1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1986, 1988, 1991, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
8 * to the University of California by American Telephone and Telegraph
9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 *    notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 *    notice, this list of conditions and the following disclaimer in the
19 *    documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37#include <sys/cdefs.h>
38#include "opt_ddb.h"
39#include "opt_ekcd.h"
40#include "opt_kdb.h"
41#include "opt_panic.h"
42#include "opt_printf.h"
43#include "opt_sched.h"
44#include "opt_watchdog.h"
45
46#include <sys/param.h>
47#include <sys/systm.h>
48#include <sys/bio.h>
49#include <sys/boottrace.h>
50#include <sys/buf.h>
51#include <sys/conf.h>
52#include <sys/compressor.h>
53#include <sys/cons.h>
54#include <sys/disk.h>
55#include <sys/eventhandler.h>
56#include <sys/filedesc.h>
57#include <sys/jail.h>
58#include <sys/kdb.h>
59#include <sys/kernel.h>
60#include <sys/kerneldump.h>
61#include <sys/kthread.h>
62#include <sys/ktr.h>
63#include <sys/malloc.h>
64#include <sys/mbuf.h>
65#include <sys/mount.h>
66#include <sys/priv.h>
67#include <sys/proc.h>
68#include <sys/reboot.h>
69#include <sys/resourcevar.h>
70#include <sys/rwlock.h>
71#include <sys/sbuf.h>
72#include <sys/sched.h>
73#include <sys/smp.h>
74#include <sys/sysctl.h>
75#include <sys/sysproto.h>
76#include <sys/taskqueue.h>
77#include <sys/vnode.h>
78#include <sys/watchdog.h>
79
80#include <crypto/chacha20/chacha.h>
81#include <crypto/rijndael/rijndael-api-fst.h>
82#include <crypto/sha2/sha256.h>
83
84#include <ddb/ddb.h>
85
86#include <machine/cpu.h>
87#include <machine/dump.h>
88#include <machine/pcb.h>
89#include <machine/smp.h>
90
91#include <security/mac/mac_framework.h>
92
93#include <vm/vm.h>
94#include <vm/vm_object.h>
95#include <vm/vm_page.h>
96#include <vm/vm_pager.h>
97#include <vm/swap_pager.h>
98
99#include <sys/signalvar.h>
100
101static MALLOC_DEFINE(M_DUMPER, "dumper", "dumper block buffer");
102
103#ifndef PANIC_REBOOT_WAIT_TIME
104#define PANIC_REBOOT_WAIT_TIME 15 /* default to 15 seconds */
105#endif
106static int panic_reboot_wait_time = PANIC_REBOOT_WAIT_TIME;
107SYSCTL_INT(_kern, OID_AUTO, panic_reboot_wait_time, CTLFLAG_RWTUN,
108    &panic_reboot_wait_time, 0,
109    "Seconds to wait before rebooting after a panic");
110static int reboot_wait_time = 0;
111SYSCTL_INT(_kern, OID_AUTO, reboot_wait_time, CTLFLAG_RWTUN,
112    &reboot_wait_time, 0,
113    "Seconds to wait before rebooting");
114
115/*
116 * Note that stdarg.h and the ANSI style va_start macro is used for both
117 * ANSI and traditional C compilers.
118 */
119#include <machine/stdarg.h>
120
121#ifdef KDB
122#ifdef KDB_UNATTENDED
123int debugger_on_panic = 0;
124#else
125int debugger_on_panic = 1;
126#endif
127SYSCTL_INT(_debug, OID_AUTO, debugger_on_panic,
128    CTLFLAG_RWTUN, &debugger_on_panic, 0,
129    "Run debugger on kernel panic");
130
131static bool debugger_on_recursive_panic = false;
132SYSCTL_BOOL(_debug, OID_AUTO, debugger_on_recursive_panic,
133    CTLFLAG_RWTUN, &debugger_on_recursive_panic, 0,
134    "Run debugger on recursive kernel panic");
135
136int debugger_on_trap = 0;
137SYSCTL_INT(_debug, OID_AUTO, debugger_on_trap,
138    CTLFLAG_RWTUN, &debugger_on_trap, 0,
139    "Run debugger on kernel trap before panic");
140
141#ifdef KDB_TRACE
142static int trace_on_panic = 1;
143static bool trace_all_panics = true;
144#else
145static int trace_on_panic = 0;
146static bool trace_all_panics = false;
147#endif
148SYSCTL_INT(_debug, OID_AUTO, trace_on_panic,
149    CTLFLAG_RWTUN | CTLFLAG_SECURE,
150    &trace_on_panic, 0, "Print stack trace on kernel panic");
151SYSCTL_BOOL(_debug, OID_AUTO, trace_all_panics, CTLFLAG_RWTUN,
152    &trace_all_panics, 0, "Print stack traces on secondary kernel panics");
153#endif /* KDB */
154
155static int sync_on_panic = 0;
156SYSCTL_INT(_kern, OID_AUTO, sync_on_panic, CTLFLAG_RWTUN,
157	&sync_on_panic, 0, "Do a sync before rebooting from a panic");
158
159static bool poweroff_on_panic = 0;
160SYSCTL_BOOL(_kern, OID_AUTO, poweroff_on_panic, CTLFLAG_RWTUN,
161	&poweroff_on_panic, 0, "Do a power off instead of a reboot on a panic");
162
163static bool powercycle_on_panic = 0;
164SYSCTL_BOOL(_kern, OID_AUTO, powercycle_on_panic, CTLFLAG_RWTUN,
165	&powercycle_on_panic, 0, "Do a power cycle instead of a reboot on a panic");
166
167static SYSCTL_NODE(_kern, OID_AUTO, shutdown, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
168    "Shutdown environment");
169
170#ifndef DIAGNOSTIC
171static int show_busybufs;
172#else
173static int show_busybufs = 1;
174#endif
175SYSCTL_INT(_kern_shutdown, OID_AUTO, show_busybufs, CTLFLAG_RW,
176    &show_busybufs, 0,
177    "Show busy buffers during shutdown");
178
179int suspend_blocked = 0;
180SYSCTL_INT(_kern, OID_AUTO, suspend_blocked, CTLFLAG_RW,
181	&suspend_blocked, 0, "Block suspend due to a pending shutdown");
182
183#ifdef EKCD
184FEATURE(ekcd, "Encrypted kernel crash dumps support");
185
186MALLOC_DEFINE(M_EKCD, "ekcd", "Encrypted kernel crash dumps data");
187
188struct kerneldumpcrypto {
189	uint8_t			kdc_encryption;
190	uint8_t			kdc_iv[KERNELDUMP_IV_MAX_SIZE];
191	union {
192		struct {
193			keyInstance	aes_ki;
194			cipherInstance	aes_ci;
195		} u_aes;
196		struct chacha_ctx	u_chacha;
197	} u;
198#define	kdc_ki	u.u_aes.aes_ki
199#define	kdc_ci	u.u_aes.aes_ci
200#define	kdc_chacha	u.u_chacha
201	uint32_t		kdc_dumpkeysize;
202	struct kerneldumpkey	kdc_dumpkey[];
203};
204#endif
205
206struct kerneldumpcomp {
207	uint8_t			kdc_format;
208	struct compressor	*kdc_stream;
209	uint8_t			*kdc_buf;
210	size_t			kdc_resid;
211};
212
213static struct kerneldumpcomp *kerneldumpcomp_create(struct dumperinfo *di,
214		    uint8_t compression);
215static void	kerneldumpcomp_destroy(struct dumperinfo *di);
216static int	kerneldumpcomp_write_cb(void *base, size_t len, off_t off, void *arg);
217
218static int kerneldump_gzlevel = 6;
219SYSCTL_INT(_kern, OID_AUTO, kerneldump_gzlevel, CTLFLAG_RWTUN,
220    &kerneldump_gzlevel, 0,
221    "Kernel crash dump compression level");
222
223/*
224 * Variable panicstr contains argument to first call to panic; used as flag
225 * to indicate that the kernel has already called panic.
