xref: /illumos-gate/usr/src/uts/common/os/dumpsubr.c (revision e77c795bcbe51aebd7579fe13cbf2a6d56eca47f)
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  */
25 
26 #include <sys/types.h>
27 #include <sys/param.h>
28 #include <sys/systm.h>
29 #include <sys/vm.h>
30 #include <sys/proc.h>
31 #include <sys/file.h>
32 #include <sys/conf.h>
33 #include <sys/kmem.h>
34 #include <sys/mem.h>
35 #include <sys/mman.h>
36 #include <sys/vnode.h>
37 #include <sys/errno.h>
38 #include <sys/memlist.h>
39 #include <sys/dumphdr.h>
40 #include <sys/dumpadm.h>
41 #include <sys/ksyms.h>
42 #include <sys/compress.h>
43 #include <sys/stream.h>
44 #include <sys/strsun.h>
45 #include <sys/cmn_err.h>
46 #include <sys/bitmap.h>
47 #include <sys/modctl.h>
48 #include <sys/utsname.h>
49 #include <sys/systeminfo.h>
50 #include <sys/vmem.h>
51 #include <sys/log.h>
52 #include <sys/var.h>
53 #include <sys/debug.h>
54 #include <sys/sunddi.h>
55 #include <fs/fs_subr.h>
56 #include <sys/fs/snode.h>
57 #include <sys/ontrap.h>
58 #include <sys/panic.h>
59 #include <sys/dkio.h>
60 #include <sys/vtoc.h>
61 #include <sys/errorq.h>
62 #include <sys/fm/util.h>
63 #include <sys/fs/zfs.h>
64 
65 #include <vm/hat.h>
66 #include <vm/as.h>
67 #include <vm/page.h>
68 #include <vm/pvn.h>
69 #include <vm/seg.h>
70 #include <vm/seg_kmem.h>
71 #include <sys/clock_impl.h>
72 #include <sys/hold_page.h>
73 
74 #include <bzip2/bzlib.h>
75 
76 /*
77  * Crash dump time is dominated by disk write time.  To reduce this,
78  * the stronger compression method bzip2 is applied to reduce the dump
79  * size and hence reduce I/O time.  However, bzip2 is much more
80  * computationally expensive than the existing lzjb algorithm, so to
81  * avoid increasing compression time, CPUs that are otherwise idle
82  * during panic are employed to parallelize the compression task.
83  * Many helper CPUs are needed to prevent bzip2 from being a
84  * bottleneck, and on systems with too few CPUs, the lzjb algorithm is
85  * parallelized instead. Lastly, I/O and compression are performed by
86  * different CPUs, and are hence overlapped in time, unlike the older
87  * serial code.
88  *
89  * Another important consideration is the speed of the dump
90  * device. Faster disks need less CPUs in order to benefit from
91  * parallel lzjb versus parallel bzip2. Therefore, the CPU count
92  * threshold for switching from parallel lzjb to paralled bzip2 is
93  * elevated for faster disks. The dump device speed is adduced from
94  * the setting for dumpbuf.iosize, see dump_update_clevel.
95  */
96 
97 /*
98  * exported vars
99  */
100 kmutex_t	dump_lock;		/* lock for dump configuration */
101 dumphdr_t	*dumphdr;		/* dump header */
102 int		dump_conflags = DUMP_KERNEL; /* dump configuration flags */
103 vnode_t		*dumpvp;		/* dump device vnode pointer */
104 u_offset_t	dumpvp_size;		/* size of dump device, in bytes */
105 char		*dumppath;		/* pathname of dump device */
106 int		dump_timeout = 120;	/* timeout for dumping pages */
107 int		dump_timeleft;		/* portion of dump_timeout remaining */
108 int		dump_ioerr;		/* dump i/o error */
109 int		dump_check_used;	/* enable check for used pages */
110 char	    *dump_stack_scratch; /* scratch area for saving stack summary */
111 
112 /*
113  * Tunables for dump compression and parallelism. These can be set via
114  * /etc/system.
115  *
116  * dump_ncpu_low	number of helpers for parallel lzjb
117  *	This is also the minimum configuration.
118  *
119  * dump_bzip2_level	bzip2 compression level: 1-9
120  *	Higher numbers give greater compression, but take more memory
121  *	and time. Memory used per helper is ~(dump_bzip2_level * 1MB).
122  *
123  * dump_plat_mincpu	the cross-over limit for using bzip2 (per platform):
124  *	if dump_plat_mincpu == 0, then always do single threaded dump
125  *	if ncpu >= dump_plat_mincpu then try to use bzip2
126  *
127  * dump_metrics_on	if set, metrics are collected in the kernel, passed
128  *	to savecore via the dump file, and recorded by savecore in
129  *	METRICS.txt.
130  */
131 uint_t dump_ncpu_low = 4;	/* minimum config for parallel lzjb */
132 uint_t dump_bzip2_level = 1;	/* bzip2 level (1-9) */
133 
134 /* Use dump_plat_mincpu_default unless this variable is set by /etc/system */
135 #define	MINCPU_NOT_SET	((uint_t)-1)
136 uint_t dump_plat_mincpu = MINCPU_NOT_SET;
137 
138 /* tunables for pre-reserved heap */
139 uint_t dump_kmem_permap = 1024;
140 uint_t dump_kmem_pages = 8;
141 
142 /* Define multiple buffers per helper to avoid stalling */
143 #define	NCBUF_PER_HELPER	2
144 #define	NCMAP_PER_HELPER	4
145 
146 /* minimum number of helpers configured */
147 #define	MINHELPERS	(dump_ncpu_low)
148 #define	MINCBUFS	(MINHELPERS * NCBUF_PER_HELPER)
149 
150 /*
151  * Define constant parameters.
152  *
153  * CBUF_SIZE		size of an output buffer
154  *
155  * CBUF_MAPSIZE		size of virtual range for mapping pages
156  *
157  * CBUF_MAPNP		size of virtual range in pages
158  *
159  */
160 #define	DUMP_1KB	((size_t)1 << 10)
161 #define	DUMP_1MB	((size_t)1 << 20)
162 #define	CBUF_SIZE	((size_t)1 << 17)
163 #define	CBUF_MAPSHIFT	(22)
164 #define	CBUF_MAPSIZE	((size_t)1 << CBUF_MAPSHIFT)
165 #define	CBUF_MAPNP	((size_t)1 << (CBUF_MAPSHIFT - PAGESHIFT))
166 
167 /*
168  * Compression metrics are accumulated nano-second subtotals. The
169  * results are normalized by the number of pages dumped. A report is
170  * generated when dumpsys() completes and is saved in the dump image
171  * after the trailing dump header.
172  *
173  * Metrics are always collected. Set the variable dump_metrics_on to
174  * cause metrics to be saved in the crash file, where savecore will
175  * save it in the file METRICS.txt.
176  */
177 #define	PERPAGES \
178 	PERPAGE(bitmap) PERPAGE(map) PERPAGE(unmap) \
179 	PERPAGE(copy) PERPAGE(compress) \
180 	PERPAGE(write) \
181 	PERPAGE(inwait) PERPAGE(outwait)
182 
183 typedef struct perpage {
184 #define	PERPAGE(x) hrtime_t x;
185 	PERPAGES
186 #undef PERPAGE
187 } perpage_t;
188 
189 /*
190  * This macro controls the code generation for collecting dump
191  * performance information. By default, the code is generated, but
192  * automatic saving of the information is disabled. If dump_metrics_on
193  * is set to 1, the timing information is passed to savecore via the
194  * crash file, where it is appended to the file dump-dir/METRICS.txt.
195  */
196 #define	COLLECT_METRICS
197 
198 #ifdef COLLECT_METRICS
199 uint_t dump_metrics_on = 0;	/* set to 1 to enable recording metrics */
200 
201 #define	HRSTART(v, m)		v##ts.m = gethrtime()
202 #define	HRSTOP(v, m)		v.m += gethrtime() - v##ts.m
203 #define	HRBEGIN(v, m, s)	v##ts.m = gethrtime(); v.size += s
204 #define	HREND(v, m)		v.m += gethrtime() - v##ts.m
205 #define	HRNORM(v, m, n)		v.m /= (n)
206 
207 #else
208 #define	HRSTART(v, m)
209 #define	HRSTOP(v, m)
210 #define	HRBEGIN(v, m, s)
211 #define	HREND(v, m)
212 #define	HRNORM(v, m, n)
213 #endif	/* COLLECT_METRICS */
214 
215 /*
216  * Buffers for copying and compressing memory pages.
217  *
218  * cbuf_t buffer controllers: used for both input and output.
219  *
220  * The buffer state indicates how it is being used:
221  *
222  * CBUF_FREEMAP: CBUF_MAPSIZE virtual address range is available for
223  * mapping input pages.
224  *
225  * CBUF_INREADY: input pages are mapped and ready for compression by a
226  * helper.
227  *
228  * CBUF_USEDMAP: mapping has been consumed by a helper. Needs unmap.
229  *
230  * CBUF_FREEBUF: CBUF_SIZE output buffer, which is available.
231  *
232  * CBUF_WRITE: CBUF_SIZE block of compressed pages from a helper,
233  * ready to write out.
234  *
235  * CBUF_ERRMSG: CBUF_SIZE block of error messages from a helper
236  * (reports UE errors.)
237  */
238 
239 typedef enum cbufstate {
240 	CBUF_FREEMAP,
241 	CBUF_INREADY,
242 	CBUF_USEDMAP,
243 	CBUF_FREEBUF,
244 	CBUF_WRITE,
245 	CBUF_ERRMSG
246 } cbufstate_t;
247 
248 typedef struct cbuf cbuf_t;
249 
250 struct cbuf {
251 	cbuf_t *next;			/* next in list */
252 	cbufstate_t state;		/* processing state */
253 	size_t used;			/* amount used */
254 	size_t size;			/* mem size */
255 	char *buf;			/* kmem or vmem */
256 	pgcnt_t pagenum;		/* index to pfn map */
257 	pgcnt_t bitnum;			/* first set bitnum */
258 	pfn_t pfn;			/* first pfn in mapped range */
259 	int off;			/* byte offset to first pfn */
260 };
261 
262 static char dump_osimage_uuid[36 + 1];
263 
264 #define	isdigit(ch)	((ch) >= '0' && (ch) <= '9')
265 #define	isxdigit(ch)	(isdigit(ch) || ((ch) >= 'a' && (ch) <= 'f') || \
266 			((ch) >= 'A' && (ch) <= 'F'))
267 
268 /*
269  * cqueue_t queues: a uni-directional channel for communication
270  * from the master to helper tasks or vice-versa using put and
271  * get primitives. Both mappings and data buffers are passed via
272  * queues. Producers close a queue when done. The number of
273  * active producers is reference counted so the consumer can
274  * detect end of data. Concurrent access is mediated by atomic
275  * operations for panic dump, or mutex/cv for live dump.
276  *
277  * There a four queues, used as follows:
278  *
279  * Queue		Dataflow		NewState
280  * --------------------------------------------------
281  * mainq		master -> master	FREEMAP
282  * master has initialized or unmapped an input buffer
283  * --------------------------------------------------
284  * helperq		master -> helper	INREADY
285  * master has mapped input for use by helper
286  * --------------------------------------------------
287  * mainq		master <- helper	USEDMAP
288  * helper is done with input
289  * --------------------------------------------------
290  * freebufq		master -> helper	FREEBUF
291  * master has initialized or written an output buffer
292  * --------------------------------------------------
293  * mainq		master <- helper	WRITE
294  * block of compressed pages from a helper
295  * --------------------------------------------------
296  * mainq		master <- helper	ERRMSG
297  * error messages from a helper (memory error case)
298  * --------------------------------------------------
299  * writerq		master <- master	WRITE
300  * non-blocking queue of blocks to write
301  * --------------------------------------------------
302  */
303 typedef struct cqueue {
304 	cbuf_t *volatile first;		/* first in list */
305 	cbuf_t *last;			/* last in list */
306 	hrtime_t ts;			/* timestamp */
307 	hrtime_t empty;			/* total time empty */
308 	kmutex_t mutex;			/* live state lock */
309 	kcondvar_t cv;			/* live wait var */
310 	lock_t spinlock;		/* panic mode spin lock */
311 	volatile uint_t open;		/* producer ref count */
312 } cqueue_t;
313 
314 /*
315  * Convenience macros for using the cqueue functions
316  * Note that the caller must have defined "dumpsync_t *ds"
317  */
318 #define	CQ_IS_EMPTY(q)					\
319 	(ds->q.first == NULL)
320 
321 #define	CQ_OPEN(q)					\
322 	atomic_inc_uint(&ds->q.open)
323 
324 #define	CQ_CLOSE(q)					\
325 	dumpsys_close_cq(&ds->q, ds->live)
326 
327 #define	CQ_PUT(q, cp, st)				\
328 	dumpsys_put_cq(&ds->q, cp, st, ds->live)
329 
330 #define	CQ_GET(q)					\
331 	dumpsys_get_cq(&ds->q, ds->live)
332 
333 /*
334  * Dynamic state when dumpsys() is running.
335  */
336 typedef struct dumpsync {
337 	pgcnt_t npages;			/* subtotal of pages dumped */
338 	pgcnt_t pages_mapped;		/* subtotal of pages mapped */
339 	pgcnt_t pages_used;		/* subtotal of pages used per map */
340 	size_t nwrite;			/* subtotal of bytes written */
341 	uint_t live;			/* running live dump */
342 	uint_t neednl;			/* will need to print a newline */
343 	uint_t percent;			/* dump progress */
344 	uint_t percent_done;		/* dump progress reported */
345 	cqueue_t freebufq;		/* free kmem bufs for writing */
346 	cqueue_t mainq;			/* input for main task */
347 	cqueue_t helperq;		/* input for helpers */
348 	cqueue_t writerq;		/* input for writer */
349 	hrtime_t start;			/* start time */
350 	hrtime_t elapsed;		/* elapsed time when completed */
351 	hrtime_t iotime;		/* time spent writing nwrite bytes */
352 	hrtime_t iowait;		/* time spent waiting for output */
353 	hrtime_t iowaitts;		/* iowait timestamp */
354 	perpage_t perpage;		/* metrics */
355 	perpage_t perpagets;
356 	int dumpcpu;			/* master cpu */
357 } dumpsync_t;
358 
359 static dumpsync_t dumpsync;		/* synchronization vars */
360 
361 /*
362  * helper_t helpers: contains the context for a stream. CPUs run in
363  * parallel at dump time; each CPU creates a single stream of
364  * compression data.  Stream data is divided into CBUF_SIZE blocks.
365  * The blocks are written in order within a stream. But, blocks from
366  * multiple streams can be interleaved. Each stream is identified by a
367  * unique tag.
