jseward | 2886b0e | 2004-01-04 03:46:11 +0000 | [diff] [blame] | 1 | |
nethercote | bb1c991 | 2004-01-04 16:43:23 +0000 | [diff] [blame] | 2 | /*--------------------------------------------------------------------*/ |
nethercote | 107e1c0 | 2004-10-13 17:55:31 +0000 | [diff] [blame^] | 3 | /*--- User-mode execve(), and other stuff shared between stage1 ---*/ |
| 4 | /*--- and stage2. ume.c ---*/ |
nethercote | bb1c991 | 2004-01-04 16:43:23 +0000 | [diff] [blame] | 5 | /*--------------------------------------------------------------------*/ |
| 6 | |
jseward | 2886b0e | 2004-01-04 03:46:11 +0000 | [diff] [blame] | 7 | /* |
| 8 | This file is part of Valgrind, an extensible x86 protected-mode |
| 9 | emulator for monitoring program execution on x86-Unixes. |
| 10 | |
| 11 | Copyright (C) 2000-2004 Julian Seward |
| 12 | jseward@acm.org |
| 13 | |
| 14 | This program is free software; you can redistribute it and/or |
| 15 | modify it under the terms of the GNU General Public License as |
| 16 | published by the Free Software Foundation; either version 2 of the |
| 17 | License, or (at your option) any later version. |
| 18 | |
| 19 | This program is distributed in the hope that it will be useful, but |
| 20 | WITHOUT ANY WARRANTY; without even the implied warranty of |
| 21 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 22 | General Public License for more details. |
| 23 | |
| 24 | You should have received a copy of the GNU General Public License |
| 25 | along with this program; if not, write to the Free Software |
| 26 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 27 | 02111-1307, USA. |
| 28 | |
| 29 | The GNU General Public License is contained in the file COPYING. |
| 30 | */ |
| 31 | |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 32 | |
| 33 | #define _GNU_SOURCE |
| 34 | #define _FILE_OFFSET_BITS 64 |
| 35 | |
nethercote | f1e5e15 | 2004-09-01 23:58:16 +0000 | [diff] [blame] | 36 | #include "core.h" |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 37 | |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 38 | #include <sys/mman.h> |
| 39 | #include <fcntl.h> |
| 40 | #include <errno.h> |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 41 | #include <stdio.h> |
| 42 | #include <string.h> |
| 43 | #include <stdlib.h> |
| 44 | #include <unistd.h> |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 45 | #include <assert.h> |
| 46 | |
| 47 | #include "ume.h" |
| 48 | |
nethercote | 1fe5450 | 2004-07-26 15:28:33 +0000 | [diff] [blame] | 49 | struct elfinfo |
| 50 | { |
| 51 | ESZ(Ehdr) e; |
| 52 | ESZ(Phdr) *p; |
| 53 | int fd; |
| 54 | }; |
| 55 | |
nethercote | 30d3784 | 2004-07-26 10:05:55 +0000 | [diff] [blame] | 56 | static void check_mmap(void* res, void* base, int len) |
nethercote | bfed1c8 | 2004-07-17 12:57:44 +0000 | [diff] [blame] | 57 | { |
| 58 | if ((void*)-1 == res) { |
nethercote | 969ecf1 | 2004-10-13 17:29:01 +0000 | [diff] [blame] | 59 | fprintf(stderr, "valgrind: mmap(%p, %d) failed in UME.\n", base, len); |
nethercote | bfed1c8 | 2004-07-17 12:57:44 +0000 | [diff] [blame] | 60 | exit(1); |
| 61 | } |
