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From: Oleg Nesterov <oleg@redhat.com>
To: Borislav Petkov <bp@suse.de>
Cc: Dave Hansen <dave.hansen@intel.com>,
	Ingo Molnar <mingo@kernel.org>,
	Andy Lutomirski <luto@amacapital.net>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Pekka Riikonen <priikone@iki.fi>, Rik van Riel <riel@redhat.com>,
	Suresh Siddha <sbsiddha@gmail.com>,
	LKML <linux-kernel@vger.kernel.org>,
	"Yu, Fenghua" <fenghua.yu@intel.com>,
	Quentin Casasnovas <quentin.casasnovas@oracle.com>
Subject: Re: [PATCH 4/4] x86/fpu: don't abuse drop_init_fpu() in flush_thread()
Date: Mon, 16 Mar 2015 15:39:44 +0100	[thread overview]
Message-ID: <20150316143944.GA3300@redhat.com> (raw)
In-Reply-To: <20150316093537.GC22995@pd.tnic>

On 03/16, Borislav Petkov wrote:
>
> -static inline void drop_init_fpu(struct task_struct *tsk)
> +/*
> + * Reset the FPU state in the eager case and drop it in the lazy case (later use
> + * will reinit it).
> + */
> +static inline void fpu_reset_state(struct task_struct *tsk)

ACK!

Perhaps you can also find a beter name for __save_init_fpu/etc ;) The
name clearly suggests that it does "save + init" while in fact it does
"save and may be destroy FPU state". At least for the callers, the fact
that "destroy" is actually "init" doesn't really matter.

But lets not rename it right now. This can conflict with the fixes we
need to do first.

Oleg.


  parent reply	other threads:[~2015-03-16 14:42 UTC|newest]

