imgact_elf.c revision 43596
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 * $Id: imgact_elf.c,v 1.47 1999/01/29 22:59:43 dillon Exp $ 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 72static int elf_check_header __P((const Elf_Ehdr *hdr, int type)); 73static int elf_freebsd_fixup __P((long **stack_base, 74 struct image_params *imgp)); 75static int elf_load_file __P((struct proc *p, char *file, u_long *addr, 76 u_long *entry)); 77static 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)); 81static int exec_elf_imgact __P((struct image_params *imgp)); 82 83static int elf_trace = 0; 84SYSCTL_INT(_debug, OID_AUTO, elf_trace, CTLFLAG_RW, &elf_trace, 0, ""); 85 86static 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 104static Elf_Brandinfo freebsd_brand_info = { 105 "FreeBSD", 106 "", 107 "/usr/libexec/ld-elf.so.1", 108 &elf_freebsd_sysvec 109 }; 110static Elf_Brandinfo *elf_brand_list[MAX_BRANDS] = { 111 &freebsd_brand_info, 112 NULL, NULL, NULL, 113 NULL, NULL, NULL, NULL 114 }; 115 116int 117elf_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 132int 133elf_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 148int 149elf_brand_inuse(Elf_Brandinfo *entry) 150{ 151 struct proc *p; 152 153 for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) { 154 if (p->p_sysent == entry->sysvec) 155 return TRUE; 156 } 157 158 return FALSE; 159} 160 161static int 162elf_check_header(const Elf_Ehdr *hdr, int type) 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_type != type || hdr->e_version != ELF_TARG_VER) 174 return ENOEXEC; 175 176 return 0; 177} 178 179static int 180elf_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_NEEDED | MAP_COPY_ON_WRITE); 218 vm_map_unlock(&vmspace->vm_map); 219 if (rv != KERN_SUCCESS) 220 return EINVAL; 221 222 /* prefault the page tables */ 223 pmap_object_init_pt(&vmspace->vm_pmap, 224 map_addr, 225 object, 226 (vm_pindex_t) OFF_TO_IDX(file_addr), 227 map_len, 228 0); 229 230 /* we can stop now if we've covered it all */ 231 if (memsz == filsz) 232 return 0; 233 } 234 235 236 /* 237 * We have to get the remaining bit of the file into the first part 238 * of the oversized map segment. This is normally because the .data 239 * segment in the file is extended to provide bss. It's a neat idea 240 * to try and save a page, but it's a pain in the behind to implement. 241 */ 242 copy_len = (offset + filsz) - trunc_page(offset + filsz); 243 map_addr = trunc_page((vm_offset_t)vmaddr + filsz); 244 map_len = round_page((vm_offset_t)vmaddr + memsz) - map_addr; 245 246 /* This had damn well better be true! */ 247 if (map_len != 0) { 248 vm_map_lock(&vmspace->vm_map); 249 rv = vm_map_insert(&vmspace->vm_map, NULL, 0, 250 map_addr, map_addr + map_len, 251 VM_PROT_ALL, VM_PROT_ALL, 0); 252 vm_map_unlock(&vmspace->vm_map); 253 if (rv != KERN_SUCCESS) 254 return EINVAL; 255 } 256 257 if (copy_len != 0) { 258 vm_object_reference(object); 259 rv = vm_map_find(exec_map, 260 object, 261 trunc_page(offset + filsz), 262 &data_buf, 263 PAGE_SIZE, 264 TRUE, 265 VM_PROT_READ, 266 VM_PROT_ALL, 267 MAP_COPY_ON_WRITE | MAP_COPY_NEEDED); 268 if (rv != KERN_SUCCESS) { 269 vm_object_deallocate(object); 270 return EINVAL; 271 } 272 pmap_object_init_pt(exec_map->pmap, data_buf, object, 273 (vm_pindex_t) OFF_TO_IDX(trunc_page(offset + filsz)), 274 PAGE_SIZE, 1); 275 276 /* send the page fragment to user space */ 277 error = copyout((caddr_t)data_buf, (caddr_t)map_addr, copy_len); 278 vm_map_remove(exec_map, data_buf, data_buf + PAGE_SIZE); 279 if (error) 280 return (error); 281 } 282 283 /* 284 * set it to the specified protection 285 */ 286 vm_map_protect(&vmspace->vm_map, map_addr, map_addr + map_len, prot, 287 FALSE); 288 289 return error; 290} 291 292static int 293elf_load_file(struct proc *p, char *file, u_long *addr, u_long *entry) 294{ 295 const Elf_Ehdr *hdr = NULL; 296 const Elf_Phdr *phdr = NULL; 297 struct nameidata nd; 298 struct vmspace *vmspace = p->p_vmspace; 299 struct vattr attr; 300 struct image_params image_params, *imgp; 301 vm_prot_t prot; 302 unsigned long text_size = 0, data_size = 0; 303 unsigned long text_addr = 0, data_addr = 0; 304 int error, i; 305 306 imgp = &image_params; 307 /* 308 * Initialize part of the common data 309 */ 310 imgp->proc = p; 311 imgp->uap = NULL; 312 imgp->attr = &attr; 313 imgp->firstpage = NULL; 314 imgp->image_header = (char *)kmem_alloc_wait(exec_map, PAGE_SIZE); 315 316 if (imgp->image_header == NULL) { 317 nd.ni_vp = NULL; 318 error = ENOMEM; 319 goto fail; 320 } 321 322 NDINIT(&nd, LOOKUP, LOCKLEAF|FOLLOW, UIO_SYSSPACE, file, p); 323 324 if ((error = namei(&nd)) != 0) { 325 nd.ni_vp = NULL; 326 goto fail; 327 } 328 329 imgp->vp = nd.ni_vp; 330 331 /* 332 * Check permissions, modes, uid, etc on the file, and "open" it. 333 */ 334 error = exec_check_permissions(imgp); 335 if (error) { 336 VOP_UNLOCK(nd.ni_vp, 0, p); 337 goto fail; 338 } 339 340 error = exec_map_first_page(imgp); 341 VOP_UNLOCK(nd.ni_vp, 0, p); 342 if (error) 343 goto fail; 344 345 hdr = (const Elf_Ehdr *)imgp->image_header; 346 if ((error = elf_check_header(hdr, ET_DYN)) != 0) 347 goto fail; 348 349 /* Only support headers that fit within first page for now */ 350 if ((hdr->e_phoff > PAGE_SIZE) || 351 (hdr->e_phoff + hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE) { 352 error = ENOEXEC; 353 goto fail; 354 } 355 356 phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff); 357 358 for (i = 0; i < hdr->e_phnum; i++) { 359 if (phdr[i].p_type == PT_LOAD) { /* Loadable segment */ 360 prot = 0; 361 if (phdr[i].p_flags & PF_X) 362 prot |= VM_PROT_EXECUTE; 363 if (phdr[i].p_flags & PF_W) 364 prot |= VM_PROT_WRITE; 365 if (phdr[i].p_flags & PF_R) 366 prot |= VM_PROT_READ; 367 368 if ((error = elf_load_section(p, vmspace, nd.ni_vp, 369 phdr[i].p_offset, 370 (caddr_t)phdr[i].p_vaddr + 371 (*addr), 372 phdr[i].p_memsz, 373 phdr[i].p_filesz, prot)) != 0) 374 goto fail; 375 376 /* 377 * Is this .text or .data ?? 