1/* Copyright (C) 2009-2023 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18#include <errno.h>
19#include <signal.h>
20#include <string.h>
21#include <unistd.h>
22#include <pthreadP.h>
23#include <tls.h>
24#include <sysdep.h>
25#include <shlib-compat.h>
26
27int
28__pthread_sigqueue (pthread_t threadid, int signo, const union sigval value)
29{
30#ifdef __NR_rt_tgsigqueueinfo
31 struct pthread *pd = (struct pthread *) threadid;
32
33 /* Force load of pd->tid into local variable or register. Otherwise
34 if a thread exits between ESRCH test and tgkill, we might return
35 EINVAL, because pd->tid would be cleared by the kernel. */
36 pid_t tid = atomic_forced_read (pd->tid);
37 if (__glibc_unlikely (tid <= 0))
38 /* Not a valid thread handle. */
39 return ESRCH;
40
41 /* Disallow sending the signal we use for cancellation, timers,
42 for the setxid implementation. */
43 if (signo == SIGCANCEL || signo == SIGTIMER || signo == SIGSETXID)
44 return EINVAL;
45
46 pid_t pid = getpid ();
47
48 /* Set up the siginfo_t structure. */
49 siginfo_t info;
50 memset (&info, '\0', sizeof (siginfo_t));
51 info.si_signo = signo;
52 info.si_code = SI_QUEUE;
53 info.si_pid = pid;
54 info.si_uid = __getuid ();
55 info.si_value = value;
56
57 /* We have a special syscall to do the work. */
58 int val = INTERNAL_SYSCALL_CALL (rt_tgsigqueueinfo, pid, tid, signo,
59 &info);
60 return (INTERNAL_SYSCALL_ERROR_P (val)
61 ? INTERNAL_SYSCALL_ERRNO (val) : 0);
62#else
63 return ENOSYS;
64#endif
65}
66versioned_symbol (libc, __pthread_sigqueue, pthread_sigqueue, GLIBC_2_34);
67
68#if OTHER_SHLIB_COMPAT (libpthread, GLIBC_2_11, GLIBC_2_34)
69compat_symbol (libpthread, __pthread_sigqueue, pthread_sigqueue, GLIBC_2_11);
70#endif
71