Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/imgact_elf.c
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1 /*- 2 * Copyright (c) 2000 David O'Brien 3 * Copyright (c) 1995-1996 Søren 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 * $FreeBSD: releng/5.1/sys/kern/imgact_elf.c 111119 2003-02-19 05:47:46Z imp $ 31 */ 32 33 #include <sys/param.h> 34 #include <sys/exec.h> 35 #include <sys/fcntl.h> 36 #include <sys/imgact.h> 37 #include <sys/imgact_elf.h> 38 #include <sys/kernel.h> 39 #include <sys/lock.h> 40 #include <sys/malloc.h> 41 #include <sys/mutex.h> 42 #include <sys/mman.h> 43 #include <sys/namei.h> 44 #include <sys/pioctl.h> 45 #include <sys/proc.h> 46 #include <sys/procfs.h> 47 #include <sys/resourcevar.h> 48 #include <sys/systm.h> 49 #include <sys/signalvar.h> 50 #include <sys/stat.h> 51 #include <sys/sx.h> 52 #include <sys/syscall.h> 53 #include <sys/sysctl.h> 54 #include <sys/sysent.h> 55 #include <sys/vnode.h> 56 57 #include <vm/vm.h> 58 #include <vm/vm_kern.h> 59 #include <vm/vm_param.h> 60 #include <vm/pmap.h> 61 #include <vm/vm_map.h> 62 #include <vm/vm_object.h> 63 #include <vm/vm_extern.h> 64 65 #include <machine/elf.h> 66 #include <machine/md_var.h> 67 68 #define OLD_EI_BRAND 8 69 70 static int __elfN(check_header)(const Elf_Ehdr *hdr); 71 static Elf_Brandinfo *__elfN(get_brandinfo)(const Elf_Ehdr *hdr, 72 const char *interp); 73 static int __elfN(load_file)(struct proc *p, const char *file, u_long *addr, 74 u_long *entry, size_t pagesize); 75 static int __elfN(load_section)(struct proc *p, 76 struct vmspace *vmspace, struct vnode *vp, vm_object_t object, 77 vm_offset_t offset, caddr_t vmaddr, size_t memsz, size_t filsz, 78 vm_prot_t prot, size_t pagesize); 79 static int __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp); 80 81 SYSCTL_NODE(_kern, OID_AUTO, __CONCAT(elf, __ELF_WORD_SIZE), CTLFLAG_RW, 0, 82 ""); 83 84 int __elfN(fallback_brand) = -1; 85 SYSCTL_INT(__CONCAT(_kern_elf, __ELF_WORD_SIZE), OID_AUTO, 86 fallback_brand, CTLFLAG_RW, &__elfN(fallback_brand), 0, 87 __XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE)) " brand of last resort"); 88 TUNABLE_INT("kern.elf" __XSTRING(__ELF_WORD_SIZE) ".fallback_brand", 89 &__elfN(fallback_brand)); 90 91 static int elf_trace = 0; 92 SYSCTL_INT(_debug, OID_AUTO, __elfN(trace), CTLFLAG_RW, &elf_trace, 0, ""); 93 94 static int elf_legacy_coredump = 0; 95 SYSCTL_INT(_debug, OID_AUTO, __elfN(legacy_coredump), CTLFLAG_RW, 96 &elf_legacy_coredump, 0, ""); 97 98 static Elf_Brandinfo *elf_brand_list[MAX_BRANDS]; 99 100 int 101 __elfN(insert_brand_entry)(Elf_Brandinfo *entry) 102 { 103 int i; 104 105 for (i = 0; i < MAX_BRANDS; i++) { 106 if (elf_brand_list[i] == NULL) { 107 elf_brand_list[i] = entry; 108 break; 109 } 110 } 111 if (i == MAX_BRANDS) 112 return (-1); 113 return (0); 114 } 115 116 int 117 __elfN(remove_brand_entry)(Elf_Brandinfo *entry) 118 { 119 int i; 120 121 for (i = 0; i < MAX_BRANDS; i++) { 122 if (elf_brand_list[i] == entry) { 123 elf_brand_list[i] = NULL; 124 break; 125 } 126 } 127 if (i == MAX_BRANDS) 128 return (-1); 129 return (0); 130 } 131 132 int 133 __elfN(brand_inuse)(Elf_Brandinfo *entry) 134 { 135 struct proc *p; 136 int rval = FALSE; 137 138 sx_slock(&allproc_lock); 139 LIST_FOREACH(p, &allproc, p_list) { 140 if (p->p_sysent == entry->sysvec) { 141 rval = TRUE; 142 break; 143 } 144 } 145 sx_sunlock(&allproc_lock); 146 147 return (rval); 148 } 149 150 static Elf_Brandinfo * 151 __elfN(get_brandinfo)(const Elf_Ehdr *hdr, const char *interp) 152 { 153 Elf_Brandinfo *bi; 154 int i; 155 156 /* 157 * We support three types of branding -- (1) the ELF EI_OSABI field 158 * that SCO added to the ELF spec, (2) FreeBSD 3.x's traditional string 159 * branding w/in the ELF header, and (3) path of the `interp_path' 160 * field. We should also look for an ".note.ABI-tag" ELF section now 161 * in all Linux ELF binaries, FreeBSD 4.1+, and some NetBSD ones. 162 */ 163 164 /* If the executable has a brand, search for it in the brand list. */ 165 for (i = 0; i < MAX_BRANDS; i++) { 166 bi = elf_brand_list[i]; 167 if (bi != NULL && hdr->e_machine == bi->machine && 168 (hdr->e_ident[EI_OSABI] == bi->brand || 169 strncmp((const char *)&hdr->e_ident[OLD_EI_BRAND], 170 bi->compat_3_brand, strlen(bi->compat_3_brand)) == 0)) 171 return (bi); 172 } 173 174 /* Lacking a known brand, search