On 2025/07/01 22:55, Dave Martin wrote:
> This series aims to clean up an aspect of coredump generation:
>
> ELF coredumps contain a set of notes describing the state of machine
> registers and other information about the dumped process.
>
> Notes are identified by a numeric identifier n_type and a "name"
> string, although this terminology is somewhat misleading. Officially,
> the "name" of a note is really an "originator" or namespace identifier
> that indicates how to interpret n_type [1], although in practice it is
> often used more loosely.
>
> Either way, each kind of note needs _both_ a specific "name" string and
> a specific n_type to identify it robustly.
>
> To centralise this knowledge in one place and avoid the need for ad-hoc
> code to guess the correct name for a given note, commit 7da8e4ad4df0
> ("elf: Define note name macros") [2] added an explicit NN_<foo> #define
> in elf.h to give the name corresponding to each named note type
> NT_<foo>.
>
> Now that the note name for each note is specified explicitly, the
> remaining guesswork for determining the note name for common and
> arch-specific regsets in ELF core dumps can be eliminated.
>
> This series aims to do just that:
>
> * Patch 2 adds a user_regset field to specify the note name, and a
> helper macro to populate it correctly alongside the note type.
>
> * Patch 3 ports away the ad-hoc note names in the common coredump
> code.
>
> * Patches 4-22 make the arch-specific changes. (This is pretty
> mechanical for most arches.)
>
> * The final patch adds a WARN() when no note name is specified,
> and simplifies the fallback guess. This should only be applied
> when all arches have ported across.
>
> See the individual patches for details.
>
>
> Testing:
>
> * x86, arm64: Booted in a VM and triggered a core dump with no WARN(),
> and verified that the dumped notes are the same.
>
> * arm: Build-tested only (for now).
>
> * Other arches: not tested yet
>
> Any help with testing is appreciated. If the following generates the
> same notes (as dumped by readelf -n core) and doesn't trigger a WARN,
> then we are probably good.
>
> $ sleep 60 &
> $ kill -QUIT $!
>
> (Register content might differ between runs, but it should be safe to
> ignore that -- this series only deals with the note names and types.)
>
> Cheers
> ---Dave
>
>
> [1] System V Application Binary Interface, Edition 4.1,
> Section 5 (Program Loading and Dynamic Linking) -> "Note Section"
>
> https://refspecs.linuxfoundation.org/elf/gabi41.pdf
>
> [2] elf: Define note name macros
>
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/include/uapi/linux/elf.h?id=7da8e4ad4df0dd12f37357af62ce1b63e75ae2e6
>
>
> Dave Martin (23):
> regset: Fix kerneldoc for struct regset_get() in user_regset
> regset: Add explicit core note name in struct user_regset
> binfmt_elf: Dump non-arch notes with strictly matching name and type
> ARC: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names
> ARM: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names
> arm64: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note
> names
> csky: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names
> hexagon: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note
> names
> LoongArch: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note
> names
> m68k: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names
> MIPS: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names
> nios2: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note
> names
> openrisc: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note
> names
> parisc: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note
> names
> powerpc/ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note
> names
> riscv: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note
> names
> s390/ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names
> sh: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names
> sparc: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note
> names
> x86/ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names
> um: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names
> xtensa: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note
> names
> binfmt_elf: Warn on missing or suspicious regset note names
>
> arch/arc/kernel/ptrace.c | 4 +-
> arch/arm/kernel/ptrace.c | 6 +-
> arch/arm64/kernel/ptrace.c | 52 ++++++++---------
> arch/csky/kernel/ptrace.c | 4 +-
> arch/hexagon/kernel/ptrace.c | 2 +-
> arch/loongarch/kernel/ptrace.c | 16 ++---
> arch/m68k/kernel/ptrace.c | 4 +-
> arch/mips/kernel/ptrace.c | 20 +++----
> arch/nios2/kernel/ptrace.c | 2 +-
> arch/openrisc/kernel/ptrace.c | 4 +-
> arch/parisc/kernel/ptrace.c | 8 +--
> arch/powerpc/kernel/ptrace/ptrace-view.c | 74 ++++++++++++------------
> arch/riscv/kernel/ptrace.c | 12 ++--
> arch/s390/kernel/ptrace.c | 42 +++++++-------
> arch/sh/kernel/ptrace_32.c | 4 +-
> arch/sparc/kernel/ptrace_32.c | 4 +-
> arch/sparc/kernel/ptrace_64.c | 8 +--
> arch/x86/kernel/ptrace.c | 22 +++----
> arch/x86/um/ptrace.c | 10 ++--
> arch/xtensa/kernel/ptrace.c | 4 +-
> fs/binfmt_elf.c | 36 +++++++-----
> fs/binfmt_elf_fdpic.c | 17 +++---
> include/linux/regset.h | 12 +++-
> 23 files changed, 194 insertions(+), 173 deletions(-)
>
>
> base-commit: 86731a2a651e58953fc949573895f2fa6d456841
For the whole series:
Reviewed-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp>
Regards,
Akihiko Odaki