1 /*- 2 * Copyright (c) 2003 Kip Macy 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $DragonFly: src/sys/kern/kern_checkpoint.c,v 1.6 2005/10/27 03:15:47 sephe Exp $ 27 */ 28 29 #include <sys/types.h> 30 #include <sys/param.h> 31 #include <sys/proc.h> 32 #include <sys/module.h> 33 #include <sys/sysent.h> 34 #include <sys/kernel.h> 35 #include <sys/systm.h> 36 #include <sys/nlookup.h> 37 38 #include <sys/file.h> 39 /* only on dragonfly */ 40 #include <sys/file2.h> 41 #include <sys/fcntl.h> 42 #include <sys/signal.h> 43 #include <vm/vm_param.h> 44 #include <vm/vm.h> 45 #include <sys/imgact_elf.h> 46 #include <sys/procfs.h> 47 48 #include <sys/lock.h> 49 #include <vm/pmap.h> 50 #include <vm/vm_map.h> 51 #include <vm/vm_extern.h> 52 #include <sys/mman.h> 53 #include <sys/sysent.h> 54 #include <sys/sysproto.h> 55 #include <sys/resource.h> 56 #include <sys/resourcevar.h> 57 #include <sys/malloc.h> 58 #include <sys/stat.h> 59 #include <sys/uio.h> 60 #include <sys/namei.h> 61 #include <sys/vnode.h> 62 #include <machine/limits.h> 63 #include <i386/include/frame.h> 64 #include <sys/signalvar.h> 65 #include <sys/syslog.h> 66 #include <sys/sysctl.h> 67 #include <i386/include/sigframe.h> 68 #include <sys/exec.h> 69 #include <sys/unistd.h> 70 #include <sys/time.h> 71 #include <sys/kern_syscall.h> 72 #include <sys/checkpoint.h> 73 #include <sys/mount.h> 74 #include <sys/ckpt.h> 75 76 77 static int elf_loadphdrs(struct file *fp, Elf_Phdr *phdr, int numsegs); 78 static int elf_getnotes(struct proc *p, struct file *fp, size_t notesz); 79 static int elf_demarshalnotes(void *src, prpsinfo_t *psinfo, 80 prstatus_t *status, prfpregset_t *fpregset, int nthreads); 81 static int elf_loadnotes(struct proc *, prpsinfo_t *, prstatus_t *, 82 prfpregset_t *); 83 static int elf_getsigs(struct proc *p, struct file *fp); 84 static int elf_getfiles(struct proc *p, struct file *fp); 85 static int elf_gettextvp(struct proc *p, struct file *fp); 86 static char *ckpt_expand_name(const char *name, uid_t uid, pid_t pid); 87 88 static int ckptgroup = 0; /* wheel only, -1 for any group */ 89 SYSCTL_INT(_kern, OID_AUTO, ckptgroup, CTLFLAG_RW, &ckptgroup, 0, ""); 90 91 /* ref count to see how many processes that are being checkpointed */ 92 static int chptinuse = 0; 93 94 static __inline 95 int 96 read_check(struct file *fp, void *buf, size_t nbyte) 97 { 98 size_t nread; 99 int error; 100 101 PRINTF(("reading %d bytes\n", nbyte)); 102 error = fp_read(fp, buf, nbyte, &nread, 1); 103 if (error) { 104 PRINTF(("read failed - %d", error)); 105 } else if (nread != nbyte) { 106 PRINTF(("wanted to read %d - read %d\n", nbyte, nread)); 107 error = EINVAL; 108 } 109 return error; 110 } 111 112 static int 113 elf_gethdr(struct file *fp, Elf_Ehdr *ehdr) 114 { 115 size_t nbyte = sizeof(Elf_Ehdr); 116 int error; 117 118 if ((error = read_check(fp, ehdr, nbyte)) != 0) 119 goto done; 120 if (!