xref: /illumos-gate/usr/src/uts/common/os/main.c (revision ac2250cb76bb32944fd2c8a3ba2cd3f79747748d)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright (c) 1988, 2010, Oracle and/or its affiliates. All rights reserved.
24  */
25 
26 /*	Copyright (c) 1988 AT&T	*/
27 /*	  All Rights Reserved		*/
28 
29 /*
30  * Copyright 2019 Joyent, Inc.
31  * Copyright 2026 Oxide Computer Company
32  */
33 
34 #include <sys/types.h>
35 #include <sys/param.h>
36 #include <sys/sysmacros.h>
37 #include <sys/pcb.h>
38 #include <sys/systm.h>
39 #include <sys/signal.h>
40 #include <sys/cred.h>
41 #include <sys/user.h>
42 #include <sys/vfs.h>
43 #include <sys/vnode.h>
44 #include <sys/proc.h>
45 #include <sys/time.h>
46 #include <sys/file.h>
47 #include <sys/priocntl.h>
48 #include <sys/procset.h>
49 #include <sys/disp.h>
50 #include <sys/callo.h>
51 #include <sys/callb.h>
52 #include <sys/debug.h>
53 #include <sys/conf.h>
54 #include <sys/bootconf.h>
55 #include <sys/utsname.h>
56 #include <sys/cmn_err.h>
57 #include <sys/vmparam.h>
58 #include <sys/modctl.h>
59 #include <sys/vm.h>
60 #include <sys/callb.h>
61 #include <sys/ddi_periodic.h>
62 #include <sys/kmem.h>
63 #include <sys/vmem.h>
64 #include <sys/cpuvar.h>
65 #include <sys/cladm.h>
66 #include <sys/corectl.h>
67 #include <sys/exec.h>
68 #include <sys/syscall.h>
69 #include <sys/reboot.h>
70 #include <sys/task.h>
71 #include <sys/exacct.h>
72 #include <sys/autoconf.h>
73 #include <sys/errorq.h>
74 #include <sys/class.h>
75 #include <sys/stack.h>
76 #include <sys/brand.h>
77 #include <sys/mmapobj.h>
78 #include <sys/smt.h>
79 
80 #include <vm/as.h>
81 #include <vm/seg_kmem.h>
82 #include <sys/dc_ki.h>
83 
84 #include <c2/audit.h>
85 #include <sys/bootprops.h>
86 
87 /* well known processes */
88 proc_t *proc_sched;		/* memory scheduler */
89 proc_t *proc_init;		/* init */
90 proc_t *proc_pageout;		/* pageout daemon */
91 proc_t *proc_fsflush;		/* fsflush daemon */
92 
93 pgcnt_t	maxmem;		/* Maximum available memory in pages.	*/
94 pgcnt_t	freemem;	/* Current available memory in pages.	*/
95 int	interrupts_unleashed;	/* set when we do the first spl0() */
96 
97 kmem_cache_t *process_cache;	/* kmem cache for proc structures */
98 
99 /*
100  * Indicates whether the auditing module (c2audit) is loaded. Possible
101  * values are:
102  * 0 - c2audit module is excluded in /etc/system and cannot be loaded
103  * 1 - c2audit module is not loaded but can be anytime
104  * 2 - c2audit module is loaded
105  */
106 int audit_active = C2AUDIT_DISABLED;
107 
108 /*
109  * Process 0's lwp directory and lwpid hash table.
110  */
111 lwpdir_t p0_lwpdir[2];
112 tidhash_t p0_tidhash[2];
113 lwpent_t p0_lep;
114 
115 /*
116  * Machine-independent initialization code
117  * Called from cold start routine as
118  * soon as a stack and segmentation
119  * have been established.
120  * Functions:
121  *	clear and free user core
122  *	turn on clock
123  *	hand craft 0th process
124  *	call all initialization routines
125  *	fork	- process 0 to schedule
126  *		- process 1 execute bootstrap
127  *		- process 2 to page out
128  *	create system threads
129  */
130 
131 int cluster_bootflags = 0;
132 
133 void
cluster_wrapper(void)134 cluster_wrapper(void)
135 {
136 	cluster();
137 	panic("cluster()  returned");
138 }
139 
140 char initname[INITNAME_SZ] = "/sbin/init";	/* also referenced by zone0 */
141 char initargs[BOOTARGS_MAX] = "";		/* also referenced by zone0 */
142 
143 /*
144  * Construct a stack for init containing the arguments to it, then
145  * pass control to exec_common.
