From: Linus Torvalds <torvalds@linux-foundation.org>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Andi Kleen <andi@firstfloor.org>,
"H. Peter Anvin" <hpa@zytor.com>,
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 10:43:33 -0800 (PST) [thread overview]
Message-ID: <alpine.LFD.2.00.1002161041130.4141@localhost.localdomain> (raw)
In-Reply-To: <20100216174437.GA28323@redhat.com>
On Tue, 16 Feb 2010, Oleg Nesterov wrote:
>
> and, following this logic, shouldn't set_personality_64bit() clear
> TS_COMPAT ?
Yes, I think it should. If we come from a 32-bit environment, and execute
a 64-bit binary, I think the execve() environment of the new 64-bit binary
should be _exactly_ the same as if it was executed from a 64-bit one.
Of course, it's entirely possible that TS_COMPAT simply doesn't matter at
all in either context, but I do think that we should strive for "the
binary does exactly the same regardless of whether it was started from
a 32-bit or a 64-bit binary".
And the best way to guarantee that is to make sure that we really do set
the environment to the same thing. So yes, set_personality_64bit() should
clear all the 32-bit compat bits.
Linus
next prev parent reply other threads:[~2010-02-16 18:44 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
2010-02-17 15:40 ` Oleg Nesterov
2010-02-16 18:43 ` Linus Torvalds [this message]
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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