AccessViolationException or InvalidOperationException thrown in local method with .NET 8 preview 7 nightly

[martincostello]

Description

To check some fresh changes in the aspnetcore repo for Request Delegate Generator with interceptors, @captainsafia asked me to do some tests with the preview 7 nightlies.

In the course of that testing I updated a codebase that is working correctly .NET 7 and with 8.0.100-preview.6.23330.14 to version 8.0.100-preview.7.23363.2 of the SDK.

When pushing the changes to GitHub Actions CI, there's some weird failures happening only Linux. There's some code that's alternating between either failing with an AccessViolationException and crashing the test process, or throwing InvalidOperationException and making the HTTP server "go a bit weird".

The code for the method where the exceptions are coming from can be found here (don't judge it too harshly 😄).

Reproduction Steps

1. Clone martincostello/adventofcode@51f7c63 on Linux
2. Run build.ps1

Expected behavior

The application is successfully compiled and all the tests pass.

Actual behavior

Either an AccessViolationException is thrown and the test process crashes:

The active test run was aborted. Reason: Test host process crashed : Fatal error. System.AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
   at MartinCostello.AdventOfCode.Puzzles.Y2021.Day22.<Reboot>g__Reboot|8_1(System.Collections.Generic.List`1<System.ValueTuple`2<Cuboid,Boolean>>)
   at MartinCostello.AdventOfCode.Puzzles.Y2021.Day22.Reboot(System.Collections.Generic.IList`1<System.String>, Boolean)
   at MartinCostello.AdventOfCode.Puzzles.Y2021.Day22+<SolveCoreAsync>d__9.MoveNext()
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[MartinCostello.AdventOfCode.Puzzles.Y2021.Day22+<SolveCoreAsync>d__9, AdventOfCode, Version=8.0.0.0, Culture=neutral, PublicKeyToken=9a192a7522c9e1a0]](<SolveCoreAsync>d__9 ByRef)
   at System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].Start[[MartinCostello.AdventOfCode.Puzzles.Y2021.Day22+<SolveCoreAsync>d__9, AdventOfCode, Version=8.0.0.0, Culture=neutral, PublicKeyToken=9a192a7522c9e1a0]](<SolveCoreAsync>d__9 ByRef)
   at MartinCostello.AdventOfCode.Puzzles.Y2021.Day22.SolveCoreAsync(System.String[], System.Threading.CancellationToken)
   at MartinCostello.AdventOfCode.Puzzle+<SolveAsync>d__18.MoveNext()
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[MartinCostello.AdventOfCode.Puzzle+<SolveAsync>d__18, AdventOfCode, Version=8.0.0.0, Culture=neutral, PublicKeyToken=9a192a7522c9e1a0]](<SolveAsync>d__18 ByRef)
   at MartinCostello.AdventOfCode.Puzzles.PuzzleTest+<SolvePuzzleAsync>d__8`1[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].MoveNext()
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[MartinCostello.AdventOfCode.Puzzles.PuzzleTest+<SolvePuzzleAsync>d__8`1[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]], AdventOfCode.Tests, Version=8.0.0.0, Culture=neutral, PublicKeyToken=9a192a7522c9e1a0]](<SolvePuzzleAsync>d__8`1<System.__Canon> ByRef)
   at MartinCostello.AdventOfCode.Puzzles.PuzzleTest.SolvePuzzleAsync[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](System.String[])
   at MartinCostello.AdventOfCode.Puzzles.PuzzleTest+<SolvePuzzleAsync>d__7`1[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].MoveNext()
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[MartinCostello.AdventOfCode.Puzzles.PuzzleTest+<SolvePuzzleAsync>d__7`1[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]], AdventOfCode.Tests, Version=8.0.0.0, Culture=neutral, PublicKeyToken=9a192a7522c9e1a0]](<SolvePuzzleAsync>d__7`1<System.__Canon> ByRef)
   at MartinCostello.AdventOfCode.Puzzles.PuzzleTest.SolvePuzzleAsync[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]]()
   at MartinCostello.AdventOfCode.Puzzles.Y2021.Day22Tests+<Y2021_Day22_Solve_Returns_Correct_Solution>d__4.MoveNext()