(ehdr->e_ehsize == sizeof(Elf_Ehdr))) { 121 PRINTF(("wrong elf header size: %d\n" 122 "expected size : %d\n", 123 ehdr->e_ehsize, sizeof(Elf_Ehdr))); 124 return EINVAL; 125 } 126 if (!(ehdr->e_phentsize == sizeof(Elf_Phdr))) { 127 PRINTF(("wrong program header size: %d\n" 128 "expected size : %d\n", 129 ehdr->e_phentsize, sizeof(Elf_Phdr))); 130 return EINVAL; 131 } 132 133 if (!(ehdr->e_ident[EI_MAG0] == ELFMAG0 && 134 ehdr->e_ident[EI_MAG1] == ELFMAG1 && 135 ehdr->e_ident[EI_MAG2] == ELFMAG2 && 136 ehdr->e_ident[EI_MAG3] == ELFMAG3 && 137 ehdr->e_ident[EI_CLASS] == ELF_CLASS && 138 ehdr->e_ident[EI_DATA] == ELF_DATA && 139 ehdr->e_ident[EI_VERSION] == EV_CURRENT && 140 ehdr->e_ident[EI_OSABI] == ELFOSABI_FREEBSD && 141 ehdr->e_ident[EI_ABIVERSION] == 0)) { 142 PRINTF(("bad elf header\n there are %d segments\n", 143 ehdr->e_phnum)); 144 return EINVAL; 145 146 } 147 PRINTF(("Elf header size: %d\n", ehdr->e_ehsize)); 148 PRINTF(("Program header size: %d\n", ehdr->e_phentsize)); 149 PRINTF(("Number of Program headers: %d\n", ehdr->e_phnum)); 150 done: 151 return error; 152 } 153 154 static int 155 elf_getphdrs(struct file *fp, Elf_Phdr *phdr, size_t nbyte) 156 { 157 int i; 158 int error; 159 int nheaders = nbyte/sizeof(Elf_Phdr); 160 161 PRINTF(("reading phdrs section\n")); 162 if ((error = read_check(fp, phdr, nbyte)) != 0) 163 goto done; 164 printf("headers section:\n"); 165 for (i = 0; i < nheaders; i++) { 166 printf("entry type: %d\n", phdr[i].p_type); 167 printf("file offset: %d\n", phdr[i].p_offset); 168 printf("virt address: %p\n", (uint32_t *)phdr[i].p_vaddr); 169 printf("file size: %d\n", phdr[i].p_filesz); 170 printf("memory size: %d\n", phdr[i].p_memsz); 171 printf("\n"); 172 } 173 done: 174 return error; 175 } 176 177 178 static int 179 elf_getnotes(struct proc *p, struct file *fp, size_t notesz) 180 { 181 int error; 182 int nthreads; 183 char *note; 184 prpsinfo_t *psinfo; 185 prstatus_t *status; 186 prfpregset_t *fpregset; 187 188 nthreads = (notesz - sizeof(prpsinfo_t))/(sizeof(prstatus_t) + 189 sizeof(prfpregset_t)); 190 PRINTF(("reading notes header nthreads=%d\n", nthreads)); 191 if (nthreads <= 0 || nthreads > CKPT_MAXTHREADS) 192 return EINVAL; 193 194 psinfo = malloc(sizeof(prpsinfo_t), M_TEMP, M_ZERO | M_WAITOK); 195 status = malloc(nthreads*sizeof(prstatus_t), M_TEMP, M_WAITOK); 196 fpregset = malloc(nthreads*sizeof(prfpregset_t), M_TEMP, M_WAITOK); 197 note = malloc(notesz, M_TEMP, M_WAITOK); 198 199 200 PRINTF(("reading notes section\n")); 201 if ((error = read_check(fp, note, notesz)) != 0) 202 goto done; 203 error = elf_demarshalnotes(note, psinfo, status, fpregset, nthreads); 204 if (error) 205 goto done; 206 /* fetch register state from notes */ 207 error = elf_loadnotes(p, psinfo, status, fpregset); 208 done: 209 if (psinfo) 210 free(psinfo, M_TEMP); 211 if (status) 212 free(status, M_TEMP); 213 