| 62 | } |
| 63 | |
nethercote | 31779c7 | 2004-07-30 21:50:15 +0000 | [diff] [blame] | 64 | // 'extra' allows the caller to pass in extra args to 'fn', like free |
| 65 | // variables to a closure. |
| 66 | void foreach_map(int (*fn)(char *start, char *end, |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 67 | const char *perm, off_t offset, |
nethercote | 31779c7 | 2004-07-30 21:50:15 +0000 | [diff] [blame] | 68 | int maj, int min, int ino, void* extra), |
| 69 | void* extra) |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 70 | { |
| 71 | static char buf[10240]; |
| 72 | char *bufptr = buf; |
| 73 | int ret, fd; |
| 74 | |
| 75 | fd = open("/proc/self/maps", O_RDONLY); |
| 76 | |
| 77 | if (fd == -1) { |
| 78 | perror("open /proc/self/maps"); |
| 79 | return; |
| 80 | } |
| 81 | |
| 82 | ret = read(fd, buf, sizeof(buf)); |
| 83 | |
| 84 | if (ret == -1) { |
| 85 | perror("read /proc/self/maps"); |
| 86 | close(fd); |
| 87 | return; |
| 88 | } |
| 89 | close(fd); |
| 90 | |
| 91 | if (ret == sizeof(buf)) { |
| 92 | fprintf(stderr, "buf too small\n"); |
| 93 | return; |
| 94 | } |
| 95 | |
| 96 | while(bufptr && bufptr < buf+ret) { |
| 97 | char perm[5]; |
| 98 | off_t offset; |
| 99 | int maj, min; |
| 100 | int ino; |
| 101 | void *segstart, *segend; |
| 102 | |
| 103 | sscanf(bufptr, "%p-%p %s %Lx %x:%x %d", |
| 104 | &segstart, &segend, perm, &offset, &maj, &min, &ino); |
| 105 | bufptr = strchr(bufptr, '\n'); |
| 106 | if (bufptr != NULL) |
| 107 | bufptr++; /* skip \n */ |
| 108 | |
nethercote | 31779c7 | 2004-07-30 21:50:15 +0000 | [diff] [blame] | 109 | if (!(*fn)(segstart, segend, perm, offset, maj, min, ino, extra)) |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 110 | break; |
| 111 | } |
| 112 | } |
| 113 | |
nethercote | 31779c7 | 2004-07-30 21:50:15 +0000 | [diff] [blame] | 114 | /*------------------------------------------------------------*/ |
| 115 | /*--- Finding auxv on the stack ---*/ |
| 116 | /*------------------------------------------------------------*/ |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 117 | |
| 118 | struct ume_auxv *find_auxv(int *esp) |
| 119 | { |
| 120 | esp++; /* skip argc */ |
| 121 | |
| 122 | while(*esp != 0) /* skip argv */ |
| 123 | esp++; |
| 124 | esp++; |
| 125 | |
| 126 | while(*esp != 0) /* skip env */ |
| 127 | esp++; |
| 128 | esp++; |
| 129 | |
| 130 | return (struct ume_auxv *)esp; |
| 131 | } |
| 132 | |
nethercote | 31779c7 | 2004-07-30 21:50:15 +0000 | [diff] [blame] | 133 | /*------------------------------------------------------------*/ |
| 134 | /*--- Loading ELF files ---*/ |
| 135 | /*------------------------------------------------------------*/ |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 136 | |
| 137 | struct elfinfo *readelf(int fd, const char *filename) |
| 138 | { |
| 139 | struct elfinfo *e = malloc(sizeof(*e)); |
| 140 | int phsz; |
| 141 | |
nethercote | 7c018f4 | 2004-07-17 16:40:50 +0000 | [diff] [blame] | 142 | assert(e); |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 143 | e->fd = fd; |
| 144 | |
| 145 | if (pread(fd, &e->e, sizeof(e->e), 0) != sizeof(e->e)) { |