226 */
227const char *panicstr __read_mostly;
228bool scheduler_stopped __read_frequently;
229
230int dumping __read_mostly;		/* system is dumping */
231int rebooting __read_mostly;		/* system is rebooting */
232bool dumped_core __read_mostly;		/* system successfully dumped core */
233/*
234 * Used to serialize between sysctl kern.shutdown.dumpdevname and list
235 * modifications via ioctl.
236 */
237static struct mtx dumpconf_list_lk;
238MTX_SYSINIT(dumper_configs, &dumpconf_list_lk, "dumper config list", MTX_DEF);
239
240/* Our selected dumper(s). */
241static TAILQ_HEAD(dumpconflist, dumperinfo) dumper_configs =
242    TAILQ_HEAD_INITIALIZER(dumper_configs);
243
244/* Context information for dump-debuggers, saved by the dump_savectx() macro. */
245struct pcb dumppcb;			/* Registers. */
246lwpid_t dumptid;			/* Thread ID. */
247
248static struct cdevsw reroot_cdevsw = {
249     .d_version = D_VERSION,
250     .d_name    = "reroot",
251};
252
253static void poweroff_wait(void *, int);
254static void shutdown_halt(void *junk, int howto);
255static void shutdown_panic(void *junk, int howto);
256static void shutdown_reset(void *junk, int howto);
257static int kern_reroot(void);
258
259/* register various local shutdown events */
260static void
261shutdown_conf(void *unused)
262{
263
264	EVENTHANDLER_REGISTER(shutdown_final, poweroff_wait, NULL,
265	    SHUTDOWN_PRI_FIRST);
266	EVENTHANDLER_REGISTER(shutdown_final, shutdown_panic, NULL,
267	    SHUTDOWN_PRI_LAST + 100);
268	EVENTHANDLER_REGISTER(shutdown_final, shutdown_halt, NULL,
269	    SHUTDOWN_PRI_LAST + 200);
270}
271
272SYSINIT(shutdown_conf, SI_SUB_INTRINSIC, SI_ORDER_ANY, shutdown_conf, NULL);
273
274/*
275 * The only reason this exists is to create the /dev/reroot/ directory,
276 * used by reroot code in init(8) as a mountpoint for tmpfs.
277 */
278static void
279reroot_conf(void *unused)
280{
281	int error;
282	struct cdev *cdev;
283
284	error = make_dev_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK, &cdev,
285	    &reroot_cdevsw, NULL, UID_ROOT, GID_WHEEL, 0600, "reroot/reroot");
286	if (error != 0) {
287		printf("%s: failed to create device node, error %d",
288		    __func__, error);
289	}
290}
291
292SYSINIT(reroot_conf, SI_SUB_DEVFS, SI_ORDER_ANY, reroot_conf, NULL);
293
294/*
295 * The system call that results in a reboot.
296 */
297/* ARGSUSED */
298int
299sys_reboot(struct thread *td, struct reboot_args *uap)
300{
301	int error;
302
303	error = 0;
304#ifdef MAC
305	error = mac_system_check_reboot(td->td_ucred, uap->opt);
306#endif
307	if (error == 0)
308		error = priv_check(td, PRIV_REBOOT);
309	if (error == 0) {
310		if (uap->opt & RB_REROOT)
311			error = kern_reroot();
312		else
313			kern_reboot(uap->opt);
314	}
315	return (error);
316}
317
318static void
319shutdown_nice_task_fn(void *arg, int pending __unused)
320{
321	int howto;
322
323	howto = (uintptr_t)arg;
324	/* Send a signal to init(8) and have it shutdown the world. */
325	PROC_LOCK(initproc);
326	if ((howto & RB_POWEROFF) != 0) {
327		BOOTTRACE("SIGUSR2 to init(8)");
328		kern_psignal(initproc, SIGUSR2);
329	} else if ((howto & RB_POWERCYCLE) != 0) {
330		BOOTTRACE("SIGWINCH to init(8)");
331		kern_psignal(initproc, SIGWINCH);
332	} else if ((howto & RB_HALT) != 0) {
333		BOOTTRACE("SIGUSR1 to init(8)");
334		kern_psignal(initproc, SIGUSR1);
335	} else {
336		BOOTTRACE("SIGINT to init(8)");
337		kern_psignal(initproc, SIGINT);
338	}
339	PROC_UNLOCK(initproc);
340}
341
342static struct task shutdown_nice_task = TASK_INITIALIZER(0,
343    &shutdown_nice_task_fn, NULL);
344
345/*
346 * Called by events that want to shut down.. e.g  <CTL><ALT><DEL> on a PC
347 */
348void
349shutdown_nice(int howto)
350{
351
352	if (initproc != NULL && !SCHEDULER_STOPPED()) {
353		BOOTTRACE("shutdown initiated");
354		shutdown_nice_task.ta_context = (void *)(uintptr_t)howto;
355		taskqueue_enqueue(taskqueue_fast, &shutdown_nice_task);
356	} else {
357		/*
358		 * No init(8) running, or scheduler would not allow it
359		 * to run, so simply reboot.
360		 */
361		kern_reboot(howto | RB_NOSYNC);
362	}
363}
364
365static void
366print_uptime(void)
367{
368	int f;
369	struct timespec ts;
370
371	getnanouptime(&ts);
372	printf("Uptime: ");
373	f = 0;
374	if (ts.tv_sec >= 86400) {
375		printf("%ldd", (long)ts.tv_sec / 86400);
376		ts.tv_sec %= 86400;
377		f = 1;
378	}
379	if (f || ts.tv_sec >= 3600) {
380		printf("%ldh", (long)ts.tv_sec / 3600);
381		ts.tv_sec %= 3600;
382		f = 1;
383	}
384	if (f || ts.tv_sec >= 60) {
385		printf("%ldm", (long)ts.tv_sec / 60);
386		ts.tv_sec %= 60;
387		f = 1;
388	}
389	printf("%lds\n", (long)ts.tv_sec);
390}
391
392int
393doadump(boolean_t textdump)
394{
395	boolean_t coredump;
396	int error;
397
398	error = 0;
399	if (dumping)
400		return (EBUSY);
401	if (TAILQ_EMPTY(&dumper_configs))
402		return (ENXIO);
403
404	dump_savectx();
405	dumping++;
406
407	coredump = TRUE;
408#ifdef DDB
409	if (textdump && textdump_pending) {
410		coredump = FALSE;
411		textdump_dumpsys(TAILQ_FIRST(&dumper_configs));
412	}
413#endif
414	if (coredump) {
415		struct dumperinfo *di;
416
417		TAILQ_FOREACH(di, &dumper_configs, di_next) {
418			error = dumpsys(di);
419			if (error == 0) {
420				dumped_core = true;
421				break;
422			}
423		}
424	}
425
426	dumping--;
427	return (error);
428}
429
430/*
431 * Trace the shutdown reason.
432 */
433static void
434reboottrace(int howto)
435{
436	if ((howto & RB_DUMP) != 0) {
437		if ((howto & RB_HALT) != 0)
438			BOOTTRACE("system panic: halting...");
439		if ((howto & RB_POWEROFF) != 0)
440			BOOTTRACE("system panic: powering off...");
441		if ((howto & (RB_HALT|RB_POWEROFF)) == 0)
442			BOOTTRACE("system panic: rebooting...");
443	} else {
444		if ((howto & RB_HALT) != 0)
445			BOOTTRACE("system halting...");
446		if ((howto & RB_POWEROFF) != 0)
447			BOOTTRACE("system powering off...");
448		if ((howto & (RB_HALT|RB_POWEROFF)) == 0)
449			BOOTTRACE("system rebooting...");
450	}
451}
452
453/*
454 * kern_reboot(9): Shut down the system cleanly to prepare for reboot, halt, or
455 * power off.
456 */
457void
458kern_reboot(int howto)
459{
460	static int once = 0;
461
462	if (initproc != NULL && curproc != initproc)
463		BOOTTRACE("kernel shutdown (dirty) started");
464	else
465		BOOTTRACE("kernel shutdown (clean) started");
466
467	/*
468	 * Normal paths here don't hold Giant, but we can wind up here
469	 * unexpectedly with it held.  Drop it now so we don't have to
470	 * drop and pick it up elsewhere. The paths it is locking will
471	 * never be returned to, and it is preferable to preclude
472	 * deadlock than to lock against code that won't ever
473	 * continue.
