From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from Galois.linutronix.de (Galois.linutronix.de [IPv6:2001:470:1f0b:db:abcd:42:0:1]) (using TLSv1.2 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 019091A0025 for ; Wed, 22 Apr 2015 00:15:11 +1000 (AEST) Date: Tue, 21 Apr 2015 16:14:26 +0200 (CEST) From: Thomas Gleixner To: Arnd Bergmann Subject: Re: [Y2038] [PATCH 04/11] posix timers:Introduce the 64bit methods with timespec64 type for k_clock structure In-Reply-To: <3755355.Xf0HbltZXg@wuerfel> Message-ID: References: <1429509459-17068-1-git-send-email-baolin.wang@linaro.org> <1429509459-17068-5-git-send-email-baolin.wang@linaro.org> <3755355.Xf0HbltZXg@wuerfel> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: pang.xunlei@linaro.org, peterz@infradead.org, heiko.carstens@de.ibm.com, paulus@samba.org, cl@linux.com, heenasirwani@gmail.com, linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, y2038@lists.linaro.org, rafael.j.wysocki@intel.com, ahh@google.com, fweisbec@gmail.com, pjt@google.com, riel@redhat.com, richardcochran@gmail.com, tj@kernel.org, john.stultz@linaro.org, rth@twiddle.net, Baolin Wang , gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, schwidefsky@de.ibm.com, linux390@de.ibm.com, linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, 21 Apr 2015, Arnd Bergmann wrote: > > COMPAT_SYSCALL_DEFINE2(timer_gettime, timer_t, timer_id, > > struct compat_itimerspec __user *, setting) > > As a side note, I want to kill off the get_fs()/set_fs() calls in > the process. These always make me dizzy when I try to work out whether > there is a potential security hole (there is not in this case), and > they can be slow on some architectures. Yeah. I have to take a deep breath every time I look at those :) > My preferred solution is one where we end up with the same syscalls > for both 32-bit and 64-bit, and basically use the > compat_sys_timer_gettime() implementation (or a simplified version) > for the existing , something like this: No objections from my side. I was not looking into the syscall magic yet. I just wanted to avoid the code churn and have the guts of the syscalls factored out for simple reusage. .... > Note the use of a separate __kernel_itimerspec64 for the user interface > here, which I think will be needed to hide the differences between the > normal itimerspec on 64-bit machines, and the new itimerspec on 32-bit > platforms that will be defined differently (using 'long long'). Confused. timespec64 / itimerspec64 should be the same independent of 64bit and 32bit. So why do we need another variant ? > I would also prefer not too many people to work on the syscalls, and > would rather have Baolin not touch any of the syscall prototypes for > the moment. I did not ask him to change any of the syscall prototypes. I just wanted him to split out the guts of the syscall into a seperate static function to avoid all that code churn. Thanks, tglx