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1 : : /* Return size of GNU compressed section. 2 : : Copyright (C) 2015 Red Hat, Inc. 3 : : This file is part of elfutils. 4 : : 5 : : This file is free software; you can redistribute it and/or modify 6 : : it under the terms of either 7 : : 8 : : * the GNU Lesser General Public License as published by the Free 9 : : Software Foundation; either version 3 of the License, or (at 10 : : your option) any later version 11 : : 12 : : or 13 : : 14 : : * the GNU General Public License as published by the Free 15 : : Software Foundation; either version 2 of the License, or (at 16 : : your option) any later version 17 : : 18 : : or both in parallel, as here. 19 : : 20 : : elfutils is distributed in the hope that it will be useful, but 21 : : WITHOUT ANY WARRANTY; without even the implied warranty of 22 : : MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 23 : : General Public License for more details. 24 : : 25 : : You should have received copies of the GNU General Public License and 26 : : the GNU Lesser General Public License along with this program. If 27 : : not, see <http://www.gnu.org/licenses/>. */ 28 : : 29 : : #ifdef HAVE_CONFIG_H 30 : : # include <config.h> 31 : : #endif 32 : : 33 : : #include "libdwelfP.h" 34 : : #include "libelfP.h" 35 : : 36 : : ssize_t 37 : 72 : dwelf_scn_gnu_compressed_size (Elf_Scn *scn) 38 : : { 39 [ - + ]: 72 : if (scn == NULL) 40 : : return -1; 41 : : 42 : 72 : GElf_Shdr shdr; 43 [ - + ]: 72 : if (gelf_getshdr (scn, &shdr) == NULL) 44 : : return -1; 45 : : 46 : : /* Allocated or no bits sections can never be compressed. */ 47 [ - + ]: 72 : if ((shdr.sh_flags & SHF_ALLOC) != 0 48 [ - + ]: 72 : || shdr.sh_type == SHT_NULL 49 [ - + ]: 72 : || shdr.sh_type == SHT_NOBITS) 50 : : return -1; 51 : : 52 : 72 : Elf_Data *d = elf_rawdata (scn, NULL); 53 [ - + ]: 72 : if (d == NULL) 54 : : return -1; 55 : : 56 [ - + ]: 72 : if (d->d_size >= 4 + 8 57 [ - + ]: 72 : && memcmp (d->d_buf, "ZLIB", 4) == 0) 58 : : { 59 : : /* There is a 12-byte header of "ZLIB" followed by 60 : : an 8-byte big-endian size. There is only one type and 61 : : alignment isn't preserved separately. */ 62 : 72 : uint64_t size; 63 [ + - ]: 72 : memcpy (&size, d->d_buf + 4, sizeof size); 64 [ + - ]: 72 : size = be64toh (size); 65 : : 66 : : /* One more sanity check, size should be bigger than original 67 : : data size plus some overhead (4 chars ZLIB + 8 bytes size + 6 68 : : bytes zlib stream overhead + 5 bytes overhead max for one 16K 69 : : block) and should fit into a size_t. */ 70 [ + - ]: 72 : if (size + 4 + 8 + 6 + 5 < d->d_size || size > SIZE_MAX) 71 : : return -1; 72 : : 73 : 72 : return size; 74 : : } 75 : : 76 : : return -1; 77 : : }