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.
next prev parent 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
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