[5.10,14/20] exit: Expose "oops_count" to sysfs

Message ID	20230124193004.206841-15-ebiggers@kernel.org (mailing list archive)
State	Handled Elsewhere
Headers	show Return-Path: <linux-hardening-owner@vger.kernel.org> From: Eric Biggers <ebiggers@kernel.org> To: stable@vger.kernel.org, Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Kees Cook <keescook@chromium.org>, SeongJae Park <sj@kernel.org>, Seth Jenkins <sethjenkins@google.com>, Jann Horn <jannh@google.com>, "Eric W . Biederman" <ebiederm@xmission.com>, linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>, Luis Chamberlain <mcgrof@kernel.org> Subject: [PATCH 5.10 14/20] exit: Expose "oops_count" to sysfs Date: Tue, 24 Jan 2023 11:29:58 -0800 Message-Id: <20230124193004.206841-15-ebiggers@kernel.org> In-Reply-To: <20230124193004.206841-1-ebiggers@kernel.org> References: <20230124193004.206841-1-ebiggers@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	Backport oops_limit to 5.10 \| expand [5.10,00/20] Backport oops_limit to 5.10 [5.10,01/20] sysctl: add a new register_sysctl_init() interface [5.10,02/20] kernel/panic: move panic sysctls to its own file [5.10,03/20] panic: unset panic_on_warn inside panic() [5.10,04/20] ubsan: no need to unset panic_on_warn in ubsan_epilogue() [5.10,05/20] kasan: no need to unset panic_on_warn in end_report() [5.10,06/20] exit: Add and use make_task_dead. [5.10,07/20] objtool: Add a missing comma to avoid string concatenation [5.10,08/20] hexagon: Fix function name in die() [5.10,09/20] h8300: Fix build errors from do_exit() to make_task_dead() transition [5.10,10/20] csky: Fix function name in csky_alignment() and die() [5.10,11/20] ia64: make IA64_MCA_RECOVERY bool instead of tristate [5.10,12/20] panic: Separate sysctl logic from CONFIG_SMP [5.10,13/20] exit: Put an upper limit on how often we can oops [5.10,14/20] exit: Expose "oops_count" to sysfs [5.10,15/20] exit: Allow oops_limit to be disabled [5.10,16/20] panic: Consolidate open-coded panic_on_warn checks [5.10,17/20] panic: Introduce warn_limit [5.10,18/20] panic: Expose "warn_count" to sysfs [5.10,19/20] docs: Fix path paste-o for /sys/kernel/warn_count [5.10,20/20] exit: Use READ_ONCE() for all oops/warn limit reads

Message ID

20230124193004.206841-15-ebiggers@kernel.org (mailing list archive)

State

Handled Elsewhere

Headers

From: Eric Biggers <ebiggers@kernel.org>
To: stable@vger.kernel.org,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Kees Cook <keescook@chromium.org>, SeongJae Park <sj@kernel.org>,
        Seth Jenkins <sethjenkins@google.com>,
        Jann Horn <jannh@google.com>,
        "Eric W . Biederman" <ebiederm@xmission.com>,
        linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org,
        Arnd Bergmann <arnd@arndb.de>,
        Luis Chamberlain <mcgrof@kernel.org>
Subject: [PATCH 5.10 14/20] exit: Expose "oops_count" to sysfs
Date: Tue, 24 Jan 2023 11:29:58 -0800
Message-Id: <20230124193004.206841-15-ebiggers@kernel.org>
In-Reply-To: <20230124193004.206841-1-ebiggers@kernel.org>
References: <20230124193004.206841-1-ebiggers@kernel.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Series

Backport oops_limit to 5.10 | expand

Commit Message

Eric Biggers Jan. 24, 2023, 7:29 p.m. UTC

From: Kees Cook <keescook@chromium.org>

commit 9db89b41117024f80b38b15954017fb293133364 upstream.

Since Oops count is now tracked and is a fairly interesting signal, add
the entry /sys/kernel/oops_count to expose it to userspace.

Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Jann Horn <jannh@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221117234328.594699-3-keescook@chromium.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
---
 .../ABI/testing/sysfs-kernel-oops_count       |  6 +++++
 kernel/exit.c                                 | 22 +++++++++++++++++--
 2 files changed, 26 insertions(+), 2 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-kernel-oops_count

diff --git a/Documentation/ABI/testing/sysfs-kernel-oops_count b/Documentation/ABI/testing/sysfs-kernel-oops_count
new file mode 100644
index 0000000000000..156cca9dbc960
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-kernel-oops_count
@@ -0,0 +1,6 @@ 
+What:		/sys/kernel/oops_count
+Date:		November 2022
+KernelVersion:	6.2.0
+Contact:	Linux Kernel Hardening List <linux-hardening@vger.kernel.org>
+Description:
+		Shows how many times the system has Oopsed since last boot.
diff --git a/kernel/exit.c b/kernel/exit.c
index db832cff6b7b2..b519abee2c541 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -64,6 +64,7 @@ 
 #include <linux/rcuwait.h>
 #include <linux/compat.h>
 #include <linux/io_uring.h>
+#include <linux/sysfs.h>
 
 #include <linux/uaccess.h>
 #include <asm/unistd.h>
@@ -96,6 +97,25 @@  static __init int kernel_exit_sysctls_init(void)
 late_initcall(kernel_exit_sysctls_init);
 #endif
 
+static atomic_t oops_count = ATOMIC_INIT(0);
+
+#ifdef CONFIG_SYSFS
+static ssize_t oops_count_show(struct kobject *kobj, struct kobj_attribute *attr,
+			       char *page)
+{
+	return sysfs_emit(page, "%d\n", atomic_read(&oops_count));
+}
+
+static struct kobj_attribute oops_count_attr = __ATTR_RO(oops_count);
+
+static __init int kernel_exit_sysfs_init(void)
+{
+	sysfs_add_file_to_group(kernel_kobj, &oops_count_attr.attr, NULL);
+	return 0;
+}
+late_initcall(kernel_exit_sysfs_init);
+#endif
+
 static void __unhash_process(struct task_struct *p, bool group_dead)
 {
 	nr_threads--;
@@ -892,8 +912,6 @@  EXPORT_SYMBOL_GPL(do_exit);
 
 void __noreturn make_task_dead(int signr)
 {
-	static atomic_t oops_count = ATOMIC_INIT(0);
-
 	/*
 	 * Take the task off the cpu after something catastrophic has
 	 * happened.

[5.10,14/20] exit: Expose "oops_count" to sysfs

Commit Message

Patch