xref: /freebsd/sys/kern/kern_dump.c (revision fcb560670601b2a4d87bb31d7531c8dcc37ee71b)
1 /*-
2  * Copyright (c) 2002 Marcel Moolenaar
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include "opt_watchdog.h"
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/conf.h>
35 #include <sys/cons.h>
36 #include <sys/kernel.h>
37 #include <sys/proc.h>
38 #include <sys/kerneldump.h>
39 #ifdef SW_WATCHDOG
40 #include <sys/watchdog.h>
41 #endif
42 #include <vm/vm.h>
43 #include <vm/vm_param.h>
44 #include <vm/pmap.h>
45 #include <machine/dump.h>
46 #include <machine/elf.h>
47 #include <machine/md_var.h>
48 #include <machine/pcb.h>
49 
50 CTASSERT(sizeof(struct kerneldumpheader) == 512);
51 
52 /*
53  * Don't touch the first SIZEOF_METADATA bytes on the dump device. This
54  * is to protect us from metadata and to protect metadata from us.
55  */
56 #define	SIZEOF_METADATA		(64*1024)
57 
58 #define	MD_ALIGN(x)	(((off_t)(x) + PAGE_MASK) & ~PAGE_MASK)
59 #define	DEV_ALIGN(x)	(((off_t)(x) + (DEV_BSIZE-1)) & ~(DEV_BSIZE-1))
60 
61 off_t dumplo;
62 
63 /* Handle buffered writes. */
64 static char buffer[DEV_BSIZE];
65 static size_t fragsz;
66 
67 struct dump_pa dump_map[DUMPSYS_MD_PA_NPAIRS];
68 
69 void
70 dumpsys_gen_pa_init(void)
71 {
72 #if !defined(__sparc__) && !defined(__powerpc__)
73 	int n, idx;
74 
75 	bzero(dump_map, sizeof(dump_map));
76 	for (n = 0; n < sizeof(dump_map) / sizeof(dump_map[0]); n++) {
77 		idx = n * 2;
78 		if (dump_avail[idx] == 0 && dump_avail[idx + 1] == 0)
79 			break;
80 		dump_map[n].pa_start = dump_avail[idx];
81 		dump_map[n].pa_size = dump_avail[idx + 1] - dump_avail[idx];
82 	}
83 #endif
84 }
85 
86 struct dump_pa *
87 dumpsys_gen_pa_next(struct dump_pa *mdp)
88 {
89 
90 	if (mdp == NULL)
91 		return (&dump_map[0]);
92 
93 	mdp++;
94 	if (mdp->pa_size == 0)
95 		mdp = NULL;
96 	return (mdp);
97 }
98 
99 void
100 dumpsys_gen_wbinv_all(void)
101 {
102 }
103 
104 void
105 dumpsys_gen_unmap_chunk(vm_paddr_t pa __unused, size_t chunk __unused,
106     void *va __unused)
107 {
108 }
109 
110 int
111 dumpsys_gen_write_aux_headers(struct dumperinfo *di)
112 {
113 
114 	return (0);
115 }
116 
117 int
118 dumpsys_buf_write(struct dumperinfo *di, char *ptr, size_t sz)
119 {
120 	size_t len;
121 	int error;
122 
123 	while (sz) {
124 		len = DEV_BSIZE - fragsz;
125 		if (len > sz)
126 			len = sz;
127 		bcopy(ptr, buffer + fragsz, len);
128 		fragsz += len;
129 		ptr += len;
130 		sz -= len;
131 		if (fragsz == DEV_BSIZE) {
132 			error = dump_write(di, buffer, 0, dumplo,
133 			    DEV_BSIZE);
134 			if (error)
135 				return (error);
136 			dumplo += DEV_BSIZE;
137 			fragsz = 0;
138 		}
139 	}
140 	return (0);
141 }
142 
143 int
144 dumpsys_buf_flush(struct dumperinfo *di)
145 {
146 	int error;
147 
148 	if (fragsz == 0)
149 		return (0);
150 
151 	error = dump_write(di, buffer, 0, dumplo, DEV_BSIZE);
152 	dumplo += DEV_BSIZE;
153 	fragsz = 0;
154 	return (error);
155 }
156 
157 CTASSERT(PAGE_SHIFT < 20);
158 #define PG2MB(pgs) ((pgs + (1 << (20 - PAGE_SHIFT)) - 1) >> (20 - PAGE_SHIFT))
159 
160 int
161 dumpsys_cb_dumpdata(struct dump_pa *mdp, int seqnr, void *arg)
162 {
