[compiler-rt] [scudo] [MTE] resize stack depot for allocation ring buffer (PR #74515)

[via llvm-commits]

================
@@ -954,45 +962,54 @@ class Allocator {
 
   static const uptr MaxTraceSize = 64;
 
-  static void collectTraceMaybe(const StackDepot *Depot,
+  static void collectTraceMaybe(const char *RawStackDepot,
                                 uintptr_t (&Trace)[MaxTraceSize], u32 Hash) {
+    auto *Depot = reinterpret_cast<const StackDepot *>(RawStackDepot);
     uptr RingPos, Size;
-    if (!Depot->find(Hash, &RingPos, &Size))
+    if (!Depot->find(RawStackDepot, Hash, &RingPos, &Size))
       return;
     for (unsigned I = 0; I != Size && I != MaxTraceSize; ++I)
-      Trace[I] = static_cast<uintptr_t>((*Depot)[RingPos + I]);
+      Trace[I] = static_cast<uintptr_t>(Depot->at(RawStackDepot, RingPos + I));
   }
 
   static void getErrorInfo(struct scudo_error_info *ErrorInfo,
                            uintptr_t FaultAddr, const char *DepotPtr,
-                           const char *RegionInfoPtr, const char *RingBufferPtr,
-                           size_t RingBufferSize, const char *Memory,
-                           const char *MemoryTags, uintptr_t MemoryAddr,
-                           size_t MemorySize) {
+                           size_t DepotSize, const char *RegionInfoPtr,
+                           const char *RingBufferPtr, size_t RingBufferSize,
+                           const char *Memory, const char *MemoryTags,
+                           uintptr_t MemoryAddr, size_t MemorySize) {
     *ErrorInfo = {};
     if (!allocatorSupportsMemoryTagging<Config>() ||
         MemoryAddr + MemorySize < MemoryAddr)
       return;
 
-    auto *Depot = reinterpret_cast<const StackDepot *>(DepotPtr);
+    if (DepotPtr && DepotSize < sizeof(StackDepot)) {
+      return;
+    }
+    if (DepotPtr &&
+        !reinterpret_cast<const StackDepot *>(DepotPtr)->isValid(DepotSize)) {
----------------
ChiaHungDuan wrote:

I would suggest doing
```
// Some comment
if (!DepotPtr)
  return;

// the following logics
```

https://github.com/llvm/llvm-project/pull/74515