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Re: [PATCH -tip 1/3] Pass mm->flags to binfmt core_dump for bitflag consistency
- From: Ingo Molnar <mingo at elte dot hu>
- To: Andrew Morton <akpm at linux-foundation dot org>
- Cc: Masami Hiramatsu <mhiramat at redhat dot com>, lkml <linux-kernel at vger dot kernel dot org>, systemtap <systemtap at sources dot redhat dot com>, DLE <dle-develop at lists dot sourceforge dot net>, Hidehiro Kawai <hidehiro dot kawai dot ez at hitachi dot com>, Oleg Nesterov <oleg at redhat dot com>, Roland McGrath <roland at redhat dot com>
- Date: Sat, 14 Nov 2009 00:24:57 +0100
- Subject: Re: [PATCH -tip 1/3] Pass mm->flags to binfmt core_dump for bitflag consistency
- References: <20091113225226.15079.90813.stgit@harusame> <20091113150904.56c15910.akpm@linux-foundation.org>
* Andrew Morton <akpm@linux-foundation.org> wrote:
> On Fri, 13 Nov 2009 17:52:27 -0500
> Masami Hiramatsu <mhiramat@redhat.com> wrote:
>
> > Pass mm->flags to binfmt core_dump for bitflag consistency.
> > Since mm->flags bit flags is not protected by locks, it will be
> > changed while dumping core. This patch copies mm->flags to a
> > mm_flags local variable at the beginning of do_coredump() and
> > use it while dumping. mm_flags also includes dump_filter which
> > filters elf sections from core file in elf_core_dump().
> > So, this patch also passes mm_flags to each binfmt->core_dump().
>
> I can kind-of guess the answer, but it would be much more reliable if
> we were to hear this from yourself:
>
> Why did you write this patch? What problem is being observed?
i'm not Masami so i'm only guessing that while writing the tracepoint a
race got noticed but that otherwise there's no big practical effect,
'just' a cleanliness problem fixed.
Ingo