linux_exec_elf32.c revision 1.51.2.7
1 /* $NetBSD: linux_exec_elf32.c,v 1.51.2.7 2002/09/17 21:19:01 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 #include <sys/cdefs.h> 45 __KERNEL_RCSID(0, "$NetBSD: linux_exec_elf32.c,v 1.51.2.7 2002/09/17 21:19:01 nathanw Exp $"); 46 47 #ifndef ELFSIZE 48 #define ELFSIZE 32 /* XXX should die */ 49 #endif 50 51 #include <sys/param.h> 52 #include <sys/systm.h> 53 #include <sys/kernel.h> 54 #include <sys/proc.h> 55 #include <sys/malloc.h> 56 #include <sys/namei.h> 57 #include <sys/vnode.h> 58 #include <sys/mount.h> 59 #include <sys/exec.h> 60 #include <sys/exec_elf.h> 61 62 #include <sys/mman.h> 63 #include <sys/sa.h> 64 #include <sys/syscallargs.h> 65 66 #include <machine/cpu.h> 67 #include <machine/reg.h> 68 69 #include <compat/linux/common/linux_types.h> 70 #include <compat/linux/common/linux_signal.h> 71 #include <compat/linux/common/linux_util.h> 72 #include <compat/linux/common/linux_exec.h> 73 #include <compat/linux/common/linux_machdep.h> 74 75 #include <compat/linux/linux_syscallargs.h> 76 #include <compat/linux/linux_syscall.h> 77 78 static int ELFNAME2(linux,signature) __P((struct proc *, struct exec_package *, 79 Elf_Ehdr *, char *)); 80 #ifdef LINUX_GCC_SIGNATURE 81 static int ELFNAME2(linux,gcc_signature) __P((struct proc *p, 82 struct exec_package *, Elf_Ehdr *)); 83 #endif 84 #ifdef LINUX_ATEXIT_SIGNATURE 85 static int ELFNAME2(linux,atexit_signature) __P((struct proc *p, 86 struct exec_package *, Elf_Ehdr *)); 87 #endif 88 89 #ifdef DEBUG_LINUX 90 #define DPRINTF(a) uprintf a 91 #else 92 #define DPRINTF(a) 93 #endif 94 95 #ifdef LINUX_ATEXIT_SIGNATURE 96 /* 97 * On the PowerPC, statically linked Linux binaries are not recognized 98 * by linux_signature nor by linux_gcc_signature. Fortunately, thoses 99 * binaries features a __libc_atexit ELF section. We therefore assume we 100 * have a Linux binary if we find this section. 101 */ 102 static int 103 ELFNAME2(linux,atexit_signature)(p, epp, eh) 104 struct proc *p; 105 struct exec_package *epp; 106 Elf_Ehdr *eh; 107 { 108 size_t shsize; 109 int strndx; 110 size_t i; 111 static const char signature[] = "__libc_atexit"; 112 char* strtable; 113 Elf_Shdr *sh; 114 115 int error; 116 117 /* 118 * load the section header table 119 */ 120 shsize = eh->e_shnum * sizeof(Elf_Shdr); 121 sh = (Elf_Shdr *) malloc(shsize, M_TEMP, M_WAITOK); 122 error = exec_read_from(p, epp->ep_vp, eh->e_shoff, sh, shsize); 123 if (error) 124 goto out; 125 126 /* 127 * Now let's find the string table. If it does not exists, give up. 128 */ 129 strndx = (int)(eh->e_shstrndx); 130 if (strndx == SHN_UNDEF) { 131 error = ENOEXEC; 132 goto out; 133 } 134 135 /* 136 * strndx is the index in section header table of the string table 137 * section get the whole string table in strtable, and then we get access to the names 138 * s->sh_name is the offset of the section name in strtable. 139 */ 140 strtable = malloc(sh[strndx].sh_size, M_TEMP, M_WAITOK); 141 error = exec_read_from(p, epp->ep_vp, sh[strndx].sh_offset, strtable, 142 sh[strndx].sh_size); 143 if (error) 144 goto out; 145 146 for (i = 0; i < eh->e_shnum; i++) { 147 Elf_Shdr *s = &sh[i]; 148 if (!memcmp((void*)(&(strtable[s->sh_name])), signature, 149 sizeof(signature))) { 150 DPRINTF(("linux_atexit_sig=%s\n", 151 &(strtable[s->sh_name]))); 152 error = 0; 153 goto out; 154 } 155 } 156 error = ENOEXEC; 157 158 out: 159 free(sh, M_TEMP); 160 free(strtable, M_TEMP); 161 return (error); 162 } 163 #endif 164 165 #ifdef LINUX_GCC_SIGNATURE 166 /* 167 * Take advantage of the fact that all the linux binaries are compiled 168 * with gcc, and gcc sticks in the comment field a signature. Note that 169 * on SVR4 binaries, the gcc signature will follow the OS name signature, 170 * that will not be a problem. We don't bother to read in the string table, 171 * but we check all the progbits headers. 172 * 173 * XXX This only works in the i386. On the alpha (at least) 174 * XXX we have the same gcc signature which incorrectly identifies 175 * XXX NetBSD binaries as Linux. 