nethercote | 08eaff3 | 2004-07-22 12:41:12 +0000 | [diff] [blame] | 146 | fprintf(stderr, "valgrind: %s: can't read elf header: %s\n", |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 147 | filename, strerror(errno)); |
| 148 | return NULL; |
| 149 | } |
| 150 | |
| 151 | if (memcmp(&e->e.e_ident[0], ELFMAG, SELFMAG) != 0) { |
nethercote | 08eaff3 | 2004-07-22 12:41:12 +0000 | [diff] [blame] | 152 | fprintf(stderr, "valgrind: %s: bad ELF magic\n", filename); |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 153 | return NULL; |
| 154 | } |
nethercote | bdaa89f | 2004-10-09 19:08:08 +0000 | [diff] [blame] | 155 | if (e->e.e_ident[EI_CLASS] != VG_ELF_CLASS) { |
| 156 | fprintf(stderr, "valgrind: wrong executable class (eg. 32-bit instead\n" |
| 157 | "valgrind: of 64-bit)\n"); |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 158 | return NULL; |
| 159 | } |
nethercote | bdaa89f | 2004-10-09 19:08:08 +0000 | [diff] [blame] | 160 | if (e->e.e_ident[EI_DATA] != VG_ELF_ENDIANNESS) { |
| 161 | fprintf(stderr, "valgrind: wrong endian-ness\n"); |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 162 | return NULL; |
| 163 | } |
| 164 | if (!(e->e.e_type == ET_EXEC || e->e.e_type == ET_DYN)) { |
nethercote | 08eaff3 | 2004-07-22 12:41:12 +0000 | [diff] [blame] | 165 | fprintf(stderr, "valgrind: need executable\n"); |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 166 | return NULL; |
| 167 | } |
| 168 | |
nethercote | bdaa89f | 2004-10-09 19:08:08 +0000 | [diff] [blame] | 169 | if (e->e.e_machine != VG_ELF_MACHINE) { |
| 170 | fprintf(stderr, "valgrind: wrong architecture\n"); |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 171 | return NULL; |
| 172 | } |
| 173 | |
| 174 | if (e->e.e_phentsize != sizeof(ESZ(Phdr))) { |
nethercote | 08eaff3 | 2004-07-22 12:41:12 +0000 | [diff] [blame] | 175 | fprintf(stderr, "valgrind: sizeof Phdr wrong\n"); |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 176 | return NULL; |
| 177 | } |
| 178 | |
| 179 | phsz = sizeof(ESZ(Phdr)) * e->e.e_phnum; |
| 180 | e->p = malloc(phsz); |
nethercote | 7c018f4 | 2004-07-17 16:40:50 +0000 | [diff] [blame] | 181 | assert(e->p); |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 182 | |
| 183 | if (pread(fd, e->p, phsz, e->e.e_phoff) != phsz) { |
nethercote | 08eaff3 | 2004-07-22 12:41:12 +0000 | [diff] [blame] | 184 | fprintf(stderr, "valgrind: can't read phdr: %s\n", strerror(errno)); |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 185 | return NULL; |
| 186 | } |
| 187 | |
| 188 | return e; |
| 189 | } |
| 190 | |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 191 | /* Map an ELF file. Returns the brk address. */ |
fitzhardinge | b50068f | 2004-02-24 23:42:55 +0000 | [diff] [blame] | 192 | ESZ(Addr) mapelf(struct elfinfo *e, ESZ(Addr) base) |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 193 | { |
| 194 | int i; |
nethercote | bfed1c8 | 2004-07-17 12:57:44 +0000 | [diff] [blame] | 195 | void* res; |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 196 | ESZ(Addr) elfbrk = 0; |
| 197 | |
| 198 | for(i = 0; i < e->e.e_phnum; i++) { |
