[PATCH] D66826: [ASan] Make insertion of version mismatch guard configurable

[Julian Lettner via Phabricator via llvm-commits]

yln created this revision.
Herald added subscribers: llvm-commits, hiraditya.
Herald added a project: LLVM.
yln added reviewers: kubamracek, dcoughlin, delcypher, eugenis.

By default ASan calls a versioned function
`__asan_version_mismatch_check_vXXX` to ensure that the compiler ABI
version and runtime ABI version are compatible. This ensures that we get
a predictable linker error instead of hard-to-debug runtime errors.

Sometimes, however, we want to skip this safety guard. This new command
line option allows us to do just that.

rdar://47891956


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D66826

Files:
  llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
  llvm/test/Instrumentation/AddressSanitizer/version-mismatch-check.ll


Index: llvm/test/Instrumentation/AddressSanitizer/version-mismatch-check.ll
===================================================================
--- /dev/null
+++ llvm/test/Instrumentation/AddressSanitizer/version-mismatch-check.ll
@@ -0,0 +1,12 @@
+; Check that the ASan module constructor guards against compiler/runtime version
+; mismatch.
+
+; RUN: opt < %s -asan-module                                        -S | FileCheck %s
+; RUN: opt < %s -asan-module -asan-guard-against-version-mismatch=0 -S | FileCheck %s --check-prefix=NOGUARD
+
+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"
+target triple = "x86_64-unknown-linux-gnu"
+
+; CHECK-LABEL: define internal void @asan.module_ctor()
+; CHECK:         call void @__asan_version_mismatch_check_v
+; NOGUARD-NOT:   call void @__asan_version_mismatch_check_v
Index: llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
===================================================================
--- llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -193,6 +193,11 @@
     cl::desc("Enable recovery mode (continue-after-error)."),
     cl::Hidden, cl::init(false));
 
+static cl::opt<bool> ClInsertVersionCheck(
+    "asan-guard-against-version-mismatch",
+    cl::desc("Guard against compiler/runtime version mismatch."),
+    cl::Hidden, cl::init(true));
+
 // This flag may need to be replaced with -f[no-]asan-reads.
 static cl::opt<bool> ClInstrumentReads("asan-instrument-reads",
                                        cl::desc("instrument read instructions"),
@@ -2426,8 +2431,9 @@
 
   // Create a module constructor. A destructor is created lazily because not all
   // platforms, and not all modules need it.
+  std::string AsanVersion = std::to_string(GetAsanVersion(M));
   std::string VersionCheckName =
-      kAsanVersionCheckNamePrefix + std::to_string(GetAsanVersion(M));
+      ClInsertVersionCheck ? (kAsanVersionCheckNamePrefix + AsanVersion) : "";
   std::tie(AsanCtorFunction, std::ignore) = createSanitizerCtorAndInitFunctions(
       M, kAsanModuleCtorName, kAsanInitName, /*InitArgTypes=*/{},
       /*InitArgs=*/{}, VersionCheckName);


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