474	 */
475	while (!SCHEDULER_STOPPED() && mtx_owned(&Giant))
476		mtx_unlock(&Giant);
477
478#if defined(SMP)
479	/*
480	 * Bind us to the first CPU so that all shutdown code runs there.  Some
481	 * systems don't shutdown properly (i.e., ACPI power off) if we
482	 * run on another processor.
483	 */
484	if (!SCHEDULER_STOPPED()) {
485		thread_lock(curthread);
486		sched_bind(curthread, CPU_FIRST());
487		thread_unlock(curthread);
488		KASSERT(PCPU_GET(cpuid) == CPU_FIRST(),
489		    ("%s: not running on cpu 0", __func__));
490	}
491#endif
492	/* We're in the process of rebooting. */
493	rebooting = 1;
494	reboottrace(howto);
495
496	/*
497	 * Do any callouts that should be done BEFORE syncing the filesystems.
498	 */
499	EVENTHANDLER_INVOKE(shutdown_pre_sync, howto);
500	BOOTTRACE("shutdown pre sync complete");
501
502	/*
503	 * Now sync filesystems
504	 */
505	if (!cold && (howto & RB_NOSYNC) == 0 && once == 0) {
506		once = 1;
507		BOOTTRACE("bufshutdown begin");
508		bufshutdown(show_busybufs);
509		BOOTTRACE("bufshutdown end");
510	}
511
512	print_uptime();
513
514	cngrab();
515
516	/*
517	 * Ok, now do things that assume all filesystem activity has
518	 * been completed.
519	 */
520	EVENTHANDLER_INVOKE(shutdown_post_sync, howto);
521	BOOTTRACE("shutdown post sync complete");
522
523	if ((howto & (RB_HALT|RB_DUMP)) == RB_DUMP && !cold && !dumping)
524		doadump(TRUE);
525
526	/* Now that we're going to really halt the system... */
527	BOOTTRACE("shutdown final begin");
528
529	if (shutdown_trace)
530		boottrace_dump_console();
531
532	EVENTHANDLER_INVOKE(shutdown_final, howto);
533
534	/*
535	 * Call this directly so that reset is attempted even if shutdown
536	 * handlers are not yet registered.
537	 */
538	shutdown_reset(NULL, howto);
539
540	for(;;) ;	/* safety against shutdown_reset not working */
541	/* NOTREACHED */
542}
543
544/*
545 * The system call that results in changing the rootfs.
546 */
547static int
548kern_reroot(void)
549{
550	struct vnode *oldrootvnode, *vp;
551	struct mount *mp, *devmp;
552	int error;
553
554	if (curproc != initproc)
555		return (EPERM);
556
557	/*
558	 * Mark the filesystem containing currently-running executable
559	 * (the temporary copy of init(8)) busy.
560	 */
561	vp = curproc->p_textvp;
562	error = vn_lock(vp, LK_SHARED);
563	if (error != 0)
564		return (error);
565	mp = vp->v_mount;
566	error = vfs_busy(mp, MBF_NOWAIT);
567	if (error != 0) {
568		vfs_ref(mp);
569		VOP_UNLOCK(vp);
570		error = vfs_busy(mp, 0);
571		vn_lock(vp, LK_SHARED | LK_RETRY);
572		vfs_rel(mp);
573		if (error != 0) {
574			VOP_UNLOCK(vp);
575			return (ENOENT);
576		}
577		if (VN_IS_DOOMED(vp)) {
578			VOP_UNLOCK(vp);
579			vfs_unbusy(mp);
580			return (ENOENT);
581		}
582	}
583	VOP_UNLOCK(vp);
584
585	/*
586	 * Remove the filesystem containing currently-running executable
587	 * from the mount list, to prevent it from being unmounted
588	 * by vfs_unmountall(), and to avoid confusing vfs_mountroot().
589	 *
590	 * Also preserve /dev - forcibly unmounting it could cause driver
591	 * reinitialization.
592	 */
593
594	vfs_ref(rootdevmp);
595	devmp = rootdevmp;
596	rootdevmp = NULL;
597
598	mtx_lock(&mountlist_mtx);
599	TAILQ_REMOVE(&mountlist, mp, mnt_list);
600	TAILQ_REMOVE(&mountlist, devmp, mnt_list);
601	mtx_unlock(&mountlist_mtx);
602
603	oldrootvnode = rootvnode;
604
605	/*
606	 * Unmount everything except for the two filesystems preserved above.
607	 */
608	vfs_unmountall();
609
610	/*
611	 * Add /dev back; vfs_mountroot() will move it into its new place.
612	 */
613	mtx_lock(&mountlist_mtx);
614	TAILQ_INSERT_HEAD(&mountlist, devmp, mnt_list);
615	mtx_unlock(&mountlist_mtx);
616	rootdevmp = devmp;
617	vfs_rel(rootdevmp);
618
619	/*
620	 * Mount the new rootfs.
621	 */
622	vfs_mountroot();
623
624	/*
625	 * Update all references to the old rootvnode.
626	 */
627	mountcheckdirs(oldrootvnode, rootvnode);
628
629	/*
630	 * Add the temporary filesystem back and unbusy it.
631	 */
632	mtx_lock(&mountlist_mtx);
633	TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);
634	mtx_unlock(&mountlist_mtx);
635	vfs_unbusy(mp);
636
637	return (0);
638}
639
640/*
641 * If the shutdown was a clean halt, behave accordingly.
642 */
643static void
644shutdown_halt(void *junk, int howto)
645{
646
647	if (howto & RB_HALT) {
648		printf("\n");
649		printf("The operating system has halted.\n");
650		printf("Please press any key to reboot.\n\n");
651
652		wdog_kern_pat(WD_TO_NEVER);
653
654		switch (cngetc()) {
655		case -1:		/* No console, just die */
656			cpu_halt();
657			/* NOTREACHED */
658		default:
659			break;
660		}
661	}
662}
663
664/*
665 * Check to see if the system panicked, pause and then reboot
666 * according to the specified delay.
667 */
668static void
669shutdown_panic(void *junk, int howto)
670{
671	int loop;
672
673	if (howto & RB_DUMP) {
674		if (panic_reboot_wait_time != 0) {
675			if (panic_reboot_wait_time != -1) {
676				printf("Automatic reboot in %d seconds - "
677				       "press a key on the console to abort\n",
678					panic_reboot_wait_time);
679				for (loop = panic_reboot_wait_time * 10;
680				     loop > 0; --loop) {
681					DELAY(1000 * 100); /* 1/10th second */
682					/* Did user type a key? */
683					if (cncheckc() != -1)
684						break;
685				}
686				if (!loop)
687					return;
688			}
689		} else { /* zero time specified - reboot NOW */
690			return;
691		}
692		printf("--> Press a key on the console to reboot,\n");
693		printf("--> or switch off the system now.\n");
694		cngetc();
695	}
696}
697
698/*
699 * Everything done, now reset
700 */
701static void
702shutdown_reset(void *junk, int howto)
703{
704
705	printf("Rebooting...\n");
706	DELAY(reboot_wait_time * 1000000);
707
708	/*
709	 * Acquiring smp_ipi_mtx here has a double effect:
710	 * - it disables interrupts avoiding CPU0 preemption
711	 *   by fast handlers (thus deadlocking  against other CPUs)
712	 * - it avoids deadlocks against smp_rendezvous() or, more
713	 *   generally, threads busy-waiting, with this spinlock held,
714	 *   and waiting for responses by threads on other CPUs
715	 *   (ie. smp_tlb_shootdown()).
716	 *
717	 * For the !SMP case it just needs to handle the former problem.
