exec_elf32.c revision 1.107
1/* $NetBSD: exec_elf32.c,v 1.107 2005/10/07 08:33:10 simonb 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 1.107 2005/10/07 08:33:10 simonb 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#include <sys/param.h> 75#include <sys/proc.h> 76#include <sys/malloc.h> 77#include <sys/namei.h> 78#include <sys/vnode.h> 79#include <sys/exec.h> 80#include <sys/exec_elf.h> 81#include <sys/syscall.h> 82#include <sys/signalvar.h> 83#include <sys/mount.h> 84#include <sys/stat.h> 85 86#include <machine/cpu.h> 87#include <machine/reg.h> 88 89extern const struct emul emul_netbsd; 90 91#define elf_check_header ELFNAME(check_header) 92#define elf_copyargs ELFNAME(copyargs) 93#define elf_load_file ELFNAME(load_file) 94#define elf_load_psection ELFNAME(load_psection) 95#define exec_elf_makecmds ELFNAME2(exec,makecmds) 96#define netbsd_elf_signature ELFNAME2(netbsd,signature) 97#define netbsd_elf_probe ELFNAME2(netbsd,probe) 98 99int elf_load_file(struct proc *, struct exec_package *, char *, 100 struct exec_vmcmd_set *, u_long *, struct elf_args *, Elf_Addr *); 101void elf_load_psection(struct exec_vmcmd_set *, struct vnode *, 102 const Elf_Phdr *, Elf_Addr *, u_long *, int *, int); 103 104int netbsd_elf_signature(struct proc *, struct exec_package *, Elf_Ehdr *); 105int netbsd_elf_probe(struct proc *, struct exec_package *, void *, char *, 106 vaddr_t *); 107 108/* round up and down to page boundaries. */ 109#define ELF_ROUND(a, b) (((a) + (b) - 1) & ~((b) - 1)) 110#define ELF_TRUNC(a, b) ((a) & ~((b) - 1)) 111 112#define MAXPHNUM 50 113 114/* 115 * Copy arguments onto the stack in the normal way, but add some 116 * extra information in case of dynamic binding. 117 */ 118int 119elf_copyargs(struct proc *p, struct exec_package *pack, 120 struct ps_strings *arginfo, char **stackp, void *argp) 121{ 122 size_t len; 123 AuxInfo ai[ELF_AUX_ENTRIES], *a; 124 struct elf_args *ap; 125 int error; 126 127 if ((error = copyargs(p, pack, arginfo, stackp, argp)) != 0) 128 return error; 129 130 a = ai; 131 132 /* 133 * Push extra arguments on the stack needed by dynamically 134 * linked binaries 135 */ 136 if ((ap = (struct elf_args *)pack->ep_emul_arg)) { 137 struct vattr *vap = pack->ep_vap; 138 139 a->a_type = AT_PHDR; 140 a->a_v = ap->arg_phaddr; 141 a++; 142 143 a->a_type = AT_PHENT; 144 a->a_v = ap->arg_phentsize; 145 a++; 146 147 a->a_type = AT_PHNUM; 148 a->a_v = ap->arg_phnum; 149 a++; 150 151 a->a_type = AT_PAGESZ; 152 a->a_v = PAGE_SIZE; 153 a++; 154 155 a->a_type = AT_BASE; 156 a->a_v = ap->arg_interp; 157 a++; 158 159 a->a_type = AT_FLAGS; 160 a->a_v = 0; 161 a++; 162 163 a->a_type = AT_ENTRY; 164 a->a_v = ap->arg_entry; 165 a++; 166 167 a->a_type = AT_EUID; 168 if (vap->va_mode & S_ISUID) 169 a->a_v = vap->va_uid; 170 else 171 a->a_v = p->p_ucred->cr_uid; 172 a++; 173 174 a->a_type = AT_RUID; 175 a->a_v = p->p_cred->p_ruid; 176 a++; 177 178 a->a_type = AT_EGID; 179 if (vap->va_mode & S_ISGID) 180 a->a_v = vap->va_gid; 181 else 182 a->a_v = p->p_ucred->cr_gid; 183 a++; 184 185 a->a_type = AT_RGID; 186 a->a_v = p->p_cred->p_rgid; 187 a++; 188 189 free(ap, M_TEMP); 190 pack->ep_emul_arg = NULL; 191 } 192 193 a->a_type = AT_NULL; 194 a->a_v = 0; 195 a++; 196 197 len = (a - ai) * sizeof(AuxInfo); 198 if ((error = copyout(ai, *stackp, len)) != 0) 199 return error; 200 *stackp += len; 201 202 return 0; 203} 204 205/* 206 * elf_check_header(): 207 * 208 * Check header for validity; return 0 of ok ENOEXEC if error 209 */ 210int 211elf_check_header(Elf_Ehdr *eh, int type) 212{ 213 214 if (memcmp(eh->e_ident, ELFMAG, SELFMAG) != 0 || 215 eh->e_ident[EI_CLASS] != ELFCLASS) 216 return ENOEXEC; 217 218 switch (eh->e_machine) { 219 220 ELFDEFNNAME(MACHDEP_ID_CASES) 221 222 default: 223 return ENOEXEC; 224 } 225 226 if (ELF_EHDR_FLAGS_OK(eh) == 0) 227 return ENOEXEC; 228 229 if (eh->e_type != type) 230 return ENOEXEC; 231 232 if (eh->e_shnum > 32768 || eh->e_phnum > 128) 233 return ENOEXEC; 234 235 return 0; 236} 237 238/* 239 * elf_load_psection(): 240 * 241 * Load a psection at the appropriate address 242 */ 243void 244elf_load_psection(struct exec_vmcmd_set *vcset, struct vnode *vp, 245 const Elf_Phdr *ph, Elf_Addr *addr, u_long *size, int *prot, int flags) 246{ 247 u_long msize, psize, rm, rf; 248 long diff, offset; 249 250 /* 251 * If the user specified an address, then we load there. 252 */ 253 if (*addr == ELFDEFNNAME(NO_ADDR)) 254 *addr = ph->p_vaddr; 255 256 if (ph->p_align > 1) { 257 /* 258 * Make sure we are virtually aligned as we are supposed to be. 259 */ 260 diff = ph->p_vaddr - ELF_TRUNC(ph->p_vaddr, ph->p_align); 261 KASSERT(*addr - diff == ELF_TRUNC(*addr, ph->p_align)); 262 /* 263 * But make sure to not map any pages before the start of the 264 * psection by limiting the difference to within a page. 265 */ 266 diff &= PAGE_MASK; 267 } else 268 diff = 0; 269 270 *prot |= (ph->p_flags & PF_R) ? VM_PROT_READ : 0; 271 *prot |= (ph->p_flags & PF_W) ? VM_PROT_WRITE : 0; 272 *prot |= (ph->p_flags & PF_X) ? VM_PROT_EXECUTE : 0; 273 274 /* 275 * Adjust everything so it all starts on a page boundary. 276 */ 277 *addr -= diff; 278 offset = ph->p_offset - diff; 279 *size = ph->p_filesz + diff; 280 msize = ph->p_memsz + diff; 281 282 if (ph->p_align >= PAGE_SIZE) { 283 if ((ph->p_flags & PF_W) != 0) { 284 /* 285 * Because the pagedvn pager can't handle zero fill 286 * of the last data page if it's not page aligned we 287 * map the last page readvn. 288 */ 289 psize = trunc_page(*size); 290 } else { 291 psize = round_page(*size); 292 } 293 } else { 294 psize = *size; 295 } 296 297 if (psize > 0) { 298 NEW_VMCMD2(vcset, ph->p_align < PAGE_SIZE ? 299 vmcmd_map_readvn : vmcmd_map_pagedvn, psize, *addr, vp, 300 offset, *prot, flags); 301 flags &= VMCMD_RELATIVE; 302 } 303 if (psize < *size) { 304 NEW_VMCMD2(vcset, vmcmd_map_readvn, *size - psize, 305 *addr + psize, vp, offset + psize, *prot, flags); 306 } 307 308 /* 309 * Check if we need to extend the size of the segment (does 310 * bss extend page the next page boundary)? 