368  */
369 typedef struct helper {
370 	int helper;			/* bound helper id */
371 	int tag;			/* compression stream tag */
372 	perpage_t perpage;		/* per page metrics */
373 	perpage_t perpagets;		/* per page metrics (timestamps) */
374 	taskqid_t taskqid;		/* live dump task ptr */
375 	int in, out;			/* buffer offsets */
376 	cbuf_t *cpin, *cpout, *cperr;	/* cbuf objects in process */
377 	dumpsync_t *ds;			/* pointer to sync vars */
378 	size_t used;			/* counts input consumed */
379 	char *page;			/* buffer for page copy */
380 	char *lzbuf;			/* lzjb output */
381 	bz_stream bzstream;		/* bzip2 state */
382 } helper_t;
383 
384 #define	MAINHELPER	(-1)		/* helper is also the main task */
385 #define	FREEHELPER	(-2)		/* unbound helper */
386 #define	DONEHELPER	(-3)		/* helper finished */
387 
388 /*
389  * configuration vars for dumpsys
390  */
391 typedef struct dumpcfg {
392 	int	threshold;	/* ncpu threshold for bzip2 */
393 	int	nhelper;	/* number of helpers */
394 	int	nhelper_used;	/* actual number of helpers used */
395 	int	ncmap;		/* number VA pages for compression */
396 	int	ncbuf;		/* number of bufs for compression */
397 	int	ncbuf_used;	/* number of bufs in use */
398 	uint_t	clevel;		/* dump compression level */
399 	helper_t *helper;	/* array of helpers */
400 	cbuf_t	*cmap;		/* array of input (map) buffers */
401 	cbuf_t	*cbuf;		/* array of output  buffers */
402 	ulong_t	*helpermap;	/* set of dumpsys helper CPU ids */
403 	ulong_t	*bitmap;	/* bitmap for marking pages to dump */
404 	ulong_t	*rbitmap;	/* bitmap for used CBUF_MAPSIZE ranges */
405 	pgcnt_t	bitmapsize;	/* size of bitmap */
406 	pgcnt_t	rbitmapsize;	/* size of bitmap for ranges */
407 	pgcnt_t found4m;	/* number ranges allocated by dump */
408 	pgcnt_t foundsm;	/* number small pages allocated by dump */
409 	pid_t	*pids;		/* list of process IDs at dump time */
410 	size_t	maxsize;	/* memory size needed at dump time */
411 	size_t	maxvmsize;	/* size of reserved VM */
412 	char	*maxvm;		/* reserved VM for spare pages */
413 	lock_t	helper_lock;	/* protect helper state */
414 	char	helpers_wanted;	/* flag to enable parallelism */
415 	char	helper_present;	/* at least one helper showed up */
416 } dumpcfg_t;
417 
418 static dumpcfg_t dumpcfg;	/* config vars */
419 
420 /*
421  * The dump I/O buffer.
422  *
423  * There is one I/O buffer used by dumpvp_write and dumvp_flush. It is
424  * sized according to the optimum device transfer speed.
425  */
426 typedef struct dumpbuf {
427 	vnode_t	*cdev_vp;	/* VCHR open of the dump device */
428 	len_t	vp_limit;	/* maximum write offset */
429 	offset_t vp_off;	/* current dump device offset */
430 	char	*cur;		/* dump write pointer */
431 	char	*start;		/* dump buffer address */
432 	char	*end;		/* dump buffer end */
433 	size_t	size;		/* size of dumpbuf in bytes */
434 	size_t	iosize;		/* best transfer size for device */
435 } dumpbuf_t;
436 
437 dumpbuf_t dumpbuf;		/* I/O buffer */
438 
439 /*
440  * The dump I/O buffer must be at least one page, at most xfer_size
441  * bytes, and should scale with physmem in between.  The transfer size
442  * passed in will either represent a global default (maxphys) or the
443  * best size for the device.  The size of the dumpbuf I/O buffer is
444  * limited by dumpbuf_limit (8MB by default) because the dump
445  * performance saturates beyond a certain size.  The default is to
446  * select 1/4096 of the memory.
447  */
448 static int	dumpbuf_fraction = 12;	/* memory size scale factor */
449 static size_t	dumpbuf_limit = 8 * DUMP_1MB;	/* max I/O buf size */
450 
451 static size_t
452 dumpbuf_iosize(size_t xfer_size)
453 {
454 	size_t iosize = ptob(physmem >> dumpbuf_fraction);
455 
456 	if (iosize < PAGESIZE)
457 		iosize = PAGESIZE;
458 	else if (iosize > xfer_size)
459 		iosize = xfer_size;
460 	if (iosize > dumpbuf_limit)
461 		iosize = dumpbuf_limit;
462 	return (iosize & PAGEMASK);
463 }
464 
465 /*
466  * resize the I/O buffer
467  */
468 static void
469 dumpbuf_resize(void)
470 {
471 	char *old_buf = dumpbuf.start;
472 	size_t old_size = dumpbuf.size;
473 	char *new_buf;
474 	size_t new_size;
475 
476 	ASSERT(MUTEX_HELD(&dump_lock));
477 
478 	new_size = dumpbuf_iosize(MAX(dumpbuf.iosize, maxphys));
479 	if (new_size <= old_size)
480 		return; /* no need to reallocate buffer */
481 
482 	new_buf = kmem_alloc(new_size, KM_SLEEP);
483 	dumpbuf.size = new_size;
484 	dumpbuf.start = new_buf;
485 	dumpbuf.end = new_buf + new_size;
486 	kmem_free(old_buf, old_size);
487 }
488 
489 /*
490  * dump_update_clevel is called when dumpadm configures the dump device.
491  * 	Calculate number of helpers and buffers.
492  * 	Allocate the minimum configuration for now.
493  *
494  * When the dump file is configured we reserve a minimum amount of
495  * memory for use at crash time. But we reserve VA for all the memory
496  * we really want in order to do the fastest dump possible. The VA is
497  * backed by pages not being dumped, according to the bitmap. If
498  * there is insufficient spare memory, however, we fall back to the
499  * minimum.
500  *
501  * Live dump (savecore -L) always uses the minimum config.
502  *
503  * clevel 0 is single threaded lzjb
504  * clevel 1 is parallel lzjb
505  * clevel 2 is parallel bzip2
506  *
507  * The ncpu threshold is selected with dump_plat_mincpu.
508  * On OPL, set_platform_defaults() overrides the sun4u setting.
509  * The actual values are defined via DUMP_PLAT_*_MINCPU macros.
510  *
511  * Architecture		Threshold	Algorithm
512  * sun4u       		<  51		parallel lzjb
513  * sun4u       		>= 51		parallel bzip2(*)
514  * sun4u OPL   		<  8		parallel lzjb
515  * sun4u OPL   		>= 8		parallel bzip2(*)
516  * sun4v       		<  128		parallel lzjb
517  * sun4v       		>= 128		parallel bzip2(*)
518  * x86			< 11		parallel lzjb
519  * x86			>= 11		parallel bzip2(*)
520  * 32-bit      		N/A		single-threaded lzjb
521  *
522  * (*) bzip2 is only chosen if there is sufficient available
523  * memory for buffers at dump time. See dumpsys_get_maxmem().
524  *
525  * Faster dump devices have larger I/O buffers. The threshold value is
526  * increased according to the size of the dump I/O buffer, because
527  * parallel lzjb performs better with faster disks. For buffers >= 1MB
528  * the threshold is 3X; for buffers >= 256K threshold is 2X.
529  *
530  * For parallel dumps, the number of helpers is ncpu-1. The CPU
531  * running panic runs the main task. For single-threaded dumps, the
532  * panic CPU does lzjb compression (it is tagged as MAINHELPER.)
533  *
534  * Need multiple buffers per helper so that they do not block waiting
535  * for the main task.
536  *				parallel	single-threaded
537  * Number of output buffers:	nhelper*2		1
538  * Number of mapping buffers:	nhelper*4		1
539  *
540  */
541 static void
542 dump_update_clevel()
543 {
544 	int tag;
545 	size_t bz2size;
546 	helper_t *hp, *hpend;
547 	cbuf_t *cp, *cpend;
548 	dumpcfg_t *old = &dumpcfg;
549 	dumpcfg_t newcfg = *old;
550 	dumpcfg_t *new = &newcfg;
551 
552 	ASSERT(MUTEX_HELD(&dump_lock));
553 
554 	/*
555 	 * Free the previously allocated bufs and VM.
556 	 */
557 	if (old->helper != NULL) {
558 
559 		/* helpers */
560 		hpend = &old->helper[old->nhelper];
561 		for (hp = old->helper; hp != hpend; hp++) {
562 			if (hp->lzbuf != NULL)
563 				kmem_free(hp->lzbuf, PAGESIZE);
564 			if (hp->page != NULL)
565 				kmem_free(hp->page, PAGESIZE);
566 		}
567 		kmem_free(old->helper, old->nhelper * sizeof (helper_t));
568 
569 		/* VM space for mapping pages */
570 		cpend = &old->cmap[old->ncmap];
571 		for (cp = old->cmap; cp != cpend; cp++)
572 			vmem_xfree(heap_arena, cp->buf, CBUF_MAPSIZE);
573 		kmem_free(old->cmap, old->ncmap * sizeof (cbuf_t));
574 
575 		/* output bufs */
576 		cpend = &old->cbuf[old->ncbuf];
577 		for (cp = old->cbuf; cp != cpend; cp++)
578 			if (cp->buf != NULL)
579 				kmem_free(cp->buf, cp->size);
580 		kmem_free(old->cbuf, old->ncbuf * sizeof (cbuf_t));
581 
582 		/* reserved VM for dumpsys_get_maxmem */
583 		if (old->maxvmsize > 0)
584 			vmem_xfree(heap_arena, old->maxvm, old->maxvmsize);
585 	}
586 
587 	/*
588 	 * Allocate memory and VM.
589 	 * One CPU runs dumpsys, the rest are helpers.
590 	 */
591 	new->nhelper = ncpus - 1;
592 	if (new->nhelper < 1)
593 		new->nhelper = 1;
594 
595 	if (new->nhelper > DUMP_MAX_NHELPER)
596 		new->nhelper = DUMP_MAX_NHELPER;
597 
598 	/* use platform default, unless /etc/system overrides */
599 	if (dump_plat_mincpu == MINCPU_NOT_SET)
600 		dump_plat_mincpu = dump_plat_mincpu_default;
601 
602 	/* increase threshold for faster disks */
603 	new->threshold = dump_plat_mincpu;
604 	if (dumpbuf.iosize >= DUMP_1MB)
605 		new->threshold *= 3;
606 	else if (dumpbuf.iosize >= (256 * DUMP_1KB))
607 		new->threshold *= 2;
608 
609 	/* figure compression level based upon the computed threshold. */
610 	if (dump_plat_mincpu == 0 || new->nhelper < 2) {
611 		new->clevel = 0;
612 		new->nhelper = 1;
613 	} else if ((new->nhelper + 1) >= new->threshold) {
614 		new->clevel = DUMP_CLEVEL_BZIP2;
615 	} else {
616 		new->clevel = DUMP_CLEVEL_LZJB;
617 	}
618 
619 	if (new->clevel == 0) {
620 		new->ncbuf = 1;
621 		new->ncmap = 1;
622 	} else {
623 		new->ncbuf = NCBUF_PER_HELPER * new->nhelper;
624 		new->ncmap = NCMAP_PER_HELPER * new->nhelper;
625 	}
626 
627 	/*
628 	 * Allocate new data structures and buffers for MINHELPERS,
629 	 * and also figure the max desired size.
630 	 */
631 	bz2size = BZ2_bzCompressInitSize(dump_bzip2_level);
632 	new->maxsize = 0;
633 	new->maxvmsize = 0;
634 	new->maxvm = NULL;
635 	tag = 1;
636 	new->helper = kmem_zalloc(new->nhelper * sizeof (helper_t), KM_SLEEP);
637 	hpend = &new->helper[new->nhelper];
638 	for (hp = new->helper; hp != hpend; hp++) {
639 		hp->tag = tag++;
640 		if (hp < &new->helper[MINHELPERS]) {
641 			hp->lzbuf = kmem_alloc(PAGESIZE, KM_SLEEP);
642 			hp->page = kmem_alloc(PAGESIZE, KM_SLEEP);
643 		} else if (new->clevel < DUMP_CLEVEL_BZIP2) {
644 			new->maxsize += 2 * PAGESIZE;
645 		} else {
646 			new->maxsize += PAGESIZE;
647 		}
648 		if (new->clevel >= DUMP_CLEVEL_BZIP2)
649 			new->maxsize += bz2size;
650 	}
651 
652 	new->cbuf = kmem_zalloc(new->ncbuf * sizeof (cbuf_t), KM_SLEEP);
653 	cpend = &new->cbuf[new->ncbuf];
654 	for (cp = new->cbuf; cp != cpend; cp++) {
655 		cp->state = CBUF_FREEBUF;
656 		cp->size = CBUF_SIZE;
657 		if (cp < &new->cbuf[MINCBUFS])
658 			cp->buf = kmem_alloc(cp->size, KM_SLEEP);
659 		else
660 			new->maxsize += cp->size;
661 	}
662 
663 	new->cmap = kmem_zalloc(new->ncmap * sizeof (cbuf_t), KM_SLEEP);
664 	cpend = &new->cmap[new->ncmap];
665 	for (cp = new->cmap; cp != cpend; cp++) {
666 		cp->state = CBUF_FREEMAP;
667 		cp->size = CBUF_MAPSIZE;
668 		cp->buf = vmem_xalloc(heap_arena, CBUF_MAPSIZE, CBUF_MAPSIZE,
669 		    0, 0, NULL, NULL, VM_SLEEP);
670 	}
671 
672 	/* reserve VA to be backed with spare pages at crash time */
673 	if (new->maxsize > 0) {
674 		new->maxsize = P2ROUNDUP(new->maxsize, PAGESIZE);
675 		new->maxvmsize = P2ROUNDUP(new->maxsize, CBUF_MAPSIZE);
676 		new->maxvm = vmem_xalloc(heap_arena, new->maxvmsize,
677 		    CBUF_MAPSIZE, 0, 0, NULL, NULL, VM_SLEEP);
678 	}
679 
680 	/*
681 	 * Reserve memory for kmem allocation calls made during crash
682 	 * dump.  The hat layer allocates memory for each mapping
683 	 * created, and the I/O path allocates buffers and data structs.
684 	 * Add a few pages for safety.
685 	 */
686 	kmem_dump_init((new->ncmap * dump_kmem_permap) +
687 	    (dump_kmem_pages * PAGESIZE));
688 
689 	/* set new config pointers */
690 	*old = *new;
691 }
692 
693 /*
694  * Define a struct memlist walker to optimize bitnum to pfn
695  * lookup. The walker maintains the state of the list traversal.
696  */
697 typedef struct dumpmlw {
698 	struct memlist	*mp;		/* current memlist */
699 	pgcnt_t		basenum;	/* bitnum base offset */
700 	pgcnt_t		mppages;	/* current memlist size */
701 	pgcnt_t		mpleft;		/* size to end of current memlist */
702 	pfn_t		mpaddr;		/* first pfn in memlist */
703 } dumpmlw_t;
704 
705 /* initialize the walker */
706 static inline void
707 dump_init_memlist_walker(dumpmlw_t *pw)
708 {
709 	pw->mp = phys_install;
710 	pw->basenum = 0;
711 	pw->mppages = pw->mp->ml_size >> PAGESHIFT;
712 	pw->mpleft = pw->mppages;
713 	pw->mpaddr = pw->mp->ml_address >> PAGESHIFT;
714 }
715 
716 /*
717  * Lookup pfn given bitnum. The memlist can be quite long on some
718  * systems (e.g.: one per board). To optimize sequential lookups, the
719  * caller initializes and presents a memlist walker.
720  */
721 static pfn_t
722 dump_bitnum_to_pfn(pgcnt_t bitnum, dumpmlw_t *pw)
723 {
724 	bitnum -= pw->basenum;
725 	while (pw->mp != NULL) {
726 		if (bitnum < pw->mppages) {
727 			pw->mpleft = pw->mppages - bitnum;
728 			return (pw->mpaddr + bitnum);
729 		}
730 		bitnum -= pw->mppages;
731 		pw->basenum += pw->mppages;
732 		pw->mp = pw->mp->ml_next;
733 		if (pw->mp != NULL) {
734 			pw->mppages = pw->mp->ml_size >> PAGESHIFT;
735 			pw->mpleft = pw->mppages;
736 			pw->mpaddr = pw->mp->ml_address >> PAGESHIFT;
737 		}
738 	}
739 	return (PFN_INVALID);
740 }
741 
742 static pgcnt_t
743 dump_pfn_to_bitnum(pfn_t pfn)
744 {
745 	struct memlist *mp;
746 	pgcnt_t bitnum = 0;
747 
748 	for (mp = phys_install; mp != NULL; mp = mp->ml_next) {
749 		if (pfn >= (mp->ml_address >> PAGESHIFT) &&
750 		    pfn < ((mp->ml_address + mp->ml_size) >> PAGESHIFT))
751 			return (bitnum + pfn - (mp->ml_address >> PAGESHIFT));
752 		bitnum += mp->ml_size >> PAGESHIFT;
753 	}
754 	return ((pgcnt_t)-1);
755 }
756 
757 /*
758  * Set/test bitmap for a CBUF_MAPSIZE range which includes pfn. The
759  * mapping of pfn to range index is imperfect because pfn and bitnum
760  * do not have the same phase. To make sure a CBUF_MAPSIZE range is
761  * covered, call this for both ends:
762  *	dump_set_used(base)
763  *	dump_set_used(base+CBUF_MAPNP-1)
764  *
765  * This is used during a panic dump to mark pages allocated by
766  * dumpsys_get_maxmem(). The macro IS_DUMP_PAGE(pp) is used by
767  * page_get_mnode_freelist() to make sure pages used by dump are never
768  * allocated.
