1 /* $NetBSD: exec_elf32.c,v 1.126 2007/11/26 19:01:58 pooka 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 1.126 2007/11/26 19:01:58 pooka 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; 134 AuxInfo ai[ELF_AUX_ENTRIES], *a; 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; 142 143 /* 144 * Push extra arguments on the stack needed by dynamically 145 * linked binaries 146 */ 147 if ((ap = (struct elf_args *)pack->ep_emul_arg)) { 148 struct vattr *vap = pack->ep_vap; 149 150 a->a_type = AT_PHDR; 151 a->a_v = ap->arg_phaddr; 152 a++; 153 154 a->a_type = AT_PHENT; 155 a->a_v = ap->arg_phentsize; 156 a++; 157 158 a->a_type = AT_PHNUM; 159 a->a_v = ap->arg_phnum; 160 a++; 161 162 a->a_type = AT_PAGESZ; 163 a->a_v = PAGE_SIZE; 164 a++; 165 166 a->a_type = AT_BASE; 167 a->a_v = ap->arg_interp; 168 a++; 169 170 a->a_type = AT_FLAGS; 171 a->a_v = 0; 172 a++; 173 174 a->a_type = AT_ENTRY; 175 a->a_v = ap->arg_entry; 176 a++; 177 178 a->a_type = AT_EUID; 179 if (vap->va_mode & S_ISUID) 180 a->a_v = vap->va_uid; 181 else 182 a->a_v = kauth_cred_geteuid(l->l_cred); 183 a++; 184 185 a->a_type = AT_RUID; 186 a->a_v = kauth_cred_getuid(l->l_cred); 187 a++; 188 189 a->a_type = AT_EGID; 190 if (vap->va_mode & S_ISGID) 191 a->a_v = vap->va_gid; 192 else 193 a->a_v = kauth_cred_getegid(l->l_cred); 194 a++; 195 196 a->a_type = AT_RGID; 197 a->a_v = kauth_cred_getgid(l->l_cred); 198 a++; 199 200 free(ap, M_TEMP); 201 pack->ep_emul_arg = NULL; 202 } 203 204 a->a_type = AT_NULL; 205 a->a_v = 0; 206 a++; 207 208 len = (a - ai) * sizeof(AuxInfo); 209 if ((error = copyout(ai, *stackp, len)) != 0) 210 return error; 211 *stackp += len; 212 213 return 0; 214 } 215 216 /* 217 * elf_check_header(): 218 * 219 * Check header for validity; return 0 of ok ENOEXEC if error 220 */ 221 int 222 elf_check_header(Elf_Ehdr *eh, int type) 223 { 224 225 if (memcmp(eh->e_ident, ELFMAG, SELFMAG) != 0 || 226 eh->e_ident[EI_CLASS] != ELFCLASS) 227 return ENOEXEC; 228 229 switch (eh->e_machine) { 230 231 ELFDEFNNAME(MACHDEP_ID_CASES) 232 233 default: 234 return ENOEXEC; 235 } 236 237 if (ELF_EHDR_FLAGS_OK(eh) == 0) 238 return ENOEXEC; 239 240 if (eh->e_type != type) 241 return ENOEXEC; 242 243 if (eh->e_shnum > 32768 || eh->e_phnum > 128) 244 return ENOEXEC; 245 246 return 0; 247 } 248 249 /* 250 * elf_load_psection(): 251 * 252 * Load a psection at the appropriate address 253 */ 254 void 255 elf_load_psection(struct exec_vmcmd_set *vcset, struct vnode *vp, 256 const Elf_Phdr *ph, Elf_Addr *addr, u_long *size, int *prot, int flags) 257 { 258 u_long msize, psize, rm, rf; 259 long diff, offset; 260 261 /* 262 * If the user specified an address, then we load there. 