for a recognized interpreter. */ 175 if (interp != NULL) { 176 for (i = 0; i < MAX_BRANDS; i++) { 177 bi = elf_brand_list[i]; 178 if (bi != NULL && hdr->e_machine == bi->machine && 179 strcmp(interp, bi->interp_path) == 0) 180 return (bi); 181 } 182 } 183 184 /* Lacking a recognized interpreter, try the default brand */ 185 for (i = 0; i < MAX_BRANDS; i++) { 186 bi = elf_brand_list[i]; 187 if (bi != NULL && hdr->e_machine == bi->machine && 188 __elfN(fallback_brand) == bi->brand) 189 return (bi); 190 } 191 return (NULL); 192 } 193 194 static int 195 __elfN(check_header)(const Elf_Ehdr *hdr) 196 { 197 Elf_Brandinfo *bi; 198 int i; 199 200 if (!IS_ELF(*hdr) || 201 hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || 202 hdr->e_ident[EI_DATA] != ELF_TARG_DATA || 203 hdr->e_ident[EI_VERSION] != EV_CURRENT) 204 return (ENOEXEC); 205 206 /* 207 * Make sure we have at least one brand for this machine. 208 */ 209 210 for (i = 0; i < MAX_BRANDS; i++) { 211 bi = elf_brand_list[i]; 212 if (bi != NULL && bi->machine == hdr->e_machine) 213 break; 214 } 215 if (i == MAX_BRANDS) 216 return (ENOEXEC); 217 218 if (hdr->e_version != ELF_TARG_VER) 219 return (ENOEXEC); 220 221 return (0); 222 } 223 224 static int 225 __elfN(map_partial)(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 226 vm_offset_t start, vm_offset_t end, vm_prot_t prot, 227 vm_prot_t max) 228 { 229 int error, rv; 230 vm_offset_t off; 231 vm_offset_t data_buf = 0; 232 233 /* 234 * Create the page if it doesn't exist yet. Ignore errors. 235 */ 236 vm_map_lock(map); 237 vm_map_insert(map, NULL, 0, trunc_page(start), round_page(end), max, 238 max, 0); 239 vm_map_unlock(map); 240 241 /* 242 * Find the page from the underlying object. 243 */ 244 if (object) { 245 vm_object_reference(object); 246 rv = vm_map_find(exec_map, 247 object, 248 trunc_page(offset), 249 &data_buf, 250 PAGE_SIZE, 251 TRUE, 252 VM_PROT_READ, 253 VM_PROT_ALL, 254 MAP_COPY_ON_WRITE | MAP_PREFAULT_PARTIAL); 255 if (rv != KERN_SUCCESS) { 256 vm_object_deallocate(object); 257 return (rv); 258 } 259 260 off = offset - trunc_page(offset); 261 error = copyout((caddr_t)data_buf + off, (caddr_t)start, 262 end - start); 263 vm_map_remove(exec_map, data_buf, data_buf + PAGE_SIZE); 264 if (error) { 265 return (KERN_FAILURE); 266 } 267 } 268 269 return (KERN_SUCCESS); 270 } 271 272 static int 273 __elfN(map_insert)(vm_map_t map, vm_object_t object, vm_ooffset_t offset, 274 vm_offset_t start, vm_offset_t end, vm_prot_t prot, 275 vm_prot_t max, int cow) 276 { 277 int rv; 278 279 if (start != trunc_page(start)) { 280 rv = __elfN(map_partial)(map, object, offset, start, 281 round_page(start), prot, max); 282 if (rv) 283 return (rv); 284 offset += round_page(start) - start; 285 start = round_page(start); 286 } 287 if (end != round_page(end)) { 288 rv = __elfN(map_partial)(map, object, offset + 289 trunc_page(end) - start, trunc_page(end), end, prot, max); 290 if (rv) 291 return (rv); 292 end = trunc_page(end); 293 } 294 if (end > start) { 295 if (offset & PAGE_MASK) { 296 vm_offset_t data_buf, off; 297 vm_size_t sz; 298 int error; 299 300 /* 301 * The mapping is not page aligned. This means we have 302 * to copy the data. Sigh. 303 */ 304 rv = vm_map_find(map, 0, 0, &start, end - start, 305 FALSE, prot, max, 0); 306 if (rv) 307 return (rv); 308 while (start < end) { 309 vm_object_reference(object); 310 rv = vm_map_find(exec_map, 311 object, 312 trunc_page(offset), 313 &data_buf, 314 2 * PAGE_SIZE, 315 TRUE, 316 VM_PROT_READ, 317 VM_PROT_ALL, 318 (MAP_COPY_ON_WRITE 319 | MAP_PREFAULT_PARTIAL)); 320 if (rv != KERN_SUCCESS) { 321 vm_object_deallocate(object); 322 return (rv); 323 } 324 off = offset - trunc_page(offset); 325 sz = end - start; 326 if (sz > PAGE_SIZE) 327 sz = PAGE_SIZE; 328 error = copyout((caddr_t)data_buf + off, 329 (caddr_t)start, sz); 330 vm_map_remove(exec_map, data_buf, 331 data_buf + 2 * PAGE_SIZE); 332 if (error) { 333 return (KERN_FAILURE); 334 } 335 start += sz; 336 } 337 rv = KERN_SUCCESS; 338 } else { 339 vm_map_lock(map); 340 rv = vm_map_insert(map, object, offset, start, end, 341 prot, max, cow); 342 vm_map_unlock(map); 343 } 344 return (rv); 345 } else { 346 return (KERN_SUCCESS); 347 } 348 } 349 350 static int 351 __elfN(load_section)(struct proc *p, struct vmspace *vmspace, 352 struct vnode *vp, vm_object_t object, vm_offset_t offset, 353 caddr_t vmaddr, size_t memsz, size_t filsz, vm_prot_t prot, 354 size_t pagesize) 355 { 356 size_t map_len; 357 vm_offset_t map_addr; 358 int error, rv, cow; 359 size_t copy_len; 360 vm_offset_t file_addr; 361 vm_offset_t data_buf = 0; 362 363 GIANT_REQUIRED; 364 365 error = 0; 366 367 /* 368 * It's necessary to fail if the filsz + offset taken from the 369 * header is greater than the actual file pager object's size. 370 * If we were to allow this, then the vm_map_find() below would 371 * walk right off the end of the file object and into the ether. 