1 /* $NetBSD: exec_elf32.c,v 1.127 2007/12/03 02:06:58 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 1994, 2000, 2005 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. 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 * Copyright (c) 1996 Christopher G. Demetriou 41 * All rights reserved. 42 * 43 * Redistribution and use in source and binary forms, with or without 44 * modification, are permitted provided that the following conditions 45 * are met: 46 * 1. Redistributions of source code must retain the above copyright 47 * notice, this list of conditions and the following disclaimer. 48 * 2. Redistributions in binary form must reproduce the above copyright 49 * notice, this list of conditions and the following disclaimer in the 50 * documentation and/or other materials provided with the distribution. 51 * 3. The name of the author may not be used to endorse or promote products 52 * derived from this software without specific prior written permission 53 * 54 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 55 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 56 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 57 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 58 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 59 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 60 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 61 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 62 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 63 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 64 */ 65 66 #include <sys/cdefs.h> 67 __KERNEL_RCSID(1, "$NetBSD: exec_elf32.c,v 1.127 2007/12/03 02:06:58 christos Exp $"); 68 69 /* If not included by exec_elf64.c, ELFSIZE won't be defined. */ 70 #ifndef ELFSIZE 71 #define ELFSIZE 32 72 #endif 73 74 #ifdef _KERNEL_OPT 75 #include "opt_pax.h" 76 #endif /* _KERNEL_OPT */ 77 78 #include <sys/param.h> 79 #include <sys/proc.h> 80 #include <sys/malloc.h> 81 #include <sys/namei.h> 82 #include <sys/vnode.h> 83 #include <sys/exec.h> 84 #include <sys/exec_elf.h> 85 #include <sys/syscall.h> 86 #include <sys/signalvar.h> 87 #include <sys/mount.h> 88 #include <sys/stat.h> 89 #include <sys/kauth.h> 90 91 #include <sys/cpu.h> 92 #include <machine/reg.h> 93 94 #include <compat/common/compat_util.h> 95 96 #if defined(PAX_MPROTECT) || defined(PAX_SEGVGUARD) 97 #include <sys/pax.h> 98 #endif /* PAX_MPROTECT || PAX_SEGVGUARD */ 99 100 extern const struct emul emul_netbsd; 101 102 #define elf_check_header ELFNAME(check_header) 103 #define elf_copyargs ELFNAME(copyargs) 104 #define elf_load_file ELFNAME(load_file) 105 #define elf_load_psection ELFNAME(load_psection) 106 #define exec_elf_makecmds ELFNAME2(exec,makecmds) 107 #define netbsd_elf_signature ELFNAME2(netbsd,signature) 108 #define netbsd_elf_probe ELFNAME2(netbsd,probe) 109 110 int elf_load_file(struct lwp *, struct exec_package *, char *, 111 struct exec_vmcmd_set *, u_long *, struct elf_args *, Elf_Addr *); 112 void elf_load_psection(struct exec_vmcmd_set *, struct vnode *, 113 const Elf_Phdr *, Elf_Addr *, u_long *, int *, int); 114 