From a3ba27daef3bf81a134eb0208a8c5207b829f560 Mon Sep 17 00:00:00 2001 From: Gerd Moellmann Date: Fri, 27 Oct 2000 18:43:39 +0000 Subject: [PATCH] Add code from mcheck.c of glibc-1.09.1. (freehook, reallochook): Handle null pointer arguments. (__malloc_initialize) [GC_MCHECK]: Call mcheck. --- src/ChangeLog | 6 ++ src/gmalloc.c | 243 ++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 249 insertions(+) diff --git a/src/ChangeLog b/src/ChangeLog index f68e735ad7b..952b9fa9295 100644 --- a/src/ChangeLog +++ b/src/ChangeLog @@ -1,3 +1,9 @@ +2000-10-27 Gerd Moellmann + + * gmalloc.c [GC_MCHECK]: Add code from mcheck.c of glibc-1.09.1. + (freehook, reallochook): Handle null pointer arguments. + (__malloc_initialize) [GC_MCHECK]: Call mcheck. + 2000-10-27 Stefan Monnier * regex.c (POP_FAILURE_REG_OR_COUNT, re_match_2_internal) diff --git a/src/gmalloc.c b/src/gmalloc.c index e7cc2c3947e..751e90baf13 100644 --- a/src/gmalloc.c +++ b/src/gmalloc.c @@ -522,6 +522,10 @@ __malloc_initialize () if (__malloc_initialized) return 0; +#ifdef GC_MCHECK + mcheck (NULL); +#endif + if (__malloc_initialize_hook) (*__malloc_initialize_hook) (); @@ -1718,3 +1722,242 @@ valloc (size) } #endif /* Not ELIDE_VALLOC. */ + +#ifdef GC_MCHECK + +/* Standard debugging hooks for `malloc'. + Copyright 1990, 1991, 1992, 1993, 1994 Free Software Foundation, Inc. + Written May 1989 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. */ + +#ifdef emacs +#include +#else +#ifndef _MALLOC_INTERNAL +#define _MALLOC_INTERNAL +#include +#include +#endif +#endif + +/* Old hook values. */ +static void (*old_free_hook) __P ((__ptr_t ptr)); +static __ptr_t (*old_malloc_hook) __P ((__malloc_size_t size)); +static __ptr_t (*old_realloc_hook) __P ((__ptr_t ptr, __malloc_size_t size)); + +/* Function to call when something awful happens. */ +static void (*abortfunc) __P ((enum mcheck_status)); + +/* Arbitrary magical numbers. */ +#define MAGICWORD 0xfedabeeb +#define MAGICFREE 0xd8675309 +#define MAGICBYTE ((char) 0xd7) +#define MALLOCFLOOD ((char) 0x93) +#define FREEFLOOD ((char) 0x95) + +struct hdr + { + __malloc_size_t size; /* Exact size requested by user. */ + unsigned long int magic; /* Magic number to check header integrity. */ + }; + +#if defined(_LIBC) || defined(STDC_HEADERS) || defined(USG) +#define flood memset +#else +static void flood __P ((__ptr_t, int, __malloc_size_t)); +static void +flood (ptr, val, size) + __ptr_t ptr; + int val; + __malloc_size_t size; +{ + char *cp = ptr; + while (size--) + *cp++ = val; +} +#endif + +static enum mcheck_status checkhdr __P ((const struct hdr *)); +static enum mcheck_status +checkhdr (hdr) + const struct hdr *hdr; +{ + enum mcheck_status status; + switch (hdr->magic) + { + default: + status = MCHECK_HEAD; + break; + case MAGICFREE: + status = MCHECK_FREE; + break; + case MAGICWORD: + if (((char *) &hdr[1])[hdr->size] != MAGICBYTE) + status = MCHECK_TAIL; + else + status = MCHECK_OK; + break; + } + if (status != MCHECK_OK) + (*abortfunc) (status); + return