Author: Yi Kong Date: 2023-08-03T19:53:54+09:00 New Revision: c7cacb2f6efe07fa4a1129bb7e2389312670b84a
URL: https://github.com/llvm/llvm-project/commit/c7cacb2f6efe07fa4a1129bb7e2389312670b84a DIFF: https://github.com/llvm/llvm-project/commit/c7cacb2f6efe07fa4a1129bb7e2389312670b84a.diff LOG: Fix __cfi_check not aligned to 4k on relocatable files with no executable code CrossDSOCFIPass is supposed to replace this stub function to a properly aligned function. However the pass is not ran if the file has no executable code, thus producing incorrectly aligned __cfi_check. Fixes https://github.com/llvm/llvm-project/issues/45638. Differential Revision: https://reviews.llvm.org/D155736 Added: clang/test/CodeGen/cfi-cross-dso-align.c Modified: clang/lib/CodeGen/CGExpr.cpp Removed: ################################################################################ diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp index ed6095f7cfeb0d..15aa1b730d268b 100644 --- a/clang/lib/CodeGen/CGExpr.cpp +++ b/clang/lib/CodeGen/CGExpr.cpp @@ -3445,14 +3445,12 @@ void CodeGenFunction::EmitCfiCheckStub() { llvm::Function *F = llvm::Function::Create( llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy}, false), llvm::GlobalValue::WeakAnyLinkage, "__cfi_check", M); + F->setAlignment(llvm::Align(4096)); CGM.setDSOLocal(F); llvm::BasicBlock *BB = llvm::BasicBlock::Create(Ctx, "entry", F); - // FIXME: consider emitting an intrinsic call like - // call void @llvm.cfi_check(i64 %0, i8* %1, i8* %2) - // which can be lowered in CrossDSOCFI pass to the actual contents of - // __cfi_check. This would allow inlining of __cfi_check calls. - llvm::CallInst::Create( - llvm::Intrinsic::getDeclaration(M, llvm::Intrinsic::trap), "", BB); + // CrossDSOCFI pass is not executed if there is no executable code. + SmallVector<llvm::Value*> Args{F->getArg(2), F->getArg(1)}; + llvm::CallInst::Create(M->getFunction("__cfi_check_fail"), Args, "", BB); llvm::ReturnInst::Create(Ctx, nullptr, BB); } @@ -3546,9 +3544,6 @@ void CodeGenFunction::EmitCfiCheckFail() { } FinishFunction(); - // The only reference to this function will be created during LTO link. - // Make sure it survives until then. - CGM.addUsedGlobal(F); } void CodeGenFunction::EmitUnreachable(SourceLocation Loc) { diff --git a/clang/test/CodeGen/cfi-cross-dso-align.c b/clang/test/CodeGen/cfi-cross-dso-align.c new file mode 100644 index 00000000000000..e023601184fe99 --- /dev/null +++ b/clang/test/CodeGen/cfi-cross-dso-align.c @@ -0,0 +1,8 @@ +// RUN: %clang_cc1 -triple x86_64-unknown-linux -O0 -fsanitize-cfi-cross-dso \ +// RUN: -emit-llvm -o - %s | FileCheck %s + +int a; + +// CHECK: define weak void @__cfi_check(i64 %[[TYPE:.*]], ptr %[[ADDR:.*]], ptr %[[DATA:.*]]) align 4096 +// CHECK-NEXT: entry: +// CHECK-NEXT: call void @__cfi_check_fail(ptr %[[DATA]], ptr %[[ADDR]]) _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
