| 1 | /* |
| 2 | * Copyright (c) 1993 Paul Kranenburg |
| 3 | * All rights reserved. |
| 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 | * 3. All advertising materials mentioning features or use of this software |
| 14 | * must display the following acknowledgement: |
| 15 | * This product includes software developed by Paul Kranenburg. |
| 16 | * 4. The name of the author may not be used to endorse or promote products |
| 17 | * derived from this software withough specific prior written permission |
| 18 | * |
| 19 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| 20 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| 21 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| 22 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 23 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 24 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 25 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 26 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 27 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| 28 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 29 | * |
| 30 | * $Id: md.c,v 1.8 1994/01/19 15:00:37 davidg Exp $ |
| 31 | */ |
| 32 | |
| 33 | #include <sys/param.h> |
| 34 | #include <stdio.h> |
| 35 | #include <stdlib.h> |
| 36 | #include <sys/types.h> |
| 37 | #include <fcntl.h> |
| 38 | #include <a.out.h> |
| 39 | #include <stab.h> |
| 40 | #include <string.h> |
| 41 | |
| 42 | #include "ld.h" |
| 43 | |
| 44 | /* |
| 45 | * Get relocation addend corresponding to relocation record RP |
| 46 | * from address ADDR |
| 47 | */ |
| 48 | long |
| 49 | md_get_addend(rp, addr) |
| 50 | struct relocation_info *rp; |
| 51 | unsigned char *addr; |
| 52 | { |
| 53 | switch (RELOC_TARGET_SIZE(rp)) { |
| 54 | case 0: |
| 55 | return get_byte(addr); |
| 56 | break; |
| 57 | case 1: |
| 58 | return get_short(addr); |
| 59 | break; |
| 60 | case 2: |
| 61 | return get_long(addr); |
| 62 | break; |
| 63 | } |
| 64 | } |
| 65 | |
| 66 | /* |
| 67 | * Put RELOCATION at ADDR according to relocation record RP. |
| 68 | */ |
| 69 | void |
| 70 | md_relocate(rp, relocation, addr, relocatable_output) |
| 71 | struct relocation_info *rp; |
| 72 | long relocation; |
| 73 | unsigned char *addr; |
| 74 | { |
| 75 | switch (RELOC_TARGET_SIZE(rp)) { |
| 76 | case 0: |
| 77 | put_byte(addr, relocation); |
| 78 | break; |
| 79 | case 1: |
| 80 | put_short(addr, relocation); |
| 81 | break; |
| 82 | case 2: |
| 83 | put_long(addr, relocation); |
| 84 | break; |
| 85 | default: |
| 86 | fatal("Unsupported relocation size: %x", RELOC_TARGET_SIZE(rp)); |
| 87 | } |
| 88 | } |
| 89 | |
| 90 | /* |
| 91 | * Machine dependent part of claim_rrs_reloc(). |
| 92 | * Set RRS relocation type. |
| 93 | */ |
| 94 | int |
| 95 | md_make_reloc(rp, r, type) |
| 96 | struct relocation_info *rp, *r; |
| 97 | int type; |
| 98 | { |
| 99 | /* Relocation size */ |
| 100 | r->r_length = rp->r_length; |
| 101 | |
| 102 | if (RELOC_PCREL_P(rp)) |
| 103 | r->r_pcrel = 1; |
| 104 | |
| 105 | if (type & RELTYPE_RELATIVE) |
| 106 | r->r_relative = 1; |
| 107 | |
| 108 | if (type & RELTYPE_COPY) |
| 109 | r->r_copy = 1; |
| 110 | |
| 111 | return 0; |
| 112 | } |
| 113 | |
| 114 | /* |
| 115 | * Set up a transfer from jmpslot at OFFSET (relative to the PLT table) |
| 116 | * to the binder slot (which is at offset 0 of the PLT). |
