From: Torok Edwin <edwintorok@gmail.com>
Date: Sun, 28 Mar 2010 11:07:36 +0000 (+0000)
Subject: Fix use-of-uninitialized value when RWX memory can't be allocated (PR6701).
X-Git-Url: http://plrg.eecs.uci.edu/git/?p=oota-llvm.git;a=commitdiff_plain;h=b4bc96317a64b5f824ebef4b0c1c7024017f52c6

Fix use-of-uninitialized value when RWX memory can't be allocated (PR6701).

SELinux doesn't allow 'execmem', returning MAP_FAILED and 'Permission denied'
for mmap or RWX memory. In this case AllocateRWX was returning a MemoryBlock
with uninitialized fields, which sometimes caused crashes.

This patch initializes MemoryBlock fields to 0, so that the RWX-failure check
works.
It doesn't fix the SELinux 'execmem' issues though (the JIT will not work when
SELinux is in enforcing mode).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99762 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/llvm/System/Memory.h b/include/llvm/System/Memory.h
index 69251dd2bfb..01bcab1f007 100644
--- a/include/llvm/System/Memory.h
+++ b/include/llvm/System/Memory.h
@@ -27,7 +27,7 @@ namespace sys {
   /// @brief Memory block abstraction.
   class MemoryBlock {
   public:
-    MemoryBlock() { }
+    MemoryBlock() : Address(0), Size(0) { }
     MemoryBlock(void *addr, size_t size) : Address(addr), Size(size) { }
     void *base() const { return Address; }
     size_t size() const { return Size; }