1 /*- 2 * Copyright (c) 2000 David O'Brien 3 * Copyright (c) 1995-1996 S�ren Schmidt 4 * Copyright (c) 1996 Peter Wemm 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer 12 * in this position and unchanged. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. The name of the author may not be used to endorse or promote products 17 * derived from this software without specific prior written permission 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 #include <sys/cdefs.h> 32 __FBSDID("$FreeBSD$"); 33 34 #include <sys/param.h> 35 #include <sys/exec.h> 36 #include <sys/fcntl.h> 37 #include <sys/imgact.h> 38 #include <sys/imgact_elf.h> 39 #include <sys/kernel.h> 40 #include <sys/lock.h> 41 #include <sys/malloc.h> 42 #include <sys/mutex.h> 43 #include <sys/mman.h> 44 #include <sys/namei.h> 45 #include <sys/pioctl.h> 46 #include <sys/proc.h> 47 #include <sys/procfs.h> 48 #include <sys/resourcevar.h> 49 #include <sys/systm.h> 50 #include <sys/signalvar.h> 51 #include <sys/stat.h> 52 #include <sys/sx.h> 53 #include <sys/syscall.h> 54 #include <sys/sysctl.h> 55 #include <sys/sysent.h> 56 #include <sys/vnode.h> 57 58 #include <vm/vm.h> 59 #include <vm/vm_kern.h> 60 #include <vm/vm_param.h> 61 #include <vm/pmap.h> 62 #include <vm/vm_map.h> 63 #include <vm/vm_object.h> 64 #include <vm/vm_extern.h> 65 66 #include <machine/elf.h> 67 #include <machine/md_var.h> 68 69 #define OLD_EI_BRAND 8 70 71 static int __elfN(check_header)(const Elf_Ehdr *hdr); 72 static Elf_Brandinfo *__elfN(get_brandinfo)(const Elf_Ehdr *hdr, 73 const char *interp); 74 static int __elfN(load_file)(struct proc *p, const char *file, u_long *addr, 75 u_long *entry, size_t pagesize); 76 static int __elfN(load_section)(struct proc *p, 77 struct vmspace *vmspace, struct vnode *vp, vm_object_t object, 78 vm_offset_t offset, caddr_t vmaddr, size_t memsz, size_t filsz, 79 vm_prot_t prot, size_t pagesize); 80 static int __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp); 81 82 SYSCTL_NODE(_kern, OID_AUTO, __CONCAT(elf, __ELF_WORD_SIZE), CTLFLAG_RW, 0, 83 ""); 84 85 #ifdef __arm__ 86 int __elfN(fallback_brand) = 9; 87 #else 88 int __elfN(fallback_brand) = -1; 89 #endif 90 SYSCTL_INT(__CONCAT(_kern_elf, __ELF_WORD_SIZE), OID_AUTO, 91 fallback_brand, CTLFLAG_RW, &__elfN(fallback_brand), 0, 92 __XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE)) " brand of last resort"); 93 TUNABLE_INT("kern.elf" __XSTRING(__ELF_WORD_SIZE) ".fallback_brand", 94 &__elfN(fallback_brand)); 95 96 static int elf_trace = 0; 97 SYSCTL_INT(_debug, OID_AUTO, __elfN(trace), CTLFLAG_RW, &elf_trace, 0, ""); 98 99 static int elf_legacy_coredump = 0; 100 SYSCTL_INT(_debug, OID_AUTO, __elfN(legacy_coredump), CTLFLAG_RW, 101 &elf_legacy_coredump, 0, ""); 102 103 static Elf_Brandinfo *elf_brand_list[MAX_BRANDS]; 104 105 int 106 __elfN(insert_brand_entry)(Elf_Brandinfo *entry) 107 { 108 int i; 109 110 for (i = 0; i < MAX_BRANDS; i++) { 111 if (elf_brand_list[i] == NULL) { 112 elf_brand_list[i] = entry; 113 break; 114 } 115 } 116 if (i == MAX_BRANDS) 117 return (-1); 118 return (0); 119 } 120 121 int 122 __elfN(remove_brand_entry)(Elf_Brandinfo *entry) 123 { 124 int i; 125 126 for (i = 0; i < MAX_BRANDS; i++) { 127 if (elf_brand_list[i] == entry) { 128 elf_brand_list[i] = NULL; 129 break; 130 } 131 } 132 if (i == MAX_BRANDS) 133 return (-1); 134 return (0); 135 } 136 137 int 138 __elfN(brand_inuse)(Elf_Brandinfo *entry) 139 { 140 struct proc *p; 141 int rval = FALSE; 142 143 sx_slock(&allproc_lock); 144 LIST_FOREACH(p, &allproc, p_list) { 145 if (p->p_sysent == entry->sysvec) { 146 rval = TRUE; 147 break; 148 } 149 } 150 sx_sunlock(&allproc_lock); 151 152 return (rval); 153 } 154 155 static Elf_Brandinfo * 156 __elfN(get_brandinfo)(const Elf_Ehdr *hdr, const char *interp) 157 { 158 Elf_Brandinfo *bi; 159 int i; 160 161 /* 162 * We support three types of branding -- (1) the ELF EI_OSABI field 163 * that SCO added to the ELF spec, (2) FreeBSD 3.x's traditional string 164 * branding w/in the ELF header, and (3) path of the `interp_path' 165 * field. We should also look for an ".note.ABI-tag" ELF section now 166 * in all Linux ELF binaries, FreeBSD 4.1+, and some NetBSD ones. 167 */ 168 169 /* If the executable has a brand, search for it in the brand list. */ 170 for (i = 0; i < MAX_BRANDS; i++) { 171 bi = elf_brand_list[i]; 172 if (bi != NULL && hdr->e_machine == bi->machine && 173 (hdr->e_ident[EI_OSABI] == bi->brand || 174 strncmp((const char *)&hdr->e_ident[OLD_EI_BRAND], 175 bi->compat_3_brand, strlen(bi->compat_3_brand)) == 0)) 176 return (bi); 177 } 178 179 /* Lacking a known brand, search for a recognized interpreter. */ 180 if (interp != NULL) { 181 for (i = 0; i < MAX_BRANDS; i++) { 182 bi = elf_brand_list[i]; 183 if (bi != NULL && hdr->e_machine == bi->machine && 184 strcmp(interp, bi->interp_path) == 0) 185 return (bi); 186 } 187 } 188 189 /* Lacking a recognized interpreter, try the default brand */ 190 for (i = 0; i < MAX_BRANDS; i++) { 191 bi = elf_brand_list[i]; 192 if (bi != NULL && hdr->e_machine == bi->machine && 193 __elfN(fallback_brand) == bi->brand) 194 return (bi); 195 } 196 return (NULL); 197 } 198 199 static int 200 __elfN(check_header)(const Elf_Ehdr *hdr) 201 { 202 Elf_Brandinfo *bi; 203 int i; 204 205 if (!IS_ELF(*hdr) || 206 hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || 207 hdr->e_ident[EI_DATA] != ELF_TARG_DATA || 208 hdr->e_ident[EI_VERSION] != EV_CURRENT || 209 hdr->e_phentsize != sizeof(Elf_Phdr) || 210 hdr->e_version != ELF_TARG_VER) 211 return (ENOEXEC); 212 213 /* 214 * Make sure we have at least one brand for this machine. 215 */ 216 217 for (i = 0; i < MAX_BRANDS; i++) { 218 bi = elf_brand_list[i]; 219 if (bi != NULL && bi->machine == hdr->e_machine) 220 break; 221 } 222 if (i == MAX_BRANDS) 223 return (ENOEXEC); 224 225 return (0); 226 } 227 228 static int 229 __elfN(map_partial)(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 230 vm_offset_t start, vm_offset_t end, vm_prot_t prot, 231 vm_prot_t max) 232 { 233 int error, rv; 234 vm_offset_t off; 235 vm_offset_t data_buf = 0; 236 237 /* 238 * Create the page if it doesn't exist yet. Ignore errors. 239 */ 240 vm_map_lock(map); 241 vm_map_insert(map, NULL, 0, trunc_page(start), round_page(end), max, 242 max, 0); 243 vm_map_unlock(map); 244 245 /* 246 * Find the page from the underlying object. 247 */ 248 if (object) { 249 vm_object_reference(object); 250 rv = vm_map_find(exec_map, 251 object, 252 trunc_page(offset), 253 &data_buf, 254 PAGE_SIZE, 255 TRUE, 256 VM_PROT_READ, 257 VM_PROT_ALL, 258 MAP_COPY_ON_WRITE | MAP_PREFAULT_PARTIAL); 259 if (rv != KERN_SUCCESS) { 260 vm_object_deallocate(object); 261 return (rv); 262 } 263 264 off = offset - trunc_page(offset); 265 error = copyout((caddr_t)data_buf + off, (caddr_t)start, 266 end - start); 267 vm_map_remove(exec_map, data_buf, data_buf + PAGE_SIZE); 268 if (error) { 269 return (KERN_FAILURE); 270 } 271 } 272 273 return (KERN_SUCCESS); 274 } 275 276 static int 277 __elfN(map_insert)(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 278 vm_offset_t start, vm_offset_t end, vm_prot_t prot, 279 vm_prot_t max, int cow) 280 { 281 vm_offset_t data_buf, off; 282 vm_size_t sz; 283 int error, rv; 284 285 if (start != trunc_page(start)) { 286 rv = __elfN(map_partial)(map, object, offset, start, 287 round_page(start), prot, max); 288 if (rv) 289 return (rv); 290 offset += round_page(start) - start; 291 start = round_page(start); 292 } 293 if (end != round_page(end)) { 294 rv = __elfN(map_partial)(map, object, offset + 295 trunc_page(end) - start, trunc_page(end), end, prot, max); 296 if (rv) 297 return (rv); 298 end = trunc_page(end); 299 } 300 if (end > start) { 301 if (offset & PAGE_MASK) { 302 /* 303 * The mapping is not page aligned. This means we have 304 * to copy the data. Sigh. 305 */ 306 rv = vm_map_find(map, 0, 0, &start, end - start, 307 FALSE, prot, max, 0); 308 if (rv) 309 return (rv); 310 data_buf = 0; 311 while (start < end) { 312 vm_object_reference(object); 313 rv = vm_map_find(exec_map, 314 object, 315 trunc_page(offset), 316 &data_buf, 317 2 * PAGE_SIZE, 318 TRUE, 319 VM_PROT_READ, 320 VM_PROT_ALL, 321 (MAP_COPY_ON_WRITE 322 | MAP_PREFAULT_PARTIAL)); 323 if (rv != KERN_SUCCESS) { 324 vm_object_deallocate(object); 325 return (rv); 326 } 327 off = offset - trunc_page(offset); 328 sz = end - start; 329 if (sz > PAGE_SIZE) 330 sz = PAGE_SIZE; 331 error = copyout((caddr_t)data_buf + off, 332 (caddr_t)start, sz); 333 vm_map_remove(exec_map, data_buf, 334 data_buf + 2 * PAGE_SIZE); 335 if (error) { 336 return (KERN_FAILURE); 337 } 338 start += sz; 339 } 340 rv = KERN_SUCCESS; 341 } else { 342 vm_map_lock(map); 343 rv = vm_map_insert(map, object, offset, start, end, 344 prot, max, cow); 345 vm_map_unlock(map); 346 } 347 return (rv); 348 } else { 349 return (KERN_SUCCESS); 350 } 351 } 352 353 static int 354 __elfN(load_section)(struct proc *p, struct vmspace *vmspace, 355 struct vnode *vp, vm_object_t object, vm_offset_t offset, 356 caddr_t vmaddr, size_t memsz, size_t filsz, vm_prot_t prot, 357 size_t pagesize) 358 { 359 size_t map_len; 360 vm_offset_t map_addr; 361 int error, rv, cow; 362 size_t copy_len; 363 vm_offset_t file_addr; 364 vm_offset_t data_buf = 0; 365 366 GIANT_REQUIRED; 367 368 error = 0; 369 370 /* 371 * It's necessary to fail if the filsz + offset taken from the 372 * header is greater than the actual file pager object's size. 373 * If we were to allow this, then the vm_map_find() below would 374 * walk right off the end of the file object and into the ether. 