[llvm] r273339 - [asan] Do not instrument pointers with address space attributes

[Anna Zaks via llvm-commits]

Author: zaks
Date: Tue Jun 21 19:15:52 2016
New Revision: 273339

URL: http://llvm.org/viewvc/llvm-project?rev=273339&view=rev
Log:
[asan] Do not instrument pointers with address space attributes

Do not instrument pointers with address space attributes since we cannot track
them anyway. Instrumenting them results in false positives in ASan and a
compiler crash in TSan. (The compiler should not crash in any case, but that's
a different problem.)

Added:
    llvm/trunk/test/Instrumentation/AddressSanitizer/asan_address_space_attr.ll
    llvm/trunk/test/Instrumentation/ThreadSanitizer/tsan_address_space_attr.ll
Modified:
    llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp
    llvm/trunk/lib/Transforms/Instrumentation/ThreadSanitizer.cpp

Modified: llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp?rev=273339&r1=273338&r2=273339&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp (original)
+++ llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp Tue Jun 21 19:15:52 2016
@@ -952,6 +952,14 @@ Value *AddressSanitizer::isInterestingMe
     PtrOperand = XCHG->getPointerOperand();
   }
 
+  // Do not instrument acesses from different address spaces; we cannot deal
+  // with them.
+  if (PtrOperand) {
+    Type *PtrTy = cast<PointerType>(PtrOperand->getType()->getScalarType());
+    if (PtrTy->getPointerAddressSpace() != 0)
+      return nullptr;
+  }
+
   // Treat memory accesses to promotable allocas as non-interesting since they
   // will not cause memory violations. This greatly speeds up the instrumented
   // executable at -O0.

Modified: llvm/trunk/lib/Transforms/Instrumentation/ThreadSanitizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/ThreadSanitizer.cpp?rev=273339&r1=273338&r2=273339&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Instrumentation/ThreadSanitizer.cpp (original)
+++ llvm/trunk/lib/Transforms/Instrumentation/ThreadSanitizer.cpp Tue Jun 21 19:15:52 2016
@@ -276,6 +276,15 @@ static bool shouldInstrumentReadWriteFro
     if (GV->getName() == "__llvm_gcov_ctr")
       return false;
   }
+
+  // Do not instrument acesses from different address spaces; we cannot deal
+  // with them.
+  if (Addr) {
+    Type *PtrTy = cast<PointerType>(Addr->getType()->getScalarType());
+    if (PtrTy->getPointerAddressSpace() != 0)
+      return false;
+  }
+
   return true;
 }
 

Added: llvm/trunk/test/Instrumentation/AddressSanitizer/asan_address_space_attr.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Instrumentation/AddressSanitizer/asan_address_space_attr.ll?rev=273339&view=auto
==============================================================================
--- llvm/trunk/test/Instrumentation/AddressSanitizer/asan_address_space_attr.ll (added)
+++ llvm/trunk/test/Instrumentation/AddressSanitizer/asan_address_space_attr.ll Tue Jun 21 19:15:52 2016
@@ -0,0 +1,32 @@
+; RUN: opt < %s -asan -S | FileCheck %s
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.11.0"
+
+; Checks that we do not instrument loads and stores comming from custom address space.
+; These result in invalid (false positive) reports.
+; int foo(int argc, const char * argv[]) {
+;   void *__attribute__((address_space(256))) *gs_base = (((void * __attribute__((address_space(256))) *)0));
+;   void *somevalue = gs_base[-1];
+;   return somevalue;
+; }
+
+define i32 @foo(i32 %argc, i8** %argv) sanitize_address {
+entry:
+  %retval = alloca i32, align 4
+  %argc.addr = alloca i32, align 4
+  %argv.addr = alloca i8**, align 8
+  %gs_base = alloca i8* addrspace(256)*, align 8
+  %somevalue = alloca i8*, align 8
+  store i32 0, i32* %retval, align 4
+  store i32 %argc, i32* %argc.addr, align 4
+  store i8** %argv, i8*** %argv.addr, align 8
+  store i8* addrspace(256)* null, i8* addrspace(256)** %gs_base, align 8
+  %0 = load i8* addrspace(256)*, i8* addrspace(256)** %gs_base, align 8
+  %arrayidx = getelementptr inbounds i8*, i8* addrspace(256)* %0, i64 -1
+  %1 = load i8*, i8* addrspace(256)* %arrayidx, align 8
+  store i8* %1, i8** %somevalue, align 8
+  %2 = load i8*, i8** %somevalue, align 8
+  %3 = ptrtoint i8* %2 to i32
+  ret i32 %3
+}
+; CHECK-NOT: call void @__asan_report_load8

Added: llvm/trunk/test/Instrumentation/ThreadSanitizer/tsan_address_space_attr.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Instrumentation/ThreadSanitizer/tsan_address_space_attr.ll?rev=273339&view=auto
==============================================================================
--- llvm/trunk/test/Instrumentation/ThreadSanitizer/tsan_address_space_attr.ll (added)
+++ llvm/trunk/test/Instrumentation/ThreadSanitizer/tsan_address_space_attr.ll Tue Jun 21 19:15:52 2016
@@ -0,0 +1,33 @@
+; RUN: opt < %s -tsan -S | FileCheck %s
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.11.0"
+
+; Checks that we do not instrument loads and stores comming from custom address space.
+; These result in crashing the compiler.
+; int foo(int argc, const char * argv[]) {
+;   void *__attribute__((address_space(256))) *gs_base = (((void * __attribute__((address_space(256))) *)0));
+;   void *somevalue = gs_base[-1];
+;   return somevalue;
+; }
+
+define i32 @foo(i32 %argc, i8** %argv) sanitize_thread {
+entry:
+  %retval = alloca i32, align 4
+  %argc.addr = alloca i32, align 4
+  %argv.addr = alloca i8**, align 8
+  %gs_base = alloca i8* addrspace(256)*, align 8
+  %somevalue = alloca i8*, align 8
+  store i32 0, i32* %retval, align 4
+  store i32 %argc, i32* %argc.addr, align 4
+  store i8** %argv, i8*** %argv.addr, align 8
+  store i8* addrspace(256)* null, i8* addrspace(256)** %gs_base, align 8
+  %0 = load i8* addrspace(256)*, i8* addrspace(256)** %gs_base, align 8
+  %arrayidx = getelementptr inbounds i8*, i8* addrspace(256)* %0, i64 -1
+  %1 = load i8*, i8* addrspace(256)* %arrayidx, align 8
+  store i8* %1, i8** %somevalue, align 8
+  %2 = load i8*, i8** %somevalue, align 8
+  %3 = ptrtoint i8* %2 to i32
+  ret i32 %3
+}
+; CHECK-NOT: call void @__tsan_read
+; CHECK-NOT: addrspacecast