All of lore.kernel.org
 help / color / mirror / Atom feed
From: Ingo Molnar <mingo@kernel.org>
To: Jan Beulich <JBeulich@suse.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
	mingo@elte.hu, tglx@linutronix.de,
	Andrew Morton <akpm@linux-foundation.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	arjan@linux.intel.com, linux@roeck-us.net,
	linux-kernel@vger.kernel.org, hpa@zytor.com
Subject: Re: [PATCH 1/2] x86: unify copy_from_user() size checking
Date: Tue, 29 Oct 2013 11:12:57 +0100	[thread overview]
Message-ID: <20131029101257.GA25953@gmail.com> (raw)
In-Reply-To: <526F971F02000078000FD841@nat28.tlf.novell.com>


* Jan Beulich <JBeulich@suse.com> wrote:

> >>> On 29.10.13 at 10:54, Ingo Molnar <mingo@kernel.org> wrote:
> 
> > * Jan Beulich <JBeulich@suse.com> wrote:
> > 
> >> >>> On 26.10.13 at 12:31, Ingo Molnar <mingo@kernel.org> wrote:
> >> > * Jan Beulich <JBeulich@suse.com> wrote:
> >> >> I'd like to point out though that with __compiletime_object_size()
> >> >> being restricted to gcc before 4.6, the whole construct is going to
> >> >> become more and more pointless going forward. I would question
> >> >> however that commit 2fb0815c9ee6b9ac50e15dd8360ec76d9fa46a2 ("gcc4:
> >> >> disable __compiletime_object_size for GCC 4.6+") was really necessary,
> >> >> and instead this should have been dealt with as is done here from the
> >> >> beginning.
> >> > 
> >> > Can we now revert 2fb0815c9ee6?
> >> 
> >> Actually I'm afraid parisc would first need to follow the changes 
> >> done on x86 here, or else they'd run into (compile time) issues 
> >> (s390 and tile only emit warnings, i.e. would at worst suffer 
> >> cosmetically unless subtrees putting -Werror in place are 
> >> affected).
> > 
> > Given how trivial __compiletime_object_size() is, we could replicate 
> > a (differently named) copy of that in x86 uaccess.h?
> 
> I would never have dared to suggest something like that...
> 
> But if you're fine with that, I can certainly do so. I'd then even 
> wonder whether we shouldn't re-use the same name,
> #undef-ing the one we got from compiler*.h - after all the
> goal would be for compiler-gcc4.h to change in exactly that way.

Yeah, I think that would work.

> > This is something that would be pretty platform dependent 
> > anyway.
> 
> Why do you think so? That's entirely a compiler construct.

Yeah, what I mean is that the progress of kernel support here is 
done on a per platform manner anyway, the 'generic' piece in 
compiler.h and compiler-gcc4.h is tiny and more of a hindrance than 
a useful generalization/sharing of code...

Thanks,

	Ingo

  reply	other threads:[~2013-10-29 10:13 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-10-21  8:43 [PATCH 1/2] x86: unify copy_from_user() size checking Jan Beulich
2013-10-26 10:31 ` Ingo Molnar
2013-10-26 16:05   ` Guenter Roeck
2013-10-28  7:23   ` Jan Beulich
2013-10-28 10:55     ` Ingo Molnar
2013-10-29  9:43   ` Jan Beulich
2013-10-29  9:54     ` Ingo Molnar
2013-10-29 10:08       ` Jan Beulich
2013-10-29 10:12         ` Ingo Molnar [this message]
2013-11-25 16:15           ` [PATCH] x86: override __compiletime_object_size() Jan Beulich
2013-11-27 14:03             ` Ingo Molnar
2013-11-27 14:20               ` Jan Beulich
2013-11-27 14:36                 ` Ingo Molnar
2013-10-26 13:51 ` [tip:x86/asm] x86: Unify copy_from_user() size checking tip-bot for Jan Beulich

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=20131029101257.GA25953@gmail.com \
    --to=mingo@kernel.org \
    --cc=JBeulich@suse.com \
    --cc=a.p.zijlstra@chello.nl \
    --cc=akpm@linux-foundation.org \
    --cc=arjan@linux.intel.com \
    --cc=hpa@zytor.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux@roeck-us.net \
    --cc=mingo@elte.hu \
    --cc=tglx@linutronix.de \
    --cc=torvalds@linux-foundation.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.