1/* Copyright (C) 2009-2021 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@redhat.com>, 2009.
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 <errno.h>
20#include <signal.h>
21#include <string.h>
22#include <unistd.h>
23#include <pthreadP.h>
24#include <tls.h>
25#include <sysdep.h>
26
27
28int
29pthread_sigqueue (pthread_t threadid, int signo, const union sigval value)
30{
31#ifdef __NR_rt_tgsigqueueinfo
32 struct pthread *pd = (struct pthread *) threadid;
33
34 /* Make sure the descriptor is valid. */
35 if (DEBUGGING_P && INVALID_TD_P (pd))
36 /* Not a valid thread handle. */
37 return ESRCH;
38
39 /* Force load of pd->tid into local variable or register. Otherwise
40 if a thread exits between ESRCH test and tgkill, we might return
41 EINVAL, because pd->tid would be cleared by the kernel. */
42 pid_t tid = atomic_forced_read (pd->tid);
43 if (__glibc_unlikely (tid <= 0))
44 /* Not a valid thread handle. */
45 return ESRCH;
46
47 /* Disallow sending the signal we use for cancellation, timers,
48 for the setxid implementation. */
49 if (signo == SIGCANCEL || signo == SIGTIMER || signo == SIGSETXID)
50 return EINVAL;
51
52 pid_t pid = getpid ();
53
54 /* Set up the siginfo_t structure. */
55 siginfo_t info;
56 memset (&info, '\0', sizeof (siginfo_t));
57 info.si_signo = signo;
58 info.si_code = SI_QUEUE;
59 info.si_pid = pid;
60 info.si_uid = getuid ();
61 info.si_value = value;
62
63 /* We have a special syscall to do the work. */
64 int val = INTERNAL_SYSCALL_CALL (rt_tgsigqueueinfo, pid, tid, signo,
65 &info);
66 return (INTERNAL_SYSCALL_ERROR_P (val)
67 ? INTERNAL_SYSCALL_ERRNO (val) : 0);
68#else
69 return ENOSYS;
70#endif
71}
72