146  */
147 int
exec_init(const char * initpath,const char * args)148 exec_init(const char *initpath, const char *args)
149 {
150 	uintptr_t ucp;
151 	uintptr_t uap;
152 	uintptr_t *argv;
153 	uintptr_t exec_fnamep;
154 	char *scratchargs;
155 	int i, sarg;
156 	size_t argvlen, alen;
157 	size_t wlen = sizeof (uintptr_t);
158 	boolean_t in_arg;
159 	int argc = 0;
160 	int error = 0, count = 0;
161 	proc_t *p = ttoproc(curthread);
162 	klwp_t *lwp = ttolwp(curthread);
163 	int brand_action;
164 
165 	if (args == NULL)
166 		args = "";
167 
168 	alen = strlen(initpath) + 1 + strlen(args) + 1;
169 	scratchargs = kmem_alloc(alen, KM_SLEEP);
170 	(void) snprintf(scratchargs, alen, "%s %s", initpath, args);
171 
172 	/*
173 	 * We do a quick two state parse of the string to sort out how big
174 	 * argc should be.
175 	 */
176 	in_arg = B_FALSE;
177 	for (i = 0; i < strlen(scratchargs); i++) {
178 		if (scratchargs[i] == ' ' || scratchargs[i] == '\0') {
179 			if (in_arg) {
180 				in_arg = B_FALSE;
181 				argc++;
182 			}
183 		} else {
184 			in_arg = B_TRUE;
185 		}
186 	}
187 	argvlen = sizeof (uintptr_t) * (argc + 1);
188 	argv = kmem_zalloc(argvlen, KM_SLEEP);
189 
190 	/*
191 	 * We pull off a bit of a hack here.  We work our way through the
192 	 * args string, putting nulls at the ends of space delimited tokens
193 	 * (boot args don't support quoting at this time).  Then we just
194 	 * copy the whole mess to userland in one go.  In other words, we
195 	 * transform this: "init -s -r\0" into this on the stack:
196 	 *
197 	 *	-0x00 \0
198 	 *	-0x01 r
199 	 *	-0x02 -  <--------.
200 	 *	-0x03 \0	  |
201 	 *	-0x04 s		  |
202 	 *	-0x05 -  <------. |
203 	 *	-0x06 \0	| |
204 	 *	-0x07 t		| |
205 	 *	-0x08 i		| |
206 	 *	-0x09 n		| |
207 	 *	-0x0a i  <---.  | |
208 	 *	-0x10 NULL   |  | |	(argv[3])
209 	 *	-0x14   -----|--|-'	(argv[2])
210 	 *	-0x18  ------|--'	(argv[1])
211 	 *	-0x1c -------'		(argv[0])
212 	 *
213 	 * Since we know the value of ucp at the beginning of this process,
214 	 * we can trivially compute the argv[] array which we also need to
215 	 * place in userland: argv[i] = ucp - sarg(i), where ucp is the
216 	 * stack ptr, and sarg is the string index of the start of the
217 	 * argument.
