xref: /onnv-gate/usr/src/uts/common/os/panic.c (revision 0:68f95e015346)
1*0Sstevel@tonic-gate /*
2*0Sstevel@tonic-gate  * CDDL HEADER START
3*0Sstevel@tonic-gate  *
4*0Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*0Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
6*0Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
7*0Sstevel@tonic-gate  * with the License.
8*0Sstevel@tonic-gate  *
9*0Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*0Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
11*0Sstevel@tonic-gate  * See the License for the specific language governing permissions
12*0Sstevel@tonic-gate  * and limitations under the License.
13*0Sstevel@tonic-gate  *
14*0Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
15*0Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*0Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
17*0Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
18*0Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
19*0Sstevel@tonic-gate  *
20*0Sstevel@tonic-gate  * CDDL HEADER END
21*0Sstevel@tonic-gate  */
22*0Sstevel@tonic-gate /*
23*0Sstevel@tonic-gate  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
24*0Sstevel@tonic-gate  * Use is subject to license terms.
25*0Sstevel@tonic-gate  */
26*0Sstevel@tonic-gate 
27*0Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
28*0Sstevel@tonic-gate 
29*0Sstevel@tonic-gate /*
30*0Sstevel@tonic-gate  * When the operating system detects that it is in an invalid state, a panic
31*0Sstevel@tonic-gate  * is initiated in order to minimize potential damage to user data and to
32*0Sstevel@tonic-gate  * facilitate debugging.  There are three major tasks to be performed in
33*0Sstevel@tonic-gate  * a system panic: recording information about the panic in memory (and thus
34*0Sstevel@tonic-gate  * making it part of the crash dump), synchronizing the file systems to
35*0Sstevel@tonic-gate  * preserve user file data, and generating the crash dump.  We define the
36*0Sstevel@tonic-gate  * system to be in one of four states with respect to the panic code:
37*0Sstevel@tonic-gate  *
38*0Sstevel@tonic-gate  * CALM    - the state of the system prior to any thread initiating a panic
39*0Sstevel@tonic-gate  *
40*0Sstevel@tonic-gate  * QUIESCE - the state of the system when the first thread to initiate
41*0Sstevel@tonic-gate  *           a system panic records information about the cause of the panic
42*0Sstevel@tonic-gate  *           and renders the system quiescent by stopping other processors
43*0Sstevel@tonic-gate  *
44*0Sstevel@tonic-gate  * SYNC    - the state of the system when we synchronize the file systems
45*0Sstevel@tonic-gate  * DUMP    - the state when we generate the crash dump.
46*0Sstevel@tonic-gate  *
47*0Sstevel@tonic-gate  * The transitions between these states are irreversible: once we begin
48*0Sstevel@tonic-gate  * panicking, we only make one attempt to perform the actions associated with
49*0Sstevel@tonic-gate  * each state.
50*0Sstevel@tonic-gate  *
51*0Sstevel@tonic-gate  * The panic code itself must be re-entrant because actions taken during any
52*0Sstevel@tonic-gate  * state may lead to another system panic.  Additionally, any Solaris
53*0Sstevel@tonic-gate  * thread may initiate a panic at any time, and so we must have synchronization
54*0Sstevel@tonic-gate  * between threads which attempt to initiate a state transition simultaneously.
55*0Sstevel@tonic-gate  * The panic code makes use of a special locking primitive, a trigger, to
56*0Sstevel@tonic-gate  * perform this synchronization.  A trigger is simply a word which is set
57*0Sstevel@tonic-gate  * atomically and can only be set once.  We declare three triggers, one for
58*0Sstevel@tonic-gate  * each transition between the four states.  When a thread enters the panic
59*0Sstevel@tonic-gate  * code it attempts to set each trigger; if it fails it moves on to the
60*0Sstevel@tonic-gate  * next trigger.  A special case is the first trigger: if two threads race
61*0Sstevel@tonic-gate  * to perform the transition to QUIESCE, the losing thread may execute before
62*0Sstevel@tonic-gate  * the winner has a chance to stop its CPU.  To solve this problem, we have
63*0Sstevel@tonic-gate  * the loser look ahead to see if any other triggers are set; if not, it
64*0Sstevel@tonic-gate  * presumes a panic is underway and simply spins.  Unfortunately, since we
65*0Sstevel@tonic-gate  * are panicking, it is not possible to know this with absolute certainty.
