xref: /freebsd/sys/arm/arm/minidump_machdep.c (revision a0ee8cc6)
1 /*-
2  * Copyright (c) 2008 Semihalf, Grzegorz Bernacki
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  * from: FreeBSD: src/sys/i386/i386/minidump_machdep.c,v 1.6 2008/08/17 23:27:27
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include "opt_watchdog.h"
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/conf.h>
37 #include <sys/cons.h>
38 #include <sys/kernel.h>
39 #include <sys/kerneldump.h>
40 #include <sys/msgbuf.h>
41 #ifdef SW_WATCHDOG
42 #include <sys/watchdog.h>
43 #endif
44 #include <vm/vm.h>
45 #include <vm/pmap.h>
46 #include <machine/atomic.h>
47 #include <machine/elf.h>
48 #include <machine/md_var.h>
49 #include <machine/vmparam.h>
50 #include <machine/minidump.h>
51 #include <machine/cpufunc.h>
52 
53 CTASSERT(sizeof(struct kerneldumpheader) == 512);
54 
55 /*
56  * Don't touch the first SIZEOF_METADATA bytes on the dump device. This
57  * is to protect us from metadata and to protect metadata from us.
58  */
59 #define	SIZEOF_METADATA		(64*1024)
60 
61 uint32_t *vm_page_dump;
62 int vm_page_dump_size;
63 
64 #ifndef ARM_NEW_PMAP
65 
66 static struct kerneldumpheader kdh;
67 
68 static off_t dumplo;
69 
70 /* Handle chunked writes. */
71 static size_t fragsz, offset;
72 static void *dump_va;
73 static uint64_t counter, progress;
74 
75 CTASSERT(sizeof(*vm_page_dump) == 4);
76 
77 static int
78 is_dumpable(vm_paddr_t pa)
79 {
80 	int i;
81 
82 	for (i = 0; dump_avail[i] != 0 || dump_avail[i + 1] != 0; i += 2) {
83 		if (pa >= dump_avail[i] && pa < dump_avail[i + 1])
84 			return (1);
85 	}
86 	return (0);
87 }
88 
89 #define PG2MB(pgs) (((pgs) + (1 << 8) - 1) >> 8)
90 
91 static int
92 blk_flush(struct dumperinfo *di)
93 {
94 	int error;
95 
96 	if (fragsz == 0)
97 		return (0);
98 
99 	error = dump_write(di, (char*)dump_va + offset, 0, dumplo, fragsz - offset);
100 	dumplo += (fragsz - offset);
101 	fragsz = 0;
102 	offset = 0;
103 	return (error);
104 }
105 
106 static int
107 blk_write(struct dumperinfo *di, char *ptr, vm_paddr_t pa, size_t sz)
108 {
109 	size_t len;
110 	int error, i, c;
111 	u_int maxdumpsz;
112 
113 	maxdumpsz = di->maxiosize;
114 
115 	if (maxdumpsz == 0)	/* seatbelt */
116 		maxdumpsz = PAGE_SIZE;
117 
118 	error = 0;
119 
120 	if (ptr != NULL && pa != 0) {
121 		printf("cant have both va and pa!\n");
122 		return (EINVAL);
123 	}
124 
125 	if (ptr != NULL) {
126 		/* If we're doing a virtual dump, flush any pre-existing pa pages */
127 		error = blk_flush(di);
128 		if (error)
129 			return (error);
130 	}
131 
132 	while (sz) {
133 		if (fragsz == 0) {
134 			offset = pa & PAGE_MASK;
135 			fragsz += offset;
136 		}
137 		len = maxdumpsz - fragsz;
138 		if (len > sz)
139 			len = sz;
140 		counter += len;
141 		progress -= len;
142 
143 		if (counter >> 22) {
144 			printf(" %lld", PG2MB(progress >> PAGE_SHIFT));
145 			counter &= (1<<22) - 1;
146 		}
147 
148 #ifdef SW_WATCHDOG
149 		wdog_kern_pat(WD_LASTVAL);
150 #endif
151 		if (ptr) {
152 			error = dump_write(di, ptr, 0, dumplo, len);
153 			if (error)
154 				return (error);
155 			dumplo += len;
156 			ptr += len;
157 			sz -= len;
158 		} else {
159 			for (i = 0; i < len; i += PAGE_SIZE)
160 				dump_va = pmap_kenter_temporary(pa + i,
161 				    (i + fragsz) >> PAGE_SHIFT);
162 			fragsz += len;
163 			pa += len;
164 			sz -= len;
165 			if (fragsz == maxdumpsz) {
166 				error = blk_flush(di);
167 				if (error)
168 					return (error);
169 			}
170 		}
171 
172 		/* Check for user abort. */
173 		c = cncheckc();
174 		if (c == 0x03)
175 			return (ECANCELED);
176 		if (c != -1)
177 			printf(" (CTRL-C to abort) ");
178 	}
179 
180 	return (0);
181 }
182 
183 static int
184 blk_write_cont(struct dumperinfo *di, vm_paddr_t pa, size_t sz)
185 {
186 	int error;
187 
188 	error = blk_write(di, 0, pa, sz);
189 	if (error)
190 		return (error);
191 
192 	error = blk_flush(di);
193 	if (error)
194 		return (error);
195 
196 	return (0);
197 }
198 
199 /* A fake page table page, to avoid having to handle both 4K and 2M pages */
200 static pt_entry_t fakept[NPTEPG];
201 
202 int
203 minidumpsys(struct dumperinfo *di)
204 {
205 	struct minidumphdr mdhdr;
206 	uint64_t dumpsize;
207 	uint32_t ptesize;
208 	uint32_t bits;
209 	uint32_t pa, prev_pa = 0, count = 0;
210 	vm_offset_t va;
211 	pd_entry_t *pdp;
212 	pt_entry_t *pt, *ptp;
213 	int i, k, bit, error;
214 	char *addr;
215 
216 	/*
217 	 * Flush caches.  Note that in the SMP case this operates only on the
218 	 * current CPU's L1 cache.  Before we reach this point, code in either
219 	 * the system shutdown or kernel debugger has called stop_cpus() to stop
220 	 * all cores other than this one.  Part of the ARM handling of
221 	 * stop_cpus() is to call wbinv_all() on that core's local L1 cache.  So
222 	 * by time we get to here, all that remains is to flush the L1 for the
223 	 * current CPU, then the L2.
224 	 */
225 	cpu_idcache_wbinv_all();
226 	cpu_l2cache_wbinv_all();
227 
228 	counter = 0;
229 	/* Walk page table pages, set bits in vm_page_dump */
230 	ptesize = 0;
231 	for (va = KERNBASE; va < kernel_vm_end; va += NBPDR) {
232 		/*
233 		 * We always write a page, even if it is zero. Each
234 		 * page written corresponds to 2MB of space
235 		 */
236 		ptesize += L2_TABLE_SIZE_REAL;
237 		pmap_get_pde_pte(pmap_kernel(), va, &pdp, &ptp);
238 		if (pmap_pde_v(pdp) && pmap_pde_section(pdp)) {
239 			/* This is a section mapping 1M page. */
240 			pa = (*pdp & L1_S_ADDR_MASK) | (va & ~L1_S_ADDR_MASK);
241 			for (k = 0; k < (L1_S_SIZE / PAGE_SIZE); k++) {
242 				if (is_dumpable(pa))
243 					dump_add_page(pa);
244 				pa += PAGE_SIZE;
245 			}
246 			continue;
247 		}
248 		if (pmap_pde_v(pdp) && pmap_pde_page(pdp)) {
249 			/* Set bit for each valid page in this 1MB block */
250 			addr = pmap_kenter_temporary(*pdp & L1_C_ADDR_MASK, 0);
251 			pt = (pt_entry_t*)(addr +
252 			    (((uint32_t)*pdp  & L1_C_ADDR_MASK) & PAGE_MASK));
253 			for (k = 0; k < 256; k++) {
254 				if ((pt[k] & L2_TYPE_MASK) == L2_TYPE_L) {
255 					pa = (pt[k] & L2_L_FRAME) |
256 					    (va & L2_L_OFFSET);
257 					for (i = 0; i < 16; i++) {
258 						if (is_dumpable(pa))
259 							dump_add_page(pa);
260 						k++;
261 						pa += PAGE_SIZE;
262 					}
263 				} else if ((pt[k] & L2_TYPE_MASK) == L2_TYPE_S) {
264 					pa = (pt[k] & L2_S_FRAME) |
265 					    (va & L2_S_OFFSET);
266 					if (is_dumpable(pa))
267 						dump_add_page(pa);
268 				}
269 			}
270 		} else {
271 			/* Nothing, we're going to dump a null page */
