From patchwork Fri Aug 19 22:17:24 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Guilherme G. Piccoli" X-Patchwork-Id: 12949302 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F1B38C32771 for ; Fri, 19 Aug 2022 22:21:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241409AbiHSWVm (ORCPT ); Fri, 19 Aug 2022 18:21:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45316 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241296AbiHSWVl (ORCPT ); Fri, 19 Aug 2022 18:21:41 -0400 Received: from fanzine2.igalia.com (fanzine.igalia.com [178.60.130.6]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5D519D9D7B; Fri, 19 Aug 2022 15:21:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type: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=I7PX0cg9hYhaVm6PvmjCfqAqk9/uhuAJh0bXjru0KJ8=; b=apxqB5qmqlzzY5vxuVHk/oybLg LGISEVYytiLSHzQM1NRBWL9ge/1BR3a5d4xyO3rwazWkQf6rO2OS/n67HAwdwBeLdPfOO/5+ptmdA nchEn0YnVSqzWI5LYJNJK99CREIoOfURPC5OxlOLbxBjzRqQBhWocnTVkl+50cp4hx2RdCPpm05KJ kQ0gUbNDHLN2x4iyxKfxMIsc6UVssvkUQWUb7CBWr3lNyq23EXMGdsgyAbCl6t5yNi3gsN1Pa8ZaO 6yXzHFVJTNoduFjBMFPFWJoF5WZJ0C44LC+4711S5JBo2OioK7T+35306PeO7vksSE6XS9+9PuVVj ZSO7++KA==; Received: from [179.232.144.59] (helo=localhost) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_SECP256R1__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim) id 1oPAMu-00Cb1Q-Tz; Sat, 20 Aug 2022 00:21:33 +0200 From: "Guilherme G. Piccoli" To: akpm@linux-foundation.org, bhe@redhat.com, pmladek@suse.com, kexec@lists.infradead.org Cc: linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org, netdev@vger.kernel.org, x86@kernel.org, kernel-dev@igalia.com, kernel@gpiccoli.net, halves@canonical.com, fabiomirmar@gmail.com, alejandro.j.jimenez@oracle.com, andriy.shevchenko@linux.intel.com, arnd@arndb.de, bp@alien8.de, corbet@lwn.net, d.hatayama@jp.fujitsu.com, dave.hansen@linux.intel.com, dyoung@redhat.com, feng.tang@intel.com, gregkh@linuxfoundation.org, mikelley@microsoft.com, hidehiro.kawai.ez@hitachi.com, jgross@suse.com, john.ogness@linutronix.de, keescook@chromium.org, luto@kernel.org, mhiramat@kernel.org, mingo@redhat.com, paulmck@kernel.org, peterz@infradead.org, rostedt@goodmis.org, senozhatsky@chromium.org, stern@rowland.harvard.edu, tglx@linutronix.de, vgoyal@redhat.com, vkuznets@redhat.com, will@kernel.org, xuqiang36@huawei.com, "Guilherme G. Piccoli" , linux-um@lists.infradead.org, Anton Ivanov , Johannes Berg , Richard Weinberger Subject: [PATCH V3 04/11] um: Improve panic notifiers consistency and ordering Date: Fri, 19 Aug 2022 19:17:24 -0300 Message-Id: <20220819221731.480795-5-gpiccoli@igalia.com> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220819221731.480795-1-gpiccoli@igalia.com> References: <20220819221731.480795-1-gpiccoli@igalia.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Currently the panic notifiers from user mode linux don't follow the convention for most of the other notifiers present in the kernel (indentation, priority setting, numeric return). More important, the priorities could be improved, since it's a special case (userspace), hence we could run the notifiers earlier; user mode linux shouldn't care much with other panic notifiers but the ordering among the mconsole and arch notifier is important, given that the arch one effectively triggers a core dump. Fix that by running the mconsole notifier as the first panic notifier, followed by the architecture one (that coredumps). Cc: Anton Ivanov Cc: Johannes Berg Cc: Richard Weinberger Signed-off-by: Guilherme G. Piccoli V3: - No changes. V2: - Kept the notifier header to avoid implicit usage - thanks Johannes for the suggestion! --- arch/um/drivers/mconsole_kern.c | 7 +++---- arch/um/kernel/um_arch.c | 8 ++++---- 2 files changed, 7 insertions(+), 8 deletions(-) diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c index 8ca67a692683..69af3ce8407a 100644 --- a/arch/um/drivers/mconsole_kern.c +++ b/arch/um/drivers/mconsole_kern.c @@ -846,13 +846,12 @@ static int notify_panic(struct notifier_block *self, unsigned long unused1, mconsole_notify(notify_socket, MCONSOLE_PANIC, message, strlen(message) + 1); - return 0; + return NOTIFY_DONE; } static struct notifier_block panic_exit_notifier = { - .notifier_call = notify_panic, - .next = NULL, - .priority = 1 + .notifier_call = notify_panic, + .priority = INT_MAX, /* run as soon as possible */ }; static int add_notifier(void) diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c index e0de60e503b9..ae272878f692 100644 --- a/arch/um/kernel/um_arch.c +++ b/arch/um/kernel/um_arch.c @@ -247,13 +247,13 @@ static int panic_exit(struct notifier_block *self, unsigned long unused1, bust_spinlocks(0); uml_exitcode = 1; os_dump_core(); - return 0; + + return NOTIFY_DONE; } static struct notifier_block panic_exit_notifier = { - .notifier_call = panic_exit, - .next = NULL, - .priority = 0 + .notifier_call = panic_exit, + .priority = INT_MAX - 1, /* run as 2nd notifier, won't return */ }; void uml_finishsetup(void)