From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Ilya Zykov <ilya@ilyx.ru>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Alan Cox <alan@linux.intel.com>,
linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org
Subject: Re: [PATCH] tty: Correct tty buffer flush.
Date: Tue, 4 Dec 2012 14:12:23 +0000 [thread overview]
Message-ID: <20121204141223.2ecb0f76@pyramind.ukuu.org.uk> (raw)
In-Reply-To: <50BDF661.30303@ilyx.ru>
On Tue, 04 Dec 2012 17:10:57 +0400
Ilya Zykov <ilya@ilyx.ru> wrote:
> The root of problem is carelessly zeroing pointer(in function __tty_buffer_flush()),
> when another thread can use it. It can be cause of "NULL pointer dereference".
> Main idea of the patch, this is never free last (struct tty_buffer) in the active buffer.
> Only flush the data for ldisc(tty->buf.head->read = tty->buf.head->commit).
> At that moment driver can collect(write) data in buffer without conflict.
> It is repeat behavior of flush_to_ldisc(), only without feeding data to ldisc.
>
> Also revert:
> commit c56a00a165712fd73081f40044b1e64407bb1875
> tty: hold lock across tty buffer finding and buffer filling
> In order to delete the unneeded locks any more.
>
> Signed-off-by: Ilya Zykov <ilya@ilyx.ru>
Acked-by: Alan Cox <alan@linux.intel.com>
next prev parent reply other threads:[~2012-12-04 14:12 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-04 13:10 [PATCH] tty: Correct tty buffer flush Ilya Zykov
2012-12-04 14:12 ` Alan Cox [this message]
2013-01-16 8:55 ` Ilya Zykov
2013-01-19 0:07 ` Greg Kroah-Hartman
2013-01-19 14:16 ` Ilya Zykov
[not found] ` <CA+icZUXG-srV6i9PaMgdhRG2gCpU4T+VaxhZj_=E4XjAgh8REQ@mail.gmail.com>
2013-01-19 15:47 ` Sedat Dilek
[not found] <50BC76E9.2070703@ilyx.ru>
2013-03-04 19:19 ` Ilya Zykov
2013-03-17 4:06 ` Ben Hutchings
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20121204141223.2ecb0f76@pyramind.ukuu.org.uk \
--to=alan@lxorguk.ukuu.org.uk \
--cc=alan@linux.intel.com \
--cc=gregkh@linuxfoundation.org \
--cc=ilya@ilyx.ru \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-serial@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox