1 /*-
2  * Copyright (c) 2006 Peter Wemm
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  * $FreeBSD: src/sys/amd64/amd64/minidump_machdep.c,v 1.10 2009/05/29 21:27:12 jamie Exp $
27  */
28 
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/conf.h>
32 #include <sys/cons.h>
33 #include <sys/device.h>
34 #include <sys/globaldata.h>
35 #include <sys/kernel.h>
36 #include <sys/kerneldump.h>
37 #include <sys/msgbuf.h>
38 #include <vm/vm.h>
39 #include <vm/vm_kern.h>
40 #include <vm/pmap.h>
41 #include <machine/atomic.h>
42 #include <machine/elf.h>
43 #include <machine/globaldata.h>
44 #include <machine/md_var.h>
45 #include <machine/vmparam.h>
46 #include <machine/minidump.h>
47 
48 CTASSERT(sizeof(struct kerneldumpheader) == 512);
49 
50 /*
51  * Don't touch the first SIZEOF_METADATA bytes on the dump device. This
52  * is to protect us from metadata and to protect metadata from us.
53  */
54 #define	SIZEOF_METADATA		(64*1024)
55 
56 #define	MD_ALIGN(x)	(((off_t)(x) + PAGE_MASK) & ~PAGE_MASK)
57 #define	DEV_ALIGN(x)	(((off_t)(x) + (DEV_BSIZE-1)) & ~(DEV_BSIZE-1))
58 
59 extern uint64_t KPDPphys;
60 
61 uint64_t *vm_page_dump;
62 int vm_page_dump_size;
63 
64 static struct kerneldumpheader kdh;
65 static off_t dumplo;
66 
67 /* Handle chunked writes. */
68 static size_t fragsz;
69 static void *dump_va;
70 static size_t counter, progress;
71 
72 CTASSERT(sizeof(*vm_page_dump) == 8);
73 
74 static int
75 is_dumpable(vm_paddr_t pa)
76 {
77 	int i;
78 
79 	for (i = 0; dump_avail[i] != 0 || dump_avail[i + 1] != 0; i += 2) {
80 		if (pa >= dump_avail[i] && pa < dump_avail[i + 1])
81 			return (1);
82 	}
83 	return (0);
84 }
85 
86 #define PG2MB(pgs) (((pgs) + (1 << 8) - 1) >> 8)
87 
88 static int
89 blk_flush(struct dumperinfo *di)
90 {
91 	int error;
92 
93 	if (fragsz == 0)
94 		return (0);
95 
96 	error = dev_ddump(di->priv, dump_va, 0, dumplo, fragsz);
97 	dumplo += fragsz;
98 	fragsz = 0;
99 	return (error);
100 }
101 
102 static int
103 blk_write(struct dumperinfo *di, char *ptr, vm_paddr_t pa, size_t sz)
104 {
105 	size_t len;
106 	int error, i, c;
107 	int max_iosize;
108 
109 	error = 0;
110 	if ((sz & PAGE_MASK)) {
111 		kprintf("size not page aligned\n");
112 		return (EINVAL);
113 	}
114 	if (ptr != NULL && pa != 0) {
115 		kprintf("can't have both va and pa!\n");
116 		return (EINVAL);
117 	}
118 	if (pa != 0 && (((uintptr_t)pa) & PAGE_MASK) != 0) {
119 		kprintf("address not page aligned\n");
120 		return (EINVAL);
121 	}
122 	if (ptr != NULL) {
123 		/*
124 		 * If we're doing a virtual dump, flush any
125 		 * pre-existing pa pages
126 		 */
127 		error = blk_flush(di);
128 		if (error)
129 			return (error);
130 	}
131 	max_iosize = min(MAXPHYS, di->maxiosize);
132 	while (sz) {
133 		len = max_iosize - fragsz;
134 		if (len > sz)
135 			len = sz;
136 		counter += len;
