1 /* $OpenBSD: exec_elf.c,v 1.187 2024/07/14 11:14:29 jca Exp $ */ 2 3 /* 4 * Copyright (c) 1996 Per Fogelstrom 5 * All rights reserved. 6 * 7 * Copyright (c) 1994 Christos Zoulas 8 * All rights reserved. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. The name of the author may not be used to endorse or promote products 19 * derived from this software without specific prior written permission 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 * 32 */ 33 34 /* 35 * Copyright (c) 2001 Wasabi Systems, Inc. 36 * All rights reserved. 37 * 38 * Written by Jason R. Thorpe for Wasabi Systems, Inc. 39 * 40 * Redistribution and use in source and binary forms, with or without 41 * modification, are permitted provided that the following conditions 42 * are met: 43 * 1. Redistributions of source code must retain the above copyright 44 * notice, this list of conditions and the following disclaimer. 45 * 2. Redistributions in binary form must reproduce the above copyright 46 * notice, this list of conditions and the following disclaimer in the 47 * documentation and/or other materials provided with the distribution. 48 * 3. All advertising materials mentioning features or use of this software 49 * must display the following acknowledgement: 50 * This product includes software developed for the NetBSD Project by 51 * Wasabi Systems, Inc. 52 * 4. The name of Wasabi Systems, Inc. may not be used to endorse 53 * or promote products derived from this software without specific prior 54 * written permission. 55 * 56 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND 57 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 58 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 59 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC 60 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 61 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 62 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 63 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 64 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 65 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 66 * POSSIBILITY OF SUCH DAMAGE. 67 */ 68 69 #include <sys/param.h> 70 #include <sys/systm.h> 71 #include <sys/proc.h> 72 #include <sys/malloc.h> 73 #include <sys/pool.h> 74 #include <sys/mount.h> 75 #include <sys/namei.h> 76 #include <sys/vnode.h> 77 #include <sys/core.h> 78 #include <sys/exec.h> 79 #include <sys/exec_elf.h> 80 #include <sys/fcntl.h> 81 #include <sys/ptrace.h> 82 #include <sys/signalvar.h> 83 #include <sys/pledge.h> 84 #include <sys/syscall.h> 85 86 #include <sys/mman.h> 87 88 #include <uvm/uvm_extern.h> 89 90 #include <machine/reg.h> 91 #include <machine/exec.h> 92 #include <machine/elf.h> 93 94 int elf_load_file(struct proc *, char *, struct exec_package *, 95 struct elf_args *); 96 int elf_check_header(Elf_Ehdr *); 97 int elf_read_from(struct proc *, struct vnode *, u_long, void *, int); 98 void elf_load_psection(struct exec_vmcmd_set *, struct vnode *, 99 Elf_Phdr *, Elf_Addr *, Elf_Addr *, int *, int); 100 int elf_os_pt_note_name(Elf_Note *); 101 int elf_os_pt_note(struct proc *, struct exec_package *, Elf_Ehdr *, int *); 102 int elf_read_pintable(struct proc *p, struct vnode *vp, Elf_Phdr *pp, 103 u_int **pinp, int is_ldso, size_t len); 104 105 /* round up and down to page boundaries. */ 106 #define ELF_ROUND(a, b) (((a) + (b) - 1) & ~((b) - 1)) 107 #define ELF_TRUNC(a, b) ((a) & ~((b) - 1)) 108 109 /* 110 * We limit the number of program headers to 32, this should 111 * be a reasonable limit for ELF, the most we have seen so far is 12 112 */ 113 #define ELF_MAX_VALID_PHDR 32 114 115 #define ELF_NOTE_NAME_OPENBSD 0x01 116 117 struct elf_note_name { 118 char *name; 119 int id; 120 } elf_note_names[] = { 121 { "OpenBSD", ELF_NOTE_NAME_OPENBSD }, 122 }; 123 124 #define ELFROUNDSIZE sizeof(Elf_Word) 125 #define elfround(x) roundup((x), ELFROUNDSIZE) 126 127 128 /* 129 * Check header for validity; return 0 for ok, ENOEXEC if error 130 */ 131 int 132 elf_check_header(Elf_Ehdr *ehdr) 133 { 134 /* 135 * We need to check magic, class size, endianness, and version before 136 * we look at the rest of the Elf_Ehdr structure. These few elements 137 * are represented in a machine independent fashion. 138 */ 139 if (!IS_ELF(*ehdr) || 140 ehdr->e_ident[EI_CLASS] != ELF_TARG_CLASS || 141 ehdr->e_ident[EI_DATA] != ELF_TARG_DATA || 142 ehdr->e_ident[EI_VERSION] != ELF_TARG_VER) 143 return (ENOEXEC); 144 145 /* Now check the machine dependent header */ 146 if (ehdr->e_machine != ELF_TARG_MACH || 147 ehdr->e_version != ELF_TARG_VER) 148 return (ENOEXEC); 149 150 /* Don't allow an insane amount of sections. */ 151 if (ehdr->e_phnum > ELF_MAX_VALID_PHDR) 152 return (ENOEXEC); 153 154 return (0); 155 } 156 157 /* 158 * Load a psection at the appropriate address 159 */ 160 void 161 elf_load_psection(struct exec_vmcmd_set *vcset, struct vnode *vp, 162 Elf_Phdr *ph, Elf_Addr *addr, Elf_Addr *size, int *prot, int flags) 163 { 164 u_long msize, lsize, psize, rm, rf; 165 long diff, offset, bdiff; 166 Elf_Addr base; 167 168 /* 169 * If the user specified an address, then we load there. 