[release/9.0-staging] Add acquire barrier to populate bit reading - #119967
#119967Merged
AaronRobinsonMSFT merged 1 commit intoSep 24, 2025
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[release/9.0-staging] Add acquire barrier to populate bit reading#119967AaronRobinsonMSFT merged 1 commit intorelease/9.0-stagingdotnet/runtime:release/9.0-stagingfrom backport/pr-117523-to-release/9.0-stagingdotnet/runtime:backport/pr-117523-to-release/9.0-stagingCopy head branch name to clipboard
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The setting of the NDirectMethodDesc::kNDirectPopulated bit is done via an interlocked operation. This bit is used to indicate if the NDirectMethodDesc has been populated with the needed information to load the P/Invoke. The reading of this bit however was missing an acquire barrier and thus setting of fields between the check and set weren't being observed correctly.
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davidwrighton
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Sep 23, 2025
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/ba-g unrelelated timeouts |
AaronRobinsonMSFT
merged commit Sep 24, 2025
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Backport of #117523 to release/9.0-staging
/cc @AaronRobinsonMSFT
Fixes #119947
Customer Impact
See confirmation the fix addressed the issue in .NET 10 and the OP is requesting backport to .NET 9 - #119947. The original issue can be found at #112565.
The setting of the
PInvokeMethodDesc::kPInvokePopulatedbit is done via an interlocked operation. This bit is used to indicate if thePInvokeMethodDeschas been populated with the needed information to load the P/Invoke. The reading of this bit however was missing an acquire barrier and thus setting of fields between the check and set weren't being observed correctly.Regression
It isn't obvious when this was likely introduced, but it is likely been in the code base for many years. It was likely uncovered by refactors of PInvoke code paths.
Testing
This was checked in .NET 10 and the external user has been running without observing a crash for several weeks.
Risk
Low. This has been running in .NET 10 preview for several weeks and an external user has been running with these bits without observing the issue.