Tell Valgrind when we modify already-executed machine code so it knows

to re-instrument the code.  We depend on the system valgrind.h to
avoid adding a new license.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98529 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 65 insertions, 0 deletions

diff --git a/lib/System/CMakeLists.txt b/lib/System/CMakeLists.txt
index f311e86..b43c3af 100644
--- a/lib/System/CMakeLists.txt
+++ b/lib/System/CMakeLists.txt
@@ -17,6 +17,7 @@ add_llvm_library(LLVMSystem
   ThreadLocal.cpp
   Threading.cpp
   TimeValue.cpp
+  Valgrind.cpp
   Unix/Alarm.inc
   Unix/Host.inc
   Unix/Memory.inc
diff --git a/lib/System/Memory.cpp b/lib/System/Memory.cpp
index e2d838d..ef23b8d 100644
--- a/lib/System/Memory.cpp
+++ b/lib/System/Memory.cpp
@@ -13,6 +13,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/System/Memory.h"
+#include "llvm/System/Valgrind.h"
 #include "llvm/Config/config.h"
 
 namespace llvm {
@@ -68,4 +69,6 @@ void llvm::sys::Memory::InvalidateInstructionCache(const void *Addr,
 #  endif
 
 #endif  // end apple
+
+  ValgrindDiscardTranslations(Addr, Len);
 }
diff --git a/lib/System/Valgrind.cpp b/lib/System/Valgrind.cpp
new file mode 100644
index 0000000..c76cfe4
--- /dev/null
+++ b/lib/System/Valgrind.cpp
@@ -0,0 +1,54 @@
+//===-- Valgrind.cpp - Implement Valgrind communication ---------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  Defines Valgrind communication methods, if HAVE_VALGRIND_VALGRIND_H is
+//  defined.  If we have valgrind.h but valgrind isn't running, its macros are
+//  no-ops.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/System/Valgrind.h"
+#include "llvm/Config/config.h"
+
+#if HAVE_VALGRIND_VALGRIND_H
+#include <valgrind/valgrind.h>
+
+static bool InitNotUnderValgrind() {
+  return !RUNNING_ON_VALGRIND;
+}
+
+// This bool is negated from what we'd expect because code may run before it
+// gets initialized.  If that happens, it will appear to be 0 (false), and we
+// want that to cause the rest of the code in this file to run the
+// Valgrind-provided macros.
+static const bool NotUnderValgrind = InitNotUnderValgrind();
+
+bool llvm::sys::RunningOnValgrind() {
+  if (NotUnderValgrind)
+    return false;
+  return RUNNING_ON_VALGRIND;
+}
+
+void llvm::sys::ValgrindDiscardTranslations(const void *Addr, size_t Len) {
+  if (NotUnderValgrind)
+    return;
+
+  VALGRIND_DISCARD_TRANSLATIONS(Addr, Len);
+}
+
+#else  // !HAVE_VALGRIND_VALGRIND_H
+
+bool llvm::sys::RunningOnValgrind() {
+  return false;
+}
+
+void llvm::sys::ValgrindDiscardTranslations(const void *Addr, size_t Len) {
+}
+
+#endif  // !HAVE_VALGRIND_VALGRIND_H
diff --git a/lib/Target/X86/X86JITInfo.cpp b/lib/Target/X86/X86JITInfo.cpp
index d297d24..6f0a8d9 100644
--- a/lib/Target/X86/X86JITInfo.cpp
+++ b/lib/Target/X86/X86JITInfo.cpp
@@ -19,6 +19,7 @@
 #include "llvm/Function.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/ErrorHandling.h"
+#include "llvm/System/Valgrind.h"
 #include <cstdlib>
 #include <cstring>
 using namespace llvm;
@@ -37,6 +38,10 @@ void X86JITInfo::replaceMachineCodeForFunction(void *Old, void *New) {
   unsigned NewAddr = (intptr_t)New;
   unsigned OldAddr = (intptr_t)OldWord;
   *OldWord = NewAddr - OldAddr - 4; // Emit PC-relative addr of New code.
+
+  // X86 doesn't need to invalidate the processor cache, so just invalidate
+  // Valgrind's cache directly.
+  sys::ValgrindDiscardTranslations(Old, 5);
 }
 
 
@@ -393,8 +398,10 @@ X86CompilationCallback2(intptr_t *StackPtr, intptr_t RetAddr) {
       *(intptr_t *)(RetAddr - 0xa) = NewVal;
       ((unsigned char*)RetAddr)[0] = (2 | (4 << 3) | (3 << 6));
     }
+    sys::ValgrindDiscardTranslations((void*)(RetAddr-0xc), 0xd);
 #else
     ((unsigned char*)RetAddr)[-1] = 0xE9;
+    sys::ValgrindDiscardTranslations((void*)(RetAddr-1), 5);
 #endif
   }