xref: /freebsd/lib/libkvm/kvm_minidump_aarch64.c (revision 1f474190)
1 /*-
2  * Copyright (c) 2006 Peter Wemm
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  *
25  * From: FreeBSD: src/lib/libkvm/kvm_minidump_amd64.c r261799
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 /*
32  * ARM64 (AArch64) machine dependent routines for kvm and minidumps.
33  */
34 
35 #include <sys/param.h>
36 #include <stdint.h>
37 #include <stdlib.h>
38 #include <string.h>
39 #include <unistd.h>
40 #include <vm/vm.h>
41 #include <kvm.h>
42 
43 #include "../../sys/arm64/include/minidump.h"
44 
45 #include <limits.h>
46 
47 #include "kvm_private.h"
48 #include "kvm_aarch64.h"
49 
50 #define	aarch64_round_page(x)	roundup2((kvaddr_t)(x), AARCH64_PAGE_SIZE)
51 
52 struct vmstate {
53 	struct minidumphdr hdr;
54 };
55 
56 static aarch64_pte_t
57 _aarch64_pte_get(kvm_t *kd, u_long pteindex)
58 {
59 	aarch64_pte_t *pte = _kvm_pmap_get(kd, pteindex, sizeof(*pte));
60 
61 	return le64toh(*pte);
62 }
63 
64 static int
65 _aarch64_minidump_probe(kvm_t *kd)
66 {
67 
68 	return (_kvm_probe_elf_kernel(kd, ELFCLASS64, EM_AARCH64) &&
69 	    _kvm_is_minidump(kd));
70 }
71 
72 static void
73 _aarch64_minidump_freevtop(kvm_t *kd)
74 {
75 	struct vmstate *vm = kd->vmst;
76 
77 	free(vm);
78 	kd->vmst = NULL;
79 }
80 
81 static int
82 _aarch64_minidump_initvtop(kvm_t *kd)
83 {
84 	struct vmstate *vmst;
85 	off_t off, dump_avail_off, sparse_off;
86 
87 	vmst = _kvm_malloc(kd, sizeof(*vmst));
88 	if (vmst == NULL) {
89 		_kvm_err(kd, kd->program, "cannot allocate vm");
90 		return (-1);
91 	}
92 	kd->vmst = vmst;
93 	if (pread(kd->pmfd, &vmst->hdr, sizeof(vmst->hdr), 0) !=
94 	    sizeof(vmst->hdr)) {
95 		_kvm_err(kd, kd->program, "cannot read dump header");
96 		return (-1);
97 	}
98 	if (strncmp(MINIDUMP_MAGIC, vmst->hdr.magic,
99 	    sizeof(vmst->hdr.magic)) != 0) {
100 		_kvm_err(kd, kd->program, "not a minidump for this platform");
101 		return (-1);
102 	}
103 
104 	vmst->hdr.version = le32toh(vmst->hdr.version);
105 	if (vmst->hdr.version != MINIDUMP_VERSION && vmst->hdr.version != 1) {
106 		_kvm_err(kd, kd->program, "wrong minidump version. "
107 		    "Expected %d got %d", MINIDUMP_VERSION, vmst->hdr.version);
108 		return (-1);
109 	}
110 	vmst->hdr.msgbufsize = le32toh(vmst->hdr.msgbufsize);
111 	vmst->hdr.bitmapsize = le32toh(vmst->hdr.bitmapsize);
112 	vmst->hdr.pmapsize = le32toh(vmst->hdr.pmapsize);
113 	vmst->hdr.kernbase = le64toh(vmst->hdr.kernbase);
114 	vmst->hdr.dmapphys = le64toh(vmst->hdr.dmapphys);
115 	vmst->hdr.dmapbase = le64toh(vmst->hdr.dmapbase);
116 	vmst->hdr.dmapend = le64toh(vmst->hdr.dmapend);
117 	vmst->hdr.dumpavailsize = vmst->hdr.version == MINIDUMP_VERSION ?
