Merge "Zygote: Add Arm pointer authentication keychange support."
diff --git a/core/jni/com_android_internal_os_Zygote.cpp b/core/jni/com_android_internal_os_Zygote.cpp
index 18be374..fbb35e0 100644
--- a/core/jni/com_android_internal_os_Zygote.cpp
+++ b/core/jni/com_android_internal_os_Zygote.cpp
@@ -95,6 +95,19 @@
#include "nativebridge/native_bridge.h"
+/* Functions in the callchain during the fork shall not be protected with
+ Armv8.3-A Pointer Authentication, otherwise child will not be able to return. */
+#ifdef __ARM_FEATURE_PAC_DEFAULT
+#ifdef __ARM_FEATURE_BTI_DEFAULT
+#define NO_PAC_FUNC __attribute__((target("branch-protection=bti")))
+#else
+#define NO_PAC_FUNC __attribute__((target("branch-protection=none")))
+#endif /* __ARM_FEATURE_BTI_DEFAULT */
+#else /* !__ARM_FEATURE_PAC_DEFAULT */
+#define NO_PAC_FUNC
+#endif /* __ARM_FEATURE_PAC_DEFAULT */
+
+
namespace {
// TODO (chriswailes): Add a function to initialize native Zygote data.
@@ -985,7 +998,23 @@
gUsapPoolCount = 0;
}
+NO_PAC_FUNC
+static void PAuthKeyChange(JNIEnv* env) {
+#ifdef __aarch64__
+ unsigned long int hwcaps = getauxval(AT_HWCAP);
+ if (hwcaps & HWCAP_PACA) {
+ const unsigned long key_mask = PR_PAC_APIAKEY | PR_PAC_APIBKEY |
+ PR_PAC_APDAKEY | PR_PAC_APDBKEY | PR_PAC_APGAKEY;
+ if (prctl(PR_PAC_RESET_KEYS, key_mask, 0, 0, 0) != 0) {
+ ALOGE("Failed to change the PAC keys: %s", strerror(errno));
+ RuntimeAbort(env, __LINE__, "PAC key change failed.");
+ }
+ }
+#endif
+}
+
// Utility routine to fork a process from the zygote.
+NO_PAC_FUNC
static pid_t ForkCommon(JNIEnv* env, bool is_system_server,
const std::vector<int>& fds_to_close,
const std::vector<int>& fds_to_ignore,
@@ -1036,6 +1065,7 @@
}
// The child process.
+ PAuthKeyChange(env);
PreApplicationInit();
// Clean up any descriptors which must be closed immediately
@@ -1486,6 +1516,7 @@
PreApplicationInit();
}
+NO_PAC_FUNC
static jint com_android_internal_os_Zygote_nativeForkAndSpecialize(
JNIEnv* env, jclass, jint uid, jint gid, jintArray gids,
jint runtime_flags, jobjectArray rlimits,
@@ -1533,6 +1564,7 @@
return pid;
}
+NO_PAC_FUNC
static jint com_android_internal_os_Zygote_nativeForkSystemServer(
JNIEnv* env, jclass, uid_t uid, gid_t gid, jintArray gids,
jint runtime_flags, jobjectArray rlimits, jlong permitted_capabilities,
@@ -1600,6 +1632,7 @@
* @param is_priority_fork Controls the nice level assigned to the newly created process
* @return
*/
+NO_PAC_FUNC
static jint com_android_internal_os_Zygote_nativeForkUsap(JNIEnv* env,
jclass,
jint read_pipe_fd,