path: root/malloc/malloc-debug.c

/* Malloc debug DSO.
   Copyright (C) 2021-2023 Free Software Foundation, Inc.
   Copyright The GNU Toolchain Authors.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public License as
   published by the Free Software Foundation; either version 2.1 of the
   License, or (at your option) any later version.

   The GNU C 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If
   not, see <https://www.gnu.org/licenses/>.  */

#include <atomic.h>
#include <libc-symbols.h>
#include <shlib-compat.h>
#include <string.h>
#include <unistd.h>
#include <sys/param.h>

/* Support only the glibc allocators.  */
extern void *__libc_malloc (size_t);
extern void __libc_free (void *);
extern void *__libc_realloc (void *, size_t);
extern void *__libc_memalign (size_t, size_t);
extern void *__libc_valloc (size_t);
extern void *__libc_pvalloc (size_t);
extern void *__libc_calloc (size_t, size_t);

#define DEBUG_FN(fn) \
  static __typeof (__libc_ ## fn) __debug_ ## fn

DEBUG_FN(malloc);
DEBUG_FN(free);
DEBUG_FN(realloc);
DEBUG_FN(memalign);
DEBUG_FN(valloc);
DEBUG_FN(pvalloc);
DEBUG_FN(calloc);

static int debug_initialized = -1;

enum malloc_debug_hooks
{
  MALLOC_NONE_HOOK = 0,
  MALLOC_MCHECK_HOOK = 1 << 0, /* mcheck()  */
  MALLOC_MTRACE_HOOK = 1 << 1, /* mtrace()  */
  MALLOC_CHECK_HOOK = 1 << 2,  /* MALLOC_CHECK_ or glibc.malloc.check.  */
};
static unsigned __malloc_debugging_hooks;

static __always_inline bool
__is_malloc_debug_enabled (enum malloc_debug_hooks flag)
{
  return __malloc_debugging_hooks & flag;
}

static __always_inline void
__malloc_debug_enable (enum malloc_debug_hooks flag)
{
  __malloc_debugging_hooks |= flag;
}

static __always_inline void
__malloc_debug_disable (enum malloc_debug_hooks flag)
{
  __malloc_debugging_hooks &= ~flag;
}

#include "mcheck.c"
#include "mtrace.c"
#include "malloc-check.c"

#if SHLIB_COMPAT (libc_malloc_debug, GLIBC_2_0, GLIBC_2_24)
extern void (*__malloc_initialize_hook) (void);
compat_symbol_reference (libc, __malloc_initialize_hook,
			 __malloc_initialize_hook, GLIBC_2_0);
#endif

static void *malloc_hook_ini (size_t, const void *) __THROW;
static void *realloc_hook_ini (void *, size_t, const void *) __THROW;
static void *memalign_hook_ini (size_t, size_t, const void *) __THROW;

void (*__free_hook) (void *, const void *) = NULL;
void *(*__malloc_hook) (size_t, const void *) = malloc_hook_ini;
void *(*__realloc_hook) (void *, size_t, const void *) = realloc_hook_ini;
void *(*__memalign_hook) (size_t, size_t, const void *