linux_exec_elf32.c revision 1.51.2.1
1 /* $NetBSD: linux_exec_elf32.c,v 1.51.2.1 2001/08/24 00:08:49 nathanw Exp $ */ 2 3 /*- 4 * Copyright (c) 1995, 1998, 2000, 2001 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Christos Zoulas, Frank van der Linden, Eric Haszlakiewicz and 9 * Emmanuel Dreyfus. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the NetBSD 22 * Foundation, Inc. and its contributors. 23 * 4. Neither the name of The NetBSD Foundation nor the names of its 24 * contributors may be used to endorse or promote products derived 25 * from this software without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 37 * POSSIBILITY OF SUCH DAMAGE. 38 */ 39 40 /* 41 * based on exec_aout.c, sunos_exec.c and svr4_exec.c 42 */ 43 44 #ifndef ELFSIZE 45 #define ELFSIZE 32 /* XXX should die */ 46 #endif 47 48 #include <sys/param.h> 49 #include <sys/systm.h> 50 #include <sys/kernel.h> 51 #include <sys/proc.h> 52 #include <sys/malloc.h> 53 #include <sys/namei.h> 54 #include <sys/vnode.h> 55 #include <sys/mount.h> 56 #include <sys/exec.h> 57 #include <sys/exec_elf.h> 58 59 #include <sys/mman.h> 60 #include <sys/syscallargs.h> 61 62 #include <machine/cpu.h> 63 #include <machine/reg.h> 64 65 #include <compat/linux/common/linux_types.h> 66 #include <compat/linux/common/linux_signal.h> 67 #include <compat/linux/common/linux_util.h> 68 #include <compat/linux/common/linux_exec.h> 69 #include <compat/linux/common/linux_machdep.h> 70 71 #include <compat/linux/linux_syscallargs.h> 72 #include <compat/linux/linux_syscall.h> 73 74 static int ELFNAME2(linux,signature) __P((struct proc *, struct exec_package *, 75 Elf_Ehdr *, char *)); 76 #ifdef LINUX_GCC_SIGNATURE 77 static int ELFNAME2(linux,gcc_signature) __P((struct proc *p, 78 struct exec_package *, Elf_Ehdr *)); 79 #endif 80 #ifdef LINUX_ATEXIT_SIGNATURE 81 static int ELFNAME2(linux,atexit_signature) __P((struct proc *p, 82 struct exec_package *, Elf_Ehdr *)); 83 #endif 84 85 #ifdef LINUX_ATEXIT_SIGNATURE 86 /* 87 * On the PowerPC, statically linked Linux binaries are not recognized 88 * by linux_signature nor by linux_gcc_signature. Fortunately, thoses 89 * binaries features a __libc_atexit ELF section. We therefore assume we 90 * have a Linux binary if we find this section. 91 */ 92 static int 93 ELFNAME2(linux,atexit_signature)(p, epp, eh) 94 struct proc *p; 95 struct exec_package *epp; 96 Elf_Ehdr *eh; 97 { 98 size_t shsize; 99 int strndx; 100 size_t i; 101 static const char signature[] = "__libc_atexit"; 102 char* strtable; 103 Elf_Shdr *sh; 104 105 int error; 106 107 /* 108 * load the section header table 109 */ 110 shsize = eh->e_shnum * sizeof(Elf_Shdr); 111 sh = (Elf_Shdr *) malloc(shsize, M_TEMP, M_WAITOK); 112 error = exec_read_from(p, epp->ep_vp, eh->e_shoff, sh, shsize); 113 if (error) 114 goto out; 115 116 /* 117 * Now let's find the string table. If it does not exists, give up. 118 */ 119 strndx = (int)(eh->e_shstrndx); 120 if (strndx == SHN_UNDEF) { 121 error = ENOEXEC; 122 goto out; 123 } 124 125 /* 126 * strndx is the index in section header table of the string table 127 * section get the whole string table in strtable, and then we get access to the names 128 * s->sh_name is the offset of the section name in strtable. 129 */ 130 strtable = malloc(sh[strndx].sh_size, M_TEMP, M_WAITOK); 131 error = exec_read_from(p, epp->ep_vp, sh[strndx].sh_offset, strtable, 132 sh[strndx].sh_size); 133 if (error) 134 goto out; 135 136 for (i = 0; i < eh->e_shnum; i++) { 137 Elf_Shdr *s = &sh[i]; 138 if (!memcmp((void*)(&(strtable[s->sh_name])), signature, 139 sizeof(signature))) { 140 #ifdef DEBUG_LINUX 141 printf("linux_atexit_sig=%s\n",&(strtable[s->sh_name])); 142 #endif 143 error = 0; 144 goto out; 145 } 146 } 147 error = ENOEXEC; 148 149 out: 150 free(sh, M_TEMP); 151 free(strtable, M_TEMP); 152 return (error); 153 } 154 #endif 155 156 #ifdef LINUX_GCC_SIGNATURE 157 /* 158 * Take advantage of the fact that all the linux binaries are compiled 159 * with gcc, and gcc sticks in the comment field a signature. Note that 160 * on SVR4 binaries, the gcc signature will follow the OS name signature, 161 * that will not be a problem. We don't bother to read in the string table, 162 * but we check all the progbits headers. 