llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-backend-aarch64 Author: Jack Styles (Stylie777) <details> <summary>Changes</summary> Currently, LLVM enables `-mbranch-protection=standard` as `bti+pac-ret`. To align LLVM with the behaviour in GNU, this has been updated to `bti+pac-ret+pc` when FEAT_PAuth_LR is enabled as an optional feature via the `-mcpu=` options. If this is not enabled, then this will revert to the existing behaviour. --- Full diff: https://github.com/llvm/llvm-project/pull/90614.diff 8 Files Affected: - (modified) clang/lib/Basic/Targets/AArch64.cpp (+1-1) - (modified) clang/lib/Driver/ToolChains/Clang.cpp (+17-1) - (modified) clang/test/Preprocessor/aarch64-target-features.c (+4) - (modified) llvm/docs/ReleaseNotes.rst (+5) - (modified) llvm/include/llvm/TargetParser/AArch64TargetParser.h (+2) - (modified) llvm/include/llvm/TargetParser/ARMTargetParserCommon.h (+1-1) - (modified) llvm/lib/TargetParser/AArch64TargetParser.cpp (+5) - (modified) llvm/lib/TargetParser/ARMTargetParserCommon.cpp (+2-1) ``````````diff diff --git a/clang/lib/Basic/Targets/AArch64.cpp b/clang/lib/Basic/Targets/AArch64.cpp index c8d243a8fb7aea..5a46a3e6c6fd3e 100644 --- a/clang/lib/Basic/Targets/AArch64.cpp +++ b/clang/lib/Basic/Targets/AArch64.cpp @@ -224,7 +224,7 @@ bool AArch64TargetInfo::validateBranchProtection(StringRef Spec, StringRef, BranchProtectionInfo &BPI, StringRef &Err) const { llvm::ARM::ParsedBranchProtection PBP; - if (!llvm::ARM::parseBranchProtection(Spec, PBP, Err)) + if (!llvm::ARM::parseBranchProtection(Spec, PBP, Err, HasPAuthLR)) return false; BPI.SignReturnAddr = diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp index 1988a90a48ae6b..057a0d850ed9b3 100644 --- a/clang/lib/Driver/ToolChains/Clang.cpp +++ b/clang/lib/Driver/ToolChains/Clang.cpp @@ -1511,7 +1511,23 @@ static void CollectARMPACBTIOptions(const ToolChain &TC, const ArgList &Args, } else { StringRef DiagMsg; llvm::ARM::ParsedBranchProtection PBP; - if (!llvm::ARM::parseBranchProtection(A->getValue(), PBP, DiagMsg)) + + // To know if we need to enable PAuth-LR As part of the standard branch + // protection option, it needs to be determined if the feature has been + // activated in the `march` argument. This information is stored within the + // CmdArgs variable and can be found using a search. + if (isAArch64) { + auto isPAuthLR = [](const char *member) { + llvm::AArch64::ExtensionInfo pauthlr_extension = + llvm::AArch64::getExtensionByID(llvm::AArch64::AEK_PAUTHLR); + return (pauthlr_extension.Feature.compare(member) == 0); + }; + + if (std::any_of(CmdArgs.begin(), CmdArgs.end(), isPAuthLR)) + EnablePAuthLR = true; + } + if (!llvm::ARM::parseBranchProtection(A->getValue(), PBP, DiagMsg, + EnablePAuthLR)) D.Diag(diag::err_drv_unsupported_option_argument) << A->getSpelling() << DiagMsg; if (!isAArch64 && PBP.Key == "b_key") diff --git a/clang/test/Preprocessor/aarch64-target-features.c