From 4b95b0df973027f4682549b0bd27bf9e05d8155f Mon Sep 17 00:00:00 2001 From: bunnei Date: Thu, 27 May 2021 14:47:24 -0700 Subject: [PATCH] video_core: rasterizer_cache: Use u16 for cached page count. - Greatly reduces the risk of overflow, at the cost of doubling the size of this array. --- src/video_core/rasterizer_accelerated.cpp | 6 +++--- src/video_core/rasterizer_accelerated.h | 12 ++++++------ 2 files changed, 9 insertions(+), 9 deletions(-) diff --git a/src/video_core/rasterizer_accelerated.cpp b/src/video_core/rasterizer_accelerated.cpp index 62d84c0f8..6decd2546 100644 --- a/src/video_core/rasterizer_accelerated.cpp +++ b/src/video_core/rasterizer_accelerated.cpp @@ -18,10 +18,10 @@ RasterizerAccelerated::~RasterizerAccelerated() = default; void RasterizerAccelerated::UpdatePagesCachedCount(VAddr addr, u64 size, int delta) { const auto page_end = Common::DivCeil(addr + size, Core::Memory::PAGE_SIZE); for (auto page = addr >> Core::Memory::PAGE_BITS; page != page_end; ++page) { - auto& count = cached_pages.at(page >> 3).Count(page); + auto& count = cached_pages.at(page >> 2).Count(page); if (delta > 0) { - ASSERT_MSG(count < UINT8_MAX, "Count may overflow!"); + ASSERT_MSG(count < UINT16_MAX, "Count may overflow!"); } else if (delta < 0) { ASSERT_MSG(count > 0, "Count may underflow!"); } else { @@ -29,7 +29,7 @@ void RasterizerAccelerated::UpdatePagesCachedCount(VAddr addr, u64 size, int del } // Adds or subtracts 1, as count is a unsigned 8-bit value - count += static_cast(delta); + count += static_cast(delta); // Assume delta is either -1 or 1 if (count == 0) { diff --git a/src/video_core/rasterizer_accelerated.h b/src/video_core/rasterizer_accelerated.h index 9227a4adc..ea879bfdd 100644 --- a/src/video_core/rasterizer_accelerated.h +++ b/src/video_core/rasterizer_accelerated.h @@ -29,20 +29,20 @@ private: public: CacheEntry() = default; - std::atomic_uint8_t& Count(std::size_t page) { - return values[page & 7]; + std::atomic_uint16_t& Count(std::size_t page) { + return values[page & 3]; } - const std::atomic_uint8_t& Count(std::size_t page) const { - return values[page & 7]; + const std::atomic_uint16_t& Count(std::size_t page) const { + return values[page & 3]; } private: - std::array values{}; + std::array values{}; }; static_assert(sizeof(CacheEntry) == 8, "CacheEntry should be 8 bytes!"); - std::array cached_pages; + std::array cached_pages; Core::Memory::Memory& cpu_memory; };