311 */ 312 rm = round_page(*addr + msize); 313 rf = round_page(*addr + *size); 314 315 if (rm != rf) { 316 NEW_VMCMD2(vcset, vmcmd_map_zero, rm - rf, rf, NULLVP, 317 0, *prot, flags & VMCMD_RELATIVE); 318 *size = msize; 319 } 320} 321 322/* 323 * elf_load_file(): 324 * 325 * Load a file (interpreter/library) pointed to by path 326 * [stolen from coff_load_shlib()]. Made slightly generic 327 * so it might be used externally. 328 */ 329int 330elf_load_file(struct proc *p, struct exec_package *epp, char *path, 331 struct exec_vmcmd_set *vcset, u_long *entryoff, struct elf_args *ap, 332 Elf_Addr *last) 333{ 334 int error, i; 335 struct nameidata nd; 336 struct vnode *vp; 337 struct vattr attr; 338 Elf_Ehdr eh; 339 Elf_Phdr *ph = NULL; 340 const Elf_Phdr *ph0; 341 const Elf_Phdr *base_ph; 342 const Elf_Phdr *last_ph; 343 u_long phsize; 344 Elf_Addr addr = *last; 345 346 /* 347 * 1. open file 348 * 2. read filehdr 349 * 3. map text, data, and bss out of it using VM_* 350 */ 351 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, path, p); 352 if ((error = namei(&nd)) != 0) 353 return error; 354 vp = nd.ni_vp; 355 356 /* 357 * Similarly, if it's not marked as executable, or it's not a regular 358 * file, we don't allow it to be used. 359 */ 360 if (vp->v_type != VREG) { 361 error = EACCES; 362 goto badunlock; 363 } 364 if ((error = VOP_ACCESS(vp, VEXEC, p->p_ucred, p)) != 0) 365 goto badunlock; 366 367 /* get attributes */ 368 if ((error = VOP_GETATTR(vp, &attr, p->p_ucred, p)) != 0) 369 goto badunlock; 370 371 /* 372 * Check mount point. Though we're not trying to exec this binary, 373 * we will be executing code from it, so if the mount point 374 * disallows execution or set-id-ness, we punt or kill the set-id. 375 */ 376 if (vp->v_mount->mnt_flag & MNT_NOEXEC) { 377 error = EACCES; 378 goto badunlock; 379 } 380 if (vp->v_mount->mnt_flag & MNT_NOSUID) 381 epp->ep_vap->va_mode &= ~(S_ISUID | S_ISGID); 382 383#ifdef notyet /* XXX cgd 960926 */ 384 XXX cgd 960926: (maybe) VOP_OPEN it (and VOP_CLOSE in copyargs?) 385#endif 386 387 error = vn_marktext(vp); 388 if (error) 389 goto badunlock; 390 391 VOP_UNLOCK(vp, 0); 392 393 if ((error = exec_read_from(p, vp, 0, &eh, sizeof(eh))) != 0) 394 goto bad; 395 396 if ((error = elf_check_header(&eh, ET_DYN)) != 0) 397 goto bad; 398 399 if (eh.e_phnum > MAXPHNUM) 400 goto bad; 401 402 phsize = eh.e_phnum * sizeof(Elf_Phdr); 403 ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK); 404 405 if ((error = exec_read_from(p, vp, eh.e_phoff, ph, phsize)) != 0) 406 goto bad; 407 408#ifdef ELF_INTERP_NON_RELOCATABLE 409 /* 410 * Evil hack: Only MIPS should be non-relocatable, and the 411 * psections should have a high address (typically 0x5ffe0000). 412 * If it's now relocatable, it should be linked at 0 and the 413 * psections should have zeros in the upper part of the address. 414 * Otherwise, force the load at the linked address. 415 */ 416 if (*last == ELF_LINK_ADDR && (ph->p_vaddr & 0xffff0000) == 0) 417 *last = ELFDEFNNAME(NO_ADDR); 418#endif 419 420 /* 421 * If no position to load the interpreter was set by a probe 422 * function, pick the same address that a non-fixed mmap(0, ..) 423 * would (i.e. something safely out of the way). 