272 		}
273 	}
274 
275 	/* Calculate dump size. */
276 	dumpsize = ptesize;
277 	dumpsize += round_page(msgbufp->msg_size);
278 	dumpsize += round_page(vm_page_dump_size);
279 
280 	for (i = 0; i < vm_page_dump_size / sizeof(*vm_page_dump); i++) {
281 		bits = vm_page_dump[i];
282 		while (bits) {
283 			bit = ffs(bits) - 1;
284 			pa = (((uint64_t)i * sizeof(*vm_page_dump) * NBBY) +
285 			    bit) * PAGE_SIZE;
286 			/* Clear out undumpable pages now if needed */
287 			if (is_dumpable(pa))
288 				dumpsize += PAGE_SIZE;
289 			else
290 				dump_drop_page(pa);
291 			bits &= ~(1ul << bit);
292 		}
293 	}
294 
295 	dumpsize += PAGE_SIZE;
296 
297 	/* Determine dump offset on device. */
298 	if (di->mediasize < SIZEOF_METADATA + dumpsize + sizeof(kdh) * 2) {
299 		error = ENOSPC;
300 		goto fail;
301 	}
302 
303 	dumplo = di->mediaoffset + di->mediasize - dumpsize;
304 	dumplo -= sizeof(kdh) * 2;
305 	progress = dumpsize;
306 
307 	/* Initialize mdhdr */
308 	bzero(&mdhdr, sizeof(mdhdr));
309 	strcpy(mdhdr.magic, MINIDUMP_MAGIC);
310 	mdhdr.version = MINIDUMP_VERSION;
311 	mdhdr.msgbufsize = msgbufp->msg_size;
312 	mdhdr.bitmapsize = vm_page_dump_size;
313 	mdhdr.ptesize = ptesize;
314 	mdhdr.kernbase = KERNBASE;
315 	mdhdr.arch = __ARM_ARCH;
316 #if __ARM_ARCH >= 6
317 	mdhdr.mmuformat = MINIDUMP_MMU_FORMAT_V6;
318 #else
319 	mdhdr.mmuformat = MINIDUMP_MMU_FORMAT_V4;
320 #endif
321 	mkdumpheader(&kdh, KERNELDUMPMAGIC, KERNELDUMP_ARM_VERSION, dumpsize,
322 	    di->blocksize);
323 
324 	printf("Physical memory: %u MB\n", ptoa((uintmax_t)physmem) / 1048576);
325 	printf("Dumping %llu MB:", (long long)dumpsize >> 20);
326 
327 	/* Dump leader */
328 	error = dump_write(di, &kdh, 0, dumplo, sizeof(kdh));
329 	if (error)
330 		goto fail;
331 	dumplo += sizeof(kdh);
332 
333 	/* Dump my header */
334 	bzero(&fakept, sizeof(fakept));
335 	bcopy(&mdhdr, &fakept, sizeof(mdhdr));
336 	error = blk_write(di, (char *)&fakept, 0, PAGE_SIZE);
337 	if (error)
338 		goto fail;
339 
340 	/* Dump msgbuf up front */
341 	error = blk_write(di, (char *)msgbufp->msg_ptr, 0, round_page(msgbufp->msg_size));
342 	if (error)
343 		goto fail;
344 
345 	/* Dump bitmap */
346 	error = blk_write(di, (char *)vm_page_dump, 0,
347 	    round_page(vm_page_dump_size));
348 	if (error)
349 		goto fail;
350 
351 	/* Dump kernel page table pages */
352 	for (va = KERNBASE; va < kernel_vm_end; va += NBPDR) {
353 		/* We always write a page, even if it is zero */
354 		pmap_get_pde_pte(pmap_kernel(), va, &pdp, &ptp);
355 
356 		if (pmap_pde_v(pdp) && pmap_pde_section(pdp))  {
357 			if (count) {
358 				error = blk_write_cont(di, prev_pa,
359 				    count * L2_TABLE_SIZE_REAL);
360 				if (error)
361 					goto fail;
362 				count = 0;
363 				prev_pa = 0;
364 			}
365 			/* This is a single 2M block. Generate a fake PTP */
366 			pa = (*pdp & L1_S_ADDR_MASK) | (va & ~L1_S_ADDR_MASK);
367 			for (k = 0; k < (L1_S_SIZE / PAGE_SIZE); k++) {
368 				fakept[k] = L2_S_PROTO | (pa + (k * PAGE_SIZE)) |
369 				    L2_S_PROT(PTE_KERNEL,
370 				    VM_PROT_READ | VM_PROT_WRITE);
371 			}
372 			error = blk_write(di, (char *)&fakept, 0,
373 			    L2_TABLE_SIZE_REAL);
374 			if (error)
375 				goto fail;
