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) 1995-1996 Søren Schmidt 3 * Copyright (c) 1996 Peter Wemm 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer 11 * in this position and unchanged. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software withough specific prior written permission 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 * 29 * $FreeBSD$ 30 */ 31 32 #include <sys/param.h> 33 #include <sys/exec.h> 34 #include <sys/fcntl.h> 35 #include <sys/imgact.h> 36 #include <sys/imgact_elf.h> 37 #include <sys/kernel.h> 38 #include <sys/malloc.h> 39 #include <sys/mman.h> 40 #include <sys/namei.h> 41 #include <sys/pioctl.h> 42 #include <sys/proc.h> 43 #include <sys/procfs.h> 44 #include <sys/resourcevar.h> 45 #include <sys/signalvar.h> 46 #include <sys/stat.h> 47 #include <sys/syscall.h> 48 #include <sys/sysctl.h> 49 #include <sys/sysent.h> 50 #include <sys/systm.h> 51 #include <sys/vnode.h> 52 53 #include <vm/vm.h> 54 #include <vm/vm_kern.h> 55 #include <vm/vm_param.h> 56 #include <vm/pmap.h> 57 #include <sys/lock.h> 58 #include <vm/vm_map.h> 59 #include <vm/vm_object.h> 60 #include <vm/vm_extern.h> 61 62 #include <machine/elf.h> 63 #include <machine/md_var.h> 64 65 #define OLD_EI_BRAND 8 66 67 __ElfType(Brandinfo); 68 __ElfType(Auxargs); 69 70 static int elf_check_header __P((const Elf_Ehdr *hdr)); 71 static int elf_freebsd_fixup __P((register_t **stack_base, 72 struct image_params *imgp)); 73 static int elf_load_file __P((struct proc *p, const char *file, u_long *addr, 74 u_long *entry)); 75 static int elf_load_section __P((struct proc *p, 76 struct vmspace *vmspace, struct vnode *vp, 77 vm_offset_t offset, caddr_t vmaddr, size_t memsz, size_t filsz, 78 vm_prot_t prot)); 79 static int exec_elf_imgact __P((struct image_params *imgp)); 80 81 static int elf_trace = 0; 82 SYSCTL_INT(_debug, OID_AUTO, elf_trace, CTLFLAG_RW, &elf_trace, 0, ""); 83 static int elf_legacy_coredump = 0; 84 SYSCTL_INT(_debug, OID_AUTO, elf_legacy_coredump, CTLFLAG_RW, 85 &elf_legacy_coredump, 0, ""); 86 87 static struct sysentvec elf_freebsd_sysvec = { 88 SYS_MAXSYSCALL, 89 sysent, 90 0, 91 0, 92 0, 93 0, 94 0, 95 0, 96 elf_freebsd_fixup, 97 sendsig, 98 sigcode, 99 &szsigcode, 100 0, 101 "FreeBSD ELF", 102 elf_coredump, 103 NULL, 104 MINSIGSTKSZ 105 }; 106 107 static Elf_Brandinfo freebsd_brand_info = { 108 ELFOSABI_FREEBSD, 109 "FreeBSD", 110 "", 111 "/usr/libexec/ld-elf.so.1", 112 &elf_freebsd_sysvec 113 }; 114 static Elf_Brandinfo *elf_brand_list[MAX_BRANDS] = { 115 &freebsd_brand_info, 116 NULL, NULL, NULL, 117 NULL, NULL, NULL, NULL 118 }; 119 120 int 121 elf_insert_brand_entry(Elf_Brandinfo *entry) 122 { 123 int i; 124 125 for (i=1; i<MAX_BRANDS; i++) { 126 if (elf_brand_list[i] == NULL) { 127 elf_brand_list[i] = entry; 128 break; 129 } 130 } 131 if (i == MAX_BRANDS) 132 return -1; 133 return 0; 134 } 135 136 int 137 elf_remove_brand_entry(Elf_Brandinfo *entry) 138 { 139 int i; 140 141 for (i=1; i<MAX_BRANDS; i++) { 142 if (elf_brand_list[i] == entry) { 143 elf_brand_list[i] = NULL; 144 break; 145 } 146 } 147 if (i == MAX_BRANDS) 148 return -1; 149 return 0; 150 } 151 152 int 153 elf_brand_inuse(Elf_Brandinfo *entry) 154 { 155 struct proc *p; 156 int rval = FALSE; 157 158 LIST_FOREACH(p, &allproc, p_list) { 159 if (p->p_sysent == entry->sysvec) { 160 rval = TRUE; 161 break; 162 } 163 } 164 165 return (rval); 166 } 167 168 static int 169 elf_check_header(const Elf_Ehdr *hdr) 170 { 171 if (!IS_ELF(*hdr) || 172 hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || 173 hdr->e_ident[EI_DATA] != ELF_TARG_DATA || 174 hdr->e_ident[EI_VERSION] != EV_CURRENT) 175 return ENOEXEC; 176 177 if (!ELF_MACHINE_OK(hdr->e_machine)) 178 return ENOEXEC; 179 180 if (hdr->e_version != ELF_TARG_VER) 181 return ENOEXEC; 182 183 return 0; 184 } 185 186 static int 187 elf_load_section(struct proc *p, struct vmspace *vmspace, struct vnode *vp, vm_offset_t offset, caddr_t vmaddr, size_t memsz, size_t filsz, vm_prot_t prot) 188 { 189 size_t map_len; 190 vm_offset_t map_addr; 191 int error, rv, cow; 192 size_t copy_len; 193 vm_object_t object; 194 vm_offset_t file_addr; 195 vm_offset_t data_buf = 0; 196 197 VOP_GETVOBJECT(vp, &object); 198 error = 0; 199 200 /* 201 * It's necessary to fail if the filsz + offset taken from the 202 * header is greater than the actual file pager object's size. 203 * If we were to allow this, then the vm_map_find() below would 204 * walk right off the end of the file object and into the ether. 205 * 206 * While I'm here, might as well check for something else that 207 * is invalid: filsz cannot be greater than memsz. 208 */ 209 if ((off_t)filsz + offset > object->un_pager.vnp.vnp_size || 210 filsz > memsz) { 211 uprintf("elf_load_section: truncated ELF file\n"); 212 return (ENOEXEC); 213 } 214 215 map_addr = trunc_page((vm_offset_t)vmaddr); 216 file_addr = trunc_page(offset); 217 218 /* 219 * We have two choices. We can either clear the data in the last page 220 * of an oversized mapping, or we can start the anon mapping a page 221 * early and copy the initialized data into that first page. We 222 * choose the second.. 223 */ 224 if (memsz > filsz) 225 map_len = trunc_page(offset+filsz) - file_addr; 226 else 227 map_len = round_page(offset+filsz) - file_addr; 228 229 if (map_len != 0) { 230 vm_object_reference(object); 231 232 /* cow flags: don't dump readonly sections in core */ 233 cow = MAP_COPY_ON_WRITE | MAP_PREFAULT | 234 (prot & VM_PROT_WRITE ? 0 : MAP_DISABLE_COREDUMP); 235 236 vm_map_lock(&vmspace->vm_map); 237 rv = vm_map_insert(&vmspace->vm_map, 238 object, 239 file_addr, /* file offset */ 240 map_addr, /* virtual start */ 241 map_addr + map_len,/* virtual end */ 242 prot, 243 VM_PROT_ALL, 244 cow); 245 vm_map_unlock(&vmspace->vm_map); 246 if (rv != KERN_SUCCESS) { 247 vm_object_deallocate(object); 248 return EINVAL; 249 } 250 251 /* we can stop now if we've covered it all */ 252 if (memsz == filsz) { 253 return 0; 254 } 255 } 256 257 258 /* 259 * We have to get the remaining bit of the file into the first part 260 * of the oversized map segment. This is normally because the .data 261 * segment in the file is extended to provide bss. It's a neat idea 262 * to try and save a page, but it's a pain in the behind to implement. 263 */ 264 copy_len = (offset + filsz) - trunc_page(offset + filsz); 265 map_addr = trunc_page((vm_offset_t)vmaddr + filsz); 266 map_len = round_page((vm_offset_t)vmaddr + memsz) - map_addr; 267 268 /* This had damn well better be true! */ 269 if (map_len != 0) { 270 vm_map_lock(&vmspace->vm_map); 271 rv = vm_map_insert(&vmspace->vm_map, NULL, 0, 272 map_addr, map_addr + map_len, 273 VM_PROT_ALL, VM_PROT_ALL, 0); 274 vm_map_unlock(&vmspace->vm_map); 275 if (rv != KERN_SUCCESS) { 276 return EINVAL; 277 } 278 } 279 280 if (copy_len != 0) { 281 vm_object_reference(object); 282 rv = vm_map_find(exec_map, 283 object, 284 trunc_page(offset + filsz), 285 &data_buf, 286 PAGE_SIZE, 287 TRUE, 288 VM_PROT_READ, 289 VM_PROT_ALL, 290 MAP_COPY_ON_WRITE | MAP_PREFAULT_PARTIAL); 291 if (rv != KERN_SUCCESS) { 292 vm_object_deallocate(object); 293 return EINVAL; 294 } 295 296 /* send the page fragment to user space */ 297 error = copyout((caddr_t)data_buf, (caddr_t)map_addr, copy_len); 298 vm_map_remove(exec_map, data_buf, data_buf + PAGE_SIZE); 299 if (error) { 300 return (error); 301 } 302 } 303 304 /* 305 * set it to the specified protection 306 */ 307 vm_map_protect(&vmspace->vm_map, map_addr, map_addr + map_len, prot, 308 FALSE); 309 310 return error; 311 } 312 313 /* 314 * Load the file "file" into memory. It may be either a shared object 315 * or an executable. 