170 */ 171 if (*addr != ELF_NO_ADDR) { 172 if (ph->p_align > 1) { 173 *addr = ELF_TRUNC(*addr, ph->p_align); 174 diff = ph->p_vaddr - ELF_TRUNC(ph->p_vaddr, ph->p_align); 175 /* page align vaddr */ 176 base = *addr + trunc_page(ph->p_vaddr) 177 - ELF_TRUNC(ph->p_vaddr, ph->p_align); 178 } else { 179 diff = 0; 180 base = *addr + trunc_page(ph->p_vaddr) - ph->p_vaddr; 181 } 182 } else { 183 *addr = ph->p_vaddr; 184 if (ph->p_align > 1) 185 *addr = ELF_TRUNC(*addr, ph->p_align); 186 base = trunc_page(ph->p_vaddr); 187 diff = ph->p_vaddr - *addr; 188 } 189 bdiff = ph->p_vaddr - trunc_page(ph->p_vaddr); 190 191 /* 192 * Enforce W^X and map W|X segments without X permission 193 * initially. The dynamic linker will make these read-only 194 * and add back X permission after relocation processing. 195 * Static executables with W|X segments will probably crash. 196 */ 197 *prot |= (ph->p_flags & PF_R) ? PROT_READ : 0; 198 *prot |= (ph->p_flags & PF_W) ? PROT_WRITE : 0; 199 if ((ph->p_flags & PF_W) == 0) 200 *prot |= (ph->p_flags & PF_X) ? PROT_EXEC : 0; 201 202 /* 203 * Apply immutability as much as possible, but not text/rodata 204 * segments of textrel binaries, or RELRO or PT_OPENBSD_MUTABLE 205 * sections, or LOADS marked PF_OPENBSD_MUTABLE, or LOADS which 206 * violate W^X. 207 * Userland (meaning crt0 or ld.so) will repair those regions. 208 */ 209 if ((ph->p_flags & (PF_X | PF_W)) != (PF_X | PF_W) && 210 ((ph->p_flags & PF_OPENBSD_MUTABLE) == 0)) 211 flags |= VMCMD_IMMUTABLE; 212 if ((flags & VMCMD_TEXTREL) && (ph->p_flags & PF_W) == 0) 213 flags &= ~VMCMD_IMMUTABLE; 214 215 msize = ph->p_memsz + diff; 216 offset = ph->p_offset - bdiff; 217 lsize = ph->p_filesz + bdiff; 218 psize = round_page(lsize); 219 220 /* 221 * Because the pagedvn pager can't handle zero fill of the last 222 * data page if it's not page aligned we map the last page readvn. 223 */ 224 if (ph->p_flags & PF_W) { 225 psize = trunc_page(lsize); 226 if (psize > 0) 227 NEW_VMCMD2(vcset, vmcmd_map_pagedvn, psize, base, vp, 228 offset, *prot, flags); 229 if (psize != lsize) { 230 NEW_VMCMD2(vcset, vmcmd_map_readvn, lsize - psize, 231 base + psize, vp, offset + psize, *prot, flags); 232 } 233 } else { 234 NEW_VMCMD2(vcset, vmcmd_map_pagedvn, psize, base, vp, offset, 235 *prot, flags); 236 } 237 238 /* 239 * Check if we need to extend the size of the segment 240 */ 241 rm = round_page(*addr + ph->p_memsz + diff); 242 rf = round_page(*addr + ph->p_filesz + diff); 243 244 if (rm != rf) { 245 NEW_VMCMD2(vcset, vmcmd_map_zero, rm - rf, rf, NULLVP, 0, 246 *prot, flags); 247 } 248 *size = msize; 249 } 250 251 /* 252 * Read from vnode into buffer at offset. 253 */ 254 int 255 elf_read_from(struct proc *p, struct vnode *vp, u_long off, void *buf, 256 int size) 257 { 258 int error; 259 size_t resid; 260 261 if ((error = vn_rdwr(UIO_READ, vp, buf, size, off, UIO_SYSSPACE, 262 0, p->p_ucred, &resid, p)) != 0) 263 return error; 264 /* 265 * See if we got all of it 266 */ 267 if (resid != 0) 268 return (ENOEXEC); 269 return (0); 270 } 271 272 /* 273 * rebase the pin offsets inside a base,len window for the text segment only. 274 */ 275 void 276 elf_adjustpins(vaddr_t *basep, size_t *lenp, u_int *pins, int npins, u_int offset) 277 { 278 int i; 279 280 /* Adjust offsets, base, len */ 281 for (i = 0; i < npins; i++) { 282 if (pins[i] == -1 || pins[i] == 0) 283 continue; 284 pins[i] -= offset; 285 } 286 *basep += offset; 287 *lenp -= offset; 288 } 289 290 int 291 elf_read_pintable(struct proc *p, struct vnode *vp, Elf_Phdr *pp, 292 u_int **pinp, int is_ldso, size_t len) 293 { 294 struct pinsyscalls { 295 u_int offset; 296 u_int sysno; 297 } *syscalls = NULL; 298 int i, nsyscalls = 0, npins = 0; 299 u_int *pins = NULL; 300 301 if (pp->p_filesz > SYS_MAXSYSCALL * 2 * sizeof(*syscalls) || 302 pp->p_filesz % sizeof(*syscalls) != 0) 303 goto bad; 304 nsyscalls = pp->p_filesz / sizeof(*syscalls); 305 syscalls = malloc(pp->p_filesz, M_PINSYSCALL, M_WAITOK); 306 if (elf_read_from(p, vp, pp->p_offset, syscalls, 307 pp->p_filesz) != 0) 308 goto bad; 309 310 /* Validate, and calculate pintable size */ 311 for (i = 0; i < nsyscalls; i++) { 312 if (syscalls[i].sysno <= 0 || 313 syscalls[i].sysno >= SYS_MAXSYSCALL || 314 syscalls[i].offset > len) 315 goto bad; 316 npins = MAX(npins, syscalls[i].sysno); 317 } 318 if (is_ldso) 319 npins = MAX(npins, SYS_kbind); /* XXX see ld.so/loader.c */ 320 npins++; 321 322 /* Fill pintable: 0 = invalid, -1 = allowed, else offset from base */ 323 pins = mallocarray(npins, sizeof(u_int), M_PINSYSCALL, M_WAITOK|M_ZERO); 324 for (i = 0; i < nsyscalls; i++) { 325 if (pins[syscalls[i].sysno]) 326 pins[syscalls[i].sysno] = -1; /* duplicated */ 327 else 328 pins[syscalls[i].sysno] = syscalls[i].offset; 329 } 330 if (is_ldso) 331 pins[SYS_kbind] = -1; /* XXX see ld.so/loader.c */ 332 *pinp = pins; 333 pins = NULL; 334 bad: 335 free(syscalls, M_PINSYSCALL, nsyscalls * sizeof(*syscalls)); 336 free(pins, M_PINSYSCALL, npins * sizeof(u_int)); 337 return npins; 338 } 339 340 /* 341 * Load a file (interpreter/library) pointed to by path [stolen from 342 * coff_load_shlib()]. Made slightly generic so it might be used externally. 