diff --git a/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp b/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp index 152105c20b11..1095a1f5787a 100644 --- a/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp +++ b/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp @@ -265,6 +265,8 @@ void AArch64AsmPrinter::emitStartOfAsmFile(Module &M) { S, MCConstantExpr::create(Feat00Value, MMI->getContext())); } + // TODO: enhance naming to distinguish MachO ptrauth ABI version and ELF + // pauthabi platform and version if (TM.getTargetTriple().isOSBinFormatMachO()) EmitPtrAuthVersion(M); @@ -283,13 +285,24 @@ void AArch64AsmPrinter::emitStartOfAsmFile(Module &M) { if (Sign->getZExtValue()) Flags |= ELF::GNU_PROPERTY_AARCH64_FEATURE_1_PAC; - if (Flags == 0) - return; + uint64_t PAuthABIPlatform = -1; + if (const auto *PAP = mdconst::extract_or_null( + M.getModuleFlag("aarch64-elf-pauthabi-platform"))) + PAuthABIPlatform = PAP->getZExtValue(); + uint64_t PAuthABIVersion = -1; + if (const auto *PAV = mdconst::extract_or_null( + M.getModuleFlag("aarch64-elf-pauthabi-version"))) + PAuthABIVersion = PAV->getZExtValue(); + + if ((PAuthABIPlatform == uint64_t(-1)) != (PAuthABIVersion == uint64_t(-1))) + report_fatal_error( + "either both or no 'aarch64-elf-pauthabi-platform' and " + "'aarch64-elf-pauthabi-version' module flags must be present"); // Emit a .note.gnu.property section with the flags. auto *TS = static_cast(OutStreamer->getTargetStreamer()); - TS->emitNoteSection(Flags); + TS->emitNoteSection(Flags, PAuthABIPlatform, PAuthABIVersion); } void AArch64AsmPrinter::emitFunctionHeaderComment() { diff --git a/llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp b/llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp index e1d6dd7a056b..0b13f5868e60 100644 --- a/llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp +++ b/llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.cpp @@ -56,10 +56,20 @@ void AArch64TargetStreamer::emitConstantPools() { void AArch64TargetStreamer::finish() { if (MarkBTIProperty) emitNoteSection(ELF::GNU_PROPERTY_AARCH64_FEATURE_1_BTI); + // TODO: do we need to handle GNU_PROPERTY_AARCH64_FEATURE_PAUTH here? } -void AArch64TargetStreamer::emitNoteSection(unsigned Flags) { - if (Flags == 0) +void AArch64TargetStreamer::emitNoteSection(unsigned Flags, + uint64_t PAuthABIPlatform, + uint64_t PAuthABIVersion) { + assert((PAuthABIPlatform == uint64_t(-1)) == + (PAuthABIVersion == uint64_t(-1))); + uint64_t DescSz = 0; + if (Flags != 0) + DescSz += 4 * 4; + if (PAuthABIPlatform != uint64_t(-1)) + DescSz += 4 + 4 + 8 * 2; + if (DescSz == 0) return; MCStreamer &OutStreamer = getStreamer(); @@ -80,15 +90,25 @@ void AArch64TargetStreamer::emitNoteSection(unsigned Flags) { // Emit the note header. OutStreamer.emitValueToAlignment(Align(8)); OutStreamer.emitIntValue(4, 4); // data size for "GNU\0" - OutStreamer.emitIntValue(4 * 4, 4); // Elf_Prop size + OutStreamer.emitIntValue(DescSz, 4); // Elf_Prop array size OutStreamer.emitIntValue(ELF::NT_GNU_PROPERTY_TYPE_0, 4); OutStreamer.emitBytes(StringRef("GNU", 4)); // note name // Emit the PAC/BTI properties. - OutStreamer.emitIntValue(ELF::GNU_PROPERTY_AARCH64_FEATURE_1_AND, 4); - OutStreamer.emitIntValue(4, 4); // data size - OutStreamer.emitIntValue(Flags, 4); // data - OutStreamer.emitIntValue(0, 4); // pad + if (Flags != 0) { + OutStreamer.emitIntValue(ELF::GNU_PROPERTY_AARCH64_FEATURE_1_AND, 4); + OutStreamer.emitIntValue(4, 4); // data size + OutStreamer.emitIntValue(Flags, 4); // data + OutStreamer.emitIntValue(0, 4); // pad + } + + // Emit the PAuth ABI compatibility info + if (PAuthABIPlatform != uint64_t(-1)) { + OutStreamer.emitIntValue(ELF::GNU_PROPERTY_AARCH64_FEATURE_PAUTH, 4); + OutStreamer.emitIntValue(8 * 2, 4); // data size + OutStreamer.emitIntValue(PAuthABIPlatform, 8); + OutStreamer.emitIntValue(PAuthABIVersion, 8); + } OutStreamer.endSection(Nt); OutStreamer.switchSection(Cur); diff --git a/llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.h b/llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.h index b3bce9960772..716ca1b3286c 100644 --- a/llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.h +++ b/llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.h @@ -35,7 +35,8 @@ class AArch64TargetStreamer : public MCTargetStreamer { void emitCurrentConstantPool(); /// Callback used to implement the .note.gnu.property section. - void emitNoteSection(unsigned Flags); + void emitNoteSection(unsigned Flags, uint64_t PAuthABIPlatform = -1, + uint64_t PAuthABIVersion = -1); /// Callback used to implement the .inst directive. virtual void emitInst(uint32_t Inst); diff --git a/llvm/test/CodeGen/AArch64/note-gnu-property-elf-pauthabi.ll b/llvm/test/CodeGen/AArch64/note-gnu-property-elf-pauthabi.ll new file mode 100644 index 000000000000..46d88c69690d --- /dev/null +++ b/llvm/test/CodeGen/AArch64/note-gnu-property-elf-pauthabi.ll @@ -0,0 +1,50 @@ +; RUN: rm -rf %t && split-file %s %t && cd %t + +;--- ok.ll + +; RUN: llc -mtriple=aarch64-linux ok.ll -o - | \ +; RUN: FileCheck %s --check-prefix=ASM +; RUN: llc -mtriple=aarch64-linux ok.ll -filetype=obj -o - | \ +; RUN: llvm-readelf --notes - | FileCheck %s --check-prefix=OBJ + +!llvm.module.flags = !{!0, !1} + +!0 = !{i32 1, !"aarch64-elf-pauthabi-platform", i32 2} +!1 = !{i32 1, !"aarch64-elf-pauthabi-version", i32 31} + +; ASM: .section .note.gnu.property,"a",@note +; ASM-NEXT: .p2align 3, 0x0 +; ASM-NEXT: .word 4 +; ASM-NEXT: .word 24 +; ASM-NEXT: .word 5 +; ASM-NEXT: .asciz "GNU" +; 3221225473 = 0xc0000001 = GNU_PROPERTY_AARCH64_FEATURE_PAUTH +; ASM-NEXT: .word 3221225473 +; ASM-NEXT: .word 16 +; ASM-NEXT: .xword 2 +; ASM-NEXT: .xword 31 + +; OBJ: Displaying notes found in: .note.gnu.property +; OBJ-NEXT: Owner Data size Description +; OBJ-NEXT: GNU 0x00000018 NT_GNU_PROPERTY_TYPE_0 (property note) +; OBJ-NEXT: AArch64 PAuth ABI tag: platform 0x2 (linux), version 0x1f (PointerAuthCalls, PointerAuthReturns, PointerAuthVTPtrAddressDiscrimination, PointerAuthVTPtrTypeDiscrimination, PointerAuthInitFini) + +; ERR: either both or no 'aarch64-elf-pauthabi-platform' and 'aarch64-elf-pauthabi-version' module flags must be present + +;--- err1.ll + +; RUN: not --crash llc -mtriple=aarch64-linux err1.ll 2>&1 -o - | \ +; RUN: FileCheck %s --check-prefix=ERR + +!llvm.module.flags = !{!0} + +!0 = !{i32 1, !"aarch64-elf-pauthabi-platform", i32 2} + +;--- err2.ll + +; RUN: not --crash llc -mtriple=aarch64-linux err2.ll 2>&1 -o - | \ +; RUN: FileCheck %s --check-prefix=ERR + +!llvm.module.flags = !{!0} + +!0 = !{i32 1, !"aarch64-elf-pauthabi-version", i32 31}