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[MartinCostello.AdventOfCode.Puzzles.Y2021.Day22Tests+<Y2021_Day22_Solve_Returns_Correct_Solution>d__4, AdventOfCode.Tests, Version=8.0.0.0, Culture=neutral, PublicKeyToken=9a192a7522c9e1a0]](<Y2021_Day22_Solve_Returns_Correct_Solution>d__4 ByRef)
   at System.Runtime.CompilerServices.AsyncTaskMethodBuilder.Start[[MartinCostello.AdventOfCode.Puzzles.Y2021.Day22Tests+<Y2021_Day22_Solve_Returns_Correct_Solution>d__4, AdventOfCode.Tests, Version=8.0.0.0, Culture=neutral, PublicKeyToken=9a192a7522c9e1a0]](<Y2021_Day22_Solve_Returns_Correct_Solution>d__4 ByRef)
   at MartinCostello.AdventOfCode.Puzzles.Y2021.Day22Tests.Y2021_Day22_Solve_Returns_Correct_Solution()
   at System.RuntimeMethodHandle.InvokeMethod(System.Object, Void**, System.Signature, Boolean)
   at System.Reflection.MethodInvoker.Invoke(System.Object, IntPtr*, System.Reflection.BindingFlags)
   at System.Reflection.RuntimeMethodInfo.Invoke(System.Object, System.Reflection.BindingFlags, System.Reflection.Binder, System.Object[], System.Globalization.CultureInfo)
   at Xunit.Sdk.TestInvoker`1+<>c__DisplayClass48_0+<<InvokeTestMethodAsync>b__1>d[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].MoveNext()
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[Xunit.Sdk.TestInvoker`1+<>c__DisplayClass48_0+<<InvokeTestMethodAsync>b__1>d[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]], xunit.execution.dotnet, Version=2.5.0.0, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c]](<<InvokeTestMethodAsync>b__1>d<System.__Canon> ByRef)
   at Xunit.Sdk.TestInvoker`1+<>c__DisplayClass48_0[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].<InvokeTestMethodAsync>b__1()
   at Xunit.Sdk.ExecutionTimer+<AggregateAsync>d__4.MoveNext()
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[Xunit.Sdk.ExecutionTimer+<AggregateAsync>d__4, xunit.execution.dotnet, Version=2.5.0.0, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c]](<AggregateAsync>d__4 ByRef)
   at Xunit.Sdk.ExceptionAggregator+<RunAsync>d__9.MoveNext()
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[Xunit.Sdk.ExceptionAggregator+<RunAsync>d__9, xunit.core, Version=2.5.0.0, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c]](<RunAsync>d__9 ByRef)
   at Xunit.Sdk.TestInvoker`1+<InvokeTestMethodAsync>d__48[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].MoveNext()
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[Xunit.Sdk.TestInvoker`1+<InvokeTestMethodAsync>d__48[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]], xunit.execution.dotnet, Version=2.5.0.0, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c]](<InvokeTestMethodAsync>d__48<System.__Canon> ByRef)
   at Xunit.Sdk.TestInvoker`1+<<RunAsync>b__47_0>d[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].MoveNext()
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[Xunit.Sdk.TestInvoker`1+<<RunAsync>b__47_0>d[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]], xunit.execution.dotnet, Version=2.5.0.0, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c]](<<RunAsync>b__47_0>d<System.__Canon> ByRef)
   at Xunit.Sdk.TestInvoker`1[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].<RunAsync>b__47_0()
   at Xunit.Sdk.ExceptionAggregator+<RunAsync>d__10`1[[System.Decimal, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].MoveNext()
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[Xunit.Sdk.ExceptionAggregator+<RunAsync>d__10`1[[System.Decimal, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]], xunit.core, Version=2.5.0.0, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c]](<RunAsync>d__10`1<System.Decimal> ByRef)
   at Xunit.Sdk.XunitTestRunner+<InvokeTestAsync>d__4.MoveNext()
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[Xunit.Sdk.XunitTestRunner+<InvokeTestAsync>d__4, xunit.execution.dotnet, Version=2.5.0.0, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c]](<InvokeTestAsync>d__4 ByRef)
   at Xunit.Sdk.ExceptionAggregator+<RunAsync>d__10`1[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].MoveNext()

