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) 2000, 2010, Oracle and/or its affiliates. All rights reserved. 24 */ 25 26 #include <stdio.h> 27 #include <string.h> 28 #include <link.h> 29 #include <debug.h> 30 #include "msg.h" 31 #include "_libld.h" 32 33 /* 34 * Determine whether a (COMDAT) group has already been encountered. If so, 35 * indicate that the group descriptor has an overriding group (gd_oisc). This 36 * indication triggers the ld_place_section() to discard this group, while the 37 * gd_oisc information provides for complete diagnostics of the override. 38 * Otherwise, this is the first occurrence of this group, therefore the group 39 * descriptor is saved for future comparisons. 40 */ 41 static uintptr_t 42 gpavl_loaded(Ofl_desc *ofl, Group_desc *gdp) 43 { 44 Isd_node isd, *isdp; 45 avl_tree_t *avlt; 46 avl_index_t where; 47 48 /* 49 * Create a groups avl tree if required. 50 */ 51 if ((avlt = ofl->ofl_groups) == NULL) { 52 if ((avlt = libld_calloc(sizeof (avl_tree_t), 1)) == NULL) 53 return (S_ERROR); 54 avl_create(avlt, isdavl_compare, sizeof (Isd_node), 55 SGSOFFSETOF(Isd_node, isd_avl)); 56 ofl->ofl_groups = avlt; 57 } 58 59 /* 60 * An SHT_GROUP section is identified by the name of its signature 61 * symbol rather than section name. Although the section names are 62 * often unique, this is not required, and some compilers set it to 63 * a generic name like ".group". 64 */ 65 isd.isd_name = gdp->gd_name; 66 isd.isd_hash = sgs_str_hash(isd.isd_name); 67 68 if ((isdp = avl_find(avlt, &isd, &where)) != NULL) { 69 gdp->gd_oisc = isdp->isd_isp; 70 return (1); 71 } 72 73 /* 74 * This is a new group - so keep it. 75 */ 76 if ((isdp = libld_calloc(sizeof (Isd_node), 1)) == NULL) 77 return (S_ERROR); 78 79 isdp->isd_name = isd.isd_name; 80 isdp->isd_hash = isd.isd_hash; 81 isdp->isd_isp = gdp->gd_isc; 82 83 avl_insert(avlt, isdp, where); 84 return (0); 85 } 86 87 Group_desc * 88 ld_get_group(Ofl_desc *ofl, Is_desc *isp) 89 { 90 Ifl_desc *ifl = isp->is_file; 91 uint_t scnndx = isp->is_scnndx; 92 Group_desc *gdp; 93 Aliste idx; 94 95 /* 96 * Scan the GROUP sections associated with this file to find the 97 * matching group section. 98 */ 99 for (ALIST_TRAVERSE(ifl->ifl_groups, idx, gdp)) { 100 size_t ndx; 101 Word *data; 102 103 if (isp->is_shdr->sh_type == SHT_GROUP) { 104 if (isp->is_scnndx == gdp->gd_isc->is_scnndx) 105 return (gdp); 106 continue; 107 } 108 109 data = gdp->gd_data; 110 for (ndx = 1; ndx < gdp->gd_cnt; ndx++) { 111 if (data[ndx] == scnndx) 112 return (gdp); 113 } 114 } 115 116 eprintf(ofl->ofl_lml, ERR_FATAL, MSG_INTL(MSG_ELF_NOGROUPSECT), 117 ifl->ifl_name, EC_WORD(isp->is_scnndx), isp->is_name); 118 ofl->ofl_flags |= FLG_OF_FATAL; 119 return (NULL); 120 } 121 122 uintptr_t 123 ld_group_process(Is_desc *gisc, Ofl_desc *ofl) 124 { 125 Ifl_desc *gifl = gisc->is_file; 126 Shdr *sshdr, *gshdr = gisc->is_shdr; 127 Is_desc *isc; 128 Sym *sym; 129 const char *str; 130 Group_desc gd; 131 size_t ndx; 132 int gnu_stt_section; 133 134 /* 135 * Confirm that the sh_link points to a valid section. 136 */ 137 if ((gshdr->sh_link == SHN_UNDEF) || 138 (gshdr->sh_link >= gifl->ifl_shnum) || 139 ((isc = gifl->ifl_isdesc[gshdr->sh_link]) == NULL)) { 140 eprintf(ofl->ofl_lml, ERR_FATAL, MSG_INTL(MSG_FIL_INVSHLINK), 141 gifl->ifl_name, EC_WORD(gisc->is_scnndx), 142 gisc->is_name, EC_XWORD(gshdr->sh_link)); 143 ofl->ofl_flags |= FLG_OF_FATAL; 144 return (0); 145 } 146 if (gshdr->sh_entsize == 0) { 147 eprintf(ofl->ofl_lml, ERR_FATAL, MSG_INTL(MSG_FIL_INVSHENTSIZE), 148 gifl->ifl_name, EC_WORD(gisc->is_scnndx), gisc->is_name, 149 EC_XWORD(gshdr->sh_entsize)); 150 ofl->ofl_flags |= FLG_OF_FATAL; 151 return (0); 152 } 153 154 /* 155 * Get the associated symbol table. Sanity check the sh_info field 156 * (which points to the signature symbol table entry) against the size 157 * of the symbol table. 