MemorySanitizer does not support all intrinsics we use [172238865]

Internal Cleanup

Status Update

No update yet.

Description

ni...@google.com

created issue #1

Nov 2, 2020 04:50PM

LLVM's MemorySanitizer instrumentation does not support all the intrinsics used by Reactor/SwiftShader.

This includes masked_gather, masked_scatter, x86_sse_movmsk_ps, x86_sse2_cvtps2dq, and x86_sse2_pmovmskb_128. The default handling of unknown instructions is to check operands for poison bits, but unpoison the result. This leads to false positives and false negatives.

Scatter/gather were handled as part of b/155148722 by emulating them, but if LLVM adds native instrumentation support for them we can revert that. Similarly we may suggest supporting additional sse intrinsics and won't require Reactor-side workarounds or accept false negatives.

Comments

ap...@google.com <ap...@google.com> #2May 12, 2021 09:41PM

Project: platform/frameworks/support
Branch: androidx-master-dev

commit b4a3fe1d53c8c8082cf16795da164c446f7fd912
Author: Ian Lake <ilake@google.com>
Date: Wed Jul 15 14:34:08 2020

Add a hook that fires before the Activity's super.onCreate()

Provide a standard, composable API for libraries and
developers to run code as soon as possible after a
Context is available to an Activity (i.e., before the
logic in the base Activity.onCreate() runs and before any
layout is inflated).

This updates the code in FragmentActivity and
AppCompatActivity to use that new API.

Test: new activity tests pass
Test: existing fragment and appcompat tests still pass
BUG: 161390636
Relnote: "`ComponentActivity` now implements
`ContextAware`, allowing you to add one or more
`OnContextAvailableListener` instances which will
receive a callback before the base `Activity.onCreate()`."

Change-Id: I513da73bc0862b62af4166be35ba353fc7869a09

M activity/activity/api/1.2.0-alpha07.txt
M activity/activity/api/current.txt
M activity/activity/api/public_plus_experimental_1.2.0-alpha07.txt
M activity/activity/api/public_plus_experimental_current.txt
M activity/activity/api/restricted_1.2.0-alpha07.txt
M activity/activity/api/restricted_current.txt
M activity/activity/src/androidTest/java/androidx/activity/ComponentActivityLifecycleTest.kt
A activity/activity/src/androidTest/java/androidx/activity/contextaware/ContextAwareHelperTest.kt
M activity/activity/src/main/java/androidx/activity/ComponentActivity.java
A activity/activity/src/main/java/androidx/activity/contextaware/ContextAware.java
A activity/activity/src/main/java/androidx/activity/contextaware/ContextAwareHelper.java
A activity/activity/src/main/java/androidx/activity/contextaware/OnContextAvailableListener.java
M appcompat/appcompat/build.gradle
M appcompat/appcompat/src/main/java/androidx/appcompat/app/AppCompatActivity.java
M fragment/fragment/src/main/java/androidx/fragment/app/FragmentActivity.java

https://android-review.googlesource.com/1364176

ap...@google.com <ap...@google.com> #3May 12, 2021 09:41PM

Project: platform/frameworks/support
Branch: androidx-master-dev

commit 494d98d48e3c95c4338bda7ed1bf46797de257f6
Author: Ian Lake <ilake@google.com>
Date: Mon Aug 03 13:07:36 2020

Deliver the Context when added after it is available

Previously, an OnContextAvailableListener would only
receive a callback if added prior to the Context
being made available.

Rather than allow developers fall into a pitfall
where they add a listener and never receive a
callback, synchronously deliver the currently
available Context to listeners.

Test: updated activity tests pass
BUG: 161390636
Relnote: N/A
Change-Id: I24eff02712c90e84e1998407082e0b07cf04b44a

M activity/activity/api/current.txt
M activity/activity/api/public_plus_experimental_current.txt
M activity/activity/api/restricted_current.txt
M activity/activity/src/androidTest/java/androidx/activity/contextaware/ContextAwareHelperTest.kt
M activity/activity/src/main/java/androidx/activity/ComponentActivity.java
M activity/activity/src/main/java/androidx/activity/contextaware/ContextAware.java
M activity/activity/src/main/java/androidx/activity/contextaware/ContextAwareHelper.java

https://android-review.googlesource.com/1386006

ni...@google.com <ni...@google.com> #4May 3, 2022 08:30PM

Project: platform/frameworks/support
Branch: androidx-master-dev

commit 5d11382f47626211d512b9135f6b5f40b88f6647
Author: Ian Lake <ilake@google.com>
Date: Mon Aug 03 12:45:55 2020

Simplify OnContextAvailableListener interface

Rather than pass the ContextAware object,
the Context, and a Bundle for saved instance
state, pass only the Context to the
onContextAvailable() callback.

The ContextAware parameter is not needed in
general (unregistering is a corner case that
can be handled by capturing a reference to the
ContextAware).

The saved instance state Bundle is not needed
when we can ensure that the
SavedStateRegistry has had its state restored
before the listeners are called. This ensures
that all Saved State logic is centralized in
the API specifically built for saving state
rather than leaking into other APIs.

To accomplish this API change, the storage of
FragmentManager's and AppCompatDelegate's saved
state was moved to SavedStateRegistry as part of
FragmentActivity and AppCompatActivity,
respectively. Longer term, FragmentManager and
AppCompatDelegate should provide public APIs for
connecting directly to SavedStateRegistry, but
that is out of scope for this change.