Or an InvalidOperationException is thrown from some tests and then the HTTP server stops responding:

 System.InvalidOperationException: Collection was modified; enumeration operation may not execute.
    at MartinCostello.AdventOfCode.Puzzles.Y2021.Day22.<Reboot>g__Reboot|8_1(List`1 cuboids) in /_/src/AdventOfCode/Puzzles/Y2021/Day22.cs:line 74
    at MartinCostello.AdventOfCode.Puzzles.Y2021.Day22.Reboot(IList`1 instructions, Boolean initialize) in /_/src/AdventOfCode/Puzzles/Y2021/Day22.cs:line 46
    at MartinCostello.AdventOfCode.Puzzles.Y2021.Day22.SolveCoreAsync(String[] args, CancellationToken cancellationToken) in /_/src/AdventOfCode/Puzzles/Y2021/Day22.cs:line 146
    at MartinCostello.AdventOfCode.Puzzle.SolveAsync(String[] args, CancellationToken cancellationToken) in /_/src/AdventOfCode/Puzzle.cs:line 57
    at MartinCostello.AdventOfCode.Site.PuzzlesApi.SolvePuzzleAsync(Int32 year, Int32 day, HttpRequest request, IFormFile resource, PuzzleFactory factory, ILogger`1 logger, CancellationToken cancellationToken) in /_/src/AdventOfCode.Site/PuzzlesApi.cs:line 117

Regression?

Yes - the same code works in .NET 7 and .NET 8 preview 6.

Known Workarounds

Set DOTNET_JitEnablePhysicalPromotion=0.

#88842 (comment)

Configuration

.NET SDK 8.0.100-preview.7.23363.2

Other information

No response

Edit: Turns out the "weird server" bits aren't new, I just hadn't spotted them before.

[jakobbotsch]

Hi @martincostello – does the issue reproduce with DOTNET_JitEnablePhysicalPromotion=0 set in the environment?

[martincostello]

Let me set that now and see... ⏳

[martincostello]

@jakobbotsch It would appear that setting that resolves the problem.

Tagging subscribers to this area: @JulieLeeMSFT, @jakobbotsch
See info in area-owners.md if you want to be subscribed.

Issue Details

---

Description

To check some fresh changes in the aspnetcore repo for Request Delegate Generator with interceptors, @captainsafia asked me to do some tests with the preview 7 nightlies.

In the course of that testing I updated a codebase that is working correctly .NET 7 and with 8.0.100-preview.6.23330.14 to version 8.0.100-preview.7.23363.2 of the SDK.

When pushing the changes to GitHub Actions CI, there's some weird failures happening only Linux. There's some code that's alternating between either failing with an AccessViolationException and crashing the test process, or throwing InvalidOperationException and making the HTTP server "go a bit weird".

The code for the method where the exceptions are coming from can be found here (don't judge it too harshly 😄).

Reproduction Steps

1. Clone martincostello/adventofcode@51f7c63 on Linux
2. Run build.ps1

Expected behavior

The application is successfully compiled and all the tests pass.

Actual behavior

Either an AccessViolationException is thrown and the test process crashes:

