From patchwork Tue Apr 5 07:28:41 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 556719 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 C62CDC43217 for ; Tue, 5 Apr 2022 12:03:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244830AbiDEMBb (ORCPT ); Tue, 5 Apr 2022 08:01:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50492 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1357834AbiDEK1T (ORCPT ); Tue, 5 Apr 2022 06:27:19 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CC4043FD85; Tue, 5 Apr 2022 03:10:50 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 261B06172B; Tue, 5 Apr 2022 10:10:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0F7A9C385A1; Tue, 5 Apr 2022 10:10:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649153449; bh=snFwEXRVi+rH5Kfk1ZLVOv0Z4MbhVqryYgzUp1zleHQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wd5tNbLh+AtAVRkOYpH7qMWZP9yS64VlyjzUsJYLjQMIjC1wj9/fPVMlD6/26kjXY qKH7dnQGa1YVw2RwMe0u6S56KFepEc7S/piJVNr1NEqmBYsY/MkXvrEnTHjP78VUn2 0bF2QGWr6DzsdTmPxk0W+rDsAOAfkVxNn0AhGBdU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Randy Dunlap , Igor Zhbanov , Borislav Petkov , Andrew Morton , Petr Mladek , Sergey Senozhatsky , Steven Rostedt , John Ogness , Sasha Levin Subject: [PATCH 5.10 227/599] printk: fix return value of printk.devkmsg __setup handler Date: Tue, 5 Apr 2022 09:28:41 +0200 Message-Id: <20220405070305.596926678@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220405070258.802373272@linuxfoundation.org> References: <20220405070258.802373272@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Randy Dunlap [ Upstream commit b665eae7a788c5e2bc10f9ac3c0137aa0ad1fc97 ] If an invalid option value is used with "printk.devkmsg=", it is silently ignored. If a valid option value is used, it is honored but the wrong return value (0) is used, indicating that the command line option had an error and was not handled. This string is not added to init's environment strings due to init/main.c::unknown_bootoption() checking for a '.' in the boot option string and then considering that string to be an "Unused module parameter". Print a warning message if a bad option string is used. Always return 1 from the __setup handler to indicate that the command line option has been handled. Fixes: 750afe7babd1 ("printk: add kernel parameter to control writes to /dev/kmsg") Signed-off-by: Randy Dunlap Reported-by: Igor Zhbanov Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru Cc: Borislav Petkov Cc: Andrew Morton Cc: Petr Mladek Cc: Sergey Senozhatsky Cc: Steven Rostedt Cc: John Ogness Reviewed-by: John Ogness Reviewed-by: Sergey Senozhatsky Reviewed-by: Petr Mladek Signed-off-by: Petr Mladek Link: https://lore.kernel.org/r/20220228220556.23484-1-rdunlap@infradead.org Signed-off-by: Sasha Levin --- kernel/printk/printk.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 85351a12c85d..17a310dcb6d9 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -146,8 +146,10 @@ static int __control_devkmsg(char *str) static int __init control_devkmsg(char *str) { - if (__control_devkmsg(str) < 0) + if (__control_devkmsg(str) < 0) { + pr_warn("printk.devkmsg: bad option string '%s'\n", str); return 1; + } /* * Set sysctl string accordingly: @@ -166,7 +168,7 @@ static int __init control_devkmsg(char *str) */ devkmsg_log |= DEVKMSG_LOG_MASK_LOCK; - return 0; + return 1; } __setup("printk.devkmsg=", control_devkmsg);