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 (c) 1995, 2010, Oracle and/or its affiliates. All rights reserved. 24 */ 25 26 /* 27 * Copyright 2019 Joyent, Inc. 28 */ 29 30 /* 31 * While this is no longer relevant to the kernel, we keep it in its 32 * traditional location to match the other variants, used from the ld 33 * code. 34 */ 35 36 #define ELF_TARGET_386 37 #if defined(DO_RELOC_LIBLD) 38 #undef DO_RELOC_LIBLD 39 #define DO_RELOC_LIBLD_X86 40 #endif 41 #include <stdio.h> 42 #include "sgs.h" 43 #include "machdep.h" 44 #include "libld.h" 45 #include "reloc.h" 46 #include "conv.h" 47 #include "msg.h" 48 49 /* 50 * We need to build this code differently when it is used for 51 * cross linking: 52 * - Data alignment requirements can differ from those 53 * of the running system, so we can't access data 54 * in units larger than a byte 55 * - We have to include code to do byte swapping when the 56 * target and linker host use different byte ordering, 57 * but such code is a waste when running natively. 58 */ 59 #if !defined(DO_RELOC_LIBLD) || defined(__i386) || defined(__amd64) 60 #define DORELOC_NATIVE 61 #endif 62 63 /* 64 * This table represents the current relocations that do_reloc() is able to 65 * process. The relocations below that are marked SPECIAL are relocations that 66 * take special processing and shouldn't actually ever be passed to do_reloc(). 67 */ 68 const Rel_entry reloc_table[R_386_NUM] = { 69 /* R_386_NONE */ {0, FLG_RE_NOTREL, 0, 0, 0}, 70 /* R_386_32 */ {0, FLG_RE_NOTREL, 4, 0, 0}, 71 /* R_386_PC32 */ {0, FLG_RE_PCREL, 4, 0, 0}, 72 /* R_386_GOT32 */ {0, FLG_RE_GOTADD, 4, 0, 0}, 73 /* R_386_PLT32 */ {0, FLG_RE_PLTREL | FLG_RE_PCREL, 4, 0, 0}, 74 /* R_386_COPY */ {0, FLG_RE_NOTREL, 0, 0, 0}, /* SPECIAL */ 75 /* R_386_GLOB_DAT */ {0, FLG_RE_NOTREL, 4, 0, 0}, 76 /* R_386_JMP_SLOT */ {0, FLG_RE_NOTREL, 4, 0, 0}, /* SPECIAL */ 77 /* R_386_RELATIVE */ {0, FLG_RE_NOTREL, 4, 0, 0}, 78 /* R_386_GOTOFF */ {0, FLG_RE_GOTREL, 4, 0, 0}, 79 /* R_386_GOTPC */ {0, FLG_RE_PCREL | FLG_RE_GOTPC | FLG_RE_LOCLBND, 4, 80 0, 0}, 81 /* R_386_32PLT */ {0, FLG_RE_PLTREL, 4, 0, 0}, 82 /* R_386_TLS_GD_PLT */ {0, FLG_RE_PLTREL | FLG_RE_PCREL | FLG_RE_TLSGD, 4, 83 0, 0}, 84 /* R_386_TLS_LDM_PLT */ {0, FLG_RE_PLTREL | FLG_RE_PCREL | FLG_RE_TLSLD, 4, 85 0, 0}, 86 /* R_386_TLS_TPOFF */ {0, FLG_RE_NOTREL, 4, 0, 0}, 87 /* R_386_TLS_IE */ {0, FLG_RE_GOTADD | FLG_RE_TLSIE, 4, 0, 0}, 88 /* R_386_TLS_GOTIE */ {0, FLG_RE_GOTADD | FLG_RE_TLSIE, 4, 0, 0}, 89 /* R_386_TLS_LE */ {0, FLG_RE_TLSLE, 4, 0, 0}, 90 /* R_386_TLS_GD */ {0, FLG_RE_GOTADD | FLG_RE_TLSGD, 4, 0, 0}, 91 /* R_386_TLS_LDM */ {0, FLG_RE_GOTADD | FLG_RE_TLSLD, 4, 0, 0}, 92 /* R_386_16 */ {0, FLG_RE_NOTREL, 2, 0, 0}, 93 /* R_386_PC16 */ {0, FLG_RE_PCREL, 2, 0, 0}, 94 /* R_386_8 */ {0, FLG_RE_NOTREL, 1, 0, 0}, 95 /* R_386_PC8 */ {0, FLG_RE_PCREL, 1, 0, 0}, 96 /* R_386_UNKNOWN24 */ {0, FLG_RE_NOTSUP, 0, 0, 0}, 97 /* R_386_UNKNOWN25 */ {0, FLG_RE_NOTSUP, 0, 0, 0}, 98 /* R_386_UNKNOWN26 */ {0, FLG_RE_NOTSUP, 0, 0, 0}, 99 /* R_386_UNKNOWN27 */ {0, FLG_RE_NOTSUP, 0, 0, 0}, 100 /* R_386_UNKNOWN28 */ {0, FLG_RE_NOTSUP, 0, 0, 0}, 101 /* R_386_UNKNOWN29 */ {0, FLG_RE_NOTSUP, 0, 0, 0}, 102 /* R_386_UNKNOWN30 */ {0, FLG_RE_NOTSUP, 0, 0, 0}, 103 /* R_386_UNKNOWN31 */ {0, FLG_RE_NOTSUP, 0, 0, 0}, 104 /* R_386_TLS_LDO_32 */ {0, FLG_RE_TLSLD, 4, 0, 0}, 105 /* R_386_UNKNOWN33 */ {0, FLG_RE_NOTSUP, 0, 0, 0}, 106 /* R_386_UNKNOWN34 */ {0, FLG_RE_NOTSUP, 0, 0, 0}, 107 /* R_386_TLS_DTPMOD32 */ {0, FLG_RE_NOTREL, 4, 0, 0}, 108 /* R_386_TLS_DTPOFF32 */ {0, FLG_RE_NOTREL, 4, 0, 0}, 109 /* R_386_UNKONWN37 */ {0, FLG_RE_NOTSUP, 0, 0, 0}, 110 /* R_386_SIZE32 */ {0, FLG_RE_SIZE | FLG_RE_VERIFY, 4, 0, 0} 111 }; 112 113 /* 114 * Write a single relocated value to its reference location. 115 * We assume we wish to add the relocation amount, value, to the 116 * value of the address already present at the offset. 117 * 118 * NAME VALUE FIELD CALCULATION 119 * 120 * R_386_NONE 0 none none 121 * R_386_32 1 word32 S + A 122 * R_386_PC32 2 word32 S + A - P 123 * R_386_GOT32 3 word32 G + A - P 124 * R_386_PLT32 4 word32 L + A - P 125 * R_386_COPY 5 none none 126 * R_386_GLOB_DAT 6 word32 S 127 * R_386_JMP_SLOT 7 word32 S 128 * R_386_RELATIVE 8 word32 B + A 129 * R_386_GOTOFF 9 word32 S + A - GOT 130 * R_386_GOTPC 10 word32 GOT + A - P 131 * R_386_32PLT 11 word32 L + A 132 * R_386_TLS_GD_PLT 12 word32 @tlsgdplt 133 * R_386_TLS_LDM_PLT 13 word32 @tlsldmplt 134 * R_386_TLS_TPOFF 14 word32 @ntpoff(S) 135 * R_386_TLS_IE 15 word32 @indntpoff(S) 136 * R_386_TLS_GD 18 word32 @tlsgd(S) 137 * R_386_TLS_LDM 19 word32 @tlsldm(S) 138 * R_386_16 20 word16 S + A 139 * R_386_PC16 21 word16 S + A - P 140 * R_386_8 22 word8 S + A 141 * R_386_PC8 23 word8 S + A - P 142 * R_386_TLS_LDO_32 32 word32 @dtpoff(S) 143 * R_386_TLS_DTPMOD32 35 word32 @dtpmod(S) 144 * R_386_TLS_DTPOFF32 36 word32 @dtpoff(S) 145 * R_386_SIZE32 38 word32 Z + A 146 * 147 * Relocations 0-10 are from Figure 4-4: Relocation Types from the 148 * intel ABI. Relocation 11 (R_386_32PLT) is from the C++ intel abi 149 * and is in the process of being registered with intel ABI (1/13/94). 150 * 151 * Relocations R_386_TLS_* are added to support Thread-Local storage 152 * as recorded in PSARC/2001/509 153 * 154 * Relocation calculations: 155 * 156 * CALCULATION uses the following notation: 157 * A the addend used 158 * B the base address of the shared object in memory 159 * G the offset into the global offset table 160 * GOT the address of teh global offset table 161 * L the procedure linkage entry 162 * P the place of the storage unit being relocated 163 * S the value of the symbol 164 * Z the size of the symbol whose index resides in the relocation 165 * entry 166 * 167 * @dtlndx(x): Allocate two contiguous entries in the GOT table to hold 168 * a Tls_index structure (for passing to __tls_get_addr()). The 169 * instructions referencing this entry will be bound to the first 170 * of the two GOT entries. 