From patchwork Thu Feb 2 05:44:04 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 13125356 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 20334C64EC6 for ; Thu, 2 Feb 2023 05:45:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231971AbjBBFp5 (ORCPT ); Thu, 2 Feb 2023 00:45:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41320 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231362AbjBBFpg (ORCPT ); Thu, 2 Feb 2023 00:45:36 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5BB49367C8; Wed, 1 Feb 2023 21:45:30 -0800 (PST) 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 AA2386150C; Thu, 2 Feb 2023 05:45:29 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A3EFFC4339C; Thu, 2 Feb 2023 05:45:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1675316729; bh=F6gV3Nc4RzN8pDwwOc0MdHuzOpEsbmsKn97m0ZuPXgY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jSpq7SOBfpRoXmIqShON34N25+npPt4unzDb1I0Y0ttt/9ZnlLk9j2TmLOS7MX1zl lSM3LcfJYu8GWF0Aq2jUnghkeK7LgRSH26bvWOUvYIzd8Wh/5IfRfHNr+Jt04S7QPb N+waywK2l0WWl/mE/Hwcc7+3vGTfoLgbEFLHaeyK4SJqy0HO2bhq2C9VAGiVDT5kzf Vt3WFLWxQ0YDDlKEo6qNKr9sjgDIj5mBXRA0XNA3lnpOVOB50lUWzb9qybWvYtullC 0kzi5iJEmSpXGo9TsRRHhjLjhQGY9t3MgXVarD36UesS8KVC/8M2h+6dbWKpF4yc6j F332BZBH7N2fQ== From: Eric Biggers To: stable@vger.kernel.org Cc: Harshit Mogalapalli , Kees Cook , SeongJae Park , Seth Jenkins , Jann Horn , "Eric W . Biederman" , linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org, Petr Mladek , Andrew Morton , tangmeng , "Guilherme G. Piccoli" , Sebastian Andrzej Siewior , Tiezhu Yang , Luis Chamberlain Subject: [PATCH 4.14 14/16] panic: Expose "warn_count" to sysfs Date: Wed, 1 Feb 2023 21:44:04 -0800 Message-Id: <20230202054406.221721-15-ebiggers@kernel.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230202054406.221721-1-ebiggers@kernel.org> References: <20230202054406.221721-1-ebiggers@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org From: Kees Cook commit 8b05aa26336113c4cea25f1c333ee8cd4fc212a6 upstream. Since Warn count is now tracked and is a fairly interesting signal, add the entry /sys/kernel/warn_count to expose it to userspace. Cc: Petr Mladek Cc: Andrew Morton Cc: tangmeng Cc: "Guilherme G. Piccoli" Cc: Sebastian Andrzej Siewior Cc: Tiezhu Yang Reviewed-by: Luis Chamberlain Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20221117234328.594699-6-keescook@chromium.org Signed-off-by: Eric Biggers --- .../ABI/testing/sysfs-kernel-warn_count | 6 +++++ kernel/panic.c | 22 +++++++++++++++++-- 2 files changed, 26 insertions(+), 2 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-kernel-warn_count diff --git a/Documentation/ABI/testing/sysfs-kernel-warn_count b/Documentation/ABI/testing/sysfs-kernel-warn_count new file mode 100644 index 0000000000000..08f083d2fd51b --- /dev/null +++ b/Documentation/ABI/testing/sysfs-kernel-warn_count @@ -0,0 +1,6 @@ +What: /sys/kernel/oops_count +Date: November 2022 +KernelVersion: 6.2.0 +Contact: Linux Kernel Hardening List +Description: + Shows how many times the system has Warned since last boot. diff --git a/kernel/panic.c b/kernel/panic.c index bfe6e4c5cd0e7..8f7bf0a8cef1a 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -28,6 +28,7 @@ #include #include #include +#include #define PANIC_TIMER_STEP 100 #define PANIC_BLINK_SPD 18 @@ -68,6 +69,25 @@ static __init int kernel_panic_sysctls_init(void) late_initcall(kernel_panic_sysctls_init); #endif +static atomic_t warn_count = ATOMIC_INIT(0); + +#ifdef CONFIG_SYSFS +static ssize_t warn_count_show(struct kobject *kobj, struct kobj_attribute *attr, + char *page) +{ + return sysfs_emit(page, "%d\n", atomic_read(&warn_count)); +} + +static struct kobj_attribute warn_count_attr = __ATTR_RO(warn_count); + +static __init int kernel_panic_sysfs_init(void) +{ + sysfs_add_file_to_group(kernel_kobj, &warn_count_attr.attr, NULL); + return 0; +} +late_initcall(kernel_panic_sysfs_init); +#endif + static long no_blink(int state) { return 0; @@ -145,8 +165,6 @@ EXPORT_SYMBOL(nmi_panic); void check_panic_on_warn(const char *origin) { - static atomic_t warn_count = ATOMIC_INIT(0); - if (panic_on_warn) panic("%s: panic_on_warn set ...\n", origin);