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/exec.h> 36 #include <sys/fcntl.h> 37 #include <sys/imgact.h> 38 #include <sys/imgact_elf.h> 39 #include <sys/kernel.h> 40 #include <sys/malloc.h> 41 #include <sys/mman.h> 42 #include <sys/namei.h> 43 #include <sys/pioctl.h> 44 #include <sys/proc.h> 45 #include <sys/procfs.h> 46 #include <sys/resourcevar.h> 47 #include <sys/signalvar.h> 48 #include <sys/stat.h> 49 #include <sys/syscall.h> 50 #include <sys/sysctl.h> 51 #include <sys/sysent.h> 52 #include <sys/systm.h> 53 #include <sys/vnode.h> 54 55 #include <vm/vm.h> 56 #include <vm/vm_kern.h> 57 #include <vm/vm_param.h> 58 #include <vm/pmap.h> 59 #include <sys/lock.h> 60 #include <vm/vm_map.h> 61 #include <vm/vm_object.h> 62 #include <vm/vm_extern.h> 63 64 #include <machine/elf.h> 65 #include <machine/md_var.h> 66 67 #define OLD_EI_BRAND 8 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((register_t **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 static struct sysentvec elf_freebsd_sysvec = { 87 SYS_MAXSYSCALL, 88 sysent, 89 0, 90 0, 91 0, 92 0, 93 0, 94 0, 95 elf_freebsd_fixup, 96 sendsig, 97 sigcode, 98 &szsigcode, 99 0, 100 "FreeBSD ELF", 101 elf_coredump 102 }; 103 104 static Elf_Brandinfo freebsd_brand_info = { 105 ELFOSABI_FREEBSD, 106 "", 107 "/usr/libexec/ld-elf.so.1", 108 &elf_freebsd_sysvec 109 }; 110 static Elf_Brandinfo *elf_brand_list[MAX_BRANDS] = { 111 &freebsd_brand_info, 112 NULL, NULL, NULL, 113 NULL, NULL, NULL, NULL 114 }; 115 116 int 117 elf_insert_brand_entry(Elf_Brandinfo *entry) 118 { 119 int i; 120 121 for (i=1; i<MAX_BRANDS; i++) { 122 if (elf_brand_list[i] == NULL) { 123 elf_brand_list[i] = entry; 124 break; 125 } 126 } 127 if (i == MAX_BRANDS) 128 return -1; 129 return 0; 130 } 131 132 int 133 elf_remove_brand_entry(Elf_Brandinfo *entry) 134 { 135 int i; 136 137 for (i=1; i<MAX_BRANDS; i++) { 138 if (elf_brand_list[i] == entry) { 139 elf_brand_list[i] = NULL; 140 break; 141 } 142 } 143 if (i == MAX_BRANDS) 144 return -1; 145 return 0; 146 } 147 148 int 149 elf_brand_inuse(Elf_Brandinfo *entry) 150 { 151 struct proc *p; 152 153 LIST_FOREACH(p, &allproc, p_list) { 154 if (p->p_sysent == entry->sysvec) 155 return TRUE; 156 } 157 158 return FALSE; 159 } 160 161 static int 162 elf_check_header(const Elf_Ehdr *hdr) 163 { 164 if (!IS_ELF(*hdr) || 165 hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || 166 hdr->e_ident[EI_DATA] != ELF_TARG_DATA || 167 hdr->e_ident[EI_VERSION] != EV_CURRENT) 168 return ENOEXEC; 169 170 if (!ELF_MACHINE_OK(hdr->e_machine)) 171 return ENOEXEC; 172 173 if (hdr->e_version != ELF_TARG_VER) 174 return ENOEXEC; 175 176 return 0; 177 } 178 179 static int 180 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) 181 { 182 size_t map_len; 183 vm_offset_t map_addr; 184 int error, rv; 185 size_t copy_len; 186 vm_object_t object; 187 vm_offset_t file_addr; 188 vm_offset_t data_buf = 0; 189 190 object = vp->v_object; 191 error = 0; 192 193 map_addr = trunc_page((vm_offset_t)vmaddr); 194 file_addr = trunc_page(offset); 195 196 /* 197 * We have two choices. We can either clear the data in the last page 198 * of an oversized mapping, or we can start the anon mapping a page 199 * early and copy the initialized data into that first page. We 200 * choose the second.. 