Index: lib/CodeGen/TargetLoweringBase.cpp =================================================================== --- lib/CodeGen/TargetLoweringBase.cpp +++ lib/CodeGen/TargetLoweringBase.cpp @@ -1609,13 +1609,16 @@ // Currently only support "standard" __stack_chk_guard. // TODO: add LOAD_STACK_GUARD support. void TargetLoweringBase::insertSSPDeclarations(Module &M) const { - M.getOrInsertGlobal("__stack_chk_guard", Type::getInt8PtrTy(M.getContext())); + if (!M.getNamedValue("__stack_chk_guard")) + new GlobalVariable(M, Type::getInt8PtrTy(M.getContext()), false, + GlobalVariable::ExternalLinkage, + nullptr, "__stack_chk_guard"); } // Currently only support "standard" __stack_chk_guard. // TODO: add LOAD_STACK_GUARD support. Value *TargetLoweringBase::getSDagStackGuard(const Module &M) const { - return M.getGlobalVariable("__stack_chk_guard", true); + return M.getNamedValue("__stack_chk_guard"); } Value *TargetLoweringBase::getSSPStackGuardCheck(const Module &M) const { Index: test/CodeGen/AArch64/stackguard-internal.ll =================================================================== --- /dev/null +++ test/CodeGen/AArch64/stackguard-internal.ll @@ -0,0 +1,21 @@ +; RUN: llc -O3 %s -o - | FileCheck %s +target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128" +target triple = "aarch64-linux-gnu" + +; Make sure we correctly lower stack guards even if __stack_chk_guard +; is an alias. (The alias is created by GlobalMerge.) +; CHECK: adrp {{.*}}, __stack_chk_guard +; CHECK: ldr {{.*}}, [{{.*}}, :lo12:__stack_chk_guard] +; CHECK: .set __stack_chk_guard, .L_MergedGlobals+4 + +@__stack_chk_guard = internal global [8 x i32] zeroinitializer, align 4 +@x = internal global i32 0, align 4 + +define i32 @b() nounwind sspstrong { +entry: + %z = alloca [10 x i32], align 4 + %arraydecay = getelementptr inbounds [10 x i32], [10 x i32]* %z, i64 0, i64 0 + %call = call i32 @a(i32* getelementptr inbounds ([8 x i32], [8 x i32]* @__stack_chk_guard, i64 0, i64 0), i32* nonnull @x, i32* nonnull %arraydecay) #3 + ret i32 %call +} +declare i32 @a(i32*, i32*, i32*)