372 * 373 * While I'm here, might as well check for something else that 374 * is invalid: filsz cannot be greater than memsz. 375 */ 376 if ((off_t)filsz + offset > object->un_pager.vnp.vnp_size || 377 filsz > memsz) { 378 uprintf("elf_load_section: truncated ELF file\n"); 379 return (ENOEXEC); 380 } 381 382 #define trunc_page_ps(va, ps) ((va) & ~(ps - 1)) 383 #define round_page_ps(va, ps) (((va) + (ps - 1)) & ~(ps - 1)) 384 385 map_addr = trunc_page_ps((vm_offset_t)vmaddr, pagesize); 386 file_addr = trunc_page_ps(offset, pagesize); 387 388 /* 389 * We have two choices. We can either clear the data in the last page 390 * of an oversized mapping, or we can start the anon mapping a page 391 * early and copy the initialized data into that first page. We 392 * choose the second.. 393 */ 394 if (memsz > filsz) 395 map_len = trunc_page_ps(offset + filsz, pagesize) - file_addr; 396 else 397 map_len = round_page_ps(offset + filsz, pagesize) - file_addr; 398 399 if (map_len != 0) { 400 vm_object_reference(object); 401 402 /* cow flags: don't dump readonly sections in core */ 403 cow = MAP_COPY_ON_WRITE | MAP_PREFAULT | 404 (prot & VM_PROT_WRITE ? 0 : MAP_DISABLE_COREDUMP); 405 406 rv = __elfN(map_insert)(&vmspace->vm_map, 407 object, 408 file_addr, /* file offset */ 409 map_addr, /* virtual start */ 410 map_addr + map_len,/* virtual end */ 411 prot, 412 VM_PROT_ALL, 413 cow); 414 if (rv != KERN_SUCCESS) { 415 vm_object_deallocate(object); 416 return (EINVAL); 417 } 418 419 /* we can stop now if we've covered it all */ 420 if (memsz == filsz) { 421 return (0); 422 } 423 } 424 425 426 /* 427 * We have to get the remaining bit of the file into the first part 428 * of the oversized map segment. This is normally because the .data 429 * segment in the file is extended to provide bss. It's a neat idea 430 * to try and save a page, but it's a pain in the behind to implement. 431 */ 432 copy_len = (offset + filsz) - trunc_page_ps(offset + filsz, pagesize); 433 map_addr = trunc_page_ps((vm_offset_t)vmaddr + filsz, pagesize); 434 map_len = round_page_ps((vm_offset_t)vmaddr + memsz, pagesize) - 435 map_addr; 436 437 /* This had damn well better be true! */ 438 if (map_len != 0) { 439 rv = __elfN(map_insert)(&vmspace->vm_map, NULL, 0, map_addr, 440 map_addr + map_len, VM_PROT_ALL, VM_PROT_ALL, 0); 441 if (rv != KERN_SUCCESS) { 442 return (EINVAL); 443 } 444 } 445 446 if (copy_len != 0) { 447 vm_offset_t off; 448 vm_object_reference(object); 449 rv = vm_map_find(exec_map, 450 object, 451 trunc_page(offset + filsz), 452 &data_buf, 453 PAGE_SIZE, 454 TRUE, 455 VM_PROT_READ, 456 VM_PROT_ALL, 457 MAP_COPY_ON_WRITE | MAP_PREFAULT_PARTIAL); 458 if (rv != KERN_SUCCESS) { 459 vm_object_deallocate(object); 460 return (EINVAL); 461 } 462 463 /* send the page fragment to user space */ 464 off = trunc_page_ps(offset + filsz, pagesize) - 465 trunc_page(offset + filsz); 466 error = copyout((caddr_t)data_buf + off, (caddr_t)map_addr, 467 copy_len); 468 vm_map_remove(exec_map, data_buf, data_buf + PAGE_SIZE); 469 if (error) { 470 return (error); 471 } 472 } 473 474 /* 475 * set it to the specified protection. 476 * XXX had better undo the damage from pasting over the cracks here! 477 */ 478 vm_map_protect(&vmspace->vm_map, trunc_page(map_addr), 479 round_page(map_addr + map_len), prot, FALSE); 480 481 return (error); 482 } 483 484 /* 485 * Load the file "file" into memory. It may be either a shared object 486 * or an executable. 487 * 488 * The "addr" reference parameter is in/out. On entry, it specifies 489 * the address where a shared object should be loaded. If the file is 490 * an executable, this value is ignored. On exit, "addr" specifies 491 * where the file was actually loaded. 