xref: /freebsd/lib/libkvm/kvm_arm.c (revision 6574b8ed19b093f0af09501d2c9676c28993cb97)
1 /*-
2  * Copyright (c) 2005 Olivier Houchard
3  * Copyright (c) 1989, 1992, 1993
4  *	The Regents of the University of California.  All rights reserved.
5  *
6  * This code is derived from software developed by the Computer Systems
7  * Engineering group at Lawrence Berkeley Laboratory under DARPA contract
8  * BG 91-66 and contributed to Berkeley.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 4. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
27  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
28  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
29  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
30  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
31  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 /*
35  * ARM machine dependent routines for kvm.
36  */
37 
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40 
41 #include <sys/param.h>
42 #include <sys/elf32.h>
43 #include <sys/mman.h>
44 
45 #ifndef CROSS_LIBKVM
46 #include <vm/vm.h>
47 #include <vm/vm_param.h>
48 #include <vm/pmap.h>
49 #include <machine/pmap.h>
50 #else
51 #include "../../sys/arm/include/pte.h"
52 #include "../../sys/arm/include/vmparam.h"
53 #endif
54 
55 #include <db.h>
56 #include <limits.h>
57 #include <kvm.h>
58 #include <stdlib.h>
59 #include <string.h>
60 #include <unistd.h>
61 
62 #include "kvm_private.h"
63 
64 /* minidump must be the first item! */
65 struct vmstate {
66 	int minidump;		/* 1 = minidump mode */
67 	pd_entry_t *l1pt;
68 	void *mmapbase;
69 	size_t mmapsize;
70 };
71 
72 static int
73 _kvm_maphdrs(kvm_t *kd, size_t sz)
74 {
75 	struct vmstate *vm = kd->vmst;
76 
77 	/* munmap() previous mmap(). */
78 	if (vm->mmapbase != NULL) {
79 		munmap(vm->mmapbase, vm->mmapsize);
80 		vm->mmapbase = NULL;
81 	}
82 
83 	vm->mmapsize = sz;
84 	vm->mmapbase = mmap(NULL, sz, PROT_READ, MAP_PRIVATE, kd->pmfd, 0);
85 	if (vm->mmapbase == MAP_FAILED) {
86 		_kvm_err(kd, kd->program, "cannot mmap corefile");
87 		return (-1);
88 	}
89 
90 	return (0);
91 }
92 
93 /*
94  * Translate a physical memory address to a file-offset in the crash-dump.
95  */
96 static size_t
97 _kvm_pa2off(kvm_t *kd, uint64_t pa, off_t *ofs, size_t pgsz)
98 {
99 	Elf32_Ehdr *e = kd->vmst->mmapbase;
100 	Elf32_Phdr *p = (Elf32_Phdr*)((char*)e + e->e_phoff);
101 	int n = e->e_phnum;
102 
103 	while (n && (pa < p->p_paddr || pa >= p->p_paddr + p->p_memsz))
104 		p++, n--;
105 	if (n == 0)
106 		return (0);
107 
108 	*ofs = (pa - p->p_paddr) + p->p_offset;
109 	if (pgsz == 0)
110 		return (p->p_memsz - (pa - p->p_paddr));
111 	return (pgsz - ((size_t)pa & (pgsz - 1)));
112 }
113 
114 void
115 _kvm_freevtop(kvm_t *kd)
116 {
117 	if (kd->vmst != 0) {
118 		if (kd->vmst->minidump)
119 			return (_kvm_minidump_freevtop(kd));
120 		if (kd->vmst->mmapbase != NULL)
121 			munmap(kd->vmst->mmapbase, kd->vmst->mmapsize);
122 		free(kd->vmst);
123 		kd->vmst = NULL;
124 	}
125 }
126 
127 int
128 _kvm_initvtop(kvm_t *kd)
129 {
130 	struct vmstate *vm;
131 	struct nlist nl[2];
132 	u_long kernbase, physaddr, pa;
133 	pd_entry_t *l1pt;
134 	Elf32_Ehdr *ehdr;
135 	size_t hdrsz;
136 	char minihdr[8];
137 
138 	if (!kd->rawdump) {
139 		if (pread(kd->pmfd, &minihdr, 8, 0) == 8) {
140 			if (memcmp(&minihdr, "minidump", 8) == 0)
141 				return (_kvm_minidump_initvtop(kd));
142 		} else {
143 			_kvm_err(kd, kd->program, "cannot read header");
144 			return (-1);
145 		}
146 	}
147 
148 	vm = _kvm_malloc(kd, sizeof(*vm));
149 	if (vm == 0) {
150 		_kvm_err(kd, kd->program, "cannot allocate vm");
151 		return (-1);
