xref: /freebsd/sys/arm/arm/minidump_machdep.c (revision 685dc743dc3b5645e34836464128e1c0558b404b)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 #include "opt_watchdog.h"
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/conf.h>
38 #include <sys/cons.h>
39 #include <sys/kernel.h>
40 #include <sys/kerneldump.h>
41 #include <sys/msgbuf.h>
42 #include <sys/watchdog.h>
43 #include <vm/vm.h>
44 #include <vm/vm_param.h>
45 #include <vm/vm_page.h>
46 #include <vm/vm_phys.h>
47 #include <vm/vm_dumpset.h>
48 #include <vm/pmap.h>
49 #include <machine/atomic.h>
50 #include <machine/cpu.h>
51 #include <machine/elf.h>
52 #include <machine/md_var.h>
53 #include <machine/minidump.h>
54 
55 CTASSERT(sizeof(struct kerneldumpheader) == 512);
56 
57 static struct kerneldumpheader kdh;
58 
59 /* Handle chunked writes. */
60 static size_t fragsz;
61 static void *dump_va;
62 
63 static int
blk_flush(struct dumperinfo * di)64 blk_flush(struct dumperinfo *di)
65 {
66 	int error;
67 
68 	if (fragsz == 0)
69 		return (0);
70 
71 	error = dump_append(di, dump_va, fragsz);
72 	fragsz = 0;
73 	return (error);
74 }
75 
76 static int
blk_write(struct dumperinfo * di,char * ptr,vm_paddr_t pa,size_t sz)77 blk_write(struct dumperinfo *di, char *ptr, vm_paddr_t pa, size_t sz)
78 {
79 	size_t len;
80 	int error, i, c;
81 	u_int maxdumpsz;
82 
83 	maxdumpsz = min(di->maxiosize, MAXDUMPPGS * PAGE_SIZE);
84 	if (maxdumpsz == 0)	/* seatbelt */
85 		maxdumpsz = PAGE_SIZE;
86 	error = 0;
87 	if (ptr != NULL && pa != 0) {
88 		printf("cant have both va and pa!\n");
89 		return (EINVAL);
90 	}
91 	if (pa != 0) {
92 		if ((sz % PAGE_SIZE) != 0) {
93 			printf("size not page aligned\n");
94 			return (EINVAL);
95 		}
96 		if ((pa & PAGE_MASK) != 0) {
97 			printf("address not page aligned\n");
98 			return (EINVAL);
99 		}
100 	}
101 	if (ptr != NULL) {
102 		/* Flush any pre-existing pa pages before a virtual dump. */
103 		error = blk_flush(di);
104 		if (error)
105 			return (error);
106 	}
107 	while (sz) {
108 		len = maxdumpsz - fragsz;
109 		if (len > sz)
110 			len = sz;
111 
112 		dumpsys_pb_progress(len);
113 		wdog_kern_pat(WD_LASTVAL);
114 
115 		if (ptr) {
116 			error = dump_append(di, ptr, len);
117 			if (error)
118 				return (error);
119 			ptr += len;
120 			sz -= len;
121 		} else {
122 			for (i = 0; i < len; i += PAGE_SIZE)
123 				dump_va = pmap_kenter_temporary(pa + i,
124 				    (i + fragsz) >> PAGE_SHIFT);
125 			fragsz += len;
126 			pa += len;
127 			sz -= len;
128 			if (fragsz == maxdumpsz) {
129 				error = blk_flush(di);
130 				if (error)
131 					return (error);
132 			}
133 		}
134 
135 		/* Check for user abort. */
136 		c = cncheckc();
137 		if (c == 0x03)
138 			return (ECANCELED);
139 		if (c != -1)
140 			printf(" (CTRL-C to abort) ");
141 	}
142 
143 	return (0);
144 }
145 
146 /* A buffer for general use. Its size must be one page at least. */
147 static char dumpbuf[PAGE_SIZE] __aligned(sizeof(uint64_t));
148 CTASSERT(sizeof(dumpbuf) % sizeof(pt2_entry_t) == 0);
149 
150 int
cpu_minidumpsys(struct dumperinfo * di,const struct minidumpstate * state)151 cpu_minidumpsys(struct dumperinfo *di, const struct minidumpstate *state)
152 {
153 	struct minidumphdr mdhdr;
154 	struct msgbuf *mbp;
155 	uint64_t dumpsize, *dump_avail_buf;
156 	uint32_t ptesize;
157 	uint32_t pa, prev_pa = 0, count = 0;
158 	vm_offset_t va, kva_end;
159 	int error, i;
160 	char *addr;
161 
162 	/*
163 	 * Flush caches.  Note that in the SMP case this operates only on the
164 	 * current CPU's L1 cache.  Before we reach this point, code in either
165 	 * the system shutdown or kernel debugger has called stop_cpus() to stop
166 	 * all cores other than this one.  Part of the ARM handling of
167 	 * stop_cpus() is to call wbinv_all() on that core's local L1 cache.  So
168 	 * by time we get to here, all that remains is to flush the L1 for the
169 	 * current CPU, then the L2.
170 	 */
171 	dcache_wbinv_poc_all();
172 
173 	/* Snapshot the KVA upper bound in case it grows. */
174 	kva_end = kernel_vm_end;
175 
176 	/*
177 	 * Walk the kernel page table pages, setting the active entries in the
178 	 * dump bitmap.
179 	 */
180 	ptesize = 0;
181 	for (va = KERNBASE; va < kva_end; va += PAGE_SIZE) {
182 		pa = pmap_dump_kextract(va, NULL);
183 		if (pa != 0 && vm_phys_is_dumpable(pa))
184 			vm_page_dump_add(state->dump_bitset, pa);
185 		ptesize += sizeof(pt2_entry_t);
186 	}
187 
188 	/* Calculate dump size. */
189 	mbp = state->msgbufp;
190 	dumpsize = ptesize;
191 	dumpsize += round_page(mbp->msg_size);
192 	dumpsize += round_page(nitems(dump_avail) * sizeof(uint64_t));
193 	dumpsize += round_page(BITSET_SIZE(vm_page_dump_pages));
194 	VM_PAGE_DUMP_FOREACH(state->dump_bitset, pa) {
195 		/* Clear out undumpable pages now if needed */
196 		if (vm_phys_is_dumpable(pa))
197 			dumpsize += PAGE_SIZE;
198 		else
199 			vm_page_dump_drop(state->dump_bitset, pa);
200 	}
201 	dumpsize += PAGE_SIZE;
202 
203 	dumpsys_pb_init(dumpsize);
204 
205 	/* Initialize mdhdr */
206 	bzero(&mdhdr, sizeof(mdhdr));
207 	strcpy(mdhdr.magic, MINIDUMP_MAGIC);
208 	mdhdr.version = MINIDUMP_VERSION;
209 	mdhdr.msgbufsize = mbp->msg_size;
210 	mdhdr.bitmapsize = round_page(BITSET_SIZE(vm_page_dump_pages));
211 	mdhdr.ptesize = ptesize;
212 	mdhdr.kernbase = KERNBASE;
213 	mdhdr.arch = __ARM_ARCH;
214 	mdhdr.mmuformat = MINIDUMP_MMU_FORMAT_V6;
215 	mdhdr.dumpavailsize = round_page(nitems(dump_avail) * sizeof(uint64_t));
216 
217 	dump_init_header(di, &kdh, KERNELDUMPMAGIC, KERNELDUMP_ARM_VERSION,
218 	    dumpsize);
219 
220 	error = dump_start(di, &kdh);
221 	if (error != 0)
222 		goto fail;
223 
224 	printf("Physical memory: %u MB\n", ptoa((uintmax_t)physmem) / 1048576);