378 * 379 * We only handle one each of those yet XXX 380 */ 381 if (hdr->e_entry >= phdr[i].p_vaddr && 382 hdr->e_entry <(phdr[i].p_vaddr+phdr[i].p_memsz)) { 383 text_addr = trunc_page(phdr[i].p_vaddr+(*addr)); 384 text_size = round_page(phdr[i].p_memsz + 385 phdr[i].p_vaddr - 386 trunc_page(phdr[i].p_vaddr)); 387 *entry=(unsigned long)hdr->e_entry+(*addr); 388 } else { 389 data_addr = trunc_page(phdr[i].p_vaddr+(*addr)); 390 data_size = round_page(phdr[i].p_memsz + 391 phdr[i].p_vaddr - 392 trunc_page(phdr[i].p_vaddr)); 393 } 394 } 395 } 396 397fail: 398 if (imgp->firstpage) 399 exec_unmap_first_page(imgp); 400 if (imgp->image_header) 401 kmem_free_wakeup(exec_map, (vm_offset_t)imgp->image_header, 402 PAGE_SIZE); 403 if (nd.ni_vp) 404 vrele(nd.ni_vp); 405 406 return error; 407} 408 409static int 410exec_elf_imgact(struct image_params *imgp) 411{ 412 const Elf_Ehdr *hdr = (const Elf_Ehdr *) imgp->image_header; 413 const Elf_Phdr *phdr; 414 Elf_Auxargs *elf_auxargs = NULL; 415 struct vmspace *vmspace; 416 vm_prot_t prot; 417 u_long text_size = 0, data_size = 0; 418 u_long text_addr = 0, data_addr = 0; 419 u_long addr, entry = 0, proghdr = 0; 420 int error, i; 421 const char *interp = NULL; 422 Elf_Brandinfo *brand_info; 423 const char *brand; 424 char path[MAXPATHLEN]; 425 426 /* 427 * Do we have a valid ELF header ? 428 */ 429 if (elf_check_header(hdr, ET_EXEC)) 430 return -1; 431 432 /* 433 * From here on down, we return an errno, not -1, as we've 434 * detected an ELF file. 435 */ 436 437 if ((hdr->e_phoff > PAGE_SIZE) || 438 (hdr->e_phoff + hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE) { 439 /* Only support headers in first page for now */ 440 return ENOEXEC; 441 } 442 phdr = (const Elf_Phdr*)(imgp->image_header + hdr->e_phoff); 443 444 /* 445 * From this point on, we may have resources that need to be freed. 446 */ 447 if ((error = exec_extract_strings(imgp)) != 0) 448 goto fail; 449 450 exec_new_vmspace(imgp); 451 452 vmspace = imgp->proc->p_vmspace; 453 454 for (i = 0; i < hdr->e_phnum; i++) { 455 switch(phdr[i].p_type) { 456 457 case PT_LOAD: /* Loadable segment */ 458 prot = 0; 459 if (phdr[i].p_flags & PF_X) 460 prot |= VM_PROT_EXECUTE; 461 if (phdr[i].p_flags & PF_W) 462 prot |= VM_PROT_WRITE; 463 if (phdr[i].p_flags & PF_R) 464 prot |= VM_PROT_READ; 465 466 if ((error = elf_load_section(imgp->proc, 467 vmspace, imgp->vp, 468 phdr[i].p_offset, 469 (caddr_t)phdr[i].p_vaddr, 470 phdr[i].p_memsz, 471 phdr[i].p_filesz, prot)) != 0) 472 goto fail; 473 474 /* 475 * Is this .text or .data ?? 