375 * 376 * While I'm here, might as well check for something else that 377 * is invalid: filsz cannot be greater than memsz. 378 */ 379 if ((off_t)filsz + offset > object->un_pager.vnp.vnp_size || 380 filsz > memsz) { 381 uprintf("elf_load_section: truncated ELF file\n"); 382 return (ENOEXEC); 383 } 384 385 #define trunc_page_ps(va, ps) ((va) & ~(ps - 1)) 386 #define round_page_ps(va, ps) (((va) + (ps - 1)) & ~(ps - 1)) 387 388 map_addr = trunc_page_ps((vm_offset_t)vmaddr, pagesize); 389 file_addr = trunc_page_ps(offset, pagesize); 390 391 /* 392 * We have two choices. We can either clear the data in the last page 393 * of an oversized mapping, or we can start the anon mapping a page 394 * early and copy the initialized data into that first page. We 395 * choose the second.. 396 */ 397 if (memsz > filsz) 398 map_len = trunc_page_ps(offset + filsz, pagesize) - file_addr; 399 else 400 map_len = round_page_ps(offset + filsz, pagesize) - file_addr; 401 402 if (map_len != 0) { 403 vm_object_reference(object); 404 405 /* cow flags: don't dump readonly sections in core */ 406 cow = MAP_COPY_ON_WRITE | MAP_PREFAULT | 407 (prot & VM_PROT_WRITE ? 0 : MAP_DISABLE_COREDUMP); 408 409 rv = __elfN(map_insert)(&vmspace->vm_map, 410 object, 411 file_addr, /* file offset */ 412 map_addr, /* virtual start */ 413 map_addr + map_len,/* virtual end */ 414 prot, 415 VM_PROT_ALL, 416 cow); 417 if (rv != KERN_SUCCESS) { 418 vm_object_deallocate(object); 419 return (EINVAL); 420 } 421 422 /* we can stop now if we've covered it all */ 423 if (memsz == filsz) { 424 return (0); 425 } 426 } 427 428 429 /* 430 * We have to get the remaining bit of the file into the first part 431 * of the oversized map segment. This is normally because the .data 432 * segment in the file is extended to provide bss. It's a neat idea 433 * to try and save a page, but it's a pain in the behind to implement. 434 */ 435 copy_len = (offset + filsz) - trunc_page_ps(offset + filsz, pagesize); 436 map_addr = trunc_page_ps((vm_offset_t)vmaddr + filsz, pagesize); 437 map_len = round_page_ps((vm_offset_t)vmaddr + memsz, pagesize) - 438 map_addr; 439 440 /* This had damn well better be true! */ 441 if (map_len != 0) { 442 rv = __elfN(map_insert)(&vmspace->vm_map, NULL, 0, map_addr, 443 map_addr + map_len, VM_PROT_ALL, VM_PROT_ALL, 0); 444 if (rv != KERN_SUCCESS) { 445 return (EINVAL); 446 } 447 } 448 449 if (copy_len != 0) { 450 vm_offset_t off; 451 vm_object_reference(object); 452 rv = vm_map_find(exec_map, 453 object, 454 trunc_page(offset + filsz), 455 &data_buf, 456 PAGE_SIZE, 457 TRUE, 458 VM_PROT_READ, 459 VM_PROT_ALL, 460 MAP_COPY_ON_WRITE | MAP_PREFAULT_PARTIAL); 461 if (rv != KERN_SUCCESS) { 462 vm_object_deallocate(object); 463 return (EINVAL); 464 } 465 466 /* send the page fragment to user space */ 467 off = trunc_page_ps(offset + filsz, pagesize) - 468 trunc_page(offset + filsz); 469 error = copyout((caddr_t)data_buf + off, (caddr_t)map_addr, 470 copy_len); 471 vm_map_remove(exec_map, data_buf, data_buf + PAGE_SIZE); 472 if (error) { 473 return (error); 474 } 475 } 476 477 /* 478 * set it to the specified protection. 479 * XXX had better undo the damage from pasting over the cracks here! 480 */ 481 vm_map_protect(&vmspace->vm_map, trunc_page(map_addr), 482 round_page(map_addr + map_len), prot, FALSE); 483 484 return (error); 485 } 486 487 /* 488 * Load the file "file" into memory. It may be either a shared object 489 * or an executable. 490 * 491 * The "addr" reference parameter is in/out. On entry, it specifies 492 * the address where a shared object should be loaded. If the file is 493 * an executable, this value is ignored. On exit, "addr" specifies 494 * where the file was actually loaded. 