115 int netbsd_elf_signature(struct lwp *, struct exec_package *, Elf_Ehdr *); 116 int netbsd_elf_probe(struct lwp *, struct exec_package *, void *, char *, 117 vaddr_t *); 118 119 /* round up and down to page boundaries. */ 120 #define ELF_ROUND(a, b) (((a) + (b) - 1) & ~((b) - 1)) 121 #define ELF_TRUNC(a, b) ((a) & ~((b) - 1)) 122 123 #define MAXPHNUM 50 124 125 /* 126 * Copy arguments onto the stack in the normal way, but add some 127 * extra information in case of dynamic binding. 128 */ 129 int 130 elf_copyargs(struct lwp *l, struct exec_package *pack, 131 struct ps_strings *arginfo, char **stackp, void *argp) 132 { 133 size_t len, vlen; 134 AuxInfo ai[ELF_AUX_ENTRIES], *a, *execname; 135 struct elf_args *ap; 136 int error; 137 138 if ((error = copyargs(l, pack, arginfo, stackp, argp)) != 0) 139 return error; 140 141 a = ai; 142 execname = NULL; 143 144 /* 145 * Push extra arguments on the stack needed by dynamically 146 * linked binaries 147 */ 148 if ((ap = (struct elf_args *)pack->ep_emul_arg)) { 149 struct vattr *vap = pack->ep_vap; 150 151 a->a_type = AT_PHDR; 152 a->a_v = ap->arg_phaddr; 153 a++; 154 155 a->a_type = AT_PHENT; 156 a->a_v = ap->arg_phentsize; 157 a++; 158 159 a->a_type = AT_PHNUM; 160 a->a_v = ap->arg_phnum; 161 a++; 162 163 a->a_type = AT_PAGESZ; 164 a->a_v = PAGE_SIZE; 165 a++; 166 167 a->a_type = AT_BASE; 168 a->a_v = ap->arg_interp; 169 a++; 170 171 a->a_type = AT_FLAGS; 172 a->a_v = 0; 173 a++; 174 175 a->a_type = AT_ENTRY; 176 a->a_v = ap->arg_entry; 177 a++; 178 179 a->a_type = AT_EUID; 180 if (vap->va_mode & S_ISUID) 181 a->a_v = vap->va_uid; 182 else 183 a->a_v = kauth_cred_geteuid(l->l_cred); 184 a++; 185 186 a->a_type = AT_RUID; 187 a->a_v = kauth_cred_getuid(l->l_cred); 188 a++; 189 190 a->a_type = AT_EGID; 191 if (vap->va_mode & S_ISGID) 192 a->a_v = vap->va_gid; 193 else 194 a->a_v = kauth_cred_getegid(l->l_cred); 195 a++; 196 197 a->a_type = AT_RGID; 198 a->a_v = kauth_cred_getgid(l->l_cred); 199 a++; 200 201 if (pack->ep_path) { 202 execname = a; 203 a->a_type = AT_SUN_EXECNAME; 204 a++; 205 } 206 207 free(ap, M_TEMP); 208 pack->ep_emul_arg = NULL; 209 } 210 211 a->a_type = AT_NULL; 212 a->a_v = 0; 213 a++; 214 215 vlen = (a - ai) * sizeof(AuxInfo); 216 217 if (execname) { 218 char *path = pack->ep_path; 219 execname->a_v = (intptr_t)(*stackp + vlen); 220 len = strlen(path) + 1; 221 if ((error = copyout(path, (*stackp + vlen), len)) != 0) 222 return error; 223 len = ALIGN(len); 224 } else 225 len = 0; 226 227 if ((error = copyout(ai, *stackp, vlen)) != 0) 228 return error; 229 *stackp += vlen + len; 230 231 return 0; 232 } 233 234 /* 235 * elf_check_header(): 236 * 237 * Check header for validity; return 0 of ok ENOEXEC if error 238 */ 239 int 240 elf_check_header(Elf_Ehdr *eh, int type) 241 { 242 243 if (memcmp(eh->e_ident, ELFMAG, SELFMAG) != 0 || 244 eh->e_ident[EI_CLASS] != ELFCLASS) 245 return ENOEXEC; 246 247 switch (eh->e_machine) { 248 249 ELFDEFNNAME(MACHDEP_ID_CASES) 250 251 default: 252 return ENOEXEC; 253 } 254 255 if (ELF_EHDR_FLAGS_OK(eh) == 0) 256 return ENOEXEC; 257 258 if (eh->e_type != type) 