From: rajathnr@gmail.com (Rajath N R)
To: kernelnewbies@lists.kernelnewbies.org
Subject: Semaphore
Date: Tue, 28 Feb 2012 13:53:17 +0530 [thread overview]
Message-ID: <CACvbU7pVVapOUsp=NGpSWrx55Qaus-pomV4EnNgW5UMuxX_uCg@mail.gmail.com> (raw)
In-Reply-To: <20120224102459.GS10865@thebe.jupiter.sigsegv.be>
Hi,
I think santosh is talking about user land IPC (semget). thread/process
which has acquired a sema lock/sem down using semop(2) syscall.
Thanks,
Rajath
On Fri, Feb 24, 2012 at 3:54 PM, Kristof Provost <kristof@sigsegv.be> wrote:
> On 2012-02-24 12:15:03 (+0200), Kosta Zertsekel <zertsekel@gmail.com>
> wrote:
> > I think of user land program opening a socket and crashing on
> > segmentation fault.
> > In code 'socket' syscall does:
> > sock_map_fd --> sock_alloc_file --> alloc_file --> ... get lost ...
> > Where exactly in this case lock is held - I mean the lock that gets
> > released when user land process dies?
>
> In this case there doesn't appear to be any lock. The sock_map_fd
> function is most probably called from the socket syscall. This call
> isn't locked. Multiple processes can be in the socket syscall at the
> same time.
> There certainly won't be a (kernel) lock which is held between two system
> calls.
>
> Regards,
> Kristof
>
>
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> Kernelnewbies mailing list
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>
--
Thanks & Regards,
Rajath N R
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next prev parent reply other threads:[~2012-02-28 8:23 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-21 13:47 Semaphore SaNtosh kuLkarni
2012-02-21 15:12 ` Semaphore Konstantin Zertsekel
2012-02-21 16:14 ` Semaphore Dave Hylands
2012-02-22 9:01 ` Semaphore Konstantin Zertsekel
2012-02-22 9:48 ` Semaphore Kristof Provost
2012-02-22 11:53 ` Semaphore Anuz Pratap Singh Tomar
2012-02-22 12:11 ` Semaphore Kristof Provost
2012-02-22 14:31 ` Semaphore Sri Ram Vemulpali
2012-02-23 6:12 ` Semaphore SaNtosh kuLkarni
2012-02-24 7:07 ` Semaphore Kosta Zertsekel
2012-02-24 9:04 ` Semaphore Kristof Provost
2012-02-24 9:25 ` Semaphore Kosta Zertsekel
2012-02-24 9:28 ` Semaphore Kristof Provost
2012-02-24 10:15 ` Semaphore Kosta Zertsekel
2012-02-24 10:24 ` Semaphore Kristof Provost
2012-02-28 8:23 ` Rajath N R [this message]
2012-02-28 8:33 ` Semaphore Rajath N R
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