263 */ 264 if (*addr == ELFDEFNNAME(NO_ADDR)) 265 *addr = ph->p_vaddr; 266 267 if (ph->p_align > 1) { 268 /* 269 * Make sure we are virtually aligned as we are supposed to be. 270 */ 271 diff = ph->p_vaddr - ELF_TRUNC(ph->p_vaddr, ph->p_align); 272 KASSERT(*addr - diff == ELF_TRUNC(*addr, ph->p_align)); 273 /* 274 * But make sure to not map any pages before the start of the 275 * psection by limiting the difference to within a page. 276 */ 277 diff &= PAGE_MASK; 278 } else 279 diff = 0; 280 281 *prot |= (ph->p_flags & PF_R) ? VM_PROT_READ : 0; 282 *prot |= (ph->p_flags & PF_W) ? VM_PROT_WRITE : 0; 283 *prot |= (ph->p_flags & PF_X) ? VM_PROT_EXECUTE : 0; 284 285 /* 286 * Adjust everything so it all starts on a page boundary. 287 */ 288 *addr -= diff; 289 offset = ph->p_offset - diff; 290 *size = ph->p_filesz + diff; 291 msize = ph->p_memsz + diff; 292 293 if (ph->p_align >= PAGE_SIZE) { 294 if ((ph->p_flags & PF_W) != 0) { 295 /* 296 * Because the pagedvn pager can't handle zero fill 297 * of the last data page if it's not page aligned we 298 * map the last page readvn. 299 */ 300 psize = trunc_page(*size); 301 } else { 302 psize = round_page(*size); 303 } 304 } else { 305 psize = *size; 306 } 307 308 if (psize > 0) { 309 NEW_VMCMD2(vcset, ph->p_align < PAGE_SIZE ? 310 vmcmd_map_readvn : vmcmd_map_pagedvn, psize, *addr, vp, 311 offset, *prot, flags); 312 flags &= VMCMD_RELATIVE; 313 } 314 if (psize < *size) { 315 NEW_VMCMD2(vcset, vmcmd_map_readvn, *size - psize, 316 *addr + psize, vp, offset + psize, *prot, flags); 317 } 318 319 /* 320 * Check if we need to extend the size of the segment (does 321 * bss extend page the next page boundary)? 322 */ 323 rm = round_page(*addr + msize); 324 rf = round_page(*addr + *size); 325 326 if (rm != rf) { 327 NEW_VMCMD2(vcset, vmcmd_map_zero, rm - rf, rf, NULLVP, 328 0, *prot, flags & VMCMD_RELATIVE); 329 *size = msize; 330 } 331 } 332 333 /* 334 * elf_load_file(): 335 * 336 * Load a file (interpreter/library) pointed to by path 337 * [stolen from coff_load_shlib()]. Made slightly generic 338 * so it might be used externally. 339 */ 340 int 341 elf_load_file(struct lwp *l, struct exec_package *epp, char *path, 342 struct exec_vmcmd_set *vcset, u_long *entryoff, struct elf_args *ap, 343 Elf_Addr *last) 344 { 345 int error, i; 346 struct vnode *vp; 347 struct vattr attr; 348 Elf_Ehdr eh; 349 Elf_Phdr *ph = NULL; 350 const Elf_Phdr *ph0; 351 const Elf_Phdr *base_ph; 352 const Elf_Phdr *last_ph; 353 u_long phsize; 354 Elf_Addr addr = *last; 355 struct proc *p; 356 357 p = l->l_proc; 358 359 /* 360 * 1. open file 361 * 2. read filehdr 362 * 3. map text, data, and bss out of it using VM_* 363 */ 364 vp = epp->ep_interp; 365 if (vp == NULL) { 366 error = emul_find_interp(l, epp, path); 367 if (error != 0) 368 return error; 369 vp = epp->ep_interp; 370 } 371 /* We'll tidy this ourselves - otherwise we have locking issues */ 372 epp->ep_interp = NULL; 373 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 374 375 /* 376 * Similarly, if it's not marked as executable, or it's not a regular 377 * file, we don't allow it to be used. 378 */ 379 if (vp->v_type != VREG) { 380 error = EACCES; 381 goto badunlock; 382 } 383 if ((error = VOP_ACCESS(vp, VEXEC, l->l_cred)) != 0) 384 goto badunlock; 385 386 /* get attributes */ 387 if ((error = VOP_GETATTR(vp, &attr, l->l_cred)) != 0) 388 goto badunlock; 389 390 /* 391 * Check mount point. Though we're not trying to exec this binary, 392 * we will be executing code from it, so if the mount point 393 * disallows execution or set-id-ness, we punt or kill the set-id. 394 */ 395 if (vp->v_mount->mnt_flag & MNT_NOEXEC) { 396 error = EACCES; 397 goto badunlock; 398 } 399 if (vp->v_mount->mnt_flag & MNT_NOSUID) 400 epp->ep_vap->va_mode &= ~(S_ISUID | S_ISGID); 401 402 #ifdef notyet /* XXX cgd 960926 */ 403 XXX cgd 960926: (maybe) VOP_OPEN it (and VOP_CLOSE in copyargs?) 404 #endif 405 406 error = vn_marktext(vp); 407 if (error) 408 goto badunlock; 409 410 VOP_UNLOCK(vp, 0); 411 412 if ((error = exec_read_from(l, vp, 0, &eh, sizeof(eh))) != 0) 413 goto bad; 414 415 if ((error = elf_check_header(&eh, ET_DYN)) != 0) 416 goto bad; 417 418 if (eh.e_phnum > MAXPHNUM) 419 goto bad; 420 421 phsize = eh.e_phnum * sizeof(Elf_Phdr); 422 ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK); 423 424 if ((error = exec_read_from(l, vp, eh.e_phoff, ph, phsize)) != 0) 425 goto bad; 426 427 #ifdef ELF_INTERP_NON_RELOCATABLE 428 /* 429 * Evil hack: Only MIPS should be non-relocatable, and the 430 * psections should have a high address (typically 0x5ffe0000). 431 * If it's now relocatable, it should be linked at 0 and the 432 * psections should have zeros in the upper part of the address. 433 * Otherwise, force the load at the linked address. 434 */ 435 if (*last == ELF_LINK_ADDR && (ph->p_vaddr & 0xffff0000) == 0) 436 *last = ELFDEFNNAME(NO_ADDR); 437 #endif 438 439 /* 440 * If no position to load the interpreter was set by a probe 441 * function, pick the same address that a non-fixed mmap(0, ..) 442 * would (i.e. something safely out of the way). 443 */ 444 if (*last == ELFDEFNNAME(NO_ADDR)) { 445 u_long limit = 0; 446 /* 447 * Find the start and ending addresses of the psections to 448 * be loaded. This will give us the size. 449 */ 450 for (i = 0, ph0 = ph, base_ph = NULL; i < eh.e_phnum; 451 i++, ph0++) { 452 if (ph0->p_type == PT_LOAD) { 453 u_long psize = ph0->p_vaddr + ph0->p_memsz; 454 if (base_ph == NULL) 455 base_ph = ph0; 456 if (psize > limit) 457 limit = psize; 458 } 459 } 460 461 if (base_ph == NULL) { 462 error = ENOEXEC; 463 goto bad; 464 } 465 466 /* 467 * Now compute the size and load address. 468 */ 469 addr = (*epp->ep_esch->es_emul->e_vm_default_addr)(p, 470 epp->ep_daddr, 471 round_page(limit) - trunc_page(base_ph->p_vaddr)); 472 } else 473 addr = *last; /* may be ELF_LINK_ADDR */ 474 475 /* 476 * Load all the necessary sections 477 */ 478 for (i = 0, ph0 = ph, base_ph = NULL, last_ph = NULL; 479 i < eh.e_phnum; i++, ph0++) { 480 switch (ph0->p_type) { 481 case PT_LOAD: { 482 u_long size; 483 int prot = 0; 484 int flags; 485 486 if (base_ph == NULL) { 487 /* 488 * First encountered psection is always the 489 * base psection. Make sure it's aligned 490 * properly (align down for topdown and align 491 * upwards for not topdown). 