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=BAYES_00, 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 B2F85C433EF for ; Mon, 13 Sep 2021 15:57:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8A2A361151 for ; Mon, 13 Sep 2021 15:57:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345191AbhIMP6x convert rfc822-to-8bit (ORCPT ); Mon, 13 Sep 2021 11:58:53 -0400 Received: from eu-smtp-delivery-151.mimecast.com ([185.58.85.151]:41565 "EHLO eu-smtp-delivery-151.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345583AbhIMP63 (ORCPT ); Mon, 13 Sep 2021 11:58:29 -0400 Received: from AcuMS.aculab.com (156.67.243.121 [156.67.243.121]) (Using TLS) by relay.mimecast.com with ESMTP id uk-mta-266-1-KPiJzgMQSV9QbqBO6u9w-1; Mon, 13 Sep 2021 16:57:11 +0100 X-MC-Unique: 1-KPiJzgMQSV9QbqBO6u9w-1 Received: from AcuMS.Aculab.com (fd9f:af1c:a25b:0:994c:f5c2:35d6:9b65) by AcuMS.aculab.com (fd9f:af1c:a25b:0:994c:f5c2:35d6:9b65) with Microsoft SMTP Server (TLS) id 15.0.1497.23; Mon, 13 Sep 2021 16:57:08 +0100 Received: from AcuMS.Aculab.com ([fe80::994c:f5c2:35d6:9b65]) by AcuMS.aculab.com ([fe80::994c:f5c2:35d6:9b65%12]) with mapi id 15.00.1497.023; Mon, 13 Sep 2021 16:57:08 +0100 From: David Laight To: 'Guenter Roeck' , Andrew Morton CC: Masahiro Yamada , "linux-xtensa@linux-xtensa.org" , "linux-kernel@vger.kernel.org" , Chris Zankel , Max Filippov Subject: RE: [PATCH] xtensa: Increase size of gcc stack frame check Thread-Topic: [PATCH] xtensa: Increase size of gcc stack frame check Thread-Index: AQHXp4FD14pA8IBSYEm3jyWL1V8qFauiH7lQ Date: Mon, 13 Sep 2021 15:57:08 +0000 Message-ID: <315e4a23990444f585a15d2e23a39b8f@AcuMS.aculab.com> References: <20210912025235.3514761-1-linux@roeck-us.net> In-Reply-To: <20210912025235.3514761-1-linux@roeck-us.net> Accept-Language: en-GB, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=C51A453 smtp.mailfrom=david.laight@aculab.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Guenter Roeck > Sent: 12 September 2021 03:53 > > xtensa frame size is larger than the frame size for almost all other > architectures. This results in more than 50 "the frame size of is > larger than 1024 bytes" errors when trying to build xtensa:allmodconfig. > > Increase frame size for xtensa to 1536 bytes to avoid compile errors > due to frame size limits. Have you done anything to check what happens at run-time? I'd guess that the deepest stack use is inside printk() in some obscure error path. In reality all these 1k+ stack frames need killing rather than the limit for the compiler warning increased. While it may be sensible for a system call entry function so allocate a reasonable size buffer on stack (as poll() and sendmsg() probably do) allocating big buffers way down the call stack could easily cause stack overflow. Even a 1k stack frame is huge. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)