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=-3.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 4BD24C352AA for ; Mon, 7 Oct 2019 11:24:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 158C021835 for ; Mon, 7 Oct 2019 11:24:18 +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="v1HIiNoW" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728053AbfJGLYR (ORCPT ); Mon, 7 Oct 2019 07:24:17 -0400 Received: from merlin.infradead.org ([205.233.59.134]:58462 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728001AbfJGLYI (ORCPT ); Mon, 7 Oct 2019 07:24:08 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-Id:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=/dXEM5OM4zrNkl3+H0fx7UYSDgq0oZpTD7FikSQnxaI=; b=v1HIiNoWA/ooj2MTshslA7lR2T qzcA9/BEQX+TaoIgjVD/1ispR2dsZMJD70ugVzVnvBsk/VVvLpQRxLS+Z/kP4bMXAr/n3wFJLzs4p xwPmkEigNXaWOQgaCDx8gVc4Pi6m7LyTffQ4/b/VjlEDp54eTZOKxKdtpW/muxTLRGCigDVZt5Z14 s7Qec/gHvlQQ5uk5Ys6SIGx52CJPbuIUeXXlWF2xUL07OEcs6Pi4peSsXl8M1TPBiNbXlIkESFLZf qfeRBtbzoCBiwPMZazq22ICGJ/FHObIKgG+7p9BFOCYFMF/qhqZm5gEXrItf14kbC4vAlSX8GqgAD ULQkPLmQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.2 #3 (Red Hat Linux)) id 1iHR6y-0002BU-AK; Mon, 07 Oct 2019 11:23:32 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 0080F306C06; Mon, 7 Oct 2019 13:22:36 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 8A05620244FAE; Mon, 7 Oct 2019 13:23:26 +0200 (CEST) Message-Id: <20191007082700.08643163.5@infradead.org> User-Agent: quilt/0.65 Date: Mon, 07 Oct 2019 10:25:43 +0200 From: Peter Zijlstra To: x86@kernel.org Cc: peterz@infradead.org, linux-kernel@vger.kernel.org, rostedt@goodmis.org, mhiramat@kernel.org, bristot@redhat.com, jbaron@akamai.com, torvalds@linux-foundation.org, tglx@linutronix.de, mingo@kernel.org, namit@vmware.com, hpa@zytor.com, luto@kernel.org, ard.biesheuvel@linaro.org, Mathieu Desnoyers , "Joel Fernandes (Google)" , Robert Richter , "Paul E. McKenney" , Yonghong Song , Alexei Starovoitov , Ingo Molnar , oprofile-list@lists.sf.net, Daniel Borkmann , Song Liu , Martin KaFai Lau Subject: [PATCH v2 2/4] module: Fix up module_notifier return values. References: <20191007082541.64146933.7@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org While auditing all module notifiers I noticed a whole bunch of fail wrt the return value. Notifiers have a 'special' return semantics. As is; NOTIFY_DONE vs NOTIFY_OK is a bit vague; but notifier_from_errno(0) results in NOTIFY_OK and NOTIFY_DONE has a comment that says "Don't care". >>From this I've used NOTIFY_DONE when the function completely ignores the callback and notifier_to_error() isn't used. Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Mathieu Desnoyers Reviewed-by: Joel Fernandes (Google) Reviewed-by: Robert Richter Cc: Steven Rostedt Cc: "Paul E. McKenney" Cc: Yonghong Song Cc: Alexei Starovoitov Cc: Ingo Molnar Cc: Ard Biesheuvel Cc: oprofile-list@lists.sf.net Cc: Daniel Borkmann Cc: Thomas Gleixner Cc: Song Liu Cc: Martin KaFai Lau --- drivers/oprofile/buffer_sync.c | 4 ++-- kernel/trace/bpf_trace.c | 8 ++++++-- kernel/trace/trace.c | 2 +- kernel/trace/trace_events.c | 2 +- kernel/trace/trace_printk.c | 4 ++-- kernel/tracepoint.c | 2 +- 6 files changed, 13 insertions(+), 9 deletions(-) --- a/drivers/oprofile/buffer_sync.c +++ b/drivers/oprofile/buffer_sync.c @@ -116,7 +116,7 @@ module_load_notify(struct notifier_block { #ifdef CONFIG_MODULES if (val != MODULE_STATE_COMING) - return 0; + return NOTIFY_DONE; /* FIXME: should we process all CPU buffers ? */ mutex_lock(&buffer_mutex); @@ -124,7 +124,7 @@ module_load_notify(struct notifier_block add_event_entry(MODULE_LOADED_CODE); mutex_unlock(&buffer_mutex); #endif - return 0; + return NOTIFY_OK; } --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1451,10 +1451,11 @@ static int bpf_event_notify(struct notif { struct bpf_trace_module *btm, *tmp; struct module *mod = module; + int ret = 0; if (mod->num_bpf_raw_events == 0 || (op != MODULE_STATE_COMING && op != MODULE_STATE_GOING)) - return 0; + goto out; mutex_lock(&bpf_module_mutex); @@ -1464,6 +1465,8 @@ static int bpf_event_notify(struct notif if (btm) { btm->module = module; list_add(&btm->list, &bpf_trace_modules); + } else { + ret = -ENOMEM; } break; case MODULE_STATE_GOING: @@ -1479,7 +1482,8 @@ static int bpf_event_notify(struct notif mutex_unlock(&bpf_module_mutex); - return 0; +out: + return notifier_from_errno(ret); } static struct notifier_block bpf_module_nb = { --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -8696,7 +8696,7 @@ static int trace_module_notify(struct no break; } - return 0; + return NOTIFY_OK; } static struct notifier_block trace_module_nb = { --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -2442,7 +2442,7 @@ static int trace_module_notify(struct no mutex_unlock(&trace_types_lock); mutex_unlock(&event_mutex); - return 0; + return NOTIFY_OK; } static struct notifier_block trace_module_nb = { --- a/kernel/trace/trace_printk.c +++ b/kernel/trace/trace_printk.c @@ -95,7 +95,7 @@ static int module_trace_bprintk_format_n if (val == MODULE_STATE_COMING) hold_module_trace_bprintk_format(start, end); } - return 0; + return NOTIFY_OK; } /* @@ -173,7 +173,7 @@ __init static int module_trace_bprintk_format_notify(struct notifier_block *self, unsigned long val, void *data) { - return 0; + return NOTIFY_OK; } static inline const char ** find_next_mod_format(int start_index, void *v, const char **fmt, loff_t *pos) --- a/kernel/tracepoint.c +++ b/kernel/tracepoint.c @@ -521,7 +521,7 @@ static int tracepoint_module_notify(stru case MODULE_STATE_UNFORMED: break; } - return ret; + return notifier_from_errno(ret); } static struct notifier_block tracepoint_module_nb = {