Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 804 insertions, 0 deletions

diff --git a/kernel/panic.c b/kernel/panic.c
new file mode 100644
index 000000000..bc39e2b27
--- /dev/null
+++ b/kernel/panic.c
@@ -0,0 +1,804 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/kernel/panic.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ */
+
+/*
+ * This function is used through-out the kernel (including mm and fs)
+ * to indicate a major problem.
+ */
+#include <linux/debug_locks.h>
+#include <linux/sched/debug.h>
+#include <linux/interrupt.h>
+#include <linux/kgdb.h>
+#include <linux/kmsg_dump.h>
+#include <linux/kallsyms.h>
+#include <linux/notifier.h>
+#include <linux/vt_kern.h>
+#include <linux/module.h>
+#include <linux/random.h>
+#include <linux/ftrace.h>
+#include <linux/reboot.h>
+#include <linux/delay.h>
+#include <linux/kexec.h>
+#include <linux/sched.h>
+#include <linux/sysrq.h>
+#include <linux/init.h>
+#include <linux/nmi.h>
+#include <linux/console.h>
+#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
+#define PANIC_BLINK_SPD 18
+
+#ifdef CONFIG_SMP
+/*
+ * Should we dump all CPUs backtraces in an oops event?
+ * Defaults to 0, can be changed via sysctl.
+ */
+static unsigned int __read_mostly sysctl_oops_all_cpu_backtrace;
+#else
+#define sysctl_oops_all_cpu_backtrace 0
+#endif /* CONFIG_SMP */
+
+int panic_on_oops = CONFIG_PANIC_ON_OOPS_VALUE;
+static unsigned long tainted_mask =
+	IS_ENABLED(CONFIG_GCC_PLUGIN_RANDSTRUCT) ? (1 << TAINT_RANDSTRUCT) : 0;
+static int pause_on_oops;
+static int pause_on_oops_flag;
+static DEFINE_SPINLOCK(pause_on_oops_lock);
+bool crash_kexec_post_notifiers;
+int panic_on_warn __read_mostly;
+unsigned long panic_on_taint;
+bool panic_on_taint_nousertaint = false;
+static unsigned int warn_limit __read_mostly;
+
+int panic_timeout = CONFIG_PANIC_TIMEOUT;
+EXPORT_SYMBOL_GPL(panic_timeout);
+
+#define PANIC_PRINT_TASK_INFO		0x00000001
+#define PANIC_PRINT_MEM_INFO		0x00000002
+#define PANIC_PRINT_TIMER_INFO		0x00000004
+#define PANIC_PRINT_LOCK_INFO		0x00000008
+#define PANIC_PRINT_FTRACE_INFO		0x00000010
+#define PANIC_PRINT_ALL_PRINTK_MSG	0x00000020
+unsigned long panic_print;
+
+ATOMIC_NOTIFIER_HEAD(panic_notifier_list);
+
+EXPORT_SYMBOL(panic_notifier_list);
+
+#ifdef CONFIG_SYSCTL
+static struct ctl_table kern_panic_table[] = {
+#ifdef CONFIG_SMP
+	{
+		.procname       = "oops_all_cpu_backtrace",
+		.data           = &sysctl_oops_all_cpu_backtrace,
+		.maxlen         = sizeof(int),
+		.mode           = 0644,
+		.proc_handler   = proc_dointvec_minmax,
+		.extra1         = SYSCTL_ZERO,
+		.extra2         = SYSCTL_ONE,
+	},
+#endif
+	{
+		.procname       = "warn_limit",
+		.data           = &warn_limit,
+		.maxlen         = sizeof(warn_limit),
+		.mode           = 0644,
+		.proc_handler   = proc_douintvec,
+	},
+	{ }
+};
+
+static __init int kernel_panic_sysctls_init(void)
+{
+	register_sysctl_init("kernel", kern_panic_table);
+	return 0;
+}
+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;
+}
+
+/* Returns how long it waited in ms */
+long (*panic_blink)(int state);
+EXPORT_SYMBOL(panic_blink);
+
+/*
+ * Stop ourself in panic -- architecture code may override this
+ */
+void __weak panic_smp_self_stop(void)
+{
+	while (1)
+		cpu_relax();
+}
+
+/*
+ * Stop ourselves in NMI context if another CPU has already panicked. Arch code
+ * may override this to prepare for crash dumping, e.g. save regs info.