b/clang/test/Preprocessor/aarch64-target-features.c index 85762b7fed4d71..31af14f748b765 100644 --- a/clang/test/Preprocessor/aarch64-target-features.c +++ b/clang/test/Preprocessor/aarch64-target-features.c @@ -616,6 +616,9 @@ // ================== Check Armv9.5-A Pointer Authentication Enhancements(PAuth_LR). // RUN: %clang -target arm64-none-linux-gnu -march=armv8-a -x c -E -dM %s -o - | FileCheck -check-prefix=CHECK-PAUTH-LR-OFF %s // RUN: %clang -target arm64-none-linux-gnu -march=armv9.5-a -x c -E -dM %s -o - | FileCheck -check-prefix=CHECK-PAUTH-LR-OFF %s +// RUN: %clang -target arm64-none-linux-gnu -march=armv9.5-a -mbranch-protection=standard -x c -E -dM %s -o - | FileCheck -check-prefixes=CHECK-PAUTH-LR-OFF,CHECK-BRANCH-PROTECTION-NO-PC %s +// RUN: %clang -target arm64-none-linux-gnu -march=armv9.5-a+pauth-lr -mbranch-protection=standard -x c -E -dM %s -o - | FileCheck -check-prefixes=CHECK-PAUTH-LR,CHECK-BRANCH-PROTECTION-PC %s +// RUN: %clang -target arm64-none-linux-gnu -march=armv9.5-a+nopauth-lr -mbranch-protection=standard -x c -E -dM %s -o - | FileCheck -check-prefixes=CHECK-PAUTH-LR-OFF,CHECK-BRANCH-PROTECTION-NO-PC %s // RUN: %clang -target arm64-none-linux-gnu -march=armv8-a+pauth -mbranch-protection=none -x c -E -dM %s -o - | FileCheck -check-prefix=CHECK-PAUTH-LR-OFF %s // RUN: %clang -target arm64-none-linux-gnu -march=armv8-a+pauth-lr -mbranch-protection=none -x c -E -dM %s -o - | FileCheck -check-prefix=CHECK-PAUTH-LR %s // RUN: %clang -target arm64-none-linux-gnu -march=armv8-a+pauth-lr -mbranch-protection=bti -x c -E -dM %s -o - | FileCheck -check-prefix=CHECK-PAUTH-LR %s @@ -636,6 +639,7 @@ // RUN: %clang -target arm64-none-linux-gnu -march=armv8-a+pauth-lr -mbranch-protection=pac-ret+pc+b-key -x c -E -dM %s -o - | FileCheck -check-prefixes=CHECK-PAUTH-LR,CHECK-BRANCH-PROTECTION-PC-BKEY %s // RUN: %clang -target arm64-none-linux-gnu -march=armv8-a+pauth-lr -mbranch-protection=pac-ret+pc+leaf -x c -E -dM %s -o - | FileCheck -check-prefixes=CHECK-PAUTH-LR,CHECK-BRANCH-PROTECTION-PC-LEAF %s // RUN: %clang -target arm64-none-linux-gnu -march=armv8-a+pauth-lr -mbranch-protection=pac-ret+pc+leaf+b-key -x c -E -dM %s -o - | FileCheck -check-prefixes=CHECK-PAUTH-LR,CHECK-BRANCH-PROTECTION-PC-LEAF-BKEY %s +// CHECK-BRANCH-PROTECTION-NO-PC: #define __ARM_FEATURE_PAC_DEFAULT 1 // CHECK-BRANCH-PROTECTION-PC: #define __ARM_FEATURE_PAC_DEFAULT 9 // CHECK-BRANCH-PROTECTION-PC-BKEY: #define __ARM_FEATURE_PAC_DEFAULT 10 // CHECK-BRANCH-PROTECTION-PC-LEAF: #define __ARM_FEATURE_PAC_DEFAULT 13 diff --git a/llvm/docs/ReleaseNotes.rst b/llvm/docs/ReleaseNotes.rst index 46d79d6c5822b1..e98d31694046c8 100644 --- a/llvm/docs/ReleaseNotes.rst +++ b/llvm/docs/ReleaseNotes.rst @@ -76,6 +76,11 @@ Changes to the AArch64 Backend * Added support for Cortex-A78AE, Cortex-A520AE, Cortex-A720AE, Neoverse-N3, Neoverse-V3 and Neoverse-V3AE CPUs. +* `-mbranch-protection=standard` now