718	 */
719#ifdef SMP
720	mtx_lock_spin(&smp_ipi_mtx);
721#else
722	spinlock_enter();
723#endif
724
725	cpu_reset();
726	/* NOTREACHED */ /* assuming reset worked */
727}
728
729#if defined(WITNESS) || defined(INVARIANT_SUPPORT)
730static int kassert_warn_only = 0;
731#ifdef KDB
732static int kassert_do_kdb = 0;
733#endif
734#ifdef KTR
735static int kassert_do_ktr = 0;
736#endif
737static int kassert_do_log = 1;
738static int kassert_log_pps_limit = 4;
739static int kassert_log_mute_at = 0;
740static int kassert_log_panic_at = 0;
741static int kassert_suppress_in_panic = 0;
742static int kassert_warnings = 0;
743
744SYSCTL_NODE(_debug, OID_AUTO, kassert, CTLFLAG_RW | CTLFLAG_MPSAFE, NULL,
745    "kassert options");
746
747#ifdef KASSERT_PANIC_OPTIONAL
748#define KASSERT_RWTUN	CTLFLAG_RWTUN
749#else
750#define KASSERT_RWTUN	CTLFLAG_RDTUN
751#endif
752
753SYSCTL_INT(_debug_kassert, OID_AUTO, warn_only, KASSERT_RWTUN,
754    &kassert_warn_only, 0,
755    "KASSERT triggers a panic (0) or just a warning (1)");
756
757#ifdef KDB
758SYSCTL_INT(_debug_kassert, OID_AUTO, do_kdb, KASSERT_RWTUN,
759    &kassert_do_kdb, 0, "KASSERT will enter the debugger");
760#endif
761
762#ifdef KTR
763SYSCTL_UINT(_debug_kassert, OID_AUTO, do_ktr, KASSERT_RWTUN,
764    &kassert_do_ktr, 0,
765    "KASSERT does a KTR, set this to the KTRMASK you want");
766#endif
767
768SYSCTL_INT(_debug_kassert, OID_AUTO, do_log, KASSERT_RWTUN,
769    &kassert_do_log, 0,
770    "If warn_only is enabled, log (1) or do not log (0) assertion violations");
771
772SYSCTL_INT(_debug_kassert, OID_AUTO, warnings, CTLFLAG_RD | CTLFLAG_STATS,
773    &kassert_warnings, 0, "number of KASSERTs that have been triggered");
774
775SYSCTL_INT(_debug_kassert, OID_AUTO, log_panic_at, KASSERT_RWTUN,
776    &kassert_log_panic_at, 0, "max number of KASSERTS before we will panic");
777
778SYSCTL_INT(_debug_kassert, OID_AUTO, log_pps_limit, KASSERT_RWTUN,
779    &kassert_log_pps_limit, 0, "limit number of log messages per second");
780
781SYSCTL_INT(_debug_kassert, OID_AUTO, log_mute_at, KASSERT_RWTUN,
782    &kassert_log_mute_at, 0, "max number of KASSERTS to log");
783
784SYSCTL_INT(_debug_kassert, OID_AUTO, suppress_in_panic, KASSERT_RWTUN,
785    &kassert_suppress_in_panic, 0,
786    "KASSERTs will be suppressed while handling a panic");
787#undef KASSERT_RWTUN
788
789static int kassert_sysctl_kassert(SYSCTL_HANDLER_ARGS);
790
791SYSCTL_PROC(_debug_kassert, OID_AUTO, kassert,
792    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE | CTLFLAG_MPSAFE, NULL, 0,
793    kassert_sysctl_kassert, "I",
794    "set to trigger a test kassert");
795
796static int
797kassert_sysctl_kassert(SYSCTL_HANDLER_ARGS)
798{
799	int error, i;
800
801	error = sysctl_wire_old_buffer(req, sizeof(int));
802	if (error == 0) {
803		i = 0;
804		error = sysctl_handle_int(oidp, &i, 0, req);
805	}
806	if (error != 0 || req->newptr == NULL)
807		return (error);
808	KASSERT(0, ("kassert_sysctl_kassert triggered kassert %d", i));
809	return (0);
810}
811
812#ifdef KASSERT_PANIC_OPTIONAL
813/*
814 * Called by KASSERT, this decides if we will panic
815 * or if we will log via printf and/or ktr.
816 */
817void
818kassert_panic(const char *fmt, ...)
819{
820	static char buf[256];
821	va_list ap;
822
823	va_start(ap, fmt);
824	(void)vsnprintf(buf, sizeof(buf), fmt, ap);
825	va_end(ap);
826
827	/*
828	 * If we are suppressing secondary panics, log the warning but do not
829	 * re-enter panic/kdb.
830	 */
831	if (KERNEL_PANICKED() && kassert_suppress_in_panic) {
832		if (kassert_do_log) {
833			printf("KASSERT failed: %s\n", buf);
834#ifdef KDB
835			if (trace_all_panics && trace_on_panic)
836				kdb_backtrace();
837#endif
838		}
839		return;
840	}
841
842	/*
843	 * panic if we're not just warning, or if we've exceeded
844	 * kassert_log_panic_at warnings.
845	 */
846	if (!kassert_warn_only ||
847	    (kassert_log_panic_at > 0 &&
848	     kassert_warnings >= kassert_log_panic_at)) {
849		va_start(ap, fmt);
850		vpanic(fmt, ap);
851		/* NORETURN */
852	}
853#ifdef KTR
854	if (kassert_do_ktr)
855		CTR0(ktr_mask, buf);
856#endif /* KTR */
857	/*
858	 * log if we've not yet met the mute limit.
859	 */
860	if (kassert_do_log &&
861	    (kassert_log_mute_at == 0 ||
862	     kassert_warnings < kassert_log_mute_at)) {
863		static  struct timeval lasterr;
864		static  int curerr;
865
866		if (ppsratecheck(&lasterr, &curerr, kassert_log_pps_limit)) {
867			printf("KASSERT failed: %s\n", buf);
868			kdb_backtrace();
869		}
870	}
871#ifdef KDB
872	if (kassert_do_kdb) {
873		kdb_enter(KDB_WHY_KASSERT, buf);
874	}
875#endif
876	atomic_add_int(&kassert_warnings, 1);
877}
878#endif /* KASSERT_PANIC_OPTIONAL */
879#endif
880
881/*
882 * Panic is called on unresolvable fatal errors.  It prints "panic: mesg",
883 * and then reboots.  If we are called twice, then we avoid trying to sync
884 * the disks as this often leads to recursive panics.
885 */
886void
887panic(const char *fmt, ...)
888{
889	va_list ap;
890
891	va_start(ap, fmt);
892	vpanic(fmt, ap);
893}
894
895void
896vpanic(const char *fmt, va_list ap)
897{
898#ifdef SMP
899	cpuset_t other_cpus;
900#endif
901	struct thread *td = curthread;
902	int bootopt, newpanic;
903	static char buf[256];
904
905	/*
906	 * 'fmt' must not be NULL as it is put into 'panicstr' which is then
907	 * used as a flag to detect if the kernel has panicked.  Also, although
908	 * vsnprintf() supports a NULL 'fmt' argument, use a more informative
909	 * message.
910	 */
911	if (fmt == NULL)
912		fmt = "<no panic string!>";
913
914	spinlock_enter();
915
916#ifdef SMP
917	/*
918	 * stop_cpus_hard(other_cpus) should prevent multiple CPUs from
919	 * concurrently entering panic.  Only the winner will proceed
920	 * further.
921	 */
922	if (!KERNEL_PANICKED() && !kdb_active) {
923		other_cpus = all_cpus;
924		CPU_CLR(PCPU_GET(cpuid), &other_cpus);
925		stop_cpus_hard(other_cpus);
926	}
927#endif
928
929	/*
930	 * Ensure that the scheduler is stopped while panicking, even if panic
931	 * has been entered from kdb.