259 return ENOEXEC; 260 261 if (eh->e_shnum > 32768 || eh->e_phnum > 128) 262 return ENOEXEC; 263 264 return 0; 265 } 266 267 /* 268 * elf_load_psection(): 269 * 270 * Load a psection at the appropriate address 271 */ 272 void 273 elf_load_psection(struct exec_vmcmd_set *vcset, struct vnode *vp, 274 const Elf_Phdr *ph, Elf_Addr *addr, u_long *size, int *prot, int flags) 275 { 276 u_long msize, psize, rm, rf; 277 long diff, offset; 278 279 /* 280 * If the user specified an address, then we load there. 281 */ 282 if (*addr == ELFDEFNNAME(NO_ADDR)) 283 *addr = ph->p_vaddr; 284 285 if (ph->p_align > 1) { 286 /* 287 * Make sure we are virtually aligned as we are supposed to be. 288 */ 289 diff = ph->p_vaddr - ELF_TRUNC(ph->p_vaddr, ph->p_align); 290 KASSERT(*addr - diff == ELF_TRUNC(*addr, ph->p_align)); 291 /* 292 * But make sure to not map any pages before the start of the 293 * psection by limiting the difference to within a page. 294 */ 295 diff &= PAGE_MASK; 296 } else 297 diff = 0; 298 299 *prot |= (ph->p_flags & PF_R) ? VM_PROT_READ : 0; 300 *prot |= (ph->p_flags & PF_W) ? VM_PROT_WRITE : 0; 301 *prot |= (ph->p_flags & PF_X) ? VM_PROT_EXECUTE : 0; 302 303 /* 304 * Adjust everything so it all starts on a page boundary. 305 */ 306 *addr -= diff; 307 offset = ph->p_offset - diff; 308 *size = ph->p_filesz + diff; 309 msize = ph->p_memsz + diff; 310 311 if (ph->p_align >= PAGE_SIZE) { 312 if ((ph->p_flags & PF_W) != 0) { 313 /* 314 * Because the pagedvn pager can't handle zero fill 315 * of the last data page if it's not page aligned we 316 * map the last page readvn. 317 */ 318 psize = trunc_page(*size); 319 } else { 320 psize = round_page(*size); 321 } 322 } else { 323 psize = *size; 324 } 325 326 if (psize > 0) { 327 NEW_VMCMD2(vcset, ph->p_align < PAGE_SIZE ? 328 vmcmd_map_readvn : vmcmd_map_pagedvn, psize, *addr, vp, 329 offset, *prot, flags); 330 flags &= VMCMD_RELATIVE; 331 } 332 if (psize < *size) { 333 NEW_VMCMD2(vcset, vmcmd_map_readvn, *size - psize, 334 *addr + psize, vp, offset + psize, *prot, flags); 335 } 336 337 /* 338 * Check if we need to extend the size of the segment (does 339 * bss extend page the next page boundary)? 340 */ 341 rm = round_page(*addr + msize); 342 rf = round_page(*addr + *size); 343 344 if (rm != rf) { 345 NEW_VMCMD2(vcset, vmcmd_map_zero, rm - rf, rf, NULLVP, 346 0, *prot, flags & VMCMD_RELATIVE); 347 *size = msize; 348 } 349 } 350 351 /* 352 * elf_load_file(): 353 * 354 * Load a file (interpreter/library) pointed to by path 355 * [stolen from coff_load_shlib()]. Made slightly generic 356 * so it might be used externally. 357 */ 358 int 359 elf_load_file(struct lwp *l, struct exec_package *epp, char *path, 360 struct exec_vmcmd_set *vcset, u_long *entryoff, struct elf_args *ap, 361 Elf_Addr *last) 362 { 363 int error, i; 364 struct vnode *vp; 365 struct vattr attr; 366 Elf_Ehdr eh; 367 Elf_Phdr *ph = NULL; 368 const Elf_Phdr *ph0; 369 const Elf_Phdr *base_ph; 370 const Elf_Phdr *last_ph; 371 u_long phsize; 372 Elf_Addr addr = *last; 373 struct proc *p; 374 375 p = l->l_proc; 376 377 /* 378 * 1. open file 379 * 2. read