| 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 1.20 2008/09/17 21:44:18 dillon 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 | #include <sys/fcntl.h> |
| 40 | #include <sys/signal.h> |
| 41 | #include <vm/vm_param.h> |
| 42 | #include <vm/vm.h> |
| 43 | #include <sys/imgact_elf.h> |
| 44 | #include <sys/procfs.h> |
| 45 | |
| 46 | #include <sys/lock.h> |
| 47 | #include <vm/pmap.h> |
| 48 | #include <vm/vm_map.h> |
| 49 | #include <vm/vm_extern.h> |
| 50 | #include <sys/mman.h> |
| 51 | #include <sys/sysent.h> |
| 52 | #include <sys/sysproto.h> |
| 53 | #include <sys/resource.h> |
| 54 | #include <sys/resourcevar.h> |
| 55 | #include <sys/malloc.h> |
| 56 | #include <sys/stat.h> |
| 57 | #include <sys/uio.h> |
| 58 | #include <sys/namei.h> |
| 59 | #include <sys/vnode.h> |
| 60 | #include <machine/limits.h> |
| 61 | #include <machine/frame.h> |
| 62 | #include <sys/signalvar.h> |
| 63 | #include <sys/syslog.h> |
| 64 | #include <sys/sysctl.h> |
| 65 | #include <machine/sigframe.h> |
| 66 | #include <sys/exec.h> |
| 67 | #include <sys/unistd.h> |
| 68 | #include <sys/time.h> |
| 69 | #include <sys/kern_syscall.h> |
| 70 | #include <sys/checkpoint.h> |
| 71 | #include <sys/mount.h> |
| 72 | #include <sys/ckpt.h> |
| 73 | |
| 74 | #include <sys/mplock2.h> |
| 75 | #include <sys/file2.h> |
| 76 | |
| 77 | static int elf_loadphdrs(struct file *fp, Elf_Phdr *phdr, int numsegs); |
| 78 | static int elf_getnotes(struct lwp *lp, 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 lwp *, prpsinfo_t *, prstatus_t *, |
| 82 | prfpregset_t *); |
| 83 | static int elf_getsigs(struct lwp *lp, struct file *fp); |
| 84 | static int elf_getfiles(struct lwp *lp, 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, UIO_SYSSPACE); |
| 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_NONE && |
| 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 lwp *lp, 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 = kmalloc(sizeof(prpsinfo_t), M_TEMP, M_ZERO | M_WAITOK); |
| 195 | status = kmalloc(nthreads*sizeof(prstatus_t), M_TEMP, M_WAITOK); |
| 196 | fpregset = kmalloc(nthreads*sizeof(prfpregset_t), M_TEMP, M_WAITOK); |
| 197 | note = kmalloc(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(lp, psinfo, status, fpregset); |
| 208 | done: |
| 209 | if (psinfo) |
| 210 | kfree(psinfo, M_TEMP); |
| 211 | if (status) |
| 212 | kfree(status, M_TEMP); |
| 213 | if (fpregset) |
| 214 | kfree(fpregset, M_TEMP); |
| 215 | if (note) |
| 216 | kfree(note, M_TEMP); |
| 217 | return error; |
| 218 | } |
| 219 | |
| 220 | static int |
| 221 | ckpt_thaw_proc(struct lwp *lp, struct file *fp) |
| 222 | { |
| 223 | struct proc *p = lp->lwp_proc; |
| 224 | Elf_Phdr *phdr = NULL; |
| 225 | Elf_Ehdr *ehdr = NULL; |
| 226 | int error; |
| 227 | size_t nbyte; |
| 228 | |
| 229 | TRACE_ENTER; |
| 230 | |
| 231 | ehdr = kmalloc(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 = kmalloc(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(lp, 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(lp, fp)) != 0) { |
