xref: /freebsd/sys/arm/arm/minidump_machdep.c (revision 7cc42f6d)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2006 Peter Wemm
5  * Copyright (c) 2008 Semihalf, Grzegorz Bernacki
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  *
29  * from: FreeBSD: src/sys/i386/i386/minidump_machdep.c,v 1.6 2008/08/17 23:27:27
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include "opt_watchdog.h"
36 
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/conf.h>
40 #include <sys/cons.h>
41 #include <sys/kernel.h>
42 #include <sys/kerneldump.h>
43 #include <sys/msgbuf.h>
44 #ifdef SW_WATCHDOG
45 #include <sys/watchdog.h>
46 #endif
47 #include <vm/vm.h>
48 #include <vm/vm_param.h>
49 #include <vm/vm_page.h>
50 #include <vm/vm_phys.h>
51 #include <vm/pmap.h>
52 #include <machine/atomic.h>
53 #include <machine/cpu.h>
54 #include <machine/elf.h>
55 #include <machine/md_var.h>
56 #include <machine/minidump.h>
57 
58 CTASSERT(sizeof(struct kerneldumpheader) == 512);
59 
60 static struct kerneldumpheader kdh;
61 
62 /* Handle chunked writes. */
63 static size_t fragsz;
64 static void *dump_va;
65 static uint64_t counter, progress;
66 
67 static int
68 is_dumpable(vm_paddr_t pa)
69 {
70 	int i;
71 
72 	for (i = 0; dump_avail[i] != 0 || dump_avail[i + 1] != 0; i += 2) {
73 		if (pa >= dump_avail[i] && pa < dump_avail[i + 1])
74 			return (1);
75 	}
76 	return (0);
77 }
78 
79 #define PG2MB(pgs) (((pgs) + (1 << 8) - 1) >> 8)
80 
81 static int
82 blk_flush(struct dumperinfo *di)
83 {
84 	int error;
85 
86 	if (fragsz == 0)
87 		return (0);
88 
89 	error = dump_append(di, dump_va, 0, fragsz);
90 	fragsz = 0;
91 	return (error);
92 }
93 
94 static int
95 blk_write(struct dumperinfo *di, char *ptr, vm_paddr_t pa, size_t sz)
96 {
97 	size_t len;
98 	int error, i, c;
99 	u_int maxdumpsz;
100 
101 	maxdumpsz = min(di->maxiosize, MAXDUMPPGS * PAGE_SIZE);
102 	if (maxdumpsz == 0)	/* seatbelt */
103 		maxdumpsz = PAGE_SIZE;
104 	error = 0;
105 	if (ptr != NULL && pa != 0) {
106 		printf("cant have both va and pa!\n");
107 		return (EINVAL);
108 	}
109 	if (pa != 0) {
110 		if ((sz % PAGE_SIZE) != 0) {
111 			printf("size not page aligned\n");
112 			return (EINVAL);
113 		}
114 		if ((pa & PAGE_MASK) != 0) {
115 			printf("address not page aligned\n");
116 			return (EINVAL);
117 		}
118 	}
119 	if (ptr != NULL) {
120 		/* Flush any pre-existing pa pages before a virtual dump. */
121 		error = blk_flush(di);
122 		if (error)
123 			return (error);
124 	}
125 	while (sz) {
126 		len = maxdumpsz - fragsz;
127 		if (len > sz)
128 			len = sz;
129 		counter += len;
130 		progress -= len;
131 		if (counter >> 22) {
132 			printf(" %lld", PG2MB(progress >> PAGE_SHIFT));
133 			counter &= (1<<22) - 1;
134 		}
135 
136 #ifdef SW_WATCHDOG
137 		wdog_kern_pat(WD_LASTVAL);
138 #endif
139 		if (ptr) {
140 			error = dump_append(di, ptr, 0, len);
