[PATCH] D85040: [MSAN] Instrument freeze instruction by clearing shadow

[Gui Andrade via Phabricator via llvm-commits]

guiand updated this revision to Diff 282337.
guiand added a comment.

Fixed to actually set the shadow and origin. Sorry for the mix-up!


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D85040/new/

https://reviews.llvm.org/D85040

Files:
  llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
  llvm/test/Instrumentation/MemorySanitizer/freeze.ll


Index: llvm/test/Instrumentation/MemorySanitizer/freeze.ll
===================================================================
--- /dev/null
+++ llvm/test/Instrumentation/MemorySanitizer/freeze.ll
@@ -0,0 +1,20 @@
+; RUN: opt < %s -msan-check-access-address=0 -S -passes=msan 2>&1 | FileCheck %s
+; RUN: opt < %s -msan-check-access-address=0 -msan-track-origins=2 -S -passes=msan 2>&1 | FileCheck %s -check-prefixes=CHECK,CHECK-ORIGIN
+; RUN: opt < %s -msan -msan-check-access-address=0 -S | FileCheck %s
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define i32 @nofreeze(i32* %ptr) sanitize_memory {
+    %val = load i32, i32* %ptr
+    ; CHECK: [[SHADOW_PTR:%.*]] = inttoptr
+    ; CHECK: [[SHADOW:%.*]] = load i32, i32* [[SHADOW_PTR]]
+    ; CHECK: store i32 [[SHADOW]], {{.*}} @__msan_retval_tls
+    ret i32 %val
+}
+
+define i32 @freeze_inst(i32* %ptr) sanitize_memory {
+    %val = load i32, i32* %ptr
+    %freeze_val = freeze i32 %val
+    ; CHECK: store i32 0, {{.*}} @__msan_retval_tls
+    ret i32 %freeze_val
+}
Index: llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
===================================================================
--- llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
+++ llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
@@ -4220,6 +4220,11 @@
     setOrigin(&I, getCleanOrigin());
   }
 
+  void visitFreezeInstruction(FreezeInst &I) {
+    // Freeze always returns a fully defined value.
+    setShadow(&I, getCleanShadow(&I));
+  }
+
   void visitInstruction(Instruction &I) {
     // Everything else: stop propagating and check for poisoned shadow.
     if (ClDumpStrictInstructions)


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