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6069 libdisasm: instrlen arch op should have a sane default
Reviewed by: Robert Mustacchi <rm@joyent.com>
Approved by: Dan McDonald <danmcd@omniti.com>
6068 libdisasm: previnstr arch op should have a sane default
Reviewed by: Robert Mustacchi <rm@joyent.com>
Approved by: Dan McDonald <danmcd@omniti.com>
6067 libdisasm: use C99 designated initializers for arch ops
Reviewed by: Robert Mustacchi <rm@joyent.com>
Approved by: Dan McDonald <danmcd@omniti.com>
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--- old/usr/src/lib/libdisasm/common/dis_i386.c
+++ new/usr/src/lib/libdisasm/common/dis_i386.c
1 1 /*
2 2 * CDDL HEADER START
3 3 *
4 4 * The contents of this file are subject to the terms of the
5 5 * Common Development and Distribution License (the "License").
6 6 * You may not use this file except in compliance with the License.
7 7 *
8 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 9 * or http://www.opensolaris.org/os/licensing.
10 10 * See the License for the specific language governing permissions
11 11 * and limitations under the License.
12 12 *
13 13 * When distributing Covered Code, include this CDDL HEADER in each
14 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 15 * If applicable, add the following below this CDDL HEADER, with the
16 16 * fields enclosed by brackets "[]" replaced with your own identifying
17 17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 18 *
19 19 * CDDL HEADER END
20 20 */
21 21
22 22 /*
23 23 * Copyright 2007 Sun Microsystems, Inc. All rights reserved.
24 24 * Use is subject to license terms.
25 25 * Copyright 2012 Joshua M. Clulow <josh@sysmgr.org>
26 26 * Copyright 2015 Nexenta Systems, Inc. All rights reserved.
27 27 */
28 28
29 29 #include <libdisasm.h>
30 30
31 31 #include "dis_tables.h"
32 32 #include "libdisasm_impl.h"
33 33
34 34 typedef struct dis_handle_i386 {
35 35 int dhx_mode;
36 36 dis86_t dhx_dis;
37 37 uint64_t dhx_end;
38 38 } dis_handle_i386_t;
39 39
40 40 /*
41 41 * Returns true if we are near the end of a function. This is a cheap hack at
42 42 * detecting NULL padding between functions. If we're within a few bytes of the
43 43 * next function, or past the start, then return true.
44 44 */
45 45 static int
46 46 check_func(void *data)
47 47 {
48 48 dis_handle_t *dhp = data;
49 49 uint64_t start;
50 50 size_t len;
51 51
52 52 if (dhp->dh_lookup(dhp->dh_data, dhp->dh_addr, NULL, 0, &start, &len)
53 53 != 0)
54 54 return (0);
55 55
56 56 if (start < dhp->dh_addr)
57 57 return (dhp->dh_addr > start + len - 0x10);
58 58
59 59 return (1);
60 60 }
61 61
62 62 static int
63 63 get_byte(void *data)
64 64 {
65 65 uchar_t byte;
66 66 dis_handle_t *dhp = data;
67 67
68 68 if (dhp->dh_read(dhp->dh_data, dhp->dh_addr, &byte, sizeof (byte)) !=
69 69 sizeof (byte))
70 70 return (-1);
71 71
72 72 dhp->dh_addr++;
73 73
74 74 return ((int)byte);
75 75 }
76 76
77 77 static int
78 78 do_lookup(void *data, uint64_t addr, char *buf, size_t buflen)
79 79 {
80 80 dis_handle_t *dhp = data;
81 81
82 82 return (dhp->dh_lookup(dhp->dh_data, addr, buf, buflen, NULL, NULL));
83 83 }
84 84
85 85 static void
86 86 dis_i386_handle_detach(dis_handle_t *dhp)
87 87 {
88 88 dis_free(dhp->dh_arch_private, sizeof (dis_handle_i386_t));
89 89 dhp->dh_arch_private = NULL;
90 90 }
91 91
92 92 static int
93 93 dis_i386_handle_attach(dis_handle_t *dhp)
94 94 {
95 95 dis_handle_i386_t *dhx;
96 96
97 97 /*
98 98 * Validate architecture flags
99 99 */
100 100 if (dhp->dh_flags & ~(DIS_X86_SIZE16 | DIS_X86_SIZE32 | DIS_X86_SIZE64 |
101 101 DIS_OCTAL | DIS_NOIMMSYM)) {
102 102 (void) dis_seterrno(E_DIS_INVALFLAG);
103 103 return (-1);
104 104 }
105 105
106 106 /*
107 107 * Create and initialize the internal structure
108 108 */
109 109 if ((dhx = dis_zalloc(sizeof (dis_handle_i386_t))) == NULL) {
110 110 (void) dis_seterrno(E_DIS_NOMEM);
111 111 return (-1);
112 112 }
113 113 dhp->dh_arch_private = dhx;
114 114
115 115 /*
116 116 * Initialize x86-specific architecture structure
117 117 */
118 118 if (dhp->dh_flags & DIS_X86_SIZE16)
119 119 dhx->dhx_mode = SIZE16;
120 120 else if (dhp->dh_flags & DIS_X86_SIZE64)
121 121 dhx->dhx_mode = SIZE64;