316 * 317 * The "addr" reference parameter is in/out. On entry, it specifies 318 * the address where a shared object should be loaded. If the file is 319 * an executable, this value is ignored. On exit, "addr" specifies 320 * where the file was actually loaded. 321 * 322 * The "entry" reference parameter is out only. On exit, it specifies 323 * the entry point for the loaded file. 324 */ 325 static int 326 elf_load_file(struct proc *p, const char *file, u_long *addr, u_long *entry) 327 { 328 struct { 329 struct nameidata nd; 330 struct vattr attr; 331 struct image_params image_params; 332 } *tempdata; 333 const Elf_Ehdr *hdr = NULL; 334 const Elf_Phdr *phdr = NULL; 335 struct nameidata *nd; 336 struct vmspace *vmspace = p->p_vmspace; 337 struct vattr *attr; 338 struct image_params *imgp; 339 vm_prot_t prot; 340 u_long rbase; 341 u_long base_addr = 0; 342 int error, i, numsegs; 343 344 tempdata = malloc(sizeof(*tempdata), M_TEMP, M_WAITOK); 345 nd = &tempdata->nd; 346 attr = &tempdata->attr; 347 imgp = &tempdata->image_params; 348 349 /* 350 * Initialize part of the common data 351 */ 352 imgp->proc = p; 353 imgp->uap = NULL; 354 imgp->attr = attr; 355 imgp->firstpage = NULL; 356 imgp->image_header = (char *)kmem_alloc_wait(exec_map, PAGE_SIZE); 357 358 if (imgp->image_header == NULL) { 359 nd->ni_vp = NULL; 360 error = ENOMEM; 361 goto fail; 362 } 363 364 NDINIT(nd, LOOKUP, LOCKLEAF|FOLLOW, UIO_SYSSPACE, file, p); 365 366 if ((error = namei(nd)) != 0) { 367 nd->ni_vp = NULL; 368 goto fail; 369 } 370 NDFREE(nd, NDF_ONLY_PNBUF); 371 imgp->vp = nd->ni_vp; 372 373 /* 374 * Check permissions, modes, uid, etc on the file, and "open" it. 375 */ 376 error = exec_check_permissions(imgp); 377 if (error) { 378 VOP_UNLOCK(nd->ni_vp, 0, p); 379 goto fail; 380 } 381 382 error = exec_map_first_page(imgp); 383 /* 384 * Also make certain that the interpreter stays the same, so set 385 * its VTEXT flag, too. 386 */ 387 if (error == 0) 388 nd->ni_vp->v_flag |= VTEXT; 389 VOP_UNLOCK(nd->ni_vp, 0, p); 390 if (error) 391 goto fail; 392 393 hdr = (const Elf_Ehdr *)imgp->image_header; 394 if ((error = elf_check_header(hdr)) != 0) 395 goto fail; 396 if (hdr->e_type == ET_DYN) 397 rbase = *addr; 398 else if (hdr->e_type == ET_EXEC) 399 rbase = 0; 400 else { 401 error = ENOEXEC; 402 goto fail; 403 } 404 405 /* Only support headers that fit within first page for now */ 406 if ((hdr->e_phoff > PAGE_SIZE) || 407 (hdr->e_phoff + hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE) { 408 error = ENOEXEC; 409 goto fail; 410 } 411 412 phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff); 413 414 for (i = 0, numsegs = 0; i < hdr->e_phnum; i++) { 415 if (phdr[i].p_type == PT_LOAD) { /* Loadable segment */ 416 prot = 0; 417 if (phdr[i].p_flags & PF_X) 418 prot |= VM_PROT_EXECUTE; 419 if (phdr[i].p_flags & PF_W) 420 prot |= VM_PROT_WRITE; 421 if (phdr[i].p_flags & PF_R) 422 prot |= VM_PROT_READ; 423 424 if ((error = elf_load_section(p, vmspace, nd->ni_vp, 425 phdr[i].p_offset, 426 (caddr_t)phdr[i].p_vaddr + 427 rbase, 428 phdr[i].p_memsz, 429 phdr[i].p_filesz, prot)) != 0) 430 goto fail; 431 /* 432 * Establish the base address if this is the 433 * first segment. 