[llvm] bee2654 - [Asan] Skip pre-split coroutine and noop coroutine frame (#99415)

[via llvm-commits]

Author: Wei Wang
Date: 2024-07-22T10:53:40-07:00
New Revision: bee2654300a8f524e05dd4cad41411d597246ac0

URL: https://github.com/llvm/llvm-project/commit/bee2654300a8f524e05dd4cad41411d597246ac0
DIFF: https://github.com/llvm/llvm-project/commit/bee2654300a8f524e05dd4cad41411d597246ac0.diff

LOG: [Asan] Skip pre-split coroutine and noop coroutine frame (#99415)

CoroSplit expects the second parameter of `llvm.coro.id` to be the
promise alloca. Applying Asan on a pre-split coroutine breaks this
assumption and causes split to fail. This should be NFC because asan
pass happens late in the pipeline where all coroutines are split. This
is to prevent crash in case the order of passes are switched.

Also `NoopCoro.Frame.Const` is a special coroutine frame that does
nothing when resumed or destroyed. There is no point to do
instrumentation on it.

Added: 
    llvm/test/Instrumentation/AddressSanitizer/skip-coro.ll

Modified: 
    llvm/lib/Transforms/Coroutines/CoroEarly.cpp
    llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/Coroutines/CoroEarly.cpp b/llvm/lib/Transforms/Coroutines/CoroEarly.cpp
index 489106422e199..d8e827e9cebcf 100644
--- a/llvm/lib/Transforms/Coroutines/CoroEarly.cpp
+++ b/llvm/lib/Transforms/Coroutines/CoroEarly.cpp
@@ -148,6 +148,7 @@ void Lowerer::lowerCoroNoop(IntrinsicInst *II) {
     NoopCoro = new GlobalVariable(M, NoopCoroConst->getType(), /*isConstant=*/true,
                                 GlobalVariable::PrivateLinkage, NoopCoroConst,
                                 "NoopCoro.Frame.Const");
+    cast<GlobalVariable>(NoopCoro)->setNoSanitizeMetadata();
   }
 
   Builder.SetInsertPoint(II);

diff  --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index 149866a8e4200..9fb1df7ab2b79 100644
--- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -2947,6 +2947,8 @@ bool AddressSanitizer::instrumentFunction(Function &F,
   if (F.getLinkage() == GlobalValue::AvailableExternallyLinkage) return false;
   if (!ClDebugFunc.empty() && ClDebugFunc == F.getName()) return false;
   if (F.getName().starts_with("__asan_")) return false;
+  if (F.isPresplitCoroutine())
+    return false;
 
   bool FunctionModified = false;
 

diff  --git a/llvm/test/Instrumentation/AddressSanitizer/skip-coro.ll b/llvm/test/Instrumentation/AddressSanitizer/skip-coro.ll
new file mode 100644
index 0000000000000..65b27ee2241dd
--- /dev/null
+++ b/llvm/test/Instrumentation/AddressSanitizer/skip-coro.ll
@@ -0,0 +1,34 @@
+; Tests that asan skips pre-split coroutine and NoopCoro.Frame
+; RUN: opt < %s -S -passes=coro-early,asan | FileCheck %s
+
+; CHECK: %NoopCoro.Frame = type { ptr, ptr }
+; CHECK: @NoopCoro.Frame.Const = private constant %NoopCoro.Frame { ptr @__NoopCoro_ResumeDestroy, ptr @__NoopCoro_ResumeDestroy }
+; CHECK-NOT: @0 = private alias { %NoopCoro.Frame,
+
+%struct.Promise = type { %"struct.std::__n4861::coroutine_handle" }
+%"struct.std::__n4861::coroutine_handle" = type { ptr }
+
+; CHECK-LABEL: @foo(
+define ptr @foo() #0 {
+; CHECK-NEXT: entry
+; CHECK-NOT: %asan_local_stack_base
+entry:
+  %__promise = alloca %struct.Promise, align 8
+  %0 = call token @llvm.coro.id(i32 16, ptr nonnull %__promise, ptr null, ptr null)
+  %1 = call ptr @llvm.coro.noop()
+  ret ptr %1
+}
+
+declare token @llvm.coro.id(i32, ptr readnone, ptr nocapture readonly, ptr)
+declare ptr @llvm.coro.noop()
+
+attributes #0 = { sanitize_address presplitcoroutine }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "hand-written", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
+!1 = !DIFile(filename: "<stdin>", directory: "")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}