495 * 496 * The "entry" reference parameter is out only. On exit, it specifies 497 * the entry point for the loaded file. 498 */ 499 static int 500 __elfN(load_file)(struct proc *p, const char *file, u_long *addr, 501 u_long *entry, size_t pagesize) 502 { 503 struct { 504 struct nameidata nd; 505 struct vattr attr; 506 struct image_params image_params; 507 } *tempdata; 508 const Elf_Ehdr *hdr = NULL; 509 const Elf_Phdr *phdr = NULL; 510 struct nameidata *nd; 511 struct vmspace *vmspace = p->p_vmspace; 512 struct vattr *attr; 513 struct image_params *imgp; 514 vm_prot_t prot; 515 u_long rbase; 516 u_long base_addr = 0; 517 int error, i, numsegs; 518 519 if (curthread->td_proc != p) 520 panic("elf_load_file - thread"); /* XXXKSE DIAGNOSTIC */ 521 522 tempdata = malloc(sizeof(*tempdata), M_TEMP, M_WAITOK); 523 nd = &tempdata->nd; 524 attr = &tempdata->attr; 525 imgp = &tempdata->image_params; 526 527 /* 528 * Initialize part of the common data 529 */ 530 imgp->proc = p; 531 imgp->userspace_argv = NULL; 532 imgp->userspace_envv = NULL; 533 imgp->attr = attr; 534 imgp->firstpage = NULL; 535 imgp->image_header = NULL; 536 imgp->object = NULL; 537 imgp->execlabel = NULL; 538 539 /* XXXKSE */ 540 NDINIT(nd, LOOKUP, LOCKLEAF|FOLLOW, UIO_SYSSPACE, file, curthread); 541 542 if ((error = namei(nd)) != 0) { 543 nd->ni_vp = NULL; 544 goto fail; 545 } 546 NDFREE(nd, NDF_ONLY_PNBUF); 547 imgp->vp = nd->ni_vp; 548 549 /* 550 * Check permissions, modes, uid, etc on the file, and "open" it. 551 */ 552 error = exec_check_permissions(imgp); 553 if (error) { 554 VOP_UNLOCK(nd->ni_vp, 0, curthread); /* XXXKSE */ 555 goto fail; 556 } 557 558 error = exec_map_first_page(imgp); 559 /* 560 * Also make certain that the interpreter stays the same, so set 561 * its VV_TEXT flag, too. 562 */ 563 if (error == 0) 564 nd->ni_vp->v_vflag |= VV_TEXT; 565 566 VOP_GETVOBJECT(nd->ni_vp, &imgp->object); 567 vm_object_reference(imgp->object); 568 569 VOP_UNLOCK(nd->ni_vp, 0, curthread); /* XXXKSE */ 570 if (error) 571 goto fail; 572 573 hdr = (const Elf_Ehdr *)imgp->image_header; 574 if ((error = __elfN(check_header)(hdr)) != 0) 575 goto fail; 576 if (hdr->e_type == ET_DYN) 577 rbase = *addr; 578 else if (hdr->e_type == ET_EXEC) 579 rbase = 0; 580 else { 581 error = ENOEXEC; 582 goto fail; 583 } 584 585 /* Only support headers that fit within first page for now */ 586 /* (multiplication of two Elf_Half fields will not overflow) */ 587 if ((hdr->e_phoff > PAGE_SIZE) || 588 (hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE - hdr->e_phoff) { 589 error = ENOEXEC; 590 goto fail; 591 } 592 593 phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff); 594 595 for (i = 0, numsegs = 0; i < hdr->e_phnum; i++) { 596 if (phdr[i].p_type == PT_LOAD) { /* Loadable segment */ 597 prot = 0; 598 if (phdr[i].p_flags & PF_X) 599 prot |= VM_PROT_EXECUTE; 600 if (phdr[i].p_flags & PF_W) 601 prot |= VM_PROT_WRITE; 602 if (phdr[i].p_flags & PF_R) 603 prot |= VM_PROT_READ; 604 605 if ((error = __elfN(load_section)(p, vmspace, 606 nd->ni_vp, imgp->object, phdr[i].p_offset, 607 (caddr_t)(uintptr_t)phdr[i].p_vaddr + rbase, 608 phdr[i].p_memsz, phdr[i].p_filesz, prot, 609 pagesize)) != 0) 610 goto fail; 611 /* 612 * Establish the base address if this is the 613 * first segment. 614 */ 615 if (numsegs == 0) 616 base_addr = trunc_page(phdr[i].p_vaddr + 617 rbase); 618 numsegs++; 619 } 620 } 621 *addr = base_addr; 622 *entry = (unsigned long)hdr->e_entry + rbase; 623 624 fail: 625 if (imgp->firstpage) 626 exec_unmap_first_page(imgp); 627 if (imgp->object) 628 vm_object_deallocate(imgp->object); 629 630 if (nd->ni_vp) 631 vrele(nd->ni_vp); 632 633 free(tempdata, M_TEMP); 634 635 return (error); 636 } 637 638 static int 639 __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp) 640 { 641 const Elf_Ehdr *hdr = (const Elf_Ehdr *)imgp->image_header; 642 const Elf_Phdr *phdr; 643 Elf_Auxargs *elf_auxargs = NULL; 644 struct vmspace *vmspace; 645 vm_prot_t prot; 646 u_long text_size = 0, data_size = 0, total_size = 0; 647 u_long text_addr = 0, data_addr = 0; 648 u_long seg_size, seg_addr; 649 u_long addr, entry = 0, proghdr = 0; 650 int error, i; 651 const char *interp = NULL; 652 Elf_Brandinfo *brand_info; 653 char *path; 654 struct thread *td = curthread; 655 struct sysentvec *sv; 656 657 GIANT_REQUIRED; 658 659 /* 660 * Do we have a valid ELF header ? 661 */ 662 if (__elfN(check_header)(hdr) != 0 || hdr->e_type != ET_EXEC) 663 return (-1); 664 665 /* 666 * From here on down, we return an errno, not -1, as we've 667 * detected an ELF file. 668 */ 669 670 if ((hdr->e_phoff > PAGE_SIZE) || 671 (hdr->e_phoff + hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE) { 672 /* Only support headers in first page for now */ 673 return (ENOEXEC); 674 } 675 phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff); 676 677 /* 678 * From this point on, we may have resources that need to be freed. 