xref: /freebsd/lib/libkvm/kvm_minidump_riscv.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
1 /*-
2  * Copyright (c) 2006 Peter Wemm
3  * Copyright (c) 2019 Mitchell Horne
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * From: FreeBSD: src/lib/libkvm/kvm_minidump_amd64.c r261799
27  */
28 
29 #include <sys/cdefs.h>
30 /*
31  * RISC-V machine dependent routines for kvm and minidumps.
32  */
33 
34 #include <sys/param.h>
35 #include <stdint.h>
36 #include <stdlib.h>
37 #include <string.h>
38 #include <unistd.h>
39 #include <vm/vm.h>
40 #include <kvm.h>
41 
42 #include "../../sys/riscv/include/minidump.h"
43 
44 #include <limits.h>
45 
46 #include "kvm_private.h"
47 #include "kvm_riscv.h"
48 
49 #define	riscv_round_page(x)	roundup2((kvaddr_t)(x), RISCV_PAGE_SIZE)
50 
51 struct vmstate {
52 	struct minidumphdr hdr;
53 };
54 
55 static riscv_pt_entry_t
56 _riscv_pte_get(kvm_t *kd, u_long pteindex)
57 {
58 	riscv_pt_entry_t *pte = _kvm_pmap_get(kd, pteindex, sizeof(*pte));
59 
60 	return le64toh(*pte);
61 }
62 
63 static int
64 _riscv_minidump_probe(kvm_t *kd)
65 {
66 
67 	return (_kvm_probe_elf_kernel(kd, ELFCLASS64, EM_RISCV) &&
68 	    _kvm_is_minidump(kd));
69 }
70 
71 static void
72 _riscv_minidump_freevtop(kvm_t *kd)
73 {
74 	struct vmstate *vm = kd->vmst;
75 
76 	free(vm);
77 	kd->vmst = NULL;
78 }
79 
80 static int
81 _riscv_minidump_initvtop(kvm_t *kd)
82 {
83 	struct vmstate *vmst;
84 	off_t off, dump_avail_off, sparse_off;
85 
86 	vmst = _kvm_malloc(kd, sizeof(*vmst));
87 	if (vmst == NULL) {
88 		_kvm_err(kd, kd->program, "cannot allocate vm");
89 		return (-1);
90 	}
91 	kd->vmst = vmst;
92 	if (pread(kd->pmfd, &vmst->hdr, sizeof(vmst->hdr), 0) !=
93 	    sizeof(vmst->hdr)) {
94 		_kvm_err(kd, kd->program, "cannot read dump header");
95 		return (-1);
96 	}
97 	if (strncmp(MINIDUMP_MAGIC, vmst->hdr.magic,
98 	    sizeof(vmst->hdr.magic)) != 0) {
99 		_kvm_err(kd, kd->program, "not a minidump for this platform");
100 		return (-1);
101 	}
102 
103 	vmst->hdr.version = le32toh(vmst->hdr.version);
104 	if (vmst->hdr.version != MINIDUMP_VERSION && vmst->hdr.version != 1) {
105 		_kvm_err(kd, kd->program, "wrong minidump version. "
106 		    "Expected %d got %d", MINIDUMP_VERSION, vmst->hdr.version);
107 		return (-1);
108 	}
109 	vmst->hdr.msgbufsize = le32toh(vmst->hdr.msgbufsize);
110 	vmst->hdr.bitmapsize = le32toh(vmst->hdr.bitmapsize);
111 	vmst->hdr.pmapsize = le32toh(vmst->hdr.pmapsize);
112 	vmst->hdr.kernbase = le64toh(vmst->hdr.kernbase);
113 	vmst->hdr.dmapphys = le64toh(vmst->hdr.dmapphys);
114 	vmst->hdr.dmapbase = le64toh(vmst->hdr.dmapbase);
115 	vmst->hdr.dmapend = le64toh(vmst->hdr.dmapend);
116 	vmst->hdr.dumpavailsize = vmst->hdr.version == MINIDUMP_VERSION ?