769  */
770 #define	CBUF_MAPP2R(pfn)	((pfn) >> (CBUF_MAPSHIFT - PAGESHIFT))
771 
772 static void
773 dump_set_used(pfn_t pfn)
774 {
775 
776 	pgcnt_t bitnum, rbitnum;
777 
778 	bitnum = dump_pfn_to_bitnum(pfn);
779 	ASSERT(bitnum != (pgcnt_t)-1);
780 
781 	rbitnum = CBUF_MAPP2R(bitnum);
782 	ASSERT(rbitnum < dumpcfg.rbitmapsize);
783 
784 	BT_SET(dumpcfg.rbitmap, rbitnum);
785 }
786 
787 int
788 dump_test_used(pfn_t pfn)
789 {
790 	pgcnt_t bitnum, rbitnum;
791 
792 	bitnum = dump_pfn_to_bitnum(pfn);
793 	ASSERT(bitnum != (pgcnt_t)-1);
794 
795 	rbitnum = CBUF_MAPP2R(bitnum);
796 	ASSERT(rbitnum < dumpcfg.rbitmapsize);
797 
798 	return (BT_TEST(dumpcfg.rbitmap, rbitnum));
799 }
800 
801 /*
802  * dumpbzalloc and dumpbzfree are callbacks from the bzip2 library.
803  * dumpsys_get_maxmem() uses them for BZ2_bzCompressInit().
804  */
805 static void *
806 dumpbzalloc(void *opaque, int items, int size)
807 {
808 	size_t *sz;
809 	char *ret;
810 
811 	ASSERT(opaque != NULL);
812 	sz = opaque;
813 	ret = dumpcfg.maxvm + *sz;
814 	*sz += items * size;
815 	*sz = P2ROUNDUP(*sz, BZ2_BZALLOC_ALIGN);
816 	ASSERT(*sz <= dumpcfg.maxvmsize);
817 	return (ret);
818 }
819 
820 /*ARGSUSED*/
821 static void
822 dumpbzfree(void *opaque, void *addr)
823 {
824 }
825 
826 /*
827  * Perform additional checks on the page to see if we can really use
828  * it. The kernel (kas) pages are always set in the bitmap. However,
829  * boot memory pages (prom_ppages or P_BOOTPAGES) are not in the
830  * bitmap. So we check for them.
831  */
832 static inline int
833 dump_pfn_check(pfn_t pfn)
834 {
835 	page_t *pp = page_numtopp_nolock(pfn);
836 	if (pp == NULL || pp->p_pagenum != pfn ||
837 #if defined(__sparc)
838 	    pp->p_vnode == &promvp ||
839 #else
840 	    PP_ISBOOTPAGES(pp) ||
841 #endif
842 	    pp->p_toxic != 0)
843 		return (0);
844 	return (1);
845 }
846 
847 /*
848  * Check a range to see if all contained pages are available and
849  * return non-zero if the range can be used.
850  */
851 static inline int
852 dump_range_check(pgcnt_t start, pgcnt_t end, pfn_t pfn)
853 {
854 	for (; start < end; start++, pfn++) {
855 		if (BT_TEST(dumpcfg.bitmap, start))
856 			return (0);
857 		if (!dump_pfn_check(pfn))
858 			return (0);
859 	}
860 	return (1);
861 }
862 
863 /*
864  * dumpsys_get_maxmem() is called during panic. Find unused ranges
865  * and use them for buffers. If we find enough memory switch to
866  * parallel bzip2, otherwise use parallel lzjb.
867  *
868  * It searches the dump bitmap in 2 passes. The first time it looks
869  * for CBUF_MAPSIZE ranges. On the second pass it uses small pages.
870  */
871 static void
872 dumpsys_get_maxmem()
873 {
874 	dumpcfg_t *cfg = &dumpcfg;
875 	cbuf_t *endcp = &cfg->cbuf[cfg->ncbuf];
876 	helper_t *endhp = &cfg->helper[cfg->nhelper];
877 	pgcnt_t bitnum, end;
878 	size_t sz, endsz, bz2size;
879 	pfn_t pfn, off;
880 	cbuf_t *cp;
881 	helper_t *hp, *ohp;
882 	dumpmlw_t mlw;
883 	int k;
884 
885 	/*
886 	 * Fall back to doing a serial dump if no helpers showed
887 	 * up. It is possible for other CPUs to be stuck in PROM, or
888 	 * DRd out. panic("sync initiated") in sync_handler() is one
889 	 * case. A parallel dump will hang (dump time out) unless
890 	 * there is at least one helper CPU. At this point dumpsys()
891 	 * has done some I/O, which means there has been plenty of
892 	 * time for helpers to arrive.
893 	 */
894 	if (!cfg->helper_present) {
895 		cfg->clevel = 0;
896 		return;
897 	}
898 
899 	/*
900 	 * There may be no point in looking for spare memory. If
901 	 * dumping all memory, then none is spare. If doing a serial
902 	 * dump, then already have buffers.
903 	 */
904 	if (cfg->maxsize == 0 || cfg->clevel < DUMP_CLEVEL_LZJB ||
905 	    (dump_conflags & DUMP_ALL) != 0) {
906 		if (cfg->clevel > DUMP_CLEVEL_LZJB)
907 			cfg->clevel = DUMP_CLEVEL_LZJB;
908 		return;
909 	}
910 
911 	sz = 0;
912 	cfg->found4m = 0;
913 	cfg->foundsm = 0;
914 
915 	/* bitmap of ranges used to estimate which pfns are being used */
916 	bzero(dumpcfg.rbitmap, BT_SIZEOFMAP(dumpcfg.rbitmapsize));
917 
918 	/* find ranges that are not being dumped to use for buffers */
919 	dump_init_memlist_walker(&mlw);
920 	for (bitnum = 0; bitnum < dumpcfg.bitmapsize; bitnum = end) {
921 		dump_timeleft = dump_timeout;
922 		end = bitnum + CBUF_MAPNP;
923 		pfn = dump_bitnum_to_pfn(bitnum, &mlw);
924 		ASSERT(pfn != PFN_INVALID);
925 
926 		/* skip partial range at end of mem segment */
927 		if (mlw.mpleft < CBUF_MAPNP) {
928 			end = bitnum + mlw.mpleft;
929 			continue;
930 		}
931 
932 		/* skip non aligned pages */
933 		off = P2PHASE(pfn, CBUF_MAPNP);
934 		if (off != 0) {
935 			end -= off;
936 			continue;
937 		}
938 
939 		if (!dump_range_check(bitnum, end, pfn))
940 			continue;
941 
942 		ASSERT((sz + CBUF_MAPSIZE) <= cfg->maxvmsize);
943 		hat_devload(kas.a_hat, cfg->maxvm + sz, CBUF_MAPSIZE, pfn,
944 		    PROT_READ | PROT_WRITE, HAT_LOAD_NOCONSIST);
945 		sz += CBUF_MAPSIZE;
946 		cfg->found4m++;
947 
948 		/* set the bitmap for both ends to be sure to cover the range */
949 		dump_set_used(pfn);
950 		dump_set_used(pfn + CBUF_MAPNP - 1);
951 
952 		if (sz >= cfg->maxsize)
953 			goto foundmax;
954 	}
955 
956 	/* Add small pages if we can't find enough large pages. */
957 	dump_init_memlist_walker(&mlw);
958 	for (bitnum = 0; bitnum < dumpcfg.bitmapsize; bitnum = end) {
959 		dump_timeleft = dump_timeout;
960 		end = bitnum + CBUF_MAPNP;
961 		pfn = dump_bitnum_to_pfn(bitnum, &mlw);
962 		ASSERT(pfn != PFN_INVALID);
963 
964 		/* Find any non-aligned pages at start and end of segment. */
965 		off = P2PHASE(pfn, CBUF_MAPNP);
966 		if (mlw.mpleft < CBUF_MAPNP) {
967 			end = bitnum + mlw.mpleft;
968 		} else if (off != 0) {
969 			end -= off;
970 		} else if (cfg->found4m && dump_test_used(pfn)) {
971 			continue;
972 		}
973 
974 		for (; bitnum < end; bitnum++, pfn++) {
975 			dump_timeleft = dump_timeout;
976 			if (BT_TEST(dumpcfg.bitmap, bitnum))
977 				continue;
978 			if (!dump_pfn_check(pfn))
979 				continue;
980 			ASSERT((sz + PAGESIZE) <= cfg->maxvmsize);
981 			hat_devload(kas.a_hat, cfg->maxvm + sz, PAGESIZE, pfn,
982 			    PROT_READ | PROT_WRITE, HAT_LOAD_NOCONSIST);
983 			sz += PAGESIZE;
984 			cfg->foundsm++;
985 			dump_set_used(pfn);
986 			if (sz >= cfg->maxsize)
987 				goto foundmax;
988 		}
989 	}
990 
991 	/* Fall back to lzjb if we did not get enough memory for bzip2. */
992 	endsz = (cfg->maxsize * cfg->threshold) / cfg->nhelper;
993 	if (sz < endsz) {
994 		cfg->clevel = DUMP_CLEVEL_LZJB;
995 	}
996 
997 	/* Allocate memory for as many helpers as we can. */
998 foundmax:
999 
1000 	/* Byte offsets into memory found and mapped above */
1001 	endsz = sz;
1002 	sz = 0;
1003 
1004 	/* Set the size for bzip2 state. Only bzip2 needs it. */
1005 	bz2size = BZ2_bzCompressInitSize(dump_bzip2_level);
1006 
1007 	/* Skip the preallocate output buffers. */
1008 	cp = &cfg->cbuf[MINCBUFS];
1009 
1010 	/* Use this to move memory up from the preallocated helpers. */
1011 	ohp = cfg->helper;
1012 
1013 	/* Loop over all helpers and allocate memory. */
1014 	for (hp = cfg->helper; hp < endhp; hp++) {
1015 
1016 		/* Skip preallocated helpers by checking hp->page. */
1017 		if (hp->page == NULL) {
1018 			if (cfg->clevel <= DUMP_CLEVEL_LZJB) {
1019 				/* lzjb needs 2 1-page buffers */
1020 				if ((sz + (2 * PAGESIZE)) > endsz)
1021 					break;
1022 				hp->page = cfg->maxvm + sz;
1023 				sz += PAGESIZE;
1024 				hp->lzbuf = cfg->maxvm + sz;
1025 				sz += PAGESIZE;
1026 
1027 			} else if (ohp->lzbuf != NULL) {
1028 				/* re-use the preallocted lzjb page for bzip2 */
1029 				hp->page = ohp->lzbuf;
1030 				ohp->lzbuf = NULL;
1031 				++ohp;
1032 
1033 			} else {
1034 				/* bzip2 needs a 1-page buffer */
1035 				if ((sz + PAGESIZE) > endsz)
1036 					break;
1037 				hp->page = cfg->maxvm + sz;
1038 				sz += PAGESIZE;
1039 			}
1040 		}
1041 
1042 		/*
1043 		 * Add output buffers per helper. The number of
1044 		 * buffers per helper is determined by the ratio of
1045 		 * ncbuf to nhelper.
1046 		 */
1047 		for (k = 0; cp < endcp && (sz + CBUF_SIZE) <= endsz &&
1048 		    k < NCBUF_PER_HELPER; k++) {
1049 			cp->state = CBUF_FREEBUF;
1050 			cp->size = CBUF_SIZE;
1051 			cp->buf = cfg->maxvm + sz;
1052 			sz += CBUF_SIZE;
1053 			++cp;
1054 		}
1055 
1056 		/*
1057 		 * bzip2 needs compression state. Use the dumpbzalloc
1058 		 * and dumpbzfree callbacks to allocate the memory.
1059 		 * bzip2 does allocation only at init time.
1060 		 */
1061 		if (cfg->clevel >= DUMP_CLEVEL_BZIP2) {
1062 			if ((sz + bz2size) > endsz) {
1063 				hp->page = NULL;
1064 				break;
1065 			} else {
1066 				hp->bzstream.opaque = &sz;
1067 				hp->bzstream.bzalloc = dumpbzalloc;
1068 				hp->bzstream.bzfree = dumpbzfree;
1069 				(void) BZ2_bzCompressInit(&hp->bzstream,
1070 				    dump_bzip2_level, 0, 0);
1071 				hp->bzstream.opaque = NULL;
1072 			}
1073 		}
1074 	}
1075 
1076 	/* Finish allocating output buffers */
1077 	for (; cp < endcp && (sz + CBUF_SIZE) <= endsz; cp++) {
1078 		cp->state = CBUF_FREEBUF;
1079 		cp->size = CBUF_SIZE;
1080 		cp->buf = cfg->maxvm + sz;
1081 		sz += CBUF_SIZE;
1082 	}
1083 
1084 	/* Enable IS_DUMP_PAGE macro, which checks for pages we took. */
1085 	if (cfg->found4m || cfg->foundsm)
1086 		dump_check_used = 1;
1087 
1088 	ASSERT(sz <= endsz);
1089 }
1090 
1091 static void
1092 dumphdr_init(void)
1093 {
1094 	pgcnt_t npages = 0;
1095 
1096 	ASSERT(MUTEX_HELD(&dump_lock));
1097 
1098 	if (dumphdr == NULL) {
1099 		dumphdr = kmem_zalloc(sizeof (dumphdr_t), KM_SLEEP);
1100 		dumphdr->dump_magic = DUMP_MAGIC;
1101 		dumphdr->dump_version = DUMP_VERSION;
1102 		dumphdr->dump_wordsize = DUMP_WORDSIZE;
1103 		dumphdr->dump_pageshift = PAGESHIFT;
1104 		dumphdr->dump_pagesize = PAGESIZE;
1105 		dumphdr->dump_utsname = utsname;
1106 		(void) strcpy(dumphdr->dump_platform, platform);
1107 		dumpbuf.size = dumpbuf_iosize(maxphys);
1108 		dumpbuf.start = kmem_alloc(dumpbuf.size, KM_SLEEP);
1109 		dumpbuf.end = dumpbuf.start + dumpbuf.size;
1110 		dumpcfg.pids = kmem_alloc(v.v_proc * sizeof (pid_t), KM_SLEEP);
1111 		dumpcfg.helpermap = kmem_zalloc(BT_SIZEOFMAP(NCPU), KM_SLEEP);
1112 		LOCK_INIT_HELD(&dumpcfg.helper_lock);
1113 		dump_stack_scratch = kmem_alloc(STACK_BUF_SIZE, KM_SLEEP);
1114 		(void) strncpy(dumphdr->dump_uuid, dump_get_uuid(),
1115 		    sizeof (dumphdr->dump_uuid));
1116 	}
1117 
1118 	npages = num_phys_pages();
1119 
1120 	if (dumpcfg.bitmapsize != npages) {
1121 		size_t rlen = CBUF_MAPP2R(P2ROUNDUP(npages, CBUF_MAPNP));
1122 		void *map = kmem_alloc(BT_SIZEOFMAP(npages), KM_SLEEP);
1123 		void *rmap = kmem_alloc(BT_SIZEOFMAP(rlen), KM_SLEEP);
1124 
1125 		if (dumpcfg.bitmap != NULL)
1126 			kmem_free(dumpcfg.bitmap, BT_SIZEOFMAP(dumpcfg.