476 * 477 * We only handle one each of those yet XXX 478 */ 479 if (hdr->e_entry >= phdr[i].p_vaddr && 480 hdr->e_entry <(phdr[i].p_vaddr+phdr[i].p_memsz)) { 481 text_addr = trunc_page(phdr[i].p_vaddr); 482 text_size = round_page(phdr[i].p_memsz + 483 phdr[i].p_vaddr - 484 text_addr); 485 entry = (u_long)hdr->e_entry; 486 } else { 487 data_addr = trunc_page(phdr[i].p_vaddr); 488 data_size = round_page(phdr[i].p_memsz + 489 phdr[i].p_vaddr - 490 data_addr); 491 } 492 break; 493 case PT_INTERP: /* Path to interpreter */ 494 if (phdr[i].p_filesz > MAXPATHLEN || 495 phdr[i].p_offset + phdr[i].p_filesz > PAGE_SIZE) { 496 error = ENOEXEC; 497 goto fail; 498 } 499 interp = imgp->image_header + phdr[i].p_offset; 500 break; 501 case PT_PHDR: /* Program header table info */ 502 proghdr = phdr[i].p_vaddr; 503 break; 504 default: 505 break; 506 } 507 } 508 509 vmspace->vm_tsize = text_size >> PAGE_SHIFT; 510 vmspace->vm_taddr = (caddr_t)(uintptr_t)text_addr; 511 vmspace->vm_dsize = data_size >> PAGE_SHIFT; 512 vmspace->vm_daddr = (caddr_t)(uintptr_t)data_addr; 513 514 addr = 2L*MAXDSIZ; /* May depend on OS type XXX */ 515 516 imgp->entry_addr = entry; 517 518 /* If the executable has a brand, search for it in the brand list. */ 519 brand_info = NULL; 520 brand = (const char *)&hdr->e_ident[EI_BRAND]; 521 if (brand[0] != '\0') { 522 for (i = 0; i < MAX_BRANDS; i++) { 523 Elf_Brandinfo *bi = elf_brand_list[i]; 524 525 if (bi != NULL && strcmp(brand, bi->brand) == 0) { 526 brand_info = bi; 527 break; 528 } 529 } 530 } 531 532 /* Lacking a known brand, search for a recognized interpreter. */ 533 if (brand_info == NULL && interp != NULL) { 534 for (i = 0; i < MAX_BRANDS; i++) { 535 Elf_Brandinfo *bi = elf_brand_list[i]; 536 537 if (bi != NULL && 538 strcmp(interp, bi->interp_path) == 0) { 539 brand_info = bi; 540 break; 541 } 542 } 543 } 544 545#ifdef __alpha__ 546 /* XXX - Assume FreeBSD on the alpha. */ 547 if (brand_info == NULL) 548 brand_info = &freebsd_brand_info; 549#endif 550 551 if (brand_info == NULL) { 552 if (brand[0] == 0) 553 uprintf("ELF binary type not known." 554 " Use \"brandelf\" to brand it.\n"); 555 else 556 uprintf("ELF binary type \"%.*s\" not known.\n", 557 EI_NIDENT - EI_BRAND, brand); 558 error = ENOEXEC; 559 goto fail; 560 } 561 562 imgp->proc->p_sysent = brand_info->sysvec; 563 if (interp != NULL) { 564 snprintf(path, sizeof(path), "%s%s", 565 brand_info->emul_path, interp); 566 if ((error = elf_load_file(imgp->proc, path, &addr, 567 &imgp->entry_addr)) != 0) { 568 uprintf("ELF interpreter %s not found\n", path); 569 goto fail; 570 } 571 } 572 573 /* 574 * Construct auxargs table (used by the fixup routine) 575 */ 576 elf_auxargs = malloc(sizeof(Elf_Auxargs), M_TEMP, M_WAITOK); 577 elf_auxargs->execfd = -1; 578 elf_auxargs->phdr = proghdr; 579 elf_auxargs->phent = hdr->e_phentsize; 580 elf_auxargs->phnum = hdr->e_phnum; 581 elf_auxargs->pagesz = PAGE_SIZE; 582 elf_auxargs->base = addr; 583 elf_auxargs->flags = 0; 584 elf_auxargs->entry = entry; 585 elf_auxargs->trace = elf_trace; 586 587 imgp->auxargs = elf_auxargs; 588 imgp->interpreted = 0; 589 590 /* don't allow modifying