201 */ 202 if (memsz > filsz) 203 map_len = trunc_page(offset+filsz) - file_addr; 204 else 205 map_len = round_page(offset+filsz) - file_addr; 206 207 if (map_len != 0) { 208 vm_object_reference(object); 209 vm_map_lock(&vmspace->vm_map); 210 rv = vm_map_insert(&vmspace->vm_map, 211 object, 212 file_addr, /* file offset */ 213 map_addr, /* virtual start */ 214 map_addr + map_len,/* virtual end */ 215 prot, 216 VM_PROT_ALL, 217 MAP_COPY_ON_WRITE | MAP_PREFAULT); 218 vm_map_unlock(&vmspace->vm_map); 219 if (rv != KERN_SUCCESS) { 220 vm_object_deallocate(object); 221 return EINVAL; 222 } 223 224 /* we can stop now if we've covered it all */ 225 if (memsz == filsz) 226 return 0; 227 } 228 229 230 /* 231 * We have to get the remaining bit of the file into the first part 232 * of the oversized map segment. This is normally because the .data 233 * segment in the file is extended to provide bss. It's a neat idea 234 * to try and save a page, but it's a pain in the behind to implement. 235 */ 236 copy_len = (offset + filsz) - trunc_page(offset + filsz); 237 map_addr = trunc_page((vm_offset_t)vmaddr + filsz); 238 map_len = round_page((vm_offset_t)vmaddr + memsz) - map_addr; 239 240 /* This had damn well better be true! */ 241 if (map_len != 0) { 242 vm_map_lock(&vmspace->vm_map); 243 rv = vm_map_insert(&vmspace->vm_map, NULL, 0, 244 map_addr, map_addr + map_len, 245 VM_PROT_ALL, VM_PROT_ALL, 0); 246 vm_map_unlock(&vmspace->vm_map); 247 if (rv != KERN_SUCCESS) 248 return EINVAL; 249 } 250 251 if (copy_len != 0) { 252 vm_object_reference(object); 253 rv = vm_map_find(exec_map, 254 object, 255 trunc_page(offset + filsz), 256 &data_buf, 257 PAGE_SIZE, 258 TRUE, 259 VM_PROT_READ, 260 VM_PROT_ALL, 261 MAP_COPY_ON_WRITE | MAP_PREFAULT_PARTIAL); 262 if (rv != KERN_SUCCESS) { 263 vm_object_deallocate(object); 264 return EINVAL; 265 } 266 267 /* send the page fragment to user space */ 268 error = copyout((caddr_t)data_buf, (caddr_t)map_addr, copy_len); 269 vm_map_remove(exec_map, data_buf, data_buf + PAGE_SIZE); 270 if (error) 271 return (error); 272 } 273 274 /* 275 * set it to the specified protection 276 */ 277 vm_map_protect(&vmspace->vm_map, map_addr, map_addr + map_len, prot, 278 FALSE); 279 280 return error; 281 } 282 283 /* 284 * Load the file "file" into memory. It may be either a shared object 285 * or an executable. 286 * 287 * The "addr" reference parameter is in/out. On entry, it specifies 288 * the address where a shared object should be loaded. If the file is 289 * an executable, this value is ignored. On exit, "addr" specifies 290 * where the file was actually loaded. 