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Re: [PATCH -tip 1/3] Pass mm->flags to binfmt core_dump for bitflag consistency
- From: Roland McGrath <roland at redhat dot com>
- To: Masami Hiramatsu <mhiramat at redhat dot com>
- Cc: Ingo Molnar <mingo at elte dot hu>, 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>, Andrew Morton <akpm at linux-foundation dot org>, Oleg Nesterov <oleg at redhat dot com>
- Date: Fri, 13 Nov 2009 15:16:02 -0800 (PST)
- Subject: Re: [PATCH -tip 1/3] Pass mm->flags to binfmt core_dump for bitflag consistency
- References: <20091113225226.15079.90813.stgit@harusame>
To clarify, proc_coredump_filter_write() is the one place that can change
mm->flags during a core dump. I don't think any other is possible while
all the other tasks sharing that mm are prevented from running. Is there
any other way that mm->flags might change during do_coredump()?
I don't see anything wrong with this change. But (assuming that is the
only case), there is another approach we could take instead. That is,
have proc_coredump_filter_write() do:
down_read(&mm->mmap_sem);
ret = mm->core_state ? -EBUSY : 0;
up_read(&mm->mmap_sem);
Thanks,
Roland