filehdr 380 * 3. map text, data, and bss out of it using VM_* 381 */ 382 vp = epp->ep_interp; 383 if (vp == NULL) { 384 error = emul_find_interp(l, epp, path); 385 if (error != 0) 386 return error; 387 vp = epp->ep_interp; 388 } 389 /* We'll tidy this ourselves - otherwise we have locking issues */ 390 epp->ep_interp = NULL; 391 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 392 393 /* 394 * Similarly, if it's not marked as executable, or it's not a regular 395 * file, we don't allow it to be used. 396 */ 397 if (vp->v_type != VREG) { 398 error = EACCES; 399 goto badunlock; 400 } 401 if ((error = VOP_ACCESS(vp, VEXEC, l->l_cred)) != 0) 402 goto badunlock; 403 404 /* get attributes */ 405 if ((error = VOP_GETATTR(vp, &attr, l->l_cred)) != 0) 406 goto badunlock; 407 408 /* 409 * Check mount point. Though we're not trying to exec this binary, 410 * we will be executing code from it, so if the mount point 411 * disallows execution or set-id-ness, we punt or kill the set-id. 412 */ 413 if (vp->v_mount->mnt_flag & MNT_NOEXEC) { 414 error = EACCES; 415 goto badunlock; 416 } 417 if (vp->v_mount->mnt_flag & MNT_NOSUID) 418 epp->ep_vap->va_mode &= ~(S_ISUID | S_ISGID); 419 420 #ifdef notyet /* XXX cgd 960926 */ 421 XXX cgd 960926: (maybe) VOP_OPEN it (and VOP_CLOSE in copyargs?) 422 #endif 423 424 error = vn_marktext(vp); 425 if (error) 426 goto badunlock; 427 428 VOP_UNLOCK(vp, 0); 429 430 if ((error = exec_read_from(l, vp, 0, &eh, sizeof(eh))) != 0) 431 goto bad; 432 433 if ((error = elf_check_header(&eh, ET_DYN)) != 0) 434 goto bad; 435 436 if (eh.e_phnum > MAXPHNUM) 437 goto bad; 438 439 phsize = eh.e_phnum * sizeof(Elf_Phdr); 440 ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK); 441 442 if ((error = exec_read_from(l, vp, eh.e_phoff, ph, phsize)) != 0) 443 goto bad; 444 445 #ifdef ELF_INTERP_NON_RELOCATABLE 446 /* 447 * Evil hack: Only MIPS should be non-relocatable, and the 448 * psections should have a high address (typically 0x5ffe0000). 449 * If it's now relocatable, it should be linked at 0 and the 450 * psections should have zeros in the upper part of the address. 451 * Otherwise, force the load at the linked address. 452 */ 453 if (*last == ELF_LINK_ADDR && (ph->p_vaddr & 0xffff0000) == 0) 454 *last = ELFDEFNNAME(NO_ADDR); 455 #endif 456 457 /* 458 * If no position to load the interpreter was set by a probe 459 * function, pick the same address that a non-fixed mmap(0, ..) 460 * would (i.e. something safely out of the way). 461 */ 462 if (*last == ELFDEFNNAME(NO_ADDR)) { 463 u_long limit = 0; 464 /* 465 * Find the start and ending addresses of the psections to 466 * be loaded. This will give us the size. 467 */ 468 for (i = 0, ph0 = ph, base_ph = NULL; i < eh.e_phnum; 469 i++, ph0++) { 470 if (ph0->p_type == PT_LOAD) { 471 u_long psize = ph0->p_vaddr + ph0->p_memsz; 472 if (base_ph == NULL) 473 base_ph = ph0; 474 if (psize > limit) 475 limit = psize; 476 } 477 } 478 479 if (base_ph == NULL) { 480 error = ENOEXEC; 481 goto bad; 482 } 483 484 /* 485 * Now compute the size and load address. 