1 /*- 2 * Copyright (c) 1995-1996 S�ren 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 "opt_rlimit.h" 33 34 #include <sys/param.h> 35 #include <sys/acct.h> 36 #include <sys/exec.h> 37 #include <sys/fcntl.h> 38 #include <sys/imgact.h> 39 #include <sys/imgact_elf.h> 40 #include <sys/kernel.h> 41 #include <sys/malloc.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/signalvar.h> 49 #include <sys/stat.h> 50 #include <sys/syscall.h> 51 #include <sys/sysctl.h> 52 #include <sys/sysent.h> 53 #include <sys/systm.h> 54 #include <sys/vnode.h> 55 56 #include <vm/vm.h> 57 #include <vm/vm_kern.h> 58 #include <vm/vm_param.h> 59 #include <vm/pmap.h> 60 #include <sys/lock.h> 61 #include <vm/vm_map.h> 62 #include <vm/vm_object.h> 63 #include <vm/vm_prot.h> 64 #include <vm/vm_extern.h> 65 66 #include <machine/elf.h> 67 #include <machine/md_var.h> 68 69 __ElfType(Brandinfo); 70 __ElfType(Auxargs); 71 72 static int elf_check_header __P((const Elf_Ehdr *hdr)); 73 static int elf_freebsd_fixup __P((long **stack_base, 74 struct image_params *imgp)); 75 static int elf_load_file __P((struct proc *p, const char *file, u_long *addr, 76 u_long *entry)); 77 static int elf_load_section __P((struct proc *p, 78 struct vmspace *vmspace, struct vnode *vp, 79 vm_offset_t offset, caddr_t vmaddr, size_t memsz, size_t filsz, 80 vm_prot_t prot)); 81 static int exec_elf_imgact __P((struct image_params *imgp)); 82 83 static int elf_trace = 0; 84 SYSCTL_INT(_debug, OID_AUTO, elf_trace, CTLFLAG_RW, &elf_trace, 0, ""); 85 86 /* 87 * XXX Maximum length of an ELF brand (sysctl wants a statically-allocated 88 * buffer). 89 */ 90 #define MAXBRANDLEN 16 91 92 static struct sysentvec elf_freebsd_sysvec = { 93 SYS_MAXSYSCALL, 94 sysent, 95 0, 96 0, 97 0, 98 0, 99 0, 100 0, 101 elf_freebsd_fixup, 102 sendsig, 103 sigcode, 104 &szsigcode, 105 0, 106 "FreeBSD ELF", 107 elf_coredump 108 }; 109 110 static Elf_Brandinfo freebsd_brand_info = { 111 "FreeBSD", 112 "", 113 "/usr/libexec/ld-elf.so.1", 114 &elf_freebsd_sysvec 115 }; 116 static Elf_Brandinfo *elf_brand_list[MAX_BRANDS] = { 117 &freebsd_brand_info, 118 NULL, NULL, NULL, 119 NULL, NULL, NULL, NULL 120 }; 121 122 int 123 elf_insert_brand_entry(Elf_Brandinfo *entry) 124 { 125 int i; 126 127 for (i=1; i<MAX_BRANDS; i++) { 128 if (elf_brand_list[i] == NULL) { 129 elf_brand_list[i] = entry; 130 break; 131 } 132 } 133 if (i == MAX_BRANDS) 134 return -1; 135 return 0; 136 } 137 138 int 139 elf_remove_brand_entry(Elf_Brandinfo *entry) 140 { 141 int i; 142 143 for (i=1; i<MAX_BRANDS; i++) { 144 if (elf_brand_list[i] == entry) { 145 elf_brand_list[i] = NULL; 146 break; 147 } 148 } 149 if (i == MAX_BRANDS) 150 return -1; 151 return 0; 152 } 153 154 int 155 elf_brand_inuse(Elf_Brandinfo *entry) 156 { 157 struct proc *p; 158 159 for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) { 160 if (p->p_sysent == entry->sysvec) 161 return TRUE; 162 } 163 164 return FALSE; 165 } 166 167 static int 168 elf_check_header(const Elf_Ehdr *hdr) 169 { 170 if (!IS_ELF(*hdr) || 171 hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || 172 hdr->e_ident[EI_DATA] != ELF_TARG_DATA || 173 hdr->e_ident[EI_VERSION] != EV_CURRENT) 174 return ENOEXEC; 175 176 if (!ELF_MACHINE_OK(hdr->e_machine)) 177 return ENOEXEC; 178 179 if (hdr->e_version != ELF_TARG_VER) 180 return ENOEXEC; 181 182 return 0; 