163 	struct dumperinfo *di = (struct dumperinfo*)arg;
164 	vm_paddr_t pa;
165 	void *va;
166 	uint64_t pgs;
167 	size_t counter, sz, chunk;
168 	int c, error;
169 	u_int maxdumppgs;
170 
171 	error = 0;	/* catch case in which chunk size is 0 */
172 	counter = 0;	/* Update twiddle every 16MB */
173 	va = 0;
174 	pgs = mdp->pa_size / PAGE_SIZE;
175 	pa = mdp->pa_start;
176 	maxdumppgs = min(di->maxiosize / PAGE_SIZE, MAXDUMPPGS);
177 	if (maxdumppgs == 0)	/* seatbelt */
178 		maxdumppgs = 1;
179 
180 	printf("  chunk %d: %juMB (%ju pages)", seqnr, (uintmax_t)PG2MB(pgs),
181 	    (uintmax_t)pgs);
182 
183 	dumpsys_wbinv_all();
184 	while (pgs) {
185 		chunk = pgs;
186 		if (chunk > maxdumppgs)
187 			chunk = maxdumppgs;
188 		sz = chunk << PAGE_SHIFT;
189 		counter += sz;
190 		if (counter >> 24) {
191 			printf(" %ju", (uintmax_t)PG2MB(pgs));
192 			counter &= (1 << 24) - 1;
193 		}
194 
195 		dumpsys_map_chunk(pa, chunk, &va);
196 #ifdef SW_WATCHDOG
197 		wdog_kern_pat(WD_LASTVAL);
198 #endif
199 
200 		error = dump_write(di, va, 0, dumplo, sz);
201 		dumpsys_unmap_chunk(pa, chunk, va);
202 		if (error)
203 			break;
204 		dumplo += sz;
205 		pgs -= chunk;
206 		pa += sz;
207 
208 		/* Check for user abort. */
209 		c = cncheckc();
210 		if (c == 0x03)
211 			return (ECANCELED);
212 		if (c != -1)
213 			printf(" (CTRL-C to abort) ");
214 	}
215 	printf(" ... %s\n", (error) ? "fail" : "ok");
216 	return (error);
217 }
218 
219 int
220 dumpsys_foreach_chunk(dumpsys_callback_t cb, void *arg)
221 {
222 	struct dump_pa *mdp;
223 	int error, seqnr;
224 
225 	seqnr = 0;
226 	mdp = dumpsys_pa_next(NULL);
227 	while (mdp != NULL) {
228 		error = (*cb)(mdp, seqnr++, arg);
229 		if (error)
230 			return (-error);
231 		mdp = dumpsys_pa_next(mdp);
232 	}
233 	return (seqnr);
234 }
235 
236 static off_t fileofs;
237 
238 static int
239 cb_dumphdr(struct dump_pa *mdp, int seqnr, void *arg)
240 {
241 	struct dumperinfo *di = (struct dumperinfo*)arg;
242 	Elf_Phdr phdr;
243 	uint64_t size;
244 	int error;
245 
246 	size = mdp->pa_size;
247 	bzero(&phdr, sizeof(phdr));
248 	phdr.p_type = PT_LOAD;
249 	phdr.p_flags = PF_R;			/* XXX */
250 	phdr.p_offset = fileofs;
251 #ifdef __powerpc__
252 	phdr.p_vaddr = (do_minidump? mdp->pa_start : ~0L);
253 	phdr.p_paddr = (do_minidump? ~0L : mdp->pa_start);
254 #else
255 	phdr.p_vaddr = mdp->pa_start;
256 	phdr.p_paddr = mdp->pa_start;
257 #endif
258 	phdr.p_filesz = size;
259 	phdr.p_memsz = size;
260 	phdr.p_align = PAGE_SIZE;
261 
262 	error = dumpsys_buf_write(di, (char*)&phdr, sizeof(phdr));
263 	fileofs += phdr.p_filesz;
264 	return (error);
265 }
266 
267 static int
268 cb_size(struct dump_pa *mdp, int seqnr, void *arg)
269 {
270 	uint64_t *sz;
271 
272 	sz = (uint64_t *)arg;
273 	*sz += (uint64_t)mdp->pa_size;
274 	return (0);
275 }
276 
277 int
278 dumpsys_generic(struct dumperinfo *di)
279 {
280 	static struct kerneldumpheader kdh;
281 	Elf_Ehdr ehdr;
282 	uint64_t dumpsize;
283 	off_t hdrgap;
284 	size_t hdrsz;
285 	int error;
286 
287 #ifndef __powerpc__
288 	if (do_minidump)
289 		return (minidumpsys(di));
290 #endif
291 
292 	bzero(&ehdr, sizeof(ehdr));
