Commit 29a1c2e7 authored by Steve Fink's avatar Steve Fink
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Bug 1682068 - Fix rooting hazard in ImageBitmap::CreateInternal by avoiding...

Bug 1682068 - Fix rooting hazard in ImageBitmap::CreateInternal by avoiding movable data. r=jrmuizel, a=RyanVM

Differential Revision:
parent c0359728
......@@ -880,13 +880,26 @@ already_AddRefed<ImageBitmap> ImageBitmap::CreateInternal(
// Create and Crop the raw data into a layers::Image
RefPtr<layers::Image> data;
// If the data could move during a GC, copy it out into a local buffer that
// lives until a CreateImageFromRawData lower in the stack copies it.
// Reassure the static analysis that we know what we're doing.
size_t maxInline = JS_MaxMovableTypedArraySize();
uint8_t inlineDataBuffer[maxInline];
uint8_t* fixedData = array.FixedData(inlineDataBuffer, maxInline);
// Lie to the hazard analysis and say that we're done with everything that
// `array` was using (safe because the data buffer is fixed, and the holding
// JSObject is being kept alive elsewhere.)
if (NS_IsMainThread()) {
data = CreateImageFromRawData(imageSize, imageStride, FORMAT, array.Data(),
dataLength, aCropRect);
data = CreateImageFromRawData(imageSize, imageStride, FORMAT,
fixedData, dataLength, aCropRect);
} else {
RefPtr<CreateImageFromRawDataInMainThreadSyncTask> task =
new CreateImageFromRawDataInMainThreadSyncTask(
array.Data(), dataLength, imageStride, FORMAT, imageSize, aCropRect,
fixedData, dataLength, imageStride, FORMAT, imageSize, aCropRect,
task->Dispatch(Canceling, aRv);
......@@ -896,7 +909,7 @@ already_AddRefed<ImageBitmap> ImageBitmap::CreateInternal(
return nullptr;
// Create an ImageBimtap.
// Create an ImageBitmap.
RefPtr<ImageBitmap> ret =
new ImageBitmap(aGlobal, data, false /* write-only */, alphaType);
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