| 199 | ESZ(Phdr) *ph = &e->p[i]; |
| 200 | ESZ(Addr) addr, brkaddr; |
| 201 | ESZ(Word) memsz; |
| 202 | |
| 203 | if (ph->p_type != PT_LOAD) |
| 204 | continue; |
| 205 | |
| 206 | addr = ph->p_vaddr+base; |
| 207 | memsz = ph->p_memsz; |
| 208 | brkaddr = addr+memsz; |
| 209 | |
| 210 | if (brkaddr > elfbrk) |
| 211 | elfbrk = brkaddr; |
| 212 | } |
| 213 | |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 214 | for(i = 0; i < e->e.e_phnum; i++) { |
| 215 | ESZ(Phdr) *ph = &e->p[i]; |
| 216 | ESZ(Addr) addr, bss, brkaddr; |
| 217 | ESZ(Off) off; |
| 218 | ESZ(Word) filesz; |
| 219 | ESZ(Word) memsz; |
| 220 | ESZ(Word) align; |
| 221 | unsigned prot = 0; |
| 222 | |
| 223 | if (ph->p_type != PT_LOAD) |
| 224 | continue; |
| 225 | |
| 226 | if (ph->p_flags & PF_X) |
| 227 | prot |= PROT_EXEC; |
| 228 | if (ph->p_flags & PF_W) |
| 229 | prot |= PROT_WRITE; |
| 230 | if (ph->p_flags & PF_R) |
| 231 | prot |= PROT_READ; |
| 232 | |
| 233 | align = ph->p_align; |
| 234 | |
| 235 | addr = ph->p_vaddr+base; |
| 236 | off = ph->p_offset; |
| 237 | filesz = ph->p_filesz; |
| 238 | bss = addr+filesz; |
| 239 | memsz = ph->p_memsz; |
| 240 | brkaddr = addr+memsz; |
| 241 | |
nethercote | bfed1c8 | 2004-07-17 12:57:44 +0000 | [diff] [blame] | 242 | res = mmap((char *)ROUNDDN(addr, align), |
| 243 | ROUNDUP(bss, align)-ROUNDDN(addr, align), |
| 244 | prot, MAP_FIXED|MAP_PRIVATE, e->fd, ROUNDDN(off, align)); |
| 245 | check_mmap(res, (char*)ROUNDDN(addr,align), |
| 246 | ROUNDUP(bss, align)-ROUNDDN(addr, align)); |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 247 | |
| 248 | /* if memsz > filesz, then we need to fill the remainder with zeroed pages */ |
| 249 | if (memsz > filesz) { |
| 250 | UInt bytes; |
| 251 | |
| 252 | bytes = ROUNDUP(brkaddr, align)-ROUNDUP(bss, align); |
nethercote | bfed1c8 | 2004-07-17 12:57:44 +0000 | [diff] [blame] | 253 | if (bytes > 0) { |
| 254 | res = mmap((char *)ROUNDUP(bss, align), bytes, |
| 255 | prot, MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE, -1, 0); |
| 256 | check_mmap(res, (char*)ROUNDUP(bss,align), bytes); |
| 257 | } |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 258 | |
| 259 | bytes = bss & (VKI_BYTES_PER_PAGE - 1); |
| 260 | if (bytes > 0) { |
| 261 | bytes = VKI_BYTES_PER_PAGE - bytes; |
| 262 | memset((char *)bss, 0, bytes); |
| 263 | } |
| 264 | } |
| 265 | } |
| 266 | |
| 267 | return elfbrk; |
| 268 | } |
| 269 | |
nethercote | 31779c7 | 2004-07-30 21:50:15 +0000 | [diff] [blame] | 270 | // Forward declaration. |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 271 | static int do_exec_inner(const char *exe, struct exeinfo *info); |
| 272 | |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 273 | static int match_ELF(const char *hdr, int len) |
| 274 | { |
| 275 | ESZ(Ehdr) *e = (ESZ(Ehdr) *)hdr; |
| 276 | return (len > sizeof(*e)) && memcmp(&e->e_ident[0], ELFMAG, SELFMAG) == 0; |
| 277 | } |
| 278 | |
nethercote | 31779c7 | 2004-07-30 21:50:15 +0000 | [diff] [blame] | 279 | static int load_ELF(char *hdr, int len, int fd, const char *name, |
