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=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,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 00031C33CB3 for ; Wed, 15 Jan 2020 12:42:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C1F5A22522 for ; Wed, 15 Jan 2020 12:42:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579092136; bh=nSCqvKODAoL0joKlazTXynwBxMDxfJl7wyUtw2MF4Uw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=isde2PUIf2SjNW0yuLhnvZu+BuCXmoYr0QBHQ1vJwagvA01oD0FYDLnKO32gyPmm5 NNT1yIdc5zmoAnlxZ70W+3OLHlg9fdWc06Ayo/X0Go4Z4CDJ6vSgdlFZ0FqspcEd2h RlFzHQ6PuxZyaKjSnBrrq0bsKJtpCFF6QSNloVCU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729080AbgAOMmP (ORCPT ); Wed, 15 Jan 2020 07:42:15 -0500 Received: from mail.kernel.org ([198.145.29.99]:56356 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726310AbgAOMmN (ORCPT ); Wed, 15 Jan 2020 07:42:13 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 D0D5F22522; Wed, 15 Jan 2020 12:42:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579092133; bh=nSCqvKODAoL0joKlazTXynwBxMDxfJl7wyUtw2MF4Uw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=KjuBOnTNvH+42s0Re5I/lqzWJeCybk8Hvm0vqAsrClq3TeGojXX8g8bSAiD/mF/jL Xlb0Jw+h2ug9g8theJAoWLXVcQ+EvDQXjcJWSPtj0XgJPmw1TA5wUb6mG+kbAgap0Y s5DHa8i6hMFZ4l7wzb1QBAzxo+q7UpP2RnUtCR4k= Date: Wed, 15 Jan 2020 13:42:10 +0100 From: Greg Kroah-Hartman To: Dmitry Safonov Cc: linux-kernel@vger.kernel.org, Dmitry Safonov <0x7f454c46@gmail.com>, Jiri Slaby , Vasiliy Khoruzhick , linux-serial@vger.kernel.org Subject: Re: [PATCH-next 3/3] serial/sysrq: Add MAGIC_SYSRQ_SERIAL_SEQUENCE Message-ID: <20200115124210.GA3486045@kroah.com> References: <20200109215444.95995-1-dima@arista.com> <20200109215444.95995-4-dima@arista.com> <20200110164643.GB1822445@kroah.com> <41435a7b-48a2-438c-998a-14481fbc3a1a@arista.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <41435a7b-48a2-438c-998a-14481fbc3a1a@arista.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 14, 2020 at 07:10:47PM +0000, Dmitry Safonov wrote: > On 1/10/20 10:32 PM, Dmitry Safonov wrote: > > On 1/10/20 4:46 PM, Greg Kroah-Hartman wrote: > > [..] > >>> diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c > >>> index 6ac9dfed3423..f70eba032d0b 100644 > >>> --- a/drivers/tty/serial/serial_core.c > >>> +++ b/drivers/tty/serial/serial_core.c > >>> @@ -3081,6 +3081,38 @@ void uart_insert_char(struct uart_port *port, unsigned int status, > >>> } > >>> EXPORT_SYMBOL_GPL(uart_insert_char); > >>> > >>> +const char sysrq_toggle_seq[] = CONFIG_MAGIC_SYSRQ_SERIAL_SEQUENCE; > >>> + > >>> +static void uart_sysrq_on(struct work_struct *w) > >>> +{ > >>> + sysrq_toggle_support(1); > >>> + pr_info("SysRq is enabled by magic sequience on serial\n"); > >> > >> Do we want to say what serial port it is enabled on? > > > > Makes sense, will add. > > Ah, I've managed to forget to mention that I didn't add the port name > into the message in v2. I experimented a bit - it's getting a bit > complicated how-to protect (char *name) for just this message. > Like, SysRq can be theoretically enabled on two serials at the same > moment - so some locking is needed to make the printed name sane. > > As sysrq_toggle_support() is a global-enable knob for sysrq (also can be > switched in /proc/sys/kernel/sysrq) I'm not sure if it's worth to > complicate code to print through which serial console SysRq has been > enabled. > > I can still do it in v3 if you insist. No worries, if it's too hard to get to, that's fine. If it was available, it would have been nice to have. thanks, greg k-h