| 252 | kprintf("failure in recovering signals\n"); |
| 253 | goto done; |
| 254 | } |
| 255 | |
| 256 | /* fetch open files */ |
| 257 | if ((error = elf_getfiles(lp, 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 | vsetflags(p->p_textvp, VCKPT); |
| 275 | vref(p->p_textvp); |
| 276 | } |
| 277 | done: |
| 278 | if (ehdr) |
| 279 | kfree(ehdr, M_TEMP); |
| 280 | if (phdr) |
| 281 | kfree(phdr, M_TEMP); |
| 282 | TRACE_EXIT; |
| 283 | return error; |
| 284 | } |
| 285 | |
| 286 | static int |
| 287 | elf_loadnotes(struct lwp *lp, prpsinfo_t *psinfo, prstatus_t *status, |
| 288 | prfpregset_t *fpregset) |
| 289 | { |
| 290 | struct proc *p = lp->lwp_proc; |
| 291 | int error; |
| 292 | |
| 293 | /* validate status and psinfo */ |
| 294 | TRACE_ENTER; |
| 295 | if (status->pr_version != PRSTATUS_VERSION || |
| 296 | status->pr_statussz != sizeof(prstatus_t) || |
| 297 | status->pr_gregsetsz != sizeof(gregset_t) || |
| 298 | status->pr_fpregsetsz != sizeof(fpregset_t) || |
| 299 | psinfo->pr_version != PRPSINFO_VERSION || |
| 300 | psinfo->pr_psinfosz != sizeof(prpsinfo_t)) { |
| 301 | PRINTF(("status check failed\n")); |
| 302 | error = EINVAL; |
| 303 | goto done; |
| 304 | } |
| 305 | /* XXX lwp handle more than one lwp*/ |
| 306 | if ((error = set_regs(lp, &status->pr_reg)) != 0) |
| 307 | goto done; |
| 308 | error = set_fpregs(lp, fpregset); |
| 309 | strlcpy(p->p_comm, psinfo->pr_fname, sizeof(p->p_comm)); |
| 310 | /* XXX psinfo->pr_psargs not yet implemented */ |
| 311 | done: |
| 312 | TRACE_EXIT; |
| 313 | return error; |
| 314 | } |
| 315 | |
| 316 | static int |
| 317 | elf_getnote(void *src, size_t *off, const char *name, unsigned int type, |
| 318 | void **desc, size_t descsz) |
| 319 | { |
| 320 | Elf_Note note; |
| 321 | int error; |
| 322 | |
| 323 | TRACE_ENTER; |
| 324 | if (src == NULL) { |
| 325 | error = EFAULT; |
| 326 | goto done; |
| 327 | } |
| 328 | bcopy((char *)src + *off, ¬e, sizeof note); |
| 329 | |
| 330 | PRINTF(("at offset: %d expected note of type: %d - got: %d\n", |
| 331 | *off, type, note.n_type)); |
| 332 | *off += sizeof note; |
| 333 | if (type != note.n_type) { |
| 334 | TRACE_ERR; |
| 335 | error = EINVAL; |
| 336 | goto done; |
| 337 | } |
| 338 | if (strncmp(name, (char *) src + *off, note.n_namesz) != 0) { |
| 339 | error = EINVAL; |
| 340 | goto done; |
| 341 | } |
| 342 | *off += roundup2(note.n_namesz, sizeof(Elf_Size)); |
| 343 | if (note.n_descsz != descsz) { |
| 344 | TRACE_ERR; |
| 345 | error = EINVAL; |
| 346 | goto done; |
| 347 | } |
| 348 | if (desc) |
| 349 | bcopy((char *)src + *off, *desc, note.n_descsz); |
| 350 | *off += roundup2(note.n_descsz, sizeof(Elf_Size)); |
| 351 | error = 0; |
| 352 | done: |
| 353 | TRACE_EXIT; |
| 354 | return error; |
| 355 | } |
| 356 | |
| 357 | static int |
| 358 | elf_demarshalnotes(void *src, prpsinfo_t *psinfo, prstatus_t *status, |
