1 /* More debugging hooks for `malloc'.
2 Copyright (C) 1991, 92, 93, 94, 96, 97, 98 Free Software Foundation, Inc.
3 Written April 2, 1991 by John Gilmore of Cygnus Support.
4 Based on mcheck.c by Mike Haertel.
6 This library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Library General Public License as
8 published by the Free Software Foundation; either version 2 of the
9 License, or (at your option) any later version.
11 This library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Library General Public License for more details.
16 You should have received a copy of the GNU Library General Public
17 License along with this library; see the file COPYING.LIB. If not,
18 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA.
21 The author may be reached (Email) at the address mike@ai.mit.edu,
22 or (US mail) as Mike Haertel c/o Free Software Foundation. */
24 #ifndef _MALLOC_INTERNAL
25 #define _MALLOC_INTERNAL
28 #include <bits/libc-lock.h>
32 #include <elf/ldsodefs.h>
37 #ifndef __GNU_LIBRARY__
38 extern char *getenv ();
43 #if defined _LIBC && defined USE_IN_LIBIO
44 # include <libio/iolibio.h>
45 # define setvbuf(s, b, f, l) _IO_setvbuf (s, b, f, l)
48 #define TRACE_BUFFER_SIZE 512
50 static FILE *mallstream
;
51 static const char mallenv
[]= "MALLOC_TRACE";
52 static char malloc_trace_buffer
[TRACE_BUFFER_SIZE
];
54 __libc_lock_define_initialized (static, lock
);
56 /* Address to breakpoint on accesses to... */
59 /* File name and line number information, for callers that had
60 the foresight to call through a macro. */
64 /* Old hook values. */
65 static void (*tr_old_free_hook
) __P ((__ptr_t ptr
, const __ptr_t
));
66 static __ptr_t (*tr_old_malloc_hook
) __P ((__malloc_size_t size
,
68 static __ptr_t (*tr_old_realloc_hook
) __P ((__ptr_t ptr
,
72 /* This function is called when the block being alloc'd, realloc'd, or
73 freed has an address matching the variable "mallwatch". In a debugger,
74 set "mallwatch" to the address of interest, then put a breakpoint on
77 void tr_break
__P ((void));
83 static void tr_where
__P ((const __ptr_t
)) internal_function
;
91 fprintf (mallstream
, "@ %s:%d ", _mtrace_file
, _mtrace_line
);
94 else if (caller
!= NULL
)
98 if (_dl_addr (caller
, &info
))
100 fprintf (mallstream
, "@ %s%s%s%s%s[%p]",
101 info
.dli_fname
?: "", info
.dli_fname
? ":" : "",
102 info
.dli_sname
? "(" : "",
103 info
.dli_sname
?: "", info
.dli_sname
? ") " : " ",
108 fprintf (mallstream
, "@ [%p] ", caller
);
112 static void tr_freehook
__P ((__ptr_t
, const __ptr_t
));
114 tr_freehook (ptr
, caller
)
116 const __ptr_t caller
;
119 /* Be sure to print it first. */
120 fprintf (mallstream
, "- %p\n", ptr
);
121 if (ptr
== mallwatch
)
123 __libc_lock_lock (lock
);
124 __free_hook
= tr_old_free_hook
;
125 if (tr_old_free_hook
!= NULL
)
126 (*tr_old_free_hook
) (ptr
, caller
);
129 __free_hook
= tr_freehook
;
130 __libc_lock_unlock (lock
);
133 static __ptr_t tr_mallochook
__P ((__malloc_size_t
, const __ptr_t
));
135 tr_mallochook (size
, caller
)
136 __malloc_size_t size
;
137 const __ptr_t caller
;
141 __libc_lock_lock (lock
);
143 __malloc_hook