679 */ 680 681 VOP_UNLOCK(imgp->vp, 0, td); 682 683 for (i = 0; i < hdr->e_phnum; i++) { 684 switch (phdr[i].p_type) { 685 case PT_INTERP: /* Path to interpreter */ 686 if (phdr[i].p_filesz > MAXPATHLEN || 687 phdr[i].p_offset + phdr[i].p_filesz > PAGE_SIZE) { 688 error = ENOEXEC; 689 goto fail; 690 } 691 interp = imgp->image_header + phdr[i].p_offset; 692 break; 693 default: 694 break; 695 } 696 } 697 698 brand_info = __elfN(get_brandinfo)(hdr, interp); 699 if (brand_info == NULL) { 700 uprintf("ELF binary type \"%u\" not known.\n", 701 hdr->e_ident[EI_OSABI]); 702 error = ENOEXEC; 703 goto fail; 704 } 705 sv = brand_info->sysvec; 706 if (interp != NULL && brand_info->interp_newpath != NULL) 707 interp = brand_info->interp_newpath; 708 709 if ((error = exec_extract_strings(imgp)) != 0) 710 goto fail; 711 712 exec_new_vmspace(imgp, sv); 713 714 vmspace = imgp->proc->p_vmspace; 715 716 for (i = 0; i < hdr->e_phnum; i++) { 717 switch (phdr[i].p_type) { 718 case PT_LOAD: /* Loadable segment */ 719 prot = 0; 720 if (phdr[i].p_flags & PF_X) 721 prot |= VM_PROT_EXECUTE; 722 if (phdr[i].p_flags & PF_W) 723 prot |= VM_PROT_WRITE; 724 if (phdr[i].p_flags & PF_R) 725 prot |= VM_PROT_READ; 726 727 #if defined(__ia64__) && __ELF_WORD_SIZE == 32 && defined(IA32_ME_HARDER) 728 /* 729 * Some x86 binaries assume read == executable, 730 * notably the M3 runtime and therefore cvsup 731 */ 732 if (prot & VM_PROT_READ) 733 prot |= VM_PROT_EXECUTE; 734 #endif 735 736 if ((error = __elfN(load_section)(imgp->proc, vmspace, 737 imgp->vp, imgp->object, phdr[i].p_offset, 738 (caddr_t)(uintptr_t)phdr[i].p_vaddr, 739 phdr[i].p_memsz, phdr[i].p_filesz, prot, 740 sv->sv_pagesize)) != 0) 741 goto fail; 742 743 /* 744 * If this segment contains the program headers, 745 * remember their virtual address for the AT_PHDR 746 * aux entry. Static binaries don't usually include 747 * a PT_PHDR entry. 748 */ 749 if (phdr[i].p_offset == 0 && 750 hdr->e_phoff + hdr->e_phnum * hdr->e_phentsize 751 <= phdr[i].p_filesz) 752 proghdr = phdr[i].p_vaddr + hdr->e_phoff; 753 754 seg_addr = trunc_page(phdr[i].p_vaddr); 755 seg_size = round_page(phdr[i].p_memsz + 756 phdr[i].p_vaddr - seg_addr); 757 758 /* 759 * Is this .text or .data? We can't use 760 * VM_PROT_WRITE or VM_PROT_EXEC, it breaks the 761 * alpha terribly and possibly does other bad 762 * things so we stick to the old way of figuring 763 * it out: If the segment contains the program 764 * entry point, it's a text segment, otherwise it 765 * is a data segment. 766 * 767 * Note that obreak() assumes that data_addr + 768 * data_size == end of data load area, and the ELF 769 * file format expects segments to be sorted by 770 * address. If multiple data segments exist, the 771 * last one will be used. 772 */ 773 if (hdr->e_entry >= phdr[i].p_vaddr && 774 hdr->e_entry < (phdr[i].p_vaddr + 775 phdr[i].p_memsz)) { 776 text_size = seg_size; 777 text_addr = seg_addr; 778 entry = (u_long)hdr->e_entry; 779 } else { 780 data_size = seg_size; 781 data_addr = seg_addr; 782 } 783 total_size += seg_size; 784 break; 785 case PT_PHDR: /* Program header table info */ 786 proghdr = phdr[i].p_vaddr; 787 break; 788 default: 789 break; 790 } 791 } 792 793 if (data_addr == 0 && data_size == 0) { 794 data_addr = text_addr; 795 data_size = text_size; 796 } 797 798 /* 799 * Check limits. It should be safe to check the 800 * limits after loading the segments since we do 801 * not actually fault in all the segments pages. 802 */ 803 PROC_LOCK(imgp->proc); 804 if (data_size > lim_cur(imgp->proc, RLIMIT_DATA) || 805 text_size > maxtsiz || 806 total_size > lim_cur(imgp->proc, RLIMIT_VMEM)) { 807 PROC_UNLOCK(imgp->proc); 808 error = ENOMEM; 809 goto fail; 810 } 811 812 vmspace->vm_tsize = text_size >> PAGE_SHIFT; 813 vmspace->vm_taddr = (caddr_t)(uintptr_t)text_addr; 814 vmspace->vm_dsize = data_size >> PAGE_SHIFT; 815 vmspace->vm_daddr = (caddr_t)(uintptr_t)data_addr; 816 817 /* 818 * We load the dynamic linker where a userland call 819 * to mmap(0, ...) would put it. The rationale behind this 820 * calculation is that it leaves room for the heap to grow to 821 * its maximum allowed size. 822 */ 823 addr = round_page((vm_offset_t)imgp->proc->p_vmspace->vm_daddr + 824 lim_max(imgp->proc, RLIMIT_DATA)); 825 PROC_UNLOCK(imgp->proc); 826 827 imgp->entry_addr = entry; 828 829 imgp->proc->p_sysent = sv; 830 if (interp != NULL && brand_info->emul_path != NULL && 831 brand_info->emul_path[0] != '\0') { 832 path = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 833 snprintf(path, MAXPATHLEN, "%s%s", brand_info->emul_path, 834 interp); 835 error = __elfN(load_file)(imgp->proc, path, &addr, 836 &imgp->entry_addr, sv->sv_pagesize); 837 free(path, M_TEMP); 838 if (error == 0) 839 interp = NULL; 840 } 841 if (interp != NULL) { 842 error = __elfN(load_file)(imgp->proc, interp, &addr, 843 &imgp->entry_addr, sv->sv_pagesize); 844 if (error != 0) { 845 uprintf("ELF interpreter %s not found\n", interp); 846 goto fail; 847 } 848 } 849 850 /* 851 * Construct auxargs table (used by the fixup routine) 852 */ 853 elf_auxargs = malloc(sizeof(Elf_Auxargs), M_TEMP, M_WAITOK); 854 elf_auxargs->execfd = -1; 855 elf_auxargs->phdr = proghdr; 856 elf_auxargs->phent = hdr->e_phentsize; 857 elf_auxargs->phnum = hdr->e_phnum; 858 elf_auxargs->pagesz = PAGE_SIZE; 859 elf_auxargs->base = addr; 860 elf_auxargs->flags = 0; 861 elf_auxargs->entry = entry; 862 elf_auxargs->trace = elf_trace; 863 864 imgp->auxargs = elf_auxargs; 865 imgp->interpreted = 0; 866 867 fail: 868 vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY, td); 869 return (error); 870 } 871 872 #define suword __CONCAT(suword, __ELF_WORD_SIZE) 873 874 int 875 __elfN(freebsd_fixup)(register_t **stack_base, struct image_params *imgp) 876 { 877 Elf_Auxargs *args = (Elf_Auxargs *)imgp->auxargs; 878 Elf_Addr *base; 879 Elf_Addr *pos; 880 881 base = (Elf_Addr *)*stack_base; 882 pos = base + (imgp->argc + imgp->envc + 2); 883 884 if (args->trace) { 885 AUXARGS_ENTRY(pos, AT_DEBUG, 1); 886 } 887 if (args->execfd != -1) { 888 AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd); 889 } 890 AUXARGS_ENTRY(pos, AT_PHDR, args->phdr); 891 AUXARGS_ENTRY(pos, AT_PHENT, args->phent); 892 AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum); 893 AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz); 894 AUXARGS_ENTRY(pos, AT_FLAGS, args->flags); 895 AUXARGS_ENTRY(pos, AT_ENTRY, args->entry); 896 AUXARGS_ENTRY(pos, AT_BASE, args->base); 897 AUXARGS_ENTRY(pos, AT_NULL, 0); 898 899 free(imgp->auxargs, M_TEMP); 900 imgp->auxargs = NULL; 901 902 base--; 903 suword(base, (long)imgp->argc); 904 *stack_base = (register_t *)base; 905 return (0); 906 } 907 908 /* 909 * Code for generating ELF core dumps. 910 */ 911 912 typedef void (*segment_callback)(vm_map_entry_t, void *); 913 914 /* Closure for cb_put_phdr(). */ 915 struct phdr_closure { 916 Elf_Phdr *phdr; /* Program header to fill in */ 917 Elf_Off offset; /* Offset of segment in core file */ 918 }; 919 920 /* Closure for cb_size_segment(). */ 921 struct sseg_closure { 922 int count; /* Count of writable segments. */ 923 size_t size; /* Total size of all writable segments. */ 924 }; 925 926 static void cb_put_phdr(vm_map_entry_t, void *); 927 static void cb_size_segment(vm_map_entry_t, void *); 928 static void each_writable_segment(struct thread *, segment_callback, void *); 929 static int __elfN(corehdr)(struct thread *, struct vnode *, struct ucred *, 930 int, void *, size_t); 931 static void __elfN(puthdr)(struct thread *, void *, size_t *, int); 932 static void __elfN(putnote)(void *, size_t *, const char *, int, 933 const void *, size_t); 934 935 extern int osreldate; 936 937 int 938 __elfN(coredump)(td, vp, limit) 939 struct thread *td; 940 struct vnode *vp; 941 off_t limit; 942 { 943 struct ucred *cred = td->td_ucred; 944 int error = 0; 945 struct sseg_closure seginfo; 946 void *hdr; 947 size_t hdrsize; 948 949 /* Size the program segments. */ 950 seginfo.count = 0; 951 seginfo.size = 0; 952 each_writable_segment(td, cb_size_segment, &seginfo); 953 954 /* 955 * Calculate the size of the core file header area by making 956 * a dry run of generating it. Nothing is written, but the 957 * size is calculated. 958 */ 959 hdrsize = 0; 960 __elfN(puthdr)(td, (void *)NULL, &hdrsize, seginfo.count); 961 962 if (hdrsize + seginfo.size >= limit) 963 return (EFAULT); 964 965 /* 966 * Allocate memory for building the header, fill it up, 967 * and write it out. 968 */ 969 hdr = malloc(hdrsize, M_TEMP, M_WAITOK); 970 if (hdr == NULL) { 971 return (EINVAL); 972 } 973 error = __elfN(corehdr)(td, vp, cred, seginfo.count, hdr, hdrsize); 974 975 /* Write the contents of all of the writable segments. */ 976 if (error == 0) { 977 Elf_Phdr *php; 978 off_t offset; 979 int i; 980 981 php = (Elf_Phdr *)((char *)hdr + sizeof(Elf_Ehdr)) + 1; 982 offset = hdrsize; 983 for (i = 0; i < seginfo.count; i++) { 984 error = vn_rdwr_inchunks(UIO_WRITE, vp, 985 (caddr_t)(uintptr_t)php->p_vaddr, 986 php->p_filesz, offset, UIO_USERSPACE, 987 IO_UNIT | IO_DIRECT, cred, NOCRED, NULL, 988 curthread); /* XXXKSE */ 989 if (error != 0) 990 break; 991 offset += php->p_filesz; 992 php++; 993 } 994 } 995 free(hdr, M_TEMP); 996 997 return (error); 998 } 999 1000 /* 1001 * A callback for each_writable_segment() to write out the segment's 1002 * program header entry. 