minidump_machdep.c revision 280712 
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: head/sys/arm/arm/minidump_machdep.c 280712 2015-03-26 21:13:53Z ian $");
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
53CTASSERT(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
61uint32_t *vm_page_dump;
62int vm_page_dump_size;
63
64#ifndef ARM_NEW_PMAP
65
66static struct kerneldumpheader kdh;
67
68static off_t dumplo;
69
70/* Handle chunked writes. */
71static size_t fragsz, offset;
72static void *dump_va;
73static uint64_t counter, progress;
74
75CTASSERT(sizeof(*vm_page_dump) == 4);
76
77static int
78is_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
91static int
92blk_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
106static int
107blk_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
183static int
184blk_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 */
200static pt_entry_t fakept[NPTEPG];
201
202int
203minidumpsys(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
316	mkdumpheader(&kdh, KERNELDUMPMAGIC, KERNELDUMP_ARM_VERSION, dumpsize,
317	    di->blocksize);
318
319	printf("Physical memory: %u MB\n", ptoa((uintmax_t)physmem) / 1048576);
320	printf("Dumping %llu MB:", (long long)dumpsize >> 20);
321
322	/* Dump leader */
323	error = dump_write(di, &kdh, 0, dumplo, sizeof(kdh));
324	if (error)
325		goto fail;
326	dumplo += sizeof(kdh);
327
328	/* Dump my header */
329	bzero(&fakept, sizeof(fakept));
330	bcopy(&mdhdr, &fakept, sizeof(mdhdr));
331	error = blk_write(di, (char *)&fakept, 0, PAGE_SIZE);
332	if (error)
333		goto fail;
334
335	/* Dump msgbuf up front */
336	error = blk_write(di, (char *)msgbufp->msg_ptr, 0, round_page(msgbufp->msg_size));
337	if (error)
338		goto fail;
339
340	/* Dump bitmap */
341	error = blk_write(di, (char *)vm_page_dump, 0,
342	    round_page(vm_page_dump_size));
343	if (error)
344		goto fail;
345
346	/* Dump kernel page table pages */
347	for (va = KERNBASE; va < kernel_vm_end; va += NBPDR) {
348		/* We always write a page, even if it is zero */
349		pmap_get_pde_pte(pmap_kernel(), va, &pdp, &ptp);
350
351		if (pmap_pde_v(pdp) && pmap_pde_section(pdp))  {
352			if (count) {
353				error = blk_write_cont(di, prev_pa,
354				    count * L2_TABLE_SIZE_REAL);
355				if (error)
356					goto fail;
357				count = 0;
358				prev_pa = 0;
359			}
360			/* This is a single 2M block. Generate a fake PTP */
361			pa = (*pdp & L1_S_ADDR_MASK) | (va & ~L1_S_ADDR_MASK);
362			for (k = 0; k < (L1_S_SIZE / PAGE_SIZE); k++) {
363				fakept[k] = L2_S_PROTO | (pa + (k * PAGE_SIZE)) |
364				    L2_S_PROT(PTE_KERNEL,
365				    VM_PROT_READ | VM_PROT_WRITE);
366			}
367			error = blk_write(di, (char *)&fakept, 0,
368			    L2_TABLE_SIZE_REAL);
369			if (error)
370				goto fail;
371			/* Flush, in case we reuse fakept in the same block */
372			error = blk_flush(di);
373			if (error)
374				goto fail;
375			continue;
376		}
377		if (pmap_pde_v(pdp) && pmap_pde_page(pdp)) {
378			pa = *pdp & L1_C_ADDR_MASK;
379			if (!count) {
380				prev_pa = pa;
381				count++;
382			}
383			else {
384				if (pa == (prev_pa + count * L2_TABLE_SIZE_REAL))
385					count++;
386				else {
387					error = blk_write_cont(di, prev_pa,
388					    count * L2_TABLE_SIZE_REAL);
389					if (error)
390						goto fail;
391					count = 1;
392					prev_pa = pa;
393				}
394			}
395		} else {
396			if (count) {
397				error = blk_write_cont(di, prev_pa,
398				    count * L2_TABLE_SIZE_REAL);
399				if (error)
400					goto fail;
401				count = 0;
402				prev_pa = 0;
403			}
404			bzero(fakept, sizeof(fakept));
405			error = blk_write(di, (char *)&fakept, 0,
406			    L2_TABLE_SIZE_REAL);
407			if (error)
408				goto fail;
409			/* Flush, in case we reuse fakept in the same block */
410			error = blk_flush(di);
411			if (error)
412				goto fail;
413		}
414	}
415
416	if (count) {
417		error = blk_write_cont(di, prev_pa, count * L2_TABLE_SIZE_REAL);
418		if (error)
419			goto fail;
420		count = 0;
421		prev_pa = 0;
422	}
423
424	/* Dump memory chunks */
425	for (i = 0; i < vm_page_dump_size / sizeof(*vm_page_dump); i++) {
426		bits = vm_page_dump[i];
427		while (bits) {
428			bit = ffs(bits) - 1;
429			pa = (((uint64_t)i * sizeof(*vm_page_dump) * NBBY) +
430			    bit) * PAGE_SIZE;
431			if (!count) {
432				prev_pa = pa;
433				count++;
434			} else {
435				if (pa == (prev_pa + count * PAGE_SIZE))
436					count++;
437				else {
438					error = blk_write_cont(di, prev_pa,
439					    count * PAGE_SIZE);
440					if (error)
441						goto fail;
442					count = 1;
443					prev_pa = pa;
444				}
445			}
446			bits &= ~(1ul << bit);
447		}
448	}
449	if (count) {
450		error = blk_write_cont(di, prev_pa, count * PAGE_SIZE);
451		if (error)
452			goto fail;
453		count = 0;
454		prev_pa = 0;
455	}
456
457	/* Dump trailer */
458	error = dump_write(di, &kdh, 0, dumplo, sizeof(kdh));
459	if (error)
460		goto fail;
461	dumplo += sizeof(kdh);
462
463	/* Signal completion, signoff and exit stage left. */
464	dump_write(di, NULL, 0, 0, 0);
465	printf("\nDump complete\n");
466	return (0);
467
468fail:
469	if (error < 0)
470		error = -error;
471
472	if (error == ECANCELED)
473		printf("\nDump aborted\n");
474	else if (error == ENOSPC)
475		printf("\nDump failed. Partition too small.\n");
476	else
477		printf("\n** DUMP FAILED (ERROR %d) **\n", error);
478	return (error);
479	return (0);
480}
481
482#else /* ARM_NEW_PMAP */
483
484int
485minidumpsys(struct dumperinfo *di)
486{
487
488	return (0);
489}
490
491#endif
492
493void
494dump_add_page(vm_paddr_t pa)
495{
496	int idx, bit;
497
498	pa >>= PAGE_SHIFT;
499	idx = pa >> 5;		/* 2^5 = 32 */
500	bit = pa & 31;
501	atomic_set_int(&vm_page_dump[idx], 1ul << bit);
502}
503
504void
505dump_drop_page(vm_paddr_t pa)
506{
507	int idx, bit;
508
509	pa >>= PAGE_SHIFT;
510	idx = pa >> 5;		/* 2^5 = 32 */
511	bit = pa & 31;
512	atomic_clear_int(&vm_page_dump[idx], 1ul << bit);
513}
514