xref: /freebsd/sys/arm/arm/minidump_machdep.c (revision 206b73d0)
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 uint32_t *vm_page_dump;
61 int vm_page_dump_size;
62 
63 static struct kerneldumpheader kdh;
64 
65 /* Handle chunked writes. */
66 static size_t fragsz;
67 static void *dump_va;
68 static uint64_t counter, progress;
69 
70 CTASSERT(sizeof(*vm_page_dump) == 4);
71 
72 static int
73 is_dumpable(vm_paddr_t pa)
74 {
75 	int i;
76 
77 	for (i = 0; dump_avail[i] != 0 || dump_avail[i + 1] != 0; i += 2) {
78 		if (pa >= dump_avail[i] && pa < dump_avail[i + 1])
79 			return (1);
80 	}
81 	return (0);
82 }
83 
84 #define PG2MB(pgs) (((pgs) + (1 << 8) - 1) >> 8)
85 
86 static int
87 blk_flush(struct dumperinfo *di)
88 {
89 	int error;
90 
91 	if (fragsz == 0)
92 		return (0);
93 
94 	error = dump_append(di, dump_va, 0, fragsz);
95 	fragsz = 0;
96 	return (error);
97 }
98 
99 static int
100 blk_write(struct dumperinfo *di, char *ptr, vm_paddr_t pa, size_t sz)
101 {
102 	size_t len;
103 	int error, i, c;
104 	u_int maxdumpsz;
105 
106 	maxdumpsz = min(di->maxiosize, MAXDUMPPGS * PAGE_SIZE);
107 	if (maxdumpsz == 0)	/* seatbelt */
108 		maxdumpsz = PAGE_SIZE;
109 	error = 0;
110 	if (ptr != NULL && pa != 0) {
111 		printf("cant have both va and pa!\n");
112 		return (EINVAL);
113 	}
114 	if (pa != 0) {
115 		if ((sz % PAGE_SIZE) != 0) {
116 			printf("size not page aligned\n");
117 			return (EINVAL);
118 		}
119 		if ((pa & PAGE_MASK) != 0) {
120 			printf("address not page aligned\n");
121 			return (EINVAL);
122 		}
123 	}
124 	if (ptr != NULL) {
125 		/* Flush any pre-existing pa pages before a virtual dump. */
126 		error = blk_flush(di);
127 		if (error)
128 			return (error);
129 	}
130 	while (sz) {
131 		len = maxdumpsz - fragsz;
132 		if (len > sz)
133 			len = sz;
134 		counter += len;
135 		progress -= len;
136 		if (counter >> 22) {
137 			printf(" %lld", PG2MB(progress >> PAGE_SHIFT));
138 			counter &= (1<<22) - 1;
139 		}
140 
141 #ifdef SW_WATCHDOG
142 		wdog_kern_pat(WD_LASTVAL);
143 #endif
144 		if (ptr) {
145 			error = dump_append(di, ptr, 0, len);
146 			if (error)
147 				return (error);
148 			ptr += len;
149 			sz -= len;
150 		} else {
151 			for (i = 0; i < len; i += PAGE_SIZE)
152 				dump_va = pmap_kenter_temporary(pa + i,
153 				    (i + fragsz) >> PAGE_SHIFT);
154 			fragsz += len;
155 			pa += len;
156 			sz -= len;
157 			if (fragsz == maxdumpsz) {
158 				error = blk_flush(di);
159 				if (error)
160 					return (error);
161 			}
162 		}
163 
164 		/* Check for user abort. */
165 		c = cncheckc();
166 		if (c == 0x03)
167 			return (ECANCELED);
168 		if (c != -1)
169 			printf(" (CTRL-C to abort) ");
170 	}
171 
172 	return (0);
173 }
174 
175 /* A buffer for general use. Its size must be one page at least. */
176 static char dumpbuf[PAGE_SIZE];
177 CTASSERT(sizeof(dumpbuf) % sizeof(pt2_entry_t) == 0);
178 
179 int
180 minidumpsys(struct dumperinfo *di)
181 {
182 	struct minidumphdr mdhdr;
183 	uint64_t dumpsize;
184 	uint32_t ptesize;
185 	uint32_t bits;
186 	uint32_t pa, prev_pa = 0, count = 0;
187 	vm_offset_t va;
188 	int i, bit, error;
189 	char *addr;
190 
191 	/*
192 	 * Flush caches.  Note that in the SMP case this operates only on the
193 	 * current CPU's L1 cache.  Before we reach this point, code in either
194 	 * the system shutdown or kernel debugger has called stop_cpus() to stop
195 	 * all cores other than this one.  Part of the ARM handling of
196 	 * stop_cpus() is to call wbinv_all() on that core's local L1 cache.  So
197 	 * by time we get to here, all that remains is to flush the L1 for the
198 	 * current CPU, then the L2.
199 	 */
200 	dcache_wbinv_poc_all();
201 
202 	counter = 0;
203 	/* Walk page table pages, set bits in vm_page_dump */
204 	ptesize = 0;
205 	for (va = KERNBASE; va < kernel_vm_end; va += PAGE_SIZE) {
206 		pa = pmap_dump_kextract(va, NULL);
207 		if (pa != 0 && is_dumpable(pa))
208 			dump_add_page(pa);
209 		ptesize += sizeof(pt2_entry_t);
210 	}
211 
212 	/* Calculate dump size. */
213 	dumpsize = ptesize;
214 	dumpsize += round_page(msgbufp->msg_size);
215 	dumpsize += round_page(vm_page_dump_size);
216 	for (i = 0; i < vm_page_dump_size / sizeof(*vm_page_dump); i++) {
217 		bits = vm_page_dump[i];
218 		while (bits) {
219 			bit = ffs(bits) - 1;
220 			pa = (((uint64_t)i * sizeof(*vm_page_dump) * NBBY) +
221 			    bit) * PAGE_SIZE;
222 			/* Clear out undumpable pages now if needed */
223 			if (is_dumpable(pa))
224 				dumpsize += PAGE_SIZE;
225 			else
226 				dump_drop_page(pa);
227 			bits &= ~(1ul << bit);
228 		}
229 	}
230 	dumpsize += PAGE_SIZE;
231 
232 	progress = dumpsize;
233 
234 	/* Initialize mdhdr */
235 	bzero(&mdhdr, sizeof(mdhdr));
236 	strcpy(mdhdr.magic, MINIDUMP_MAGIC);
237 	mdhdr.version = MINIDUMP_VERSION;
238 	mdhdr.msgbufsize = msgbufp->msg_size;
239 	mdhdr.bitmapsize = vm_page_dump_size;
240 	mdhdr.ptesize = ptesize;
241 	mdhdr.kernbase = KERNBASE;
242 	mdhdr.arch = __ARM_ARCH;
243 #if __ARM_ARCH >= 6
244 	mdhdr.mmuformat = MINIDUMP_MMU_FORMAT_V6;
245 #else
246 	mdhdr.mmuformat = MINIDUMP_MMU_FORMAT_V4;
247 #endif
248 	dump_init_header(di, &kdh, KERNELDUMPMAGIC, KERNELDUMP_ARM_VERSION,
249 	    dumpsize);
250 
251 	error = dump_start(di, &kdh);
252 	if (error != 0)
253 		goto fail;
254 
255 	printf("Physical memory: %u MB\n", ptoa((uintmax_t)physmem) / 1048576);
256 	printf("Dumping %llu MB:", (long long)dumpsize >> 20);
257 
258 	/* Dump my header */
259 	bzero(dumpbuf, sizeof(dumpbuf));
260 	bcopy(&mdhdr, dumpbuf, sizeof(mdhdr));
261 	error = blk_write(di, dumpbuf, 0, PAGE_SIZE);
262 	if (error)
263 		goto fail;
264 
265 	/* Dump msgbuf up front */
266 	error = blk_write(di, (char *)msgbufp->msg_ptr, 0,
267 	    round_page(msgbufp->msg_size));
268 	if (error)
269 		goto fail;
270 
271 	/* Dump bitmap */
272 	error = blk_write(di, (char *)vm_page_dump, 0,
273 	    round_page(vm_page_dump_size));
274 	if (error)
275 		goto fail;
276 
277 	/* Dump kernel page table pages */
278 	addr = dumpbuf;
279 	for (va = KERNBASE; va < kernel_vm_end; va += PAGE_SIZE) {
280 		pmap_dump_kextract(va, (pt2_entry_t *)addr);
281 		addr += sizeof(pt2_entry_t);
282 		if (addr == dumpbuf + sizeof(dumpbuf)) {
283 			error = blk_write(di, dumpbuf, 0, sizeof(dumpbuf));
284 			if (error != 0)
285 				goto fail;
286 			addr = dumpbuf;
287 		}
288 	}
289 	if (addr != dumpbuf) {
290 		error = blk_write(di, dumpbuf, 0, addr - dumpbuf);
291 		if (error != 0)
292 			goto fail;
293 	}
294 
295 	/* Dump memory chunks */
296 	for (i = 0; i < vm_page_dump_size / sizeof(*vm_page_dump); i++) {
297 		bits = vm_page_dump[i];
298 		while (bits) {
299 			bit = ffs(bits) - 1;
300 			pa = (((uint64_t)i * sizeof(*vm_page_dump) * NBBY) +
301 			    bit) * PAGE_SIZE;
302 			if (!count) {
303 				prev_pa = pa;
304 				count++;
305 			} else {
306 				if (pa == (prev_pa + count * PAGE_SIZE))
307 					count++;
308 				else {
309 					error = blk_write(di, NULL, prev_pa,
310 					    count * PAGE_SIZE);
311 					if (error)
312 						goto fail;
313 					count = 1;
314 					prev_pa = pa;
315 				}
316 			}
317 			bits &= ~(1ul << bit);
318 		}
319 	}
320 	if (count) {
321 		error = blk_write(di, NULL, prev_pa, count * PAGE_SIZE);
322 		if (error)
323 			goto fail;
324 		count = 0;
325 		prev_pa = 0;
326 	}
327 
328 	error = blk_flush(di);
329 	if (error)
330 		goto fail;
331 
332 	error = dump_finish(di, &kdh);
333 	if (error != 0)
334 		goto fail;
335 
336 	printf("\nDump complete\n");
337 	return (0);
338 
339 fail:
340 	if (error < 0)
341 		error = -error;
342 
343 	if (error == ECANCELED)
344 		printf("\nDump aborted\n");
345 	else if (error == E2BIG || error == ENOSPC) {
346 		printf("\nDump failed. Partition too small (about %lluMB were "
347 		    "needed this time).\n", (long long)dumpsize >> 20);
348 	} else
349 		printf("\n** DUMP FAILED (ERROR %d) **\n", error);
350 	return (error);
351 }
352 
353 void
354 dump_add_page(vm_paddr_t pa)
355 {
356 	int idx, bit;
357 
358 	pa >>= PAGE_SHIFT;
359 	idx = pa >> 5;		/* 2^5 = 32 */
360 	bit = pa & 31;
361 	atomic_set_int(&vm_page_dump[idx], 1ul << bit);
362 }
363 
364 void
365 dump_drop_page(vm_paddr_t pa)
366 {
367 	int idx, bit;
368 
369 	pa >>= PAGE_SHIFT;
370 	idx = pa >> 5;		/* 2^5 = 32 */
371 	bit = pa & 31;
372 	atomic_clear_int(&vm_page_dump[idx], 1ul << bit);
373 }
374