This is a note to let you know that I've just added the patch titled panic: Expose "warn_count" to sysfs to the 4.19-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-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From stable-owner@xxxxxxxxxxxxxxx Fri Feb 3 01:28:53 2023 From: Eric Biggers <ebiggers@xxxxxxxxxx> Date: Thu, 2 Feb 2023 16:27:15 -0800 Subject: panic: Expose "warn_count" to sysfs To: stable@xxxxxxxxxxxxxxx Cc: Harshit Mogalapalli <harshit.m.mogalapalli@xxxxxxxxxx>, Kees Cook <keescook@xxxxxxxxxxxx>, SeongJae Park <sj@xxxxxxxxxx>, Seth Jenkins <sethjenkins@xxxxxxxxxx>, Jann Horn <jannh@xxxxxxxxxx>, "Eric W . Biederman" <ebiederm@xxxxxxxxxxxx>, linux-hardening@xxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx, Petr Mladek <pmladek@xxxxxxxx>, Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>, tangmeng <tangmeng@xxxxxxxxxxxxx>, "Guilherme G. Piccoli" <gpiccoli@xxxxxxxxxx>, Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>, Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>, Luis Chamberlain <mcgrof@xxxxxxxxxx> Message-ID: <20230203002717.49198-14-ebiggers@xxxxxxxxxx> 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: Eric Biggers <ebiggers@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- Documentation/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 --- /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/kernel/panic.c +++ b/kernel/panic.c @@ -29,6 +29,7 @@ #include <linux/bug.h> #include <linux/ratelimit.h> #include <linux/debugfs.h> +#include <linux/sysfs.h> #include <asm/sections.h> #define PANIC_TIMER_STEP 100 @@ -71,6 +72,25 @@ 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; @@ -148,8 +168,6 @@ 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); Patches currently in stable-queue which might be from stable-owner@xxxxxxxxxxxxxxx are queue-4.19/panic-unset-panic_on_warn-inside-panic.patch queue-4.19/objtool-add-a-missing-comma-to-avoid-string-concatenation.patch queue-4.19/hexagon-fix-function-name-in-die.patch queue-4.19/exit-add-and-use-make_task_dead.patch queue-4.19/h8300-fix-build-errors-from-do_exit-to-make_task_dead-transition.patch queue-4.19/panic-consolidate-open-coded-panic_on_warn-checks.patch queue-4.19/exit-put-an-upper-limit-on-how-often-we-can-oops.patch queue-4.19/panic-introduce-warn_limit.patch queue-4.19/exit-allow-oops_limit-to-be-disabled.patch queue-4.19/ia64-make-ia64_mca_recovery-bool-instead-of-tristate.patch queue-4.19/exit-use-read_once-for-all-oops-warn-limit-reads.patch queue-4.19/exit-expose-oops_count-to-sysfs.patch queue-4.19/panic-expose-warn_count-to-sysfs.patch queue-4.19/docs-fix-path-paste-o-for-sys-kernel-warn_count.patch queue-4.19/sysctl-add-a-new-register_sysctl_init-interface.patch