66*0Sstevel@tonic-gate  *
67*0Sstevel@tonic-gate  * There are two common reasons for re-entering the panic code once a panic
68*0Sstevel@tonic-gate  * has been initiated: (1) after we debug_enter() at the end of QUIESCE,
69*0Sstevel@tonic-gate  * the operator may type "sync" instead of "go", and the PROM's sync callback
70*0Sstevel@tonic-gate  * routine will invoke panic(); (2) if the clock routine decides that sync
71*0Sstevel@tonic-gate  * or dump is not making progress, it will invoke panic() to force a timeout.
72*0Sstevel@tonic-gate  * The design assumes that a third possibility, another thread causing an
73*0Sstevel@tonic-gate  * unrelated panic while sync or dump is still underway, is extremely unlikely.
74*0Sstevel@tonic-gate  * If this situation occurs, we may end up triggering dump while sync is
75*0Sstevel@tonic-gate  * still in progress.  This third case is considered extremely unlikely because
76*0Sstevel@tonic-gate  * all other CPUs are stopped and low-level interrupts have been blocked.
77*0Sstevel@tonic-gate  *
78*0Sstevel@tonic-gate  * The panic code is entered via a call directly to the vpanic() function,
79*0Sstevel@tonic-gate  * or its varargs wrappers panic() and cmn_err(9F).  The vpanic routine
80*0Sstevel@tonic-gate  * is implemented in assembly language to record the current machine
81*0Sstevel@tonic-gate  * registers, attempt to set the trigger for the QUIESCE state, and
82*0Sstevel@tonic-gate  * if successful, switch stacks on to the panic_stack before calling into
83*0Sstevel@tonic-gate  * the common panicsys() routine.  The first thread to initiate a panic
84*0Sstevel@tonic-gate  * is allowed to make use of the reserved panic_stack so that executing
85*0Sstevel@tonic-gate  * the panic code itself does not overwrite valuable data on that thread's
86*0Sstevel@tonic-gate  * stack *ahead* of the current stack pointer.  This data will be preserved
87*0Sstevel@tonic-gate  * in the crash dump and may prove invaluable in determining what this
88*0Sstevel@tonic-gate  * thread has previously been doing.  The first thread, saved in panic_thread,
89*0Sstevel@tonic-gate  * is also responsible for stopping the other CPUs as quickly as possible,
90*0Sstevel@tonic-gate  * and then setting the various panic_* variables.  Most important among
91*0Sstevel@tonic-gate  * these is panicstr, which allows threads to subsequently bypass held
92*0Sstevel@tonic-gate  * locks so that we can proceed without ever blocking.  We must stop the
93*0Sstevel@tonic-gate  * other CPUs *prior* to setting panicstr in case threads running there are
94*0Sstevel@tonic-gate  * currently spinning to acquire a lock; we want that state to be preserved.
95*0Sstevel@tonic-gate  * Every thread which initiates a panic has its T_PANIC flag set so we can
96*0Sstevel@tonic-gate  * identify all such threads in the crash dump.
97*0Sstevel@tonic-gate  *
98*0Sstevel@tonic-gate  * The panic_thread is also allowed to make use of the special memory buffer
99*0Sstevel@tonic-gate  * panicbuf, which on machines with appropriate hardware is preserved across
100*0Sstevel@tonic-gate  * reboots.  We allow the panic_thread to store its register set and panic
101*0Sstevel@tonic-gate  * message in this buffer, so even if we fail to obtain a crash dump we will
102*0Sstevel@tonic-gate  * be able to examine the machine after reboot and determine some of the
103*0Sstevel@tonic-gate  * state at the time of the panic.  If we do get a dump, the panic buffer
104*0Sstevel@tonic-gate  * data is structured so that a debugger can easily consume the information
105*0Sstevel@tonic-gate  * therein (see <sys/panic.h>).
106*0Sstevel@tonic-gate  *
107*0Sstevel@tonic-gate  * Each platform or architecture is required to implement the functions
108*0Sstevel@tonic-gate  * panic_savetrap() to record trap-specific information to panicbuf,
109*0Sstevel@tonic-gate  * panic_saveregs() to record a register set to panicbuf, panic_stopcpus()
110*0Sstevel@tonic-gate  * to halt all CPUs but the panicking CPU, panic_quiesce_hw() to perform
111*0Sstevel@tonic-gate  * miscellaneous platform-specific tasks *after* panicstr is set,
112*0Sstevel@tonic-gate  * panic_showtrap() to print trap-specific information to the console,
113*0Sstevel@tonic-gate  * and panic_dump_hw() to perform platform tasks prior to calling dumpsys().