434 */ 435 if (numsegs == 0) 436 base_addr = trunc_page(phdr[i].p_vaddr + rbase); 437 numsegs++; 438 } 439 } 440 *addr = base_addr; 441 *entry=(unsigned long)hdr->e_entry + rbase; 442 443 fail: 444 if (imgp->firstpage) 445 exec_unmap_first_page(imgp); 446 if (imgp->image_header) 447 kmem_free_wakeup(exec_map, (vm_offset_t)imgp->image_header, 448 PAGE_SIZE); 449 if (nd->ni_vp) 450 vrele(nd->ni_vp); 451 452 free(tempdata, M_TEMP); 453 454 return error; 455 } 456 457 /* 458 * non static, as it can be overridden by start_init() 459 */ 460 int fallback_elf_brand = -1; 461 SYSCTL_INT(_kern, OID_AUTO, fallback_elf_brand, CTLFLAG_RW, 462 &fallback_elf_brand, -1, 463 "ELF brand of last resort"); 464 465 static int 466 exec_elf_imgact(struct image_params *imgp) 467 { 468 const Elf_Ehdr *hdr = (const Elf_Ehdr *) imgp->image_header; 469 const Elf_Phdr *phdr; 470 Elf_Auxargs *elf_auxargs = NULL; 471 struct vmspace *vmspace; 472 vm_prot_t prot; 473 u_long text_size = 0, data_size = 0, total_size = 0; 474 u_long text_addr = 0, data_addr = 0; 475 u_long seg_size, seg_addr; 476 u_long addr, entry = 0, proghdr = 0; 477 int error, i; 478 const char *interp = NULL; 479 Elf_Brandinfo *brand_info; 480 char *path; 481 482 /* 483 * Do we have a valid ELF header ? 484 */ 485 if (elf_check_header(hdr) != 0 || hdr->e_type != ET_EXEC) 486 return -1; 487 488 /* 489 * From here on down, we return an errno, not -1, as we've 490 * detected an ELF file. 491 */ 492 493 if ((hdr->e_phoff > PAGE_SIZE) || 494 (hdr->e_phoff + hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE) { 495 /* Only support headers in first page for now */ 496 return ENOEXEC; 497 } 498 phdr = (const Elf_Phdr*)(imgp->image_header + hdr->e_phoff); 499 500 /* 501 * From this point on, we may have resources that need to be freed. 502 */ 503 504 if ((error = exec_extract_strings(imgp)) != 0) 505 goto fail; 506 507 exec_new_vmspace(imgp); 508 509 /* 510 * Yeah, I'm paranoid. There is every reason in the world to get 511 * VTEXT now since from here on out, there are places we can have 512 * a context switch. Better safe than sorry; I really don't want 513 * the file to change while it's being loaded. 514 */ 515 simple_lock(&imgp->vp->v_interlock); 516 imgp->vp->v_flag |= VTEXT; 517 simple_unlock(&imgp->vp->v_interlock); 518 519 vmspace = imgp->proc->p_vmspace; 520 521 for (i = 0; i < hdr->e_phnum; i++) { 522 switch(phdr[i].p_type) { 523 524 case PT_LOAD: /* Loadable segment */ 525 prot = 0; 526 if (phdr[i].p_flags & PF_X) 527 prot |= VM_PROT_EXECUTE; 528 if (phdr[i].p_flags & PF_W) 529 prot |= VM_PROT_WRITE; 530 if (phdr[i].p_flags & PF_R) 531 prot |= VM_PROT_READ; 532 533 if ((error = elf_load_section(imgp->proc, 534 vmspace, imgp->vp, 535 phdr[i].p_offset, 536 (caddr_t)phdr[i].p_vaddr, 537 phdr[i].p_memsz, 538 phdr[i].p_filesz, prot)) != 0) 539 goto fail; 540 541 seg_addr = trunc_page(phdr[i].p_vaddr); 542 seg_size = round_page(phdr[i].p_memsz + 543 phdr[i].p_vaddr - seg_addr); 544 545 /* 546 * Is this .text or .data? We can't use 547 * VM_PROT_WRITE or VM_PROT_EXEC, it breaks the 548 * alpha terribly and possibly does other bad 549 * things so we stick to the old way of figuring 550 * it out: If the segment contains the program 551 * entry point, it's a text segment, otherwise it 552 * is a data segment. 553 * 554 * Note that obreak() assumes that data_addr + 555 * data_size == end of data load area, and the ELF 556 * file format expects segments to be sorted by 557 * address. If multiple data segments exist, the 558 * last one will be used. 559 */ 560 if (hdr->e_entry >= phdr[i].p_vaddr && 561 hdr->e_entry < (phdr[i].p_vaddr + 562 phdr[i].p_memsz)) { 563 text_size = seg_size; 564 text_addr = seg_addr; 565 entry = (u_long)hdr->e_entry; 566 } else { 567 data_size = seg_size; 568 data_addr = seg_addr; 569 } 570 total_size += seg_size; 571 572 /* 573 * Check limits. It should be safe to check the 574 * limits after loading the segment since we do 575 * not actually fault in all the segment's pages. 