xref: /illumos-gate/usr/src/uts/common/os/dumpsubr.c (revision 8dfe5547fbf0979fc1065a8b6fddc1e940a7cf4f)
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) 1998, 2010, Oracle and/or its affiliates. All rights reserved.
24  * Copyright 2018 Joyent, Inc.
25  */
26 
27 #include <sys/types.h>
28 #include <sys/param.h>
29 #include <sys/systm.h>
30 #include <sys/vm.h>
31 #include <sys/proc.h>
32 #include <sys/file.h>
33 #include <sys/conf.h>
34 #include <sys/kmem.h>
35 #include <sys/mem.h>
36 #include <sys/mman.h>
37 #include <sys/vnode.h>
38 #include <sys/errno.h>
39 #include <sys/memlist.h>
40 #include <sys/dumphdr.h>
41 #include <sys/dumpadm.h>
42 #include <sys/ksyms.h>
43 #include <sys/compress.h>
44 #include <sys/stream.h>
45 #include <sys/strsun.h>
46 #include <sys/cmn_err.h>
47 #include <sys/bitmap.h>
48 #include <sys/modctl.h>
49 #include <sys/utsname.h>
50 #include <sys/systeminfo.h>
51 #include <sys/vmem.h>
52 #include <sys/log.h>
53 #include <sys/var.h>
54 #include <sys/debug.h>
55 #include <sys/sunddi.h>
56 #include <fs/fs_subr.h>
57 #include <sys/fs/snode.h>
58 #include <sys/ontrap.h>
59 #include <sys/panic.h>
60 #include <sys/dkio.h>
61 #include <sys/vtoc.h>
62 #include <sys/errorq.h>
63 #include <sys/fm/util.h>
64 #include <sys/fs/zfs.h>
65 
66 #include <vm/hat.h>
67 #include <vm/as.h>
68 #include <vm/page.h>
69 #include <vm/pvn.h>
70 #include <vm/seg.h>
71 #include <vm/seg_kmem.h>
72 #include <sys/clock_impl.h>
73 #include <sys/hold_page.h>
74 
75 #include <bzip2/bzlib.h>
76 
77 #define	ONE_GIG	(1024 * 1024 * 1024UL)
78 
79 /*
80  * Crash dump time is dominated by disk write time.  To reduce this,
81  * the stronger compression method bzip2 is applied to reduce the dump
82  * size and hence reduce I/O time.  However, bzip2 is much more
83  * computationally expensive than the existing lzjb algorithm, so to
84  * avoid increasing compression time, CPUs that are otherwise idle
85  * during panic are employed to parallelize the compression task.
86  * Many helper CPUs are needed to prevent bzip2 from being a
87  * bottleneck, and on systems with too few CPUs, the lzjb algorithm is
88  * parallelized instead. Lastly, I/O and compression are performed by
89  * different CPUs, and are hence overlapped in time, unlike the older
90  * serial code.
91  *
92  * Another important consideration is the speed of the dump
93  * device. Faster disks need less CPUs in order to benefit from
94  * parallel lzjb versus parallel bzip2. Therefore, the CPU count
95  * threshold for switching from parallel lzjb to paralled bzip2 is
96  * elevated for faster disks. The dump device speed is adduced from
97  * the setting for dumpbuf.iosize, see dump_update_clevel.
98  */
99 
100 /*
101  * exported vars
102  */
103 kmutex_t	dump_lock;		/* lock for dump configuration */
104 dumphdr_t	*dumphdr;		/* dump header */
105 int		dump_conflags = DUMP_KERNEL; /* dump configuration flags */
106 vnode_t		*dumpvp;		/* dump device vnode pointer */
107 u_offset_t	dumpvp_size;		/* size of dump device, in bytes */
108 char		*dumppath;		/* pathname of dump device */
109 int		dump_timeout = 120;	/* timeout for dumping pages */
110 int		dump_timeleft;		/* portion of dump_timeout remaining */
111 int		dump_ioerr;		/* dump i/o error */
112 int		dump_check_used;	/* enable check for used pages */
113 char	    *dump_stack_scratch; /* scratch area for saving stack summary */
114 
115 /*
116  * Tunables for dump compression and parallelism. These can be set via
117  * /etc/system.
118  *
119  * dump_ncpu_low	number of helpers for parallel lzjb
120  *	This is also the minimum configuration.
121  *
122  * dump_bzip2_level	bzip2 compression level: 1-9
123  *	Higher numbers give greater compression, but take more memory
124  *	and time. Memory used per helper is ~(dump_bzip2_level * 1MB).
125  *
126  * dump_plat_mincpu	the cross-over limit for using bzip2 (per platform):
127  *	if dump_plat_mincpu == 0, then always do single threaded dump
128  *	if ncpu >= dump_plat_mincpu then try to use bzip2
129  *
130  * dump_metrics_on	if set, metrics are collected in the kernel, passed
131  *	to savecore via the dump file, and recorded by savecore in
132  *	METRICS.txt.
133  */
134 uint_t dump_ncpu_low = 4;	/* minimum config for parallel lzjb */
135 uint_t dump_bzip2_level = 1;	/* bzip2 level (1-9) */
136 
137 /* Use dump_plat_mincpu_default unless this variable is set by /etc/system */
138 #define	MINCPU_NOT_SET	((uint_t)-1)
139 uint_t dump_plat_mincpu = MINCPU_NOT_SET;
140 
141 /* tunables for pre-reserved heap */
142 uint_t dump_kmem_permap = 1024;
143 uint_t dump_kmem_pages = 0;
144 
145 /* Define multiple buffers per helper to avoid stalling */
146 #define	NCBUF_PER_HELPER	2
147 #define	NCMAP_PER_HELPER	4
148 
149 /* minimum number of helpers configured */
150 #define	MINHELPERS	(dump_ncpu_low)
151 #define	MINCBUFS	(MINHELPERS * NCBUF_PER_HELPER)
152 
153 /*
154  * Define constant parameters.
155  *
156  * CBUF_SIZE		size of an output buffer
157  *
158  * CBUF_MAPSIZE		size of virtual range for mapping pages
159  *
160  * CBUF_MAPNP		size of virtual range in pages
161  *
162  */
163 #define	DUMP_1KB	((size_t)1 << 10)
164 #define	DUMP_1MB	((size_t)1 << 20)
165 #define	CBUF_SIZE	((size_t)1 << 17)
166 #define	CBUF_MAPSHIFT	(22)
167 #define	CBUF_MAPSIZE	((size_t)1 << CBUF_MAPSHIFT)
168 #define	CBUF_MAPNP	((size_t)1 << (CBUF_MAPSHIFT - PAGESHIFT))
169 
170 /*
171  * Compression metrics are accumulated nano-second subtotals. The
172  * results are normalized by the number of pages dumped. A report is
173  * generated when dumpsys() completes and is saved in the dump image
174  * after the trailing dump header.
175  *
176  * Metrics are always collected. Set the variable dump_metrics_on to
177  * cause metrics to be saved in the crash file, where savecore will
178  * save it in the file METRICS.txt.
179  */
180 #define	PERPAGES \
181 	PERPAGE(bitmap) PERPAGE(map) PERPAGE(unmap) \
182 	PERPAGE(copy) PERPAGE(compress) \
183 	PERPAGE(write) \
184 	PERPAGE(inwait) PERPAGE(outwait)
185 
186 typedef struct perpage {
187 #define	PERPAGE(x) hrtime_t x;
188 	PERPAGES
189 #undef PERPAGE
190 } perpage_t;
191 
192 /*
193  * This macro controls the code generation for collecting dump
194  * performance information. By default, the code is generated, but
195  * automatic saving of the information is disabled. If dump_metrics_on
196  * is set to 1, the timing information is passed to savecore via the
197  * crash file, where it is appended to the file dump-dir/METRICS.txt.
198  */
199 #define	COLLECT_METRICS
200 
201 #ifdef COLLECT_METRICS
202 uint_t dump_metrics_on = 0;	/* set to 1 to enable recording metrics */
203 
204 #define	HRSTART(v, m)		v##ts.m = gethrtime()
205 #define	HRSTOP(v, m)		v.m += gethrtime() - v##ts.m
206 #define	HRBEGIN(v, m, s)	v##ts.m = gethrtime(); v.size += s
207 #define	HREND(v, m)		v.m += gethrtime() - v##ts.m
208 #define	HRNORM(v, m, n)		v.m /= (n)
209 
210 #else
211 #define	HRSTART(v, m)
212 #define	HRSTOP(v, m)
213 #define	HRBEGIN(v, m, s)
214 #define	HREND(v, m)
215 #define	HRNORM(v, m, n)
216 #endif	/* COLLECT_METRICS */
217 
218 /*
219  * Buffers for copying and compressing memory pages.
220  *
221  * cbuf_t buffer controllers: used for both input and output.
222  *
223  * The buffer state indicates how it is being used:
224  *
225  * CBUF_FREEMAP: CBUF_MAPSIZE virtual address range is available for
226  * mapping input pages.
227  *
228  * CBUF_INREADY: input pages are mapped and ready for compression by a
229  * helper.
230  *
231  * CBUF_USEDMAP: mapping has been consumed by a helper. Needs unmap.
232  *
233  * CBUF_FREEBUF: CBUF_SIZE output buffer, which is available.
234  *
235  * CBUF_WRITE: CBUF_SIZE block of compressed pages from a helper,
236  * ready to write out.
237  *
238  * CBUF_ERRMSG: CBUF_SIZE block of error messages from a helper
239  * (reports UE errors.)
240  */
241 
242 typedef enum cbufstate {
243 	CBUF_FREEMAP,
244 	CBUF_INREADY,
245 	CBUF_USEDMAP,
246 	CBUF_FREEBUF,
247 	CBUF_WRITE,
248 	CBUF_ERRMSG
249 } cbufstate_t;
250 
251 typedef struct cbuf cbuf_t;
252 
253 struct cbuf {
254 	cbuf_t *next;			/* next in list */
255 	cbufstate_t state;		/* processing state */
256 	size_t used;			/* amount used */
257 	size_t size;			/* mem size */
258 	char *buf;			/* kmem or vmem */
259 	pgcnt_t pagenum;		/* index to pfn map */
260 	pgcnt_t bitnum;			/* first set bitnum */
261 	pfn_t pfn;			/* first pfn in mapped range */
262 	int off;			/* byte offset to first pfn */
263 };
264 
265 static char dump_osimage_uuid[36 + 1];
266 
267 #define	isdigit(ch)	((ch) >= '0' && (ch) <= '9')
268 #define	isxdigit(ch)	(isdigit(ch) || ((ch) >= 'a' && (ch) <= 'f') || \
269 			((ch) >= 'A' && (ch) <= 'F'))
270 
271 /*
272  * cqueue_t queues: a uni-directional channel for communication
273  * from the master to helper tasks or vice-versa using put and
274  * get primitives. Both mappings and data buffers are passed via
275  * queues. Producers close a queue when done. The number of
276  * active producers is reference counted so the consumer can
277  * detect end of data. Concurrent access is mediated by atomic
278  * operations for panic dump, or mutex/cv for live dump.
279  *
280  * There a four queues, used as follows:
281  *
282  * Queue		Dataflow		NewState
283  * --------------------------------------------------
284  * mainq		master -> master	FREEMAP
285  * master has initialized or unmapped an input buffer
286  * --------------------------------------------------
287  * helperq		master -> helper	INREADY
288  * master has mapped input for use by helper
289  * --------------------------------------------------
290  * mainq		master <- helper	USEDMAP
291  * helper is done with input
292  * --------------------------------------------------
293  * freebufq		master -> helper	FREEBUF
294  * master has initialized or written an output buffer
295  * --------------------------------------------------
296  * mainq		master <- helper	WRITE
297  * block of compressed pages from a helper
298  * --------------------------------------------------
299  * mainq		master <- helper	ERRMSG
300  * error messages from a helper (memory error case)
301  * --------------------------------------------------
302  * writerq		master <- master	WRITE
303  * non-blocking queue of blocks to write
304  * --------------------------------------------------
305  */
306 typedef struct cqueue {
307 	cbuf_t *volatile first;		/* first in list */
308 	cbuf_t *last;			/* last in list */
309 	hrtime_t ts;			/* timestamp */
310 	hrtime_t empty;			/* total time empty */
311 	kmutex_t mutex;			/* live state lock */
312 	kcondvar_t cv;			/* live wait var */
313 	lock_t spinlock;		/* panic mode spin lock */
314 	volatile uint_t open;		/* producer ref count */
315 } cqueue_t;
316 
317 /*
318  * Convenience macros for using the cqueue functions
319  * Note that the caller must have defined "dumpsync_t *ds"
320  */
321 #define	CQ_IS_EMPTY(q)					\
322 	(ds->q.first == NULL)
323 
324 #define	CQ_OPEN(q)					\
325 	atomic_inc_uint(&ds->q.open)
326 
327 #define	CQ_CLOSE(q)					\
328 	dumpsys_close_cq(&ds->q, ds->live)
329 
330 #define	CQ_PUT(q, cp, st)				\
331 	dumpsys_put_cq(&ds->q, cp, st, ds->live)
332 
333 #define	CQ_GET(q)					\
334 	dumpsys_get_cq(&ds->q, ds->live)
335 
336 /*
337  * Dynamic state when dumpsys() is running.
338  */
339 typedef struct dumpsync {
340 	pgcnt_t npages;			/* subtotal of pages dumped */
341 	pgcnt_t pages_mapped;		/* subtotal of pages mapped */
342 	pgcnt_t pages_used;		/* subtotal of pages used per map */
343 	size_t nwrite;			/* subtotal of bytes written */
344 	uint_t live;			/* running live dump */
345 	uint_t neednl;			/* will need to print a newline */
346 	uint_t percent;			/* dump progress */
347 	uint_t percent_done;		/* dump progress reported */
348 	int sec_done;			/* dump progress last report time */
349 	cqueue_t freebufq;		/* free kmem bufs for writing */
350 	cqueue_t mainq;			/* input for main task */
351 	cqueue_t helperq;		/* input for helpers */
352 	cqueue_t writerq;		/* input for writer */
353 	hrtime_t start;			/* start time */
354 	hrtime_t elapsed;		/* elapsed time when completed */
355 	hrtime_t iotime;		/* time spent writing nwrite bytes */
356 	hrtime_t iowait;		/* time spent waiting for output */
357 	hrtime_t iowaitts;		/* iowait timestamp */
358 	perpage_t perpage;		/* metrics */
359 	perpage_t perpagets;
360 	int dumpcpu;			/* master cpu */
361 } dumpsync_t;
362 
363 static dumpsync_t dumpsync;		/* synchronization vars */
364 
365 /*
366  * helper_t helpers: contains the context for a stream. CPUs run in
367  * parallel at dump time; each CPU creates a single stream of
368  * compression data.  Stream data is divided into CBUF_SIZE blocks.
369  * The blocks are written in order within a stream. But, blocks from
370  * multiple streams can be interleaved. Each stream is identified by a
371  * unique tag.