492 */ 493 base_ph = ph0; 494 flags = VMCMD_BASE; 495 if (addr == ELF_LINK_ADDR) 496 addr = ph0->p_vaddr; 497 if (p->p_vmspace->vm_map.flags & VM_MAP_TOPDOWN) 498 addr = ELF_TRUNC(addr, ph0->p_align); 499 else 500 addr = ELF_ROUND(addr, ph0->p_align); 501 } else { 502 u_long limit = round_page(last_ph->p_vaddr 503 + last_ph->p_memsz); 504 u_long base = trunc_page(ph0->p_vaddr); 505 506 /* 507 * If there is a gap in between the psections, 508 * map it as inaccessible so nothing else 509 * mmap'ed will be placed there. 510 */ 511 if (limit != base) { 512 NEW_VMCMD2(vcset, vmcmd_map_zero, 513 base - limit, 514 limit - base_ph->p_vaddr, NULLVP, 515 0, VM_PROT_NONE, VMCMD_RELATIVE); 516 } 517 518 addr = ph0->p_vaddr - base_ph->p_vaddr; 519 flags = VMCMD_RELATIVE; 520 } 521 last_ph = ph0; 522 elf_load_psection(vcset, vp, &ph[i], &addr, 523 &size, &prot, flags); 524 /* 525 * If entry is within this psection then this 526 * must contain the .text section. *entryoff is 527 * relative to the base psection. 528 */ 529 if (eh.e_entry >= ph0->p_vaddr && 530 eh.e_entry < (ph0->p_vaddr + size)) { 531 *entryoff = eh.e_entry - base_ph->p_vaddr; 532 } 533 addr += size; 534 break; 535 } 536 537 case PT_DYNAMIC: 538 case PT_PHDR: 539 break; 540 541 case PT_NOTE: 542 break; 543 544 default: 545 break; 546 } 547 } 548 549 free(ph, M_TEMP); 550 /* 551 * This value is ignored if TOPDOWN. 552 */ 553 *last = addr; 554 vrele(vp); 555 return 0; 556 557 badunlock: 558 VOP_UNLOCK(vp, 0); 559 560 bad: 561 if (ph != NULL) 562 free(ph, M_TEMP); 563 #ifdef notyet /* XXX cgd 960926 */ 564 (maybe) VOP_CLOSE it 565 #endif 566 vrele(vp); 567 return error; 568 } 569 570 /* 571 * exec_elf_makecmds(): Prepare an Elf binary's exec package 572 * 573 * First, set of the various offsets/lengths in the exec package. 574 * 575 * Then, mark the text image busy (so it can be demand paged) or error 576 * out if this is not possible. Finally, set up vmcmds for the 577 * text, data, bss, and stack segments. 578 */ 579 int 580 exec_elf_makecmds(struct lwp *l, struct exec_package *epp) 581 { 582 Elf_Ehdr *eh = epp->ep_hdr; 583 Elf_Phdr *ph, *pp; 584 Elf_Addr phdr = 0, pos = 0; 585 int error, i, nload; 586 char *interp = NULL; 587 u_long phsize; 588 struct proc *p; 589 590 if (epp->ep_hdrvalid < sizeof(Elf_Ehdr)) 591 return ENOEXEC; 592 593 /* 594 * XXX allow for executing shared objects. It seems silly 595 * but other ELF-based systems allow it as well. 596 */ 597 if (elf_check_header(eh, ET_EXEC) != 0 && 598 elf_check_header(eh, ET_DYN) != 0) 599 return ENOEXEC; 600 601 if (eh->e_phnum > MAXPHNUM) 602 return ENOEXEC; 603 604 error = vn_marktext(epp->ep_vp); 605 if (error) 606 return error; 607 608 /* 609 * Allocate space to hold all the program headers, and read them 610 * from the file 611 */ 612 p = l->l_proc; 613 