171 * 172 * @tmndx(x): Allocate two contiguous entries in the GOT table to hold 173 * a Tls_index structure (for passing to __tls_get_addr()). The 174 * ti_offset field of the Tls_index will be set to 0 (zero) and the 175 * ti_module will be filled in at run-time. The call to 176 * __tls_get_addr() will return the starting offset of the dynamic 177 * TLS block. 178 * 179 * @dtpoff(x): calculate the tlsoffset relative to the TLS block. 180 * 181 * @tpoff(x): calculate the tlsoffset relative to the TLS block. 182 * 183 * @dtpmod(x): calculate the module id of the object containing symbol x. 184 * 185 * The calculations in the CALCULATION column are assumed to have 186 * been performed before calling this function except for the addition of 187 * the addresses in the instructions. 188 */ 189 #if defined(DO_RELOC_LIBLD) 190 /*ARGSUSED5*/ 191 int 192 do_reloc_ld(Rel_desc *rdesc, uchar_t *off, Xword *value, 193 rel_desc_sname_func_t rel_desc_sname_func, 194 const char *file, int bswap, void *lml) 195 #else 196 int 197 do_reloc_rtld(uchar_t rtype, uchar_t *off, Xword *value, const char *sym, 198 const char *file, void *lml) 199 #endif 200 { 201 #ifdef DO_RELOC_LIBLD 202 #define sym (* rel_desc_sname_func)(rdesc) 203 uchar_t rtype = rdesc->rel_rtype; 204 #endif 205 const Rel_entry *rep; 206 207 rep = &reloc_table[rtype]; 208 209 switch (rep->re_fsize) { 210 case 1: 211 /* LINTED */ 212 *((uchar_t *)off) += (uchar_t)(*value); 213 break; 214 215 case 2: 216 #if defined(DORELOC_NATIVE) 217 /* LINTED */ 218 *((Half *)off) += (Half)(*value); 219 #else 220 { 221 Half v; 222 uchar_t *v_bytes = (uchar_t *)&v; 223 224 if (bswap) { 225 UL_ASSIGN_BSWAP_HALF(v_bytes, off); 226 v += *value; 227 UL_ASSIGN_BSWAP_HALF(off, v_bytes); 228 } else { 229 UL_ASSIGN_HALF(v_bytes, off); 230 v += *value; 231 UL_ASSIGN_HALF(off, v_bytes); 232 } 233 } 234 #endif 235 break; 236 237 case 4: 238 #if defined(DORELOC_NATIVE) 239 /* LINTED */ 240 *((Xword *)off) += *value; 241 #else 242 { 243 Word v; 244 uchar_t *v_bytes = (uchar_t *)&v; 245 246 if (bswap) { 247 UL_ASSIGN_BSWAP_WORD(v_bytes, off); 248 v += *value; 249 UL_ASSIGN_BSWAP_WORD(off, v_bytes); 250 } else { 251 UL_ASSIGN_WORD(v_bytes, off); 252 v += *value; 253 UL_ASSIGN_WORD(off, v_bytes); 254 } 255 } 256 #endif 257 break; 258 default: 259 /* 260 * To keep chkmsg() happy: MSG_INTL(MSG_REL_UNSUPSZ) 261 */ 262 REL_ERR_UNSUPSZ(lml, file, sym, rtype, rep->re_fsize); 263 return (0); 264 } 265 return (1); 266 267 #ifdef DO_RELOC_LIBLD 268 #undef sym 269 #endif 270 } 271