1/* Catastrophic failure reports. Generic POSIX.1 version.
2 Copyright (C) 1993-2024 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 <atomic.h>
20#include <errno.h>
21#include <fcntl.h>
22#include <ldsodefs.h>
23#include <libc-pointer-arith.h>
24#include <paths.h>
25#include <stdarg.h>
26#include <stdbool.h>
27#include <stdio.h>
28#include <stdlib.h>
29#include <string.h>
30#include <sysdep.h>
31#include <unistd.h>
32#include <sys/mman.h>
33#include <sys/uio.h>
34#include <not-cancel.h>
35#include <setvmaname.h>
36
37#ifdef FATAL_PREPARE_INCLUDE
38#include FATAL_PREPARE_INCLUDE
39#endif
40
41#ifndef WRITEV_FOR_FATAL
42# define WRITEV_FOR_FATAL writev_for_fatal
43static bool
44writev_for_fatal (int fd, const struct iovec *iov, size_t niov, size_t total)
45{
46 return TEMP_FAILURE_RETRY (__writev (fd, iov, niov)) == total;
47}
48#endif
49
50/* Abort with an error message. */
51void
52__libc_message_impl (const char *fmt, ...)
53{
54 va_list ap;
55 int fd = -1;
56
57#ifdef FATAL_PREPARE
58 FATAL_PREPARE;
59#endif
60
61 if (fd == -1)
62 fd = STDERR_FILENO;
63
64 struct iovec iov[LIBC_MESSAGE_MAX_ARGS * 2 - 1];
65 int iovcnt = 0;
66 ssize_t total = 0;
67
68 va_start (ap, fmt);
69 const char *cp = fmt;
70 while (*cp != '\0')
71 {
72 /* Find the next "%s" or the end of the string. */
73 const char *next = cp;
74 while (next[0] != '%' || next[1] != 's')
75 {
76 next = __strchrnul (s: next + 1, c: '%');
77
78 if (next[0] == '\0')
79 break;
80 }
81
82 /* Determine what to print. */
83 const char *str;
84 size_t len;
85 if (cp[0] == '%' && cp[1] == 's')
86 {
87 str = va_arg (ap, const char *);
88 len = strlen (s: str);
89 cp += 2;
90 }
91 else
92 {
93 str = cp;
94 len = next - cp;
95 cp = next;
96 }
97
98 iov[iovcnt].iov_base = (char *) str;
99 iov[iovcnt].iov_len = len;
100 total += len;
101 iovcnt++;
102 }
103 va_end (ap);
104
105 if (iovcnt > 0)
106 {
107 WRITEV_FOR_FATAL (fd, iov, niov: iovcnt, total);
108
109 total = ALIGN_UP (total + sizeof (struct abort_msg_s) + 1,
110 GLRO(dl_pagesize));
111 struct abort_msg_s *buf = __mmap (NULL, len: total,
112 PROT_READ | PROT_WRITE,
113 MAP_ANON | MAP_PRIVATE, fd: -1, offset: 0);
114 if (__glibc_likely (buf != MAP_FAILED))
115 {
116 buf->size = total;
117 char *wp = buf->msg;
118 for (int cnt = 0; cnt < iovcnt; ++cnt)
119 wp = mempcpy (wp, iov[cnt].iov_base, iov[cnt].iov_len);
120 *wp = '\0';
121
122 __set_vma_name (start: buf, len: total, name: " glibc: fatal");
123
124 /* We have to free the old buffer since the application might
125 catch the SIGABRT signal. */
126 struct abort_msg_s *old = atomic_exchange_acquire (&__abort_msg,
127 buf);
128 if (old != NULL)
129 __munmap (addr: old, len: old->size);
130 }
131 }
132
133 /* Kill the application. */
134 abort ();
135}
136
137
138void
139__libc_fatal (const char *message)
140{
141 /* The loop is added only to keep gcc happy. */
142 while (1)
143 __libc_message ("%s", message);
144}
145libc_hidden_def (__libc_fatal)
146

source code of glibc/sysdeps/posix/libc_fatal.c