#include <linux/sysrq.h>
#include <linux/interrupt.h>
#include <linux/nmi.h>
+#include <linux/kexec.h>
-int panic_timeout;
int panic_on_oops;
int tainted;
+static int pause_on_oops;
+static int pause_on_oops_flag;
+static DEFINE_SPINLOCK(pause_on_oops_lock);
-EXPORT_SYMBOL(panic_timeout);
+int panic_timeout;
-struct notifier_block *panic_notifier_list;
+ATOMIC_NOTIFIER_HEAD(panic_notifier_list);
EXPORT_SYMBOL(panic_notifier_list);
long i;
static char buf[1024];
va_list args;
-#if defined(CONFIG_ARCH_S390)
+#if defined(CONFIG_S390)
unsigned long caller = (unsigned long) __builtin_return_address(0);
#endif
+ /*
+ * 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...
+ */
+ preempt_disable();
+
bust_spinlocks(1);
va_start(args, fmt);
vsnprintf(buf, sizeof(buf), fmt, args);
printk(KERN_EMERG "Kernel panic - not syncing: %s\n",buf);
bust_spinlocks(0);
+ /*
+ * If we have crashed and we have a crash kernel loaded let it handle
+ * everything else.
+ * Do we want to call this before we try to display a message?
+ */
+ crash_kexec(NULL);
+
#ifdef CONFIG_SMP
+ /*
+ * 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();
#endif
- notifier_call_chain(&panic_notifier_list, 0, buf);
+ atomic_notifier_call_chain(&panic_notifier_list, 0, buf);
if (!panic_blink)
panic_blink = no_blink;
- if (panic_timeout > 0)
- {
+ if (panic_timeout > 0) {
/*
* Delay timeout seconds before rebooting the machine.
* We can't use the "normal" timers since we just panicked..
mdelay(1);
i++;
}
- /*
- * Should we run the reboot notifier. For the moment Im
- * choosing not too. It might crash, be corrupt or do
- * more harm than good for other reasons.
+ /* 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.
*/
- machine_restart(NULL);
+ emergency_restart();
}
#ifdef __sparc__
{
printk(KERN_EMERG "Press Stop-A (L1-A) to return to the boot prom\n");
}
#endif
-#if defined(CONFIG_ARCH_S390)
+#if defined(CONFIG_S390)
disabled_wait(caller);
#endif
local_irq_enable();
for (i = 0;;) {
+ touch_softlockup_watchdog();
i += panic_blink(i);
mdelay(1);
i++;
snprintf(buf, sizeof(buf), "Not tainted");
return(buf);
}
+EXPORT_SYMBOL(print_tainted);
void add_taint(unsigned flag)
{
tainted |= flag;
}
EXPORT_SYMBOL(add_taint);
+
+static int __init pause_on_oops_setup(char *str)
+{
+ pause_on_oops = simple_strtoul(str, NULL, 0);
+ return 1;
+}
+__setup("pause_on_oops=", pause_on_oops_setup);
+
+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..
+ */
+int 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)
+{
+ do_oops_enter_exit();
+}
+
+/*
+ * Called when the architecture exits its oops handler, after printing
+ * everything.
+ */
+void oops_exit(void)
+{
+ do_oops_enter_exit();
+}
git://git.onelab.eu / linux-2.6.git / blobdiff