| 280 | struct exeinfo *info) |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 281 | { |
| 282 | struct elfinfo *e; |
| 283 | struct elfinfo *interp = NULL; |
fitzhardinge | ca9bd9c | 2004-09-08 20:05:02 +0000 | [diff] [blame] | 284 | ESZ(Addr) exeoff = 0; /* offset between link address and load address */ |
| 285 | ESZ(Addr) minaddr = ~0; /* lowest mapped address */ |
| 286 | ESZ(Addr) maxaddr = 0; /* highest mapped address */ |
| 287 | ESZ(Addr) interp_addr = 0; /* interpreter (ld.so) address */ |
| 288 | ESZ(Word) interp_size = 0; /* interpreter size */ |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 289 | int i; |
| 290 | void *entry; |
| 291 | |
| 292 | e = readelf(fd, name); |
| 293 | |
| 294 | if (e == NULL) |
| 295 | return ENOEXEC; |
| 296 | |
| 297 | info->phnum = e->e.e_phnum; |
| 298 | info->entry = e->e.e_entry; |
| 299 | |
| 300 | for(i = 0; i < e->e.e_phnum; i++) { |
| 301 | ESZ(Phdr) *ph = &e->p[i]; |
| 302 | |
| 303 | switch(ph->p_type) { |
| 304 | case PT_PHDR: |
| 305 | info->phdr = ph->p_vaddr; |
| 306 | break; |
| 307 | |
| 308 | case PT_LOAD: |
| 309 | if (ph->p_vaddr < minaddr) |
| 310 | minaddr = ph->p_vaddr; |
| 311 | if (ph->p_vaddr+ph->p_memsz > maxaddr) |
| 312 | maxaddr = ph->p_vaddr+ph->p_memsz; |
| 313 | break; |
| 314 | |
| 315 | case PT_INTERP: { |
| 316 | char *buf = malloc(ph->p_filesz+1); |
| 317 | int j; |
| 318 | int intfd; |
| 319 | int baseaddr_set; |
| 320 | |
nethercote | 7c018f4 | 2004-07-17 16:40:50 +0000 | [diff] [blame] | 321 | assert(buf); |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 322 | pread(fd, buf, ph->p_filesz, ph->p_offset); |
| 323 | buf[ph->p_filesz] = '\0'; |
| 324 | |
| 325 | intfd = open(buf, O_RDONLY); |
| 326 | if (intfd == -1) { |
| 327 | perror("open interp"); |
| 328 | exit(1); |
| 329 | } |
| 330 | |
| 331 | interp = readelf(intfd, buf); |
| 332 | if (interp == NULL) { |
| 333 | fprintf(stderr, "Can't read interpreter\n"); |
| 334 | return 1; |
| 335 | } |
| 336 | free(buf); |
| 337 | |
| 338 | baseaddr_set = 0; |
| 339 | for(j = 0; j < interp->e.e_phnum; j++) { |
| 340 | ESZ(Phdr) *iph = &interp->p[j]; |
| 341 | ESZ(Addr) end; |
| 342 | |
| 343 | if (iph->p_type != PT_LOAD) |
| 344 | continue; |
| 345 | |
| 346 | if (!baseaddr_set) { |
| 347 | interp_addr = iph->p_vaddr; |
| 348 | baseaddr_set = 1; |
| 349 | } |
| 350 | |
| 351 | /* assumes that all segments in the interp are close */ |
| 352 | end = (iph->p_vaddr - interp_addr) + iph->p_memsz; |
| 353 | |
| 354 | if (end > interp_size) |
| 355 | interp_size = end; |
| 356 | } |
| 357 | break; |
nethercote | b24cbc8 | 2004-09-03 23:25:33 +0000 | [diff] [blame] | 358 | |
| 359 | default: |
| 360 | // do nothing |
| 361 | break; |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 362 | } |
| 363 | } |
| 364 | } |
| 365 | |
fitzhardinge | ca9bd9c | 2004-09-08 20:05:02 +0000 | [diff] [blame] | 366 | if (e->e.e_type == ET_DYN) { |
| 367 | /* PIE executable */ |
| 368 | exeoff = info->exe_base - minaddr; |
| 369 | } |
| 370 | |
| 371 | minaddr += exeoff; |
| 372 | maxaddr += exeoff; |
| 373 | info->phdr += exeoff; |
| 374 | info->entry += exeoff; |
