[PATCH] D121858: [scudo] Don't unmap other low memory pages if mapping doesn't exist

[Dominic Chen via Phabricator via llvm-commits]

ddcc created this revision.
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Tests can register multiple allocators, but only the first will initialize since it initializes the TSDRegistrySharedT. Then, destruction of subsequent allocator may end up unmapping a nullptr PrimaryBase with non-zero PrimarySize.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D121858

Files:
  compiler-rt/lib/scudo/standalone/primary64.h


Index: compiler-rt/lib/scudo/standalone/primary64.h
===================================================================
--- compiler-rt/lib/scudo/standalone/primary64.h
+++ compiler-rt/lib/scudo/standalone/primary64.h
@@ -89,7 +89,8 @@
       RegionInfo *Region = getRegionInfo(I);
       *Region = {};
     }
-    unmap(reinterpret_cast<void *>(PrimaryBase), PrimarySize, UNMAP_ALL, &Data);
+    if (PrimaryBase)
+      unmap(reinterpret_cast<void *>(PrimaryBase), PrimarySize, UNMAP_ALL, &Data);
     PrimaryBase = 0U;
   }
 


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