372  */
373 typedef struct helper {
374 	int helper;			/* bound helper id */
375 	int tag;			/* compression stream tag */
376 	perpage_t perpage;		/* per page metrics */
377 	perpage_t perpagets;		/* per page metrics (timestamps) */
378 	taskqid_t taskqid;		/* live dump task ptr */
379 	int in, out;			/* buffer offsets */
380 	cbuf_t *cpin, *cpout, *cperr;	/* cbuf objects in process */
381 	dumpsync_t *ds;			/* pointer to sync vars */
382 	size_t used;			/* counts input consumed */
383 	char *page;			/* buffer for page copy */
384 	char *lzbuf;			/* lzjb output */
385 	bz_stream bzstream;		/* bzip2 state */
386 } helper_t;
387 
388 #define	MAINHELPER	(-1)		/* helper is also the main task */
389 #define	FREEHELPER	(-2)		/* unbound helper */
390 #define	DONEHELPER	(-3)		/* helper finished */
391 
392 /*
393  * configuration vars for dumpsys
394  */
395 typedef struct dumpcfg {
396 	int	threshold;	/* ncpu threshold for bzip2 */
397 	int	nhelper;	/* number of helpers */
398 	int	nhelper_used;	/* actual number of helpers used */
399 	int	ncmap;		/* number VA pages for compression */
400 	int	ncbuf;		/* number of bufs for compression */
401 	int	ncbuf_used;	/* number of bufs in use */
402 	uint_t	clevel;		/* dump compression level */
403 	helper_t *helper;	/* array of helpers */
404 	cbuf_t	*cmap;		/* array of input (map) buffers */
405 	cbuf_t	*cbuf;		/* array of output  buffers */
406 	ulong_t	*helpermap;	/* set of dumpsys helper CPU ids */
407 	ulong_t	*bitmap;	/* bitmap for marking pages to dump */
408 	ulong_t	*rbitmap;	/* bitmap for used CBUF_MAPSIZE ranges */
409 	pgcnt_t	bitmapsize;	/* size of bitmap */
410 	pgcnt_t	rbitmapsize;	/* size of bitmap for ranges */
411 	pgcnt_t found4m;	/* number ranges allocated by dump */
412 	pgcnt_t foundsm;	/* number small pages allocated by dump */
413 	pid_t	*pids;		/* list of process IDs at dump time */
414 	size_t	maxsize;	/* memory size needed at dump time */
415 	size_t	maxvmsize;	/* size of reserved VM */
416 	char	*maxvm;		/* reserved VM for spare pages */
417 	lock_t	helper_lock;	/* protect helper state */
418 	char	helpers_wanted;	/* flag to enable parallelism */
419 } dumpcfg_t;
420 
421 static dumpcfg_t dumpcfg;	/* config vars */
422 
423 /*
424  * The dump I/O buffer.
425  *
426  * There is one I/O buffer used by dumpvp_write and dumvp_flush. It is
427  * sized according to the optimum device transfer speed.
428  */
429 typedef struct dumpbuf {
430 	vnode_t	*cdev_vp;	/* VCHR open of the dump device */
431 	len_t	vp_limit;	/* maximum write offset */
432 	offset_t vp_off;	/* current dump device offset */
433 	char	*cur;		/* dump write pointer */
434 	char	*start;		/* dump buffer address */
435 	char	*end;		/* dump buffer end */
436 	size_t	size;		/* size of dumpbuf in bytes */
437 	size_t	iosize;		/* best transfer size for device */
438 } dumpbuf_t;
439 
440 dumpbuf_t dumpbuf;		/* I/O buffer */
441 
442 /*
443  * The dump I/O buffer must be at least one page, at most xfer_size
444  * bytes, and should scale with physmem in between.  The transfer size
445  * passed in will either represent a global default (maxphys) or the
446  * best size for the device.  The size of the dumpbuf I/O buffer is
447  * limited by dumpbuf_limit (8MB by default) because the dump
448  * performance saturates beyond a certain size.  The default is to
449  * select 1/4096 of the memory.
450  */
451 static int	dumpbuf_fraction = 12;	/* memory size scale factor */
452 static size_t	dumpbuf_limit = 8 * DUMP_1MB;	/* max I/O buf size */
453 
454 static size_t
455 dumpbuf_iosize(size_t xfer_size)
456 {
457 	size_t iosize = ptob(physmem >> dumpbuf_fraction);
458 
459 	if (iosize < PAGESIZE)
460 		iosize = PAGESIZE;
461 	else if (iosize > xfer_size)
462 		iosize = xfer_size;
463 	if (iosize > dumpbuf_limit)
464 		iosize = dumpbuf_limit;
465 	return (iosize & PAGEMASK);
466 }
467 
468 /*
469  * resize the I/O buffer
470  */
471 static void
472 dumpbuf_resize(void)
473 {
474 	char *old_buf = dumpbuf.start;
475 	size_t old_size = dumpbuf.size;
476 	char *new_buf;
477 	size_t new_size;
478 
479 	ASSERT(MUTEX_HELD(&dump_lock));
480 
481 	new_size = dumpbuf_iosize(MAX(dumpbuf.iosize, maxphys));
482 	if (new_size <= old_size)
483 		return; /* no need to reallocate buffer */
484 
485 	new_buf = kmem_alloc(new_size, KM_SLEEP);
486 	dumpbuf.size = new_size;
487 	dumpbuf.start = new_buf;
488 	dumpbuf.end = new_buf + new_size;
489 	kmem_free(old_buf, old_size);
490 }
491 
492 /*
493  * dump_update_clevel is called when dumpadm configures the dump device.
494  * 	Calculate number of helpers and buffers.
495  * 	Allocate the minimum configuration for now.
496  *
497  * When the dump file is configured we reserve a minimum amount of
498  * memory for use at crash time. But we reserve VA for all the memory
499  * we really want in order to do the fastest dump possible. The VA is
500  * backed by pages not being dumped, according to the bitmap. If
501  * there is insufficient spare memory, however, we fall back to the
502  * minimum.
503  *
504  * Live dump (savecore -L) always uses the minimum config.
505  *
506  * clevel 0 is single threaded lzjb
507  * clevel 1 is parallel lzjb
508  * clevel 2 is parallel bzip2
509  *
510  * The ncpu threshold is selected with dump_plat_mincpu.
511  * On OPL, set_platform_defaults() overrides the sun4u setting.
512  * The actual values are defined via DUMP_PLAT_*_MINCPU macros.
513  *
514  * Architecture		Threshold	Algorithm
515  * sun4u       		<  51		parallel lzjb
516  * sun4u       		>= 51		parallel bzip2(*)
517  * sun4u OPL   		<  8		parallel lzjb
518  * sun4u OPL   		>= 8		parallel bzip2(*)
519  * sun4v       		<  128		parallel lzjb
520  * sun4v       		>= 128		parallel bzip2(*)
521  * x86			< 11		parallel lzjb
522  * x86			>= 11		parallel bzip2(*)
523  * 32-bit      		N/A		single-threaded lzjb
524  *
525  * (*) bzip2 is only chosen if there is sufficient available
526  * memory for buffers at dump time. See dumpsys_get_maxmem().
527  *
528  * Faster dump devices have larger I/O buffers. The threshold value is
529  * increased according to the size of the dump I/O buffer, because
530  * parallel lzjb performs better with faster disks. For buffers >= 1MB
531  * the threshold is 3X; for buffers >= 256K threshold is 2X.
532  *
533  * For parallel dumps, the number of helpers is ncpu-1. The CPU
534  * running panic runs the main task. For single-threaded dumps, the
535  * panic CPU does lzjb compression (it is tagged as MAINHELPER.)
536  *
537  * Need multiple buffers per helper so that they do not block waiting
538  * for the main task.
539  *				parallel	single-threaded
540  * Number of output buffers:	nhelper*2		1
541  * Number of mapping buffers:	nhelper*4		1
542  *
543  */
544 static void
545 dump_update_clevel()
546 {
547 	int tag;
548 	size_t bz2size;
549 	helper_t *hp, *hpend;
550 	cbuf_t *cp, *cpend;
551 	dumpcfg_t *old = &dumpcfg;
552 	dumpcfg_t newcfg = *old;
553 	dumpcfg_t *new = &newcfg;
554 
555 	ASSERT(MUTEX_HELD(&dump_lock));
556 
557 	/*
558 	 * Free the previously allocated bufs and VM.
559 	 */
560 	if (old->helper != NULL) {
561 
562 		/* helpers */
563 		hpend = &old->helper[old->nhelper];
564 		for (hp = old->helper; hp != hpend; hp++) {
565 			if (hp->lzbuf != NULL)
566 				kmem_free(hp->lzbuf, PAGESIZE);
567 			if (hp->page != NULL)
568 				kmem_free(hp->page, PAGESIZE);
569 		}
570 		kmem_free(old->helper, old->nhelper * sizeof (helper_t));
571 
572 		/* VM space for mapping pages */
573 		cpend = &old->cmap[old->ncmap];
574 		for (cp = old->cmap; cp != cpend; cp++)
575 			vmem_xfree(heap_arena, cp->buf, CBUF_MAPSIZE);
576 		kmem_free(old->cmap, old->ncmap * sizeof (cbuf_t));
577 
578 		/* output bufs */
579 		cpend = &old->cbuf[old->ncbuf];
580 		for (cp = old->cbuf; cp != cpend; cp++)
581 			if (cp->buf != NULL)
582 				kmem_free(cp->buf, cp->size);
583 		kmem_free(old->cbuf, old->ncbuf * sizeof (cbuf_t));
584 
585 		/* reserved VM for dumpsys_get_maxmem */
586 		if (old->maxvmsize > 0)
587 			vmem_xfree(heap_arena, old->maxvm, old->maxvmsize);
588 	}
589 
590 	/*
591 	 * Allocate memory and VM.
592 	 * One CPU runs dumpsys, the rest are helpers.
593 	 */
594 	new->nhelper = ncpus - 1;
595 	if (new->nhelper < 1)
596 		new->nhelper = 1;
597 
598 	if (new->nhelper > DUMP_MAX_NHELPER)
599 		new->nhelper = DUMP_MAX_NHELPER;
600 
601 	/* use platform default, unless /etc/system overrides */
602 	if (dump_plat_mincpu == MINCPU_NOT_SET)
603 		dump_plat_mincpu = dump_plat_mincpu_default;
604 
605 	/* increase threshold for faster disks */
606 	new->threshold = dump_plat_mincpu;
607 	if (dumpbuf.iosize >= DUMP_1MB)
608 		new->threshold *= 3;
609 	else if (dumpbuf.iosize >= (256 * DUMP_1KB))
610 		new->threshold *= 2;
611 
612 	/* figure compression level based upon the computed threshold. */
613 	if (dump_plat_mincpu == 0 || new->nhelper < 2) {
614 		new->clevel = 0;
615 		new->nhelper = 1;
616 	} else if ((new->nhelper + 1) >= new->threshold) {
617 		new->clevel = DUMP_CLEVEL_BZIP2;
618 	} else {
619 		new->clevel = DUMP_CLEVEL_LZJB;
620 	}
621 
622 	if (new->clevel == 0) {
623 		new->ncbuf = 1;
624 		new->ncmap = 1;
625 	} else {
626 		new->ncbuf = NCBUF_PER_HELPER * new->nhelper;
627 		new->ncmap = NCMAP_PER_HELPER * new->nhelper;
628 	}
629 
630 	/*
631 	 * Allocate new data structures and buffers for MINHELPERS,
632 	 * and also figure the max desired size.
633 	 */
634 	bz2size = BZ2_bzCompressInitSize(dump_bzip2_level);
635 	new->maxsize = 0;
636 	new->maxvmsize = 0;
637 	new->maxvm = NULL;
638 	tag = 1;
639 	new->helper = kmem_zalloc(new->nhelper * sizeof (helper_t), KM_SLEEP);
640 	hpend = &new->helper[new->nhelper];
641 	for (hp = new->helper; hp != hpend; hp++) {
642 		hp->tag = tag++;
643 		if (hp < &new->helper[MINHELPERS]) {
644 			hp->lzbuf = kmem_alloc(PAGESIZE, KM_SLEEP);
645 			hp->page = kmem_alloc(PAGESIZE, KM_SLEEP);
646 		} else if (new->clevel < DUMP_CLEVEL_BZIP2) {
647 			new->maxsize += 2 * PAGESIZE;
648 		} else {
649 			new->maxsize += PAGESIZE;
650 		}
651 		if (new->clevel >= DUMP_CLEVEL_BZIP2)
652 			new->maxsize += bz2size;
653 	}
654 
655 	new->cbuf = kmem_zalloc(new->ncbuf * sizeof (cbuf_t), KM_SLEEP);
656 	cpend = &new->cbuf[new->ncbuf];
657 	for (cp = new->cbuf; cp != cpend; cp++) {
658 		cp->state = CBUF_FREEBUF;
659 		cp->size = CBUF_SIZE;
660 		if (cp < &new->cbuf[MINCBUFS])
661 			cp->buf = kmem_alloc(cp->size, KM_SLEEP);
662 		else
663 			new->maxsize += cp->size;
664 	}
665 
666 	new->cmap = kmem_zalloc(new->ncmap * sizeof (cbuf_t), KM_SLEEP);
667 	cpend = &new->cmap[new->ncmap];
668 	for (cp = new->cmap; cp != cpend; cp++) {
669 		cp->state = CBUF_FREEMAP;
670 		cp->size = CBUF_MAPSIZE;
671 		cp->buf = vmem_xalloc(heap_arena, CBUF_MAPSIZE, CBUF_MAPSIZE,
672 		    0, 0, NULL, NULL, VM_SLEEP);
673 	}
674 
675 	/* reserve VA to be backed with spare pages at crash time */
676 	if (new->maxsize > 0) {
677 		new->maxsize = P2ROUNDUP(new->maxsize, PAGESIZE);
678 		new->maxvmsize = P2ROUNDUP(new->maxsize, CBUF_MAPSIZE);
679 		new->maxvm = vmem_xalloc(heap_arena, new->maxvmsize,
680 		    CBUF_MAPSIZE, 0, 0, NULL, NULL, VM_SLEEP);
681 	}
682 
683 	/*
684 	 * Reserve memory for kmem allocation calls made during crash dump.  The
685 	 * hat layer allocates memory for each mapping created, and the I/O path
686 	 * allocates buffers and data structs.
687 	 *
688 	 * On larger systems, we easily exceed the lower amount, so we need some
689 	 * more space; the cut-over point is relatively arbitrary.  If we run
690 	 * out, the only impact is that kmem state in the dump becomes
691 	 * inconsistent.
692 	 */
693 
694 	if (dump_kmem_pages == 0) {
695 		if (physmem > (16 * ONE_GIG) / PAGESIZE)
696 			dump_kmem_pages = 20;
697 		else
698 			dump_kmem_pages = 8;
699 	}
700 
701 	kmem_dump_init((new->ncmap * dump_kmem_permap) +
702 	    (dump_kmem_pages * PAGESIZE));
703 
704 	/* set new config pointers */
705 	*old = *new;
706 }
707 
708 /*
709  * Define a struct memlist walker to optimize bitnum to pfn
710  * lookup. The walker maintains the state of the list traversal.
711  */
712 typedef struct dumpmlw {
713 	struct memlist	*mp;		/* current memlist */
714 	pgcnt_t		basenum;	/* bitnum base offset */
715 	pgcnt_t		mppages;	/* current memlist size */
716 	pgcnt_t		mpleft;		/* size to end of current memlist */
717 	pfn_t		mpaddr;		/* first pfn in memlist */
718 } dumpmlw_t;
719 
720 /* initialize the walker */
721 static inline void
722 dump_init_memlist_walker(dumpmlw_t *pw)
723 {
724 	pw->mp = phys_install;
725 	pw->basenum = 0;
726 	pw->mppages = pw->mp->ml_size >> PAGESHIFT;
727 	pw->mpleft = pw->mppages;
728 	pw->mpaddr = pw->mp->ml_address >> PAGESHIFT;
729 }
730 
731 /*
732  * Lookup pfn given bitnum. The memlist can be quite long on some
733  * systems (e.g.: one per board). To optimize sequential lookups, the
734  * caller initializes and presents a memlist walker.