225 	printf("Dumping %llu MB:", (long long)dumpsize >> 20);
226 
227 	/* Dump my header */
228 	bzero(dumpbuf, sizeof(dumpbuf));
229 	bcopy(&mdhdr, dumpbuf, sizeof(mdhdr));
230 	error = blk_write(di, dumpbuf, 0, PAGE_SIZE);
231 	if (error)
232 		goto fail;
233 
234 	/* Dump msgbuf up front */
235 	error = blk_write(di, mbp->msg_ptr, 0, round_page(mbp->msg_size));
236 	if (error)
237 		goto fail;
238 
239 	/* Dump dump_avail.  Make a copy using 64-bit physical addresses. */
240 	_Static_assert(nitems(dump_avail) * sizeof(uint64_t) <= sizeof(dumpbuf),
241 	    "Large dump_avail not handled");
242 	bzero(dumpbuf, sizeof(dumpbuf));
243 	dump_avail_buf = (uint64_t *)dumpbuf;
244 	for (i = 0; dump_avail[i] != 0 || dump_avail[i + 1] != 0; i += 2) {
245 		dump_avail_buf[i] = dump_avail[i];
246 		dump_avail_buf[i + 1] = dump_avail[i + 1];
247 	}
248 	error = blk_write(di, dumpbuf, 0, PAGE_SIZE);
249 	if (error)
250 		goto fail;
251 
252 	/* Dump bitmap */
253 	error = blk_write(di, (char *)state->dump_bitset, 0,
254 	    round_page(BITSET_SIZE(vm_page_dump_pages)));
255 	if (error)
256 		goto fail;
257 
258 	/* Dump kernel page table pages */
259 	addr = dumpbuf;
260 	for (va = KERNBASE; va < kva_end; va += PAGE_SIZE) {
261 		pmap_dump_kextract(va, (pt2_entry_t *)addr);
262 		addr += sizeof(pt2_entry_t);
263 		if (addr == dumpbuf + sizeof(dumpbuf)) {
264 			error = blk_write(di, dumpbuf, 0, sizeof(dumpbuf));
265 			if (error != 0)
266 				goto fail;
267 			addr = dumpbuf;
268 		}
269 	}
270 	if (addr != dumpbuf) {
271 		error = blk_write(di, dumpbuf, 0, addr - dumpbuf);
272 		if (error != 0)
273 			goto fail;
274 	}
275 
276 	/* Dump memory chunks */
277 	VM_PAGE_DUMP_FOREACH(state->dump_bitset, pa) {
278 		if (!count) {
279 			prev_pa = pa;
280 			count++;
281 		} else {
282 			if (pa == (prev_pa + count * PAGE_SIZE))
283 				count++;
284 			else {
285 				error = blk_write(di, NULL, prev_pa,
286 				    count * PAGE_SIZE);
287 				if (error)
288 					goto fail;
289 				count = 1;
290 				prev_pa = pa;
291 			}
292 		}
293 	}
294 	if (count) {
295 		error = blk_write(di, NULL, prev_pa, count * PAGE_SIZE);
296 		if (error)
297 			goto fail;
298 		count = 0;
299 		prev_pa = 0;
300 	}
301 
302 	error = blk_flush(di);
303 	if (error)
304 		goto fail;
305 
306 	error = dump_finish(di, &kdh);
307 	if (error != 0)
308 		goto fail;
309 
310 	printf("\nDump complete\n");
311 	return (0);
312 
313 fail:
314 	if (error < 0)
315 		error = -error;
316 
317 	if (error == ECANCELED)
318 		printf("\nDump aborted\n");
319 	else if (error == E2BIG || error == ENOSPC) {
320 		printf("\nDump failed. Partition too small (about %lluMB were "
321 		    "needed this time).\n", (long long)dumpsize >> 20);
322 	} else
323 		printf("\n** DUMP FAILED (ERROR %d) **\n", error);
324 	return (error);
325 }
326