1003 */ 1004 static void 1005 cb_put_phdr(entry, closure) 1006 vm_map_entry_t entry; 1007 void *closure; 1008 { 1009 struct phdr_closure *phc = (struct phdr_closure *)closure; 1010 Elf_Phdr *phdr = phc->phdr; 1011 1012 phc->offset = round_page(phc->offset); 1013 1014 phdr->p_type = PT_LOAD; 1015 phdr->p_offset = phc->offset; 1016 phdr->p_vaddr = entry->start; 1017 phdr->p_paddr = 0; 1018 phdr->p_filesz = phdr->p_memsz = entry->end - entry->start; 1019 phdr->p_align = PAGE_SIZE; 1020 phdr->p_flags = 0; 1021 if (entry->protection & VM_PROT_READ) 1022 phdr->p_flags |= PF_R; 1023 if (entry->protection & VM_PROT_WRITE) 1024 phdr->p_flags |= PF_W; 1025 if (entry->protection & VM_PROT_EXECUTE) 1026 phdr->p_flags |= PF_X; 1027 1028 phc->offset += phdr->p_filesz; 1029 phc->phdr++; 1030 } 1031 1032 /* 1033 * A callback for each_writable_segment() to gather information about 1034 * the number of segments and their total size. 1035 */ 1036 static void 1037 cb_size_segment(entry, closure) 1038 vm_map_entry_t entry; 1039 void *closure; 1040 { 1041 struct sseg_closure *ssc = (struct sseg_closure *)closure; 1042 1043 ssc->count++; 1044 ssc->size += entry->end - entry->start; 1045 } 1046 1047 /* 1048 * For each writable segment in the process's memory map, call the given 1049 * function with a pointer to the map entry and some arbitrary 1050 * caller-supplied data. 1051 */ 1052 static void 1053 each_writable_segment(td, func, closure) 1054 struct thread *td; 1055 segment_callback func; 1056 void *closure; 1057 { 1058 struct proc *p = td->td_proc; 1059 vm_map_t map = &p->p_vmspace->vm_map; 1060 vm_map_entry_t entry; 1061 1062 for (entry = map->header.next; entry != &map->header; 1063 entry = entry->next) { 1064 vm_object_t obj; 1065 1066 /* 1067 * Don't dump inaccessible mappings, deal with legacy 1068 * coredump mode. 1069 * 1070 * Note that read-only segments related to the elf binary 1071 * are marked MAP_ENTRY_NOCOREDUMP now so we no longer 1072 * need to arbitrarily ignore such segments. 1073 */ 1074 if (elf_legacy_coredump) { 1075 if ((entry->protection & VM_PROT_RW) != VM_PROT_RW) 1076 continue; 1077 } else { 1078 if ((entry->protection & VM_PROT_ALL) == 0) 1079 continue; 1080 } 1081 1082 /* 1083 * Dont include memory segment in the coredump if 1084 * MAP_NOCORE is set in mmap(2) or MADV_NOCORE in 1085 * madvise(2). Do not dump submaps (i.e. parts of the 1086 * kernel map). 1087 */ 1088 if (entry->eflags & (MAP_ENTRY_NOCOREDUMP|MAP_ENTRY_IS_SUB_MAP)) 1089 continue; 1090 1091 if ((obj = entry->object.vm_object) == NULL) 1092 continue; 1093 1094 /* Find the deepest backing object. */ 1095 while (obj->backing_object != NULL) 1096 obj = obj->backing_object; 1097 1098 /* Ignore memory-mapped devices and such things. */ 1099 if (obj->type != OBJT_DEFAULT && 1100 obj->type != OBJT_SWAP && 1101 obj->type != OBJT_VNODE) 1102 continue; 1103 1104 (*func)(entry, closure); 1105 } 1106 } 1107 1108 /* 1109 * Write the core file header to the file, including padding up to 1110 * the page boundary. 1111 */ 1112 static int 1113 __elfN(corehdr)(td, vp, cred, numsegs, hdr, hdrsize) 1114 struct thread *td; 1115 struct vnode *vp; 1116 struct ucred *cred; 1117 int numsegs; 1118 size_t hdrsize; 1119 void *hdr; 1120 { 1121 size_t off; 1122 1123 /* Fill in the header. */ 1124 bzero(hdr, hdrsize); 1125 off = 0; 1126 __elfN(puthdr)(td, hdr, &off, numsegs); 1127 1128 /* Write it to the core file. */ 1129 return (vn_rdwr_inchunks(UIO_WRITE, vp, hdr, hdrsize, (off_t)0, 1130 UIO_SYSSPACE, IO_UNIT | IO_DIRECT, cred, NOCRED, NULL, 1131 td)); /* XXXKSE */ 1132 } 1133 1134 static void 1135 __elfN(puthdr)(struct thread *td, void *dst, size_t *off, int numsegs) 1136 { 1137 struct { 1138 prstatus_t status; 1139 prfpregset_t fpregset; 1140 prpsinfo_t psinfo; 1141 } *tempdata; 1142 prstatus_t *status; 1143 prfpregset_t *fpregset; 1144 prpsinfo_t *psinfo; 1145 struct proc *p; 1146 struct thread *thr; 1147 size_t ehoff, noteoff, notesz, phoff; 1148 1149 p = td->td_proc; 1150 1151 ehoff = *off; 1152 *off += sizeof(Elf_Ehdr); 1153 1154 phoff = *off; 1155 *off += (numsegs + 1) * sizeof(Elf_Phdr); 1156 1157 noteoff = *off; 1158 /* 1159 * Don't allocate space for the notes if we're just calculating 1160 * the size of the header. We also don't collect the data. 1161 */ 1162 if (dst != NULL) { 1163 tempdata = malloc(sizeof(*tempdata), M_TEMP, M_ZERO|M_WAITOK); 1164 