This is a note to let you know that I've just added the patch titled
exit: Expose "oops_count" to sysfs
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
exit-expose-oops_count-to-sysfs.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 9db89b41117024f80b38b15954017fb293133364 Mon Sep 17 00:00:00 2001
From: Kees Cook <keescook@xxxxxxxxxxxx>
Date: Thu, 17 Nov 2022 15:43:23 -0800
Subject: exit: Expose "oops_count" to sysfs
From: Kees Cook <keescook@xxxxxxxxxxxx>
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@xxxxxxxxxxxx>
Cc: Jann Horn <jannh@xxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Reviewed-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20221117234328.594699-3-keescook@xxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
Documentation/ABI/testing/sysfs-kernel-oops_count | 6 ++++++
MAINTAINERS | 1 +
kernel/exit.c | 22 ++++++++++++++++++++--
3 files changed, 27 insertions(+), 2 deletions(-)
create mode 100644 Documentation/ABI/testing/sysfs-kernel-oops_count
--- /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@xxxxxxxxxxxxxxx>
+Description:
+ Shows how many times the system has Oopsed since last boot.
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11112,6 +11112,7 @@ M: Kees Cook <keescook@xxxxxxxxxxxx>
L: linux-hardening@xxxxxxxxxxxxxxx
S: Supported
T: git git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git for-next/hardening
+F: Documentation/ABI/testing/sysfs-kernel-oops_count
F: include/linux/overflow.h
F: include/linux/randomize_kstack.h
F: mm/usercopy.c
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -67,6 +67,7 @@
#include <linux/io_uring.h>
#include <linux/kprobes.h>
#include <linux/rethook.h>
+#include <linux/sysfs.h>
#include <linux/uaccess.h>
#include <asm/unistd.h>
@@ -99,6 +100,25 @@ static __init int kernel_exit_sysctls_in
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--;
@@ -901,8 +921,6 @@ void __noreturn do_exit(long code)
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.
Patches currently in stable-queue which might be from keescook@xxxxxxxxxxxx are
queue-6.1/panic-consolidate-open-coded-panic_on_warn-checks.patch
queue-6.1/exit-put-an-upper-limit-on-how-often-we-can-oops.patch
queue-6.1/panic-introduce-warn_limit.patch
queue-6.1/exit-allow-oops_limit-to-be-disabled.patch
queue-6.1/panic-separate-sysctl-logic-from-config_smp.patch
queue-6.1/exit-use-read_once-for-all-oops-warn-limit-reads.patch
queue-6.1/exit-expose-oops_count-to-sysfs.patch
queue-6.1/panic-expose-warn_count-to-sysfs.patch
queue-6.1/docs-fix-path-paste-o-for-sys-kernel-warn_count.patch
