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From: Jonathan Corbet <corbet@lwn.net>
To: Nathaniel Yazdani <n1ght.4nd.d4y@gmail.com>
Cc: viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH for-next 3/4] epoll: struct epoll support
Date: Mon, 24 Feb 2014 11:59:07 -0700
Message-ID: <20140224115907.07092911@lwn.net> (raw)
In-Reply-To: <1393206162-18151-4-git-send-email-n1ght.4nd.d4y@gmail.com>

So I was just looking things over quickly, and something jumped out at
me.  In ep_control():

> +	} else if (!(*io) && epi) {
> +		/* delete this eventpoll entry */
> +		if (is_file_epoll(target)) {
> +			tep = target->private_data;
> +			mutex_lock_nested(&tep->mtx, 1);
> +		}
> +		if (is_file_epoll(target))
> +			mutex_lock_nested(&tep->mtx, 1);

How could that possibly work?  I can't imagine tep->mtx is going to
react well to being locked a second time...

jon

  reply index

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-02-24  1:42 [RFC PATCH for-next 0/4] epoll: combined control/wait syscall Nathaniel Yazdani
2014-02-24  1:42 ` [RFC PATCH for-next 1/4] epoll: struct epoll userspace definiton Nathaniel Yazdani
2014-02-24  5:29   ` Eric Wong
     [not found]     ` <CAJ3m7Bq1y+MLn=HFY3AADnVc2HK31+WANahiYLUcdBw=hh_2pg@mail.gmail.com>
     [not found]       ` <20140225101527.GA9963@dcvr.yhbt.net>
2014-02-26  0:13         ` Nathaniel Yazdani
2014-02-24  1:42 ` [RFC PATCH for-next 2/4] epoll: epoll() syscall declaration Nathaniel Yazdani
2014-02-24  5:32   ` Eric Wong
2014-02-24  5:44     ` Nathaniel Yazdani
2014-02-25 10:30       ` Eric Wong
2014-02-25 23:44         ` Nathaniel Yazdani
2014-02-24  1:42 ` [RFC PATCH for-next 3/4] epoll: struct epoll support Nathaniel Yazdani
2014-02-24 18:59   ` Jonathan Corbet [this message]
2014-02-24 19:24     ` Nathaniel Yazdani
2014-02-24  1:42 ` [RFC PATCH for-next 4/4] epoll: epoll() syscall definition Nathaniel Yazdani
2014-02-25 10:21   ` Eric Wong
2014-02-25 23:46     ` Nathaniel Yazdani

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