576 */ 577 if (data_size > 578 imgp->proc->p_rlimit[RLIMIT_DATA].rlim_cur || 579 text_size > maxtsiz || 580 total_size > 581 imgp->proc->p_rlimit[RLIMIT_VMEM].rlim_cur) { 582 error = ENOMEM; 583 goto fail; 584 } 585 break; 586 case PT_INTERP: /* Path to interpreter */ 587 if (phdr[i].p_filesz > MAXPATHLEN || 588 phdr[i].p_offset + phdr[i].p_filesz > PAGE_SIZE) { 589 error = ENOEXEC; 590 goto fail; 591 } 592 interp = imgp->image_header + phdr[i].p_offset; 593 break; 594 case PT_PHDR: /* Program header table info */ 595 proghdr = phdr[i].p_vaddr; 596 break; 597 default: 598 break; 599 } 600 } 601 602 vmspace->vm_tsize = text_size >> PAGE_SHIFT; 603 vmspace->vm_taddr = (caddr_t)(uintptr_t)text_addr; 604 vmspace->vm_dsize = data_size >> PAGE_SHIFT; 605 vmspace->vm_daddr = (caddr_t)(uintptr_t)data_addr; 606 607 addr = ELF_RTLD_ADDR(vmspace); 608 609 imgp->entry_addr = entry; 610 611 brand_info = NULL; 612 613 /* We support three types of branding -- (1) the ELF EI_OSABI field 614 * that SCO added to the ELF spec, (2) FreeBSD 3.x's traditional string 615 * branding w/in the ELF header, and (3) path of the `interp_path' 616 * field. We should also look for an ".note.ABI-tag" ELF section now 617 * in all Linux ELF binaries, FreeBSD 4.1+, and some NetBSD ones. 618 */ 619 620 /* If the executable has a brand, search for it in the brand list. */ 621 if (brand_info == NULL) { 622 for (i = 0; i < MAX_BRANDS; i++) { 623 Elf_Brandinfo *bi = elf_brand_list[i]; 624 625 if (bi != NULL && 626 (hdr->e_ident[EI_OSABI] == bi->brand 627 || 0 == 628 strncmp((const char *)&hdr->e_ident[OLD_EI_BRAND], 629 bi->compat_3_brand, strlen(bi->compat_3_brand)))) { 630 brand_info = bi; 631 break; 632 } 633 } 634 } 635 636 /* Lacking a known brand, search for a recognized interpreter. */ 637 if (brand_info == NULL && interp != NULL) { 638 for (i = 0; i < MAX_BRANDS; i++) { 639 Elf_Brandinfo *bi = elf_brand_list[i]; 640 641 if (bi != NULL && 642 strcmp(interp, bi->interp_path) == 0) { 643 brand_info = bi; 644 break; 645 } 646 } 647 } 648 649 /* Lacking a recognized interpreter, try the default brand */ 650 if (brand_info == NULL) { 651 for (i = 0; i < MAX_BRANDS; i++) { 652 Elf_Brandinfo *bi = elf_brand_list[i]; 653 654 if (bi != NULL && fallback_elf_brand == bi->brand) { 655 brand_info = bi; 656 break; 657 } 658 } 659 } 660 661 if (brand_info == NULL) { 662 uprintf("ELF binary type \"%u\" not known.\n", 663 hdr->e_ident[EI_OSABI]); 664 error = ENOEXEC; 665 goto fail; 666 } 667 668 imgp->proc->p_sysent = brand_info->sysvec; 669 if (interp != NULL) { 670 path = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 671 snprintf(path, MAXPATHLEN, "%s%s", 672 brand_info->emul_path, interp); 673 if ((error = elf_load_file(imgp->proc, path, &addr, 674 &imgp->entry_addr)) != 0) { 675 if ((error = elf_load_file(imgp->proc, interp, &addr, 676 &imgp->entry_addr)) != 0) { 677 uprintf("ELF interpreter %s not found\n", path); 678 free(path, M_TEMP); 679 goto fail; 680 } 681 } 682 free(path, M_TEMP); 683 } 684 685 /* 686 * Construct auxargs table (used by the fixup routine) 687 */ 688 elf_auxargs = malloc(sizeof(Elf_Auxargs), M_TEMP, M_WAITOK); 689 elf_auxargs->execfd = -1; 690 elf_auxargs->phdr = proghdr; 691 elf_auxargs->phent = hdr->e_phentsize; 692 elf_auxargs->phnum = hdr->e_phnum; 693 elf_auxargs->pagesz = PAGE_SIZE; 694 elf_auxargs->base = addr; 695 elf_auxargs->flags = 0; 696 elf_auxargs->entry = entry; 697 elf_auxargs->trace = elf_trace; 698 699 imgp->auxargs = elf_auxargs; 700 imgp->interpreted = 0; 701 702 fail: 703 return error; 704 } 705 706 static int 707 elf_freebsd_fixup(register_t **stack_base, struct image_params *imgp) 708 { 709 Elf_Auxargs *args = (Elf_Auxargs *)imgp->auxargs; 710 register_t *pos; 711 712 pos = *stack_base + (imgp->argc + imgp->envc + 2); 713 714 if (args->trace) { 715 AUXARGS_ENTRY(pos, AT_DEBUG, 