183 } 184 185 static int 186 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) 187 { 188 size_t map_len; 189 vm_offset_t map_addr; 190 int error, rv; 191 size_t copy_len; 192 vm_object_t object; 193 vm_offset_t file_addr; 194 vm_offset_t data_buf = 0; 195 196 object = vp->v_object; 197 error = 0; 198 199 map_addr = trunc_page((vm_offset_t)vmaddr); 200 file_addr = trunc_page(offset); 201 202 /* 203 * We have two choices. We can either clear the data in the last page 204 * of an oversized mapping, or we can start the anon mapping a page 205 * early and copy the initialized data into that first page. We 206 * choose the second.. 207 */ 208 if (memsz > filsz) 209 map_len = trunc_page(offset+filsz) - file_addr; 210 else 211 map_len = round_page(offset+filsz) - file_addr; 212 213 if (map_len != 0) { 214 vm_object_reference(object); 215 vm_map_lock(&vmspace->vm_map); 216 rv = vm_map_insert(&vmspace->vm_map, 217 object, 218 file_addr, /* file offset */ 219 map_addr, /* virtual start */ 220 map_addr + map_len,/* virtual end */ 221 prot, 222 VM_PROT_ALL, 223 MAP_COPY_ON_WRITE | MAP_PREFAULT); 224 vm_map_unlock(&vmspace->vm_map); 225 if (rv != KERN_SUCCESS) 226 return EINVAL; 227 228 /* we can stop now if we've covered it all */ 229 if (memsz == filsz) 230 return 0; 231 } 232 233 234 /* 235 * We have to get the remaining bit of the file into the first part 236 * of the oversized map segment. This is normally because the .data 237 * segment in the file is extended to provide bss. It's a neat idea 238 * to try and save a page, but it's a pain in the behind to implement. 239 */ 240 copy_len = (offset + filsz) - trunc_page(offset + filsz); 241 map_addr = trunc_page((vm_offset_t)vmaddr + filsz); 242 map_len = round_page((vm_offset_t)vmaddr + memsz) - map_addr; 243 244 /* This had damn well better be true! */ 245 if (map_len != 0) { 246 vm_map_lock(&vmspace->vm_map); 247 rv = vm_map_insert(&vmspace->vm_map, NULL, 0, 248 map_addr, map_addr + map_len, 249 VM_PROT_ALL, VM_PROT_ALL, 0); 250 vm_map_unlock(&vmspace->vm_map); 251 if (rv != KERN_SUCCESS) 252 return EINVAL; 253 } 254 255 if (copy_len != 0) { 256 vm_object_reference(object); 257 rv = vm_map_find(exec_map, 258 object, 259 trunc_page(offset + filsz), 260 &data_buf, 261 PAGE_SIZE, 262 TRUE, 263 VM_PROT_READ, 264 VM_PROT_ALL, 265 MAP_COPY_ON_WRITE | MAP_PREFAULT_PARTIAL); 266 if (rv != KERN_SUCCESS) { 267 vm_object_deallocate(object); 268 return EINVAL; 269 } 270 271 /* send the page fragment to user space */ 272 error = copyout((caddr_t)data_buf, (caddr_t)map_addr, copy_len); 273 vm_map_remove(exec_map, data_buf, data_buf + PAGE_SIZE); 274 if (error) 275 return (error); 276 } 277 278 /* 279 * set it to the specified protection 280 */ 281 vm_map_protect(&vmspace->vm_map, map_addr, map_addr + map_len, prot, 282 FALSE); 283 284 return error; 285 } 286 287 /* 288 * Load the file "file" into memory. It may be either a shared object 289 * or an executable. 290 * 291 * The "addr" reference parameter is in/out. On entry, it specifies 292 * the address where a shared object should be loaded. If the file is 293 * an executable, this value is ignored. On exit, "addr" specifies 294 * where the file was actually loaded. 