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From: Andi Kleen <ak@suse.de>
To: Zachary Amsden <zach@vmware.com>
Cc: Chuck Ebbert <76306.1226@compuserve.com>,
	Andrew Morton <akpm@osdl.org>, Linus Torvalds <torvalds@osdl.org>,
	linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [patch] i386: remove IOPL check on task switch
Date: Sat, 4 Nov 2006 21:02:12 +0100	[thread overview]
Message-ID: <200611042102.13026.ak@suse.de> (raw)
In-Reply-To: <454CEC5C.2050507@vmware.com>

 
> Ok, checking shows Linus put it back to stop NT leakage. 

It is also needed to stop AC leakage

> This is  
> correct, but unlikely.  Would be nice to avoid it unless absolutely 
> necessary.  Perhaps xor eflags old and new and only set_system_eflags() 
> if non-ALU bits have changed.

If it's worth it...

If it's worth for the context switch i think it would make 
more sense to do it for the normal restore_flags() etc. which are much
more common (and could be actually handled in most cases with test + jump + sti)

-Andi

  parent reply	other threads:[~2006-11-04 20:02 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-11-03 23:57 [patch] i386: remove IOPL check on task switch Chuck Ebbert
2006-11-04 19:19 ` Zachary Amsden
2006-11-04 19:39   ` Zachary Amsden
2006-11-04 19:52     ` Linus Torvalds
2006-11-04 20:09       ` Zachary Amsden
2006-11-04 20:02     ` Andi Kleen [this message]
  -- strict thread matches above, loose matches on Subject: below --
2006-11-04  0:00 Chuck Ebbert
2006-11-03  6:27 Chuck Ebbert
2006-11-03 18:06 ` Zachary Amsden
2006-11-03 18:41   ` Andi Kleen

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