486 */ 487 addr = (*epp->ep_esch->es_emul->e_vm_default_addr)(p, 488 epp->ep_daddr, 489 round_page(limit) - trunc_page(base_ph->p_vaddr)); 490 } else 491 addr = *last; /* may be ELF_LINK_ADDR */ 492 493 /* 494 * Load all the necessary sections 495 */ 496 for (i = 0, ph0 = ph, base_ph = NULL, last_ph = NULL; 497 i < eh.e_phnum; i++, ph0++) { 498 switch (ph0->p_type) { 499 case PT_LOAD: { 500 u_long size; 501 int prot = 0; 502 int flags; 503 504 if (base_ph == NULL) { 505 /* 506 * First encountered psection is always the 507 * base psection. Make sure it's aligned 508 * properly (align down for topdown and align 509 * upwards for not topdown). 510 */ 511 base_ph = ph0; 512 flags = VMCMD_BASE; 513 if (addr == ELF_LINK_ADDR) 514 addr = ph0->p_vaddr; 515 if (p->p_vmspace->vm_map.flags & VM_MAP_TOPDOWN) 516 addr = ELF_TRUNC(addr, ph0->p_align); 517 else 518 addr = ELF_ROUND(addr, ph0->p_align); 519 } else { 520 u_long limit = round_page(last_ph->p_vaddr 521 + last_ph->p_memsz); 522 u_long base = trunc_page(ph0->p_vaddr); 523 524 /* 525 * If there is a gap in between the psections, 526 * map it as inaccessible so nothing else 527 * mmap'ed will be placed there. 528 */ 529 if (limit != base) { 530 NEW_VMCMD2(vcset, vmcmd_map_zero, 531 base - limit, 532 limit - base_ph->p_vaddr, NULLVP, 533 0, VM_PROT_NONE, VMCMD_RELATIVE); 534 } 535 536 addr = ph0->p_vaddr - base_ph->p_vaddr; 537 flags = VMCMD_RELATIVE; 538 } 539 last_ph = ph0; 540 elf_load_psection(vcset, vp, &ph[i], &addr, 541 &size, &prot, flags); 542 /* 543 * If entry is within this psection then this 544 * must contain the .text section. *entryoff is 545 * relative to the base psection. 546 */ 547 if (eh.e_entry >= ph0->p_vaddr && 548 eh.e_entry < (ph0->p_vaddr + size)) { 549 *entryoff = eh.e_entry - base_ph->p_vaddr; 550 } 551 addr += size; 552 break; 553 } 554 555 case PT_DYNAMIC: 556 case PT_PHDR: 557 break; 558 559 case PT_NOTE: 560 break; 561 562 default: 563 break; 564 } 565 } 566 567 free(ph, M_TEMP); 568 /* 569 * This value is ignored if TOPDOWN. 570 */ 571 *last = addr; 572 vrele(vp); 573 return 0; 574 575 badunlock: 576 VOP_UNLOCK(vp, 0); 577 578 bad: 579 if (ph != NULL) 580 free(ph, M_TEMP); 581 #ifdef notyet /* XXX cgd 960926 */ 582 (maybe) VOP_CLOSE it 583 #endif 584 vrele(vp); 585 return error; 586 } 587 588 /* 589 * exec_elf_makecmds(): Prepare an Elf binary's exec package 590 * 591 * First, set of the various offsets/lengths in the exec package. 592 * 593 * Then, mark the text image busy (so it can be demand paged) or error 594 * out if this is not possible. Finally, set up vmcmds for the 595 * text, data, bss, and stack segments. 596 */ 597 int 598 exec_elf_makecmds(struct lwp *l, struct exec_package *epp) 599 { 600 Elf_Ehdr *eh = epp->ep_hdr; 601 Elf_Phdr *ph, *pp; 602 Elf_Addr phdr = 0, pos = 0; 603 int error, i, nload; 604 char *interp = NULL; 605 u_long phsize; 606 struct proc *p; 607 608 if (epp->ep_hdrvalid < sizeof(Elf_Ehdr)) 609 return ENOEXEC; 610 611 /* 612 * XXX allow for executing shared objects. It seems silly 613 * but other ELF-based systems allow it as well. 614 */ 615 if (elf_check_header(eh, ET_EXEC) != 0 && 616 