291 * 292 * The "entry" reference parameter is out only. On exit, it specifies 293 * the entry point for the loaded file. 294 */ 295 static int 296 elf_load_file(struct proc *p, const char *file, u_long *addr, u_long *entry) 297 { 298 const Elf_Ehdr *hdr = NULL; 299 const Elf_Phdr *phdr = NULL; 300 struct nameidata nd; 301 struct vmspace *vmspace = p->p_vmspace; 302 struct vattr attr; 303 struct image_params image_params, *imgp; 304 vm_prot_t prot; 305 u_long rbase; 306 u_long base_addr = 0; 307 int error, i, numsegs; 308 309 imgp = &image_params; 310 /* 311 * Initialize part of the common data 312 */ 313 imgp->proc = p; 314 imgp->uap = NULL; 315 imgp->attr = &attr; 316 imgp->firstpage = NULL; 317 imgp->image_header = (char *)kmem_alloc_wait(exec_map, PAGE_SIZE); 318 319 if (imgp->image_header == NULL) { 320 nd.ni_vp = NULL; 321 error = ENOMEM; 322 goto fail; 323 } 324 325 NDINIT(&nd, LOOKUP, LOCKLEAF|FOLLOW, UIO_SYSSPACE, file, p); 326 327 if ((error = namei(&nd)) != 0) { 328 nd.ni_vp = NULL; 329 goto fail; 330 } 331 NDFREE(&nd, NDF_ONLY_PNBUF); 332 imgp->vp = nd.ni_vp; 333 334 /* 335 * Check permissions, modes, uid, etc on the file, and "open" it. 336 */ 337 error = exec_check_permissions(imgp); 338 if (error) { 339 VOP_UNLOCK(nd.ni_vp, 0, p); 340 goto fail; 341 } 342 343 error = exec_map_first_page(imgp); 344 VOP_UNLOCK(nd.ni_vp, 0, p); 345 if (error) 346 goto fail; 347 348 hdr = (const Elf_Ehdr *)imgp->image_header; 349 if ((error = elf_check_header(hdr)) != 0) 350 goto fail; 351 if (hdr->e_type == ET_DYN) 352 rbase = *addr; 353 else if (hdr->e_type == ET_EXEC) 354 rbase = 0; 355 else { 356 error = ENOEXEC; 357 goto fail; 358 } 359 360 /* Only support headers that fit within first page for now */ 361 if ((hdr->e_phoff > PAGE_SIZE) || 362 (hdr->e_phoff + hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE) { 363 error = ENOEXEC; 364 goto fail; 365 } 366 367 phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff); 368 369 for (i = 0, numsegs = 0; i < hdr->e_phnum; i++) { 370 if (phdr[i].p_type == PT_LOAD) { /* Loadable segment */ 371 prot = 0; 372 if (phdr[i].p_flags & PF_X) 373 prot |= VM_PROT_EXECUTE; 374 if (phdr[i].p_flags & PF_W) 375 prot |= VM_PROT_WRITE; 376 if (phdr[i].p_flags & PF_R) 377 prot |= VM_PROT_READ; 378 379 if ((error = elf_load_section(p, vmspace, nd.ni_vp, 380 phdr[i].p_offset, 381 (caddr_t)phdr[i].p_vaddr + 382 rbase, 383 phdr[i].p_memsz, 384 phdr[i].p_filesz, prot)) != 0) 385 goto fail; 386 /* 387 * Establish the base address if this is the 388 * first segment. 389 */ 390 if (numsegs == 0) 391 base_addr = trunc_page(phdr[i].p_vaddr + rbase); 392 numsegs++; 393 } 394 } 395 *addr = base_addr; 396 *entry=(unsigned long)hdr->e_entry + rbase; 397 398 fail: 399 if (imgp->firstpage) 400 exec_unmap_first_page(imgp); 401 if (imgp->image_header) 402 kmem_free_wakeup(exec_map, (vm_offset_t)imgp->image_header, 403 PAGE_SIZE); 404 if (nd.ni_vp) 405 vrele(nd.ni_vp); 406 407 return error; 408 } 409 410 static int fallback_elf_brand = ELFOSABI_FREEBSD; 411 SYSCTL_INT(_kern, OID_AUTO, fallback_elf_brand, CTLFLAG_RW, 412 &fallback_elf_brand, ELFOSABI_FREEBSD, 413 "ELF brand of last resort"); 414 415 static int 416 exec_elf_imgact(struct image_params *imgp) 417 { 418 const Elf_Ehdr *hdr = (const Elf_Ehdr *) imgp->image_header; 419 const Elf_Phdr *phdr; 420 Elf_Auxargs *elf_auxargs = NULL; 421 struct vmspace *vmspace; 422 vm_prot_t prot; 423 u_long text_size = 0, data_size = 0; 424 u_long text_addr = 0, data_addr = 0; 425 u_long addr, entry = 0, proghdr = 0; 426 int error, i; 427 const char *interp = NULL; 428 Elf_Brandinfo *brand_info; 429 char path[MAXPATHLEN]; 430 431 /* 432 * Do we have a valid ELF header ? 