492 * 493 * The "entry" reference parameter is out only. On exit, it specifies 494 * the entry point for the loaded file. 495 */ 496 static int 497 __elfN(load_file)(struct proc *p, const char *file, u_long *addr, 498 u_long *entry, size_t pagesize) 499 { 500 struct { 501 struct nameidata nd; 502 struct vattr attr; 503 struct image_params image_params; 504 } *tempdata; 505 const Elf_Ehdr *hdr = NULL; 506 const Elf_Phdr *phdr = NULL; 507 struct nameidata *nd; 508 struct vmspace *vmspace = p->p_vmspace; 509 struct vattr *attr; 510 struct image_params *imgp; 511 vm_prot_t prot; 512 u_long rbase; 513 u_long base_addr = 0; 514 int error, i, numsegs; 515 516 if (curthread->td_proc != p) 517 panic("elf_load_file - thread"); /* XXXKSE DIAGNOSTIC */ 518 519 tempdata = malloc(sizeof(*tempdata), M_TEMP, M_WAITOK); 520 nd = &tempdata->nd; 521 attr = &tempdata->attr; 522 imgp = &tempdata->image_params; 523 524 /* 525 * Initialize part of the common data 526 */ 527 imgp->proc = p; 528 imgp->userspace_argv = NULL; 529 imgp->userspace_envv = NULL; 530 imgp->attr = attr; 531 imgp->firstpage = NULL; 532 imgp->image_header = (char *)kmem_alloc_wait(exec_map, PAGE_SIZE); 533 imgp->object = NULL; 534 imgp->execlabel = NULL; 535 536 if (imgp->image_header == NULL) { 537 nd->ni_vp = NULL; 538 error = ENOMEM; 539 goto fail; 540 } 541 542 /* XXXKSE */ 543 NDINIT(nd, LOOKUP, LOCKLEAF|FOLLOW, UIO_SYSSPACE, file, curthread); 544 545 if ((error = namei(nd)) != 0) { 546 nd->ni_vp = NULL; 547 goto fail; 548 } 549 NDFREE(nd, NDF_ONLY_PNBUF); 550 imgp->vp = nd->ni_vp; 551 552 /* 553 * Check permissions, modes, uid, etc on the file, and "open" it. 554 */ 555 error = exec_check_permissions(imgp); 556 if (error) { 557 VOP_UNLOCK(nd->ni_vp, 0, curthread); /* XXXKSE */ 558 goto fail; 559 } 560 561 error = exec_map_first_page(imgp); 562 /* 563 * Also make certain that the interpreter stays the same, so set 564 * its VV_TEXT flag, too. 565 */ 566 if (error == 0) 567 nd->ni_vp->v_vflag |= VV_TEXT; 568 569 VOP_GETVOBJECT(nd->ni_vp, &imgp->object); 570 vm_object_reference(imgp->object); 571 572 VOP_UNLOCK(nd->ni_vp, 0, curthread); /* XXXKSE */ 573 if (error) 574 goto fail; 575 576 hdr = (const Elf_Ehdr *)imgp->image_header; 577 if ((error = __elfN(check_header)(hdr)) != 0) 578 goto fail; 579 if (hdr->e_type == ET_DYN) 580 rbase = *addr; 581 else if (hdr->e_type == ET_EXEC) 582 rbase = 0; 583 else { 584 error = ENOEXEC; 585 goto fail; 586 } 587 588 /* Only support headers that fit within first page for now */ 589 if ((hdr->e_phoff > PAGE_SIZE) || 590 (hdr->e_phoff + hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE) { 591 error = ENOEXEC; 592 goto fail; 593 } 594 595 phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff); 596 597 for (i = 0, numsegs = 0; i < hdr->e_phnum; i++) { 598 if (phdr[i].p_type == PT_LOAD) { /* Loadable segment */ 599 prot = 0; 600 if (phdr[i].p_flags & PF_X) 601 prot |= VM_PROT_EXECUTE; 602 if (phdr[i].p_flags & PF_W) 603 prot |= VM_PROT_WRITE; 604 if (phdr[i].p_flags & PF_R) 605 prot |= VM_PROT_READ; 606 607 if ((error = __elfN(load_section)(p, vmspace, 608 nd->ni_vp, imgp->object, phdr[i].p_offset, 609 (caddr_t)(uintptr_t)phdr[i].p_vaddr + rbase, 610 phdr[i].p_memsz, phdr[i].p_filesz, prot, 611 pagesize)) != 0) 612 goto fail; 613 /* 614 * Establish the base address if this is the 615 * first segment. 616 */ 617 if (numsegs == 0) 618 base_addr = trunc_page(phdr[i].p_vaddr + 619 rbase); 620 numsegs++; 621 } 622 } 623 *addr = base_addr; 624 *entry = (unsigned long)hdr->e_entry + rbase; 625 626 fail: 627 if (imgp->firstpage) 628 exec_unmap_first_page(imgp); 629 if (imgp->image_header) 630 kmem_free_wakeup(exec_map, (vm_offset_t)imgp->image_header, 631 PAGE_SIZE); 632 if (imgp->object) 633 vm_object_deallocate(imgp->object); 634 635 if (nd->ni_vp) 636 vrele(nd->ni_vp); 637 638 free(tempdata, M_TEMP); 639 640 return (error); 641 } 642 643 static int 644 __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp) 645 { 646 const Elf_Ehdr *hdr = (const Elf_Ehdr *)imgp->image_header; 647 const Elf_Phdr *phdr; 648 Elf_Auxargs *elf_auxargs = NULL; 649 struct vmspace *vmspace; 650 vm_prot_t prot; 651 u_long text_size = 0, data_size = 0, total_size = 0; 652 u_long text_addr = 0, data_addr = 0; 653 u_long seg_size, seg_addr; 654 u_long addr, entry = 0, proghdr = 0; 655 int error, i; 656 const char *interp = NULL; 657 Elf_Brandinfo *brand_info; 658 char *path; 659 struct thread *td = curthread; 660 struct sysentvec *sv; 661 662 GIANT_REQUIRED; 663 664 /* 665 * Do we have a valid ELF header ? 