the file while we run it */ 591 imgp->vp->v_flag |= VTEXT; 592 593fail: 594 return error; 595} 596 597static int 598elf_freebsd_fixup(long **stack_base, struct image_params *imgp) 599{ 600 Elf_Auxargs *args = (Elf_Auxargs *)imgp->auxargs; 601 long *pos; 602 603 pos = *stack_base + (imgp->argc + imgp->envc + 2); 604 605 if (args->trace) { 606 AUXARGS_ENTRY(pos, AT_DEBUG, 1); 607 } 608 if (args->execfd != -1) { 609 AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd); 610 } 611 AUXARGS_ENTRY(pos, AT_PHDR, args->phdr); 612 AUXARGS_ENTRY(pos, AT_PHENT, args->phent); 613 AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum); 614 AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz); 615 AUXARGS_ENTRY(pos, AT_FLAGS, args->flags); 616 AUXARGS_ENTRY(pos, AT_ENTRY, args->entry); 617 AUXARGS_ENTRY(pos, AT_BASE, args->base); 618 AUXARGS_ENTRY(pos, AT_NULL, 0); 619 620 free(imgp->auxargs, M_TEMP); 621 imgp->auxargs = NULL; 622 623 (*stack_base)--; 624 suword(*stack_base, (long) imgp->argc); 625 return 0; 626} 627 628/* 629 * Code for generating ELF core dumps. 630 */ 631 632typedef void (*segment_callback) __P((vm_map_entry_t, void *)); 633 634/* Closure for cb_put_phdr(). */ 635struct phdr_closure { 636 Elf_Phdr *phdr; /* Program header to fill in */ 637 Elf_Off offset; /* Offset of segment in core file */ 638}; 639 640/* Closure for cb_size_segment(). */ 641struct sseg_closure { 642 int count; /* Count of writable segments. */ 643 size_t size; /* Total size of all writable segments. */ 644}; 645 646static void cb_put_phdr __P((vm_map_entry_t, void *)); 647static void cb_size_segment __P((vm_map_entry_t, void *)); 648static void each_writable_segment __P((struct proc *, segment_callback, 649 void *)); 650static int elf_corehdr __P((struct proc *, struct vnode *, struct ucred *, 651 int, void *, size_t)); 652static void elf_puthdr __P((struct proc *, void *, size_t *, 653 const prstatus_t *, const prfpregset_t *, const prpsinfo_t *, int)); 654static void elf_putnote __P((void *, size_t *, const char *, int, 655 const void *, size_t)); 656 657extern int osreldate; 658 659int 660elf_coredump(p) 661 register struct proc *p; 662{ 663 register struct vnode *vp; 664 register struct ucred *cred = p->p_cred->pc_ucred; 665 struct nameidata nd; 666 struct vattr vattr; 667 int error, error1; 668 char *name; /* name of corefile */ 669 struct sseg_closure seginfo; 670 void *hdr; 671 size_t hdrsize; 672 673 STOPEVENT(p, S_CORE, 0); 674 675 if (sugid_coredump == 0 && p->p_flag & P_SUGID) 676 return (EFAULT); 677 678 /* Size the program segments. */ 679 seginfo.count = 0; 680 seginfo.size = 0; 681 each_writable_segment(p, cb_size_segment, &seginfo); 682 683 /* 684 * Calculate the size of the core file header area by making 685 * a dry run of generating it. Nothing is written, but the 686 * size is calculated. 