735  */
736 static pfn_t
737 dump_bitnum_to_pfn(pgcnt_t bitnum, dumpmlw_t *pw)
738 {
739 	bitnum -= pw->basenum;
740 	while (pw->mp != NULL) {
741 		if (bitnum < pw->mppages) {
742 			pw->mpleft = pw->mppages - bitnum;
743 			return (pw->mpaddr + bitnum);
744 		}
745 		bitnum -= pw->mppages;
746 		pw->basenum += pw->mppages;
747 		pw->mp = pw->mp->ml_next;
748 		if (pw->mp != NULL) {
749 			pw->mppages = pw->mp->ml_size >> PAGESHIFT;
750 			pw->mpleft = pw->mppages;
751 			pw->mpaddr = pw->mp->ml_address >> PAGESHIFT;
752 		}
753 	}
754 	return (PFN_INVALID);
755 }
756 
757 static pgcnt_t
758 dump_pfn_to_bitnum(pfn_t pfn)
759 {
760 	struct memlist *mp;
761 	pgcnt_t bitnum = 0;
762 
763 	for (mp = phys_install; mp != NULL; mp = mp->ml_next) {
764 		if (pfn >= (mp->ml_address >> PAGESHIFT) &&
765 		    pfn < ((mp->ml_address + mp->ml_size) >> PAGESHIFT))
766 			return (bitnum + pfn - (mp->ml_address >> PAGESHIFT));
767 		bitnum += mp->ml_size >> PAGESHIFT;
768 	}
769 	return ((pgcnt_t)-1);
770 }
771 
772 /*
773  * Set/test bitmap for a CBUF_MAPSIZE range which includes pfn. The
774  * mapping of pfn to range index is imperfect because pfn and bitnum
775  * do not have the same phase. To make sure a CBUF_MAPSIZE range is
776  * covered, call this for both ends:
777  *	dump_set_used(base)
778  *	dump_set_used(base+CBUF_MAPNP-1)
779  *
780  * This is used during a panic dump to mark pages allocated by
781  * dumpsys_get_maxmem(). The macro IS_DUMP_PAGE(pp) is used by
782  * page_get_mnode_freelist() to make sure pages used by dump are never
783  * allocated.
784  */
785 #define	CBUF_MAPP2R(pfn)	((pfn) >> (CBUF_MAPSHIFT - PAGESHIFT))
786 
787 static void
788 dump_set_used(pfn_t pfn)
789 {
790 
791 	pgcnt_t bitnum, rbitnum;
792 
793 	bitnum = dump_pfn_to_bitnum(pfn);
794 	ASSERT(bitnum != (pgcnt_t)-1);
795 
796 	rbitnum = CBUF_MAPP2R(bitnum);
797 	ASSERT(rbitnum < dumpcfg.rbitmapsize);
798 
799 	BT_SET(dumpcfg.rbitmap, rbitnum);
800 }
801 
802 int
803 dump_test_used(pfn_t pfn)
804 {
805 	pgcnt_t bitnum, rbitnum;
806 
807 	bitnum = dump_pfn_to_bitnum(pfn);
808 	ASSERT(bitnum != (pgcnt_t)-1);
809 
810 	rbitnum = CBUF_MAPP2R(bitnum);
811 	ASSERT(rbitnum < dumpcfg.rbitmapsize);
812 
813 	return (BT_TEST(dumpcfg.rbitmap, rbitnum));
814 }
815 
816 /*
817  * dumpbzalloc and dumpbzfree are callbacks from the bzip2 library.
818  * dumpsys_get_maxmem() uses them for BZ2_bzCompressInit().
819  */
820 static void *
821 dumpbzalloc(void *opaque, int items, int size)
822 {
823 	size_t *sz;
824 	char *ret;
825 
826 	ASSERT(opaque != NULL);
827 	sz = opaque;
828 	ret = dumpcfg.maxvm + *sz;
829 	*sz += items * size;
830 	*sz = P2ROUNDUP(*sz, BZ2_BZALLOC_ALIGN);
831 	ASSERT(*sz <= dumpcfg.maxvmsize);
832 	return (ret);
833 }
834 
835 /*ARGSUSED*/
836 static void
837 dumpbzfree(void *opaque, void *addr)
838 {
839 }
840 
841 /*
842  * Perform additional checks on the page to see if we can really use
843  * it. The kernel (kas) pages are always set in the bitmap. However,
844  * boot memory pages (prom_ppages or P_BOOTPAGES) are not in the
845  * bitmap. So we check for them.
846  */
847 static inline int
848 dump_pfn_check(pfn_t pfn)
849 {
850 	page_t *pp = page_numtopp_nolock(pfn);
851 	if (pp == NULL || pp->p_pagenum != pfn ||
852 #if defined(__sparc)
853 	    pp->p_vnode == &promvp ||
854 #else
855 	    PP_ISBOOTPAGES(pp) ||
856 #endif
857 	    pp->p_toxic != 0)
858 		return (0);
859 	return (1);
860 }
861 
862 /*
863  * Check a range to see if all contained pages are available and
864  * return non-zero if the range can be used.
865  */
866 static inline int
867 dump_range_check(pgcnt_t start, pgcnt_t end, pfn_t pfn)
868 {
869 	for (; start < end; start++, pfn++) {
870 		if (BT_TEST(dumpcfg.bitmap, start))
871 			return (0);
872 		if (!dump_pfn_check(pfn))
873 			return (0);
874 	}
875 	return (1);
876 }
877 
878 /*
879  * dumpsys_get_maxmem() is called during panic. Find unused ranges
880  * and use them for buffers. If we find enough memory switch to
881  * parallel bzip2, otherwise use parallel lzjb.
882  *
883  * It searches the dump bitmap in 2 passes. The first time it looks
884  * for CBUF_MAPSIZE ranges. On the second pass it uses small pages.
885  */
886 static void
887 dumpsys_get_maxmem()
888 {
889 	dumpcfg_t *cfg = &dumpcfg;
890 	cbuf_t *endcp = &cfg->cbuf[cfg->ncbuf];
891 	helper_t *endhp = &cfg->helper[cfg->nhelper];
892 	pgcnt_t bitnum, end;
893 	size_t sz, endsz, bz2size;
894 	pfn_t pfn, off;
895 	cbuf_t *cp;
896 	helper_t *hp, *ohp;
897 	dumpmlw_t mlw;
898 	int k;
899 
900 	/*
901 	 * Setting dump_plat_mincpu to 0 at any time forces a serial
902 	 * dump.
903 	 */
904 	if (dump_plat_mincpu == 0) {
905 		cfg->clevel = 0;
906 		return;
907 	}
908 
909 	/*
910 	 * There may be no point in looking for spare memory. If
911 	 * dumping all memory, then none is spare. If doing a serial
912 	 * dump, then already have buffers.
913 	 */
914 	if (cfg->maxsize == 0 || cfg->clevel < DUMP_CLEVEL_LZJB ||
915 	    (dump_conflags & DUMP_ALL) != 0) {
916 		if (cfg->clevel > DUMP_CLEVEL_LZJB)
917 			cfg->clevel = DUMP_CLEVEL_LZJB;
918 		return;
919 	}
920 
921 	sz = 0;
922 	cfg->found4m = 0;
923 	cfg->foundsm = 0;
924 
925 	/* bitmap of ranges used to estimate which pfns are being used */
926 	bzero(dumpcfg.rbitmap, BT_SIZEOFMAP(dumpcfg.rbitmapsize));
927 
928 	/* find ranges that are not being dumped to use for buffers */
929 	dump_init_memlist_walker(&mlw);
930 	for (bitnum = 0; bitnum < dumpcfg.bitmapsize; bitnum = end) {
931 		dump_timeleft = dump_timeout;
932 		end = bitnum + CBUF_MAPNP;
933 		pfn = dump_bitnum_to_pfn(bitnum, &mlw);
934 		ASSERT(pfn != PFN_INVALID);
935 
936 		/* skip partial range at end of mem segment */
937 		if (mlw.mpleft < CBUF_MAPNP) {
938 			end = bitnum + mlw.mpleft;
939 			continue;
940 		}
941 
942 		/* skip non aligned pages */
943 		off = P2PHASE(pfn, CBUF_MAPNP);
944 		if (off != 0) {
945 			end -= off;
946 			continue;
947 		}
948 
949 		if (!dump_range_check(bitnum, end, pfn))
950 			continue;
951 
952 		ASSERT((sz + CBUF_MAPSIZE) <= cfg->maxvmsize);
953 		hat_devload(kas.a_hat, cfg->maxvm + sz, CBUF_MAPSIZE, pfn,
954 		    PROT_READ | PROT_WRITE, HAT_LOAD_NOCONSIST);
955 		sz += CBUF_MAPSIZE;
956 		cfg->found4m++;
957 
958 		/* set the bitmap for both ends to be sure to cover the range */
959 		dump_set_used(pfn);
960 		dump_set_used(pfn + CBUF_MAPNP - 1);
961 
962 		if (sz >= cfg->maxsize)
963 			goto foundmax;
964 	}
965 
966 	/* Add small pages if we can't find enough large pages. */
967 	dump_init_memlist_walker(&mlw);
968 	for (bitnum = 0; bitnum < dumpcfg.bitmapsize; bitnum = end) {
969 		dump_timeleft = dump_timeout;
970 		end = bitnum + CBUF_MAPNP;
971 		pfn = dump_bitnum_to_pfn(bitnum, &mlw);
972 		ASSERT(pfn != PFN_INVALID);
973 
974 		/* Find any non-aligned pages at start and end of segment. */
975 		off = P2PHASE(pfn, CBUF_MAPNP);
976 		if (mlw.mpleft < CBUF_MAPNP) {
977 			end = bitnum + mlw.mpleft;
978 		} else if (off != 0) {
979 			end -= off;
980 		} else if (cfg->found4m && dump_test_used(pfn)) {
981 			continue;
982 		}
983 
984 		for (; bitnum < end; bitnum++, pfn++) {
985 			dump_timeleft = dump_timeout;
986 			if (BT_TEST(dumpcfg.bitmap, bitnum))
987 				continue;
988 			if (!dump_pfn_check(pfn))
989 				continue;
990 			ASSERT((sz + PAGESIZE) <= cfg->maxvmsize);
991 			hat_devload(kas.a_hat, cfg->maxvm + sz, PAGESIZE, pfn,
992 			    PROT_READ | PROT_WRITE, HAT_LOAD_NOCONSIST);
993 			sz += PAGESIZE;
994 			cfg->foundsm++;
995 			dump_set_used(pfn);
996 			if (sz >= cfg->maxsize)
997 				goto foundmax;
998 		}
999 	}
1000 
1001 	/* Fall back to lzjb if we did not get enough memory for bzip2. */
1002 	endsz = (cfg->maxsize * cfg->threshold) / cfg->nhelper;
1003 	if (sz < endsz) {
1004 		cfg->clevel = DUMP_CLEVEL_LZJB;
1005 	}
1006 
1007 	/* Allocate memory for as many helpers as we can. */
1008 foundmax:
1009 
1010 	/* Byte offsets into memory found and mapped above */
1011 	endsz = sz;
1012 	sz = 0;
1013 
1014 	/* Set the size for bzip2 state. Only bzip2 needs it. */
1015 	bz2size = BZ2_bzCompressInitSize(dump_bzip2_level);
1016 
1017 	/* Skip the preallocate output buffers. */
1018 	cp = &cfg->cbuf[MINCBUFS];
1019 
1020 	/* Use this to move memory up from the preallocated helpers. */
1021 	ohp = cfg->helper;
1022 
1023 	/* Loop over all helpers and allocate memory. */
1024 	for (hp = cfg->helper; hp < endhp; hp++) {
1025 
1026 		/* Skip preallocated helpers by checking hp->page. */
1027 		if (hp->page == NULL) {
1028 			if (cfg->clevel <= DUMP_CLEVEL_LZJB) {
1029 				/* lzjb needs 2 1-page buffers */
1030 				if ((sz + (2 * PAGESIZE)) > endsz)
1031 					break;
1032 				hp->page = cfg->maxvm + sz;
1033 				sz += PAGESIZE;
1034 				hp->lzbuf = cfg->maxvm + sz;
1035 				sz += PAGESIZE;
1036 
1037 			} else if (ohp->lzbuf != NULL) {
1038 				/* re-use the preallocted lzjb page for bzip2 */
1039 				hp->page = ohp->lzbuf;
1040 				ohp->lzbuf = NULL;
1041 				++ohp;
1042 
1043 			} else {
1044 				/* bzip2 needs a 1-page buffer */
1045 				if ((sz + PAGESIZE) > endsz)
1046 					break;
1047 				hp->page = cfg->maxvm + sz;
1048 				sz += PAGESIZE;
1049 			}
1050 		}
1051 
1052 		/*
1053 		 * Add output buffers per helper. The number of
1054 		 * buffers per helper is determined by the ratio of
1055 		 * ncbuf to nhelper.
1056 		 */
1057 		for (k = 0; cp < endcp && (sz + CBUF_SIZE) <= endsz &&
1058 		    k < NCBUF_PER_HELPER; k++) {
1059 			cp->state = CBUF_FREEBUF;
1060 			cp->size = CBUF_SIZE;
1061 			cp->buf = cfg->maxvm + sz;
1062 			sz += CBUF_SIZE;
1063 			++cp;
1064 		}
1065 
1066 		/*
1067 		 * bzip2 needs compression state. Use the dumpbzalloc
1068 		 * and dumpbzfree callbacks to allocate the memory.
1069 		 * bzip2 does allocation only at init time.
1070 		 */
1071 		if (cfg->clevel >= DUMP_CLEVEL_BZIP2) {
1072 			if ((sz + bz2size) > endsz) {
1073 				hp->page = NULL;
1074 				break;
1075 			} else {
1076 				hp->bzstream.opaque = &sz;
1077 				hp->bzstream.bzalloc = dumpbzalloc;
1078 				hp->bzstream.bzfree = dumpbzfree;
1079 				(void) BZ2_bzCompressInit(&hp->bzstream,
1080 				    dump_bzip2_level, 0, 0);
1081 				hp->bzstream.opaque = NULL;
1082 			}
1083 		}
1084 	}
1085 
1086 	/* Finish allocating output buffers */
1087 	for (; cp < endcp && (sz + CBUF_SIZE) <= endsz; cp++) {
1088 		cp->state = CBUF_FREEBUF;
1089 		cp->size = CBUF_SIZE;
1090 		cp->buf = cfg->maxvm + sz;
1091 		sz += CBUF_SIZE;
1092 	}
1093 
1094 	/* Enable IS_DUMP_PAGE macro, which checks for pages we took. */
1095 	if (cfg->found4m || cfg->foundsm)
1096 		dump_check_used = 1;
1097 
1098 	ASSERT(sz <= endsz);
1099 }
1100 
1101 static void
1102 dumphdr_init(void)
1103 {
1104 	pgcnt_t npages = 0;
1105 
1106 	ASSERT(MUTEX_HELD(&dump_lock));
1107 
1108 	if (dumphdr == NULL) {
1109 		dumphdr = kmem_zalloc(sizeof (dumphdr_t), KM_SLEEP);
1110 		dumphdr->dump_magic = DUMP_MAGIC;
1111 		dumphdr->dump_version = DUMP_VERSION;
1112 		dumphdr->dump_wordsize = DUMP_WORDSIZE;
1113 		dumphdr->dump_pageshift = PAGESHIFT;
1114 		dumphdr->dump_pagesize = PAGESIZE;
1115 		dumphdr->dump_utsname = utsname;
1116 		(void) strcpy(dumphdr->dump_platform, platform);
1117 		dumpbuf.size = dumpbuf_iosize(maxphys);
1118 		dumpbuf.start = kmem_alloc(dumpbuf.size, KM_SLEEP);
1119 		dumpbuf.end = dumpbuf.start + dumpbuf.size;
1120 		dumpcfg.pids = kmem_alloc(v.v_proc * sizeof (pid_t), KM_SLEEP);
1121 		dumpcfg.helpermap = kmem_zalloc(BT_SIZEOFMAP(NCPU), KM_SLEEP);
1122 		LOCK_INIT_HELD(&dumpcfg.helper_lock);
1123 		dump_stack_scratch = kmem_alloc(STACK_BUF_SIZE, KM_SLEEP);
1124 		(void) strncpy(dumphdr->dump_uuid, dump_get_uuid(),
1125 		    sizeof (dumphdr->dump_uuid));
1126 	}
1127 
1128 	npages = num_phys_pages();
1129 
1130 	if (dumpcfg.bitmapsize != npages) {
1131 		size_t rlen = CBUF_MAPP2R(P2ROUNDUP(npages, CBUF_MAPNP));
1132 		void *map = kmem_alloc(BT_SIZEOFMAP(npages), KM_SLEEP);
1133 		void *rmap = kmem_alloc(BT_SIZEOFMAP(rlen), KM_SLEEP);
1134 
1135 		if (dumpcfg.bitmap != NULL)
1136 			kmem_free(dumpcfg.bitmap, BT_SIZEOFMAP(dumpcfg.