666 */ 667 if (__elfN(check_header)(hdr) != 0 || hdr->e_type != ET_EXEC) 668 return (-1); 669 670 /* 671 * From here on down, we return an errno, not -1, as we've 672 * detected an ELF file. 673 */ 674 675 if ((hdr->e_phoff > PAGE_SIZE) || 676 (hdr->e_phoff + hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE) { 677 /* Only support headers in first page for now */ 678 return (ENOEXEC); 679 } 680 phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff); 681 682 /* 683 * From this point on, we may have resources that need to be freed. 684 */ 685 686 VOP_UNLOCK(imgp->vp, 0, td); 687 688 for (i = 0; i < hdr->e_phnum; i++) { 689 switch (phdr[i].p_type) { 690 case PT_INTERP: /* Path to interpreter */ 691 if (phdr[i].p_filesz > MAXPATHLEN || 692 phdr[i].p_offset + phdr[i].p_filesz > PAGE_SIZE) { 693 error = ENOEXEC; 694 goto fail; 695 } 696 interp = imgp->image_header + phdr[i].p_offset; 697 break; 698 default: 699 break; 700 } 701 } 702 703 brand_info = __elfN(get_brandinfo)(hdr, interp); 704 if (brand_info == NULL) { 705 uprintf("ELF binary type \"%u\" not known.\n", 706 hdr->e_ident[EI_OSABI]); 707 error = ENOEXEC; 708 goto fail; 709 } 710 sv = brand_info->sysvec; 711 712 if ((error = exec_extract_strings(imgp)) != 0) 713 goto fail; 714 715 exec_new_vmspace(imgp, sv); 716 717 vmspace = imgp->proc->p_vmspace; 718 719 for (i = 0; i < hdr->e_phnum; i++) { 720 switch (phdr[i].p_type) { 721 case PT_LOAD: /* Loadable segment */ 722 prot = 0; 723 if (phdr[i].p_flags & PF_X) 724 prot |= VM_PROT_EXECUTE; 725 if (phdr[i].p_flags & PF_W) 726 prot |= VM_PROT_WRITE; 727 if (phdr[i].p_flags & PF_R) 728 prot |= VM_PROT_READ; 729 730 #if defined(__ia64__) && __ELF_WORD_SIZE == 32 && defined(IA32_ME_HARDER) 731 /* 732 * Some x86 binaries assume read == executable, 733 * notably the M3 runtime and therefore cvsup 734 */ 735 if (prot & VM_PROT_READ) 736 prot |= VM_PROT_EXECUTE; 737 #endif 738 739 if ((error = __elfN(load_section)(imgp->proc, vmspace, 740 imgp->vp, imgp->object, phdr[i].p_offset, 741 (caddr_t)(uintptr_t)phdr[i].p_vaddr, 742 phdr[i].p_memsz, phdr[i].p_filesz, prot, 743 sv->sv_pagesize)) != 0) 744 goto fail; 745 746 seg_addr = trunc_page(phdr[i].p_vaddr); 747 seg_size = round_page(phdr[i].p_memsz + 748 phdr[i].p_vaddr - seg_addr); 749 750 /* 751 * Is this .text or .data? We can't use 752 * VM_PROT_WRITE or VM_PROT_EXEC, it breaks the 753 * alpha terribly and possibly does other bad 754 * things so we stick to the old way of figuring 755 * it out: If the segment contains the program 756 * entry point, it's a text segment, otherwise it 757 * is a data segment. 758 * 759 * Note that obreak() assumes that data_addr + 760 * data_size == end of data load area, and the ELF 761 * file format expects segments to be sorted by 762 * address. If multiple data segments exist, the 763 * last one will be used. 764 */ 765 if (hdr->e_entry >= phdr[i].p_vaddr && 766 hdr->e_entry < (phdr[i].p_vaddr + 767 phdr[i].p_memsz)) { 768 text_size = seg_size; 769 text_addr = seg_addr; 770 entry = (u_long)hdr->e_entry; 771 } else { 772 data_size = seg_size; 773 data_addr = seg_addr; 774 } 775 total_size += seg_size; 776 break; 777 case PT_PHDR: /* Program header table info */ 778 proghdr = phdr[i].p_vaddr; 779 break; 780 default: 781 break; 782 } 783 } 784 785 if (data_addr == 0 && data_size == 0) { 786 data_addr = text_addr; 787 data_size = text_size; 788 } 789 790 /* 791 * Check limits. It should be safe to check the 792 * limits after loading the segments since we do 793 * not actually fault in all the segments pages. 794 */ 795 if (data_size > 796 imgp->proc->p_rlimit[RLIMIT_DATA].rlim_cur || 797 text_size > maxtsiz || 798 total_size > 799 imgp->proc->p_rlimit[RLIMIT_VMEM].rlim_cur) { 800 error = ENOMEM; 801 goto fail; 802 } 803 804 vmspace->vm_tsize = text_size >> PAGE_SHIFT; 805 vmspace->vm_taddr = (caddr_t)(uintptr_t)text_addr; 806 vmspace->vm_dsize = data_size >> PAGE_SHIFT; 807 vmspace->vm_daddr = (caddr_t)(uintptr_t)data_addr; 808 809 addr = ELF_RTLD_ADDR(vmspace); 810 811 imgp->entry_addr = entry; 812 813 imgp->proc->p_sysent = sv; 814 if (interp != NULL) { 815 path = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 816 snprintf(path, MAXPATHLEN, "%s%s", brand_info->emul_path, 817 