xref: /freebsd/lib/libkvm/kvm_minidump_arm.c (revision 2e1417489338b971e5fd599ff48b5f65df9e8d3b)
1 /*-
2  * Copyright (c) 2008 Semihalf, Grzegorz Bernacki
3  * Copyright (c) 2006 Peter Wemm
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_i386.c,v 1.2 2006/06/05 08:51:14
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 /*
33  * ARM machine dependent routines for kvm and minidumps.
34  */
35 
36 #include <sys/param.h>
37 #include <sys/user.h>
38 #include <sys/proc.h>
39 #include <sys/stat.h>
40 #include <sys/mman.h>
41 #include <sys/fnv_hash.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <unistd.h>
45 #include <nlist.h>
46 #include <kvm.h>
47 
48 #include <vm/vm.h>
49 #include <vm/vm_param.h>
50 
51 #include <machine/elf.h>
52 #include <machine/cpufunc.h>
53 #include <machine/minidump.h>
54 
55 #include <limits.h>
56 
57 #include "kvm_private.h"
58 
59 struct hpte {
60 	struct hpte	*next;
61 	uint64_t	pa;
62 	int64_t		off;
63 };
64 
65 #define HPT_SIZE 1024
66 
67 /* minidump must be the first field */
68 struct vmstate {
69 	int		minidump;		/* 1 = minidump mode */
70 	struct		minidumphdr hdr;
71 	void		*hpt_head[HPT_SIZE];
72 	uint32_t	*bitmap;
73 	void		*ptemap;
74 };
75 
76 static void
77 hpt_insert(kvm_t *kd, uint64_t pa, int64_t off)
78 {
79 	struct hpte *hpte;
80 	uint32_t fnv = FNV1_32_INIT;
81 
82 	fnv = fnv_32_buf(&pa, sizeof(pa), fnv);
83 	fnv &= (HPT_SIZE - 1);
84 	hpte = malloc(sizeof(*hpte));
85 	hpte->pa = pa;
86 	hpte->off = off;
87 	hpte->next = kd->vmst->hpt_head[fnv];
88 	kd->vmst->hpt_head[fnv] = hpte;
89 }
90 
91 static int64_t
92 hpt_find(kvm_t *kd, uint64_t pa)
93 {
94 	struct hpte *hpte;
95 	uint32_t fnv = FNV1_32_INIT;
96 
97 	fnv = fnv_32_buf(&pa, sizeof(pa), fnv);
98 	fnv &= (HPT_SIZE - 1);
99 	for (hpte = kd->vmst->hpt_head[fnv]; hpte != NULL; hpte = hpte->next)
100 		if (pa == hpte->pa)
101 			return (hpte->off);
102 
103 	return (-1);
104 }
105 
106 static int
107 inithash(kvm_t *kd, uint32_t *base, int len, off_t off)
108 {
109 	uint64_t idx, pa;
110 	uint32_t bit, bits;
111 
112 	for (idx = 0; idx < len / sizeof(*base); idx++) {
113 		bits = base[idx];
114 		while (bits) {
115 			bit = ffs(bits) - 1;
116 			bits &= ~(1ul << bit);
117 			pa = (idx * sizeof(*base) * NBBY + bit) * PAGE_SIZE;
118 			hpt_insert(kd, pa, off);
119 			off += PAGE_SIZE;
120 		}
121 	}
122 	return (off);
123 }
124 
125 void
126 _kvm_minidump_freevtop(kvm_t *kd)
127 {
128 	struct vmstate *vm = kd->vmst;
129 
130 	if (vm->bitmap)
131 		free(vm->bitmap);
132 	if (vm->ptemap)
133 		free(vm->ptemap);
134 	free(vm);
135 	kd->vmst = NULL;
136 }
137 
138 int
139 _kvm_minidump_initvtop(kvm_t *kd)
140 {
141 	struct vmstate *vmst;
142 	off_t off;
143 
144 	vmst = _kvm_malloc(kd, sizeof(*vmst));
145 	if (vmst == 0) {
146 		_kvm_err(kd, kd->program, "cannot allocate vm");
147 		return (-1);
148 	}
149 
150 	kd->vmst = vmst;
151 	vmst->minidump = 1;
152 
153 	if (pread(kd->pmfd, &vmst->hdr,
154 	    sizeof(vmst->hdr), 0) != sizeof(vmst->hdr)) {
155 		_kvm_err(kd, kd->program, "cannot read dump header");