= tr_old_malloc_hook
;
144 if (tr_old_malloc_hook
!= NULL
)
145 hdr
= (__ptr_t
) (*tr_old_malloc_hook
) (size
, caller
);
147 hdr
= (__ptr_t
) malloc (size
);
148 __malloc_hook
= tr_mallochook
;
150 __libc_lock_unlock (lock
);
153 /* We could be printing a NULL here; that's OK. */
154 fprintf (mallstream
, "+ %p %#lx\n", hdr
, (unsigned long int) size
);
156 if (hdr
== mallwatch
)
162 static __ptr_t tr_reallochook
__P ((__ptr_t
, __malloc_size_t
, const __ptr_t
));
164 tr_reallochook (ptr
, size
, caller
)
166 __malloc_size_t size
;
167 const __ptr_t caller
;
171 if (ptr
== mallwatch
)
174 __libc_lock_lock (lock
);
176 __free_hook
= tr_old_free_hook
;
177 __malloc_hook
= tr_old_malloc_hook
;
178 __realloc_hook
= tr_old_realloc_hook
;
179 if (tr_old_realloc_hook
!= NULL
)
180 hdr
= (__ptr_t
) (*tr_old_realloc_hook
) (ptr
, size
, caller
);
182 hdr
= (__ptr_t
) realloc (ptr
, size
);
183 __free_hook
= tr_freehook
;
184 __malloc_hook
= tr_mallochook
;
185 __realloc_hook
= tr_reallochook
;
187 __libc_lock_unlock (lock
);
191 /* Failed realloc. */
192 fprintf (mallstream
, "! %p %#lx\n", ptr
, (unsigned long int) size
);
193 else if (ptr
== NULL
)
194 fprintf (mallstream
, "+ %p %#lx\n", hdr
, (unsigned long int) size
);
196 fprintf (mallstream
, "< %p\n> %p %#lx\n", ptr
, hdr
,
197 (unsigned long int) size
);
199 if (hdr
== mallwatch
)
207 extern void __libc_freeres (void);
209 /* This function gets called to make sure all memory the library
210 allocates get freed and so does not irritate the user when studying
211 the mtrace output. */
213 release_libc_mem (void)
215 /* Only call the free function if we still are running in mtrace mode. */
216 if (mallstream
!= NULL
)
222 /* We enable tracing if either the environment variable MALLOC_TRACE
223 is set, or if the variable mallwatch has been patched to an address
224 that the debugging user wants us to stop on. When patching mallwatch,
225 don't forget to set a breakpoint on tr_break! */
231 static int added_atexit_handler
= 0;
235 /* Don't panic if we're called more than once. */
236 if (mallstream
!= NULL
)
240 /* When compiling the GNU libc we use the secure getenv function
241 which prevents the misuse in case of SUID or SGID enabled
243 mallfile
= __secure_getenv (mallenv
);
245 mallfile
= getenv (mallenv
);
247 if (mallfile
!= NULL
|| mallwatch
!= NULL
)
249 mallstream
= fopen (mallfile
!= NULL
? mallfile
: "/dev/null", "w");
250 if (mallstream
!= NULL
)
252 /* Be sure it doesn't malloc its buffer! */
253 setvbuf (mallstream
, malloc_trace_buffer
, _IOFBF
, TRACE_BUFFER_SIZE
);
254 fprintf (mallstream
, "= Start\n");
255 tr_old_free_hook
= __free_hook
;
256 __free_hook
= tr_freehook
;
257 tr_old_malloc_hook
= __malloc_hook
;
258 __malloc_hook
= tr_mallochook
;
259 tr_old_realloc_hook
= __realloc_hook
;
260 __realloc_hook
= tr_reallochook
;
262 if (!added_atexit_handler
)
264 added_atexit_handler
= 1;
265 atexit (release_libc_mem
);
275 if (mallstream
== NULL
)
278 fprintf (mallstream
, "= End\n");
281 __free_hook
= tr_old_free_hook
;
282 __malloc_hook
= tr_old_malloc_hook
;
283 __realloc_hook
= tr_old_realloc_hook
;