diff options
Diffstat (limited to 'core/java')
| -rw-r--r-- | core/java/com/android/internal/os/Zygote.java | 7 | ||||
| -rw-r--r-- | core/java/com/android/internal/os/ZygoteInit.java | 16 |
2 files changed, 20 insertions, 3 deletions
diff --git a/core/java/com/android/internal/os/Zygote.java b/core/java/com/android/internal/os/Zygote.java index 0381a75d722b..395c05561fb5 100644 --- a/core/java/com/android/internal/os/Zygote.java +++ b/core/java/com/android/internal/os/Zygote.java @@ -1103,4 +1103,11 @@ public final class Zygote { * fully-feature Memory Tagging, rather than the static Tagged Pointers. */ public static native boolean nativeSupportsTaggedPointers(); + + /** + * Returns the current native tagging level, as one of the + * MEMORY_TAG_LEVEL_* constants. Returns zero if no tagging is present, or + * we failed to determine the level. + */ + public static native int nativeCurrentTaggingLevel(); } diff --git a/core/java/com/android/internal/os/ZygoteInit.java b/core/java/com/android/internal/os/ZygoteInit.java index 6335baa97e57..7fde5474ec92 100644 --- a/core/java/com/android/internal/os/ZygoteInit.java +++ b/core/java/com/android/internal/os/ZygoteInit.java @@ -791,9 +791,19 @@ public class ZygoteInit { Zygote.applyInvokeWithSystemProperty(parsedArgs); if (Zygote.nativeSupportsMemoryTagging()) { - /* 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; + /* The system server has ASYNC MTE by default, in order to allow + * system services to specify their own MTE level later, as you + * can't re-enable MTE once it's disabled. */ + String mode = SystemProperties.get("arm64.memtag.process.system_server", "async"); + if (mode.equals("async")) { + parsedArgs.mRuntimeFlags |= Zygote.MEMORY_TAG_LEVEL_ASYNC; + } else if (mode.equals("sync")) { + parsedArgs.mRuntimeFlags |= Zygote.MEMORY_TAG_LEVEL_SYNC; + } else if (!mode.equals("off")) { + /* When we have an invalid memory tag level, keep the current level. */ + parsedArgs.mRuntimeFlags |= Zygote.nativeCurrentTaggingLevel(); + Slog.e(TAG, "Unknown memory tag level for the system server: \"" + mode + "\""); + } } else if (Zygote.nativeSupportsTaggedPointers()) { /* Enable pointer tagging in the system server. Hardware support for this is present * in all ARMv8 CPUs. */ |