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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A2C0AC433F5 for ; Fri, 29 Oct 2021 12:31:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7DFC061166 for ; Fri, 29 Oct 2021 12:31:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230134AbhJ2Mdv (ORCPT ); Fri, 29 Oct 2021 08:33:51 -0400 Received: from helcar.hmeau.com ([216.24.177.18]:56388 "EHLO deadmen.hmeau.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230273AbhJ2Mdt (ORCPT ); Fri, 29 Oct 2021 08:33:49 -0400 Received: from gondobar.mordor.me.apana.org.au ([192.168.128.4] helo=gondobar) by deadmen.hmeau.com with esmtp (Exim 4.92 #5 (Debian)) id 1mgR2Q-0001j9-GE; Fri, 29 Oct 2021 20:31:14 +0800 Received: from herbert by gondobar with local (Exim 4.92) (envelope-from ) id 1mgR2B-0001EN-RN; Fri, 29 Oct 2021 20:30:59 +0800 Date: Fri, 29 Oct 2021 20:30:59 +0800 From: Herbert Xu To: Meng Li Cc: horia.geanta@nxp.com, pankaj.gupta@nxp.com, davem@davemloft.net, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] driver: crypto: caam: instead this_cpu_ptr with raw_cpu_ptr Message-ID: <20211029123059.GA4648@gondor.apana.org.au> References: <20211019063719.18251-1-Meng.Li@windriver.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211019063719.18251-1-Meng.Li@windriver.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org On Tue, Oct 19, 2021 at 02:37:19PM +0800, Meng Li wrote: > When enable the kernel debug config, there is below calltrace detected: > BUG: using smp_processor_id() in preemptible [00000000] code: cryptomgr_test/339 > caller is debug_smp_processor_id+0x20/0x30 > CPU: 9 PID: 339 Comm: cryptomgr_test Not tainted 5.10.63-yocto-standard #1 > Hardware name: NXP Layerscape LX2160ARDB (DT) > Call trace: > dump_backtrace+0x0/0x1a0 > show_stack+0x24/0x30 > dump_stack+0xf0/0x13c > check_preemption_disabled+0x100/0x110 > debug_smp_processor_id+0x20/0x30 > dpaa2_caam_enqueue+0x10c/0x25c > ...... > cryptomgr_test+0x38/0x60 > kthread+0x158/0x164 > ret_from_fork+0x10/0x38 > According to the comment in commit ac5d15b4519f("crypto: caam/qi2 > - use affine DPIOs "), it doesn't matter whether preemption is > disable or not. So, only instead this_cpu_ptr with raw_cpu_ptr to > avoid above call trace. Please put the reason why raw is safe into a comment in the code. Readers shouldn't need to run git whatschanged to figure out why this is safe. Thanks, -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt