xref: /freebsd/lib/libkvm/kvm_minidump_aarch64.c (revision 031beb4e239bfce798af17f5fe8dba8bcaf13d99)
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, size)	roundup2((kvaddr_t)(x), size)
49 #define	aarch64_trunc_page(x, size)	rounddown2((kvaddr_t)(x), size)
50 
51 struct vmstate {
52 	struct minidumphdr hdr;
53 	size_t page_size;
54 	u_int l3_shift;
55 };
56 
57 static aarch64_pte_t
58 _aarch64_pte_get(kvm_t *kd, u_long pteindex)
59 {
60 	aarch64_pte_t *pte = _kvm_pmap_get(kd, pteindex, sizeof(*pte));
61 
62 	return le64toh(*pte);
63 }
64 
65 static int
66 _aarch64_minidump_probe(kvm_t *kd)
67 {
68 
69 	return (_kvm_probe_elf_kernel(kd, ELFCLASS64, EM_AARCH64) &&
70 	    _kvm_is_minidump(kd));
71 }
72 
73 static void
74 _aarch64_minidump_freevtop(kvm_t *kd)
75 {
76 	struct vmstate *vm = kd->vmst;
77 
78 	free(vm);
79 	kd->vmst = NULL;
80 }
81 
82 static int
83 _aarch64_minidump_initvtop(kvm_t *kd)
84 {
85 	struct vmstate *vmst;
86 	off_t off, dump_avail_off, sparse_off;
87 
88 	vmst = _kvm_malloc(kd, sizeof(*vmst));
89 	if (vmst == NULL) {
90 		_kvm_err(kd, kd->program, "cannot allocate vm");
91 		return (-1);
92 	}
93 	kd->vmst = vmst;
94 	if (pread(kd->pmfd, &vmst->hdr, sizeof(vmst->hdr), 0) !=
95 	    sizeof(vmst->hdr)) {
96 		_kvm_err(kd, kd->program, "cannot read dump header");
97 		return (-1);
98 	}
99 	if (strncmp(MINIDUMP_MAGIC, vmst->hdr.magic,
100 	    sizeof(vmst->hdr.magic)) != 0) {
101 		_kvm_err(kd, kd->program, "not a minidump for this platform");
102 		return (-1);
103 	}
104 
105 	vmst->hdr.version = le32toh(vmst->hdr.version);
106 	if (vmst->hdr.version > MINIDUMP_VERSION || vmst->hdr.version < 1) {
107 		_kvm_err(kd, kd->program, "wrong minidump version. "
108 		    "Expected %d got %d", MINIDUMP_VERSION, vmst->hdr.version);
109 		return (-1);
110 	}
111 	vmst->hdr.msgbufsize = le32toh(vmst->hdr.msgbufsize);
112 	vmst->hdr.bitmapsize = le32toh(vmst->hdr.bitmapsize);
113 	vmst->hdr.pmapsize = le32toh(vmst->hdr.pmapsize);
114 	vmst->hdr.kernbase = le64toh(vmst->hdr.kernbase);
115 	vmst->hdr.dmapphys = le64toh(vmst->hdr.dmapphys);
116 	vmst->hdr.dmapbase = le64toh(vmst->hdr.dmapbase);
117 	vmst->hdr.dmapend = le64toh(vmst->hdr.dmapend);
118 	/* dumpavailsize added in version 2 */
119 	if (vmst->hdr.version >= 2) {
120 		vmst->hdr.dumpavailsize = le32toh(vmst->hdr.dumpavailsize);
121 	} else {
122 		vmst->hdr.dumpavailsize = 0;
123 	}
124 	/* flags added in version 3 */
125 	if (vmst->hdr.version >= 3) {
126 		vmst->hdr.flags = le32toh(vmst->hdr.flags);
127 	} else {
128 		vmst->hdr.flags = MINIDUMP_FLAG_PS_4K;
129 	}
130 
131 	switch (vmst->hdr.flags & MINIDUMP_FLAG_PS_MASK) {
132 	case MINIDUMP_FLAG_PS_4K:
133 		vmst->page_size = AARCH64_PAGE_SIZE_4K;
134 		vmst->l3_shift = AARCH64_L3_SHIFT_4K;
135 		break;
136 	case MINIDUMP_FLAG_PS_16K:
137 		vmst->page_size = AARCH64_PAGE_SIZE_16K;
138 		vmst->l3_shift = AARCH64_L3_SHIFT_16K;
139 		break;
140 	default:
141 		_kvm_err(kd, kd->program, "unknown page size flag %x",
142 		    vmst->hdr.flags & MINIDUMP_FLAG_PS_MASK);
143 		return (-1);
144 	}
145 
146 	/* Skip header and msgbuf */
147 	dump_avail_off = vmst->page_size +
148 	    aarch64_round_page(vmst->hdr.msgbufsize, vmst->page_size);
149 
150 	/* Skip dump_avail */
151 	off = dump_avail_off +
152 	    aarch64_round_page(vmst->hdr.dumpavailsize, vmst->page_size);
153 
154 	/* build physical address lookup table for sparse pages */
155 	sparse_off = off +
156 	    aarch64_round_page(vmst->hdr.bitmapsize, vmst->page_size) +
157 	    aarch64_round_page(vmst->hdr.pmapsize, vmst->page_size);
158 	if (_kvm_pt_init(kd, vmst->hdr.dumpavailsize, dump_avail_off,
159 	    vmst->hdr.bitmapsize, off, sparse_off, vmst->page_size) == -1) {
160 		return (-1);
161 	}
162 	off += aarch64_round_page(vmst->hdr.bitmapsize, vmst->page_size);
163 
164 	if (_kvm_pmap_init(kd, vmst->hdr.pmapsize, off) == -1) {
165 		return (-1);
166 	}
167 	off += aarch64_round_page(vmst->hdr.pmapsize, vmst->page_size);
168 
169 	return (0);
170 }
171 
172 static int
173 _aarch64_minidump_vatop(kvm_t *kd, kvaddr_t va, off_t *pa)
174 {
175 	struct vmstate *vm;
176 	aarch64_physaddr_t offset;
177 	aarch64_pte_t l3;
178 	kvaddr_t l3_index;
179 	aarch64_physaddr_t a;
180 	off_t ofs;
181 
182 	vm = kd->vmst;
183 	offset = va & (kd->vmst->page_size - 1);
184 
185 	if (va >= vm->hdr.dmapbase && va < vm->hdr.dmapend) {
186 		a = aarch64_trunc_page(va - vm->hdr.dmapbase + vm->hdr.dmapphys,
187 		    kd->vmst->page_size);
188 		ofs = _kvm_pt_find(kd, a, kd->vmst->page_size);
189 		if (ofs == -1) {
190 			_kvm_err(kd, kd->program, "_aarch64_minidump_vatop: "
191 			    "direct map address 0x%jx not in minidump",
192 			    (uintmax_t)va);
193 			goto invalid;
194 		}
195 		*pa = ofs + offset;
196 		return (kd->vmst->page_size - offset);
197 	} else if (va >= vm->hdr.kernbase) {
198 		l3_index = (va - vm->hdr.kernbase) >> kd->vmst->l3_shift;
199 		if (l3_index >= vm->hdr.pmapsize / sizeof(l3))
200 			goto invalid;
201 		l3 = _aarch64_pte_get(kd, l3_index);
202 		if ((l3 & AARCH64_ATTR_DESCR_MASK) != AARCH64_L3_PAGE) {
203 			_kvm_err(kd, kd->program,
204 			    "_aarch64_minidump_vatop: pde not valid");
205 			goto invalid;
206 		}
207 		a = l3 & ~AARCH64_ATTR_MASK;
208 		ofs = _kvm_pt_find(kd, a, kd->vmst->page_size);
209 		if (ofs == -1) {
210 			_kvm_err(kd, kd->program, "_aarch64_minidump_vatop: "
211 			    "physical address 0x%jx not in minidump",
212 			    (uintmax_t)a);
213 			goto invalid;
214 		}
215 		*pa = ofs + offset;
216 		return (kd->vmst->page_size - offset);
217 	} else {
218 		_kvm_err(kd, kd->program,
219 	    "_aarch64_minidump_vatop: virtual address 0x%jx not minidumped",
220 		    (uintmax_t)va);
221 		goto invalid;
222 	}
223 
224 invalid:
225 	_kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
226 	return (0);
227 }
228 
229 static int
230 _aarch64_minidump_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa)
231 {
232 
233 	if (ISALIVE(kd)) {
234 		_kvm_err(kd, 0,
235 		    "_aarch64_minidump_kvatop called in live kernel!");
236 		return (0);
237 	}
238 	return (_aarch64_minidump_vatop(kd, va, pa));
239 }
240 
241 static int
242 _aarch64_native(kvm_t *kd __unused)
243 {
244 
245 #ifdef __aarch64__
246 	return (1);
247 #else
248 	return (0);
249 #endif
250 }
251 
252 static vm_prot_t
253 _aarch64_entry_to_prot(aarch64_pte_t pte)
254 {
255 	vm_prot_t prot = VM_PROT_READ;
256 
257 	/* Source: arm64/arm64/pmap.c:pmap_protect() */
258 	if ((pte & AARCH64_ATTR_AP(AARCH64_ATTR_AP_RO)) == 0)
259 		prot |= VM_PROT_WRITE;
260 	if ((pte & AARCH64_ATTR_XN) == 0)
261 		prot |= VM_PROT_EXECUTE;
262 	return prot;
263 }
264 
265 static int
266 _aarch64_minidump_walk_pages(kvm_t *kd, kvm_walk_pages_cb_t *cb, void *arg)
267 {
268 	struct vmstate *vm = kd->vmst;
269 	u_long nptes = vm->hdr.pmapsize / sizeof(aarch64_pte_t);
270 	u_long bmindex, dva, pa, pteindex, va;
271 	struct kvm_bitmap bm;
272 	vm_prot_t prot;
273 	int ret = 0;
274 
275 	if (!_kvm_bitmap_init(&bm, vm->hdr.bitmapsize, &bmindex))
276 		return (0);
277 
278 	for (pteindex = 0; pteindex < nptes; pteindex++) {
279 		aarch64_pte_t pte = _aarch64_pte_get(kd, pteindex);
280 
281 		if ((pte & AARCH64_ATTR_DESCR_MASK) != AARCH64_L3_PAGE)
282 			continue;
283 
284 		va = vm->hdr.kernbase + (pteindex << kd->vmst->l3_shift);
285 		pa = pte & ~AARCH64_ATTR_MASK;
286 		dva = vm->hdr.dmapbase + pa;
287 		if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva,
288 		    _aarch64_entry_to_prot(pte), kd->vmst->page_size, 0)) {
289 			goto out;
290 		}
291 	}
292 
293 	while (_kvm_bitmap_next(&bm, &bmindex)) {
294 		pa = _kvm_bit_id_pa(kd, bmindex, kd->vmst->page_size);
295 		if (pa == _KVM_PA_INVALID)
296 			break;
297 		dva = vm->hdr.dmapbase + pa;
298 		if (vm->hdr.dmapend < (dva + kd->vmst->page_size))
299 			break;
300 		va = 0;
301 		prot = VM_PROT_READ | VM_PROT_WRITE;
302 		if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva,
303 		    prot, kd->vmst->page_size, 0)) {
304 			goto out;
305 		}
306 	}
307 	ret = 1;
308 
309 out:
310 	_kvm_bitmap_deinit(&bm);
311 	return (ret);
312 }
313 
314 static struct kvm_arch kvm_aarch64_minidump = {
315 	.ka_probe = _aarch64_minidump_probe,
316 	.ka_initvtop = _aarch64_minidump_initvtop,
317 	.ka_freevtop = _aarch64_minidump_freevtop,
318 	.ka_kvatop = _aarch64_minidump_kvatop,
319 	.ka_native = _aarch64_native,
320 	.ka_walk_pages = _aarch64_minidump_walk_pages,
321 };
322 
323 KVM_ARCH(kvm_aarch64_minidump);
324