| 359 | prfpregset_t *fpregset, int nthreads) |
| 360 | { |
| 361 | int i; |
| 362 | int error; |
| 363 | size_t off = 0; |
| 364 | |
| 365 | TRACE_ENTER; |
| 366 | error = elf_getnote(src, &off, "CORE", NT_PRPSINFO, |
| 367 | (void **)&psinfo, sizeof(prpsinfo_t)); |
| 368 | if (error) |
| 369 | goto done; |
| 370 | error = elf_getnote(src, &off, "CORE", NT_PRSTATUS, |
| 371 | (void **)&status, sizeof(prstatus_t)); |
| 372 | if (error) |
| 373 | goto done; |
| 374 | error = elf_getnote(src, &off, "CORE", NT_FPREGSET, |
| 375 | (void **)&fpregset, sizeof(prfpregset_t)); |
| 376 | if (error) |
| 377 | goto done; |
| 378 | |
| 379 | /* |
| 380 | * The remaining portion needs to be an integer multiple |
| 381 | * of prstatus_t and prfpregset_t |
| 382 | */ |
| 383 | for (i = 0 ; i < nthreads - 1; i++) { |
| 384 | status++; fpregset++; |
| 385 | error = elf_getnote(src, &off, "CORE", NT_PRSTATUS, |
| 386 | (void **)&status, sizeof (prstatus_t)); |
| 387 | if (error) |
| 388 | goto done; |
| 389 | error = elf_getnote(src, &off, "CORE", NT_FPREGSET, |
| 390 | (void **)&fpregset, sizeof(prfpregset_t)); |
| 391 | if (error) |
| 392 | goto done; |
| 393 | } |
| 394 | |
| 395 | done: |
| 396 | TRACE_EXIT; |
| 397 | return error; |
| 398 | } |
| 399 | |
| 400 | |
| 401 | static int |
| 402 | mmap_phdr(struct file *fp, Elf_Phdr *phdr) |
| 403 | { |
| 404 | int error; |
| 405 | size_t len; |
| 406 | int prot; |
| 407 | void *addr; |
| 408 | int flags; |
| 409 | off_t pos; |
| 410 | |
| 411 | TRACE_ENTER; |
| 412 | pos = phdr->p_offset; |
| 413 | len = phdr->p_filesz; |
| 414 | addr = (void *)phdr->p_vaddr; |
| 415 | flags = MAP_FIXED | MAP_NOSYNC | MAP_PRIVATE; |
| 416 | prot = 0; |
| 417 | if (phdr->p_flags & PF_R) |
| 418 | prot |= PROT_READ; |
| 419 | if (phdr->p_flags & PF_W) |
| 420 | prot |= PROT_WRITE; |
| 421 | if (phdr->p_flags & PF_X) |
| 422 | prot |= PROT_EXEC; |
| 423 | if ((error = fp_mmap(addr, len, prot, flags, fp, pos, &addr)) != 0) { |
| 424 | PRINTF(("mmap failed: %d\n", error); ); |
| 425 | } |
| 426 | PRINTF(("map @%08x-%08x fileoff %08x-%08x\n", (int)addr, |
| 427 | (int)((char *)addr + len), (int)pos, (int)(pos + len))); |
| 428 | TRACE_EXIT; |
| 429 | return error; |
| 430 | } |
| 431 | |
| 432 | /* |
| 433 | * Load memory mapped segments. The segments are backed by the checkpoint |
| 434 | * file. |
| 435 | */ |
| 436 | static int |
| 437 | elf_loadphdrs(struct file *fp, Elf_Phdr *phdr, int numsegs) |
| 438 | { |
| 439 | int i; |
| 440 | int error = 0; |
| 441 | |
| 442 | TRACE_ENTER; |
| 443 | for (i = 1; i < numsegs; i++) { |
| 444 | if ((error = mmap_phdr(fp, &phdr[i])) != 0) |
| 445 | break; |
| 446 | } |
| 447 | TRACE_EXIT; |
| 448 | return error; |
| 449 | } |
| 450 | |
| 451 | static int |
| 452 | elf_getsigs(struct lwp *lp, struct file *fp) |
| 453 | { |
| 454 | struct proc *p = lp->lwp_proc; |
| 455 | int error; |
| 456 | struct ckpt_siginfo *csi; |
| 457 | |
| 458 | TRACE_ENTER; |
