1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2007 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 /* 28 * Copyright 2007 Jason King. All rights reserved. 29 * Use is subject to license terms. 30 * Copyright 2012 Joshua M. Clulow <josh@sysmgr.org> 31 */ 32 33 /* 34 * The sparc disassembler is mostly straightforward, each instruction is 35 * represented by an inst_t structure. The inst_t definitions are organized 36 * into tables. The tables are correspond to the opcode maps documented in the 37 * various sparc architecture manuals. Each table defines the bit range of the 38 * instruction whose value act as an index into the array of instructions. A 39 * table can also refer to another table if needed. Each table also contains 40 * a function pointer of type format_fcn that knows how to output the 41 * instructions in the table, as well as handle any synthetic instructions 42 * 43 * Unfortunately, the changes from sparcv8 -> sparcv9 not only include new 44 * instructions, they sometimes renamed or just reused the same instruction to 45 * do different operations (i.e. the sparcv8 coprocessor instructions). To 46 * accommodate this, each table can define an overlay table. The overlay table 47 * is a list of (table index, architecture, new instruction definition) values. 48 * 49 * 50 * Traversal starts with the first table, 51 * get index value from the instruction 52 * if an relevant overlay entry exists for this index, 53 * grab the overlay definition 54 * else 55 * grab the definition from the array (corresponding to the index value) 56 * 57 * If the entry is an instruction, 58 * call print function of instruction. 59 * If the entry is a pointer to another table 60 * traverse the table 61 * If not valid, 62 * return an error 63 * 64 * 65 * To keep dis happy, for sparc, instead of actually returning an error, if 66 * the instruction cannot be disassembled, we instead merely place the value 67 * of the instruction into the output buffer. 68 * 69 * Adding new instructions: 70 * 71 * With the above information, it hopefully makes it clear how to add support 72 * for decoding new instructions. Presumably, with new instructions will come 73 * a new dissassembly mode (I.e. DIS_SPARC_V8, DIS_SPARC_V9, etc.). 74 * 75 * If the dissassembled format does not correspond to one of the existing 76 * formats, a new formatter will have to be written. The 'flags' value of 77 * inst_t is intended to instruct the corresponding formatter about how to 78 * output the instruction. 79 * 80 * If the corresponding entry in the correct table is currently unoccupied, 81 * simply replace the INVALID entry with the correct definition. The INST and 82 * TABLE macros are suggested to be used for this. If there is already an 83 * instruction defined, then the entry must be placed in an overlay table. If 84 * no overlay table exists for the instruction table, one will need to be 85 * created. 86 */ 87 88 #include <libdisasm.h> 89 #include <stdlib.h> 90 #include <stdio.h> 91 #include <sys/types.h> 92 #include <sys/byteorder.h> 93 #include <string.h> 94 95 #include "libdisasm_impl.h" 96 #include "dis_sparc.h" 97 98 static const inst_t *dis_get_overlay(dis_handle_t *, const table_t *, 99 uint32_t); 100 static uint32_t dis_get_bits(uint32_t, int, int); 101 102 #if !defined(DIS_STANDALONE) 103 static void do_binary(uint32_t); 104 #endif /* DIS_STANDALONE */ 105 106 static void 107 dis_sparc_handle_detach(dis_handle_t *dhp) 108 { 109 dis_free(dhp->dh_arch_private, sizeof (dis_handle_sparc_t)); 110 dhp->dh_arch_private = NULL; 111 } 112 113 static int 114 dis_sparc_handle_attach(dis_handle_t *dhp) 115 { 116 dis_handle_sparc_t *dhx; 117 118 #if !defined(DIS_STANDALONE) 119 char *opt = NULL; 120 char *opt2, *save, *end; 121 #endif 122 123 /* Validate architecture flags */ 124 if ((dhp->dh_flags & (DIS_SPARC_V8|DIS_SPARC_V9|DIS_SPARC_V9_SGI)) 125 == 0) { 126 (void) dis_seterrno(E_DIS_INVALFLAG); 127 return (-1); 128 } 129 130 if ((dhx = dis_zalloc(sizeof (dis_handle_sparc_t))) == NULL) { 131 (void) dis_seterrno(E_DIS_NOMEM); 132 return (NULL); 133 } 134 dhx->dhx_debug = DIS_DEBUG_COMPAT; 135 dhp->dh_arch_private = dhx; 136 137 #if !defined(DIS_STANDALONE) 138 139 opt = getenv("_LIBDISASM_DEBUG"); 140 if (opt == NULL) 141 return (0); 142 143 opt2 = strdup(opt); 144 if (opt2 == NULL) { 145 dis_handle_destroy(dhp); 146 dis_free(dhx, sizeof (dis_handle_sparc_t)); 147 (void) dis_seterrno(E_DIS_NOMEM); 148 return (-1); 149 } 150 save = opt2; 151 152 while (opt2 != NULL) { 