xref: /freebsd-13-stable/lib/libkvm/kvm_minidump_aarch64.c (revision 3d497e17ebd33fe0f58d773e35ab994d750258d6)
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 /*
30  * ARM64 (AArch64) machine dependent routines for kvm and minidumps.
31  */
32 
33 #include <sys/param.h>
34 #include <stdint.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <unistd.h>
38 #include <vm/vm.h>
39 #include <kvm.h>
40 
41 #include "../../sys/arm64/include/minidump.h"
42 
43 #include <limits.h>
44 
45 #include "kvm_private.h"
46 #include "kvm_aarch64.h"
47 
48 #define	aarch64_round_page(x)	roundup2((kvaddr_t)(x), AARCH64_PAGE_SIZE)
49 
50 struct vmstate {
51 	struct minidumphdr hdr;
52 };
53 
54 static aarch64_pte_t
_aarch64_pte_get(kvm_t * kd,u_long pteindex)55 _aarch64_pte_get(kvm_t *kd, u_long pteindex)
56 {
57 	aarch64_pte_t *pte = _kvm_pmap_get(kd, pteindex, sizeof(*pte));
58 
59 	return le64toh(*pte);
60 }
61 
62 static int
_aarch64_minidump_probe(kvm_t * kd)63 _aarch64_minidump_probe(kvm_t *kd)
64 {
65 
66 	return (_kvm_probe_elf_kernel(kd, ELFCLASS64, EM_AARCH64) &&
67 	    _kvm_is_minidump(kd));
68 }
69 
70 static void
_aarch64_minidump_freevtop(kvm_t * kd)71 _aarch64_minidump_freevtop(kvm_t *kd)
72 {
73 	struct vmstate *vm = kd->vmst;
74 
75 	free(vm);
76 	kd->vmst = NULL;
77 }
78 
79 static int
_aarch64_minidump_initvtop(kvm_t * kd)80 _aarch64_minidump_initvtop(kvm_t *kd)
81 {
82 	struct vmstate *vmst;
83 	off_t off, dump_avail_off, sparse_off;
84 
85 	vmst = _kvm_malloc(kd, sizeof(*vmst));
86 	if (vmst == NULL) {
87 		_kvm_err(kd, kd->program, "cannot allocate vm");
88 		return (-1);
89 	}
90 	kd->vmst = vmst;
91 	if (pread(kd->pmfd, &vmst->hdr, sizeof(vmst->hdr), 0) !=
92 	    sizeof(vmst->hdr)) {
93 		_kvm_err(kd, kd->program, "cannot read dump header");
94 		return (-1);
95 	}
96 	if (strncmp(MINIDUMP_MAGIC, vmst->hdr.magic,
97 	    sizeof(vmst->hdr.magic)) != 0) {
98 		_kvm_err(kd, kd->program, "not a minidump for this platform");
99 		return (-1);
100 	}
101 
102 	vmst->hdr.version = le32toh(vmst->hdr.version);
103 	if (vmst->hdr.version != MINIDUMP_VERSION && vmst->hdr.version != 1) {
104 		_kvm_err(kd, kd->program, "wrong minidump version. "
105 		    "Expected %d got %d", MINIDUMP_VERSION, vmst->hdr.version);
106 		return (-1);
107 	}
108 	vmst->hdr.msgbufsize = le32toh(vmst->hdr.msgbufsize);
109 	vmst->hdr.bitmapsize = le32toh(vmst->hdr.bitmapsize);
110 	vmst->hdr.pmapsize = le32toh(vmst->hdr.pmapsize);
111 	vmst->hdr.kernbase = le64toh(vmst->hdr.kernbase);
112 	vmst->hdr.dmapphys = le64toh(vmst->hdr.dmapphys);
113 	vmst->hdr.dmapbase = le64toh(vmst->hdr.dmapbase);
114 	vmst->hdr.dmapend = le64toh(vmst->hdr.dmapend);
115 	vmst->hdr.dumpavailsize = vmst->hdr.version == MINIDUMP_VERSION ?