114*0Sstevel@tonic-gate  *
115*0Sstevel@tonic-gate  * A Note on Word Formation, courtesy of the Oxford Guide to English Usage:
116*0Sstevel@tonic-gate  *
117*0Sstevel@tonic-gate  * Words ending in -c interpose k before suffixes which otherwise would
118*0Sstevel@tonic-gate  * indicate a soft c, and thus the verb and adjective forms of 'panic' are
119*0Sstevel@tonic-gate  * spelled "panicked", "panicking", and "panicky" respectively.  Use of
120*0Sstevel@tonic-gate  * the ill-conceived "panicing" and "panic'd" is discouraged.
121*0Sstevel@tonic-gate  */
122*0Sstevel@tonic-gate 
123*0Sstevel@tonic-gate #include <sys/types.h>
124*0Sstevel@tonic-gate #include <sys/varargs.h>
125*0Sstevel@tonic-gate #include <sys/sysmacros.h>
126*0Sstevel@tonic-gate #include <sys/cmn_err.h>
127*0Sstevel@tonic-gate #include <sys/cpuvar.h>
128*0Sstevel@tonic-gate #include <sys/thread.h>
129*0Sstevel@tonic-gate #include <sys/t_lock.h>
130*0Sstevel@tonic-gate #include <sys/cred.h>
131*0Sstevel@tonic-gate #include <sys/systm.h>
132*0Sstevel@tonic-gate #include <sys/uadmin.h>
133*0Sstevel@tonic-gate #include <sys/callb.h>
134*0Sstevel@tonic-gate #include <sys/vfs.h>
135*0Sstevel@tonic-gate #include <sys/log.h>
136*0Sstevel@tonic-gate #include <sys/disp.h>
137*0Sstevel@tonic-gate #include <sys/param.h>
138*0Sstevel@tonic-gate #include <sys/dumphdr.h>
139*0Sstevel@tonic-gate #include <sys/ftrace.h>
140*0Sstevel@tonic-gate #include <sys/reboot.h>
141*0Sstevel@tonic-gate #include <sys/debug.h>
142*0Sstevel@tonic-gate #include <sys/stack.h>
143*0Sstevel@tonic-gate #include <sys/spl.h>
144*0Sstevel@tonic-gate #include <sys/errorq.h>
145*0Sstevel@tonic-gate #include <sys/panic.h>
146*0Sstevel@tonic-gate 
147*0Sstevel@tonic-gate /*
148*0Sstevel@tonic-gate  * Panic variables which are set once during the QUIESCE state by the
149*0Sstevel@tonic-gate  * first thread to initiate a panic.  These are examined by post-mortem
150*0Sstevel@tonic-gate  * debugging tools; the inconsistent use of 'panic' versus 'panic_' in
151*0Sstevel@tonic-gate  * the variable naming is historical and allows legacy tools to work.
152*0Sstevel@tonic-gate  */
153*0Sstevel@tonic-gate #pragma align STACK_ALIGN(panic_stack)
154*0Sstevel@tonic-gate char panic_stack[PANICSTKSIZE];		/* reserved stack for panic_thread */
155*0Sstevel@tonic-gate kthread_t *panic_thread;		/* first thread to call panicsys() */
156*0Sstevel@tonic-gate cpu_t panic_cpu;			/* cpu from first call to panicsys() */
157*0Sstevel@tonic-gate label_t panic_regs;			/* setjmp label from panic_thread */
158*0Sstevel@tonic-gate struct regs *panic_reg;			/* regs struct from first panicsys() */
159*0Sstevel@tonic-gate char *volatile panicstr;		/* format string to first panicsys() */
160*0Sstevel@tonic-gate va_list panicargs;			/* arguments to first panicsys() */
161*0Sstevel@tonic-gate clock_t panic_lbolt;			/* lbolt at time of panic */
162*0Sstevel@tonic-gate int64_t panic_lbolt64;			/* lbolt64 at time of panic */
163*0Sstevel@tonic-gate hrtime_t panic_hrtime;			/* hrtime at time of panic */
164*0Sstevel@tonic-gate timespec_t panic_hrestime;		/* hrestime at time of panic */
165*0Sstevel@tonic-gate int panic_ipl;				/* ipl on panic_cpu at time of panic */
166*0Sstevel@tonic-gate ushort_t panic_schedflag;		/* t_schedflag for panic_thread */
167*0Sstevel@tonic-gate cpu_t *panic_bound_cpu;			/* t_bound_cpu for panic_thread */
168*0Sstevel@tonic-gate char panic_preempt;			/* t_preempt for panic_thread */
169*0Sstevel@tonic-gate 
170*0Sstevel@tonic-gate /*
171*0Sstevel@tonic-gate  * Panic variables which can be set via /etc/system or patched while
172*0Sstevel@tonic-gate  * the system is in operation.  Again, the stupid names are historic.