117 	    le32toh(vmst->hdr.dumpavailsize) : 0;
118 
119 	/* Skip header and msgbuf */
120 	dump_avail_off = RISCV_PAGE_SIZE + riscv_round_page(vmst->hdr.msgbufsize);
121 
122 	/* Skip dump_avail */
123 	off = dump_avail_off + riscv_round_page(vmst->hdr.dumpavailsize);
124 
125 	/* build physical address lookup table for sparse pages */
126 	sparse_off = off + riscv_round_page(vmst->hdr.bitmapsize) +
127 	    riscv_round_page(vmst->hdr.pmapsize);
128 	if (_kvm_pt_init(kd, vmst->hdr.dumpavailsize, dump_avail_off,
129 	    vmst->hdr.bitmapsize, off, sparse_off, RISCV_PAGE_SIZE) == -1) {
130 		return (-1);
131 	}
132 	off += riscv_round_page(vmst->hdr.bitmapsize);
133 
134 	if (_kvm_pmap_init(kd, vmst->hdr.pmapsize, off) == -1) {
135 		return (-1);
136 	}
137 	off += riscv_round_page(vmst->hdr.pmapsize);
138 
139 	return (0);
140 }
141 
142 static int
143 _riscv_minidump_vatop(kvm_t *kd, kvaddr_t va, off_t *pa)
144 {
145 	struct vmstate *vm;
146 	riscv_physaddr_t offset;
147 	riscv_pt_entry_t l3;
148 	kvaddr_t l3_index;
149 	riscv_physaddr_t a;
150 	off_t ofs;
151 
152 	vm = kd->vmst;
153 	offset = va & RISCV_PAGE_MASK;
154 
155 	if (va >= vm->hdr.dmapbase && va < vm->hdr.dmapend) {
156 		a = (va - vm->hdr.dmapbase + vm->hdr.dmapphys) &
157 		    ~RISCV_PAGE_MASK;
158 		ofs = _kvm_pt_find(kd, a, RISCV_PAGE_SIZE);
159 		if (ofs == -1) {
160 			_kvm_err(kd, kd->program, "_riscv_minidump_vatop: "
161 			    "direct map address 0x%jx not in minidump",
162 			    (uintmax_t)va);
163 			goto invalid;
164 		}
165 		*pa = ofs + offset;
166 		return (RISCV_PAGE_SIZE - offset);
167 	} else if (va >= vm->hdr.kernbase) {
168 		l3_index = (va - vm->hdr.kernbase) >> RISCV_L3_SHIFT;
169 		if (l3_index >= vm->hdr.pmapsize / sizeof(l3))
170 			goto invalid;
171 		l3 = _riscv_pte_get(kd, l3_index);
172 		if ((l3 & RISCV_PTE_V) == 0 || (l3 & RISCV_PTE_RWX) == 0) {
173 			_kvm_err(kd, kd->program,
174 			    "_riscv_minidump_vatop: pte not valid");
175 			goto invalid;
176 		}
177 		a = (l3 >> RISCV_PTE_PPN0_S) << RISCV_L3_SHIFT;
178 		ofs = _kvm_pt_find(kd, a, RISCV_PAGE_SIZE);
179 		if (ofs == -1) {
180 			_kvm_err(kd, kd->program, "_riscv_minidump_vatop: "
181 			    "physical address 0x%jx not in minidump",
182 			    (uintmax_t)a);
183 			goto invalid;
184 		}
185 		*pa = ofs + offset;
186 		return (RISCV_PAGE_SIZE - offset);
187 	} else {
188 		_kvm_err(kd, kd->program,
189 	    "_riscv_minidump_vatop: virtual address 0x%jx not minidumped",
190 		    (uintmax_t)va);
191 		goto invalid;
192 	}
193 
194 invalid:
195 	_kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
196 	return (0);
197 }
198 
199 static int
200 _riscv_minidump_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa)
201 {
202 
203 	if (ISALIVE(kd)) {
204 		_kvm_err(kd, 0,
205 		    "_riscv_minidump_kvatop called in live kernel!");
206 		return (0);
207 	}
208 	return (_riscv_minidump_vatop(kd, va, pa));
209 }
210 
211 static int
212 _riscv_native(kvm_t *kd __unused)
213 {
214 
215 #ifdef __riscv
216 	return (1);
217 #else
218 	return (0);
219 #endif
220 }
221 
222 static vm_prot_t
223 _riscv_entry_to_prot(riscv_pt_entry_t pte)
224 {
225 	vm_prot_t prot = VM_PROT_READ;
226 
227 	if ((pte & RISCV_PTE_W) != 0)
228 		prot |= VM_PROT_WRITE;
229 	if ((pte & RISCV_PTE_X) != 0)
230 		prot |= VM_PROT_EXECUTE;
231 	return prot;
232 }
233 
234 static int
235 _riscv_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(riscv_pt_entry_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 		riscv_pt_entry_t pte = _riscv_pte_get(kd, pteindex);
249 
250 		if (((pte & RISCV_PTE_V) == 0) ||
251 		    ((pte & RISCV_PTE_RWX) == 0))
252 			continue;
253 
254 		va = vm->hdr.kernbase + (pteindex << RISCV_L3_SHIFT);
255 		pa = (pte >> RISCV_PTE_PPN0_S) << RISCV_L3_SHIFT;
256 		dva = vm->hdr.dmapbase + pa;
257 		if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva,
258 		    _riscv_entry_to_prot(pte), RISCV_PAGE_SIZE, 0)) {
259 			goto out;
260 		}
261 	}
262 
263 	while (_kvm_bitmap_next(&bm, &bmindex)) {
264 		pa = _kvm_bit_id_pa(kd, bmindex, RISCV_PAGE_SIZE);
265 		if (pa == _KVM_PA_INVALID)
266 			break;
267 		dva = vm->hdr.dmapbase + pa;
268 		if (vm->hdr.dmapend < (dva + RISCV_PAGE_SIZE))
269 			break;
270 		va = 0;
271 		prot = VM_PROT_READ | VM_PROT_WRITE;
272 		if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva,
273 		    prot, RISCV_PAGE_SIZE, 0)) {
274 			goto out;
275 		}
276 	}
277 	ret = 1;
278 
279 out:
280 	_kvm_bitmap_deinit(&bm);
281 	return (ret);
282 }
283 
284 static struct kvm_arch kvm_riscv_minidump = {
285 	.ka_probe = _riscv_minidump_probe,
286 	.ka_initvtop = _riscv_minidump_initvtop,
287 	.ka_freevtop = _riscv_minidump_freevtop,
288 	.ka_kvatop = _riscv_minidump_kvatop,
289 	.ka_native = _riscv_native,
290 	.ka_walk_pages = _riscv_minidump_walk_pages,
291 };
292 
293 KVM_ARCH(kvm_riscv_minidump);
294