1 /* $NetBSD: linux_exec_elf32.c,v 1.45 2000/06/29 02:40:39 mrg Exp $ */ 2 3 /*- 4 * Copyright (c) 1995, 1998 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 and Eric Haszlakiewicz. 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 /* 40 * based on exec_aout.c, sunos_exec.c and svr4_exec.c 41 */ 42 43 #ifndef ELFSIZE 44 #define ELFSIZE 32 /* XXX should die */ 45 #endif 46 47 #include <sys/param.h> 48 #include <sys/systm.h> 49 #include <sys/kernel.h> 50 #include <sys/proc.h> 51 #include <sys/malloc.h> 52 #include <sys/namei.h> 53 #include <sys/vnode.h> 54 #include <sys/mount.h> 55 #include <sys/exec.h> 56 #include <sys/exec_elf.h> 57 58 #include <sys/mman.h> 59 #include <sys/syscallargs.h> 60 61 #include <machine/cpu.h> 62 #include <machine/reg.h> 63 64 #include <compat/linux/common/linux_types.h> 65 #include <compat/linux/common/linux_signal.h> 66 #include <compat/linux/common/linux_util.h> 67 #include <compat/linux/common/linux_exec.h> 68 #include <compat/linux/common/linux_machdep.h> 69 #include <compat/linux/common/linux_errno.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 *)); 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 81 #define LINUX_ELF_AUX_ARGSIZ howmany(sizeof(AuxInfo) * 8, sizeof(char *)) 82 83 84 extern char linux_sigcode[], linux_esigcode[]; 85 extern struct sysent linux_sysent[]; 86 extern char *linux_syscallnames[]; 87 88 struct emul ELFNAMEEND(emul_linux) = { 89 "linux", 90 native_to_linux_errno, 91 linux_sendsig, 92 LINUX_SYS_syscall, 93 LINUX_SYS_MAXSYSCALL, 94 linux_sysent, 95 linux_syscallnames, 96 LINUX_ELF_AUX_ARGSIZ, 97 ELFNAME(copyargs), 98 linux_setregs, 99 linux_sigcode, 100 linux_esigcode, 101 }; 102 103 104 #ifdef LINUX_GCC_SIGNATURE 105 /* 106 * Take advantage of the fact that all the linux binaries are compiled 107 * with gcc, and gcc sticks in the comment field a signature. Note that 108 * on SVR4 binaries, the gcc signature will follow the OS name signature, 109 * that will not be a problem. We don't bother to read in the string table, 110 * but we check all the progbits headers. 111 * 112 * XXX This only works in the i386. On the alpha (at least) 113 * XXX we have the same gcc signature which incorrectly identifies 114 * XXX NetBSD binaries as Linux. 115 */ 116 static int 117 ELFNAME2(linux,gcc_signature)(p, epp, eh) 118 struct proc *p; 119 struct exec_package *epp; 120 Elf_Ehdr *eh; 121 { 122 size_t shsize = sizeof(Elf_Shdr) * eh->e_shnum; 123 size_t i; 124 static const char signature[] = "\0GCC: (GNU) "; 125 char buf[sizeof(signature) - 1]; 126 Elf_Shdr *sh; 127 int error; 128 129 error = ENOEXEC; 130 sh = (Elf_Shdr *) malloc(shsize, M_TEMP, M_WAITOK); 131 132 if ((error = ELFNAME(read_from)(p, epp->ep_vp, eh->e_shoff, 133 (caddr_t) sh, shsize)) != 0) 134 goto out; 135 136 for (i = 0; i < eh->e_shnum; i++) { 137 Elf_Shdr *s = &sh[i]; 138 139 /* 140 * Identify candidates for the comment header; 141 * Header cannot have a load address, or flags and 142 * it must be large enough. 