Thread overview: 126+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-04 18:30 Oops with tip/x86/fpu Dave Hansen
2015-03-04 19:06 ` Oleg Nesterov
2015-03-04 19:12   ` Dave Hansen
2015-03-04 20:06   ` Borislav Petkov
2015-03-05 15:14     ` Oleg Nesterov
     [not found]       ` <20150305182203.GA4203@redhat.com>
2015-03-05 18:34         ` Dave Hansen
2015-03-05 18:46           ` Oleg Nesterov
2015-03-05 18:41         ` Dave Hansen
2015-03-26 22:37         ` Yu, Fenghua
2015-03-26 22:43           ` Dave Hansen
2015-03-26 22:48             ` Yu, Fenghua
2015-03-27  7:30               ` Quentin Casasnovas
2015-03-27 19:06           ` Oleg Nesterov
2015-03-05  8:38   ` Quentin Casasnovas
2015-03-05 15:13     ` Oleg Nesterov
2015-03-05 18:42       ` Borislav Petkov
2015-03-05 22:16         ` Dave Hansen
2015-03-05 19:51 ` [PATCH 0/1] x86/fpu: math_state_restore() should not blindly disable irqs Oleg Nesterov
2015-03-05 19:51   ` [PATCH 1/1] " Oleg Nesterov
2015-03-05 20:11     ` Ingo Molnar
2015-03-05 21:25       ` Oleg Nesterov
2015-03-06  7:58         ` Ingo Molnar
2015-03-06 13:26           ` Oleg Nesterov
2015-03-06 13:39             ` Oleg Nesterov
2015-03-06 13:46             ` Ingo Molnar
2015-03-06 14:01               ` Oleg Nesterov
2015-03-06 14:17                 ` Oleg Nesterov
2015-03-06 15:00                 ` David Vrabel
2015-03-06 15:36                   ` Oleg Nesterov
2015-03-06 16:15                     ` David Vrabel
2015-03-06 16:31                       ` Oleg Nesterov
2015-03-06 17:33           ` Linus Torvalds
2015-03-06 18:15             ` Oleg Nesterov
2015-03-06 19:23             ` Andy Lutomirski
2015-03-06 22:00               ` Linus Torvalds
2015-03-06 22:28                 ` Andy Lutomirski
2015-03-07 10:36                   ` Ingo Molnar
2015-03-07 20:11                     ` Linus Torvalds
2015-03-08  8:55                       ` Ingo Molnar
2015-03-08 11:38                         ` Ingo Molnar
2015-03-08 13:59                         ` Andy Lutomirski
2015-03-08 14:38                           ` Andy Lutomirski
2015-03-07 10:32             ` Ingo Molnar
2015-03-07 15:38   ` [PATCH 0/1] x86/fpu: x86/fpu: avoid math_state_restore() without used_math() in __restore_xstate_sig() Oleg Nesterov
2015-03-07 15:38     ` [PATCH 1/1] " Oleg Nesterov
2015-03-09 14:07       ` Borislav Petkov
2015-03-09 14:34         ` Oleg Nesterov
2015-03-09 15:18           ` Borislav Petkov
2015-03-09 16:24             ` Oleg Nesterov
2015-03-09 16:53               ` Borislav Petkov
2015-03-09 17:05                 ` Oleg Nesterov
2015-03-09 17:23                   ` Borislav Petkov
2015-03-16 12:07       ` [tip:x86/urgent] x86/fpu: Avoid " tip-bot for Oleg Nesterov
2015-03-05 20:35 ` [PATCH 0/1] x86/fpu: math_state_restore() should not blindly disable irqs Oleg Nesterov
2015-03-09 17:10 ` [PATCH] x86/fpu: drop_fpu() should not assume that tsk == current Oleg Nesterov
2015-03-09 17:36   ` Rik van Riel
2015-03-09 17:48   ` Borislav Petkov
2015-03-09 18:06     ` Oleg Nesterov
2015-03-09 18:10       ` Borislav Petkov
2015-03-16 12:07   ` [tip:x86/urgent] x86/fpu: Drop_fpu() should not assume that tsk equals current tip-bot for Oleg Nesterov
2015-03-11 17:33 ` [PATCH 0/4] x86/fpu: avoid math_state_restore() on kthread exec Oleg Nesterov
2015-03-11 17:34   ` [PATCH 1/4] x86/fpu: document user_fpu_begin() Oleg Nesterov
2015-03-13  9:47     ` Borislav Petkov
2015-03-13 14:34       ` Oleg Nesterov
2015-03-23 12:20     ` [tip:x86/fpu] x86/fpu: Document user_fpu_begin() tip-bot for Oleg Nesterov
2015-03-11 17:34   ` [PATCH 2/4] x86/fpu: introduce restore_init_xstate() Oleg Nesterov
2015-03-13 10:34     ` Borislav Petkov
2015-03-13 14:39       ` Oleg Nesterov
2015-03-13 15:20         ` Borislav Petkov
2015-03-16 19:05           ` Rik van Riel
2015-03-23 12:20     ` [tip:x86/fpu] x86/fpu: Introduce restore_init_xstate() tip-bot for Oleg Nesterov
2015-03-11 17:34   ` [PATCH 3/4] x86/fpu: use restore_init_xstate() instead of math_state_restore() on kthread exec Oleg Nesterov
2015-03-13 10:48     ` Borislav Petkov
2015-03-13 14:45       ` Oleg Nesterov
2015-03-13 15:51         ` Borislav Petkov
2015-03-23 12:21     ` [tip:x86/fpu] x86/fpu: Use " tip-bot for Oleg Nesterov
2015-03-11 17:35   ` [PATCH 4/4] x86/fpu: don't abuse drop_init_fpu() in flush_thread() Oleg Nesterov
2015-03-13 10:52     ` Borislav Petkov
2015-03-13 14:55       ` Oleg Nesterov
2015-03-13 16:19         ` Borislav Petkov
2015-03-13 16:26           ` Oleg Nesterov
2015-03-13 19:27             ` Borislav Petkov
2015-03-14 14:48               ` Oleg Nesterov
2015-03-15 17:36                 ` Borislav Petkov
2015-03-15 18:16                   ` Oleg Nesterov
2015-03-15 18:50                     ` Borislav Petkov
2015-03-15 20:04                       ` Oleg Nesterov
2015-03-15 20:38                         ` Borislav Petkov
2015-03-16  9:35                           ` Borislav Petkov
2015-03-16 10:28                             ` Ingo Molnar
2015-03-16 14:39                             ` Oleg Nesterov [this message]
2015-03-16 15:26                               ` Borislav Petkov
2015-03-16 15:34                             ` Andy Lutomirski
2015-03-16 15:35                               ` Borislav Petkov
2015-03-13 17:30     ` [PATCH v2 " Oleg Nesterov
2015-03-14 10:55       ` Borislav Petkov
2015-03-14 10:57         ` [PATCH] x86/fpu: Fold __drop_fpu() into its sole user Borislav Petkov
2015-03-14 15:15           ` Oleg Nesterov
2015-03-16 10:27           ` Ingo Molnar
2015-03-23 12:21       ` [tip:x86/fpu] x86/fpu: Don't abuse drop_init_fpu() in flush_thread() tip-bot for Oleg Nesterov
2015-03-13 18:26 ` [PATCH 0/1] x86/cpu: don't allocate fpu->state for swapper/0 Oleg Nesterov
2015-03-13 18:27   ` [PATCH 1/1] " Oleg Nesterov
2015-03-16 10:18     ` Borislav Petkov
2015-03-23 12:22     ` [tip:x86/fpu] x86/fpu: Don't " tip-bot for Oleg Nesterov
2015-03-14 11:16   ` [PATCH 0/1] x86/cpu: don't " Borislav Petkov
2015-03-14 15:13     ` [PATCH 0/1] x86/cpu: kill eager_fpu_init_bp() Oleg Nesterov
2015-03-14 15:13       ` [PATCH 1/1] " Oleg Nesterov
2015-03-16 12:44         ` Borislav Petkov
2015-03-23 12:22         ` [tip:x86/fpu] x86/fpu: Kill eager_fpu_init_bp() tip-bot for Oleg Nesterov
2015-03-15 16:49 ` [PATCH RFC 0/2] x86/fpu: avoid "xstate_fault" in xsave_user/xrestore_user Oleg Nesterov
2015-03-15 16:50   ` [PATCH RFC 1/2] x86: introduce __user_insn() and __check_insn() Oleg Nesterov
2015-03-15 16:50   ` [PATCH RFC 2/2] x86/fpu: change xsave_user() and xrestore_user() to use __user_insn() Oleg Nesterov
2015-03-16 22:43     ` Quentin Casasnovas
2015-03-17  9:35       ` Borislav Petkov
2015-03-16 14:36   ` [PATCH RFC 0/2] x86/fpu: avoid "xstate_fault" in xsave_user/xrestore_user Borislav Petkov
2015-03-16 14:57     ` Oleg Nesterov
2015-03-16 17:58       ` Borislav Petkov
2015-03-16 22:37   ` Quentin Casasnovas
2015-03-17  9:47     ` Borislav Petkov
2015-03-17 10:00       ` Quentin Casasnovas
2015-03-17 11:20         ` Borislav Petkov
2015-03-17 11:36           ` Quentin Casasnovas
2015-03-17 12:07             ` Borislav Petkov
2015-03-18  9:06               ` Quentin Casasnovas
2015-03-18  9:53                 ` Borislav Petkov
2015-03-17 10:07       ` Quentin Casasnovas

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