137 		progress -= len;
138 		if (counter >> 24) {
139 			kprintf(" %ld", PG2MB(progress >> PAGE_SHIFT));
140 			counter &= (1<<24) - 1;
141 		}
142 		if (ptr) {
143 			/*kprintf("s");*/
144 			error = dev_ddump(di->priv, ptr, 0, dumplo, len);
145 			/* kprintf("t");*/
146 			if (error)
147 				return (error);
148 			dumplo += len;
149 			ptr += len;
150 			sz -= len;
151 		} else {
152 			for (i = 0; i < len; i += PAGE_SIZE) {
153 				dump_va = pmap_kenter_temporary(pa + i,
154 						(i + fragsz) >> PAGE_SHIFT);
155 			}
156 			smp_invltlb();
157 			fragsz += len;
158 			pa += len;
159 			sz -= len;
160 			if (fragsz == max_iosize) {
161 				error = blk_flush(di);
162 				if (error)
163 					return (error);
164 			}
165 		}
166 	}
167 
168 	/* Check for user abort. */
169 	c = cncheckc();
170 	if (c == 0x03)
171 		return (ECANCELED);
172 	if (c != -1)
173 		kprintf(" (CTRL-C to abort) ");
174 
175 	return (0);
176 }
177 
178 /* A fake page table page, to avoid having to handle both 4K and 2M pages */
179 static pt_entry_t fakept[NPTEPG];
180 
181 void
182 minidumpsys(struct dumperinfo *di)
183 {
184 	uint64_t dumpsize;
185 	uint32_t ptesize;
186 	vm_offset_t va;
187 	vm_offset_t kern_end;
188 	int error;
189 	uint64_t bits;
190 	uint64_t *pdp, *pd, *pt, pa;
191 	int i, j, k, bit;
192 	struct minidumphdr mdhdr;
193 	struct mdglobaldata *md;
194 
195 	counter = 0;
196 	/*
197 	 * Walk page table pages, set bits in vm_page_dump.
198 	 *
199 	 * NOTE: kernel_vm_end can actually be below KERNBASE.
200 	 * 	 Just use KvaEnd.  Also note that loops which go
201 	 *	 all the way to the end of the address space might
202 	 *	 overflow the loop variable.
203 	 */
204 	ptesize = 0;
205 
206 	md = (struct mdglobaldata *)globaldata_find(0);
207 
208 	kern_end = KvaEnd;
209 	if (kern_end < (vm_offset_t)&(md[ncpus]))
210 		kern_end = (vm_offset_t)&(md[ncpus]);
211 
212 	pdp = (uint64_t *)PHYS_TO_DMAP(KPDPphys);
213 	for (va = VM_MIN_KERNEL_ADDRESS; va < kern_end; va += NBPDR) {
214 		/*
215 		 * The loop probably overflows a 64-bit int due to NBPDR.
216 		 */
217 		if (va < VM_MIN_KERNEL_ADDRESS)
218 			break;
219 
220 		/*
221 		 * We always write a page, even if it is zero. Each
222 		 * page written corresponds to 2MB of space
223 		 */
224 		i = (va >> PDPSHIFT) & ((1ul << NPDPEPGSHIFT) - 1);
225 		ptesize += PAGE_SIZE;
226 		if ((pdp[i] & PG_V) == 0)
227 			continue;
228 		pd = (uint64_t *)PHYS_TO_DMAP(pdp[i] & PG_FRAME);
229 		j = ((va >> PDRSHIFT) & ((1ul << NPDEPGSHIFT) - 1));
230 		if ((pd[j] & (PG_PS | PG_V)) == (PG_PS | PG_V))  {
231 			/* This is an entire 2M page. */
232 			pa = pd[j] & PG_PS_FRAME;
233 			for (k = 0; k < NPTEPG; k++) {
234 				if (is_dumpable(pa))
235 					dump_add_page(pa);
236 				pa += PAGE_SIZE;
237 			}
238 			continue;
239 		}
240 		if ((pd[j] & PG_V) == PG_V) {
