Merge "libc: Add membarrier to common seccomp allowed list" am: dca7d3fae5

am: 3a1bae5cd8

Change-Id: I5272122714ee2b5a9e57c14bb7c29bce0400b536

3 files changed, 106 insertions, 0 deletions

diff --git a/libc/SECCOMP_WHITELIST_COMMON.TXT b/libc/SECCOMP_WHITELIST_COMMON.TXT
index 60568e66d7..f6e9539600 100644
--- a/libc/SECCOMP_WHITELIST_COMMON.TXT
+++ b/libc/SECCOMP_WHITELIST_COMMON.TXT
@@ -59,6 +59,9 @@ int	sigreturn:sigreturn(unsigned long __unused)	arm,x86,mips
 # already allowed.
 ssize_t	readlink:readlink(const char *path, char *buf, size_t bufsiz)	arm,x86,x86_64,mips
 
+# Probed for and conditionally used by ART.
+int membarrier(int cmd, int flags) all
+
 # Useful new syscalls which we don't yet use in bionic.
 int sched_getattr(pid_t pid, struct sched_attr* attr, unsigned int flags) all
 int sched_setattr(pid_t pid, struct sched_attr* attr, unsigned int size, unsigned int flags) all
diff --git a/tests/Android.bp b/tests/Android.bp
index fa66f93b00..ffa6b2a28a 100644
--- a/tests/Android.bp
+++ b/tests/Android.bp
@@ -104,6 +104,7 @@ cc_test_library {
         "malloc_test.cpp",
         "math_test.cpp",
         "math_force_long_double_test.cpp",
+        "membarrier_test.cpp",
         "mntent_test.cpp",
         "netdb_test.cpp",
         "net_if_test.cpp",
diff --git a/tests/membarrier_test.cpp b/tests/membarrier_test.cpp
new file mode 100644
index 0000000000..4c58d308ee
--- /dev/null
+++ b/tests/membarrier_test.cpp
@@ -0,0 +1,102 @@
+/*
+ * 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 <gtest/gtest.h>
+
+// membarrier(2) is only supported for bionic builds (b/111199492).
+#if defined(__BIONIC__)
+
+#include <linux/membarrier.h>
+#include <sys/syscall.h>
+
+class ScopedErrnoCleaner {
+ public:
+  ScopedErrnoCleaner() { errno = 0; }
+  ~ScopedErrnoCleaner() { errno = 0; }
+};
+
+bool HasMembarrier() {
+  ScopedErrnoCleaner errno_cleaner;
+  bool present = syscall(__NR_membarrier, MEMBARRIER_CMD_QUERY, 0) > 0;
+  return present;
+}
+
+TEST(membarrier, query) {
+  ScopedErrnoCleaner errno_cleaner;
+  int supported = syscall(__NR_membarrier, MEMBARRIER_CMD_QUERY, 0);
+  if (errno == 0) {
+    ASSERT_TRUE(supported >= 0);
+  } else {
+    ASSERT_TRUE(errno == ENOSYS && supported == -1);
+  }
+}
+
+TEST(membarrier, global_barrier) {
+  if (!HasMembarrier()) {
+    return;
+  }
+
+  ScopedErrnoCleaner errno_cleaner;
+  int supported = syscall(__NR_membarrier, MEMBARRIER_CMD_QUERY, 0);
+  ASSERT_LE(0, supported);
+
+  if ((supported & MEMBARRIER_CMD_GLOBAL) != 0) {
+    ASSERT_EQ(0, syscall(__NR_membarrier, MEMBARRIER_CMD_GLOBAL, 0));
+  }
+}
+
+static void TestRegisterAndBarrierCommands(int membarrier_cmd_register,
+                                           int membarrier_cmd_barrier) {
+  if (!HasMembarrier()) {
+    return;
+  }
+
+  ScopedErrnoCleaner errno_cleaner;
+
+  // Check barrier use without prior registration.
+  if (membarrier_cmd_register == MEMBARRIER_CMD_REGISTER_GLOBAL_EXPEDITED) {
+    // Global barrier use is always okay.
+    ASSERT_EQ(0, syscall(__NR_membarrier, membarrier_cmd_barrier, 0));
+  } else {
+    // Private barrier should fail.
+    ASSERT_EQ(-1, syscall(__NR_membarrier, membarrier_cmd_barrier, 0));
+    ASSERT_EQ(EPERM, errno);
+    errno = 0;
+  }
+
+  // Check registration for barrier succeeds.
+  ASSERT_EQ(0, syscall(__NR_membarrier, membarrier_cmd_register, 0));
+
+  // Check barrier use after registration succeeds.
+  ASSERT_EQ(0, syscall(__NR_membarrier, membarrier_cmd_barrier, 0));
+}
+
+TEST(membarrier, global_expedited) {
+  TestRegisterAndBarrierCommands(MEMBARRIER_CMD_REGISTER_GLOBAL_EXPEDITED,
+                                 MEMBARRIER_CMD_GLOBAL_EXPEDITED);
+}
+
+TEST(membarrier, private_expedited) {
+  TestRegisterAndBarrierCommands(MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED,
+                                 MEMBARRIER_CMD_PRIVATE_EXPEDITED);
+}
+
+TEST(membarrier, private_expedited_sync_core) {
+  TestRegisterAndBarrierCommands(MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED_SYNC_CORE,
+                                 MEMBARRIER_CMD_PRIVATE_EXPEDITED_SYNC_CORE);
+}
+
+#endif  // __BIONIC__