433 */ 434 if (elf_check_header(hdr) != 0 || hdr->e_type != ET_EXEC) 435 return -1; 436 437 /* 438 * From here on down, we return an errno, not -1, as we've 439 * detected an ELF file. 440 */ 441 442 if ((hdr->e_phoff > PAGE_SIZE) || 443 (hdr->e_phoff + hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE) { 444 /* Only support headers in first page for now */ 445 return ENOEXEC; 446 } 447 phdr = (const Elf_Phdr*)(imgp->image_header + hdr->e_phoff); 448 449 /* 450 * From this point on, we may have resources that need to be freed. 451 */ 452 if ((error = exec_extract_strings(imgp)) != 0) 453 goto fail; 454 455 exec_new_vmspace(imgp); 456 457 vmspace = imgp->proc->p_vmspace; 458 459 for (i = 0; i < hdr->e_phnum; i++) { 460 switch(phdr[i].p_type) { 461 462 case PT_LOAD: /* Loadable segment */ 463 prot = 0; 464 if (phdr[i].p_flags & PF_X) 465 prot |= VM_PROT_EXECUTE; 466 if (phdr[i].p_flags & PF_W) 467 prot |= VM_PROT_WRITE; 468 if (phdr[i].p_flags & PF_R) 469 prot |= VM_PROT_READ; 470 471 if ((error = elf_load_section(imgp->proc, 472 vmspace, imgp->vp, 473 phdr[i].p_offset, 474 (caddr_t)phdr[i].p_vaddr, 475 phdr[i].p_memsz, 476 phdr[i].p_filesz, prot)) != 0) 477 goto fail; 478 479 /* 480 * Is this .text or .data ?? 481 * 482 * We only handle one each of those yet XXX 483 */ 484 if (hdr->e_entry >= phdr[i].p_vaddr && 485 hdr->e_entry <(phdr[i].p_vaddr+phdr[i].p_memsz)) { 486 text_addr = trunc_page(phdr[i].p_vaddr); 487 text_size = round_page(phdr[i].p_memsz + 488 phdr[i].p_vaddr - 489 text_addr); 490 entry = (u_long)hdr->e_entry; 491 } else { 492 data_addr = trunc_page(phdr[i].p_vaddr); 493 data_size = round_page(phdr[i].p_memsz + 494 phdr[i].p_vaddr - 495 data_addr); 496 } 497 break; 498 case PT_INTERP: /* Path to interpreter */ 499 if (phdr[i].p_filesz > MAXPATHLEN || 500 phdr[i].p_offset + phdr[i].p_filesz > PAGE_SIZE) { 501 error = ENOEXEC; 502 goto fail; 503 } 504 interp = imgp->image_header + phdr[i].p_offset; 505 break; 506 case PT_PHDR: /* Program header table info */ 507 proghdr = phdr[i].p_vaddr; 508 break; 509 default: 510 break; 511 } 512 } 513 514 vmspace->vm_tsize = text_size >> PAGE_SHIFT; 515 vmspace->vm_taddr = (caddr_t)(uintptr_t)text_addr; 516 vmspace->vm_dsize = data_size >> PAGE_SHIFT; 517 vmspace->vm_daddr = (caddr_t)(uintptr_t)data_addr; 518 519 addr = ELF_RTLD_ADDR(vmspace); 520 521 imgp->entry_addr = entry; 522 523 brand_info = NULL; 524 525 /* XXX For now we look for the magic "FreeBSD" that we used to put 526 * into the ELF header at the EI_ABIVERSION location. If found use 527 * that information rather than figuring out the ABI from proper 528 * branding. This should be removed for 5.0-RELEASE. The Linux caes 529 * can be figured out from the `interp_path' field. 