#include <linux/nmi.h>
#include <linux/dmi.h>
+#define PANIC_TIMER_STEP 100
+#define PANIC_BLINK_SPD 18
+
int panic_on_oops;
static unsigned long tainted_mask;
static int pause_on_oops;
static DEFINE_SPINLOCK(pause_on_oops_lock);
int panic_timeout;
+EXPORT_SYMBOL_GPL(panic_timeout);
ATOMIC_NOTIFIER_HEAD(panic_notifier_list);
EXPORT_SYMBOL(panic_notifier_list);
+static long no_blink(int state)
+{
+ return 0;
+}
+
/* Returns how long it waited in ms */
-long (*panic_blink)(long time);
+long (*panic_blink)(int state);
EXPORT_SYMBOL(panic_blink);
-static void panic_blink_one_second(void)
+/*
+ * Stop ourself in panic -- architecture code may override this
+ */
+void __weak panic_smp_self_stop(void)
{
- static long i = 0, end;
-
- if (panic_blink) {
- end = i + MSEC_PER_SEC;
-
- while (i < end) {
- i += panic_blink(i);
- mdelay(1);
- i++;
- }
- } else {
- /*
- * When running under a hypervisor a small mdelay may get
- * rounded up to the hypervisor timeslice. For example, with
- * a 1ms in 10ms hypervisor timeslice we might inflate a
- * mdelay(1) loop by 10x.
- *
- * If we have nothing to blink, spin on 1 second calls to
- * mdelay to avoid this.
- */
- mdelay(MSEC_PER_SEC);
- }
+ while (1)
+ cpu_relax();
}
/**
*
* This function never returns.
*/
-NORET_TYPE void panic(const char * fmt, ...)
+void panic(const char *fmt, ...)
{
+ static DEFINE_SPINLOCK(panic_lock);
static char buf[1024];
va_list args;
- long i;
+ long i, i_next = 0;
+ int state = 0;
/*
* 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().
*/
- preempt_disable();
+ if (!spin_trylock(&panic_lock))
+ panic_smp_self_stop();
console_verbose();
bust_spinlocks(1);
va_end(args);
printk(KERN_EMERG "Kernel panic - not syncing: %s\n",buf);
#ifdef CONFIG_DEBUG_BUGVERBOSE
- dump_stack();
+ /*
+ * Avoid nested stack-dumping if a panic occurs during oops processing
+ */
+ if (!oops_in_progress)
+ dump_stack();
#endif
/*
bust_spinlocks(0);
+ if (!panic_blink)
+ panic_blink = no_blink;
+
if (panic_timeout > 0) {
/*
* Delay timeout seconds before rebooting the machine.
*/
printk(KERN_EMERG "Rebooting in %d seconds..", panic_timeout);
- for (i = 0; i < panic_timeout; i++) {
+ for (i = 0; i < panic_timeout * 1000; i += PANIC_TIMER_STEP) {
touch_nmi_watchdog();
- panic_blink_one_second();
+ 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
}
#endif
local_irq_enable();
- while (1) {
+ for (i = 0; ; i += PANIC_TIMER_STEP) {
touch_softlockup_watchdog();
- panic_blink_one_second();
+ if (i >= i_next) {
+ i += panic_blink(state ^= 1);
+ i_next = i + 3600 / PANIC_BLINK_SPD;
+ }
+ mdelay(PANIC_TIMER_STEP);
}
}
{ TAINT_WARN, 'W', ' ' },
{ TAINT_CRAP, 'C', ' ' },
{ TAINT_FIRMWARE_WORKAROUND, 'I', ' ' },
+ { TAINT_OOT_MODULE, 'O', ' ' },
};
/**
* 'W' - Taint on warning.
* 'C' - modules from drivers/staging are loaded.
* 'I' - Working around severe firmware bug.
+ * 'O' - Out-of-tree module has been loaded.
*
* The string is overwritten by the next call to print_tainted().
*/
* Can't trust the integrity of the kernel anymore.
* We don't call directly debug_locks_off() because the issue
* is not necessarily serious enough to set oops_in_progress to 1
- * Also we want to keep up lockdep for staging development and
- * post-warning case.
+ * Also we want to keep up lockdep for staging/out-of-tree
+ * development and post-warning case.
*/
- if (flag != TAINT_CRAP && flag != TAINT_WARN && __debug_locks_off())
- printk(KERN_WARNING "Disabling lock debugging due to kernel taint\n");
+ switch (flag) {
+ case TAINT_CRAP:
+ case TAINT_OOT_MODULE:
+ case TAINT_WARN:
+ case TAINT_FIRMWARE_WORKAROUND:
+ break;
+
+ default:
+ if (__debug_locks_off())
+ printk(KERN_WARNING "Disabling lock debugging due to kernel taint\n");
+ }
set_bit(flag, &tainted_mask);
}
}
late_initcall(init_oops_id);
-static void print_oops_end_marker(void)
+void print_oops_end_marker(void)
{
init_oops_id();
printk(KERN_WARNING "---[ end trace %016llx ]---\n",
core_param(panic, panic_timeout, int, 0644);
core_param(pause_on_oops, pause_on_oops, int, 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);