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/* 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 pfd[2];
pid_t pid;
siginfo_t info = {
.si_signo = 0,
};
ASSERT_EQ(pipe(pfd), 0);
pid = sys_clone3(&args);
ASSERT_GE(pid, 0);
if (pid == 0) {
char buf[2];
close(pfd[1]);
kill(getpid(), SIGSTOP);
ASSERT_EQ(read(pfd[0], buf, 1), 1);
close(pfd[0]);
kill(getpid(), SIGSTOP);
exit(EXIT_SUCCESS);
}
close(pfd[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, WCONTINUED, NULL), 0);
ASSERT_EQ(write(pfd[1], "C", 1), 1);
close(pfd[1]);
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;
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
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