| 459 | csi = kmalloc(sizeof(struct ckpt_siginfo), M_TEMP, M_ZERO | M_WAITOK); |
| 460 | if ((error = read_check(fp, csi, sizeof(struct ckpt_siginfo))) != 0) |
| 461 | goto done; |
| 462 | |
| 463 | if (csi->csi_ckptpisz != sizeof(struct ckpt_siginfo)) { |
| 464 | TRACE_ERR; |
| 465 | error = EINVAL; |
| 466 | goto done; |
| 467 | } |
| 468 | bcopy(&csi->csi_sigacts, p->p_sigacts, sizeof(p->p_sigacts)); |
| 469 | bcopy(&csi->csi_itimerval, &p->p_realtimer, sizeof(struct itimerval)); |
| 470 | SIG_CANTMASK(csi->csi_sigmask); |
| 471 | /* XXX lwp handle more than one lwp */ |
| 472 | bcopy(&csi->csi_sigmask, &lp->lwp_sigmask, sizeof(sigset_t)); |
| 473 | p->p_sigparent = csi->csi_sigparent; |
| 474 | done: |
| 475 | if (csi) |
| 476 | kfree(csi, M_TEMP); |
| 477 | TRACE_EXIT; |
| 478 | return error; |
| 479 | } |
| 480 | |
| 481 | /* |
| 482 | * Returns a locked, refd vnode |
| 483 | */ |
| 484 | static int |
| 485 | ckpt_fhtovp(fhandle_t *fh, struct vnode **vpp) |
| 486 | { |
| 487 | struct mount *mp; |
| 488 | int error; |
| 489 | |
| 490 | TRACE_ENTER; |
| 491 | mp = vfs_getvfs(&fh->fh_fsid); |
| 492 | |
| 493 | if (!mp) { |
| 494 | TRACE_ERR; |
| 495 | PRINTF(("failed to get mount - ESTALE\n")); |
| 496 | TRACE_EXIT; |
| 497 | return ESTALE; |
| 498 | } |
| 499 | error = VFS_FHTOVP(mp, NULL, &fh->fh_fid, vpp); |
| 500 | if (error) { |
| 501 | PRINTF(("failed with: %d\n", error)); |
| 502 | TRACE_ERR; |
| 503 | TRACE_EXIT; |
| 504 | return error; |
| 505 | } |
| 506 | TRACE_EXIT; |
| 507 | return 0; |
| 508 | } |
| 509 | |
| 510 | static int |
| 511 | mmap_vp(struct vn_hdr *vnh) |
| 512 | { |
| 513 | struct vnode *vp; |
| 514 | Elf_Phdr *phdr; |
| 515 | struct file *fp; |
| 516 | int error; |
| 517 | TRACE_ENTER; |
| 518 | |
| 519 | phdr = &vnh->vnh_phdr; |
| 520 | |
| 521 | if ((error = ckpt_fhtovp(&vnh->vnh_fh, &vp)) != 0) |
| 522 | return error; |
| 523 | /* |
| 524 | * XXX O_RDONLY -> or O_RDWR if file is PROT_WRITE, MAP_SHARED |
| 525 | */ |
| 526 | if ((error = fp_vpopen(vp, O_RDONLY, &fp)) != 0) { |
| 527 | vput(vp); |
| 528 | return error; |
| 529 | } |
| 530 | error = mmap_phdr(fp, phdr); |
| 531 | fp_close(fp); |
| 532 | TRACE_EXIT; |
| 533 | return error; |
| 534 | } |
| 535 | |
| 536 | |
| 537 | static int |
| 538 | elf_gettextvp(struct proc *p, struct file *fp) |
| 539 | { |
| 540 | int i; |
| 541 | int error; |
| 542 | int vpcount; |
| 543 | struct ckpt_vminfo vminfo; |
| 544 | struct vn_hdr *vnh = NULL; |
| 545 | |
| 546 | TRACE_ENTER; |
| 547 | if ((error = read_check(fp, &vminfo, sizeof(vminfo))) != 0) |
| 548 | goto done; |
| 549 | if (vminfo.cvm_dsize < 0 || |
| 550 | vminfo.cvm_dsize > p->p_rlimit[RLIMIT_DATA].rlim_cur || |
| 551 | vminfo.cvm_tsize < 0 || |
| 552 | (u_quad_t)vminfo.cvm_tsize > maxtsiz || |
| 553 | vminfo.cvm_daddr >= (caddr_t)VM_MAX_USER_ADDRESS || |
| 554 | vminfo.cvm_taddr >= (caddr_t)VM_MAX_USER_ADDRESS |
| 555 | ) { |
| 556 | error = ERANGE; |
| 557 | goto done; |
