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