status = &tempdata->status; 1165 fpregset = &tempdata->fpregset; 1166 psinfo = &tempdata->psinfo; 1167 } else { 1168 tempdata = NULL; 1169 status = NULL; 1170 fpregset = NULL; 1171 psinfo = NULL; 1172 } 1173 1174 if (dst != NULL) { 1175 psinfo->pr_version = PRPSINFO_VERSION; 1176 psinfo->pr_psinfosz = sizeof(prpsinfo_t); 1177 strlcpy(psinfo->pr_fname, p->p_comm, sizeof(psinfo->pr_fname)); 1178 /* 1179 * XXX - We don't fill in the command line arguments properly 1180 * yet. 1181 */ 1182 strlcpy(psinfo->pr_psargs, p->p_comm, 1183 sizeof(psinfo->pr_psargs)); 1184 } 1185 __elfN(putnote)(dst, off, "FreeBSD", NT_PRPSINFO, psinfo, 1186 sizeof *psinfo); 1187 1188 /* 1189 * To have the debugger select the right thread (LWP) as the initial 1190 * thread, we dump the state of the thread passed to us in td first. 1191 * This is the thread that causes the core dump and thus likely to 1192 * be the right thread one wants to have selected in the debugger. 1193 */ 1194 thr = td; 1195 while (thr != NULL) { 1196 if (dst != NULL) { 1197 status->pr_version = PRSTATUS_VERSION; 1198 status->pr_statussz = sizeof(prstatus_t); 1199 status->pr_gregsetsz = sizeof(gregset_t); 1200 status->pr_fpregsetsz = sizeof(fpregset_t); 1201 status->pr_osreldate = osreldate; 1202 status->pr_cursig = p->p_sig; 1203 status->pr_pid = thr->td_tid; 1204 fill_regs(thr, &status->pr_reg); 1205 fill_fpregs(thr, fpregset); 1206 } 1207 __elfN(putnote)(dst, off, "FreeBSD", NT_PRSTATUS, status, 1208 sizeof *status); 1209 __elfN(putnote)(dst, off, "FreeBSD", NT_FPREGSET, fpregset, 1210 sizeof *fpregset); 1211 /* 1212 * Allow for MD specific notes, as well as any MD 1213 * specific preparations for writing MI notes. 1214 */ 1215 __elfN(dump_thread)(thr, dst, off); 1216 1217 thr = (thr == td) ? TAILQ_FIRST(&p->p_threads) : 1218 TAILQ_NEXT(thr, td_plist); 1219 if (thr == td) 1220 thr = TAILQ_NEXT(thr, td_plist); 1221 } 1222 1223 notesz = *off - noteoff; 1224 1225 if (dst != NULL) 1226 free(tempdata, M_TEMP); 1227 1228 /* Align up to a page boundary for the program segments. */ 1229 *off = round_page(*off); 1230 1231 if (dst != NULL) { 1232 Elf_Ehdr *ehdr; 1233 Elf_Phdr *phdr; 1234 struct phdr_closure phc; 1235 1236 /* 1237 * Fill in the ELF header. 1238 */ 1239 ehdr = (Elf_Ehdr *)((char *)dst + ehoff); 1240 ehdr->e_ident[EI_MAG0] = ELFMAG0; 1241 ehdr->e_ident[EI_MAG1] = ELFMAG1; 1242 ehdr->e_ident[EI_MAG2] = ELFMAG2; 1243 ehdr->e_ident[EI_MAG3] = ELFMAG3; 1244 ehdr->e_ident[EI_CLASS] = ELF_CLASS; 1245 ehdr->e_ident[EI_DATA] = ELF_DATA; 1246 ehdr->e_ident[EI_VERSION] = EV_CURRENT; 1247 ehdr->e_ident[EI_OSABI] = ELFOSABI_FREEBSD; 1248 ehdr->e_ident[EI_ABIVERSION] = 0; 1249 ehdr->e_ident[EI_PAD] = 0; 1250 ehdr->e_type = ET_CORE; 1251 ehdr->e_machine = ELF_ARCH; 1252 ehdr->e_version = EV_CURRENT; 1253 ehdr->e_entry = 0; 1254 ehdr->e_phoff = phoff; 1255 ehdr->e_flags = 0; 1256 ehdr->e_ehsize = sizeof(Elf_Ehdr); 1257 ehdr->e_phentsize = sizeof(Elf_Phdr); 1258 ehdr->e_phnum = numsegs + 1; 1259 ehdr->e_shentsize = sizeof(Elf_Shdr); 1260 ehdr->e_shnum = 0; 1261 ehdr->e_shstrndx = SHN_UNDEF; 1262 1263 /* 1264 * Fill in the program header entries. 1265 */ 1266 phdr = (Elf_Phdr *)((char *)dst + phoff); 1267 1268 /* The note segement. */ 1269 phdr->p_type = PT_NOTE; 1270 phdr->p_offset = noteoff; 1271 phdr->p_vaddr = 0; 1272 phdr->p_paddr = 0; 1273 phdr->p_filesz = notesz; 1274 phdr->p_memsz = 0; 1275 phdr->p_flags = 0; 1276 phdr->p_align = 0; 1277 phdr++; 1278 1279 /* All the writable segments from the program. */ 1280 phc.phdr = phdr; 1281 phc.offset = *off; 1282 each_writable_segment(td, cb_put_phdr, &phc); 1283 } 1284 } 1285 1286 static void 1287 __elfN(putnote)(void *dst, size_t *off, const char *name, int type, 1288 const void *desc, size_t descsz) 1289 { 1290 Elf_Note note; 1291 1292 note.n_namesz = strlen(name) + 1; 1293 note.n_descsz = descsz; 1294 note.n_type = type; 1295 if (dst != NULL) 1296 bcopy(¬e, (char *)dst + *off, sizeof note); 1297 *off += sizeof note; 1298 if (dst != NULL) 1299 bcopy(name, (char *)dst + *off, note.n_namesz); 1300 *off += roundup2(note.n_namesz, sizeof(Elf_Size)); 1301 if (dst != NULL) 1302 bcopy(desc, (char *)dst + *off, note.n_descsz); 1303 *off += roundup2(note.n_descsz, sizeof(Elf_Size)); 1304 } 1305 1306 /* 1307 * Tell kern_execve.c about it, with a little help from the linker. 1308 */ 1309 static struct execsw __elfN(execsw) = { 1310 __CONCAT(exec_, __elfN(imgact)), 1311 __XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE)) 1312 }; 1313 EXEC_SET(__CONCAT(elf, __ELF_WORD_SIZE), __elfN(execsw)); 1314