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-rw-r--r--gnu/lib/libmalloc/mcheck.c133
1 files changed, 133 insertions, 0 deletions
diff --git a/gnu/lib/libmalloc/mcheck.c b/gnu/lib/libmalloc/mcheck.c
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+++ b/gnu/lib/libmalloc/mcheck.c
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+/* Standard debugging hooks for `malloc'.
+ Copyright 1990, 1991, 1992, 1993 Free Software Foundation
+ 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. */
+
+#ifndef _MALLOC_INTERNAL
+#define _MALLOC_INTERNAL
+#include <malloc.h>
+#endif
+
+/* Old hook values. */
+static void (*old_free_hook) __P ((__ptr_t ptr));
+static __ptr_t (*old_malloc_hook) __P ((size_t size));
+static __ptr_t (*old_realloc_hook) __P ((__ptr_t ptr, size_t size));
+
+/* Function to call when something awful happens. */
+static void (*abortfunc) __P ((void));
+
+/* Arbitrary magical numbers. */
+#define MAGICWORD 0xfedabeeb
+#define MAGICBYTE ((char) 0xd7)
+
+struct hdr
+ {
+ size_t size; /* Exact size requested by user. */
+ unsigned long int magic; /* Magic number to check header integrity. */
+ };
+
+static void checkhdr __P ((const struct hdr *));
+static void
+checkhdr (hdr)
+ const struct hdr *hdr;
+{
+ if (hdr->magic != MAGICWORD || ((char *) &hdr[1])[hdr->size] != MAGICBYTE)
+ (*abortfunc) ();
+}
+
+static void freehook __P ((__ptr_t));
+static void
+freehook (ptr)
+ __ptr_t ptr;
+{
+ struct hdr *hdr = ((struct hdr *) ptr) - 1;
+ checkhdr (hdr);
+ hdr->magic = 0;
+ __free_hook = old_free_hook;
+ free (hdr);
+ __free_hook = freehook;
+}
+
+static __ptr_t mallochook __P ((size_t));
+static __ptr_t
+mallochook (size)
+ 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;
+ return (__ptr_t) (hdr + 1);
+}
+
+static __ptr_t reallochook __P ((__ptr_t, size_t));
+static __ptr_t
+reallochook (ptr, size)
+ __ptr_t ptr;
+ size_t size;
+{
+ struct hdr *hdr = ((struct hdr *) ptr) - 1;
+
+ checkhdr (hdr);
+ __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;
+ ((char *) &hdr[1])[size] = MAGICBYTE;
+ return (__ptr_t) (hdr + 1);
+}
+
+int
+mcheck (func)
+ void (*func) __P ((void));
+{
+ extern void abort __P ((void));
+ static int mcheck_used = 0;
+
+ abortfunc = (func != NULL) ? func : abort;
+
+ /* 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;
+}
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