424 */ 425 if (*last == ELFDEFNNAME(NO_ADDR)) { 426 u_long limit = 0; 427 /* 428 * Find the start and ending addresses of the psections to 429 * be loaded. This will give us the size. 430 */ 431 for (i = 0, ph0 = ph, base_ph = NULL; i < eh.e_phnum; 432 i++, ph0++) { 433 if (ph0->p_type == PT_LOAD) { 434 u_long psize = ph0->p_vaddr + ph0->p_memsz; 435 if (base_ph == NULL) 436 base_ph = ph0; 437 if (psize > limit) 438 limit = psize; 439 } 440 } 441 442 /* 443 * Now compute the size and load address. 444 */ 445 addr = (*epp->ep_esch->es_emul->e_vm_default_addr)(p, 446 epp->ep_daddr, 447 round_page(limit) - trunc_page(base_ph->p_vaddr)); 448 } else 449 addr = *last; /* may be ELF_LINK_ADDR */ 450 451 /* 452 * Load all the necessary sections 453 */ 454 for (i = 0, ph0 = ph, base_ph = NULL, last_ph = NULL; 455 i < eh.e_phnum; i++, ph0++) { 456 switch (ph0->p_type) { 457 case PT_LOAD: { 458 u_long size; 459 int prot = 0; 460 int flags; 461 462 if (base_ph == NULL) { 463 /* 464 * First encountered psection is always the 465 * base psection. Make sure it's aligned 466 * properly (align down for topdown and align 467 * upwards for not topdown). 468 */ 469 base_ph = ph0; 470 flags = VMCMD_BASE; 471 if (addr == ELF_LINK_ADDR) 472 addr = ph0->p_vaddr; 473 if (p->p_vmspace->vm_map.flags & VM_MAP_TOPDOWN) 474 addr = ELF_TRUNC(addr, ph0->p_align); 475 else 476 addr = ELF_ROUND(addr, ph0->p_align); 477 } else { 478 u_long limit = round_page(last_ph->p_vaddr 479 + last_ph->p_memsz); 480 u_long base = trunc_page(ph0->p_vaddr); 481 482 /* 483 * If there is a gap in between the psections, 484 * map it as inaccessible so nothing else 485 * mmap'ed will be placed there. 486 */ 487 if (limit != base) { 488 NEW_VMCMD2(vcset, vmcmd_map_zero, 489 base - limit, 490 limit - base_ph->p_vaddr, NULLVP, 491 0, VM_PROT_NONE, VMCMD_RELATIVE); 492 } 493 494 addr = ph0->p_vaddr - base_ph->p_vaddr; 495 flags = VMCMD_RELATIVE; 496 } 497 last_ph = ph0; 498 elf_load_psection(vcset, vp, &ph[i], &addr, 499 &size, &prot, flags); 500 /* 501 * If entry is within this psection then this 502 * must contain the .text section. *entryoff is 503 * relative to the base psection. 504 */ 505 if (eh.e_entry >= ph0->p_vaddr && 506 eh.e_entry < (ph0->p_vaddr + size)) { 507 *entryoff = eh.e_entry - base_ph->p_vaddr; 508 } 509 addr += size; 510 break; 511 } 512 513 case PT_DYNAMIC: 514 case PT_PHDR: 515 case PT_NOTE: 516 break; 517 518 default: 519 break; 520 } 521 } 522 523 free(ph, M_TEMP); 524 /* 525 * This value is ignored if TOPDOWN. 526 */ 527 *last = addr; 528 vrele(vp); 529 return 0; 530 531badunlock: 532 VOP_UNLOCK(vp, 0); 533 534bad: 535 if (ph != NULL) 536 free(ph, M_TEMP); 537#ifdef notyet /* XXX cgd 960926 */ 538 (maybe) VOP_CLOSE it 539#endif 540 vrele(vp); 541 return error; 542} 543 544/* 545 * exec_elf_makecmds(): Prepare an Elf binary's exec package 546 * 547 * First, set of the various offsets/lengths in the exec package. 548 * 549 * Then, mark the text image busy (so it can be demand paged) or error 550 * out if this is not possible. Finally, set up vmcmds for the 551 * text, data, bss, and stack segments. 