1137 			    bitmapsize));
1138 		if (dumpcfg.rbitmap != NULL)
1139 			kmem_free(dumpcfg.rbitmap, BT_SIZEOFMAP(dumpcfg.
1140 			    rbitmapsize));
1141 		dumpcfg.bitmap = map;
1142 		dumpcfg.bitmapsize = npages;
1143 		dumpcfg.rbitmap = rmap;
1144 		dumpcfg.rbitmapsize = rlen;
1145 	}
1146 }
1147 
1148 /*
1149  * Establish a new dump device.
1150  */
1151 int
1152 dumpinit(vnode_t *vp, char *name, int justchecking)
1153 {
1154 	vnode_t *cvp;
1155 	vattr_t vattr;
1156 	vnode_t *cdev_vp;
1157 	int error = 0;
1158 
1159 	ASSERT(MUTEX_HELD(&dump_lock));
1160 
1161 	dumphdr_init();
1162 
1163 	cvp = common_specvp(vp);
1164 	if (cvp == dumpvp)
1165 		return (0);
1166 
1167 	/*
1168 	 * Determine whether this is a plausible dump device.  We want either:
1169 	 * (1) a real device that's not mounted and has a cb_dump routine, or
1170 	 * (2) a swapfile on some filesystem that has a vop_dump routine.
1171 	 */
1172 	if ((error = VOP_OPEN(&cvp, FREAD | FWRITE, kcred, NULL)) != 0)
1173 		return (error);
1174 
1175 	vattr.va_mask = AT_SIZE | AT_TYPE | AT_RDEV;
1176 	if ((error = VOP_GETATTR(cvp, &vattr, 0, kcred, NULL)) == 0) {
1177 		if (vattr.va_type == VBLK || vattr.va_type == VCHR) {
1178 			if (devopsp[getmajor(vattr.va_rdev)]->
1179 			    devo_cb_ops->cb_dump == nodev)
1180 				error = ENOTSUP;
1181 			else if (vfs_devismounted(vattr.va_rdev))
1182 				error = EBUSY;
1183 			if (strcmp(ddi_driver_name(VTOS(cvp)->s_dip),
1184 			    ZFS_DRIVER) == 0 &&
1185 			    IS_SWAPVP(common_specvp(cvp)))
1186 					error = EBUSY;
1187 		} else {
1188 			if (vn_matchopval(cvp, VOPNAME_DUMP, fs_nosys) ||
1189 			    !IS_SWAPVP(cvp))
1190 				error = ENOTSUP;
1191 		}
1192 	}
1193 
1194 	if (error == 0 && vattr.va_size < 2 * DUMP_LOGSIZE + DUMP_ERPTSIZE)
1195 		error = ENOSPC;
1196 
1197 	if (error || justchecking) {
1198 		(void) VOP_CLOSE(cvp, FREAD | FWRITE, 1, (offset_t)0,
1199 		    kcred, NULL);
1200 		return (error);
1201 	}
1202 
1203 	VN_HOLD(cvp);
1204 
1205 	if (dumpvp != NULL)
1206 		dumpfini();	/* unconfigure the old dump device */
1207 
1208 	dumpvp = cvp;
1209 	dumpvp_size = vattr.va_size & -DUMP_OFFSET;
1210 	dumppath = kmem_alloc(strlen(name) + 1, KM_SLEEP);
1211 	(void) strcpy(dumppath, name);
1212 	dumpbuf.iosize = 0;
1213 
1214 	/*
1215 	 * If the dump device is a block device, attempt to open up the
1216 	 * corresponding character device and determine its maximum transfer
1217 	 * size.  We use this information to potentially resize dumpbuf to a
1218 	 * larger and more optimal size for performing i/o to the dump device.
1219 	 */
1220 	if (cvp->v_type == VBLK &&
1221 	    (cdev_vp = makespecvp(VTOS(cvp)->s_dev, VCHR)) != NULL) {
1222 		if (VOP_OPEN(&cdev_vp, FREAD | FWRITE, kcred, NULL) == 0) {
1223 			size_t blk_size;
1224 			struct dk_cinfo dki;
1225 			struct dk_minfo minf;
1226 
1227 			if (VOP_IOCTL(cdev_vp, DKIOCGMEDIAINFO,
1228 			    (intptr_t)&minf, FKIOCTL, kcred, NULL, NULL)
1229 			    == 0 && minf.dki_lbsize != 0)
1230 				blk_size = minf.dki_lbsize;
1231 			else
1232 				blk_size = DEV_BSIZE;
1233 
1234 			if (VOP_IOCTL(cdev_vp, DKIOCINFO, (intptr_t)&dki,
1235 			    FKIOCTL, kcred, NULL, NULL) == 0) {
1236 				dumpbuf.iosize = dki.dki_maxtransfer * blk_size;
1237 				dumpbuf_resize();
1238 			}
1239 			/*
1240 			 * If we are working with a zvol then dumpify it
1241 			 * if it's not being used as swap.
1242 			 */
1243 			if (strcmp(dki.dki_dname, ZVOL_DRIVER) == 0) {
1244 				if (IS_SWAPVP(common_specvp(cvp)))
1245 					error = EBUSY;
1246 				else if ((error = VOP_IOCTL(cdev_vp,
1247 				    DKIOCDUMPINIT, NULL, FKIOCTL, kcred,
1248 				    NULL, NULL)) != 0)
1249 					dumpfini();
1250 			}
1251 
1252 			(void) VOP_CLOSE(cdev_vp, FREAD | FWRITE, 1, 0,
1253 			    kcred, NULL);
1254 		}
1255 
1256 		VN_RELE(cdev_vp);
1257 	}
1258 
1259 	cmn_err(CE_CONT, "?dump on %s size %llu MB\n", name, dumpvp_size >> 20);
1260 
1261 	dump_update_clevel();
1262 
1263 	return (error);
1264 }
1265 
1266 void
1267 dumpfini(void)
1268 {
1269 	vattr_t vattr;
1270 	boolean_t is_zfs = B_FALSE;
1271 	vnode_t *cdev_vp;
1272 	ASSERT(MUTEX_HELD(&dump_lock));
1273 
1274 	kmem_free(dumppath, strlen(dumppath) + 1);
1275 
1276 	/*
1277 	 * Determine if we are using zvols for our dump device
1278 	 */
1279 	vattr.va_mask = AT_RDEV;
1280 	if (VOP_GETATTR(dumpvp, &vattr, 0, kcred, NULL) == 0) {
1281 		is_zfs = (getmajor(vattr.va_rdev) ==
1282 		    ddi_name_to_major(ZFS_DRIVER)) ? B_TRUE : B_FALSE;
1283 	}
1284 
1285 	/*
1286 	 * If we have a zvol dump device then we call into zfs so
1287 	 * that it may have a chance to cleanup.
1288 	 */
1289 	if (is_zfs &&
1290 	    (cdev_vp = makespecvp(VTOS(dumpvp)->s_dev, VCHR)) != NULL) {
1291 		if (VOP_OPEN(&cdev_vp, FREAD | FWRITE, kcred, NULL) == 0) {
1292 			(void) VOP_IOCTL(cdev_vp, DKIOCDUMPFINI, NULL, FKIOCTL,
1293 			    kcred, NULL, NULL);
1294 			(void) VOP_CLOSE(cdev_vp, FREAD | FWRITE, 1, 0,
1295 			    kcred, NULL);
1296 		}
1297 		VN_RELE(cdev_vp);
1298 	}
1299 
1300 	(void) VOP_CLOSE(dumpvp, FREAD | FWRITE, 1, (offset_t)0, kcred, NULL);
1301 
1302 	VN_RELE(dumpvp);
1303 
1304 	dumpvp = NULL;
1305 	dumpvp_size = 0;
1306 	dumppath = NULL;
1307 }
1308 
1309 static offset_t
1310 dumpvp_flush(void)
1311 {
1312 	size_t size = P2ROUNDUP(dumpbuf.cur - dumpbuf.start, PAGESIZE);
1313 	hrtime_t iotime;
1314 	int err;
1315 
1316 	if (dumpbuf.vp_off + size > dumpbuf.vp_limit) {
1317 		dump_ioerr = ENOSPC;
1318 		dumpbuf.vp_off = dumpbuf.vp_limit;
1319 	} else if (size != 0) {
1320 		iotime = gethrtime();
1321 		dumpsync.iowait += iotime - dumpsync.iowaitts;
1322 		if (panicstr)
1323 			err = VOP_DUMP(dumpvp, dumpbuf.start,
1324 			    lbtodb(dumpbuf.vp_off), btod(size), NULL);
1325 		else
1326 			err = vn_rdwr(UIO_WRITE, dumpbuf.cdev_vp != NULL ?
1327 			    dumpbuf.cdev_vp : dumpvp, dumpbuf.start, size,
1328 			    dumpbuf.vp_off, UIO_SYSSPACE, 0, dumpbuf.vp_limit,
1329 			    kcred, 0);
1330 		if (err && dump_ioerr == 0)
1331 			dump_ioerr = err;
1332 		dumpsync.iowaitts = gethrtime();
1333 		dumpsync.iotime += dumpsync.iowaitts - iotime;
1334 		dumpsync.nwrite += size;
1335 		dumpbuf.vp_off += size;
1336 	}
1337 	dumpbuf.cur = dumpbuf.start;
1338 	dump_timeleft = dump_timeout;
1339 	return (dumpbuf.vp_off);
1340 }
1341 
1342 /* maximize write speed by keeping seek offset aligned with size */
1343 void
1344 dumpvp_write(const void *va, size_t size)
1345 {
1346 	size_t len, off, sz;
1347 
1348 	while (size != 0) {
1349 		len = MIN(size, dumpbuf.end - dumpbuf.cur);
1350 		if (len == 0) {
1351 			off = P2PHASE(dumpbuf.vp_off, dumpbuf.size);
1352 			if (off == 0 || !ISP2(dumpbuf.size)) {
1353 				(void) dumpvp_flush();
1354 			} else {
1355 				sz = dumpbuf.size - off;
1356 				dumpbuf.cur = dumpbuf.start + sz;
1357 				(void) dumpvp_flush();
1358 				ovbcopy(dumpbuf.start + sz, dumpbuf.start, off);
1359 				dumpbuf.cur += off;
1360 			}
1361 		} else {
1362 			bcopy(va, dumpbuf.cur, len);
1363 			va = (char *)va + len;
1364 			dumpbuf.cur += len;
1365 			size -= len;
1366 		}
1367 	}
1368 }
1369 
1370 /*ARGSUSED*/
1371 static void
1372 dumpvp_ksyms_write(const void *src, void *dst, size_t size)
1373 {
1374 	dumpvp_write(src, size);
1375 }
1376 
1377 /*
1378  * Mark 'pfn' in the bitmap and dump its translation table entry.
1379  */
1380 void
1381 dump_addpage(struct as *as, void *va, pfn_t pfn)
1382 {
1383 	mem_vtop_t mem_vtop;
1384 	pgcnt_t bitnum;
1385 
1386 	if ((bitnum = dump_pfn_to_bitnum(pfn)) != (pgcnt_t)-1) {
1387 		if (!BT_TEST(dumpcfg.bitmap, bitnum)) {
1388 			dumphdr->dump_npages++;
1389 			BT_SET(dumpcfg.bitmap, bitnum);
1390 		}
1391 		dumphdr->dump_nvtop++;
1392 		mem_vtop.m_as = as;
1393 		mem_vtop.m_va = va;
1394 		mem_vtop.m_pfn = pfn;
1395 		dumpvp_write(&mem_vtop, sizeof (mem_vtop_t));
1396 	}
1397 	dump_timeleft = dump_timeout;
1398 }
1399 
1400 /*
1401  * Mark 'pfn' in the bitmap
1402  */
1403 void
1404 dump_page(pfn_t pfn)
1405 {
1406 	pgcnt_t bitnum;
1407 
1408 	if ((bitnum = dump_pfn_to_bitnum(pfn)) != (pgcnt_t)-1) {
1409 		if (!BT_TEST(dumpcfg.bitmap, bitnum)) {
1410 			dumphdr->dump_npages++;
1411 			BT_SET(dumpcfg.bitmap, bitnum);
1412 		}
1413 	}
1414 	dump_timeleft = dump_timeout;
1415 }
1416 
1417 /*
1418  * Dump the <as, va, pfn> information for a given address space.
1419  * SEGOP_DUMP() will call dump_addpage() for each page in the segment.
1420  */
1421 static void
1422 dump_as(struct as *as)
1423 {
1424 	struct seg *seg;
1425 
1426 	AS_LOCK_ENTER(as, RW_READER);
1427 	for (seg = AS_SEGFIRST(as); seg; seg = AS_SEGNEXT(as, seg)) {
1428 		if (seg->s_as != as)
1429 			break;
1430 		if (seg->s_ops == NULL)
1431 			continue;
1432 		SEGOP_DUMP(seg);
1433 	}
1434 	AS_LOCK_EXIT(as);
1435 
1436 	if (seg != NULL)
1437 		cmn_err(CE_WARN, "invalid segment %p in address space %p",
1438 		    (void *)seg, (void *)as);
1439 }
1440 
1441 static int
1442 dump_process(pid_t pid)
1443 {
1444 	proc_t *p = sprlock(pid);
1445 
1446 	if (p == NULL)
1447 		return (-1);
1448 	if (p->p_as != &kas) {
1449 		mutex_exit(&p->p_lock);
1450 		dump_as(p->p_as);
1451 		mutex_enter(&p->p_lock);
1452 	}
1453 
1454 	sprunlock(p);
1455 
1456 	return (0);
1457 }
1458 
1459 /*
1460  * The following functions (dump_summary(), dump_ereports(), and
1461  * dump_messages()), write data to an uncompressed area within the
1462  * crashdump. The layout of these is
1463  *
1464  * +------------------------------------------------------------+
1465  * |     compressed pages       | summary | ereports | messages |
1466  * +------------------------------------------------------------+
1467  *
1468  * With the advent of saving a compressed crash dump by default, we
1469  * need to save a little more data to describe the failure mode in
1470  * an uncompressed buffer available before savecore uncompresses
1471  * the dump. Initially this is a copy of the stack trace. Additional
1472  * summary information should be added here.