| 558 | } |
| 559 | |
| 560 | vmspace_exec(p, NULL); |
| 561 | p->p_vmspace->vm_daddr = vminfo.cvm_daddr; |
| 562 | p->p_vmspace->vm_dsize = vminfo.cvm_dsize; |
| 563 | p->p_vmspace->vm_taddr = vminfo.cvm_taddr; |
| 564 | p->p_vmspace->vm_tsize = vminfo.cvm_tsize; |
| 565 | if ((error = read_check(fp, &vpcount, sizeof(int))) != 0) |
| 566 | goto done; |
| 567 | vnh = kmalloc(sizeof(struct vn_hdr) * vpcount, M_TEMP, M_WAITOK); |
| 568 | if ((error = read_check(fp, vnh, sizeof(struct vn_hdr)*vpcount)) != 0) |
| 569 | goto done; |
| 570 | for (i = 0; i < vpcount; i++) { |
| 571 | if ((error = mmap_vp(&vnh[i])) != 0) |
| 572 | goto done; |
| 573 | } |
| 574 | |
| 575 | done: |
| 576 | if (vnh) |
| 577 | kfree(vnh, M_TEMP); |
| 578 | TRACE_EXIT; |
| 579 | return error; |
| 580 | } |
| 581 | |
| 582 | |
| 583 | |
| 584 | /* place holder */ |
| 585 | static int |
| 586 | elf_getfiles(struct lwp *lp, struct file *fp) |
| 587 | { |
| 588 | int error; |
| 589 | int i; |
| 590 | int filecount; |
| 591 | int fd; |
| 592 | struct ckpt_filehdr filehdr; |
| 593 | struct ckpt_fileinfo *cfi_base = NULL; |
| 594 | struct filedesc *fdp = lp->lwp_proc->p_fd; |
| 595 | struct vnode *vp; |
| 596 | struct file *tempfp; |
| 597 | struct file *ofp; |
| 598 | |
| 599 | TRACE_ENTER; |
| 600 | if ((error = read_check(fp, &filehdr, sizeof(filehdr))) != 0) |
| 601 | goto done; |
| 602 | filecount = filehdr.cfh_nfiles; |
| 603 | cfi_base = kmalloc(filecount*sizeof(struct ckpt_fileinfo), M_TEMP, M_WAITOK); |
| 604 | error = read_check(fp, cfi_base, filecount*sizeof(struct ckpt_fileinfo)); |
| 605 | if (error) |
| 606 | goto done; |
| 607 | |
| 608 | /* |
| 609 | * Close all file descriptors >= 3. These descriptors are from the |
| 610 | * checkpt(1) program itself and should not be retained. |
| 611 | * |
| 612 | * XXX we need a flag so a checkpoint restore can opt to supply the |
| 613 | * descriptors, or the non-regular-file descripors. |
| 614 | */ |
| 615 | for (i = 3; i < fdp->fd_nfiles; ++i) |
| 616 | kern_close(i); |
| 617 | |
| 618 | /* |
| 619 | * Scan files to load |
| 620 | */ |
| 621 | for (i = 0; i < filecount; i++) { |
| 622 | struct ckpt_fileinfo *cfi= &cfi_base[i]; |
| 623 | /* |
| 624 | * Ignore placeholder entries where cfi_index is less then |
| 625 | * zero. This will occur if the elf core dump code thinks |
| 626 | * it can save a vnode but winds up not being able to. |
| 627 | */ |
| 628 | if (cfi->cfi_index < 0) |
| 629 | continue; |
| 630 | |
| 631 | /* |
| 632 | * Restore a saved file descriptor. If CKFIF_ISCKPTFD is |
| 633 | * set the descriptor represents the checkpoint file itself, |
| 634 | * probably due to the user calling sys_checkpoint(). We |
| 635 | * want to use the fp being used to restore the checkpoint |
| 636 | * instead of trying to restore the original filehandle. |
| 637 | */ |
| 638 | if (cfi->cfi_ckflags & CKFIF_ISCKPTFD) { |
| 639 | fhold(fp); |
| 640 | tempfp = fp; |
| 641 | error = 0; |
