third_party/tcmalloc/chromium/src/malloc_hook_mmap_linux.h

   1 // Copyright (c) 2005, Google Inc.
   2 // All rights reserved.
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   9 // notice, this list of conditions and the following disclaimer.
  10 //     * Redistributions in binary form must reproduce the above
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  15 // contributors may be used to endorse or promote products derived from
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  17 //
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  21 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  22 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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  25 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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  28 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29
  30 // ---
  31 // Author: Sanjay Ghemawat <opensource@google.com>
  32
  33 // We define mmap() and mmap64(), which somewhat reimplements libc's mmap
  34 // syscall stubs.  Unfortunately libc only exports the stubs via weak symbols
  35 // (which we're overriding with our mmap64() and mmap() wrappers) so we can't
  36 // just call through to them.
  37
  38 #ifndef __linux
  39 # error Should only be including malloc_hook_mmap_linux.h on linux systems.
  40 #endif
  41
  42 #include <unistd.h>
  43 #include <syscall.h>
  44 #include <sys/mman.h>
  45 #include <errno.h>
  46 #include "base/linux_syscall_support.h"
  47
  48 // The x86-32 case and the x86-64 case differ:
  49 // 32b has a mmap2() syscall, 64b does not.
  50 // 64b and 32b have different calling conventions for mmap().
  51
  52 // I test for 64-bit first so I don't have to do things like
  53 // '#if (defined(__mips__) && !defined(__MIPS64__))' as a mips32 check.
  54 #if defined(__x86_64__) || defined(__PPC64__) || (defined(_MIPS_SIM) && _MIPS_SIM == _ABI64)
  55
  56 static inline void* do_mmap64(void *start, size_t length,
  57                               int prot, int flags,
  58                               int fd, __off64_t offset) __THROW {
  59   // The original gperftools uses sys_mmap() here.  But, it is not allowed by
  60   // Chromium's sandbox.
  61   return (void *)syscall(SYS_mmap, start, length, prot, flags, fd, offset);
  62 }
  63
  64 #define MALLOC_HOOK_HAVE_DO_MMAP64 1
  65
  66 #elif defined(__i386__) || defined(__PPC__) || defined(__mips__) || \
  67       defined(__arm__)
  68
  69 static inline void* do_mmap64(void *start, size_t length,
  70                               int prot, int flags,
  71                               int fd, __off64_t offset) __THROW {
  72   void *result;
  73
  74   // Try mmap2() unless it's not supported
  75   static bool have_mmap2 = true;
  76   if (have_mmap2) {
  77     static int pagesize = 0;
  78     if (!pagesize) pagesize = getpagesize();
  79
  80     // Check that the offset is page aligned
  81     if (offset & (pagesize - 1)) {
  82       result = MAP_FAILED;
  83       errno = EINVAL;
  84       goto out;
  85     }
  86
  87     result = (void *)syscall(SYS_mmap2,
  88                              start, length, prot, flags, fd,
  89                              (off_t) (offset / pagesize));
  90     if (result != MAP_FAILED || errno != ENOSYS)  goto out;
  91
  92     // We don't have mmap2() after all - don't bother trying it in future
  93     have_mmap2 = false;
  94   }
  95
  96   if (((off_t)offset) != offset) {
  97     // If we're trying to map a 64-bit offset, fail now since we don't
  98     // have 64-bit mmap() support.
  99     result = MAP_FAILED;
 100     errno = EINVAL;
 101     goto out;
 102   }
 103
 104 #ifdef __NR_mmap
 105   {
 106     // Fall back to old 32-bit offset mmap() call
 107     // Old syscall interface cannot handle six args, so pass in an array
 108     int32 args[6] = { (int32) start, (int32) length, prot, flags, fd,
 109                       (off_t) offset };
 110     result = (void *)syscall(SYS_mmap, args);
 111   }
 112 #else
 113   // Some Linux ports like ARM EABI Linux has no mmap, just mmap2.
 114   result = MAP_FAILED;
 115 #endif
 116
 117  out:
 118   return result;
 119 }
 120
 121 #define MALLOC_HOOK_HAVE_DO_MMAP64 1
 122
 123 #endif  // #if defined(__x86_64__)
 124
 125
 126 #ifdef MALLOC_HOOK_HAVE_DO_MMAP64
 127
 128 // We use do_mmap64 abstraction to put MallocHook::InvokeMmapHook
 129 // calls right into mmap and mmap64, so that the stack frames in the caller's
 130 // stack are at the same offsets for all the calls of memory allocating
 131 // functions.
