xref: /freebsd/lib/libkvm/kvm_minidump_aarch64.c (revision 405c3050f102b8c74782f0366c8ead927bd07b68)
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, 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) {
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 
118 	/* Skip header and msgbuf */
119 	off = AARCH64_PAGE_SIZE + aarch64_round_page(vmst->hdr.msgbufsize);
120 
121 	/* build physical address lookup table for sparse pages */
122 	sparse_off = off + aarch64_round_page(vmst->hdr.bitmapsize) +
123 	    aarch64_round_page(vmst->hdr.pmapsize);
124 	if (_kvm_pt_init(kd, vmst->hdr.bitmapsize, off, sparse_off,
125 	    AARCH64_PAGE_SIZE, sizeof(uint64_t)) == -1) {
126 		return (-1);
127 	}
128 	off += aarch64_round_page(vmst->hdr.bitmapsize);
129 
130 	if (_kvm_pmap_init(kd, vmst->hdr.pmapsize, off) == -1) {
131 		return (-1);
132 	}
133 	off += aarch64_round_page(vmst->hdr.pmapsize);
134 
135 	return (0);
136 }
137 
138 static int
139 _aarch64_minidump_vatop(kvm_t *kd, kvaddr_t va, off_t *pa)
140 {
141 	struct vmstate *vm;
142 	aarch64_physaddr_t offset;
143 	aarch64_pte_t l3;
144 	kvaddr_t l3_index;
145 	aarch64_physaddr_t a;
146 	off_t ofs;
147 
148 	vm = kd->vmst;
149 	offset = va & AARCH64_PAGE_MASK;
150 
151 	if (va >= vm->hdr.dmapbase && va < vm->hdr.dmapend) {
152 		a = (va - vm->hdr.dmapbase + vm->hdr.dmapphys) &
153 		    ~AARCH64_PAGE_MASK;
154 		ofs = _kvm_pt_find(kd, a, AARCH64_PAGE_SIZE);
155 		if (ofs == -1) {
156 			_kvm_err(kd, kd->program, "_aarch64_minidump_vatop: "
157 			    "direct map address 0x%jx not in minidump",
158 			    (uintmax_t)va);
159 			goto invalid;
160 		}
161 		*pa = ofs + offset;
162 		return (AARCH64_PAGE_SIZE - offset);
163 	} else if (va >= vm->hdr.kernbase) {
164 		l3_index = (va - vm->hdr.kernbase) >> AARCH64_L3_SHIFT;
165 		if (l3_index >= vm->hdr.pmapsize / sizeof(l3))
166 			goto invalid;
167 		l3 = _aarch64_pte_get(kd, l3_index);
168 		if ((l3 & AARCH64_ATTR_DESCR_MASK) != AARCH64_L3_PAGE) {
169 			_kvm_err(kd, kd->program,
170 			    "_aarch64_minidump_vatop: pde not valid");
171 			goto invalid;
172 		}
173 		a = l3 & ~AARCH64_ATTR_MASK;
174 		ofs = _kvm_pt_find(kd, a, AARCH64_PAGE_SIZE);
175 		if (ofs == -1) {
176 			_kvm_err(kd, kd->program, "_aarch64_minidump_vatop: "
177 			    "physical address 0x%jx not in minidump",
178 			    (uintmax_t)a);
179 			goto invalid;
180 		}
181 		*pa = ofs + offset;
182 		return (AARCH64_PAGE_SIZE - offset);
183 	} else {
184 		_kvm_err(kd, kd->program,
185 	    "_aarch64_minidump_vatop: virtual address 0x%jx not minidumped",
186 		    (uintmax_t)va);
187 		goto invalid;
188 	}
189 
190 invalid:
191 	_kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
192 	return (0);
193 }
194 
195 static int
196 _aarch64_minidump_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa)
197 {
198 
199 	if (ISALIVE(kd)) {
200 		_kvm_err(kd, 0,
201 		    "_aarch64_minidump_kvatop called in live kernel!");
202 		return (0);
203 	}
204 	return (_aarch64_minidump_vatop(kd, va, pa));
205 }
206 
207 static int
208 _aarch64_native(kvm_t *kd __unused)
209 {
210 
211 #ifdef __aarch64__
212 	return (1);
213 #else
214 	return (0);
215 #endif
216 }
217 
218 static vm_prot_t
219 _aarch64_entry_to_prot(aarch64_pte_t pte)
220 {
221 	vm_prot_t prot = VM_PROT_READ;
222 
223 	/* Source: arm64/arm64/pmap.c:pmap_protect() */
224 	if ((pte & AARCH64_ATTR_AP(AARCH64_ATTR_AP_RO)) == 0)
225 		prot |= VM_PROT_WRITE;
226 	if ((pte & AARCH64_ATTR_XN) == 0)
227 		prot |= VM_PROT_EXECUTE;
228 	return prot;
229 }
230 
231 static int
232 _aarch64_minidump_walk_pages(kvm_t *kd, kvm_walk_pages_cb_t *cb, void *arg)
233 {
234 	struct vmstate *vm = kd->vmst;
235 	u_long nptes = vm->hdr.pmapsize / sizeof(aarch64_pte_t);
236 	u_long bmindex, dva, pa, pteindex, va;
237 	struct kvm_bitmap bm;
238 	vm_prot_t prot;
239 	int ret = 0;
240 
241 	if (!_kvm_bitmap_init(&bm, vm->hdr.bitmapsize, &bmindex))
242 		return (0);
243 
244 	for (pteindex = 0; pteindex < nptes; pteindex++) {
245 		aarch64_pte_t pte = _aarch64_pte_get(kd, pteindex);
246 
247 		if ((pte & AARCH64_ATTR_DESCR_MASK) != AARCH64_L3_PAGE)
248 			continue;
249 
250 		va = vm->hdr.kernbase + (pteindex << AARCH64_L3_SHIFT);
251 		pa = pte & ~AARCH64_ATTR_MASK;
252 		dva = vm->hdr.dmapbase + pa;
253 		if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva,
254 		    _aarch64_entry_to_prot(pte), AARCH64_PAGE_SIZE, 0)) {
255 			goto out;
256 		}
257 	}
258 
259 	while (_kvm_bitmap_next(&bm, &bmindex)) {
260 		pa = bmindex * AARCH64_PAGE_SIZE;
261 		dva = vm->hdr.dmapbase + pa;
262 		if (vm->hdr.dmapend < (dva + AARCH64_PAGE_SIZE))
263 			break;
264 		va = 0;
265 		prot = VM_PROT_READ | VM_PROT_WRITE;
266 		if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva,
267 		    prot, AARCH64_PAGE_SIZE, 0)) {
268 			goto out;
269 		}
270 	}
271 	ret = 1;
272 
273 out:
274 	_kvm_bitmap_deinit(&bm);
275 	return (ret);
276 }
277 
278 static struct kvm_arch kvm_aarch64_minidump = {
279 	.ka_probe = _aarch64_minidump_probe,
280 	.ka_initvtop = _aarch64_minidump_initvtop,
281 	.ka_freevtop = _aarch64_minidump_freevtop,
282 	.ka_kvatop = _aarch64_minidump_kvatop,
283 	.ka_native = _aarch64_native,
284 	.ka_walk_pages = _aarch64_minidump_walk_pages,
285 };
286 
287 KVM_ARCH(kvm_aarch64_minidump);
288