1473  */
1474 
1475 void
1476 dump_summary(void)
1477 {
1478 	u_offset_t dumpvp_start;
1479 	summary_dump_t sd;
1480 
1481 	if (dumpvp == NULL || dumphdr == NULL)
1482 		return;
1483 
1484 	dumpbuf.cur = dumpbuf.start;
1485 
1486 	dumpbuf.vp_limit = dumpvp_size - (DUMP_OFFSET + DUMP_LOGSIZE +
1487 	    DUMP_ERPTSIZE);
1488 	dumpvp_start = dumpbuf.vp_limit - DUMP_SUMMARYSIZE;
1489 	dumpbuf.vp_off = dumpvp_start;
1490 
1491 	sd.sd_magic = SUMMARY_MAGIC;
1492 	sd.sd_ssum = checksum32(dump_stack_scratch, STACK_BUF_SIZE);
1493 	dumpvp_write(&sd, sizeof (sd));
1494 	dumpvp_write(dump_stack_scratch, STACK_BUF_SIZE);
1495 
1496 	sd.sd_magic = 0; /* indicate end of summary */
1497 	dumpvp_write(&sd, sizeof (sd));
1498 	(void) dumpvp_flush();
1499 }
1500 
1501 void
1502 dump_ereports(void)
1503 {
1504 	u_offset_t dumpvp_start;
1505 	erpt_dump_t ed;
1506 
1507 	if (dumpvp == NULL || dumphdr == NULL)
1508 		return;
1509 
1510 	dumpbuf.cur = dumpbuf.start;
1511 	dumpbuf.vp_limit = dumpvp_size - (DUMP_OFFSET + DUMP_LOGSIZE);
1512 	dumpvp_start = dumpbuf.vp_limit - DUMP_ERPTSIZE;
1513 	dumpbuf.vp_off = dumpvp_start;
1514 
1515 	fm_ereport_dump();
1516 	if (panicstr)
1517 		errorq_dump();
1518 
1519 	bzero(&ed, sizeof (ed)); /* indicate end of ereports */
1520 	dumpvp_write(&ed, sizeof (ed));
1521 	(void) dumpvp_flush();
1522 
1523 	if (!panicstr) {
1524 		(void) VOP_PUTPAGE(dumpvp, dumpvp_start,
1525 		    (size_t)(dumpbuf.vp_off - dumpvp_start),
1526 		    B_INVAL | B_FORCE, kcred, NULL);
1527 	}
1528 }
1529 
1530 void
1531 dump_messages(void)
1532 {
1533 	log_dump_t ld;
1534 	mblk_t *mctl, *mdata;
1535 	queue_t *q, *qlast;
1536 	u_offset_t dumpvp_start;
1537 
1538 	if (dumpvp == NULL || dumphdr == NULL || log_consq == NULL)
1539 		return;
1540 
1541 	dumpbuf.cur = dumpbuf.start;
1542 	dumpbuf.vp_limit = dumpvp_size - DUMP_OFFSET;
1543 	dumpvp_start = dumpbuf.vp_limit - DUMP_LOGSIZE;
1544 	dumpbuf.vp_off = dumpvp_start;
1545 
1546 	qlast = NULL;
1547 	do {
1548 		for (q = log_consq; q->q_next != qlast; q = q->q_next)
1549 			continue;
1550 		for (mctl = q->q_first; mctl != NULL; mctl = mctl->b_next) {
1551 			dump_timeleft = dump_timeout;
1552 			mdata = mctl->b_cont;
1553 			ld.ld_magic = LOG_MAGIC;
1554 			ld.ld_msgsize = MBLKL(mctl->b_cont);
1555 			ld.ld_csum = checksum32(mctl->b_rptr, MBLKL(mctl));
1556 			ld.ld_msum = checksum32(mdata->b_rptr, MBLKL(mdata));
1557 			dumpvp_write(&ld, sizeof (ld));
1558 			dumpvp_write(mctl->b_rptr, MBLKL(mctl));
1559 			dumpvp_write(mdata->b_rptr, MBLKL(mdata));
1560 		}
1561 	} while ((qlast = q) != log_consq);
1562 
1563 	ld.ld_magic = 0;		/* indicate end of messages */
1564 	dumpvp_write(&ld, sizeof (ld));
1565 	(void) dumpvp_flush();
1566 	if (!panicstr) {
1567 		(void) VOP_PUTPAGE(dumpvp, dumpvp_start,
1568 		    (size_t)(dumpbuf.vp_off - dumpvp_start),
1569 		    B_INVAL | B_FORCE, kcred, NULL);
1570 	}
1571 }
1572 
1573 /*
1574  * The following functions are called on multiple CPUs during dump.
1575  * They must not use most kernel services, because all cross-calls are
1576  * disabled during panic. Therefore, blocking locks and cache flushes
1577  * will not work.
1578  */
1579 
1580 /*
1581  * Copy pages, trapping ECC errors. Also, for robustness, trap data
1582  * access in case something goes wrong in the hat layer and the
1583  * mapping is broken.
1584  */
1585 static int
1586 dump_pagecopy(void *src, void *dst)
1587 {
1588 	long *wsrc = (long *)src;
1589 	long *wdst = (long *)dst;
1590 	const ulong_t ncopies = PAGESIZE / sizeof (long);
1591 	volatile int w = 0;
1592 	volatile int ueoff = -1;
1593 	on_trap_data_t otd;
1594 
1595 	if (on_trap(&otd, OT_DATA_EC | OT_DATA_ACCESS)) {
1596 		if (ueoff == -1)
1597 			ueoff = w * sizeof (long);
1598 		/* report "bad ECC" or "bad address" */
1599 #ifdef _LP64
1600 		if (otd.ot_trap & OT_DATA_EC)
1601 			wdst[w++] = 0x00badecc00badecc;
1602 		else
1603 			wdst[w++] = 0x00badadd00badadd;
1604 #else
1605 		if (otd.ot_trap & OT_DATA_EC)
1606 			wdst[w++] = 0x00badecc;
1607 		else
1608 			wdst[w++] = 0x00badadd;
1609 #endif
1610 	}
1611 	while (w < ncopies) {
1612 		wdst[w] = wsrc[w];
1613 		w++;
1614 	}
1615 	no_trap();
1616 	return (ueoff);
1617 }
1618 
1619 static void
1620 dumpsys_close_cq(cqueue_t *cq, int live)
1621 {
1622 	if (live) {
1623 		mutex_enter(&cq->mutex);
1624 		atomic_dec_uint(&cq->open);
1625 		cv_signal(&cq->cv);
1626 		mutex_exit(&cq->mutex);
1627 	} else {
1628 		atomic_dec_uint(&cq->open);
1629 	}
1630 }
1631 
1632 static inline void
1633 dumpsys_spinlock(lock_t *lp)
1634 {
1635 	uint_t backoff = 0;
1636 	int loop_count = 0;
1637 
1638 	while (LOCK_HELD(lp) || !lock_spin_try(lp)) {
1639 		if (++loop_count >= ncpus) {
1640 			backoff = mutex_lock_backoff(0);
1641 			loop_count = 0;
1642 		} else {
1643 			backoff = mutex_lock_backoff(backoff);
1644 		}
1645 		mutex_lock_delay(backoff);
1646 	}
1647 }
1648 
1649 static inline void
1650 dumpsys_spinunlock(lock_t *lp)
1651 {
1652 	lock_clear(lp);
1653 }
1654 
1655 static inline void
1656 dumpsys_lock(cqueue_t *cq, int live)
1657 {
1658 	if (live)
1659 		mutex_enter(&cq->mutex);
1660 	else
1661 		dumpsys_spinlock(&cq->spinlock);
1662 }
1663 
1664 static inline void
1665 dumpsys_unlock(cqueue_t *cq, int live, int signal)
1666 {
1667 	if (live) {
1668 		if (signal)
1669 			cv_signal(&cq->cv);
1670 		mutex_exit(&cq->mutex);
1671 	} else {
1672 		dumpsys_spinunlock(&cq->spinlock);
1673 	}
1674 }
1675 
1676 static void
1677 dumpsys_wait_cq(cqueue_t *cq, int live)
1678 {
1679 	if (live) {
1680 		cv_wait(&cq->cv, &cq->mutex);
1681 	} else {
1682 		dumpsys_spinunlock(&cq->spinlock);
1683 		while (cq->open)
1684 			if (cq->first)
1685 				break;
1686 		dumpsys_spinlock(&cq->spinlock);
1687 	}
1688 }
1689 
1690 static void
1691 dumpsys_put_cq(cqueue_t *cq, cbuf_t *cp, int newstate, int live)
1692 {
1693 	if (cp == NULL)
1694 		return;
1695 
1696 	dumpsys_lock(cq, live);
1697 
1698 	if (cq->ts != 0) {
1699 		cq->empty += gethrtime() - cq->ts;
1700 		cq->ts = 0;
1701 	}
1702 
1703 	cp->state = newstate;
1704 	cp->next = NULL;
1705 	if (cq->last == NULL)
1706 		cq->first = cp;
1707 	else
1708 		cq->last->next = cp;
1709 	cq->last = cp;
1710 
1711 	dumpsys_unlock(cq, live, 1);
1712 }
1713 
1714 static cbuf_t *
1715 dumpsys_get_cq(cqueue_t *cq, int live)
1716 {
1717 	cbuf_t *cp;
1718 	hrtime_t now = gethrtime();
1719 
1720 	dumpsys_lock(cq, live);
1721 
1722 	/* CONSTCOND */
1723 	while (1) {
1724 		cp = (cbuf_t *)cq->first;
1725 		if (cp == NULL) {
1726 			if (cq->open == 0)
1727 				break;
1728 			dumpsys_wait_cq(cq, live);
1729 			continue;
1730 		}
1731 		cq->first = cp->next;
1732 		if (cq->first == NULL) {
1733 			cq->last = NULL;
1734 			cq->ts = now;
1735 		}
1736 		break;
1737 	}
1738 
1739 	dumpsys_unlock(cq, live, cq->first != NULL || cq->open == 0);
1740 	return (cp);
1741 }
1742 
1743 /*
1744  * Send an error message to the console. If the main task is running
1745  * just write the message via uprintf. If a helper is running the
1746  * message has to be put on a queue for the main task. Setting fmt to
1747  * NULL means flush the error message buffer. If fmt is not NULL, just
1748  * add the text to the existing buffer.
1749  */
1750 static void
1751 dumpsys_errmsg(helper_t *hp, const char *fmt, ...)
1752 {
1753 	dumpsync_t *ds = hp->ds;
1754 	cbuf_t *cp = hp->cperr;
1755 	va_list adx;
1756 
1757 	if (hp->helper == MAINHELPER) {
1758 		if (fmt != NULL) {
1759 			if (ds->neednl) {
1760 				uprintf("\n");
1761 				ds->neednl = 0;
1762 			}
1763 			va_start(adx, fmt);
1764 			vuprintf(fmt, adx);
1765 			va_end(adx);
1766 		}
1767 	} else if (fmt == NULL) {
1768 		if (cp != NULL) {
1769 			CQ_PUT(mainq, cp, CBUF_ERRMSG);
1770 			hp->cperr = NULL;
1771 		}
1772 	} else {
1773 		if (hp->cperr == NULL) {
1774 			cp = CQ_GET(freebufq);
1775 			hp->cperr = cp;
1776 			cp->used = 0;
1777 		}
1778 		va_start(adx, fmt);
1779 		cp->used += vsnprintf(cp->buf + cp->used, cp->size - cp->used,
1780 		    fmt, adx);
1781 		va_end(adx);
1782 		if ((cp->used + LOG_MSGSIZE) > cp->size) {
1783 			CQ_PUT(mainq, cp, CBUF_ERRMSG);
1784 			hp->cperr = NULL;
1785 		}
1786 	}
1787 }
1788 
1789 /*
1790  * Write an output buffer to the dump file. If the main task is
1791  * running just write the data. If a helper is running the output is
1792  * placed on a queue for the main task.
1793  */
1794 static void
1795 dumpsys_swrite(helper_t *hp, cbuf_t *cp, size_t used)
1796 {
1797 	dumpsync_t *ds = hp->ds;
1798 
1799 	if (hp->helper == MAINHELPER) {
1800 		HRSTART(ds->perpage, write);
1801 		dumpvp_write(cp->buf, used);
1802 		HRSTOP(ds->perpage, write);
1803 		CQ_PUT(freebufq, cp, CBUF_FREEBUF);
1804 	} else {
1805 		cp->used = used;
1806 		CQ_PUT(mainq, cp, CBUF_WRITE);
1807 	}
1808 }
1809 
1810 /*
1811  * Copy one page within the mapped range. The offset starts at 0 and
1812  * is relative to the first pfn. cp->buf + cp->off is the address of
1813  * the first pfn. If dump_pagecopy returns a UE offset, create an
1814  * error message.  Returns the offset to the next pfn in the range
1815  * selected by the bitmap.
1816  */
1817 static int
1818 dumpsys_copy_page(helper_t *hp, int offset)
1819 {
1820 	cbuf_t *cp = hp->cpin;
1821 	int ueoff;
1822 
1823 	ASSERT(cp->off + offset + PAGESIZE <= cp->size);
1824 	ASSERT(BT_TEST(dumpcfg.bitmap, cp->bitnum));
1825 
1826 	ueoff = dump_pagecopy(cp->buf + cp->off + offset, hp->page);
1827 
1828 	/* ueoff is the offset in the page to a UE error */
1829 	if (ueoff != -1) {
1830 		uint64_t pa = ptob(cp->pfn) + offset + ueoff;
1831 
1832 		dumpsys_errmsg(hp, "cpu %d: memory error at PA 0x%08x.%08x\n",
1833 		    CPU->cpu_id, (uint32_t)(pa >> 32), (uint32_t)pa);
1834 	}
1835 
1836 	/*
1837 	 * Advance bitnum and offset to the next input page for the
1838 	 * next call to this function.
1839 	 */
1840 	offset += PAGESIZE;
1841 	cp->bitnum++;
1842 	while (cp->off + offset < cp->size) {
1843 		if (BT_TEST(dumpcfg.bitmap, cp->bitnum))
1844 			break;
1845 		offset += PAGESIZE;
1846 		cp->bitnum++;
1847 	}
1848 
1849 	return (offset);
1850 }
1851 
1852 /*
1853  * Read the helper queue, and copy one mapped page. Return 0 when
1854  * done. Return 1 when a page has been copied into hp->page.
1855  */
1856 static int
1857 dumpsys_sread(helper_t *hp)
1858 {
1859 	dumpsync_t *ds = hp->ds;
1860 
1861 	/* CONSTCOND */
1862 	while (1) {
1863 
1864 		/* Find the next input buffer. */
1865 		if (hp->cpin == NULL) {
1866 			HRSTART(hp->perpage, inwait);
1867 
1868 			/* CONSTCOND */
1869 			while (1) {
1870 				hp->cpin = CQ_GET(helperq);
1871 				dump_timeleft = dump_timeout;
1872 
1873 				/*
1874 				 * NULL return means the helper queue
1875 				 * is closed and empty.
1876 				 */
1877 				if (hp->cpin == NULL)
1878 					break;
1879 
1880 				/* Have input, check for dump I/O error. */
1881 				if (!dump_ioerr)
1882 					break;
1883 
1884 				/*
1885 				 * If an I/O error occurs, stay in the
1886 				 * loop in order to empty the helper
1887 				 * queue. Return the buffers to the
1888 				 * main task to unmap and free it.
1889 				 */
1890 				hp->cpin->used = 0;
1891 				CQ_PUT(mainq, hp->cpin, CBUF_USEDMAP);
1892 			}
1893 			HRSTOP(hp->perpage, inwait);
1894 
1895 			/* Stop here when the helper queue is closed. */
1896 			if (hp->cpin == NULL)
1897 				break;
1898 
1899 			/* Set the offset=0 to get the first pfn. */
1900 			hp->in = 0;
1901 
1902 			/* Set the total processed to 0 */
1903 			hp->used = 0;
1904 		}
1905 
1906 		/* Process the next page. */
1907 		if (hp->used < hp->cpin->used) {
1908 
1909 			/*
1910 			 * Get the next page from the input buffer and
1911 			 * return a copy.
1912 			 */
1913 			ASSERT(hp->in != -1);
1914 			HRSTART(hp->perpage, copy);
1915 			hp->in = dumpsys_copy_page(hp, hp->in);
1916 			hp->used += PAGESIZE;
1917 			HRSTOP(hp->perpage, copy);
1918 			break;
1919 
1920 		} else {
1921 
1922 			/*
1923 			 * Done with the input. Flush the VM and
1924 			 * return the buffer to the main task.
