diff options
Diffstat (limited to 'malloc/malloc-debug.c')
| -rw-r--r-- | malloc/malloc-debug.c | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/malloc/malloc-debug.c b/malloc/malloc-debug.c new file mode 100644 index 0000000000..41dfcd3369 --- /dev/null +++ b/malloc/malloc-debug.c @@ -0,0 +1,189 @@ +/* Malloc debug DSO. + Copyright (C) 2021 Free Software Foundation, Inc. + 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); + +extern void (*__free_hook) (void *, const void *); +compat_symbol_reference (libc, __free_hook, __free_hook, GLIBC_2_0); +extern void * (*__malloc_hook) (size_t, const void *); +compat_symbol_reference (libc, __malloc_hook, __malloc_hook, GLIBC_2_0); +extern void * (*__realloc_hook) (void *, size_t, const void *); +compat_symbol_reference (libc, __realloc_hook, __realloc_hook, GLIBC_2_0); +extern void * (*__memalign_hook) (size_t, size_t, const void *); +compat_symbol_reference (libc, __memalign_hook, __memalign_hook, GLIBC_2_0); + +static size_t pagesize; + +/* The allocator functions. */ + +static void * +__debug_malloc (size_t bytes) +{ + void *(*hook) (size_t, const void *) = atomic_forced_read (__malloc_hook); + if (__builtin_expect (hook != NULL, 0)) + return (*hook)(bytes, RETURN_ADDRESS (0)); + + return __libc_malloc (bytes); +} +strong_alias (__debug_malloc, malloc) + +static void +__debug_free (void *mem) +{ + void (*hook) (void *, const void *) = atomic_forced_read (__free_hook); + if (__builtin_expect (hook != NULL, 0)) + { + (*hook)(mem, RETURN_ADDRESS (0)); + return; + } + __libc_free (mem); +} +strong_alias (__debug_free, free) + +static void * +__debug_realloc (void *oldmem, size_t bytes) +{ + void *(*hook) (void *, size_t, const void *) = + atomic_forced_read (__realloc_hook); + if (__builtin_expect (hook != NULL, 0)) + return (*hook)(oldmem, bytes, RETURN_ADDRESS (0)); + + return __libc_realloc (oldmem, bytes); +} +strong_alias (__debug_realloc, realloc) + +static void * +_debug_mid_memalign (size_t alignment, size_t bytes, const void *address) +{ + void *(*hook) (size_t, size_t, const void *) = + atomic_forced_read (__memalign_hook); + if (__builtin_expect (hook != NULL, 0)) + return (*hook)(alignment, bytes, address); + + return __libc_memalign (alignment, bytes); +} + +static void * +__debug_memalign (size_t alignment, size_t bytes) +{ + return _debug_mid_memalign (alignment, bytes, RETURN_ADDRESS (0)); +} +strong_alias (__debug_memalign, memalign) +strong_alias (__debug_memalign, aligned_alloc) + +static void * +__debug_pvalloc (size_t bytes) +{ + size_t rounded_bytes; + + if (!pagesize) + pagesize = sysconf (_SC_PAGESIZE); + + /* ALIGN_UP with overflow check. */ + if (__glibc_unlikely (__builtin_add_overflow (bytes, + pagesize - 1, + &rounded_bytes))) + { + errno = ENOMEM; + return NULL; + } + rounded_bytes = rounded_bytes & -(pagesize - 1); + + return _debug_mid_memalign (pagesize, rounded_bytes, RETURN_ADDRESS (0)); +} +strong_alias (__debug_pvalloc, pvalloc) + +static void * +__debug_valloc (size_t bytes) +{ + if (!pagesize) + pagesize = sysconf (_SC_PAGESIZE); + + return _debug_mid_memalign (pagesize, bytes, RETURN_ADDRESS (0)); +} +strong_alias (__debug_valloc, valloc) + +static int +__debug_posix_memalign (void **memptr, size_t alignment, size_t bytes) +{ + /* Test whether the SIZE argument is valid. It must be a power of + two multiple of sizeof (void *). */ + if (alignment % sizeof (void *) != 0 + || !powerof2 (alignment / sizeof (void *)) + || alignment == 0) + return EINVAL; + + *memptr = _debug_mid_memalign (alignment, bytes, RETURN_ADDRESS (0)); + + if (*memptr == NULL) + return ENOMEM; + + return 0; +} +strong_alias (__debug_posix_memalign, posix_memalign) + +static void * +__debug_calloc (size_t nmemb, size_t size) +{ + void *(*hook) (size_t, const void *) = atomic_forced_read (__malloc_hook); + if (__builtin_expect (hook != NULL, 0)) + { + size_t bytes; + + if (__glibc_unlikely (__builtin_mul_overflow (nmemb, size, &bytes))) + { + errno = ENOMEM; + return NULL; + } + + void *mem = (*hook)(bytes, RETURN_ADDRESS (0)); + + if (mem != NULL) + memset (mem, 0, bytes); + + return mem; + } + + return __libc_calloc (nmemb, size); +} +strong_alias (__debug_calloc, calloc) |