Merge pull request #4194 from ReinUsesLisp/fix-shader-cache

shader_cache: Fix use-after-free and orphan invalidation cache entries

src/video_core/shader_cache.h

@@ -20,6 +20,7 @@ namespace VideoCommon {
 template <class T>
 class ShaderCache {
     static constexpr u64 PAGE_BITS = 14;
+    static constexpr u64 PAGE_SIZE = u64(1) << PAGE_BITS;
 
     struct Entry {
         VAddr addr_start;
@@ -87,8 +88,8 @@ protected:
         const VAddr addr_end = addr + size;
         Entry* const entry = NewEntry(addr, addr_end, data.get());
 
-        const u64 page_end = addr_end >> PAGE_BITS;
+        const u64 page_end = (addr_end + PAGE_SIZE - 1) >> PAGE_BITS;
-        for (u64 page = addr >> PAGE_BITS; page <= page_end; ++page) {
+        for (u64 page = addr >> PAGE_BITS; page < page_end; ++page) {
             invalidation_cache[page].push_back(entry);
         }
 
@@ -108,20 +109,13 @@ private:
     /// @pre invalidation_mutex is locked
     void InvalidatePagesInRegion(VAddr addr, std::size_t size) {
         const VAddr addr_end = addr + size;
-        const u64 page_end = addr_end >> PAGE_BITS;
+        const u64 page_end = (addr_end + PAGE_SIZE - 1) >> PAGE_BITS;
-        for (u64 page = addr >> PAGE_BITS; page <= page_end; ++page) {
+        for (u64 page = addr >> PAGE_BITS; page < page_end; ++page) {
-            const auto it = invalidation_cache.find(page);
+            auto it = invalidation_cache.find(page);
             if (it == invalidation_cache.end()) {
                 continue;
             }
-
+            InvalidatePageEntries(it->second, addr, addr_end);
-            std::vector<Entry*>& entries = it->second;
-            InvalidatePageEntries(entries, addr, addr_end);
-
-            // If there's nothing else in this page, remove it to avoid overpopulating the hash map.
-            if (entries.empty()) {
-                invalidation_cache.erase(it);
-            }
         }
     }
 
@@ -131,15 +125,22 @@ private:
         if (marked_for_removal.empty()) {
             return;
         }
-        std::scoped_lock lock{lookup_mutex};
+        // Remove duplicates
+        std::sort(marked_for_removal.begin(), marked_for_removal.end());
+        marked_for_removal.erase(std::unique(marked_for_removal.begin(), marked_for_removal.end()),
+                                 marked_for_removal.end());
 
         std::vector<T*> removed_shaders;
         removed_shaders.reserve(marked_for_removal.size());
 
+        std::scoped_lock lock{lookup_mutex};
+
         for (Entry* const entry : marked_for_removal) {
-            if (lookup_cache.erase(entry->addr_start) > 0) {
             removed_shaders.push_back(entry->data);
-            }
+
+            const auto it = lookup_cache.find(entry->addr_start);
+            ASSERT(it != lookup_cache.end());
+            lookup_cache.erase(it);
         }
         marked_for_removal.clear();
 
@@ -154,17 +155,33 @@ private:
     /// @param addr_end        Non-inclusive end address of the invalidation
     /// @pre invalidation_mutex is locked
     void InvalidatePageEntries(std::vector<Entry*>& entries, VAddr addr, VAddr addr_end) {
-        auto it = entries.begin();
+        std::size_t index = 0;
-        while (it != entries.end()) {
+        while (index < entries.size()) {
-            Entry* const entry = *it;
+            Entry* const entry = entries[index];
             if (!entry->Overlaps(addr, addr_end)) {
-                ++it;
+                ++index;
                 continue;
             }
-            UnmarkMemory(entry);
-            marked_for_removal.push_back(entry);
 
-            it = entries.erase(it);
+            UnmarkMemory(entry);
+            RemoveEntryFromInvalidationCache(entry);
+            marked_for_removal.push_back(entry);
+        }
+    }
+
+    /// @brief Removes all references to an entry in the invalidation cache
+    /// @param entry Entry to remove from the invalidation cache
+    /// @pre invalidation_mutex is locked
+    void RemoveEntryFromInvalidationCache(const Entry* entry) {
+        const u64 page_end = (entry->addr_end + PAGE_SIZE - 1) >> PAGE_BITS;
+        for (u64 page = entry->addr_start >> PAGE_BITS; page < page_end; ++page) {
+            const auto entries_it = invalidation_cache.find(page);
+            ASSERT(entries_it != invalidation_cache.end());
+            std::vector<Entry*>& entries = entries_it->second;
+
+            const auto entry_it = std::find(entries.begin(), entries.end(), entry);
+            ASSERT(entry_it != entries.end());
+            entries.erase(entry_it);
         }
     }
 
@@ -182,16 +199,11 @@ private:
     }
 
     /// @brief Removes a vector of shaders from a list
-    /// @param removed_shaders Shaders to be removed from the storage, it can contain duplicates
+    /// @param removed_shaders Shaders to be removed from the storage
     /// @pre invalidation_mutex is locked
     /// @pre lookup_mutex is locked
     void RemoveShadersFromStorage(std::vector<T*> removed_shaders) {
-        // Remove duplicates
+        // Notify removals
-        std::sort(removed_shaders.begin(), removed_shaders.end());
-        removed_shaders.erase(std::unique(removed_shaders.begin(), removed_shaders.end()),
-                              removed_shaders.end());
-
-        // Now that there are no duplicates, we can notify removals
         for (T* const shader : removed_shaders) {
             OnShaderRemoval(shader);
         }