All of lore.kernel.org
 help / color / mirror / Atom feed
From: "H. Peter Anvin" <hpa@zytor.com>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Andi Kleen <andi@firstfloor.org>,
	Roland McGrath <roland@redhat.com>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/3] x86: set_personality_ia32() abuses TS_COMPAT
Date: Tue, 16 Feb 2010 09:51:03 -0800	[thread overview]
Message-ID: <4B7ADB07.1050500@zytor.com> (raw)
In-Reply-To: <20100216174437.GA28323@redhat.com>

On 02/16/2010 09:44 AM, Oleg Nesterov wrote:
> On 02/16, Linus Torvalds wrote:
>>
>> And after we have switched to 32-bit mode, we _are_ inside a 32-bit system
>> call: the execve has "changed" from a 64-bit one to a 32-bit one.
>>
>> So I really don't understand why you dislike TS_COMPAT here.
> 
> and, following this logic, shouldn't set_personality_64bit() clear
> TS_COMPAT ?
> 

It's quite possible it should... I haven't dug into if that isn't either
done elsewhere or isn't done for some other reason.  This would be worth
looking into.

> OK, in any case I do not claim we need fixes. Just I am confused.

Trying to understand the code is good.  However, you seem to have
started out with a point of view that we should have the minimal set of
state changes possible instead of keeping state as self-consistent as
possible.  Invariants are a Very Good Thing.  Documented invariants are
even better ;)

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.


  reply	other threads:[~2010-02-16 17:51 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-02-15 16:17 x86: get rid of the insane TIF_ABI_PENDING bit Oleg Nesterov
2010-02-15 16:23 ` H. Peter Anvin
2010-02-15 16:50   ` Oleg Nesterov
2010-02-15 18:06     ` H. Peter Anvin
2010-02-15 18:52       ` Oleg Nesterov
2010-02-15 19:07 ` H. Peter Anvin
2010-02-15 19:10 ` H. Peter Anvin
2010-02-15 19:41   ` Roland McGrath
2010-02-15 20:07     ` H. Peter Anvin
2010-02-15 21:14       ` Roland McGrath
2010-02-15 20:43     ` H. Peter Anvin
2010-02-15 21:05       ` Roland McGrath
2010-02-16 10:19       ` Oleg Nesterov
2010-02-16 10:23         ` Andi Kleen
2010-02-16 14:01           ` [PATCH 0/3] Was: " Oleg Nesterov
2010-02-16 14:02             ` [PATCH 1/3] x86: set_personality_ia32() misses force_personality32 Oleg Nesterov
2010-02-16 23:27               ` [tip:x86/urgent] " tip-bot for Oleg Nesterov
2010-02-16 14:02             ` [PATCH 2/3] x86: set_personality_ia32() abuses TS_COMPAT Oleg Nesterov
2010-02-16 15:40               ` Linus Torvalds
2010-02-16 17:16                 ` Oleg Nesterov
2010-02-16 17:38                   ` H. Peter Anvin
2010-02-16 17:44                 ` Oleg Nesterov
2010-02-16 17:51                   ` H. Peter Anvin [this message]
2010-02-17 15:40                     ` Oleg Nesterov
2010-02-16 18:43                   ` Linus Torvalds
2010-02-16 14:03             ` [PATCH 3/3] x86: ELF_PLAT_INIT() shouldn't worry about TIF_IA32 Oleg Nesterov
2010-02-16 14:24               ` Oleg Nesterov

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=4B7ADB07.1050500@zytor.com \
    --to=hpa@zytor.com \
    --cc=akpm@linux-foundation.org \
    --cc=andi@firstfloor.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=oleg@redhat.com \
    --cc=roland@redhat.com \
    --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.