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/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#define LOG_TAG "MemoryHeapBase"
#include <errno.h>
#include <fcntl.h>
#include <linux/memfd.h>
#include <stdint.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <unistd.h>
#include <binder/MemoryHeapBase.h>
#include <cutils/ashmem.h>
#include <cutils/atomic.h>
#include <log/log.h>
namespace android {
// ---------------------------------------------------------------------------
#ifdef __BIONIC__
static int memfd_create_region(const char* name, size_t size) {
int fd = memfd_create(name, MFD_CLOEXEC | MFD_ALLOW_SEALING);
if (fd == -1) {
ALOGE("%s: memfd_create(%s, %zd) failed: %s\n", __func__, name, size, strerror(errno));
return -1;
}
if (ftruncate(fd, size) == -1) {
ALOGE("%s, ftruncate(%s, %zd) failed for memfd creation: %s\n", __func__, name, size,
strerror(errno));
close(fd);
return -1;
}
return fd;
}
#endif
MemoryHeapBase::MemoryHeapBase()
: mFD(-1), mSize(0), mBase(MAP_FAILED),
mDevice(nullptr), mNeedUnmap(false), mOffset(0)
{
}
MemoryHeapBase::MemoryHeapBase(size_t size, uint32_t flags, char const * name)
: mFD(-1), mSize(0), mBase(MAP_FAILED), mFlags(flags),
mDevice(nullptr), mNeedUnmap(false), mOffset(0)
{
const size_t pagesize = getpagesize();
size = ((size + pagesize - 1) & ~(pagesize - 1));
int fd = -1;
if (mFlags & FORCE_MEMFD) {
#ifdef __BIONIC__
ALOGV("MemoryHeapBase: Attempting to force MemFD");
fd = memfd_create_region(name ? name : "MemoryHeapBase", size);
if (fd < 0 || (mapfd(fd, true, size) != NO_ERROR)) return;
const int SEAL_FLAGS = ((mFlags & READ_ONLY) ? F_SEAL_FUTURE_WRITE : 0) |
((mFlags & MEMFD_ALLOW_SEALING) ? 0 : F_SEAL_SEAL);
if (SEAL_FLAGS && (fcntl(fd, F_ADD_SEALS, SEAL_FLAGS) == -1)) {
ALOGE("MemoryHeapBase: MemFD %s sealing with flags %x failed with error %s", name,
SEAL_FLAGS, strerror(errno));
munmap(mBase, mSize);
mBase = nullptr;
mSize = 0;
close(fd);
}
return;
#else
mFlags &= ~(FORCE_MEMFD | MEMFD_ALLOW_SEALING);
#endif
}
if (mFlags & MEMFD_ALLOW_SEALING) {
LOG_ALWAYS_FATAL("Invalid Flags. MEMFD_ALLOW_SEALING only valid with FORCE_MEMFD.");
}
fd = ashmem_create_region(name ? name : "MemoryHeapBase", size);
ALOGE_IF(fd < 0, "MemoryHeapBase: error creating ashmem region: %s", strerror(errno));
if (fd < 0 || (mapfd(fd, true, size) != NO_ERROR)) return;
if (mFlags & READ_ONLY) {
ashmem_set_prot_region(fd, PROT_READ);
}
}
MemoryHeapBase::MemoryHeapBase(const char* device, size_t size, uint32_t flags)
: mFD(-1), mSize(0), mBase(MAP_FAILED), mFlags(flags),
mDevice(nullptr), mNeedUnmap(false), mOffset(0)
{
if (flags & (FORCE_MEMFD | MEMFD_ALLOW_SEALING)) {
LOG_ALWAYS_FATAL("FORCE_MEMFD, MEMFD_ALLOW_SEALING only valid with creating constructor");
}
int open_flags = O_RDWR;
if (flags & NO_CACHING)
open_flags |= O_SYNC;
int fd = open(device, open_flags);
ALOGE_IF(fd<0, "error opening %s: %s", device, strerror(errno));
if (fd >= 0) {
const size_t pagesize = getpagesize();
size = ((size + pagesize-1) & ~(pagesize-1));
if (mapfd(fd, false, size) == NO_ERROR) {
mDevice = device;
}
}
}
MemoryHeapBase::MemoryHeapBase(int fd, size_t size, uint32_t flags, off_t offset)
: mFD(-1), mSize(0), mBase(MAP_FAILED), mFlags(flags),
mDevice(nullptr), mNeedUnmap(false), mOffset(0)
{
if (flags & (FORCE_MEMFD | MEMFD_ALLOW_SEALING)) {
LOG_ALWAYS_FATAL("FORCE_MEMFD, MEMFD_ALLOW_SEALING only valid with creating constructor");
}
const size_t pagesize = getpagesize();
size = ((size + pagesize-1) & ~(pagesize-1));
mapfd(fcntl(fd, F_DUPFD_CLOEXEC, 0), false, size, offset);
}
status_t MemoryHeapBase::init(int fd, void *base, size_t size, int flags, const char* device)
{
if (mFD != -1) {
return INVALID_OPERATION;
}
mFD = fd;
mBase = base;
mSize = size;
mFlags = flags;
mDevice = device;
return NO_ERROR;
}
status_t MemoryHeapBase::mapfd(int fd, bool writeableByCaller, size_t size, off_t offset)
{
if (size == 0) {
// try to figure out the size automatically
struct stat sb;
if (fstat(fd, &sb) == 0) {
size = (size_t)sb.st_size;
// sb.st_size is off_t which on ILP32 may be 64 bits while size_t is 32 bits.
if ((off_t)size != sb.st_size) {
ALOGE("%s: size of file %lld cannot fit in memory",
__func__, (long long)sb.st_size);
return INVALID_OPERATION;
}
}
// if it didn't work, let mmap() fail.
}
if ((mFlags & DONT_MAP_LOCALLY) == 0) {
int prot = PROT_READ;
if (writeableByCaller || (mFlags & READ_ONLY) == 0) {
prot |= PROT_WRITE;
}
void* base = (uint8_t*)mmap(nullptr, size,
prot, MAP_SHARED, fd, offset);
if (base == MAP_FAILED) {
ALOGE("mmap(fd=%d, size=%zu) failed (%s)",
fd, size, strerror(errno));
close(fd);
return -errno;
}
//ALOGD("mmap(fd=%d, base=%p, size=%zu)", fd, base, size);
mBase = base;
mNeedUnmap = true;
} else {
mBase = nullptr; // not MAP_FAILED
mNeedUnmap = false;
}
mFD = fd;
mSize = size;
mOffset = offset;
return NO_ERROR;
}
MemoryHeapBase::~MemoryHeapBase()
{
dispose();
}
void MemoryHeapBase::dispose()
{
int fd = android_atomic_or(-1, &mFD);
if (fd >= 0) {
if (mNeedUnmap) {
//ALOGD("munmap(fd=%d, base=%p, size=%zu)", fd, mBase, mSize);
munmap(mBase, mSize);
}
mBase = nullptr;
mSize = 0;
close(fd);
}
}
int MemoryHeapBase::getHeapID() const {
return mFD;
}
void* MemoryHeapBase::getBase() const {
return mBase;
}
size_t MemoryHeapBase::getSize() const {
return mSize;
}
uint32_t MemoryHeapBase::getFlags() const {
return mFlags;
}
const char* MemoryHeapBase::getDevice() const {
return mDevice;
}
off_t MemoryHeapBase::getOffset() const {
return mOffset;
}
// ---------------------------------------------------------------------------
} // namespace android
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