163 * 164 * XXX This only works in the i386. On the alpha (at least) 165 * XXX we have the same gcc signature which incorrectly identifies 166 * XXX NetBSD binaries as Linux. 167 */ 168 static int 169 ELFNAME2(linux,gcc_signature)(p, epp, eh) 170 struct proc *p; 171 struct exec_package *epp; 172 Elf_Ehdr *eh; 173 { 174 size_t shsize; 175 size_t i; 176 static const char signature[] = "\0GCC: (GNU) "; 177 char buf[sizeof(signature) - 1]; 178 Elf_Shdr *sh; 179 int error; 180 181 shsize = eh->e_shnum * sizeof(Elf_Shdr); 182 sh = (Elf_Shdr *) malloc(shsize, M_TEMP, M_WAITOK); 183 error = exec_read_from(p, epp->ep_vp, eh->e_shoff, sh, shsize); 184 if (error) 185 goto out; 186 187 for (i = 0; i < eh->e_shnum; i++) { 188 Elf_Shdr *s = &sh[i]; 189 190 /* 191 * Identify candidates for the comment header; 192 * Header cannot have a load address, or flags and 193 * it must be large enough. 194 */ 195 if (s->sh_type != SHT_PROGBITS || 196 s->sh_addr != 0 || 197 s->sh_flags != 0 || 198 s->sh_size < sizeof(signature) - 1) 199 continue; 200 201 error = exec_read_from(p, epp->ep_vp, s->sh_offset, buf, 202 sizeof(signature) - 1); 203 if (error) 204 continue; 205 206 /* 207 * error is 0, if the signatures match we are done. 208 */ 209 #ifdef DEBUG_LINUX 210 printf("linux_gcc_sig: sig=%s\n", buf); 211 #endif 212 if (!memcmp(buf, signature, sizeof(signature) - 1)) { 213 error = 0; 214 goto out; 215 } 216 } 217 error = ENOEXEC; 218 219 out: 220 free(sh, M_TEMP); 221 return (error); 222 } 223 #endif 224 225 static int 226 ELFNAME2(linux,signature)(p, epp, eh, itp) 227 struct proc *p; 228 struct exec_package *epp; 229 Elf_Ehdr *eh; 230 char *itp; 231 { 232 size_t i; 233 Elf_Phdr *ph; 234 size_t phsize; 235 int error; 236 237 phsize = eh->e_phnum * sizeof(Elf_Phdr); 238 ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK); 239 error = exec_read_from(p, epp->ep_vp, eh->e_phoff, ph, phsize); 240 if (error) 241 goto out; 242 243 for (i = 0; i < eh->e_phnum; i++) { 244 Elf_Phdr *ephp = &ph[i]; 245 Elf_Nhdr *np; 246 u_int32_t *abi; 247 248 if (ephp->p_type != PT_NOTE || 249 ephp->p_filesz > 1024 || 250 ephp->p_filesz < sizeof(Elf_Nhdr) + 20) 251 continue; 252 253 np = (Elf_Nhdr *)malloc(ephp->p_filesz, M_TEMP, M_WAITOK); 254 error = exec_read_from(p, epp->ep_vp, ephp->p_offset, np, 255 ephp->p_filesz); 256 if (error) 257 goto next; 258 259 if (np->n_type != ELF_NOTE_TYPE_ABI_TAG || 260 np->n_namesz != ELF_NOTE_ABI_NAMESZ || 261 np->n_descsz != ELF_NOTE_ABI_DESCSZ || 262 memcmp((caddr_t)(np + 1), ELF_NOTE_ABI_NAME, 263 ELF_NOTE_ABI_NAMESZ)) 264 goto next; 265 266 /* Make sure the OS is Linux. */ 267 abi = (u_int32_t *)((caddr_t)np + sizeof(Elf_Nhdr) + 268 np->n_namesz); 269 if (abi[0] == ELF_NOTE_ABI_OS_LINUX) 270 error = 0; 271 else 272 error = ENOEXEC; 273 free(np, M_TEMP); 274 goto out; 275 276 next: 277 free(np, M_TEMP); 278 continue; 279 } 280 281 /* Check for certain intepreter names. */ 282 if (itp[0]) { 283 if (!strncmp(itp, "/lib/ld-linux", 13) || 284 !strncmp(itp, "/lib/ld.so.", 11)) 285 error = 0; 286 else 287 error = ENOEXEC; 288 goto out; 289 } 290 291 error = ENOEXEC; 292 out: 293 free(ph, M_TEMP); 294 return (error); 295 } 296 297 int 298 ELFNAME2(linux,probe)(p, epp, eh, itp, pos) 299 struct proc *p; 300 struct exec_package *epp; 301 void *eh; 302 char *itp; 303 vaddr_t *pos; 304 { 305 const char *bp; 306 int error; 307 size_t len; 308 309 #ifdef LINUX_GCC_SIGNATURE 310 if ((error = ELFNAME2(linux,signature)(p, epp, eh, itp)) != 0) 311 if ((error = ELFNAME2(linux,gcc_signature)(p, epp, eh)) != 0) 312 return error; 313 #else 314 #ifdef LINUX_ATEXIT_SIGNATURE 315 if ((error = ELFNAME2(linux,signature)(p, epp, eh, itp)) != 0) 316 if ((error = ELFNAME2(linux,atexit_signature)(p, epp, eh)) != 0) 317 return error; 318 #else 319 if ((error = ELFNAME2(linux,signature)(p, epp, eh, itp)) != 0) 320 return error; 321 #endif 322 #endif 323 324 if (itp[0]) { 325 if ((error = emul_find(p, NULL, epp->ep_esch->es_emul->e_path, 326 itp, &bp, 0))) 327 return error; 328 if ((error = copystr(bp, itp, MAXPATHLEN, &len))) 329 return error; 330 free((void *)bp, M_TEMP); 331 } 332 *pos = ELF_NO_ADDR; 333 #ifdef DEBUG_LINUX 334 printf("linux_probe: returning 0\n"); 335 #endif 336 return 0; 337 } 338 339
Indexes created Mon Sep 22 13:09:51 GMT 2025