1127 			    bitmapsize));
1128 		if (dumpcfg.rbitmap != NULL)
1129 			kmem_free(dumpcfg.rbitmap, BT_SIZEOFMAP(dumpcfg.
1130 			    rbitmapsize));
1131 		dumpcfg.bitmap = map;
1132 		dumpcfg.bitmapsize = npages;
1133 		dumpcfg.rbitmap = rmap;
1134 		dumpcfg.rbitmapsize = rlen;
1135 	}
1136 }
1137 
1138 /*
1139  * Establish a new dump device.
1140  */
1141 int
1142 dumpinit(vnode_t *vp, char *name, int justchecking)
1143 {
1144 	vnode_t *cvp;
1145 	vattr_t vattr;
1146 	vnode_t *cdev_vp;
1147 	int error = 0;
1148 
1149 	ASSERT(MUTEX_HELD(&dump_lock));
1150 
1151 	dumphdr_init();
1152 
1153 	cvp = common_specvp(vp);
1154 	if (cvp == dumpvp)
1155 		return (0);
1156 
1157 	/*
1158 	 * Determine whether this is a plausible dump device.  We want either:
1159 	 * (1) a real device that's not mounted and has a cb_dump routine, or
1160 	 * (2) a swapfile on some filesystem that has a vop_dump routine.
1161 	 */
1162 	if ((error = VOP_OPEN(&cvp, FREAD | FWRITE, kcred, NULL)) != 0)
1163 		return (error);
1164 
1165 	vattr.va_mask = AT_SIZE | AT_TYPE | AT_RDEV;
1166 	if ((error = VOP_GETATTR(cvp, &vattr, 0, kcred, NULL)) == 0) {
1167 		if (vattr.va_type == VBLK || vattr.va_type == VCHR) {
1168 			if (devopsp[getmajor(vattr.va_rdev)]->
1169 			    devo_cb_ops->cb_dump == nodev)
1170 				error = ENOTSUP;
1171 			else if (vfs_devismounted(vattr.va_rdev))
1172 				error = EBUSY;
1173 			if (strcmp(ddi_driver_name(VTOS(cvp)->s_dip),
1174 			    ZFS_DRIVER) == 0 &&
1175 			    IS_SWAPVP(common_specvp(cvp)))
1176 					error = EBUSY;
1177 		} else {
1178 			if (vn_matchopval(cvp, VOPNAME_DUMP, fs_nosys) ||
1179 			    !IS_SWAPVP(cvp))
1180 				error = ENOTSUP;
1181 		}
1182 	}
1183 
1184 	if (error == 0 && vattr.va_size < 2 * DUMP_LOGSIZE + DUMP_ERPTSIZE)
1185 		error = ENOSPC;
1186 
1187 	if (error || justchecking) {
1188 		(void) VOP_CLOSE(cvp, FREAD | FWRITE, 1, (offset_t)0,
1189 		    kcred, NULL);
1190 		return (error);
1191 	}
1192 
1193 	VN_HOLD(cvp);
1194 
1195 	if (dumpvp != NULL)
1196 		dumpfini();	/* unconfigure the old dump device */
1197 
1198 	dumpvp = cvp;
1199 	dumpvp_size = vattr.va_size & -DUMP_OFFSET;
1200 	dumppath = kmem_alloc(strlen(name) + 1, KM_SLEEP);
1201 	(void) strcpy(dumppath, name);
1202 	dumpbuf.iosize = 0;
1203 
1204 	/*
1205 	 * If the dump device is a block device, attempt to open up the
1206 	 * corresponding character device and determine its maximum transfer
1207 	 * size.  We use this information to potentially resize dumpbuf to a
1208 	 * larger and more optimal size for performing i/o to the dump device.
1209 	 */
1210 	if (cvp->v_type == VBLK &&
1211 	    (cdev_vp = makespecvp(VTOS(cvp)->s_dev, VCHR)) != NULL) {
1212 		if (VOP_OPEN(&cdev_vp, FREAD | FWRITE, kcred, NULL) == 0) {
1213 			size_t blk_size;
1214 			struct dk_cinfo dki;
1215 			struct dk_minfo minf;
1216 
1217 			if (VOP_IOCTL(cdev_vp, DKIOCGMEDIAINFO,
1218 			    (intptr_t)&minf, FKIOCTL, kcred, NULL, NULL)
1219 			    == 0 && minf.dki_lbsize != 0)
1220 				blk_size = minf.dki_lbsize;
1221 			else
1222 				blk_size = DEV_BSIZE;
1223 
1224 			if (VOP_IOCTL(cdev_vp, DKIOCINFO, (intptr_t)&dki,
1225 			    FKIOCTL, kcred, NULL, NULL) == 0) {
1226 				dumpbuf.iosize = dki.dki_maxtransfer * blk_size;
1227 				dumpbuf_resize();
1228 			}
1229 			/*
1230 			 * If we are working with a zvol then dumpify it
1231 			 * if it's not being used as swap.
1232 			 */
1233 			if (strcmp(dki.dki_dname, ZVOL_DRIVER) == 0) {
1234 				if (IS_SWAPVP(common_specvp(cvp)))
1235 					error = EBUSY;
1236 				else if ((error = VOP_IOCTL(cdev_vp,
1237 				    DKIOCDUMPINIT, NULL, FKIOCTL, kcred,
1238 				    NULL, NULL)) != 0)
1239 					dumpfini();
1240 			}
1241 
1242 			(void) VOP_CLOSE(cdev_vp, FREAD | FWRITE, 1, 0,
1243 			    kcred, NULL);
1244 		}
1245 
1246 		VN_RELE(cdev_vp);
1247 	}
1248 
1249 	cmn_err(CE_CONT, "?dump on %s size %llu MB\n", name, dumpvp_size >> 20);
1250 
1251 	dump_update_clevel();
1252 
1253 	return (error);
1254 }
1255 
1256 void
1257 dumpfini(void)
1258 {
1259 	vattr_t vattr;
1260 	boolean_t is_zfs = B_FALSE;
1261 	vnode_t *cdev_vp;
1262 	ASSERT(MUTEX_HELD(&dump_lock));
1263 
1264 	kmem_free(dumppath, strlen(dumppath) + 1);
1265 
1266 	/*
1267 	 * Determine if we are using zvols for our dump device
1268 	 */
1269 	vattr.va_mask = AT_RDEV;
1270 	if (VOP_GETATTR(dumpvp, &vattr, 0, kcred, NULL) == 0) {
1271 		is_zfs = (getmajor(vattr.va_rdev) ==
1272 		    ddi_name_to_major(ZFS_DRIVER)) ? B_TRUE : B_FALSE;
1273 	}
1274 
1275 	/*
1276 	 * If we have a zvol dump device then we call into zfs so
1277 	 * that it may have a chance to cleanup.
1278 	 */
1279 	if (is_zfs &&
1280 	    (cdev_vp = makespecvp(VTOS(dumpvp)->s_dev, VCHR)) != NULL) {
1281 		if (VOP_OPEN(&cdev_vp, FREAD | FWRITE, kcred, NULL) == 0) {
1282 			(void) VOP_IOCTL(cdev_vp, DKIOCDUMPFINI, NULL, FKIOCTL,
1283 			    kcred, NULL, NULL);
1284 			(void) VOP_CLOSE(cdev_vp, FREAD | FWRITE, 1, 0,
1285 			    kcred, NULL);
1286 		}
1287 		VN_RELE(cdev_vp);
1288 	}
1289 
1290 	(void) VOP_CLOSE(dumpvp, FREAD | FWRITE, 1, (offset_t)0, kcred, NULL);
1291 
1292 	VN_RELE(dumpvp);
1293 
1294 	dumpvp = NULL;
1295 	dumpvp_size = 0;
1296 	dumppath = NULL;
1297 }
1298 
1299 static offset_t
1300 dumpvp_flush(void)
1301 {
1302 	size_t size = P2ROUNDUP(dumpbuf.cur - dumpbuf.start, PAGESIZE);
1303 	hrtime_t iotime;
1304 	int err;
1305 
1306 	if (dumpbuf.vp_off + size > dumpbuf.vp_limit) {
1307 		dump_ioerr = ENOSPC;
1308 		dumpbuf.vp_off = dumpbuf.vp_limit;
1309 	} else if (size != 0) {
1310 		iotime = gethrtime();
1311 		dumpsync.iowait += iotime - dumpsync.iowaitts;
1312 		if (panicstr)
1313 			err = VOP_DUMP(dumpvp, dumpbuf.start,
1314 			    lbtodb(dumpbuf.vp_off), btod(size), NULL);
1315 		else
1316 			err = vn_rdwr(UIO_WRITE, dumpbuf.cdev_vp != NULL ?
1317 			    dumpbuf.cdev_vp : dumpvp, dumpbuf.start, size,
1318 			    dumpbuf.vp_off, UIO_SYSSPACE, 0, dumpbuf.vp_limit,
1319 			    kcred, 0);
1320 		if (err && dump_ioerr == 0)
1321 			dump_ioerr = err;
1322 		dumpsync.iowaitts = gethrtime();
1323 		dumpsync.iotime += dumpsync.iowaitts - iotime;
1324 		dumpsync.nwrite += size;
1325 		dumpbuf.vp_off += size;
1326 	}
1327 	dumpbuf.cur = dumpbuf.start;
1328 	dump_timeleft = dump_timeout;
1329 	return (dumpbuf.vp_off);
1330 }
1331 
1332 /* maximize write speed by keeping seek offset aligned with size */
1333 void
1334 dumpvp_write(const void *va, size_t size)
1335 {
1336 	size_t len, off, sz;
1337 
1338 	while (size != 0) {
1339 		len = MIN(size, dumpbuf.end - dumpbuf.cur);
1340 		if (len == 0) {
1341 			off = P2PHASE(dumpbuf.vp_off, dumpbuf.size);
1342 			if (off == 0 || !ISP2(dumpbuf.size)) {
1343 				(void) dumpvp_flush();
1344 			} else {
1345 				sz = dumpbuf.size - off;
1346 				dumpbuf.cur = dumpbuf.start + sz;
1347 				(void) dumpvp_flush();
1348 				ovbcopy(dumpbuf.start + sz, dumpbuf.start, off);
1349 				dumpbuf.cur += off;
1350 			}
1351 		} else {
1352 			bcopy(va, dumpbuf.cur, len);
1353 			va = (char *)va + len;
1354 			dumpbuf.cur += len;
1355 			size -= len;
1356 		}
1357 	}
1358 }
1359 
1360 /*ARGSUSED*/
1361 static void
1362 dumpvp_ksyms_write(const void *src, void *dst, size_t size)
1363 {
1364 	dumpvp_write(src, size);
1365 }
1366 
1367 /*
1368  * Mark 'pfn' in the bitmap and dump its translation table entry.
1369  */
1370 void
1371 dump_addpage(struct as *as, void *va, pfn_t pfn)
1372 {
1373 	mem_vtop_t mem_vtop;
1374 	pgcnt_t bitnum;
1375 
1376 	if ((bitnum = dump_pfn_to_bitnum(pfn)) != (pgcnt_t)-1) {
1377 		if (!BT_TEST(dumpcfg.bitmap, bitnum)) {
1378 			dumphdr->dump_npages++;
1379 			BT_SET(dumpcfg.bitmap, bitnum);
1380 		}
1381 		dumphdr->dump_nvtop++;
1382 		mem_vtop.m_as = as;
1383 		mem_vtop.m_va = va;
1384 		mem_vtop.m_pfn = pfn;
1385 		dumpvp_write(&mem_vtop, sizeof (mem_vtop_t));
1386 	}
1387 	dump_timeleft = dump_timeout;
1388 }
1389 
1390 /*
1391  * Mark 'pfn' in the bitmap
1392  */
1393 void
1394 dump_page(pfn_t pfn)
1395 {
1396 	pgcnt_t bitnum;
1397 
1398 	if ((bitnum = dump_pfn_to_bitnum(pfn)) != (pgcnt_t)-1) {
1399 		if (!BT_TEST(dumpcfg.bitmap, bitnum)) {
1400 			dumphdr->dump_npages++;
1401 			BT_SET(dumpcfg.bitmap, bitnum);
1402 		}
1403 	}
1404 	dump_timeleft = dump_timeout;
1405 }
1406 
1407 /*
1408  * Dump the <as, va, pfn> information for a given address space.
1409  * SEGOP_DUMP() will call dump_addpage() for each page in the segment.
1410  */
1411 static void
1412 dump_as(struct as *as)
1413 {
1414 	struct seg *seg;
1415 
1416 	AS_LOCK_ENTER(as, &as->a_lock, RW_READER);
1417 	for (seg = AS_SEGFIRST(as); seg; seg = AS_SEGNEXT(as, seg)) {
1418 		if (seg->s_as != as)
1419 			break;
1420 		if (seg->s_ops == NULL)
1421 			continue;
1422 		SEGOP_DUMP(seg);
1423 	}
1424 	AS_LOCK_EXIT(as, &as->a_lock);
1425 
1426 	if (seg != NULL)
1427 		cmn_err(CE_WARN, "invalid segment %p in address space %p",
1428 		    (void *)seg, (void *)as);
1429 }
1430 
1431 static int
1432 dump_process(pid_t pid)
1433 {
1434 	proc_t *p = sprlock(pid);
1435 
1436 	if (p == NULL)
1437 		return (-1);
1438 	if (p->p_as != &kas) {
1439 		mutex_exit(&p->p_lock);
1440 		dump_as(p->p_as);
1441 		mutex_enter(&p->p_lock);
1442 	}
1443 
1444 	sprunlock(p);
1445 
1446 	return (0);
1447 }
1448 
1449 /*
1450  * The following functions (dump_summary(), dump_ereports(), and
1451  * dump_messages()), write data to an uncompressed area within the
1452  * crashdump. The layout of these is
1453  *
1454  * +------------------------------------------------------------+
1455  * |     compressed pages       | summary | ereports | messages |
1456  * +------------------------------------------------------------+
1457  *
1458  * With the advent of saving a compressed crash dump by default, we
1459  * need to save a little more data to describe the failure mode in
1460  * an uncompressed buffer available before savecore uncompresses
1461  * the dump. Initially this is a copy of the stack trace. Additional
1462  * summary information should be added here.