530 */ 531 if (strcmp("FreeBSD", (const char *)&hdr->e_ident[OLD_EI_BRAND]) == 0) 532 brand_info = &freebsd_brand_info; 533 534 /* If the executable has a brand, search for it in the brand list. */ 535 if (brand_info == NULL) { 536 for (i = 0; i < MAX_BRANDS; i++) { 537 Elf_Brandinfo *bi = elf_brand_list[i]; 538 539 if (bi != NULL && hdr->e_ident[EI_OSABI] == bi->brand) { 540 brand_info = bi; 541 break; 542 } 543 } 544 } 545 546 /* Lacking a known brand, search for a recognized interpreter. */ 547 if (brand_info == NULL && interp != NULL) { 548 for (i = 0; i < MAX_BRANDS; i++) { 549 Elf_Brandinfo *bi = elf_brand_list[i]; 550 551 if (bi != NULL && 552 strcmp(interp, bi->interp_path) == 0) { 553 brand_info = bi; 554 break; 555 } 556 } 557 } 558 559 /* Lacking a recognized interpreter, try the default brand */ 560 if (brand_info == NULL) { 561 for (i = 0; i < MAX_BRANDS; i++) { 562 Elf_Brandinfo *bi = elf_brand_list[i]; 563 564 if (bi != NULL && fallback_elf_brand == bi->brand) { 565 brand_info = bi; 566 break; 567 } 568 } 569 } 570 571 /* XXX - Assume FreeBSD after the branding method change. */ 572 if (brand_info == NULL) 573 brand_info = &freebsd_brand_info; 574 575 if (brand_info == NULL) { 576 uprintf("ELF binary type \"%u\" not known.\n", 577 hdr->e_ident[EI_OSABI]); 578 error = ENOEXEC; 579 goto fail; 580 } 581 582 imgp->proc->p_sysent = brand_info->sysvec; 583 if (interp != NULL) { 584 snprintf(path, sizeof(path), "%s%s", 585 brand_info->emul_path, interp); 586 if ((error = elf_load_file(imgp->proc, path, &addr, 587 &imgp->entry_addr)) != 0) { 588 if ((error = elf_load_file(imgp->proc, interp, &addr, 589 &imgp->entry_addr)) != 0) { 590 uprintf("ELF interpreter %s not found\n", path); 591 goto fail; 592 } 593 } 594 } 595 596 /* 597 * Construct auxargs table (used by the fixup routine) 598 */ 599 elf_auxargs = malloc(sizeof(Elf_Auxargs), M_TEMP, M_WAITOK); 600 elf_auxargs->execfd = -1; 601 elf_auxargs->phdr = proghdr; 602 elf_auxargs->phent = hdr->e_phentsize; 603 elf_auxargs->phnum = hdr->e_phnum; 604 elf_auxargs->pagesz = PAGE_SIZE; 605 elf_auxargs->base = addr; 606 elf_auxargs->flags = 0; 607 elf_auxargs->entry = entry; 608 elf_auxargs->trace = elf_trace; 609 610 imgp->auxargs = elf_auxargs; 611 imgp->interpreted = 0; 612 613 /* don't allow modifying the file while we run it */ 614 imgp->vp->v_flag |= VTEXT; 615 616 fail: 617 return error; 618 } 619 620 static int 621 elf_freebsd_fixup(register_t **stack_base, struct image_params *imgp) 622 { 623 Elf_Auxargs *args = (Elf_Auxargs *)imgp->auxargs; 624 register_t *pos; 625 626 pos = *stack_base + (imgp->argc + imgp->envc + 2); 627 628 if (args->trace) { 629 AUXARGS_ENTRY(pos, AT_DEBUG, 1); 630 } 631 if (args->execfd != -1) { 632 AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd); 633 } 634 AUXARGS_ENTRY(pos, AT_PHDR, args->phdr); 635 AUXARGS_ENTRY(pos, AT_PHENT, args->phent); 636 AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum); 637 AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz); 638 AUXARGS_ENTRY(pos, AT_FLAGS, args->flags); 639 AUXARGS_ENTRY(pos, AT_ENTRY, args->entry); 640 AUXARGS_ENTRY(pos, AT_BASE, args->base); 641 AUXARGS_ENTRY(pos, AT_NULL, 0); 642 643 free(imgp->auxargs, M_TEMP); 644 imgp->auxargs = NULL; 645 646 (*stack_base)--; 647 suword(*stack_base, (long) imgp->argc); 648 return 0; 649 } 650 651 /* 652 * Code for generating ELF core dumps. 653 */ 654 655 typedef void (*segment_callback) __P((vm_map_entry_t, void *)); 656 657 /* Closure for cb_put_phdr(). */ 658 struct phdr_closure { 659 Elf_Phdr *phdr; /* Program header to fill in */ 660 Elf_Off offset; /* Offset of segment in core file */ 661 }; 662 663 /* Closure for cb_size_segment(). */ 664 struct sseg_closure { 665 int count; /* Count of writable segments. */ 666 size_t size; /* Total size of all writable segments. */ 667 }; 668 669 static void cb_put_phdr __P((vm_map_entry_t, void *)); 670 static void cb_size_segment __P((vm_map_entry_t, void *)); 671 static void each_writable_segment __P((struct proc *, segment_callback, 672 void *)); 673 static int elf_corehdr __P((struct proc *, struct vnode *, struct ucred *, 674 int, void *, size_t)); 675 static void elf_puthdr __P((struct proc *, void *, size_t *, 676 const prstatus_t *, const prfpregset_t *, const prpsinfo_t *, int)); 677 static void elf_putnote __P((void *, size_t *, const char *, int, 678 const void *, size_t)); 679 680 extern int osreldate; 681 682 int 683 elf_coredump(p, vp, limit) 684 register struct proc *p; 685 register struct vnode *vp; 686 off_t limit; 687 { 688 register struct ucred *cred = p->p_ucred; 689 int error = 0; 690 struct sseg_closure seginfo; 691 void *hdr; 692 size_t hdrsize; 693 694 /* Size the program segments. */ 695 seginfo.count = 0; 696 seginfo.size = 0; 697 each_writable_segment(p, cb_size_segment, &seginfo); 698 699 /* 700 * Calculate the size of the core file header area by making 701 * a dry run of generating it. Nothing is written, but the 702 * size is calculated. 703 */ 704 hdrsize = 0; 705 elf_puthdr((struct proc *)NULL, (void *)NULL, &hdrsize, 706 (const prstatus_t *)NULL, (const prfpregset_t *)NULL, 707 (const prpsinfo_t *)NULL, seginfo.count); 708 709 if (hdrsize + seginfo.size >= limit) 710 return (EFAULT); 711 712 /* 713 * Allocate memory for building the header, fill it up, 714 * and write it out. 715 */ 716 hdr = malloc(hdrsize, M_TEMP, M_WAITOK); 717 if (hdr == NULL) { 718 return EINVAL; 719 } 720 error = elf_corehdr(p, vp, cred, seginfo.count, hdr, hdrsize); 721 722 /* Write the contents of all of the writable segments. */ 723 if (error == 0) { 724 Elf_Phdr *php; 725 off_t offset; 726 int i; 727 728 php = (Elf_Phdr *)((char *)hdr + sizeof(Elf_Ehdr)) + 1; 729 offset = hdrsize; 730 for (i = 0; i < seginfo.count; i++) { 731 error = vn_rdwr(UIO_WRITE, vp, (caddr_t)php->p_vaddr, 732 php->p_filesz, offset, UIO_USERSPACE, 733 IO_NODELOCKED|IO_UNIT, cred, (int *)NULL, p); 734 if (error != 0) 735 break; 736 offset += php->p_filesz; 737 php++; 738 } 739 } 740 free(hdr, M_TEMP); 741 742 return error; 743 } 744 745 /* 746 * A callback for each_writable_segment() to write out the segment's 747 * program header entry. 748 */ 749 static void 750 cb_put_phdr(entry, closure) 751 vm_map_entry_t entry; 752 void *closure; 753 { 754 struct phdr_closure *phc = (struct phdr_closure *)closure; 755 Elf_Phdr *phdr = phc->phdr; 756 757 phc->offset = round_page(phc->offset); 758 759 phdr->p_type = PT_LOAD; 760 phdr->p_offset = phc->offset; 761 phdr->p_vaddr = entry->start; 762 phdr->p_paddr = 0; 763 phdr->p_filesz = phdr->p_memsz = entry->end - entry->start; 764 phdr->p_align = PAGE_SIZE; 765 phdr->p_flags = 0; 766 if (entry->protection & VM_PROT_READ) 767 phdr->p_flags |= PF_R; 