122 122 else
123 123 dhx->dhx_mode = SIZE32;
124 124
125 125 if (dhp->dh_flags & DIS_OCTAL)
126 126 dhx->dhx_dis.d86_flags = DIS_F_OCTAL;
127 127
128 128 dhx->dhx_dis.d86_sprintf_func = dis_snprintf;
129 129 dhx->dhx_dis.d86_get_byte = get_byte;
130 130 dhx->dhx_dis.d86_sym_lookup = do_lookup;
131 131 dhx->dhx_dis.d86_check_func = check_func;
132 132
133 133 dhx->dhx_dis.d86_data = dhp;
134 134
135 135 return (0);
136 136 }
137 137
138 138 static int
139 139 dis_i386_disassemble(dis_handle_t *dhp, uint64_t addr, char *buf,
140 140 size_t buflen)
141 141 {
142 142 dis_handle_i386_t *dhx = dhp->dh_arch_private;
143 143 dhp->dh_addr = addr;
144 144
145 145 /* DIS_NOIMMSYM might not be set until now, so update */
146 146 if (dhp->dh_flags & DIS_NOIMMSYM)
147 147 dhx->dhx_dis.d86_flags |= DIS_F_NOIMMSYM;
148 148 else
149 149 dhx->dhx_dis.d86_flags &= ~DIS_F_NOIMMSYM;
150 150
151 151 if (dtrace_disx86(&dhx->dhx_dis, dhx->dhx_mode) != 0)
152 152 return (-1);
153 153
154 154 if (buf != NULL)
155 155 dtrace_disx86_str(&dhx->dhx_dis, dhx->dhx_mode, addr, buf,
156 156 buflen);
157 157
158 158 return (0);
159 159 }
160 160
161 161 /* ARGSUSED */
162 162 static int
163 163 dis_i386_max_instrlen(dis_handle_t *dhp)
164 164 {
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165 165 return (15);
166 166 }
167 167
168 168 /* ARGSUSED */
169 169 static int
170 170 dis_i386_min_instrlen(dis_handle_t *dhp)
171 171 {
172 172 return (1);
173 173 }
174 174
175 -/*
176 - * Return the previous instruction. On x86, we have no choice except to
177 - * disassemble everything from the start of the symbol, and stop when we have
178 - * reached our instruction address. If we're not in the middle of a known
179 - * symbol, then we return the same address to indicate failure.
180 - */
181 -static uint64_t
182 -dis_i386_previnstr(dis_handle_t *dhp, uint64_t pc, int n)
183 -{
184 - uint64_t *hist, addr, start;
185 - int cur, nseen;
186 - uint64_t res = pc;
187 -
188 - if (n <= 0)
189 - return (pc);
190 -
191 - if (dhp->dh_lookup(dhp->dh_data, pc, NULL, 0, &start, NULL) != 0 ||
192 - start == pc)
193 - return (res);
194 -
195 - hist = dis_zalloc(sizeof (uint64_t) * n);
196 -
197 - for (cur = 0, nseen = 0, addr = start; addr < pc; addr = dhp->dh_addr) {
198 - hist[cur] = addr;
199 - cur = (cur + 1) % n;
200 - nseen++;
201 -
202 - /* if we cannot make forward progress, give up */
203 - if (dis_disassemble(dhp, addr, NULL, 0) != 0)
204 - goto done;
205 - }
206 -
207 - if (addr != pc) {
208 - /*
209 - * We scanned past %pc, but didn't find an instruction that
210 - * started at %pc. This means that either the caller specified
211 - * an invalid address, or we ran into something other than code
212 - * during our scan. Virtually any combination of bytes can be
213 - * construed as a valid Intel instruction, so any non-code bytes
214 - * we encounter will have thrown off the scan.
215 - */
216 - goto done;
217 - }
218 -
219 - res = hist[(cur + n - MIN(n, nseen)) % n];
220 -
221 -done:
222 - dis_free(hist, sizeof (uint64_t) * n);
223 - return (res);
224 -}
225 -
226 175 static int
227 176 dis_i386_supports_flags(int flags)
228 177 {
229 178 int archflags = flags & DIS_ARCH_MASK;
230 179
231 180 if (archflags == DIS_X86_SIZE16 || archflags == DIS_X86_SIZE32 ||
232 181 archflags == DIS_X86_SIZE64)
233 182 return (1);
234 183
235 184 return (0);
236 185 }
237 186
238 -static int
239 -dis_i386_instrlen(dis_handle_t *dhp, uint64_t pc)
240 -{
241 - if (dis_disassemble(dhp, pc, NULL, 0) != 0)
242 - return (-1);
243 -
244 - return (dhp->dh_addr - pc);
245 -}
246 -
247 187 dis_arch_t dis_arch_i386 = {
248 - dis_i386_supports_flags,
249 - dis_i386_handle_attach,
250 - dis_i386_handle_detach,
251 - dis_i386_disassemble,
252 - dis_i386_previnstr,
253 - dis_i386_min_instrlen,
254 - dis_i386_max_instrlen,
255 - dis_i386_instrlen,
188 + .da_supports_flags = dis_i386_supports_flags,
189 + .da_handle_attach = dis_i386_handle_attach,
190 + .da_handle_detach = dis_i386_handle_detach,
191 + .da_disassemble = dis_i386_disassemble,
192 + .da_min_instrlen = dis_i386_min_instrlen,
193 + .da_max_instrlen = dis_i386_max_instrlen,
256 194 };
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