[llvm-readobj] Add support for machine-independent NetBSD ELF core notes.

[fcambus]

Summary

Notes generated in NetBSD core files provide additional information about processes.

These notes are described in core.5, which can be viewed here: https://man.netbsd.org/core.5

[MaskRay]

llvm/test/tools/llvm-readobj/ELF/note-netbsd-core.test

16

Delete trailing space

llvm/tools/llvm-readobj/ELFDumper.cpp

5463

Is it startswith? The test doesn't have a case for NetBSD-CORE with a suffix.

[fcambus]

Here is a new revision with the trailing spaces removed and linting
issue fixed, and updated tests.

llvm/tools/llvm-readobj/ELFDumper.cpp

5463

Yes, startswith is required as some notes have names of the form NetBSD-CORE@nn where nn is the LWP ID of the execution context.

But you are right, the test was wrong for NT_NETBSDCORE_LWPSTATUS notes, sorry about that.

[MaskRay]

llvm/tools/llvm-readobj/ELFDumper.cpp

5463

Check ELFType == ELF::ET_CORE first to skip string comparison for the majority cases.

[fcambus]

Check ELFType == ELF::ET_CORE first in getNoteTypeName().

llvm/include/llvm/BinaryFormat/ELF.h

enum {
   NT_FREEBSD_PROCSTAT_GROUPS = 11,
   NT_FREEBSD_PROCSTAT_UMASK = 12,
   NT_FREEBSD_PROCSTAT_RLIMIT = 13,
   NT_FREEBSD_PROCSTAT_OSREL = 14,
   NT_FREEBSD_PROCSTAT_PSSTRINGS = 15,
   NT_FREEBSD_PROCSTAT_AUXV = 16,
 };
 
+// NetBSD core note types.
+enum {
+  NT_NETBSDCORE_PROCINFO = 1,
+  NT_NETBSDCORE_AUXV = 2,
+  NT_NETBSDCORE_LWPSTATUS = 24,
+};
+
 // OpenBSD core note types.
 enum {
   NT_OPENBSD_PROCINFO = 10,
   NT_OPENBSD_AUXV = 11,
   NT_OPENBSD_REGS = 20,
   NT_OPENBSD_FPREGS = 21,
   NT_OPENBSD_XFPREGS = 22,
   NT_OPENBSD_WCOOKIE = 23,

llvm/lib/ObjectYAML/ELFYAML.cpp

#define ECase(X) IO.enumCase(Value, #X, ELF::X)
   ECase(NT_FREEBSD_PROCSTAT_FILES);
   ECase(NT_FREEBSD_PROCSTAT_VMMAP);
   ECase(NT_FREEBSD_PROCSTAT_GROUPS);
   ECase(NT_FREEBSD_PROCSTAT_UMASK);
   ECase(NT_FREEBSD_PROCSTAT_RLIMIT);
   ECase(NT_FREEBSD_PROCSTAT_OSREL);
   ECase(NT_FREEBSD_PROCSTAT_PSSTRINGS);
   ECase(NT_FREEBSD_PROCSTAT_AUXV);
+  // NetBSD core note types.
+  ECase(NT_NETBSDCORE_PROCINFO);
+  ECase(NT_NETBSDCORE_AUXV);
+  ECase(NT_NETBSDCORE_LWPSTATUS);
   // OpenBSD core note types.
   ECase(NT_OPENBSD_PROCINFO);
   ECase(NT_OPENBSD_AUXV);
   ECase(NT_OPENBSD_REGS);
   ECase(NT_OPENBSD_FPREGS);
   ECase(NT_OPENBSD_XFPREGS);
   ECase(NT_OPENBSD_WCOOKIE);
   // AMD specific notes. (Code Object V2)

