linux_exec_elf32.c revision 1.42.2.4
1 /* $NetBSD: linux_exec_elf32.c,v 1.42.2.4 2001/01/05 17:35:26 bouyer Exp $ */ 2 3 /*- 4 * Copyright (c) 1995, 1998, 2000 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 70 #include <compat/linux/linux_syscallargs.h> 71 #include <compat/linux/linux_syscall.h> 72 73 static int ELFNAME2(linux,signature) __P((struct proc *, struct exec_package *, 74 Elf_Ehdr *, char *)); 75 #ifdef LINUX_GCC_SIGNATURE 76 static int ELFNAME2(linux,gcc_signature) __P((struct proc *p, 77 struct exec_package *, Elf_Ehdr *)); 78 #endif 79 80 #ifdef LINUX_GCC_SIGNATURE 81 /* 82 * Take advantage of the fact that all the linux binaries are compiled 83 * with gcc, and gcc sticks in the comment field a signature. Note that 84 * on SVR4 binaries, the gcc signature will follow the OS name signature, 85 * that will not be a problem. We don't bother to read in the string table, 86 * but we check all the progbits headers. 87 * 88 * XXX This only works in the i386. On the alpha (at least) 89 * XXX we have the same gcc signature which incorrectly identifies 90 * XXX NetBSD binaries as Linux. 91 */ 92 static int 93 ELFNAME2(linux,gcc_signature)(p, epp, eh) 94 struct proc *p; 95 struct exec_package *epp; 96 Elf_Ehdr *eh; 97 { 98 size_t shsize; 99 size_t i; 100 static const char signature[] = "\0GCC: (GNU) "; 101 char buf[sizeof(signature) - 1]; 102 Elf_Shdr *sh; 103 int error; 104 105 shsize = eh->e_shnum * sizeof(Elf_Shdr); 106 sh = (Elf_Shdr *) malloc(shsize, M_TEMP, M_WAITOK); 107 error = ELFNAME(read_from)(p, epp->ep_vp, eh->e_shoff, (caddr_t)sh, 108 shsize); 109 if (error) 110 goto out; 111 112 for (i = 0; i < eh->e_shnum; i++) { 113 Elf_Shdr *s = &sh[i]; 114 115 /* 116 * Identify candidates for the comment header; 117 * Header cannot have a load address, or flags and 118 * it must be large enough. 119 */ 120 if (s->sh_type != SHT_PROGBITS || 121 s->sh_addr != 0 || 122 s->sh_flags != 0 || 123 s->sh_size < sizeof(signature) - 1) 124 continue; 125 126 error = ELFNAME(read_from)(p, epp->ep_vp, s->sh_offset, 127 (caddr_t)buf, sizeof(signature) - 1); 128 if (error) 129 continue; 130 131 /* 132 * error is 0, if the signatures match we are done. 133 */ 134 #ifdef DEBUG_LINUX 135 printf("linux_gcc_sig: sig=%s\n", buf); 136 #endif 137 if (!memcmp(buf, signature, sizeof(signature) - 1)) { 138 error = 0; 139 goto out; 140 } 141 } 142 error = ENOEXEC; 143 144 out: 145 free(sh, M_TEMP); 146 return (error); 147 } 148 #endif 149 150 static int 151 ELFNAME2(linux,signature)(p, epp, eh, itp) 152 struct proc *p; 153 struct exec_package *epp; 154 Elf_Ehdr *eh; 155 char *itp; 156 { 157 size_t i; 158 Elf_Phdr *ph; 159 size_t phsize; 160 int error; 161 162 phsize = eh->e_phnum * sizeof(Elf_Phdr); 163 ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK); 164 error = ELFNAME(read_from)(p, epp->ep_vp, eh->e_phoff, (caddr_t)ph, 165 phsize); 166 if (error) 167 goto out; 168 169 for (i = 0; i < eh->e_phnum; i++) { 170 Elf_Phdr *ephp = &ph[i]; 171 Elf_Nhdr *np; 172 u_int32_t *abi; 173 174 if (ephp->p_type != PT_NOTE || 175 ephp->p_filesz > 1024 || 176 ephp->p_filesz < sizeof(Elf_Nhdr) + 20) 177 continue; 178 179 np = (Elf_Nhdr *)malloc(ephp->p_filesz, M_TEMP, M_WAITOK); 180 error = ELFNAME(read_from)(p, epp->ep_vp, ephp->p_offset, 181 (caddr_t)np, ephp->p_filesz); 182 if (error) 183 goto next; 184 185 if (np->n_type != ELF_NOTE_TYPE_ABI_TAG || 186 np->n_namesz != ELF_NOTE_ABI_NAMESZ || 187 np->n_descsz != ELF_NOTE_ABI_DESCSZ || 188 memcmp((caddr_t)(np + 1), ELF_NOTE_ABI_NAME, 189 ELF_NOTE_ABI_NAMESZ)) 190 goto next; 191 192 /* Make sure the OS is Linux. */ 193 abi = (u_int32_t *)((caddr_t)np + sizeof(Elf_Nhdr) + 194 np->n_namesz); 195 if (abi[0] == ELF_NOTE_ABI_OS_LINUX) 196 error = 0; 197 else 198 error = ENOEXEC; 199 free(np, M_TEMP); 200 goto out; 201 202 next: 203 free(np, M_TEMP); 204 continue; 205 } 206 207 /* Check for certain intepreter names. */ 208 if (itp[0]) { 209 if (!strncmp(itp, "/lib/ld-linux", 13) || 210 !strncmp(itp, "/lib/ld.so.", 11)) 211 error = 0; 212 else 213 error = ENOEXEC; 214 goto out; 215 } 216 217 error = ENOEXEC; 218 out: 219 free(ph, M_TEMP); 220 return (error); 221 } 222 223 int 224 ELFNAME2(linux,probe)(p, epp, eh, itp, pos) 225 struct proc *p; 226 struct exec_package *epp; 227 void *eh; 228 char *itp; 229 vaddr_t *pos; 230 { 231 const char *bp; 232 int error; 233 size_t len; 234 235 if ((error = ELFNAME2(linux,signature)(p, epp, eh, itp)) != 0) 236 #ifdef LINUX_GCC_SIGNATURE 237 if ((error = ELFNAME2(linux,gcc_signature)(p, epp, eh)) != 0) 238 return error; 239 #else 240 return error; 241 #endif 242 243 if (itp[0]) { 244 if ((error = emul_find(p, NULL, epp->ep_esch->es_emul->e_path, 245 itp, &bp, 0))) 246 return error; 247 if ((error = copystr(bp, itp, MAXPATHLEN, &len))) 248 return error; 249 free((void *)bp, M_TEMP); 250 } 251 *pos = ELF_NO_ADDR; 252 #ifdef DEBUG_LINUX 253 printf("linux_probe: returning 0\n"); 254 #endif 255 return 0; 256 } 257 258
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