[llvm] [NFC] [HWASan] [MTE] factor out threadlong increment (PR #110340)
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Fri Sep 27 16:31:48 PDT 2024
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-backend-aarch64
Author: Florian Mayer (fmayer)
<details>
<summary>Changes</summary>
---
Full diff: https://github.com/llvm/llvm-project/pull/110340.diff
4 Files Affected:
- (modified) llvm/include/llvm/Transforms/Utils/MemoryTaggingSupport.h (+2)
- (modified) llvm/lib/Target/AArch64/AArch64StackTagging.cpp (+2-13)
- (modified) llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp (+1-29)
- (modified) llvm/lib/Transforms/Utils/MemoryTaggingSupport.cpp (+34)
``````````diff
diff --git a/llvm/include/llvm/Transforms/Utils/MemoryTaggingSupport.h b/llvm/include/llvm/Transforms/Utils/MemoryTaggingSupport.h
index 1401c5fcde5f77..60255d57364099 100644
--- a/llvm/include/llvm/Transforms/Utils/MemoryTaggingSupport.h
+++ b/llvm/include/llvm/Transforms/Utils/MemoryTaggingSupport.h
@@ -99,6 +99,8 @@ Value *getPC(const Triple &TargetTriple, IRBuilder<> &IRB);
Value *getAndroidSlotPtr(IRBuilder<> &IRB, int Slot);
void annotateDebugRecords(AllocaInfo &Info, unsigned int Tag);
+Value *incrementThreadLong(IRBuilder<> &IRB, Value *ThreadLong,
+ unsigned int Inc);
} // namespace memtag
} // namespace llvm
diff --git a/llvm/lib/Target/AArch64/AArch64StackTagging.cpp b/llvm/lib/Target/AArch64/AArch64StackTagging.cpp
index 72823fdcd858df..72266e261a1f6c 100644
--- a/llvm/lib/Target/AArch64/AArch64StackTagging.cpp
+++ b/llvm/lib/Target/AArch64/AArch64StackTagging.cpp
@@ -507,19 +507,8 @@ Instruction *AArch64StackTagging::insertBaseTaggedPointer(
Value *RecordPtr = IRB.CreateIntToPtr(ThreadLong, IRB.getPtrTy(0));
IRB.CreateStore(PC, RecordPtr);
IRB.CreateStore(TaggedFP, IRB.CreateConstGEP1_64(IntptrTy, RecordPtr, 1));
- // Update the ring buffer. Top byte of ThreadLong defines the size of the
- // buffer in pages, it must be a power of two, and the start of the buffer
- // must be aligned by twice that much. Therefore wrap around of the ring
- // buffer is simply Addr &= ~((ThreadLong >> 56) << 12).
- // The use of AShr instead of LShr is due to
- // https://bugs.llvm.org/show_bug.cgi?id=39030
- // Runtime library makes sure not to use the highest bit.
- Value *WrapMask = IRB.CreateXor(
- IRB.CreateShl(IRB.CreateAShr(ThreadLong, 56), 12, "", true, true),
- ConstantInt::get(IntptrTy, (uint64_t)-1));
- Value *ThreadLongNew = IRB.CreateAnd(
- IRB.CreateAdd(ThreadLong, ConstantInt::get(IntptrTy, 16)), WrapMask);
- IRB.CreateStore(ThreadLongNew, SlotPtr);
+
+ IRB.CreateStore(memtag::incrementThreadLong(IRB, ThreadLong, 16), SlotPtr);
}
return Base;
}
diff --git a/llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp
index 669b63343e994e..cc7f20cffea771 100644
--- a/llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp
@@ -1421,35 +1421,7 @@ void HWAddressSanitizer::emitPrologue(IRBuilder<> &IRB, bool WithFrameRecord) {
IRB.CreateIntToPtr(ThreadLongMaybeUntagged, IRB.getPtrTy(0));
IRB.CreateStore(FrameRecordInfo, RecordPtr);
- // Update the ring buffer. Top byte of ThreadLong defines the size of the
- // buffer in pages, it must be a power of two, and the start of the buffer
- // must be aligned by twice that much. Therefore wrap around of the ring
- // buffer is simply Addr &= ~((ThreadLong >> 56) << 12).
