1 /* Free resources associated with Elf descriptor. 2 Copyright (C) 1998,1999,2000,2001,2002,2004,2005,2007,2015,2016 Red Hat, Inc. 3 This file is part of elfutils. 4 Written by Ulrich Drepper <drepper (at) redhat.com>, 1998. 5 6 This file is free software; you can redistribute it and/or modify 7 it under the terms of either 8 9 * the GNU Lesser General Public License as published by the Free 10 Software Foundation; either version 3 of the License, or (at 11 your option) any later version 12 13 or 14 15 * the GNU General Public License as published by the Free 16 Software Foundation; either version 2 of the License, or (at 17 your option) any later version 18 19 or both in parallel, as here. 20 21 elfutils is distributed in the hope that it will be useful, but 22 WITHOUT ANY WARRANTY; without even the implied warranty of 23 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 24 General Public License for more details. 25 26 You should have received copies of the GNU General Public License and 27 the GNU Lesser General Public License along with this program. If 28 not, see <http://www.gnu.org/licenses/>. */ 29 30 #ifdef HAVE_CONFIG_H 31 # include <config.h> 32 #endif 33 34 #include <assert.h> 35 #include <stddef.h> 36 #include <stdlib.h> 37 #include <sys/mman.h> 38 39 #include "libelfP.h" 40 41 42 int 43 elf_end (Elf *elf) 44 { 45 Elf *parent; 46 47 if (elf == NULL) 48 /* This is allowed and is a no-op. */ 49 return 0; 50 51 /* Make sure we are alone. */ 52 rwlock_wrlock (elf->lock); 53 54 if (elf->ref_count != 0 && --elf->ref_count != 0) 55 { 56 /* Not yet the last activation. */ 57 int result = elf->ref_count; 58 rwlock_unlock (elf->lock); 59 return result; 60 } 61 62 if (elf->kind == ELF_K_AR) 63 { 64 /* We cannot remove the descriptor now since we still have some 65 descriptors which depend on it. But we can free the archive 66 symbol table since this is only available via the archive ELF 67 descriptor. The long name table cannot be freed yet since 68 the archive headers for the ELF files in the archive point 69 into this array. */ 70 if (elf->state.ar.ar_sym != (Elf_Arsym *) -1l) 71 free (elf->state.ar.ar_sym); 72 elf->state.ar.ar_sym = NULL; 73 74 if (elf->state.ar.children != NULL) 75 return 0; 76 } 77 78 /* Remove this structure from the children list. */ 79 parent = elf->parent; 80 if (parent != NULL) 81 { 82 /* This is tricky. Lock must be acquire from the father to 83 the child but here we already have the child lock. We 84 solve this problem by giving free the child lock. The 85 state of REF_COUNT==0 is handled all over the library, so 86 this should be ok. */ 87 rwlock_unlock (elf->lock); 88 rwlock_rdlock (parent->lock); 89 rwlock_wrlock (elf->lock); 90 91 if (parent->state.ar.children == elf) 92 parent->state.ar.children = elf->next; 93 else 94 { 95 struct Elf *child = parent->state.ar.children; 96 97 while (child->next != elf) 98 child = child->next; 99 100 child->next = elf->next; 101 } 102 103 rwlock_unlock (parent->lock); 104 } 105 106 /* This was the last activation. Free all resources. */ 107 switch (elf->kind) 108 { 109 case ELF_K_AR: 110 if (elf->state.ar.long_names != NULL) 111 free (elf->state.ar.long_names); 112 break; 113 114 case ELF_K_ELF: 115 { 116 Elf_Data_Chunk *rawchunks 117 = (elf->class == ELFCLASS32 118 || (offsetof (struct Elf, state.elf32.rawchunks) 119 == offsetof (struct Elf, state.elf64.rawchunks)) 120 ? elf->state.elf32.rawchunks 121 : elf->state.elf64.rawchunks); 122 while (rawchunks != NULL) 123 { 124 Elf_Data_Chunk *next = rawchunks->next; 125 if (rawchunks->dummy_scn.flags & ELF_F_MALLOCED) 126 free (rawchunks->data.d.d_buf); 127 free (rawchunks); 128 rawchunks = next; 129 } 130 131 Elf_ScnList *list = (elf->class == ELFCLASS32 132 || (offsetof (struct Elf, state.elf32.scns) 133 == offsetof (struct Elf, state.elf64.scns)) 134 ? &elf->state.elf32.scns 135 : &elf->state.elf64.scns); 136 137 do 138 { 139 /* Free all separately allocated section headers. */ 140 size_t cnt = list->max; 141 142 while (cnt-- > 0) 143 { 144 /* These pointers can be NULL; it's safe to use 145 'free' since it will check for this. */ 146 Elf_Scn *scn = &list->data[cnt]; 147 Elf_Data_List *runp; 148 149 if ((scn->shdr_flags & ELF_F_MALLOCED) != 0) 150 /* It doesn't matter which pointer. */ 151 free (scn->shdr.e32); 152 153 /* Free zdata if uncompressed, but not yet used as 154 rawdata_base. If it is already used it will be 155 freed below. */ 156 if (scn->zdata_base != scn->rawdata_base) 157 free (scn->zdata_base); 158 159 /* If the file has the same byte order and the 160 architecture doesn't require overly stringent 161 alignment the raw data buffer is the same as the 162 one used for presenting to the caller. */ 163 if (scn->data_base != scn->rawdata_base) 164 free (scn->data_base); 165 166 /* The section data is allocated if we couldn't mmap 167 the file. Or if we had to decompress. */ 168 if (elf->map_address == NULL 169 || scn->rawdata_base == scn->zdata_base 170 || (scn->flags & ELF_F_MALLOCED) != 0) 171 free (scn->rawdata_base); 172 173 /* Free the list of data buffers for the section. 174 We don't free the buffers themselves since this 175 is the users job. */ 176 runp = scn->data_list.next; 177 while (runp != NULL) 178 { 179 Elf_Data_List *oldp = runp; 180 runp = runp->next; 181 if ((oldp->flags & ELF_F_MALLOCED) != 0) 182 free (oldp); 183 } 184 } 185 186 /* Free the memory for the array. */ 187 Elf_ScnList *oldp = list; 188 list = list->next; 189 assert (list == NULL || oldp->cnt == oldp->max); 190 if (oldp != (elf->class == ELFCLASS32 191 || (offsetof (struct Elf, state.elf32.scns) 192 == offsetof (struct Elf, state.elf64.scns)) 193 ? &elf->state.elf32.scns 194 : &elf->state.elf64.scns)) 195 free (oldp); 196 } 197 while (list != NULL); 198 } 199 200 /* Free the section header. */ 201 if (elf->state.elf.shdr_malloced != 0) 202 free (elf->class == ELFCLASS32 203 || (offsetof (struct Elf, state.elf32.shdr) 204 == offsetof (struct Elf, state.elf64.shdr)) 205 ? (void *) elf->state.elf32.shdr 206 : (void *) elf->state.elf64.shdr); 207 208 /* Free the program header. */ 209 if ((elf->state.elf.phdr_flags & ELF_F_MALLOCED) != 0) 210 free (elf->class == ELFCLASS32 211 || (offsetof (struct Elf, state.elf32.phdr) 212 == offsetof (struct Elf, state.elf64.phdr)) 213 ? (void *) elf->state.elf32.phdr 214 : (void *) elf->state.elf64.phdr); 215 break; 216 217 default: 218 break; 219 } 220 221 if (elf->map_address != NULL && parent == NULL) 222 { 223 /* The file was read or mapped for this descriptor. */ 224 if ((elf->flags & ELF_F_MALLOCED) != 0) 225 free (elf->map_address); 226 else if ((elf->flags & ELF_F_MMAPPED) != 0) 227 munmap (elf->map_address, elf->maximum_size); 228 } 229 230 rwlock_unlock (elf->lock); 231 rwlock_fini (elf->lock); 232 233 /* Finally the descriptor itself. */ 234 free (elf); 235 236 return (parent != NULL && parent->ref_count == 0 237 ? INTUSE(elf_end) (parent) : 0); 238 } 239 INTDEF(elf_end) 240