+ */
+void __weak nmi_panic_self_stop(struct pt_regs *regs)
+{
+	panic_smp_self_stop();
+}
+
+/*
+ * Stop other CPUs in panic.  Architecture dependent code may override this
+ * with more suitable version.  For example, if the architecture supports
+ * crash dump, it should save registers of each stopped CPU and disable
+ * per-CPU features such as virtualization extensions.
+ */
+void __weak crash_smp_send_stop(void)
+{
+	static int cpus_stopped;
+
+	/*
+	 * This function can be called twice in panic path, but obviously
+	 * we execute this only once.
+	 */
+	if (cpus_stopped)
+		return;
+
+	/*
+	 * Note smp_send_stop is the usual smp shutdown function, which
+	 * unfortunately means it may not be hardened to work in a panic
+	 * situation.
+	 */
+	smp_send_stop();
+	cpus_stopped = 1;
+}
+
+atomic_t panic_cpu = ATOMIC_INIT(PANIC_CPU_INVALID);
+
+/*
+ * A variant of panic() called from NMI context. We return if we've already
+ * panicked on this CPU. If another CPU already panicked, loop in
+ * nmi_panic_self_stop() which can provide architecture dependent code such
+ * as saving register state for crash dump.
+ */
+void nmi_panic(struct pt_regs *regs, const char *msg)
+{
+	int old_cpu, cpu;
+
+	cpu = raw_smp_processor_id();
+	old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, cpu);
+
+	if (old_cpu == PANIC_CPU_INVALID)
+		panic("%s", msg);
+	else if (old_cpu != cpu)
+		nmi_panic_self_stop(regs);
+}
+EXPORT_SYMBOL(nmi_panic);
+
+static void panic_print_sys_info(void)
+{
+	if (panic_print & PANIC_PRINT_ALL_PRINTK_MSG)
+		console_flush_on_panic(CONSOLE_REPLAY_ALL);
+
+	if (panic_print & PANIC_PRINT_TASK_INFO)
+		show_state();
+
+	if (panic_print & PANIC_PRINT_MEM_INFO)
+		show_mem(0, NULL);
+
+	if (panic_print & PANIC_PRINT_TIMER_INFO)
+		sysrq_timer_list_show();
+
+	if (panic_print & PANIC_PRINT_LOCK_INFO)
+		debug_show_all_locks();
+
+	if (panic_print & PANIC_PRINT_FTRACE_INFO)
+		ftrace_dump(DUMP_ALL);
+}
+
+void check_panic_on_warn(const char *origin)
+{
+	unsigned int limit;
+
+	if (panic_on_warn)
+		panic("%s: panic_on_warn set ...\n", origin);
+
+	limit = READ_ONCE(warn_limit);
+	if (atomic_inc_return(&warn_count) >= limit && limit)
+		panic("%s: system warned too often (kernel.warn_limit is %d)",
+		      origin, limit);
+}
+
+/**
+ *	panic - halt the system
+ *	@fmt: The text string to print
+ *
+ *	Display a message, then perform cleanups.
+ *
+ *	This function never returns.
+ */
+void panic(const char *fmt, ...)
+{
+	static char buf[1024];
+	va_list args;
+	long i, i_next = 0, len;
+	int state = 0;
+	int old_cpu, this_cpu;
+	bool _crash_kexec_post_notifiers = crash_kexec_post_notifiers;
+
+	if (panic_on_warn) {
+		/*
+		 * This thread may hit another WARN() in the panic path.
+		 * Resetting this prevents additional WARN() from panicking the
+		 * system on this thread.  Other threads are blocked by the
+		 * panic_mutex in panic().
+		 */
+		panic_on_warn = 0;
+	}
+
+	/*
+	 * Disable local interrupts. This will prevent panic_smp_self_stop
+	 * from deadlocking the first cpu that invokes the panic, since
+	 * there is nothing to prevent an interrupt handler (that runs
+	 * after setting panic_cpu) from invoking panic() again.
+	 */
+	local_irq_disable();
+	preempt_disable_notrace();
+
+	/*
+	 * It's possible to come here directly from a panic-assertion and
+	 * not have preempt disabled. Some functions called from here want
+	 * preempt to be disabled. No point enabling it later though...
+	 *
+	 * Only one CPU is allowed to execute the panic code from here. For
+	 * multiple parallel invocations of panic, all other CPUs either
+	 * stop themself or will wait until they are stopped by the 1st CPU
+	 * with smp_send_stop().
+	 *
+	 * `old_cpu == PANIC_CPU_INVALID' means this is the 1st CPU which
+	 * comes here, so go ahead.