if (fpregset) 214 free(fpregset, M_TEMP); 215 if (note) 216 free(note, M_TEMP); 217 return error; 218 } 219 220 static int 221 ckpt_thaw_proc(struct proc *p, struct file *fp) 222 { 223 224 Elf_Phdr *phdr = NULL; 225 Elf_Ehdr *ehdr = NULL; 226 int error; 227 size_t nbyte; 228 229 TRACE_ENTER; 230 231 ehdr = malloc(sizeof(Elf_Ehdr), M_TEMP, M_ZERO | M_WAITOK); 232 233 if ((error = elf_gethdr(fp, ehdr)) != 0) 234 goto done; 235 nbyte = sizeof(Elf_Phdr) * ehdr->e_phnum; 236 phdr = malloc(nbyte, M_TEMP, M_WAITOK); 237 238 /* fetch description of program writable mappings */ 239 if ((error = elf_getphdrs(fp, phdr, nbyte)) != 0) 240 goto done; 241 242 /* fetch notes section containing register state */ 243 if ((error = elf_getnotes(p, fp, phdr->p_filesz)) != 0) 244 goto done; 245 246 /* fetch program text vnodes */ 247 if ((error = elf_gettextvp(p, fp)) != 0) 248 goto done; 249 250 /* fetch signal disposition */ 251 if ((error = elf_getsigs(p, fp)) != 0) { 252 printf("failure in recovering signals\n"); 253 goto done; 254 } 255 256 /* fetch open files */ 257 if ((error = elf_getfiles(p, fp)) != 0) 258 goto done; 259 260 /* handle mappings last in case we are reading from a socket */ 261 error = elf_loadphdrs(fp, phdr, ehdr->e_phnum); 262 263 /* 264 * Set the textvp to the checkpoint file and mark the vnode so 265 * a future checkpointing of this checkpoint-restored program 266 * will copy out the contents of the mappings rather then trying 267 * to record the vnode info related to the checkpoint file, which 268 * is likely going to be destroyed when the program is re-checkpointed. 269 */ 270 if (error == 0 && fp->f_data && fp->f_type == DTYPE_VNODE) { 271 if (p->p_textvp) 272 vrele(p->p_textvp); 273 p->p_textvp = (struct vnode *)fp->f_data; 274 p->p_textvp->v_flag |= VCKPT; 275 vref(p->p_textvp); 276 } 277 done: 278 if (ehdr) 279 free(ehdr, M_TEMP); 280 if (phdr) 281 free(phdr, M_TEMP); 282 TRACE_EXIT; 283 return error; 284 } 285 286 static int 287 elf_loadnotes(struct proc *p, prpsinfo_t *psinfo, prstatus_t *status, 288 prfpregset_t *fpregset) 289 { 290 int error; 291 292 /* validate status and psinfo */ 293 TRACE_ENTER; 294 if (status->pr_version != PRSTATUS_VERSION || 295 status->pr_statussz != sizeof(prstatus_t) || 296 status->pr_gregsetsz != sizeof(gregset_t) || 297 status->pr_fpregsetsz != sizeof(fpregset_t) || 298 psinfo->pr_version != PRPSINFO_VERSION || 299 psinfo->pr_psinfosz != sizeof(prpsinfo_t)) { 300 PRINTF(("status check failed\n")); 301 error = EINVAL; 302 goto done; 303 } 304 if ((error = set_regs(&p->p_lwp, &status->pr_reg)) != 0) 305 goto done; 306 error = set_fpregs(&p->p_lwp, fpregset); 307 strlcpy(p->p_comm, psinfo->pr_fname, sizeof(p->p_comm)); 308 /* XXX psinfo->pr_psargs not yet implemented */ 309 done: 310 TRACE_EXIT; 311 return error; 312 } 313 314 static int 315 elf_getnote(void *src, size_t *off, const char *name, unsigned int type, 316 void **desc, size_t descsz) 317 { 318 Elf_Note note; 319 int error; 320 321 TRACE_ENTER; 322 if (src == NULL) { 323 error = EFAULT; 324 goto done; 325 } 326 bcopy((char *)src + *off, ¬e, sizeof note); 327 328 PRINTF(("at offset: %d expected note of type: %d - got: %d\n", 329 *off, type, note.n_type)); 330 *off += sizeof note; 331 if (type != note.n_type) { 332 TRACE_ERR; 333 error = EINVAL; 334 goto done; 335 } 336 if (strncmp(name, (char *) src + *off, note.n_namesz) != 0) { 337 error = EINVAL; 338 goto done; 339 } 340 *off += roundup2(note.n_namesz, sizeof(Elf_Size)); 341 if (note.n_descsz != descsz) { 342 TRACE_ERR; 343 error = EINVAL; 344 goto done; 345 } 346 if (desc) 347 bcopy((char *)src + *off, *desc, note.n_descsz); 348 *off += roundup2(note.n_descsz, sizeof(Elf_Size)); 349 error = 0; 350 done: 351 TRACE_EXIT; 352 return error; 353 } 354 355 static int 356 elf_demarshalnotes(void *src, prpsinfo_t *psinfo, prstatus_t *status, 357 prfpregset_t *fpregset, int nthreads) 358 { 359 int i; 360 int error; 361 int off = 0; 362 363 TRACE_ENTER; 364 error = elf_getnote(src, &off, "FreeBSD", NT_PRSTATUS, 365 (void **)&status, sizeof(prstatus_t)); 366 if (error) 367 goto done; 368 error = elf_getnote(src, &off, "FreeBSD", NT_FPREGSET, 369 (void **)&fpregset, sizeof(prfpregset_t)); 370 if (error) 371 goto done; 372 error = elf_getnote(src, &off, "FreeBSD", NT_PRPSINFO, 373 (void **)&psinfo, sizeof(prpsinfo_t)); 374 if (error) 375 goto done; 376 377 /* 378 * The remaining portion needs to be an integer multiple 379 * of prstatus_t and prfpregset_t 380 */ 381 for (i = 0 ; i < nthreads - 1; i++) { 382 status++; fpregset++; 383 error = elf_getnote(src, &off, "FreeBSD", NT_PRSTATUS, 384 (void **)&status, sizeof (prstatus_t)); 385 if (error) 386 goto done; 387 error = elf_getnote(src, &off, "FreeBSD", NT_FPREGSET, 388 (void **)&fpregset, sizeof(prfpregset_t)); 389 if (error) 390 goto done; 391 } 392 393 done: 394 TRACE_EXIT; 395 return error; 396 } 397 398 399 static int 400 mmap_phdr(struct file *fp, Elf_Phdr *phdr) 401 { 402 int error; 403 size_t len; 404 int prot; 405 void *addr; 406 int flags; 407 off_t pos; 408 409 TRACE_ENTER; 410 pos = phdr->p_offset; 411 len = phdr->p_filesz; 412 addr = (void *)phdr->p_vaddr; 413 flags = MAP_FIXED | MAP_NOSYNC | MAP_PRIVATE; 414 prot = 0; 415 if (phdr->p_flags & PF_R) 416 prot |= PROT_READ; 417 if (phdr->p_flags & PF_W) 418 prot |= PROT_WRITE; 419 if (phdr->p_flags & PF_X) 420 prot |= PROT_EXEC; 421 if ((error = fp_mmap(addr, len, prot, flags, fp, pos, &addr)) != 0) { 422 PRINTF(("mmap failed: %d\n", error); ); 423 } 424 PRINTF(("map @%08x-%08x fileoff %08x-%08x\n", (int)addr, 425 (int)((char *)addr + len), (int)pos, (int)(pos + len))); 426 TRACE_EXIT; 427 return error; 428 } 429 430 431 static int 432 elf_loadphdrs(struct file *fp, Elf_Phdr *phdr, int numsegs) 433 { 434 int