1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/libexec/lib/src/elf.cc Wed May 11 17:23:11 2022 +0200
1.3 @@ -0,0 +1,158 @@
1.4 +/*
1.5 + * ELF payload decoding support.
1.6 + *
1.7 + * Copyright (C) 2022 Paul Boddie <paul@boddie.org.uk>
1.8 + *
1.9 + * This program is free software; you can redistribute it and/or
1.10 + * modify it under the terms of the GNU General Public License as
1.11 + * published by the Free Software Foundation; either version 2 of
1.12 + * the License, or (at your option) any later version.
1.13 + *
1.14 + * This program is distributed in the hope that it will be useful,
1.15 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
1.16 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
1.17 + * GNU General Public License for more details.
1.18 + *
1.19 + * You should have received a copy of the GNU General Public License
1.20 + * along with this program; if not, write to the Free Software
1.21 + * Foundation, Inc., 51 Franklin Street, Fifth Floor,
1.22 + * Boston, MA 02110-1301, USA
1.23 + */
1.24 +
1.25 +#include <l4/util/elf.h>
1.26 +
1.27 +#include "elf.h"
1.28 +
1.29 +
1.30 +
1.31 +/* Generic segment creation from program segments. */
1.32 +
1.33 +Segment *ProgramSegment::segment()
1.34 +{
1.35 + return new Segment(
1.36 + region_address(),
1.37 + region_size(),
1.38 + region_flags(),
1.39 + file_offset(),
1.40 + file_contents());
1.41 +}
1.42 +
1.43 +
1.44 +
1.45 +/* Program segment construction for 32- or 64-bit variants. */
1.46 +
1.47 +template <typename PROGRAM_HEADER>
1.48 +ProgramSegmentVariant<PROGRAM_HEADER>::ProgramSegmentVariant(PROGRAM_HEADER *header)
1.49 +: _header(header)
1.50 +{
1.51 +}
1.52 +
1.53 +template <typename PROGRAM_HEADER>
1.54 +bool ProgramSegmentVariant<PROGRAM_HEADER>::loadable()
1.55 +{
1.56 + return _header->p_type == PT_LOAD;
1.57 +}
1.58 +
1.59 +template <typename PROGRAM_HEADER>
1.60 +offset_t ProgramSegmentVariant<PROGRAM_HEADER>::file_contents()
1.61 +{
1.62 + return _header->p_filesz;
1.63 +}
1.64 +
1.65 +template <typename PROGRAM_HEADER>
1.66 +offset_t ProgramSegmentVariant<PROGRAM_HEADER>::file_offset()
1.67 +{
1.68 + return _header->p_offset;
1.69 +}
1.70 +
1.71 +template <typename PROGRAM_HEADER>
1.72 +l4_addr_t ProgramSegmentVariant<PROGRAM_HEADER>::region_address()
1.73 +{
1.74 + return _header->p_vaddr;
1.75 +}
1.76 +
1.77 +template <typename PROGRAM_HEADER>
1.78 +offset_t ProgramSegmentVariant<PROGRAM_HEADER>::region_size()
1.79 +{
1.80 + return _header->p_memsz;
1.81 +}
1.82 +
1.83 +template <typename PROGRAM_HEADER>
1.84 +l4re_rm_flags_t ProgramSegmentVariant<PROGRAM_HEADER>::region_flags()
1.85 +{
1.86 + l4re_rm_flags_t flags = 0;
1.87 +
1.88 + if (_header->p_flags & PF_R)
1.89 + flags |= L4RE_RM_F_R;
1.90 + if (_header->p_flags & PF_W)
1.91 + flags |= L4RE_RM_F_W;
1.92 + if (_header->p_flags & PF_X)
1.93 + flags |= L4RE_RM_F_X;
1.94 +
1.95 + return flags;
1.96 +}
1.97 +
1.98 +
1.99 +
1.100 +/* ELF payload construction for 32- or 64-bit variants. */
1.101 +
1.102 +template <typename HEADER, typename PROGRAM_HEADER>
1.103 +PayloadVariant<HEADER, PROGRAM_HEADER>::PayloadVariant(HEADER *header)
1.104 +: _header(header)
1.105 +{
1.106 +}
1.107 +
1.108 +template <typename HEADER, typename PROGRAM_HEADER>
1.109 +l4_addr_t PayloadVariant<HEADER, PROGRAM_HEADER>::entry_point()
1.110 +{
1.111 + return _header->e_entry;
1.112 +}
1.113 +
1.114 +template <typename HEADER, typename PROGRAM_HEADER>
1.115 +offset_t PayloadVariant<HEADER, PROGRAM_HEADER>::header_extent()
1.116 +{
1.117 + return sizeof(HEADER);
1.118 +}
1.119 +
1.120 +template <typename HEADER, typename PROGRAM_HEADER>
1.121 +offset_t PayloadVariant<HEADER, PROGRAM_HEADER>::program_header_extent()
1.122 +{
1.123 + return _header->e_phoff + _header->e_phentsize * _header->e_phnum;
1.124 +}
1.125 +
1.126 +template <typename HEADER, typename PROGRAM_HEADER>
1.127 +unsigned int PayloadVariant<HEADER, PROGRAM_HEADER>::segments()
1.128 +{
1.129 + return _header->e_phnum;
1.130 +}
1.131 +
1.132 +template <typename HEADER, typename PROGRAM_HEADER>
1.133 +ProgramSegment *PayloadVariant<HEADER, PROGRAM_HEADER>::segment(unsigned int i)
1.134 +{
1.135 + if (i >= segments())
1.136 + return NULL;
1.137 +
1.138 + return new ProgramSegmentVariant<PROGRAM_HEADER>(
1.139 + (PROGRAM_HEADER *) ((char *) _header + _header->e_phoff +
1.140 + _header->e_phentsize * i));
1.141 +}
1.142 +
1.143 +
1.144 +
1.145 +/* Return the appropriate payload object. */
1.146 +
1.147 +Payload *get_payload(char *buf)
1.148 +{
1.149 + switch (buf[EI_CLASS])
1.150 + {
1.151 + case (char) 1:
1.152 + return new PayloadVariant<Elf32_Ehdr, Elf32_Phdr>((Elf32_Ehdr *) buf);
1.153 + case (char) 2:
1.154 + return new PayloadVariant<Elf64_Ehdr, Elf64_Phdr>((Elf64_Ehdr *) buf);
1.155 + default:
1.156 + return NULL;
1.157 + }
1.158 +}
1.159 +
1.160 +/* vim: tabstop=2 expandtab shiftwidth=2
1.161 +*/