768 if (entry->protection & VM_PROT_WRITE) 769 phdr->p_flags |= PF_W; 770 if (entry->protection & VM_PROT_EXECUTE) 771 phdr->p_flags |= PF_X; 772 773 phc->offset += phdr->p_filesz; 774 phc->phdr++; 775 } 776 777 /* 778 * A callback for each_writable_segment() to gather information about 779 * the number of segments and their total size. 780 */ 781 static void 782 cb_size_segment(entry, closure) 783 vm_map_entry_t entry; 784 void *closure; 785 { 786 struct sseg_closure *ssc = (struct sseg_closure *)closure; 787 788 ssc->count++; 789 ssc->size += entry->end - entry->start; 790 } 791 792 /* 793 * For each writable segment in the process's memory map, call the given 794 * function with a pointer to the map entry and some arbitrary 795 * caller-supplied data. 796 */ 797 static void 798 each_writable_segment(p, func, closure) 799 struct proc *p; 800 segment_callback func; 801 void *closure; 802 { 803 vm_map_t map = &p->p_vmspace->vm_map; 804 vm_map_entry_t entry; 805 806 for (entry = map->header.next; entry != &map->header; 807 entry = entry->next) { 808 vm_object_t obj; 809 810 if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) || 811 (entry->protection & (VM_PROT_READ|VM_PROT_WRITE)) != 812 (VM_PROT_READ|VM_PROT_WRITE)) 813 continue; 814 815 /* 816 ** Dont include memory segment in the coredump if 817 ** MAP_NOCORE is set in mmap(2) or MADV_NOCORE in 818 ** madvise(2). 819 */ 820 if (entry->eflags & MAP_ENTRY_NOCOREDUMP) 821 continue; 822 823 if ((obj = entry->object.vm_object) == NULL) 824 continue; 825 826 /* Find the deepest backing object. */ 827 while (obj->backing_object != NULL) 828 obj = obj->backing_object; 829 830 /* Ignore memory-mapped devices and such things. */ 831 if (obj->type != OBJT_DEFAULT && 832 obj->type != OBJT_SWAP && 833 obj->type != OBJT_VNODE) 834 continue; 835 836 (*func)(entry, closure); 837 } 838 } 839 840 /* 841 * Write the core file header to the file, including padding up to 842 * the page boundary. 843 */ 844 static int 845 elf_corehdr(p, vp, cred, numsegs, hdr, hdrsize) 846 struct proc *p; 847 struct vnode *vp; 848 struct ucred *cred; 849 int numsegs; 850 size_t hdrsize; 851 void *hdr; 852 { 853 size_t off; 854 prstatus_t status; 855 prfpregset_t fpregset; 856 prpsinfo_t psinfo; 857 858 /* Gather the information for the header. */ 859 bzero(&status, sizeof status); 860 status.pr_version = PRSTATUS_VERSION; 861 status.pr_statussz = sizeof(prstatus_t); 862 status.pr_gregsetsz = sizeof(gregset_t); 863 status.pr_fpregsetsz = sizeof(fpregset_t); 864 status.pr_osreldate = osreldate; 865 status.pr_cursig = p->p_sig; 866 status.pr_pid = p->p_pid; 867 fill_regs(p, &status.pr_reg); 868 869 fill_fpregs(p, &fpregset); 870 871 bzero(&psinfo, sizeof psinfo); 872 psinfo.pr_version = PRPSINFO_VERSION; 873 psinfo.pr_psinfosz = sizeof(prpsinfo_t); 874 strncpy(psinfo.pr_fname, p->p_comm, MAXCOMLEN); 875 /* XXX - We don't fill in the command line arguments properly yet. */ 876 strncpy(psinfo.pr_psargs, p->p_comm, PRARGSZ); 877 878 /* Fill in the header. */ 879 bzero(hdr, hdrsize); 880 off = 0; 881 elf_puthdr(p, hdr, &off, &status, &fpregset, &psinfo, numsegs); 882 883 /* Write it to the core file. */ 