| 375 | |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 376 | if (info->exe_base != info->exe_end) { |
| 377 | if (minaddr >= maxaddr || |
| 378 | (minaddr < info->exe_base || |
| 379 | maxaddr > info->exe_end)) { |
nethercote | 2e1cb4c | 2004-08-05 12:16:13 +0000 | [diff] [blame] | 380 | fprintf(stderr, "Executable range %p-%p is outside the\n" |
| 381 | "acceptable range %p-%p\n", |
| 382 | (void *)minaddr, (void *)maxaddr, |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 383 | (void *)info->exe_base, (void *)info->exe_end); |
| 384 | return ENOMEM; |
| 385 | } |
| 386 | } |
| 387 | |
fitzhardinge | ca9bd9c | 2004-09-08 20:05:02 +0000 | [diff] [blame] | 388 | info->brkbase = mapelf(e, exeoff); /* map the executable */ |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 389 | |
fitzhardinge | 9236079 | 2003-12-24 10:11:11 +0000 | [diff] [blame] | 390 | if (info->brkbase == 0) |
| 391 | return ENOMEM; |
| 392 | |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 393 | if (interp != NULL) { |
| 394 | /* reserve a chunk of address space for interpreter */ |
nethercote | bfed1c8 | 2004-07-17 12:57:44 +0000 | [diff] [blame] | 395 | void* res; |
| 396 | char* base = (char *)info->exe_base; |
| 397 | char* baseoff; |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 398 | int flags = MAP_PRIVATE|MAP_ANONYMOUS; |
| 399 | |
| 400 | if (info->map_base != 0) { |
| 401 | base = (char *)info->map_base; |
| 402 | flags |= MAP_FIXED; |
| 403 | } |
| 404 | |
nethercote | bfed1c8 | 2004-07-17 12:57:44 +0000 | [diff] [blame] | 405 | res = mmap(base, interp_size, PROT_NONE, flags, -1, 0); |
| 406 | check_mmap(res, base, interp_size); |
| 407 | base = res; |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 408 | |
| 409 | baseoff = base - interp_addr; |
| 410 | |
fitzhardinge | b50068f | 2004-02-24 23:42:55 +0000 | [diff] [blame] | 411 | mapelf(interp, (ESZ(Addr))baseoff); |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 412 | |
| 413 | close(interp->fd); |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 414 | |
| 415 | entry = baseoff + interp->e.e_entry; |
| 416 | info->interp_base = (ESZ(Addr))base; |
thughes | 54d0859 | 2004-09-26 14:42:47 +0000 | [diff] [blame] | 417 | |
| 418 | free(interp); |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 419 | } else |
fitzhardinge | ca9bd9c | 2004-09-08 20:05:02 +0000 | [diff] [blame] | 420 | entry = (void *)e->e.e_entry + exeoff; |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 421 | |
| 422 | info->exe_base = minaddr; |
| 423 | info->exe_end = maxaddr; |
| 424 | |
| 425 | info->init_eip = (addr_t)entry; |
| 426 | |
| 427 | free(e); |
| 428 | |
| 429 | return 0; |
| 430 | } |
| 431 | |
| 432 | |
| 433 | static int match_script(const char *hdr, Int len) |
| 434 | { |
| 435 | return (len > 2) && memcmp(hdr, "#!", 2) == 0; |
| 436 | } |
| 437 | |
nethercote | 31779c7 | 2004-07-30 21:50:15 +0000 | [diff] [blame] | 438 | static int load_script(char *hdr, int len, int fd, const char *name, |
| 439 | struct exeinfo *info) |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 440 | { |
| 441 | char *interp; |
