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