687 */ 688 hdrsize = 0; 689 elf_puthdr((struct proc *)NULL, (void *)NULL, &hdrsize, 690 (const prstatus_t *)NULL, (const prfpregset_t *)NULL, 691 (const prpsinfo_t *)NULL, seginfo.count); 692 693 if (hdrsize + seginfo.size >= p->p_rlimit[RLIMIT_CORE].rlim_cur) 694 return (EFAULT); 695 name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid); 696 if (name == NULL) 697 return (EFAULT); /* XXX -- not the best error */ 698 699 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, name, p); 700 error = vn_open(&nd, O_CREAT | FWRITE, S_IRUSR | S_IWUSR); 701 free(name, M_TEMP); 702 if (error) 703 return (error); 704 vp = nd.ni_vp; 705 706 /* Don't dump to non-regular files or files with links. */ 707 if (vp->v_type != VREG || 708 VOP_GETATTR(vp, &vattr, cred, p) || vattr.va_nlink != 1) { 709 error = EFAULT; 710 goto out; 711 } 712 VATTR_NULL(&vattr); 713 vattr.va_size = 0; 714 VOP_LEASE(vp, p, cred, LEASE_WRITE); 715 VOP_SETATTR(vp, &vattr, cred, p); 716 p->p_acflag |= ACORE; 717 718 719 /* 720 * Allocate memory for building the header, fill it up, 721 * and write it out. 722 */ 723 hdr = malloc(hdrsize, M_TEMP, M_WAITOK); 724 if (hdr == NULL) { 725 error = EINVAL; 726 goto out; 727 } 728 error = elf_corehdr(p, vp, cred, seginfo.count, hdr, hdrsize); 729 730 /* Write the contents of all of the writable segments. */ 731 if (error == 0) { 732 Elf_Phdr *php; 733 off_t offset; 734 int i; 735 736 php = (Elf_Phdr *)((char *)hdr + sizeof(Elf_Ehdr)) + 1; 737 offset = hdrsize; 738 for (i = 0; i < seginfo.count; i++) { 739 error = vn_rdwr(UIO_WRITE, vp, (caddr_t)php->p_vaddr, 740 php->p_filesz, offset, UIO_USERSPACE, 741 IO_NODELOCKED|IO_UNIT, cred, (int *)NULL, p); 742 if (error != 0) 743 break; 744 offset += php->p_filesz; 745 php++; 746 } 747 } 748 free(hdr, M_TEMP); 749 750out: 751 VOP_UNLOCK(vp, 0, p); 752 error1 = vn_close(vp, FWRITE, cred, p); 753 if (error == 0) 754 error = error1; 755 return (error); 756} 757 758/* 759 * A callback for each_writable_segment() to write out the segment's 760 * program header entry. 761 */ 762static void 763cb_put_phdr(entry, closure) 764 vm_map_entry_t entry; 765 void *closure; 766{ 767 struct phdr_closure *phc = (struct phdr_closure *)closure; 768 Elf_Phdr *phdr = phc->phdr; 769 770 phc->offset = round_page(phc->offset); 771 772 phdr->p_type = PT_LOAD; 773 phdr->p_offset = phc->offset; 774 phdr->p_vaddr = entry->start; 775 phdr->p_paddr = 0; 776 phdr->p_filesz = phdr->p_memsz = entry->end - entry->start; 777 phdr->p_align = PAGE_SIZE; 778 phdr->p_flags = 0; 779 if (entry->protection & VM_PROT_READ) 780 phdr->p_flags |= PF_R; 781 if (entry->protection & VM_PROT_WRITE) 782 phdr->p_flags |= PF_W; 783 if (entry->protection & VM_PROT_EXECUTE) 784 phdr->p_flags |= PF_X; 785 786 phc->offset += phdr->p_filesz; 787 phc->phdr++; 788} 789 790/* 791 * A callback for each_writable_segment() to gather information about 792 * the number of segments and their total size. 793 */ 794static void 795cb_size_segment(entry, closure) 