295 * 296 * The "entry" reference parameter is out only. On exit, it specifies 297 * the entry point for the loaded file. 298 */ 299 static int 300 elf_load_file(struct proc *p, const char *file, u_long *addr, u_long *entry) 301 { 302 const Elf_Ehdr *hdr = NULL; 303 const Elf_Phdr *phdr = NULL; 304 struct nameidata nd; 305 struct vmspace *vmspace = p->p_vmspace; 306 struct vattr attr; 307 struct image_params image_params, *imgp; 308 vm_prot_t prot; 309 u_long rbase; 310 u_long base_addr = 0; 311 int error, i, numsegs; 312 313 imgp = &image_params; 314 /* 315 * Initialize part of the common data 316 */ 317 imgp->proc = p; 318 imgp->uap = NULL; 319 imgp->attr = &attr; 320 imgp->firstpage = NULL; 321 imgp->image_header = (char *)kmem_alloc_wait(exec_map, PAGE_SIZE); 322 323 if (imgp->image_header == NULL) { 324 nd.ni_vp = NULL; 325 error = ENOMEM; 326 goto fail; 327 } 328 329 NDINIT(&nd, LOOKUP, LOCKLEAF|FOLLOW, UIO_SYSSPACE, file, p); 330 331 if ((error = namei(&nd)) != 0) { 332 nd.ni_vp = NULL; 333 goto fail; 334 } 335 336 imgp->vp = nd.ni_vp; 337 338 /* 339 * Check permissions, modes, uid, etc on the file, and "open" it. 340 */ 341 error = exec_check_permissions(imgp); 342 if (error) { 343 VOP_UNLOCK(nd.ni_vp, 0, p); 344 goto fail; 345 } 346 347 error = exec_map_first_page(imgp); 348 VOP_UNLOCK(nd.ni_vp, 0, p); 349 if (error) 350 goto fail; 351 352 hdr = (const Elf_Ehdr *)imgp->image_header; 353 if ((error = elf_check_header(hdr)) != 0) 354 goto fail; 355 if (hdr->e_type == ET_DYN) 356 rbase = *addr; 357 else if (hdr->e_type == ET_EXEC) 358 rbase = 0; 359 else { 360 error = ENOEXEC; 361 goto fail; 362 } 363 364 /* Only support headers that fit within first page for now */ 365 if ((hdr->e_phoff > PAGE_SIZE) || 366 (hdr->e_phoff + hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE) { 367 error = ENOEXEC; 368 goto fail; 369 } 370 371 phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff); 372 373 for (i = 0, numsegs = 0; i < hdr->e_phnum; i++) { 374 if (phdr[i].p_type == PT_LOAD) { /* Loadable segment */ 375 prot = 0; 376 if (phdr[i].p_flags & PF_X) 377 prot |= VM_PROT_EXECUTE; 378 if (phdr[i].p_flags & PF_W) 379 prot |= VM_PROT_WRITE; 380 if (phdr[i].p_flags & PF_R) 381 prot |= VM_PROT_READ; 382 383 if ((error = elf_load_section(p, vmspace, nd.ni_vp, 384 phdr[i].p_offset, 385 (caddr_t)phdr[i].p_vaddr + 386 rbase, 387 phdr[i].p_memsz, 388 phdr[i].p_filesz, prot)) != 0) 389 goto fail; 390 /* 391 * Establish the base address if this is the 392 * first segment. 393 */ 394 if (numsegs == 0) 395 base_addr = trunc_page(phdr[i].p_vaddr + rbase); 396 numsegs++; 397 } 398 } 399 *addr = base_addr; 400 *entry=(unsigned long)hdr->e_entry + rbase; 401 402 fail: 403 if (imgp->firstpage) 404 exec_unmap_first_page(imgp); 405 if (imgp->image_header) 406 kmem_free_wakeup(exec_map, (vm_offset_t)imgp->image_header, 407 PAGE_SIZE); 408 if (nd.ni_vp) 409 vrele(nd.ni_vp); 410 411 return error; 412 } 413 414 static char fallback_elf_brand[MAXBRANDLEN+1] = { "none" }; 415 SYSCTL_STRING(_kern, OID_AUTO, fallback_elf_brand, CTLFLAG_RW, 416 fallback_elf_brand, sizeof(fallback_elf_brand), 417 "ELF brand of last resort"); 418 419 static int 420 exec_elf_imgact(struct image_params *imgp) 421 { 422 const Elf_Ehdr *hdr = (const Elf_Ehdr *) imgp->image_header; 423 const Elf_Phdr *phdr; 424 Elf_Auxargs *elf_auxargs = NULL; 425 struct vmspace *vmspace; 426 vm_prot_t prot; 427 u_long text_size = 0, data_size = 0; 428 u_long text_addr = 0, data_addr = 0; 429 u_long addr, entry = 0, proghdr = 0; 430 int error, i; 431 const char *interp = NULL; 432 Elf_Brandinfo *brand_info; 433 const char *brand; 434 char path[MAXPATHLEN]; 435 436 /* 437 * Do we have a valid ELF header ? 