+	 * `old_cpu == this_cpu' means we came from nmi_panic() which sets
+	 * panic_cpu to this CPU.  In this case, this is also the 1st CPU.
+	 */
+	this_cpu = raw_smp_processor_id();
+	old_cpu  = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, this_cpu);
+
+	if (old_cpu != PANIC_CPU_INVALID && old_cpu != this_cpu)
+		panic_smp_self_stop();
+
+	console_verbose();
+	bust_spinlocks(1);
+	va_start(args, fmt);
+	len = vscnprintf(buf, sizeof(buf), fmt, args);
+	va_end(args);
+
+	if (len && buf[len - 1] == '\n')
+		buf[len - 1] = '\0';
+
+	pr_emerg("Kernel panic - not syncing: %s\n", buf);
+#ifdef CONFIG_DEBUG_BUGVERBOSE
+	/*
+	 * Avoid nested stack-dumping if a panic occurs during oops processing
+	 */
+	if (!test_taint(TAINT_DIE) && oops_in_progress <= 1)
+		dump_stack();
+#endif
+
+	/*
+	 * If kgdb is enabled, give it a chance to run before we stop all
+	 * the other CPUs or else we won't be able to debug processes left
+	 * running on them.
+	 */
+	kgdb_panic(buf);
+
+	/*
+	 * If we have crashed and we have a crash kernel loaded let it handle
+	 * everything else.
+	 * If we want to run this after calling panic_notifiers, pass
+	 * the "crash_kexec_post_notifiers" option to the kernel.
+	 *
+	 * Bypass the panic_cpu check and call __crash_kexec directly.
+	 */
+	if (!_crash_kexec_post_notifiers) {
+		printk_safe_flush_on_panic();
+		__crash_kexec(NULL);
+
+		/*
+		 * Note smp_send_stop is the usual smp shutdown function, which
+		 * unfortunately means it may not be hardened to work in a
+		 * panic situation.
+		 */
+		smp_send_stop();
+	} else {
+		/*
+		 * If we want to do crash dump after notifier calls and
+		 * kmsg_dump, we will need architecture dependent extra
+		 * works in addition to stopping other CPUs.
+		 */
+		crash_smp_send_stop();
+	}
+
+	/*
+	 * Run any panic handlers, including those that might need to
+	 * add information to the kmsg dump output.
+	 */
+	atomic_notifier_call_chain(&panic_notifier_list, 0, buf);
+
+	/* Call flush even twice. It tries harder with a single online CPU */
+	printk_safe_flush_on_panic();
+	kmsg_dump(KMSG_DUMP_PANIC);
+
+	/*
+	 * If you doubt kdump always works fine in any situation,
+	 * "crash_kexec_post_notifiers" offers you a chance to run
+	 * panic_notifiers and dumping kmsg before kdump.
+	 * Note: since some panic_notifiers can make crashed kernel
+	 * more unstable, it can increase risks of the kdump failure too.
+	 *
+	 * Bypass the panic_cpu check and call __crash_kexec directly.
+	 */
+	if (_crash_kexec_post_notifiers)
+		__crash_kexec(NULL);
+
+#ifdef CONFIG_VT
+	unblank_screen();
+#endif
+	console_unblank();
+
+	/*
+	 * We may have ended up stopping the CPU holding the lock (in
+	 * smp_send_stop()) while still having some valuable data in the console
+	 * buffer.  Try to acquire the lock then release it regardless of the
+	 * result.  The release will also print the buffers out.  Locks debug
+	 * should be disabled to avoid reporting bad unlock balance when
+	 * panic() is not being callled from OOPS.
+	 */
+	debug_locks_off();
+	console_flush_on_panic(CONSOLE_FLUSH_PENDING);
+
+	panic_print_sys_info();
+
+	if (!panic_blink)
+		panic_blink = no_blink;
+
+	if (panic_timeout > 0) {
+		/*
+		 * Delay timeout seconds before rebooting the machine.
+		 * We can't use the "normal" timers since we just panicked.
+		 */
+		pr_emerg("Rebooting in %d seconds..\n", panic_timeout);
+
+		for (i = 0; i < panic_timeout * 1000; i += PANIC_TIMER_STEP) {
+			touch_nmi_watchdog();
+			if (i >= i_next) {
+				i += panic_blink(state ^= 1);
+				i_next = i + 3600 / PANIC_BLINK_SPD;
+			}
+			mdelay(PANIC_TIMER_STEP);
+		}
+	}
+	if (panic_timeout != 0) {
+		/*
+		 * This will not be a clean reboot, with everything
+		 * shutting down.  But if there is a chance of
+		 * rebooting the system it will be rebooted.
