From de162a648b3bb1c8080460bfb8392951340ef40b Mon Sep 17 00:00:00 2001
From: riperiperi <rhy3756547@hotmail.com>
Date: Fri, 18 Nov 2022 20:47:29 +0000
Subject: [PATCH] Gpu: Fix thread safety of ReregisterRanges (#3865)
A quick fix to prevent reading the wrong value of Count when reregistering ranges for a new target buffer. Buffer flushes from another thread can modify the range list when the lock isn't active, which can change the count.
This prevents some crashes in Pokemon Scarlet/Violet. It's probably likely that buffer migration during flush is causing some other issues in this game, but this at least prevents the crashing.
---
Ryujinx.Graphics.Gpu/Memory/BufferModifiedRangeList.cs | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/Ryujinx.Graphics.Gpu/Memory/BufferModifiedRangeList.cs b/Ryujinx.Graphics.Gpu/Memory/BufferModifiedRangeList.cs
index b9b533fb73..07dbd2094a 100644
--- a/Ryujinx.Graphics.Gpu/Memory/BufferModifiedRangeList.cs
+++ b/Ryujinx.Graphics.Gpu/Memory/BufferModifiedRangeList.cs
@@ -325,13 +325,15 @@ namespace Ryujinx.Graphics.Gpu.Memory
public void ReregisterRanges(Action<ulong, ulong> rangeAction)
{
ref var ranges = ref ThreadStaticArray<BufferModifiedRange>.Get();
+ int count;
// Range list must be consistent for this operation.
lock (_lock)
{
- if (ranges.Length < Count)
+ count = Count;
+ if (ranges.Length < count)
{
- Array.Resize(ref ranges, Count);
+ Array.Resize(ref ranges, count);
}
int i = 0;
@@ -342,7 +344,7 @@ namespace Ryujinx.Graphics.Gpu.Memory
}
ulong currentSync = _context.SyncNumber;
- for (int i = 0; i < Count; i++)
+ for (int i = 0; i < count; i++)
{
BufferModifiedRange range = ranges[i];
if (range.SyncNumber != currentSync)