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=-5.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 A675EC31E49 for ; Wed, 19 Jun 2019 12:02:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 760EB20665 for ; Wed, 19 Jun 2019 12:02:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="FcgOzzaU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731673AbfFSMCF (ORCPT ); Wed, 19 Jun 2019 08:02:05 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:44618 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726246AbfFSMCE (ORCPT ); Wed, 19 Jun 2019 08:02:04 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=ri7qjhjVCgbjO6ig3doTj7RVbO2jjytVB0LcoWHrHhU=; b=FcgOzzaUp3Q5CfIuOaKoL+MDK KYCzrxCmEMdfjNQSrLlvvwFbZrSjOWK3jSgSFnTe+ewKfop5MWztgIuCls6ghDvHF0Qem3tYDpX/7 AIZGONFJINJi/oYjy23u7u/yTrkGtoMRLk/IR9AJG5/yFV4c4SeCcZroBm8mbs5ENlLckoz1WK96K Nm+9k30Tfq9+JtM7kkfqZWWi7T9DZYxNwGc38WqEK44vn8z7W4l9EWSzv4y1Ic2LfM7KHDlimJkIA LiCGZk5VfImotto+QulyqEy3vwqM0SKLUITsKvVrLvUW2EDp1GxWLni53nccRpPNu2GGFUWTLzJaF eS+nqrQbA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.92 #3 (Red Hat Linux)) id 1hdZHR-0008GE-3H; Wed, 19 Jun 2019 12:01:33 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 7A0272020FD6B; Wed, 19 Jun 2019 14:01:31 +0200 (CEST) Date: Wed, 19 Jun 2019 14:01:31 +0200 From: Peter Zijlstra To: Miroslav Benes Cc: Jessica Yu , linux-kernel@vger.kernel.org, jpoimboe@redhat.com, jikos@kernel.org, pmladek@suse.com, rostedt@goodmis.org, ast@kernel.org, daniel@iogearbox.net, "Rafael J. Wysocki" Subject: Re: [RFC][PATCH] module: Propagate MODULE_STATE_COMING notifier errors Message-ID: <20190619120131.GS3463@hirez.programming.kicks-ass.net> References: <20190617090335.GX3436@hirez.programming.kicks-ass.net> <20190619112350.GN3419@hirez.programming.kicks-ass.net> <20190619113324.GO3463@hirez.programming.kicks-ass.net> <20190619113508.GP3463@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190619113508.GP3463@hirez.programming.kicks-ass.net> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 19, 2019 at 01:35:08PM +0200, Peter Zijlstra wrote: > On Wed, Jun 19, 2019 at 01:33:24PM +0200, Peter Zijlstra wrote: > > How's something like so: > > > > diff --git a/kernel/module.c b/kernel/module.c > > index 80c7c09584cf..eba6560c89da 100644 > > --- a/kernel/module.c > > +++ b/kernel/module.c > > @@ -3631,16 +3631,28 @@ static int complete_formation(struct module *mod, struct load_info *info) > > > > static int prepare_coming_module(struct module *mod) > > { > > - int err; > > + struct blocking_notifier_head *nh = &module_notify_list; > > + int err, nr; > > > > ftrace_module_enable(mod); > > err = klp_module_coming(mod); > > if (err) > > return err; > > > > - blocking_notifier_call_chain(&module_notify_list, > > - MODULE_STATE_COMING, mod); > > - return 0; > > + if (!rcu_access_pointer(nh->head)) > > + return 0; > > + > > + down_read(&nh->rwsem); > > + ret = notifier_call_chain(&nh->head, MODULE_STATE_COMING, mod, -1, &nr); > > + if (ret & NOTIFIER_STOP_MASK) > > It compiles _lots_ better with s/ret/err/ on. > > > + notifier_call_chain(&nh->head, MODULE_STATE_GOING, mod, nr, NULL); > > + up_read(&nh->rwsem); > > + > > + err = notifier_to_err(err); > > + if (err) > > + klp_module_going(mod); > > + > > + return err; > > } > > > > static int unknown_module_param_cb(char *param, char *val, const char *modname, Rafael, how is kernel/power/user.c snapshot_open() not broken (any any other __pm_notifier_call_chain() user)? afaict the __pm_notifier_call_chain() thing is broken in two ways: - there can be a change to the notifier list between the PREPARE and POST iteration - the error value isn't put through notifier_to_errno().