[clang] 04bd2c3 - [local-bounds] Ignore volatile operations

[Vitaly Buka via cfe-commits]

Author: Vitaly Buka
Date: 2020-05-05T23:08:08-07:00
New Revision: 04bd2c37caf48e79589dbccc486c6ad2541bec7a

URL: https://github.com/llvm/llvm-project/commit/04bd2c37caf48e79589dbccc486c6ad2541bec7a
DIFF: https://github.com/llvm/llvm-project/commit/04bd2c37caf48e79589dbccc486c6ad2541bec7a.diff

LOG: [local-bounds] Ignore volatile operations

Summary:
-fsanitize=local-bounds is very similar to ``object-size`` and
should also ignore volatile pointers.
https://clang.llvm.org/docs/UndefinedBehaviorSanitizer.html#volatile

Reviewers: chandlerc, rsmith

Reviewed By: rsmith

Subscribers: cfe-commits, hiraditya, llvm-commits

Tags: #llvm, #clang

Differential Revision: https://reviews.llvm.org/D78607

Added: 
    

Modified: 
    clang/docs/UndefinedBehaviorSanitizer.rst
    llvm/lib/Transforms/Instrumentation/BoundsChecking.cpp
    llvm/test/Instrumentation/BoundsChecking/simple.ll

Removed: 
    


################################################################################
diff  --git a/clang/docs/UndefinedBehaviorSanitizer.rst b/clang/docs/UndefinedBehaviorSanitizer.rst
index 493b9478bdf3..0a27810150db 100644
--- a/clang/docs/UndefinedBehaviorSanitizer.rst
+++ b/clang/docs/UndefinedBehaviorSanitizer.rst
@@ -81,7 +81,9 @@ Available checks are:
      ``true`` nor ``false``.
   -  ``-fsanitize=builtin``: Passing invalid values to compiler builtins.
   -  ``-fsanitize=bounds``: Out of bounds array indexing, in cases
-     where the array bound can be statically determined.
+     where the array bound can be statically determined. The check includes
+     ``-fsanitize=array-bounds`` and ``-fsanitize=local-bounds``. Note that
+     ``-fsanitize=local-bounds`` is not included in ``-fsanitize=undefined``.
   -  ``-fsanitize=enum``: Load of a value of an enumerated type which
      is not in the range of representable values for that enumerated
      type.
@@ -173,7 +175,8 @@ Available checks are:
 You can also use the following check groups:
   -  ``-fsanitize=undefined``: All of the checks listed above other than
      ``float-divide-by-zero``, ``unsigned-integer-overflow``,
-     ``implicit-conversion``, and the ``nullability-*`` group of checks.
+     ``implicit-conversion``, ``local-bounds`` and the ``nullability-*`` group
+     of checks.
   -  ``-fsanitize=undefined-trap``: Deprecated alias of
      ``-fsanitize=undefined``.
   -  ``-fsanitize=implicit-integer-truncation``: Catches lossy integral
@@ -202,7 +205,7 @@ You can also use the following check groups:
 Volatile
 --------
 
-The ``null``, ``alignment``, ``object-size``, and ``vptr`` checks do not apply
+The ``null``, ``alignment``, ``object-size``, ``local-bounds``, and ``vptr`` checks do not apply
 to pointers to types with the ``volatile`` qualifier.
 
