From 0b1842294f5f43ea2ee42bb8afd26e57c9250f4b Mon Sep 17 00:00:00 2001 From: bunnei Date: Fri, 23 Nov 2018 12:58:55 -0500 Subject: memory_manager: Do not allow 0 to be a valid GPUVAddr. - Fixes a bug with Undertale using 0 for a render target. --- src/video_core/memory_manager.cpp | 7 +++++++ src/video_core/memory_manager.h | 3 ++- 2 files changed, 9 insertions(+), 1 deletion(-) (limited to 'src') diff --git a/src/video_core/memory_manager.cpp b/src/video_core/memory_manager.cpp index 77a20bb84..47247f097 100644 --- a/src/video_core/memory_manager.cpp +++ b/src/video_core/memory_manager.cpp @@ -9,6 +9,13 @@ namespace Tegra { +MemoryManager::MemoryManager() { + // Mark the first page as reserved, so that 0 is not a valid GPUVAddr. Otherwise, games might + // try to use 0 as a valid address, which is also used to mean nullptr. This fixes a bug with + // Undertale using 0 for a render target. + PageSlot(0) = static_cast(PageStatus::Reserved); +} + GPUVAddr MemoryManager::AllocateSpace(u64 size, u64 align) { const std::optional gpu_addr{FindFreeBlock(0, size, align, PageStatus::Unmapped)}; diff --git a/src/video_core/memory_manager.h b/src/video_core/memory_manager.h index 4eb338aa2..fb03497ca 100644 --- a/src/video_core/memory_manager.h +++ b/src/video_core/memory_manager.h @@ -18,7 +18,7 @@ using GPUVAddr = u64; class MemoryManager final { public: - MemoryManager() = default; + MemoryManager(); GPUVAddr AllocateSpace(u64 size, u64 align); GPUVAddr AllocateSpace(GPUVAddr gpu_addr, u64 size, u64 align); @@ -37,6 +37,7 @@ private: enum class PageStatus : u64 { Unmapped = 0xFFFFFFFFFFFFFFFFULL, Allocated = 0xFFFFFFFFFFFFFFFEULL, + Reserved = 0xFFFFFFFFFFFFFFFDULL, }; std::optional FindFreeBlock(GPUVAddr region_start, u64 size, u64 align, -- cgit v1.2.3