796 vm_map_entry_t entry; 797 void *closure; 798{ 799 struct sseg_closure *ssc = (struct sseg_closure *)closure; 800 801 ssc->count++; 802 ssc->size += entry->end - entry->start; 803} 804 805/* 806 * For each writable segment in the process's memory map, call the given 807 * function with a pointer to the map entry and some arbitrary 808 * caller-supplied data. 809 */ 810static void 811each_writable_segment(p, func, closure) 812 struct proc *p; 813 segment_callback func; 814 void *closure; 815{ 816 vm_map_t map = &p->p_vmspace->vm_map; 817 vm_map_entry_t entry; 818 819 for (entry = map->header.next; entry != &map->header; 820 entry = entry->next) { 821 vm_object_t obj; 822 823 if (entry->eflags & (MAP_ENTRY_IS_A_MAP|MAP_ENTRY_IS_SUB_MAP) || 824 (entry->protection & (VM_PROT_READ|VM_PROT_WRITE)) != 825 (VM_PROT_READ|VM_PROT_WRITE)) 826 continue; 827 828 if ((obj = entry->object.vm_object) == NULL) 829 continue; 830 831 /* Find the deepest backing object. */ 832 while (obj->backing_object != NULL) 833 obj = obj->backing_object; 834 835 /* Ignore memory-mapped devices and such things. */ 836 if (obj->type != OBJT_DEFAULT && 837 obj->type != OBJT_SWAP && 838 obj->type != OBJT_VNODE) 839 continue; 840 841 (*func)(entry, closure); 842 } 843} 844 845/* 846 * Write the core file header to the file, including padding up to 847 * the page boundary. 848 */ 849static int 850elf_corehdr(p, vp, cred, numsegs, hdr, hdrsize) 851 struct proc *p; 852 struct vnode *vp; 853 struct ucred *cred; 854 int numsegs; 855 size_t hdrsize; 856 void *hdr; 857{ 858 size_t off; 859 prstatus_t status; 860 prfpregset_t fpregset; 861 prpsinfo_t psinfo; 862 863 /* Gather the information for the header. */ 864 bzero(&status, sizeof status); 865 status.pr_version = PRSTATUS_VERSION; 866 status.pr_statussz = sizeof(prstatus_t); 867 status.pr_gregsetsz = sizeof(gregset_t); 868 status.pr_fpregsetsz = sizeof(fpregset_t); 869 status.pr_osreldate = osreldate; 870 status.pr_cursig = p->p_sig; 871 status.pr_pid = p->p_pid; 872 fill_regs(p, &status.pr_reg); 873 874 fill_fpregs(p, &fpregset); 875 876 bzero(&psinfo, sizeof psinfo); 877 psinfo.pr_version = PRPSINFO_VERSION; 878 psinfo.pr_psinfosz = sizeof(prpsinfo_t); 879 strncpy(psinfo.pr_fname, p->p_comm, MAXCOMLEN); 880 /* XXX - We don't fill in the command line arguments properly yet. */ 881 strncpy(psinfo.pr_psargs, p->p_comm, PRARGSZ); 882 883 /* Fill in the header. */ 884 bzero(hdr, hdrsize); 885 off = 0; 886 elf_puthdr(p, hdr, &off, &status, &fpregset, &psinfo, numsegs); 887 888 /* Write it to the core file. */ 889 return vn_rdwr(UIO_WRITE, vp, hdr, hdrsize, (off_t)0, 890 UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT, cred, NULL, p); 891} 892 893static void 894elf_puthdr(struct proc *p, void *dst, size_t *off, const prstatus_t *status, 895 const prfpregset_t *fpregset, const prpsinfo_t *psinfo, int numsegs) 896{ 897 size_t ehoff; 898 size_t