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