1463  */
1464 
1465 void
1466 dump_summary(void)
1467 {
1468 	u_offset_t dumpvp_start;
1469 	summary_dump_t sd;
1470 
1471 	if (dumpvp == NULL || dumphdr == NULL)
1472 		return;
1473 
1474 	dumpbuf.cur = dumpbuf.start;
1475 
1476 	dumpbuf.vp_limit = dumpvp_size - (DUMP_OFFSET + DUMP_LOGSIZE +
1477 	    DUMP_ERPTSIZE);
1478 	dumpvp_start = dumpbuf.vp_limit - DUMP_SUMMARYSIZE;
1479 	dumpbuf.vp_off = dumpvp_start;
1480 
1481 	sd.sd_magic = SUMMARY_MAGIC;
1482 	sd.sd_ssum = checksum32(dump_stack_scratch, STACK_BUF_SIZE);
1483 	dumpvp_write(&sd, sizeof (sd));
1484 	dumpvp_write(dump_stack_scratch, STACK_BUF_SIZE);
1485 
1486 	sd.sd_magic = 0; /* indicate end of summary */
1487 	dumpvp_write(&sd, sizeof (sd));
1488 	(void) dumpvp_flush();
1489 }
1490 
1491 void
1492 dump_ereports(void)
1493 {
1494 	u_offset_t dumpvp_start;
1495 	erpt_dump_t ed;
1496 
1497 	if (dumpvp == NULL || dumphdr == NULL)
1498 		return;
1499 
1500 	dumpbuf.cur = dumpbuf.start;
1501 	dumpbuf.vp_limit = dumpvp_size - (DUMP_OFFSET + DUMP_LOGSIZE);
1502 	dumpvp_start = dumpbuf.vp_limit - DUMP_ERPTSIZE;
1503 	dumpbuf.vp_off = dumpvp_start;
1504 
1505 	fm_ereport_dump();
1506 	if (panicstr)
1507 		errorq_dump();
1508 
1509 	bzero(&ed, sizeof (ed)); /* indicate end of ereports */
1510 	dumpvp_write(&ed, sizeof (ed));
1511 	(void) dumpvp_flush();
1512 
1513 	if (!panicstr) {
1514 		(void) VOP_PUTPAGE(dumpvp, dumpvp_start,
1515 		    (size_t)(dumpbuf.vp_off - dumpvp_start),
1516 		    B_INVAL | B_FORCE, kcred, NULL);
1517 	}
1518 }
1519 
1520 void
1521 dump_messages(void)
1522 {
1523 	log_dump_t ld;
1524 	mblk_t *mctl, *mdata;
1525 	queue_t *q, *qlast;
1526 	u_offset_t dumpvp_start;
1527 
1528 	if (dumpvp == NULL || dumphdr == NULL || log_consq == NULL)
1529 		return;
1530 
1531 	dumpbuf.cur = dumpbuf.start;
1532 	dumpbuf.vp_limit = dumpvp_size - DUMP_OFFSET;
1533 	dumpvp_start = dumpbuf.vp_limit - DUMP_LOGSIZE;
1534 	dumpbuf.vp_off = dumpvp_start;
1535 
1536 	qlast = NULL;
1537 	do {
1538 		for (q = log_consq; q->q_next != qlast; q = q->q_next)
1539 			continue;
1540 		for (mctl = q->q_first; mctl != NULL; mctl = mctl->b_next) {
1541 			dump_timeleft = dump_timeout;
1542 			mdata = mctl->b_cont;
1543 			ld.ld_magic = LOG_MAGIC;
1544 			ld.ld_msgsize = MBLKL(mctl->b_cont);
1545 			ld.ld_csum = checksum32(mctl->b_rptr, MBLKL(mctl));
1546 			ld.ld_msum = checksum32(mdata->b_rptr, MBLKL(mdata));
1547 			dumpvp_write(&ld, sizeof (ld));
1548 			dumpvp_write(mctl->b_rptr, MBLKL(mctl));
1549 			dumpvp_write(mdata->b_rptr, MBLKL(mdata));
1550 		}
1551 	} while ((qlast = q) != log_consq);
1552 
1553 	ld.ld_magic = 0;		/* indicate end of messages */
1554 	dumpvp_write(&ld, sizeof (ld));
1555 	(void) dumpvp_flush();
1556 	if (!panicstr) {
1557 		(void) VOP_PUTPAGE(dumpvp, dumpvp_start,
1558 		    (size_t)(dumpbuf.vp_off - dumpvp_start),
1559 		    B_INVAL | B_FORCE, kcred, NULL);
1560 	}
1561 }
1562 
1563 /*
1564  * The following functions are called on multiple CPUs during dump.
1565  * They must not use most kernel services, because all cross-calls are
1566  * disabled during panic. Therefore, blocking locks and cache flushes
1567  * will not work.
1568  */
1569 
1570 /*
1571  * Copy pages, trapping ECC errors. Also, for robustness, trap data
1572  * access in case something goes wrong in the hat layer and the
1573  * mapping is broken.
1574  */
1575 static int
1576 dump_pagecopy(void *src, void *dst)
1577 {
1578 	long *wsrc = (long *)src;
1579 	long *wdst = (long *)dst;
1580 	const ulong_t ncopies = PAGESIZE / sizeof (long);
1581 	volatile int w = 0;
1582 	volatile int ueoff = -1;
1583 	on_trap_data_t otd;
1584 
1585 	if (on_trap(&otd, OT_DATA_EC | OT_DATA_ACCESS)) {
1586 		if (ueoff == -1)
1587 			ueoff = w * sizeof (long);
1588 		/* report "bad ECC" or "bad address" */
1589 #ifdef _LP64
1590 		if (otd.ot_trap & OT_DATA_EC)
1591 			wdst[w++] = 0x00badecc00badecc;
1592 		else
1593 			wdst[w++] = 0x00badadd00badadd;
1594 #else
1595 		if (otd.ot_trap & OT_DATA_EC)
1596 			wdst[w++] = 0x00badecc;
1597 		else
1598 			wdst[w++] = 0x00badadd;
1599 #endif
1600 	}
1601 	while (w < ncopies) {
1602 		wdst[w] = wsrc[w];
1603 		w++;
1604 	}
1605 	no_trap();
1606 	return (ueoff);
1607 }
1608 
1609 static void
1610 dumpsys_close_cq(cqueue_t *cq, int live)
1611 {
1612 	if (live) {
1613 		mutex_enter(&cq->mutex);
1614 		atomic_dec_uint(&cq->open);
1615 		cv_signal(&cq->cv);
1616 		mutex_exit(&cq->mutex);
1617 	} else {
1618 		atomic_dec_uint(&cq->open);
1619 	}
1620 }
1621 
1622 static inline void
1623 dumpsys_spinlock(lock_t *lp)
1624 {
1625 	uint_t backoff = 0;
1626 	int loop_count = 0;
1627 
1628 	while (LOCK_HELD(lp) || !lock_spin_try(lp)) {
1629 		if (++loop_count >= ncpus) {
1630 			backoff = mutex_lock_backoff(0);
1631 			loop_count = 0;
1632 		} else {
1633 			backoff = mutex_lock_backoff(backoff);
1634 		}
1635 		mutex_lock_delay(backoff);
1636 	}
1637 }
1638 
1639 static inline void
1640 dumpsys_spinunlock(lock_t *lp)
1641 {
1642 	lock_clear(lp);
1643 }
1644 
1645 static inline void
1646 dumpsys_lock(cqueue_t *cq, int live)
1647 {
1648 	if (live)
1649 		mutex_enter(&cq->mutex);
1650 	else
1651 		dumpsys_spinlock(&cq->spinlock);
1652 }
1653 
1654 static inline void
1655 dumpsys_unlock(cqueue_t *cq, int live, int signal)
1656 {
1657 	if (live) {
1658 		if (signal)
1659 			cv_signal(&cq->cv);
1660 		mutex_exit(&cq->mutex);
1661 	} else {
1662 		dumpsys_spinunlock(&cq->spinlock);
1663 	}
1664 }
1665 
1666 static void
1667 dumpsys_wait_cq(cqueue_t *cq, int live)
1668 {
1669 	if (live) {
1670 		cv_wait(&cq->cv, &cq->mutex);
1671 	} else {
1672 		dumpsys_spinunlock(&cq->spinlock);
1673 		while (cq->open)
1674 			if (cq->first)
1675 				break;
1676 		dumpsys_spinlock(&cq->spinlock);
1677 	}
1678 }
1679 
1680 static void
1681 dumpsys_put_cq(cqueue_t *cq, cbuf_t *cp, int newstate, int live)
1682 {
1683 	if (cp == NULL)
1684 		return;
1685 
1686 	dumpsys_lock(cq, live);
1687 
1688 	if (cq->ts != 0) {
1689 		cq->empty += gethrtime() - cq->ts;
1690 		cq->ts = 0;
1691 	}
1692 
1693 	cp->state = newstate;
1694 	cp->next = NULL;
1695 	if (cq->last == NULL)
1696 		cq->first = cp;
1697 	else
1698 		cq->last->next = cp;
1699 	cq->last = cp;
1700 
1701 	dumpsys_unlock(cq, live, 1);
1702 }
1703 
1704 static cbuf_t *
1705 dumpsys_get_cq(cqueue_t *cq, int live)
1706 {
1707 	cbuf_t *cp;
1708 	hrtime_t now = gethrtime();
1709 
1710 	dumpsys_lock(cq, live);
1711 
1712 	/* CONSTCOND */
1713 	while (1) {
1714 		cp = (cbuf_t *)cq->first;
1715 		if (cp == NULL) {
1716 			if (cq->open == 0)
1717 				break;
1718 			dumpsys_wait_cq(cq, live);
1719 			continue;
1720 		}
1721 		cq->first = cp->next;
1722 		if (cq->first == NULL) {
1723 			cq->last = NULL;
1724 			cq->ts = now;
1725 		}
1726 		break;
1727 	}
1728 
1729 	dumpsys_unlock(cq, live, cq->first != NULL || cq->open == 0);
1730 	return (cp);
1731 }
1732 
1733 /*
1734  * Send an error message to the console. If the main task is running
1735  * just write the message via uprintf. If a helper is running the
1736  * message has to be put on a queue for the main task. Setting fmt to
1737  * NULL means flush the error message buffer. If fmt is not NULL, just
1738  * add the text to the existing buffer.
1739  */
1740 static void
1741 dumpsys_errmsg(helper_t *hp, const char *fmt, ...)
1742 {
1743 	dumpsync_t *ds = hp->ds;
1744 	cbuf_t *cp = hp->cperr;
1745 	va_list adx;
1746 
1747 	if (hp->helper == MAINHELPER) {
1748 		if (fmt != NULL) {
1749 			if (ds->neednl) {
1750 				uprintf("\n");
1751 				ds->neednl = 0;
1752 			}
1753 			va_start(adx, fmt);
1754 			vuprintf(fmt, adx);
1755 			va_end(adx);
1756 		}
1757 	} else if (fmt == NULL) {
1758 		if (cp != NULL) {
1759 			CQ_PUT(mainq, cp, CBUF_ERRMSG);
1760 			hp->cperr = NULL;
1761 		}
1762 	} else {
1763 		if (hp->cperr == NULL) {
1764 			cp = CQ_GET(freebufq);
1765 			hp->cperr = cp;
1766 			cp->used = 0;
1767 		}
1768 		va_start(adx, fmt);
1769 		cp->used += vsnprintf(cp->buf + cp->used, cp->size - cp->used,
1770 		    fmt, adx);
1771 		va_end(adx);
1772 		if ((cp->used + LOG_MSGSIZE) > cp->size) {
1773 			CQ_PUT(mainq, cp, CBUF_ERRMSG);
1774 			hp->cperr = NULL;
1775 		}
1776 	}
1777 }
1778 
1779 /*
1780  * Write an output buffer to the dump file. If the main task is
1781  * running just write the data. If a helper is running the output is
1782  * placed on a queue for the main task.
1783  */
1784 static void
1785 dumpsys_swrite(helper_t *hp, cbuf_t *cp, size_t used)
1786 {
1787 	dumpsync_t *ds = hp->ds;
1788 
1789 	if (hp->helper == MAINHELPER) {
1790 		HRSTART(ds->perpage, write);
1791 		dumpvp_write(cp->buf, used);
1792 		HRSTOP(ds->perpage, write);
1793 		CQ_PUT(freebufq, cp, CBUF_FREEBUF);
1794 	} else {
1795 		cp->used = used;
1796 		CQ_PUT(mainq, cp, CBUF_WRITE);
1797 	}
1798 }
1799 
1800 /*
1801  * Copy one page within the mapped range. The offset starts at 0 and
1802  * is relative to the first pfn. cp->buf + cp->off is the address of
1803  * the first pfn. If dump_pagecopy returns a UE offset, create an
1804  * error message.  Returns the offset to the next pfn in the range
1805  * selected by the bitmap.
1806  */
1807 static int
1808 dumpsys_copy_page(helper_t *hp, int offset)
1809 {
1810 	cbuf_t *cp = hp->cpin;
1811 	int ueoff;
1812 
1813 	ASSERT(cp->off + offset + PAGESIZE <= cp->size);
1814 	ASSERT(BT_TEST(dumpcfg.bitmap, cp->bitnum));
1815 
1816 	ueoff = dump_pagecopy(cp->buf + cp->off + offset, hp->page);
1817 
1818 	/* ueoff is the offset in the page to a UE error */
1819 	if (ueoff != -1) {
1820 		uint64_t pa = ptob(cp->pfn) + offset + ueoff;
1821 
1822 		dumpsys_errmsg(hp, "cpu %d: memory error at PA 0x%08x.%08x\n",
1823 		    CPU->cpu_id, (uint32_t)(pa >> 32), (uint32_t)pa);
1824 	}
1825 
1826 	/*
1827 	 * Advance bitnum and offset to the next input page for the
1828 	 * next call to this function.
1829 	 */
1830 	offset += PAGESIZE;
1831 	cp->bitnum++;
1832 	while (cp->off + offset < cp->size) {
1833 		if (BT_TEST(dumpcfg.bitmap, cp->bitnum))
1834 			break;
1835 		offset += PAGESIZE;
1836 		cp->bitnum++;
1837 	}
1838 
1839 	return (offset);
1840 }
1841 
1842 /*
1843  * Read the helper queue, and copy one mapped page. Return 0 when
1844  * done. Return 1 when a page has been copied into hp->page.
1845  */
1846 static int
1847 dumpsys_sread(helper_t *hp)
1848 {
1849 	dumpsync_t *ds = hp->ds;
1850 
1851 	/* CONSTCOND */
1852 	while (1) {
1853 
1854 		/* Find the next input buffer. */
1855 		if (hp->cpin == NULL) {
1856 			HRSTART(hp->perpage, inwait);
1857 
1858 			/* CONSTCOND */
1859 			while (1) {
1860 				hp->cpin = CQ_GET(helperq);
1861 				dump_timeleft = dump_timeout;
1862 
1863 				/*
1864 				 * NULL return means the helper queue
1865 				 * is closed and empty.
1866 				 */
1867 				if (hp->cpin == NULL)
1868 					break;
1869 
1870 				/* Have input, check for dump I/O error. */
1871 				if (!dump_ioerr)
1872 					break;
1873 
1874 				/*
1875 				 * If an I/O error occurs, stay in the
1876 				 * loop in order to empty the helper
1877 				 * queue. Return the buffers to the
1878 				 * main task to unmap and free it.
1879 				 */
1880 				hp->cpin->used = 0;
1881 				CQ_PUT(mainq, hp->cpin, CBUF_USEDMAP);
1882 			}
1883 			HRSTOP(hp->perpage, inwait);
1884 
1885 			/* Stop here when the helper queue is closed. */
1886 			if (hp->cpin == NULL)
1887 				break;
1888 
1889 			/* Set the offset=0 to get the first pfn. */
1890 			hp->in = 0;
1891 
1892 			/* Set the total processed to 0 */
1893 			hp->used = 0;
1894 		}
1895 
1896 		/* Process the next page. */
1897 		if (hp->used < hp->cpin->used) {
1898 
1899 			/*
1900 			 * Get the next page from the input buffer and
1901 			 * return a copy.
1902 			 */
1903 			ASSERT(hp->in != -1);
1904 			HRSTART(hp->perpage, copy);
1905 			hp->in = dumpsys_copy_page(hp, hp->in);
1906 			hp->used += PAGESIZE;
1907 			HRSTOP(hp->perpage, copy);
1908 			break;
1909 
1910 		} else {
1911 
1912 			/*
1913 			 * Done with the input. Flush the VM and
1914 			 * return the buffer to the main task.
