[v2,0/5] elf: Define note name macros

Message

Akihiko Odaki Jan. 4, 2025, 2:38 p.m. UTC

elf.h had a comment saying:
> Notes used in ET_CORE. Architectures export some of the arch register
> sets using the corresponding note types via the PTRACE_GETREGSET and
> PTRACE_SETREGSET requests.
> The note name for these types is "LINUX", except NT_PRFPREG that is
> named "CORE".

However, NT_PRSTATUS is also named "CORE". It is also unclear what
"these types" refers to.

To fix these problems, define a name for each note type. The added
definitions are macros so the kernel and userspace can directly refer to
them.

Signed-off-by: Akihiko Odaki <[e-mail]>
---
Changes in v2:
- Added a macro definition for each note type instead of trying to
  describe in a comment.
- Link to v1: https://lore.kernel.org/r/[e-mail]

---
Akihiko Odaki (5):
      elf: Define note name macros
      binfmt_elf: Use note name macros
      powwerpc: Use note name macros
      crash: Use note name macros
      crash: Remove KEXEC_CORE_NOTE_NAME

 arch/powerpc/kernel/fadump.c               |  2 +-
 arch/powerpc/platforms/powernv/opal-core.c |  8 +--
 arch/s390/kernel/crash_dump.c              |  2 +-
 fs/binfmt_elf.c                            | 21 ++++----
 fs/binfmt_elf_fdpic.c                      |  8 +--
 fs/proc/kcore.c                            | 12 ++---
 include/linux/kexec.h                      |  2 -
 include/linux/vmcore_info.h                |  3 +-
 include/uapi/linux/elf.h                   | 86 ++++++++++++++++++++++++++++--
 kernel/crash_core.c                        |  2 +-
 10 files changed, 111 insertions(+), 35 deletions(-)
---
base-commit: a32e14f8aef69b42826cf0998b068a43d486a9e9
change-id: 20241210-elf-b80ea3949c39

Best regards,

Comments

Baoquan He Jan. 6, 2025, 6:07 a.m. UTC | #1

On 01/04/25 at 11:38pm, Akihiko Odaki wrote:
> elf.h had a comment saying:
> > Notes used in ET_CORE. Architectures export some of the arch register
> > sets using the corresponding note types via the PTRACE_GETREGSET and
> > PTRACE_SETREGSET requests.
> > The note name for these types is "LINUX", except NT_PRFPREG that is
> > named "CORE".
> 
> However, NT_PRSTATUS is also named "CORE". It is also unclear what
> "these types" refers to.
> 
> To fix these problems, define a name for each note type. The added
> definitions are macros so the kernel and userspace can directly refer to
> them.
> 
> Signed-off-by: Akihiko Odaki <[e-mail]>
> ---
> Changes in v2:
> - Added a macro definition for each note type instead of trying to
>   describe in a comment.
> - Link to v1: https://lore.kernel.org/r/[e-mail]

The entire patchset looks good to me, thx.

Acked-by: Baoquan He <[e-mail]>

Dave Martin Jan. 6, 2025, 3:23 p.m. UTC | #2

Hi,

On Sat, Jan 04, 2025 at 11:38:33PM +0900, Akihiko Odaki wrote:
> elf.h had a comment saying:
> > Notes used in ET_CORE. Architectures export some of the arch register
> > sets using the corresponding note types via the PTRACE_GETREGSET and
> > PTRACE_SETREGSET requests.
> > The note name for these types is "LINUX", except NT_PRFPREG that is
> > named "CORE".
> 
> However, NT_PRSTATUS is also named "CORE". It is also unclear what
> "these types" refers to.
> 
> To fix these problems, define a name for each note type. The added
> definitions are macros so the kernel and userspace can directly refer to
> them.
> 
> Signed-off-by: Akihiko Odaki <[e-mail]>

Should this be Cc'd at least to the GNU binutils or gdb folks?
Also the glibc and elfutils projects, both of which maintain a version
of elf.h.  They may have their own view on the best way to approach
this issue.

If cross-posting to other project mailing lists, it might make sense to
add a bit more background explaining the motivation for the change.

[...]

Cheers
---Dave