Test: activity, fragment, and appcompat tests pass
BUG: 161390636
Relnote: N/A
Change-Id: I32fdd4b2c4c391c3fa97158dbd7508fa96b08d7a

M activity/activity/api/current.txt
M activity/activity/api/public_plus_experimental_current.txt
M activity/activity/api/restricted_current.txt
M activity/activity/src/androidTest/java/androidx/activity/ComponentActivityLifecycleTest.kt
M activity/activity/src/androidTest/java/androidx/activity/ComponentActivitySavedStateTest.kt
M activity/activity/src/androidTest/java/androidx/activity/contextaware/ContextAwareHelperTest.kt
M activity/activity/src/main/java/androidx/activity/ComponentActivity.java
M activity/activity/src/main/java/androidx/activity/contextaware/ContextAwareHelper.java
M activity/activity/src/main/java/androidx/activity/contextaware/OnContextAvailableListener.java
M appcompat/appcompat/src/main/java/androidx/appcompat/app/AppCompatActivity.java
M fragment/fragment/src/androidTest/java/androidx/fragment/app/FragmentArchLifecycleTest.kt
M fragment/fragment/src/main/java/androidx/fragment/app/FragmentActivity.java

https://android-review.googlesource.com/1385861

ap...@google.com <ap...@google.com> #5May 3, 2022 08:52PM

Project: platform/frameworks/support
Branch: androidx-master-dev

commit d830158f1671930bab215716e329349a42eec1dd
Author: Ian Lake <ilake@google.com>
Date: Fri Jul 31 14:14:29 2020

Add suspending withContextAvailable to ContextAware

Expand the ContextAware interface to allow developers
to synchronously peek to see if the context is
availble.

This allows us to write a Kotlin extension
withContextAvailable() that runs a non-suspending
block once the context becomes available (either
synchronously if it is already available or by
using a OnContextAvailableListener under the hood
if not).

Test: new tests pass
BUG: 161390636
Relnote: "Added a `peekAvailableContext()` API to
`ContextAware` to allow you to synchronously determine
if a Context is available. A suspending Kotlin extension
`withContextAvailable()` allows you to run a
non-suspending block when the Context becomes available
and return a result."

Change-Id: I8290cd9de8231913036d23a233c177ed45d2d370

M activity/activity-ktx/api/current.txt
M activity/activity-ktx/api/public_plus_experimental_current.txt
M activity/activity-ktx/api/restricted_current.txt
A activity/activity-ktx/src/androidTest/java/androidx/activity/contextaware/ContextAwareTest.kt
A activity/activity-ktx/src/main/java/androidx/activity/contextaware/ContextAware.kt
M activity/activity/api/current.txt
M activity/activity/api/public_plus_experimental_current.txt
M activity/activity/api/restricted_current.txt
M activity/activity/src/androidTest/java/androidx/activity/contextaware/ContextAwareHelperTest.kt
M activity/activity/src/main/java/androidx/activity/ComponentActivity.java
M activity/activity/src/main/java/androidx/activity/contextaware/ContextAware.java
M activity/activity/src/main/java/androidx/activity/contextaware/ContextAwareHelper.java

https://android-review.googlesource.com/1384202

ap...@google.com <ap...@google.com> #6May 7, 2022 03:59AM

The new ContextAware API will be available in Activity 1.2.0-alpha08 and is used by Fragment 1.3.0-alpha08 and AppCompat 1.3.0-alpha02 to implement FragmentManager's and AppCompatDelegate's pre-onCreate() logic.

ap...@google.com <ap...@google.com> #7May 7, 2022 03:59AM

Wait, this can't work as advertised.

FragmentActivity extends ComponentActivity

public FragmentActivity(@LayoutRes int contentLayoutId) {
    super(contentLayoutId);
    init();
}

private void init() {
    addOnContextAvailableListener(new OnContextAvailableListener() {
        // ...
    }
}

ComponentActivity

@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
    // ...
    mContextAwareHelper.dispatchOnContextAvailable(this);
    super.onCreate(savedInstanceState);
    //...
}

Call FragmentActivity constructor,
which calls ComponentActivity super constructor,
which dispatches context available... to noone,
and calls platform Activity.onCreate.
Bubble up to FragmentActivity constructor and register context listener,
which is invoked synchronously but only after platform Activity.onCreate has already been called.

Did I miss something? I'm confused.

ap...@google.com <ap...@google.com> #8May 12, 2022 12:02AM

Never mind, constructor vs onCreate. :facepalm: Sorry.

ni...@google.com <ni...@google.com> #9May 12, 2022 12:05AM

Re #8 - the fact that these are different things is indeed exactly why this API exists :)

ap...@google.com <ap...@google.com> #10May 19, 2022 09:01PM

https://docs.google.com/document/d/1hyftTRyqV7ZJ5s2b_-Q9K6RJdpgedgvKP4vYoTK7i1A/edit?usp=drive_web ([Feedback] Bass Booster)

ni...@google.com <ni...@google.com> #11Jun 1, 2022 07:28PM

As part of writing https://reviews.llvm.org/D124871 I observed that handleVectorConvertIntrinsic() could be suitable for handling rounding operations as well. The current code propagates just the poisoned bits, while handleVectorConvertIntrinsic() checks the whole input argument for any poisoned bits and broadcasts it to the entire output.