1915 			 */
1916 			if (panicstr && hp->helper != MAINHELPER)
1917 				hat_flush_range(kas.a_hat,
1918 				    hp->cpin->buf, hp->cpin->size);
1919 			dumpsys_errmsg(hp, NULL);
1920 			CQ_PUT(mainq, hp->cpin, CBUF_USEDMAP);
1921 			hp->cpin = NULL;
1922 		}
1923 	}
1924 
1925 	return (hp->cpin != NULL);
1926 }
1927 
1928 /*
1929  * Compress size bytes starting at buf with bzip2
1930  * mode:
1931  *	BZ_RUN		add one more compressed page
1932  *	BZ_FINISH	no more input, flush the state
1933  */
1934 static void
1935 dumpsys_bzrun(helper_t *hp, void *buf, size_t size, int mode)
1936 {
1937 	dumpsync_t *ds = hp->ds;
1938 	const int CSIZE = sizeof (dumpcsize_t);
1939 	bz_stream *ps = &hp->bzstream;
1940 	int rc = 0;
1941 	uint32_t csize;
1942 	dumpcsize_t cs;
1943 
1944 	/* Set input pointers to new input page */
1945 	if (size > 0) {
1946 		ps->avail_in = size;
1947 		ps->next_in = buf;
1948 	}
1949 
1950 	/* CONSTCOND */
1951 	while (1) {
1952 
1953 		/* Quit when all input has been consumed */
1954 		if (ps->avail_in == 0 && mode == BZ_RUN)
1955 			break;
1956 
1957 		/* Get a new output buffer */
1958 		if (hp->cpout == NULL) {
1959 			HRSTART(hp->perpage, outwait);
1960 			hp->cpout = CQ_GET(freebufq);
1961 			HRSTOP(hp->perpage, outwait);
1962 			ps->avail_out = hp->cpout->size - CSIZE;
1963 			ps->next_out = hp->cpout->buf + CSIZE;
1964 		}
1965 
1966 		/* Compress input, or finalize */
1967 		HRSTART(hp->perpage, compress);
1968 		rc = BZ2_bzCompress(ps, mode);
1969 		HRSTOP(hp->perpage, compress);
1970 
1971 		/* Check for error */
1972 		if (mode == BZ_RUN && rc != BZ_RUN_OK) {
1973 			dumpsys_errmsg(hp, "%d: BZ_RUN error %s at page %lx\n",
1974 			    hp->helper, BZ2_bzErrorString(rc),
1975 			    hp->cpin->pagenum);
1976 			break;
1977 		}
1978 
1979 		/* Write the buffer if it is full, or we are flushing */
1980 		if (ps->avail_out == 0 || mode == BZ_FINISH) {
1981 			csize = hp->cpout->size - CSIZE - ps->avail_out;
1982 			cs = DUMP_SET_TAG(csize, hp->tag);
1983 			if (csize > 0) {
1984 				(void) memcpy(hp->cpout->buf, &cs, CSIZE);
1985 				dumpsys_swrite(hp, hp->cpout, csize + CSIZE);
1986 				hp->cpout = NULL;
1987 			}
1988 		}
1989 
1990 		/* Check for final complete */
1991 		if (mode == BZ_FINISH) {
1992 			if (rc == BZ_STREAM_END)
1993 				break;
1994 			if (rc != BZ_FINISH_OK) {
1995 				dumpsys_errmsg(hp, "%d: BZ_FINISH error %s\n",
1996 				    hp->helper, BZ2_bzErrorString(rc));
1997 				break;
1998 			}
1999 		}
2000 	}
2001 
2002 	/* Cleanup state and buffers */
2003 	if (mode == BZ_FINISH) {
2004 
2005 		/* Reset state so that it is re-usable. */
2006 		(void) BZ2_bzCompressReset(&hp->bzstream);
2007 
2008 		/* Give any unused outout buffer to the main task */
2009 		if (hp->cpout != NULL) {
2010 			hp->cpout->used = 0;
2011 			CQ_PUT(mainq, hp->cpout, CBUF_ERRMSG);
2012 			hp->cpout = NULL;
2013 		}
2014 	}
2015 }
2016 
2017 static void
2018 dumpsys_bz2compress(helper_t *hp)
2019 {
2020 	dumpsync_t *ds = hp->ds;
2021 	dumpstreamhdr_t sh;
2022 
2023 	(void) strcpy(sh.stream_magic, DUMP_STREAM_MAGIC);
2024 	sh.stream_pagenum = (pgcnt_t)-1;
2025 	sh.stream_npages = 0;
2026 	hp->cpin = NULL;
2027 	hp->cpout = NULL;
2028 	hp->cperr = NULL;
2029 	hp->in = 0;
2030 	hp->out = 0;
2031 	hp->bzstream.avail_in = 0;
2032 
2033 	/* Bump reference to mainq while we are running */
2034 	CQ_OPEN(mainq);
2035 
2036 	/* Get one page at a time */
2037 	while (dumpsys_sread(hp)) {
2038 		if (sh.stream_pagenum != hp->cpin->pagenum) {
2039 			sh.stream_pagenum = hp->cpin->pagenum;
2040 			sh.stream_npages = btop(hp->cpin->used);
2041 			dumpsys_bzrun(hp, &sh, sizeof (sh), BZ_RUN);
2042 		}
2043 		dumpsys_bzrun(hp, hp->page, PAGESIZE, 0);
2044 	}
2045 
2046 	/* Done with input, flush any partial buffer */
2047 	if (sh.stream_pagenum != (pgcnt_t)-1) {
2048 		dumpsys_bzrun(hp, NULL, 0, BZ_FINISH);
2049 		dumpsys_errmsg(hp, NULL);
2050 	}
2051 
2052 	ASSERT(hp->cpin == NULL && hp->cpout == NULL && hp->cperr == NULL);
2053 
2054 	/* Decrement main queue count, we are done */
2055 	CQ_CLOSE(mainq);
2056 }
2057 
2058 /*
2059  * Compress with lzjb
2060  * write stream block if full or size==0
2061  * if csize==0 write stream header, else write <csize, data>
2062  * size==0 is a call to flush a buffer
2063  * hp->cpout is the buffer we are flushing or filling
2064  * hp->out is the next index to fill data
2065  * osize is either csize+data, or the size of a stream header
2066  */
2067 static void
2068 dumpsys_lzjbrun(helper_t *hp, size_t csize, void *buf, size_t size)
2069 {
2070 	dumpsync_t *ds = hp->ds;
2071 	const int CSIZE = sizeof (dumpcsize_t);
2072 	dumpcsize_t cs;
2073 	size_t osize = csize > 0 ? CSIZE + size : size;
2074 
2075 	/* If flush, and there is no buffer, just return */
2076 	if (size == 0 && hp->cpout == NULL)
2077 		return;
2078 
2079 	/* If flush, or cpout is full, write it out */
2080 	if (size == 0 ||
2081 	    hp->cpout != NULL && hp->out + osize > hp->cpout->size) {
2082 
2083 		/* Set tag+size word at the front of the stream block. */
2084 		cs = DUMP_SET_TAG(hp->out - CSIZE, hp->tag);
2085 		(void) memcpy(hp->cpout->buf, &cs, CSIZE);
2086 
2087 		/* Write block to dump file. */
2088 		dumpsys_swrite(hp, hp->cpout, hp->out);
2089 
2090 		/* Clear pointer to indicate we need a new buffer */
2091 		hp->cpout = NULL;
2092 
2093 		/* flushing, we are done */
2094 		if (size == 0)
2095 			return;
2096 	}
2097 
2098 	/* Get an output buffer if we dont have one. */
2099 	if (hp->cpout == NULL) {
2100 		HRSTART(hp->perpage, outwait);
2101 		hp->cpout = CQ_GET(freebufq);
2102 		HRSTOP(hp->perpage, outwait);
2103 		hp->out = CSIZE;
2104 	}
2105 
2106 	/* Store csize word. This is the size of compressed data. */
2107 	if (csize > 0) {
2108 		cs = DUMP_SET_TAG(csize, 0);
2109 		(void) memcpy(hp->cpout->buf + hp->out, &cs, CSIZE);
2110 		hp->out += CSIZE;
2111 	}
2112 
2113 	/* Store the data. */
2114 	(void) memcpy(hp->cpout->buf + hp->out, buf, size);
2115 	hp->out += size;
2116 }
2117 
2118 static void
2119 dumpsys_lzjbcompress(helper_t *hp)
2120 {
2121 	dumpsync_t *ds = hp->ds;
2122 	size_t csize;
2123 	dumpstreamhdr_t sh;
2124 
2125 	(void) strcpy(sh.stream_magic, DUMP_STREAM_MAGIC);
2126 	sh.stream_pagenum = (pfn_t)-1;
2127 	sh.stream_npages = 0;
2128 	hp->cpin = NULL;
2129 	hp->cpout = NULL;
2130 	hp->cperr = NULL;
2131 	hp->in = 0;
2132 	hp->out = 0;
2133 
2134 	/* Bump reference to mainq while we are running */
2135 	CQ_OPEN(mainq);
2136 
2137 	/* Get one page at a time */
2138 	while (dumpsys_sread(hp)) {
2139 
2140 		/* Create a stream header for each new input map */
2141 		if (sh.stream_pagenum != hp->cpin->pagenum) {
2142 			sh.stream_pagenum = hp->cpin->pagenum;
2143 			sh.stream_npages = btop(hp->cpin->used);
2144 			dumpsys_lzjbrun(hp, 0, &sh, sizeof (sh));
2145 		}
2146 
2147 		/* Compress one page */
2148 		HRSTART(hp->perpage, compress);
2149 		csize = compress(hp->page, hp->lzbuf, PAGESIZE);
2150 		HRSTOP(hp->perpage, compress);
2151 
2152 		/* Add csize+data to output block */
2153 		ASSERT(csize > 0 && csize <= PAGESIZE);
2154 		dumpsys_lzjbrun(hp, csize, hp->lzbuf, csize);
2155 	}
2156 
2157 	/* Done with input, flush any partial buffer */
2158 	if (sh.stream_pagenum != (pfn_t)-1) {
2159 		dumpsys_lzjbrun(hp, 0, NULL, 0);
2160 		dumpsys_errmsg(hp, NULL);
2161 	}
2162 
2163 	ASSERT(hp->cpin == NULL && hp->cpout == NULL && hp->cperr == NULL);
2164 
2165 	/* Decrement main queue count, we are done */
2166 	CQ_CLOSE(mainq);
2167 }
2168 
2169 /*
2170  * Dump helper called from panic_idle() to compress pages.  CPUs in
2171  * this path must not call most kernel services.
2172  *
2173  * During panic, all but one of the CPUs is idle. These CPUs are used
2174  * as helpers working in parallel to copy and compress memory
2175  * pages. During a panic, however, these processors cannot call any
2176  * kernel services. This is because mutexes become no-ops during
2177  * panic, and, cross-call interrupts are inhibited.  Therefore, during
2178  * panic dump the helper CPUs communicate with the panic CPU using
2179  * memory variables. All memory mapping and I/O is performed by the
2180  * panic CPU.
2181  *
2182  * At dump configuration time, helper_lock is set and helpers_wanted
2183  * is 0. dumpsys() decides whether to set helpers_wanted before
2184  * clearing helper_lock.
2185  *
2186  * At panic time, idle CPUs spin-wait on helper_lock, then alternately
2187  * take the lock and become a helper, or return.
2188  */
2189 void
2190 dumpsys_helper()
2191 {
2192 	if (!dumpcfg.helper_present)
2193 		dumpcfg.helper_present = 1;
2194 	dumpsys_spinlock(&dumpcfg.helper_lock);
2195 	if (dumpcfg.helpers_wanted) {
2196 		helper_t *hp, *hpend = &dumpcfg.helper[dumpcfg.nhelper];
2197 
2198 		for (hp = dumpcfg.helper; hp != hpend; hp++) {
2199 			if (hp->helper == FREEHELPER) {
2200 				hp->helper = CPU->cpu_id;
2201 				BT_SET(dumpcfg.helpermap, CPU->cpu_seqid);
2202 
2203 				dumpsys_spinunlock(&dumpcfg.helper_lock);
2204 
2205 				if (dumpcfg.clevel < DUMP_CLEVEL_BZIP2)
2206 					dumpsys_lzjbcompress(hp);
2207 				else
2208 					dumpsys_bz2compress(hp);
2209 
2210 				hp->helper = DONEHELPER;
2211 				return;
2212 			}
2213 		}
2214 
2215 		/* No more helpers are needed. */
2216 		dumpcfg.helpers_wanted = 0;
2217 
2218 	}
2219 	dumpsys_spinunlock(&dumpcfg.helper_lock);
2220 }
2221 
2222 /*
2223  * No-wait helper callable in spin loops.
2224  *
2225  * Do not wait for helper_lock. Just check helpers_wanted. The caller
2226  * may decide to continue. This is the "c)ontinue, s)ync, r)eset? s"
2227  * case.
2228  */
2229 void
2230 dumpsys_helper_nw()
2231 {
2232 	if (!dumpcfg.helper_present)
2233 		dumpcfg.helper_present = 1;
2234 	if (dumpcfg.helpers_wanted)
2235 		dumpsys_helper();
2236 }
2237 
2238 /*
2239  * Dump helper for live dumps.
2240  * These run as a system task.
2241  */
2242 static void
2243 dumpsys_live_helper(void *arg)
2244 {
2245 	helper_t *hp = arg;
2246 
2247 	BT_ATOMIC_SET(dumpcfg.helpermap, CPU->cpu_seqid);
2248 	if (dumpcfg.clevel < DUMP_CLEVEL_BZIP2)
2249 		dumpsys_lzjbcompress(hp);
2250 	else
2251 		dumpsys_bz2compress(hp);
2252 }
2253 
2254 /*
2255  * Compress one page with lzjb (single threaded case)
2256  */
2257 static void
2258 dumpsys_lzjb_page(helper_t *hp, cbuf_t *cp)
2259 {
2260 	dumpsync_t *ds = hp->ds;
2261 	uint32_t csize;
2262 
2263 	hp->helper = MAINHELPER;
2264 	hp->in = 0;
2265 	hp->used = 0;
2266 	hp->cpin = cp;
2267 	while (hp->used < cp->used) {
2268 		HRSTART(hp->perpage, copy);
2269 		hp->in = dumpsys_copy_page(hp, hp->in);
2270 		hp->used += PAGESIZE;
2271 		HRSTOP(hp->perpage, copy);
2272 
2273 		HRSTART(hp->perpage, compress);
2274 		csize = compress(hp->page, hp->lzbuf, PAGESIZE);
2275 		HRSTOP(hp->perpage, compress);
2276 
2277 		HRSTART(hp->perpage, write);
2278 		dumpvp_write(&csize, sizeof (csize));
2279 		dumpvp_write(hp->lzbuf, csize);
2280 		HRSTOP(hp->perpage, write);
2281 	}
2282 	CQ_PUT(mainq, hp->cpin, CBUF_USEDMAP);
2283 	hp->cpin = NULL;
2284 }
2285 
2286 /*
2287  * Main task to dump pages. This is called on the dump CPU.
2288  */
2289 static void
2290 dumpsys_main_task(void *arg)
2291 {
2292 	dumpsync_t *ds = arg;
2293 	pgcnt_t pagenum = 0, bitnum = 0, hibitnum;
2294 	dumpmlw_t mlw;
2295 	cbuf_t *cp;
2296 	pgcnt_t baseoff, pfnoff;
2297 	pfn_t base, pfn;
2298 	int sec;
2299 
2300 	dump_init_memlist_walker(&mlw);
2301 
2302 	/* CONSTCOND */
2303 	while (1) {
2304 
2305 		if (ds->percent > ds->percent_done) {
2306 			ds->percent_done = ds->percent;
2307 			sec = (gethrtime() - ds->start) / 1000 / 1000 / 1000;
2308 			uprintf("^\r%2d:%02d %3d%% done",
2309 			    sec / 60, sec % 60, ds->percent);
2310 			ds->neednl = 1;
2311 		}
2312 
2313 		while (CQ_IS_EMPTY(mainq) && !CQ_IS_EMPTY(writerq)) {
2314 
2315 			/* the writerq never blocks */
2316 			cp = CQ_GET(writerq);
2317 			if (cp == NULL)
2318 				break;
2319 
2320 			dump_timeleft = dump_timeout;
2321 
2322 			HRSTART(ds->perpage, write);
2323 			dumpvp_write(cp->buf, cp->used);
2324 			HRSTOP(ds->perpage, write);
2325 
2326 			CQ_PUT(freebufq, cp, CBUF_FREEBUF);
2327 		}
2328 
2329 		/*
2330 		 * Wait here for some buffers to process. Returns NULL
2331 		 * when all helpers have terminated and all buffers
2332 		 * have been processed.