343 */ 344 int 345 elf_load_file(struct proc *p, char *path, struct exec_package *epp, 346 struct elf_args *ap) 347 { 348 int error, i; 349 struct nameidata nd; 350 Elf_Ehdr eh; 351 Elf_Phdr *ph = NULL, *syscall_ph = NULL; 352 u_long phsize = 0; 353 Elf_Addr addr; 354 struct vnode *vp; 355 Elf_Phdr *base_ph = NULL; 356 struct interp_ld_sec { 357 Elf_Addr vaddr; 358 u_long memsz; 359 } loadmap[ELF_MAX_VALID_PHDR]; 360 int nload, idx = 0; 361 Elf_Addr pos; 362 int file_align; 363 int loop; 364 size_t randomizequota = ELF_RANDOMIZE_LIMIT; 365 vaddr_t text_start = -1, text_end = 0; 366 367 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, path, p); 368 nd.ni_pledge = PLEDGE_RPATH; 369 nd.ni_unveil = UNVEIL_READ; 370 if ((error = namei(&nd)) != 0) { 371 return (error); 372 } 373 vp = nd.ni_vp; 374 if (vp->v_type != VREG) { 375 error = EACCES; 376 goto bad; 377 } 378 if ((error = VOP_GETATTR(vp, epp->ep_vap, p->p_ucred, p)) != 0) 379 goto bad; 380 if (vp->v_mount->mnt_flag & MNT_NOEXEC) { 381 error = EACCES; 382 goto bad; 383 } 384 if ((error = VOP_ACCESS(vp, VREAD, p->p_ucred, p)) != 0) 385 goto bad1; 386 if ((error = elf_read_from(p, nd.ni_vp, 0, &eh, sizeof(eh))) != 0) 387 goto bad1; 388 389 if (elf_check_header(&eh) || eh.e_type != ET_DYN) { 390 error = ENOEXEC; 391 goto bad1; 392 } 393 394 ph = mallocarray(eh.e_phnum, sizeof(Elf_Phdr), M_TEMP, M_WAITOK); 395 phsize = eh.e_phnum * sizeof(Elf_Phdr); 396 397 if ((error = elf_read_from(p, nd.ni_vp, eh.e_phoff, ph, phsize)) != 0) 398 goto bad1; 399 400 for (i = 0; i < eh.e_phnum; i++) { 401 if ((ph[i].p_align > 1) && !powerof2(ph[i].p_align)) { 402 error = EINVAL; 403 goto bad1; 404 } 405 406 if (ph[i].p_type == PT_LOAD) { 407 if (ph[i].p_filesz > ph[i].p_memsz || 408 ph[i].p_memsz == 0) { 409 error = EINVAL; 410 goto bad1; 411 } 412 loadmap[idx].vaddr = trunc_page(ph[i].p_vaddr); 413 loadmap[idx].memsz = round_page (ph[i].p_vaddr + 414 ph[i].p_memsz - loadmap[idx].vaddr); 415 file_align = ph[i].p_align; 416 idx++; 417 } 418 } 419 nload = idx; 420 421 /* 422 * Load the interpreter where a non-fixed mmap(NULL, ...) 423 * would (i.e. something safely out of the way). 424 */ 425 pos = uvm_map_hint(p->p_vmspace, PROT_EXEC, VM_MIN_ADDRESS, 426 VM_MAXUSER_ADDRESS); 427 pos = ELF_ROUND(pos, file_align); 428 429 loop = 0; 430 for (i = 0; i < nload;/**/) { 431 vaddr_t addr; 432 struct uvm_object *uobj; 433 off_t uoff; 434 size_t size; 435 436 #ifdef this_needs_fixing 437 if (i == 0) { 438 uobj = &vp->v_uvm.u_obj; 439 /* need to fix uoff */ 440 } else { 441 #endif 442 uobj = NULL; 443 uoff = 0; 444 #ifdef this_needs_fixing 445 } 446 #endif 447 448 addr = trunc_page(pos + loadmap[i].vaddr); 449 size = round_page(addr + loadmap[i].memsz) - addr; 450 451 /* CRAP - map_findspace does not avoid daddr+BRKSIZ */ 452 if ((addr + size > (vaddr_t)p->p_vmspace->vm_daddr) && 453 (addr < (vaddr_t)p->p_vmspace->vm_daddr + BRKSIZ)) 454 addr = round_page((vaddr_t)p->p_vmspace->vm_daddr + 455 BRKSIZ); 456 457 if (uvm_map_mquery(&p->p_vmspace->vm_map, &addr, size, 458 (i == 0 ? uoff : UVM_UNKNOWN_OFFSET), 0) != 0) { 459 if (loop == 0) { 460 loop = 1; 461 i = 0; 462 pos = 0; 463 continue; 464 } 465 error = ENOMEM; 466 goto bad1; 467 } 468 if (addr != pos + loadmap[i].vaddr) { 469 /* base changed. */ 470 pos = addr - trunc_page(loadmap[i].vaddr); 471 pos = ELF_ROUND(pos,file_align); 472 i = 0; 473 continue; 474 } 475 476 i++; 477 } 478 479 /* 480 * Load all the necessary sections 481 */ 482 for (i = 0; i < eh.e_phnum; i++) { 483 Elf_Addr size = 0; 484 int prot = 0; 485 int flags; 486 487 switch (ph[i].p_type) { 488 case PT_LOAD: 489 if (base_ph == NULL) { 490 flags = VMCMD_BASE; 491 addr = pos; 492 base_ph = &ph[i]; 493 } else { 494 flags = VMCMD_RELATIVE; 495 addr = ph[i].p_vaddr - base_ph->p_vaddr; 496 } 497 elf_load_psection(&epp->ep_vmcmds, nd.ni_vp, 498 &ph[i], &addr, &size, &prot, flags); 499 /* If entry is within this section it must be text */ 500 if (eh.e_entry >= ph[i].p_vaddr && 501 eh.e_entry < (ph[i].p_vaddr + size)) { 502 /* LOAD containing e_entry may not be writable */ 503 if (prot & PROT_WRITE) { 504 error = ENOEXEC; 505 goto bad1; 506 } 507 epp->ep_entry = addr + eh.e_entry - 508 ELF_TRUNC(ph[i].p_vaddr,ph[i].p_align); 509 if (flags == VMCMD_RELATIVE) 510 epp->ep_entry += pos; 511 ap->arg_interp = pos; 512 } 513 if (prot & PROT_EXEC) { 514 if (addr < text_start) 515 text_start = addr; 516 if (addr+size >= text_end) 517 text_end = addr + size; 518 } 519 addr += size; 520 break; 521 522 case PT_PHDR: 523 case PT_NOTE: 524 break; 525 526 case PT_OPENBSD_RANDOMIZE: 527 if (ph[i].p_memsz > randomizequota) { 528 error = ENOMEM; 529 goto bad1; 530 } 531 randomizequota -= ph[i].p_memsz; 532 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_randomize, 533 ph[i].p_memsz, ph[i].p_vaddr + pos, NULLVP, 0, 0); 534 break; 535 536 case PT_DYNAMIC: 537 #if defined (__mips__) 538 /* DT_DEBUG is not ready on mips */ 539 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_mutable, 540 ph[i].p_memsz, ph[i].p_vaddr + pos, NULLVP, 0, 0); 541 #endif 542 break; 543 case PT_GNU_RELRO: 544 case PT_OPENBSD_MUTABLE: 545 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_mutable, 546 ph[i].p_memsz, ph[i].p_vaddr + pos, NULLVP, 0, 0); 547 break; 548 case PT_OPENBSD_SYSCALLS: 549 syscall_ph = &ph[i]; 550 break; 551 default: 552 break; 553 } 554 } 555 556 if (syscall_ph) { 557 struct process *pr = p->p_p; 558 vaddr_t base = pos; 559 size_t len = text_end; 560 u_int *pins; 561 int npins; 562 563 npins = elf_read_pintable(p, nd.ni_vp, syscall_ph, 564 &pins, 1, len); 565 if (npins) { 566 elf_adjustpins(&base, &len, pins, npins, 567 text_start); 568 pr->ps_pin.pn_start = base; 569 pr->ps_pin.pn_end = base + len; 570 pr->ps_pin.pn_pins = pins; 571 pr->ps_pin.pn_npins = npins; 572 pr->ps_flags |= PS_PIN; 573 } 574 } 575 576 vn_marktext(nd.ni_vp); 577 578 bad1: 579 VOP_CLOSE(nd.ni_vp, FREAD, p->p_ucred, p); 580 bad: 581 free(ph, M_TEMP, phsize); 582 583 vput(nd.ni_vp); 584 return (error); 585 } 586 587 /* 588 * Prepare an Elf binary's exec package 589 * 590 * First, set of the various offsets/lengths in the exec package. 591 * 592 * Then, mark the text image busy (so it can be demand paged) or error out if 593 * this is not possible. Finally, set up vmcmds for the text, data, bss, and 594 * stack segments. 