linux-kernel - [PATCH 009/208] x86/fpu: Optimize fpu__unlazy

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue,  5 May 2015 18:23:49 +0200
From:	Ingo Molnar <mingo@...nel.org>
To:	linux-kernel@...r.kernel.org
Cc:	Andy Lutomirski <luto@...capital.net>,
	Borislav Petkov <bp@...en8.de>,
	Dave Hansen <dave.hansen@...ux.intel.com>,
	Fenghua Yu <fenghua.yu@...el.com>,
	"H. Peter Anvin" <hpa@...or.com>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Oleg Nesterov <oleg@...hat.com>,
	Thomas Gleixner <tglx@...utronix.de>
Subject: [PATCH 009/208] x86/fpu: Optimize fpu__unlazy_stopped()

This function is only called for stopped child tasks, so the
fpu__save() branch will never get called - remove it.

Reviewed-by: Borislav Petkov <bp@...en8.de>
Cc: Andy Lutomirski <luto@...capital.net>
Cc: Dave Hansen <dave.hansen@...ux.intel.com>
Cc: Fenghua Yu <fenghua.yu@...el.com>
Cc: H. Peter Anvin <hpa@...or.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Oleg Nesterov <oleg@...hat.com>
Cc: Thomas Gleixner <tglx@...utronix.de>
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
 arch/x86/kernel/i387.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index 909d10d2fb70..76006a701dbb 100644
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -291,8 +291,6 @@ static int fpu__unlazy_stopped(struct task_struct *child)
 		return -EINVAL;
 
 	if (tsk_used_math(child)) {
-		if (cpu_has_fpu && child == current)
-			fpu__save(child);
 		task_disable_lazy_fpu_restore(child);
 		return 0;
 	}
-- 
2.1.0

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/