1 /* SPDX-License-Identifier: GPL-2.0 */ 2 3 #ifndef __PIDFD_H 4 #define __PIDFD_H 5 6 #define _GNU_SOURCE 7 #include <errno.h> 8 #include <fcntl.h> 9 #include <sched.h> 10 #include <signal.h> 11 #include <stdio.h> 12 #include <stdlib.h> 13 #include <string.h> 14 #include <syscall.h> 15 #include <sys/mount.h> 16 17 #include "../kselftest.h" 18 19 #ifndef P_PIDFD 20 #define P_PIDFD 3 21 #endif 22 23 #ifndef CLONE_PIDFD 24 #define CLONE_PIDFD 0x00001000 25 #endif 26 27 #ifndef __NR_pidfd_open 28 #define __NR_pidfd_open -1 29 #endif 30 31 #ifndef __NR_pidfd_send_signal 32 #define __NR_pidfd_send_signal -1 33 #endif 34 35 #ifndef __NR_clone3 36 #define __NR_clone3 -1 37 #endif 38 39 /* 40 * The kernel reserves 300 pids via RESERVED_PIDS in kernel/pid.c 41 * That means, when it wraps around any pid < 300 will be skipped. 42 * So we need to use a pid > 300 in order to test recycling. 43 */ 44 #define PID_RECYCLE 1000 45 46 /* 47 * Define a few custom error codes for the child process to clearly indicate 48 * what is happening. This way we can tell the difference between a system 49 * error, a test error, etc. 50 */ 51 #define PIDFD_PASS 0 52 #define PIDFD_FAIL 1 53 #define PIDFD_ERROR 2 54 #define PIDFD_SKIP 3 55 #define PIDFD_XFAIL 4 56 57 int wait_for_pid(pid_t pid) 58 { 59 int status, ret; 60 61 again: 62 ret = waitpid(pid, &status, 0); 63 if (ret == -1) { 64 if (errno == EINTR) 65 goto again; 66 67 return -1; 68 } 69 70 if (!WIFEXITED(status)) 71 return -1; 72 73 return WEXITSTATUS(status); 74 } 75 76 static inline int sys_pidfd_open(pid_t pid, unsigned int flags) 77 { 78 return syscall(__NR_pidfd_open, pid, flags); 79 } 80 81 static inline int sys_pidfd_send_signal(int pidfd, int sig, siginfo_t *info, 82 unsigned int flags) 83 { 84 return syscall(__NR_pidfd_send_signal, pidfd, sig, info, flags); 85 } 86 87 #endif /* __PIDFD_H */ 88