void
kdb_panic(const char *msg)
{
#ifdef SMP
cpuset_t other_cpus;
other_cpus = all_cpus;
CPU_CLR(PCPU_GET(cpuid), &other_cpus);
stop_cpus_hard(other_cpus);
#endif
printf("KDB: panic\n");
panic("%s", msg);
}
void
vpanic(const char *fmt, va_list ap)
{
#ifdef SMP
cpuset_t other_cpus;
#endif
struct thread *td = curthread;
int bootopt, newpanic;
static char buf[256];
spinlock_enter();
#ifdef SMP
/*
* stop_cpus_hard(other_cpus) should prevent multiple CPUs from
* concurrently entering panic. Only the winner will proceed
* further.
*/
if (panicstr == NULL && !kdb_active) {
other_cpus = all_cpus;
CPU_CLR(PCPU_GET(cpuid), &other_cpus);
stop_cpus_hard(other_cpus);
}
/*
* Ensure that the scheduler is stopped while panicking, even if panic
* has been entered from kdb.
*/
td->td_stopsched = 1;
#endif
bootopt = RB_AUTOBOOT;
newpanic = 0;
if (panicstr)
bootopt |= RB_NOSYNC;
else {
bootopt |= RB_DUMP;
panicstr = fmt;
newpanic = 1;
}
if (newpanic) {
(void)vsnprintf(buf, sizeof(buf), fmt, ap);
panicstr = buf;
cngrab();
printf("panic: %s\n", buf);
} else {
printf("panic: ");
vprintf(fmt, ap);
printf("\n");
}
#ifdef SMP
printf("cpuid = %d\n", PCPU_GET(cpuid));
#endif
#ifdef KDB
if (newpanic && trace_on_panic)
kdb_backtrace();
if (debugger_on_panic)
kdb_enter(KDB_WHY_PANIC, "panic");
#endif
/*thread_lock(td); */
td->td_flags |= TDF_INPANIC;
/* thread_unlock(td); */
if (!sync_on_panic)
bootopt |= RB_NOSYNC;
kern_reboot(bootopt);
}
/*
* Panic is called on unresolvable fatal errors. It prints "panic: mesg",
* and then reboots. If we are called twice, then we avoid trying to sync
* the disks as this often leads to recursive panics.
*/
void
panic(const char *fmt, ...)
{
#ifdef SMP
static volatile u_int panic_cpu = NOCPU;
cpuset_t other_cpus;
#endif
struct thread *td = curthread;
int bootopt, newpanic;
va_list ap;
static char buf[256];
if (stop_scheduler_on_panic)
spinlock_enter();
else
critical_enter();
#ifdef SMP
/*
* We don't want multiple CPU's to panic at the same time, so we
* use panic_cpu as a simple spinlock. We have to keep checking
* panic_cpu if we are spinning in case the panic on the first
* CPU is canceled.
*/
if (panic_cpu != PCPU_GET(cpuid))
while (atomic_cmpset_int(&panic_cpu, NOCPU,
PCPU_GET(cpuid)) == 0)
while (panic_cpu != NOCPU)
; /* nothing */
if (stop_scheduler_on_panic) {
if (panicstr == NULL && !kdb_active) {
other_cpus = all_cpus;
CPU_CLR(PCPU_GET(cpuid), &other_cpus);
stop_cpus_hard(other_cpus);
}
/*
* We set stop_scheduler here and not in the block above,
* because we want to ensure that if panic has been called and
* stop_scheduler_on_panic is true, then stop_scheduler will
* always be set. Even if panic has been entered from kdb.
*/
td->td_stopsched = 1;
}
#endif
bootopt = RB_AUTOBOOT;
newpanic = 0;
if (panicstr)
bootopt |= RB_NOSYNC;
else {
bootopt |= RB_DUMP;
panicstr = fmt;
newpanic = 1;
}
va_start(ap, fmt);
if (newpanic) {
(void)vsnprintf(buf, sizeof(buf), fmt, ap);
panicstr = buf;
cngrab();
printf("panic: %s\n", buf);
} else {
printf("panic: ");
vprintf(fmt, ap);
printf("\n");
}
va_end(ap);
#ifdef SMP
printf("cpuid = %d\n", PCPU_GET(cpuid));
#endif
#ifdef KDB
if (newpanic && trace_on_panic)
kdb_backtrace();
if (debugger_on_panic)
kdb_enter(KDB_WHY_PANIC, "panic");
#endif
/*thread_lock(td); */
td->td_flags |= TDF_INPANIC;
/* thread_unlock(td); */
if (!sync_on_panic)
bootopt |= RB_NOSYNC;
if (!stop_scheduler_on_panic)
critical_exit();
kern_reboot(bootopt);
}
