From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Rostedt Subject: [PATCH RT 07/25][RFC 3.0.23-rt39-rc1] x86: vdso: Remove bogus locking in update_vsyscall_tz() Date: Tue, 06 Mar 2012 11:16:43 -0500 Message-ID: <20120306161946.377520329@goodmis.org> References: <20120306161636.491172179@goodmis.org> Cc: Thomas Gleixner , Carsten Emde , John Kacur , stable-rt@vger.kernel.org To: linux-kernel@vger.kernel.org, linux-rt-users Return-path: Content-Disposition: inline; filename=0007-x86-vdso-Remove-bogus-locking-in-update_vsyscall_tz.patch Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-rt-users.vger.kernel.org From: Thomas Gleixner Changing the sequence count in update_vsyscall_tz() is completely pointless. The vdso code copies the data unprotected. There is no point to change this as sys_tz is nowhere protected at all. See sys_gettimeofday(). Signed-off-by: Thomas Gleixner Cc: stable-rt@vger.kernel.org Signed-off-by: Steven Rostedt --- arch/x86/kernel/vsyscall_64.c | 5 ----- 1 files changed, 0 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/vsyscall_64.c b/arch/x86/kernel/vsyscall_64.c index 0a7dc13..c378a18 100644 --- a/arch/x86/kernel/vsyscall_64.c +++ b/arch/x86/kernel/vsyscall_64.c @@ -58,12 +58,7 @@ DEFINE_VVAR(struct vsyscall_gtod_data, vsyscall_gtod_data) = void update_vsyscall_tz(void) { - unsigned long flags; - - write_seqlock_irqsave(&vsyscall_gtod_data.lock, flags); - /* sys_tz has changed */ vsyscall_gtod_data.sys_tz = sys_tz; - write_sequnlock_irqrestore(&vsyscall_gtod_data.lock, flags); } void update_vsyscall(struct timespec *wall_time, struct timespec *wtm, -- 1.7.8.3