595 */ 596 int 597 exec_elf_makecmds(struct proc *p, struct exec_package *epp) 598 { 599 Elf_Ehdr *eh = epp->ep_hdr; 600 Elf_Phdr *ph, *pp, *base_ph = NULL, *syscall_ph = NULL; 601 Elf_Addr phdr = 0, exe_base = 0, exe_end = 0; 602 int error, i, has_phdr = 0, names = 0, textrel = 0; 603 char *interp = NULL; 604 u_long phsize; 605 size_t randomizequota = ELF_RANDOMIZE_LIMIT; 606 607 if (epp->ep_hdrvalid < sizeof(Elf_Ehdr)) 608 return (ENOEXEC); 609 610 if (elf_check_header(eh) || 611 (eh->e_type != ET_EXEC && eh->e_type != ET_DYN)) 612 return (ENOEXEC); 613 614 /* 615 * check if vnode is in open for writing, because we want to demand- 616 * page out of it. if it is, don't do it, for various reasons. 617 */ 618 if (epp->ep_vp->v_writecount != 0) { 619 #ifdef DIAGNOSTIC 620 if (epp->ep_vp->v_flag & VTEXT) 621 panic("exec: a VTEXT vnode has writecount != 0"); 622 #endif 623 return (ETXTBSY); 624 } 625 /* 626 * Allocate space to hold all the program headers, and read them 627 * from the file 628 */ 629 ph = mallocarray(eh->e_phnum, sizeof(Elf_Phdr), M_TEMP, M_WAITOK); 630 phsize = eh->e_phnum * sizeof(Elf_Phdr); 631 632 if ((error = elf_read_from(p, epp->ep_vp, eh->e_phoff, ph, 633 phsize)) != 0) 634 goto bad; 635 636 epp->ep_tsize = ELF_NO_ADDR; 637 epp->ep_dsize = ELF_NO_ADDR; 638 639 for (i = 0, pp = ph; i < eh->e_phnum; i++, pp++) { 640 if ((pp->p_align > 1) && !powerof2(pp->p_align)) { 641 error = EINVAL; 642 goto bad; 643 } 644 645 if (pp->p_type == PT_INTERP && !interp) { 646 if (pp->p_filesz < 2 || pp->p_filesz > MAXPATHLEN) 647 goto bad; 648 interp = pool_get(&namei_pool, PR_WAITOK); 649 if ((error = elf_read_from(p, epp->ep_vp, 650 pp->p_offset, interp, pp->p_filesz)) != 0) { 651 goto bad; 652 } 653 if (interp[pp->p_filesz - 1] != '\0') 654 goto bad; 655 } else if (pp->p_type == PT_LOAD) { 656 if (pp->p_filesz > pp->p_memsz || 657 pp->p_memsz == 0) { 658 error = EINVAL; 659 goto bad; 660 } 661 if (base_ph == NULL) 662 base_ph = pp; 663 } else if (pp->p_type == PT_PHDR) { 664 has_phdr = 1; 665 } 666 } 667 668 /* 669 * Verify this is an OpenBSD executable. If it's marked that way 670 * via a PT_NOTE then also check for a PT_OPENBSD_WXNEEDED segment. 671 */ 672 if ((error = elf_os_pt_note(p, epp, epp->ep_hdr, &names)) != 0) 673 goto bad; 674 if (eh->e_ident[EI_OSABI] == ELFOSABI_OPENBSD) 675 names |= ELF_NOTE_NAME_OPENBSD; 676 677 if (eh->e_type == ET_DYN) { 678 /* need phdr and load sections for PIE */ 679 if (!has_phdr || base_ph == NULL || base_ph->p_vaddr != 0) { 680 error = EINVAL; 681 goto bad; 682 } 683 /* randomize exe_base for PIE */ 684 exe_base = uvm_map_pie(base_ph->p_align); 685 686 /* 687 * Check if DYNAMIC contains DT_TEXTREL 688 */ 689 for (i = 0, pp = ph; i < eh->e_phnum; i++, pp++) { 690 Elf_Dyn *dt; 691 int j; 692 693 switch (pp->p_type) { 694 case PT_DYNAMIC: 695 if (pp->p_filesz > 64*1024) 696 break; 697 dt = malloc(pp->p_filesz, M_TEMP, M_WAITOK); 698 error = vn_rdwr(UIO_READ, epp->ep_vp, 699 (caddr_t)dt, pp->p_filesz, pp->p_offset, 700 UIO_SYSSPACE, IO_UNIT, p->p_ucred, NULL, p); 701 if (error) { 702 free(dt, M_TEMP, pp->p_filesz); 703 break; 704 } 705 for (j = 0; j < pp->p_filesz / sizeof(*dt); j++) { 706 if (dt[j].d_tag == DT_TEXTREL) { 707 textrel = VMCMD_TEXTREL; 708 break; 709 } 710 } 711 free(dt, M_TEMP, pp->p_filesz); 712 break; 713 default: 714 break; 715 } 716 } 717 } 718 719 /* 720 * Load all the necessary sections 721 */ 722 for (i = 0, pp = ph; i < eh->e_phnum; i++, pp++) { 723 Elf_Addr addr, size = 0; 724 int prot = 0; 725 int flags = 0; 726 727 switch (pp->p_type) { 728 case PT_LOAD: 729 if (exe_base != 0) { 730 if (pp == base_ph) { 731 flags = VMCMD_BASE; 732 addr = exe_base; 733 } else { 734 flags = VMCMD_RELATIVE; 735 addr = pp->p_vaddr - base_ph->p_vaddr; 736 } 737 } else 738 addr = ELF_NO_ADDR; 739 740 /* Static binaries may not call pinsyscalls() */ 741 if (interp == NULL) 742 p->p_vmspace->vm_map.flags |= VM_MAP_PINSYSCALL_ONCE; 743 744 /* 745 * Calculates size of text and data segments 746 * by starting at first and going to end of last. 747 * 'rwx' sections are treated as data. 748 * this is correct for BSS_PLT, but may not be 749 * for DATA_PLT, is fine for TEXT_PLT. 750 */ 751 elf_load_psection(&epp->ep_vmcmds, epp->ep_vp, 752 pp, &addr, &size, &prot, flags | textrel); 753 754 /* 755 * Update exe_base in case alignment was off. 756 * For PIE, addr is relative to exe_base so 757 * adjust it (non PIE exe_base is 0 so no change). 758 */ 759 if (flags == VMCMD_BASE) 760 exe_base = addr; 761 else 762 addr += exe_base; 763 764 /* 765 * Decide whether it's text or data by looking 766 * at the protection of the section 767 */ 768 if (prot & PROT_WRITE) { 769 /* data section */ 770 if (epp->ep_dsize == ELF_NO_ADDR) { 771 epp->ep_daddr = addr; 772 epp->ep_dsize = size; 773 } else { 774 if (addr < epp->ep_daddr) { 775 epp->ep_dsize = 776 epp->ep_dsize + 777 epp->ep_daddr - 778 addr; 779 epp->ep_daddr = addr; 780 } else 781 epp->ep_dsize = addr+size - 782 epp->ep_daddr; 783 } 784 } else if (prot & PROT_EXEC) { 785 /* text section */ 786 if (epp->ep_tsize == ELF_NO_ADDR) { 787 epp->ep_taddr = addr; 788 epp->ep_tsize = size; 789 } else { 790 if (addr < epp->ep_taddr) { 791 epp->ep_tsize = 792 epp->ep_tsize + 793 epp->ep_taddr - 794 addr; 795 epp->ep_taddr = addr; 796 } else 797 epp->ep_tsize = addr+size - 798 epp->ep_taddr; 799 } 800 if (interp == NULL) 801 exe_end = epp->ep_taddr + 802 epp->ep_tsize; /* end of TEXT */ 803 } 804 break; 805 806 