diff --git a/llvm/include/llvm/IR/AutoUpgrade.h b/llvm/include/llvm/IR/AutoUpgrade.h index 152f781ffa9b30..1ef32bcb121bec 100644 --- a/llvm/include/llvm/IR/AutoUpgrade.h +++ b/llvm/include/llvm/IR/AutoUpgrade.h @@ -88,6 +88,9 @@ namespace llvm { /// info. Return true if module is modified. bool UpgradeDebugInfo(Module &M); + /// Copies module attributes to the functions in the module. + void CopyModuleAttrToFunctions(Module &M); + /// Check whether a string looks like an old loop attachment tag. inline bool mayBeOldLoopAttachmentTag(StringRef Name) { return Name.starts_with("llvm.vectorizer."); diff --git a/llvm/lib/IR/AutoUpgrade.cpp b/llvm/lib/IR/AutoUpgrade.cpp index b90bbe71ac1896..3b784b06397445 100644 --- a/llvm/lib/IR/AutoUpgrade.cpp +++ b/llvm/lib/IR/AutoUpgrade.cpp @@ -5169,6 +5169,72 @@ void llvm::UpgradeFunctionAttributes(Function &F) { Arg.removeAttrs(AttributeFuncs::typeIncompatible(Arg.getType())); } +// Check if the module attribute is present and not zero. +static bool isModuleAttributeSet(Module &M, const StringRef &ModAttr) { + const auto *Attr = + mdconst::extract_or_null(M.getModuleFlag(ModAttr)); + return Attr && Attr->getZExtValue(); +} + +// Copy an attribute from module to the function if exists. +// First value of the pair is used when the module attribute is not zero +// the second otherwise. +static void +CopyModuleAttributeToFunction(Function &F, StringRef FnAttrName, + StringRef ModAttrName, + std::pair Values) { + if (F.hasFnAttribute(FnAttrName)) + return; + F.addFnAttr(FnAttrName, isModuleAttributeSet(*F.getParent(), ModAttrName) + ? Values.first + : Values.second); +} + +// Copy a boolean attribute from module to the function if exists. +// Module attribute treated false if zero otherwise true. +static void CopyModuleAttributeToFunction(Function &F, StringRef AttrName) { + CopyModuleAttributeToFunction( + F, AttrName, AttrName, + std::make_pair("true", "false")); +} + +// Copy an attribute from module to the function if exists. +// First value of the pair is used when the module attribute is not zero +// the second otherwise. +static void +CopyModuleAttributeToFunction(Function &F, StringRef AttrName, + std::pair Values) { + CopyModuleAttributeToFunction(F, AttrName, AttrName, Values); +} + +void llvm::CopyModuleAttrToFunctions(Module &M) { + Triple T(M.getTargetTriple()); + if (!T.isThumb() && !T.isARM() && !T.isAArch64()) + return; + + for (Function &F : M.getFunctionList()) { + if (F.isDeclaration()) + continue; + + if (!F.hasFnAttribute("sign-return-address")) { + StringRef SignType = "none"; + if (isModuleAttributeSet(M, "sign-return-address")) + SignType = "non-leaf"; + + if (isModuleAttributeSet(M, "sign-return-address-all")) + SignType = "all"; + + F.addFnAttr("sign-return-address", SignType); + } + CopyModuleAttributeToFunction(F, "branch-target-enforcement"); + CopyModuleAttributeToFunction(F, "branch-protection-pauth-lr"); + CopyModuleAttributeToFunction(F, "guarded-control-stack"); + CopyModuleAttributeToFunction( + F, "sign-return-address-key", + std::make_pair("b_key", "a_key")); + } +} + static bool isOldLoopArgument(Metadata *MD) { auto *T = dyn_cast_or_null(MD); if (!T) diff --git a/llvm/lib/Linker/IRMover.cpp b/llvm/lib/Linker/IRMover.cpp index 37d21119447b9c..026d466ed8539e 100644 --- a/llvm/lib/Linker/IRMover.cpp +++ b/llvm/lib/Linker/IRMover.cpp @@ -1606,6 +1606,11 @@ Error IRLinker::run() { // Loop over all of the linked