153 end = strchr(opt2, ','); 154 155 if (end != 0) 156 *end++ = '\0'; 157 158 if (strcasecmp("synth-all", opt2) == 0) 159 dhx->dhx_debug |= DIS_DEBUG_SYN_ALL; 160 161 if (strcasecmp("compat", opt2) == 0) 162 dhx->dhx_debug |= DIS_DEBUG_COMPAT; 163 164 if (strcasecmp("synth-none", opt2) == 0) 165 dhx->dhx_debug &= ~(DIS_DEBUG_SYN_ALL|DIS_DEBUG_COMPAT); 166 167 if (strcasecmp("binary", opt2) == 0) 168 dhx->dhx_debug |= DIS_DEBUG_PRTBIN; 169 170 if (strcasecmp("format", opt2) == 0) 171 dhx->dhx_debug |= DIS_DEBUG_PRTFMT; 172 173 if (strcasecmp("all", opt2) == 0) 174 dhx->dhx_debug = DIS_DEBUG_ALL; 175 176 if (strcasecmp("none", opt2) == 0) 177 dhx->dhx_debug = DIS_DEBUG_NONE; 178 179 opt2 = end; 180 } 181 free(save); 182 #endif /* DIS_STANDALONE */ 183 return (0); 184 } 185 186 /* ARGSUSED */ 187 static int 188 dis_sparc_max_instrlen(dis_handle_t *dhp) 189 { 190 return (4); 191 } 192 193 /* ARGSUSED */ 194 static int 195 dis_sparc_min_instrlen(dis_handle_t *dhp) 196 { 197 return (4); 198 } 199 200 /* 201 * The dis_i386.c comment for this says it returns the previous instruction, 202 * however, I'm fairly sure it's actually returning the _address_ of the 203 * nth previous instruction. 204 */ 205 /* ARGSUSED */ 206 static uint64_t 207 dis_sparc_previnstr(dis_handle_t *dhp, uint64_t pc, int n) 208 { 209 if (n <= 0) 210 return (pc); 211 212 if (pc < n) 213 return (pc); 214 215 return (pc - n*4); 216 } 217 218 /* ARGSUSED */ 219 static int 220 dis_sparc_instrlen(dis_handle_t *dhp, uint64_t pc) 221 { 222 return (4); 223 } 224 225 static int 226 dis_sparc_disassemble(dis_handle_t *dhp, uint64_t addr, char *buf, 227 size_t buflen) 228 { 229 dis_handle_sparc_t *dhx = dhp->dh_arch_private; 230 const table_t *tp = &initial_table; 231 const inst_t *inp = NULL; 232 233 uint32_t instr; 234 uint32_t idx = 0; 235 236 if (dhp->dh_read(dhp->dh_data, addr, &instr, sizeof (instr)) != 237 sizeof (instr)) 238 return (-1); 239 240 dhx->dhx_buf = buf; 241 dhx->dhx_buflen = buflen; 242 dhp->dh_addr = addr; 243 244 buf[0] = '\0'; 245 246 /* this allows sparc code to be tested on x86 */ 247 #if !defined(DIS_STANDALONE) 248 instr = BE_32(instr); 249 #endif /* DIS_STANDALONE */ 250 251 #if !defined(DIS_STANDALONE) 252 if ((dhx->dhx_debug & DIS_DEBUG_PRTBIN) != 0) 253 do_binary(instr); 254 #endif /* DIS_STANDALONE */ 255 256 /* CONSTCOND */ 257 while (1) { 258 idx = dis_get_bits(instr, tp->tbl_field, tp->tbl_len); 259 inp = &tp->tbl_inp[idx]; 260 261 inp = dis_get_overlay(dhp, tp, idx); 262 263 if ((inp->in_type == INST_NONE) || 264 ((inp->in_arch & dhp->dh_flags) == 0)) 265 goto error; 266 267 if (inp->in_type == INST_TBL) { 268 tp = inp->in_data.in_tbl; 269 continue; 270 } 271 272 break; 273 } 274 275 if (tp->tbl_fmt(dhp, instr, inp, idx) == 0) 276 return (0); 277 278 error: 279 280 (void) dis_snprintf(buf, buflen, 281 ((dhp->dh_flags & DIS_OCTAL) != 0) ? "0%011lo" : "0x%08lx", 282 instr); 283 284 return (0); 285 } 286 287 static uint32_t 288 dis_get_bits(uint32_t instr, int offset, int length) 289 { 290 uint32_t mask, val; 291 int i; 292 293 for (i = 0, mask = 0; i < length; ++i) 294 mask |= (1UL << i); 295 296 mask = mask << (offset - length + 1); 297 298 val = instr & mask; 299 300 val = val >> (offset - length + 1); 301 302 return (val); 303 } 304 305 static const inst_t * 306 dis_get_overlay(dis_handle_t *dhp, const table_t *tp, uint32_t idx) 307 { 308 const inst_t *ip = &tp->tbl_inp[idx]; 309 int i; 310 311 if (tp->tbl_ovp == NULL) 312 return (ip); 313 314 for (i = 0; tp->tbl_ovp[i].ov_idx != -1; ++i) { 315 if (tp->tbl_ovp[i].ov_idx != idx) 316 continue; 317 318 if ((tp->tbl_ovp[i].ov_inst.in_arch & dhp->dh_flags) == 0) 319 continue; 320 321 ip = &tp->tbl_ovp[i].ov_inst; 322 break; 323 } 324 325 return (ip); 326 } 327 328 #if !defined(DIS_STANDALONE) 329 static void 330 do_binary(uint32_t instr) 331 { 332 (void) fprintf(stderr, "DISASM: "); 333 prt_binary(instr, 32); 334 (void) fprintf(stderr, "\n"); 335 } 336 #endif /* DIS_STANDALONE */ 337 338 static int 339 dis_sparc_supports_flags(int flags) 340 { 341 int archflags = flags & DIS_ARCH_MASK; 342 343 if (archflags == DIS_SPARC_V8 || 344 (archflags & (DIS_SPARC_V9 | DIS_SPARC_V8)) == DIS_SPARC_V9) 345 return (1); 346 347 return (0); 348 } 349 350 const dis_arch_t dis_arch_sparc = { 351 dis_sparc_supports_flags, 352 dis_sparc_handle_attach, 353 dis_sparc_handle_detach, 354 dis_sparc_disassemble, 355 dis_sparc_previnstr, 356 dis_sparc_min_instrlen, 357 dis_sparc_max_instrlen, 358 dis_sparc_instrlen 359 }; 360