Merge "Check 64-to-32-bit transition in system_server for Tagged Ptrs [#2]."... (6beee1e0) · Commits · e / os / android_frameworks_base

services/core/java/com/android/server/am/ProcessList.java

+41 −9

Original line number	Diff line number	Diff line
		@@ -1668,6 +1668,33 @@ public final class ProcessList {
		return gidArray;
		}

		private boolean shouldEnableTaggedPointers(ProcessRecord app) {
		// Ensure we have platform + kernel support for TBI.
		if (!Zygote.nativeSupportsTaggedPointers()) {
		return false;
		}

		// Check to ensure the app hasn't explicitly opted-out of TBI via. the manifest attribute.
		if (!app.info.allowsNativeHeapPointerTagging()) {
		return false;
		}

		// Check to see that the compat feature for TBI is enabled.
		if (!mPlatformCompat.isChangeEnabled(NATIVE_HEAP_POINTER_TAGGING, app.info)) {
		return false;
		}

		return true;
		}

		private int decideTaggingLevel(ProcessRecord app) {
		if (shouldEnableTaggedPointers(app)) {
		return Zygote.MEMORY_TAG_LEVEL_TBI;
		}

		return 0;
		}

		private int decideGwpAsanLevel(ProcessRecord app) {
		// Look at the process attribute first.
		if (app.processInfo != null
		@@ -1856,15 +1883,6 @@ public final class ProcessList {
		runtimeFlags \|= Zygote.USE_APP_IMAGE_STARTUP_CACHE;
		}

		if (Zygote.nativeSupportsTaggedPointers()) {
		// Enable heap pointer tagging if supported by the kernel, unless disabled by the
		// app manifest, target sdk level, or compat feature.
		if (app.info.allowsNativeHeapPointerTagging()
		&& mPlatformCompat.isChangeEnabled(NATIVE_HEAP_POINTER_TAGGING, app.info)) {
		runtimeFlags \|= Zygote.MEMORY_TAG_LEVEL_TBI;
		}
		}

		runtimeFlags \|= decideGwpAsanLevel(app);

		String invokeWith = null;
		@@ -1895,6 +1913,20 @@ public final class ProcessList {
		app.setRequiredAbi(requiredAbi);
		app.instructionSet = instructionSet;

		// If instructionSet is non-null, this indicates that the system_server is spawning a
		// process with an ISA that may be different from its own. System (kernel and hardware)
		// compatililty for these features is checked in the decideTaggingLevel in the
		// system_server process (not the child process). As TBI is only supported in aarch64,
		// we can simply ensure that the new process is also aarch64. This prevents the mismatch
		// where a 64-bit system server spawns a 32-bit child that thinks it should enable some
		// tagging variant. Theoretically, a 32-bit system server could exist that spawns 64-bit
		// processes, in which case the new process won't get any tagging. This is fine as we
		// haven't seen this configuration in practice, and we can reasonable assume that if
		// tagging is desired, the system server will be 64-bit.
		if (instructionSet == null \|\| instructionSet.equals("arm64")) {
		runtimeFlags \|= decideTaggingLevel(app);
		}

		// the per-user SELinux context must be set
		if (TextUtils.isEmpty(app.info.seInfoUser)) {
		Slog.wtf(ActivityManagerService.TAG, "SELinux tag not defined",