- // The use of AShr instead of LShr is due to
- // https://bugs.llvm.org/show_bug.cgi?id=39030
- // Runtime library makes sure not to use the highest bit.
- //
- // Mechanical proof of this address calculation can be found at:
- // https://github.com/google/sanitizers/blob/master/hwaddress-sanitizer/prove_hwasanwrap.smt2
- //
- // Example of the wrap case for N = 1
- // Pointer: 0x01AAAAAAAAAAAFF8
- // +
- // 0x0000000000000008
- // =
- // 0x01AAAAAAAAAAB000
- // &
- // WrapMask: 0xFFFFFFFFFFFFF000
- // =
- // 0x01AAAAAAAAAAA000
- //
- // Then the WrapMask will be a no-op until the next wrap case.
- Value *WrapMask = IRB.CreateXor(
- IRB.CreateShl(IRB.CreateAShr(ThreadLong, 56), 12, "", true, true),
- ConstantInt::get(IntptrTy, (uint64_t)-1));
- Value *ThreadLongNew = IRB.CreateAnd(
- IRB.CreateAdd(ThreadLong, ConstantInt::get(IntptrTy, 8)), WrapMask);
- IRB.CreateStore(ThreadLongNew, SlotPtr);
+ IRB.CreateStore(memtag::incrementThreadLong(IRB, ThreadLong, 8), SlotPtr);
break;
}
case none: {
diff --git a/llvm/lib/Transforms/Utils/MemoryTaggingSupport.cpp b/llvm/lib/Transforms/Utils/MemoryTaggingSupport.cpp
index c5d22fbcc4e639..1cb1a7b396badc 100644
--- a/llvm/lib/Transforms/Utils/MemoryTaggingSupport.cpp
+++ b/llvm/lib/Transforms/Utils/MemoryTaggingSupport.cpp
@@ -338,5 +338,39 @@ void annotateDebugRecords(AllocaInfo &Info, unsigned int Tag) {
llvm::for_each(Info.DbgVariableRecords, AnnotateDbgRecord);
}
+Value *incrementThreadLong(IRBuilder<> &IRB, Value *ThreadLong,
+ unsigned int Inc) {
+ // Update the ring buffer. Top byte of ThreadLong defines the size of the
+ // buffer in pages, it must be a power of two, and the start of the buffer
+ // must be aligned by twice that much. Therefore wrap around of the ring
+ // buffer is simply Addr &= ~((ThreadLong >> 56) << 12).
+ // The use of AShr instead of LShr is due to
+ // https://bugs.llvm.org/show_bug.cgi?id=39030
+ // Runtime library makes sure not to use the highest bit.
+ //
+ // Mechanical proof of this address calculation can be found at:
+ // https://github.com/google/sanitizers/blob/master/hwaddress-sanitizer/prove_hwasanwrap.smt2
+ //
+ // Example of the wrap case for N = 1
+ // Pointer: 0x01AAAAAAAAAAAFF8
+ // +
+ // 0x0000000000000008
+ // =
+ // 0x01AAAAAAAAAAB000
+ // &
+ // WrapMask: 0xFFFFFFFFFFFFF000
+ // =
+ // 0x01AAAAAAAAAAA000
+ //
+ // Then the WrapMask will be a no-op until the next wrap case.
+ assert((4096 % Inc) == 0);
+ Value *WrapMask = IRB.CreateXor(
+ IRB.CreateShl(IRB.CreateAShr(ThreadLong, 56), 12, "", true, true),
+ ConstantInt::get(ThreadLong->getType(), (uint64_t)-1));
+ return IRB.CreateAnd(
+ IRB.CreateAdd(ThreadLong, ConstantInt::get(ThreadLong->getType(), Inc)),
+ WrapMask);
+}
+
} // namespace memtag
} // namespace llvm
``````````
</details>
https://github.com/llvm/llvm-project/pull/110340
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