# \[GIT PULL\] per signal\_struct coredumps

- List: linux-api
- 3 messages, 3 authors
- Page: https://ratatoskr.run/linux-api/2021/11/1562162/t

## \[GIT PULL\] per signal\_struct coredumps

- From: Eric W. Biederman \<hidden\>
- Date: 2021-11-03 19:07:48 
- Message: https://ratatoskr.run/linux-api/2021/11/1562162.md

```text

Linus,

Please pull the per_signal_struct_coredumps-for-v5.16 branch from the git tree:

  git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace.git per_signal_struct_coredumps-for-v5.16

  HEAD: 3f66f86bfed33dee2e9c1d0e14486915bb0750b0 per signal_struct coredumps


Current coredumps are mixed up with the exit code, the signal handling
code, and the ptrace code making coredumps much more complicated than
necessary and difficult to follow.

This series of changes starts with ptrace_stop and cleans it up,
making it easier to follow what is happening in ptrace_stop.
Then cleans up the exec interactions with coredumps.
Then cleans up the coredump interactions with exit.
Then the coredump interactions with the signal handling code is cleaned
up.

The first and last changes are bug fixes for minor bugs.

I believe the fact that vfork followed by execve can kill the process
the called vfork if exec fails is sufficient justification to change
the userspace visible behavior.

In previous discussions some of these changes were organized differently
and individually appeared to make the code base worse.  As currently
written I believe they all stand on their own as cleanups and bug fixes.

Which means that even if the worst should happen and the last change
needs to be reverted for some unimaginable reason, the code base will
still be improved.

If the worst does not happen there are a more cleanups that can be made.
Signals that generate coredumps can easily become eligible for short
circuit delivery in complete_signal.  The entire rendezvous for
generating a coredump can move into get_signal.  The function
force_sig_info_to_task be written in a way that does not modify the
signal handling state of the target task (because coredumps are eligible
for short circuit delivery).  Many of these future cleanups can be done
another way but nothing so cleanly as if coredumps become per
signal_struct.

Eric W. Biederman (7):
      signal: Remove the bogus sigkill_pending in ptrace_stop
      ptrace: Remove the unnecessary arguments from arch_ptrace_stop
      exec: Check for a pending fatal signal instead of core_state
      exit: Factor coredump_exit_mm out of exit_mm
      coredump:  Don't perform any cleanups before dumping core
      coredump: Limit coredumps to a single thread group
      per signal_struct coredumps

 arch/ia64/include/asm/ptrace.h  |  4 +-
 arch/sparc/include/asm/ptrace.h |  8 ++--
 fs/binfmt_elf.c                 |  4 +-
 fs/binfmt_elf_fdpic.c           |  2 +-
 fs/coredump.c                   | 88 ++++++-----------------------------------
 fs/exec.c                       | 14 +++----
 fs/proc/array.c                 |  6 +--
 include/linux/mm_types.h        | 13 ------
 include/linux/ptrace.h          | 22 +++++------
 include/linux/sched.h           |  1 +
 include/linux/sched/signal.h    | 13 ++++++
 kernel/exit.c                   | 76 +++++++++++++++++++----------------
 kernel/fork.c                   |  4 +-
 kernel/signal.c                 | 49 ++++-------------------
 mm/debug.c                      |  4 +-
 mm/oom_kill.c                   |  6 +--
 16 files changed, 106 insertions(+), 208 deletions(-)

Link: https://lkml.kernel.org/r/87v92qx2c6.fsf@disp2133
Signed-off-by: "Eric W. Biederman" <redacted>

Eric
```

## Re: \[GIT PULL\] per signal\_struct coredumps

- From: pr-tracker-bot@kernel.org
- Date: 2021-11-03 19:32:59 
- Message: https://ratatoskr.run/linux-api/2021/11/1562176.md

```text
The pull request you sent on Wed, 03 Nov 2021 14:07:36 -0500:

> git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace.git per_signal_struct_coredumps-for-v5.16

has been merged into torvalds/linux.git:
https://git.kernel.org/torvalds/c/a602285ac11b019e9ce7c3907328e9f95f4967f0

Thank you!

-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/prtracker.html
```

## Re: \[GIT PULL\] per signal\_struct coredumps

- From: Linus Torvalds \<torvalds@linux-foundation.org\>
- Date: 2021-11-03 19:35:07 
- Message: https://ratatoskr.run/linux-api/2021/11/1562180.md

```text
On Wed, Nov 3, 2021 at 12:07 PM Eric W. Biederman [ref] wrote:
>
> Please pull the per_signal_struct_coredumps-for-v5.16 branch

I've pulled it, but I'm not convinced about that odd extra merge
commit that contains the commentary.

That's what signed tags are for, and they have that explanation that
then makes it into the merge - plus they have the crypto signature to
show it all comes from you.

So that would have been the much better model than a fake extra merge.

But at least that extra merge did have explanations, so at least it
doesn't trigger me on _that_ level.

               Linus
```