xref: /freebsd/lib/libkvm/kvm_minidump_arm.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2008 Semihalf, Grzegorz Bernacki
5  * Copyright (c) 2006 Peter Wemm
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  * From: FreeBSD: src/lib/libkvm/kvm_minidump_i386.c,v 1.2 2006/06/05 08:51:14
29  */
30 
31 #include <sys/cdefs.h>
32 /*
33  * ARM machine dependent routines for kvm and minidumps.
34  */
35 
36 #include <sys/endian.h>
37 #include <sys/param.h>
38 #include <vm/vm.h>
39 #include <kvm.h>
40 #include <limits.h>
41 #include <stdint.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <unistd.h>
45 
46 #include "../../sys/arm/include/minidump.h"
47 
48 #include "kvm_private.h"
49 #include "kvm_arm.h"
50 
51 #define	arm_round_page(x)	roundup2((kvaddr_t)(x), ARM_PAGE_SIZE)
52 
53 struct vmstate {
54 	struct		minidumphdr hdr;
55 	unsigned char	ei_data;
56 };
57 
58 static arm_pt_entry_t
59 _arm_pte_get(kvm_t *kd, u_long pteindex)
60 {
61 	arm_pt_entry_t *pte = _kvm_pmap_get(kd, pteindex, sizeof(*pte));
62 
63 	return _kvm32toh(kd, *pte);
64 }
65 
66 static int
67 _arm_minidump_probe(kvm_t *kd)
68 {
69 
70 	return (_kvm_probe_elf_kernel(kd, ELFCLASS32, EM_ARM) &&
71 	    _kvm_is_minidump(kd));
72 }
73 
74 static void
75 _arm_minidump_freevtop(kvm_t *kd)
76 {
77 	struct vmstate *vm = kd->vmst;
78 
79 	free(vm);
80 	kd->vmst = NULL;
81 }
82 
83 static int
84 _arm_minidump_initvtop(kvm_t *kd)
85 {
86 	struct vmstate *vmst;
87 	off_t off, dump_avail_off, sparse_off;
88 
89 	vmst = _kvm_malloc(kd, sizeof(*vmst));
90 	if (vmst == NULL) {
91 		_kvm_err(kd, kd->program, "cannot allocate vm");
92 		return (-1);
93 	}
94 
95 	kd->vmst = vmst;
96 
97 	if (pread(kd->pmfd, &vmst->hdr,
98 	    sizeof(vmst->hdr), 0) != sizeof(vmst->hdr)) {
99 		_kvm_err(kd, kd->program, "cannot read dump header");
100 		return (-1);
101 	}
102 
103 	if (strncmp(MINIDUMP_MAGIC, vmst->hdr.magic,
104 	    sizeof(vmst->hdr.magic)) != 0) {
105 		_kvm_err(kd, kd->program, "not a minidump for this platform");
106 		return (-1);
107 	}
108 	vmst->hdr.version = _kvm32toh(kd, vmst->hdr.version);
109 	if (vmst->hdr.version != MINIDUMP_VERSION && vmst->hdr.version != 1) {
110 		_kvm_err(kd, kd->program, "wrong minidump version. "
111 		    "Expected %d got %d", MINIDUMP_VERSION, vmst->hdr.version);
112 		return (-1);
113 	}
114 	vmst->hdr.msgbufsize = _kvm32toh(kd, vmst->hdr.msgbufsize);
115 	vmst->hdr.bitmapsize = _kvm32toh(kd, vmst->hdr.bitmapsize);
116 	vmst->hdr.ptesize = _kvm32toh(kd, vmst->hdr.ptesize);
117 	vmst->hdr.kernbase = _kvm32toh(kd, vmst->hdr.kernbase);
118 	vmst->hdr.arch = _kvm32toh(kd, vmst->hdr.arch);
119 	vmst->hdr.mmuformat = _kvm32toh(kd, vmst->hdr.mmuformat);
120 	if (vmst->hdr.mmuformat == MINIDUMP_MMU_FORMAT_UNKNOWN) {
121 		/* This is a safe default as 1K pages are not used. */
122 		vmst->hdr.mmuformat = MINIDUMP_MMU_FORMAT_V6;
123 	}
124 	vmst->hdr.dumpavailsize = vmst->hdr.version == MINIDUMP_VERSION ?
