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// -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*-
// Copyright (c) 2005, Google Inc.
// All rights reserved.
//
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// 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 <opensource@google.com>
// 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 <unistd.h>
#include <syscall.h>
#include <sys/mman.h>
#include <errno.h>
#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 || _MIPS_SIM == _ABIN32)) \
|| defined(__s390__)
static inline void* do_mmap64(void *start, size_t length,
int prot, int flags,
int fd, off64_t offset) __THROW {
#if defined(__s390__)
long args[6] = { (long)start, (long)length, (long)prot, (long)flags,
(long)fd, (long)offset };
return (void*)syscall(SYS_mmap, args);
#else
return (void*)syscall(SYS_mmap, start, length, prot, flags, fd, offset);
#endif
}
#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
#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 mmap64 and mmap doesn't get #define'd away by <sys/mman.h>
# undef mmap64
# 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(intptr_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<size_t>(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 = syscall(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 = (void*)syscall(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;
}
#ifdef HAVE___SBRK
// libc's version:
extern "C" void* __sbrk(intptr_t increment);
extern "C" void* sbrk(intptr_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