932	 */
933	scheduler_stopped = true;
934
935	bootopt = RB_AUTOBOOT;
936	newpanic = 0;
937	if (KERNEL_PANICKED())
938		bootopt |= RB_NOSYNC;
939	else {
940		bootopt |= RB_DUMP;
941		panicstr = fmt;
942		newpanic = 1;
943	}
944
945	/* Unmute when panic */
946	cn_mute = 0;
947
948	if (newpanic) {
949		(void)vsnprintf(buf, sizeof(buf), fmt, ap);
950		panicstr = buf;
951		cngrab();
952		printf("panic: %s\n", buf);
953	} else {
954		printf("panic: ");
955		vprintf(fmt, ap);
956		printf("\n");
957	}
958#ifdef SMP
959	printf("cpuid = %d\n", PCPU_GET(cpuid));
960#endif
961	printf("time = %jd\n", (intmax_t )time_second);
962#ifdef KDB
963	if ((newpanic || trace_all_panics) && trace_on_panic)
964		kdb_backtrace();
965	if (debugger_on_panic)
966		kdb_enter(KDB_WHY_PANIC, "panic");
967	else if (!newpanic && debugger_on_recursive_panic)
968		kdb_enter(KDB_WHY_PANIC, "re-panic");
969#endif
970	/*thread_lock(td); */
971	td->td_flags |= TDF_INPANIC;
972	/* thread_unlock(td); */
973	if (!sync_on_panic)
974		bootopt |= RB_NOSYNC;
975	if (poweroff_on_panic)
976		bootopt |= RB_POWEROFF;
977	if (powercycle_on_panic)
978		bootopt |= RB_POWERCYCLE;
979	kern_reboot(bootopt);
980}
981
982/*
983 * Support for poweroff delay.
984 *
985 * Please note that setting this delay too short might power off your machine
986 * before the write cache on your hard disk has been flushed, leading to
987 * soft-updates inconsistencies.
988 */
989#ifndef POWEROFF_DELAY
990# define POWEROFF_DELAY 5000
991#endif
992static int poweroff_delay = POWEROFF_DELAY;
993
994SYSCTL_INT(_kern_shutdown, OID_AUTO, poweroff_delay, CTLFLAG_RW,
995    &poweroff_delay, 0, "Delay before poweroff to write disk caches (msec)");
996
997static void
998poweroff_wait(void *junk, int howto)
999{
1000
1001	if ((howto & (RB_POWEROFF | RB_POWERCYCLE)) == 0 || poweroff_delay <= 0)
1002		return;
1003	DELAY(poweroff_delay * 1000);
1004}
1005
1006/*
1007 * Some system processes (e.g. syncer) need to be stopped at appropriate
1008 * points in their main loops prior to a system shutdown, so that they
1009 * won't interfere with the shutdown process (e.g. by holding a disk buf
1010 * to cause sync to fail).  For each of these system processes, register
1011 * shutdown_kproc() as a handler for one of shutdown events.
1012 */
1013static int kproc_shutdown_wait = 60;
1014SYSCTL_INT(_kern_shutdown, OID_AUTO, kproc_shutdown_wait, CTLFLAG_RW,
1015    &kproc_shutdown_wait, 0, "Max wait time (sec) to stop for each process");
1016
1017void
1018kproc_shutdown(void *arg, int howto)
1019{
1020	struct proc *p;
1021	int error;
1022
1023	if (SCHEDULER_STOPPED())
1024		return;
1025
1026	p = (struct proc *)arg;
1027	printf("Waiting (max %d seconds) for system process `%s' to stop... ",
1028	    kproc_shutdown_wait, p->p_comm);
1029	error = kproc_suspend(p, kproc_shutdown_wait * hz);
1030
1031	if (error == EWOULDBLOCK)
1032		printf("timed out\n");
1033	else
1034		printf("done\n");
1035}
1036
1037void
1038kthread_shutdown(void *arg, int howto)
1039{
1040	struct thread *td;
1041	int error;
1042
1043	if (SCHEDULER_STOPPED())
1044		return;
1045
1046	td = (struct thread *)arg;
1047	printf("Waiting (max %d seconds) for system thread `%s' to stop... ",
1048	    kproc_shutdown_wait, td->td_name);
1049	error = kthread_suspend(td, kproc_shutdown_wait * hz);
1050
1051	if (error == EWOULDBLOCK)
1052		printf("timed out\n");
1053	else
1054		printf("done\n");
1055}
1056
1057static int
1058dumpdevname_sysctl_handler(SYSCTL_HANDLER_ARGS)
1059{
1060	char buf[256];
1061	struct dumperinfo *di;
1062	struct sbuf sb;
1063	int error;
1064
1065	error = sysctl_wire_old_buffer(req, 0);
1066	if (error != 0)
1067		return (error);
1068
1069	sbuf_new_for_sysctl(&sb, buf, sizeof(buf), req);
1070
1071	mtx_lock(&dumpconf_list_lk);
1072	TAILQ_FOREACH(di, &dumper_configs, di_next) {
1073		if (di != TAILQ_FIRST(&dumper_configs))
1074			sbuf_putc(&sb, ',');
1075		sbuf_cat(&sb, di->di_devname);
1076	}
1077	mtx_unlock(&dumpconf_list_lk);
1078
1079	error = sbuf_finish(&sb);
1080	sbuf_delete(&sb);
1081	return (error);
1082}
1083SYSCTL_PROC(_kern_shutdown, OID_AUTO, dumpdevname,
1084    CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, &dumper_configs, 0,
1085    dumpdevname_sysctl_handler, "A",
1086    "Device(s) for kernel dumps");
1087
1088static int _dump_append(struct dumperinfo *di, void *virtual, size_t length);
1089
1090#ifdef EKCD
1091static struct kerneldumpcrypto *
1092kerneldumpcrypto_create(size_t blocksize, uint8_t encryption,
1093    const uint8_t *key, uint32_t encryptedkeysize, const uint8_t *encryptedkey)
1094{
1095	struct kerneldumpcrypto *kdc;
1096	struct kerneldumpkey *kdk;
1097	uint32_t dumpkeysize;
1098
1099	dumpkeysize = roundup2(sizeof(*kdk) + encryptedkeysize, blocksize);
1100	kdc = malloc(sizeof(*kdc) + dumpkeysize, M_EKCD, M_WAITOK | M_ZERO);
1101
1102	arc4rand(kdc->kdc_iv, sizeof(kdc->kdc_iv), 0);
1103
1104	kdc->kdc_encryption = encryption;
1105	switch (kdc->kdc_encryption) {
1106	case KERNELDUMP_ENC_AES_256_CBC:
1107		if (rijndael_makeKey(&kdc->kdc_ki, DIR_ENCRYPT, 256, key) <= 0)
1108			goto failed;
1109		break;
1110	case KERNELDUMP_ENC_CHACHA20:
1111		chacha_keysetup(&kdc->kdc_chacha, key, 256);
1112		break;
1113	default:
1114		goto failed;
1115	}
1116
1117	kdc->kdc_dumpkeysize = dumpkeysize;
1118	kdk = kdc->kdc_dumpkey;
1119	kdk->kdk_encryption = kdc->kdc_encryption;
1120	memcpy(kdk->kdk_iv, kdc->kdc_iv, sizeof(kdk->kdk_iv));
1121	kdk->kdk_encryptedkeysize = htod32(encryptedkeysize);
1122	memcpy(kdk->kdk_encryptedkey, encryptedkey, encryptedkeysize);
1123
1124	return (kdc);
1125failed:
1126	zfree(kdc, M_EKCD);
1127	return (NULL);
1128}
1129
1130static int
1131kerneldumpcrypto_init(struct kerneldumpcrypto *kdc)
1132{
1133	uint8_t hash[SHA256_DIGEST_LENGTH];
1134	SHA256_CTX ctx;
1135	struct kerneldumpkey *kdk;
1136	int error;
1137
1138	error = 0;
1139
1140	if (kdc == NULL)
1141		return (0);
1142
1143	/*
1144	 * When a user enters ddb it can write a crash dump multiple times.
1145	 * Each time it should be encrypted using a different IV.