interp); 818 if ((error = __elfN(load_file)(imgp->proc, path, &addr, 819 &imgp->entry_addr, sv->sv_pagesize)) != 0) { 820 if ((error = __elfN(load_file)(imgp->proc, interp, 821 &addr, &imgp->entry_addr, sv->sv_pagesize)) != 0) { 822 uprintf("ELF interpreter %s not found\n", 823 path); 824 free(path, M_TEMP); 825 goto fail; 826 } 827 } 828 free(path, M_TEMP); 829 } 830 831 /* 832 * Construct auxargs table (used by the fixup routine) 833 */ 834 elf_auxargs = malloc(sizeof(Elf_Auxargs), M_TEMP, M_WAITOK); 835 elf_auxargs->execfd = -1; 836 elf_auxargs->phdr = proghdr; 837 elf_auxargs->phent = hdr->e_phentsize; 838 elf_auxargs->phnum = hdr->e_phnum; 839 elf_auxargs->pagesz = PAGE_SIZE; 840 elf_auxargs->base = addr; 841 elf_auxargs->flags = 0; 842 elf_auxargs->entry = entry; 843 elf_auxargs->trace = elf_trace; 844 845 imgp->auxargs = elf_auxargs; 846 imgp->interpreted = 0; 847 848 fail: 849 vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY, td); 850 return (error); 851 } 852 853 #define suword __CONCAT(suword, __ELF_WORD_SIZE) 854 855 int 856 __elfN(freebsd_fixup)(register_t **stack_base, struct image_params *imgp) 857 { 858 Elf_Auxargs *args = (Elf_Auxargs *)imgp->auxargs; 859 Elf_Addr *base; 860 Elf_Addr *pos; 861 862 base = (Elf_Addr *)*stack_base; 863 pos = base + (imgp->argc + imgp->envc + 2); 864 865 if (args->trace) { 866 AUXARGS_ENTRY(pos, AT_DEBUG, 1); 867 } 868 if (args->execfd != -1) { 869 AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd); 870 } 871 AUXARGS_ENTRY(pos, AT_PHDR, args->phdr); 872 AUXARGS_ENTRY(pos, AT_PHENT, args->phent); 873 AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum); 874 AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz); 875 AUXARGS_ENTRY(pos, AT_FLAGS, args->flags); 876 AUXARGS_ENTRY(pos, AT_ENTRY, args->entry); 877 AUXARGS_ENTRY(pos, AT_BASE, args->base); 878 AUXARGS_ENTRY(pos, AT_NULL, 0); 879 880 free(imgp->auxargs, M_TEMP); 881 imgp->auxargs = NULL; 882 883 base--; 884 suword(base, (long)imgp->argc); 885 *stack_base = (register_t *)base; 886 return (0); 887 } 888 889 /* 890 * Code for generating ELF core dumps. 891 */ 892 893 typedef void (*segment_callback)(vm_map_entry_t, void *); 894 895 /* Closure for cb_put_phdr(). */ 896 struct phdr_closure { 897 Elf_Phdr *phdr; /* Program header to fill in */ 898 Elf_Off offset; /* Offset of segment in core file */ 899 }; 900 901 /* Closure for cb_size_segment(). */ 902 struct sseg_closure { 903 int count; /* Count of writable segments. */ 904 size_t size; /* Total size of all writable segments. */ 905 }; 906 907 static void cb_put_phdr(vm_map_entry_t, void *); 908 static void cb_size_segment(vm_map_entry_t, void *); 909 static void each_writable_segment(struct proc *, segment_callback, void *); 910 static int __elfN(corehdr)(struct thread *, struct vnode *, struct ucred *, 911 int, void *, size_t); 912 static void __elfN(puthdr)(struct proc *, void *, size_t *, 913 const prstatus_t *, const prfpregset_t *, const prpsinfo_t *, int); 914 static void __elfN(putnote)(void *, size_t *, const char *, int, 915 const void *, size_t); 916 917 extern int osreldate; 918 919 int 920 __elfN(coredump)(td, vp, limit) 921 struct thread *td; 922 register struct vnode *vp; 923 off_t limit; 924 { 925 register struct proc *p = td->td_proc; 926 register struct ucred *cred = td->td_ucred; 927 int error = 0; 928 struct sseg_closure seginfo; 929 void *hdr; 930 size_t hdrsize; 931 932 /* Size the program segments. */ 933 seginfo.count = 0; 934 seginfo.size = 0; 935 each_writable_segment(p, cb_size_segment, &seginfo); 936 937 /* 938 * Calculate the size of the core file header area by making 939 * a dry run of generating it. Nothing is written, but the 940 * size is calculated. 941 */ 942 hdrsize = 0; 943 __elfN(puthdr)((struct proc *)NULL, (void *)NULL, &hdrsize, 944 (const prstatus_t *)NULL, (const prfpregset_t *)NULL, 945 (const prpsinfo_t *)NULL, seginfo.count); 946 947 if (hdrsize + seginfo.size >= limit) 948 return (EFAULT); 949 950 /* 951 * Allocate memory for building the header, fill it up, 952 * and write it out. 953 */ 954 hdr = malloc(hdrsize, M_TEMP, M_WAITOK); 955 if (hdr == NULL) { 956 return (EINVAL); 957 } 958 error = __elfN(corehdr)(td, vp, cred, seginfo.count, hdr, hdrsize); 959 960 /* Write the contents of all of the writable segments. */ 961 if (error == 0) { 962 Elf_Phdr *php; 963 off_t offset; 964 int i; 965 966 php = (Elf_Phdr *)((char *)hdr + sizeof(Elf_Ehdr)) + 1; 967 offset = hdrsize; 968 for (i = 0; i < seginfo.count; i++) { 969 error = vn_rdwr_inchunks(UIO_WRITE, vp, 970 (caddr_t)(uintptr_t)php->p_vaddr, 971 php->p_filesz, offset, UIO_USERSPACE, 972 IO_UNIT | IO_DIRECT, cred, NOCRED, (int *)NULL, 973 curthread); /* XXXKSE */ 974 if (error != 0) 975 break; 976 offset += php->p_filesz; 977 php++; 978 } 979 } 980 free(hdr, M_TEMP); 981 982 return (error); 983 } 984 985 /* 986 * A callback for each_writable_segment() to write out the segment's 987 * program header entry. 