enables FEAT_PAuth_LR by +default when the feature is enabled. The new behaviour results +in `standard` being equal to `bti+pac-ret+pc` when `+pauth-lr` +is passed as part of `-mcpu=`options. + Changes to the AMDGPU Backend ----------------------------- diff --git a/llvm/include/llvm/TargetParser/AArch64TargetParser.h b/llvm/include/llvm/TargetParser/AArch64TargetParser.h index 0d1cfd152151aa..d39fc5667358a0 100644 --- a/llvm/include/llvm/TargetParser/AArch64TargetParser.h +++ b/llvm/include/llvm/TargetParser/AArch64TargetParser.h @@ -853,6 +853,8 @@ inline constexpr Alias CpuAliases[] = {{"cobalt-100", "neoverse-n2"}, inline constexpr Alias ExtAliases[] = {{"rdma", "rdm"}}; +const ExtensionInfo &getExtensionByID(ArchExtKind(ExtID)); + bool getExtensionFeatures( const AArch64::ExtensionBitset &Extensions, std::vector<StringRef> &Features); diff --git a/llvm/include/llvm/TargetParser/ARMTargetParserCommon.h b/llvm/include/llvm/TargetParser/ARMTargetParserCommon.h index 8ae553ca80ddc3..f6115718e9f5fd 100644 --- a/llvm/include/llvm/TargetParser/ARMTargetParserCommon.h +++ b/llvm/include/llvm/TargetParser/ARMTargetParserCommon.h @@ -46,7 +46,7 @@ struct ParsedBranchProtection { }; bool parseBranchProtection(StringRef Spec, ParsedBranchProtection &PBP, - StringRef &Err); + StringRef &Err, bool EnablePAuthLR = false); } // namespace ARM } // namespace llvm diff --git a/llvm/lib/TargetParser/AArch64TargetParser.cpp b/llvm/lib/TargetParser/AArch64TargetParser.cpp index 71099462d5ecff..026214e7e2eac5 100644 --- a/llvm/lib/TargetParser/AArch64TargetParser.cpp +++ b/llvm/lib/TargetParser/AArch64TargetParser.cpp @@ -280,3 +280,8 @@ bool AArch64::ExtensionSet::parseModifier(StringRef Modifier) { } return false; } + +const AArch64::ExtensionInfo & +AArch64::getExtensionByID(AArch64::ArchExtKind ExtID) { + return lookupExtensionByID(ExtID); +} diff --git a/llvm/lib/TargetParser/ARMTargetParserCommon.cpp b/llvm/lib/TargetParser/ARMTargetParserCommon.cpp index 45d04f9bcbfb6a..d6ce6581bb1a92 100644 --- a/llvm/lib/TargetParser/ARMTargetParserCommon.cpp +++ b/llvm/lib/TargetParser/ARMTargetParserCommon.cpp @@ -139,7 +139,7 @@ ARM::EndianKind ARM::parseArchEndian(StringRef Arch) { // returned in `PBP`. Returns false in error, with `Err` containing // an erroneous part of the spec. bool ARM::parseBranchProtection(StringRef Spec, ParsedBranchProtection &PBP, - StringRef &Err) { + StringRef &Err, bool EnablePAuthLR) { PBP = {"none", "a_key", false, false, false}; if (Spec == "none") return true; // defaults are ok @@ -148,6 +148,7 @@ bool ARM::parseBranchProtection(StringRef Spec, ParsedBranchProtection &PBP, PBP.Scope = "non-leaf"; PBP.BranchTargetEnforcement = true; PBP.GuardedControlStack = true; + PBP.BranchProtectionPAuthLR = EnablePAuthLR; return true; } `````````` </details> https://github.com/llvm/llvm-project/pull/90614 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