118 	    le32toh(vmst->hdr.dumpavailsize) : 0;
119 
120 	/* Skip header and msgbuf */
121 	dump_avail_off = AARCH64_PAGE_SIZE + aarch64_round_page(vmst->hdr.msgbufsize);
122 
123 	/* Skip dump_avail */
124 	off = dump_avail_off + aarch64_round_page(vmst->hdr.dumpavailsize);
125 
126 	/* build physical address lookup table for sparse pages */
127 	sparse_off = off + aarch64_round_page(vmst->hdr.bitmapsize) +
128 	    aarch64_round_page(vmst->hdr.pmapsize);
129 	if (_kvm_pt_init(kd, vmst->hdr.dumpavailsize, dump_avail_off,
130 	    vmst->hdr.bitmapsize, off, sparse_off, AARCH64_PAGE_SIZE,
131 	    sizeof(uint64_t)) == -1) {
132 		return (-1);
133 	}
134 	off += aarch64_round_page(vmst->hdr.bitmapsize);
135 
136 	if (_kvm_pmap_init(kd, vmst->hdr.pmapsize, off) == -1) {
137 		return (-1);
138 	}
139 	off += aarch64_round_page(vmst->hdr.pmapsize);
140 
141 	return (0);
142 }
143 
144 static int
145 _aarch64_minidump_vatop(kvm_t *kd, kvaddr_t va, off_t *pa)
146 {
147 	struct vmstate *vm;
148 	aarch64_physaddr_t offset;
149 	aarch64_pte_t l3;
150 	kvaddr_t l3_index;
151 	aarch64_physaddr_t a;
152 	off_t ofs;
153 
154 	vm = kd->vmst;
155 	offset = va & AARCH64_PAGE_MASK;
156 
157 	if (va >= vm->hdr.dmapbase && va < vm->hdr.dmapend) {
158 		a = (va - vm->hdr.dmapbase + vm->hdr.dmapphys) &
159 		    ~AARCH64_PAGE_MASK;
160 		ofs = _kvm_pt_find(kd, a, AARCH64_PAGE_SIZE);
161 		if (ofs == -1) {
162 			_kvm_err(kd, kd->program, "_aarch64_minidump_vatop: "
163 			    "direct map address 0x%jx not in minidump",
164 			    (uintmax_t)va);
165 			goto invalid;
166 		}
167 		*pa = ofs + offset;
168 		return (AARCH64_PAGE_SIZE - offset);
169 	} else if (va >= vm->hdr.kernbase) {
170 		l3_index = (va - vm->hdr.kernbase) >> AARCH64_L3_SHIFT;
171 		if (l3_index >= vm->hdr.pmapsize / sizeof(l3))
172 			goto invalid;
173 		l3 = _aarch64_pte_get(kd, l3_index);
174 		if ((l3 & AARCH64_ATTR_DESCR_MASK) != AARCH64_L3_PAGE) {
175 			_kvm_err(kd, kd->program,
176 			    "_aarch64_minidump_vatop: pde not valid");
177 			goto invalid;
178 		}
179 		a = l3 & ~AARCH64_ATTR_MASK;
180 		ofs = _kvm_pt_find(kd, a, AARCH64_PAGE_SIZE);
181 		if (ofs == -1) {
182 			_kvm_err(kd, kd->program, "_aarch64_minidump_vatop: "
183 			    "physical address 0x%jx not in minidump",
184 			    (uintmax_t)a);
185 			goto invalid;
186 		}
187 		*pa = ofs + offset;
188 		return (AARCH64_PAGE_SIZE - offset);
189 	} else {
190 		_kvm_err(kd, kd->program,
191 	    "_aarch64_minidump_vatop: virtual address 0x%jx not minidumped",
192 		    (uintmax_t)va);
193 		goto invalid;
194 	}
195 
196 invalid:
197 	_kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
