1 /* TMP_ALLOC routines for debugging.
2
3 Copyright 2000, 2001, 2004 Free Software Foundation, Inc.
4
5 This file is part of the GNU MP Library.
6
7 The GNU MP Library is free software; you can redistribute it and/or modify
8 it under the terms of either:
9
10 * the GNU Lesser General Public License as published by the Free
11 Software Foundation; either version 3 of the License, or (at your
12 option) any later version.
13
14 or
15
16 * the GNU General Public License as published by the Free Software
17 Foundation; either version 2 of the License, or (at your option) any
18 later version.
19
20 or both in parallel, as here.
21
22 The GNU MP Library is distributed in the hope that it will be useful, but
23 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
24 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
25 for more details.
26
27 You should have received copies of the GNU General Public License and the
28 GNU Lesser General Public License along with the GNU MP Library. If not,
29 see https://www.gnu.org/licenses/. */
30
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include "gmp-impl.h"
35
36
37 /* This method aims to help a malloc debugger find problems. A linked list
38 of allocated block is kept for TMP_FREE to release. This is reentrant
39 and thread safe.
40
41 Each TMP_ALLOC is a separate malloced block, so redzones or sentinels
42 applied by a malloc debugger either above or below can guard against
43 accesses outside the allocated area.
44
45 A marker is a "struct tmp_debug_t *" so that TMP_DECL can initialize it
46 to NULL and we can detect TMP_ALLOC without TMP_MARK.
47
48 It will work to realloc an MPZ_TMP_INIT variable, but when TMP_FREE comes
49 to release the memory it will have the old size, thereby triggering an
50 error from tests/memory.c.
51
52 Possibilities:
53
54 It'd be possible to keep a global list of active "struct tmp_debug_t"
55 records, so at the end of a program any TMP leaks could be printed. But
56 if only a couple of routines are under test at any one time then the
57 likely culprit should be easy enough to spot. */
58
59
60 void
__gmp_tmp_debug_mark(const char * file,int line,struct tmp_debug_t ** markp,struct tmp_debug_t * mark,const char * decl_name,const char * mark_name)61 __gmp_tmp_debug_mark (const char *file, int line,
62 struct tmp_debug_t **markp, struct tmp_debug_t *mark,
63 const char *decl_name, const char *mark_name)
64 {
65 if (strcmp (mark_name, decl_name) != 0)
66 {
67 __gmp_assert_header (file, line);
68 fprintf (stderr, "GNU MP: TMP_MARK(%s) but TMP_DECL(%s) is in scope\n",
69 mark_name, decl_name);
70 abort ();
71 }
72
73 if (*markp != NULL)
74 {
75 __gmp_assert_header (file, line);
76 fprintf (stderr, "GNU MP: Repeat of TMP_MARK(%s)\n", mark_name);
77 if (mark->file != NULL && mark->file[0] != '\0' && mark->line != -1)
78 {
79 __gmp_assert_header (mark->file, mark->line);
80 fprintf (stderr, "previous was here\n");
81 }
82 abort ();
83 }
84
85 *markp = mark;
86 mark->file = file;
87 mark->line = line;
88 mark->list = NULL;
89 }
90
91 void *
__gmp_tmp_debug_alloc(const char * file,int line,int dummy,struct tmp_debug_t ** markp,const char * decl_name,size_t size)92 __gmp_tmp_debug_alloc (const char *file, int line, int dummy,
93 struct tmp_debug_t **markp,
94 const char *decl_name, size_t size)
95 {
96 struct tmp_debug_t *mark = *markp;
97 struct tmp_debug_entry_t *p;
98
99 ASSERT_ALWAYS (size >= 1);
100
101 if (mark == NULL)
102 {
103 __gmp_assert_header (file, line);
104 fprintf (stderr, "GNU MP: TMP_ALLOC without TMP_MARK(%s)\n", decl_name);
105 abort ();
106 }
107
108 p = __GMP_ALLOCATE_FUNC_TYPE (1, struct tmp_debug_entry_t);
109 p->size = size;
110 p->block = (*__gmp_allocate_func) (size);
111 p->next = mark->list;
112 mark->list = p;
113 return p->block;
114 }
115
116 void
__gmp_tmp_debug_free(const char * file,int line,int dummy,struct tmp_debug_t ** markp,const char * decl_name,const char * free_name)117 __gmp_tmp_debug_free (const char *file, int line, int dummy,
118 struct tmp_debug_t **markp,
119 const char *decl_name, const char *free_name)
120 {
121 struct tmp_debug_t *mark = *markp;
122 struct tmp_debug_entry_t *p, *next;
123
124 if (mark == NULL)
125 {
126 __gmp_assert_header (file, line);
127 fprintf (stderr, "GNU MP: TMP_FREE(%s) without TMP_MARK(%s)\n",
128 free_name, decl_name);
129 abort ();
130 }
131
132 if (strcmp (free_name, decl_name) != 0)
133 {
134 __gmp_assert_header (file, line);
135 fprintf (stderr, "GNU MP: TMP_FREE(%s) when TMP_DECL(%s) is in scope\n",
136 free_name, decl_name);
137 abort ();
138 }
139
140 p = mark->list;
141 while (p != NULL)
142 {
143 next = p->next;
144 (*__gmp_free_func) (p->block, p->size);
145 __GMP_FREE_FUNC_TYPE (p, 1, struct tmp_debug_entry_t);
146 p = next;
147 }
148
149 *markp = NULL;
150 }
151