The active test run was aborted. Reason: Test host process crashed : Fatal error. System.AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
   at MartinCostello.AdventOfCode.Puzzles.Y2021.Day22.<Reboot>g__Reboot|8_1(System.Collections.Generic.List`1<System.ValueTuple`2<Cuboid,Boolean>>)
   at MartinCostello.AdventOfCode.Puzzles.Y2021.Day22.Reboot(System.Collections.Generic.IList`1<System.String>, Boolean)
   at MartinCostello.AdventOfCode.Puzzles.Y2021.Day22+<SolveCoreAsync>d__9.MoveNext()
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[MartinCostello.AdventOfCode.Puzzles.Y2021.Day22+<SolveCoreAsync>d__9, AdventOfCode, Version=8.0.0.0, Culture=neutral, PublicKeyToken=9a192a7522c9e1a0]](<SolveCoreAsync>d__9 ByRef)
   at System.Runtime.CompilerServices.AsyncTaskMethodBuilder`1[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].Start[[MartinCostello.AdventOfCode.Puzzles.Y2021.Day22+<SolveCoreAsync>d__9, AdventOfCode, Version=8.0.0.0, Culture=neutral, PublicKeyToken=9a192a7522c9e1a0]](<SolveCoreAsync>d__9 ByRef)
   at MartinCostello.AdventOfCode.Puzzles.Y2021.Day22.SolveCoreAsync(System.String[], System.Threading.CancellationToken)
   at MartinCostello.AdventOfCode.Puzzle+<SolveAsync>d__18.MoveNext()
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[MartinCostello.AdventOfCode.Puzzle+<SolveAsync>d__18, AdventOfCode, Version=8.0.0.0, Culture=neutral, PublicKeyToken=9a192a7522c9e1a0]](<SolveAsync>d__18 ByRef)
   at MartinCostello.AdventOfCode.Puzzles.PuzzleTest+<SolvePuzzleAsync>d__8`1[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].MoveNext()
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[MartinCostello.AdventOfCode.Puzzles.PuzzleTest+<SolvePuzzleAsync>d__8`1[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]], AdventOfCode.Tests, Version=8.0.0.0, Culture=neutral, PublicKeyToken=9a192a7522c9e1a0]](<SolvePuzzleAsync>d__8`1<System.__Canon> ByRef)
   at MartinCostello.AdventOfCode.Puzzles.PuzzleTest.SolvePuzzleAsync[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](System.String[])
   at MartinCostello.AdventOfCode.Puzzles.PuzzleTest+<SolvePuzzleAsync>d__7`1[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].MoveNext()
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[MartinCostello.AdventOfCode.Puzzles.PuzzleTest+<SolvePuzzleAsync>d__7`1[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]], AdventOfCode.Tests, Version=8.0.0.0, Culture=neutral, PublicKeyToken=9a192a7522c9e1a0]](<SolvePuzzleAsync>d__7`1<System.__Canon> ByRef)
   at MartinCostello.AdventOfCode.Puzzles.PuzzleTest.SolvePuzzleAsync[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]]()
   at MartinCostello.AdventOfCode.Puzzles.Y2021.Day22Tests+<Y2021_Day22_Solve_Returns_Correct_Solution>d__4.MoveNext()
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[MartinCostello.AdventOfCode.Puzzles.Y2021.Day22Tests+<Y2021_Day22_Solve_Returns_Correct_Solution>d__4, AdventOfCode.Tests, Version=8.0.0.0, Culture=neutral, PublicKeyToken=9a192a7522c9e1a0]](<Y2021_Day22_Solve_Returns_Correct_Solution>d__4 ByRef)
   at System.Runtime.CompilerServices.AsyncTaskMethodBuilder.Start[[MartinCostello.AdventOfCode.Puzzles.Y2021.Day22Tests+<Y2021_Day22_Solve_Returns_Correct_Solution>d__4, AdventOfCode.Tests, Version=8.0.0.0, Culture=neutral, PublicKeyToken=9a192a7522c9e1a0]](<Y2021_Day22_Solve_Returns_Correct_Solution>d__4 ByRef)
   at MartinCostello.AdventOfCode.Puzzles.Y2021.Day22Tests.Y2021_Day22_Solve_Returns_Correct_Solution()
   at System.RuntimeMethodHandle.InvokeMethod(System.Object, Void**, System.Signature, Boolean)
   at System.Reflection.MethodInvoker.Invoke(System.Object, IntPtr*, System.Reflection.BindingFlags)
   at System.Reflection.RuntimeMethodInfo.Invoke(System.Object, System.Reflection.BindingFlags, System.Reflection.Binder, System.Object[], System.Globalization.CultureInfo)
   at Xunit.Sdk.TestInvoker`1+<>c__DisplayClass48_0+<<InvokeTestMethodAsync>b__1>d[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].MoveNext()
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[Xunit.Sdk.TestInvoker`1+<>c__DisplayClass48_0+<<InvokeTestMethodAsync>b__1>d[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]], xunit.execution.dotnet, Version=2.5.0.0, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c]](<<InvokeTestMethodAsync>b__1>d<System.__Canon> ByRef)
   at Xunit.Sdk.TestInvoker`1+<>c__DisplayClass48_0[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].<InvokeTestMethodAsync>b__1()
   at Xunit.Sdk.ExecutionTimer+<AggregateAsync>d__4.MoveNext()
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[Xunit.Sdk.ExecutionTimer+<AggregateAsync>d__4, xunit.execution.dotnet, Version=2.5.0.0, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c]](<AggregateAsync>d__4 ByRef)
   at Xunit.Sdk.ExceptionAggregator+<RunAsync>d__9.MoveNext()
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[Xunit.Sdk.ExceptionAggregator+<RunAsync>d__9, xunit.core, Version=2.5.0.0, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c]](<RunAsync>d__9 ByRef)
   at Xunit.Sdk.TestInvoker`1+<InvokeTestMethodAsync>d__48[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].MoveNext()
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[Xunit.Sdk.TestInvoker`1+<InvokeTestMethodAsync>d__48[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]], xunit.execution.dotnet, Version=2.5.0.0, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c]](<InvokeTestMethodAsync>d__48<System.__Canon> ByRef)
   at Xunit.Sdk.TestInvoker`1+<<RunAsync>b__47_0>d[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].MoveNext()
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[Xunit.Sdk.TestInvoker`1+<<RunAsync>b__47_0>d[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]], xunit.execution.dotnet, Version=2.5.0.0, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c]](<<RunAsync>b__47_0>d<System.__Canon> ByRef)
   at Xunit.Sdk.TestInvoker`1[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].<RunAsync>b__47_0()
   at Xunit.Sdk.ExceptionAggregator+<RunAsync>d__10`1[[System.Decimal, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].MoveNext()
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[Xunit.Sdk.ExceptionAggregator+<RunAsync>d__10`1[[System.Decimal, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]], xunit.core, Version=2.5.0.0, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c]](<RunAsync>d__10`1<System.Decimal> ByRef)
   at Xunit.Sdk.XunitTestRunner+<InvokeTestAsync>d__4.MoveNext()
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[Xunit.Sdk.XunitTestRunner+<InvokeTestAsync>d__4, xunit.execution.dotnet, Version=2.5.0.0, Culture=neutral, PublicKeyToken=8d05b1bb7a6fdb6c]](<InvokeTestAsync>d__4 ByRef)
   at Xunit.Sdk.ExceptionAggregator+<RunAsync>d__10`1[[System.__Canon, System.Private.CoreLib, Version=8.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].MoveNext()