141 			if (error)
142 				return (error);
143 			ptr += len;
144 			sz -= len;
145 		} else {
146 			for (i = 0; i < len; i += PAGE_SIZE)
147 				dump_va = pmap_kenter_temporary(pa + i,
148 				    (i + fragsz) >> PAGE_SHIFT);
149 			fragsz += len;
150 			pa += len;
151 			sz -= len;
152 			if (fragsz == maxdumpsz) {
153 				error = blk_flush(di);
154 				if (error)
155 					return (error);
156 			}
157 		}
158 
159 		/* Check for user abort. */
160 		c = cncheckc();
161 		if (c == 0x03)
162 			return (ECANCELED);
163 		if (c != -1)
164 			printf(" (CTRL-C to abort) ");
165 	}
166 
167 	return (0);
168 }
169 
170 /* A buffer for general use. Its size must be one page at least. */
171 static char dumpbuf[PAGE_SIZE];
172 CTASSERT(sizeof(dumpbuf) % sizeof(pt2_entry_t) == 0);
173 
174 int
175 minidumpsys(struct dumperinfo *di)
176 {
177 	struct minidumphdr mdhdr;
178 	uint64_t dumpsize;
179 	uint32_t ptesize;
180 	uint32_t pa, prev_pa = 0, count = 0;
181 	vm_offset_t va;
182 	int error;
183 	char *addr;
184 
185 	/*
186 	 * Flush caches.  Note that in the SMP case this operates only on the
187 	 * current CPU's L1 cache.  Before we reach this point, code in either
188 	 * the system shutdown or kernel debugger has called stop_cpus() to stop
189 	 * all cores other than this one.  Part of the ARM handling of
190 	 * stop_cpus() is to call wbinv_all() on that core's local L1 cache.  So
191 	 * by time we get to here, all that remains is to flush the L1 for the
192 	 * current CPU, then the L2.
193 	 */
194 	dcache_wbinv_poc_all();
195 
196 	counter = 0;
197 	/* Walk page table pages, set bits in vm_page_dump */
198 	ptesize = 0;
199 	for (va = KERNBASE; va < kernel_vm_end; va += PAGE_SIZE) {
200 		pa = pmap_dump_kextract(va, NULL);
201 		if (pa != 0 && is_dumpable(pa))
202 			dump_add_page(pa);
203 		ptesize += sizeof(pt2_entry_t);
204 	}
205 
206 	/* Calculate dump size. */
207 	dumpsize = ptesize;
208 	dumpsize += round_page(msgbufp->msg_size);
209 	dumpsize += round_page(sizeof(dump_avail));
210 	dumpsize += round_page(BITSET_SIZE(vm_page_dump_pages));
211 	VM_PAGE_DUMP_FOREACH(pa) {
212 		/* Clear out undumpable pages now if needed */
213 		if (is_dumpable(pa))
214 			dumpsize += PAGE_SIZE;
215 		else
216 			dump_drop_page(pa);
217 	}
218 	dumpsize += PAGE_SIZE;
219 
220 	progress = dumpsize;
221 
222 	/* Initialize mdhdr */
223 	bzero(&mdhdr, sizeof(mdhdr));
224 	strcpy(mdhdr.magic, MINIDUMP_MAGIC);
225 	mdhdr.version = MINIDUMP_VERSION;
226 	mdhdr.msgbufsize = msgbufp->msg_size;
227 	mdhdr.bitmapsize = round_page(BITSET_SIZE(vm_page_dump_pages));
228 	mdhdr.ptesize = ptesize;
229 	mdhdr.kernbase = KERNBASE;
230 	mdhdr.arch = __ARM_ARCH;
231 #if __ARM_ARCH >= 6
232 	mdhdr.mmuformat = MINIDUMP_MMU_FORMAT_V6;
233 #else
234 	mdhdr.mmuformat = MINIDUMP_MMU_FORMAT_V4;
235 #endif
236 	mdhdr.dumpavailsize = round_page(sizeof(dump_avail));
