Reapply "Add local impl of mapper for libhidlmemory"
This reverts commit 5410c8c04a03527289f69df063cfe9ea30349d2c.
Test: atest CtsMediaAudioTestCases
Tets: remove android.hidl.memory@1.0-impl.so from device &&
atest CtsMediaAudioTestCases && check for call_once log
Bug: 205764958
Bug: 310700278
Bug: 310680652
Change-Id: Iebaf64882949d5923362f80e79eeed8f8fece7bb
diff --git a/libhidlmemory/mapping.cpp b/libhidlmemory/mapping.cpp
index 8f0bcf4..3fcc354 100644
--- a/libhidlmemory/mapping.cpp
+++ b/libhidlmemory/mapping.cpp
@@ -19,6 +19,7 @@
#include <mutex>
#include <string>
+#include <AshmemMemory.h>
#include <hidlmemory/mapping.h>
#include <android-base/logging.h>
@@ -35,6 +36,33 @@
static std::map<std::string, sp<IMapper>> gMappersByName;
static std::mutex gMutex;
+static std::once_flag gOnceFlagLog;
+
+static sp<IMemory> createAshmemMemory(const hidl_memory& mem) {
+ if (mem.handle()->numFds == 0) {
+ return nullptr;
+ }
+
+ // If ashmem service runs in 32-bit (size_t is uint32_t) and a 64-bit
+ // client process requests a memory > 2^32 bytes, the size would be
+ // converted to a 32-bit number in mmap. mmap could succeed but the
+ // mapped memory's actual size would be smaller than the reported size.
+ if (mem.size() > SIZE_MAX) {
+ ALOGE("Cannot map %" PRIu64 " bytes of memory because it is too large.", mem.size());
+ android_errorWriteLog(0x534e4554, "79376389");
+ return nullptr;
+ }
+
+ int fd = mem.handle()->data[0];
+ void* data = mmap(0, mem.size(), PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+ if (data == MAP_FAILED) {
+ // mmap never maps at address zero without MAP_FIXED, so we can avoid
+ // exposing clients to MAP_FAILED.
+ return nullptr;
+ }
+
+ return new impl::AshmemMemory(mem, data);
+}
static inline sp<IMapper> getMapperService(const std::string& name) {
std::unique_lock<std::mutex> _lock(gMutex);
@@ -55,8 +83,14 @@
sp<IMapper> mapper = getMapperService(memory.name());
if (mapper == nullptr) {
- LOG(ERROR) << "Could not fetch mapper for " << memory.name() << " shared memory";
- return nullptr;
+ if (memory.name() == "ashmem") {
+ std::call_once(gOnceFlagLog,
+ [&]() { LOG(INFO) << "Using libhidlmemory mapper for ashmem."; });
+ return createAshmemMemory(memory);
+ } else {
+ LOG(ERROR) << "Could not fetch mapper for " << memory.name() << " shared memory";
+ return nullptr;
+ }
}
if (mapper->isRemote()) {