diff options
Diffstat (limited to 'e2fsck/mtrace.c')
| -rw-r--r-- | e2fsck/mtrace.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/e2fsck/mtrace.c b/e2fsck/mtrace.c new file mode 100644 index 0000000..2b7b34a --- /dev/null +++ b/e2fsck/mtrace.c @@ -0,0 +1,160 @@ +/* More debugging hooks for `malloc'. + Copyright (C) 1991, 1992 Free Software Foundation, Inc. + Written April 2, 1991 by John Gilmore of Cygnus Support. + Based on mcheck.c by Mike Haertel. + +This library is free software; you can redistribute it and/or +modify it under the terms of the GNU Library General Public License as +published by the Free Software Foundation; either version 2 of the +License, or (at your option) any later version. + +This 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 +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with this library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 675 Mass Ave, +Cambridge, MA 02139, USA. + + The author may be reached (Email) at the address mike@ai.mit.edu, + or (US mail) as Mike Haertel c/o Free Software Foundation. */ + +#include "config.h" + +#ifndef _MALLOC_INTERNAL +#define _MALLOC_INTERNAL +#include "./mtrace.h" +#endif + +#include <stdio.h> + +#ifndef __GNU_LIBRARY__ +extern char *getenv (); +#else +#include <stdlib.h> +#endif + +static FILE *mallstream; +static char mallenv[]= "MALLOC_TRACE"; +static char mallbuf[BUFSIZ]; /* Buffer for the output. */ + +/* Address to breakpoint on accesses to... */ +__ptr_t mallwatch; + +/* Old hook values. */ +static void (*tr_old_free_hook) __P ((__ptr_t ptr)); +static __ptr_t (*tr_old_malloc_hook) __P ((size_t size)); +static __ptr_t (*tr_old_realloc_hook) __P ((__ptr_t ptr, size_t size)); + +/* + * Added by TYT, 10/10/93 --- so that we can print + */ +FILE *malloc_get_mallstream() +{ + return mallstream; +} + +/* This function is called when the block being alloc'd, realloc'd, or + freed has an address matching the variable "mallwatch". In a debugger, + set "mallwatch" to the address of interest, then put a breakpoint on + tr_break. */ + +void tr_break __P ((void)); +void +tr_break () +{ +} + +static void tr_freehook __P ((__ptr_t)); +static void +tr_freehook (ptr) + __ptr_t ptr; +{ + fprintf (mallstream, "- %p\n", ptr); /* Be sure to print it first. */ + if (ptr == mallwatch) + tr_break (); + __free_hook = tr_old_free_hook; + free (ptr); + __free_hook = tr_freehook; +} + +static __ptr_t tr_mallochook __P ((size_t)); +static __ptr_t +tr_mallochook (size) + size_t size; +{ + __ptr_t hdr; + + __malloc_hook = tr_old_malloc_hook; + hdr = (__ptr_t) malloc (size); + __malloc_hook = tr_mallochook; + + /* We could be printing a NULL here; that's OK. */ + fprintf (mallstream, "+ %p %d\n", hdr, size); + + if (hdr == mallwatch) + tr_break (); + + return hdr; +} + +static __ptr_t tr_reallochook __P ((__ptr_t, size_t)); +static __ptr_t +tr_reallochook (ptr, size) + __ptr_t ptr; + size_t size; +{ + __ptr_t hdr; + + if (ptr == mallwatch) + tr_break (); + + __free_hook = tr_old_free_hook; + __malloc_hook = tr_old_malloc_hook; + __realloc_hook = tr_old_realloc_hook; + hdr = (__ptr_t) realloc (ptr, size); + __free_hook = tr_freehook; + __malloc_hook = tr_mallochook; + __realloc_hook = tr_reallochook; + if (hdr == NULL) + /* Failed realloc. */ + fprintf (mallstream, "! %p %d\n", ptr, size); + else + fprintf (mallstream, "< %p\n> %p %d\n", ptr, hdr, size); + + if (hdr == mallwatch) + tr_break (); + + return hdr; +} + +/* We enable tracing if either the environment variable MALLOC_TRACE + is set, or if the variable mallwatch has been patched to an address + that the debugging user wants us to stop on. When patching mallwatch, + don't forget to set a breakpoint on tr_break! */ + +void +mtrace () +{ + char *mallfile; + + mallfile = getenv (mallenv); + if (mallfile != NULL || mallwatch != NULL) + { + mallstream = fopen (mallfile != NULL ? mallfile : "/dev/null", "w"); + if (mallstream != NULL) + { + /* Be sure it doesn't malloc its buffer! */ + setbuf (mallstream, mallbuf); + fprintf (mallstream, "= Start\n"); + tr_old_free_hook = __free_hook; + __free_hook = tr_freehook; + tr_old_malloc_hook = __malloc_hook; + __malloc_hook = tr_mallochook; + tr_old_realloc_hook = __realloc_hook; + __realloc_hook = tr_reallochook; + } + } +} |