237 	dump_init_header(di, &kdh, KERNELDUMPMAGIC, KERNELDUMP_ARM_VERSION,
238 	    dumpsize);
239 
240 	error = dump_start(di, &kdh);
241 	if (error != 0)
242 		goto fail;
243 
244 	printf("Physical memory: %u MB\n", ptoa((uintmax_t)physmem) / 1048576);
245 	printf("Dumping %llu MB:", (long long)dumpsize >> 20);
246 
247 	/* Dump my header */
248 	bzero(dumpbuf, sizeof(dumpbuf));
249 	bcopy(&mdhdr, dumpbuf, sizeof(mdhdr));
250 	error = blk_write(di, dumpbuf, 0, PAGE_SIZE);
251 	if (error)
252 		goto fail;
253 
254 	/* Dump msgbuf up front */
255 	error = blk_write(di, (char *)msgbufp->msg_ptr, 0,
256 	    round_page(msgbufp->msg_size));
257 	if (error)
258 		goto fail;
259 
260 	/* Dump dump_avail */
261 	_Static_assert(sizeof(dump_avail) <= sizeof(dumpbuf),
262 	    "Large dump_avail not handled");
263 	bzero(dumpbuf, sizeof(dumpbuf));
264 	memcpy(dumpbuf, dump_avail, sizeof(dump_avail));
265 	error = blk_write(di, dumpbuf, 0, PAGE_SIZE);
266 	if (error)
267 		goto fail;
268 
269 	/* Dump bitmap */
270 	error = blk_write(di, (char *)vm_page_dump, 0,
271 	    round_page(BITSET_SIZE(vm_page_dump_pages)));
272 	if (error)
273 		goto fail;
274 
275 	/* Dump kernel page table pages */
276 	addr = dumpbuf;
277 	for (va = KERNBASE; va < kernel_vm_end; va += PAGE_SIZE) {
278 		pmap_dump_kextract(va, (pt2_entry_t *)addr);
279 		addr += sizeof(pt2_entry_t);
280 		if (addr == dumpbuf + sizeof(dumpbuf)) {
281 			error = blk_write(di, dumpbuf, 0, sizeof(dumpbuf));
282 			if (error != 0)
283 				goto fail;
284 			addr = dumpbuf;
285 		}
286 	}
287 	if (addr != dumpbuf) {
288 		error = blk_write(di, dumpbuf, 0, addr - dumpbuf);
289 		if (error != 0)
290 			goto fail;
291 	}
292 
293 	/* Dump memory chunks */
294 	VM_PAGE_DUMP_FOREACH(pa) {
295 		if (!count) {
296 			prev_pa = pa;
297 			count++;
298 		} else {
299 			if (pa == (prev_pa + count * PAGE_SIZE))
300 				count++;
301 			else {
302 				error = blk_write(di, NULL, prev_pa,
303 				    count * PAGE_SIZE);
304 				if (error)
305 					goto fail;
306 				count = 1;
307 				prev_pa = pa;
308 			}
309 		}
310 	}
311 	if (count) {
312 		error = blk_write(di, NULL, prev_pa, count * PAGE_SIZE);
313 		if (error)
314 			goto fail;
315 		count = 0;
316 		prev_pa = 0;
317 	}
318 
319 	error = blk_flush(di);
320 	if (error)
321 		goto fail;
322 
323 	error = dump_finish(di, &kdh);
324 	if (error != 0)
325 		goto fail;
326 
327 	printf("\nDump complete\n");
328 	return (0);
329 
330 fail:
331 	if (error < 0)
332 		error = -error;
333 
334 	if (error == ECANCELED)
335 		printf("\nDump aborted\n");
336 	else if (error == E2BIG || error == ENOSPC) {
337 		printf("\nDump failed. Partition too small (about %lluMB were "
338 		    "needed this time).\n", (long long)dumpsize >> 20);
339 	} else
340 		printf("\n** DUMP FAILED (ERROR %d) **\n", error);
341 	return (error);
342 }
343