xref: /freebsd/lib/libkvm/kvm_arm.c (revision e9ac41698b2f322d55ccf9da50a3596edb2c1800)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 2005 Olivier Houchard
5  * Copyright (c) 1989, 1992, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software developed by the Computer Systems
9  * Engineering group at Lawrence Berkeley Laboratory under DARPA contract
10  * BG 91-66 and contributed to Berkeley.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
25  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
29  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
30  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
31  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
32  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
33  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34  */
35 
36 /*
37  * ARM machine dependent routines for kvm.
38  */
39 
40 #include <sys/param.h>
41 #include <sys/endian.h>
42 #include <kvm.h>
43 #include <limits.h>
44 #include <stdint.h>
45 #include <stdlib.h>
46 #include <unistd.h>
47 
48 #ifdef __arm__
49 #include <machine/vmparam.h>
50 #endif
51 
52 #include "kvm_private.h"
53 #include "kvm_arm.h"
54 
55 struct vmstate {
56 	arm_pd_entry_t *l1pt;
57 	size_t phnum;
58 	GElf_Phdr *phdr;
59 };
60 
61 /*
62  * Translate a physical memory address to a file-offset in the crash-dump.
63  */
64 static size_t
65 _kvm_pa2off(kvm_t *kd, uint64_t pa, off_t *ofs, size_t pgsz)
66 {
67 	struct vmstate *vm = kd->vmst;
68 	GElf_Phdr *p;
69 	size_t n;
70 
71 	p = vm->phdr;
72 	n = vm->phnum;
73 	while (n && (pa < p->p_paddr || pa >= p->p_paddr + p->p_memsz))
74 		p++, n--;
75 	if (n == 0)
76 		return (0);
77 
78 	*ofs = (pa - p->p_paddr) + p->p_offset;
79 	if (pgsz == 0)
80 		return (p->p_memsz - (pa - p->p_paddr));
81 	return (pgsz - ((size_t)pa & (pgsz - 1)));
82 }
83 
84 static void
85 _arm_freevtop(kvm_t *kd)
86 {
87 	struct vmstate *vm = kd->vmst;
88 
89 	free(vm->phdr);
90 	free(vm);
91 	kd->vmst = NULL;
92 }
93 
94 static int
95 _arm_probe(kvm_t *kd)
96 {
97 
98 	return (_kvm_probe_elf_kernel(kd, ELFCLASS32, EM_ARM) &&
99 	    !_kvm_is_minidump(kd));
100 }
101 
102 static int
103 _arm_initvtop(kvm_t *kd)
104 {
105 	struct vmstate *vm;
106 	struct kvm_nlist nl[2];
107 	kvaddr_t kernbase;
108 	arm_physaddr_t physaddr, pa;
109 	arm_pd_entry_t *l1pt;
110 	size_t i;
111 	int found;
112 
113 	if (kd->rawdump) {
114 		_kvm_err(kd, kd->program, "raw dumps not supported on arm");
115 		return (-1);
116 	}
117 
118 	vm = _kvm_malloc(kd, sizeof(*vm));
119 	if (vm == NULL) {
120 		_kvm_err(kd, kd->program, "cannot allocate vm");
121 		return (-1);
122 	}
123 	kd->vmst = vm;
124 	vm->l1pt = NULL;
125 
126 	if (_kvm_read_core_phdrs(kd, &vm->phnum, &vm->phdr) == -1)
127 		return (-1);
128 
129 	found = 0;
130 	for (i = 0; i < vm->phnum; i++) {
131 		if (vm->phdr[i].p_type == PT_DUMP_DELTA) {
132 			kernbase = vm->phdr[i].p_vaddr;
133 			physaddr = vm->phdr[i].p_paddr;
134 			found = 1;
135 			break;
136 		}
137 	}
138 
139 	nl[1].n_name = NULL;
140 	if (!found) {
141 		nl[0].n_name = "kernbase";
142 		if (kvm_nlist2(kd, nl) != 0) {
143 #ifdef __arm__
144 			kernbase = KERNBASE;
145 #else
146 		_kvm_err(kd, kd->program, "cannot resolve kernbase");
147 		return (-1);
148 #endif
149 		} else
150 			kernbase = nl[0].n_value;
151 
152 		nl[0].n_name = "physaddr";
153 		if (kvm_nlist2(kd, nl) != 0) {
154 			_kvm_err(kd, kd->program, "couldn't get phys addr");
155 			return (-1);
156 		}
