1/* Wait for process to change state. Linux version.
2 Copyright (C) 2019-2021 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <sys/wait.h>
20#include <sys/resource.h>
21#include <sys/types.h>
22#include <sysdep-cancel.h>
23#include <tv32-compat.h>
24
25pid_t
26__wait4_time64 (pid_t pid, int *stat_loc, int options, struct __rusage64 *usage)
27{
28#ifdef __NR_wait4
29# if __KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64
30 return SYSCALL_CANCEL (wait4, pid, stat_loc, options, usage);
31# else
32 pid_t ret;
33 struct __rusage32 usage32;
34
35 ret = SYSCALL_CANCEL (wait4, pid, stat_loc, options,
36 usage != NULL ? &usage32 : NULL);
37
38 if (ret > 0 && usage != NULL)
39 rusage32_to_rusage64 (&usage32, usage);
40
41 return ret;
42# endif
43#elif defined (__ASSUME_WAITID_PID0_P_PGID)
44 idtype_t idtype = P_PID;
45
46 if (pid < -1)
47 {
48 idtype = P_PGID;
49 pid *= -1;
50 }
51 else if (pid == -1)
52 idtype = P_ALL;
53 else if (pid == 0)
54 idtype = P_PGID;
55
56 options |= WEXITED;
57
58 siginfo_t infop;
59
60# if __KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64
61 if (SYSCALL_CANCEL (waitid, idtype, pid, &infop, options, usage) < 0)
62 return -1;
63# else
64 {
65 struct __rusage32 usage32;
66 if (SYSCALL_CANCEL (waitid, idtype, pid, &infop, options, &usage32) < 0)
67 return -1;
68 if (usage != NULL)
69 rusage32_to_rusage64 (&usage32, usage);
70 }
71# endif
72
73 if (stat_loc)
74 {
75 switch (infop.si_code)
76 {
77 case CLD_EXITED:
78 *stat_loc = W_EXITCODE (infop.si_status, 0);
79 break;
80 case CLD_DUMPED:
81 *stat_loc = WCOREFLAG | infop.si_status;
82 break;
83 case CLD_KILLED:
84 *stat_loc = infop.si_status;
85 break;
86 case CLD_TRAPPED:
87 case CLD_STOPPED:
88 *stat_loc = W_STOPCODE (infop.si_status);
89 break;
90 case CLD_CONTINUED:
91 *stat_loc = __W_CONTINUED;
92 break;
93 default:
94 *stat_loc = 0;
95 break;
96 }
97 }
98
99 return infop.si_pid;
100#else
101/* Linux waitid prior kernel 5.4 does not support waiting for the current
102 process. It is possible to emulate wait4 it by calling getpgid for
103 PID 0, however, it would require an additional syscall and it is inherent
104 racy: after the current process group is received and before it is passed
105 to waitid a signal could arrive causing the current process group to
106 change. */
107# error "The kernel ABI does not provide a way to implement wait4"
108#endif
109}
110
111#if __TIMESIZE != 64
112libc_hidden_def (__wait4_time64)
113
114pid_t
115__wait4 (pid_t pid, int *stat_loc, int options, struct rusage *usage)
116{
117 pid_t ret;
118 struct __rusage64 usage64;
119
120 ret = __wait4_time64 (pid, stat_loc, options,
121 usage != NULL ? &usage64 : NULL);
122
123 if (ret > 0 && usage != 0)
124 rusage64_to_rusage (&usage64, usage);
125
126 return ret;
127}
128#endif
129libc_hidden_def (__wait4);
130weak_alias (__wait4, wait4)
131