| 642 | } else { |
| 643 | error = ckpt_fhtovp(&cfi->cfi_fh, &vp); |
| 644 | if (error == 0) { |
| 645 | error = fp_vpopen(vp, OFLAGS(cfi->cfi_flags), |
| 646 | &tempfp); |
| 647 | if (error) |
| 648 | vput(vp); |
| 649 | } |
| 650 | } |
| 651 | if (error) |
| 652 | break; |
| 653 | tempfp->f_offset = cfi->cfi_offset; |
| 654 | |
| 655 | /* |
| 656 | * If overwriting a descriptor close the old descriptor. This |
| 657 | * only occurs if the saved core saved descriptors that we |
| 658 | * have not already closed. |
| 659 | */ |
| 660 | if (cfi->cfi_index < fdp->fd_nfiles && |
| 661 | (ofp = fdp->fd_files[cfi->cfi_index].fp) != NULL) { |
| 662 | kern_close(cfi->cfi_index); |
| 663 | } |
| 664 | |
| 665 | /* |
| 666 | * Allocate the descriptor we want. |
| 667 | */ |
| 668 | if (fdalloc(lp->lwp_proc, cfi->cfi_index, &fd) != 0) { |
| 669 | PRINTF(("can't currently restore fd: %d\n", |
| 670 | cfi->cfi_index)); |
| 671 | fp_close(fp); |
| 672 | goto done; |
| 673 | } |
| 674 | KKASSERT(fd == cfi->cfi_index); |
| 675 | fsetfd(fdp, tempfp, fd); |
| 676 | fdrop(tempfp); |
| 677 | cfi++; |
| 678 | PRINTF(("restoring %d\n", cfi->cfi_index)); |
| 679 | } |
| 680 | |
| 681 | done: |
| 682 | if (cfi_base) |
| 683 | kfree(cfi_base, M_TEMP); |
| 684 | TRACE_EXIT; |
| 685 | return error; |
| 686 | } |
| 687 | |
| 688 | static int |
| 689 | ckpt_freeze_proc(struct lwp *lp, struct file *fp) |
| 690 | { |
| 691 | struct proc *p = lp->lwp_proc; |
| 692 | rlim_t limit; |
| 693 | int error; |
| 694 | |
| 695 | PRINTF(("calling generic_elf_coredump\n")); |
| 696 | limit = p->p_rlimit[RLIMIT_CORE].rlim_cur; |
| 697 | if (limit) { |
| 698 | proc_stop(p); |
| 699 | while (p->p_nstopped < p->p_nthreads - 1) |
| 700 | tsleep(&p->p_nstopped, 0, "freeze", 1); |
| 701 | error = generic_elf_coredump(lp, SIGCKPT, fp, limit); |
| 702 | proc_unstop(p); |
| 703 | } else { |
| 704 | error = ERANGE; |
| 705 | } |
| 706 | return error; |
| 707 | } |
| 708 | |
| 709 | /* |
| 710 | * MPALMOSTSAFE |
| 711 | */ |
| 712 | int |
| 713 | sys_sys_checkpoint(struct sys_checkpoint_args *uap) |
| 714 | { |
| 715 | int error = 0; |
| 716 | struct thread *td = curthread; |
| 717 | struct proc *p = td->td_proc; |
| 718 | struct filedesc *fdp = p->p_fd; |
| 719 | struct file *fp; |
| 720 | |
| 721 | /* |
| 722 | * Only certain groups (to reduce our security exposure). -1 |
| 723 | * allows any group. |
| 724 | */ |
| 725 | if (ckptgroup >= 0 && groupmember(ckptgroup, td->td_ucred) == 0) |
| 726 | return (EPERM); |
| 727 | |
| 728 | /* |
| 729 | * For now we can only checkpoint the current process |
| 730 | */ |
| 731 | if (uap->pid != -1 && uap->pid != p->p_pid) |
| 732 | return (EINVAL); |
| 733 | |
| 734 | get_mplock(); |
| 735 | |
| 736 | switch (uap->type) { |
| 737 | case CKPT_FREEZE: |
| 738 | fp = NULL; |
| 739 | if (uap->fd == -1 && uap->pid == (pid_t)-1) |
| 740 | error = checkpoint_signal_handler(td->td_lwp); |
| 741 | else if ((fp = holdfp(fdp, uap->fd, FWRITE)) == NULL) |