1); 716 } 717 if (args->execfd != -1) { 718 AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd); 719 } 720 AUXARGS_ENTRY(pos, AT_PHDR, args->phdr); 721 AUXARGS_ENTRY(pos, AT_PHENT, args->phent); 722 AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum); 723 AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz); 724 AUXARGS_ENTRY(pos, AT_FLAGS, args->flags); 725 AUXARGS_ENTRY(pos, AT_ENTRY, args->entry); 726 AUXARGS_ENTRY(pos, AT_BASE, args->base); 727 AUXARGS_ENTRY(pos, AT_NULL, 0); 728 729 free(imgp->auxargs, M_TEMP); 730 imgp->auxargs = NULL; 731 732 (*stack_base)--; 733 suword(*stack_base, (long) imgp->argc); 734 return 0; 735 } 736 737 /* 738 * Code for generating ELF core dumps. 739 */ 740 741 typedef void (*segment_callback) __P((vm_map_entry_t, void *)); 742 743 /* Closure for cb_put_phdr(). */ 744 struct phdr_closure { 745 Elf_Phdr *phdr; /* Program header to fill in */ 746 Elf_Off offset; /* Offset of segment in core file */ 747 }; 748 749 /* Closure for cb_size_segment(). */ 750 struct sseg_closure { 751 int count; /* Count of writable segments. */ 752 size_t size; /* Total size of all writable segments. */ 753 }; 754 755 static void cb_put_phdr __P((vm_map_entry_t, void *)); 756 static void cb_size_segment __P((vm_map_entry_t, void *)); 757 static void each_writable_segment __P((struct proc *, segment_callback, 758 void *)); 759 static int elf_corehdr __P((struct proc *, struct vnode *, struct ucred *, 760 int, void *, size_t)); 761 static void elf_puthdr __P((struct proc *, void *, size_t *, 762 const prstatus_t *, const prfpregset_t *, const prpsinfo_t *, int)); 763 static void elf_putnote __P((void *, size_t *, const char *, int, 764 const void *, size_t)); 765 766 extern int osreldate; 767 768 int 769 elf_coredump(p, vp, limit) 770 register struct proc *p; 771 register struct vnode *vp; 772 off_t limit; 773 { 774 register struct ucred *cred = p->p_ucred; 775 int error = 0; 776 struct sseg_closure seginfo; 777 void *hdr; 778 size_t hdrsize; 779 780 /* Size the program segments. */ 781 seginfo.count = 0; 782 seginfo.size = 0; 783 each_writable_segment(p, cb_size_segment, &seginfo); 784 785 /* 786 * Calculate the size of the core file header area by making 787 * a dry run of generating it. Nothing is written, but the 788 * size is calculated. 789 */ 790 hdrsize = 0; 791 elf_puthdr((struct proc *)NULL, (void *)NULL, &hdrsize, 792 (const prstatus_t *)NULL, (const prfpregset_t *)NULL, 793 (const prpsinfo_t *)NULL, seginfo.count); 794 795 if (hdrsize + seginfo.size >= limit) 796 return (EFAULT); 797 798 /* 799 * Allocate memory for building the header, fill it up, 800 * and write it out. 801 */ 802 hdr = malloc(hdrsize, M_TEMP, M_WAITOK); 803 if (hdr == NULL) { 804 return EINVAL; 805 } 806 error = elf_corehdr(p, vp, cred, seginfo.count, hdr, hdrsize); 807 808 /* Write the contents of all of the writable segments. */ 809 if (error == 0) { 810 Elf_Phdr *php; 811 off_t offset; 812 int i; 813 814 php = (Elf_Phdr *)((char *)hdr + sizeof(Elf_Ehdr)) + 1; 815 offset = hdrsize; 816 for (i = 0; i < seginfo.count; i++) { 817 error = vn_rdwr_inchunks(UIO_WRITE, vp, 818 (caddr_t)php->p_vaddr, 819 php->p_filesz, offset, UIO_USERSPACE, 820 IO_UNIT | IO_DIRECT, cred, (int *)NULL, p); 821 if (error != 0) 822 break; 823 offset += php->p_filesz; 824 php++; 825 } 826 } 827 free(hdr, M_TEMP); 828 829 return error; 830 } 831 832 /* 833 * A callback for each_writable_segment() to write out the segment's 834 * program header entry. 