From: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
To: pageexec@freemail.hu
Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
Andi Kleen <andi@firstfloor.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [patch 06/11] Text Edit Lock - Alternative code for x86
Date: Thu, 6 Dec 2007 09:44:32 -0500 [thread overview]
Message-ID: <20071206144431.GA11846@Krystal> (raw)
In-Reply-To: <475804F5.4781.35D49FA@pageexec.freemail.hu>
* pageexec@freemail.hu (pageexec@freemail.hu) wrote:
> On 5 Dec 2007 at 21:02, Mathieu Desnoyers wrote:
>
> > Fix a memcpy that should be a text_poke (in apply_alternatives).
> >
> > Use kernel_wp_save/kernel_wp_restore in text_poke to support DEBUG_RODATA
> > correctly and so the CPU HOTPLUG special case can be removed.
> >
> > Add text_poke_early, for alternatives and paravirt boot-time and module load
> > time patching.
> >
> > Notes:
> > - we use a macro for kernel_wp_save/restore to mimic local_irq_save/restore: the
> > argument is passed without &.
>
> sorry to chime in again, but lately i've been thinking that the
> cr0 argument is not really needed if one can ensure that calls
> to the kernel open/close macros won't nest (i checked and even
> in the PaX case it's easy to ensure, even desirable in fact).
>
> in your case it's also true for now and i can't think of a situation
> where you'd really want to nest in the future (that'd mean opening
> up the kernel while some complex piece of code runs, more complex
> than a mere memset at least ;-). what do you think?
>
It is correct to assume that the WP bit will always be activated, in
every configuration, even though we don't use the DEBUG_RODATA ?
--
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
next prev parent reply other threads:[~2007-12-06 14:44 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-12-06 2:02 [patch 00/11] Text Edit Lock for 2.6.24-rc4-git3 Mathieu Desnoyers
2007-12-06 2:02 ` [patch 01/11] Kprobes - use a mutex to protect the instruction pages list Mathieu Desnoyers
2007-12-06 2:02 ` [patch 02/11] Kprobes - do not use kprobes mutex in arch code Mathieu Desnoyers
2007-12-06 2:02 ` [patch 03/11] Kprobes - declare kprobe_mutex static Mathieu Desnoyers
2007-12-06 2:02 ` [patch 04/11] Add INIT_ARRAY() to kernel.h Mathieu Desnoyers
2007-12-06 2:02 ` [patch 05/11] Text Edit Lock - Architecture Independent Code Mathieu Desnoyers
2007-12-06 2:02 ` [patch 06/11] Text Edit Lock - Alternative code for x86 Mathieu Desnoyers
2007-12-06 12:19 ` pageexec
2007-12-06 14:21 ` Mathieu Desnoyers
2007-12-06 14:44 ` Mathieu Desnoyers [this message]
2007-12-06 13:58 ` pageexec
2007-12-06 15:17 ` [patch 06/11] Text Edit Lock - Alternative code for x86 (update) Mathieu Desnoyers
2007-12-06 2:02 ` [patch 07/11] Text Edit Lock - kprobes architecture independent support Mathieu Desnoyers
2007-12-06 2:02 ` [patch 08/11] Text Edit Lock - kprobes x86_32 Mathieu Desnoyers
2007-12-06 2:02 ` [patch 09/11] Text Edit Lock - kprobes x86_64 Mathieu Desnoyers
2007-12-06 2:02 ` [patch 10/11] Text Edit Lock - x86_32 standardize debug rodata Mathieu Desnoyers
2007-12-06 2:02 ` [patch 11/11] Text Edit Lock - x86_64 " Mathieu Desnoyers
2007-12-06 9:47 ` [patch 00/11] Text Edit Lock for 2.6.24-rc4-git3 Heiko Carstens
2007-12-06 14:07 ` Mathieu Desnoyers
-- strict thread matches above, loose matches on Subject: below --
2007-11-13 18:46 [patch 00/11] Text Edit Lock Mathieu Desnoyers
2007-11-13 18:46 ` [patch 06/11] Text Edit Lock - Alternative code for x86 Mathieu Desnoyers
2007-11-13 20:54 ` pageexec
2007-11-13 22:10 ` Mathieu Desnoyers
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