From: Vedant Kumar <vsk@apple.com>
Date: Fri, 16 Jun 2017 03:27:36 +0000 (+0000)
Subject: [ubsan] PR33081: Skip the standard type checks for volatile
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=ff94b5e7fe537029dd2a96c48198b1bcb27b0958;p=clang

[ubsan] PR33081: Skip the standard type checks for volatile

Skip checks for null dereference, alignment violation, object size
violation, and dynamic type violation if the pointer points to volatile
data.

Differential Revision: https://reviews.llvm.org/D34262

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@305546 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index 15829888ea..7359006677 100644
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -549,6 +549,11 @@ void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
   if (Ptr->getType()->getPointerAddressSpace())
     return;
 
+  // Don't check pointers to volatile data. The behavior here is implementation-
+  // defined.
+  if (Ty.isVolatileQualified())
+    return;
+
   SanitizerScope SanScope(this);
 
   SmallVector<std::pair<llvm::Value *, SanitizerMask>, 3> Checks;
diff --git a/test/CodeGen/ubsan-volatile.c b/test/CodeGen/ubsan-volatile.c
new file mode 100644
index 0000000000..ce54aada81
--- /dev/null
+++ b/test/CodeGen/ubsan-volatile.c
@@ -0,0 +1,7 @@
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 -fsanitize=null,alignment,object-size,vptr -S -emit-llvm %s -o - | FileCheck %s
+
+// CHECK: @volatile_null_deref
+void volatile_null_deref(volatile int *p) {
+  // CHECK-NOT: call{{.*}}ubsan
+  *p;
+}