835 */ 836 static void 837 cb_put_phdr(entry, closure) 838 vm_map_entry_t entry; 839 void *closure; 840 { 841 struct phdr_closure *phc = (struct phdr_closure *)closure; 842 Elf_Phdr *phdr = phc->phdr; 843 844 phc->offset = round_page(phc->offset); 845 846 phdr->p_type = PT_LOAD; 847 phdr->p_offset = phc->offset; 848 phdr->p_vaddr = entry->start; 849 phdr->p_paddr = 0; 850 phdr->p_filesz = phdr->p_memsz = entry->end - entry->start; 851 phdr->p_align = PAGE_SIZE; 852 phdr->p_flags = 0; 853 if (entry->protection & VM_PROT_READ) 854 phdr->p_flags |= PF_R; 855 if (entry->protection & VM_PROT_WRITE) 856 phdr->p_flags |= PF_W; 857 if (entry->protection & VM_PROT_EXECUTE) 858 phdr->p_flags |= PF_X; 859 860 phc->offset += phdr->p_filesz; 861 phc->phdr++; 862 } 863 864 /* 865 * A callback for each_writable_segment() to gather information about 866 * the number of segments and their total size. 867 */ 868 static void 869 cb_size_segment(entry, closure) 870 vm_map_entry_t entry; 871 void *closure; 872 { 873 struct sseg_closure *ssc = (struct sseg_closure *)closure; 874 875 ssc->count++; 876 ssc->size += entry->end - entry->start; 877 } 878 879 /* 880 * For each writable segment in the process's memory map, call the given 881 * function with a pointer to the map entry and some arbitrary 882 * caller-supplied data. 883 */ 884 static void 885 each_writable_segment(p, func, closure) 886 struct proc *p; 887 segment_callback func; 888 void *closure; 889 { 890 vm_map_t map = &p->p_vmspace->vm_map; 891 vm_map_entry_t entry; 892 893 for (entry = map->header.next; entry != &map->header; 894 entry = entry->next) { 895 vm_object_t obj; 896 897 /* 898 * Don't dump inaccessible mappings, deal with legacy 899 * coredump mode. 900 * 901 * Note that read-only segments related to the elf binary 902 * are marked MAP_ENTRY_NOCOREDUMP now so we no longer 903 * need to arbitrarily ignore such segments. 904 */ 905 if (elf_legacy_coredump) { 906 if ((entry->protection & VM_PROT_RW) != VM_PROT_RW) 907 continue; 908 } else { 909 if ((entry->protection & VM_PROT_ALL) == 0) 910 continue; 911 } 912 913 /* 914 * Dont include memory segment in the coredump if 915 * MAP_NOCORE is set in mmap(2) or MADV_NOCORE in 916 * madvise(2). Do not dump submaps (i.e. parts of the 917 * kernel map). 918 */ 919 if (entry->eflags & (MAP_ENTRY_NOCOREDUMP|MAP_ENTRY_IS_SUB_MAP)) 920 continue; 921 922 if ((obj = entry->object.vm_object) == NULL) 923 continue; 924 925 /* Find the deepest backing object. */ 926 while (obj->backing_object != NULL) 927 obj = obj->backing_object; 928 929 /* Ignore memory-mapped devices and such things. */ 930 if (obj->type != OBJT_DEFAULT && 931 obj->type != OBJT_SWAP && 932 obj->type != OBJT_VNODE) 933 continue; 934 935 (*func)(entry, closure); 936 } 937 } 938 939 /* 940 * Write the core file header to the file, including padding up to 941 * the page boundary. 942 */ 943 static int 944 elf_corehdr(p, vp, cred, numsegs, hdr, hdrsize) 945 struct proc *p; 946 struct vnode *vp; 947 struct ucred *cred; 948 int numsegs; 949 size_t hdrsize; 950 void *hdr; 951 { 952 struct { 953 prstatus_t status; 954 prfpregset_t fpregset; 955 prpsinfo_t psinfo; 956 } *tempdata; 957 size_t off; 958 prstatus_t *status; 959 prfpregset_t *fpregset; 960 prpsinfo_t *psinfo; 961 962 tempdata = malloc(sizeof(*tempdata), M_TEMP, M_ZERO | M_WAITOK); 963 status = &tempdata->status; 964 fpregset = &tempdata->fpregset; 965 psinfo = &tempdata->psinfo; 966 967 /* Gather the information for the header. */ 968 status->pr_version = PRSTATUS_VERSION; 969 status->pr_statussz = sizeof(prstatus_t); 970 status->pr_gregsetsz = sizeof(gregset_t); 971 status->pr_fpregsetsz = sizeof(fpregset_t); 972 status->pr_osreldate = osreldate; 973 status->pr_cursig = p->p_sig; 974 status->pr_pid = p->p_pid; 975 fill_regs(p, &status->pr_reg); 976 977 fill_fpregs(p, fpregset); 978 979 psinfo->pr_version = PRPSINFO_VERSION; 980 psinfo->pr_psinfosz = sizeof(prpsinfo_t); 981 strncpy(psinfo->pr_fname, p->p_comm, sizeof(psinfo->pr_fname) - 