phoff; 899 size_t noteoff; 900 size_t notesz; 901 902 ehoff = *off; 903 *off += sizeof(Elf_Ehdr); 904 905 phoff = *off; 906 *off += (numsegs + 1) * sizeof(Elf_Phdr); 907 908 noteoff = *off; 909 elf_putnote(dst, off, "FreeBSD", NT_PRSTATUS, status, 910 sizeof *status); 911 elf_putnote(dst, off, "FreeBSD", NT_FPREGSET, fpregset, 912 sizeof *fpregset); 913 elf_putnote(dst, off, "FreeBSD", NT_PRPSINFO, psinfo, 914 sizeof *psinfo); 915 notesz = *off - noteoff; 916 917 /* Align up to a page boundary for the program segments. */ 918 *off = round_page(*off); 919 920 if (dst != NULL) { 921 Elf_Ehdr *ehdr; 922 Elf_Phdr *phdr; 923 struct phdr_closure phc; 924 925 /* 926 * Fill in the ELF header. 927 */ 928 ehdr = (Elf_Ehdr *)((char *)dst + ehoff); 929 ehdr->e_ident[EI_MAG0] = ELFMAG0; 930 ehdr->e_ident[EI_MAG1] = ELFMAG1; 931 ehdr->e_ident[EI_MAG2] = ELFMAG2; 932 ehdr->e_ident[EI_MAG3] = ELFMAG3; 933 ehdr->e_ident[EI_CLASS] = ELF_CLASS; 934 ehdr->e_ident[EI_DATA] = ELF_DATA; 935 ehdr->e_ident[EI_VERSION] = EV_CURRENT; 936 ehdr->e_ident[EI_PAD] = 0; 937 strncpy(ehdr->e_ident + EI_BRAND, "FreeBSD", 938 EI_NIDENT - EI_BRAND); 939 ehdr->e_type = ET_CORE; 940 ehdr->e_machine = ELF_ARCH; 941 ehdr->e_version = EV_CURRENT; 942 ehdr->e_entry = 0; 943 ehdr->e_phoff = phoff; 944 ehdr->e_flags = 0; 945 ehdr->e_ehsize = sizeof(Elf_Ehdr); 946 ehdr->e_phentsize = sizeof(Elf_Phdr); 947 ehdr->e_phnum = numsegs + 1; 948 ehdr->e_shentsize = sizeof(Elf_Shdr); 949 ehdr->e_shnum = 0; 950 ehdr->e_shstrndx = SHN_UNDEF; 951 952 /* 953 * Fill in the program header entries. 954 */ 955 phdr = (Elf_Phdr *)((char *)dst + phoff); 956 957 /* The note segement. */ 958 phdr->p_type = PT_NOTE; 959 phdr->p_offset = noteoff; 960 phdr->p_vaddr = 0; 961 phdr->p_paddr = 0; 962 phdr->p_filesz = notesz; 963 phdr->p_memsz = 0; 964 phdr->p_flags = 0; 965 phdr->p_align = 0; 966 phdr++; 967 968 /* All the writable segments from the program. */ 969 phc.phdr = phdr; 970 phc.offset = *off; 971 each_writable_segment(p, cb_put_phdr, &phc); 972 } 973} 974 975static void 976elf_putnote(void *dst, size_t *off, const char *name, int type, 977 const void *desc, size_t descsz) 978{ 979 Elf_Note note; 980 981 note.n_namesz = strlen(name) + 1; 982 note.n_descsz = descsz; 983 note.n_type = type; 984 if (dst != NULL) 985 bcopy(¬e, (char *)dst + *off, sizeof note); 986 *off += sizeof note; 987 if (dst != NULL) 988 bcopy(name, (char *)dst + *off, note.n_namesz); 989 *off += roundup2(note.n_namesz, sizeof(Elf_Size)); 990 if (dst != NULL) 991 bcopy(desc, (char *)dst + *off, note.n_descsz); 992 *off += roundup2(note.n_descsz, sizeof(Elf_Size)); 993} 994 995/* 996 * Tell kern_execve.c about it, with a little help from the linker. 997 * Since `const' objects end up in the text segment, TEXT_SET is the 998 * correct directive to use. 999 */ 1000static struct execsw elf_execsw = {exec_elf_imgact, "ELF"}; 1001EXEC_SET(elf, elf_execsw); 1002