| 442 | char *const end = hdr+len; |
| 443 | char *cp; |
| 444 | char *arg = NULL; |
| 445 | int eol; |
| 446 | |
| 447 | interp = hdr + 2; |
| 448 | while(interp < end && (*interp == ' ' || *interp == '\t')) |
| 449 | interp++; |
| 450 | |
| 451 | if (*interp != '/') |
| 452 | return ENOEXEC; /* absolute path only for interpreter */ |
| 453 | |
| 454 | /* skip over interpreter name */ |
| 455 | for(cp = interp; cp < end && *cp != ' ' && *cp != '\t' && *cp != '\n'; cp++) |
| 456 | ; |
| 457 | |
| 458 | eol = (*cp == '\n'); |
| 459 | |
| 460 | *cp++ = '\0'; |
| 461 | |
| 462 | if (!eol && cp < end) { |
| 463 | /* skip space before arg */ |
| 464 | while (cp < end && (*cp == '\t' || *cp == ' ')) |
| 465 | cp++; |
| 466 | |
| 467 | /* arg is from here to eol */ |
| 468 | arg = cp; |
| 469 | while (cp < end && *cp != '\n') |
| 470 | cp++; |
| 471 | *cp = '\0'; |
| 472 | } |
| 473 | |
nethercote | d6a5687 | 2004-07-26 15:32:47 +0000 | [diff] [blame] | 474 | info->interp_name = strdup(interp); |
| 475 | assert(NULL != info->interp_name); |
nethercote | 71980f0 | 2004-01-24 18:18:54 +0000 | [diff] [blame] | 476 | if (arg != NULL && *arg != '\0') { |
nethercote | d6a5687 | 2004-07-26 15:32:47 +0000 | [diff] [blame] | 477 | info->interp_args = strdup(arg); |
| 478 | assert(NULL != info->interp_args); |
nethercote | 71980f0 | 2004-01-24 18:18:54 +0000 | [diff] [blame] | 479 | } |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 480 | |
| 481 | if (info->argv && info->argv[0] != NULL) |
| 482 | info->argv[0] = (char *)name; |
| 483 | |
| 484 | if (0) |
nethercote | d6a5687 | 2004-07-26 15:32:47 +0000 | [diff] [blame] | 485 | printf("#! script: interp_name=\"%s\" interp_args=\"%s\"\n", |
| 486 | info->interp_name, info->interp_args); |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 487 | |
| 488 | return do_exec_inner(interp, info); |
| 489 | } |
| 490 | |
fitzhardinge | fd7da3a | 2004-09-08 20:05:29 +0000 | [diff] [blame] | 491 | /* |
| 492 | Emulate the normal Unix permissions checking algorithm. |
| 493 | |
| 494 | If owner matches, then use the owner permissions, else |
| 495 | if group matches, then use the group permissions, else |
| 496 | use other permissions. |
| 497 | |
| 498 | Note that we can't deal with SUID/SGID, so we refuse to run them |
| 499 | (otherwise the executable may misbehave if it doesn't have the |
| 500 | permissions it thinks it does). |
| 501 | */ |
| 502 | static int check_perms(int fd) |
| 503 | { |
| 504 | struct stat st; |
| 505 | |
| 506 | if (fstat(fd, &st) == -1) |
| 507 | return errno; |
| 508 | |
| 509 | if (st.st_mode & (S_ISUID | S_ISGID)) { |
| 510 | //fprintf(stderr, "Can't execute suid/sgid executable %s\n", exe); |
| 511 | return EACCES; |
| 512 | } |
| 513 | |
| 514 | if (geteuid() == st.st_uid) { |
| 515 | if (!(st.st_mode & S_IXUSR)) |
| 516 | return EACCES; |
| 517 | } else { |
| 518 | int grpmatch = 0; |
| 519 | |
| 520 | if (getegid() == st.st_gid) |
| 521 | grpmatch = 1; |
| 522 | else { |
| 523 | gid_t groups[32]; |
| 524 | int ngrp = getgroups(32, groups); |
| 525 | int i; |
| 526 | |
| 527 | for(i = 0; i < ngrp; i++) |
