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
|
/* Return error detail for failing <dlfcn.h> functions.
Copyright (C) 1995,1996,1997,1998,1999,2000,2002,2003
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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <dlfcn.h>
#include <libintl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <bits/libc-lock.h>
/* Type for storing results of dynamic loading actions. */
struct dl_action_result
{
int errcode;
int returned;
const char *objname;
const char *errstring;
};
static struct dl_action_result last_result;
static struct dl_action_result *static_buf;
/* This is the key for the thread specific memory. */
static __libc_key_t key;
__libc_once_define (static, once);
/* Destructor for the thread-specific data. */
static void init (void);
static void free_key_mem (void *mem);
char *
dlerror (void)
{
char *buf = NULL;
struct dl_action_result *result;
/* If we have not yet initialized the buffer do it now. */
__libc_once (once, init);
/* Get error string. */
result = (struct dl_action_result *) __libc_getspecific (key);
if (result == NULL)
result = &last_result;
/* Test whether we already returned the string. */
if (result->returned != 0)
{
/* We can now free the string. */
if (result->errstring != NULL)
{
if (strcmp (result->errstring, "out of memory") != 0)
free ((char *) result->errstring);
result->errstring = NULL;
}
}
else if (result->errstring != NULL)
{
buf = (char *) result->errstring;
int n;
if (result->errcode == 0)
n = __asprintf (&buf, "%s%s%s",
result->objname,
result->objname[0] == '\0' ? "" : ": ",
_(result->errstring));
else
n = __asprintf (&buf, "%s%s%s: %s",
result->objname,
result->objname[0] == '\0' ? "" : ": ",
_(result->errstring),
strerror (result->errcode));
if (n != -1)
{
/* We don't need the error string anymore. */
if (strcmp (result->errstring, "out of memory") != 0)
free ((char *) result->errstring);
result->errstring = buf;
}
/* Mark the error as returned. */
result->returned = 1;
}
return buf;
}
int
internal_function
_dlerror_run (void (*operate) (void *), void *args)
{
struct dl_action_result *result;
/* If we have not yet initialized the buffer do it now. */
__libc_once (once, init);
/* Get error string and number. */
if (static_buf != NULL)
result = static_buf;
else
{
/* We don't use the static buffer and so we have a key. Use it
to get the thread-specific buffer. */
result = __libc_getspecific (key);
if (result == NULL)
{
result = (struct dl_action_result *) calloc (1, sizeof (*result));
if (result == NULL)
/* We are out of memory. Since this is no really critical
situation we carry on by using the global variable.
This might lead to conflicts between the threads but
they soon all will have memory problems. */
result = &last_result;
else
/* Set the tsd. */
__libc_setspecific (key, result);
}
}
if (result->errstring != NULL)
{
/* Free the error string from the last failed command. This can
happen if `dlerror' was not run after an error was found. */
if (strcmp (result->errstring, "out of memory") != 0)
free ((char *) result->errstring);
result->errstring = NULL;
}
result->errcode = _dl_catch_error (&result->objname, &result->errstring,
operate, args);
/* If no error we mark that no error string is available. */
result->returned = result->errstring == NULL;
return result->errstring != NULL;
}
/* Initialize buffers for results. */
static void
init (void)
{
if (__libc_key_create (&key, free_key_mem))
/* Creating the key failed. This means something really went
wrong. In any case use a static buffer which is better than
nothing. */
static_buf = &last_result;
}
static void
__attribute__ ((destructor))
fini (void)
{
if (last_result.errstring != NULL
&& strcmp (last_result.errstring, "out of memory") != 0)
free ((char *) last_result.errstring);
}
/* Free the thread specific data, this is done if a thread terminates. */
static void
free_key_mem (void *mem)
{
struct dl_action_result *result = (struct dl_action_result *) mem;
if (result->errstring != NULL
&& strcmp (result->errstring, "out of memory") != 0)
free ((char *) result->errstring);
free (mem);
__libc_setspecific (key, NULL);
}
|
