Merge pull request #12173 from AdmiralCurtiss/fixed-mapping-assert

Common/MemArena: LazyMemoryRegion fixes.
dolphin-emu · Sep 7, 2023 · cc01b4b · cc01b4b
2 parents c0440df + 422bc7a
commit cc01b4b
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Showing 3 changed files with 17 additions and 4 deletions.
diff --git a/Source/Core/Common/MemArenaAndroid.cpp b/Source/Core/Common/MemArenaAndroid.cpp
@@ -155,8 +155,11 @@ void* LazyMemoryRegion::Create(size_t size)
 {
   ASSERT(!m_memory);
 
+  if (size == 0)
+    return nullptr;
+
   void* memory = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
-  if (!memory)
+  if (memory == MAP_FAILED)
   {
     NOTICE_LOG_FMT(MEMMAP, "Memory allocation of {} bytes failed.", size);
     return nullptr;
@@ -172,7 +175,9 @@ void LazyMemoryRegion::Clear()
 {
   ASSERT(m_memory);
 
-  mmap(m_memory, m_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
+  void* new_memory = mmap(m_memory, m_size, PROT_READ | PROT_WRITE,
+                          MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
+  ASSERT(new_memory == m_memory);
 }
 
 void LazyMemoryRegion::Release()

diff --git a/Source/Core/Common/MemArenaUnix.cpp b/Source/Core/Common/MemArenaUnix.cpp
@@ -121,8 +121,11 @@ void* LazyMemoryRegion::Create(size_t size)
 {
   ASSERT(!m_memory);
 
+  if (size == 0)
+    return nullptr;
+
   void* memory = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
-  if (!memory)
+  if (memory == MAP_FAILED)
   {
     NOTICE_LOG_FMT(MEMMAP, "Memory allocation of {} bytes failed.", size);
     return nullptr;
@@ -138,7 +141,9 @@ void LazyMemoryRegion::Clear()
 {
   ASSERT(m_memory);
 
-  mmap(m_memory, m_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
+  void* new_memory = mmap(m_memory, m_size, PROT_READ | PROT_WRITE,
+                          MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
+  ASSERT(new_memory == m_memory);
 }
 
 void LazyMemoryRegion::Release()

diff --git a/Source/Core/Common/MemArenaWin.cpp b/Source/Core/Common/MemArenaWin.cpp
@@ -445,6 +445,9 @@ void* LazyMemoryRegion::Create(size_t size)
 {
   ASSERT(!m_memory);
 
+  if (size == 0)
+    return nullptr;
+
   void* memory = VirtualAlloc(nullptr, size, MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);
   if (!memory)
   {