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From 8b0f2fff6e080c053e4fd94d44a694768b8c156e Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Wed, 5 Aug 2015 05:35:26 -0700
Subject: [PATCH 78/84] Apply split-layout-llvm.patch
https://llvm.org/bugs/show_bug.cgi?id=24155
---
lib/Transforms/Instrumentation/MemorySanitizer.cpp | 31 ++++++++++++++++------
1 file changed, 23 insertions(+), 8 deletions(-)
diff --git a/lib/Transforms/Instrumentation/MemorySanitizer.cpp b/lib/Transforms/Instrumentation/MemorySanitizer.cpp
index 286a563..2ab8bfc 100644
--- a/lib/Transforms/Instrumentation/MemorySanitizer.cpp
+++ b/lib/Transforms/Instrumentation/MemorySanitizer.cpp
@@ -194,6 +194,12 @@ static cl::opt<bool> ClCheckConstantShadow("msan-check-constant-shadow",
static const char *const kMsanModuleCtorName = "msan.module_ctor";
static const char *const kMsanInitName = "__msan_init";
+static cl::opt<bool> ClSplitLayout(
+ "msan-split-layout", cl::desc(
+ "use experimental memory layout compatible with "
+ "non-pie and non-aslr execution"),
+ cl::Hidden, cl::init(true));
+
namespace {
// Memory map parameters used in application-to-shadow address calculation.
@@ -228,6 +234,13 @@ static const MemoryMapParams Linux_X86_64_MemoryMapParams = {
0x200000000000, // OriginBase
};
+static const MemoryMapParams Linux_X86_64_Split_MemoryMapParams = {
+ 0, // AndMask (not used)
+ 0x500000000000, // XorMask
+ 0, // ShadowBase (not used)
+ 0x100000000000, // OriginBase
+};
+
// mips64 Linux
static const MemoryMapParams Linux_MIPS64_MemoryMapParams = {
0x004000000000, // AndMask
@@ -483,7 +496,8 @@ bool MemorySanitizer::doInitialization(Module &M) {
case Triple::Linux:
switch (TargetTriple.getArch()) {
case Triple::x86_64:
- MapParams = Linux_X86_MemoryMapParams.bits64;
+ MapParams = ClSplitLayout ? &Linux_X86_64_Split_MemoryMapParams
+ : Linux_X86_MemoryMapParams.bits64;
break;
case Triple::x86:
MapParams = Linux_X86_MemoryMapParams.bits32;
@@ -893,16 +907,17 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
///
/// Offset = (Addr & ~AndMask) ^ XorMask
Value *getShadowPtrOffset(Value *Addr, IRBuilder<> &IRB) {
+ Value *OffsetLong = IRB.CreatePointerCast(Addr, MS.IntptrTy);
+
uint64_t AndMask = MS.MapParams->AndMask;
- assert(AndMask != 0 && "AndMask shall be specified");
- Value *OffsetLong =
- IRB.CreateAnd(IRB.CreatePointerCast(Addr, MS.IntptrTy),
- ConstantInt::get(MS.IntptrTy, ~AndMask));
+ if (AndMask)
+ OffsetLong =
+ IRB.CreateAnd(OffsetLong, ConstantInt::get(MS.IntptrTy, ~AndMask));
uint64_t XorMask = MS.MapParams->XorMask;
- if (XorMask != 0)
- OffsetLong = IRB.CreateXor(OffsetLong,
- ConstantInt::get(MS.IntptrTy, XorMask));
+ if (XorMask)
+ OffsetLong =
+ IRB.CreateXor(OffsetLong, ConstantInt::get(MS.IntptrTy, XorMask));
return OffsetLong;
}
--
2.6.4
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