i; 435 int error = 0; 436 437 TRACE_ENTER; 438 for (i = 1; i < numsegs; i++) { 439 if ((error = mmap_phdr(fp, &phdr[i])) != 0) 440 break; 441 } 442 TRACE_EXIT; 443 return error; 444 } 445 446 static int 447 elf_getsigs(struct proc *p, struct file *fp) 448 { 449 int error; 450 struct ckpt_siginfo *csi; 451 struct sigacts *tmpsigacts; 452 453 TRACE_ENTER; 454 csi = malloc(sizeof(struct ckpt_siginfo), M_TEMP, M_ZERO | M_WAITOK); 455 if ((error = read_check(fp, csi, sizeof(struct ckpt_siginfo))) != 0) 456 goto done; 457 458 if (csi->csi_ckptpisz != sizeof(struct ckpt_siginfo)) { 459 TRACE_ERR; 460 error = EINVAL; 461 goto done; 462 } 463 tmpsigacts = p->p_procsig->ps_sigacts; 464 bcopy(&csi->csi_procsig, p->p_procsig, sizeof(struct procsig)); 465 p->p_procsig->ps_sigacts = tmpsigacts; 466 bcopy(&csi->csi_sigacts, p->p_procsig->ps_sigacts, sizeof(struct sigacts)); 467 bcopy(&csi->csi_itimerval, &p->p_realtimer, sizeof(struct itimerval)); 468 SIG_CANTMASK(csi->csi_sigmask); 469 bcopy(&csi->csi_sigmask, &p->p_sigmask, sizeof(sigset_t)); 470 p->p_sigparent = csi->csi_sigparent; 471 done: 472 if (csi) 473 free(csi, M_TEMP); 474 TRACE_EXIT; 475 return error; 476 } 477 478 /* 479 * Returns a locked, refd vnode 480 */ 481 static int 482 ckpt_fhtovp(fhandle_t *fh, struct vnode **vpp) 483 { 484 struct mount *mp; 485 int error; 486 487 TRACE_ENTER; 488 mp = vfs_getvfs(&fh->fh_fsid); 489 490 if (!mp) { 491 TRACE_ERR; 492 PRINTF(("failed to get mount - ESTALE\n")); 493 TRACE_EXIT; 494 return ESTALE; 495 } 496 error = VFS_FHTOVP(mp, &fh->fh_fid, vpp); 497 if (error) { 498 PRINTF(("failed with: %d\n", error)); 499 TRACE_ERR; 500 TRACE_EXIT; 501 return error; 502 } 503 TRACE_EXIT; 504 return 0; 505 } 506 507 static int 508 mmap_vp(struct vn_hdr *vnh) 509 { 510 struct vnode *vp; 511 Elf_Phdr *phdr; 512 struct file *fp; 513 int error; 514 TRACE_ENTER; 515 516 phdr = &vnh->vnh_phdr; 517 518 if ((error = ckpt_fhtovp(&vnh->vnh_fh, &vp)) != 0) 519 return error; 520 /* 521 * XXX O_RDONLY -> or O_RDWR if file is PROT_WRITE, MAP_SHARED 522 */ 523 if ((error = fp_vpopen(vp, O_RDONLY, &fp)) != 0) { 524 vput(vp); 525 return error; 526 } 527 error = mmap_phdr(fp, phdr); 528 fp_close(fp); 529 TRACE_EXIT; 530 return error; 531 } 532 533 534 static int 535 elf_gettextvp(struct proc *p, struct file *fp) 536 { 537 int i; 538 int error; 539 int vpcount; 540 struct ckpt_vminfo vminfo; 541 struct vn_hdr *vnh = NULL; 542 543 TRACE_ENTER; 544 if ((error = read_check(fp, &vminfo, sizeof(vminfo))) != 0) 545 goto done; 546 if (vminfo.cvm_dsize < 0 || 547 vminfo.cvm_dsize > p->p_rlimit[RLIMIT_DATA].rlim_cur || 548 vminfo.cvm_tsize < 0 || 549 (u_quad_t)vminfo.cvm_tsize > maxtsiz || 550 vminfo.cvm_daddr >= (caddr_t)VM_MAXUSER_ADDRESS || 551 vminfo.cvm_taddr >= (caddr_t)VM_MAXUSER_ADDRESS 552 ) { 553 error = ERANGE; 554 goto done; 555 } 556 557 vmspace_exec(p, NULL); 558 