Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964868AbWIPXim (ORCPT ); Sat, 16 Sep 2006 19:38:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964872AbWIPXim (ORCPT ); Sat, 16 Sep 2006 19:38:42 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:53654 "EHLO mx2.mail.elte.hu") by vger.kernel.org with ESMTP id S964868AbWIPXim (ORCPT ); Sat, 16 Sep 2006 19:38:42 -0400 Date: Sun, 17 Sep 2006 01:30:38 +0200 From: Ingo Molnar To: Andrew Morton Cc: Mathieu Desnoyers , Jes Sorensen , Roman Zippel , tglx@linutronix.de, karim@opersys.com, Paul Mundt , linux-kernel@vger.kernel.org, Christoph Hellwig , Ingo Molnar , Greg Kroah-Hartman , Tom Zanussi , ltt-dev@shafik.org, Michel Dagenais , fche@redhat.com Subject: Re: [patch] kprobes: optimize branch placement Message-ID: <20060916233038.GC23132@elte.hu> References: <20060915202233.GA23318@Krystal> <450BCAF1.2030205@sgi.com> <20060916172419.GA15427@Krystal> <20060916173552.GA7362@elte.hu> <20060916175606.GA2837@Krystal> <20060916191043.GA22558@elte.hu> <20060916193745.GA29022@elte.hu> <20060916202939.GA4520@elte.hu> <20060916204342.GA5208@elte.hu> <20060916155657.a233b54d.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060916155657.a233b54d.akpm@osdl.org> User-Agent: Mutt/1.4.2.1i X-ELTE-SpamScore: -2.9 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.9 required=5.9 tests=ALL_TRUSTED,AWL,BAYES_50 autolearn=no SpamAssassin version=3.0.3 -3.3 ALL_TRUSTED Did not pass through any untrusted hosts 0.5 BAYES_50 BODY: Bayesian spam probability is 40 to 60% [score: 0.5000] -0.1 AWL AWL: From: address is in the auto white-list X-ELTE-VirusStatus: clean Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1699 Lines: 42 * Andrew Morton wrote: > On Sat, 16 Sep 2006 22:43:42 +0200 > Ingo Molnar wrote: > > > --- linux.orig/arch/i386/kernel/kprobes.c > > +++ linux/arch/i386/kernel/kprobes.c > > @@ -354,9 +354,8 @@ no_kprobe: > > */ > > fastcall void *__kprobes trampoline_handler(struct pt_regs *regs) > > { > > - struct kretprobe_instance *ri = NULL; > > - struct hlist_head *head; > > - struct hlist_node *node, *tmp; > > + struct kretprobe_instance *ri = NULL, *tmp; > > + struct list_head *head; > > unsigned long flags, orig_ret_address = 0; > > unsigned long trampoline_address =(unsigned long)&kretprobe_trampoline; > > Wanna fix the whitespace wreckage while you're there?? will do. If you consider this for -mm then there's some djprobes noise in the patch [djprobes isnt upstream yet] - it's not completely sanitized yet. (but it should actually work if applied to upstream - kprobes and djprobes are disjunct.) Also, i havent tested with CONFIG_KPROBES turned off, etc. I'll do a clean queue. > i386's kprobe_handler() appears to forget to reenable preemption in > the if (p->pre_handler && p->pre_handler(p, regs)) case? that portion seems a bit tricky - i think what happens is that the pre_handler() sets stuff up for single-stepping, and then we do this recursive single-stepping (during which preemption remains disabled), and _then_ do we re-enable preemption. Ingo - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/