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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /kernel/panic.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'kernel/panic.c')
-rw-r--r--kernel/panic.c808
1 files changed, 808 insertions, 0 deletions
diff --git a/kernel/panic.c b/kernel/panic.c
new file mode 100644
index 000000000..63e94f3bd
--- /dev/null
+++ b/kernel/panic.c
@@ -0,0 +1,808 @@
+// 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/panic_notifier.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 <linux/context_tracking.h>
+#include <trace/events/error_report.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_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
+#define PANIC_PRINT_ALL_CPU_BT 0x00000040
+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(bool console_flush)
+{
+ if (console_flush) {
+ if (panic_print & PANIC_PRINT_ALL_PRINTK_MSG)
+ console_flush_on_panic(CONSOLE_REPLAY_ALL);
+ return;
+ }
+
+ 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);
+}
+
+/*
+ * Helper that triggers the NMI backtrace (if set in panic_print)
+ * and then performs the secondary CPUs shutdown - we cannot have
+ * the NMI backtrace after the CPUs are off!
+ */
+static void panic_other_cpus_shutdown(bool crash_kexec)
+{
+ if (panic_print & PANIC_PRINT_ALL_CPU_BT)
+ trigger_all_cpu_backtrace();
+
+ /*
+ * Note that smp_send_stop() is the usual SMP shutdown function,
+ * which unfortunately may not be hardened to work in a panic
+ * situation. If we want to do crash dump after notifier calls
+ * and kmsg_dump, we will need architecture dependent extra
+ * bits in addition to stopping other CPUs, hence we rely on
+ * crash_smp_send_stop() for that.
+ */
+ if (!crash_kexec)
+ smp_send_stop();
+ else
+ crash_smp_send_stop();
+}
+
+/**
+ * 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)
+ __crash_kexec(NULL);
+
+ panic_other_cpus_shutdown(_crash_kexec_post_notifiers);
+
+ /*
+ * 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);
+
+ panic_print_sys_info(false);
+
+ 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);
+
+ 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(true);
+
+ 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 },
+ [ TAINT_TEST ] = { 'N', ' ', 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();
+}
+
+static void print_oops_end_marker(void)
+{
+ pr_warn("---[ end trace %016llx ]---\n", 0ULL);
+}
+
+/*
+ * 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();
+ trace_error_report_end(ERROR_DETECTOR_WARN, (unsigned long)caller);
+
+ /* 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, ...)
+{
+ bool rcu = warn_rcu_enter();
+ struct warn_args args;
+
+ pr_warn(CUT_HERE);
+
+ if (!fmt) {
+ __warn(file, line, __builtin_return_address(0), taint,
+ NULL, NULL);
+ warn_rcu_exit(rcu);
+ return;
+ }
+
+ args.fmt = fmt;
+ va_start(args.args, fmt);
+ __warn(file, line, __builtin_return_address(0), taint, NULL, &args);
+ va_end(args.args);
+ warn_rcu_exit(rcu);
+}
+EXPORT_SYMBOL(warn_slowpath_fmt);
+#else
+void __warn_printk(const char *fmt, ...)
+{
+ bool rcu = warn_rcu_enter();
+ va_list args;
+
+ pr_warn(CUT_HERE);
+
+ va_start(args, fmt);
+ vprintk(fmt, args);
+ va_end(args);
+ warn_rcu_exit(rcu);
+}
+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);