218 	 */
219 	ucp = (uintptr_t)p->p_usrstack;
220 
221 	argc = 0;
222 	in_arg = B_FALSE;
223 	sarg = 0;
224 
225 	for (i = 0; i < alen; i++) {
226 		if (scratchargs[i] == ' ' || scratchargs[i] == '\0') {
227 			if (in_arg == B_TRUE) {
228 				in_arg = B_FALSE;
229 				scratchargs[i] = '\0';
230 				argv[argc++] = ucp - (alen - sarg);
231 			}
232 		} else if (in_arg == B_FALSE) {
233 			in_arg = B_TRUE;
234 			sarg = i;
235 		}
236 	}
237 
238 	exec_fnamep = argv[0];
239 
240 	ucp -= alen;
241 	error |= copyout(scratchargs, (caddr_t)ucp, alen);
242 
243 	if (p->p_model == DATAMODEL_ILP32) {
244 		uintptr32_t *argv32;
245 
246 		argv32 = kmem_zalloc(argvlen / 2, KM_SLEEP);
247 
248 		for (i = 0; i < argc; i++)
249 			argv32[i] = (uintptr32_t)argv[i];
250 
251 		kmem_free(argv, argvlen);
252 		argv = (uintptr_t *)argv32;
253 		argvlen /= 2;
254 
255 		wlen = sizeof (uintptr32_t);
256 	}
257 
258 	uap = P2ALIGN(ucp, wlen);
259 	/* advance to be below the word we're in */
260 	uap -= wlen;
261 	/* advance argc words down, plus one for NULL */
262 	uap -= (argc + 1) * wlen;
263 	error |= copyout(argv, (caddr_t)uap, argvlen);
264 
265 	if (error != 0) {
266 		zcmn_err(p->p_zone->zone_id, CE_WARN,
267 		    "Could not construct stack for init.\n");
268 		kmem_free(argv, argvlen);
269 		kmem_free(scratchargs, alen);
270 		return (EFAULT);
271 	}
272 
273 	kmem_free(argv, argvlen);
274 	kmem_free(scratchargs, alen);
275 
276 	/*
277 	 * Point at the arguments.
278 	 */
279 	lwp->lwp_ap = lwp->lwp_arg;
280 	lwp->lwp_arg[0] = exec_fnamep;
281 	lwp->lwp_arg[1] = uap;
282 	lwp->lwp_arg[2] = 0;
283 	curthread->t_post_sys = 1;
284 	curthread->t_sysnum = SYS_execve;
285 
286 	/*
287 	 * If we are executing init from zsched, we may have inherited its
288 	 * parent process's signal mask.  Clear it now so that we behave in
289 	 * the same way as when started from the global zone.
290 	 */
291 	sigemptyset(&curthread->t_hold);
292 
293 	brand_action = ZONE_IS_BRANDED(p->p_zone) ? EBA_BRAND : EBA_NONE;
294 again:
295 	error = exec_common((const char *)exec_fnamep,
296 	    (const char **)uap, NULL, NULL, brand_action, UIO_USERSPACE);
297 
298 	/*
299 	 * Normally we would just set lwp_argsaved and t_post_sys and
300 	 * let post_syscall reset lwp_ap for us.  Unfortunately,
301 	 * exec_init isn't always called from a system call.  Instead
302 	 * of making a mess of trap_cleanup, we just reset the args
303 	 * pointer here.
304 	 */
305 	reset_syscall_args();
306 
307 	switch (error) {
308 	case 0:
309 		return (0);
310 
311 	case ENOENT:
312 		zcmn_err(p->p_zone->zone_id, CE_WARN,
313 		    "exec(%s) failed (file not found).\n", initpath);
314 		return (ENOENT);
315 
316 	case EAGAIN:
317 	case EINTR:
318 		++count;
319 		if (count < 5) {
320 			zcmn_err(p->p_zone->zone_id, CE_WARN,
321 			    "exec(%s) failed with errno %d.  Retrying...\n",
322 			    initpath, error);
323 			goto again;
324 		}
325 	}
326 
327 	zcmn_err(p->p_zone->zone_id, CE_WARN,
328 	    "exec(%s) failed with errno %d.", initpath, error);
329 	return (error);
330 }
331 
332 /*
333  * This routine does all of the common setup for invoking init; global
334  * and non-global zones employ this routine for the functionality which is
335  * in common.
336  *
337  * This program (init, presumably) must be a 32-bit process.
