This is a note to let you know that I've just added the patch titled
panic: Expose "warn_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:
panic-expose-warn_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 8b05aa26336113c4cea25f1c333ee8cd4fc212a6 Mon Sep 17 00:00:00 2001
From: Kees Cook <keescook@xxxxxxxxxxxx>
Date: Thu, 17 Nov 2022 15:43:26 -0800
Subject: panic: Expose "warn_count" to sysfs
From: Kees Cook <keescook@xxxxxxxxxxxx>
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 <pmladek@xxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: tangmeng <tangmeng@xxxxxxxxxxxxx>
Cc: "Guilherme G. Piccoli" <gpiccoli@xxxxxxxxxx>
Cc: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Cc: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
Reviewed-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20221117234328.594699-6-keescook@xxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
Documentation/ABI/testing/sysfs-kernel-warn_count | 6 ++++++
MAINTAINERS | 1 +
kernel/panic.c | 22 ++++++++++++++++++++--
3 files changed, 27 insertions(+), 2 deletions(-)
create mode 100644 Documentation/ABI/testing/sysfs-kernel-warn_count
--- /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 <linux-hardening@xxxxxxxxxxxxxxx>
+Description:
+ Shows how many times the system has Warned since last boot.
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11113,6 +11113,7 @@ 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: Documentation/ABI/testing/sysfs-kernel-warn_count
F: include/linux/overflow.h
F: include/linux/randomize_kstack.h
F: mm/usercopy.c
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -32,6 +32,7 @@
#include <linux/bug.h>
#include <linux/ratelimit.h>
#include <linux/debugfs.h>
+#include <linux/sysfs.h>
#include <trace/events/error_report.h>
#include <asm/sections.h>
@@ -107,6 +108,25 @@ static __init int kernel_panic_sysctls_i
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;
@@ -211,8 +231,6 @@ static void panic_print_sys_info(bool co
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);
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