2333 		 */
2334 		cp = CQ_GET(mainq);
2335 
2336 		if (cp == NULL) {
2337 
2338 			/* Drain the write queue. */
2339 			if (!CQ_IS_EMPTY(writerq))
2340 				continue;
2341 
2342 			/* Main task exits here. */
2343 			break;
2344 		}
2345 
2346 		dump_timeleft = dump_timeout;
2347 
2348 		switch (cp->state) {
2349 
2350 		case CBUF_FREEMAP:
2351 
2352 			/*
2353 			 * Note that we drop CBUF_FREEMAP buffers on
2354 			 * the floor (they will not be on any cqueue)
2355 			 * when we no longer need them.
2356 			 */
2357 			if (bitnum >= dumpcfg.bitmapsize)
2358 				break;
2359 
2360 			if (dump_ioerr) {
2361 				bitnum = dumpcfg.bitmapsize;
2362 				CQ_CLOSE(helperq);
2363 				break;
2364 			}
2365 
2366 			HRSTART(ds->perpage, bitmap);
2367 			for (; bitnum < dumpcfg.bitmapsize; bitnum++)
2368 				if (BT_TEST(dumpcfg.bitmap, bitnum))
2369 					break;
2370 			HRSTOP(ds->perpage, bitmap);
2371 			dump_timeleft = dump_timeout;
2372 
2373 			if (bitnum >= dumpcfg.bitmapsize) {
2374 				CQ_CLOSE(helperq);
2375 				break;
2376 			}
2377 
2378 			/*
2379 			 * Try to map CBUF_MAPSIZE ranges. Can't
2380 			 * assume that memory segment size is a
2381 			 * multiple of CBUF_MAPSIZE. Can't assume that
2382 			 * the segment starts on a CBUF_MAPSIZE
2383 			 * boundary.
2384 			 */
2385 			pfn = dump_bitnum_to_pfn(bitnum, &mlw);
2386 			ASSERT(pfn != PFN_INVALID);
2387 			ASSERT(bitnum + mlw.mpleft <= dumpcfg.bitmapsize);
2388 
2389 			base = P2ALIGN(pfn, CBUF_MAPNP);
2390 			if (base < mlw.mpaddr) {
2391 				base = mlw.mpaddr;
2392 				baseoff = P2PHASE(base, CBUF_MAPNP);
2393 			} else {
2394 				baseoff = 0;
2395 			}
2396 
2397 			pfnoff = pfn - base;
2398 			if (pfnoff + mlw.mpleft < CBUF_MAPNP) {
2399 				hibitnum = bitnum + mlw.mpleft;
2400 				cp->size = ptob(pfnoff + mlw.mpleft);
2401 			} else {
2402 				hibitnum = bitnum - pfnoff + CBUF_MAPNP -
2403 				    baseoff;
2404 				cp->size = CBUF_MAPSIZE - ptob(baseoff);
2405 			}
2406 
2407 			cp->pfn = pfn;
2408 			cp->bitnum = bitnum++;
2409 			cp->pagenum = pagenum++;
2410 			cp->off = ptob(pfnoff);
2411 
2412 			for (; bitnum < hibitnum; bitnum++)
2413 				if (BT_TEST(dumpcfg.bitmap, bitnum))
2414 					pagenum++;
2415 
2416 			dump_timeleft = dump_timeout;
2417 			cp->used = ptob(pagenum - cp->pagenum);
2418 
2419 			HRSTART(ds->perpage, map);
2420 			hat_devload(kas.a_hat, cp->buf, cp->size, base,
2421 			    PROT_READ, HAT_LOAD_NOCONSIST);
2422 			HRSTOP(ds->perpage, map);
2423 
2424 			ds->pages_mapped += btop(cp->size);
2425 			ds->pages_used += pagenum - cp->pagenum;
2426 
2427 			CQ_OPEN(mainq);
2428 
2429 			/*
2430 			 * If there are no helpers the main task does
2431 			 * non-streams lzjb compress.
2432 			 */
2433 			if (dumpcfg.clevel == 0) {
2434 				dumpsys_lzjb_page(dumpcfg.helper, cp);
2435 				break;
2436 			}
2437 
2438 			/* pass mapped pages to a helper */
2439 			CQ_PUT(helperq, cp, CBUF_INREADY);
2440 
2441 			/* the last page was done */
2442 			if (bitnum >= dumpcfg.bitmapsize)
2443 				CQ_CLOSE(helperq);
2444 
2445 			break;
2446 
2447 		case CBUF_USEDMAP:
2448 
2449 			ds->npages += btop(cp->used);
2450 
2451 			HRSTART(ds->perpage, unmap);
2452 			hat_unload(kas.a_hat, cp->buf, cp->size, HAT_UNLOAD);
2453 			HRSTOP(ds->perpage, unmap);
2454 
2455 			if (bitnum < dumpcfg.bitmapsize)
2456 				CQ_PUT(mainq, cp, CBUF_FREEMAP);
2457 			CQ_CLOSE(mainq);
2458 
2459 			ASSERT(ds->npages <= dumphdr->dump_npages);
2460 			ds->percent = ds->npages * 100LL / dumphdr->dump_npages;
2461 			break;
2462 
2463 		case CBUF_WRITE:
2464 
2465 			CQ_PUT(writerq, cp, CBUF_WRITE);
2466 			break;
2467 
2468 		case CBUF_ERRMSG:
2469 
2470 			if (cp->used > 0) {
2471 				cp->buf[cp->size - 2] = '\n';
2472 				cp->buf[cp->size - 1] = '\0';
2473 				if (ds->neednl) {
2474 					uprintf("\n%s", cp->buf);
2475 					ds->neednl = 0;
2476 				} else {
2477 					uprintf("%s", cp->buf);
2478 				}
2479 				/* wait for console output */
2480 				drv_usecwait(200000);
2481 				dump_timeleft = dump_timeout;
2482 			}
2483 			CQ_PUT(freebufq, cp, CBUF_FREEBUF);
2484 			break;
2485 
2486 		default:
2487 			uprintf("dump: unexpected buffer state %d, "
2488 			    "buffer will be lost\n", cp->state);
2489 			break;
2490 
2491 		} /* end switch */
2492 
2493 	} /* end while(1) */
2494 }
2495 
2496 #ifdef	COLLECT_METRICS
2497 size_t
2498 dumpsys_metrics(dumpsync_t *ds, char *buf, size_t size)
2499 {
2500 	dumpcfg_t *cfg = &dumpcfg;
2501 	int myid = CPU->cpu_seqid;
2502 	int i, compress_ratio;
2503 	int sec, iorate;
2504 	helper_t *hp, *hpend = &cfg->helper[cfg->nhelper];
2505 	char *e = buf + size;
2506 	char *p = buf;
2507 
2508 	sec = ds->elapsed / (1000 * 1000 * 1000ULL);
2509 	if (sec < 1)
2510 		sec = 1;
2511 
2512 	if (ds->iotime < 1)
2513 		ds->iotime = 1;
2514 	iorate = (ds->nwrite * 100000ULL) / ds->iotime;
2515 
2516 	compress_ratio = 100LL * ds->npages / btopr(ds->nwrite + 1);
2517 
2518 #define	P(...) (p += p < e ? snprintf(p, e - p, __VA_ARGS__) : 0)
2519 
2520 	P("Master cpu_seqid,%d\n", CPU->cpu_seqid);
2521 	P("Master cpu_id,%d\n", CPU->cpu_id);
2522 	P("dump_flags,0x%x\n", dumphdr->dump_flags);
2523 	P("dump_ioerr,%d\n", dump_ioerr);
2524 
2525 	P("Helpers:\n");
2526 	for (i = 0; i < ncpus; i++) {
2527 		if ((i & 15) == 0)
2528 			P(",,%03d,", i);
2529 		if (i == myid)
2530 			P("   M");
2531 		else if (BT_TEST(cfg->helpermap, i))
2532 			P("%4d", cpu_seq[i]->cpu_id);
2533 		else
2534 			P("   *");
2535 		if ((i & 15) == 15)
2536 			P("\n");
2537 	}
2538 
2539 	P("ncbuf_used,%d\n", cfg->ncbuf_used);
2540 	P("ncmap,%d\n", cfg->ncmap);
2541 
2542 	P("Found %ldM ranges,%ld\n", (CBUF_MAPSIZE / DUMP_1MB), cfg->found4m);
2543 	P("Found small pages,%ld\n", cfg->foundsm);
2544 
2545 	P("Compression level,%d\n", cfg->clevel);
2546 	P("Compression type,%s %s\n", cfg->clevel == 0 ? "serial" : "parallel",
2547 	    cfg->clevel >= DUMP_CLEVEL_BZIP2 ? "bzip2" : "lzjb");
2548 	P("Compression ratio,%d.%02d\n", compress_ratio / 100, compress_ratio %
2549 	    100);
2550 	P("nhelper_used,%d\n", cfg->nhelper_used);
2551 
2552 	P("Dump I/O rate MBS,%d.%02d\n", iorate / 100, iorate % 100);
2553 	P("..total bytes,%lld\n", (u_longlong_t)ds->nwrite);
2554 	P("..total nsec,%lld\n", (u_longlong_t)ds->iotime);
2555 	P("dumpbuf.iosize,%ld\n", dumpbuf.iosize);
2556 	P("dumpbuf.size,%ld\n", dumpbuf.size);
2557 
2558 	P("Dump pages/sec,%llu\n", (u_longlong_t)ds->npages / sec);
2559 	P("Dump pages,%llu\n", (u_longlong_t)ds->npages);
2560 	P("Dump time,%d\n", sec);
2561 
2562 	if (ds->pages_mapped > 0)
2563 		P("per-cent map utilization,%d\n", (int)((100 * ds->pages_used)
2564 		    / ds->pages_mapped));
2565 
2566 	P("\nPer-page metrics:\n");
2567 	if (ds->npages > 0) {
2568 		for (hp = cfg->helper; hp != hpend; hp++) {
2569 #define	PERPAGE(x)	ds->perpage.x += hp->perpage.x;
2570 			PERPAGES;
2571 #undef PERPAGE
2572 		}
2573 #define	PERPAGE(x) \
2574 		P("%s nsec/page,%d\n", #x, (int)(ds->perpage.x / ds->npages));
2575 		PERPAGES;
2576 #undef PERPAGE
2577 		P("freebufq.empty,%d\n", (int)(ds->freebufq.empty /
2578 		    ds->npages));
2579 		P("helperq.empty,%d\n", (int)(ds->helperq.empty /
2580 		    ds->npages));
2581 		P("writerq.empty,%d\n", (int)(ds->writerq.empty /
2582 		    ds->npages));
2583 		P("mainq.empty,%d\n", (int)(ds->mainq.empty / ds->npages));
2584 
2585 		P("I/O wait nsec/page,%llu\n", (u_longlong_t)(ds->iowait /
2586 		    ds->npages));
2587 	}
2588 #undef P
2589 	if (p < e)
2590 		bzero(p, e - p);
2591 	return (p - buf);
2592 }
2593 #endif	/* COLLECT_METRICS */
2594 
2595 /*
2596  * Dump the system.
2597  */
2598 void
2599 dumpsys(void)
2600 {
2601 	dumpsync_t *ds = &dumpsync;
2602 	taskq_t *livetaskq = NULL;
2603 	pfn_t pfn;
2604 	pgcnt_t bitnum;
2605 	proc_t *p;
2606 	helper_t *hp, *hpend = &dumpcfg.helper[dumpcfg.nhelper];
2607 	cbuf_t *cp;
2608 	pid_t npids, pidx;
2609 	char *content;
2610 	char *buf;
2611 	size_t size;
2612 	int save_dump_clevel;
2613 	dumpmlw_t mlw;
2614 	dumpcsize_t datatag;
2615 	dumpdatahdr_t datahdr;
2616 
2617 	if (dumpvp == NULL || dumphdr == NULL) {
2618 		uprintf("skipping system dump - no dump device configured\n");
2619 		if (panicstr) {
2620 			dumpcfg.helpers_wanted = 0;
2621 			dumpsys_spinunlock(&dumpcfg.helper_lock);
2622 		}
2623 		return;
2624 	}
2625 	dumpbuf.cur = dumpbuf.start;
2626 
2627 	/* clear the sync variables */
2628 	ASSERT(dumpcfg.nhelper > 0);
2629 	bzero(ds, sizeof (*ds));
2630 	ds->dumpcpu = CPU->cpu_id;
2631 
2632 	/*
2633 	 * Calculate the starting block for dump.  If we're dumping on a
2634 	 * swap device, start 1/5 of the way in; otherwise, start at the
2635 	 * beginning.  And never use the first page -- it may be a disk label.
2636 	 */
2637 	if (dumpvp->v_flag & VISSWAP)
2638 		dumphdr->dump_start = P2ROUNDUP(dumpvp_size / 5, DUMP_OFFSET);
2639 	else
2640 		dumphdr->dump_start = DUMP_OFFSET;
2641 
2642 	dumphdr->dump_flags = DF_VALID | DF_COMPLETE | DF_LIVE | DF_COMPRESSED;
2643 	dumphdr->dump_crashtime = gethrestime_sec();
2644 	dumphdr->dump_npages = 0;
2645 	dumphdr->dump_nvtop = 0;
2646 	bzero(dumpcfg.bitmap, BT_SIZEOFMAP(dumpcfg.bitmapsize));
2647 	dump_timeleft = dump_timeout;
2648 
2649 	if (panicstr) {
2650 		dumphdr->dump_flags &= ~DF_LIVE;
2651 		(void) VOP_DUMPCTL(dumpvp, DUMP_FREE, NULL, NULL);
2652 		(void) VOP_DUMPCTL(dumpvp, DUMP_ALLOC, NULL, NULL);
2653 		(void) vsnprintf(dumphdr->dump_panicstring, DUMP_PANICSIZE,
2654 		    panicstr, panicargs);
2655 
2656 	}
2657 
2658 	if (dump_conflags & DUMP_ALL)
2659 		content = "all";
2660 	else if (dump_conflags & DUMP_CURPROC)
2661 		content = "kernel + curproc";
2662 	else
2663 		content = "kernel";
2664 	uprintf("dumping to %s, offset %lld, content: %s\n", dumppath,
2665 	    dumphdr->dump_start, content);
2666 
2667 	/* Make sure nodename is current */
2668 	bcopy(utsname.nodename, dumphdr->dump_utsname.nodename, SYS_NMLN);
2669 
2670 	/*
2671 	 * If this is a live dump, try to open a VCHR vnode for better
2672 	 * performance. We must take care to flush the buffer cache
2673 	 * first.
2674 	 */
2675 	if (!panicstr) {
2676 		vnode_t *cdev_vp, *cmn_cdev_vp;
2677 
2678 		ASSERT(dumpbuf.cdev_vp == NULL);
2679 		cdev_vp = makespecvp(VTOS(dumpvp)->s_dev, VCHR);
2680 		if (cdev_vp != NULL) {
2681 			cmn_cdev_vp = common_specvp(cdev_vp);
2682 			if (VOP_OPEN(&cmn_cdev_vp, FREAD | FWRITE, kcred, NULL)
2683 			    == 0) {
2684 				if (vn_has_cached_data(dumpvp))
2685 					(void) pvn_vplist_dirty(dumpvp, 0, NULL,
2686 					    B_INVAL | B_TRUNC, kcred);
2687 				dumpbuf.cdev_vp = cmn_cdev_vp;
2688 			} else {
2689 				VN_RELE(cdev_vp);
2690 			}
2691 		}
2692 	}
2693 
2694 	/*
2695 	 * Store a hires timestamp so we can look it up during debugging.