338  */
339 int
start_init_common()340 start_init_common()
341 {
342 	proc_t *p = curproc;
343 	ASSERT_STACK_ALIGNED();
344 	p->p_zone->zone_proc_initpid = p->p_pid;
345 
346 	p->p_cstime = p->p_stime = p->p_cutime = p->p_utime = 0;
347 	p->p_usrstack = (caddr_t)USRSTACK32;
348 	p->p_model = DATAMODEL_ILP32;
349 	p->p_stkprot = PROT_ZFOD & ~PROT_EXEC;
350 	p->p_datprot = PROT_ZFOD & ~PROT_EXEC;
351 	p->p_stk_ctl = INT32_MAX;
352 
353 	p->p_as = as_alloc();
354 	p->p_as->a_proc = p;
355 	p->p_as->a_userlimit = (caddr_t)USERLIMIT32;
356 	(void) hat_setup(p->p_as->a_hat, HAT_INIT);
357 
358 	init_core();
359 
360 	init_mstate(curthread, LMS_SYSTEM);
361 	return (exec_init(p->p_zone->zone_initname, p->p_zone->zone_bootargs));
362 }
363 
364 /*
365  * Start the initial user process for the global zone; once running, if
366  * init should subsequently fail, it will be automatically be caught in the
367  * exit(2) path, and restarted by restart_init().
368  */
369 static void
start_init(void)370 start_init(void)
371 {
372 	proc_init = curproc;
373 
374 	ASSERT(curproc->p_zone->zone_initname != NULL);
375 
376 	if (start_init_common() != 0)
377 		halt("unix: Could not start init");
378 	lwp_rtt();
379 }
380 
381 void
main(void)382 main(void)
383 {
384 	proc_t		*p = ttoproc(curthread);	/* &p0 */
385 	int		(**initptr)();
386 	extern void	sched();
387 	extern void	fsflush();
388 	extern int	(*init_tbl[])();
389 	extern int	(*mp_init_tbl[])();
390 	extern id_t	syscid, defaultcid;
391 	extern int	swaploaded;
392 	extern int	netboot;
393 	extern ib_boot_prop_t *iscsiboot_prop;
394 	extern void	vm_init(void);
395 	extern void	cbe_init_pre(void);
396 	extern void	cbe_init(void);
397 	extern void	clock_tick_init_pre(void);
398 	extern void	clock_tick_init_post(void);
399 	extern void	clock_init(void);
400 	extern void	physio_bufs_init(void);
401 	extern void	pm_cfb_setup_intr(void);
402 	extern int	pm_adjust_timestamps(dev_info_t *, void *);
403 	extern void	start_other_cpus(int);
404 	extern void	sysevent_evc_thrinit();
405 	extern kmutex_t	ualock;
406 #if defined(__x86)
407 	extern void	fastboot_post_startup(void);
408 	extern void	progressbar_start(void);
409 #endif
410 	/*
411 	 * In the horrible world of x86 in-lines, you can't get symbolic
412 	 * structure offsets a la genassym.  This assertion is here so
413 	 * that the next poor slob who innocently changes the offset of
414 	 * cpu_thread doesn't waste as much time as I just did finding
415 	 * out that it's hard-coded in i86/ml/i86.il.  Similarly for
416 	 * curcpup.  You're welcome.
417 	 */
418 	ASSERT(CPU == CPU->cpu_self);
419 	ASSERT(curthread == CPU->cpu_thread);
420 	ASSERT_STACK_ALIGNED();
421 
422 	/*
423 	 * We take the ualock until we have completed the startup
424 	 * to prevent kadmin() from disrupting this work. In particular,
425 	 * we don't want kadmin() to bring the system down while we are
426 	 * trying to start it up.
427 	 */
428 	mutex_enter(&ualock);
429 
430 	/*
431 	 * Setup root lgroup and leaf lgroup for CPU 0
432 	 */
433 	lgrp_init(LGRP_INIT_STAGE2);
434 
435 	/*
436 	 * Once 'startup()' completes, the thread_reaper() daemon would be
437 	 * created(in thread_init()). After that, it is safe to create threads
438 	 * that could exit. These exited threads will get reaped.
439 	 */
440 	startup();
441 	segkmem_gc();
442 	callb_init();
443 	cbe_init_pre();	/* x86 must initialize gethrtimef before timer_init */
444 	ddi_periodic_init();
445 	cbe_init();
446 	callout_init();	/* callout table MUST be init'd after cyclics */
447 	clock_tick_init_pre();
448 	clock_init();
449 
450 #if defined(__x86)
451 	/*
452 	 * The progressbar thread uses cv_reltimedwait() and hence needs to be
453 	 * started after the callout mechanism has been initialized.
