Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933230AbaDBTx1 (ORCPT ); Wed, 2 Apr 2014 15:53:27 -0400 Received: from e37.co.us.ibm.com ([32.97.110.158]:33584 "EHLO e37.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933034AbaDBTxU (ORCPT ); Wed, 2 Apr 2014 15:53:20 -0400 Subject: Re: [PATCH 5/7] uprobes/x86: Gather "riprel" functions together From: Jim Keniston To: Oleg Nesterov Cc: Ingo Molnar , Srikar Dronamraju , Ananth N Mavinakayanahalli , David Long , Denys Vlasenko , "Frank Ch. Eigler" , Jonathan Lebon , Masami Hiramatsu , linux-kernel@vger.kernel.org In-Reply-To: <20140331194409.GA9297@redhat.com> References: <20140331194409.GA9297@redhat.com> Content-Type: text/plain; charset="UTF-8" Date: Wed, 02 Apr 2014 12:53:15 -0700 Message-ID: <1396468395.4659.59.camel@oc7886638347.ibm.com.usor.ibm.com> Mime-Version: 1.0 X-Mailer: Evolution 2.32.3 (2.32.3-30.el6) Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14040219-7164-0000-0000-000000C01E33 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2014-03-31 at 21:44 +0200, Oleg Nesterov wrote: ... > +static void > +handle_riprel_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs, long *correction) > +{ > + if (auprobe->fixups & (UPROBE_FIX_RIP_AX | UPROBE_FIX_RIP_CX)) { > + struct arch_uprobe_task *autask; > + > + autask = ¤t->utask->autask; > + if (auprobe->fixups & UPROBE_FIX_RIP_AX) > + regs->ax = autask->saved_scratch_register; > + else > + regs->cx = autask->saved_scratch_register; > + > + /* > + * The original instruction includes a displacement, and so > + * is 4 bytes longer than what we've just single-stepped. > + * Fall through to handle stuff like "jmpq *...(%rip)" and > + * "callq *...(%rip)". > + */ > + if (correction) > + *correction += 4; > + } > +} This is another case of a glitch in the code being moved. Since this code was moved to its own function, the "Fall through" comment makes no sense. Maybe * Caller may need to apply other fixups to handle stuff * like "jmpq *...(%rip)" and "callq *...(%rip)". Jim -- 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/