1 /* Return number of program headers in the ELF file. 2 Copyright (C) 2010, 2014, 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 <assert.h> 34 #include <gelf.h> 35 #include <stddef.h> 36 37 #include "libelfP.h" 38 39 40 int 41 internal_function 42 __elf_getphdrnum_rdlock (Elf *elf, size_t *dst) 43 { 44 if (unlikely (elf->state.elf64.ehdr == NULL)) 45 { 46 /* Maybe no ELF header was created yet. */ 47 __libelf_seterrno (ELF_E_WRONG_ORDER_EHDR); 48 return -1; 49 } 50 51 *dst = (elf->class == ELFCLASS32 52 ? elf->state.elf32.ehdr->e_phnum 53 : elf->state.elf64.ehdr->e_phnum); 54 55 if (*dst == PN_XNUM) 56 { 57 const Elf_ScnList *const scns = (elf->class == ELFCLASS32 58 ? &elf->state.elf32.scns 59 : &elf->state.elf64.scns); 60 61 /* If there are no section headers, perhaps this is really just 65536 62 written without PN_XNUM support. Either that or it's bad data. */ 63 64 if (elf->class == ELFCLASS32) 65 { 66 if (likely (scns->cnt > 0 67 && elf->state.elf32.scns.data[0].shdr.e32 != NULL)) 68 *dst = scns->data[0].shdr.e32->sh_info; 69 } 70 else 71 { 72 if (likely (scns->cnt > 0 73 && elf->state.elf64.scns.data[0].shdr.e64 != NULL)) 74 *dst = scns->data[0].shdr.e64->sh_info; 75 } 76 } 77 78 return 0; 79 } 80 81 int 82 internal_function 83 __elf_getphdrnum_chk_rdlock (Elf *elf, size_t *dst) 84 { 85 int result = __elf_getphdrnum_rdlock (elf, dst); 86 87 /* Do some sanity checking to make sure phnum and phoff are consistent. */ 88 Elf64_Off off = (elf->class == ELFCLASS32 89 ? elf->state.elf32.ehdr->e_phoff 90 : elf->state.elf64.ehdr->e_phoff); 91 if (unlikely (off == 0)) 92 { 93 *dst = 0; 94 return result; 95 } 96 97 if (unlikely (off >= elf->maximum_size)) 98 { 99 __libelf_seterrno (ELF_E_INVALID_DATA); 100 return -1; 101 } 102 103 /* Check for too many sections. */ 104 size_t phdr_size = (elf->class == ELFCLASS32 105 ? sizeof (Elf32_Phdr) : sizeof (Elf64_Phdr)); 106 if (unlikely (*dst > SIZE_MAX / phdr_size)) 107 { 108 __libelf_seterrno (ELF_E_INVALID_DATA); 109 return -1; 110 } 111 112 /* Truncated file? Don't return more than can be indexed. */ 113 if (unlikely (elf->maximum_size - off < *dst * phdr_size)) 114 *dst = (elf->maximum_size - off) / phdr_size; 115 116 return result; 117 } 118 119 int 120 elf_getphdrnum (Elf *elf, size_t *dst) 121 { 122 int result; 123 124 if (elf == NULL) 125 return -1; 126 127 if (unlikely (elf->kind != ELF_K_ELF)) 128 { 129 __libelf_seterrno (ELF_E_INVALID_HANDLE); 130 return -1; 131 } 132 133 rwlock_rdlock (elf->lock); 134 result = __elf_getphdrnum_chk_rdlock (elf, dst); 135 rwlock_unlock (elf->lock); 136 137 return result; 138 } 139
