elf.c revision 1.7.24.1
1 /* $NetBSD: elf.c,v 1.7.24.1 2009/01/15 23:20:02 bouyer Exp $ */ 2 3 /*- 4 * Copyright (c) 1998 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Leo Weppelman. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 #ifdef TOSTOOLS 40 #include <stdio.h> 41 #include <stdlib.h> 42 #include <unistd.h> 43 #include <string.h> 44 #include <sys/types.h> 45 #include "exec_elf.h" 46 47 #define MALLOC(x) malloc(x) 48 49 #else 50 51 #include <lib/libsa/stand.h> 52 #include <atari_stand.h> 53 #include <libkern.h> 54 #include <sys/exec_elf.h> 55 56 #define MALLOC(x) alloc(x) 57 #endif 58 59 #include "libtos.h" 60 #include "tosdefs.h" 61 #include "kparamb.h" 62 #include "cread.h" 63 64 /* 65 * Load an elf image. 66 * Exit codes: 67 * -1 : Not an ELF file. 68 * 0 : OK 69 * error# : Error during load (*errp might contain error string). 70 */ 71 #define ELFMAGIC ((ELFMAG0 << 24) | (ELFMAG1 << 16) | \ 72 (ELFMAG2 << 8) | ELFMAG3) 73 74 int 75 elf_load(fd, od, errp, loadsyms) 76 int fd; 77 osdsc_t *od; 78 char **errp; 79 int loadsyms; 80 { 81 int i,j; 82 int err; 83 Elf32_Ehdr ehdr; 84 Elf32_Phdr *phdrs; 85 Elf32_Word symsize, symstart; 86 long kernsize; 87 88 *errp = NULL; 89 lseek(fd, (off_t)0, SEEK_SET); 90 if (read(fd, (char *)&ehdr, sizeof(ehdr)) != sizeof(ehdr)) 91 return -1; 92 93 if (*((u_int *)ehdr.e_ident) != ELFMAGIC) 94 return -1; 95 96 /* 97 * calculate highest used address 98 */ 99 i = ehdr.e_phnum * sizeof(Elf32_Phdr); 100 err = 1; 101 if ((phdrs = (Elf32_Phdr *)MALLOC(i)) == NULL) 102 goto error; 103 err = 2; 104 if (read(fd, phdrs, i) != i) 105 goto error; 106 107 kernsize = 0; 108 for (i = 0; i < ehdr.e_phnum; i++) { 109 Elf32_Word sum; 110 111 sum = phdrs[i].p_vaddr + phdrs[i].p_memsz; 112 if ((phdrs[i].p_flags & (PF_W|PF_X)) && (sum > kernsize)) 113 kernsize = sum; 114 } 115 116 /* 117 * look for symbols and calculate the size 118 * XXX: This increases the load time by a factor 2 for gzipped 119 * images! 120 */ 121 symsize = 0; 122 symstart = 0; 123 if (loadsyms) { 124 i = ehdr.e_shnum + 1; 125 err = 3; 126 if (lseek(fd, (off_t)ehdr.e_shoff, SEEK_SET) != ehdr.e_shoff) 127 goto error; 128 while (--i) { 129 Elf32_Shdr shdr; 130 131 err = 4; 132 if (read(fd, &shdr, sizeof(shdr)) != sizeof(shdr)) 133 goto error; 134 if ((shdr.sh_type == SHT_SYMTAB) || (shdr.sh_type == SHT_STRTAB)) 135 symsize += shdr.sh_size; 136 } 137 } 138 139 if (symsize) { 140 symstart = kernsize; 141 kernsize += symsize + sizeof(ehdr) + ehdr.e_shnum*sizeof(Elf32_Shdr); 142 } 143 144 /* 145 * Extract various sizes from the kernel executable 146 */ 147 od->k_esym = symsize ? kernsize : 0; 148 od->ksize = kernsize; 149 od->kentry = ehdr.e_entry; 150 151 err = 5; 152 if ((od->kstart = (u_char *)MALLOC(od->ksize)) == NULL) 153 goto error; 154 155 /* 156 * Read text & data, clear bss 157 */ 158 for (i = 0; i < ehdr.e_phnum; i++) { 159 u_char *p; 160 Elf32_Phdr *php = &phdrs[i]; 161 162 if (php->p_flags & (PF_W|PF_X)) { 163 err = 6; 164 if (lseek(fd, (off_t)php->p_offset, SEEK_SET) != php->p_offset) 165 goto error; 166 p = (u_char *)(od->kstart) + php->p_vaddr; 167 err = 7; 168 if (read(fd, p, php->p_filesz) != php->p_filesz) 169 goto error; 170 if (php->p_memsz > php->p_filesz) 171 bzero(p + php->p_filesz, php->p_memsz - php->p_filesz); 172 } 173 } 174 175 /* 176 * Read symbols and strings 177 */ 178 if (symsize) { 179 u_char *p, *symtab; 180 int nhdrs; 181 Elf32_Shdr *shp; 182 183 symtab = od->kstart + symstart; 184 185 p = symtab + sizeof(ehdr); 186 nhdrs = ehdr.e_shnum; 187 err = 8; 188 if (lseek(fd, (off_t)ehdr.e_shoff, SEEK_SET) != ehdr.e_shoff) 189 goto error; 190 err = 9; 191 if (read(fd, p, nhdrs * sizeof(*shp)) != nhdrs * sizeof(*shp)) 192 goto error; 193 shp = (Elf32_Shdr*)p; 194 p += nhdrs * sizeof(*shp); 195 for (i = 0; i < nhdrs; i++) { 196 if (shp[i].sh_type == SHT_SYMTAB) { 197 if (shp[i].sh_offset == 0) 198 continue; 199 /* Got the symbol table. */ 200 err = 10; 201 if (lseek(fd, (off_t)shp[i].sh_offset, SEEK_SET) != 202 shp[i].sh_offset) 203 goto error; 204 err = 11; 205 if (read(fd, p, shp[i].sh_size) != shp[i].sh_size) 206 goto error; 207 shp[i].sh_offset = p - symtab; 208 /* Find the string table to go with it. */ 209 j = shp[i].sh_link; 210 if (shp[j].sh_offset == 0) 211 continue; 212 p += shp[i].sh_size; 213 err = 12; 214 if (lseek(fd, (off_t)shp[j].sh_offset, SEEK_SET) != 215 shp[j].sh_offset) 216 goto error; 217 err = 13; 218 if (read(fd, p, shp[j].sh_size) != shp[j].sh_size) 219 goto error; 220 shp[j].sh_offset = p - symtab; 221 /* There should only be one symbol table. */ 222 break; 223 } 224 } 225 ehdr.e_shoff = sizeof(ehdr); 226 bcopy(&ehdr, symtab, sizeof(ehdr)); 227 } 228 return 0; 229 230 error: 231 #ifdef TOSTOOLS 232 { 233 static char *errs[] = { 234 /* 1 */ "Cannot malloc Elf phdr storage space", 235 /* 2 */ "Cannot read Elf32_Phdrs", 236 /* 3 */ "Cannot seek to e_shoff location", 237 /* 4 */ "Cannot read Elf32_shdr", 238 /* 5 */ "Cannot malloc kernel image space", 239 /* 6 */ "Seek error while reading text segment\n", 240 /* 7 */ "Read error in text segment\n", 241 /* 8 */ "Error seeking to section headers", 242 /* 9 */ "Error reading section headers", 243 /* 10 */ "Error seeking to symbols", 244 /* 11 */ "Error reading symbols", 245 /* 12 */ "Error seeking to string table", 246 /* 13 */ "Error reading strings" 247 }; 248 *errp = errs[err]; 249 } 250 #endif /* TOSTOOLS */ 251 252 return err; 253 } 254
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