| 742 | error = EBADF; |
| 743 | else |
| 744 | error = ckpt_freeze_proc(td->td_lwp, fp); |
| 745 | if (fp) |
| 746 | fdrop(fp); |
| 747 | break; |
| 748 | case CKPT_THAW: |
| 749 | if (uap->pid != -1) { |
| 750 | error = EINVAL; |
| 751 | break; |
| 752 | } |
| 753 | if ((fp = holdfp(fdp, uap->fd, FREAD)) == NULL) { |
| 754 | error = EBADF; |
| 755 | break; |
| 756 | } |
| 757 | uap->sysmsg_result = uap->retval; |
| 758 | error = ckpt_thaw_proc(td->td_lwp, fp); |
| 759 | fdrop(fp); |
| 760 | break; |
| 761 | default: |
| 762 | error = EOPNOTSUPP; |
| 763 | break; |
| 764 | } |
| 765 | rel_mplock(); |
| 766 | return error; |
| 767 | } |
| 768 | |
| 769 | int |
| 770 | checkpoint_signal_handler(struct lwp *lp) |
| 771 | { |
| 772 | struct thread *td = lp->lwp_thread; |
| 773 | struct proc *p = lp->lwp_proc; |
| 774 | char *buf; |
| 775 | struct file *fp; |
| 776 | struct nlookupdata nd; |
| 777 | int error; |
| 778 | |
| 779 | chptinuse++; |
| 780 | |
| 781 | /* |
| 782 | * Being able to checkpoint an suid or sgid program is not a good |
| 783 | * idea. |
| 784 | */ |
| 785 | if (sugid_coredump == 0 && (p->p_flag & P_SUGID)) { |
| 786 | chptinuse--; |
| 787 | return (EPERM); |
| 788 | } |
| 789 | |
| 790 | buf = ckpt_expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid); |
| 791 | if (buf == NULL) { |
| 792 | chptinuse--; |
| 793 | return (ENOMEM); |
| 794 | } |
| 795 | |
| 796 | log(LOG_INFO, "pid %d (%s), uid %d: checkpointing to %s\n", |
| 797 | p->p_pid, p->p_comm, |
| 798 | (td->td_ucred ? td->td_ucred->cr_uid : -1), |
| 799 | buf); |
| 800 | |
| 801 | PRINTF(("ckpt handler called, using '%s'\n", buf)); |
| 802 | |
| 803 | /* |
| 804 | * Use the same safety flags that the coredump code uses. Remove |
| 805 | * any previous checkpoint file before writing out the new one in |
| 806 | * case we are re-checkpointing a program that had been checkpt |
| 807 | * restored. Otherwise we will corrupt the program space (which is |
| 808 | * made up of mmap()ings of the previous checkpoint file) while we |
| 809 | * write out the new one. |
| 810 | */ |
| 811 | error = nlookup_init(&nd, buf, UIO_SYSSPACE, 0); |
| 812 | if (error == 0) |
| 813 | error = kern_unlink(&nd); |
| 814 | nlookup_done(&nd); |
| 815 | error = fp_open(buf, O_WRONLY|O_CREAT|O_TRUNC|O_NOFOLLOW, 0600, &fp); |
| 816 | if (error == 0) { |
| 817 | error = ckpt_freeze_proc(lp, fp); |
| 818 | fp_close(fp); |
| 819 | } else { |
| 820 | kprintf("checkpoint failed with open - error: %d\n", error); |
| 821 | } |
| 822 | kfree(buf, M_TEMP); |
| 823 | chptinuse--; |
| 824 | return (error); |
| 825 | } |
| 826 | |
| 827 | static char ckptfilename[MAXPATHLEN] = {"%N.ckpt"}; |
| 828 | SYSCTL_STRING(_kern, OID_AUTO, ckptfile, CTLFLAG_RW, ckptfilename, |
| 829 | sizeof(ckptfilename), "process checkpoint name format string"); |
| 830 | |
| 831 | /* |
| 832 | * expand_name(name, uid, pid) |
| 833 | * Expand the name described in corefilename, using name, uid, and pid. |
