LXR linux/tools/testing/selftests/pidfd/pidfd.h

   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
  57int wait_for_pid(pid_t pid)
  58{
  59        int status, ret;
  60
  61again:
  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
  76static inline int sys_pidfd_open(pid_t pid, unsigned int flags)
  77{
  78        return syscall(__NR_pidfd_open, pid, flags);
  79}
  80
  81static 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