+		 */
+		if (panic_reboot_mode != REBOOT_UNDEFINED)
+			reboot_mode = panic_reboot_mode;
+		emergency_restart();
+	}
+#ifdef __sparc__
+	{
+		extern int stop_a_enabled;
+		/* Make sure the user can actually press Stop-A (L1-A) */
+		stop_a_enabled = 1;
+		pr_emerg("Press Stop-A (L1-A) from sun keyboard or send break\n"
+			 "twice on console to return to the boot prom\n");
+	}
+#endif
+#if defined(CONFIG_S390)
+	disabled_wait();
+#endif
+	pr_emerg("---[ end Kernel panic - not syncing: %s ]---\n", buf);
+
+	/* Do not scroll important messages printed above */
+	suppress_printk = 1;
+	local_irq_enable();
+	for (i = 0; ; i += PANIC_TIMER_STEP) {
+		touch_softlockup_watchdog();
+		if (i >= i_next) {
+			i += panic_blink(state ^= 1);
+			i_next = i + 3600 / PANIC_BLINK_SPD;
+		}
+		mdelay(PANIC_TIMER_STEP);
+	}
+}
+
+EXPORT_SYMBOL(panic);
+
+/*
+ * TAINT_FORCED_RMMOD could be a per-module flag but the module
+ * is being removed anyway.
+ */
+const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = {
+	[ TAINT_PROPRIETARY_MODULE ]	= { 'P', 'G', true },
+	[ TAINT_FORCED_MODULE ]		= { 'F', ' ', true },
+	[ TAINT_CPU_OUT_OF_SPEC ]	= { 'S', ' ', false },
+	[ TAINT_FORCED_RMMOD ]		= { 'R', ' ', false },
+	[ TAINT_MACHINE_CHECK ]		= { 'M', ' ', false },
+	[ TAINT_BAD_PAGE ]		= { 'B', ' ', false },
+	[ TAINT_USER ]			= { 'U', ' ', false },
+	[ TAINT_DIE ]			= { 'D', ' ', false },
+	[ TAINT_OVERRIDDEN_ACPI_TABLE ]	= { 'A', ' ', false },
+	[ TAINT_WARN ]			= { 'W', ' ', false },
+	[ TAINT_CRAP ]			= { 'C', ' ', true },
+	[ TAINT_FIRMWARE_WORKAROUND ]	= { 'I', ' ', false },
+	[ TAINT_OOT_MODULE ]		= { 'O', ' ', true },
+	[ TAINT_UNSIGNED_MODULE ]	= { 'E', ' ', true },
+	[ TAINT_SOFTLOCKUP ]		= { 'L', ' ', false },
+	[ TAINT_LIVEPATCH ]		= { 'K', ' ', true },
+	[ TAINT_AUX ]			= { 'X', ' ', true },
+	[ TAINT_RANDSTRUCT ]		= { 'T', ' ', true },
+};
+
+/**
+ * print_tainted - return a string to represent the kernel taint state.
+ *
+ * For individual taint flag meanings, see Documentation/admin-guide/sysctl/kernel.rst
+ *
+ * The string is overwritten by the next call to print_tainted(),
+ * but is always NULL terminated.
+ */
+const char *print_tainted(void)
+{
+	static char buf[TAINT_FLAGS_COUNT + sizeof("Tainted: ")];
+
+	BUILD_BUG_ON(ARRAY_SIZE(taint_flags) != TAINT_FLAGS_COUNT);
+
+	if (tainted_mask) {
+		char *s;
+		int i;
+
+		s = buf + sprintf(buf, "Tainted: ");
+		for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
+			const struct taint_flag *t = &taint_flags[i];
+			*s++ = test_bit(i, &tainted_mask) ?
+					t->c_true : t->c_false;
+		}
+		*s = 0;
+	} else
+		snprintf(buf, sizeof(buf), "Not tainted");
+
+	return buf;
+}
+
+int test_taint(unsigned flag)
+{
+	return test_bit(flag, &tainted_mask);
+}
+EXPORT_SYMBOL(test_taint);
+
+unsigned long get_taint(void)
+{
+	return tainted_mask;
+}
+
+/**
+ * add_taint: add a taint flag if not already set.
