linux-kernel - [PATCH 3/9] x86/i387.c: Thread xstate is initialized only on BSP once

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]

Message-Id: <1320444241-834-4-git-send-email-fenghua.yu@intel.com>
Date:	Fri,  4 Nov 2011 15:03:55 -0700
From:	"Fenghua Yu" <fenghua.yu@...el.com>
To:	"Thomas Gleixner" <tglx@...utronix.de>,
	"H Peter Anvin" <hpa@...or.com>, "Ingo Molnar" <mingo@...e.hu>,
	"Linus Torvalds" <torvalds@...ux-foundation.org>,
	"Andrew Morton" <akpm@...ux-foundation.org>,
	"Tony Luck" <tony.luck@...el.com>,
	"Suresh B Siddha" <suresh.b.siddha@...el.com>,
	"Len Brown" <len.brown@...el.com>,
	"Srivatsa S. Bhat" <srivatsa.bhat@...ux.vnet.ibm.com>,
	Peter Zijlstra <peterz@...radead.org>
Cc:	"linux-kernel" <linux-kernel@...r.kernel.org>,
	"Fenghua Yu" <fenghua.yu@...el.com>
Subject: [PATCH 3/9] x86/i387.c: Thread xstate is initialized only on BSP once

From: Fenghua Yu <fenghua.yu@...el.com>

init_thread_xstate() is only called on BSP once to avoid to override
xstate_size.

Signed-off-by: Fenghua Yu <fenghua.yu@...el.com>
---
 arch/x86/kernel/i387.c |    9 ++++++++-
 1 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index 739d859..f721a61 100644
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -93,6 +93,7 @@ void __cpuinit fpu_init(void)
 {
 	unsigned long cr0;
 	unsigned long cr4_mask = 0;
+	static int once = 1;
 
 	if (cpu_has_fxsr)
 		cr4_mask |= X86_CR4_OSFXSR;
@@ -107,8 +108,14 @@ void __cpuinit fpu_init(void)
 		cr0 |= X86_CR0_EM;
 	write_cr0(cr0);
 
-	if (!smp_processor_id())
+	/*
+	 * init_thread_xstate is only called on BSP once to avoid to override
+	 * xstate_size.
+	 */
+	if (!smp_processor_id() && once) {
+		once = 0;
 		init_thread_xstate();
+	}
 
 	mxcsr_feature_mask_init();
 	/* clean state in init */
-- 
1.6.0.3

--
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/