376 			/* Flush, in case we reuse fakept in the same block */
377 			error = blk_flush(di);
378 			if (error)
379 				goto fail;
380 			continue;
381 		}
382 		if (pmap_pde_v(pdp) && pmap_pde_page(pdp)) {
383 			pa = *pdp & L1_C_ADDR_MASK;
384 			if (!count) {
385 				prev_pa = pa;
386 				count++;
387 			}
388 			else {
389 				if (pa == (prev_pa + count * L2_TABLE_SIZE_REAL))
390 					count++;
391 				else {
392 					error = blk_write_cont(di, prev_pa,
393 					    count * L2_TABLE_SIZE_REAL);
394 					if (error)
395 						goto fail;
396 					count = 1;
397 					prev_pa = pa;
398 				}
399 			}
400 		} else {
401 			if (count) {
402 				error = blk_write_cont(di, prev_pa,
403 				    count * L2_TABLE_SIZE_REAL);
404 				if (error)
405 					goto fail;
406 				count = 0;
407 				prev_pa = 0;
408 			}
409 			bzero(fakept, sizeof(fakept));
410 			error = blk_write(di, (char *)&fakept, 0,
411 			    L2_TABLE_SIZE_REAL);
412 			if (error)
413 				goto fail;
414 			/* Flush, in case we reuse fakept in the same block */
415 			error = blk_flush(di);
416 			if (error)
417 				goto fail;
418 		}
419 	}
420 
421 	if (count) {
422 		error = blk_write_cont(di, prev_pa, count * L2_TABLE_SIZE_REAL);
423 		if (error)
424 			goto fail;
425 		count = 0;
426 		prev_pa = 0;
427 	}
428 
429 	/* Dump memory chunks */
430 	for (i = 0; i < vm_page_dump_size / sizeof(*vm_page_dump); i++) {
431 		bits = vm_page_dump[i];
432 		while (bits) {
433 			bit = ffs(bits) - 1;
434 			pa = (((uint64_t)i * sizeof(*vm_page_dump) * NBBY) +
435 			    bit) * PAGE_SIZE;
436 			if (!count) {
437 				prev_pa = pa;
438 				count++;
439 			} else {
440 				if (pa == (prev_pa + count * PAGE_SIZE))
441 					count++;
442 				else {
443 					error = blk_write_cont(di, prev_pa,
444 					    count * PAGE_SIZE);
445 					if (error)
446 						goto fail;
447 					count = 1;
448 					prev_pa = pa;
449 				}
450 			}
451 			bits &= ~(1ul << bit);
452 		}
453 	}
454 	if (count) {
455 		error = blk_write_cont(di, prev_pa, count * PAGE_SIZE);
456 		if (error)
457 			goto fail;
458 		count = 0;
459 		prev_pa = 0;
460 	}
461 
462 	/* Dump trailer */
463 	error = dump_write(di, &kdh, 0, dumplo, sizeof(kdh));
464 	if (error)
465 		goto fail;
466 	dumplo += sizeof(kdh);
467 
468 	/* Signal completion, signoff and exit stage left. */
469 	dump_write(di, NULL, 0, 0, 0);
470 	printf("\nDump complete\n");
471 	return (0);
472 
473 fail:
474 	if (error < 0)
475 		error = -error;
476 
477 	if (error == ECANCELED)
478 		printf("\nDump aborted\n");
479 	else if (error == ENOSPC)
480 		printf("\nDump failed. Partition too small.\n");
481 	else
482 		printf("\n** DUMP FAILED (ERROR %d) **\n", error);
483 	return (error);
484 	return (0);
485 }
486 
487 #else /* ARM_NEW_PMAP */
488 
489 int
490 minidumpsys(struct dumperinfo *di)
491 {
492 
493 	return (0);
494 }
495 
496 #endif
497 
498 void
499 dump_add_page(vm_paddr_t pa)
500 {
501 	int idx, bit;
502 
503 	pa >>= PAGE_SHIFT;
504 	idx = pa >> 5;		/* 2^5 = 32 */
505 	bit = pa & 31;
506 	atomic_set_int(&vm_page_dump[idx], 1ul << bit);
507 }
508 
509 void
510 dump_drop_page(vm_paddr_t pa)
511 {
512 	int idx, bit;
513 
514 	pa >>= PAGE_SHIFT;
515 	idx = pa >> 5;		/* 2^5 = 32 */
516 	bit = pa & 31;
517 	atomic_clear_int(&vm_page_dump[idx], 1ul << bit);
518 }
519