241 			/* set bit for each valid page in this 2MB block */
242 			pt = (uint64_t *)PHYS_TO_DMAP(pd[j] & PG_FRAME);
243 			for (k = 0; k < NPTEPG; k++) {
244 				if ((pt[k] & PG_V) == PG_V) {
245 					pa = pt[k] & PG_FRAME;
246 					if (is_dumpable(pa))
247 						dump_add_page(pa);
248 				}
249 			}
250 		} else {
251 			/* nothing, we're going to dump a null page */
252 		}
253 	}
254 
255 	/* Calculate dump size. */
256 	dumpsize = ptesize;
257 	dumpsize += round_page(msgbufp->msg_size);
258 	dumpsize += round_page(vm_page_dump_size);
259 	for (i = 0; i < vm_page_dump_size / sizeof(*vm_page_dump); i++) {
260 		bits = vm_page_dump[i];
261 		while (bits) {
262 			bit = bsfq(bits);
263 			pa = (((uint64_t)i * sizeof(*vm_page_dump) * NBBY) + bit) * PAGE_SIZE;
264 			/* Clear out undumpable pages now if needed */
265 			if (is_dumpable(pa)) {
266 				dumpsize += PAGE_SIZE;
267 			} else {
268 				dump_drop_page(pa);
269 			}
270 			bits &= ~(1ul << bit);
271 		}
272 	}
273 	dumpsize += PAGE_SIZE;
274 
275 	/* Determine dump offset on device. */
276 	if (di->mediasize < SIZEOF_METADATA + dumpsize + sizeof(kdh) * 2) {
277 		error = ENOSPC;
278 		goto fail;
279 	}
280 	dumplo = di->mediaoffset + di->mediasize - dumpsize;
281 	dumplo -= sizeof(kdh) * 2;
282 	progress = dumpsize;
283 
284 	/* Initialize mdhdr */
285 	bzero(&mdhdr, sizeof(mdhdr));
286 	strcpy(mdhdr.magic, MINIDUMP_MAGIC);
287 	mdhdr.version = MINIDUMP_VERSION;
288 	mdhdr.msgbufsize = msgbufp->msg_size;
289 	mdhdr.bitmapsize = vm_page_dump_size;
290 	mdhdr.ptesize = ptesize;
291 	mdhdr.kernbase = VM_MIN_KERNEL_ADDRESS;
292 	mdhdr.dmapbase = DMAP_MIN_ADDRESS;
293 	mdhdr.dmapend = DMAP_MAX_ADDRESS;
294 
295 	mkdumpheader(&kdh, KERNELDUMPMAGIC, KERNELDUMP_AMD64_VERSION,
296 	    dumpsize, di->blocksize);
297 
298 	kprintf("Physical memory: %jd MB\n", (intmax_t)ptoa(physmem) / 1048576);
299 	kprintf("Dumping %jd MB:", (intmax_t)dumpsize >> 20);
300 
301 	/* Dump leader */
302 	error = dev_ddump(di->priv, &kdh, 0, dumplo, sizeof(kdh));
303 	if (error)
304 		goto fail;
305 	dumplo += sizeof(kdh);
306 
307 	/* Dump my header */
308 	bzero(&fakept, sizeof(fakept));
309 	bcopy(&mdhdr, &fakept, sizeof(mdhdr));
310 	error = blk_write(di, (char *)&fakept, 0, PAGE_SIZE);
311 	if (error)
312 		goto fail;
313 
314 	/* Dump msgbuf up front */
315 	error = blk_write(di, (char *)msgbufp->msg_ptr, 0, round_page(msgbufp->msg_size));
316 	if (error)
317 		goto fail;
318 
319 	/* Dump bitmap */
320 	error = blk_write(di, (char *)vm_page_dump, 0, round_page(vm_page_dump_size));
321 	if (error)
322 		goto fail;
323 
324 	/* Dump kernel page table pages */
325 	pdp = (uint64_t *)PHYS_TO_DMAP(KPDPphys);
326 	for (va = VM_MIN_KERNEL_ADDRESS; va < kern_end; va += NBPDR) {
327 		/*
328 		 * The loop probably overflows a 64-bit int due to NBPDR.
