ART: Add wrappers for membarrier and memfd_create()
Adds art::membarrer() and art::memfd_create() as wrappers around the
similarly named linux syscalls. These wrappers can fail due to missing
OS support so code that uses them needs to deal with this.
Updates the JIT code cache to use art::membarrer().
Bug: 111199492
Test: art/test.py --host
Change-Id: I122746e6293e7201077e834d8a5ed7bbba45e283
diff --git a/libartbase/base/membarrier.cc b/libartbase/base/membarrier.cc
new file mode 100644
index 0000000..490dbf3
--- /dev/null
+++ b/libartbase/base/membarrier.cc
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2018 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.
+ */
+
+#include "membarrier.h"
+
+#include <errno.h>
+
+#include <sys/syscall.h>
+#include <unistd.h>
+#include "macros.h"
+
+#if defined(__BIONIC__)
+
+#include <atomic>
+#include <android/get_device_api_level.h>
+#include <linux/membarrier.h>
+
+#define CHECK_MEMBARRIER_CMD(art_value, membarrier_value) \
+ static_assert(static_cast<int>(art_value) == membarrier_value, "Bad value for " # art_value)
+CHECK_MEMBARRIER_CMD(art::MembarrierCommand::kQuery, MEMBARRIER_CMD_QUERY);
+CHECK_MEMBARRIER_CMD(art::MembarrierCommand::kGlobal, MEMBARRIER_CMD_SHARED);
+CHECK_MEMBARRIER_CMD(art::MembarrierCommand::kPrivateExpedited, MEMBARRIER_CMD_PRIVATE_EXPEDITED);
+CHECK_MEMBARRIER_CMD(art::MembarrierCommand::kRegisterPrivateExpedited,
+ MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED);
+CHECK_MEMBARRIER_CMD(art::MembarrierCommand::kPrivateExpedited, MEMBARRIER_CMD_PRIVATE_EXPEDITED);
+#undef CHECK_MEMBARRIER_CMD
+
+#endif // __BIONIC
+
+namespace art {
+
+#if defined(__NR_membarrier)
+
+int membarrier(MembarrierCommand command) {
+#if defined(__BIONIC__)
+ // Avoid calling membarrier on older Android versions where membarrier may be barred by secomp
+ // causing the current process to be killed. The probing here could be considered expensive so
+ // endeavour not to repeat too often.
+ static int api_level = android_get_device_api_level();
+ if (api_level < __ANDROID_API_Q__) {
+ errno = ENOSYS;
+ return -1;
+ }
+#endif // __BIONIC__
+ return syscall(__NR_membarrier, static_cast<int>(command), 0);
+}
+
+#else // __NR_membarrier
+
+int membarrier(MembarrierCommand command ATTRIBUTE_UNUSED) {
+ // In principle this could be supported on linux, but Android's prebuilt glibc does not include
+ // the system call number defintions (b/111199492).
+ errno = ENOSYS;
+ return -1;
+}
+
+#endif // __NR_membarrier
+
+} // namespace art