116 	    le32toh(vmst->hdr.dumpavailsize) : 0;
117 
118 	/* Skip header and msgbuf */
119 	dump_avail_off = AARCH64_PAGE_SIZE + aarch64_round_page(vmst->hdr.msgbufsize);
120 
121 	/* Skip dump_avail */
122 	off = dump_avail_off + aarch64_round_page(vmst->hdr.dumpavailsize);
123 
124 	/* build physical address lookup table for sparse pages */
125 	sparse_off = off + aarch64_round_page(vmst->hdr.bitmapsize) +
126 	    aarch64_round_page(vmst->hdr.pmapsize);
127 	if (_kvm_pt_init(kd, vmst->hdr.dumpavailsize, dump_avail_off,
128 	    vmst->hdr.bitmapsize, off, sparse_off, AARCH64_PAGE_SIZE) == -1) {
129 		return (-1);
130 	}
131 	off += aarch64_round_page(vmst->hdr.bitmapsize);
132 
133 	if (_kvm_pmap_init(kd, vmst->hdr.pmapsize, off) == -1) {
134 		return (-1);
135 	}
136 	off += aarch64_round_page(vmst->hdr.pmapsize);
137 
138 	return (0);
139 }
140 
141 static int
_aarch64_minidump_vatop(kvm_t * kd,kvaddr_t va,off_t * pa)142 _aarch64_minidump_vatop(kvm_t *kd, kvaddr_t va, off_t *pa)
143 {
144 	struct vmstate *vm;
145 	aarch64_physaddr_t offset;
146 	aarch64_pte_t l3;
147 	kvaddr_t l3_index;
148 	aarch64_physaddr_t a;
149 	off_t ofs;
150 
151 	vm = kd->vmst;
152 	offset = va & AARCH64_PAGE_MASK;
153 
154 	if (va >= vm->hdr.dmapbase && va < vm->hdr.dmapend) {
155 		a = (va - vm->hdr.dmapbase + vm->hdr.dmapphys) &
156 		    ~AARCH64_PAGE_MASK;
157 		ofs = _kvm_pt_find(kd, a, AARCH64_PAGE_SIZE);
158 		if (ofs == -1) {
159 			_kvm_err(kd, kd->program, "_aarch64_minidump_vatop: "
160 			    "direct map address 0x%jx not in minidump",
161 			    (uintmax_t)va);
162 			goto invalid;
163 		}
164 		*pa = ofs + offset;
165 		return (AARCH64_PAGE_SIZE - offset);
166 	} else if (va >= vm->hdr.kernbase) {
167 		l3_index = (va - vm->hdr.kernbase) >> AARCH64_L3_SHIFT;
168 		if (l3_index >= vm->hdr.pmapsize / sizeof(l3))
169 			goto invalid;
170 		l3 = _aarch64_pte_get(kd, l3_index);
171 		if ((l3 & AARCH64_ATTR_DESCR_MASK) != AARCH64_L3_PAGE) {
172 			_kvm_err(kd, kd->program,
173 			    "_aarch64_minidump_vatop: pde not valid");
174 			goto invalid;
175 		}
176 		a = l3 & ~AARCH64_ATTR_MASK;
177 		ofs = _kvm_pt_find(kd, a, AARCH64_PAGE_SIZE);
178 		if (ofs == -1) {
179 			_kvm_err(kd, kd->program, "_aarch64_minidump_vatop: "
180 			    "physical address 0x%jx not in minidump",
181 			    (uintmax_t)a);
182 			goto invalid;
183 		}
184 		*pa = ofs + offset;
185 		return (AARCH64_PAGE_SIZE - offset);
186 	} else {
187 		_kvm_err(kd, kd->program,
188 	    "_aarch64_minidump_vatop: virtual address 0x%jx not minidumped",
189 		    (uintmax_t)va);
190 		goto invalid;
191 	}
192 
193 invalid:
194 	_kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
195 	return (0);
196 }
197 
198 static int