1146	 */
1147	SHA256_Init(&ctx);
1148	SHA256_Update(&ctx, kdc->kdc_iv, sizeof(kdc->kdc_iv));
1149	SHA256_Final(hash, &ctx);
1150	bcopy(hash, kdc->kdc_iv, sizeof(kdc->kdc_iv));
1151
1152	switch (kdc->kdc_encryption) {
1153	case KERNELDUMP_ENC_AES_256_CBC:
1154		if (rijndael_cipherInit(&kdc->kdc_ci, MODE_CBC,
1155		    kdc->kdc_iv) <= 0) {
1156			error = EINVAL;
1157			goto out;
1158		}
1159		break;
1160	case KERNELDUMP_ENC_CHACHA20:
1161		chacha_ivsetup(&kdc->kdc_chacha, kdc->kdc_iv, NULL);
1162		break;
1163	default:
1164		error = EINVAL;
1165		goto out;
1166	}
1167
1168	kdk = kdc->kdc_dumpkey;
1169	memcpy(kdk->kdk_iv, kdc->kdc_iv, sizeof(kdk->kdk_iv));
1170out:
1171	explicit_bzero(hash, sizeof(hash));
1172	return (error);
1173}
1174
1175static uint32_t
1176kerneldumpcrypto_dumpkeysize(const struct kerneldumpcrypto *kdc)
1177{
1178
1179	if (kdc == NULL)
1180		return (0);
1181	return (kdc->kdc_dumpkeysize);
1182}
1183#endif /* EKCD */
1184
1185static struct kerneldumpcomp *
1186kerneldumpcomp_create(struct dumperinfo *di, uint8_t compression)
1187{
1188	struct kerneldumpcomp *kdcomp;
1189	int format;
1190
1191	switch (compression) {
1192	case KERNELDUMP_COMP_GZIP:
1193		format = COMPRESS_GZIP;
1194		break;
1195	case KERNELDUMP_COMP_ZSTD:
1196		format = COMPRESS_ZSTD;
1197		break;
1198	default:
1199		return (NULL);
1200	}
1201
1202	kdcomp = malloc(sizeof(*kdcomp), M_DUMPER, M_WAITOK | M_ZERO);
1203	kdcomp->kdc_format = compression;
1204	kdcomp->kdc_stream = compressor_init(kerneldumpcomp_write_cb,
1205	    format, di->maxiosize, kerneldump_gzlevel, di);
1206	if (kdcomp->kdc_stream == NULL) {
1207		free(kdcomp, M_DUMPER);
1208		return (NULL);
1209	}
1210	kdcomp->kdc_buf = malloc(di->maxiosize, M_DUMPER, M_WAITOK | M_NODUMP);
1211	return (kdcomp);
1212}
1213
1214static void
1215kerneldumpcomp_destroy(struct dumperinfo *di)
1216{
1217	struct kerneldumpcomp *kdcomp;
1218
1219	kdcomp = di->kdcomp;
1220	if (kdcomp == NULL)
1221		return;
1222	compressor_fini(kdcomp->kdc_stream);
1223	zfree(kdcomp->kdc_buf, M_DUMPER);
1224	free(kdcomp, M_DUMPER);
1225}
1226
1227/*
1228 * Free a dumper. Must not be present on global list.
1229 */
1230void
1231dumper_destroy(struct dumperinfo *di)
1232{
1233
1234	if (di == NULL)
1235		return;
1236
1237	zfree(di->blockbuf, M_DUMPER);
1238	kerneldumpcomp_destroy(di);
1239#ifdef EKCD
1240	zfree(di->kdcrypto, M_EKCD);
1241#endif
1242	zfree(di, M_DUMPER);
1243}
1244
1245/*
1246 * Allocate and set up a new dumper from the provided template.
1247 */
1248int
1249dumper_create(const struct dumperinfo *di_template, const char *devname,
1250    const struct diocskerneldump_arg *kda, struct dumperinfo **dip)
1251{
1252	struct dumperinfo *newdi;
1253	int error = 0;
1254
1255	if (dip == NULL)
1256		return (EINVAL);
1257
1258	/* Allocate a new dumper */
1259	newdi = malloc(sizeof(*newdi) + strlen(devname) + 1, M_DUMPER,
1260	    M_WAITOK | M_ZERO);
1261	memcpy(newdi, di_template, sizeof(*newdi));
1262	newdi->blockbuf = NULL;
1263	newdi->kdcrypto = NULL;
1264	newdi->kdcomp = NULL;
1265	strcpy(newdi->di_devname, devname);
1266
1267	if (kda->kda_encryption != KERNELDUMP_ENC_NONE) {
1268#ifdef EKCD
1269		newdi->kdcrypto = kerneldumpcrypto_create(newdi->blocksize,
1270		    kda->kda_encryption, kda->kda_key,
1271		    kda->kda_encryptedkeysize, kda->kda_encryptedkey);
1272		if (newdi->kdcrypto == NULL) {
1273			error = EINVAL;
1274			goto cleanup;
1275		}
1276#else
1277		error = EOPNOTSUPP;
1278		goto cleanup;
1279#endif
1280	}
1281	if (kda->kda_compression != KERNELDUMP_COMP_NONE) {
1282#ifdef EKCD
1283		/*
1284		 * We can't support simultaneous unpadded block cipher
1285		 * encryption and compression because there is no guarantee the
1286		 * length of the compressed result is exactly a multiple of the
1287		 * cipher block size.
1288		 */
1289		if (kda->kda_encryption == KERNELDUMP_ENC_AES_256_CBC) {
1290			error = EOPNOTSUPP;
1291			goto cleanup;
1292		}
1293#endif
1294		newdi->kdcomp = kerneldumpcomp_create(newdi,
1295		    kda->kda_compression);
1296		if (newdi->kdcomp == NULL) {
1297			error = EINVAL;
1298			goto cleanup;
1299		}
1300	}
1301	newdi->blockbuf = malloc(newdi->blocksize, M_DUMPER, M_WAITOK | M_ZERO);
1302
1303	*dip = newdi;
1304	return (0);
1305cleanup:
1306	dumper_destroy(newdi);
1307	return (error);
1308}
1309
1310/*
1311 * Create a new dumper and register it in the global list.
1312 */
1313int
1314dumper_insert(const struct dumperinfo *di_template, const char *devname,
1315    const struct diocskerneldump_arg *kda)
1316{
1317	struct dumperinfo *newdi, *listdi;
1318	bool inserted;
1319	uint8_t index;
1320	int error;
1321
1322	index = kda->kda_index;
1323	MPASS(index != KDA_REMOVE && index != KDA_REMOVE_DEV &&
1324	    index != KDA_REMOVE_ALL);
1325
1326	error = priv_check(curthread, PRIV_SETDUMPER);
1327	if (error != 0)
1328		return (error);
1329
1330	error = dumper_create(di_template, devname, kda, &newdi);
1331	if (error != 0)
1332		return (error);
1333
1334	/* Add the new configuration to the queue */
1335	mtx_lock(&dumpconf_list_lk);
1336	inserted = false;
1337	TAILQ_FOREACH(listdi, &dumper_configs, di_next) {
1338		if (index == 0) {
1339			TAILQ_INSERT_BEFORE(listdi, newdi, di_next);
1340			inserted = true;
1341			break;
1342		}
1343		index--;
1344	}
1345	if (!inserted)
1346		TAILQ_INSERT_TAIL(&dumper_configs, newdi, di_next);
1347	mtx_unlock(&dumpconf_list_lk);
1348
1349	return (0);
1350}
1351
1352#ifdef DDB
1353void
1354dumper_ddb_insert(struct dumperinfo *newdi)
1355{
1356	TAILQ_INSERT_HEAD(&dumper_configs, newdi, di_next);
1357}
1358
1359void
1360dumper_ddb_remove(struct dumperinfo *di)
1361{
1362	TAILQ_REMOVE(&dumper_configs, di, di_next);
1363}
1364#endif
1365
1366static bool
1367dumper_config_match(const struct dumperinfo *di, const char *devname,
1368    const struct diocskerneldump_arg *kda)
1369{
1370	if (kda->kda_index == KDA_REMOVE_ALL)
1371		return (true);
1372
1373	if (strcmp(di->di_devname, devname) != 0)
1374		return (false);
1375
1376	/*
1377	 * Allow wildcard removal of configs matching a device on g_dev_orphan.
1378	 */
1379	if (kda->kda_index == KDA_REMOVE_DEV)
1380		return (true);
1381
1382	if (di->kdcomp != NULL) {
1383		if (di->kdcomp->kdc_format != kda->kda_compression)
1384			return (false);
1385	} else if (kda->kda_compression != KERNELDUMP_COMP_NONE)
1386		return (false);
1387#ifdef EKCD
1388	if (di->kdcrypto != NULL) {
1389		if (di->kdcrypto->kdc_encryption != kda->kda_encryption)
1390			return (false);
1391		/*
1392		 * Do we care to verify keys match to delete?  It seems weird
1393		 * to expect multiple fallback dump configurations on the same
1394		 * device that only differ in crypto key.