438 */ 439 if (elf_check_header(hdr) != 0 || hdr->e_type != ET_EXEC) 440 return -1; 441 442 /* 443 * From here on down, we return an errno, not -1, as we've 444 * detected an ELF file. 445 */ 446 447 if ((hdr->e_phoff > PAGE_SIZE) || 448 (hdr->e_phoff + hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE) { 449 /* Only support headers in first page for now */ 450 return ENOEXEC; 451 } 452 phdr = (const Elf_Phdr*)(imgp->image_header + hdr->e_phoff); 453 454 /* 455 * From this point on, we may have resources that need to be freed. 456 */ 457 if ((error = exec_extract_strings(imgp)) != 0) 458 goto fail; 459 460 exec_new_vmspace(imgp); 461 462 vmspace = imgp->proc->p_vmspace; 463 464 for (i = 0; i < hdr->e_phnum; i++) { 465 switch(phdr[i].p_type) { 466 467 case PT_LOAD: /* Loadable segment */ 468 prot = 0; 469 if (phdr[i].p_flags & PF_X) 470 prot |= VM_PROT_EXECUTE; 471 if (phdr[i].p_flags & PF_W) 472 prot |= VM_PROT_WRITE; 473 if (phdr[i].p_flags & PF_R) 474 prot |= VM_PROT_READ; 475 476 if ((error = elf_load_section(imgp->proc, 477 vmspace, imgp->vp, 478 phdr[i].p_offset, 479 (caddr_t)phdr[i].p_vaddr, 480 phdr[i].p_memsz, 481 phdr[i].p_filesz, prot)) != 0) 482 goto fail; 483 484 /* 485 * Is this .text or .data ?? 486 * 487 * We only handle one each of those yet XXX 488 */ 489 if (hdr->e_entry >= phdr[i].p_vaddr && 490 hdr->e_entry <(phdr[i].p_vaddr+phdr[i].p_memsz)) { 491 text_addr = trunc_page(phdr[i].p_vaddr); 492 text_size = round_page(phdr[i].p_memsz + 493 phdr[i].p_vaddr - 494 text_addr); 495 entry = (u_long)hdr->e_entry; 496 } else { 497 data_addr = trunc_page(phdr[i].p_vaddr); 498 data_size = round_page(phdr[i].p_memsz + 499 phdr[i].p_vaddr - 500 data_addr); 501 } 502 break; 503 case PT_INTERP: /* Path to interpreter */ 504 if (phdr[i].p_filesz > MAXPATHLEN || 505 phdr[i].p_offset + phdr[i].p_filesz > PAGE_SIZE) { 506 error = ENOEXEC; 507 goto fail; 508 } 509 interp = imgp->image_header + phdr[i].p_offset; 510 break; 511 case PT_PHDR: /* Program header table info */ 512 proghdr = phdr[i].p_vaddr; 513 break; 514 default: 515 break; 516 } 517 } 518 519 vmspace->vm_tsize = text_size >> PAGE_SHIFT; 520 vmspace->vm_taddr = (caddr_t)(uintptr_t)text_addr; 521 vmspace->vm_dsize = data_size >> PAGE_SHIFT; 522 vmspace->vm_daddr = (caddr_t)(uintptr_t)data_addr; 523 524 addr = ELF_RTLD_ADDR(vmspace); 525 526 imgp->entry_addr = entry; 527 528 /* If the executable has a brand, search for it in the brand list. */ 529 brand_info = NULL; 530 brand = (const char *)&hdr->e_ident[EI_BRAND]; 531 if (brand[0] != '\0') { 532 for (i = 0; i < MAX_BRANDS; i++) { 533 Elf_Brandinfo *bi = elf_brand_list[i]; 534 535 if (bi != NULL && strcmp(brand, bi->brand) == 0) { 536 brand_info = bi; 537 break; 538 } 539 } 540 } 541 542 /* Lacking a known brand, search for a recognized interpreter. */ 543 if (brand_info == NULL && interp != NULL) { 544 for (i = 0; i < MAX_BRANDS; i++) { 545 Elf_Brandinfo *bi = elf_brand_list[i]; 546 547 if (bi != NULL && 548 strcmp(interp, bi->interp_path) == 0) { 549 brand_info = bi; 550 break; 551 } 552 } 553 } 554 555 /* Lacking a