+ * @flag: one of the TAINT_* constants.
+ * @lockdep_ok: whether lock debugging is still OK.
+ *
+ * If something bad has gone wrong, you'll want @lockdebug_ok = false, but for
+ * some notewortht-but-not-corrupting cases, it can be set to true.
+ */
+void add_taint(unsigned flag, enum lockdep_ok lockdep_ok)
+{
+	if (lockdep_ok == LOCKDEP_NOW_UNRELIABLE && __debug_locks_off())
+		pr_warn("Disabling lock debugging due to kernel taint\n");
+
+	set_bit(flag, &tainted_mask);
+
+	if (tainted_mask & panic_on_taint) {
+		panic_on_taint = 0;
+		panic("panic_on_taint set ...");
+	}
+}
+EXPORT_SYMBOL(add_taint);
+
+static void spin_msec(int msecs)
+{
+	int i;
+
+	for (i = 0; i < msecs; i++) {
+		touch_nmi_watchdog();
+		mdelay(1);
+	}
+}
+
+/*
+ * It just happens that oops_enter() and oops_exit() are identically
+ * implemented...
+ */
+static void do_oops_enter_exit(void)
+{
+	unsigned long flags;
+	static int spin_counter;
+
+	if (!pause_on_oops)
+		return;
+
+	spin_lock_irqsave(&pause_on_oops_lock, flags);
+	if (pause_on_oops_flag == 0) {
+		/* This CPU may now print the oops message */
+		pause_on_oops_flag = 1;
+	} else {
+		/* We need to stall this CPU */
+		if (!spin_counter) {
+			/* This CPU gets to do the counting */
+			spin_counter = pause_on_oops;
+			do {
+				spin_unlock(&pause_on_oops_lock);
+				spin_msec(MSEC_PER_SEC);
+				spin_lock(&pause_on_oops_lock);
+			} while (--spin_counter);
+			pause_on_oops_flag = 0;
+		} else {
+			/* This CPU waits for a different one */
+			while (spin_counter) {
+				spin_unlock(&pause_on_oops_lock);
+				spin_msec(1);
+				spin_lock(&pause_on_oops_lock);
+			}
+		}
+	}
+	spin_unlock_irqrestore(&pause_on_oops_lock, flags);
+}
+
+/*
+ * Return true if the calling CPU is allowed to print oops-related info.
+ * This is a bit racy..
+ */
+bool oops_may_print(void)
+{
+	return pause_on_oops_flag == 0;
+}
+
+/*
+ * Called when the architecture enters its oops handler, before it prints
+ * anything.  If this is the first CPU to oops, and it's oopsing the first
+ * time then let it proceed.
+ *
+ * This is all enabled by the pause_on_oops kernel boot option.  We do all
+ * this to ensure that oopses don't scroll off the screen.  It has the
+ * side-effect of preventing later-oopsing CPUs from mucking up the display,
+ * too.
+ *
+ * It turns out that the CPU which is allowed to print ends up pausing for
+ * the right duration, whereas all the other CPUs pause for twice as long:
+ * once in oops_enter(), once in oops_exit().
+ */
+void oops_enter(void)
+{
+	tracing_off();
+	/* can't trust the integrity of the kernel anymore: */
+	debug_locks_off();
+	do_oops_enter_exit();
+
+	if (sysctl_oops_all_cpu_backtrace)
+		trigger_all_cpu_backtrace();
+}
+
+/*
+ * 64-bit random ID for oopses:
+ */
+static u64 oops_id;
+
+static int init_oops_id(void)
+{
+	if (!oops_id)
+		get_random_bytes(&oops_id, sizeof(oops_id));
+	else
+		oops_id++;
+
+	return 0;
+}
+late_initcall(init_oops_id);
+
+static void print_oops_end_marker(void)
+{
+	init_oops_id();
+	pr_warn("---[ end trace %016llx ]---\n", (unsigned long long)oops_id);
+}
+
+/*
+ * Called when the architecture exits its oops handler, after printing
+ * everything.