1395		 */
1396	} else
1397#endif
1398		if (kda->kda_encryption != KERNELDUMP_ENC_NONE)
1399			return (false);
1400
1401	return (true);
1402}
1403
1404/*
1405 * Remove and free the requested dumper(s) from the global list.
1406 */
1407int
1408dumper_remove(const char *devname, const struct diocskerneldump_arg *kda)
1409{
1410	struct dumperinfo *di, *sdi;
1411	bool found;
1412	int error;
1413
1414	error = priv_check(curthread, PRIV_SETDUMPER);
1415	if (error != 0)
1416		return (error);
1417
1418	/*
1419	 * Try to find a matching configuration, and kill it.
1420	 *
1421	 * NULL 'kda' indicates remove any configuration matching 'devname',
1422	 * which may remove multiple configurations in atypical configurations.
1423	 */
1424	found = false;
1425	mtx_lock(&dumpconf_list_lk);
1426	TAILQ_FOREACH_SAFE(di, &dumper_configs, di_next, sdi) {
1427		if (dumper_config_match(di, devname, kda)) {
1428			found = true;
1429			TAILQ_REMOVE(&dumper_configs, di, di_next);
1430			dumper_destroy(di);
1431		}
1432	}
1433	mtx_unlock(&dumpconf_list_lk);
1434
1435	/* Only produce ENOENT if a more targeted match didn't match. */
1436	if (!found && kda->kda_index == KDA_REMOVE)
1437		return (ENOENT);
1438	return (0);
1439}
1440
1441static int
1442dump_check_bounds(struct dumperinfo *di, off_t offset, size_t length)
1443{
1444
1445	if (di->mediasize > 0 && length != 0 && (offset < di->mediaoffset ||
1446	    offset - di->mediaoffset + length > di->mediasize)) {
1447		if (di->kdcomp != NULL && offset >= di->mediaoffset) {
1448			printf(
1449		    "Compressed dump failed to fit in device boundaries.\n");
1450			return (E2BIG);
1451		}
1452
1453		printf("Attempt to write outside dump device boundaries.\n"
1454	    "offset(%jd), mediaoffset(%jd), length(%ju), mediasize(%jd).\n",
1455		    (intmax_t)offset, (intmax_t)di->mediaoffset,
1456		    (uintmax_t)length, (intmax_t)di->mediasize);
1457		return (ENOSPC);
1458	}
1459	if (length % di->blocksize != 0) {
1460		printf("Attempt to write partial block of length %ju.\n",
1461		    (uintmax_t)length);
1462		return (EINVAL);
1463	}
1464	if (offset % di->blocksize != 0) {
1465		printf("Attempt to write at unaligned offset %jd.\n",
1466		    (intmax_t)offset);
1467		return (EINVAL);
1468	}
1469
1470	return (0);
1471}
1472
1473#ifdef EKCD
1474static int
1475dump_encrypt(struct kerneldumpcrypto *kdc, uint8_t *buf, size_t size)
1476{
1477
1478	switch (kdc->kdc_encryption) {
1479	case KERNELDUMP_ENC_AES_256_CBC:
1480		if (rijndael_blockEncrypt(&kdc->kdc_ci, &kdc->kdc_ki, buf,
1481		    8 * size, buf) <= 0) {
1482			return (EIO);
1483		}
1484		if (rijndael_cipherInit(&kdc->kdc_ci, MODE_CBC,
1485		    buf + size - 16 /* IV size for AES-256-CBC */) <= 0) {
1486			return (EIO);
1487		}
1488		break;
1489	case KERNELDUMP_ENC_CHACHA20:
1490		chacha_encrypt_bytes(&kdc->kdc_chacha, buf, buf, size);
1491		break;
1492	default:
1493		return (EINVAL);
1494	}
1495
1496	return (0);
1497}
1498
1499/* Encrypt data and call dumper. */
1500static int
1501dump_encrypted_write(struct dumperinfo *di, void *virtual, off_t offset,
1502    size_t length)
1503{
1504	static uint8_t buf[KERNELDUMP_BUFFER_SIZE];
1505	struct kerneldumpcrypto *kdc;
1506	int error;
1507	size_t nbytes;
1508
1509	kdc = di->kdcrypto;
1510
1511	while (length > 0) {
1512		nbytes = MIN(length, sizeof(buf));
1513		bcopy(virtual, buf, nbytes);
1514
1515		if (dump_encrypt(kdc, buf, nbytes) != 0)
1516			return (EIO);
1517
1518		error = dump_write(di, buf, offset, nbytes);
1519		if (error != 0)
1520			return (error);
1521
1522		offset += nbytes;
1523		virtual = (void *)((uint8_t *)virtual + nbytes);
1524		length -= nbytes;
1525	}
1526
1527	return (0);
1528}
1529#endif /* EKCD */
1530
1531static int
1532kerneldumpcomp_write_cb(void *base, size_t length, off_t offset, void *arg)
1533{
1534	struct dumperinfo *di;
1535	size_t resid, rlength;
1536	int error;
1537
1538	di = arg;
1539
1540	if (length % di->blocksize != 0) {
1541		/*
1542		 * This must be the final write after flushing the compression
1543		 * stream. Write as many full blocks as possible and stash the
1544		 * residual data in the dumper's block buffer. It will be
1545		 * padded and written in dump_finish().
1546		 */
1547		rlength = rounddown(length, di->blocksize);
1548		if (rlength != 0) {
1549			error = _dump_append(di, base, rlength);
1550			if (error != 0)
1551				return (error);
1552		}
1553		resid = length - rlength;
1554		memmove(di->blockbuf, (uint8_t *)base + rlength, resid);
1555		bzero((uint8_t *)di->blockbuf + resid, di->blocksize - resid);
1556		di->kdcomp->kdc_resid = resid;
1557		return (EAGAIN);
1558	}
1559	return (_dump_append(di, base, length));
1560}
1561
1562/*
1563 * Write kernel dump headers at the beginning and end of the dump extent.
1564 * Write the kernel dump encryption key after the leading header if we were
1565 * configured to do so.
1566 */
1567static int
1568dump_write_headers(struct dumperinfo *di, struct kerneldumpheader *kdh)
1569{
1570#ifdef EKCD
1571	struct kerneldumpcrypto *kdc;
1572#endif
1573	void *buf;
1574	size_t hdrsz;
1575	uint64_t extent;
1576	uint32_t keysize;
1577	int error;
1578
1579	hdrsz = sizeof(*kdh);
1580	if (hdrsz > di->blocksize)
1581		return (ENOMEM);
1582
1583#ifdef EKCD
1584	kdc = di->kdcrypto;
1585	keysize = kerneldumpcrypto_dumpkeysize(kdc);
1586#else
1587	keysize = 0;
1588#endif
1589
1590	/*
1591	 * If the dump device has special handling for headers, let it take care
1592	 * of writing them out.
1593	 */
1594	if (di->dumper_hdr != NULL)
1595		return (di->dumper_hdr(di, kdh));
1596
1597	if (hdrsz == di->blocksize)
1598		buf = kdh;
1599	else {
1600		buf = di->blockbuf;
1601		memset(buf, 0, di->blocksize);
1602		memcpy(buf, kdh, hdrsz);
1603	}
1604
1605	extent = dtoh64(kdh->dumpextent);
1606#ifdef EKCD
1607	if (kdc != NULL) {
1608		error = dump_write(di, kdc->kdc_dumpkey,
1609		    di->mediaoffset + di->mediasize - di->blocksize - extent -
1610		    keysize, keysize);
1611		if (error != 0)
1612			return (error);
1613	}
1614#endif
1615
1616	error = dump_write(di, buf,
1617	    di->mediaoffset + di->mediasize - 2 * di->blocksize - extent -
1618	    keysize, di->blocksize);
1619	if (error == 0)
1620		error = dump_write(di, buf, di->mediaoffset + di->mediasize -
1621		    di->blocksize, di->blocksize);
1622	return (error);
1623}
1624
1625/*
1626 * Don't touch the first SIZEOF_METADATA bytes on the dump device.  This is to
1627 * protect us from metadata and metadata from us.