1925 			 */
1926 			if (panicstr && hp->helper != MAINHELPER)
1927 				hat_flush_range(kas.a_hat,
1928 				    hp->cpin->buf, hp->cpin->size);
1929 			dumpsys_errmsg(hp, NULL);
1930 			CQ_PUT(mainq, hp->cpin, CBUF_USEDMAP);
1931 			hp->cpin = NULL;
1932 		}
1933 	}
1934 
1935 	return (hp->cpin != NULL);
1936 }
1937 
1938 /*
1939  * Compress size bytes starting at buf with bzip2
1940  * mode:
1941  *	BZ_RUN		add one more compressed page
1942  *	BZ_FINISH	no more input, flush the state
1943  */
1944 static void
1945 dumpsys_bzrun(helper_t *hp, void *buf, size_t size, int mode)
1946 {
1947 	dumpsync_t *ds = hp->ds;
1948 	const int CSIZE = sizeof (dumpcsize_t);
1949 	bz_stream *ps = &hp->bzstream;
1950 	int rc = 0;
1951 	uint32_t csize;
1952 	dumpcsize_t cs;
1953 
1954 	/* Set input pointers to new input page */
1955 	if (size > 0) {
1956 		ps->avail_in = size;
1957 		ps->next_in = buf;
1958 	}
1959 
1960 	/* CONSTCOND */
1961 	while (1) {
1962 
1963 		/* Quit when all input has been consumed */
1964 		if (ps->avail_in == 0 && mode == BZ_RUN)
1965 			break;
1966 
1967 		/* Get a new output buffer */
1968 		if (hp->cpout == NULL) {
1969 			HRSTART(hp->perpage, outwait);
1970 			hp->cpout = CQ_GET(freebufq);
1971 			HRSTOP(hp->perpage, outwait);
1972 			ps->avail_out = hp->cpout->size - CSIZE;
1973 			ps->next_out = hp->cpout->buf + CSIZE;
1974 		}
1975 
1976 		/* Compress input, or finalize */
1977 		HRSTART(hp->perpage, compress);
1978 		rc = BZ2_bzCompress(ps, mode);
1979 		HRSTOP(hp->perpage, compress);
1980 
1981 		/* Check for error */
1982 		if (mode == BZ_RUN && rc != BZ_RUN_OK) {
1983 			dumpsys_errmsg(hp, "%d: BZ_RUN error %s at page %lx\n",
1984 			    hp->helper, BZ2_bzErrorString(rc),
1985 			    hp->cpin->pagenum);
1986 			break;
1987 		}
1988 
1989 		/* Write the buffer if it is full, or we are flushing */
1990 		if (ps->avail_out == 0 || mode == BZ_FINISH) {
1991 			csize = hp->cpout->size - CSIZE - ps->avail_out;
1992 			cs = DUMP_SET_TAG(csize, hp->tag);
1993 			if (csize > 0) {
1994 				(void) memcpy(hp->cpout->buf, &cs, CSIZE);
1995 				dumpsys_swrite(hp, hp->cpout, csize + CSIZE);
1996 				hp->cpout = NULL;
1997 			}
1998 		}
1999 
2000 		/* Check for final complete */
2001 		if (mode == BZ_FINISH) {
2002 			if (rc == BZ_STREAM_END)
2003 				break;
2004 			if (rc != BZ_FINISH_OK) {
2005 				dumpsys_errmsg(hp, "%d: BZ_FINISH error %s\n",
2006 				    hp->helper, BZ2_bzErrorString(rc));
2007 				break;
2008 			}
2009 		}
2010 	}
2011 
2012 	/* Cleanup state and buffers */
2013 	if (mode == BZ_FINISH) {
2014 
2015 		/* Reset state so that it is re-usable. */
2016 		(void) BZ2_bzCompressReset(&hp->bzstream);
2017 
2018 		/* Give any unused outout buffer to the main task */
2019 		if (hp->cpout != NULL) {
2020 			hp->cpout->used = 0;
2021 			CQ_PUT(mainq, hp->cpout, CBUF_ERRMSG);
2022 			hp->cpout = NULL;
2023 		}
2024 	}
2025 }
2026 
2027 static void
2028 dumpsys_bz2compress(helper_t *hp)
2029 {
2030 	dumpsync_t *ds = hp->ds;
2031 	dumpstreamhdr_t sh;
2032 
2033 	(void) strcpy(sh.stream_magic, DUMP_STREAM_MAGIC);
2034 	sh.stream_pagenum = (pgcnt_t)-1;
2035 	sh.stream_npages = 0;
2036 	hp->cpin = NULL;
2037 	hp->cpout = NULL;
2038 	hp->cperr = NULL;
2039 	hp->in = 0;
2040 	hp->out = 0;
2041 	hp->bzstream.avail_in = 0;
2042 
2043 	/* Bump reference to mainq while we are running */
2044 	CQ_OPEN(mainq);
2045 
2046 	/* Get one page at a time */
2047 	while (dumpsys_sread(hp)) {
2048 		if (sh.stream_pagenum != hp->cpin->pagenum) {
2049 			sh.stream_pagenum = hp->cpin->pagenum;
2050 			sh.stream_npages = btop(hp->cpin->used);
2051 			dumpsys_bzrun(hp, &sh, sizeof (sh), BZ_RUN);
2052 		}
2053 		dumpsys_bzrun(hp, hp->page, PAGESIZE, 0);
2054 	}
2055 
2056 	/* Done with input, flush any partial buffer */
2057 	if (sh.stream_pagenum != (pgcnt_t)-1) {
2058 		dumpsys_bzrun(hp, NULL, 0, BZ_FINISH);
2059 		dumpsys_errmsg(hp, NULL);
2060 	}
2061 
2062 	ASSERT(hp->cpin == NULL && hp->cpout == NULL && hp->cperr == NULL);
2063 
2064 	/* Decrement main queue count, we are done */
2065 	CQ_CLOSE(mainq);
2066 }
2067 
2068 /*
2069  * Compress with lzjb
2070  * write stream block if full or size==0
2071  * if csize==0 write stream header, else write <csize, data>
2072  * size==0 is a call to flush a buffer
2073  * hp->cpout is the buffer we are flushing or filling
2074  * hp->out is the next index to fill data
2075  * osize is either csize+data, or the size of a stream header
2076  */
2077 static void
2078 dumpsys_lzjbrun(helper_t *hp, size_t csize, void *buf, size_t size)
2079 {
2080 	dumpsync_t *ds = hp->ds;
2081 	const int CSIZE = sizeof (dumpcsize_t);
2082 	dumpcsize_t cs;
2083 	size_t osize = csize > 0 ? CSIZE + size : size;
2084 
2085 	/* If flush, and there is no buffer, just return */
2086 	if (size == 0 && hp->cpout == NULL)
2087 		return;
2088 
2089 	/* If flush, or cpout is full, write it out */
2090 	if (size == 0 ||
2091 	    hp->cpout != NULL && hp->out + osize > hp->cpout->size) {
2092 
2093 		/* Set tag+size word at the front of the stream block. */
2094 		cs = DUMP_SET_TAG(hp->out - CSIZE, hp->tag);
2095 		(void) memcpy(hp->cpout->buf, &cs, CSIZE);
2096 
2097 		/* Write block to dump file. */
2098 		dumpsys_swrite(hp, hp->cpout, hp->out);
2099 
2100 		/* Clear pointer to indicate we need a new buffer */
2101 		hp->cpout = NULL;
2102 
2103 		/* flushing, we are done */
2104 		if (size == 0)
2105 			return;
2106 	}
2107 
2108 	/* Get an output buffer if we dont have one. */
2109 	if (hp->cpout == NULL) {
2110 		HRSTART(hp->perpage, outwait);
2111 		hp->cpout = CQ_GET(freebufq);
2112 		HRSTOP(hp->perpage, outwait);
2113 		hp->out = CSIZE;
2114 	}
2115 
2116 	/* Store csize word. This is the size of compressed data. */
2117 	if (csize > 0) {
2118 		cs = DUMP_SET_TAG(csize, 0);
2119 		(void) memcpy(hp->cpout->buf + hp->out, &cs, CSIZE);
2120 		hp->out += CSIZE;
2121 	}
2122 
2123 	/* Store the data. */
2124 	(void) memcpy(hp->cpout->buf + hp->out, buf, size);
2125 	hp->out += size;
2126 }
2127 
2128 static void
2129 dumpsys_lzjbcompress(helper_t *hp)
2130 {
2131 	dumpsync_t *ds = hp->ds;
2132 	size_t csize;
2133 	dumpstreamhdr_t sh;
2134 
2135 	(void) strcpy(sh.stream_magic, DUMP_STREAM_MAGIC);
2136 	sh.stream_pagenum = (pfn_t)-1;
2137 	sh.stream_npages = 0;
2138 	hp->cpin = NULL;
2139 	hp->cpout = NULL;
2140 	hp->cperr = NULL;
2141 	hp->in = 0;
2142 	hp->out = 0;
2143 
2144 	/* Bump reference to mainq while we are running */
2145 	CQ_OPEN(mainq);
2146 
2147 	/* Get one page at a time */
2148 	while (dumpsys_sread(hp)) {
2149 
2150 		/* Create a stream header for each new input map */
2151 		if (sh.stream_pagenum != hp->cpin->pagenum) {
2152 			sh.stream_pagenum = hp->cpin->pagenum;
2153 			sh.stream_npages = btop(hp->cpin->used);
2154 			dumpsys_lzjbrun(hp, 0, &sh, sizeof (sh));
2155 		}
2156 
2157 		/* Compress one page */
2158 		HRSTART(hp->perpage, compress);
2159 		csize = compress(hp->page, hp->lzbuf, PAGESIZE);
2160 		HRSTOP(hp->perpage, compress);
2161 
2162 		/* Add csize+data to output block */
2163 		ASSERT(csize > 0 && csize <= PAGESIZE);
2164 		dumpsys_lzjbrun(hp, csize, hp->lzbuf, csize);
2165 	}
2166 
2167 	/* Done with input, flush any partial buffer */
2168 	if (sh.stream_pagenum != (pfn_t)-1) {
2169 		dumpsys_lzjbrun(hp, 0, NULL, 0);
2170 		dumpsys_errmsg(hp, NULL);
2171 	}
2172 
2173 	ASSERT(hp->cpin == NULL && hp->cpout == NULL && hp->cperr == NULL);
2174 
2175 	/* Decrement main queue count, we are done */
2176 	CQ_CLOSE(mainq);
2177 }
2178 
2179 /*
2180  * Dump helper called from panic_idle() to compress pages.  CPUs in
2181  * this path must not call most kernel services.
2182  *
2183  * During panic, all but one of the CPUs is idle. These CPUs are used
2184  * as helpers working in parallel to copy and compress memory
2185  * pages. During a panic, however, these processors cannot call any
2186  * kernel services. This is because mutexes become no-ops during
2187  * panic, and, cross-call interrupts are inhibited.  Therefore, during
2188  * panic dump the helper CPUs communicate with the panic CPU using
2189  * memory variables. All memory mapping and I/O is performed by the
2190  * panic CPU.
2191  *
2192  * At dump configuration time, helper_lock is set and helpers_wanted
2193  * is 0. dumpsys() decides whether to set helpers_wanted before
2194  * clearing helper_lock.
2195  *
2196  * At panic time, idle CPUs spin-wait on helper_lock, then alternately
2197  * take the lock and become a helper, or return.
2198  */
2199 void
2200 dumpsys_helper()
2201 {
2202 	dumpsys_spinlock(&dumpcfg.helper_lock);
2203 	if (dumpcfg.helpers_wanted) {
2204 		helper_t *hp, *hpend = &dumpcfg.helper[dumpcfg.nhelper];
2205 
2206 		for (hp = dumpcfg.helper; hp != hpend; hp++) {
2207 			if (hp->helper == FREEHELPER) {
2208 				hp->helper = CPU->cpu_id;
2209 				BT_SET(dumpcfg.helpermap, CPU->cpu_seqid);
2210 
2211 				dumpsys_spinunlock(&dumpcfg.helper_lock);
2212 
2213 				if (dumpcfg.clevel < DUMP_CLEVEL_BZIP2)
2214 					dumpsys_lzjbcompress(hp);
2215 				else
2216 					dumpsys_bz2compress(hp);
2217 
2218 				hp->helper = DONEHELPER;
2219 				return;
2220 			}
2221 		}
2222 
2223 		/* No more helpers are needed. */
2224 		dumpcfg.helpers_wanted = 0;
2225 
2226 	}
2227 	dumpsys_spinunlock(&dumpcfg.helper_lock);
2228 }
2229 
2230 /*
2231  * No-wait helper callable in spin loops.
2232  *
2233  * Do not wait for helper_lock. Just check helpers_wanted. The caller
2234  * may decide to continue. This is the "c)ontinue, s)ync, r)eset? s"
2235  * case.
2236  */
2237 void
2238 dumpsys_helper_nw()
2239 {
2240 	if (dumpcfg.helpers_wanted)
2241 		dumpsys_helper();
2242 }
2243 
2244 /*
2245  * Dump helper for live dumps.
2246  * These run as a system task.
2247  */
2248 static void
2249 dumpsys_live_helper(void *arg)
2250 {
2251 	helper_t *hp = arg;
2252 
2253 	BT_ATOMIC_SET(dumpcfg.helpermap, CPU->cpu_seqid);
2254 	if (dumpcfg.clevel < DUMP_CLEVEL_BZIP2)
2255 		dumpsys_lzjbcompress(hp);
2256 	else
2257 		dumpsys_bz2compress(hp);
2258 }
2259 
2260 /*
2261  * Compress one page with lzjb (single threaded case)
2262  */
2263 static void
2264 dumpsys_lzjb_page(helper_t *hp, cbuf_t *cp)
2265 {
2266 	dumpsync_t *ds = hp->ds;
2267 	uint32_t csize;
2268 
2269 	hp->helper = MAINHELPER;
2270 	hp->in = 0;
2271 	hp->used = 0;
2272 	hp->cpin = cp;
2273 	while (hp->used < cp->used) {
2274 		HRSTART(hp->perpage, copy);
2275 		hp->in = dumpsys_copy_page(hp, hp->in);
2276 		hp->used += PAGESIZE;
2277 		HRSTOP(hp->perpage, copy);
2278 
2279 		HRSTART(hp->perpage, compress);
2280 		csize = compress(hp->page, hp->lzbuf, PAGESIZE);
2281 		HRSTOP(hp->perpage, compress);
2282 
2283 		HRSTART(hp->perpage, write);
2284 		dumpvp_write(&csize, sizeof (csize));
2285 		dumpvp_write(hp->lzbuf, csize);
2286 		HRSTOP(hp->perpage, write);
2287 	}
2288 	CQ_PUT(mainq, hp->cpin, CBUF_USEDMAP);
2289 	hp->cpin = NULL;
2290 }
2291 
2292 /*
2293  * Main task to dump pages. This is called on the dump CPU.
2294  */
2295 static void
2296 dumpsys_main_task(void *arg)
2297 {
2298 	dumpsync_t *ds = arg;
2299 	pgcnt_t pagenum = 0, bitnum = 0, hibitnum;
2300 	dumpmlw_t mlw;
2301 	cbuf_t *cp;
2302 	pgcnt_t baseoff, pfnoff;
2303 	pfn_t base, pfn;
2304 	int i, dumpserial;
2305 
2306 	/*
2307 	 * Fall back to serial mode if there are no helpers.
2308 	 * dump_plat_mincpu can be set to 0 at any time.
2309 	 * dumpcfg.helpermap must contain at least one member.
2310 	 */
2311 	dumpserial = 1;
2312 
2313 	if (dump_plat_mincpu != 0 && dumpcfg.clevel != 0) {
2314 		for (i = 0; i < BT_BITOUL(NCPU); ++i) {
2315 			if (dumpcfg.helpermap[i] != 0) {
2316 				dumpserial = 0;
2317 				break;
2318 			}
2319 		}
2320 	}
2321 
2322 	if (dumpserial) {
2323 		dumpcfg.clevel = 0;
2324 		if (dumpcfg.helper[0].lzbuf == NULL)
2325 			dumpcfg.helper[0].lzbuf = dumpcfg.helper[1].page;
2326 	}
2327 
2328 	dump_init_memlist_walker(&mlw);
2329 
2330 	for (;;) {
2331 		int sec = (gethrtime() - ds->start) / NANOSEC;
2332 
2333 		/*
2334 		 * Render a simple progress display on the system console to
2335 		 * make clear to the operator that the system has not hung.
2336 		 * Emit an update when dump progress has advanced by one
2337 		 * percent, or when no update has been drawn in the last
2338 		 * second.