Or an InvalidOperationException is thrown from some tests and then the HTTP server stops responding:

 System.InvalidOperationException: Collection was modified; enumeration operation may not execute.
    at MartinCostello.AdventOfCode.Puzzles.Y2021.Day22.<Reboot>g__Reboot|8_1(List`1 cuboids) in /_/src/AdventOfCode/Puzzles/Y2021/Day22.cs:line 74
    at MartinCostello.AdventOfCode.Puzzles.Y2021.Day22.Reboot(IList`1 instructions, Boolean initialize) in /_/src/AdventOfCode/Puzzles/Y2021/Day22.cs:line 46
    at MartinCostello.AdventOfCode.Puzzles.Y2021.Day22.SolveCoreAsync(String[] args, CancellationToken cancellationToken) in /_/src/AdventOfCode/Puzzles/Y2021/Day22.cs:line 146
    at MartinCostello.AdventOfCode.Puzzle.SolveAsync(String[] args, CancellationToken cancellationToken) in /_/src/AdventOfCode/Puzzle.cs:line 57
    at MartinCostello.AdventOfCode.Site.PuzzlesApi.SolvePuzzleAsync(Int32 year, Int32 day, HttpRequest request, IFormFile resource, PuzzleFactory factory, ILogger`1 logger, CancellationToken cancellationToken) in /_/src/AdventOfCode.Site/PuzzlesApi.cs:line 117

Regression?

Yes - the same code works in .NET 7 and .NET 8 preview 6.