llvm/test/tools/llvm-readobj/ELF/note-netbsd-core.test

+## Test that note values are interpreted correctly for NetBSD core files.
+# RUN: yaml2obj %s -o %t.o
+# RUN: llvm-readelf --notes %t.o | FileCheck %s --check-prefix=GNU --strict-whitespace
+# RUN: llvm-readobj --notes %t.o | FileCheck %s --check-prefix=LLVM --strict-whitespace
+
+--- !ELF
+FileHeader:
+  Class: ELFCLASS64
+  Data:  ELFDATA2LSB
+  Type:  ET_CORE
+Sections:
+  - Name: .note.foo
+    Type: SHT_NOTE
+    Notes:
+      - Name: NetBSD-CORE
+        Type: NT_NETBSDCORE_PROCINFO
+      - Name: NetBSD-CORE
+        Type: NT_NETBSDCORE_AUXV
+      - Name: NetBSD-CORE@3615
+        Type: NT_NETBSDCORE_LWPSTATUS
+
+ProgramHeaders:
+  - Type:     PT_NOTE
+    FirstSec: .note.foo
+    LastSec:  .note.foo
+
+# GNU:      Displaying notes found at file offset 0x00000078 with length 0x00000050:
+# GNU-NEXT:   Owner                Data size  Description
+# GNU-NEXT:   NetBSD-CORE          0x00000000 NT_NETBSDCORE_PROCINFO (procinfo structure)
+# GNU-NEXT:   NetBSD-CORE          0x00000000 NT_NETBSDCORE_AUXV (ELF auxiliary vector data)
+# GNU-NEXT:   NetBSD-CORE@3615     0x00000000 PT_LWPSTATUS (ptrace_lwpstatus structure)
+
+# LLVM:      Notes [
+# LLVM-NEXT:   NoteSection {
+# LLVM-NEXT:     Name: <?>
+# LLVM-NEXT:     Offset: 0x78
+# LLVM-NEXT:     Size: 0x50
+# LLVM-NEXT:     Note {
+# LLVM-NEXT:       Owner: NetBSD-CORE
+# LLVM-NEXT:       Data size: 0x0
+# LLVM-NEXT:       Type: NT_NETBSDCORE_PROCINFO (procinfo structure)
+# LLVM-NEXT:     }
+# LLVM-NEXT:     Note {
+# LLVM-NEXT:       Owner: NetBSD-CORE
+# LLVM-NEXT:       Data size: 0x0
+# LLVM-NEXT:       Type: NT_NETBSDCORE_AUXV (ELF auxiliary vector data)
+# LLVM-NEXT:     }
+# LLVM-NEXT:     Note {
+# LLVM-NEXT:       Owner: NetBSD-CORE@3615
+# LLVM-NEXT:       Data size: 0x0
+# LLVM-NEXT:       Type: PT_LWPSTATUS (ptrace_lwpstatus structure)
+# LLVM-NEXT:     }
+# LLVM-NEXT:   }
+# LLVM-NEXT: ]

llvm/tools/llvm-readobj/ELFDumper.cpp

 const NoteType FreeBSDNoteTypes[] = {
     {ELF::NT_FREEBSD_ABI_TAG, "NT_FREEBSD_ABI_TAG (ABI version tag)"},
     {ELF::NT_FREEBSD_NOINIT_TAG, "NT_FREEBSD_NOINIT_TAG (no .init tag)"},
     {ELF::NT_FREEBSD_ARCH_TAG, "NT_FREEBSD_ARCH_TAG (architecture tag)"},
     {ELF::NT_FREEBSD_FEATURE_CTL,
      "NT_FREEBSD_FEATURE_CTL (FreeBSD feature control)"},
 };
 
+const NoteType NetBSDCoreNoteTypes[] = {
+    {ELF::NT_NETBSDCORE_PROCINFO,
+     "NT_NETBSDCORE_PROCINFO (procinfo structure)"},
+    {ELF::NT_NETBSDCORE_AUXV, "NT_NETBSDCORE_AUXV (ELF auxiliary vector data)"},
+    {ELF::NT_NETBSDCORE_LWPSTATUS, "PT_LWPSTATUS (ptrace_lwpstatus structure)"},
+};
+
 const NoteType OpenBSDCoreNoteTypes[] = {
     {ELF::NT_OPENBSD_PROCINFO, "NT_OPENBSD_PROCINFO (procinfo structure)"},
     {ELF::NT_OPENBSD_AUXV, "NT_OPENBSD_AUXV (ELF auxiliary vector data)"},
     {ELF::NT_OPENBSD_REGS, "NT_OPENBSD_REGS (regular registers)"},
     {ELF::NT_OPENBSD_FPREGS, "NT_OPENBSD_FPREGS (floating point registers)"},
     {ELF::NT_OPENBSD_WCOOKIE, "NT_OPENBSD_WCOOKIE (window cookie)"},
 };
 
if (ELFType == ELF::ET_CORE) {
       StringRef Result = FindNote(FreeBSDCoreNoteTypes);
       if (!Result.empty())
         return Result;
       return FindNote(CoreNoteTypes);
     } else {
       return FindNote(FreeBSDNoteTypes);
     }
   }
+  if (Name.startswith("NetBSD-CORE") && ELFType == ELF::ET_CORE) {
+    StringRef Result = FindNote(NetBSDCoreNoteTypes);
+    if (!Result.empty())
+      return Result;
+    return FindNote(CoreNoteTypes);
+  }
   if (Name.startswith("OpenBSD") && ELFType == ELF::ET_CORE) {
     // OpenBSD also places the generic core notes in the OpenBSD namespace.
     StringRef Result = FindNote(OpenBSDCoreNoteTypes);
     if (!Result.empty())
       return Result;
     return FindNote(CoreNoteTypes);
   }
   if (Name == "AMD")