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 (at) 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 // MALLOC_HOOK_MAYBE_VOLATILE is defined at config.h in the original gperftools. 39 // Chromium does this check with the macro __MALLOC_HOOK_VOLATILE. 40 // GLibc 2.14+ requires the hook functions be declared volatile, based on the 41 // value of the define __MALLOC_HOOK_VOLATILE. For compatibility with 42 // older/non-GLibc implementations, provide an empty definition. 43 #if !defined(__MALLOC_HOOK_VOLATILE) 44 #define MALLOC_HOOK_MAYBE_VOLATILE /**/ 45 #else 46 #define MALLOC_HOOK_MAYBE_VOLATILE __MALLOC_HOOK_VOLATILE 47 #endif 48 49 #include <config.h> 50 #include <features.h> // for __GLIBC__ 51 #ifdef HAVE_SYS_CDEFS_H 52 #include <sys/cdefs.h> // for __THROW 53 #endif 54 #include <gperftools/tcmalloc.h> 55 56 #ifndef __GLIBC__ 57 # error libc_override_glibc.h is for glibc distributions only. 58 #endif 59 60 // In glibc, the memory-allocation methods are weak symbols, so we can 61 // just override them with our own. If we're using gcc, we can use 62 // __attribute__((alias)) to do the overriding easily (exception: 63 // Mach-O, which doesn't support aliases). Otherwise we have to use a 64 // function call. 65 #if !defined(__GNUC__) || defined(__MACH__) 66 67 // This also defines ReplaceSystemAlloc(). 68 # include "libc_override_redefine.h" // defines functions malloc()/etc 69 70 #else // #if !defined(__GNUC__) || defined(__MACH__) 71 72 // If we get here, we're a gcc system, so do all the overriding we do 73 // with gcc. This does the overriding of all the 'normal' memory 74 // allocation. This also defines ReplaceSystemAlloc(). 75 # include "libc_override_gcc_and_weak.h" 76 77 // We also have to do some glibc-specific overriding. Some library 78 // routines on RedHat 9 allocate memory using malloc() and free it 79 // using __libc_free() (or vice-versa). Since we provide our own 80 // implementations of malloc/free, we need to make sure that the 81 // __libc_XXX variants (defined as part of glibc) also point to the 82 // same implementations. Since it only matters for redhat, we 83 // do it inside the gcc #ifdef, since redhat uses gcc. 84 // TODO(csilvers): only do this if we detect we're an old enough glibc? 85 86 #define ALIAS(tc_fn) __attribute__ ((alias (#tc_fn))) 87 extern "C" { 88 void* __libc_malloc(size_t size) ALIAS(tc_malloc); 89 void __libc_free(void* ptr) ALIAS(tc_free); 90 void* __libc_realloc(void* ptr, size_t size) ALIAS(tc_realloc); 91 void* __libc_calloc(size_t n, size_t size) ALIAS(tc_calloc); 92 void __libc_cfree(void* ptr) ALIAS(tc_cfree); 93 void* __libc_memalign(size_t align, size_t s) ALIAS(tc_memalign); 94 void* __libc_valloc(size_t size) ALIAS(tc_valloc); 95 void* __libc_pvalloc(size_t size) ALIAS(tc_pvalloc); 96 int __posix_memalign(void** r, size_t a, size_t s) ALIAS(tc_posix_memalign); 97 } // extern "C" 98 #undef ALIAS 99 100 #endif // #if defined(__GNUC__) && !defined(__MACH__) 101 102 103 // We also have to hook libc malloc. While our work with weak symbols 104 // should make sure libc malloc is never called in most situations, it 105 // can be worked around by shared libraries with the DEEPBIND 106 // environment variable set. The below hooks libc to call our malloc 107 // routines even in that situation. In other situations, this hook 108 // should never be called. 109 extern "C" { 110 static void* glibc_override_malloc(size_t size, const void *caller) { 111 return tc_malloc(size); 112 } 113 static void* glibc_override_realloc(void *ptr, size_t size, 114 const void *caller) { 115 return tc_realloc(ptr, size); 116 } 117 static void glibc_override_free(void *ptr, const void *caller) { 118 tc_free(ptr); 119 } 120 static void* glibc_override_memalign(size_t align, size_t size, 121 const void *caller) { 122 return tc_memalign(align, size); 123 } 124 125 // We should be using __malloc_initialize_hook here, like the #if 0 126 // code below. (See http://swoolley.org/man.cgi/3/malloc_hook.) 127 // However, this causes weird linker errors with programs that link 128 // with -static, so instead we just assign the vars directly at 129 // static-constructor time. That should serve the same effect of 130 // making sure the hooks are set before the first malloc call the 131 // program makes. 132 #if 0 133 #include <malloc.h> // for __malloc_hook, etc. 134 void glibc_override_malloc_init_hook(void) { 135 __malloc_hook = glibc_override_malloc; 136 __realloc_hook = glibc_override_realloc; 137 __free_hook = glibc_override_free; 138 __memalign_hook = glibc_override_memalign; 139 } 140 141 void (* MALLOC_HOOK_MAYBE_VOLATILE __malloc_initialize_hook)(void) 142 = &glibc_override_malloc_init_hook; 143 #endif 144 145 void* (* MALLOC_HOOK_MAYBE_VOLATILE __malloc_hook)(size_t, const void*) 146 = &glibc_override_malloc; 147 void* (* MALLOC_HOOK_MAYBE_VOLATILE __realloc_hook)(void*, size_t, const void*) 148 = &glibc_override_realloc; 149 void (* MALLOC_HOOK_MAYBE_VOLATILE __free_hook)(void*, const void*) 150 = &glibc_override_free; 151 void* (* MALLOC_HOOK_MAYBE_VOLATILE __memalign_hook)(size_t,size_t, const void*) 152 = &glibc_override_memalign; 153 154 } // extern "C" 155 156 // No need to write ReplaceSystemAlloc(); one of the #includes above 157 // did it for us. 158 159 #endif // TCMALLOC_LIBC_OVERRIDE_GLIBC_INL_H_ 160
