EXPECT_EQ(close(pidfd), 0); + pidfd = -1; + + pidfd = open("/dev/null", O_RDONLY | O_CLOEXEC); + ASSERT_GE(pidfd, 0); + + pid = sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL); + ASSERT_NE(pid, 0); + EXPECT_EQ(close(pidfd), 0); + pidfd = -1; + + pid = sys_clone3(&args); + ASSERT_GE(pid, 0); + + if (pid == 0) + exit(EXIT_SUCCESS); + + pid = sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL); + ASSERT_GE(pid, 0); + ASSERT_EQ(WIFEXITED(info.si_status), true); + ASSERT_EQ(WEXITSTATUS(info.si_status), 0); + EXPECT_EQ(close(pidfd), 0); + + ASSERT_EQ(info.si_signo, SIGCHLD); + ASSERT_EQ(info.si_code, CLD_EXITED); + ASSERT_EQ(info.si_pid, parent_tid); +} + +TEST(wait_states) +{ + int pidfd = -1; + pid_t parent_tid = -1; + struct clone_args args = { + .parent_tid = ptr_to_u64(&parent_tid), + .pidfd = ptr_to_u64(&pidfd), + .flags = CLONE_PIDFD | CLONE_PARENT_SETTID, + .exit_signal = SIGCHLD, + }; + int ret; + pid_t pid; + siginfo_t info = { + .si_signo = 0, + }; + + pid = sys_clone3(&args); + ASSERT_GE(pid, 0); + + if (pid == 0) { + kill(getpid(), SIGSTOP); + kill(getpid(), SIGSTOP); + exit(EXIT_SUCCESS); + } + + 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(sys_waitid(P_PIDFD, pidfd, &info, WCONTINUED, NULL), 0); + ASSERT_EQ(info.si_signo, SIGCHLD); + ASSERT_EQ(info.si_code, CLD_CONTINUED); + ASSERT_EQ(info.si_pid, parent_tid); + + ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WUNTRACED, 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, SIGKILL, NULL, 0), 0); + + ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL), 0); + ASSERT_EQ(info.si_signo, SIGCHLD); + ASSERT_EQ(info.si_code, CLD_KILLED); + ASSERT_EQ(info.si_pid, parent_tid); + + 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(fcntl(pidfd, F_SETFL, (flags & ~O_NONBLOCK)), 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(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 |