884 return vn_rdwr(UIO_WRITE, vp, hdr, hdrsize, (off_t)0, 885 UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT, cred, NULL, p); 886 } 887 888 static void 889 elf_puthdr(struct proc *p, void *dst, size_t *off, const prstatus_t *status, 890 const prfpregset_t *fpregset, const prpsinfo_t *psinfo, int numsegs) 891 { 892 size_t ehoff; 893 size_t phoff; 894 size_t noteoff; 895 size_t notesz; 896 897 ehoff = *off; 898 *off += sizeof(Elf_Ehdr); 899 900 phoff = *off; 901 *off += (numsegs + 1) * sizeof(Elf_Phdr); 902 903 noteoff = *off; 904 elf_putnote(dst, off, "FreeBSD", NT_PRSTATUS, status, 905 sizeof *status); 906 elf_putnote(dst, off, "FreeBSD", NT_FPREGSET, fpregset, 907 sizeof *fpregset); 908 elf_putnote(dst, off, "FreeBSD", NT_PRPSINFO, psinfo, 909 sizeof *psinfo); 910 notesz = *off - noteoff; 911 912 /* Align up to a page boundary for the program segments. */ 913 *off = round_page(*off); 914 915 if (dst != NULL) { 916 Elf_Ehdr *ehdr; 917 Elf_Phdr *phdr; 918 struct phdr_closure phc; 919 920 /* 921 * Fill in the ELF header. 922 */ 923 ehdr = (Elf_Ehdr *)((char *)dst + ehoff); 924 ehdr->e_ident[EI_MAG0] = ELFMAG0; 925 ehdr->e_ident[EI_MAG1] = ELFMAG1; 926 ehdr->e_ident[EI_MAG2] = ELFMAG2; 927 ehdr->e_ident[EI_MAG3] = ELFMAG3; 928 ehdr->e_ident[EI_CLASS] = ELF_CLASS; 929 ehdr->e_ident[EI_DATA] = ELF_DATA; 930 ehdr->e_ident[EI_VERSION] = EV_CURRENT; 931 ehdr->e_ident[EI_OSABI] = ELFOSABI_FREEBSD; 932 ehdr->e_ident[EI_ABIVERSION] = 0; 933 ehdr->e_ident[EI_PAD] = 0; 934 ehdr->e_type = ET_CORE; 935 ehdr->e_machine = ELF_ARCH; 936 ehdr->e_version = EV_CURRENT; 937 ehdr->e_entry = 0; 938 ehdr->e_phoff = phoff; 939 ehdr->e_flags = 0; 940 ehdr->e_ehsize = sizeof(Elf_Ehdr); 941 ehdr->e_phentsize = sizeof(Elf_Phdr); 942 ehdr->e_phnum = numsegs + 1; 943 ehdr->e_shentsize = sizeof(Elf_Shdr); 944 ehdr->e_shnum = 0; 945 ehdr->e_shstrndx = SHN_UNDEF; 946 947 /* 948 * Fill in the program header entries. 949 */ 950 phdr = (Elf_Phdr *)((char *)dst + phoff); 951 952 /* The note segement. */ 953 phdr->p_type = PT_NOTE; 954 phdr->p_offset = noteoff; 955 phdr->p_vaddr = 0; 956 phdr->p_paddr = 0; 957 phdr->p_filesz = notesz; 958 phdr->p_memsz = 0; 959 phdr->p_flags = 0; 960 phdr->p_align = 0; 961 phdr++; 962 963 /* All the writable segments from the program. */ 964 phc.phdr = phdr; 965 phc.offset = *off; 966 each_writable_segment(p, cb_put_phdr, &phc); 967 } 968 } 969 970 static void 971 elf_putnote(void *dst, size_t *off, const char *name, int type, 972 const void *desc, size_t descsz) 973 { 974 Elf_Note note; 975 976 note.n_namesz = strlen(name) + 1; 977 note.n_descsz = descsz; 978 note.n_type = type; 979 if (dst != NULL) 980 bcopy(¬e, (char *)dst + *off, sizeof note); 981 *off += sizeof note; 982 if (dst != NULL) 983 bcopy(name, (char *)dst + *off, note.n_namesz); 984 *off += roundup2(note.n_namesz, sizeof(Elf_Size)); 985 if (dst != NULL) 986 bcopy(desc, (char *)dst + *off, note.n_descsz); 987 *off += roundup2(note.n_descsz, sizeof(Elf_Size)); 988 } 989 990 /* 991 * Tell kern_execve.c about it, with a little help from the linker. 992 */ 993 static struct execsw elf_execsw = {exec_elf_imgact, "ELF"}; 994 EXEC_SET(elf, elf_execsw); 995