| 117 | */ |
| 118 | void |
| 119 | md_make_jmpslot(sp, offset, index) |
| 120 | jmpslot_t *sp; |
| 121 | long offset; |
| 122 | long index; |
| 123 | { |
| 124 | /* |
| 125 | * i386 PC-relative "fixed point" is located right after the |
| 126 | * instruction it pertains to. |
| 127 | */ |
| 128 | u_long fudge = - (sizeof(sp->opcode) + sizeof(sp->addr) + offset); |
| 129 | |
| 130 | sp->opcode = CALL; |
| 131 | #if 0 |
| 132 | sp->addr = fudge; |
| 133 | #else |
| 134 | sp->addr[0] = fudge & 0xffff; |
| 135 | sp->addr[1] = fudge >> 16; |
| 136 | #endif |
| 137 | sp->reloc_index = index; |
| 138 | } |
| 139 | |
| 140 | /* |
| 141 | * Set up a "direct" transfer (ie. not through the run-time binder) from |
| 142 | * jmpslot at OFFSET to ADDR. Used by `ld' when the SYMBOLIC flag is on, |
| 143 | * and by `ld.so' after resolving the symbol. |
| 144 | * On the i386, we use the JMP instruction which is PC relative, so no |
| 145 | * further RRS relocations will be necessary for such a jmpslot. |
| 146 | */ |
| 147 | void |
| 148 | md_fix_jmpslot(sp, offset, addr) |
| 149 | jmpslot_t *sp; |
| 150 | long offset; |
| 151 | u_long addr; |
| 152 | { |
| 153 | u_long fudge = addr - (sizeof(sp->opcode) + sizeof(sp->addr) + offset); |
| 154 | |
| 155 | sp->opcode = JUMP; |
| 156 | #if 0 |
| 157 | sp->addr = fudge; |
| 158 | #else |
| 159 | sp->addr[0] = fudge & 0xffff; |
| 160 | sp->addr[1] = fudge >> 16; |
| 161 | #endif |
| 162 | sp->reloc_index = 0; |
| 163 | } |
| 164 | |
| 165 | /* |
| 166 | * Update the relocation record for a RRS jmpslot. |
| 167 | */ |
| 168 | void |
| 169 | md_make_jmpreloc(rp, r, type) |
| 170 | struct relocation_info *rp, *r; |
| 171 | int type; |
| 172 | { |
| 173 | jmpslot_t *sp; |
| 174 | |
| 175 | /* |
| 176 | * Fix relocation address to point to the correct |
| 177 | * location within this jmpslot. |
| 178 | */ |
| 179 | r->r_address += sizeof(sp->opcode); |
| 180 | |
| 181 | /* Relocation size */ |
| 182 | r->r_length = 2; |
| 183 | |
| 184 | /* Set relocation type */ |
| 185 | r->r_jmptable = 1; |
| 186 | if (type & RELTYPE_RELATIVE) |
| 187 | r->r_relative = 1; |
| 188 | |
| 189 | } |
| 190 | |
| 191 | /* |
| 192 | * Set relocation type for a RRS GOT relocation. |
| 193 | */ |
| 194 | void |
| 195 | md_make_gotreloc(rp, r, type) |
| 196 | struct relocation_info *rp, *r; |
| 197 | int type; |
| 198 | { |
| 199 | r->r_baserel = 1; |
| 200 | if (type & RELTYPE_RELATIVE) |
| 201 | r->r_relative = 1; |
| 202 | |
| 203 | /* Relocation size */ |
| 204 | r->r_length = 2; |
| 205 | } |
| 206 | |
| 207 | /* |
| 208 | * Set relocation type for a RRS copy operation. |
| 209 | */ |
| 210 | void |
| 211 | md_make_cpyreloc(rp, r) |
| 212 | struct relocation_info *rp, *r; |
| 213 | { |
| 214 | /* Relocation size */ |
| 215 | r->r_length = 2; |
| 216 | |
| 217 | r->r_copy = 1; |
| 218 | } |
| 219 | |
| 220 | void |
| 221 | md_set_breakpoint(where, savep) |
| 222 | long where; |
| 223 | long *savep; |
| 224 | { |
| 225 | *savep = *(long *)where; |
| 226 | *(char *)where = TRAP; |
| 227 | } |
| 228 | |
| 229 | #ifndef RTLD |
| 230 | |
| 231 | #ifdef FreeBSD |
| 232 | int netzmagic; |
| 233 | #endif |
| 234 | |
| 235 | /* |
| 236 | * Initialize (output) exec header such that useful values are |
| 237 | * obtained from subsequent N_*() macro evaluations. |
| 238 | */ |
| 239 | void |