125 	    _kvm32toh(kd, vmst->hdr.dumpavailsize) : 0;
126 
127 	/* Skip header and msgbuf */
128 	dump_avail_off = ARM_PAGE_SIZE + arm_round_page(vmst->hdr.msgbufsize);
129 
130 	/* Skip dump_avail */
131 	off = dump_avail_off + arm_round_page(vmst->hdr.dumpavailsize);
132 
133 	sparse_off = off + arm_round_page(vmst->hdr.bitmapsize) +
134 	    arm_round_page(vmst->hdr.ptesize);
135 	if (_kvm_pt_init(kd, vmst->hdr.dumpavailsize, dump_avail_off,
136 	    vmst->hdr.bitmapsize, off, sparse_off, ARM_PAGE_SIZE) == -1) {
137 		return (-1);
138 	}
139 	off += arm_round_page(vmst->hdr.bitmapsize);
140 
141 	if (_kvm_pmap_init(kd, vmst->hdr.ptesize, off) == -1) {
142 		return (-1);
143 	}
144 	off += arm_round_page(vmst->hdr.ptesize);
145 
146 	return (0);
147 }
148 
149 static int
150 _arm_minidump_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa)
151 {
152 	struct vmstate *vm;
153 	arm_pt_entry_t pte;
154 	arm_physaddr_t offset, a;
155 	kvaddr_t pteindex;
156 	off_t ofs;
157 
158 	if (ISALIVE(kd)) {
159 		_kvm_err(kd, 0, "_arm_minidump_kvatop called in live kernel!");
160 		return (0);
161 	}
162 
163 	vm = kd->vmst;
164 
165 	if (va >= vm->hdr.kernbase) {
166 		pteindex = (va - vm->hdr.kernbase) >> ARM_PAGE_SHIFT;
167 		if (pteindex >= vm->hdr.ptesize / sizeof(pte))
168 			goto invalid;
169 		pte = _arm_pte_get(kd, pteindex);
170 		if ((pte & ARM_L2_TYPE_MASK) == ARM_L2_TYPE_INV) {
171 			_kvm_err(kd, kd->program,
172 			    "_arm_minidump_kvatop: pte not valid");
173 			goto invalid;
174 		}
175 		if ((pte & ARM_L2_TYPE_MASK) == ARM_L2_TYPE_L) {
176 			/* 64K page -> convert to be like 4K page */
177 			offset = va & ARM_L2_S_OFFSET;
178 			a = (pte & ARM_L2_L_FRAME) +
179 			    (va & ARM_L2_L_OFFSET & ARM_L2_S_FRAME);
180 		} else {
181 			if (kd->vmst->hdr.mmuformat == MINIDUMP_MMU_FORMAT_V4 &&
182 			    (pte & ARM_L2_TYPE_MASK) == ARM_L2_TYPE_T) {
183 				_kvm_err(kd, kd->program,
184 				    "_arm_minidump_kvatop: pte not supported");
185 				goto invalid;
186 			}
187 			/* 4K page */
188 			offset = va & ARM_L2_S_OFFSET;
189 			a = pte & ARM_L2_S_FRAME;
190 		}
191 
192 		ofs = _kvm_pt_find(kd, a, ARM_PAGE_SIZE);
193 		if (ofs == -1) {
194 			_kvm_err(kd, kd->program, "_arm_minidump_kvatop: "
195 			    "physical address 0x%jx not in minidump",
196 			    (uintmax_t)a);
197 			goto invalid;
198 		}
199 
200 		*pa = ofs + offset;
201 		return (ARM_PAGE_SIZE - offset);
202 	} else
203 		_kvm_err(kd, kd->program, "_arm_minidump_kvatop: virtual "
204 		    "address 0x%jx not minidumped", (uintmax_t)va);
205 
206 invalid:
207 	_kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
208 	return (0);
209 }
210 
211 static vm_prot_t
212 _arm_entry_to_prot(kvm_t *kd, arm_pt_entry_t pte)
213 {
214 	struct vmstate *vm = kd->vmst;
215 	vm_prot_t prot = VM_PROT_READ;
216 
217 	/* Source: arm/arm/pmap-v4.c:pmap_fault_fixup() */
218 	if (vm->hdr.mmuformat == MINIDUMP_MMU_FORMAT_V4) {
219 		if (pte & ARM_L2_S_PROT_W)
220 			prot |= VM_PROT_WRITE;
221 		return prot;
222 	}
223 
224 	/* Source: arm/arm/pmap-v6.c:pmap_protect() */
225 	if ((pte & ARM_PTE2_RO) == 0)
226 		prot |= VM_PROT_WRITE;
227 	if ((pte & ARM_PTE2_NX) == 0)
228 		prot |= VM_PROT_EXECUTE;
229 	return prot;
230 }
231 
232 static int
233 _arm_minidump_walk_pages(kvm_t *kd, kvm_walk_pages_cb_t *cb, void *arg)
234 {
235 	struct vmstate *vm = kd->vmst;
236 	u_long nptes = vm->hdr.ptesize / sizeof(arm_pt_entry_t);
237 	u_long dva, pa, pteindex, va;
238 
239 	for (pteindex = 0; pteindex < nptes; pteindex++) {
240 		arm_pt_entry_t pte = _arm_pte_get(kd, pteindex);
241 
242 		if ((pte & ARM_L2_TYPE_MASK) == ARM_L2_TYPE_INV)
243 			continue;
244 
245 		va = vm->hdr.kernbase + (pteindex << ARM_PAGE_SHIFT);
246 		if ((pte & ARM_L2_TYPE_MASK) == ARM_L2_TYPE_L) {
247 			/* 64K page */
248 			pa = (pte & ARM_L2_L_FRAME) +
249 			    (va & ARM_L2_L_OFFSET & ARM_L2_S_FRAME);
250 		} else {
251 			if (vm->hdr.mmuformat == MINIDUMP_MMU_FORMAT_V4 &&
252 			    (pte & ARM_L2_TYPE_MASK) == ARM_L2_TYPE_T) {
253 				continue;
254 			}
255 			/* 4K page */
256 			pa = pte & ARM_L2_S_FRAME;
257 		}
258 
259 		dva = 0; /* no direct map on this platform */
260 		if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva,
261 		    _arm_entry_to_prot(kd, pte), ARM_PAGE_SIZE, 0))
262 			return (0);
263 	}
264 	return (1);
265 }
266 
267 static struct kvm_arch kvm_arm_minidump = {
268 	.ka_probe = _arm_minidump_probe,
269 	.ka_initvtop = _arm_minidump_initvtop,
270 	.ka_freevtop = _arm_minidump_freevtop,
271 	.ka_kvatop = _arm_minidump_kvatop,
272 	.ka_native = _arm_native,
273 	.ka_walk_pages = _arm_minidump_walk_pages,
274 };
275 
276 KVM_ARCH(kvm_arm_minidump);
277