From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932102AbZKCJGo (ORCPT ); Tue, 3 Nov 2009 04:06:44 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756075AbZKCJGn (ORCPT ); Tue, 3 Nov 2009 04:06:43 -0500 Received: from www84.your-server.de ([213.133.104.84]:36736 "EHLO www84.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755967AbZKCJGk (ORCPT ); Tue, 3 Nov 2009 04:06:40 -0500 Subject: Re: [PATCH] update fix X86_64 procfs provide stack information for threads From: Stefani Seibold To: Ingo Molnar Cc: linux-kernel , Andrew Morton , Americo Wang , "H. Peter Anvin" , Thomas Gleixner In-Reply-To: <20091103082843.GA27676@elte.hu> References: <1257233486.22553.6.camel@wall-e> <20091103082843.GA27676@elte.hu> Content-Type: text/plain; charset="ISO-8859-15" Date: Tue, 03 Nov 2009 10:06:24 +0100 Message-ID: <1257239184.4889.15.camel@wall-e> Mime-Version: 1.0 X-Mailer: Evolution 2.28.1 Content-Transfer-Encoding: 7bit X-Authenticated-Sender: stefani@seibold.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am Dienstag, den 03.11.2009, 09:28 +0100 schrieb Ingo Molnar: > > --- linux-2.6.32-rc5/arch/x86/include/asm/processor.h 2009-10-16 02:41:50.000000000 +0200 > > +++ linux-2.6.32-rc5.new/arch/x86/include/asm/processor.h 2009-11-02 10:39:47.177909657 +0100 > > @@ -1000,7 +1001,13 @@ > > #define thread_saved_pc(t) (*(unsigned long *)((t)->thread.sp - 8)) > > > > #define task_pt_regs(tsk) ((struct pt_regs *)(tsk)->thread.sp0 - 1) > > -#define KSTK_ESP(tsk) -1 /* sorry. doesn't work for syscall. */ > > + > > +#ifdef CONFIG_IA32_EMULATION > > +extern unsigned long KSTK_ESP(struct task_struct *task); > > +#else > > +#define KSTK_ESP(task) ((task)->thread.usersp) > > +#endif > > + > > #endif /* CONFIG_X86_64 */ > > > > extern void start_thread(struct pt_regs *regs, unsigned long new_ip, > > --- linux-2.6.32-rc5/arch/x86/kernel/process_64.c 2009-10-16 02:41:50.000000000 +0200 > > +++ linux-2.6.32-rc5.new/arch/x86/kernel/process_64.c 2009-11-02 10:48:23.614936810 +0100 > > @@ -664,3 +669,11 @@ > > return do_arch_prctl(current, code, addr); > > } > > > > +#ifdef CONFIG_IA32_EMULATION > > +unsigned long KSTK_ESP(struct task_struct *task) > > +{ > > + return (test_tsk_thread_flag(task, TIF_IA32)) ? \ > > + (task_pt_regs(task)->sp) : \ > > + ((task)->thread.usersp); > > +} > > +#endif > > That's quite ugly. The KSTK_ESP() function should be unconditional and > the #ifdef should be eliminated. If CONFIG_IA32_EMULATION is turned off > (whichis rare) then TIF_IA32 wont be set so the function should work > fine. > > Thanks, > > Ingo Hi Ingo, come on, thats not fair. This would be not the only piece of ugly code in the x86_64 implementation. It is much better than the previous hack where KSTK_ESP always returns a wrong hard coded value. That is really ugly!!!! It took me 6 hours to analyze the x64_64 code, most of them written in assembler. I think it is a first solution, which makes the procfs stack information work on this architecture and that was the goal. I will remove the #ifdef's and repost the patch. Please accept this patch, which make the KSTP_ESP thing on x86_64 better as before. I am not a x64_64 bit hacker, i have not the knowledge to make a perfect solution for this architecture. Also i am not a full time kernel hacker, i have customers who wait for their projects. Greeting, Stefani