1); 982 983 /* XXX - We don't fill in the command line arguments properly yet. */ 984 strncpy(psinfo->pr_psargs, p->p_comm, PRARGSZ); 985 986 /* Fill in the header. */ 987 bzero(hdr, hdrsize); 988 off = 0; 989 elf_puthdr(p, hdr, &off, status, fpregset, psinfo, numsegs); 990 991 free(tempdata, M_TEMP); 992 993 /* Write it to the core file. */ 994 return vn_rdwr_inchunks(UIO_WRITE, vp, hdr, hdrsize, (off_t)0, 995 UIO_SYSSPACE, IO_UNIT | IO_DIRECT, cred, NULL, p); 996 } 997 998 static void 999 elf_puthdr(struct proc *p, void *dst, size_t *off, const prstatus_t *status, 1000 const prfpregset_t *fpregset, const prpsinfo_t *psinfo, int numsegs) 1001 { 1002 size_t ehoff; 1003 size_t phoff; 1004 size_t noteoff; 1005 size_t notesz; 1006 1007 ehoff = *off; 1008 *off += sizeof(Elf_Ehdr); 1009 1010 phoff = *off; 1011 *off += (numsegs + 1) * sizeof(Elf_Phdr); 1012 1013 noteoff = *off; 1014 elf_putnote(dst, off, "FreeBSD", NT_PRSTATUS, status, 1015 sizeof *status); 1016 elf_putnote(dst, off, "FreeBSD", NT_FPREGSET, fpregset, 1017 sizeof *fpregset); 1018 elf_putnote(dst, off, "FreeBSD", NT_PRPSINFO, psinfo, 1019 sizeof *psinfo); 1020 notesz = *off - noteoff; 1021 1022 /* Align up to a page boundary for the program segments. */ 1023 *off = round_page(*off); 1024 1025 if (dst != NULL) { 1026 Elf_Ehdr *ehdr; 1027 Elf_Phdr *phdr; 1028 struct phdr_closure phc; 1029 1030 /* 1031 * Fill in the ELF header. 1032 */ 1033 ehdr = (Elf_Ehdr *)((char *)dst + ehoff); 1034 ehdr->e_ident[EI_MAG0] = ELFMAG0; 1035 ehdr->e_ident[EI_MAG1] = ELFMAG1; 1036 ehdr->e_ident[EI_MAG2] = ELFMAG2; 1037 ehdr->e_ident[EI_MAG3] = ELFMAG3; 1038 ehdr->e_ident[EI_CLASS] = ELF_CLASS; 1039 ehdr->e_ident[EI_DATA] = ELF_DATA; 1040 ehdr->e_ident[EI_VERSION] = EV_CURRENT; 1041 ehdr->e_ident[EI_OSABI] = ELFOSABI_FREEBSD; 1042 ehdr->e_ident[EI_ABIVERSION] = 0; 1043 ehdr->e_ident[EI_PAD] = 0; 1044 ehdr->e_type = ET_CORE; 1045 ehdr->e_machine = ELF_ARCH; 1046 ehdr->e_version = EV_CURRENT; 1047 ehdr->e_entry = 0; 1048 ehdr->e_phoff = phoff; 1049 ehdr->e_flags = 0; 1050 ehdr->e_ehsize = sizeof(Elf_Ehdr); 1051 ehdr->e_phentsize = sizeof(Elf_Phdr); 1052 ehdr->e_phnum = numsegs + 1; 1053 ehdr->e_shentsize = sizeof(Elf_Shdr); 1054 ehdr->e_shnum = 0; 1055 ehdr->e_shstrndx = SHN_UNDEF; 1056 1057 /* 1058 * Fill in the program header entries. 1059 */ 1060 phdr = (Elf_Phdr *)((char *)dst + phoff); 1061 1062 /* The note segement. */ 1063 phdr->p_type = PT_NOTE; 1064 phdr->p_offset = noteoff; 1065 phdr->p_vaddr = 0; 1066 phdr->p_paddr = 0; 1067 phdr->p_filesz = notesz; 1068 phdr->p_memsz = 0; 1069 phdr->p_flags = 0; 1070 phdr->p_align = 0; 1071 phdr++; 1072 1073 /* All the writable segments from the program. */ 1074 phc.phdr = phdr; 1075 phc.offset = *off; 1076 each_writable_segment(p, cb_put_phdr, &phc); 1077 } 1078 } 1079 1080 static void 1081 elf_putnote(void *dst, size_t *off, const char *name, int type, 1082 const void *desc, size_t descsz) 1083 { 1084 Elf_Note note; 1085 1086 note.n_namesz = strlen(name) + 1; 1087 note.n_descsz = descsz; 1088 note.n_type = type; 1089 if (dst != NULL) 1090 bcopy(¬e, (char *)dst + *off, sizeof note); 1091 *off += sizeof note; 1092 if (dst != NULL) 1093 bcopy(name, (char *)dst + *off, note.n_namesz); 1094 *off += roundup2(note.n_namesz, sizeof(Elf_Size)); 1095 if (dst != NULL) 1096 bcopy(desc, (char *)dst + *off, note.n_descsz); 1097 *off += roundup2(note.n_descsz, sizeof(Elf_Size)); 1098 } 1099 1100 /* 1101 * Tell kern_execve.c about it, with a little help from the linker. 1102 */ 1103 static struct execsw elf_execsw = {exec_elf_imgact, "ELF"}; 1104 EXEC_SET(elf, elf_execsw);
Cache object: ce5541c3c7ea533c263e3bd41c424815
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