From 53dd3715a511262cb0cc619958661bef2ba6e23f Mon Sep 17 00:00:00 2001 From: Tom Tromey Date: Wed, 2 Jul 2025 07:03:42 -0600 Subject: [PATCH] Fix lld crash caused by dynamic bit offset patch PR #141106 changed the debuginfo metdata to allow dynamic bit offsets and sizes. This caused a crash in lld when using LTO. The problem is that lazyLoadOneMetadata assumes that the metadata in question can be cast to MDNode; but in the typical case where the offset is a constant, this is not true. This patch changes this spot to allow non-MDNodes through. The included test case comes from the report in #141106. --- lld/test/ELF/lto/lazy-debug.ll | 107 +++++++++++++++++++++ llvm/lib/Bitcode/Reader/MetadataLoader.cpp | 6 +- 2 files changed, 111 insertions(+), 2 deletions(-) create mode 100644 lld/test/ELF/lto/lazy-debug.ll diff --git a/lld/test/ELF/lto/lazy-debug.ll b/lld/test/ELF/lto/lazy-debug.ll new file mode 100644 index 0000000000000..48d176f0f6bf6 --- /dev/null +++ b/lld/test/ELF/lto/lazy-debug.ll @@ -0,0 +1,107 @@ +; REQUIRES: aarch64 +;; Regression test for a case in lazy debuginfo loading. +;; The bug would cause ld.lld to crash. + +; RUN: split-file %s %t +; RUN: llvm-as %t/hda_codec.s -o %t/hda_codec.o +; RUN: llvm-as %t/hda_bind.s -o %t/hda_bind.o +; RUN: ld.lld -EL -maarch64elf -r %t/hda_bind.o %t/hda_codec.o -o %t/hda_codec + +;--- hda_codec.s +; ModuleID = 'hda_codec.o' +source_filename = "hda_codec.i" +target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128-Fn32" +target triple = "aarch64-unknown-linux-gnu" + +%struct.anon = type { i32 } + +@hda_set_power_state_codec = hidden local_unnamed_addr global %struct.anon zeroinitializer, align 4, !dbg !0 + +; Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(none) uwtable +define hidden void @snd_hda_codec_shutdown() local_unnamed_addr #0 !dbg !19 { +entry: + ret void, !dbg !22 +} + +attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn memory(none) uwtable "frame-pointer"="non-leaf" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="generic" "target-features"="+fp-armv8,+neon,+v8a,-fmv" } + +!llvm.dbg.cu = !{!2} +!llvm.module.flags = !{!10, !11, !12, !13, !14, !15, !16, !17} +!llvm.ident = !{!18} + +!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression()) +!1 = distinct !DIGlobalVariable(name: "hda_set_power_state_codec", scope: !2, file: !5, line: 3, type: !6, isLocal: false, isDefinition: true) +!2 = distinct !DICompileUnit(language: DW_LANG_C11, file: !3, producer: "clang version 21.0.0git (git@github.com:llvm/llvm-project.git 93849a39c432827473ca6c676f1500da69b3aaa0)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, globals: !4, splitDebugInlining: false, nameTableKind: None) +!3 = !DIFile(filename: "hda_codec.i", directory: "/tmp") +!4 = !{!0} +!5 = !DIFile(filename: "hda_codec.i", directory: "/tmp", checksumkind: CSK_MD5, checksum: "c192644b468953345ff9647026173a7b") +!6 = distinct !DICompositeType(tag: DW_TAG_structure_type, file: !5, line: 1, size: i64 32, offset: i64 0, elements: !7) +!7 = !{!8} +!8 = !DIDerivedType(tag: DW_TAG_member, name: "mfg", scope: !6, file: !5, line: 2, baseType: !9, size: i64 32, offset: i64 0) +!9 = !DIBasicType(name: "int", size: i64 32, encoding: DW_ATE_signed) +!10 = !{i32 7, !"Dwarf Version", i32 5} +!11 = !{i32 2, !"Debug Info Version", i32 3} +!12 = !{i32 1, !"wchar_size", i32 4} +!13 = !{i32 8, !"PIC Level", i32 2} +!14 = !{i32 7, !"PIE Level", i32 2} +!15 = !{i32 7, !"uwtable", i32 2} +!16 = !{i32 7, !"frame-pointer", i32 1} +!17 = !{i32 1, !"EnableSplitLTOUnit", i32 1} +!18 = !{!"clang version 21.0.0git (git@github.com:llvm/llvm-project.git 93849a39c432827473ca6c676f1500da69b3aaa0)"} +!19 = distinct !DISubprogram(name: "snd_hda_codec_shutdown", scope: !5, file: !5, line: 4, type: !20, scopeLine: 4, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !2) +!20 = !DISubroutineType(types: !21) +!21 = !