From 14ce9e15672d03cb6fc067316f90d81471398ebc Mon Sep 17 00:00:00 2001 From: riperiperi Date: Sat, 30 Jul 2022 00:16:29 +0200 Subject: Move partial unmap handler to the native signal handler (#3437) * Initial commit with a lot of testing stuff. * Partial Unmap Cleanup Part 1 * Fix some minor issues, hopefully windows tests. * Disable partial unmap tests on macos for now Weird issue. * Goodbye magic number * Add COMPlus_EnableAlternateStackCheck for tests `COMPlus_EnableAlternateStackCheck` is needed for NullReferenceException handling to work on linux after registering the signal handler, due to how dotnet registers its own signal handler. * Address some feedback * Force retry when memory is mapped in memory tracking This case existed before, but returning `false` no longer retries, so it would crash immediately after unprotecting the memory... Now, we return `true` to deliberately retry. This case existed before (was just broken by this change) and I don't really want to look into fixing the issue right now. Technically, this means that on guest code partial unmaps will retry _due to this_ rather than hitting the handler. I don't expect this to cause any issues. This should fix random crashes in Xenoblade Chronicles 2. * Use IsRangeMapped * Suppress MockMemoryManager.UnmapEvent warning This event is not signalled by the mock memory manager. * Remove 4kb mapping --- ARMeilleure/Signal/NativeSignalHandler.cs | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) (limited to 'ARMeilleure/Signal/NativeSignalHandler.cs') diff --git a/ARMeilleure/Signal/NativeSignalHandler.cs b/ARMeilleure/Signal/NativeSignalHandler.cs index cad0d420..0257f440 100644 --- a/ARMeilleure/Signal/NativeSignalHandler.cs +++ b/ARMeilleure/Signal/NativeSignalHandler.cs @@ -197,12 +197,29 @@ namespace ARMeilleure.Signal // Only call tracking if in range. context.BranchIfFalse(nextLabel, inRange, BasicBlockFrequency.Cold); - context.Copy(inRegionLocal, Const(1)); Operand offset = context.BitwiseAnd(context.Subtract(faultAddress, rangeAddress), Const(~PageMask)); // Call the tracking action, with the pointer's relative offset to the base address. Operand trackingActionPtr = context.Load(OperandType.I64, Const((ulong)signalStructPtr + rangeBaseOffset + 20)); - context.Call(trackingActionPtr, OperandType.I32, offset, Const(PageSize), isWrite, Const(0)); + + context.Copy(inRegionLocal, Const(0)); + + Operand skipActionLabel = Label(); + + // Tracking action should be non-null to call it, otherwise assume false return. + context.BranchIfFalse(skipActionLabel, trackingActionPtr); + Operand result = context.Call(trackingActionPtr, OperandType.I32, offset, Const(PageSize), isWrite, Const(0)); + context.Copy(inRegionLocal, result); + + context.MarkLabel(skipActionLabel); + + // If the tracking action returns false or does not exist, it might be an invalid access due to a partial overlap on Windows. + if (OperatingSystem.IsWindows()) + { + context.BranchIfTrue(endLabel, inRegionLocal); + + context.Copy(inRegionLocal, WindowsPartialUnmapHandler.EmitRetryFromAccessViolation(context)); + } context.Branch(endLabel); -- cgit v1.2.3