2339 		 */
2340 		if (ds->percent > ds->percent_done || sec > ds->sec_done) {
2341 			ds->sec_done = sec;
2342 			ds->percent_done = ds->percent;
2343 			uprintf("^\rdumping: %2d:%02d %3d%% done",
2344 			    sec / 60, sec % 60, ds->percent);
2345 			ds->neednl = 1;
2346 		}
2347 
2348 		while (CQ_IS_EMPTY(mainq) && !CQ_IS_EMPTY(writerq)) {
2349 
2350 			/* the writerq never blocks */
2351 			cp = CQ_GET(writerq);
2352 			if (cp == NULL)
2353 				break;
2354 
2355 			dump_timeleft = dump_timeout;
2356 
2357 			HRSTART(ds->perpage, write);
2358 			dumpvp_write(cp->buf, cp->used);
2359 			HRSTOP(ds->perpage, write);
2360 
2361 			CQ_PUT(freebufq, cp, CBUF_FREEBUF);
2362 		}
2363 
2364 		/*
2365 		 * Wait here for some buffers to process. Returns NULL
2366 		 * when all helpers have terminated and all buffers
2367 		 * have been processed.
2368 		 */
2369 		cp = CQ_GET(mainq);
2370 
2371 		if (cp == NULL) {
2372 
2373 			/* Drain the write queue. */
2374 			if (!CQ_IS_EMPTY(writerq))
2375 				continue;
2376 
2377 			/* Main task exits here. */
2378 			break;
2379 		}
2380 
2381 		dump_timeleft = dump_timeout;
2382 
2383 		switch (cp->state) {
2384 
2385 		case CBUF_FREEMAP:
2386 
2387 			/*
2388 			 * Note that we drop CBUF_FREEMAP buffers on
2389 			 * the floor (they will not be on any cqueue)
2390 			 * when we no longer need them.
2391 			 */
2392 			if (bitnum >= dumpcfg.bitmapsize)
2393 				break;
2394 
2395 			if (dump_ioerr) {
2396 				bitnum = dumpcfg.bitmapsize;
2397 				CQ_CLOSE(helperq);
2398 				break;
2399 			}
2400 
2401 			HRSTART(ds->perpage, bitmap);
2402 			for (; bitnum < dumpcfg.bitmapsize; bitnum++)
2403 				if (BT_TEST(dumpcfg.bitmap, bitnum))
2404 					break;
2405 			HRSTOP(ds->perpage, bitmap);
2406 			dump_timeleft = dump_timeout;
2407 
2408 			if (bitnum >= dumpcfg.bitmapsize) {
2409 				CQ_CLOSE(helperq);
2410 				break;
2411 			}
2412 
2413 			/*
2414 			 * Try to map CBUF_MAPSIZE ranges. Can't
2415 			 * assume that memory segment size is a
2416 			 * multiple of CBUF_MAPSIZE. Can't assume that
2417 			 * the segment starts on a CBUF_MAPSIZE
2418 			 * boundary.
2419 			 */
2420 			pfn = dump_bitnum_to_pfn(bitnum, &mlw);
2421 			ASSERT(pfn != PFN_INVALID);
2422 			ASSERT(bitnum + mlw.mpleft <= dumpcfg.bitmapsize);
2423 
2424 			base = P2ALIGN(pfn, CBUF_MAPNP);
2425 			if (base < mlw.mpaddr) {
2426 				base = mlw.mpaddr;
2427 				baseoff = P2PHASE(base, CBUF_MAPNP);
2428 			} else {
2429 				baseoff = 0;
2430 			}
2431 
2432 			pfnoff = pfn - base;
2433 			if (pfnoff + mlw.mpleft < CBUF_MAPNP) {
2434 				hibitnum = bitnum + mlw.mpleft;
2435 				cp->size = ptob(pfnoff + mlw.mpleft);
2436 			} else {
2437 				hibitnum = bitnum - pfnoff + CBUF_MAPNP -
2438 				    baseoff;
2439 				cp->size = CBUF_MAPSIZE - ptob(baseoff);
2440 			}
2441 
2442 			cp->pfn = pfn;
2443 			cp->bitnum = bitnum++;
2444 			cp->pagenum = pagenum++;
2445 			cp->off = ptob(pfnoff);
2446 
2447 			for (; bitnum < hibitnum; bitnum++)
2448 				if (BT_TEST(dumpcfg.bitmap, bitnum))
2449 					pagenum++;
2450 
2451 			dump_timeleft = dump_timeout;
2452 			cp->used = ptob(pagenum - cp->pagenum);
2453 
2454 			HRSTART(ds->perpage, map);
2455 			hat_devload(kas.a_hat, cp->buf, cp->size, base,
2456 			    PROT_READ, HAT_LOAD_NOCONSIST);
2457 			HRSTOP(ds->perpage, map);
2458 
2459 			ds->pages_mapped += btop(cp->size);
2460 			ds->pages_used += pagenum - cp->pagenum;
2461 
2462 			CQ_OPEN(mainq);
2463 
2464 			/*
2465 			 * If there are no helpers the main task does
2466 			 * non-streams lzjb compress.
2467 			 */
2468 			if (dumpserial) {
2469 				dumpsys_lzjb_page(dumpcfg.helper, cp);
2470 				break;
2471 			}
2472 
2473 			/* pass mapped pages to a helper */
2474 			CQ_PUT(helperq, cp, CBUF_INREADY);
2475 
2476 			/* the last page was done */
2477 			if (bitnum >= dumpcfg.bitmapsize)
2478 				CQ_CLOSE(helperq);
2479 
2480 			break;
2481 
2482 		case CBUF_USEDMAP:
2483 
2484 			ds->npages += btop(cp->used);
2485 
2486 			HRSTART(ds->perpage, unmap);
2487 			hat_unload(kas.a_hat, cp->buf, cp->size, HAT_UNLOAD);
2488 			HRSTOP(ds->perpage, unmap);
2489 
2490 			if (bitnum < dumpcfg.bitmapsize)
2491 				CQ_PUT(mainq, cp, CBUF_FREEMAP);
2492 			CQ_CLOSE(mainq);
2493 
2494 			ASSERT(ds->npages <= dumphdr->dump_npages);
2495 			ds->percent = ds->npages * 100LL / dumphdr->dump_npages;
2496 			break;
2497 
2498 		case CBUF_WRITE:
2499 
2500 			CQ_PUT(writerq, cp, CBUF_WRITE);
2501 			break;
2502 
2503 		case CBUF_ERRMSG:
2504 
2505 			if (cp->used > 0) {
2506 				cp->buf[cp->size - 2] = '\n';
2507 				cp->buf[cp->size - 1] = '\0';
2508 				if (ds->neednl) {
2509 					uprintf("\n%s", cp->buf);
2510 					ds->neednl = 0;
2511 				} else {
2512 					uprintf("%s", cp->buf);
2513 				}
2514 				/* wait for console output */
2515 				drv_usecwait(200000);
2516 				dump_timeleft = dump_timeout;
2517 			}
2518 			CQ_PUT(freebufq, cp, CBUF_FREEBUF);
2519 			break;
2520 
2521 		default:
2522 			uprintf("dump: unexpected buffer state %d, "
2523 			    "buffer will be lost\n", cp->state);
2524 			break;
2525 
2526 		} /* end switch */
2527 	}
2528 }
2529 
2530 #ifdef	COLLECT_METRICS
2531 size_t
2532 dumpsys_metrics(dumpsync_t *ds, char *buf, size_t size)
2533 {
2534 	dumpcfg_t *cfg = &dumpcfg;
2535 	int myid = CPU->cpu_seqid;
2536 	int i, compress_ratio;
2537 	int sec, iorate;
2538 	helper_t *hp, *hpend = &cfg->helper[cfg->nhelper];
2539 	char *e = buf + size;
2540 	char *p = buf;
2541 
2542 	sec = ds->elapsed / (1000 * 1000 * 1000ULL);
2543 	if (sec < 1)
2544 		sec = 1;
2545 
2546 	if (ds->iotime < 1)
2547 		ds->iotime = 1;
2548 	iorate = (ds->nwrite * 100000ULL) / ds->iotime;
2549 
2550 	compress_ratio = 100LL * ds->npages / btopr(ds->nwrite + 1);
2551 
2552 #define	P(...) (p += p < e ? snprintf(p, e - p, __VA_ARGS__) : 0)
2553 
2554 	P("Master cpu_seqid,%d\n", CPU->cpu_seqid);
2555 	P("Master cpu_id,%d\n", CPU->cpu_id);
2556 	P("dump_flags,0x%x\n", dumphdr->dump_flags);
2557 	P("dump_ioerr,%d\n", dump_ioerr);
2558 
2559 	P("Helpers:\n");
2560 	for (i = 0; i < ncpus; i++) {
2561 		if ((i & 15) == 0)
2562 			P(",,%03d,", i);
2563 		if (i == myid)
2564 			P("   M");
2565 		else if (BT_TEST(cfg->helpermap, i))
2566 			P("%4d", cpu_seq[i]->cpu_id);
2567 		else
2568 			P("   *");
2569 		if ((i & 15) == 15)
2570 			P("\n");
2571 	}
2572 
2573 	P("ncbuf_used,%d\n", cfg->ncbuf_used);
2574 	P("ncmap,%d\n", cfg->ncmap);
2575 
2576 	P("Found %ldM ranges,%ld\n", (CBUF_MAPSIZE / DUMP_1MB), cfg->found4m);
2577 	P("Found small pages,%ld\n", cfg->foundsm);
2578 
2579 	P("Compression level,%d\n", cfg->clevel);
2580 	P("Compression type,%s %s\n", cfg->clevel == 0 ? "serial" : "parallel",
2581 	    cfg->clevel >= DUMP_CLEVEL_BZIP2 ? "bzip2" : "lzjb");
2582 	P("Compression ratio,%d.%02d\n", compress_ratio / 100, compress_ratio %
2583 	    100);
2584 	P("nhelper_used,%d\n", cfg->nhelper_used);
2585 
2586 	P("Dump I/O rate MBS,%d.%02d\n", iorate / 100, iorate % 100);
2587 	P("..total bytes,%lld\n", (u_longlong_t)ds->nwrite);
2588 	P("..total nsec,%lld\n", (u_longlong_t)ds->iotime);
2589 	P("dumpbuf.iosize,%ld\n", dumpbuf.iosize);
2590 	P("dumpbuf.size,%ld\n", dumpbuf.size);
2591 
2592 	P("Dump pages/sec,%llu\n", (u_longlong_t)ds->npages / sec);
2593 	P("Dump pages,%llu\n", (u_longlong_t)ds->npages);
2594 	P("Dump time,%d\n", sec);
2595 
2596 	if (ds->pages_mapped > 0)
2597 		P("per-cent map utilization,%d\n", (int)((100 * ds->pages_used)
2598 		    / ds->pages_mapped));
2599 
2600 	P("\nPer-page metrics:\n");
2601 	if (ds->npages > 0) {
2602 		for (hp = cfg->helper; hp != hpend; hp++) {
2603 #define	PERPAGE(x)	ds->perpage.x += hp->perpage.x;
2604 			PERPAGES;
2605 #undef PERPAGE
2606 		}
2607 #define	PERPAGE(x) \
2608 		P("%s nsec/page,%d\n", #x, (int)(ds->perpage.x / ds->npages));
2609 		PERPAGES;
2610 #undef PERPAGE
2611 		P("freebufq.empty,%d\n", (int)(ds->freebufq.empty /
2612 		    ds->npages));
2613 		P("helperq.empty,%d\n", (int)(ds->helperq.empty /
2614 		    ds->npages));
2615 		P("writerq.empty,%d\n", (int)(ds->writerq.empty /
2616 		    ds->npages));
2617 		P("mainq.empty,%d\n", (int)(ds->mainq.empty / ds->npages));
2618 
2619 		P("I/O wait nsec/page,%llu\n", (u_longlong_t)(ds->iowait /
2620 		    ds->npages));
2621 	}
2622 #undef P
2623 	if (p < e)
2624 		bzero(p, e - p);
2625 	return (p - buf);
2626 }
2627 #endif	/* COLLECT_METRICS */
2628 
2629 /*
2630  * Dump the system.
2631  */
2632 void
2633 dumpsys(void)
2634 {
2635 	dumpsync_t *ds = &dumpsync;
2636 	taskq_t *livetaskq = NULL;
2637 	pfn_t pfn;
2638 	pgcnt_t bitnum;
2639 	proc_t *p;
2640 	helper_t *hp, *hpend = &dumpcfg.helper[dumpcfg.nhelper];
2641 	cbuf_t *cp;
2642 	pid_t npids, pidx;
2643 	char *content;
2644 	char *buf;
2645 	size_t size;
2646 	int save_dump_clevel;
2647 	dumpmlw_t mlw;
2648 	dumpcsize_t datatag;
2649 	dumpdatahdr_t datahdr;
2650 
2651 	if (dumpvp == NULL || dumphdr == NULL) {
2652 		uprintf("skipping system dump - no dump device configured\n");
2653 		if (panicstr) {
2654 			dumpcfg.helpers_wanted = 0;
2655 			dumpsys_spinunlock(&dumpcfg.helper_lock);
2656 		}
2657 		return;
2658 	}
2659 	dumpbuf.cur = dumpbuf.start;
2660 
2661 	/* clear the sync variables */
2662 	ASSERT(dumpcfg.nhelper > 0);
2663 	bzero(ds, sizeof (*ds));
2664 	ds->dumpcpu = CPU->cpu_id;
2665 
2666 	/*
2667 	 * Calculate the starting block for dump.  If we're dumping on a
2668 	 * swap device, start 1/5 of the way in; otherwise, start at the
2669 	 * beginning.  And never use the first page -- it may be a disk label.
2670 	 */
2671 	if (dumpvp->v_flag & VISSWAP)
2672 		dumphdr->dump_start = P2ROUNDUP(dumpvp_size / 5, DUMP_OFFSET);
2673 	else
2674 		dumphdr->dump_start = DUMP_OFFSET;
2675 
2676 	dumphdr->dump_flags = DF_VALID | DF_COMPLETE | DF_LIVE | DF_COMPRESSED;
2677 	dumphdr->dump_crashtime = gethrestime_sec();
2678 	dumphdr->dump_npages = 0;
2679 	dumphdr->dump_nvtop = 0;
2680 	bzero(dumpcfg.bitmap, BT_SIZEOFMAP(dumpcfg.bitmapsize));
2681 	dump_timeleft = dump_timeout;
2682 
2683 	if (panicstr) {
2684 		dumphdr->dump_flags &= ~DF_LIVE;
2685 		(void) VOP_DUMPCTL(dumpvp, DUMP_FREE, NULL, NULL);
2686 		(void) VOP_DUMPCTL(dumpvp, DUMP_ALLOC, NULL, NULL);
2687 		(void) vsnprintf(dumphdr->dump_panicstring, DUMP_PANICSIZE,
2688 		    panicstr, panicargs);
2689 
2690 	}
2691 
2692 	if (dump_conflags & DUMP_ALL)
2693 		content = "all";
2694 	else if (dump_conflags & DUMP_CURPROC)
2695 		content = "kernel + curproc";
2696 	else
2697 		content = "kernel";
2698 	uprintf("dumping to %s, offset %lld, content: %s\n", dumppath,
2699 	    dumphdr->dump_start, content);
2700 
2701 	/* Make sure nodename is current */
2702 	bcopy(utsname.nodename, dumphdr->dump_utsname.nodename, SYS_NMLN);
2703 
2704 	/*
2705 	 * If this is a live dump, try to open a VCHR vnode for better
2706 	 * performance. We must take care to flush the buffer cache
2707 	 * first.
2708 	 */
2709 	if (!panicstr) {
2710 		vnode_t *cdev_vp, *cmn_cdev_vp;
2711 
2712 		ASSERT(dumpbuf.cdev_vp == NULL);
2713 		cdev_vp = makespecvp(VTOS(dumpvp)->s_dev, VCHR);
2714 		if (cdev_vp != NULL) {
2715 			cmn_cdev_vp = common_specvp(cdev_vp);
2716 			if (VOP_OPEN(&cmn_cdev_vp, FREAD | FWRITE, kcred, NULL)
2717 			    == 0) {
2718 				if (vn_has_cached_data(dumpvp))
2719 					(void) pvn_vplist_dirty(dumpvp, 0, NULL,
2720 					    B_INVAL | B_TRUNC, kcred);
2721 				dumpbuf.cdev_vp = cmn_cdev_vp;
2722 			} else {
2723 				VN_RELE(cdev_vp);
2724 			}
2725 		}
2726 	}
2727 
2728 	/*
2729 	 * Store a hires timestamp so we can look it up during debugging.
