1 /*
2 * libc/stdlib/malloc/heap_debug.c -- optional heap debugging routines
3 *
4 * Copyright (C) 2002 NEC Corporation
5 * Copyright (C) 2002 Miles Bader <miles@gnu.org>
6 *
7 * This file is subject to the terms and conditions of the GNU Lesser
8 * General Public License. See the file COPYING.LIB in the main
9 * directory of this archive for more details.
10 *
11 * Written by Miles Bader <miles@gnu.org>
12 */
13
14 #include <stdlib.h>
15 #include <stdio.h>
16 #include <stdarg.h>
17 #include <string.h>
18 #include <unistd.h>
19
20
21 #include "malloc.h"
22 #include "heap.h"
23
24
25 #ifdef HEAP_DEBUGGING
26 int __heap_debug = 0;
27 #endif
28
29
30 static void
__heap_dump_freelist(struct heap_free_area * heap)31 __heap_dump_freelist (struct heap_free_area *heap)
32 {
33 struct heap_free_area *fa;
34 for (fa = heap; fa; fa = fa->next)
35 __malloc_debug_printf (0,
36 "0x%lx: 0x%lx - 0x%lx (%d)\tP=0x%lx, N=0x%lx",
37 (long)fa,
38 (long)HEAP_FREE_AREA_START (fa),
39 (long)HEAP_FREE_AREA_END (fa),
40 fa->size,
41 (long)fa->prev,
42 (long)fa->next);
43 }
44
45 /* Output a text representation of HEAP to stderr, labelling it with STR. */
46 void
__heap_dump(struct heap_free_area * heap,const char * str)47 __heap_dump (struct heap_free_area *heap, const char *str)
48 {
49 static smallint recursed;
50
51 if (! recursed)
52 {
53 __heap_check (heap, str);
54
55 recursed = 1;
56
57 __malloc_debug_printf (1, "%s: heap @0x%lx:", str, (long)heap);
58 __heap_dump_freelist (heap);
59 __malloc_debug_indent (-1);
60
61 recursed = 0;
62 }
63 }
64
65
66 /* Output an error message to stderr, and exit. STR is printed with the
67 failure message. */
68 static void attribute_noreturn
__heap_check_failure(struct heap_free_area * heap,struct heap_free_area * fa,const char * str,char * fmt,...)69 __heap_check_failure (struct heap_free_area *heap, struct heap_free_area *fa,
70 const char *str, char *fmt, ...)
71 {
72 va_list val;
73
74 if (str)
75 fprintf (stderr, "\nHEAP CHECK FAILURE %s: ", str);
76 else
77 fprintf (stderr, "\nHEAP CHECK FAILURE: ");
78
79 va_start (val, fmt);
80 vfprintf (stderr, fmt, val);
81 va_end (val);
82
83 fprintf (stderr, "\n");
84
85 __malloc_debug_set_indent (0);
86 __malloc_debug_printf (1, "heap dump:");
87 __heap_dump_freelist (heap);
88
89 _exit (22);
90 }
91
92 /* Do some consistency checks on HEAP. If they fail, output an error
93 message to stderr, and exit. STR is printed with the failure message. */
94 void
__heap_check(struct heap_free_area * heap,const char * str)95 __heap_check (struct heap_free_area *heap, const char *str)
96 {
97 typedef unsigned long ul_t;
98 struct heap_free_area *fa, *prev;
99 struct heap_free_area *first_fa = heap;
100
101 if (first_fa && first_fa->prev)
102 __heap_check_failure (heap, first_fa, str,
103 "first free-area has non-zero prev pointer:\n\
104 first free-area = 0x%lx\n\
105 (0x%lx)->prev = 0x%lx\n",
106 (ul_t)first_fa,
107 (ul_t)first_fa, (ul_t)first_fa->prev);
108
109 for (prev = 0, fa = first_fa; fa; prev = fa, fa = fa->next)
110 {
111 if (((ul_t)HEAP_FREE_AREA_END (fa) & (HEAP_GRANULARITY - 1))
112 || (fa->size & (HEAP_GRANULARITY - 1)))
113 __heap_check_failure (heap, fa, str, "alignment error:\n\
114 (0x%lx)->start = 0x%lx\n\
115 (0x%lx)->size = 0x%lx\n",
116 (ul_t)fa,
117 (ul_t)HEAP_FREE_AREA_START (fa),
118 (ul_t)fa, fa->size);
119
120 if (fa->prev != prev)
121 __heap_check_failure (heap, fa, str, "prev pointer corrupted:\n\
122 (0x%lx)->next = 0x%lx\n\
123 (0x%lx)->prev = 0x%lx\n",
124 (ul_t)prev, (ul_t)prev->next,
125 (ul_t)fa, (ul_t)fa->prev);
126
127 if (prev)
128 {
129 ul_t start = (ul_t)HEAP_FREE_AREA_START (fa);
130 ul_t prev_end = (ul_t)HEAP_FREE_AREA_END (prev);
131
132 if (prev_end >= start)
133 __heap_check_failure (heap, fa, str,
134 "start %s with prev free-area end:\n\
135 (0x%lx)->prev = 0x%lx\n\
136 (0x%lx)->start = 0x%lx\n\
137 (0x%lx)->end = 0x%lx\n",
138 (prev_end == start ? "unmerged" : "overlaps"),
139 (ul_t)fa, (ul_t)prev,
140 (ul_t)fa, start,
141 (ul_t)prev, prev_end);
142 }
143 }
144 }
145