454 	 */
455 	progressbar_start();
456 #endif
457 	/*
458 	 * On some platforms, clkinitf() changes the timing source that
459 	 * gethrtime_unscaled() uses to generate timestamps.  cbe_init() calls
460 	 * clkinitf(), so re-initialize the microstate counters after the
461 	 * timesource has been chosen.
462 	 */
463 	init_mstate(&t0, LMS_SYSTEM);
464 	init_cpu_mstate(CPU, CMS_SYSTEM);
465 
466 	/*
467 	 * May need to probe to determine latencies from CPU 0 after
468 	 * gethrtime() comes alive in cbe_init() and before enabling interrupts
469 	 * and copy and release any temporary memory allocated with BOP_ALLOC()
470 	 * before release_bootstrap() frees boot memory
471 	 */
472 	lgrp_init(LGRP_INIT_STAGE3);
473 
474 	/*
475 	 * Call all system initialization functions.
476 	 */
477 	for (initptr = &init_tbl[0]; *initptr; initptr++)
478 		(**initptr)();
479 	/*
480 	 * Load iSCSI boot properties
481 	 */
482 	ld_ib_prop();
483 	/*
484 	 * initialize vm related stuff.
485 	 */
486 	vm_init();
487 
488 	/*
489 	 * initialize buffer pool for raw I/O requests
490 	 */
491 	physio_bufs_init();
492 
493 	ttolwp(curthread)->lwp_error = 0; /* XXX kludge for SCSI driver */
494 
495 	/*
496 	 * Drop the interrupt level and allow interrupts.  At this point
497 	 * the DDI guarantees that interrupts are enabled.
498 	 */
499 	(void) spl0();
500 	interrupts_unleashed = 1;
501 
502 	/*
503 	 * Create kmem cache for proc structures
504 	 */
505 	process_cache = kmem_cache_create("process_cache", sizeof (proc_t),
506 	    0, NULL, NULL, NULL, NULL, NULL, 0);
507 
508 	vfs_mountroot();	/* Mount the root file system */
509 	errorq_init();		/* after vfs_mountroot() so DDI root is ready */
510 	cpu_kstat_init(CPU);	/* after vfs_mountroot() so TOD is valid */
511 	ddi_walk_devs(ddi_root_node(), pm_adjust_timestamps, NULL);
512 				/* after vfs_mountroot() so hrestime is valid */
513 
514 	post_startup();
515 	swaploaded = 1;
516 
517 	/*
518 	 * Initialize Solaris Audit Subsystem
519 	 */
520 	audit_init();
521 
522 	/*
523 	 * Start the periodic hash rescale for all vmem arenas before we load
524 	 * protocol modules and drivers via strplumb() below.  Some drivers
525 	 * might rely on heavy vmem operations that could hurt performance
526 	 * without the rescale.
527 	 */
528 	vmem_update(NULL);
529 
530 	/*
531 	 * Plumb the protocol modules and drivers only if we are not
532 	 * networked booted, in this case we already did it in rootconf().
533 	 */
534 	if (netboot == 0 && iscsiboot_prop == NULL)
535 		(void) strplumb();
536 
537 	gethrestime(&PTOU(curproc)->u_start);
538 	curthread->t_start = PTOU(curproc)->u_start.tv_sec;
539 	p->p_mstart = gethrtime();
540 
541 	/*
542 	 * Perform setup functions that can only be done after root
543 	 * and swap have been set up.
544 	 */
545 	consconfig();
546 #ifndef	__sparc
547 	release_bootstrap();
548 #endif
549 
550 	/*
551 	 * attach drivers with ddi-forceattach prop
552 	 * It must be done early enough to load hotplug drivers (e.g.
553 	 * pcmcia nexus) so that devices enumerated via hotplug is
554 	 * available before I/O subsystem is fully initialized.
555 	 */
556 	i_ddi_forceattach_drivers();
557 
558 	/*
559 	 * Set the scan rate and other parameters of the paging subsystem.
560 	 */
561 	setupclock();
562 
563 	/*
564 	 * Initialize process 0's lwp directory and lwpid hash table.