173*0Sstevel@tonic-gate  */
174*0Sstevel@tonic-gate char *panic_bootstr = NULL;		/* mdboot string to use after panic */
175*0Sstevel@tonic-gate int panic_bootfcn = AD_BOOT;		/* mdboot function to use after panic */
176*0Sstevel@tonic-gate int halt_on_panic = 0;  		/* halt after dump instead of reboot? */
177*0Sstevel@tonic-gate int nopanicdebug = 0;			/* reboot instead of call debugger? */
178*0Sstevel@tonic-gate int in_sync = 0;			/* skip vfs_syncall() and just dump? */
179*0Sstevel@tonic-gate 
180*0Sstevel@tonic-gate /*
181*0Sstevel@tonic-gate  * The do_polled_io flag is set by the panic code to inform the SCSI subsystem
182*0Sstevel@tonic-gate  * to use polled mode instead of interrupt-driven i/o.
183*0Sstevel@tonic-gate  */
184*0Sstevel@tonic-gate int do_polled_io = 0;
185*0Sstevel@tonic-gate 
186*0Sstevel@tonic-gate /*
187*0Sstevel@tonic-gate  * The panic_forced flag is set by the uadmin A_DUMP code to inform the
188*0Sstevel@tonic-gate  * panic subsystem that it should not attempt an initial debug_enter.
189*0Sstevel@tonic-gate  */
190*0Sstevel@tonic-gate int panic_forced = 0;
191*0Sstevel@tonic-gate 
192*0Sstevel@tonic-gate /*
193*0Sstevel@tonic-gate  * Triggers for panic state transitions:
194*0Sstevel@tonic-gate  */
195*0Sstevel@tonic-gate int panic_quiesce;			/* trigger for CALM    -> QUIESCE */
196*0Sstevel@tonic-gate int panic_sync;				/* trigger for QUIESCE -> SYNC */
197*0Sstevel@tonic-gate int panic_dump;				/* trigger for SYNC    -> DUMP */
198*0Sstevel@tonic-gate 
199*0Sstevel@tonic-gate void
200*0Sstevel@tonic-gate panicsys(const char *format, va_list alist, struct regs *rp, int on_panic_stack)
201*0Sstevel@tonic-gate {
202*0Sstevel@tonic-gate 	int s = spl8();
203*0Sstevel@tonic-gate 	kthread_t *t = curthread;
204*0Sstevel@tonic-gate 	cpu_t *cp = CPU;
205*0Sstevel@tonic-gate 
206*0Sstevel@tonic-gate 	caddr_t intr_stack = NULL;
207*0Sstevel@tonic-gate 	uint_t intr_actv;
208*0Sstevel@tonic-gate 
209*0Sstevel@tonic-gate 	ushort_t schedflag = t->t_schedflag;
210*0Sstevel@tonic-gate 	cpu_t *bound_cpu = t->t_bound_cpu;
211*0Sstevel@tonic-gate 	char preempt = t->t_preempt;
212*0Sstevel@tonic-gate 
213*0Sstevel@tonic-gate 	(void) setjmp(&t->t_pcb);
214*0Sstevel@tonic-gate 	t->t_flag |= T_PANIC;
215*0Sstevel@tonic-gate 
216*0Sstevel@tonic-gate 	t->t_schedflag |= TS_DONT_SWAP;
217*0Sstevel@tonic-gate 	t->t_bound_cpu = cp;
218*0Sstevel@tonic-gate 	t->t_preempt++;
219*0Sstevel@tonic-gate 
220*0Sstevel@tonic-gate 	panic_enter_hw(s);
221*0Sstevel@tonic-gate 
222*0Sstevel@tonic-gate 	/*
223*0Sstevel@tonic-gate 	 * If we're on the interrupt stack and an interrupt thread is available
224*0Sstevel@tonic-gate 	 * in this CPU's pool, preserve the interrupt stack by detaching an
225*0Sstevel@tonic-gate 	 * interrupt thread and making its stack the intr_stack.
