1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
|
/* Copyright (C) 1993-2013 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <atomic.h>
#include <errno.h>
#include <fcntl.h>
#include <ldsodefs.h>
#include <paths.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysdep.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/syslog.h>
#include <execinfo.h>
/* Abort with an error message. */
#include <not-cancel.h>
#ifdef FATAL_PREPARE_INCLUDE
#include FATAL_PREPARE_INCLUDE
#endif
struct str_list
{
const char *str;
size_t len;
struct str_list *next;
};
/* Abort with an error message. */
void
__libc_message (int do_abort, const char *fmt, ...)
{
va_list ap;
va_list ap_copy;
int fd = -1;
va_start (ap, fmt);
va_copy (ap_copy, ap);
#ifdef FATAL_PREPARE
FATAL_PREPARE;
#endif
/* Open a descriptor for /dev/tty unless the user explicitly
requests errors on standard error. */
const char *on_2 = __libc_secure_getenv ("LIBC_FATAL_STDERR_");
if (on_2 == NULL || *on_2 == '\0')
fd = open_not_cancel_2 (_PATH_TTY, O_RDWR | O_NOCTTY | O_NDELAY);
if (fd == -1)
fd = STDERR_FILENO;
struct str_list *list = NULL;
int nlist = 0;
const char *cp = fmt;
while (*cp != '\0')
{
/* Find the next "%s" or the end of the string. */
const char *next = cp;
while (next[0] != '%' || next[1] != 's')
{
next = __strchrnul (next + 1, '%');
if (next[0] == '\0')
break;
}
/* Determine what to print. */
const char *str;
size_t len;
if (cp[0] == '%' && cp[1] == 's')
{
str = va_arg (ap, const char *);
len = strlen (str);
cp += 2;
}
else
{
str = cp;
len = next - cp;
cp = next;
}
struct str_list *newp = alloca (sizeof (struct str_list));
newp->str = str;
newp->len = len;
newp->next = list;
list = newp;
++nlist;
}
bool written = false;
if (nlist > 0)
{
struct iovec *iov = alloca (nlist * sizeof (struct iovec));
ssize_t total = 0;
for (int cnt = nlist - 1; cnt >= 0; --cnt)
{
iov[cnt].iov_base = (void *) list->str;
iov[cnt].iov_len = list->len;
total += list->len;
list = list->next;
}
INTERNAL_SYSCALL_DECL (err);
ssize_t cnt;
do
cnt = INTERNAL_SYSCALL (writev, err, 3, fd, iov, nlist);
while (INTERNAL_SYSCALL_ERROR_P (cnt, err)
&& INTERNAL_SYSCALL_ERRNO (cnt, err) == EINTR);
if (cnt == total)
written = true;
if (do_abort)
{
total = ((total + 1 + GLRO(dl_pagesize) - 1)
& ~(GLRO(dl_pagesize) - 1));
struct abort_msg_s *buf = __mmap (NULL, total,
PROT_READ | PROT_WRITE,
MAP_ANON | MAP_PRIVATE, -1, 0);
if (__builtin_expect (buf != MAP_FAILED, 1))
{
buf->size = total;
char *wp = buf->msg;
for (int cnt = 0; cnt < nlist; ++cnt)
wp = mempcpy (wp, iov[cnt].iov_base, iov[cnt].iov_len);
*wp = '\0';
/* We have to free the old buffer since the application might
catch the SIGABRT signal. */
struct abort_msg_s *old = atomic_exchange_acq (&__abort_msg,
buf);
if (old != NULL)
__munmap (old, old->size);
}
}
}
va_end (ap);
/* If we had no success writing the message, use syslog. */
if (! written)
vsyslog (LOG_ERR, fmt, ap_copy);
va_end (ap_copy);
if (do_abort)
{
if (do_abort > 1 && written)
{
void *addrs[64];
#define naddrs (sizeof (addrs) / sizeof (addrs[0]))
int n = __backtrace (addrs, naddrs);
if (n > 2)
{
#define strnsize(str) str, strlen (str)
#define writestr(str) write_not_cancel (fd, str)
writestr (strnsize ("======= Backtrace: =========\n"));
__backtrace_symbols_fd (addrs + 1, n - 1, fd);
writestr (strnsize ("======= Memory map: ========\n"));
int fd2 = open_not_cancel_2 ("/proc/self/maps", O_RDONLY);
char buf[1024];
ssize_t n2;
while ((n2 = read_not_cancel (fd2, buf, sizeof (buf))) > 0)
if (write_not_cancel (fd, buf, n2) != n2)
break;
close_not_cancel_no_status (fd2);
}
}
/* Terminate the process. */
abort ();
}
}
void
__libc_fatal (message)
const char *message;
{
/* The loop is added only to keep gcc happy. */
while (1)
__libc_message (1, "%s", message);
}
libc_hidden_def (__libc_fatal)
|