phsize = eh->e_phnum * sizeof(Elf_Phdr); 614 ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK); 615 616 if ((error = exec_read_from(l, epp->ep_vp, eh->e_phoff, ph, phsize)) != 617 0) 618 goto bad; 619 620 epp->ep_taddr = epp->ep_tsize = ELFDEFNNAME(NO_ADDR); 621 epp->ep_daddr = epp->ep_dsize = ELFDEFNNAME(NO_ADDR); 622 623 for (i = 0; i < eh->e_phnum; i++) { 624 pp = &ph[i]; 625 if (pp->p_type == PT_INTERP) { 626 if (pp->p_filesz >= MAXPATHLEN) 627 goto bad; 628 interp = PNBUF_GET(); 629 interp[0] = '\0'; 630 if ((error = exec_read_from(l, epp->ep_vp, 631 pp->p_offset, interp, pp->p_filesz)) != 0) 632 goto bad; 633 break; 634 } 635 } 636 637 /* 638 * On the same architecture, we may be emulating different systems. 639 * See which one will accept this executable. 640 * 641 * Probe functions would normally see if the interpreter (if any) 642 * exists. Emulation packages may possibly replace the interpreter in 643 * interp[] with a changed path (/emul/xxx/<path>). 644 */ 645 pos = ELFDEFNNAME(NO_ADDR); 646 if (epp->ep_esch->u.elf_probe_func) { 647 vaddr_t startp = (vaddr_t)pos; 648 649 error = (*epp->ep_esch->u.elf_probe_func)(l, epp, eh, interp, 650 &startp); 651 if (error) 652 goto bad; 653 pos = (Elf_Addr)startp; 654 } 655 656 /* 657 * Load all the necessary sections 658 */ 659 for (i = nload = 0; i < eh->e_phnum; i++) { 660 Elf_Addr addr = ELFDEFNNAME(NO_ADDR); 661 u_long size = 0; 662 int prot = 0; 663 664 pp = &ph[i]; 665 666 switch (ph[i].p_type) { 667 case PT_LOAD: 668 /* 669 * XXX 670 * Can handle only 2 sections: text and data 671 */ 672 if (nload++ == 2) 673 goto bad; 674 elf_load_psection(&epp->ep_vmcmds, epp->ep_vp, 675 &ph[i], &addr, &size, &prot, VMCMD_FIXED); 676 677 /* 678 * Decide whether it's text or data by looking 679 * at the entry point. 680 */ 681 if (eh->e_entry >= addr && 682 eh->e_entry < (addr + size)) { 683 epp->ep_taddr = addr; 684 epp->ep_tsize = size; 685 if (epp->ep_daddr == ELFDEFNNAME(NO_ADDR)) { 686 epp->ep_daddr = addr; 687 epp->ep_dsize = size; 688 } 689 } else { 690 epp->ep_daddr = addr; 691 epp->ep_dsize = size; 692 } 693 break; 694 695 case PT_SHLIB: 696 /* SCO has these sections. */ 697 case PT_INTERP: 698 /* Already did this one. */ 699 case PT_DYNAMIC: 700 break; 701 case PT_NOTE: 702 break; 703 case PT_PHDR: 704 /* Note address of program headers (in text segment) */ 705 phdr = pp->p_vaddr; 706 break; 707 708 default: 709 /* 710 * Not fatal; we don't need to understand everything. 711 */ 712 break; 713 } 714 } 715 716 #if defined(PAX_MPROTECT) || defined(PAX_SEGVGUARD) 717 if (epp->ep_pax_flags) 718 pax_adjust(l, epp->ep_pax_flags); 719 #endif /* PAX_MPROTECT || PAX_SEGVGUARD */ 720 721 /* 722 * Check if we found a dynamically linked binary and arrange to load 723 * its interpreter 724 */ 725 if (interp) { 726 struct elf_args *ap; 727 int j = epp->ep_vmcmds.evs_used; 728 u_long interp_offset; 729 730 MALLOC(ap, struct elf_args *, sizeof(struct elf_args), 