elf_check_header(eh, ET_DYN) != 0) 617 return ENOEXEC; 618 619 if (eh->e_phnum > MAXPHNUM) 620 return ENOEXEC; 621 622 error = vn_marktext(epp->ep_vp); 623 if (error) 624 return error; 625 626 /* 627 * Allocate space to hold all the program headers, and read them 628 * from the file 629 */ 630 p = l->l_proc; 631 phsize = eh->e_phnum * sizeof(Elf_Phdr); 632 ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK); 633 634 if ((error = exec_read_from(l, epp->ep_vp, eh->e_phoff, ph, phsize)) != 635 0) 636 goto bad; 637 638 epp->ep_taddr = epp->ep_tsize = ELFDEFNNAME(NO_ADDR); 639 epp->ep_daddr = epp->ep_dsize = ELFDEFNNAME(NO_ADDR); 640 641 for (i = 0; i < eh->e_phnum; i++) { 642 pp = &ph[i]; 643 if (pp->p_type == PT_INTERP) { 644 if (pp->p_filesz >= MAXPATHLEN) 645 goto bad; 646 interp = PNBUF_GET(); 647 interp[0] = '\0'; 648 if ((error = exec_read_from(l, epp->ep_vp, 649 pp->p_offset, interp, pp->p_filesz)) != 0) 650 goto bad; 651 break; 652 } 653 } 654 655 /* 656 * On the same architecture, we may be emulating different systems. 657 * See which one will accept this executable. 658 * 659 * Probe functions would normally see if the interpreter (if any) 660 * exists. Emulation packages may possibly replace the interpreter in 661 * interp[] with a changed path (/emul/xxx/<path>). 662 */ 663 pos = ELFDEFNNAME(NO_ADDR); 664 if (epp->ep_esch->u.elf_probe_func) { 665 vaddr_t startp = (vaddr_t)pos; 666 667 error = (*epp->ep_esch->u.elf_probe_func)(l, epp, eh, interp, 668 &startp); 669 if (error) 670 goto bad; 671 pos = (Elf_Addr)startp; 672 } 673 674 /* 675 * Load all the necessary sections 676 */ 677 for (i = nload = 0; i < eh->e_phnum; i++) { 678 Elf_Addr addr = ELFDEFNNAME(NO_ADDR); 679 u_long size = 0; 680 int prot = 0; 681 682 pp = &ph[i]; 683 684 switch (ph[i].p_type) { 685 case PT_LOAD: 686 /* 687 * XXX 688 * Can handle only 2 sections: text and data 689 */ 690 if (nload++ == 2) 691 goto bad; 692 elf_load_psection(&epp->ep_vmcmds, epp->ep_vp, 693 &ph[i], &addr, &size, &prot, VMCMD_FIXED); 694 695 /* 696 * Decide whether it's text or data by looking 697 * at the entry point. 698 */ 699 if (eh->e_entry >= addr && 700 eh->e_entry < (addr + size)) { 701 epp->ep_taddr = addr; 702 epp->ep_tsize = size; 703 if (epp->ep_daddr == ELFDEFNNAME(NO_ADDR)) { 704 epp->ep_daddr = addr; 705 epp->ep_dsize = size; 706 } 707 } else { 708 epp->ep_daddr = addr; 709 epp->ep_dsize = size; 710 } 711 break; 712 713 case PT_SHLIB: 714 /* SCO has these sections. */ 715 case PT_INTERP: 716 /* Already did this one. */ 717 case PT_DYNAMIC: 718 break; 719 case PT_NOTE: 720 break; 721 case PT_PHDR: 722 /* Note address of program headers (in text segment) */ 723 phdr = pp->p_vaddr; 724 break; 725 726 default: 727 /* 728 * Not fatal; we don't need to understand everything. 