565 	 */
566 	p->p_lwpdir = p->p_lwpfree = p0_lwpdir;
567 	p->p_lwpdir->ld_next = p->p_lwpdir + 1;
568 	p->p_lwpdir_sz = 2;
569 	p->p_tidhash = p0_tidhash;
570 	p->p_tidhash_sz = 2;
571 	p0_lep.le_thread = curthread;
572 	p0_lep.le_lwpid = curthread->t_tid;
573 	p0_lep.le_start = curthread->t_start;
574 	lwp_hash_in(p, &p0_lep, p0_tidhash, 2, 0);
575 
576 	/*
577 	 * Initialize extended accounting.
578 	 */
579 	exacct_init();
580 
581 	/*
582 	 * Initialize threads of sysevent event channels
583 	 */
584 	sysevent_evc_thrinit();
585 
586 	/*
587 	 * This must be done after post_startup() but before
588 	 * start_other_cpus()
589 	 */
590 	lgrp_init(LGRP_INIT_STAGE4);
591 
592 	/*
593 	 * Perform MP initialization, if any.
594 	 */
595 	start_other_cpus(0);
596 
597 #ifdef	__sparc
598 	/*
599 	 * Release bootstrap here since PROM interfaces are
600 	 * used to start other CPUs above.
601 	 */
602 	release_bootstrap();
603 #endif
604 
605 	/*
606 	 * Finish lgrp initialization after all CPUS are brought online.
607 	 */
608 	lgrp_init(LGRP_INIT_STAGE5);
609 
610 	/*
611 	 * After mp_init(), number of cpus are known (this is
612 	 * true for the time being, when there are actually
613 	 * hot pluggable cpus then this scheme  would not do).
614 	 * Any per cpu initialization is done here.
615 	 */
616 	kmem_mp_init();
617 
618 	clock_tick_init_post();
619 
620 	for (initptr = &mp_init_tbl[0]; *initptr; initptr++)
621 		(**initptr)();
622 
623 	/*
624 	 * These must be called after start_other_cpus
625 	 */
626 	pm_cfb_setup_intr();
627 #if defined(__x86)
628 	fastboot_post_startup();
629 
630 	smt_late_init();
631 #endif
632 
633 	/*
634 	 * Make init process; enter scheduling loop with system process.
635 	 *
636 	 * Note that we manually assign the pids for these processes, for
637 	 * historical reasons.  If more pre-assigned pids are needed,
638 	 * FAMOUS_PIDS will have to be updated.
639 	 */
640 
641 	/* create init process */
642 	if (newproc(start_init, NULL, defaultcid, 59, NULL,
643 	    FAMOUS_PID_INIT))
644 		panic("main: unable to fork init.");
645 
646 	/* create pageout daemon */
647 	if (newproc(pageout, NULL, syscid, maxclsyspri - 1, NULL,
648 	    FAMOUS_PID_PAGEOUT))
649 		panic("main: unable to fork pageout()");
650 
651 	/* create fsflush daemon */
652 	if (newproc(fsflush, NULL, syscid, minclsyspri, NULL,
653 	    FAMOUS_PID_FSFLUSH))
654 		panic("main: unable to fork fsflush()");
655 
656 	/* create cluster process if we're a member of one */
657 	if (cluster_bootflags & CLUSTER_BOOTED) {
658 		if (newproc(cluster_wrapper, NULL, syscid, minclsyspri,
659 		    NULL, 0)) {
660 			panic("main: unable to fork cluster()");
661 		}
662 	}
663 
664 	/*
665 	 * Create system threads (threads are associated with p0)
666 	 */
667 
668 	/* create module uninstall daemon */
669 	/* BugID 1132273. If swapping over NFS need a bigger stack */
670 	(void) thread_create(NULL, 0, (void (*)())mod_uninstall_daemon,
671 	    NULL, 0, &p0, TS_RUN, minclsyspri);
672 
673 	(void) thread_create(NULL, 0, seg_pasync_thread,
674 	    NULL, 0, &p0, TS_RUN, minclsyspri);
675 
676 	pid_setmin();
677 
678 	/* system is now ready */
679 	mutex_exit(&ualock);
680 
681 	bcopy("sched", PTOU(curproc)->u_psargs, 6);
682 	bcopy("sched", PTOU(curproc)->u_comm, 5);
683 	sched();
684 	/* NOTREACHED */
685 }
686