988 */ 989 static void 990 cb_put_phdr(entry, closure) 991 vm_map_entry_t entry; 992 void *closure; 993 { 994 struct phdr_closure *phc = (struct phdr_closure *)closure; 995 Elf_Phdr *phdr = phc->phdr; 996 997 phc->offset = round_page(phc->offset); 998 999 phdr->p_type = PT_LOAD; 1000 phdr->p_offset = phc->offset; 1001 phdr->p_vaddr = entry->start; 1002 phdr->p_paddr = 0; 1003 phdr->p_filesz = phdr->p_memsz = entry->end - entry->start; 1004 phdr->p_align = PAGE_SIZE; 1005 phdr->p_flags = 0; 1006 if (entry->protection & VM_PROT_READ) 1007 phdr->p_flags |= PF_R; 1008 if (entry->protection & VM_PROT_WRITE) 1009 phdr->p_flags |= PF_W; 1010 if (entry->protection & VM_PROT_EXECUTE) 1011 phdr->p_flags |= PF_X; 1012 1013 phc->offset += phdr->p_filesz; 1014 phc->phdr++; 1015 } 1016 1017 /* 1018 * A callback for each_writable_segment() to gather information about 1019 * the number of segments and their total size. 1020 */ 1021 static void 1022 cb_size_segment(entry, closure) 1023 vm_map_entry_t entry; 1024 void *closure; 1025 { 1026 struct sseg_closure *ssc = (struct sseg_closure *)closure; 1027 1028 ssc->count++; 1029 ssc->size += entry->end - entry->start; 1030 } 1031 1032 /* 1033 * For each writable segment in the process's memory map, call the given 1034 * function with a pointer to the map entry and some arbitrary 1035 * caller-supplied data. 1036 */ 1037 static void 1038 each_writable_segment(p, func, closure) 1039 struct proc *p; 1040 segment_callback func; 1041 void *closure; 1042 { 1043 vm_map_t map = &p->p_vmspace->vm_map; 1044 vm_map_entry_t entry; 1045 1046 for (entry = map->header.next; entry != &map->header; 1047 entry = entry->next) { 1048 vm_object_t obj; 1049 1050 /* 1051 * Don't dump inaccessible mappings, deal with legacy 1052 * coredump mode. 1053 * 1054 * Note that read-only segments related to the elf binary 1055 * are marked MAP_ENTRY_NOCOREDUMP now so we no longer 1056 * need to arbitrarily ignore such segments. 1057 */ 1058 if (elf_legacy_coredump) { 1059 if ((entry->protection & VM_PROT_RW) != VM_PROT_RW) 1060 continue; 1061 } else { 1062 if ((entry->protection & VM_PROT_ALL) == 0) 1063 continue; 1064 } 1065 1066 /* 1067 * Dont include memory segment in the coredump if 1068 * MAP_NOCORE is set in mmap(2) or MADV_NOCORE in 1069 * madvise(2). Do not dump submaps (i.e. parts of the 1070 * kernel map). 1071 */ 1072 if (entry->eflags & (MAP_ENTRY_NOCOREDUMP|MAP_ENTRY_IS_SUB_MAP)) 1073 continue; 1074 1075 if ((obj = entry->object.vm_object) == NULL) 1076 continue; 1077 1078 /* Find the deepest backing object. */ 1079 while (obj->backing_object != NULL) 1080 obj = obj->backing_object; 1081 1082 /* Ignore memory-mapped devices and such things. */ 1083 if (obj->type != OBJT_DEFAULT && 1084 obj->type != OBJT_SWAP && 1085 obj->type != OBJT_VNODE) 1086 continue; 1087 1088 (*func)(entry, closure); 1089 } 1090 } 1091 1092 /* 1093 * Write the core file header to the file, including padding up to 1094 * the page boundary. 1095 */ 1096 static int 1097 __elfN(corehdr)(td, vp, cred, numsegs, hdr, hdrsize) 1098 struct thread *td; 1099 struct vnode *vp; 1100 struct ucred *cred; 1101 int numsegs; 1102 size_t hdrsize; 1103 void *hdr; 1104 { 1105 struct { 1106 prstatus_t status; 1107 prfpregset_t fpregset; 1108 prpsinfo_t psinfo; 1109 } *tempdata; 1110 struct proc *p = td->td_proc; 1111 size_t off; 1112 prstatus_t *status; 1113 prfpregset_t *fpregset; 1114 prpsinfo_t *psinfo; 1115 1116 tempdata = malloc(sizeof(*tempdata), M_TEMP, M_ZERO | M_WAITOK); 1117 status = &tempdata->status; 1118 fpregset = &tempdata->fpregset; 1119 psinfo = &tempdata->psinfo; 1120 1121 /* Gather the information for the header. */ 1122 status->pr_version = PRSTATUS_VERSION; 1123 status->pr_statussz = sizeof(prstatus_t); 