From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 154DDC2D0A3 for ; Thu, 12 Nov 2020 11:41:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8D9792074B for ; Thu, 12 Nov 2020 11:41:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="lDnDxzUP" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728116AbgKLLkn (ORCPT ); Thu, 12 Nov 2020 06:40:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32780 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728168AbgKLLjz (ORCPT ); Thu, 12 Nov 2020 06:39:55 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 83BB1C0617A7; Thu, 12 Nov 2020 03:39:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=b6ATZfVWGAVrJTHLYJ8q8DfRh8F5q774OL7MDaycL9E=; b=lDnDxzUPrpug4qGWJPiQ1cFY+2 S3j2YMIm055tPZFqM9J1KwtwdUkCv0Yt5hm4gGBNHDYJ5OVC4R+RVaIt2VRTbMldKZwSnLXHqUNti Fcjil6yScd/4sYyehst1nWnP4rDtZCp3nxXWUb2h/IhgrkXEG/HZl2gA8suUAdzdPATsfbTcVgkAb B7tnG1S3wp4/bJLnl53X2M/oGIY0UojGKj+4+2a9Qc5EsKHpHoimB/r5hZjER3qbZioBn44J6edXj 7qV8yQ1aR/w6XSfKWoZVio1IU+ot3r0DG+6zqpPAdoeUF2rynRuRbKzm/3t3Ff2hns7oDmmU8MeU8 QEGwcl/w==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kdAx4-00052B-Kw; Thu, 12 Nov 2020 11:39:42 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 39D83305C16; Thu, 12 Nov 2020 12:39:40 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id EB14A2C71BAB2; Thu, 12 Nov 2020 12:39:39 +0100 (CET) Date: Thu, 12 Nov 2020 12:39:39 +0100 From: Peter Zijlstra To: Steven Rostedt Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Andrew Morton , Miroslav Benes , Thomas Gleixner , Masami Hiramatsu , Josh Poimboeuf , Jiri Kosina , live-patching@vger.kernel.org Subject: Re: [PATCH 3/3 v5] livepatch: Use the default ftrace_ops instead of REGS when ARGS is available Message-ID: <20201112113939.GU2651@hirez.programming.kicks-ass.net> References: <20201112011516.589846126@goodmis.org> <20201112011815.755256598@goodmis.org> <20201112082144.GS2628@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201112082144.GS2628@hirez.programming.kicks-ass.net> Precedence: bulk List-ID: X-Mailing-List: live-patching@vger.kernel.org On Thu, Nov 12, 2020 at 09:21:44AM +0100, Peter Zijlstra wrote: > Also, do you want something like: > > unsigned long ftrace_regs_get_register(struct ftrace_regs *regs, unsigned int offset) > { I forgot the full regs case: if (regs->regs.cs) return regs_get_register(regs->regs, offset); > switch (offset / sizeof(long)) { > case 4: /* RBP */ > > case 8: /* R9 */ > case 9: /* R8 */ > case 10: /* RAX */ > case 11: /* RCX */ > case 12: /* RDX */ > case 13: /* RSI */ > case 14: /* RDI */ > case 15: /* ORIG_RAX */ > case 16: /* RIP */ > return *(unsigned long *)regs->regs + offset; > > default: > WARN_ON_ONCE(1); > } > return 0; > }