diff --git a/include/linux/pid.h b/include/linux/pid.h index 2a83e434db9d..9645b1194c98 100644 --- a/include/linux/pid.h +++ b/include/linux/pid.h @@ -72,6 +72,10 @@ extern struct pid init_struct_pid; extern const struct file_operations pidfd_fops; +struct file; + +extern struct pid *pidfd_pid(const struct file *file); + static inline struct pid *get_pid(struct pid *pid) { if (pid) diff --git a/include/uapi/linux/wait.h b/include/uapi/linux/wait.h index ac49a220cf2a..85b809fc9f11 100644 --- a/include/uapi/linux/wait.h +++ b/include/uapi/linux/wait.h @@ -17,6 +17,7 @@ #define P_ALL 0 #define P_PID 1 #define P_PGID 2 +#define P_PIDFD 3 #endif /* _UAPI_LINUX_WAIT_H */ diff --git a/kernel/exit.c b/kernel/exit.c index 5b4a5dcce8f8..22ab6a4bdc51 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -1554,6 +1554,23 @@ end: return retval; } +static struct pid *pidfd_get_pid(unsigned int fd) +{ + struct fd f; + struct pid *pid; + + f = fdget(fd); + if (!f.file) + return ERR_PTR(-EBADF); + + pid = pidfd_pid(f.file); + if (!IS_ERR(pid)) + get_pid(pid); + + fdput(f); + return pid; +} + static long kernel_waitid(int which, pid_t upid, struct waitid_info *infop, int options, struct rusage *ru) { @@ -1576,19 +1593,32 @@ static long kernel_waitid(int which, pid_t upid, struct waitid_info *infop, type = PIDTYPE_PID; if (upid <= 0) return -EINVAL; + + pid = find_get_pid(upid); break; case P_PGID: type = PIDTYPE_PGID; - if (upid <= 0) + if (upid < 0) return -EINVAL; + + if (upid) + pid = find_get_pid(upid); + else + pid = get_task_pid(current, PIDTYPE_PGID); + break; + case P_PIDFD: + type = PIDTYPE_PID; + if (upid < 0) + return -EINVAL; + + pid = pidfd_get_pid(upid); + if (IS_ERR(pid)) + return PTR_ERR(pid); break; default: return -EINVAL; } - if (type < PIDTYPE_MAX) - pid = find_get_pid(upid); - wo.wo_type = type; wo.wo_pid = pid; wo.wo_flags = options; diff --git a/kernel/fork.c b/kernel/fork.c index 541fd805fb88..0ad65a932936 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1690,6 +1690,14 @@ static inline void rcu_copy_process(struct task_struct *p) #endif /* #ifdef CONFIG_TASKS_RCU */ } +struct pid *pidfd_pid(const struct file *file) +{ + if (file->f_op == &pidfd_fops) + return file->private_data; + + return ERR_PTR(-EBADF); +} + static int pidfd_release(struct inode *inode, struct file *file) { struct pid *pid = file->private_data; diff --git a/kernel/signal.c b/kernel/signal.c index 534fec266a33..c4da1ef56fdf 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -3678,8 +3678,11 @@ static int copy_siginfo_from_user_any(kernel_siginfo_t *kinfo, siginfo_t *info) static struct pid *pidfd_to_pid(const struct file *file) { - if (file->f_op == &pidfd_fops) - return file->private_data; + struct pid *pid; + + pid = pidfd_pid(file); + if (!IS_ERR(pid)) + return pid; return tgid_pidfd_to_pid(file); } diff --git a/tools/testing/selftests/pidfd/.gitignore b/tools/testing/selftests/pidfd/.gitignore index 16d84d117bc0..8d069490e17b 100644 --- a/tools/testing/selftests/pidfd/.gitignore +++ b/tools/testing/selftests/pidfd/.gitignore @@ -1,2 +1,4 @@ pidfd_open_test +pidfd_poll_test pidfd_test +pidfd_wait diff --git a/tools/testing/selftests/pidfd/Makefile b/tools/testing/selftests/pidfd/Makefile index 720b2d884b3c..464c9b76148f 100644 --- a/tools/testing/selftests/pidfd/Makefile +++ b/tools/testing/selftests/pidfd/Makefile @@ -1,7 +1,7 @@ # SPDX-License-Identifier: GPL-2.0-only CFLAGS += -g -I../../../../usr/include/ -lpthread -TEST_GEN_PROGS := pidfd_test pidfd_open_test +TEST_GEN_PROGS := pidfd_test pidfd_open_test pidfd_poll_test pidfd_wait include ../lib.mk diff --git a/tools/testing/selftests/pidfd/pidfd.h b/tools/testing/selftests/pidfd/pidfd.h index 8452e910463f..c6bc68329f4b 100644 --- a/tools/testing/selftests/pidfd/pidfd.h +++ b/tools/testing/selftests/pidfd/pidfd.h @@ -16,6 +16,26 @@ #include "../kselftest.h" +#ifndef P_PIDFD +#define P_PIDFD 3 +#endif + +#ifndef CLONE_PIDFD +#define CLONE_PIDFD 0x00001000 +#endif + +#ifndef __NR_pidfd_open +#define __NR_pidfd_open -1 +#endif + +#ifndef __NR_pidfd_send_signal +#define __NR_pidfd_send_signal -1 +#endif + +#ifndef __NR_clone3 +#define __NR_clone3 -1 +#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. @@ -53,5 +73,15 @@ again: return WEXITSTATUS(status); } +static inline int sys_pidfd_open(pid_t pid, unsigned int flags) +{ + return syscall(__NR_pidfd_open, pid, flags); +} + +static inline int sys_pidfd_send_signal(int pidfd, int sig, siginfo_t *info, + unsigned int flags) +{ + return syscall(__NR_pidfd_send_signal, pidfd, sig, info, flags); +} #endif /* __PIDFD_H */ diff --git a/tools/testing/selftests/pidfd/pidfd_open_test.c b/tools/testing/selftests/pidfd/pidfd_open_test.c index 0377133dd6dc..b9fe75fc3e51 100644 --- a/tools/testing/selftests/pidfd/pidfd_open_test.c +++ b/tools/testing/selftests/pidfd/pidfd_open_test.c @@ -22,11 +22,6 @@ #include "pidfd.h" #include "../kselftest.h" -static inline int sys_pidfd_open(pid_t pid, unsigned int flags) -{ - return syscall(__NR_pidfd_open, pid, flags); -} - static int safe_int(const char *numstr, int *converted) { char *err = NULL; diff --git a/tools/testing/selftests/pidfd/pidfd_poll_test.c b/tools/testing/selftests/pidfd/pidfd_poll_test.c new file mode 100644 index 000000000000..4b115444dfe9 --- /dev/null +++ b/tools/testing/selftests/pidfd/pidfd_poll_test.c @@ -0,0 +1,117 @@ +// SPDX-License-Identifier: GPL-2.0 + +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "pidfd.h" +#include "../kselftest.h" + +static bool timeout; + +static void handle_alarm(int sig) +{ + timeout = true; +} + +int main(int argc, char **argv) +{ + struct pollfd fds; + int iter, nevents; + int nr_iterations = 10000; + + fds.events = POLLIN; + + if (argc > 2) + ksft_exit_fail_msg("Unexpected command line argument\n"); + + if (argc == 2) { + nr_iterations = atoi(argv[1]); + if (nr_iterations <= 0) + ksft_exit_fail_msg("invalid input parameter %s\n", + argv[1]); + } + + ksft_print_msg("running pidfd poll test for %d iterations\n", + nr_iterations); + + for (iter = 0; iter < nr_iterations; iter++) { + int pidfd; + int child_pid = fork(); + + if (child_pid < 0) { + if (errno == EAGAIN) { + iter--; + continue; + } + ksft_exit_fail_msg( + "%s - failed to fork a child process\n", + strerror(errno)); + } + + if (child_pid == 0) { + /* Child process just sleeps for a min and exits */ + sleep(60); + exit(EXIT_SUCCESS); + } + + /* Parent kills the child and waits for its death */ + pidfd = sys_pidfd_open(child_pid, 0); + if (pidfd < 0) + ksft_exit_fail_msg("%s - pidfd_open failed\n", + strerror(errno)); + + /* Setup 3 sec alarm - plenty of time */ + if (signal(SIGALRM, handle_alarm) == SIG_ERR) + ksft_exit_fail_msg("%s - signal failed\n", + strerror(errno)); + alarm(3); + + /* Send SIGKILL to the child */ + if (sys_pidfd_send_signal(pidfd, SIGKILL, NULL, 0)) + ksft_exit_fail_msg("%s - pidfd_send_signal failed\n", + strerror(errno)); + + /* Wait for the death notification */ + fds.fd = pidfd; + nevents = poll(&fds, 1, -1); + + /* Check for error conditions */ + if (nevents < 0) + ksft_exit_fail_msg("%s - poll failed\n", + strerror(errno)); + + if (nevents != 1) + ksft_exit_fail_msg("unexpected poll result: %d\n", + nevents); + + if (!(fds.revents & POLLIN)) + ksft_exit_fail_msg( + "unexpected event type received: 0x%x\n", + fds.revents); + + if (timeout) + ksft_exit_fail_msg( + "death notification wait timeout\n"); + + close(pidfd); + /* Wait for child to prevent zombies */ + if (waitpid(child_pid, NULL, 0) < 0) + ksft_exit_fail_msg("%s - waitpid failed\n", + strerror(errno)); + + } + + ksft_test_result_pass("pidfd poll test: pass\n"); + return ksft_exit_pass(); +} diff --git a/tools/testing/selftests/pidfd/pidfd_test.c b/tools/testing/selftests/pidfd/pidfd_test.c index b632965e60eb..7aff2d3b42c0 100644 --- a/tools/testing/selftests/pidfd/pidfd_test.c +++ b/tools/testing/selftests/pidfd/pidfd_test.c @@ -21,20 +21,12 @@ #include "pidfd.h" #include "../kselftest.h" -#ifndef __NR_pidfd_send_signal -#define __NR_pidfd_send_signal -1 -#endif - #define str(s) _str(s) #define _str(s) #s #define CHILD_THREAD_MIN_WAIT 3 /* seconds */ #define MAX_EVENTS 5 -#ifndef CLONE_PIDFD -#define CLONE_PIDFD 0x00001000 -#endif - static pid_t pidfd_clone(int flags, int *pidfd, int (*fn)(void *)) { size_t stack_size = 1024; @@ -47,12 +39,6 @@ static pid_t pidfd_clone(int flags, int *pidfd, int (*fn)(void *)) #endif } -static inline int sys_pidfd_send_signal(int pidfd, int sig, siginfo_t *info, - unsigned int flags) -{ - return syscall(__NR_pidfd_send_signal, pidfd, sig, info, flags); -} - static int signal_received; static void set_signal_received_on_sigusr1(int sig) diff --git a/tools/testing/selftests/pidfd/pidfd_wait.c b/tools/testing/selftests/pidfd/pidfd_wait.c new file mode 100644 index 000000000000..7079f8eef792 --- /dev/null +++ b/tools/testing/selftests/pidfd/pidfd_wait.c @@ -0,0 +1,271 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "pidfd.h" +#include "../kselftest.h" + +#define ptr_to_u64(ptr) ((__u64)((uintptr_t)(ptr))) + +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); +} + +static int test_pidfd_wait_simple(void) +{ + const char *test_name = "pidfd wait simple"; + int pidfd = -1, status = 0; + 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, + }; + + pidfd = open("/proc/self", O_DIRECTORY | O_RDONLY | O_CLOEXEC); + if (pidfd < 0) + ksft_exit_fail_msg("%s test: failed to open /proc/self %s\n", + test_name, strerror(errno)); + + pid = sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL); + if (pid == 0) + ksft_exit_fail_msg( + "%s test: succeeded to wait on invalid pidfd %s\n", + test_name, strerror(errno)); + close(pidfd); + pidfd = -1; + + pidfd = open("/dev/null", O_RDONLY | O_CLOEXEC); + if (pidfd == 0) + ksft_exit_fail_msg("%s test: failed to open /dev/null %s\n", + test_name, strerror(errno)); + + pid = sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL); + if (pid == 0) + ksft_exit_fail_msg( + "%s test: succeeded to wait on invalid pidfd %s\n", + test_name, strerror(errno)); + close(pidfd); + pidfd = -1; + + pid = sys_clone3(&args); + if (pid < 0) + ksft_exit_fail_msg("%s test: failed to create new process %s\n", + test_name, strerror(errno)); + + if (pid == 0) + exit(EXIT_SUCCESS); + + pid = sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL); + if (pid < 0) + ksft_exit_fail_msg( + "%s test: failed to wait on process with pid %d and pidfd %d: %s\n", + test_name, parent_tid, pidfd, strerror(errno)); + + if (!WIFEXITED(info.si_status) || WEXITSTATUS(info.si_status)) + ksft_exit_fail_msg( + "%s test: unexpected status received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, parent_tid, pidfd, strerror(errno)); + close(pidfd); + + if (info.si_signo != SIGCHLD) + ksft_exit_fail_msg( + "%s test: unexpected si_signo value %d received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, info.si_signo, parent_tid, pidfd, + strerror(errno)); + + if (info.si_code != CLD_EXITED) + ksft_exit_fail_msg( + "%s test: unexpected si_code value %d received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, info.si_code, parent_tid, pidfd, + strerror(errno)); + + if (info.si_pid != parent_tid) + ksft_exit_fail_msg( + "%s test: unexpected si_pid value %d received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, info.si_pid, parent_tid, pidfd, + strerror(errno)); + + ksft_test_result_pass("%s test: Passed\n", test_name); + return 0; +} + +static int test_pidfd_wait_states(void) +{ + const char *test_name = "pidfd wait states"; + int pidfd = -1, status = 0; + 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); + if (pid < 0) + ksft_exit_fail_msg("%s test: failed to create new process %s\n", + test_name, strerror(errno)); + + if (pid == 0) { + kill(getpid(), SIGSTOP); + kill(getpid(), SIGSTOP); + exit(EXIT_SUCCESS); + } + + ret = sys_waitid(P_PIDFD, pidfd, &info, WSTOPPED, NULL); + if (ret < 0) + ksft_exit_fail_msg( + "%s test: failed to wait on WSTOPPED process with pid %d and pidfd %d: %s\n", + test_name, parent_tid, pidfd, strerror(errno)); + + if (info.si_signo != SIGCHLD) + ksft_exit_fail_msg( + "%s test: unexpected si_signo value %d received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, info.si_signo, parent_tid, pidfd, + strerror(errno)); + + if (info.si_code != CLD_STOPPED) + ksft_exit_fail_msg( + "%s test: unexpected si_code value %d received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, info.si_code, parent_tid, pidfd, + strerror(errno)); + + if (info.si_pid != parent_tid) + ksft_exit_fail_msg( + "%s test: unexpected si_pid value %d received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, info.si_pid, parent_tid, pidfd, + strerror(errno)); + + ret = sys_pidfd_send_signal(pidfd, SIGCONT, NULL, 0); + if (ret < 0) + ksft_exit_fail_msg( + "%s test: failed to send signal to process with pid %d and pidfd %d: %s\n", + test_name, parent_tid, pidfd, strerror(errno)); + + ret = sys_waitid(P_PIDFD, pidfd, &info, WCONTINUED, NULL); + if (ret < 0) + ksft_exit_fail_msg( + "%s test: failed to wait WCONTINUED on process with pid %d and pidfd %d: %s\n", + test_name, parent_tid, pidfd, strerror(errno)); + + if (info.si_signo != SIGCHLD) + ksft_exit_fail_msg( + "%s test: unexpected si_signo value %d received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, info.si_signo, parent_tid, pidfd, + strerror(errno)); + + if (info.si_code != CLD_CONTINUED) + ksft_exit_fail_msg( + "%s test: unexpected si_code value %d received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, info.si_code, parent_tid, pidfd, + strerror(errno)); + + if (info.si_pid != parent_tid) + ksft_exit_fail_msg( + "%s test: unexpected si_pid value %d received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, info.si_pid, parent_tid, pidfd, + strerror(errno)); + + ret = sys_waitid(P_PIDFD, pidfd, &info, WUNTRACED, NULL); + if (ret < 0) + ksft_exit_fail_msg( + "%s test: failed to wait on WUNTRACED process with pid %d and pidfd %d: %s\n", + test_name, parent_tid, pidfd, strerror(errno)); + + if (info.si_signo != SIGCHLD) + ksft_exit_fail_msg( + "%s test: unexpected si_signo value %d received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, info.si_signo, parent_tid, pidfd, + strerror(errno)); + + if (info.si_code != CLD_STOPPED) + ksft_exit_fail_msg( + "%s test: unexpected si_code value %d received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, info.si_code, parent_tid, pidfd, + strerror(errno)); + + if (info.si_pid != parent_tid) + ksft_exit_fail_msg( + "%s test: unexpected si_pid value %d received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, info.si_pid, parent_tid, pidfd, + strerror(errno)); + + ret = sys_pidfd_send_signal(pidfd, SIGKILL, NULL, 0); + if (ret < 0) + ksft_exit_fail_msg( + "%s test: failed to send SIGKILL to process with pid %d and pidfd %d: %s\n", + test_name, parent_tid, pidfd, strerror(errno)); + + ret = sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL); + if (ret < 0) + ksft_exit_fail_msg( + "%s test: failed to wait on WEXITED process with pid %d and pidfd %d: %s\n", + test_name, parent_tid, pidfd, strerror(errno)); + + if (info.si_signo != SIGCHLD) + ksft_exit_fail_msg( + "%s test: unexpected si_signo value %d received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, info.si_signo, parent_tid, pidfd, + strerror(errno)); + + if (info.si_code != CLD_KILLED) + ksft_exit_fail_msg( + "%s test: unexpected si_code value %d received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, info.si_code, parent_tid, pidfd, + strerror(errno)); + + if (info.si_pid != parent_tid) + ksft_exit_fail_msg( + "%s test: unexpected si_pid value %d received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, info.si_pid, parent_tid, pidfd, + strerror(errno)); + + close(pidfd); + + ksft_test_result_pass("%s test: Passed\n", test_name); + return 0; +} + +int main(int argc, char **argv) +{ + ksft_print_header(); + ksft_set_plan(2); + + test_pidfd_wait_simple(); + test_pidfd_wait_states(); + + return ksft_exit_pass(); +}