198 	return (0);
199 }
200 
201 static int
202 _aarch64_minidump_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa)
203 {
204 
205 	if (ISALIVE(kd)) {
206 		_kvm_err(kd, 0,
207 		    "_aarch64_minidump_kvatop called in live kernel!");
208 		return (0);
209 	}
210 	return (_aarch64_minidump_vatop(kd, va, pa));
211 }
212 
213 static int
214 _aarch64_native(kvm_t *kd __unused)
215 {
216 
217 #ifdef __aarch64__
218 	return (1);
219 #else
220 	return (0);
221 #endif
222 }
223 
224 static vm_prot_t
225 _aarch64_entry_to_prot(aarch64_pte_t pte)
226 {
227 	vm_prot_t prot = VM_PROT_READ;
228 
229 	/* Source: arm64/arm64/pmap.c:pmap_protect() */
230 	if ((pte & AARCH64_ATTR_AP(AARCH64_ATTR_AP_RO)) == 0)
231 		prot |= VM_PROT_WRITE;
232 	if ((pte & AARCH64_ATTR_XN) == 0)
233 		prot |= VM_PROT_EXECUTE;
234 	return prot;
235 }
236 
237 static int
238 _aarch64_minidump_walk_pages(kvm_t *kd, kvm_walk_pages_cb_t *cb, void *arg)
239 {
240 	struct vmstate *vm = kd->vmst;
241 	u_long nptes = vm->hdr.pmapsize / sizeof(aarch64_pte_t);
242 	u_long bmindex, dva, pa, pteindex, va;
243 	struct kvm_bitmap bm;
244 	vm_prot_t prot;
245 	int ret = 0;
246 
247 	if (!_kvm_bitmap_init(&bm, vm->hdr.bitmapsize, &bmindex))
248 		return (0);
249 
250 	for (pteindex = 0; pteindex < nptes; pteindex++) {
251 		aarch64_pte_t pte = _aarch64_pte_get(kd, pteindex);
252 
253 		if ((pte & AARCH64_ATTR_DESCR_MASK) != AARCH64_L3_PAGE)
254 			continue;
255 
256 		va = vm->hdr.kernbase + (pteindex << AARCH64_L3_SHIFT);
257 		pa = pte & ~AARCH64_ATTR_MASK;
258 		dva = vm->hdr.dmapbase + pa;
259 		if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva,
260 		    _aarch64_entry_to_prot(pte), AARCH64_PAGE_SIZE, 0)) {
261 			goto out;
262 		}
263 	}
264 
265 	while (_kvm_bitmap_next(&bm, &bmindex)) {
266 		pa = _kvm_bit_id_pa(kd, bmindex, AARCH64_PAGE_SIZE);
267 		if (pa == _KVM_PA_INVALID)
268 			break;
269 		dva = vm->hdr.dmapbase + pa;
270 		if (vm->hdr.dmapend < (dva + AARCH64_PAGE_SIZE))
271 			break;
272 		va = 0;
273 		prot = VM_PROT_READ | VM_PROT_WRITE;
274 		if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva,
275 		    prot, AARCH64_PAGE_SIZE, 0)) {
276 			goto out;
277 		}
278 	}
279 	ret = 1;
280 
281 out:
282 	_kvm_bitmap_deinit(&bm);
283 	return (ret);
284 }
285 
286 static struct kvm_arch kvm_aarch64_minidump = {
287 	.ka_probe = _aarch64_minidump_probe,
288 	.ka_initvtop = _aarch64_minidump_initvtop,
289 	.ka_freevtop = _aarch64_minidump_freevtop,
290 	.ka_kvatop = _aarch64_minidump_kvatop,
291 	.ka_native = _aarch64_native,
292 	.ka_walk_pages = _aarch64_minidump_walk_pages,
293 };
294 
295 KVM_ARCH(kvm_aarch64_minidump);
296