// -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- // Copyright (c) 2005, 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. // --- // Author: Sanjay Ghemawat // We define mmap() and mmap64(), which somewhat reimplements libc's mmap // syscall stubs. Unfortunately libc only exports the stubs via weak symbols // (which we're overriding with our mmap64() and mmap() wrappers) so we can't // just call through to them. #ifndef __linux # error Should only be including malloc_hook_mmap_linux.h on linux systems. #endif #include #include #include #include #include "base/linux_syscall_support.h" // The x86-32 case and the x86-64 case differ: // 32b has a mmap2() syscall, 64b does not. // 64b and 32b have different calling conventions for mmap(). // I test for 64-bit first so I don't have to do things like // '#if (defined(__mips__) && !defined(__MIPS64__))' as a mips32 check. #if defined(__x86_64__) || defined(__PPC64__) || defined(__aarch64__) || (defined(_MIPS_SIM) && _MIPS_SIM == _ABI64) static inline void* do_mmap64(void *start, size_t length, int prot, int flags, int fd, __off64_t offset) __THROW { return sys_mmap(start, length, prot, flags, fd, offset); } #define MALLOC_HOOK_HAVE_DO_MMAP64 1 #elif defined(__i386__) || defined(__PPC__) || defined(__mips__) || \ defined(__arm__) static inline void* do_mmap64(void *start, size_t length, int prot, int flags, int fd, __off64_t offset) __THROW { void *result; // Try mmap2() unless it's not supported static bool have_mmap2 = true; if (have_mmap2) { static int pagesize = 0; if (!pagesize) pagesize = getpagesize(); // Check that the offset is page aligned if (offset & (pagesize - 1)) { result = MAP_FAILED; errno = EINVAL; goto out; } result = (void *)syscall(SYS_mmap2, start, length, prot, flags, fd, (off_t) (offset / pagesize)); if (result != MAP_FAILED || errno != ENOSYS) goto out; // We don't have mmap2() after all - don't bother trying it in future have_mmap2 = false; } if (((off_t)offset) != offset) { // If we're trying to map a 64-bit offset, fail now since we don't // have 64-bit mmap() support. result = MAP_FAILED; errno = EINVAL; goto out; } #ifdef __NR_mmap { // Fall back to old 32-bit offset mmap() call // Old syscall interface cannot handle six args, so pass in an array int32 args[6] = { (int32) start, (int32) length, prot, flags, fd, (int32)(off_t) offset }; result = (void *)syscall(SYS_mmap, args); } #else // Some Linux ports like ARM EABI Linux has no mmap, just mmap2. result = MAP_FAILED; #endif out: return result; } #define MALLOC_HOOK_HAVE_DO_MMAP64 1 #elif defined(__s390x__) static inline void* do_mmap64(void *start, size_t length, int prot, int flags, int fd, __off64_t offset) __THROW { // mmap on s390x uses the old syscall interface unsigned long args[6] = { (unsigned long) start, (unsigned long) length, (unsigned long) prot, (unsigned long) flags, (unsigned long) fd, (unsigned long) offset }; return sys_mmap(args); } #define MALLOC_HOOK_HAVE_DO_MMAP64 1 #endif // #if defined(__x86_64__) #ifdef MALLOC_HOOK_HAVE_DO_MMAP64 // We use do_mmap64 abstraction to put MallocHook::InvokeMmapHook // calls right into mmap and mmap64, so that the stack frames in the caller's // stack are at the same offsets for all the calls of memory allocating // functions. // Put all callers of MallocHook::Invoke* in this module into // malloc_hook section, // so that MallocHook::GetCallerStackTrace can function accurately: // Make sure mmap doesn't get #define'd away by # undef mmap extern "C" { void* mmap64(void *start, size_t length, int prot, int flags, int fd, __off64_t offset ) __THROW ATTRIBUTE_SECTION(malloc_hook); 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* mremap(void* old_addr, size_t old_size, size_t new_size, int flags, ...) __THROW ATTRIBUTE_SECTION(malloc_hook); void* sbrk(ptrdiff_t increment) __THROW ATTRIBUTE_SECTION(malloc_hook); } extern "C" void* mmap64(void *start, size_t length, int prot, int flags, int fd, __off64_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_mmap64(start, length, prot, flags, fd, offset); } MallocHook::InvokeMmapHook(result, start, length, prot, flags, fd, offset); return result; } # if !defined(__USE_FILE_OFFSET64) || !defined(__REDIRECT_NTH) 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_mmap64(start, length, prot, flags, fd, static_cast(offset)); // avoid sign extension } MallocHook::InvokeMmapHook(result, start, length, prot, flags, fd, offset); return result; } # endif // !defined(__USE_FILE_OFFSET64) || !defined(__REDIRECT_NTH) extern "C" int munmap(void* start, size_t length) __THROW { MallocHook::InvokeMunmapHook(start, length); int result; if (!MallocHook::InvokeMunmapReplacement(start, length, &result)) { result = sys_munmap(start, length); } return result; } extern "C" void* mremap(void* old_addr, size_t old_size, size_t new_size, int flags, ...) __THROW { va_list ap; va_start(ap, flags); void *new_address = va_arg(ap, void *); va_end(ap); void* result = sys_mremap(old_addr, old_size, new_size, flags, new_address); MallocHook::InvokeMremapHook(result, old_addr, old_size, new_size, flags, new_address); return result; } #ifndef __UCLIBC__ // libc's version: extern "C" void* __sbrk(ptrdiff_t increment); extern "C" void* sbrk(ptrdiff_t increment) __THROW { MallocHook::InvokePreSbrkHook(increment); void *result = __sbrk(increment); MallocHook::InvokeSbrkHook(result, increment); return result; } #endif /*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_mmap64(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 = syscall(SYS_munmap, start, length); } return result; } #undef MALLOC_HOOK_HAVE_DO_MMAP64 #endif // #ifdef MALLOC_HOOK_HAVE_DO_MMAP64