recognized interpreter, try the default brand */ 556 if (brand_info == NULL && fallback_elf_brand[0] != '\0') { 557 for (i = 0; i < MAX_BRANDS; i++) { 558 Elf_Brandinfo *bi = elf_brand_list[i]; 559 560 if (bi != NULL 561 && strcmp(fallback_elf_brand, bi->brand) == 0) { 562 brand_info = bi; 563 break; 564 } 565 } 566 } 567 568 #ifdef __alpha__ 569 /* XXX - Assume FreeBSD on the alpha. */ 570 if (brand_info == NULL) 571 brand_info = &freebsd_brand_info; 572 #endif 573 574 if (brand_info == NULL) { 575 if (brand[0] == 0) 576 uprintf("ELF binary type not known." 577 " Use \"brandelf\" to brand it.\n"); 578 else 579 uprintf("ELF binary type \"%.*s\" not known.\n", 580 EI_NIDENT - EI_BRAND, brand); 581 error = ENOEXEC; 582 goto fail; 583 } 584 585 imgp->proc->p_sysent = brand_info->sysvec; 586 if (interp != NULL) { 587 snprintf(path, sizeof(path), "%s%s", 588 brand_info->emul_path, interp); 589 if ((error = elf_load_file(imgp->proc, path, &addr, 590 &imgp->entry_addr)) != 0) { 591 if ((error = elf_load_file(imgp->proc, interp, &addr, 592 &imgp->entry_addr)) != 0) { 593 uprintf("ELF interpreter %s not found\n", path); 594 goto fail; 595 } 596 } 597 } 598 599 /* 600 * Construct auxargs table (used by the fixup routine) 601 */ 602 elf_auxargs = malloc(sizeof(Elf_Auxargs), M_TEMP, M_WAITOK); 603 elf_auxargs->execfd = -1; 604 elf_auxargs->phdr = proghdr; 605 elf_auxargs->phent = hdr->e_phentsize; 606 elf_auxargs->phnum = hdr->e_phnum; 607 elf_auxargs->pagesz = PAGE_SIZE; 608 elf_auxargs->base = addr; 609 elf_auxargs->flags = 0; 610 elf_auxargs->entry = entry; 611 elf_auxargs->trace = elf_trace; 612 613 imgp->auxargs = elf_auxargs; 614 imgp->interpreted = 0; 615 616 /* don't allow modifying the file while we run it */ 617 imgp->vp->v_flag |= VTEXT; 618 619 fail: 620 return error; 621 } 622 623 static int 624 elf_freebsd_fixup(long **stack_base, struct image_params *imgp) 625 { 626 Elf_Auxargs *args = (Elf_Auxargs *)imgp->auxargs; 627 long *pos; 628 629 pos = *stack_base + (imgp->argc + imgp->envc + 2); 630 631 if (args->trace) { 632 AUXARGS_ENTRY(pos, AT_DEBUG, 1); 633 } 634 if (args->execfd != -1) { 635 AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd); 636 } 637 AUXARGS_ENTRY(pos, AT_PHDR, args->phdr); 638 AUXARGS_ENTRY(pos, AT_PHENT, args->phent); 639 AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum); 640 AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz); 641 AUXARGS_ENTRY(pos, AT_FLAGS, args->flags); 642 AUXARGS_ENTRY(pos, AT_ENTRY, args->entry); 643 AUXARGS_ENTRY(pos, AT_BASE, args->base); 644 AUXARGS_ENTRY(pos, AT_NULL, 0); 645 646 free(imgp->auxargs, M_TEMP); 647 imgp->auxargs = NULL; 648 649 (*stack_base)--; 650 suword(*stack_base, (long) imgp->argc); 651 return 0; 652 } 653 654 /* 655 * Code for generating ELF core dumps. 656 */ 657 658 typedef void (*segment_callback) __P((vm_map_entry_t, void *)); 659 660 /* Closure for cb_put_phdr(). */ 661 struct phdr_closure { 662 Elf_Phdr *phdr; /* Program header to fill in */ 663 Elf_Off offset; /* Offset of segment in core file */ 664 }; 665 666 /* Closure for cb_size_segment(). */ 667 struct sseg_closure { 668 int count; /* Count of writable segments. */ 669 size_t size; /* Total size of all writable segments. */ 670 }; 671 672 static void cb_put_phdr __P((vm_map_entry_t, void *)); 673 static void cb_size_segment __P((vm_map_entry_t, void *)); 674 static void each_writable_segment __P((struct proc *, segment_callback, 675 void *)); 676 static int elf_corehdr __P((struct proc *, struct vnode *, struct ucred *, 677 int, void *, size_t)); 678 static void elf_puthdr __P((struct proc *, void *, size_t *, 679 const prstatus_t *, const prfpregset_t *, const prpsinfo_t *, int)); 680 static void elf_putnote __P((void *, size_t *, const char *, int, 681 const void *, size_t)); 682 683 extern int osreldate; 684 685 int 686 elf_coredump(p) 687 register struct proc *p; 688 { 689 register struct vnode *vp; 690 register struct ucred *cred = p->p_cred->pc_ucred; 691 struct nameidata nd; 692 struct vattr vattr; 693 int error, error1; 694 char *name; /* name of corefile */ 695 struct sseg_closure seginfo; 696 void *hdr; 697 size_t hdrsize; 698 699 STOPEVENT(p, S_CORE, 0); 700 701 if (sugid_coredump == 0 && p->p_flag & P_SUGID) 702 return (EFAULT); 703 704 /* Size the program segments. */ 705 seginfo.count = 0; 706 seginfo.size = 0; 707 each_writable_segment(p, cb_size_segment, &seginfo); 708 709 /* 710 * Calculate the size of the core file header area by making 711 * a dry run of generating it. Nothing is written, but the 712 * size is calculated. 713 */ 714 hdrsize = 0; 715 elf_puthdr((struct proc *)NULL, (void *)NULL, &hdrsize, 716 (const prstatus_t *)NULL, (const prfpregset_t *)NULL, 717 (const prpsinfo_t *)NULL, seginfo.count); 718 719 if (hdrsize + seginfo.size >= p->p_rlimit[RLIMIT_CORE].rlim_cur) 720 return (EFAULT); 721 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid); 722 if (name == NULL) 723 return (EFAULT); /* XXX -- not the best error */ 724 725 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, p); 726 error = vn_open(&nd, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR); 727 free(name, M_TEMP); 728 if (error) 729 return (error); 730 vp = nd.ni_vp; 731 732 /* Don't dump to non-regular files or files with links. */ 733 if (vp->v_type != VREG || 734 VOP_GETATTR(vp, &vattr, cred, p) || vattr.va_nlink != 1) { 735 error = EFAULT; 736 goto out; 737 } 738 VATTR_NULL(&vattr); 739 vattr.va_size = 0; 740 VOP_LEASE(vp, p, cred, LEASE_WRITE); 741 VOP_SETATTR(vp, &vattr, cred, p); 742 p->p_acflag |= ACORE; 743 744 745 /* 746 * Allocate memory for building the header, fill it up, 747 * and write it out. 748 */ 749 hdr = malloc(hdrsize, M_TEMP, M_WAITOK); 750 if (hdr == NULL) { 751 error = EINVAL; 752 goto out; 753 } 754 error = elf_corehdr(p, vp, cred, seginfo.count, hdr, hdrsize); 755 756 /* Write the contents of all of the writable segments. */ 757 if (error == 0) { 758 Elf_Phdr *php; 759 off_t offset; 760 int i; 761 762 php = (Elf_Phdr *)((char *)hdr + sizeof(Elf_Ehdr)) + 1; 763 offset = hdrsize; 764 for (i = 0; i < seginfo.count; i++) { 765 error = vn_rdwr(UIO_WRITE, vp, (caddr_t)php->p_vaddr, 766 php->p_filesz, offset, UIO_USERSPACE, 767 IO_NODELOCKED|IO_UNIT, cred, (int *)NULL, p); 768 if (error != 0) 769 break; 770 offset += php->p_filesz; 771 php++; 772 } 773 } 774 free(hdr, M_TEMP); 775 776 out: 777 VOP_UNLOCK(vp, 0, p); 778 error1 = vn_close(vp, FWRITE, cred, p); 779 if (error == 0) 780 error = error1; 781 return (error); 782 } 783 784 /* 785 * A callback for each_writable_segment() to write out the segment's 786 * program header entry. 