| 240 | md_init_header(hp, magic, flags) |
| 241 | struct exec *hp; |
| 242 | int magic, flags; |
| 243 | { |
| 244 | #ifdef NetBSD |
| 245 | if (oldmagic || magic == QMAGIC) |
| 246 | hp->a_midmag = magic; |
| 247 | else |
| 248 | N_SETMAGIC((*hp), magic, MID_I386, flags); |
| 249 | #endif |
| 250 | #ifdef FreeBSD |
| 251 | if (oldmagic) |
| 252 | hp->a_midmag = magic; |
| 253 | else if (netzmagic) |
| 254 | N_SETMAGIC_NET((*hp), magic, MID_I386, flags); |
| 255 | else |
| 256 | N_SETMAGIC((*hp), magic, MID_I386, flags); |
| 257 | #endif |
| 258 | |
| 259 | /* TEXT_START depends on the value of outheader.a_entry. */ |
| 260 | if (!(link_mode & SHAREABLE)) /*WAS: if (entry_symbol) */ |
| 261 | hp->a_entry = PAGSIZ; |
| 262 | } |
| 263 | #endif /* RTLD */ |
| 264 | |
| 265 | |
| 266 | #ifdef NEED_SWAP |
| 267 | /* |
| 268 | * Byte swap routines for cross-linking. |
| 269 | */ |
| 270 | |
| 271 | void |
| 272 | md_swapin_exec_hdr(h) |
| 273 | struct exec *h; |
| 274 | { |
| 275 | int skip = 0; |
| 276 | |
| 277 | if (!N_BADMAG(*h)) |
| 278 | skip = 1; |
| 279 | |
| 280 | swap_longs((long *)h + skip, sizeof(*h)/sizeof(long) - skip); |
| 281 | } |
| 282 | |
| 283 | void |
| 284 | md_swapout_exec_hdr(h) |
| 285 | struct exec *h; |
| 286 | { |
| 287 | /* NetBSD: Always leave magic alone */ |
| 288 | int skip = 1; |
| 289 | #if 0 |
| 290 | if (N_GETMAGIC(*h) == OMAGIC) |
| 291 | skip = 0; |
| 292 | #endif |
| 293 | |
| 294 | swap_longs((long *)h + skip, sizeof(*h)/sizeof(long) - skip); |
| 295 | } |
| 296 | |
| 297 | |
| 298 | void |
| 299 | md_swapin_reloc(r, n) |
| 300 | struct relocation_info *r; |
| 301 | int n; |
| 302 | { |
| 303 | int bits; |
| 304 | |
| 305 | for (; n; n--, r++) { |
| 306 | r->r_address = md_swap_long(r->r_address); |
| 307 | bits = ((int *)r)[1]; |
| 308 | r->r_symbolnum = md_swap_long(bits & 0xffffff00); |
| 309 | r->r_pcrel = (bits & 1); |
| 310 | r->r_length = ((bits >> 1) & 3); |
| 311 | r->r_extern = ((bits >> 3) & 1); |
| 312 | r->r_baserel = ((bits >> 4) & 1); |
| 313 | r->r_jmptable = ((bits >> 5) & 1); |
| 314 | r->r_relative = ((bits >> 6) & 1); |
| 315 | #ifdef N_SIZE |
| 316 | r->r_copy = ((bits >> 7) & 1); |
| 317 | #endif |
| 318 | } |
| 319 | } |
| 320 | |
| 321 | void |
| 322 | md_swapout_reloc(r, n) |
| 323 | struct relocation_info *r; |
| 324 | int n; |
| 325 | { |
| 326 | int bits; |
| 327 | |
| 328 | for (; n; n--, r++) { |
| 329 | r->r_address = md_swap_long(r->r_address); |
| 330 | bits = (md_swap_long(r->r_symbolnum) & 0xffffff00); |
| 331 | bits |= (r->r_pcrel & 1); |
| 332 | bits |= ((r->r_length << 1) & 6); |
| 333 | bits |= ((r->r_extern << 3) & 8); |
| 334 | bits |= ((r->r_baserel << 4) & 0x10); |
| 335 | bits |= ((r->r_jmptable << 5) & 0x20); |
| 336 | bits |= ((r->r_relative << 6) & 0x40); |
| 337 | #ifdef N_SIZE |
| 338 | bits |= ((r->r_copy << 7) & 0x80); |
| 339 | #endif |
| 340 | ((int *)r)[1] = bits; |
| 341 | } |
| 342 | } |
| 343 | |
| 344 | void |
| 345 | md_swapout_jmpslot(j, n) |
| 346 | jmpslot_t *j; |
| 347 | int n; |
| 348 | { |
| 349 | for (; n; n--, j++) { |
| 350 | j->opcode = md_swap_short(j->opcode); |
| 351 | j->addr[0] = md_swap_short(j->addr[0]); |
| 352 | j->addr[1] = md_swap_short(j->addr[1]); |
| 353 | j->reloc_index = md_swap_short(j->reloc_index); |
| 354 | } |
| 355 | } |
| 356 | |
| 357 | #endif /* NEED_SWAP */ |