{null} +!22 = !DILocation(line: 4, column: 32, scope: !19) + +^0 = module: (path: "hda_codec.o", hash: (1120894731, 3099354915, 309166549, 2100129435, 1932081428)) +^1 = gv: (name: "snd_hda_codec_shutdown", summaries: (function: (module: ^0, flags: (linkage: external, visibility: hidden, notEligibleToImport: 0, live: 0, dsoLocal: 1, canAutoHide: 0, importType: definition), insts: 1, funcFlags: (readNone: 1, readOnly: 0, noRecurse: 1, returnDoesNotAlias: 0, noInline: 0, alwaysInline: 0, noUnwind: 1, mayThrow: 0, hasUnknownCall: 0, mustBeUnreachable: 0)))) ; guid = 1539195202824839354 +^2 = gv: (name: "hda_set_power_state_codec", summaries: (variable: (module: ^0, flags: (linkage: external, visibility: hidden, notEligibleToImport: 0, live: 0, dsoLocal: 1, canAutoHide: 0, importType: definition), varFlags: (readonly: 1, writeonly: 1, constant: 0)))) ; guid = 10300548032946263328 +^3 = flags: 8 +^4 = blockcount: 0 + +;--- hda_bind.s +; ModuleID = 'hda_bind.o' +source_filename = "hda_bind.i" +target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128-Fn32" +target triple = "aarch64-unknown-linux-gnu" + +; Function Attrs: nounwind uwtable +define hidden void @hda_codec_driver_shutdown() local_unnamed_addr #0 !dbg !11 { +entry: + tail call void @snd_hda_codec_shutdown() #2, !dbg !15 + ret void, !dbg !16 +} + +declare void @snd_hda_codec_shutdown(...) local_unnamed_addr #1 + +attributes #0 = { nounwind uwtable "frame-pointer"="non-leaf" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="generic" "target-features"="+fp-armv8,+neon,+v8a,-fmv" } +attributes #1 = { "frame-pointer"="non-leaf" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="generic" "target-features"="+fp-armv8,+neon,+v8a,-fmv" } +attributes #2 = { nounwind } + +!llvm.dbg.cu = !{!0} +!llvm.module.flags = !{!2, !3, !4, !5, !6, !7, !8, !9} +!llvm.ident = !{!10} + +!0 = distinct !DICompileUnit(language: DW_LANG_C11, file: !1, producer: "clang version 21.0.0git (git@github.com:llvm/llvm-project.git 93849a39c432827473ca6c676f1500da69b3aaa0)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, splitDebugInlining: false, nameTableKind: None) +!1 = !DIFile(filename: "hda_bind.i", directory: "/tmp") +!2 = !{i32 7, !"Dwarf Version", i32 5} +!3 = !{i32 2, !"Debug Info Version", i32 3} +!4 = !{i32 1, !"wchar_size", i32 4} +!5 = !{i32 8, !"PIC Level", i32 2} +!6 = !{i32 7, !"PIE Level", i32 2} +!7 = !{i32 7, !"uwtable", i32 2} +!8 = !{i32 7, !"frame-pointer", i32 1} +!9 = !{i32 1, !"EnableSplitLTOUnit", i32 1} +!10 = !{!"clang version 21.0.0git (git@github.com:llvm/llvm-project.git 93849a39c432827473ca6c676f1500da69b3aaa0)"} +!11 = distinct !DISubprogram(name: "hda_codec_driver_shutdown", scope: !12, file: !12, line: 2, type: !13, scopeLine: 2, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0) +!12 = !DIFile(filename: "hda_bind.i", directory: "/tmp", checksumkind: CSK_MD5, checksum: "5907dd04e8964940b57448f37db201c6") +!13 = !DISubroutineType(types: !14) +!14 = !{null} +!15 = !DILocation(line: 2, column: 36, scope: !11) +!16 = !DILocation(line: 2, column: 62, scope: !11) + +^0 = module: (path: "hda_bind.o", hash: (1958332034, 2012675483, 855691486, 2017350850, 2779827776)) +^1 = gv: (name: "snd_hda_codec_shutdown") ; guid = 1539195202824839354 +^2 = gv: (name: "hda_codec_driver_shutdown", summaries: (function: (module: ^0, flags: (linkage: external, visibility: hidden, notEligibleToImport: 0, live: 0, dsoLocal: 1, canAutoHide: 0, importType: definition), insts: 2, funcFlags: (readNone: 0, readOnly: 0, noRecurse: 0, returnDoesNotAlias: 0, noInline: 0, alwaysInline: 0, noUnwind: 1, mayThrow: 0, hasUnknownCall: 0, mustBeUnreachable: 0), calls: ((callee: ^1, tail: 1))))) ; guid = 12817427500962331703 +^3 = flags: 8 +^4 = blockcount: 0 diff --git a/llvm/lib/Bitcode/Reader/MetadataLoader.cpp b/llvm/lib/Bitcode/Reader/MetadataLoader.cpp index a9467d16c9a14..d28ab7d0bb52c 100644 --- a/llvm/lib/Bitcode/Reader/MetadataLoader.cpp +++ b/llvm/lib/Bitcode/Reader/MetadataLoader.cpp @@ -1156,8 +1156,10 @@ void MetadataLoader::MetadataLoaderImpl::lazyLoadOneMetadata( assert(ID >= MDStringRef.size() && "Unexpected lazy-loading of MDString"); // Lookup first if the metadata hasn't already been loaded. if (auto *MD = MetadataList.lookup(ID)) { - auto *N = cast(MD); - if (!N->isTemporary()) + auto *N = dyn_cast(MD); + // If the node is not an MDNode, or if it is not temporary, then + // we're done. + if (!N || !N->isTemporary()) return; } SmallVector Record;