case PT_SHLIB: 807 error = ENOEXEC; 808 goto bad; 809 810 case PT_INTERP: 811 /* Already did this one */ 812 case PT_NOTE: 813 break; 814 815 case PT_PHDR: 816 /* Note address of program headers (in text segment) */ 817 phdr = pp->p_vaddr; 818 break; 819 820 case PT_OPENBSD_RANDOMIZE: 821 if (ph[i].p_memsz > randomizequota) { 822 error = ENOMEM; 823 goto bad; 824 } 825 randomizequota -= ph[i].p_memsz; 826 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_randomize, 827 ph[i].p_memsz, ph[i].p_vaddr + exe_base, NULLVP, 0, 0); 828 break; 829 830 case PT_DYNAMIC: 831 #if defined (__mips__) 832 /* DT_DEBUG is not ready on mips */ 833 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_mutable, 834 ph[i].p_memsz, ph[i].p_vaddr + exe_base, NULLVP, 0, 0); 835 #endif 836 break; 837 case PT_GNU_RELRO: 838 case PT_OPENBSD_MUTABLE: 839 NEW_VMCMD(&epp->ep_vmcmds, vmcmd_mutable, 840 ph[i].p_memsz, ph[i].p_vaddr + exe_base, NULLVP, 0, 0); 841 break; 842 case PT_OPENBSD_SYSCALLS: 843 if (interp == NULL) 844 syscall_ph = &ph[i]; 845 break; 846 default: 847 /* 848 * Not fatal, we don't need to understand everything 849 * :-) 850 */ 851 break; 852 } 853 } 854 855 if (syscall_ph) { 856 vaddr_t base = exe_base; 857 size_t len = exe_end - exe_base; 858 u_int *pins; 859 int npins; 860 861 npins = elf_read_pintable(p, epp->ep_vp, syscall_ph, 862 &pins, 0, len); 863 if (npins) { 864 elf_adjustpins(&base, &len, pins, npins, 865 epp->ep_taddr - exe_base); 866 epp->ep_pinstart = base; 867 epp->ep_pinend = base + len; 868 epp->ep_pins = pins; 869 epp->ep_npins = npins; 870 p->p_p->ps_flags |= PS_PIN; 871 } 872 } 873 874 phdr += exe_base; 875 876 /* 877 * Strangely some linux programs may have all load sections marked 878 * writeable, in this case, textsize is not -1, but rather 0; 879 */ 880 if (epp->ep_tsize == ELF_NO_ADDR) 881 epp->ep_tsize = 0; 882 /* 883 * Another possibility is that it has all load sections marked 884 * read-only. Fake a zero-sized data segment right after the 885 * text segment. 886 */ 887 if (epp->ep_dsize == ELF_NO_ADDR) { 888 epp->ep_daddr = round_page(epp->ep_taddr + epp->ep_tsize); 889 epp->ep_dsize = 0; 890 } 891 892 epp->ep_interp = interp; 893 epp->ep_entry = eh->e_entry + exe_base; 894 895 /* 896 * Check if we found a dynamically linked binary and arrange to load 897 * its interpreter when the exec file is released. 898 */ 899 if (interp || eh->e_type == ET_DYN) { 900 struct elf_args *ap; 901 902 ap = malloc(sizeof(*ap), M_TEMP, M_WAITOK); 903 904 ap->arg_phaddr = phdr; 905 ap->arg_phentsize = eh->e_phentsize; 906 ap->arg_phnum = eh->e_phnum; 907 ap->arg_entry = eh->e_entry + exe_base; 908 ap->arg_interp = exe_base; 909 910 epp->ep_args = ap; 911 } 912 913 free(ph, M_TEMP, phsize); 914 vn_marktext(epp->ep_vp); 915 return (exec_setup_stack(p, epp)); 916 917 bad: 918 if (interp) 919 pool_put(&namei_pool, interp); 920 free(ph, M_TEMP, phsize); 921 kill_vmcmds(&epp->ep_vmcmds); 922 if (error == 0) 923 return (ENOEXEC); 924 return (error); 925 } 926 927 /* 928 * Phase II of load. It is now safe to load the interpreter. Info collected 929 * when loading the program is available for setup of the interpreter. 930 */ 931 int 932 exec_elf_fixup(struct proc *p, struct exec_package *epp) 933 { 934 char *interp; 935 int error = 0; 936 struct elf_args *ap; 937 AuxInfo ai[ELF_AUX_ENTRIES], *a; 938 939 ap = epp->ep_args; 940 if (ap == NULL) { 941 return (0); 942 } 943 944 interp = epp->ep_interp; 945 946 /* disable kbind in programs that don't use ld.so */ 947 if (interp == NULL) 948 p->p_p->ps_kbind_addr = BOGO_PC; 949 950 if (interp && 951 (error = elf_load_file(p, interp, epp, ap)) != 0) { 952 uprintf("execve: cannot load %s\n", interp); 953 free(ap, M_TEMP, sizeof *ap); 954 pool_put(&namei_pool, interp); 955 kill_vmcmds(&epp->ep_vmcmds); 956 return (error); 957 } 958 /* 959 * We have to do this ourselves... 960 */ 961 error = exec_process_vmcmds(p, epp); 962 963 /* 964 * Push extra arguments on the stack needed by dynamically 965 * linked binaries 966 */ 967 if (error == 0) { 968 memset(&ai, 0, sizeof ai); 969 a = ai; 970 971 a->au_id = AUX_phdr; 972 a->au_v = ap->arg_phaddr; 973 a++; 974 975 a->au_id = AUX_phent; 976 a->au_v = ap->arg_phentsize; 977 a++; 978 979 a->au_id = AUX_phnum; 980 a->au_v = ap->arg_phnum; 981 a++; 982 983 a->au_id = AUX_pagesz; 984 a->au_v = PAGE_SIZE; 985 a++; 986 987 a->au_id = AUX_base; 988 a->au_v = ap->arg_interp; 989 a++; 990 991 a->au_id = AUX_flags; 992 a->au_v = 0; 993 a++; 994 995 a->au_id = AUX_entry; 996 a->au_v = ap->arg_entry; 997 a++; 998 999 #ifdef __HAVE_CPU_HWCAP 1000 a->au_id = AUX_hwcap; 1001 a->au_v = hwcap; 1002 a++; 1003 #endif /* __HAVE_CPU_HWCAP */ 1004 1005 #ifdef __HAVE_CPU_HWCAP2 1006 a->au_id = AUX_hwcap2; 1007 a->au_v = hwcap2; 1008 a++; 1009 #endif /* __HAVE_CPU_HWCAP2 */ 1010 1011 a->au_id = AUX_openbsd_timekeep; 1012 a->au_v = p->p_p->ps_timekeep; 1013 a++; 1014 1015 a->au_id = AUX_null; 1016 a->au_v = 0; 1017 a++; 1018 1019 error = copyout(ai, epp->ep_auxinfo, sizeof ai); 1020 } 1021 free(ap, M_TEMP, sizeof *ap); 1022 if (interp) 1023 pool_put(&namei_pool, interp); 1024 return (error); 1025 } 1026 1027 int 1028 elf_os_pt_note_name(Elf_Note *np) 1029 { 1030 int i, j; 1031 1032 for (i = 0; i < nitems(elf_note_names); i++) { 1033 size_t namlen = strlen(elf_note_names[i].name); 1034 if (np->namesz < namlen) 1035 continue; 1036 /* verify name padding (after the NUL) is NUL */ 1037 for (j = namlen + 1; j < elfround(np->namesz); j++) 1038 if (((char *)(np + 1))[j] != '\0') 1039 continue; 1040 /* verify desc padding is NUL */ 1041 for (j = np->descsz; j < elfround(np->descsz); j++) 1042 if (((char *)(np + 1))[j] != '\0') 1043 continue; 1044 if (strcmp((char *)(np + 1), elf_note_names[i].name) == 0) 1045 return elf_note_names[i].id; 1046 } 1047 return (0); 1048 } 1049 1050 int 1051 elf_os_pt_note(struct proc *p, struct exec_package *epp, Elf_Ehdr *eh, int *namesp) 1052 { 1053 Elf_Phdr *hph, *ph; 1054 Elf_Note *np = NULL; 1055 size_t phsize, offset, pfilesz = 0, total; 1056 int error, names = 0; 1057 1058 hph = mallocarray(eh->e_phnum, sizeof(Elf_Phdr), M_TEMP, M_WAITOK); 1059 phsize = eh->e_phnum * sizeof(Elf_Phdr); 1060 if ((error = elf_read_from(p, epp->ep_vp, eh->e_phoff, 1061 hph, phsize)) != 0) 1062 goto out1; 1063 1064 for (ph = hph; ph < &hph[eh->e_phnum]; ph++) { 1065 if (ph->p_type == PT_OPENBSD_WXNEEDED) { 1066 epp->ep_flags |= EXEC_WXNEEDED; 1067 continue; 1068 } 1069 if (ph->p_type == PT_OPENBSD_NOBTCFI) { 1070 epp->ep_flags |= EXEC_NOBTCFI; 1071 continue; 1072 } 1073 1074 if (ph->p_type != PT_NOTE || ph->p_filesz > 1024) 1075 continue; 1076 1077 if (np && ph->p_filesz != pfilesz) { 1078 free(np, M_TEMP, pfilesz); 1079 np = NULL; 1080 } 1081 if (!np) 1082 np = malloc(ph->p_filesz, M_TEMP, M_WAITOK); 1083 pfilesz = ph->p_filesz; 1084 if ((error = elf_read_from(p, epp->ep_vp, ph->p_offset, 1085 np, ph->p_filesz)) != 0) 1086 goto out2; 1087 1088 for (offset = 0; offset < ph->p_filesz; offset += total) { 1089 Elf_Note *np2 = (Elf_Note *)((char *)np + offset); 1090 1091 if (offset + sizeof(Elf_Note) > ph->p_filesz) 1092 break; 1093 total = sizeof(Elf_Note) + elfround(np2->namesz) + 1094 elfround(np2->descsz); 1095 if (offset + total > ph->p_filesz) 1096 break; 1097 names |= elf_os_pt_note_name(np2); 1098 } 1099 } 1100 1101 out2: 1102 free(np, M_TEMP, pfilesz); 1103 out1: 1104 free(hph, M_TEMP, phsize); 1105 *namesp = names; 1106 return ((names & ELF_NOTE_NAME_OPENBSD) ? 0 : ENOEXEC); 1107 } 1108 1109 /* 1110 * Start of routines related to dumping core 1111 */ 1112 1113 #ifdef SMALL_KERNEL 1114 int 1115 coredump_elf(struct proc *p, void *cookie) 1116 { 1117 return EPERM; 1118 } 1119 #else /* !SMALL_KERNEL */ 1120 1121 struct writesegs_state { 1122 off_t notestart; 1123 off_t secstart; 1124 off_t secoff; 1125 struct proc *p; 1126 void *iocookie; 1127 Elf_Phdr *psections; 1128 size_t psectionslen; 1129 size_t notesize; 1130 int npsections; 1131 }; 1132 1133 uvm_coredump_setup_cb coredump_setup_elf; 1134 uvm_coredump_walk_cb coredump_walk_elf; 1135 1136 int coredump_notes_elf(struct proc *, void *, size_t *); 1137 int coredump_note_elf(struct proc *, void *, size_t *); 1138 int coredump_writenote_elf(struct proc *, void *, Elf_Note *, 1139 const char *, void *); 1140 1141 extern vaddr_t sigcode_va; 1142 extern vsize_t sigcode_sz; 1143 1144 int 1145 coredump_elf(struct proc *p, void *cookie) 1146 { 1147 #ifdef DIAGNOSTIC 1148 off_t offset; 1149 #endif 1150 struct writesegs_state ws; 1151 size_t notesize; 1152 int error, i; 1153 1154 ws.p = p; 1155 ws.iocookie = cookie; 1156 ws.psections = NULL; 1157 1158 /* 1159 * Walk the map to get all the segment offsets and lengths, 1160 * write out the ELF header. 1161 */ 1162 error = uvm_coredump_walkmap(p, coredump_setup_elf, 1163 coredump_walk_elf, &ws); 1164 if (error) 1165 goto out; 1166 1167 error = coredump_write(cookie, UIO_SYSSPACE, ws.psections, 1168 ws.psectionslen, 0); 1169 if (error) 1170 goto out; 1171 1172 /* Write out the notes. */ 1173 error = coredump_notes_elf(p, cookie, ¬esize); 1174 if (error) 1175 goto out; 1176 1177 #ifdef DIAGNOSTIC 1178 if (notesize != ws.notesize) 1179 panic("coredump: notesize changed: %zu != %zu", 1180 ws.notesize, notesize); 1181 offset = ws.notestart + notesize; 1182 if (offset != ws.secstart) 1183 panic("coredump: offset %lld != secstart %lld", 1184 (long long) offset, (long long) ws.secstart); 1185 #endif 1186 1187 /* Pass 3: finally, write the sections themselves. */ 1188 for (i = 0; i < ws.npsections - 1; i++) { 1189 Elf_Phdr *pent = &ws.psections[i]; 1190 if (pent->p_filesz == 0) 1191 continue; 1192 1193 #ifdef DIAGNOSTIC 1194 if (offset != pent->p_offset) 1195 panic("coredump: offset %lld != p_offset[%d] %lld", 1196 (long long) offset, i, 1197 (long long) pent->p_filesz); 1198 #endif 1199 1200 /* 1201 * Since the sigcode is mapped execute-only, we can't 1202 * read it. So use the kernel mapping for it instead. 1203 */ 1204 if (pent->p_vaddr == p->p_p->ps_sigcode && 1205 pent->p_filesz == sigcode_sz) { 1206 error = coredump_write(cookie, UIO_SYSSPACE, 1207 (void *)sigcode_va, sigcode_sz, 0); 1208 } else { 1209 error = coredump_write(cookie, UIO_USERSPACE, 1210 (void *)(vaddr_t)pent->p_vaddr, pent->p_filesz, 1211 (pent->p_flags & PF_ISVNODE)); 1212 } 1213 if (error) 1214 goto out; 1215 1216 coredump_unmap(cookie, (vaddr_t)pent->p_vaddr, 1217 (vaddr_t)pent->p_vaddr + pent->p_filesz); 1218 1219 #ifdef DIAGNOSTIC 1220 offset += ws.psections[i].p_filesz; 1221 #endif 1222 } 1223 1224 out: 1225 free(ws.psections, M_TEMP, ws.psectionslen); 1226 return (error); 1227 } 1228 1229 1230 /* 1231 * Normally we lay out core files like this: 1232 * [ELF Header] [Program headers] [Notes] [data for PT_LOAD segments] 1233 * 1234 * However, if there's >= 65535 segments then it overflows the field 1235 * in the ELF header, so the standard specifies putting a magic 1236 * number there and saving the real count in the .sh_info field of 1237 * the first *section* header...which requires generating a section 1238 * header. To avoid confusing tools, we include an .shstrtab section 1239 * as well so all the indexes look valid. So in this case we lay 1240 * out the core file like this: 1241 * [ELF Header] [Section Headers] [.shstrtab] [Program headers] \ 1242 * [Notes] [data for PT_LOAD segments] 1243 * 1244 * The 'shstrtab' structure below is data for the second of the two 1245 * section headers, plus the .shstrtab itself, in one const buffer. 