status; +} + +static void freehook __P ((__ptr_t)); +static void +freehook (ptr) + __ptr_t ptr; +{ + struct hdr *hdr; + + if (ptr) + { + hdr = ((struct hdr *) ptr) - 1; + checkhdr (hdr); + hdr->magic = MAGICFREE; + flood (ptr, FREEFLOOD, hdr->size); + } + else + hdr = NULL; + + __free_hook = old_free_hook; + free (hdr); + __free_hook = freehook; +} + +static __ptr_t mallochook __P ((__malloc_size_t)); +static __ptr_t +mallochook (size) + __malloc_size_t size; +{ + struct hdr *hdr; + + __malloc_hook = old_malloc_hook; + hdr = (struct hdr *) malloc (sizeof (struct hdr) + size + 1); + __malloc_hook = mallochook; + if (hdr == NULL) + return NULL; + + hdr->size = size; + hdr->magic = MAGICWORD; + ((char *) &hdr[1])[size] = MAGICBYTE; + flood ((__ptr_t) (hdr + 1), MALLOCFLOOD, size); + return (__ptr_t) (hdr + 1); +} + +static __ptr_t reallochook __P ((__ptr_t, __malloc_size_t)); +static __ptr_t +reallochook (ptr, size) + __ptr_t ptr; + __malloc_size_t size; +{ + struct hdr *hdr = NULL; + __malloc_size_t osize = 0; + + if (ptr) + { + hdr = ((struct hdr *) ptr) - 1; + osize = hdr->size; + + checkhdr (hdr); + if (size < osize) + flood ((char *) ptr + size, FREEFLOOD, osize - size); + } + + __free_hook = old_free_hook; + __malloc_hook = old_malloc_hook; + __realloc_hook = old_realloc_hook; + hdr = (struct hdr *) realloc ((__ptr_t) hdr, sizeof (struct hdr) + size + 1); + __free_hook = freehook; + __malloc_hook = mallochook; + __realloc_hook = reallochook; + if (hdr == NULL) + return NULL; + + hdr->size = size; + hdr->magic = MAGICWORD; + ((char *) &hdr[1])[size] = MAGICBYTE; + if (size > osize) + flood ((char *) (hdr + 1) + osize, MALLOCFLOOD, size - osize); + return (__ptr_t) (hdr + 1); +} + +static void +mabort (status) + enum mcheck_status status; +{ + const char *msg; + switch (status) + { + case MCHECK_OK: + msg = "memory is consistent, library is buggy"; + break; + case MCHECK_HEAD: + msg = "memory clobbered before allocated block"; + break; + case MCHECK_TAIL: + msg = "memory clobbered past end of allocated block"; + break; + case MCHECK_FREE: + msg = "block freed twice"; + break; + default: + msg = "bogus mcheck_status, library is buggy"; + break; + } +#ifdef __GNU_LIBRARY__ + __libc_fatal (msg); +#else + fprintf (stderr, "mcheck: %s\n", msg); + fflush (stderr); + abort (); +#endif +} + +static int mcheck_used = 0; + +int +mcheck (func) + void (*func) __P ((enum mcheck_status)); +{ + abortfunc = (func != NULL) ? func : &mabort; + + /* These hooks may not be safely inserted if malloc is already in use. */ + if (!__malloc_initialized && !mcheck_used) + { + old_free_hook = __free_hook; + __free_hook = freehook; + old_malloc_hook = __malloc_hook; + __malloc_hook = mallochook; + old_realloc_hook = __realloc_hook; + __realloc_hook = reallochook; + mcheck_used = 1; + } + + return mcheck_used ? 0 : -1; +} + +enum mcheck_status +mprobe (__ptr_t ptr) +{ + return mcheck_used ? checkhdr (ptr) : MCHECK_DISABLED; +} + +#endif /* GC_MCHECK */ -- 2.39.2