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From: Al Viro <viro@ZenIV.linux.org.uk>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Stephen Wilson <wilsons@start.ca>, linux-kernel@vger.kernel.org
Subject: Re: Q: x86: add context tag to mark mm when running a task in 32-bit compatibility mode
Date: Tue, 27 Sep 2011 19:32:19 +0100	[thread overview]
Message-ID: <20110927183219.GL2203@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20110927170448.GA15977@redhat.com>

On Tue, Sep 27, 2011 at 07:04:48PM +0200, Oleg Nesterov wrote:
> --- x/arch/x86/kernel/process_64.c
> +++ x/arch/x86/kernel/process_64.c
> @@ -502,10 +502,6 @@ void set_personality_64bit(void)
>  	/* Make sure to be in 64bit mode */
>  	clear_thread_flag(TIF_IA32);
>  
> -	/* Ensure the corresponding mm is not marked. */
> -	if (current->mm)
> -		current->mm->context.ia32_compat = 0;

What happens when 32bit task does exec on 64bit binary?

> -	if (current->mm)
> -		current->mm->context.ia32_compat = 1;
> +	set_bit(MMF_COMPAT, &current->mm->flags);

... assuming current->mm is never NULL here.

  reply	other threads:[~2011-09-27 18:32 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-09-27 17:04 Q: x86: add context tag to mark mm when running a task in 32-bit compatibility mode Oleg Nesterov
2011-09-27 18:32 ` Al Viro [this message]
2011-09-28 15:55   ` Oleg Nesterov
2011-09-28  2:07 ` Stephen Wilson
2011-09-28 15:56   ` Oleg Nesterov
2011-09-28 18:41     ` [PATCH] x86: replace mm_context_t.ia32_compat by MMF_COMPAT Oleg Nesterov
2011-10-07  9:31       ` Johannes Weiner

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