226*0Sstevel@tonic-gate 	 */
227*0Sstevel@tonic-gate 	if (CPU_ON_INTR(cp) && cp->cpu_intr_thread != NULL) {
228*0Sstevel@tonic-gate 		kthread_t *it = cp->cpu_intr_thread;
229*0Sstevel@tonic-gate 
230*0Sstevel@tonic-gate 		intr_stack = cp->cpu_intr_stack;
231*0Sstevel@tonic-gate 		intr_actv = cp->cpu_intr_actv;
232*0Sstevel@tonic-gate 
233*0Sstevel@tonic-gate 		cp->cpu_intr_stack = thread_stk_init(it->t_stk);
234*0Sstevel@tonic-gate 		cp->cpu_intr_thread = it->t_link;
235*0Sstevel@tonic-gate 
236*0Sstevel@tonic-gate 		/*
237*0Sstevel@tonic-gate 		 * Clear only the high level bits of cpu_intr_actv.
238*0Sstevel@tonic-gate 		 * We want to indicate that high-level interrupts are
239*0Sstevel@tonic-gate 		 * not active without destroying the low-level interrupt
240*0Sstevel@tonic-gate 		 * information stored there.
241*0Sstevel@tonic-gate 		 */
242*0Sstevel@tonic-gate 		cp->cpu_intr_actv &= ((1 << (LOCK_LEVEL + 1)) - 1);
243*0Sstevel@tonic-gate 	}
244*0Sstevel@tonic-gate 
245*0Sstevel@tonic-gate 	/*
246*0Sstevel@tonic-gate 	 * Record one-time panic information and quiesce the other CPUs.
247*0Sstevel@tonic-gate 	 * Then print out the panic message and stack trace.
248*0Sstevel@tonic-gate 	 */
249*0Sstevel@tonic-gate 	if (on_panic_stack) {
250*0Sstevel@tonic-gate 		panic_data_t *pdp = (panic_data_t *)panicbuf;
251*0Sstevel@tonic-gate 
252*0Sstevel@tonic-gate 		pdp->pd_version = PANICBUFVERS;
253*0Sstevel@tonic-gate 		pdp->pd_msgoff = sizeof (panic_data_t) - sizeof (panic_nv_t);
254*0Sstevel@tonic-gate 
255*0Sstevel@tonic-gate 		if (t->t_panic_trap != NULL)
256*0Sstevel@tonic-gate 			panic_savetrap(pdp, t->t_panic_trap);
257*0Sstevel@tonic-gate 		else
258*0Sstevel@tonic-gate 			panic_saveregs(pdp, rp);
259*0Sstevel@tonic-gate 
260*0Sstevel@tonic-gate 		(void) vsnprintf(&panicbuf[pdp->pd_msgoff],
261*0Sstevel@tonic-gate 		    PANICBUFSIZE - pdp->pd_msgoff, format, alist);
262*0Sstevel@tonic-gate 
263*0Sstevel@tonic-gate 		/*
264*0Sstevel@tonic-gate 		 * Call into the platform code to stop the other CPUs.
265*0Sstevel@tonic-gate 		 * We currently have all interrupts blocked, and expect that
266*0Sstevel@tonic-gate 		 * the platform code will lower ipl only as far as needed to
267*0Sstevel@tonic-gate 		 * perform cross-calls, and will acquire as *few* locks as is
268*0Sstevel@tonic-gate 		 * possible -- panicstr is not set so we can still deadlock.