329 		 */
330 		if (va < VM_MIN_KERNEL_ADDRESS)
331 			break;
332 
333 		/*
334 		 * We always write a page, even if it is zero
335 		 */
336 		i = (va >> PDPSHIFT) & ((1ul << NPDPEPGSHIFT) - 1);
337 		if ((pdp[i] & PG_V) == 0) {
338 			bzero(fakept, sizeof(fakept));
339 			error = blk_write(di, (char *)&fakept, 0, PAGE_SIZE);
340 			if (error)
341 				goto fail;
342 			/* flush, in case we reuse fakept in the same block */
343 			error = blk_flush(di);
344 			if (error)
345 				goto fail;
346 			continue;
347 		}
348 		pd = (uint64_t *)PHYS_TO_DMAP(pdp[i] & PG_FRAME);
349 		j = ((va >> PDRSHIFT) & ((1ul << NPDEPGSHIFT) - 1));
350 		if ((pd[j] & (PG_PS | PG_V)) == (PG_PS | PG_V))  {
351 			/* This is a single 2M block. Generate a fake PTP */
352 			pa = pd[j] & PG_PS_FRAME;
353 			for (k = 0; k < NPTEPG; k++) {
354 				fakept[k] = (pa + (k * PAGE_SIZE)) | PG_V | PG_RW | PG_A | PG_M;
355 			}
356 			error = blk_write(di, (char *)&fakept, 0, PAGE_SIZE);
357 			if (error)
358 				goto fail;
359 			/* flush, in case we reuse fakept in the same block */
360 			error = blk_flush(di);
361 			if (error)
362 				goto fail;
363 			continue;
364 		}
365 		if ((pd[j] & PG_V) == PG_V) {
366 			pt = (uint64_t *)PHYS_TO_DMAP(pd[j] & PG_FRAME);
367 			error = blk_write(di, (char *)pt, 0, PAGE_SIZE);
368 			if (error)
369 				goto fail;
370 		} else {
371 			bzero(fakept, sizeof(fakept));
372 			error = blk_write(di, (char *)&fakept, 0, PAGE_SIZE);
373 			if (error)
374 				goto fail;
375 			/* flush, in case we reuse fakept in the same block */
376 			error = blk_flush(di);
377 			if (error)
378 				goto fail;
379 		}
380 	}
381 
382 	/* Dump memory chunks */
383 	/* XXX cluster it up and use blk_dump() */
384 	for (i = 0; i < vm_page_dump_size / sizeof(*vm_page_dump); i++) {
385 		bits = vm_page_dump[i];
386 		while (bits) {
387 			bit = bsfq(bits);
388 			pa = (((uint64_t)i * sizeof(*vm_page_dump) * NBBY) + bit) * PAGE_SIZE;
389 			error = blk_write(di, 0, pa, PAGE_SIZE);
390 			if (error)
391 				goto fail;
392 			bits &= ~(1ul << bit);
393 		}
394 	}
395 
396 	error = blk_flush(di);
397 	if (error)
398 		goto fail;
399 
400 	/* Dump trailer */
401 	error = dev_ddump(di->priv, &kdh, 0, dumplo, sizeof(kdh));
402 	if (error)
403 		goto fail;
404 	dumplo += sizeof(kdh);
405 
406 	/* Signal completion, signoff and exit stage left. */
407 	dev_ddump(di->priv, NULL, 0, 0, 0);
408 	kprintf("\nDump complete\n");
409 	return;
410 
411  fail:
412 	if (error < 0)
413 		error = -error;
414 
415 	if (error == ECANCELED)
416 		kprintf("\nDump aborted\n");
417 	else if (error == ENOSPC)
418 		kprintf("\nDump failed. Partition too small.\n");
419 	else
420 		kprintf("\n** DUMP FAILED (ERROR %d) **\n", error);
421 }
422 
423 void
424 dump_add_page(vm_paddr_t pa)
425 {
426 	int idx, bit;
427 
428 	pa >>= PAGE_SHIFT;
429 	idx = pa >> 6;		/* 2^6 = 64 */
430 	bit = pa & 63;
431 	atomic_set_long(&vm_page_dump[idx], 1ul << bit);
432 }
433 
434 void
435 dump_drop_page(vm_paddr_t pa)
436 {
437 	int idx, bit;
438 
439 	pa >>= PAGE_SHIFT;
440 	idx = pa >> 6;		/* 2^6 = 64 */
441 	bit = pa & 63;
442 	atomic_clear_long(&vm_page_dump[idx], 1ul << bit);
443 }
444