linux-kernel - Re: [PATCH] x86/fpu: drop_fpu() should not assume that tsk == current

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Message-ID: <20150309174825.GH12732@pd.tnic>
Date:	Mon, 9 Mar 2015 18:48:25 +0100
From:	Borislav Petkov <bp@...e.de>
To:	Oleg Nesterov <oleg@...hat.com>
Cc:	Dave Hansen <dave.hansen@...el.com>,
	Ingo Molnar <mingo@...nel.org>,
	Andy Lutomirski <luto@...capital.net>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Pekka Riikonen <priikone@....fi>,
	Rik van Riel <riel@...hat.com>,
	Suresh Siddha <sbsiddha@...il.com>,
	LKML <linux-kernel@...r.kernel.org>,
	"Yu, Fenghua" <fenghua.yu@...el.com>,
	Quentin Casasnovas <quentin.casasnovas@...cle.com>
Subject: Re: [PATCH] x86/fpu: drop_fpu() should not assume that tsk == current

On Mon, Mar 09, 2015 at 06:10:41PM +0100, Oleg Nesterov wrote:
> drop_fpu() does clear_used_math() and usually this is correct because
> tsk == current. However switch_fpu_finish()->restore_fpu_checking() is
> called before it updates the "current_task" variable. If it fails, we

You mean here "... before __switch_to() updates the current_task ... ",
I assume?

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
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