293 	ehdr.e_ident[EI_MAG0] = ELFMAG0;
294 	ehdr.e_ident[EI_MAG1] = ELFMAG1;
295 	ehdr.e_ident[EI_MAG2] = ELFMAG2;
296 	ehdr.e_ident[EI_MAG3] = ELFMAG3;
297 	ehdr.e_ident[EI_CLASS] = ELF_CLASS;
298 #if BYTE_ORDER == LITTLE_ENDIAN
299 	ehdr.e_ident[EI_DATA] = ELFDATA2LSB;
300 #else
301 	ehdr.e_ident[EI_DATA] = ELFDATA2MSB;
302 #endif
303 	ehdr.e_ident[EI_VERSION] = EV_CURRENT;
304 	ehdr.e_ident[EI_OSABI] = ELFOSABI_STANDALONE;	/* XXX big picture? */
305 	ehdr.e_type = ET_CORE;
306 	ehdr.e_machine = EM_VALUE;
307 	ehdr.e_phoff = sizeof(ehdr);
308 	ehdr.e_flags = 0;
309 	ehdr.e_ehsize = sizeof(ehdr);
310 	ehdr.e_phentsize = sizeof(Elf_Phdr);
311 	ehdr.e_shentsize = sizeof(Elf_Shdr);
312 
313 	dumpsys_pa_init();
314 
315 	/* Calculate dump size. */
316 	dumpsize = 0L;
317 	ehdr.e_phnum = dumpsys_foreach_chunk(cb_size, &dumpsize) +
318 	    DUMPSYS_NUM_AUX_HDRS;
319 	hdrsz = ehdr.e_phoff + ehdr.e_phnum * ehdr.e_phentsize;
320 	fileofs = MD_ALIGN(hdrsz);
321 	dumpsize += fileofs;
322 	hdrgap = fileofs - DEV_ALIGN(hdrsz);
323 
324 	/* Determine dump offset on device. */
325 	if (di->mediasize < SIZEOF_METADATA + dumpsize + sizeof(kdh) * 2) {
326 		error = ENOSPC;
327 		goto fail;
328 	}
329 	dumplo = di->mediaoffset + di->mediasize - dumpsize;
330 	dumplo -= sizeof(kdh) * 2;
331 
332 	mkdumpheader(&kdh, KERNELDUMPMAGIC, KERNELDUMP_ARCH_VERSION, dumpsize,
333 	    di->blocksize);
334 
335 	printf("Dumping %ju MB (%d chunks)\n", (uintmax_t)dumpsize >> 20,
336 	    ehdr.e_phnum - DUMPSYS_NUM_AUX_HDRS);
337 
338 	/* Dump leader */
339 	error = dump_write(di, &kdh, 0, dumplo, sizeof(kdh));
340 	if (error)
341 		goto fail;
342 	dumplo += sizeof(kdh);
343 
344 	/* Dump ELF header */
345 	error = dumpsys_buf_write(di, (char*)&ehdr, sizeof(ehdr));
346 	if (error)
347 		goto fail;
348 
349 	/* Dump program headers */
350 	error = dumpsys_foreach_chunk(cb_dumphdr, di);
351 	if (error < 0)
352 		goto fail;
353 	error = dumpsys_write_aux_headers(di);
354 	if (error < 0)
355 		goto fail;
356 	dumpsys_buf_flush(di);
357 
358 	/*
359 	 * All headers are written using blocked I/O, so we know the
360 	 * current offset is (still) block aligned. Skip the alignement
361 	 * in the file to have the segment contents aligned at page
362 	 * boundary. We cannot use MD_ALIGN on dumplo, because we don't
363 	 * care and may very well be unaligned within the dump device.
364 	 */
365 	dumplo += hdrgap;
366 
367 	/* Dump memory chunks (updates dumplo) */
368 	error = dumpsys_foreach_chunk(dumpsys_cb_dumpdata, di);
369 	if (error < 0)
370 		goto fail;
371 
372 	/* Dump trailer */
373 	error = dump_write(di, &kdh, 0, dumplo, sizeof(kdh));
374 	if (error)
375 		goto fail;
376 
377 	/* Signal completion, signoff and exit stage left. */
378 	dump_write(di, NULL, 0, 0, 0);
379 	printf("\nDump complete\n");
380 	return (0);
381 
382  fail:
383 	if (error < 0)
384 		error = -error;
385 
386 	if (error == ECANCELED)
387 		printf("\nDump aborted\n");
388 	else if (error == ENOSPC)
389 		printf("\nDump failed. Partition too small.\n");
390 	else
391 		printf("\n** DUMP FAILED (ERROR %d) **\n", error);
392 	return (error);
393 }
394