Known Workarounds

Set DOTNET_JitEnablePhysicalPromotion=0.

#88842 (comment)

Configuration

.NET SDK 8.0.100-preview.7.23363.2

Other information

No response

Edit: Turns out the "weird server" bits aren't new, I just hadn't spotted them before.

Author:	martincostello
Assignees:	-
Labels:	area-CodeGen-coreclr
Milestone:	-

[jakobbotsch]

Thanks for confirming. I'll take a closer look ASAP.

[jakobbotsch]

This looks like a bug in PUTARG_STK codegen or SIMD12 -> SIMD16 remapping. We have the following IR to pass a regularly promoted Cuboid to a function:

N005 ( 24, 11) [000635] --CXG------                         └──▌  CALL      byref  System.Collections.Generic.Dictionary`2[MartinCostello.AdventOfCode.Puzzles.Y2021.Day22+Cuboid,long]:FindValue(MartinCostello.AdventOfCode.Puzzles.Y2021.Day22+Cuboid):byref:this $8c1
N003 (  6,  4) [001385] -c--------- arg1 out+00                ├──▌  FIELD_LIST struct $148
N001 (  3,  2) [001386] ----------- ofs 0                      │  ├──▌  LCL_VAR   simd12 V93 tmp77        u:2 $6c1
N002 (  3,  2) [001387] ----------- ofs 12                     │  └──▌  LCL_VAR   simd12 V94 tmp78        u:2 $6c0

Lowering changes these into SIMD16s:

Mapping TYP_SIMD12 lclvar node to TYP_SIMD16:
N001 (  3,  2) [001386] -----------                         ▌  LCL_VAR   simd12 V93 tmp77        u:2 $6c1
============Mapping TYP_SIMD12 lclvar node to TYP_SIMD16:
N002 (  3,  2) [001387] -----------                         ▌  LCL_VAR   simd12 V94 tmp78        u:2 $6c0
============lowering call (before):
N001 (  3,  2) [001386] -----------                 t1386 =    LCL_VAR   simd16 V93 tmp77        u:2 $6c1
N002 (  3,  2) [001387] -----------                 t1387 =    LCL_VAR   simd16 V94 tmp78        u:2 $6c0
                                                            ┌──▌  t1386  simd16 
                                                            ├──▌  t1387  simd16 
N003 (  6,  4) [001385] -c---------                 t1385 = ▌  FIELD_LIST struct $148
N004 (  1,  1) [000206] -----------                  t206 =    LCL_VAR   ref    V05 loc4         u:3 $700
                                                            ┌──▌  t1385  struct arg1 out+00
                                                            ├──▌  t206   ref    this in rdi
N005 ( 24, 11) [000635] --CXG------                  t635 = ▌  CALL      byref  System.Collections.Generic.Dictionary`2[MartinCostello.AdventOfCode.Puzzles.Y2021.Day22+Cuboid,long]:FindValue(MartinCostello.AdventOfCode.Puzzles.Y2021.Day22+Cuboid):byref:this $8c1

Then we generate 2x 16-byte SIMD stores:

Generating: N575 (  6,  4) [001385] -c---------                 t1385 = ▌  FIELD_LIST struct REG NA $148
                                                                        ┌──▌  t1385  struct 
Generating: N577 (???,???) [001838] -----------                         ▌  PUTARG_STK [+0x00] void   (24 stackByteSize), (0 byteOffset) REG NA
							V93 in reg mm0 is becoming dead  [001386]
							Live regs: B008 {rbx r12 r13 r15 xmm0 xmm1} => B008 {rbx r12 r13 r15 xmm1}
IN008a:        vmovups  xmmword ptr [V16 rsp], xmm0
							V94 in reg mm1 is becoming dead  [001387]
							Live regs: B008 {rbx r12 r13 r15 xmm1} => B008 {rbx r12 r13 r15}
IN008b:        vmovups  xmmword ptr [V16+0xC rsp+0CH], xmm1

The second store is out-of-bounds and corrupts a (poor) physically promoted field local that was homed to stack.

[jakobbotsch]

@EgorBo Points out that this is actually the same issue as #79118, so going to kick it over to him.