linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Borislav Petkov <bp@amd64.org>
To: Amit Shah <amit.shah@redhat.com>
Cc: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com>,
	linux-kernel@vger.kernel.org,
	Anthony Liguori <anthony@codemonkey.ws>,
	Arnd Bergmann <arnd@arndb.de>, Borislav Petkov <bp@amd64.org>,
	"Franch Ch. Eigler" <fche@redhat.com>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Herbert Xu <herbert@gondor.hengli.com.au>,
	Ingo Molnar <mingo@redhat.com>,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	virtualization@lists.linux-foundation.org, qemu-devel@nongnu.org,
	yrl.pp-manager.tt@hitachi.com,
	Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Subject: Re: [RFC PATCH 2/6] virtio/console: Add a failback for unstealable pipe buffer
Date: Thu, 9 Aug 2012 11:24:46 +0200	[thread overview]
Message-ID: <20120809092446.GB27761@aftab.osrc.amd.com> (raw)
In-Reply-To: <20120809090312.GH3280@amit.redhat.com>

On Thu, Aug 09, 2012 at 02:33:12PM +0530, Amit Shah wrote:
> > @@ -807,9 +807,31 @@ static int pipe_to_sg(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
> >  
> >  		len = min(buf->len, sd->len);
> >  		sg_set_page(&(sgl->sg[sgl->n]), buf->page, len, buf->offset);
> > -		sgl->n++;
> > -		sgl->len += len;
> > +	} else {
> > +		/* Failback to copying a page */
> > +		struct page *page = alloc_page(GFP_KERNEL);
> 
> I prefer zeroing out the page.  If there's not enough data to be
> filled in the page, the remaining data can be leaked to the host.

get_zeroed_page()?

-- 
Regards/Gruss,
Boris.

Advanced Micro Devices GmbH
Einsteinring 24, 85609 Dornach
GM: Alberto Bozzo
Reg: Dornach, Landkreis Muenchen
HRB Nr. 43632 WEEE Registernr: 129 19551

  reply	other threads:[~2012-08-09  9:24 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-07-24  2:36 [RFC PATCH 0/6] virtio-trace: Support virtio-trace Yoshihiro YUNOMAE
2012-07-24  2:37 ` [RFC PATCH 1/6] virtio/console: Add splice_write support Yoshihiro YUNOMAE
2012-08-09  9:00   ` Amit Shah
2012-08-09  9:12     ` Masami Hiramatsu
2012-07-24  2:37 ` [RFC PATCH 2/6] virtio/console: Add a failback for unstealable pipe buffer Yoshihiro YUNOMAE
2012-08-09  9:03   ` Amit Shah
2012-08-09  9:24     ` Borislav Petkov [this message]
2012-08-09  9:24     ` Masami Hiramatsu
2012-08-09  9:55       ` Amit Shah
2012-08-09  9:58         ` Avi Kivity
2012-08-09 10:14           ` Amit Shah
2012-08-09 12:35       ` Steven Rostedt
2012-07-24  2:37 ` [RFC PATCH 3/6] virtio/console: Wait until the port is ready on splice Yoshihiro YUNOMAE
2012-07-24  2:37 ` [RFC PATCH 4/6] ftrace: Allow stealing pages from pipe buffer Yoshihiro YUNOMAE
2012-07-30 22:12   ` Steven Rostedt
2012-07-24  2:37 ` [RFC PATCH 5/6] virtio/console: Allocate scatterlist according to the current pipe size Yoshihiro YUNOMAE
2012-07-24  2:37 ` [RFC PATCH 6/6] tools: Add guest trace agent as a user tool Yoshihiro YUNOMAE
2012-07-24  3:27 ` [RFC PATCH 0/6] virtio-trace: Support virtio-trace Masami Hiramatsu
2012-07-24 10:02 ` Stefan Hajnoczi
2012-07-24 11:03   ` Masami Hiramatsu
2012-07-24 11:19     ` Yoshihiro YUNOMAE
2012-07-24 13:41       ` Stefan Hajnoczi
2012-07-25  9:13         ` Yoshihiro YUNOMAE
2012-07-26 10:52           ` Stefan Hajnoczi
2012-07-24 13:43     ` Stefan Hajnoczi
2012-07-24 20:26 ` [Qemu-devel] " Blue Swirl
2012-07-25  8:15   ` Masami Hiramatsu
2012-07-27 18:58     ` Blue Swirl
2012-07-26 11:35 ` Amit Shah
2012-07-27  8:55   ` Yoshihiro YUNOMAE
2012-07-27  9:43     ` Amit Shah
2012-07-31  0:52       ` Yoshihiro YUNOMAE
2012-08-09 10:16 ` Amit Shah
2012-08-21  2:17   ` Rusty Russell
2012-08-21  5:09     ` Amit Shah

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=20120809092446.GB27761@aftab.osrc.amd.com \
    --to=bp@amd64.org \
    --cc=amit.shah@redhat.com \
    --cc=anthony@codemonkey.ws \
    --cc=arnd@arndb.de \
    --cc=fche@redhat.com \
    --cc=fweisbec@gmail.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=herbert@gondor.hengli.com.au \
    --cc=linux-kernel@vger.kernel.org \
    --cc=masami.hiramatsu.pt@hitachi.com \
    --cc=mathieu.desnoyers@efficios.com \
    --cc=mingo@redhat.com \
    --cc=qemu-devel@nongnu.org \
    --cc=rostedt@goodmis.org \
    --cc=virtualization@lists.linux-foundation.org \
    --cc=yoshihiro.yunomae.ez@hitachi.com \
    --cc=yrl.pp-manager.tt@hitachi.com \
    /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;
as well as URLs for NNTP newsgroup(s).