787 */ 788 static void 789 cb_put_phdr(entry, closure) 790 vm_map_entry_t entry; 791 void *closure; 792 { 793 struct phdr_closure *phc = (struct phdr_closure *)closure; 794 Elf_Phdr *phdr = phc->phdr; 795 796 phc->offset = round_page(phc->offset); 797 798 phdr->p_type = PT_LOAD; 799 phdr->p_offset = phc->offset; 800 phdr->p_vaddr = entry->start; 801 phdr->p_paddr = 0; 802 phdr->p_filesz = phdr->p_memsz = entry->end - entry->start; 803 phdr->p_align = PAGE_SIZE; 804 phdr->p_flags = 0; 805 if (entry->protection & VM_PROT_READ) 806 phdr->p_flags |= PF_R; 807 if (entry->protection & VM_PROT_WRITE) 808 phdr->p_flags |= PF_W; 809 if (entry->protection & VM_PROT_EXECUTE) 810 phdr->p_flags |= PF_X; 811 812 phc->offset += phdr->p_filesz; 813 phc->phdr++; 814 } 815 816 /* 817 * A callback for each_writable_segment() to gather information about 818 * the number of segments and their total size. 819 */ 820 static void 821 cb_size_segment(entry, closure) 822 vm_map_entry_t entry; 823 void *closure; 824 { 825 struct sseg_closure *ssc = (struct sseg_closure *)closure; 826 827 ssc->count++; 828 ssc->size += entry->end - entry->start; 829 } 830 831 /* 832 * For each writable segment in the process's memory map, call the given 833 * function with a pointer to the map entry and some arbitrary 834 * caller-supplied data. 835 */ 836 static void 837 each_writable_segment(p, func, closure) 838 struct proc *p; 839 segment_callback func; 840 void *closure; 841 { 842 vm_map_t map = &p->p_vmspace->vm_map; 843 vm_map_entry_t entry; 844 845 for (entry = map->header.next; entry != &map->header; 846 entry = entry->next) { 847 vm_object_t obj; 848 849 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) || 850 (entry->protection & (VM_PROT_READ|VM_PROT_WRITE)) != 851 (VM_PROT_READ|VM_PROT_WRITE)) 852 continue; 853 854 if ((obj = entry->object.vm_object) == NULL) 855 continue; 856 857 /* Find the deepest backing object. */ 858 while (obj->backing_object != NULL) 859 obj = obj->backing_object; 860 861 /* Ignore memory-mapped devices and such things. */ 862 if (obj->type != OBJT_DEFAULT && 863 obj->type != OBJT_SWAP && 864 obj->type != OBJT_VNODE) 865 continue; 866 867 (*func)(entry, closure); 868 } 869 } 870 871 /* 872 * Write the core file header to the file, including padding up to 873 * the page boundary. 874 */ 875 static int 876 elf_corehdr(p, vp, cred, numsegs, hdr, hdrsize) 877 struct proc *p; 878 struct vnode *vp; 879 struct ucred *cred; 880 int numsegs; 881 size_t hdrsize; 882 void *hdr; 883 { 884 size_t off; 885 prstatus_t status; 886 prfpregset_t fpregset; 887 prpsinfo_t psinfo; 888 889 /* Gather the information for the header. */ 890 bzero(&status, sizeof status); 891 status.pr_version = PRSTATUS_VERSION; 892 status.pr_statussz = sizeof(prstatus_t); 893 status.pr_gregsetsz = sizeof(gregset_t); 894 status.pr_fpregsetsz = sizeof(fpregset_t); 895 status.pr_osreldate = osreldate; 896 status.pr_cursig = p->p_sig; 897 status.pr_pid = p->p_pid; 898 fill_regs(p, &status.pr_reg); 899 900 fill_fpregs(p, &fpregset); 901 902 bzero(&psinfo, sizeof psinfo); 903 psinfo.pr_version = PRPSINFO_VERSION; 904 psinfo.pr_psinfosz = sizeof(prpsinfo_t); 905 strncpy(psinfo.pr_fname, p->p_comm, MAXCOMLEN); 906 /* XXX - We don't fill in the command line arguments properly yet. */ 907 strncpy(psinfo.pr_psargs, p->p_comm, PRARGSZ); 908 909 /* Fill in the header. */ 