 132
 133 // Put all callers of MallocHook::Invoke* in this module into
 134 // malloc_hook section,
 135 // so that MallocHook::GetCallerStackTrace can function accurately:
 136
 137 // Make sure mmap doesn't get #define'd away by <sys/mman.h>
 138 # undef mmap
 139
 140 extern "C" {
 141   void* mmap64(void *start, size_t length, int prot, int flags,
 142                int fd, __off64_t offset  ) __THROW
 143     ATTRIBUTE_SECTION(malloc_hook);
 144   void* mmap(void *start, size_t length,int prot, int flags,
 145              int fd, off_t offset) __THROW
 146     ATTRIBUTE_SECTION(malloc_hook);
 147   int munmap(void* start, size_t length) __THROW
 148     ATTRIBUTE_SECTION(malloc_hook);
 149   void* mremap(void* old_addr, size_t old_size, size_t new_size,
 150                int flags, ...) __THROW
 151     ATTRIBUTE_SECTION(malloc_hook);
 152   void* sbrk(ptrdiff_t increment) __THROW
 153     ATTRIBUTE_SECTION(malloc_hook);
 154 }
 155
 156 extern "C" void* mmap64(void *start, size_t length, int prot, int flags,
 157                         int fd, __off64_t offset) __THROW {
 158   MallocHook::InvokePreMmapHook(start, length, prot, flags, fd, offset);
 159   void *result;
 160   if (!MallocHook::InvokeMmapReplacement(
 161           start, length, prot, flags, fd, offset, &result)) {
 162     result = do_mmap64(start, length, prot, flags, fd, offset);
 163   }
 164   MallocHook::InvokeMmapHook(result, start, length, prot, flags, fd, offset);
 165   return result;
 166 }
 167
 168 # if !defined(__USE_FILE_OFFSET64) || !defined(__REDIRECT_NTH)
 169
 170 extern "C" void* mmap(void *start, size_t length, int prot, int flags,
 171                       int fd, off_t offset) __THROW {
 172   MallocHook::InvokePreMmapHook(start, length, prot, flags, fd, offset);
 173   void *result;
 174   if (!MallocHook::InvokeMmapReplacement(
 175           start, length, prot, flags, fd, offset, &result)) {
 176     result = do_mmap64(start, length, prot, flags, fd,
 177                        static_cast<size_t>(offset)); // avoid sign extension
 178   }
 179   MallocHook::InvokeMmapHook(result, start, length, prot, flags, fd, offset);
 180   return result;
 181 }
 182
 183 # endif  // !defined(__USE_FILE_OFFSET64) || !defined(__REDIRECT_NTH)
 184
 185 extern "C" int munmap(void* start, size_t length) __THROW {
 186   MallocHook::InvokeMunmapHook(start, length);
 187   int result;
 188   if (!MallocHook::InvokeMunmapReplacement(start, length, &result)) {
 189     // The original gperftools uses sys_munmap() here.  But, it is not allowed
 190     // by Chromium's sandbox.
 191     result = syscall(SYS_munmap, start, length);
 192   }
 193   return result;
 194 }
 195
 196 extern "C" void* mremap(void* old_addr, size_t old_size, size_t new_size,
 197                         int flags, ...) __THROW {
 198   va_list ap;
 199   va_start(ap, flags);
 200   void *new_address = va_arg(ap, void *);
 201   va_end(ap);
 202   // The original gperftools uses sys_mremap() here.  But, it is not allowed by
 203   // Chromium's sandbox.
 204   void* result = (void *)syscall(
 205       SYS_mremap, old_addr, old_size, new_size, flags, new_address);
 206   MallocHook::InvokeMremapHook(result, old_addr, old_size, new_size, flags,
 207                                new_address);
 208   return result;
 209 }
 210
 211 // libc's version:
 212 extern "C" void* __sbrk(ptrdiff_t increment);
 213
 214 extern "C" void* sbrk(ptrdiff_t increment) __THROW {
 215   MallocHook::InvokePreSbrkHook(increment);
 216   void *result = __sbrk(increment);
 217   MallocHook::InvokeSbrkHook(result, increment);
 218   return result;
 219 }
 220
 221 /*static*/void* MallocHook::UnhookedMMap(void *start, size_t length, int prot,
 222                                          int flags, int fd, off_t offset) {
 223   void* result;
 224   if (!MallocHook::InvokeMmapReplacement(
 225           start, length, prot, flags, fd, offset, &result)) {
 226     result = do_mmap64(start, length, prot, flags, fd, offset);
 227   }
 228   return result;
 229 }
 230
 231 /*static*/int MallocHook::UnhookedMUnmap(void *start, size_t length) {
 232   int result;
 233   if (!MallocHook::InvokeMunmapReplacement(start, length, &result)) {
 234     result = syscall(SYS_munmap, start, length);
 235   }
 236   return result;
 237 }
 238
 239 #undef MALLOC_HOOK_HAVE_DO_MMAP64
 240
 241 #endif  // #ifdef MALLOC_HOOK_HAVE_DO_MMAP64