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authorKees Cook2022-11-17 15:43:23 -0800
committerGreg Kroah-Hartman2023-01-24 07:24:41 +0100
commit46cacd7913c86f84b784dc2e0151bfaefde315d7 (patch)
tree6e6a6060523148df1ba5ea936278cf684be47f7a
parent767997ef5dc0de5f395b69f5f26eb8b01c65ae1a (diff)
exit: Expose "oops_count" to sysfs
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--Documentation/ABI/testing/sysfs-kernel-oops_count6
-rw-r--r--MAINTAINERS1
-rw-r--r--kernel/exit.c22
3 files changed, 27 insertions, 2 deletions
diff --git a/Documentation/ABI/testing/sysfs-kernel-oops_count b/Documentation/ABI/testing/sysfs-kernel-oops_count
new file mode 100644
index 000000000000..156cca9dbc96
--- /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/MAINTAINERS b/MAINTAINERS
index 886d3f69ee64..69d0342ce36e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11112,6 +11112,7 @@ 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
diff --git a/kernel/exit.c b/kernel/exit.c
index 2ab3ead62118..dc1a32149f94 100644
--- 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_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.