 Minimal Runtime

diff  --git a/llvm/lib/Transforms/Instrumentation/BoundsChecking.cpp b/llvm/lib/Transforms/Instrumentation/BoundsChecking.cpp
index 3e7ebe54a00c..efb11b68a1e3 100644
--- a/llvm/lib/Transforms/Instrumentation/BoundsChecking.cpp
+++ b/llvm/lib/Transforms/Instrumentation/BoundsChecking.cpp
@@ -154,17 +154,22 @@ static bool addBoundsChecking(Function &F, TargetLibraryInfo &TLI,
     Value *Or = nullptr;
     BuilderTy IRB(I.getParent(), BasicBlock::iterator(&I), TargetFolder(DL));
     if (LoadInst *LI = dyn_cast<LoadInst>(&I)) {
-      Or = getBoundsCheckCond(LI->getPointerOperand(), LI, DL, TLI,
-                              ObjSizeEval, IRB, SE);
+      if (!LI->isVolatile())
+        Or = getBoundsCheckCond(LI->getPointerOperand(), LI, DL, TLI,
+                                ObjSizeEval, IRB, SE);
     } else if (StoreInst *SI = dyn_cast<StoreInst>(&I)) {
-      Or = getBoundsCheckCond(SI->getPointerOperand(), SI->getValueOperand(),
-                              DL, TLI, ObjSizeEval, IRB, SE);
+      if (!SI->isVolatile())
+        Or = getBoundsCheckCond(SI->getPointerOperand(), SI->getValueOperand(),
+                                DL, TLI, ObjSizeEval, IRB, SE);
     } else if (AtomicCmpXchgInst *AI = dyn_cast<AtomicCmpXchgInst>(&I)) {
-      Or = getBoundsCheckCond(AI->getPointerOperand(), AI->getCompareOperand(),
-                              DL, TLI, ObjSizeEval, IRB, SE);
+      if (!AI->isVolatile())
+        Or =
+            getBoundsCheckCond(AI->getPointerOperand(), AI->getCompareOperand(),
+                               DL, TLI, ObjSizeEval, IRB, SE);
     } else if (AtomicRMWInst *AI = dyn_cast<AtomicRMWInst>(&I)) {
-      Or = getBoundsCheckCond(AI->getPointerOperand(), AI->getValOperand(), DL,
-                              TLI, ObjSizeEval, IRB, SE);
+      if (!AI->isVolatile())
+        Or = getBoundsCheckCond(AI->getPointerOperand(), AI->getValOperand(),
+                                DL, TLI, ObjSizeEval, IRB, SE);
     }
     if (Or)
       TrapInfo.push_back(std::make_pair(&I, Or));

diff  --git a/llvm/test/Instrumentation/BoundsChecking/simple.ll b/llvm/test/Instrumentation/BoundsChecking/simple.ll
index db1e1eeb0006..c95bfbdd4fe9 100644
--- a/llvm/test/Instrumentation/BoundsChecking/simple.ll
+++ b/llvm/test/Instrumentation/BoundsChecking/simple.ll
@@ -46,6 +46,16 @@ define void @f3(i64 %x) nounwind {
   ret void
 }
 
+; CHECK: @store_volatile
+define void @store_volatile(i64 %x) nounwind {
+  %1 = tail call i8* @calloc(i64 4, i64 %x)
+  %2 = bitcast i8* %1 to i32*
+  %idx = getelementptr inbounds i32, i32* %2, i64 8
+; CHECK-NOT: trap
+  store volatile i32 3, i32* %idx, align 4
+  ret void
+}
+
 ; CHECK: @f4
 define void @f4(i64 %x) nounwind {
   %1 = tail call i8* @realloc(i8* null, i64 %x) nounwind
@@ -144,12 +154,23 @@ define void @f11_as1(i128 addrspace(1)* byval %x) nounwind {
 define i64 @f12(i64 %x, i64 %y) nounwind {
   %1 = tail call i8* @calloc(i64 1, i64 %x)
 ; CHECK: mul i64 %y, 8
+; CHECK: trap
   %2 = bitcast i8* %1 to i64*
   %3 = getelementptr inbounds i64, i64* %2, i64 %y
   %4 = load i64, i64* %3, align 8
   ret i64 %4
 }
 
+; CHECK: @load_volatile
+define i64 @load_volatile(i64 %x, i64 %y) nounwind {
+  %1 = tail call i8* @calloc(i64 1, i64 %x)
+; CHECK-NOT: trap
+  %2 = bitcast i8* %1 to i64*
+  %3 = getelementptr inbounds i64, i64* %2, i64 %y
+  %4 = load volatile i64, i64* %3, align 8
+  ret i64 %4
+}
+
 ; PR17402
 ; CHECK-LABEL: @f13
 define void @f13() nounwind {