1// Copyright (c) 2011, Google Inc. 2// All rights reserved. 3// 4// Redistribution and use in source and binary forms, with or without 5// modification, are permitted provided that the following conditions are 6// met: 7// 8// * Redistributions of source code must retain the above copyright 9// notice, this list of conditions and the following disclaimer. 10// * Redistributions in binary form must reproduce the above 11// copyright notice, this list of conditions and the following disclaimer 12// in the documentation and/or other materials provided with the 13// distribution. 14// * Neither the name of Google Inc. nor the names of its 15// contributors may be used to endorse or promote products derived from 16// this software without specific prior written permission. 17// 18// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 30// --- 31// Author: Craig Silverstein <opensource@google.com> 32// 33// Used to override malloc routines on systems that are using glibc. 34 35#ifndef TCMALLOC_LIBC_OVERRIDE_GLIBC_INL_H_ 36#define TCMALLOC_LIBC_OVERRIDE_GLIBC_INL_H_ 37 38#include <config.h> 39#include <features.h> // for __GLIBC__ 40#ifdef HAVE_SYS_CDEFS_H 41#include <sys/cdefs.h> // for __THROW 42#endif 43#include <gperftools/tcmalloc.h> 44 45#ifndef __GLIBC__ 46# error libc_override_glibc.h is for glibc distributions only. 47#endif 48 49// In glibc, the memory-allocation methods are weak symbols, so we can 50// just override them with our own. If we're using gcc, we can use 51// __attribute__((alias)) to do the overriding easily (exception: 52// Mach-O, which doesn't support aliases). Otherwise we have to use a 53// function call. 54#if !defined(__GNUC__) || defined(__MACH__) 55 56// This also defines ReplaceSystemAlloc(). 57# include "libc_override_redefine.h" // defines functions malloc()/etc 58 59#else // #if !defined(__GNUC__) || defined(__MACH__) 60 61// If we get here, we're a gcc system, so do all the overriding we do 62// with gcc. This does the overriding of all the 'normal' memory 63// allocation. This also defines ReplaceSystemAlloc(). 64# include "libc_override_gcc_and_weak.h" 65 66// We also have to do some glibc-specific overriding. Some library 67// routines on RedHat 9 allocate memory using malloc() and free it 68// using __libc_free() (or vice-versa). Since we provide our own 69// implementations of malloc/free, we need to make sure that the 70// __libc_XXX variants (defined as part of glibc) also point to the 71// same implementations. Since it only matters for redhat, we 72// do it inside the gcc #ifdef, since redhat uses gcc. 73// TODO(csilvers): only do this if we detect we're an old enough glibc? 74 75#define ALIAS(tc_fn) __attribute__ ((alias (#tc_fn))) 76extern "C" { 77 void* __libc_malloc(size_t size) ALIAS(tc_malloc); 78 void __libc_free(void* ptr) ALIAS(tc_free); 79 void* __libc_realloc(void* ptr, size_t size) ALIAS(tc_realloc); 80 void* __libc_calloc(size_t n, size_t size) ALIAS(tc_calloc); 81 void __libc_cfree(void* ptr) ALIAS(tc_cfree); 82 void* __libc_memalign(size_t align, size_t s) ALIAS(tc_memalign); 83 void* __libc_valloc(size_t size) ALIAS(tc_valloc); 84 void* __libc_pvalloc(size_t size) ALIAS(tc_pvalloc); 85 int __posix_memalign(void** r, size_t a, size_t s) ALIAS(tc_posix_memalign); 86} // extern "C" 87#undef ALIAS 88 89#endif // #if defined(__GNUC__) && !defined(__MACH__) 90 91 92// We also have to hook libc malloc. While our work with weak symbols 93// should make sure libc malloc is never called in most situations, it 94// can be worked around by shared libraries with the DEEPBIND 95// environment variable set. The below hooks libc to call our malloc 96// routines even in that situation. In other situations, this hook 97// should never be called. 98extern "C" { 99static void* glibc_override_malloc(size_t size, const void *caller) { 100 return tc_malloc(size); 101} 102static void* glibc_override_realloc(void *ptr, size_t size, 103 const void *caller) { 104 return tc_realloc(ptr, size); 105} 106static void glibc_override_free(void *ptr, const void *caller) { 107 tc_free(ptr); 108} 109static void* glibc_override_memalign(size_t align, size_t size, 110 const void *caller) { 111 return tc_memalign(align, size); 112} 113 114// We should be using __malloc_initialize_hook here, like the #if 0 115// code below. (See http://swoolley.org/man.cgi/3/malloc_hook.) 116// However, this causes weird linker errors with programs that link 117// with -static, so instead we just assign the vars directly at 118// static-constructor time. That should serve the same effect of 119// making sure the hooks are set before the first malloc call the 120// program makes. 121#if 0 122#include <malloc.h> // for __malloc_hook, etc. 123void glibc_override_malloc_init_hook(void) { 124 __malloc_hook = glibc_override_malloc; 125 __realloc_hook = glibc_override_realloc; 126 __free_hook = glibc_override_free; 127 __memalign_hook = glibc_override_memalign; 128} 129 130void (* MALLOC_HOOK_MAYBE_VOLATILE __malloc_initialize_hook)(void) 131 = &glibc_override_malloc_init_hook; 132#endif 133 134void* (* MALLOC_HOOK_MAYBE_VOLATILE __malloc_hook)(size_t, const void*) 135 = &glibc_override_malloc; 136void* (* MALLOC_HOOK_MAYBE_VOLATILE __realloc_hook)(void*, size_t, const void*) 137 = &glibc_override_realloc; 138void (* MALLOC_HOOK_MAYBE_VOLATILE __free_hook)(void*, const void*) 139 = &glibc_override_free; 140void* (* MALLOC_HOOK_MAYBE_VOLATILE __memalign_hook)(size_t,size_t, const void*) 141 = &glibc_override_memalign; 142 143} // extern "C" 144 145// No need to write ReplaceSystemAlloc(); one of the #includes above 146// did it for us. 147 148#endif // TCMALLOC_LIBC_OVERRIDE_GLIBC_INL_H_ 149