Received: by 2002:a25:4158:0:0:0:0:0 with SMTP id o85csp107068yba; Wed, 3 Apr 2019 05:31:17 -0700 (PDT) X-Google-Smtp-Source: APXvYqzvB8IMeDy0EZ1GhJ7V/rMY5fV86UuDGAEgSGkT4E8R+ChszPhmnxORkXQsWTHlujAdwgZw X-Received: by 2002:a62:e213:: with SMTP id a19mr14714391pfi.85.1554294677579; Wed, 03 Apr 2019 05:31:17 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1554294677; cv=none; d=google.com; s=arc-20160816; b=NRLfj0YXdpDjps0SHD0nUHM7fvv8p8OH9V9/4eg5fQYjCUOXitCoRPjPe1wyAfkek8 w7maLu/LDLzaXe3YSgXfTwkYpnPYu+/afDcnipm9ZoZbTzczm3bMuLdiv0+CPv0Zuo9J D9heBSh3Kde7OBeAPAs4NJtABRxFSLbE5o//fw2zQ33PBJVO2jLubLjjFE+4mj+h3AW9 CpHqqGCiskUVL+XcifLOTRmG5Dq/WeIWcivXiES6R5NC3GcCYI66av1snmDL/obl+9IY x3RjoNJb/wBd2iK+wIoMPuOTk8BjEDgq/GSkBivZ0A0vj+vi5G+cSgwq3XqrSSCT7RPI poRQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding:mime-version :references:in-reply-to:message-id:subject:cc:to:from:date; bh=JBfTjLzfPzW6Rh9VRDQlJW5vo7RqEalBkcaPIfGTHy8=; b=bV6zi19QpaACIXIHSkV2ZPXTCFjEGhseALbetOpy8uq/1rQYWkmS5X3A61GAViL9Fa FA6Kb8csCvm8C+qUHYxiTuT5sZL2dqSMP3IQgerj6pct0b1D9e0fPZqtHESHjky9cc79 TMz2L3ZbQfIgJSx6OrcgzFr2LQmMSbM9VhnytfaGsDjDeg0zfUHVN++4aat79aIfI0qD gi4QQTvSEbKxocDzlNsiwReEdo6t90QBpbD2MRmzlvQ3EyFdqgtYApzdbyRVwA+YV6wY HxhdnZUGwhUrHCQAXSP0IKLgLz0ABK2/angW5lqlfuMyeo2HgbzASaAwB6kkiZm+eSpv lY1g== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id j9si434198plk.125.2019.04.03.05.31.01; Wed, 03 Apr 2019 05:31:17 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726372AbfDCMaW (ORCPT + 99 others); Wed, 3 Apr 2019 08:30:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:41346 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726064AbfDCMaW (ORCPT ); Wed, 3 Apr 2019 08:30:22 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D9D1F2084C; Wed, 3 Apr 2019 12:30:20 +0000 (UTC) Date: Wed, 3 Apr 2019 08:30:19 -0400 From: Steven Rostedt To: Mark Rutland Cc: Torsten Duwe , Will Deacon , Catalin Marinas , Julien Thierry , Josh Poimboeuf , Ingo Molnar , Ard Biesheuvel , Arnd Bergmann , AKASHI Takahiro , Amit Daniel Kachhap , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, live-patching@vger.kernel.org Subject: Re: [PATCH v7 2/3] arm64: implement ftrace with regs Message-ID: <20190403083019.29f5fd9b@gandalf.local.home> In-Reply-To: <20190403024842.drobymuwvx6hmwv7@blommer> References: <20190118163736.6A99268CEB@newverein.lst.de> <20190118163908.E338E68D93@newverein.lst.de> <20190403024842.drobymuwvx6hmwv7@blommer> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 3 Apr 2019 03:48:43 +0100 Mark Rutland wrote: > We currently have: > > ftrace_make_nop(mod, rec, addr) > ftrace_make_call(rec, addr) > ftrace_modify_call(rec, old_addr, new_addr) > > ... whereas we could have: > > ftrace_call_init(mod, rec) > ftrace_call_enable(rec, addr) > ftrace_call_disable(rec, addr) > ftrace_call_modify(rec, old_addr, new_addr) > > ... so we wouldn't need to special-case anything for initialization (and > don't need MCOUNT_ADDR at all), and it would be clearer as to what was > happening at each stage. Just a note. I would be OK if someone wants to work in changing the ftrace interface to be this. I'll review the code, but I don't have the cycles to implement such a change. -- Steve