269*0Sstevel@tonic-gate 		 */
270*0Sstevel@tonic-gate 		panic_stopcpus(cp, t, s);
271*0Sstevel@tonic-gate 
272*0Sstevel@tonic-gate 		panicstr = (char *)format;
273*0Sstevel@tonic-gate 		va_copy(panicargs, alist);
274*0Sstevel@tonic-gate 		panic_lbolt = lbolt;
275*0Sstevel@tonic-gate 		panic_lbolt64 = lbolt64;
276*0Sstevel@tonic-gate 		panic_hrestime = hrestime;
277*0Sstevel@tonic-gate 		panic_hrtime = gethrtime_waitfree();
278*0Sstevel@tonic-gate 		panic_thread = t;
279*0Sstevel@tonic-gate 		panic_regs = t->t_pcb;
280*0Sstevel@tonic-gate 		panic_reg = rp;
281*0Sstevel@tonic-gate 		panic_cpu = *cp;
282*0Sstevel@tonic-gate 		panic_ipl = spltoipl(s);
283*0Sstevel@tonic-gate 		panic_schedflag = schedflag;
284*0Sstevel@tonic-gate 		panic_bound_cpu = bound_cpu;
285*0Sstevel@tonic-gate 		panic_preempt = preempt;
286*0Sstevel@tonic-gate 
287*0Sstevel@tonic-gate 		if (intr_stack != NULL) {
288*0Sstevel@tonic-gate 			panic_cpu.cpu_intr_stack = intr_stack;
289*0Sstevel@tonic-gate 			panic_cpu.cpu_intr_actv = intr_actv;
290*0Sstevel@tonic-gate 		}
291*0Sstevel@tonic-gate 
292*0Sstevel@tonic-gate 		/*
293*0Sstevel@tonic-gate 		 * Lower ipl to 10 to keep clock() from running, but allow
294*0Sstevel@tonic-gate 		 * keyboard interrupts to enter the debugger.  These callbacks
295*0Sstevel@tonic-gate 		 * are executed with panicstr set so they can bypass locks.
296*0Sstevel@tonic-gate 		 */
297*0Sstevel@tonic-gate 		splx(ipltospl(CLOCK_LEVEL));
298*0Sstevel@tonic-gate 		panic_quiesce_hw(pdp);
299*0Sstevel@tonic-gate 		(void) FTRACE_STOP();
300*0Sstevel@tonic-gate 		(void) callb_execute_class(CB_CL_PANIC, NULL);
301*0Sstevel@tonic-gate 
302*0Sstevel@tonic-gate 		if (log_intrq != NULL)
303*0Sstevel@tonic-gate 			log_flushq(log_intrq);
304*0Sstevel@tonic-gate 
305*0Sstevel@tonic-gate 		/*
306*0Sstevel@tonic-gate 		 * If log_consq has been initialized and syslogd has started,
307*0Sstevel@tonic-gate 		 * print any messages in log_consq that haven't been consumed.
308*0Sstevel@tonic-gate 		 */
309*0Sstevel@tonic-gate 		if (log_consq != NULL && log_consq != log_backlogq)
310*0Sstevel@tonic-gate 			log_printq(log_consq);
311*0Sstevel@tonic-gate 
312*0Sstevel@tonic-gate 		fm_banner();
313*0Sstevel@tonic-gate 		errorq_panic();
314*0Sstevel@tonic-gate 
315*0Sstevel@tonic-gate 		printf("\n\rpanic[cpu%d]/thread=%p: ", cp->cpu_id, (void *)t);
316*0Sstevel@tonic-gate 		vprintf(format, alist);
317*0Sstevel@tonic-gate 		printf("\n\n");
318*0Sstevel@tonic-gate 
319*0Sstevel@tonic-gate 		if (t->t_panic_trap != NULL) {
320*0Sstevel@tonic-gate 			panic_showtrap(t->t_panic_trap);
321*0Sstevel@tonic-gate 			printf("\n");
322*0Sstevel@tonic-gate 		}
323*0Sstevel@tonic-gate 
324*0Sstevel@tonic-gate 		traceregs(rp);
325*0Sstevel@tonic-gate 		printf("\n");
326*0Sstevel@tonic-gate 
327*0Sstevel@tonic-gate 		if (((boothowto & RB_DEBUG) || obpdebug) &&
328*0Sstevel@tonic-gate 		    !nopanicdebug && !panic_forced) {
329*0Sstevel@tonic-gate 			if (dumpvp != NULL) {
330*0Sstevel@tonic-gate 				debug_enter("panic: entering debugger "
331*0Sstevel@tonic-gate 				    "(continue to save dump)");
332*0Sstevel@tonic-gate 			} else {
333*0Sstevel@tonic-gate 				debug_enter("panic: entering debugger "
334*0Sstevel@tonic-gate 				    "(no dump device, continue to reboot)");
335*0Sstevel@tonic-gate 			}
336*0Sstevel@tonic-gate 		}
337*0Sstevel@tonic-gate 
338*0Sstevel@tonic-gate 	} else if (panic_dump != 0 || panic_sync != 0 || panicstr != NULL) {
339*0Sstevel@tonic-gate 		printf("\n\rpanic[cpu%d]/thread=%p: ", cp->cpu_id, (void *)t);
340*0Sstevel@tonic-gate 		vprintf(format, alist);
341*0Sstevel@tonic-gate 		printf("\n");
342*0Sstevel@tonic-gate 	} else
343*0Sstevel@tonic-gate 		goto spin;
344*0Sstevel@tonic-gate 
345*0Sstevel@tonic-gate 	/*
346*0Sstevel@tonic-gate 	 * Prior to performing sync or dump, we make sure that do_polled_io is
347*0Sstevel@tonic-gate 	 * set, but we'll leave ipl at 10; deadman(), a CY_HIGH_LEVEL cyclic,
348*0Sstevel@tonic-gate 	 * will re-enter panic if we are not making progress with sync or dump.