2730 	 */
2731 	lbolt_debug_entry();
2732 
2733 	/*
2734 	 * Leave room for the message and ereport save areas and terminal dump
2735 	 * header.
2736 	 */
2737 	dumpbuf.vp_limit = dumpvp_size - DUMP_LOGSIZE - DUMP_OFFSET -
2738 	    DUMP_ERPTSIZE;
2739 
2740 	/*
2741 	 * Write out the symbol table.  It's no longer compressed,
2742 	 * so its 'size' and 'csize' are equal.
2743 	 */
2744 	dumpbuf.vp_off = dumphdr->dump_ksyms = dumphdr->dump_start + PAGESIZE;
2745 	dumphdr->dump_ksyms_size = dumphdr->dump_ksyms_csize =
2746 	    ksyms_snapshot(dumpvp_ksyms_write, NULL, LONG_MAX);
2747 
2748 	/*
2749 	 * Write out the translation map.
2750 	 */
2751 	dumphdr->dump_map = dumpvp_flush();
2752 	dump_as(&kas);
2753 	dumphdr->dump_nvtop += dump_plat_addr();
2754 
2755 	/*
2756 	 * call into hat, which may have unmapped pages that also need to
2757 	 * be in the dump
2758 	 */
2759 	hat_dump();
2760 
2761 	if (dump_conflags & DUMP_ALL) {
2762 		mutex_enter(&pidlock);
2763 
2764 		for (npids = 0, p = practive; p != NULL; p = p->p_next)
2765 			dumpcfg.pids[npids++] = p->p_pid;
2766 
2767 		mutex_exit(&pidlock);
2768 
2769 		for (pidx = 0; pidx < npids; pidx++)
2770 			(void) dump_process(dumpcfg.pids[pidx]);
2771 
2772 		dump_init_memlist_walker(&mlw);
2773 		for (bitnum = 0; bitnum < dumpcfg.bitmapsize; bitnum++) {
2774 			dump_timeleft = dump_timeout;
2775 			pfn = dump_bitnum_to_pfn(bitnum, &mlw);
2776 			/*
2777 			 * Some hypervisors do not have all pages available to
2778 			 * be accessed by the guest OS.  Check for page
2779 			 * accessibility.
2780 			 */
2781 			if (plat_hold_page(pfn, PLAT_HOLD_NO_LOCK, NULL) !=
2782 			    PLAT_HOLD_OK)
2783 				continue;
2784 			BT_SET(dumpcfg.bitmap, bitnum);
2785 		}
2786 		dumphdr->dump_npages = dumpcfg.bitmapsize;
2787 		dumphdr->dump_flags |= DF_ALL;
2788 
2789 	} else if (dump_conflags & DUMP_CURPROC) {
2790 		/*
2791 		 * Determine which pid is to be dumped.  If we're panicking, we
2792 		 * dump the process associated with panic_thread (if any).  If
2793 		 * this is a live dump, we dump the process associated with
2794 		 * curthread.
2795 		 */
2796 		npids = 0;
2797 		if (panicstr) {
2798 			if (panic_thread != NULL &&
2799 			    panic_thread->t_procp != NULL &&
2800 			    panic_thread->t_procp != &p0) {
2801 				dumpcfg.pids[npids++] =
2802 				    panic_thread->t_procp->p_pid;
2803 			}
2804 		} else {
2805 			dumpcfg.pids[npids++] = curthread->t_procp->p_pid;
2806 		}
2807 
2808 		if (npids && dump_process(dumpcfg.pids[0]) == 0)
2809 			dumphdr->dump_flags |= DF_CURPROC;
2810 		else
2811 			dumphdr->dump_flags |= DF_KERNEL;
2812 
2813 	} else {
2814 		dumphdr->dump_flags |= DF_KERNEL;
2815 	}
2816 
2817 	dumphdr->dump_hashmask = (1 << highbit(dumphdr->dump_nvtop - 1)) - 1;
2818 
2819 	/*
2820 	 * Write out the pfn table.
2821 	 */
2822 	dumphdr->dump_pfn = dumpvp_flush();
2823 	dump_init_memlist_walker(&mlw);
2824 	for (bitnum = 0; bitnum < dumpcfg.bitmapsize; bitnum++) {
2825 		dump_timeleft = dump_timeout;
2826 		if (!BT_TEST(dumpcfg.bitmap, bitnum))
2827 			continue;
2828 		pfn = dump_bitnum_to_pfn(bitnum, &mlw);
2829 		ASSERT(pfn != PFN_INVALID);
2830 		dumpvp_write(&pfn, sizeof (pfn_t));
2831 	}
2832 	dump_plat_pfn();
2833 
2834 	/*
2835 	 * Write out all the pages.
2836 	 * Map pages, copy them handling UEs, compress, and write them out.
2837 	 * Cooperate with any helpers running on CPUs in panic_idle().
2838 	 */
2839 	dumphdr->dump_data = dumpvp_flush();
2840 
2841 	bzero(dumpcfg.helpermap, BT_SIZEOFMAP(NCPU));
2842 	ds->live = dumpcfg.clevel > 0 &&
2843 	    (dumphdr->dump_flags & DF_LIVE) != 0;
2844 
2845 	save_dump_clevel = dumpcfg.clevel;
2846 	if (panicstr)
2847 		dumpsys_get_maxmem();
2848 	else if (dumpcfg.clevel >= DUMP_CLEVEL_BZIP2)
2849 		dumpcfg.clevel = DUMP_CLEVEL_LZJB;
2850 
2851 	dumpcfg.nhelper_used = 0;
2852 	for (hp = dumpcfg.helper; hp != hpend; hp++) {
2853 		if (hp->page == NULL) {
2854 			hp->helper = DONEHELPER;
2855 			continue;
2856 		}
2857 		++dumpcfg.nhelper_used;
2858 		hp->helper = FREEHELPER;
2859 		hp->taskqid = NULL;
2860 		hp->ds = ds;
2861 		bzero(&hp->perpage, sizeof (hp->perpage));
2862 		if (dumpcfg.clevel >= DUMP_CLEVEL_BZIP2)
2863 			(void) BZ2_bzCompressReset(&hp->bzstream);
2864 	}
2865 
2866 	CQ_OPEN(freebufq);
2867 	CQ_OPEN(helperq);
2868 
2869 	dumpcfg.ncbuf_used = 0;
2870 	for (cp = dumpcfg.cbuf; cp != &dumpcfg.cbuf[dumpcfg.ncbuf]; cp++) {
2871 		if (cp->buf != NULL) {
2872 			CQ_PUT(freebufq, cp, CBUF_FREEBUF);
2873 			++dumpcfg.ncbuf_used;
2874 		}
2875 	}
2876 
2877 	for (cp = dumpcfg.cmap; cp != &dumpcfg.cmap[dumpcfg.ncmap]; cp++)
2878 		CQ_PUT(mainq, cp, CBUF_FREEMAP);
2879 
2880 	ds->start = gethrtime();
2881 	ds->iowaitts = ds->start;
2882 
2883 	/* start helpers */
2884 	if (ds->live) {
2885 		int n = dumpcfg.nhelper_used;
2886 		int pri = MINCLSYSPRI - 25;
2887 
2888 		livetaskq = taskq_create("LiveDump", n, pri, n, n,
2889 		    TASKQ_PREPOPULATE);
2890 		for (hp = dumpcfg.helper; hp != hpend; hp++) {
2891 			if (hp->page == NULL)
2892 				continue;
2893 			hp->helper = hp - dumpcfg.helper;
2894 			hp->taskqid = taskq_dispatch(livetaskq,
2895 			    dumpsys_live_helper, (void *)hp, TQ_NOSLEEP);
2896 		}
2897 
2898 	} else {
2899 		if (panicstr)
2900 			kmem_dump_begin();
2901 		dumpcfg.helpers_wanted = dumpcfg.clevel > 0;
2902 		dumpsys_spinunlock(&dumpcfg.helper_lock);
2903 	}
2904 
2905 	/* run main task */
2906 	dumpsys_main_task(ds);
2907 
2908 	ds->elapsed = gethrtime() - ds->start;
2909 	if (ds->elapsed < 1)
2910 		ds->elapsed = 1;
2911 
2912 	if (livetaskq != NULL)
2913 		taskq_destroy(livetaskq);
2914 
2915 	if (ds->neednl) {
2916 		uprintf("\n");
2917 		ds->neednl = 0;
2918 	}
2919 
2920 	/* record actual pages dumped */
2921 	dumphdr->dump_npages = ds->npages;
2922 
2923 	/* platform-specific data */
2924 	dumphdr->dump_npages += dump_plat_data(dumpcfg.cbuf[0].buf);
2925 
2926 	/* note any errors by clearing DF_COMPLETE */
2927 	if (dump_ioerr || ds->npages < dumphdr->dump_npages)
2928 		dumphdr->dump_flags &= ~DF_COMPLETE;
2929 
2930 	/* end of stream blocks */
2931 	datatag = 0;
2932 	dumpvp_write(&datatag, sizeof (datatag));
2933 
2934 	bzero(&datahdr, sizeof (datahdr));
2935 
2936 	/* buffer for metrics */
2937 	buf = dumpcfg.cbuf[0].buf;
2938 	size = MIN(dumpcfg.cbuf[0].size, DUMP_OFFSET - sizeof (dumphdr_t) -
2939 	    sizeof (dumpdatahdr_t));
2940 
2941 	/* finish the kmem intercepts, collect kmem verbose info */
2942 	if (panicstr) {
2943 		datahdr.dump_metrics = kmem_dump_finish(buf, size);
2944 		buf += datahdr.dump_metrics;
2945 		size -= datahdr.dump_metrics;
2946 	}
2947 
2948 	/* record in the header whether this is a fault-management panic */
2949 	if (panicstr)
2950 		dumphdr->dump_fm_panic = is_fm_panic();
2951 
2952 	/* compression info in data header */
2953 	datahdr.dump_datahdr_magic = DUMP_DATAHDR_MAGIC;
2954 	datahdr.dump_datahdr_version = DUMP_DATAHDR_VERSION;
2955 	datahdr.dump_maxcsize = CBUF_SIZE;
2956 	datahdr.dump_maxrange = CBUF_MAPSIZE / PAGESIZE;
2957 	datahdr.dump_nstreams = dumpcfg.nhelper_used;
2958 	datahdr.dump_clevel = dumpcfg.clevel;
2959 #ifdef COLLECT_METRICS
2960 	if (dump_metrics_on)
2961 		datahdr.dump_metrics += dumpsys_metrics(ds, buf, size);
2962 #endif
2963 	datahdr.dump_data_csize = dumpvp_flush() - dumphdr->dump_data;
2964 
2965 	/*
2966 	 * Write out the initial and terminal dump headers.
2967 	 */
2968 	dumpbuf.vp_off = dumphdr->dump_start;
2969 	dumpvp_write(dumphdr, sizeof (dumphdr_t));
2970 	(void) dumpvp_flush();
2971 
2972 	dumpbuf.vp_limit = dumpvp_size;
2973 	dumpbuf.vp_off = dumpbuf.vp_limit - DUMP_OFFSET;
2974 	dumpvp_write(dumphdr, sizeof (dumphdr_t));
2975 	dumpvp_write(&datahdr, sizeof (dumpdatahdr_t));
2976 	dumpvp_write(dumpcfg.cbuf[0].buf, datahdr.dump_metrics);
2977 
2978 	(void) dumpvp_flush();
2979 
2980 	uprintf("\r%3d%% done: %llu pages dumped, ",
2981 	    ds->percent_done, (u_longlong_t)ds->npages);
2982 
2983 	if (dump_ioerr == 0) {
2984 		uprintf("dump succeeded\n");
2985 	} else {
2986 		uprintf("dump failed: error %d\n", dump_ioerr);
2987 #ifdef DEBUG
2988 		if (panicstr)
2989 			debug_enter("dump failed");
2990 #endif
2991 	}
2992 
2993 	/*
2994 	 * Write out all undelivered messages.  This has to be the *last*
2995 	 * thing we do because the dump process itself emits messages.
2996 	 */
2997 	if (panicstr) {
2998 		dump_summary();
2999 		dump_ereports();
3000 		dump_messages();
3001 	}
3002 
3003 	delay(2 * hz);	/* let people see the 'done' message */
3004 	dump_timeleft = 0;
3005 	dump_ioerr = 0;
3006 
3007 	/* restore settings after live dump completes */
3008 	if (!panicstr) {
3009 		dumpcfg.clevel = save_dump_clevel;
3010 
3011 		/* release any VCHR open of the dump device */
3012 		if (dumpbuf.cdev_vp != NULL) {
3013 			(void) VOP_CLOSE(dumpbuf.cdev_vp, FREAD | FWRITE, 1, 0,
3014 			    kcred, NULL);
3015 			VN_RELE(dumpbuf.cdev_vp);
3016 			dumpbuf.cdev_vp = NULL;
3017 		}
3018 	}
3019 }
3020 
3021 /*
3022  * This function is called whenever the memory size, as represented
3023  * by the phys_install list, changes.
3024  */
3025 void
3026 dump_resize()
3027 {
3028 	mutex_enter(&dump_lock);
3029 	dumphdr_init();
3030 	dumpbuf_resize();
3031 	dump_update_clevel();
3032 	mutex_exit(&dump_lock);
3033 }
3034 
3035 /*
3036  * This function allows for dynamic resizing of a dump area. It assumes that
3037  * the underlying device has update its appropriate size(9P).
3038  */
3039 int
3040 dumpvp_resize()
3041 {
3042 	int error;
3043 	vattr_t vattr;
3044 
3045 	mutex_enter(&dump_lock);
3046 	vattr.va_mask = AT_SIZE;
3047 	if ((error = VOP_GETATTR(dumpvp, &vattr, 0, kcred, NULL)) != 0) {
3048 		mutex_exit(&dump_lock);
3049 		return (error);
3050 	}
3051 
3052 	if (error == 0 && vattr.va_size < 2 * DUMP_LOGSIZE + DUMP_ERPTSIZE) {
3053 		mutex_exit(&dump_lock);
3054 		return (ENOSPC);
3055 	}
3056 
3057 	dumpvp_size = vattr.va_size & -DUMP_OFFSET;
3058 	mutex_exit(&dump_lock);
3059 	return (0);
3060 }
3061 
3062 int
3063 dump_set_uuid(const char *uuidstr)
3064 {
3065 	const char *ptr;
3066 	int i;
3067 
3068 	if (uuidstr == NULL || strnlen(uuidstr, 36 + 1) != 36)
3069 		return (EINVAL);
3070 
3071 	/* uuid_parse is not common code so check manually */
3072 	for (i = 0, ptr = uuidstr; i < 36; i++, ptr++) {
3073 		switch (i) {
3074 		case 8:
3075 		case 13:
3076 		case 18:
3077 		case 23:
3078 			if (*ptr != '-')
3079 				return (EINVAL);
3080 			break;
3081 
3082 		default:
3083 			if (!isxdigit(*ptr))
3084 				return (EINVAL);
3085 			break;
3086 		}
3087 	}
3088 
3089 	if (dump_osimage_uuid[0] != '\0')
3090 		return (EALREADY);
3091 
3092 	(void) strncpy(dump_osimage_uuid, uuidstr, 36 + 1);
3093 
3094 	cmn_err(CE_CONT, "?This Solaris instance has UUID %s\n",
3095 	    dump_osimage_uuid);
3096 
3097 	return (0);
3098 }
3099 
3100 const char *
3101 dump_get_uuid(void)
3102 {
3103 	return (dump_osimage_uuid[0] != '\0' ? dump_osimage_uuid : "");
3104 }
3105