731 M_TEMP, M_WAITOK); 732 if ((error = elf_load_file(l, epp, interp, 733 &epp->ep_vmcmds, &interp_offset, ap, &pos)) != 0) { 734 FREE(ap, M_TEMP); 735 goto bad; 736 } 737 ap->arg_interp = epp->ep_vmcmds.evs_cmds[j].ev_addr; 738 epp->ep_entry = ap->arg_interp + interp_offset; 739 ap->arg_phaddr = phdr; 740 741 ap->arg_phentsize = eh->e_phentsize; 742 ap->arg_phnum = eh->e_phnum; 743 ap->arg_entry = eh->e_entry; 744 745 epp->ep_emul_arg = ap; 746 747 PNBUF_PUT(interp); 748 } else 749 epp->ep_entry = eh->e_entry; 750 751 #ifdef ELF_MAP_PAGE_ZERO 752 /* Dell SVR4 maps page zero, yeuch! */ 753 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, PAGE_SIZE, 0, 754 epp->ep_vp, 0, VM_PROT_READ); 755 #endif 756 free(ph, M_TEMP); 757 return (*epp->ep_esch->es_setup_stack)(l, epp); 758 759 bad: 760 if (interp) 761 PNBUF_PUT(interp); 762 free(ph, M_TEMP); 763 kill_vmcmds(&epp->ep_vmcmds); 764 return ENOEXEC; 765 } 766 767 int 768 netbsd_elf_signature(struct lwp *l, struct exec_package *epp, 769 Elf_Ehdr *eh) 770 { 771 size_t i; 772 Elf_Phdr *ph; 773 size_t phsize; 774 int error; 775 int isnetbsd = 0; 776 char *ndata; 777 778 epp->ep_pax_flags = 0; 779 if (eh->e_phnum > MAXPHNUM) 780 return ENOEXEC; 781 782 phsize = eh->e_phnum * sizeof(Elf_Phdr); 783 ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK); 784 error = exec_read_from(l, epp->ep_vp, eh->e_phoff, ph, phsize); 785 if (error) 786 goto out; 787 788 for (i = 0; i < eh->e_phnum; i++) { 789 Elf_Phdr *ephp = &ph[i]; 790 Elf_Nhdr *np; 791 792 if (ephp->p_type != PT_NOTE || 793 ephp->p_filesz > 1024 || 794 ephp->p_filesz < sizeof(Elf_Nhdr) + ELF_NOTE_NETBSD_NAMESZ) 795 continue; 796 797 np = (Elf_Nhdr *)malloc(ephp->p_filesz, M_TEMP, M_WAITOK); 798 error = exec_read_from(l, epp->ep_vp, ephp->p_offset, np, 799 ephp->p_filesz); 800 if (error) 801 goto next; 802 803 ndata = (char *)(np + 1); 804 switch (np->n_type) { 805 case ELF_NOTE_TYPE_NETBSD_TAG: 806 if (np->n_namesz != ELF_NOTE_NETBSD_NAMESZ || 807 np->n_descsz != ELF_NOTE_NETBSD_DESCSZ || 808 memcmp(ndata, ELF_NOTE_NETBSD_NAME, 809 ELF_NOTE_NETBSD_NAMESZ)) 810 goto next; 811 isnetbsd = 1; 812 break; 813 814 case ELF_NOTE_TYPE_PAX_TAG: 815 if (np->n_namesz != ELF_NOTE_PAX_NAMESZ || 816 np->n_descsz != ELF_NOTE_PAX_DESCSZ || 817 memcmp(ndata, ELF_NOTE_PAX_NAME, 818 ELF_NOTE_PAX_NAMESZ)) 819 goto next; 820 (void)memcpy(&epp->ep_pax_flags, 821 ndata + ELF_NOTE_PAX_NAMESZ, 822 sizeof(epp->ep_pax_flags)); 823 break; 824 825 default: 826 break; 827 } 828 829 next: 830 free(np, M_TEMP); 831 continue; 832 } 833 834 error = isnetbsd ? 0 : ENOEXEC; 835 out: 836 free(ph, M_TEMP); 837 return error; 838 } 839 840 int 841 netbsd_elf_probe(struct lwp *l, struct exec_package *epp, void *eh, char *itp, 842 vaddr_t *pos) 843 { 844 int error; 845 846 if ((error = netbsd_elf_signature(l, epp, eh)) != 0) 847 return error; 848 #ifdef ELF_INTERP_NON_RELOCATABLE 849 *pos = ELF_LINK_ADDR; 850 #endif 851 return 0; 852 } 853