Merge "Don't ask libc for PT feature w/o kernel support." (758f448f) · Commits · e / os / android_frameworks_base

core/java/com/android/internal/os/Zygote.java

+7 −0

Original line number	Diff line number	Diff line
		@@ -988,4 +988,11 @@ public final class Zygote {
		* Returns whether the hardware supports memory tagging (ARM MTE).
		*/
		public static native boolean nativeSupportsMemoryTagging();

		/**
		* Returns whether the kernel supports tagged pointers. Present in the
		* Android Common Kernel from 4.14 and up. By default, you should prefer
		* fully-feature Memory Tagging, rather than the static Tagged Pointers.
		*/
		public static native boolean nativeSupportsTaggedPointers();
		}

+2 −2

Original line number	Diff line number	Diff line
		@@ -752,9 +752,9 @@ public class ZygoteInit {
		/* The system server is more privileged than regular app processes, so it has async
		* tag checks enabled on hardware that supports memory tagging. */
		parsedArgs.mRuntimeFlags \|= Zygote.MEMORY_TAG_LEVEL_ASYNC;
		} else {
		} else if (Zygote.nativeSupportsTaggedPointers()) {
		/* Enable pointer tagging in the system server. Hardware support for this is present
		* in all ARMv8 CPUs; this flag has no effect on other platforms. */
		* in all ARMv8 CPUs. */
		parsedArgs.mRuntimeFlags \|= Zygote.MEMORY_TAG_LEVEL_TBI;
		}

+11 −0

Original line number	Diff line number	Diff line
		@@ -1899,6 +1899,15 @@ static jboolean com_android_internal_os_Zygote_nativeSupportsMemoryTagging(JNIEn
		#endif
		}

		static jboolean com_android_internal_os_Zygote_nativeSupportsTaggedPointers(JNIEnv* env, jclass) {
		#ifdef __aarch64__
		int res = prctl(PR_GET_TAGGED_ADDR_CTRL, 0, 0, 0, 0);
		return res >= 0 && res & PR_TAGGED_ADDR_ENABLE;
		#else
		return false;
		#endif
		}

		static const JNINativeMethod gMethods[] = {
		{ "nativeForkAndSpecialize",
		"(II[II[[IILjava/lang/String;Ljava/lang/String;[I[IZLjava/lang/String;Ljava/lang/String;Z)I",
		@@ -1938,6 +1947,8 @@ static const JNINativeMethod gMethods[] = {
		(void* ) com_android_internal_os_Zygote_nativeParseSigChld},
		{ "nativeSupportsMemoryTagging", "()Z",
		(void *) com_android_internal_os_Zygote_nativeSupportsMemoryTagging },
		{"nativeSupportsTaggedPointers", "()Z",
		(void*)com_android_internal_os_Zygote_nativeSupportsTaggedPointers},
		};

		int register_com_android_internal_os_Zygote(JNIEnv* env) {

+3 −1

Original line number	Diff line number	Diff line
		@@ -1682,7 +1682,9 @@ public final class ProcessList {
		\|\| mPlatformCompat.isChangeEnabled(NATIVE_MEMORY_TAGGING, app.info)) {
		runtimeFlags \|= Zygote.MEMORY_TAG_LEVEL_ASYNC;
		}
		} else {
		} else if (Zygote.nativeSupportsTaggedPointers()) {
		// Enable heap pointer tagging if supported by the kernel, unless disabled by the
		// target sdk level or compat feature.
		if (mPlatformCompat.isChangeEnabled(NATIVE_HEAP_POINTER_TAGGING, app.info)) {
		runtimeFlags \|= Zygote.MEMORY_TAG_LEVEL_TBI;
		}