1124 status->pr_gregsetsz = sizeof(gregset_t); 1125 status->pr_fpregsetsz = sizeof(fpregset_t); 1126 status->pr_osreldate = osreldate; 1127 status->pr_cursig = p->p_sig; 1128 status->pr_pid = p->p_pid; 1129 fill_regs(td, &status->pr_reg); 1130 1131 fill_fpregs(td, fpregset); 1132 1133 psinfo->pr_version = PRPSINFO_VERSION; 1134 psinfo->pr_psinfosz = sizeof(prpsinfo_t); 1135 strlcpy(psinfo->pr_fname, p->p_comm, sizeof(psinfo->pr_fname)); 1136 1137 /* XXX - We don't fill in the command line arguments properly yet. */ 1138 strlcpy(psinfo->pr_psargs, p->p_comm, sizeof(psinfo->pr_psargs)); 1139 1140 /* Fill in the header. */ 1141 bzero(hdr, hdrsize); 1142 off = 0; 1143 __elfN(puthdr)(p, hdr, &off, status, fpregset, psinfo, numsegs); 1144 1145 free(tempdata, M_TEMP); 1146 1147 /* Write it to the core file. */ 1148 return (vn_rdwr_inchunks(UIO_WRITE, vp, hdr, hdrsize, (off_t)0, 1149 UIO_SYSSPACE, IO_UNIT | IO_DIRECT, cred, NOCRED, NULL, 1150 td)); /* XXXKSE */ 1151 } 1152 1153 static void 1154 __elfN(puthdr)(struct proc *p, void *dst, size_t *off, const prstatus_t *status, 1155 const prfpregset_t *fpregset, const prpsinfo_t *psinfo, int numsegs) 1156 { 1157 size_t ehoff; 1158 size_t phoff; 1159 size_t noteoff; 1160 size_t notesz; 1161 1162 ehoff = *off; 1163 *off += sizeof(Elf_Ehdr); 1164 1165 phoff = *off; 1166 *off += (numsegs + 1) * sizeof(Elf_Phdr); 1167 1168 noteoff = *off; 1169 __elfN(putnote)(dst, off, "FreeBSD", NT_PRSTATUS, status, 1170 sizeof *status); 1171 __elfN(putnote)(dst, off, "FreeBSD", NT_FPREGSET, fpregset, 1172 sizeof *fpregset); 1173 __elfN(putnote)(dst, off, "FreeBSD", NT_PRPSINFO, psinfo, 1174 sizeof *psinfo); 1175 notesz = *off - noteoff; 1176 1177 /* Align up to a page boundary for the program segments. */ 1178 *off = round_page(*off); 1179 1180 if (dst != NULL) { 1181 Elf_Ehdr *ehdr; 1182 Elf_Phdr *phdr; 1183 struct phdr_closure phc; 1184 1185 /* 1186 * Fill in the ELF header. 1187 */ 1188 ehdr = (Elf_Ehdr *)((char *)dst + ehoff); 1189 ehdr->e_ident[EI_MAG0] = ELFMAG0; 1190 ehdr->e_ident[EI_MAG1] = ELFMAG1; 1191 ehdr->e_ident[EI_MAG2] = ELFMAG2; 1192 ehdr->e_ident[EI_MAG3] = ELFMAG3; 1193 ehdr->e_ident[EI_CLASS] = ELF_CLASS; 1194 ehdr->e_ident[EI_DATA] = ELF_DATA; 1195 ehdr->e_ident[EI_VERSION] = EV_CURRENT; 1196 ehdr->e_ident[EI_OSABI] = ELFOSABI_FREEBSD; 1197 ehdr->e_ident[EI_ABIVERSION] = 0; 1198 ehdr->e_ident[EI_PAD] = 0; 1199 ehdr->e_type = ET_CORE; 1200 ehdr->e_machine = ELF_ARCH; 1201 ehdr->e_version = EV_CURRENT; 1202 ehdr->e_entry = 0; 1203 ehdr->e_phoff = phoff; 1204 ehdr->e_flags = 0; 1205 ehdr->e_ehsize = sizeof(Elf_Ehdr); 1206 ehdr->e_phentsize = sizeof(Elf_Phdr); 1207 ehdr->e_phnum = numsegs + 1; 1208 ehdr->e_shentsize = sizeof(Elf_Shdr); 1209 ehdr->e_shnum = 0; 1210 ehdr->e_shstrndx = SHN_UNDEF; 1211 1212 /* 1213 * Fill in the program header entries. 1214 */ 1215 phdr = (Elf_Phdr *)((char *)dst + phoff); 1216 1217 /* The note segement. */ 1218 phdr->p_type = PT_NOTE; 1219 phdr->p_offset = noteoff; 1220 phdr->p_vaddr = 0; 1221 phdr->p_paddr = 0; 1222 phdr->p_filesz = notesz; 1223 phdr->p_memsz = 0; 1224 phdr->p_flags = 0; 1225 phdr->p_align = 0; 1226 phdr++; 1227 1228 /* All the writable segments from the program. */ 1229 phc.phdr = phdr; 1230 phc.offset = *off; 1231 each_writable_segment(p, cb_put_phdr, &phc); 1232 } 1233 } 1234 1235 static void 1236 __elfN(putnote)(void *dst, size_t *off, const char *name, int type, 1237 const void *desc, size_t descsz) 1238 { 1239 Elf_Note note; 1240 1241 note.n_namesz = strlen(name) + 1; 1242 note.n_descsz = descsz; 1243 note.n_type = type; 1244 if (dst != NULL) 1245 bcopy(¬e, (char *)dst + *off, sizeof note); 1246 *off += sizeof note; 1247 if (dst != NULL) 1248 bcopy(name, (char *)dst + *off, note.n_namesz); 1249 *off += roundup2(note.n_namesz, sizeof(Elf_Size)); 1250 if (dst != NULL) 1251 bcopy(desc, (char *)dst + *off, note.n_descsz); 1252 *off += roundup2(note.n_descsz, sizeof(Elf_Size)); 1253 } 1254 1255 /* 1256 * Tell kern_execve.c about it, with a little help from the linker. 1257 */ 1258 static struct execsw __elfN(execsw) = { 1259 __CONCAT(exec_, __elfN(imgact)), 1260 __XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE)) 1261 }; 1262 EXEC_SET(__CONCAT(elf, __ELF_WORD_SIZE), __elfN(execsw));
Cache object: 889a6d030b299e11a85cbfd643ba21ae
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