729 */ 730 break; 731 } 732 } 733 734 #if defined(PAX_MPROTECT) || defined(PAX_SEGVGUARD) 735 if (epp->ep_pax_flags) 736 pax_adjust(l, epp->ep_pax_flags); 737 #endif /* PAX_MPROTECT || PAX_SEGVGUARD */ 738 739 /* 740 * Check if we found a dynamically linked binary and arrange to load 741 * its interpreter 742 */ 743 if (interp) { 744 struct elf_args *ap; 745 int j = epp->ep_vmcmds.evs_used; 746 u_long interp_offset; 747 748 MALLOC(ap, struct elf_args *, sizeof(struct elf_args), 749 M_TEMP, M_WAITOK); 750 if ((error = elf_load_file(l, epp, interp, 751 &epp->ep_vmcmds, &interp_offset, ap, &pos)) != 0) { 752 FREE(ap, M_TEMP); 753 goto bad; 754 } 755 ap->arg_interp = epp->ep_vmcmds.evs_cmds[j].ev_addr; 756 epp->ep_entry = ap->arg_interp + interp_offset; 757 ap->arg_phaddr = phdr; 758 759 ap->arg_phentsize = eh->e_phentsize; 760 ap->arg_phnum = eh->e_phnum; 761 ap->arg_entry = eh->e_entry; 762 763 epp->ep_emul_arg = ap; 764 765 PNBUF_PUT(interp); 766 } else 767 epp->ep_entry = eh->e_entry; 768 769 #ifdef ELF_MAP_PAGE_ZERO 770 /* Dell SVR4 maps page zero, yeuch! */ 771 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, PAGE_SIZE, 0, 772 epp->ep_vp, 0, VM_PROT_READ); 773 #endif 774 free(ph, M_TEMP); 775 return (*epp->ep_esch->es_setup_stack)(l, epp); 776 777 bad: 778 if (interp) 779 PNBUF_PUT(interp); 780 free(ph, M_TEMP); 781 kill_vmcmds(&epp->ep_vmcmds); 782 return ENOEXEC; 783 } 784 785 int 786 netbsd_elf_signature(struct lwp *l, struct exec_package *epp, 787 Elf_Ehdr *eh) 788 { 789 size_t i; 790 Elf_Phdr *ph; 791 size_t phsize; 792 int error; 793 int isnetbsd = 0; 794 char *ndata; 795 796 epp->ep_pax_flags = 0; 797 if (eh->e_phnum > MAXPHNUM) 798 return ENOEXEC; 799 800 phsize = eh->e_phnum * sizeof(Elf_Phdr); 801 ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK); 802 error = exec_read_from(l, epp->ep_vp, eh->e_phoff, ph, phsize); 803 if (error) 804 goto out; 805 806 for (i = 0; i < eh->e_phnum; i++) { 807 Elf_Phdr *ephp = &ph[i]; 808 Elf_Nhdr *np; 809 810 if (ephp->p_type != PT_NOTE || 811 ephp->p_filesz > 1024 || 812 ephp->p_filesz < sizeof(Elf_Nhdr) + ELF_NOTE_NETBSD_NAMESZ) 813 continue; 814 815 np = (Elf_Nhdr *)malloc(ephp->p_filesz, M_TEMP, M_WAITOK); 816 error = exec_read_from(l, epp->ep_vp, ephp->p_offset, np, 817 ephp->p_filesz); 818 if (error) 819 goto next; 820 821 ndata = (char *)(np + 1); 822 switch (np->n_type) { 823 case ELF_NOTE_TYPE_NETBSD_TAG: 824 if (np->n_namesz != ELF_NOTE_NETBSD_NAMESZ || 825 np->n_descsz != ELF_NOTE_NETBSD_DESCSZ || 826 memcmp(ndata, ELF_NOTE_NETBSD_NAME, 827 ELF_NOTE_NETBSD_NAMESZ)) 828 goto next; 829 isnetbsd = 1; 830 break; 831 832 case ELF_NOTE_TYPE_PAX_TAG: 833 if (np->n_namesz != ELF_NOTE_PAX_NAMESZ || 834 np->n_descsz != ELF_NOTE_PAX_DESCSZ || 835 memcmp(ndata, ELF_NOTE_PAX_NAME, 836 ELF_NOTE_PAX_NAMESZ)) 837 goto next; 838 (void)memcpy(&epp->ep_pax_flags, 839 ndata + ELF_NOTE_PAX_NAMESZ, 840 sizeof(epp->ep_pax_flags)); 841 break; 842 843 default: 844 break; 845 } 846 847 next: 848 free(np, M_TEMP); 849 continue; 850 } 851 852 error = isnetbsd ? 0 : ENOEXEC; 853 out: 854 free(ph, M_TEMP); 855 return error; 856 } 857 858 int 859 netbsd_elf_probe(struct lwp *l, struct exec_package *epp, void *eh, char *itp, 860 vaddr_t *pos) 861 { 862 int error; 863 864 if ((error = netbsd_elf_signature(l, epp, eh)) != 0) 865 return error; 866 #ifdef ELF_INTERP_NON_RELOCATABLE 867 *pos = ELF_LINK_ADDR; 868 #endif 869 return 0; 870 } 871