157 		physaddr = nl[0].n_value;
158 	}
159 	nl[0].n_name = "kernel_l1pa";
160 	if (kvm_nlist2(kd, nl) != 0) {
161 		_kvm_err(kd, kd->program, "bad namelist");
162 		return (-1);
163 	}
164 	if (kvm_read2(kd, (nl[0].n_value - kernbase + physaddr), &pa,
165 	    sizeof(pa)) != sizeof(pa)) {
166 		_kvm_err(kd, kd->program, "cannot read kernel_l1pa");
167 		return (-1);
168 	}
169 	l1pt = _kvm_malloc(kd, ARM_L1_TABLE_SIZE);
170 	if (l1pt == NULL) {
171 		_kvm_err(kd, kd->program, "cannot allocate l1pt");
172 		return (-1);
173 	}
174 	if (kvm_read2(kd, pa, l1pt, ARM_L1_TABLE_SIZE) != ARM_L1_TABLE_SIZE) {
175 		_kvm_err(kd, kd->program, "cannot read l1pt");
176 		free(l1pt);
177 		return (-1);
178 	}
179 	vm->l1pt = l1pt;
180 	return 0;
181 }
182 
183 /* from arm/pmap.c */
184 #define	ARM_L1_IDX(va)		((va) >> ARM_L1_S_SHIFT)
185 
186 #define	l1pte_section_p(pde)	(((pde) & ARM_L1_TYPE_MASK) == ARM_L1_TYPE_S)
187 #define	l1pte_valid(pde)	((pde) != 0)
188 #define	l2pte_valid(pte)	((pte) != 0)
189 #define l2pte_index(v)		(((v) & ARM_L1_S_OFFSET) >> ARM_L2_S_SHIFT)
190 
191 
192 static int
193 _arm_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa)
194 {
195 	struct vmstate *vm = kd->vmst;
196 	arm_pd_entry_t pd;
197 	arm_pt_entry_t pte;
198 	arm_physaddr_t pte_pa;
199 	off_t pte_off;
200 
201 	if (vm->l1pt == NULL)
202 		return (_kvm_pa2off(kd, va, pa, ARM_PAGE_SIZE));
203 	pd = _kvm32toh(kd, vm->l1pt[ARM_L1_IDX(va)]);
204 	if (!l1pte_valid(pd))
205 		goto invalid;
206 	if (l1pte_section_p(pd)) {
207 		/* 1MB section mapping. */
208 		*pa = (pd & ARM_L1_S_ADDR_MASK) + (va & ARM_L1_S_OFFSET);
209 		return  (_kvm_pa2off(kd, *pa, pa, ARM_L1_S_SIZE));
210 	}
211 	pte_pa = (pd & ARM_L1_C_ADDR_MASK) + l2pte_index(va) * sizeof(pte);
212 	_kvm_pa2off(kd, pte_pa, &pte_off, ARM_L1_S_SIZE);
213 	if (pread(kd->pmfd, &pte, sizeof(pte), pte_off) != sizeof(pte)) {
214 		_kvm_syserr(kd, kd->program, "_arm_kvatop: pread");
215 		goto invalid;
216 	}
217 	pte = _kvm32toh(kd, pte);
218 	if (!l2pte_valid(pte)) {
219 		goto invalid;
220 	}
221 	if ((pte & ARM_L2_TYPE_MASK) == ARM_L2_TYPE_L) {
222 		*pa = (pte & ARM_L2_L_FRAME) | (va & ARM_L2_L_OFFSET);
223 		return (_kvm_pa2off(kd, *pa, pa, ARM_L2_L_SIZE));
224 	}
225 	*pa = (pte & ARM_L2_S_FRAME) | (va & ARM_L2_S_OFFSET);
226 	return (_kvm_pa2off(kd, *pa, pa, ARM_PAGE_SIZE));
227 invalid:
228 	_kvm_err(kd, 0, "Invalid address (%jx)", (uintmax_t)va);
229 	return 0;
230 }
231 
232 /*
233  * Machine-dependent initialization for ALL open kvm descriptors,
234  * not just those for a kernel crash dump.  Some architectures
235  * have to deal with these NOT being constants!  (i.e. m68k)
236  */
237 #ifdef FBSD_NOT_YET
238 int
239 _kvm_mdopen(kvm_t *kd)
240 {
241 
242 	kd->usrstack = USRSTACK;
243 	kd->min_uva = VM_MIN_ADDRESS;
244 	kd->max_uva = VM_MAXUSER_ADDRESS;
245 
246 	return (0);
247 }
248 #endif
249 
250 int
251 #ifdef __arm__
252 _arm_native(kvm_t *kd)
253 #else
254 _arm_native(kvm_t *kd __unused)
255 #endif
256 {
257 
258 #ifdef __arm__
259 #if _BYTE_ORDER == _LITTLE_ENDIAN
260 	return (kd->nlehdr.e_ident[EI_DATA] == ELFDATA2LSB);
261 #else
262 	return (kd->nlehdr.e_ident[EI_DATA] == ELFDATA2MSB);
263 #endif
264 #else
265 	return (0);
266 #endif
267 }
268 
269 static struct kvm_arch kvm_arm = {
270 	.ka_probe = _arm_probe,
271 	.ka_initvtop = _arm_initvtop,
272 	.ka_freevtop = _arm_freevtop,
273 	.ka_kvatop = _arm_kvatop,
274 	.ka_native = _arm_native,
275 };
276 
277 KVM_ARCH(kvm_arm);
278