+ */
+void oops_exit(void)
+{
+	do_oops_enter_exit();
+	print_oops_end_marker();
+	kmsg_dump(KMSG_DUMP_OOPS);
+}
+
+struct warn_args {
+	const char *fmt;
+	va_list args;
+};
+
+void __warn(const char *file, int line, void *caller, unsigned taint,
+	    struct pt_regs *regs, struct warn_args *args)
+{
+	disable_trace_on_warning();
+
+	if (file)
+		pr_warn("WARNING: CPU: %d PID: %d at %s:%d %pS\n",
+			raw_smp_processor_id(), current->pid, file, line,
+			caller);
+	else
+		pr_warn("WARNING: CPU: %d PID: %d at %pS\n",
+			raw_smp_processor_id(), current->pid, caller);
+
+	if (args)
+		vprintk(args->fmt, args->args);
+
+	print_modules();
+
+	if (regs)
+		show_regs(regs);
+
+	check_panic_on_warn("kernel");
+
+	if (!regs)
+		dump_stack();
+
+	print_irqtrace_events(current);
+
+	print_oops_end_marker();
+
+	/* Just a warning, don't kill lockdep. */
+	add_taint(taint, LOCKDEP_STILL_OK);
+}
+
+#ifndef __WARN_FLAGS
+void warn_slowpath_fmt(const char *file, int line, unsigned taint,
+		       const char *fmt, ...)
+{
+	struct warn_args args;
+
+	pr_warn(CUT_HERE);
+
+	if (!fmt) {
+		__warn(file, line, __builtin_return_address(0), taint,
+		       NULL, NULL);
+		return;
+	}
+
+	args.fmt = fmt;
+	va_start(args.args, fmt);
+	__warn(file, line, __builtin_return_address(0), taint, NULL, &args);
+	va_end(args.args);
+}
+EXPORT_SYMBOL(warn_slowpath_fmt);
+#else
+void __warn_printk(const char *fmt, ...)
+{
+	va_list args;
+
+	pr_warn(CUT_HERE);
+
+	va_start(args, fmt);
+	vprintk(fmt, args);
+	va_end(args);
+}
+EXPORT_SYMBOL(__warn_printk);
+#endif
+
+#ifdef CONFIG_BUG
+
+/* Support resetting WARN*_ONCE state */
+
+static int clear_warn_once_set(void *data, u64 val)
+{
+	generic_bug_clear_once();
+	memset(__start_once, 0, __end_once - __start_once);
+	return 0;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(clear_warn_once_fops, NULL, clear_warn_once_set,
+			 "%lld\n");
+
+static __init int register_warn_debugfs(void)
+{
+	/* Don't care about failure */
+	debugfs_create_file_unsafe("clear_warn_once", 0200, NULL, NULL,
+				   &clear_warn_once_fops);
+	return 0;
+}
+
+device_initcall(register_warn_debugfs);
+#endif
+
+#ifdef CONFIG_STACKPROTECTOR
+
+/*
+ * Called when gcc's -fstack-protector feature is used, and
+ * gcc detects corruption of the on-stack canary value
+ */
+__visible noinstr void __stack_chk_fail(void)
+{
+	instrumentation_begin();
+	panic("stack-protector: Kernel stack is corrupted in: %pB",
+		__builtin_return_address(0));
+	instrumentation_end();
+}
+EXPORT_SYMBOL(__stack_chk_fail);
+
+#endif
+
+core_param(panic, panic_timeout, int, 0644);
+core_param(panic_print, panic_print, ulong, 0644);
+core_param(pause_on_oops, pause_on_oops, int, 0644);
+core_param(panic_on_warn, panic_on_warn, int, 0644);
+core_param(crash_kexec_post_notifiers, crash_kexec_post_notifiers, bool, 0644);
+
+static int __init oops_setup(char *s)
+{
+	if (!s)
+		return -EINVAL;
+	if (!strcmp(s, "panic"))
+		panic_on_oops = 1;
+	return 0;
+}
+early_param("oops", oops_setup);
+
+static int __init panic_on_taint_setup(char *s)
+{
+	char *taint_str;
+
+	if (!s)
+		return -EINVAL;
+
+	taint_str = strsep(&s, ",");
+	if (kstrtoul(taint_str, 16, &panic_on_taint))
+		return -EINVAL;
+
+	/* make sure panic_on_taint doesn't hold out-of-range TAINT flags */
+	panic_on_taint &= TAINT_FLAGS_MAX;
+
+	if (!panic_on_taint)
+		return -EINVAL;
+
+	if (s && !strcmp(s, "nousertaint"))
+		panic_on_taint_nousertaint = true;
+
+	pr_info("panic_on_taint: bitmask=0x%lx nousertaint_mode=%sabled\n",
+		panic_on_taint, panic_on_taint_nousertaint ? "en" : "dis");
+
+	return 0;
+}
+early_param("panic_on_taint", panic_on_taint_setup);