552 */ 553int 554exec_elf_makecmds(struct proc *p, struct exec_package *epp) 555{ 556 Elf_Ehdr *eh = epp->ep_hdr; 557 Elf_Phdr *ph, *pp; 558 Elf_Addr phdr = 0, pos = 0; 559 int error, i, nload; 560 char *interp = NULL; 561 u_long phsize; 562 563 if (epp->ep_hdrvalid < sizeof(Elf_Ehdr)) 564 return ENOEXEC; 565 566 /* 567 * XXX allow for executing shared objects. It seems silly 568 * but other ELF-based systems allow it as well. 569 */ 570 if (elf_check_header(eh, ET_EXEC) != 0 && 571 elf_check_header(eh, ET_DYN) != 0) 572 return ENOEXEC; 573 574 if (eh->e_phnum > MAXPHNUM) 575 return ENOEXEC; 576 577 error = vn_marktext(epp->ep_vp); 578 if (error) 579 return error; 580 581 /* 582 * Allocate space to hold all the program headers, and read them 583 * from the file 584 */ 585 phsize = eh->e_phnum * sizeof(Elf_Phdr); 586 ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK); 587 588 if ((error = exec_read_from(p, epp->ep_vp, eh->e_phoff, ph, phsize)) != 589 0) 590 goto bad; 591 592 epp->ep_taddr = epp->ep_tsize = ELFDEFNNAME(NO_ADDR); 593 epp->ep_daddr = epp->ep_dsize = ELFDEFNNAME(NO_ADDR); 594 595 for (i = 0; i < eh->e_phnum; i++) { 596 pp = &ph[i]; 597 if (pp->p_type == PT_INTERP) { 598 if (pp->p_filesz >= MAXPATHLEN) 599 goto bad; 600 MALLOC(interp, char *, MAXPATHLEN, M_TEMP, M_WAITOK); 601 interp[0] = '\0'; 602 if ((error = exec_read_from(p, epp->ep_vp, 603 pp->p_offset, interp, pp->p_filesz)) != 0) 604 goto bad; 605 break; 606 } 607 } 608 609 /* 610 * On the same architecture, we may be emulating different systems. 611 * See which one will accept this executable. 612 * 613 * Probe functions would normally see if the interpreter (if any) 614 * exists. Emulation packages may possibly replace the interpreter in 615 * interp[] with a changed path (/emul/xxx/<path>). 616 */ 617 pos = ELFDEFNNAME(NO_ADDR); 618 if (epp->ep_esch->u.elf_probe_func) { 619 vaddr_t startp = (vaddr_t)pos; 620 621 error = (*epp->ep_esch->u.elf_probe_func)(p, epp, eh, interp, 622 &startp); 623 if (error) 624 goto bad; 625 pos = (Elf_Addr)startp; 626 } 627 628 /* 629 * Load all the necessary sections 630 */ 631 for (i = nload = 0; i < eh->e_phnum; i++) { 632 Elf_Addr addr = ELFDEFNNAME(NO_ADDR); 633 u_long size = 0; 634 int prot = 0; 635 636 pp = &ph[i]; 637 638 switch (ph[i].p_type) { 639 case PT_LOAD: 640 /* 641 * XXX 642 * Can handle only 2 sections: text and data 643 */ 644 if (nload++ == 2) 645 goto bad; 646 elf_load_psection(&epp->ep_vmcmds, epp->ep_vp, 647 &ph[i], &addr, &size, &prot, VMCMD_FIXED); 648 649 /* 650 * Decide whether it's text or data by looking 651 * at the entry point. 652 */ 653 if (eh->e_entry >= addr && 654 eh->e_entry < (addr + size)) { 655 epp->ep_taddr = addr; 656 epp->ep_tsize = size; 657 if (epp->ep_daddr == ELFDEFNNAME(NO_ADDR)) { 658 epp->ep_daddr = addr; 659 epp->ep_dsize = size; 660 } 661 } else { 662 epp->ep_daddr = addr; 663 epp->ep_dsize = size; 664 } 665 break; 666 667 case PT_SHLIB: 668 /* SCO has these sections. */ 669 case PT_INTERP: 670 /* Already did this one. */ 671 case PT_DYNAMIC: 672 case PT_NOTE: 673 break; 674 675 case PT_PHDR: 676 /* Note address of program headers (in text segment) */ 677 phdr = pp->p_vaddr; 678 break; 679 680 default: 681 /* 682 * Not fatal; we don't need to understand everything. 