1628 */
1629#define	SIZEOF_METADATA		(64 * 1024)
1630
1631/*
1632 * Do some preliminary setup for a kernel dump: initialize state for encryption,
1633 * if requested, and make sure that we have enough space on the dump device.
1634 *
1635 * We set things up so that the dump ends before the last sector of the dump
1636 * device, at which the trailing header is written.
1637 *
1638 *     +-----------+------+-----+----------------------------+------+
1639 *     |           | lhdr | key |    ... kernel dump ...     | thdr |
1640 *     +-----------+------+-----+----------------------------+------+
1641 *                   1 blk  opt <------- dump extent --------> 1 blk
1642 *
1643 * Dumps written using dump_append() start at the beginning of the extent.
1644 * Uncompressed dumps will use the entire extent, but compressed dumps typically
1645 * will not. The true length of the dump is recorded in the leading and trailing
1646 * headers once the dump has been completed.
1647 *
1648 * The dump device may provide a callback, in which case it will initialize
1649 * dumpoff and take care of laying out the headers.
1650 */
1651int
1652dump_start(struct dumperinfo *di, struct kerneldumpheader *kdh)
1653{
1654#ifdef EKCD
1655	struct kerneldumpcrypto *kdc;
1656#endif
1657	void *key;
1658	uint64_t dumpextent, span;
1659	uint32_t keysize;
1660	int error;
1661
1662#ifdef EKCD
1663	/* Send the key before the dump so a partial dump is still usable. */
1664	kdc = di->kdcrypto;
1665	error = kerneldumpcrypto_init(kdc);
1666	if (error != 0)
1667		return (error);
1668	keysize = kerneldumpcrypto_dumpkeysize(kdc);
1669	key = keysize > 0 ? kdc->kdc_dumpkey : NULL;
1670#else
1671	error = 0;
1672	keysize = 0;
1673	key = NULL;
1674#endif
1675
1676	if (di->dumper_start != NULL) {
1677		error = di->dumper_start(di, key, keysize);
1678	} else {
1679		dumpextent = dtoh64(kdh->dumpextent);
1680		span = SIZEOF_METADATA + dumpextent + 2 * di->blocksize +
1681		    keysize;
1682		if (di->mediasize < span) {
1683			if (di->kdcomp == NULL)
1684				return (E2BIG);
1685
1686			/*
1687			 * We don't yet know how much space the compressed dump
1688			 * will occupy, so try to use the whole swap partition
1689			 * (minus the first 64KB) in the hope that the
1690			 * compressed dump will fit. If that doesn't turn out to
1691			 * be enough, the bounds checking in dump_write()
1692			 * will catch us and cause the dump to fail.
1693			 */
1694			dumpextent = di->mediasize - span + dumpextent;
1695			kdh->dumpextent = htod64(dumpextent);
1696		}
1697
1698		/*
1699		 * The offset at which to begin writing the dump.
1700		 */
1701		di->dumpoff = di->mediaoffset + di->mediasize - di->blocksize -
1702		    dumpextent;
1703	}
1704	di->origdumpoff = di->dumpoff;
1705	return (error);
1706}
1707
1708static int
1709_dump_append(struct dumperinfo *di, void *virtual, size_t length)
1710{
1711	int error;
1712
1713#ifdef EKCD
1714	if (di->kdcrypto != NULL)
1715		error = dump_encrypted_write(di, virtual, di->dumpoff, length);
1716	else
1717#endif
1718		error = dump_write(di, virtual, di->dumpoff, length);
1719	if (error == 0)
1720		di->dumpoff += length;
1721	return (error);
1722}
1723
1724/*
1725 * Write to the dump device starting at dumpoff. When compression is enabled,
1726 * writes to the device will be performed using a callback that gets invoked
1727 * when the compression stream's output buffer is full.
1728 */
1729int
1730dump_append(struct dumperinfo *di, void *virtual, size_t length)
1731{
1732	void *buf;
1733
1734	if (di->kdcomp != NULL) {
1735		/* Bounce through a buffer to avoid CRC errors. */
1736		if (length > di->maxiosize)
1737			return (EINVAL);
1738		buf = di->kdcomp->kdc_buf;
1739		memmove(buf, virtual, length);
1740		return (compressor_write(di->kdcomp->kdc_stream, buf, length));
1741	}
1742	return (_dump_append(di, virtual, length));
1743}
1744
1745/*
1746 * Write to the dump device at the specified offset.
1747 */
1748int
1749dump_write(struct dumperinfo *di, void *virtual, off_t offset, size_t length)
1750{
1751	int error;
1752
1753	error = dump_check_bounds(di, offset, length);
1754	if (error != 0)
1755		return (error);
1756	return (di->dumper(di->priv, virtual, offset, length));
1757}
1758
1759/*
1760 * Perform kernel dump finalization: flush the compression stream, if necessary,
1761 * write the leading and trailing kernel dump headers now that we know the true
1762 * length of the dump, and optionally write the encryption key following the
1763 * leading header.
1764 */
1765int
1766dump_finish(struct dumperinfo *di, struct kerneldumpheader *kdh)
1767{
1768	int error;
1769
1770	if (di->kdcomp != NULL) {
1771		error = compressor_flush(di->kdcomp->kdc_stream);
1772		if (error == EAGAIN) {
1773			/* We have residual data in di->blockbuf. */
1774			error = _dump_append(di, di->blockbuf, di->blocksize);
1775			if (error == 0)
1776				/* Compensate for _dump_append()'s adjustment. */
1777				di->dumpoff -= di->blocksize - di->kdcomp->kdc_resid;
1778			di->kdcomp->kdc_resid = 0;
1779		}
1780		if (error != 0)
1781			return (error);
1782
1783		/*
1784		 * We now know the size of the compressed dump, so update the
1785		 * header accordingly and recompute parity.
1786		 */
1787		kdh->dumplength = htod64(di->dumpoff - di->origdumpoff);
1788		kdh->parity = 0;
1789		kdh->parity = kerneldump_parity(kdh);
1790
1791		compressor_reset(di->kdcomp->kdc_stream);
1792	}
1793
1794	error = dump_write_headers(di, kdh);
1795	if (error != 0)
1796		return (error);
1797
1798	(void)dump_write(di, NULL, 0, 0);
1799	return (0);
1800}
1801
1802void
1803dump_init_header(const struct dumperinfo *di, struct kerneldumpheader *kdh,
1804    const char *magic, uint32_t archver, uint64_t dumplen)
1805{
1806	size_t dstsize;
1807
1808	bzero(kdh, sizeof(*kdh));
1809	strlcpy(kdh->magic, magic, sizeof(kdh->magic));
1810	strlcpy(kdh->architecture, MACHINE_ARCH, sizeof(kdh->architecture));
1811	kdh->version = htod32(KERNELDUMPVERSION);
1812	kdh->architectureversion = htod32(archver);
1813	kdh->dumplength = htod64(dumplen);
1814	kdh->dumpextent = kdh->dumplength;
1815	kdh->dumptime = htod64(time_second);
1816#ifdef EKCD
1817	kdh->dumpkeysize = htod32(kerneldumpcrypto_dumpkeysize(di->kdcrypto));
1818#else
1819	kdh->dumpkeysize = 0;
1820#endif
1821	kdh->blocksize = htod32(di->blocksize);
1822	strlcpy(kdh->hostname, prison0.pr_hostname, sizeof(kdh->hostname));
1823	dstsize = sizeof(kdh->versionstring);
1824	if (strlcpy(kdh->versionstring, version, dstsize) >= dstsize)
1825		kdh->versionstring[dstsize - 2] = '\n';
1826	if (panicstr != NULL)
1827		strlcpy(kdh->panicstring, panicstr, sizeof(kdh->panicstring));
1828	if (di->kdcomp != NULL)
1829		kdh->compression = di->kdcomp->kdc_format;
1830	kdh->parity = kerneldump_parity(kdh);
1831}
1832
1833#ifdef DDB
1834DB_SHOW_COMMAND_FLAGS(panic, db_show_panic, DB_CMD_MEMSAFE)
1835{
1836
1837	if (panicstr == NULL)
1838		db_printf("panicstr not set\n");
1839	else
1840		db_printf("panic: %s\n", panicstr);
1841}
1842#endif
1843