[compiler-rt] 6584758 - [NFC][Asan] Early return from GetBlockBegin

[Vitaly Buka via llvm-commits]

Author: Vitaly Buka
Date: 2020-09-11T15:31:38-07:00
New Revision: 658475897b14781070549f72483fd283e3fe50aa

URL: https://github.com/llvm/llvm-project/commit/658475897b14781070549f72483fd283e3fe50aa
DIFF: https://github.com/llvm/llvm-project/commit/658475897b14781070549f72483fd283e3fe50aa.diff

LOG: [NFC][Asan] Early return from GetBlockBegin

Added: 
    

Modified: 
    compiler-rt/lib/sanitizer_common/sanitizer_allocator_primary64.h

Removed: 
    


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diff  --git a/compiler-rt/lib/sanitizer_common/sanitizer_allocator_primary64.h b/compiler-rt/lib/sanitizer_common/sanitizer_allocator_primary64.h
index 774c09e42495..0a18b0c58ef7 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_allocator_primary64.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_allocator_primary64.h
@@ -186,13 +186,13 @@ class SizeClassAllocator64 {
 
   void *GetBlockBegin(const void *p) {
     uptr class_id = GetSizeClass(p);
+    if (class_id >= kNumClasses) return nullptr;
     uptr size = ClassIdToSize(class_id);
     if (!size) return nullptr;
     uptr chunk_idx = GetChunkIdx((uptr)p, size);
     uptr reg_beg = GetRegionBegin(p);
     uptr beg = chunk_idx * size;
     uptr next_beg = beg + size;
-    if (class_id >= kNumClasses) return nullptr;
     const RegionInfo *region = AddressSpaceView::Load(GetRegionInfo(class_id));
     if (region->mapped_user >= next_beg)
       return reinterpret_cast<void*>(reg_beg + beg);