[compiler-rt] [scudo] do not store size inside ring buffer (PR #74541)

[Christopher Ferris via llvm-commits]

================
@@ -1408,17 +1409,19 @@ class Allocator {
                                      size_t &NextErrorReport,
                                      uintptr_t FaultAddr,
                                      const StackDepot *Depot,
-                                     const char *RingBufferPtr) {
+                                     const char *RingBufferPtr,
+                                     size_t RingBufferSize) {
     auto *RingBuffer =
         reinterpret_cast<const AllocationRingBuffer *>(RingBufferPtr);
-    if (!RingBuffer || RingBuffer->Size == 0)
+    size_t RingBufferElements = ringBufferElementsFromBytes(RingBufferSize);
+    if (!RingBuffer || RingBufferElements == 0)
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cferris1000 wrote:

Is there ever a case where RingBuffer is not null and RingBufferElements is 0?

If not, maybe it would be better to change this to something like:

if (!RingBuffer)
   return;

size_t RingBufferElements = ...;
DCHECK(RingBufferElements != 0);

https://github.com/llvm/llvm-project/pull/74541