| // Copyright (c) 2011, Google Inc. |
| // All rights reserved. |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following disclaimer |
| // in the documentation and/or other materials provided with the |
| // distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived from |
| // this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| // Override mmap/munmap/mremap/sbrk to provide support for calling the |
| // related hooks (in addition, of course, to doing what these |
| // functions normally do). |
| |
| #ifndef __FreeBSD__ |
| # error Should only be including malloc_hook_mmap_freebsd.h on FreeBSD systems. |
| #endif |
| |
| #include <unistd.h> |
| #include <sys/syscall.h> |
| #include <sys/mman.h> |
| #include <errno.h> |
| |
| // Make sure mmap doesn't get #define'd away by <sys/mman.h> |
| #undef mmap |
| |
| // According to the FreeBSD documentation, use syscall if you do not |
| // need 64-bit alignment otherwise use __syscall. Indeed, syscall |
| // doesn't work correctly in most situations on 64-bit. It's return |
| // type is 'int' so for things like SYS_mmap, it actually truncates |
| // the returned address to 32-bits. |
| #if defined(__amd64__) || defined(__x86_64__) |
| # define MALLOC_HOOK_SYSCALL __syscall |
| #else |
| # define MALLOC_HOOK_SYSCALL syscall |
| #endif |
| |
| |
| extern "C" { |
| void* mmap(void *start, size_t length,int prot, int flags, |
| int fd, off_t offset) __THROW |
| ATTRIBUTE_SECTION(malloc_hook); |
| int munmap(void* start, size_t length) __THROW |
| ATTRIBUTE_SECTION(malloc_hook); |
| void* sbrk(intptr_t increment) __THROW |
| ATTRIBUTE_SECTION(malloc_hook); |
| } |
| |
| static inline void* do_mmap(void *start, size_t length, |
| int prot, int flags, |
| int fd, off_t offset) __THROW { |
| return (void *)MALLOC_HOOK_SYSCALL(SYS_mmap, |
| start, length, prot, flags, fd, offset); |
| } |
| |
| static inline void* do_sbrk(intptr_t increment) { |
| void* curbrk = 0; |
| |
| #if defined(__x86_64__) || defined(__amd64__) |
| # ifdef PIC |
| __asm__ __volatile__( |
| "movq .curbrk@GOTPCREL(%%rip), %%rdx;" |
| "movq (%%rdx), %%rax;" |
| "movq %%rax, %0;" |
| : "=r" (curbrk) |
| :: "%rdx", "%rax"); |
| # else |
| __asm__ __volatile__( |
| "movq .curbrk(%%rip), %%rax;" |
| "movq %%rax, %0;" |
| : "=r" (curbrk) |
| :: "%rax"); |
| # endif |
| #else |
| __asm__ __volatile__( |
| "movl .curbrk, %%eax;" |
| "movl %%eax, %0;" |
| : "=r" (curbrk) |
| :: "%eax"); |
| #endif |
| |
| if (increment == 0) { |
| return curbrk; |
| } |
| |
| char* prevbrk = static_cast<char*>(curbrk); |
| void* newbrk = prevbrk + increment; |
| |
| if (brk(newbrk) == -1) { |
| return reinterpret_cast<void*>(static_cast<intptr_t>(-1)); |
| } |
| |
| return prevbrk; |
| } |
| |
| |
| extern "C" void* mmap(void *start, size_t length, int prot, int flags, |
| int fd, off_t offset) __THROW { |
| MallocHook::InvokePreMmapHook(start, length, prot, flags, fd, offset); |
| void *result; |
| if (!MallocHook::InvokeMmapReplacement( |
| start, length, prot, flags, fd, offset, &result)) { |
| result = do_mmap(start, length, prot, flags, fd, |
| static_cast<size_t>(offset)); // avoid sign extension |
| } |
| MallocHook::InvokeMmapHook(result, start, length, prot, flags, fd, offset); |
| return result; |
| } |
| |
| extern "C" int munmap(void* start, size_t length) __THROW { |
| MallocHook::InvokeMunmapHook(start, length); |
| int result; |
| if (!MallocHook::InvokeMunmapReplacement(start, length, &result)) { |
| result = MALLOC_HOOK_SYSCALL(SYS_munmap, start, length); |
| } |
| |
| return result; |
| } |
| |
| extern "C" void* sbrk(intptr_t increment) __THROW { |
| MallocHook::InvokePreSbrkHook(increment); |
| void *result = do_sbrk(increment); |
| MallocHook::InvokeSbrkHook(result, increment); |
| return result; |
| } |
| |
| /*static*/void* MallocHook::UnhookedMMap(void *start, size_t length, int prot, |
| int flags, int fd, off_t offset) { |
| void* result; |
| if (!MallocHook::InvokeMmapReplacement( |
| start, length, prot, flags, fd, offset, &result)) { |
| result = do_mmap(start, length, prot, flags, fd, offset); |
| } |
| |
| return result; |
| } |
| |
| /*static*/int MallocHook::UnhookedMUnmap(void *start, size_t length) { |
| int result; |
| if (!MallocHook::InvokeMunmapReplacement(start, length, &result)) { |
| result = MALLOC_HOOK_SYSCALL(SYS_munmap, start, length); |
| } |
| return result; |
| } |
| |
| #undef MALLOC_HOOK_SYSCALL |