values to compute type mappings. computeTypeMapping(); + // Convert module level attributes to function level attributes because + // after merging modules the attributes might change and would have different + // effect on the functions as the original module would have. + CopyModuleAttributesToFunction(*SrcM); + std::reverse(Worklist.begin(), Worklist.end()); while (!Worklist.empty()) { GlobalValue *GV = Worklist.back(); diff --git a/llvm/test/LTO/AArch64/link-branch-target-enforcement.ll b/llvm/test/LTO/AArch64/link-branch-target-enforcement.ll index ccf8cf67ede6dc..74d9c86881d52c 100644 --- a/llvm/test/LTO/AArch64/link-branch-target-enforcement.ll +++ b/llvm/test/LTO/AArch64/link-branch-target-enforcement.ll @@ -32,6 +32,7 @@ entry: ; CHECK-DUMP:
: ; CHECK-DUMP: bl 0x8 ; CHECK-DUMP: : +; CHECK-DUMP: paciasp ; `main` doesn't support BTI while `foo` does, so in the binary ; we should see only PAC which is supported by both. diff --git a/llvm/test/LTO/AArch64/link-sign-return-address.ll b/llvm/test/LTO/AArch64/link-sign-return-address.ll new file mode 100644 index 00000000000000..c25857ceed7b40 --- /dev/null +++ b/llvm/test/LTO/AArch64/link-sign-return-address.ll @@ -0,0 +1,43 @@ +; Testcase to check that module with different branch-target-enforcement can +; be mixed. +; +; RUN: llvm-as %s -o %t1.bc +; RUN: llvm-as %p/Inputs/foo.ll -o %t2.bc +; RUN: llvm-lto -exported-symbol main \ +; RUN: -exported-symbol foo \ +; RUN: -filetype=obj \ +; RUN: %t2.bc %t1.bc \ +; RUN: -o %t1.exe 2>&1 +; RUN: llvm-objdump -d %t1.exe | FileCheck --check-prefix=CHECK-DUMP %s +; RUN: llvm-readelf -n %t1.exe | FileCheck --allow-empty --check-prefix=CHECK-PROP %s + +target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128" +target triple = "aarch64-unknown-linux-gnu" + +declare i32 @foo(); + +define i32 @main() { +entry: + %add = call i32 @foo() + ret i32 %add +} + +!llvm.module.flags = !{!0, !1, !2, !3 } +!0 = !{i32 8, !"branch-target-enforcement", i32 0} +!1 = !{i32 8, !"sign-return-address", i32 0} +!2 = !{i32 8, !"sign-return-address-all", i32 0} +!3 = !{i32 8, !"sign-return-address-with-bkey", i32 0} + +; CHECK-DUMP: : +; CHECK-DUMP: paciasp +; CHECK-DUMP: mov w0, #0x2a +; CHECK-DUMP: autiasp +; CHECK-DUMP: ret +; CHECK-DUMP:
: +; CHECK-DUMP-NOT: paciasp +; CHECK-DUMP: str x30, +; CHECK-DUMP: bl 0x14 + +; `main` doesn't support PAC sign-return-address while `foo` does, so in the binary +; we should not see anything. +; CHECK-PROP-NOT: Properties: aarch64 feature: PAC \ No newline at end of file diff --git a/llvm/test/Linker/link-arm-and-thumb.ll b/llvm/test/Linker/link-arm-and-thumb.ll index a90f2128e4430a..37bd8c37f8b5e5 100644 --- a/llvm/test/Linker/link-arm-and-thumb.ll +++ b/llvm/test/Linker/link-arm-and-thumb.ll @@ -13,11 +13,12 @@ entry: ret i32 %add } -; CHECK: define i32 @main() { +; CHECK: define i32 @main() [[MAIN_ATTRS:#[0-9]+]] ; CHECK: define i32 @foo(i32 %a, i32 %b) [[ARM_ATTRS:#[0-9]+]] ; CHECK: define i32 @bar(i32 %a, i32 %b) [[THUMB_ATTRS:#[0-9]+]] -; CHECK: attributes [[ARM_ATTRS]] = { "target-features"="-thumb-mode" } -; CHECK: attributes [[THUMB_ATTRS]] = { "target-features"="+thumb-mode" } +; CHECK: attributes [[MAIN_ATTRS]] = { {{.*}} } +; CHECK: attributes [[ARM_ATTRS]] = { {{.*}} "target-features"="-thumb-mode" } +; CHECK: attributes [[THUMB_ATTRS]] = { {{.*}} "target-features"="+thumb-mode" } ; STDERR-NOT: warning: Linking two modules of different target triples: