From: kanoj@google.engr.sgi.com (Kanoj Sarcar)
To: Manfred Spraul <manfreds@colorfullife.com>
Cc: viro@math.psu.edu, sct@redhat.com, andrea@suse.de,
linux-kernel@vger.rutgers.edu, mingo@chiara.csoma.elte.hu,
torvalds@transmeta.com, linux-mm@kvack.org
Subject: Re: [more fun] Re: locking question: do_mmap(), do_munmap()
Date: Wed, 13 Oct 1999 11:34:32 -0700 (PDT) [thread overview]
Message-ID: <199910131834.LAA38192@google.engr.sgi.com> (raw)
In-Reply-To: <38043651.FA0BA70E@colorfullife.com> from "Manfred Spraul" at Oct 13, 99 09:35:45 am
>
> Alexander Viro wrote:
> > Another one: ptrace_readdata() -> access_process_vm() -> find_extend_vma()
> > -> make_pages_present(). Again, no mmap_sem in sight.
Actually, I think access_process_vm() does get mmap_sem, although
after doing the find_extend_vma, which should be fixed. I will take
care of it in my patch.
>
> Can 2 processes ptrace() each other? If yes, then this will lock-up if
> you acquire the mmap_sem.
>
Theoretically, there is no problem with 2 processes ptrace()ing each other.
IMO, no deadlock is possible in the approach I posted.
Kanoj
> --
> Manfred
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
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>
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next prev parent reply other threads:[~1999-10-13 18:34 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <Pine.LNX.4.10.9910101713010.364-100000@alpha.random>
1999-10-10 15:52 ` Manfred Spraul
1999-10-10 16:07 ` Alexander Viro
1999-10-10 16:25 ` Alexander Viro
1999-10-10 16:45 ` Manfred Spraul
1999-10-10 17:25 ` Alexander Viro
1999-10-10 17:12 ` Andrea Arcangeli
1999-10-10 17:48 ` Alexander Viro
1999-10-10 18:42 ` Manfred Spraul
1999-10-10 19:03 ` Alexander Viro
1999-10-10 21:31 ` Manfred Spraul
1999-10-10 21:53 ` Andrea Arcangeli
1999-10-10 22:34 ` Alexander Viro
1999-10-10 23:28 ` Andrea Arcangeli
1999-10-11 15:50 ` Stephen C. Tweedie
1999-10-11 16:05 ` Alexander Viro
1999-10-11 18:02 ` Manfred Spraul
1999-10-11 19:07 ` Kanoj Sarcar
1999-10-11 22:23 ` Stephen C. Tweedie
1999-10-13 1:25 ` Kanoj Sarcar
1999-10-13 7:32 ` Manfred Spraul
1999-10-15 9:58 ` Ralf Baechle
1999-10-15 17:50 ` Kanoj Sarcar
1999-10-13 10:45 ` Stephen C. Tweedie
1999-10-11 20:15 ` Stephen C. Tweedie
1999-10-11 21:14 ` Manfred Spraul
1999-10-11 21:37 ` Alexander Viro
1999-10-11 22:13 ` Manfred Spraul
1999-10-11 22:22 ` Stephen C. Tweedie
1999-10-11 23:01 ` Alexander Viro
1999-10-12 14:06 ` [more fun] " Alexander Viro
1999-10-13 7:35 ` Manfred Spraul
1999-10-13 18:34 ` Kanoj Sarcar [this message]
1999-10-13 10:16 ` Stephen C. Tweedie
1999-10-11 20:13 ` Stephen C. Tweedie
1999-10-11 21:40 ` Alexander Viro
1999-10-11 22:20 ` Stephen C. Tweedie
1999-10-11 22:31 ` Alexander Viro
1999-10-13 10:25 ` Stephen C. Tweedie
1999-10-11 15:47 ` Stephen C. Tweedie
1999-10-11 15:43 ` Stephen C. Tweedie
1999-10-10 16:56 ` Andrea Arcangeli
1999-10-11 15:41 ` Stephen C. Tweedie
1999-10-11 15:52 ` Alexander Viro
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