From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752637Ab3KTLDj (ORCPT ); Wed, 20 Nov 2013 06:03:39 -0500 Received: from e7.ny.us.ibm.com ([32.97.182.137]:50274 "EHLO e7.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751331Ab3KTLDh (ORCPT ); Wed, 20 Nov 2013 06:03:37 -0500 Date: Wed, 20 Nov 2013 16:33:20 +0530 From: Srikar Dronamraju To: Oleg Nesterov Cc: Ingo Molnar , Ingo Molnar , linux-kernel@vger.kernel.org Subject: Re: [PATCH] uprobes: Document xol_area and arch_uprobe->insn/ixol Message-ID: <20131120110320.GA22744@linux.vnet.ibm.com> Reply-To: Srikar Dronamraju References: <20131109190344.GA32281@redhat.com> <20131111084149.GC12405@gmail.com> <20131111195836.GA20615@redhat.com> <20131111210327.GG18886@gmail.com> <20131119162545.GA776@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20131119162545.GA776@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13112011-5806-0000-0000-00002378E94E Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > > OK. Let me try to make a first step to improve this a little bit... > > How about the patch below? Srikar? > > > Subject: [PATCH] uprobes: Document xol_area and arch_uprobe->insn/ixol > > Document xol_area and arch_uprobe. > > Signed-off-by: Oleg Nesterov > --- Acked-by: Srikar Dronamraju > kernel/events/uprobes.c | 15 +++++++++++++++ > 1 files changed, 15 insertions(+), 0 deletions(-) > > diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c > index 51a7f53..b886a5e 100644 > --- a/kernel/events/uprobes.c > +++ b/kernel/events/uprobes.c > @@ -73,6 +73,17 @@ struct uprobe { > struct inode *inode; /* Also hold a ref to inode */ > loff_t offset; > unsigned long flags; > + > + /* > + * The generic code assumes that it has two members of unknown type > + * owned by the arch-specific code: > + * > + * insn - copy_insn() saves the original instruction here for > + * arch_uprobe_analyze_insn(). > + * > + * ixol - potentially modified instruction to execute out of > + * line, copied to xol_area by xol_get_insn_slot(). > + */ > struct arch_uprobe arch; > }; > > @@ -86,6 +97,10 @@ struct return_instance { > }; > > /* > + * Execute out of line area: anonymous executable mapping installed > + * by the probed task to execute the copy of the original instruction > + * mangled by set_swbp(). > + * > * On a breakpoint hit, thread contests for a slot. It frees the > * slot after singlestep. Currently a fixed number of slots are > * allocated. > -- > 1.5.5.1 > > -- Thanks and Regards Srikar Dronamraju