158 */ 159 sshdr = isc->is_shdr; 160 sym = (Sym *)isc->is_indata->d_buf; 161 162 if ((sshdr->sh_info == SHN_UNDEF) || 163 (gshdr->sh_info >= (Word)(sshdr->sh_size / sshdr->sh_entsize)) || 164 ((isc = gifl->ifl_isdesc[sshdr->sh_link]) == NULL)) { 165 eprintf(ofl->ofl_lml, ERR_FATAL, MSG_INTL(MSG_FIL_INVSHINFO), 166 gifl->ifl_name, EC_WORD(gisc->is_scnndx), gisc->is_name, 167 EC_XWORD(gshdr->sh_info)); 168 ofl->ofl_flags |= FLG_OF_FATAL; 169 return (0); 170 } 171 172 sym += gshdr->sh_info; 173 174 /* 175 * Get the symbol name from the associated string table. 176 */ 177 str = (char *)isc->is_indata->d_buf; 178 str += sym->st_name; 179 180 /* 181 * The GNU assembler can use section symbols as the signature symbol 182 * as described by this comment in the gold linker (found via google): 183 * 184 * It seems that some versions of gas will create a section group 185 * associated with a section symbol, and then fail to give a name 186 * to the section symbol. In such a case, use the name of the 187 * section. 188 * 189 * In order to support such objects, we do the same. 190 */ 191 gnu_stt_section = ((sym->st_name == 0) || (*str == '\0')) && 192 (ELF_ST_TYPE(sym->st_info) == STT_SECTION); 193 if (gnu_stt_section) 194 str = gisc->is_name; 195 196 197 /* 198 * Generate a group descriptor. 199 */ 200 gd.gd_isc = gisc; 201 gd.gd_oisc = NULL; 202 gd.gd_name = str; 203 gd.gd_data = gisc->is_indata->d_buf; 204 gd.gd_cnt = gisc->is_indata->d_size / sizeof (Word); 205 206 /* 207 * If this group is a COMDAT group, validate the signature symbol. 208 */ 209 if ((gd.gd_data[0] & GRP_COMDAT) && !gnu_stt_section && 210 ((ELF_ST_BIND(sym->st_info) == STB_LOCAL) || 211 (sym->st_shndx == SHN_UNDEF))) { 212 /* If section symbol, construct a printable name for it */ 213 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION) { 214 if (gisc->is_sym_name == NULL) 215 (void) ld_stt_section_sym_name(gisc); 216 217 if (gisc->is_sym_name != NULL) 218 str = gisc->is_sym_name; 219 } 220 221 eprintf(ofl->ofl_lml, ERR_FATAL, MSG_INTL(MSG_GRP_INVALSYM), 222 gifl->ifl_name, EC_WORD(gisc->is_scnndx), 223 gisc->is_name, str); 224 ofl->ofl_flags |= FLG_OF_FATAL; 225 return (0); 226 } 227 228 /* 229 * Validate the section indices within the group. If this is a COMDAT 230 * group, mark each section as COMDAT. 231 */ 232 for (ndx = 1; ndx < gd.gd_cnt; ndx++) { 233 Word gndx; 234 235 if ((gndx = gd.gd_data[ndx]) >= gifl->ifl_shnum) { 236 eprintf(ofl->ofl_lml, ERR_FATAL, 237 MSG_INTL(MSG_GRP_INVALNDX), gifl->ifl_name, 238 EC_WORD(gisc->is_scnndx), gisc->is_name, ndx, gndx); 239 ofl->ofl_flags |= FLG_OF_FATAL; 240 return (0); 241 } 242 243 if (gd.gd_data[0] & GRP_COMDAT) 244 gifl->ifl_isdesc[gndx]->is_flags |= FLG_IS_COMDAT; 245 } 246 247 /* 248 * If this is a COMDAT group, determine whether this group has already 249 * been encountered, or whether this is the first instance of the group. 250 */ 251 if ((gd.gd_data[0] & GRP_COMDAT) && 252 (gpavl_loaded(ofl, &gd) == S_ERROR)) 253 return (S_ERROR); 254 255 /* 256 * Associate the group descriptor with this input file. 257 */ 258 if (alist_append(&(gifl->ifl_groups), &gd, sizeof (Group_desc), 259 AL_CNT_IFL_GROUPS) == NULL) 260 return (S_ERROR); 261 262 return (1); 263 } 264