176 */ 177 static int 178 ELFNAME2(linux,gcc_signature)(p, epp, eh) 179 struct proc *p; 180 struct exec_package *epp; 181 Elf_Ehdr *eh; 182 { 183 size_t shsize; 184 size_t i; 185 static const char signature[] = "\0GCC: (GNU) "; 186 char buf[sizeof(signature) - 1]; 187 Elf_Shdr *sh; 188 int error; 189 190 shsize = eh->e_shnum * sizeof(Elf_Shdr); 191 sh = (Elf_Shdr *) malloc(shsize, M_TEMP, M_WAITOK); 192 error = exec_read_from(p, epp->ep_vp, eh->e_shoff, sh, shsize); 193 if (error) 194 goto out; 195 196 for (i = 0; i < eh->e_shnum; i++) { 197 Elf_Shdr *s = &sh[i]; 198 199 /* 200 * Identify candidates for the comment header; 201 * Header cannot have a load address, or flags and 202 * it must be large enough. 203 */ 204 if (s->sh_type != SHT_PROGBITS || 205 s->sh_addr != 0 || 206 s->sh_flags != 0 || 207 s->sh_size < sizeof(signature) - 1) 208 continue; 209 210 error = exec_read_from(p, epp->ep_vp, s->sh_offset, buf, 211 sizeof(signature) - 1); 212 if (error) 213 continue; 214 215 /* 216 * error is 0, if the signatures match we are done. 217 */ 218 DPRINTF(("linux_gcc_sig: sig=%s\n", buf)); 219 if (!memcmp(buf, signature, sizeof(signature) - 1)) { 220 error = 0; 221 goto out; 222 } 223 } 224 error = ENOEXEC; 225 226 out: 227 free(sh, M_TEMP); 228 return (error); 229 } 230 #endif 231 232 static int 233 ELFNAME2(linux,signature)(p, epp, eh, itp) 234 struct proc *p; 235 struct exec_package *epp; 236 Elf_Ehdr *eh; 237 char *itp; 238 { 239 size_t i; 240 Elf_Phdr *ph; 241 size_t phsize; 242 int error; 243 static const char linux[] = "Linux"; 244 245 if (eh->e_ident[EI_OSABI] == 3 || 246 memcmp(&eh->e_ident[EI_ABIVERSION], linux, sizeof(linux)) == 0) 247 return 0; 248 249 phsize = eh->e_phnum * sizeof(Elf_Phdr); 250 ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK); 251 error = exec_read_from(p, epp->ep_vp, eh->e_phoff, ph, phsize); 252 if (error) 253 goto out; 254 255 for (i = 0; i < eh->e_phnum; i++) { 256 Elf_Phdr *ephp = &ph[i]; 257 Elf_Nhdr *np; 258 u_int32_t *abi; 259 260 if (ephp->p_type != PT_NOTE || 261 ephp->p_filesz > 1024 || 262 ephp->p_filesz < sizeof(Elf_Nhdr) + 20) 263 continue; 264 265 np = (Elf_Nhdr *)malloc(ephp->p_filesz, M_TEMP, M_WAITOK); 266 error = exec_read_from(p, epp->ep_vp, ephp->p_offset, np, 267 ephp->p_filesz); 268 if (error) 269 goto next; 270 271 if (np->n_type != ELF_NOTE_TYPE_ABI_TAG || 272 np->n_namesz != ELF_NOTE_ABI_NAMESZ || 273 np->n_descsz != ELF_NOTE_ABI_DESCSZ || 274 memcmp((caddr_t)(np + 1), ELF_NOTE_ABI_NAME, 275 ELF_NOTE_ABI_NAMESZ)) 276 goto next; 277 278 /* Make sure the OS is Linux. */ 279 abi = (u_int32_t *)((caddr_t)np + sizeof(Elf_Nhdr) + 280 np->n_namesz); 281 if (abi[0] == ELF_NOTE_ABI_OS_LINUX) 282 error = 0; 283 else 284 error = ENOEXEC; 285 free(np, M_TEMP); 286 goto out; 287 288 next: 289 free(np, M_TEMP); 290 continue; 291 } 292 293 /* Check for certain intepreter names. */ 294 if (itp[0]) { 295 if (!strncmp(itp, "/lib/ld-linux", 13) || 296 !strncmp(itp, "/lib/ld.so.", 11)) 297 error = 0; 298 else 299 error = ENOEXEC; 300 goto out; 301 } 302 303 error = ENOEXEC; 304 out: 305 free(ph, M_TEMP); 306 return (error); 307 } 308 309 int 310 ELFNAME2(linux,probe)(p, epp, eh, itp, pos) 311 struct proc *p; 312 struct exec_package *epp; 313 void *eh; 314 char *itp; 315 vaddr_t *pos; 316 { 317 const char *bp; 318 int error; 319 size_t len; 320 321 if (((error = ELFNAME2(linux,signature)(p, epp, eh, itp)) != 0) && 322 #ifdef LINUX_GCC_SIGNATURE 323 ((error = ELFNAME2(linux,gcc_signature)(p, epp, eh)) != 0) && 324 #endif 325 #ifdef LINUX_ATEXIT_SIGNATURE 326 ((error = ELFNAME2(linux,atexit_signature)(p, epp, eh)) != 0) && 327 #endif 328 1) 329 return error; 330 331 if (itp[0]) { 332 if ((error = emul_find(p, NULL, epp->ep_esch->es_emul->e_path, 333 itp, &bp, 0))) 334 return error; 335 if ((error = copystr(bp, itp, MAXPATHLEN, &len))) 336 return error; 337 free((void *)bp, M_TEMP); 338 } 339 *pos = ELF_NO_ADDR; 340 DPRINTF(("linux_probe: returning 0\n")); 341 return 0; 342 } 343 344
Indexes created Mon Sep 22 13:09:51 GMT 2025