349*0Sstevel@tonic-gate 	 */
350*0Sstevel@tonic-gate 
351*0Sstevel@tonic-gate 	/*
352*0Sstevel@tonic-gate 	 * Sync the filesystems.  Reset t_cred if not set because much of
353*0Sstevel@tonic-gate 	 * the filesystem code depends on CRED() being valid.
354*0Sstevel@tonic-gate 	 */
355*0Sstevel@tonic-gate 	if (!in_sync && panic_trigger(&panic_sync)) {
356*0Sstevel@tonic-gate 		if (t->t_cred == NULL)
357*0Sstevel@tonic-gate 			t->t_cred = kcred;
358*0Sstevel@tonic-gate 		splx(ipltospl(CLOCK_LEVEL));
359*0Sstevel@tonic-gate 		do_polled_io = 1;
360*0Sstevel@tonic-gate 		vfs_syncall();
361*0Sstevel@tonic-gate 	}
362*0Sstevel@tonic-gate 
363*0Sstevel@tonic-gate 	/*
364*0Sstevel@tonic-gate 	 * Take the crash dump.  If the dump trigger is already set, try to
365*0Sstevel@tonic-gate 	 * enter the debugger again before rebooting the system.
366*0Sstevel@tonic-gate 	 */
367*0Sstevel@tonic-gate 	if (panic_trigger(&panic_dump)) {
368*0Sstevel@tonic-gate 		panic_dump_hw(s);
369*0Sstevel@tonic-gate 		splx(ipltospl(CLOCK_LEVEL));
370*0Sstevel@tonic-gate 		do_polled_io = 1;
371*0Sstevel@tonic-gate 		dumpsys();
372*0Sstevel@tonic-gate 	} else if (((boothowto & RB_DEBUG) || obpdebug) && !nopanicdebug) {
373*0Sstevel@tonic-gate 		debug_enter("panic: entering debugger (continue to reboot)");
374*0Sstevel@tonic-gate 	} else
375*0Sstevel@tonic-gate 		printf("dump aborted: please record the above information!\n");
376*0Sstevel@tonic-gate 
377*0Sstevel@tonic-gate 	if (halt_on_panic)
378*0Sstevel@tonic-gate 		mdboot(A_REBOOT, AD_HALT, NULL);
379*0Sstevel@tonic-gate 	else
380*0Sstevel@tonic-gate 		mdboot(A_REBOOT, panic_bootfcn, panic_bootstr);
381*0Sstevel@tonic-gate spin:
382*0Sstevel@tonic-gate 	/*
383*0Sstevel@tonic-gate 	 * Restore ipl to at most CLOCK_LEVEL so we don't end up spinning
384*0Sstevel@tonic-gate 	 * and unable to jump into the debugger.
385*0Sstevel@tonic-gate 	 */
386*0Sstevel@tonic-gate 	splx(MIN(s, ipltospl(CLOCK_LEVEL)));
387*0Sstevel@tonic-gate 	for (;;);
388*0Sstevel@tonic-gate }
389*0Sstevel@tonic-gate 
390*0Sstevel@tonic-gate void
391*0Sstevel@tonic-gate panic(const char *format, ...)
392*0Sstevel@tonic-gate {
393*0Sstevel@tonic-gate 	va_list alist;
394*0Sstevel@tonic-gate 
395*0Sstevel@tonic-gate 	va_start(alist, format);
396*0Sstevel@tonic-gate 	vpanic(format, alist);
397*0Sstevel@tonic-gate 	va_end(alist);
398*0Sstevel@tonic-gate }
399