_aarch64_minidump_kvatop(kvm_t * kd,kvaddr_t va,off_t * pa)199 _aarch64_minidump_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa)
200 {
201 
202 	if (ISALIVE(kd)) {
203 		_kvm_err(kd, 0,
204 		    "_aarch64_minidump_kvatop called in live kernel!");
205 		return (0);
206 	}
207 	return (_aarch64_minidump_vatop(kd, va, pa));
208 }
209 
210 static int
_aarch64_native(kvm_t * kd __unused)211 _aarch64_native(kvm_t *kd __unused)
212 {
213 
214 #ifdef __aarch64__
215 	return (1);
216 #else
217 	return (0);
218 #endif
219 }
220 
221 static vm_prot_t
_aarch64_entry_to_prot(aarch64_pte_t pte)222 _aarch64_entry_to_prot(aarch64_pte_t pte)
223 {
224 	vm_prot_t prot = VM_PROT_READ;
225 
226 	/* Source: arm64/arm64/pmap.c:pmap_protect() */
227 	if ((pte & AARCH64_ATTR_AP(AARCH64_ATTR_AP_RO)) == 0)
228 		prot |= VM_PROT_WRITE;
229 	if ((pte & AARCH64_ATTR_XN) == 0)
230 		prot |= VM_PROT_EXECUTE;
231 	return prot;
232 }
233 
234 static int
_aarch64_minidump_walk_pages(kvm_t * kd,kvm_walk_pages_cb_t * cb,void * arg)235 _aarch64_minidump_walk_pages(kvm_t *kd, kvm_walk_pages_cb_t *cb, void *arg)
236 {
237 	struct vmstate *vm = kd->vmst;
238 	u_long nptes = vm->hdr.pmapsize / sizeof(aarch64_pte_t);
239 	u_long bmindex, dva, pa, pteindex, va;
240 	struct kvm_bitmap bm;
241 	vm_prot_t prot;
242 	int ret = 0;
243 
244 	if (!_kvm_bitmap_init(&bm, vm->hdr.bitmapsize, &bmindex))
245 		return (0);
246 
247 	for (pteindex = 0; pteindex < nptes; pteindex++) {
248 		aarch64_pte_t pte = _aarch64_pte_get(kd, pteindex);
249 
250 		if ((pte & AARCH64_ATTR_DESCR_MASK) != AARCH64_L3_PAGE)
251 			continue;
252 
253 		va = vm->hdr.kernbase + (pteindex << AARCH64_L3_SHIFT);
254 		pa = pte & ~AARCH64_ATTR_MASK;
255 		dva = vm->hdr.dmapbase + pa;
256 		if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva,
257 		    _aarch64_entry_to_prot(pte), AARCH64_PAGE_SIZE, 0)) {
258 			goto out;
259 		}
260 	}
261 
262 	while (_kvm_bitmap_next(&bm, &bmindex)) {
263 		pa = _kvm_bit_id_pa(kd, bmindex, AARCH64_PAGE_SIZE);
264 		if (pa == _KVM_PA_INVALID)
265 			break;
266 		dva = vm->hdr.dmapbase + pa;
267 		if (vm->hdr.dmapend < (dva + AARCH64_PAGE_SIZE))
268 			break;
269 		va = 0;
270 		prot = VM_PROT_READ | VM_PROT_WRITE;
271 		if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva,
272 		    prot, AARCH64_PAGE_SIZE, 0)) {
273 			goto out;
274 		}
275 	}
276 	ret = 1;
277 
278 out:
279 	_kvm_bitmap_deinit(&bm);
280 	return (ret);
281 }
282 
283 static struct kvm_arch kvm_aarch64_minidump = {
284 	.ka_probe = _aarch64_minidump_probe,
285 	.ka_initvtop = _aarch64_minidump_initvtop,
286 	.ka_freevtop = _aarch64_minidump_freevtop,
287 	.ka_kvatop = _aarch64_minidump_kvatop,
288 	.ka_native = _aarch64_native,
289 	.ka_walk_pages = _aarch64_minidump_walk_pages,
290 };
291 
292 KVM_ARCH(kvm_aarch64_minidump);
293