| 528 | if (groups[i] == st.st_gid) { |
| 529 | grpmatch = 1; |
| 530 | break; |
| 531 | } |
| 532 | } |
| 533 | |
| 534 | if (grpmatch) { |
| 535 | if (!(st.st_mode & S_IXGRP)) |
| 536 | return EACCES; |
| 537 | } else if (!(st.st_mode & S_IXOTH)) |
| 538 | return EACCES; |
| 539 | } |
| 540 | |
| 541 | return 0; |
| 542 | } |
| 543 | |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 544 | static int do_exec_inner(const char *exe, struct exeinfo *info) |
| 545 | { |
| 546 | int fd; |
fitzhardinge | d2e3711 | 2004-09-09 08:10:42 +0000 | [diff] [blame] | 547 | int err; |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 548 | char buf[VKI_BYTES_PER_PAGE]; |
| 549 | int bufsz; |
| 550 | int i; |
| 551 | int ret; |
nethercote | 31779c7 | 2004-07-30 21:50:15 +0000 | [diff] [blame] | 552 | static const struct { |
| 553 | int (*match)(const char *hdr, int len); |
| 554 | int (*load) ( char *hdr, int len, int fd2, const char *name, |
| 555 | struct exeinfo *); |
| 556 | } formats[] = { |
| 557 | { match_ELF, load_ELF }, |
| 558 | { match_script, load_script }, |
| 559 | }; |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 560 | |
| 561 | fd = open(exe, O_RDONLY); |
| 562 | if (fd == -1) { |
| 563 | if (0) |
| 564 | fprintf(stderr, "Can't open executable %s: %s\n", |
| 565 | exe, strerror(errno)); |
| 566 | return errno; |
| 567 | } |
| 568 | |
fitzhardinge | d2e3711 | 2004-09-09 08:10:42 +0000 | [diff] [blame] | 569 | err = check_perms(fd); |
fitzhardinge | fd7da3a | 2004-09-08 20:05:29 +0000 | [diff] [blame] | 570 | if (err != 0) { |
| 571 | close(fd); |
| 572 | return err; |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 573 | } |
| 574 | |
| 575 | bufsz = pread(fd, buf, sizeof(buf), 0); |
| 576 | if (bufsz < 0) { |
| 577 | fprintf(stderr, "Can't read executable header: %s\n", |
| 578 | strerror(errno)); |
| 579 | close(fd); |
| 580 | return errno; |
| 581 | } |
| 582 | |
| 583 | ret = ENOEXEC; |
| 584 | for(i = 0; i < sizeof(formats)/sizeof(*formats); i++) { |
| 585 | if ((formats[i].match)(buf, bufsz)) { |
| 586 | ret = (formats[i].load)(buf, bufsz, fd, exe, info); |
| 587 | break; |
| 588 | } |
| 589 | } |
| 590 | |
| 591 | close(fd); |
| 592 | |
| 593 | return ret; |
| 594 | } |
| 595 | |
nethercote | ea147e7 | 2004-07-26 15:43:57 +0000 | [diff] [blame] | 596 | // See ume.h for an indication of which entries of 'info' are inputs, which |
| 597 | // are outputs, and which are both. |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 598 | int do_exec(const char *exe, struct exeinfo *info) |
| 599 | { |
nethercote | d6a5687 | 2004-07-26 15:32:47 +0000 | [diff] [blame] | 600 | info->interp_name = NULL; |
| 601 | info->interp_args = NULL; |
fitzhardinge | 7e343cd | 2003-12-16 02:14:00 +0000 | [diff] [blame] | 602 | |
| 603 | return do_exec_inner(exe, info); |
| 604 | } |
nethercote | bb1c991 | 2004-01-04 16:43:23 +0000 | [diff] [blame] | 605 | |
| 606 | /*--------------------------------------------------------------------*/ |
| 607 | /*--- end ume.c ---*/ |
| 608 | /*--------------------------------------------------------------------*/ |