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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 DB6EEC43215 for ; Fri, 22 Nov 2019 08:55:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BCFBF20726 for ; Fri, 22 Nov 2019 08:55:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727072AbfKVIzf (ORCPT ); Fri, 22 Nov 2019 03:55:35 -0500 Received: from helcar.hmeau.com ([216.24.177.18]:45594 "EHLO deadmen.hmeau.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726364AbfKVIzf (ORCPT ); Fri, 22 Nov 2019 03:55:35 -0500 Received: from gondobar.mordor.me.apana.org.au ([192.168.128.4] helo=gondobar) by deadmen.hmeau.com with esmtps (Exim 4.89 #2 (Debian)) id 1iY4ij-00006J-Er; Fri, 22 Nov 2019 16:55:17 +0800 Received: from herbert by gondobar with local (Exim 4.89) (envelope-from ) id 1iY4ie-00050h-Ik; Fri, 22 Nov 2019 16:55:12 +0800 Date: Fri, 22 Nov 2019 16:55:12 +0800 From: Herbert Xu To: Chuhong Yuan Cc: Jamie Iles , "David S . Miller" , linux-arm-kernel@lists.infradead.org, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] crypto: picoxcell: add missed tasklet_kill Message-ID: <20191122085512.m75tjfa3valqfgyv@gondor.apana.org.au> References: <20191115023116.7070-1-hslester96@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191115023116.7070-1-hslester96@gmail.com> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Nov 15, 2019 at 10:31:16AM +0800, Chuhong Yuan wrote: > This driver forgets to kill tasklet when probe fails and remove. > Add the calls to fix it. > > Signed-off-by: Chuhong Yuan Yes this driver does look buggy but I think your patch isn't enough. > diff --git a/drivers/crypto/picoxcell_crypto.c b/drivers/crypto/picoxcell_crypto.c > index 3cbefb41b099..8d7c6bb2876e 100644 > --- a/drivers/crypto/picoxcell_crypto.c > +++ b/drivers/crypto/picoxcell_crypto.c > @@ -1755,6 +1755,7 @@ static int spacc_probe(struct platform_device *pdev) > if (!ret) > return 0; > > + tasklet_kill(&engine->complete); The tasklet is schedule by the IRQ handler so you should not kill it until the IRQ handler has been unregistered. This driver is also buggy because it registers the IRQ handler before initialising the tasklet. You must always be prepared for spurious IRQs. IOW, as soon as you register the IRQ handler you must be prepared for it to be called. > @@ -1771,6 +1772,7 @@ static int spacc_remove(struct platform_device *pdev) > struct spacc_alg *alg, *next; > struct spacc_engine *engine = platform_get_drvdata(pdev); > > + tasklet_kill(&engine->complete); Ditto. However, the IRQ handler is registered through devm which makes it hard to kill the tasklet after unregistering it. We should probably convert it to a normal request_irq so we can control how it's unregistered. Thanks, -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt