Commit 9db89b41 authored by Kees Cook's avatar Kees Cook
Browse files

exit: Expose "oops_count" to sysfs 



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: default avatarLuis Chamberlain <mcgrof@kernel.org>
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221117234328.594699-3-keescook@chromium.org
parent d4ccd54d

Documentation/ABI/testing/sysfs-kernel-oops_count

0 → 100644
+6 −0
Original line number Diff line number Diff line 
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.

MAINTAINERS

+1 −0
Original line number Diff line number Diff line
@@ -11106,6 +11106,7 @@ M: Kees Cook <keescook@chromium.org> 
L:	linux-hardening@vger.kernel.org

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

kernel/exit.c

+20 −2
Original line number Diff line number Diff line
@@ -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_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--;
@@ -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.