910 bzero(hdr, hdrsize); 911 off = 0; 912 elf_puthdr(p, hdr, &off, &status, &fpregset, &psinfo, numsegs); 913 914 /* Write it to the core file. */ 915 return vn_rdwr(UIO_WRITE, vp, hdr, hdrsize, (off_t)0, 916 UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT, cred, NULL, p); 917 } 918 919 static void 920 elf_puthdr(struct proc *p, void *dst, size_t *off, const prstatus_t *status, 921 const prfpregset_t *fpregset, const prpsinfo_t *psinfo, int numsegs) 922 { 923 size_t ehoff; 924 size_t phoff; 925 size_t noteoff; 926 size_t notesz; 927 928 ehoff = *off; 929 *off += sizeof(Elf_Ehdr); 930 931 phoff = *off; 932 *off += (numsegs + 1) * sizeof(Elf_Phdr); 933 934 noteoff = *off; 935 elf_putnote(dst, off, "FreeBSD", NT_PRSTATUS, status, 936 sizeof *status); 937 elf_putnote(dst, off, "FreeBSD", NT_FPREGSET, fpregset, 938 sizeof *fpregset); 939 elf_putnote(dst, off, "FreeBSD", NT_PRPSINFO, psinfo, 940 sizeof *psinfo); 941 notesz = *off - noteoff; 942 943 /* Align up to a page boundary for the program segments. */ 944 *off = round_page(*off); 945 946 if (dst != NULL) { 947 Elf_Ehdr *ehdr; 948 Elf_Phdr *phdr; 949 struct phdr_closure phc; 950 951 /* 952 * Fill in the ELF header. 953 */ 954 ehdr = (Elf_Ehdr *)((char *)dst + ehoff); 955 ehdr->e_ident[EI_MAG0] = ELFMAG0; 956 ehdr->e_ident[EI_MAG1] = ELFMAG1; 957 ehdr->e_ident[EI_MAG2] = ELFMAG2; 958 ehdr->e_ident[EI_MAG3] = ELFMAG3; 959 ehdr->e_ident[EI_CLASS] = ELF_CLASS; 960 ehdr->e_ident[EI_DATA] = ELF_DATA; 961 ehdr->e_ident[EI_VERSION] = EV_CURRENT; 962 ehdr->e_ident[EI_PAD] = 0; 963 strncpy(ehdr->e_ident + EI_BRAND, "FreeBSD", 964 EI_NIDENT - EI_BRAND); 965 ehdr->e_type = ET_CORE; 966 ehdr->e_machine = ELF_ARCH; 967 ehdr->e_version = EV_CURRENT; 968 ehdr->e_entry = 0; 969 ehdr->e_phoff = phoff; 970 ehdr->e_flags = 0; 971 ehdr->e_ehsize = sizeof(Elf_Ehdr); 972 ehdr->e_phentsize = sizeof(Elf_Phdr); 973 ehdr->e_phnum = numsegs + 1; 974 ehdr->e_shentsize = sizeof(Elf_Shdr); 975 ehdr->e_shnum = 0; 976 ehdr->e_shstrndx = SHN_UNDEF; 977 978 /* 979 * Fill in the program header entries. 980 */ 981 phdr = (Elf_Phdr *)((char *)dst + phoff); 982 983 /* The note segement. */ 984 phdr->p_type = PT_NOTE; 985 phdr->p_offset = noteoff; 986 phdr->p_vaddr = 0; 987 phdr->p_paddr = 0; 988 phdr->p_filesz = notesz; 989 phdr->p_memsz = 0; 990 phdr->p_flags = 0; 991 phdr->p_align = 0; 992 phdr++; 993 994 /* All the writable segments from the program. */ 995 phc.phdr = phdr; 996 phc.offset = *off; 997 each_writable_segment(p, cb_put_phdr, &phc); 998 } 999 } 1000 1001 static void 1002 elf_putnote(void *dst, size_t *off, const char *name, int type, 1003 const void *desc, size_t descsz) 1004 { 1005 Elf_Note note; 1006 1007 note.n_namesz = strlen(name) + 1; 1008 note.n_descsz = descsz; 1009 note.n_type = type; 1010 if (dst != NULL) 1011 bcopy(¬e, (char *)dst + *off, sizeof note); 1012 *off += sizeof note; 1013 if (dst != NULL) 1014 bcopy(name, (char *)dst + *off, note.n_namesz); 1015 *off += roundup2(note.n_namesz, sizeof(Elf_Size)); 1016 if (dst != NULL) 1017 bcopy(desc, (char *)dst + *off, note.n_descsz); 1018 *off += roundup2(note.n_descsz, sizeof(Elf_Size)); 1019 } 1020 1021 /* 1022 * Tell kern_execve.c about it, with a little help from the linker. 1023 */ 1024 static struct execsw elf_execsw = {exec_elf_imgact, "ELF"}; 1025 EXEC_SET(elf, elf_execsw); 1026