p->p_vmspace->vm_daddr = vminfo.cvm_daddr; 559 p->p_vmspace->vm_dsize = vminfo.cvm_dsize; 560 p->p_vmspace->vm_taddr = vminfo.cvm_taddr; 561 p->p_vmspace->vm_tsize = vminfo.cvm_tsize; 562 if ((error = read_check(fp, &vpcount, sizeof(int))) != 0) 563 goto done; 564 vnh = malloc(sizeof(struct vn_hdr) * vpcount, M_TEMP, M_WAITOK); 565 if ((error = read_check(fp, vnh, sizeof(struct vn_hdr)*vpcount)) != 0) 566 goto done; 567 for (i = 0; i < vpcount; i++) { 568 if ((error = mmap_vp(&vnh[i])) != 0) 569 goto done; 570 } 571 572 done: 573 if (vnh) 574 free(vnh, M_TEMP); 575 TRACE_EXIT; 576 return error; 577 } 578 579 580 581 /* place holder */ 582 static int 583 elf_getfiles(struct proc *p, struct file *fp) 584 { 585 int error; 586 int i; 587 int filecount; 588 int fd; 589 struct ckpt_filehdr filehdr; 590 struct ckpt_fileinfo *cfi_base = NULL; 591 struct vnode *vp; 592 struct file *tempfp; 593 struct file *ofp; 594 595 TRACE_ENTER; 596 if ((error = read_check(fp, &filehdr, sizeof(filehdr))) != 0) 597 goto done; 598 filecount = filehdr.cfh_nfiles; 599 cfi_base = malloc(filecount*sizeof(struct ckpt_fileinfo), M_TEMP, M_WAITOK); 600 error = read_check(fp, cfi_base, filecount*sizeof(struct ckpt_fileinfo)); 601 if (error) 602 goto done; 603 604 /* 605 * Close all file descriptors >= 3. These descriptors are from the 606 * checkpt(1) program itself and should not be retained. 607 * 608 * XXX we need a flag so a checkpoint restore can opt to supply the 609 * descriptors, or the non-regular-file descripors. 610 */ 611 for (i = 3; i < p->p_fd->fd_nfiles; ++i) 612 kern_close(i); 613 614 /* 615 * Scan files to load 616 */ 617 for (i = 0; i < filecount; i++) { 618 struct ckpt_fileinfo *cfi= &cfi_base[i]; 619 /* 620 * Ignore placeholder entries where cfi_index is less then 621 * zero. This will occur if the elf core dump code thinks 622 * it can save a vnode but winds up not being able to. 623 */ 624 if (cfi->cfi_index < 0) 625 continue; 626 627 if ((error = ckpt_fhtovp(&cfi->cfi_fh, &vp)) != 0) 628 break; 629 if ((error = fp_vpopen(vp, OFLAGS(cfi->cfi_flags), &tempfp)) != 0) { 630 vput(vp); 631 break; 632 } 633 tempfp->f_offset = cfi->cfi_offset; 634 635 /* 636 * If overwriting a descriptor close the old descriptor. This 637 * only occurs if the saved core saved descriptors that we 638 * have not already closed. 639 */ 640 if (cfi->cfi_index < p->p_fd->fd_nfiles && 641 (ofp = p->p_fd->fd_files[cfi->cfi_index].fp) != NULL) { 642 kern_close(cfi->cfi_index); 643 } 644 645 /* 646 * Allocate the descriptor we want. 647 */ 648 if (fdalloc(p, cfi->cfi_index, &fd) != 0) { 649 PRINTF(("can't currently restore fd: %d\n", 650 cfi->cfi_index)); 651 fp_close(fp); 652 goto done; 653 } 654 KKASSERT(fd == cfi->cfi_index); 655 p->p_fd->fd_files[cfi->cfi_index].fp = tempfp; 656 cfi++; 657 PRINTF(("restoring %d\n", cfi->cfi_index)); 658 } 659 660 done: 661 if (cfi_base) 662 