2696 	 */
2697 	lbolt_debug_entry();
2698 
2699 	/*
2700 	 * Leave room for the message and ereport save areas and terminal dump
2701 	 * header.
2702 	 */
2703 	dumpbuf.vp_limit = dumpvp_size - DUMP_LOGSIZE - DUMP_OFFSET -
2704 	    DUMP_ERPTSIZE;
2705 
2706 	/*
2707 	 * Write out the symbol table.  It's no longer compressed,
2708 	 * so its 'size' and 'csize' are equal.
2709 	 */
2710 	dumpbuf.vp_off = dumphdr->dump_ksyms = dumphdr->dump_start + PAGESIZE;
2711 	dumphdr->dump_ksyms_size = dumphdr->dump_ksyms_csize =
2712 	    ksyms_snapshot(dumpvp_ksyms_write, NULL, LONG_MAX);
2713 
2714 	/*
2715 	 * Write out the translation map.
2716 	 */
2717 	dumphdr->dump_map = dumpvp_flush();
2718 	dump_as(&kas);
2719 	dumphdr->dump_nvtop += dump_plat_addr();
2720 
2721 	/*
2722 	 * call into hat, which may have unmapped pages that also need to
2723 	 * be in the dump
2724 	 */
2725 	hat_dump();
2726 
2727 	if (dump_conflags & DUMP_ALL) {
2728 		mutex_enter(&pidlock);
2729 
2730 		for (npids = 0, p = practive; p != NULL; p = p->p_next)
2731 			dumpcfg.pids[npids++] = p->p_pid;
2732 
2733 		mutex_exit(&pidlock);
2734 
2735 		for (pidx = 0; pidx < npids; pidx++)
2736 			(void) dump_process(dumpcfg.pids[pidx]);
2737 
2738 		dump_init_memlist_walker(&mlw);
2739 		for (bitnum = 0; bitnum < dumpcfg.bitmapsize; bitnum++) {
2740 			dump_timeleft = dump_timeout;
2741 			pfn = dump_bitnum_to_pfn(bitnum, &mlw);
2742 			/*
2743 			 * Some hypervisors do not have all pages available to
2744 			 * be accessed by the guest OS.  Check for page
2745 			 * accessibility.
2746 			 */
2747 			if (plat_hold_page(pfn, PLAT_HOLD_NO_LOCK, NULL) !=
2748 			    PLAT_HOLD_OK)
2749 				continue;
2750 			BT_SET(dumpcfg.bitmap, bitnum);
2751 		}
2752 		dumphdr->dump_npages = dumpcfg.bitmapsize;
2753 		dumphdr->dump_flags |= DF_ALL;
2754 
2755 	} else if (dump_conflags & DUMP_CURPROC) {
2756 		/*
2757 		 * Determine which pid is to be dumped.  If we're panicking, we
2758 		 * dump the process associated with panic_thread (if any).  If
2759 		 * this is a live dump, we dump the process associated with
2760 		 * curthread.
2761 		 */
2762 		npids = 0;
2763 		if (panicstr) {
2764 			if (panic_thread != NULL &&
2765 			    panic_thread->t_procp != NULL &&
2766 			    panic_thread->t_procp != &p0) {
2767 				dumpcfg.pids[npids++] =
2768 				    panic_thread->t_procp->p_pid;
2769 			}
2770 		} else {
2771 			dumpcfg.pids[npids++] = curthread->t_procp->p_pid;
2772 		}
2773 
2774 		if (npids && dump_process(dumpcfg.pids[0]) == 0)
2775 			dumphdr->dump_flags |= DF_CURPROC;
2776 		else
2777 			dumphdr->dump_flags |= DF_KERNEL;
2778 
2779 	} else {
2780 		dumphdr->dump_flags |= DF_KERNEL;
2781 	}
2782 
2783 	dumphdr->dump_hashmask = (1 << highbit(dumphdr->dump_nvtop - 1)) - 1;
2784 
2785 	/*
2786 	 * Write out the pfn table.
2787 	 */
2788 	dumphdr->dump_pfn = dumpvp_flush();
2789 	dump_init_memlist_walker(&mlw);
2790 	for (bitnum = 0; bitnum < dumpcfg.bitmapsize; bitnum++) {
2791 		dump_timeleft = dump_timeout;
2792 		if (!BT_TEST(dumpcfg.bitmap, bitnum))
2793 			continue;
2794 		pfn = dump_bitnum_to_pfn(bitnum, &mlw);
2795 		ASSERT(pfn != PFN_INVALID);
2796 		dumpvp_write(&pfn, sizeof (pfn_t));
2797 	}
2798 	dump_plat_pfn();
2799 
2800 	/*
2801 	 * Write out all the pages.
2802 	 * Map pages, copy them handling UEs, compress, and write them out.
2803 	 * Cooperate with any helpers running on CPUs in panic_idle().
2804 	 */
2805 	dumphdr->dump_data = dumpvp_flush();
2806 
2807 	bzero(dumpcfg.helpermap, BT_SIZEOFMAP(NCPU));
2808 	ds->live = dumpcfg.clevel > 0 &&
2809 	    (dumphdr->dump_flags & DF_LIVE) != 0;
2810 
2811 	save_dump_clevel = dumpcfg.clevel;
2812 	if (panicstr)
2813 		dumpsys_get_maxmem();
2814 	else if (dumpcfg.clevel >= DUMP_CLEVEL_BZIP2)
2815 		dumpcfg.clevel = DUMP_CLEVEL_LZJB;
2816 
2817 	dumpcfg.nhelper_used = 0;
2818 	for (hp = dumpcfg.helper; hp != hpend; hp++) {
2819 		if (hp->page == NULL) {
2820 			hp->helper = DONEHELPER;
2821 			continue;
2822 		}
2823 		++dumpcfg.nhelper_used;
2824 		hp->helper = FREEHELPER;
2825 		hp->taskqid = NULL;
2826 		hp->ds = ds;
2827 		bzero(&hp->perpage, sizeof (hp->perpage));
2828 		if (dumpcfg.clevel >= DUMP_CLEVEL_BZIP2)
2829 			(void) BZ2_bzCompressReset(&hp->bzstream);
2830 	}
2831 
2832 	CQ_OPEN(freebufq);
2833 	CQ_OPEN(helperq);
2834 
2835 	dumpcfg.ncbuf_used = 0;
2836 	for (cp = dumpcfg.cbuf; cp != &dumpcfg.cbuf[dumpcfg.ncbuf]; cp++) {
2837 		if (cp->buf != NULL) {
2838 			CQ_PUT(freebufq, cp, CBUF_FREEBUF);
2839 			++dumpcfg.ncbuf_used;
2840 		}
2841 	}
2842 
2843 	for (cp = dumpcfg.cmap; cp != &dumpcfg.cmap[dumpcfg.ncmap]; cp++)
2844 		CQ_PUT(mainq, cp, CBUF_FREEMAP);
2845 
2846 	ds->start = gethrtime();
2847 	ds->iowaitts = ds->start;
2848 
2849 	/* start helpers */
2850 	if (ds->live) {
2851 		int n = dumpcfg.nhelper_used;
2852 		int pri = MINCLSYSPRI - 25;
2853 
2854 		livetaskq = taskq_create("LiveDump", n, pri, n, n,
2855 		    TASKQ_PREPOPULATE);
2856 		for (hp = dumpcfg.helper; hp != hpend; hp++) {
2857 			if (hp->page == NULL)
2858 				continue;
2859 			hp->helper = hp - dumpcfg.helper;
2860 			hp->taskqid = taskq_dispatch(livetaskq,
2861 			    dumpsys_live_helper, (void *)hp, TQ_NOSLEEP);
2862 		}
2863 
2864 	} else {
2865 		if (panicstr)
2866 			kmem_dump_begin();
2867 		dumpcfg.helpers_wanted = dumpcfg.clevel > 0;
2868 		dumpsys_spinunlock(&dumpcfg.helper_lock);
2869 	}
2870 
2871 	/* run main task */
2872 	dumpsys_main_task(ds);
2873 
2874 	ds->elapsed = gethrtime() - ds->start;
2875 	if (ds->elapsed < 1)
2876 		ds->elapsed = 1;
2877 
2878 	if (livetaskq != NULL)
2879 		taskq_destroy(livetaskq);
2880 
2881 	if (ds->neednl) {
2882 		uprintf("\n");
2883 		ds->neednl = 0;
2884 	}
2885 
2886 	/* record actual pages dumped */
2887 	dumphdr->dump_npages = ds->npages;
2888 
2889 	/* platform-specific data */
2890 	dumphdr->dump_npages += dump_plat_data(dumpcfg.cbuf[0].buf);
2891 
2892 	/* note any errors by clearing DF_COMPLETE */
2893 	if (dump_ioerr || ds->npages < dumphdr->dump_npages)
2894 		dumphdr->dump_flags &= ~DF_COMPLETE;
2895 
2896 	/* end of stream blocks */
2897 	datatag = 0;
2898 	dumpvp_write(&datatag, sizeof (datatag));
2899 
2900 	bzero(&datahdr, sizeof (datahdr));
2901 
2902 	/* buffer for metrics */
2903 	buf = dumpcfg.cbuf[0].buf;
2904 	size = MIN(dumpcfg.cbuf[0].size, DUMP_OFFSET - sizeof (dumphdr_t) -
2905 	    sizeof (dumpdatahdr_t));
2906 
2907 	/* finish the kmem intercepts, collect kmem verbose info */
2908 	if (panicstr) {
2909 		datahdr.dump_metrics = kmem_dump_finish(buf, size);
2910 		buf += datahdr.dump_metrics;
2911 		size -= datahdr.dump_metrics;
2912 	}
2913 
2914 	/* record in the header whether this is a fault-management panic */
2915 	if (panicstr)
2916 		dumphdr->dump_fm_panic = is_fm_panic();
2917 
2918 	/* compression info in data header */
2919 	datahdr.dump_datahdr_magic = DUMP_DATAHDR_MAGIC;
2920 	datahdr.dump_datahdr_version = DUMP_DATAHDR_VERSION;
2921 	datahdr.dump_maxcsize = CBUF_SIZE;
2922 	datahdr.dump_maxrange = CBUF_MAPSIZE / PAGESIZE;
2923 	datahdr.dump_nstreams = dumpcfg.nhelper_used;
2924 	datahdr.dump_clevel = dumpcfg.clevel;
2925 #ifdef COLLECT_METRICS
2926 	if (dump_metrics_on)
2927 		datahdr.dump_metrics += dumpsys_metrics(ds, buf, size);
2928 #endif
2929 	datahdr.dump_data_csize = dumpvp_flush() - dumphdr->dump_data;
2930 
2931 	/*
2932 	 * Write out the initial and terminal dump headers.
2933 	 */
2934 	dumpbuf.vp_off = dumphdr->dump_start;
2935 	dumpvp_write(dumphdr, sizeof (dumphdr_t));
2936 	(void) dumpvp_flush();
2937 
2938 	dumpbuf.vp_limit = dumpvp_size;
2939 	dumpbuf.vp_off = dumpbuf.vp_limit - DUMP_OFFSET;
2940 	dumpvp_write(dumphdr, sizeof (dumphdr_t));
2941 	dumpvp_write(&datahdr, sizeof (dumpdatahdr_t));
2942 	dumpvp_write(dumpcfg.cbuf[0].buf, datahdr.dump_metrics);
2943 
2944 	(void) dumpvp_flush();
2945 
2946 	uprintf("\r%3d%% done: %llu pages dumped, ",
2947 	    ds->percent_done, (u_longlong_t)ds->npages);
2948 
2949 	if (dump_ioerr == 0) {
2950 		uprintf("dump succeeded\n");
2951 	} else {
2952 		uprintf("dump failed: error %d\n", dump_ioerr);
2953 #ifdef DEBUG
2954 		if (panicstr)
2955 			debug_enter("dump failed");
2956 #endif
2957 	}
2958 
2959 	/*
2960 	 * Write out all undelivered messages.  This has to be the *last*
2961 	 * thing we do because the dump process itself emits messages.
2962 	 */
2963 	if (panicstr) {
2964 		dump_summary();
2965 		dump_ereports();
2966 		dump_messages();
2967 	}
2968 
2969 	delay(2 * hz);	/* let people see the 'done' message */
2970 	dump_timeleft = 0;
2971 	dump_ioerr = 0;
2972 
2973 	/* restore settings after live dump completes */
2974 	if (!panicstr) {
2975 		dumpcfg.clevel = save_dump_clevel;
2976 
2977 		/* release any VCHR open of the dump device */
2978 		if (dumpbuf.cdev_vp != NULL) {
2979 			(void) VOP_CLOSE(dumpbuf.cdev_vp, FREAD | FWRITE, 1, 0,
2980 			    kcred, NULL);
2981 			VN_RELE(dumpbuf.cdev_vp);
2982 			dumpbuf.cdev_vp = NULL;
2983 		}
2984 	}
2985 }
2986 
2987 /*
2988  * This function is called whenever the memory size, as represented
2989  * by the phys_install list, changes.
2990  */
2991 void
2992 dump_resize()
2993 {
2994 	mutex_enter(&dump_lock);
2995 	dumphdr_init();
2996 	dumpbuf_resize();
2997 	dump_update_clevel();
2998 	mutex_exit(&dump_lock);
2999 }
3000 
3001 /*
3002  * This function allows for dynamic resizing of a dump area. It assumes that
3003  * the underlying device has update its appropriate size(9P).
3004  */
3005 int
3006 dumpvp_resize()
3007 {
3008 	int error;
3009 	vattr_t vattr;
3010 
3011 	mutex_enter(&dump_lock);
3012 	vattr.va_mask = AT_SIZE;
3013 	if ((error = VOP_GETATTR(dumpvp, &vattr, 0, kcred, NULL)) != 0) {
3014 		mutex_exit(&dump_lock);
3015 		return (error);
3016 	}
3017 
3018 	if (error == 0 && vattr.va_size < 2 * DUMP_LOGSIZE + DUMP_ERPTSIZE) {
3019 		mutex_exit(&dump_lock);
3020 		return (ENOSPC);
3021 	}
3022 
3023 	dumpvp_size = vattr.va_size & -DUMP_OFFSET;
3024 	mutex_exit(&dump_lock);
3025 	return (0);
3026 }
3027 
3028 int
3029 dump_set_uuid(const char *uuidstr)
3030 {
3031 	const char *ptr;
3032 	int i;
3033 
3034 	if (uuidstr == NULL || strnlen(uuidstr, 36 + 1) != 36)
3035 		return (EINVAL);
3036 
3037 	/* uuid_parse is not common code so check manually */
3038 	for (i = 0, ptr = uuidstr; i < 36; i++, ptr++) {
3039 		switch (i) {
3040 		case 8:
3041 		case 13:
3042 		case 18:
3043 		case 23:
3044 			if (*ptr != '-')
3045 				return (EINVAL);
3046 			break;
3047 
3048 		default:
3049 			if (!isxdigit(*ptr))
3050 				return (EINVAL);
3051 			break;
3052 		}
3053 	}
3054 
3055 	if (dump_osimage_uuid[0] != '\0')
3056 		return (EALREADY);
3057 
3058 	(void) strncpy(dump_osimage_uuid, uuidstr, 36 + 1);
3059 
3060 	cmn_err(CE_CONT, "?This Solaris instance has UUID %s",
3061 	    dump_osimage_uuid);
3062 
3063 	return (0);
3064 }
3065 
3066 const char *
3067 dump_get_uuid(void)
3068 {
3069 	return (dump_osimage_uuid[0] != '\0' ? dump_osimage_uuid : "");
3070 }
3071