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
53struct vmstate {
54	struct		minidumphdr hdr;
55	unsigned char	ei_data;
56};
57
58static 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
66static 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
74static 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
83static 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
149static 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
206invalid:
207	_kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
208	return (0);
209}
210
211static 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
232static 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
267static 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
276KVM_ARCH(kvm_arm_minidump);
277