683 */ 684 break; 685 } 686 } 687 688 /* 689 * Check if we found a dynamically linked binary and arrange to load 690 * its interpreter 691 */ 692 if (interp) { 693 struct elf_args *ap; 694 int j = epp->ep_vmcmds.evs_used; 695 u_long interp_offset; 696 697 MALLOC(ap, struct elf_args *, sizeof(struct elf_args), 698 M_TEMP, M_WAITOK); 699 if ((error = elf_load_file(p, epp, interp, 700 &epp->ep_vmcmds, &interp_offset, ap, &pos)) != 0) { 701 FREE(ap, M_TEMP); 702 goto bad; 703 } 704 ap->arg_interp = epp->ep_vmcmds.evs_cmds[j].ev_addr; 705 epp->ep_entry = ap->arg_interp + interp_offset; 706 ap->arg_phaddr = phdr; 707 708 ap->arg_phentsize = eh->e_phentsize; 709 ap->arg_phnum = eh->e_phnum; 710 ap->arg_entry = eh->e_entry; 711 712 epp->ep_emul_arg = ap; 713 714 FREE(interp, M_TEMP); 715 } else 716 epp->ep_entry = eh->e_entry; 717 718#ifdef ELF_MAP_PAGE_ZERO 719 /* Dell SVR4 maps page zero, yeuch! */ 720 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_map_readvn, PAGE_SIZE, 0, 721 epp->ep_vp, 0, VM_PROT_READ); 722#endif 723 free(ph, M_TEMP); 724 return (*epp->ep_esch->es_setup_stack)(p, epp); 725 726bad: 727 if (interp) 728 FREE(interp, M_TEMP); 729 free(ph, M_TEMP); 730 kill_vmcmds(&epp->ep_vmcmds); 731 return ENOEXEC; 732} 733 734int 735netbsd_elf_signature(struct proc *p, struct exec_package *epp, 736 Elf_Ehdr *eh) 737{ 738 size_t i; 739 Elf_Phdr *ph; 740 size_t phsize; 741 int error; 742 743 if (eh->e_phnum > MAXPHNUM) 744 return ENOEXEC; 745 746 phsize = eh->e_phnum * sizeof(Elf_Phdr); 747 ph = (Elf_Phdr *)malloc(phsize, M_TEMP, M_WAITOK); 748 error = exec_read_from(p, epp->ep_vp, eh->e_phoff, ph, phsize); 749 if (error) 750 goto out; 751 752 for (i = 0; i < eh->e_phnum; i++) { 753 Elf_Phdr *ephp = &ph[i]; 754 Elf_Nhdr *np; 755 756 if (ephp->p_type != PT_NOTE || 757 ephp->p_filesz > 1024 || 758 ephp->p_filesz < sizeof(Elf_Nhdr) + ELF_NOTE_NETBSD_NAMESZ) 759 continue; 760 761 np = (Elf_Nhdr *)malloc(ephp->p_filesz, M_TEMP, M_WAITOK); 762 error = exec_read_from(p, epp->ep_vp, ephp->p_offset, np, 763 ephp->p_filesz); 764 if (error) 765 goto next; 766 767 if (np->n_type != ELF_NOTE_TYPE_NETBSD_TAG || 768 np->n_namesz != ELF_NOTE_NETBSD_NAMESZ || 769 np->n_descsz != ELF_NOTE_NETBSD_DESCSZ || 770 memcmp((caddr_t)(np + 1), ELF_NOTE_NETBSD_NAME, 771 ELF_NOTE_NETBSD_NAMESZ)) 772 goto next; 773 774 error = 0; 775 free(np, M_TEMP); 776 goto out; 777 778 next: 779 free(np, M_TEMP); 780 continue; 781 } 782 783 error = ENOEXEC; 784out: 785 free(ph, M_TEMP); 786 return error; 787} 788 789int 790netbsd_elf_probe(struct proc *p, struct exec_package *epp, 791 void *eh, char *itp, vaddr_t *pos) 792{ 793 int error; 794 795 if ((error = netbsd_elf_signature(p, epp, eh)) != 0) 796 return error; 797#ifdef ELF_INTERP_NON_RELOCATABLE 798 *pos = ELF_LINK_ADDR; 799#endif 800 return 0; 801} 802