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Merge "Check 64-to-32-bit transition in system_server for Tagged Ptrs [#2]." into rvc-dev

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This commit is contained in:
Mitch Phillips
2020-04-15 15:48:51 +00:00
committed by Android (Google) Code Review
parent e89cef4edb ba160a28fd
commit 2bf744abe1
1 changed files with 41 additions and 9 deletions
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50
services/core/java/com/android/server/am/ProcessList.java
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@@ -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",