156 		return (-1);
157 	}
158 
159 	if (strncmp(MINIDUMP_MAGIC, vmst->hdr.magic,
160 	    sizeof(vmst->hdr.magic)) != 0) {
161 		_kvm_err(kd, kd->program, "not a minidump for this platform");
162 		return (-1);
163 	}
164 	if (vmst->hdr.version != MINIDUMP_VERSION) {
165 		_kvm_err(kd, kd->program, "wrong minidump version. "
166 		    "Expected %d got %d", MINIDUMP_VERSION, vmst->hdr.version);
167 		return (-1);
168 	}
169 
170 	/* Skip header and msgbuf */
171 	off = PAGE_SIZE + round_page(vmst->hdr.msgbufsize);
172 
173 	vmst->bitmap = _kvm_malloc(kd, vmst->hdr.bitmapsize);
174 	if (vmst->bitmap == NULL) {
175 		_kvm_err(kd, kd->program, "cannot allocate %d bytes for "
176 		    "bitmap", vmst->hdr.bitmapsize);
177 		return (-1);
178 	}
179 
180 	if (pread(kd->pmfd, vmst->bitmap, vmst->hdr.bitmapsize, off) !=
181 	    (ssize_t)vmst->hdr.bitmapsize) {
182 		_kvm_err(kd, kd->program, "cannot read %d bytes for page bitmap",
183 		    vmst->hdr.bitmapsize);
184 		return (-1);
185 	}
186 	off += round_page(vmst->hdr.bitmapsize);
187 
188 	vmst->ptemap = _kvm_malloc(kd, vmst->hdr.ptesize);
189 	if (vmst->ptemap == NULL) {
190 		_kvm_err(kd, kd->program, "cannot allocate %d bytes for "
191 		    "ptemap", vmst->hdr.ptesize);
192 		return (-1);
193 	}
194 
195 	if (pread(kd->pmfd, vmst->ptemap, vmst->hdr.ptesize, off) !=
196 	    (ssize_t)vmst->hdr.ptesize) {
197 		_kvm_err(kd, kd->program, "cannot read %d bytes for ptemap",
198 		    vmst->hdr.ptesize);
199 		return (-1);
200 	}
201 
202 	off += vmst->hdr.ptesize;
203 
204 	/* Build physical address hash table for sparse pages */
205 	inithash(kd, vmst->bitmap, vmst->hdr.bitmapsize, off);
206 
207 	return (0);
208 }
209 
210 int
211 _kvm_minidump_kvatop(kvm_t *kd, u_long va, off_t *pa)
212 {
213 	struct vmstate *vm;
214 	pt_entry_t pte;
215 	u_long offset, pteindex, a;
216 	off_t ofs;
217 	uint32_t *ptemap;
218 
219 	if (ISALIVE(kd)) {
220 		_kvm_err(kd, 0, "kvm_kvatop called in live kernel!");
221 		return (0);
222 	}
223 
224 	vm = kd->vmst;
225 	ptemap = vm->ptemap;
226 
227 	if (va >= vm->hdr.kernbase) {
228 		pteindex = (va - vm->hdr.kernbase) >> PAGE_SHIFT;
229 		pte = ptemap[pteindex];
230 		if (!pte) {
231 			_kvm_err(kd, kd->program, "_kvm_vatop: pte not valid");
232 			goto invalid;
233 		}
234 		if ((pte & L2_TYPE_MASK) == L2_TYPE_L) {
235 			offset = va & L2_L_OFFSET;
236 			a = pte & L2_L_FRAME;
237 		} else if ((pte & L2_TYPE_MASK) == L2_TYPE_S) {
238 			offset = va & L2_S_OFFSET;
239 			a = pte & L2_S_FRAME;
240 		} else
241 			goto invalid;
242 
243 		ofs = hpt_find(kd, a);
244 		if (ofs == -1) {
245 			_kvm_err(kd, kd->program, "_kvm_vatop: physical "
246 			    "address 0x%lx not in minidump", a);
247 			goto invalid;
248 		}
249 
250 		*pa = ofs + offset;
251 		return (PAGE_SIZE - offset);
252 
253 	} else
254 		_kvm_err(kd, kd->program, "_kvm_vatop: virtual address 0x%lx "
255 		    "not minidumped", va);
256 
257 invalid:
258 	_kvm_err(kd, 0, "invalid address (0x%lx)", va);
259 	return (0);
260 }
261