152 	}
153 	kd->vmst = vm;
154 	vm->l1pt = NULL;
155 	if (_kvm_maphdrs(kd, sizeof(Elf32_Ehdr)) == -1)
156 		return (-1);
157 	ehdr = kd->vmst->mmapbase;
158 	hdrsz = ehdr->e_phoff + ehdr->e_phentsize * ehdr->e_phnum;
159 	if (_kvm_maphdrs(kd, hdrsz) == -1)
160 		return (-1);
161 	nl[0].n_name = "kernbase";
162 	nl[1].n_name = NULL;
163 	if (kvm_nlist(kd, nl) != 0)
164 		kernbase = KERNBASE;
165 	else
166 		kernbase = nl[0].n_value;
167 
168 	nl[0].n_name = "physaddr";
169 	if (kvm_nlist(kd, nl) != 0) {
170 		_kvm_err(kd, kd->program, "couldn't get phys addr");
171 		return (-1);
172 	}
173 	physaddr = nl[0].n_value;
174 	nl[0].n_name = "kernel_l1pa";
175 	if (kvm_nlist(kd, nl) != 0) {
176 		_kvm_err(kd, kd->program, "bad namelist");
177 		return (-1);
178 	}
179 	if (kvm_read(kd, (nl[0].n_value - kernbase + physaddr), &pa,
180 	    sizeof(pa)) != sizeof(pa)) {
181 		_kvm_err(kd, kd->program, "cannot read kernel_l1pa");
182 		return (-1);
183 	}
184 	l1pt = _kvm_malloc(kd, L1_TABLE_SIZE);
185 	if (kvm_read(kd, pa, l1pt, L1_TABLE_SIZE) != L1_TABLE_SIZE) {
186 		_kvm_err(kd, kd->program, "cannot read l1pt");
187 		free(l1pt);
188 		return (-1);
189 	}
190 	vm->l1pt = l1pt;
191 	return 0;
192 }
193 
194 /* from arm/pmap.c */
195 #define	L1_IDX(va)		(((vm_offset_t)(va)) >> L1_S_SHIFT)
196 /* from arm/pmap.h */
197 #define	L1_TYPE_INV	0x00		/* Invalid (fault) */
198 #define	L1_TYPE_C	0x01		/* Coarse L2 */
199 #define	L1_TYPE_S	0x02		/* Section */
200 #define	L1_TYPE_F	0x03		/* Fine L2 */
201 #define	L1_TYPE_MASK	0x03		/* mask of type bits */
202 
203 #define	l1pte_section_p(pde)	(((pde) & L1_TYPE_MASK) == L1_TYPE_S)
204 #define	l1pte_valid(pde)	((pde) != 0)
205 #define	l2pte_valid(pte)	((pte) != 0)
206 #define l2pte_index(v)		(((v) & L2_ADDR_BITS) >> L2_S_SHIFT)
207 
208 
209 int
210 _kvm_kvatop(kvm_t *kd, u_long va, off_t *pa)
211 {
212 	struct vmstate *vm = kd->vmst;
213 	pd_entry_t pd;
214 	pt_entry_t pte;
215 	u_long pte_pa;
216 
217 	if (kd->vmst->minidump)
218 		return (_kvm_minidump_kvatop(kd, va, pa));
219 
220 	if (vm->l1pt == NULL)
221 		return (_kvm_pa2off(kd, va, pa, PAGE_SIZE));
222 	pd = vm->l1pt[L1_IDX(va)];
223 	if (!l1pte_valid(pd))
224 		goto invalid;
225 	if (l1pte_section_p(pd)) {
226 		/* 1MB section mapping. */
227 		*pa = ((u_long)pd & L1_S_ADDR_MASK) + (va & L1_S_OFFSET);
228 		return  (_kvm_pa2off(kd, *pa, pa, L1_S_SIZE));
229 	}
230 	pte_pa = (pd & L1_ADDR_MASK) + l2pte_index(va) * sizeof(pte);
231 	_kvm_pa2off(kd, pte_pa, (off_t *)&pte_pa, L1_S_SIZE);
232 	if (lseek(kd->pmfd, pte_pa, 0) == -1) {
233 		_kvm_syserr(kd, kd->program, "_kvm_kvatop: lseek");
234 		goto invalid;
235 	}
236 	if (read(kd->pmfd, &pte, sizeof(pte)) != sizeof (pte)) {
237 		_kvm_syserr(kd, kd->program, "_kvm_kvatop: read");
238 		goto invalid;
239 	}
240 	if (!l2pte_valid(pte)) {
241 		goto invalid;
242 	}
243 	if ((pte & L2_TYPE_MASK) == L2_TYPE_L) {
244 		*pa = (pte & L2_L_FRAME) | (va & L2_L_OFFSET);
245 		return (_kvm_pa2off(kd, *pa, pa, L2_L_SIZE));
246 	}
247 	*pa = (pte & L2_S_FRAME) | (va & L2_S_OFFSET);
248 	return (_kvm_pa2off(kd, *pa, pa, PAGE_SIZE));
249 invalid:
250 	_kvm_err(kd, 0, "Invalid address (%lx)", va);
251 	return 0;
252 }
253 
254 /*
255  * Machine-dependent initialization for ALL open kvm descriptors,
256  * not just those for a kernel crash dump.  Some architectures
257  * have to deal with these NOT being constants!  (i.e. m68k)
258  */
259 #ifdef FBSD_NOT_YET
260 int
261 _kvm_mdopen(kvm_t *kd)
262 {
263 
264 	kd->usrstack = USRSTACK;
265 	kd->min_uva = VM_MIN_ADDRESS;
266 	kd->max_uva = VM_MAXUSER_ADDRESS;
267 
268 	return (0);
269 }
270 #endif
271