linux-next.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Theodore Ts'o <tytso@mit.edu>
To: Randy Dunlap <rdunlap@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>,
	linux-next@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>,
	Kees Cook <keescook@chromium.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: Re: [PATCH -next] random: needs linux/device.h for struct device
Date: Mon, 4 Nov 2013 11:32:48 -0500	[thread overview]
Message-ID: <20131104163248.GC7108@thunk.org> (raw)
In-Reply-To: <5277C5F8.3080609@infradead.org>

On Mon, Nov 04, 2013 at 08:06:16AM -0800, Randy Dunlap wrote:
> on x86_64:
> 
> drivers/char/random.c: In function 'add_device_attach_randomness':
> drivers/char/random.c:837:41: error: dereferencing pointer to incomplete type
> 
> 
> need to #include <linux/device.h> for struct device, I think.

The patch which introduced this is going to be dropped from the random
tree because I'm concerned the amount of entropy that will be added
will get overstated, especially on CPU's that don't have cycle
counters (ARM and MIPS in particular).

I plan to rework it to be safer, although I suspect using device
attach times simply won't be doable on CPU's that don't have a cycle
counter register, or some other fine-grained, highly light-weight
timer (I can't use the clocksource infrastructure since those time
sources are not necessarily available during early boot, and there is
no guarantee how expensive some of the clock sources might be; some
can be quite expensive, <cough> IBM X440 servers with their
"scalability cable" <cough>).

	   	       	    	    	 - Ted

      reply	other threads:[~2013-11-04 16:32 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-11-04  6:59 linux-next: Tree for Nov 4 Stephen Rothwell
2013-11-04 16:06 ` [PATCH -next] random: needs linux/device.h for struct device Randy Dunlap
2013-11-04 16:32   ` Theodore Ts'o [this message]

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=20131104163248.GC7108@thunk.org \
    --to=tytso@mit.edu \
    --cc=gregkh@linuxfoundation.org \
    --cc=keescook@chromium.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-next@vger.kernel.org \
    --cc=rdunlap@infradead.org \
    --cc=sfr@canb.auug.org.au \
    /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).