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 2008 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 #pragma ident "%Z%%M% %I% %E% SMI" 27 28 29 #include <stdio.h> 30 #include <strings.h> 31 #include <sys/elf.h> 32 #include <sys/elf_SPARC.h> 33 #include <alloca.h> 34 #include "_rtld.h" 35 #include "_elf.h" 36 #include "msg.h" 37 #include "conv.h" 38 39 /* 40 * 41 * Matrix of legal combinations of usage of a given register: 42 * 43 * Obj1\Obj2 Scratch Named 44 * Scratch OK NO 45 * Named NO * 46 * 47 * * OK if the symbols are identical, NO if they are not. Two symbols 48 * are identical if and only if one of the following is true: 49 * A. They are both global and have the same name. 50 * B. They are both local, have the same name, and are defined in 51 * the same object. (Note that a local symbol in one object is 52 * never identical to a local symbol in another object, even if the 53 * name is the same.) 54 * 55 * Matrix of legal combinations of st_shndx for the same register symbol: 56 * 57 * Obj1\Obj2 UNDEF ABS 58 * UNDEF OK OK 59 * ABS OK NO 60 */ 61 62 /* 63 * Test the compatiblity of two register symbols, 0 pass, >0 fail 64 */ 65 static uintptr_t 66 check_regsyms(Sym *sym1, const char *name1, Sym *sym2, const char *name2) 67 { 68 if ((sym1->st_name == 0) && (sym2->st_name == 0)) 69 return (0); /* scratches are always compatible */ 70 71 if ((ELF_ST_BIND(sym1->st_info) == STB_LOCAL) || 72 (ELF_ST_BIND(sym2->st_info) == STB_LOCAL)) { 73 if (sym1->st_value == sym2->st_value) 74 return (1); /* local symbol incompat */ 75 return (0); /* no other prob from locals */ 76 } 77 78 if (sym1->st_value == sym2->st_value) { 79 /* NOTE this just avoids strcmp */ 80 if ((sym1->st_name == 0) || (sym2->st_name == 0)) 81 return (2); /* can't match scratch to named */ 82 83 if (strcmp(name1, name2) != 0) 84 return (4); /* diff name, same register value */ 85 86 if ((sym1->st_shndx == SHN_ABS) && (sym2->st_shndx == SHN_ABS)) 87 return (3); /* multiply defined */ 88 } else if (strcmp(name1, name2) == 0) 89 return (5); /* same name, diff register value */ 90 91 return (0); 92 } 93 94 int 95 elf_regsyms(Rt_map * lmp) 96 { 97 Dyn * dyn; 98 Sym * symdef; 99 ulong_t rsymndx; 100 101 /* 102 * Scan through the .dynamic section of this object looking for all 103 * DT_REGISTER entries. For each DT_REGISTER entry found identify the 104 * register symbol it identifies and confirm that it doesn't conflict 105 * with any other register symbols. 106 */ 107 for (dyn = DYN(lmp); dyn->d_tag != DT_NULL; dyn++) { 108 Reglist * rp; 109 110 if ((dyn->d_tag != DT_SPARC_REGISTER) && 111 (dyn->d_tag != DT_DEPRECATED_SPARC_REGISTER)) 112 continue; 113 114 /* 115 * Get the local symbol table entry. 116 */ 117 rsymndx = dyn->d_un.d_val; 118 symdef = (Sym *)((unsigned long)SYMTAB(lmp) + 119 (rsymndx * SYMENT(lmp))); 120 121 for (rp = reglist; rp; rp = rp->rl_next) { 122 Conv_inv_buf_t inv_buf; 123 const char *str, *sym1, *sym2; 124 125 if (rp->rl_sym == symdef) { 126 /* 127 * Same symbol definition - everything is a-ok. 128 */ 129 return (1); 130 } 131 132 sym1 = (STRTAB(rp->rl_lmp) + rp->rl_sym->st_name); 133 sym2 = (STRTAB(lmp) + symdef->st_name); 134 135 if (check_regsyms(rp->rl_sym, sym1, symdef, sym2) == 0) 136 continue; 137 138 if ((str = demangle(sym1)) != sym1) { 139 char *_str = alloca(strlen(str) + 1); 140 (void) strcpy(_str, str); 141 sym1 = (const char *)_str; 142 } 143 sym2 = demangle(sym2); 144 145 if (LIST(lmp)->lm_flags & LML_FLG_TRC_WARN) { 146 (void) printf(MSG_INTL(MSG_LDD_REG_SYMCONF), 147 conv_sym_SPARC_value(symdef->st_value, 148 0, &inv_buf), NAME(rp->rl_lmp), 149 sym1, NAME(lmp), sym2); 150 } else { 151 eprintf(LIST(lmp), ERR_FATAL, 152 MSG_INTL(MSG_REG_SYMCONF), 153 conv_sym_SPARC_value(symdef->st_value, 154 0, &inv_buf), NAME(rp->rl_lmp), 155 sym1, NAME(lmp), sym2); 156 return (0); 157 } 158 } 159 if ((rp = calloc(sizeof (Reglist), 1)) == (Reglist *)0) 160 return (0); 161 rp->rl_lmp = lmp; 162 rp->rl_sym = symdef; 163 rp->rl_next = reglist; 164 reglist = rp; 165 } 166 return (1); 167 } 168 169 170 /* 171 * When the relocation loop realizes that it's dealing with relative 172 * relocations in a shared object, it breaks into this tighter loop 173 * as an optimization. 174 */ 175 ulong_t 176 elf_reloc_relative(ulong_t relbgn, ulong_t relend, ulong_t relsiz, 177 ulong_t basebgn, ulong_t etext, ulong_t emap) 178 { 179 ulong_t roffset = ((Rela *) relbgn)->r_offset; 180 Byte rtype; 181 182 do { 183 roffset += basebgn; 184 185 /* 186 * If this relocation is against an address not mapped in, 187 * then break out of the relative relocation loop, falling 188 * back on the main relocation loop. 189 */ 190 if (roffset < etext || roffset > emap) 191 break; 192 193 /* 194 * Perform the actual relocation. 195 */ 196 *((ulong_t *)roffset) += 197 basebgn + (long)(((Rela *)relbgn)->r_addend); 198 199 relbgn += relsiz; 200 201 if (relbgn >= relend) 202 break; 203 204 rtype = (Byte)ELF_R_TYPE(((Rela *)relbgn)->r_info, M_MACH); 205 roffset = ((Rela *)relbgn)->r_offset; 206 207 } while (rtype == R_SPARC_RELATIVE); 208 209 return (relbgn); 210 } 211 212 /* 213 * This is the tightest loop for RELATIVE relocations for those 214 * objects built with the DT_RELACOUNT .dynamic entry. 215 */ 216 ulong_t 217 elf_reloc_relacount(ulong_t relbgn, ulong_t relacount, ulong_t relsiz, 218 ulong_t basebgn) 219 { 220 ulong_t roffset = ((Rela *) relbgn)->r_offset; 221 222 for (; relacount; relacount--) { 223 roffset += basebgn; 224 225 /* 226 * Perform the actual relocation. 227 */ 228 *((ulong_t *)roffset) = 229 basebgn + (long)(((Rela *)relbgn)->r_addend); 230 231 relbgn += relsiz; 232 233 roffset = ((Rela *)relbgn)->r_offset; 234 } 235 236 return (relbgn); 237 } 238