1/* Catastrophic failure reports. Generic POSIX.1 version.
2 Copyright (C) 1993-2022 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 <paths.h>
24#include <stdarg.h>
25#include <stdbool.h>
26#include <stdio.h>
27#include <stdlib.h>
28#include <string.h>
29#include <sysdep.h>
30#include <unistd.h>
31#include <sys/mman.h>
32#include <sys/uio.h>
33#include <not-cancel.h>
34
35#ifdef FATAL_PREPARE_INCLUDE
36#include FATAL_PREPARE_INCLUDE
37#endif
38
39#ifndef WRITEV_FOR_FATAL
40# define WRITEV_FOR_FATAL writev_for_fatal
41static bool
42writev_for_fatal (int fd, const struct iovec *iov, size_t niov, size_t total)
43{
44 return TEMP_FAILURE_RETRY (__writev (fd, iov, niov)) == total;
45}
46#endif
47
48struct str_list
49{
50 const char *str;
51 size_t len;
52 struct str_list *next;
53};
54
55/* Abort with an error message. */
56void
57__libc_message (enum __libc_message_action action, const char *fmt, ...)
58{
59 va_list ap;
60 int fd = -1;
61
62 va_start (ap, fmt);
63
64#ifdef FATAL_PREPARE
65 FATAL_PREPARE;
66#endif
67
68 if (fd == -1)
69 fd = STDERR_FILENO;
70
71 struct str_list *list = NULL;
72 int nlist = 0;
73
74 const char *cp = fmt;
75 while (*cp != '\0')
76 {
77 /* Find the next "%s" or the end of the string. */
78 const char *next = cp;
79 while (next[0] != '%' || next[1] != 's')
80 {
81 next = __strchrnul (next + 1, '%');
82
83 if (next[0] == '\0')
84 break;
85 }
86
87 /* Determine what to print. */
88 const char *str;
89 size_t len;
90 if (cp[0] == '%' && cp[1] == 's')
91 {
92 str = va_arg (ap, const char *);
93 len = strlen (str);
94 cp += 2;
95 }
96 else
97 {
98 str = cp;
99 len = next - cp;
100 cp = next;
101 }
102
103 struct str_list *newp = alloca (sizeof (struct str_list));
104 newp->str = str;
105 newp->len = len;
106 newp->next = list;
107 list = newp;
108 ++nlist;
109 }
110
111 if (nlist > 0)
112 {
113 struct iovec *iov = alloca (nlist * sizeof (struct iovec));
114 ssize_t total = 0;
115
116 for (int cnt = nlist - 1; cnt >= 0; --cnt)
117 {
118 iov[cnt].iov_base = (char *) list->str;
119 iov[cnt].iov_len = list->len;
120 total += list->len;
121 list = list->next;
122 }
123
124 WRITEV_FOR_FATAL (fd, iov, nlist, total);
125
126 if ((action & do_abort))
127 {
128 total = ((total + 1 + GLRO(dl_pagesize) - 1)
129 & ~(GLRO(dl_pagesize) - 1));
130 struct abort_msg_s *buf = __mmap (NULL, total,
131 PROT_READ | PROT_WRITE,
132 MAP_ANON | MAP_PRIVATE, -1, 0);
133 if (__glibc_likely (buf != MAP_FAILED))
134 {
135 buf->size = total;
136 char *wp = buf->msg;
137 for (int cnt = 0; cnt < nlist; ++cnt)
138 wp = mempcpy (wp, iov[cnt].iov_base, iov[cnt].iov_len);
139 *wp = '\0';
140
141 /* We have to free the old buffer since the application might
142 catch the SIGABRT signal. */
143 struct abort_msg_s *old = atomic_exchange_acq (&__abort_msg,
144 buf);
145 if (old != NULL)
146 __munmap (old, old->size);
147 }
148 }
149 }
150
151 va_end (ap);
152
153 if ((action & do_abort))
154 /* Kill the application. */
155 abort ();
156}
157
158
159void
160__libc_fatal (const char *message)
161{
162 /* The loop is added only to keep gcc happy. */
163 while (1)
164 __libc_message (do_abort, "%s", message);
165}
166libc_hidden_def (__libc_fatal)
167

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