free(cfi_base, M_TEMP); 663 TRACE_EXIT; 664 return error; 665 } 666 667 static int 668 ckpt_freeze_proc (struct proc *p, struct file *fp) 669 { 670 rlim_t limit; 671 int error; 672 673 PRINTF(("calling generic_elf_coredump\n")); 674 limit = p->p_rlimit[RLIMIT_CORE].rlim_cur; 675 if (limit) { 676 error = generic_elf_coredump(p, fp, limit); 677 } else { 678 error = ERANGE; 679 } 680 return error; 681 } 682 683 int 684 sys_checkpoint(struct sys_checkpoint_args *uap) 685 { 686 int error = 0; 687 struct proc *p = curthread->td_proc; 688 struct file *fp; 689 690 /* 691 * Only certain groups (to reduce our security exposure). -1 692 * allows any group. 693 */ 694 if (ckptgroup >= 0 && groupmember(ckptgroup, p->p_ucred) == 0) 695 return (EPERM); 696 697 /* 698 * For now we can only checkpoint the current process 699 */ 700 if (uap->pid != -1 && uap->pid != p->p_pid) 701 return (EINVAL); 702 703 switch (uap->type) { 704 case CKPT_FREEZE: 705 fp = NULL; 706 if (uap->fd == -1 && uap->pid == (pid_t)-1) 707 error = checkpoint_signal_handler(p); 708 else if ((fp = holdfp(p->p_fd, uap->fd, FWRITE)) == NULL) 709 error = EBADF; 710 else 711 error = ckpt_freeze_proc(p, fp); 712 if (fp) 713 fdrop(fp, curthread); 714 break; 715 case CKPT_THAW: 716 if (uap->pid != -1) 717 return EINVAL; 718 if ((fp = holdfp(p->p_fd, uap->fd, FREAD)) == NULL) 719 return EBADF; 720 uap->sysmsg_result = uap->retval; 721 error = ckpt_thaw_proc(p, fp); 722 fdrop(fp, curthread); 723 break; 724 default: 725 error = EOPNOTSUPP; 726 break; 727 } 728 return error; 729 } 730 731 int 732 checkpoint_signal_handler(struct proc *p) 733 { 734 char *buf; 735 struct file *fp; 736 struct nlookupdata nd; 737 int error; 738 739 chptinuse++; 740 741 /* 742 * Being able to checkpoint an suid or sgid program is not a good 743 * idea. 744 */ 745 if (sugid_coredump == 0 && (p->p_flag & P_SUGID)) { 746 chptinuse--; 747 return (EPERM); 748 } 749 750 buf = ckpt_expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid); 751 if (buf == NULL) { 752 chptinuse--; 753 return (ENOMEM); 754 } 755 756 log(LOG_INFO, "pid %d (%s), uid %d: checkpointing to %s\n", 757 p->p_pid, p->p_comm, 758 (p->p_ucred ? p->p_ucred->cr_uid : -1), 759 buf); 760 761 PRINTF(("ckpt handler called, using '%s'\n", buf)); 762 763 /* 764 * Use the same safety flags that the coredump code uses. Remove 765 * any previous checkpoint file before writing out the new one in 766 * case we are re-checkpointing a program that had been checkpt 767 * restored. Otherwise we will corrupt the program space (which is 768 * made up of mmap()ings of the previous checkpoint file) while we 769 * write out the new one. 770 */ 771 error = nlookup_init(&nd, buf, UIO_SYSSPACE, 0); 772 if (error == 0) 773 error = kern_unlink(&nd); 774 nlookup_done(&nd); 775 error = fp_open(buf, O_WRONLY|O_CREAT|O_TRUNC|O_NOFOLLOW, 0600, &fp); 776 if (error == 0) { 777 error = ckpt_freeze_proc(p, fp); 778 fp_close(fp); 779 } else { 780 printf("checkpoint failed with open - error: %d\n", error); 781 } 782 free(buf, M_TEMP); 783 chptinuse--; 784 return (error); 785 } 786 787 static char ckptfilename[MAXPATHLEN] = {"%N.ckpt"}; 788 SYSCTL_STRING(_kern, OID_AUTO, ckptfile, CTLFLAG_RW, ckptfilename, 789 sizeof(ckptfilename), "process checkpoint name format string"); 790 791 /* 792 * expand_name(name, uid, pid) 793 * Expand the name described in corefilename, using name, uid, and pid. 794 * corefilename is a printf-like string, with three format specifiers: 795 * %N name of process ("name") 796 * %P process id (pid) 797 * %U user id (uid) 798 * For example, "%N.core" is the default; they can be disabled completely 799 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 800 * This is controlled by the sysctl variable kern.corefile (see above). 801 * 802 * -- taken from the coredump code 803 */ 804 805 static 806 char * 807 ckpt_expand_name(const char *name, uid_t uid, pid_t pid) 808 { 809 char *temp; 810 char *bp; 811 char buf[11]; /* Buffer for pid/uid -- max 4B */ 812 int error; 813 int i; 814 int n; 815 char *format = ckptfilename; 816 size_t namelen; 817 818 temp = malloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT); 819 if (temp == NULL) 820 return NULL; 821 namelen = strlen(name); 822 n = 0; 823 if (ckptfilename[0] != '/') { 824 if ((bp = kern_getcwd(temp, MAXPATHLEN - 1, &error)) == NULL) { 825 free(temp, M_TEMP); 826 return NULL; 827 } 828 n = strlen(bp); 829 bcopy(bp, temp, n + 1); /* normalize location of the path */ 830 temp[n++] = '/'; 831 temp[n] = '\0'; 832 } 833 for (i= 0; n < MAXPATHLEN && format[i]; i++) { 834 int l; 835 switch (format[i]) { 836 case '%': /* Format character */ 837 i++; 838 switch (format[i]) { 839 case '%': 840 temp[n++] = '%'; 841 break; 842 case 'N': /* process name */ 843 if ((n + namelen) > MAXPATHLEN) { 844 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 845 pid, name, uid, temp, name); 846 free(temp, M_TEMP); 847 return NULL; 848 } 849 memcpy(temp+n, name, namelen); 850 n += namelen; 851 break; 852 case 'P': /* process id */ 853 l = sprintf(buf, "%u", pid); 854 if ((n + l) > MAXPATHLEN) { 855 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 856 pid, name, uid, temp, name); 857 free(temp, M_TEMP); 858 return NULL; 859 } 860 memcpy(temp+n, buf, l); 861 n += l; 862 break; 863 case 'U': /* user id */ 864 l = sprintf(buf, "%u", uid); 865 if ((n + l) > MAXPATHLEN) { 866 log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", 867 pid, name, uid, temp, name); 868 free(temp, M_TEMP); 869 return NULL; 870 } 871 memcpy(temp+n, buf, l); 872 n += l; 873 break; 874 default: 875 log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format); 876 } 877 break; 878 default: 879 temp[n++] = format[i]; 880 } 881 } 882 temp[n] = '\0'; 883 return temp; 884 } 885 886