143 */ 144 if (s->sh_type != SHT_PROGBITS || 145 s->sh_addr != 0 || 146 s->sh_flags != 0 || 147 s->sh_size < sizeof(signature) - 1) 148 continue; 149 150 if ((error = ELFNAME(read_from)(p, epp->ep_vp, s->sh_offset, 151 (caddr_t) buf, sizeof(signature) - 1)) != 0) 152 goto out; 153 154 /* 155 * error is 0, if the signatures match we are done. 156 */ 157 #ifdef DEBUG_LINUX 158 printf("linux_gcc_sig: sig=%s\n", buf); 159 #endif 160 if (memcmp(buf, signature, sizeof(signature) - 1) == 0) 161 goto out; 162 } 163 164 out: 165 free(sh, M_TEMP); 166 #ifdef DEBUG_LINUX 167 printf("linux_gcc_sig: returning %d\n", error); 168 #endif 169 return error; 170 } 171 #endif 172 173 static int 174 ELFNAME2(linux,signature)(p, epp, eh) 175 struct proc *p; 176 struct exec_package *epp; 177 Elf_Ehdr *eh; 178 { 179 size_t i; 180 Elf_Phdr *ph; 181 Elf_Nhdr *notep; 182 size_t phsize; 183 int error = ENOEXEC; 184 185 phsize = eh->e_phnum * sizeof(Elf_Phdr); 186 ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK); 187 if ((error = ELFNAME(read_from)(p, epp->ep_vp, eh->e_phoff, 188 (caddr_t) ph, phsize)) != 0) 189 goto out1; 190 191 for (i = 0; i < eh->e_phnum; i++) { 192 Elf_Phdr *ephp = &ph[i]; 193 u_int32_t ostype; 194 195 if (ephp->p_type != PT_INTERP /* XAX PT_NOTE */ 196 #if 0 197 || ephp->p_flags != 0 198 || ephp->p_filesz < sizeof(Elf_Nhdr)) 199 #endif 200 ) 201 continue; 202 203 notep = (Elf_Nhdr *)malloc(ephp->p_filesz+1, M_TEMP, M_WAITOK); 204 if ((error = ELFNAME(read_from)(p, epp->ep_vp, ephp->p_offset, 205 (caddr_t)notep, ephp->p_filesz)) != 0) 206 goto out3; 207 208 /* Check for "linux" in the intepreter name. */ 209 if (ephp->p_filesz < 8 + 5) { 210 error = ENOEXEC; 211 goto out3; 212 } 213 #ifdef DEBUG_LINUX 214 printf("linux_signature: interp=%s\n", notep); 215 #endif 216 if (strncmp(&((char *)notep)[8], "linux", 5) == 0 || 217 strncmp((char *)notep, "/lib/ld.so.", 11) == 0) { 218 error = 0; 219 goto out3; 220 } 221 222 goto out2; 223 224 /* XXX XAX Should handle NETBSD_TYPE_EMULNAME */ 225 if (notep->n_type != ELF_NOTE_TYPE_OSVERSION) { 226 free(notep, M_TEMP); 227 continue; 228 } 229 230 /* Check the name and description sizes. */ 231 if (notep->n_namesz != ELF_NOTE_GNU_NAMESZ || 232 notep->n_descsz != ELF_NOTE_GNU_DESCSZ) 233 goto out2; 234 235 /* Is the name "GNU\0"? */ 236 if (memcmp((notep + sizeof(Elf_Nhdr)), 237 ELF_NOTE_GNU_NAME, ELF_NOTE_GNU_NAMESZ)) 238 goto out2; 239 240 /* Make sure the OS is Linux */ 241 ostype = (u_int32_t)(*((u_int32_t *)notep + sizeof(Elf_Nhdr) + 242 notep->n_namesz)) & ELF_NOTE_GNU_OSMASK; 243 if (ostype != ELF_NOTE_GNU_OSLINUX) 244 goto out2; 245 246 /* All checks succeeded. */ 247 error = 0; 248 goto out3; 249 } 250 251 error = ENOEXEC; 252 253 out1: 254 free(ph, M_TEMP); 255 #ifdef DEBUG_LINUX 256 printf("linux_signature: out1=%d\n", error); 257 #endif 258 return error; 259 260 out2: 261 error = ENOEXEC; 262 out3: 263 free(notep, M_TEMP); 264 free(ph, M_TEMP); 265 #ifdef DEBUG_LINUX 266 printf("linux_signature: out2,3=%d\n", error); 267 #endif 268 return error; 269 } 270 271 int 272 ELFNAME2(linux,probe)(p, epp, eh, itp, pos) 273 struct proc *p; 274 struct exec_package *epp; 275 Elf_Ehdr *eh; 276 char *itp; 277 Elf_Addr *pos; 278 { 279 const char *bp; 280 int error; 281 size_t len; 282 283 if ((error = ELFNAME2(linux,signature)(p, epp, eh)) != 0) 284 #ifdef LINUX_GCC_SIGNATURE 285 if ((error = ELFNAME2(linux,gcc_signature)(p, epp, eh)) != 0) 286 return error; 287 #else 288 return error; 289 #endif 290 291 if (itp[0]) { 292 if ((error = emul_find(p, NULL, linux_emul_path, itp, &bp, 0))) 293 return error; 294 if ((error = copystr(bp, itp, MAXPATHLEN, &len))) 295 return error; 296 free((void *)bp, M_TEMP); 297 } 298 epp->ep_emul = &ELFNAMEEND(emul_linux); 299 *pos = ELF_NO_ADDR; 300 #ifdef DEBUG_LINUX 301 printf("linux_probe: returning 0\n"); 302 #endif 303 return 0; 304 } 305 306