From 9ed1371adb219b791ac446812182e643c1f727dc Mon Sep 17 00:00:00 2001
From: Benjamin Kramer <benny.kra@googlemail.com>
Date: Thu, 20 Apr 2017 20:28:18 +0000
Subject: [PATCH] [Support] Make asan poisoning for recyclers more aggressive
 by also poisoning the 'next' pointer.

llvm-svn: 300882
---
 llvm/include/llvm/Support/ArrayRecycler.h | 5 ++---
 llvm/include/llvm/Support/Recycler.h      | 5 ++---
 2 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/llvm/include/llvm/Support/ArrayRecycler.h b/llvm/include/llvm/Support/ArrayRecycler.h
index b4222ca..68696be 100644
--- a/llvm/include/llvm/Support/ArrayRecycler.h
+++ b/llvm/include/llvm/Support/ArrayRecycler.h
@@ -47,22 +47,21 @@ template <class T, size_t Align = alignof(T)> class ArrayRecycler {
     FreeList *Entry = Bucket[Idx];
     if (!Entry)
       return nullptr;
+    __asan_unpoison_memory_region(Entry, Capacity::get(Idx).getSize());
     Bucket[Idx] = Entry->Next;
     __msan_allocated_memory(Entry, Capacity::get(Idx).getSize());
-    __asan_unpoison_memory_region(Entry, Capacity::get(Idx).getSize());
     return reinterpret_cast<T*>(Entry);
   }
 
   // Add an entry to the free list at Bucket[Idx].
   void push(unsigned Idx, T *Ptr) {
     assert(Ptr && "Cannot recycle NULL pointer");
-    __asan_poison_memory_region(Ptr, Capacity::get(Idx).getSize());
-    __asan_unpoison_memory_region(Ptr, sizeof(FreeList));
     FreeList *Entry = reinterpret_cast<FreeList*>(Ptr);
     if (Idx >= Bucket.size())
       Bucket.resize(size_t(Idx) + 1);
     Entry->Next = Bucket[Idx];
     Bucket[Idx] = Entry;
+    __asan_poison_memory_region(Ptr, Capacity::get(Idx).getSize());
   }
 
 public:
diff --git a/llvm/include/llvm/Support/Recycler.h b/llvm/include/llvm/Support/Recycler.h
index dc8b246..53db2e8 100644
--- a/llvm/include/llvm/Support/Recycler.h
+++ b/llvm/include/llvm/Support/Recycler.h
@@ -42,17 +42,16 @@ class Recycler {
 
   FreeNode *pop_val() {
     auto *Val = FreeList;
+    __asan_unpoison_memory_region(Val, Size);
     FreeList = FreeList->Next;
     __msan_allocated_memory(Val, Size);
-    __asan_unpoison_memory_region(Val, Size);
     return Val;
   }
 
   void push(FreeNode *N) {
-    __asan_poison_memory_region(N, Size);
-    __asan_unpoison_memory_region(N, sizeof(FreeNode));
     N->Next = FreeList;
     FreeList = N;
+    __asan_poison_memory_region(N, Size);
   }
 
 public:
-- 
2.7.4