1 /* Free resources associated with Elf descriptor. 2 Copyright (C) 1998,1999,2000,2001,2002,2004,2005,2007,2015 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 free (scn->rawdata_base); 171 172 /* Free the list of data buffers for the section. 173 We don't free the buffers themselves since this 174 is the users job. */ 175 runp = scn->data_list.next; 176 while (runp != NULL) 177 { 178 Elf_Data_List *oldp = runp; 179 runp = runp->next; 180 if ((oldp->flags & ELF_F_MALLOCED) != 0) 181 free (oldp); 182 } 183 } 184 185 /* Free the memory for the array. */ 186 Elf_ScnList *oldp = list; 187 list = list->next; 188 assert (list == NULL || oldp->cnt == oldp->max); 189 if (oldp != (elf->class == ELFCLASS32 190 || (offsetof (struct Elf, state.elf32.scns) 191 == offsetof (struct Elf, state.elf64.scns)) 192 ? &elf->state.elf32.scns 193 : &elf->state.elf64.scns)) 194 free (oldp); 195 } 196 while (list != NULL); 197 } 198 199 /* Free the section header. */ 200 if (elf->state.elf.shdr_malloced != 0) 201 free (elf->class == ELFCLASS32 202 || (offsetof (struct Elf, state.elf32.shdr) 203 == offsetof (struct Elf, state.elf64.shdr)) 204 ? (void *) elf->state.elf32.shdr 205 : (void *) elf->state.elf64.shdr); 206 207 /* Free the program header. */ 208 if ((elf->state.elf.phdr_flags & ELF_F_MALLOCED) != 0) 209 free (elf->class == ELFCLASS32 210 || (offsetof (struct Elf, state.elf32.phdr) 211 == offsetof (struct Elf, state.elf64.phdr)) 212 ? (void *) elf->state.elf32.phdr 213 : (void *) elf->state.elf64.phdr); 214 break; 215 216 default: 217 break; 218 } 219 220 if (elf->map_address != NULL && parent == NULL) 221 { 222 /* The file was read or mapped for this descriptor. */ 223 if ((elf->flags & ELF_F_MALLOCED) != 0) 224 free (elf->map_address); 225 else if ((elf->flags & ELF_F_MMAPPED) != 0) 226 munmap (elf->map_address, elf->maximum_size); 227 } 228 229 rwlock_unlock (elf->lock); 230 rwlock_fini (elf->lock); 231 232 /* Finally the descriptor itself. */ 233 free (elf); 234 235 return (parent != NULL && parent->ref_count == 0 236 ? INTUSE(elf_end) (parent) : 0); 237 } 238 INTDEF(elf_end) 239