1246 */ 1247 static const struct { 1248 Elf_Shdr shdr; 1249 char shstrtab[sizeof(ELF_SHSTRTAB) + 1]; 1250 } shstrtab = { 1251 .shdr = { 1252 .sh_name = 1, /* offset in .shstrtab below */ 1253 .sh_type = SHT_STRTAB, 1254 .sh_offset = sizeof(Elf_Ehdr) + 2*sizeof(Elf_Shdr), 1255 .sh_size = sizeof(ELF_SHSTRTAB) + 1, 1256 .sh_addralign = 1, 1257 }, 1258 .shstrtab = "\0" ELF_SHSTRTAB, 1259 }; 1260 1261 int 1262 coredump_setup_elf(int segment_count, void *cookie) 1263 { 1264 Elf_Ehdr ehdr; 1265 struct writesegs_state *ws = cookie; 1266 Elf_Phdr *note; 1267 int error; 1268 1269 /* Get the count of segments, plus one for the PT_NOTE */ 1270 ws->npsections = segment_count + 1; 1271 1272 /* Get the size of the notes. */ 1273 error = coredump_notes_elf(ws->p, NULL, &ws->notesize); 1274 if (error) 1275 return error; 1276 1277 /* Setup the ELF header */ 1278 memset(&ehdr, 0, sizeof(ehdr)); 1279 memcpy(ehdr.e_ident, ELFMAG, SELFMAG); 1280 ehdr.e_ident[EI_CLASS] = ELF_TARG_CLASS; 1281 ehdr.e_ident[EI_DATA] = ELF_TARG_DATA; 1282 ehdr.e_ident[EI_VERSION] = EV_CURRENT; 1283 /* XXX Should be the OSABI/ABI version of the executable. */ 1284 ehdr.e_ident[EI_OSABI] = ELFOSABI_SYSV; 1285 ehdr.e_ident[EI_ABIVERSION] = 0; 1286 ehdr.e_type = ET_CORE; 1287 /* XXX This should be the e_machine of the executable. */ 1288 ehdr.e_machine = ELF_TARG_MACH; 1289 ehdr.e_version = EV_CURRENT; 1290 ehdr.e_entry = 0; 1291 ehdr.e_flags = 0; 1292 ehdr.e_ehsize = sizeof(ehdr); 1293 ehdr.e_phentsize = sizeof(Elf_Phdr); 1294 1295 if (ws->npsections < PN_XNUM) { 1296 ehdr.e_phoff = sizeof(ehdr); 1297 ehdr.e_shoff = 0; 1298 ehdr.e_phnum = ws->npsections; 1299 ehdr.e_shentsize = 0; 1300 ehdr.e_shnum = 0; 1301 ehdr.e_shstrndx = 0; 1302 } else { 1303 /* too many segments, use extension setup */ 1304 ehdr.e_shoff = sizeof(ehdr); 1305 ehdr.e_phnum = PN_XNUM; 1306 ehdr.e_shentsize = sizeof(Elf_Shdr); 1307 ehdr.e_shnum = 2; 1308 ehdr.e_shstrndx = 1; 1309 ehdr.e_phoff = shstrtab.shdr.sh_offset + shstrtab.shdr.sh_size; 1310 } 1311 1312 /* Write out the ELF header. */ 1313 error = coredump_write(ws->iocookie, UIO_SYSSPACE, &ehdr, sizeof(ehdr), 0); 1314 if (error) 1315 return error; 1316 1317 /* 1318 * If an section header is needed to store extension info, write 1319 * it out after the ELF header and before the program header. 1320 */ 1321 if (ehdr.e_shnum != 0) { 1322 Elf_Shdr shdr = { .sh_info = ws->npsections }; 1323 error = coredump_write(ws->iocookie, UIO_SYSSPACE, &shdr, 1324 sizeof shdr, 0); 1325 if (error) 1326 return error; 1327 error = coredump_write(ws->iocookie, UIO_SYSSPACE, &shstrtab, 1328 sizeof(shstrtab.shdr) + sizeof(shstrtab.shstrtab), 0); 1329 if (error) 1330 return error; 1331 } 1332 1333 /* 1334 * Allocate the segment header array and setup to collect 1335 * the section sizes and offsets 1336 */ 1337 ws->psections = mallocarray(ws->npsections, sizeof(Elf_Phdr), 1338 M_TEMP, M_WAITOK|M_CANFAIL|M_ZERO); 1339 if (ws->psections == NULL) 1340 return ENOMEM; 1341 ws->psectionslen = ws->npsections * sizeof(Elf_Phdr); 1342 1343 ws->notestart = ehdr.e_phoff + ws->psectionslen; 1344 ws->secstart = ws->notestart + ws->notesize; 1345 ws->secoff = ws->secstart; 1346 1347 /* Fill in the PT_NOTE segment header in the last slot */ 1348 note = &ws->psections[ws->npsections - 1]; 1349 note->p_type = PT_NOTE; 1350 note->p_offset = ws->notestart; 1351 note->p_vaddr = 0; 1352 note->p_paddr = 0; 1353 note->p_filesz = ws->notesize; 1354 note->p_memsz = 0; 1355 note->p_flags = PF_R; 1356 note->p_align = ELFROUNDSIZE; 1357 1358 return (0); 1359 } 1360 1361 int 1362 coredump_walk_elf(vaddr_t start, vaddr_t realend, vaddr_t end, vm_prot_t prot, 1363 int isvnode, int nsegment, void *cookie) 1364 { 1365 struct writesegs_state *ws = cookie; 1366 Elf_Phdr phdr; 1367 vsize_t size, realsize; 1368 1369 size = end - start; 1370 realsize = realend - start; 1371 1372 phdr.p_type = PT_LOAD; 1373 phdr.p_offset = ws->secoff; 1374 phdr.p_vaddr = start; 1375 phdr.p_paddr = 0; 1376 phdr.p_filesz = realsize; 1377 phdr.p_memsz = size; 1378 phdr.p_flags = 0; 1379 if (prot & PROT_READ) 1380 phdr.p_flags |= PF_R; 1381 if (prot & PROT_WRITE) 1382 phdr.p_flags |= PF_W; 1383 if (prot & PROT_EXEC) 1384 phdr.p_flags |= PF_X; 1385 if (isvnode) 1386 phdr.p_flags |= PF_ISVNODE; 1387 phdr.p_align = PAGE_SIZE; 1388 1389 ws->secoff += phdr.p_filesz; 1390 ws->psections[nsegment] = phdr; 1391 1392 return (0); 1393 } 1394 1395 int 1396 coredump_notes_elf(struct proc *p, void *iocookie, size_t *sizep) 1397 { 1398 struct elfcore_procinfo cpi; 1399 Elf_Note nhdr; 1400 struct process *pr = p->p_p; 1401 struct proc *q; 1402 size_t size, notesize; 1403 int error; 1404 1405 KASSERT(!P_HASSIBLING(p) || pr->ps_single != NULL); 1406 size = 0; 1407 1408 /* First, write an elfcore_procinfo. */ 1409 notesize = sizeof(nhdr) + elfround(sizeof("OpenBSD")) + 1410 elfround(sizeof(cpi)); 1411 if (iocookie) { 1412 memset(&cpi, 0, sizeof(cpi)); 1413 1414 cpi.cpi_version = ELFCORE_PROCINFO_VERSION; 1415 cpi.cpi_cpisize = sizeof(cpi); 1416 cpi.cpi_signo = p->p_sisig; 1417 cpi.cpi_sigcode = p->p_sicode; 1418 1419 cpi.cpi_sigpend = p->p_siglist | pr->ps_siglist; 1420 cpi.cpi_sigmask = p->p_sigmask; 1421 cpi.cpi_sigignore = pr->ps_sigacts->ps_sigignore; 1422 cpi.cpi_sigcatch = pr->ps_sigacts->ps_sigcatch; 1423 1424 cpi.cpi_pid = pr->ps_pid; 1425 cpi.cpi_ppid = pr->ps_ppid; 1426 cpi.cpi_pgrp = pr->ps_pgid; 1427 if (pr->ps_session->s_leader) 1428 cpi.cpi_sid = pr->ps_session->s_leader->ps_pid; 1429 else 1430 cpi.cpi_sid = 0; 1431 1432 cpi.cpi_ruid = p->p_ucred->cr_ruid; 1433 cpi.cpi_euid = p->p_ucred->cr_uid; 1434 cpi.cpi_svuid = p->p_ucred->cr_svuid; 1435 1436 cpi.cpi_rgid = p->p_ucred->cr_rgid; 1437 cpi.cpi_egid = p->p_ucred->cr_gid; 1438 cpi.cpi_svgid = p->p_ucred->cr_svgid; 1439 1440 (void)strlcpy(cpi.cpi_name, pr->ps_comm, sizeof(cpi.cpi_name)); 1441 1442 nhdr.namesz = sizeof("OpenBSD"); 1443 nhdr.descsz = sizeof(cpi); 1444 nhdr.type = NT_OPENBSD_PROCINFO; 1445 1446 error = coredump_writenote_elf(p, iocookie, &nhdr, 1447 "OpenBSD", &cpi); 1448 if (error) 1449 return (error); 1450 } 1451 size += notesize; 1452 1453 /* Second, write an NT_OPENBSD_AUXV note. */ 1454 notesize = sizeof(nhdr) + elfround(sizeof("OpenBSD")) + 1455 elfround(ELF_AUX_WORDS * sizeof(char *)); 1456 if (iocookie && pr->ps_auxinfo) { 1457 1458 nhdr.namesz = sizeof("OpenBSD"); 1459 nhdr.descsz = ELF_AUX_WORDS * sizeof(char *); 1460 nhdr.type = NT_OPENBSD_AUXV; 1461 1462 error = coredump_write(iocookie, UIO_SYSSPACE, 1463 &nhdr, sizeof(nhdr), 0); 1464 if (error) 1465 return (error); 1466 1467 error = coredump_write(iocookie, UIO_SYSSPACE, 1468 "OpenBSD", elfround(nhdr.namesz), 0); 1469 if (error) 1470 return (error); 1471 1472 error = coredump_write(iocookie, UIO_USERSPACE, 1473 (caddr_t)pr->ps_auxinfo, nhdr.descsz, 0); 1474 if (error) 1475 return (error); 1476 } 1477 size += notesize; 1478 1479 #ifdef PT_WCOOKIE 1480 notesize = sizeof(nhdr) + elfround(sizeof("OpenBSD")) + 1481 elfround(sizeof(register_t)); 1482 if (iocookie) { 1483 register_t wcookie; 1484 1485 nhdr.namesz = sizeof("OpenBSD"); 1486 nhdr.descsz = sizeof(register_t); 1487 nhdr.type = NT_OPENBSD_WCOOKIE; 1488 1489 wcookie = process_get_wcookie(p); 1490 error = coredump_writenote_elf(p, iocookie, &nhdr, 1491 "OpenBSD", &wcookie); 1492 if (error) 1493 return (error); 1494 } 1495 size += notesize; 1496 #endif 1497 1498 /* 1499 * Now write the register info for the thread that caused the 1500 * coredump. 1501 */ 1502 error = coredump_note_elf(p, iocookie, ¬esize); 1503 if (error) 1504 return (error); 1505 size += notesize; 1506 1507 /* 1508 * Now, for each thread, write the register info and any other 1509 * per-thread notes. Since we're dumping core, all the other 1510 * threads in the process have been stopped and the list can't 1511 * change. 1512 */ 1513 TAILQ_FOREACH(q, &pr->ps_threads, p_thr_link) { 1514 if (q == p) /* we've taken care of this thread */ 1515 continue; 1516 error = coredump_note_elf(q, iocookie, ¬esize); 1517 if (error) 1518 return (error); 1519 size += notesize; 1520 } 1521 1522 *sizep = size; 1523 return (0); 1524 } 1525 1526 int 1527 coredump_note_elf(struct proc *p, void *iocookie, size_t *sizep) 1528 { 1529 Elf_Note nhdr; 1530 int size, notesize, error; 1531 int namesize; 1532 char name[64+ELFROUNDSIZE]; 1533 struct reg intreg; 1534 #ifdef PT_GETFPREGS 1535 struct fpreg freg; 1536 #endif 1537 #ifdef PT_PACMASK 1538 register_t pacmask[2]; 1539 #endif 1540 1541 size = 0; 1542 1543 snprintf(name, sizeof(name)-ELFROUNDSIZE, "%s@%d", 1544 "OpenBSD", p->p_tid + THREAD_PID_OFFSET); 1545 namesize = strlen(name) + 1; 1546 memset(name + namesize, 0, elfround(namesize) - namesize); 1547 1548 notesize = sizeof(nhdr) + elfround(namesize) + elfround(sizeof(intreg)); 1549 if (iocookie) { 1550 error = process_read_regs(p, &intreg); 1551 if (error) 1552 return (error); 1553 1554 nhdr.namesz = namesize; 1555 nhdr.descsz = sizeof(intreg); 1556 nhdr.type = NT_OPENBSD_REGS; 1557 1558 error = coredump_writenote_elf(p, iocookie, &nhdr, 1559 name, &intreg); 1560 if (error) 1561 return (error); 1562 1563 } 1564 size += notesize; 1565 1566 #ifdef PT_GETFPREGS 1567 notesize = sizeof(nhdr) + elfround(namesize) + elfround(sizeof(freg)); 1568 if (iocookie) { 1569 error = process_read_fpregs(p, &freg); 1570 if (error) 1571 return (error); 1572 1573 nhdr.namesz = namesize; 1574 nhdr.descsz = sizeof(freg); 1575 nhdr.type = NT_OPENBSD_FPREGS; 1576 1577 error = coredump_writenote_elf(p, iocookie, &nhdr, name, &freg); 1578 if (error) 1579 return (error); 1580 } 1581 size += notesize; 1582 #endif 1583 1584 #ifdef PT_PACMASK 1585 notesize = sizeof(nhdr) + elfround(namesize) + 1586 elfround(sizeof(pacmask)); 1587 if (iocookie) { 1588 pacmask[0] = pacmask[1] = process_get_pacmask(p); 1589 1590 nhdr.namesz = namesize; 1591 nhdr.descsz = sizeof(pacmask); 1592 nhdr.type = NT_OPENBSD_PACMASK; 1593 1594 error = coredump_writenote_elf(p, iocookie, &nhdr, 1595 name, &pacmask); 1596 if (error) 1597 return (error); 1598 } 1599 size += notesize; 1600 #endif 1601 1602 *sizep = size; 1603 /* XXX Add hook for machdep per-LWP notes. */ 1604 return (0); 1605 } 1606 1607 int 1608 coredump_writenote_elf(struct proc *p, void *cookie, Elf_Note *nhdr, 1609 const char *name, void *data) 1610 { 1611 int error; 1612 1613 error = coredump_write(cookie, UIO_SYSSPACE, nhdr, sizeof(*nhdr), 0); 1614 if (error) 1615 return error; 1616 1617 error = coredump_write(cookie, UIO_SYSSPACE, name, 1618 elfround(nhdr->namesz), 0); 1619 if (error) 1620 return error; 1621 1622 return coredump_write(cookie, UIO_SYSSPACE, data, nhdr->descsz, 0); 1623 } 1624 #endif /* !SMALL_KERNEL */ 1625