| 834 | * corefilename is a kprintf-like string, with three format specifiers: |
| 835 | * %N name of process ("name") |
| 836 | * %P process id (pid) |
| 837 | * %U user id (uid) |
| 838 | * For example, "%N.core" is the default; they can be disabled completely |
| 839 | * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". |
| 840 | * This is controlled by the sysctl variable kern.corefile (see above). |
| 841 | * |
| 842 | * -- taken from the coredump code |
| 843 | */ |
| 844 | |
| 845 | static |
| 846 | char * |
| 847 | ckpt_expand_name(const char *name, uid_t uid, pid_t pid) |
| 848 | { |
| 849 | char *temp; |
| 850 | char *bp; |
| 851 | char buf[11]; /* Buffer for pid/uid -- max 4B */ |
| 852 | int error; |
| 853 | int i; |
| 854 | int n; |
| 855 | char *format = ckptfilename; |
| 856 | size_t namelen; |
| 857 | |
| 858 | temp = kmalloc(MAXPATHLEN + 1, M_TEMP, M_NOWAIT); |
| 859 | if (temp == NULL) |
| 860 | return NULL; |
| 861 | namelen = strlen(name); |
| 862 | n = 0; |
| 863 | if (ckptfilename[0] != '/') { |
| 864 | if ((bp = kern_getcwd(temp, MAXPATHLEN - 1, &error)) == NULL) { |
| 865 | kfree(temp, M_TEMP); |
| 866 | return NULL; |
| 867 | } |
| 868 | n = strlen(bp); |
| 869 | bcopy(bp, temp, n + 1); /* normalize location of the path */ |
| 870 | temp[n++] = '/'; |
| 871 | temp[n] = '\0'; |
| 872 | } |
| 873 | for (i= 0; n < MAXPATHLEN && format[i]; i++) { |
| 874 | int l; |
| 875 | switch (format[i]) { |
| 876 | case '%': /* Format character */ |
| 877 | i++; |
| 878 | switch (format[i]) { |
| 879 | case '%': |
| 880 | temp[n++] = '%'; |
| 881 | break; |
| 882 | case 'N': /* process name */ |
| 883 | if ((n + namelen) > MAXPATHLEN) { |
| 884 | log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", |
| 885 | pid, name, uid, temp, name); |
| 886 | kfree(temp, M_TEMP); |
| 887 | return NULL; |
| 888 | } |
| 889 | memcpy(temp+n, name, namelen); |
| 890 | n += namelen; |
| 891 | break; |
| 892 | case 'P': /* process id */ |
| 893 | l = ksprintf(buf, "%u", pid); |
| 894 | if ((n + l) > MAXPATHLEN) { |
| 895 | log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", |
| 896 | pid, name, uid, temp, name); |
| 897 | kfree(temp, M_TEMP); |
| 898 | return NULL; |
| 899 | } |
| 900 | memcpy(temp+n, buf, l); |
| 901 | n += l; |
| 902 | break; |
| 903 | case 'U': /* user id */ |
| 904 | l = ksprintf(buf, "%u", uid); |
| 905 | if ((n + l) > MAXPATHLEN) { |
| 906 | log(LOG_ERR, "pid %d (%s), uid (%u): Path `%s%s' is too long\n", |
| 907 | pid, name, uid, temp, name); |
| 908 | kfree(temp, M_TEMP); |
| 909 | return NULL; |
| 910 | } |
| 911 | memcpy(temp+n, buf, l); |
| 912 | n += l; |
| 913 | break; |
| 914 | default: |
| 915 | log(LOG_ERR, "Unknown format character %c in `%s'\n", format[i], format); |
| 916 | } |
| 917 | break; |
| 918 | default: |
| 919 | temp[n++] = format[i]; |
| 920 | } |
| 921 | } |
| 922 | temp[n] = '\0'; |
| 923 | return temp; |
| 924 | } |
| 925 | |