third_party/tcmalloc/chromium/src/malloc_hook_mmap_freebsd.h

   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 // Override mmap/munmap/mremap/sbrk to provide support for calling the
  31 // related hooks (in addition, of course, to doing what these
  32 // functions normally do).
  33
  34 #ifndef __FreeBSD__
  35 # error Should only be including malloc_hook_mmap_freebsd.h on FreeBSD systems.
  36 #endif
  37
  38 #include <unistd.h>
  39 #include <sys/syscall.h>
  40 #include <sys/mman.h>
  41 #include <errno.h>
  42
  43 // Make sure mmap doesn't get #define'd away by <sys/mman.h>
  44 #undef mmap
  45
  46 // According to the FreeBSD documentation, use syscall if you do not
  47 // need 64-bit alignment otherwise use __syscall. Indeed, syscall
  48 // doesn't work correctly in most situations on 64-bit. It's return
  49 // type is 'int' so for things like SYS_mmap, it actually truncates
  50 // the returned address to 32-bits.
  51 #if defined(__amd64__) || defined(__x86_64__)
  52 # define MALLOC_HOOK_SYSCALL __syscall
  53 #else
  54 # define MALLOC_HOOK_SYSCALL syscall
  55 #endif
  56
  57
  58 extern "C" {
  59   void* mmap(void *start, size_t length,int prot, int flags,
  60              int fd, off_t offset) __THROW
  61     ATTRIBUTE_SECTION(malloc_hook);
  62   int munmap(void* start, size_t length) __THROW
  63     ATTRIBUTE_SECTION(malloc_hook);
  64   void* sbrk(intptr_t increment) __THROW
  65     ATTRIBUTE_SECTION(malloc_hook);
  66 }
  67
  68 static inline void* do_mmap(void *start, size_t length,
  69                             int prot, int flags,
  70                             int fd, off_t offset) __THROW {
  71   return (void *)MALLOC_HOOK_SYSCALL(SYS_mmap,
  72                                      start, length, prot, flags, fd, offset);
  73 }
  74
  75 static inline void* do_sbrk(intptr_t increment) {
  76   void* curbrk = 0;
  77
  78 #if defined(__x86_64__) || defined(__amd64__)
  79 # ifdef PIC
  80   __asm__ __volatile__(
  81       "movq .curbrk@GOTPCREL(%%rip), %%rdx;"
  82       "movq (%%rdx), %%rax;"
  83       "movq %%rax, %0;"
  84       : "=r" (curbrk)
  85       :: "%rdx", "%rax");
  86 # else
  87   __asm__ __volatile__(
  88       "movq .curbrk(%%rip), %%rax;"
  89       "movq %%rax, %0;"
  90       : "=r" (curbrk)
  91       :: "%rax");
  92 # endif
  93 #else
  94   __asm__ __volatile__(
  95       "movl .curbrk, %%eax;"
  96       "movl %%eax, %0;"
  97       : "=r" (curbrk)
  98       :: "%eax");
  99 #endif
 100
 101   if (increment == 0) {
 102     return curbrk;
 103   }
 104
 105   char* prevbrk = static_cast<char*>(curbrk);
 106   void* newbrk = prevbrk + increment;
 107
 108   if (brk(newbrk) == -1) {
 109     return reinterpret_cast<void*>(static_cast<intptr_t>(-1));
 110   }
 111
 112   return prevbrk;
 113 }
 114
 115
 116 extern "C" void* mmap(void *start, size_t length, int prot, int flags,
 117                       int fd, off_t offset) __THROW {
 118   MallocHook::InvokePreMmapHook(start, length, prot, flags, fd, offset);
 119   void *result;
 120   if (!MallocHook::InvokeMmapReplacement(
 121           start, length, prot, flags, fd, offset, &result)) {
 122     result = do_mmap(start, length, prot, flags, fd,
 123                        static_cast<size_t>(offset)); // avoid sign extension
 124   }
 125   MallocHook::InvokeMmapHook(result, start, length, prot, flags, fd, offset);
 126   return result;
 127 }
 128
 129 extern "C" int munmap(void* start, size_t length) __THROW {
 130   MallocHook::InvokeMunmapHook(start, length);
 131   int result;
 132   if (!MallocHook::InvokeMunmapReplacement(start, length, &result)) {
 133     result = MALLOC_HOOK_SYSCALL(SYS_munmap, start, length);
 134   }
 135
 136   return result;
 137 }
 138
 139 extern "C" void* sbrk(intptr_t increment) __THROW {
 140   MallocHook::InvokePreSbrkHook(increment);
 141   void *result = do_sbrk(increment);
 142   MallocHook::InvokeSbrkHook(result, increment);
 143   return result;
 144 }
 145
 146 /*static*/void* MallocHook::UnhookedMMap(void *start, size_t length, int prot,
 147                                          int flags, int fd, off_t offset) {
 148   void* result;
 149   if (!MallocHook::InvokeMmapReplacement(
 150           start, length, prot, flags, fd, offset, &result)) {
 151     result = do_mmap(start, length, prot, flags, fd, offset);
 152   }
 153
 154   return result;
 155 }
 156
 157 /*static*/int MallocHook::UnhookedMUnmap(void *start, size_t length) {
 158   int result;
 159   if (!MallocHook::InvokeMunmapReplacement(start, length, &result)) {
 160     result = MALLOC_HOOK_SYSCALL(SYS_munmap, start, length);
 161   }
 162   return result;
 163 }
 164
 165 #undef MALLOC_HOOK_SYSCALL