root/tools/testing/selftests/pidfd/pidfd.h

INCLUDED FROM

DEFINITIONS

1. wait_for_pid
2. sys_pidfd_open
3. sys_pidfd_send_signal

   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 */