1 /* 2 * linux/kernel/sys.c 3 * 4 * Copyright (C) 1991, 1992 Linus Torvalds 5 */ 6 7 #include <linux/export.h> 8 #include <linux/mm.h> 9 #include <linux/utsname.h> 10 #include <linux/mman.h> 11 #include <linux/reboot.h> 12 #include <linux/prctl.h> 13 #include <linux/highuid.h> 14 #include <linux/fs.h> 15 #include <linux/kmod.h> 16 #include <linux/perf_event.h> 17 #include <linux/resource.h> 18 #include <linux/kernel.h> 19 #include <linux/workqueue.h> 20 #include <linux/capability.h> 21 #include <linux/device.h> 22 #include <linux/key.h> 23 #include <linux/times.h> 24 #include <linux/posix-timers.h> 25 #include <linux/security.h> 26 #include <linux/dcookies.h> 27 #include <linux/suspend.h> 28 #include <linux/tty.h> 29 #include <linux/signal.h> 30 #include <linux/cn_proc.h> 31 #include <linux/getcpu.h> 32 #include <linux/task_io_accounting_ops.h> 33 #include <linux/seccomp.h> 34 #include <linux/cpu.h> 35 #include <linux/personality.h> 36 #include <linux/ptrace.h> 37 #include <linux/fs_struct.h> 38 #include <linux/file.h> 39 #include <linux/mount.h> 40 #include <linux/gfp.h> 41 #include <linux/syscore_ops.h> 42 #include <linux/version.h> 43 #include <linux/ctype.h> 44 45 #include <linux/compat.h> 46 #include <linux/syscalls.h> 47 #include <linux/kprobes.h> 48 #include <linux/user_namespace.h> 49 #include <linux/binfmts.h> 50 51 #include <linux/sched.h> 52 #include <linux/sched/autogroup.h> 53 #include <linux/sched/loadavg.h> 54 #include <linux/sched/stat.h> 55 #include <linux/sched/mm.h> 56 #include <linux/sched/coredump.h> 57 #include <linux/sched/task.h> 58 #include <linux/sched/cputime.h> 59 #include <linux/rcupdate.h> 60 #include <linux/uidgid.h> 61 #include <linux/cred.h> 62 63 #include <linux/kmsg_dump.h> 64 /* Move somewhere else to avoid recompiling? */ 65 #include <generated/utsrelease.h> 66 67 #include <linux/uaccess.h> 68 #include <asm/io.h> 69 #include <asm/unistd.h> 70 71 #ifndef SET_UNALIGN_CTL 72 # define SET_UNALIGN_CTL(a, b) (-EINVAL) 73 #endif 74 #ifndef GET_UNALIGN_CTL 75 # define GET_UNALIGN_CTL(a, b) (-EINVAL) 76 #endif 77 #ifndef SET_FPEMU_CTL 78 # define SET_FPEMU_CTL(a, b) (-EINVAL) 79 #endif 80 #ifndef GET_FPEMU_CTL 81 # define GET_FPEMU_CTL(a, b) (-EINVAL) 82 #endif 83 #ifndef SET_FPEXC_CTL 84 # define SET_FPEXC_CTL(a, b) (-EINVAL) 85 #endif 86 #ifndef GET_FPEXC_CTL 87 # define GET_FPEXC_CTL(a, b) (-EINVAL) 88 #endif 89 #ifndef GET_ENDIAN 90 # define GET_ENDIAN(a, b) (-EINVAL) 91 #endif 92 #ifndef SET_ENDIAN 93 # define SET_ENDIAN(a, b) (-EINVAL) 94 #endif 95 #ifndef GET_TSC_CTL 96 # define GET_TSC_CTL(a) (-EINVAL) 97 #endif 98 #ifndef SET_TSC_CTL 99 # define SET_TSC_CTL(a) (-EINVAL) 100 #endif 101 #ifndef MPX_ENABLE_MANAGEMENT 102 # define MPX_ENABLE_MANAGEMENT() (-EINVAL) 103 #endif 104 #ifndef MPX_DISABLE_MANAGEMENT 105 # define MPX_DISABLE_MANAGEMENT() (-EINVAL) 106 #endif 107 #ifndef GET_FP_MODE 108 # define GET_FP_MODE(a) (-EINVAL) 109 #endif 110 #ifndef SET_FP_MODE 111 # define SET_FP_MODE(a,b) (-EINVAL) 112 #endif 113 114 /* 115 * this is where the system-wide overflow UID and GID are defined, for 116 * architectures that now have 32-bit UID/GID but didn't in the past 117 */ 118 119 int overflowuid = DEFAULT_OVERFLOWUID; 120 int overflowgid = DEFAULT_OVERFLOWGID; 121 122 EXPORT_SYMBOL(overflowuid); 123 EXPORT_SYMBOL(overflowgid); 124 125 /* 126 * the same as above, but for filesystems which can only store a 16-bit 127 * UID and GID. as such, this is needed on all architectures 128 */ 129 130 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID; 131 int fs_overflowgid = DEFAULT_FS_OVERFLOWUID; 132 133 EXPORT_SYMBOL(fs_overflowuid); 134 EXPORT_SYMBOL(fs_overflowgid); 135 136 /* 137 * Returns true if current's euid is same as p's uid or euid, 138 * or has CAP_SYS_NICE to p's user_ns. 139 * 140 * Called with rcu_read_lock, creds are safe 141 */ 142 static bool set_one_prio_perm(struct task_struct *p) 143 { 144 const struct cred *cred = current_cred(), *pcred = __task_cred(p); 145 146 if (uid_eq(pcred->uid, cred->euid) || 147 uid_eq(pcred->euid, cred->euid)) 148 return true; 149 if (ns_capable(pcred->user_ns, CAP_SYS_NICE)) 150 return true; 151 return false; 152 } 153 154 /* 155 * set the priority of a task 156 * - the caller must hold the RCU read lock 157 */ 158 static int set_one_prio(struct task_struct *p, int niceval, int error) 159 { 160 int no_nice; 161 162 if (!set_one_prio_perm(p)) { 163 error = -EPERM; 164 goto out; 165 } 166 if (niceval < task_nice(p) && !can_nice(p, niceval)) { 167 error = -EACCES; 168 goto out; 169 } 170 no_nice = security_task_setnice(p, niceval); 171 if (no_nice) { 172 error = no_nice; 173 goto out; 174 } 175 if (error == -ESRCH) 176 error = 0; 177 set_user_nice(p, niceval); 178 out: 179 return error; 180 } 181 182 SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval) 183 { 184 struct task_struct *g, *p; 185 struct user_struct *user; 186 const struct cred *cred = current_cred(); 187 int error = -EINVAL; 188 struct pid *pgrp; 189 kuid_t uid; 190 191 if (which > PRIO_USER || which < PRIO_PROCESS) 192 goto out; 193 194 /* normalize: avoid signed division (rounding problems) */ 195 error = -ESRCH; 196 if (niceval < MIN_NICE) 197 niceval = MIN_NICE; 198 if (niceval > MAX_NICE) 199 niceval = MAX_NICE; 200 201 rcu_read_lock(); 202 read_lock(&tasklist_lock); 203 switch (which) { 204 case PRIO_PROCESS: 205 if (who) 206 p = find_task_by_vpid(who); 207 else 208 p = current; 209 if (p) 210 error = set_one_prio(p, niceval, error); 211 break; 212 case PRIO_PGRP: 213 if (who) 214 pgrp = find_vpid(who); 215 else 216 pgrp = task_pgrp(current); 217 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { 218 error = set_one_prio(p, niceval, error); 219 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); 220 break; 221 case PRIO_USER: 222 uid = make_kuid(cred->user_ns, who); 223 user = cred->user; 224 if (!who) 225 uid = cred->uid; 226 else if (!uid_eq(uid, cred->uid)) { 227 user = find_user(uid); 228 if (!user) 229 goto out_unlock; /* No processes for this user */ 230 } 231 do_each_thread(g, p) { 232 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) 233 error = set_one_prio(p, niceval, error); 234 } while_each_thread(g, p); 235 if (!uid_eq(uid, cred->uid)) 236 free_uid(user); /* For find_user() */ 237 break; 238 } 239 out_unlock: 240 read_unlock(&tasklist_lock); 241 rcu_read_unlock(); 242 out: 243 return error; 244 } 245 246 /* 247 * Ugh. To avoid negative return values, "getpriority()" will 248 * not return the normal nice-value, but a negated value that 249 * has been offset by 20 (ie it returns 40..1 instead of -20..19) 250 * to stay compatible. 251 */ 252 SYSCALL_DEFINE2(getpriority, int, which, int, who) 253 { 254 struct task_struct *g, *p; 255 struct user_struct *user; 256 const struct cred *cred = current_cred(); 257 long niceval, retval = -ESRCH; 258 struct pid *pgrp; 259 kuid_t uid; 260 261 if (which > PRIO_USER || which < PRIO_PROCESS) 262 return -EINVAL; 263 264 rcu_read_lock(); 265 read_lock(&tasklist_lock); 266 switch (which) { 267 case PRIO_PROCESS: 268 if (who) 269 p = find_task_by_vpid(who); 270 else 271 p = current; 272 if (p) { 273 niceval = nice_to_rlimit(task_nice(p)); 274 if (niceval > retval) 275 retval = niceval; 276 } 277 break; 278 case PRIO_PGRP: 279 if (who) 280 pgrp = find_vpid(who); 281 else 282 pgrp = task_pgrp(current); 283 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { 284 niceval = nice_to_rlimit(task_nice(p)); 285 if (niceval > retval) 286 retval = niceval; 287 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); 288 break; 289 case PRIO_USER: 290 uid = make_kuid(cred->user_ns, who); 291 user = cred->user; 292 if (!who) 293 uid = cred->uid; 294 else if (!uid_eq(uid, cred->uid)) { 295 user = find_user(uid); 296 if (!user) 297 goto out_unlock; /* No processes for this user */ 298 } 299 do_each_thread(g, p) { 300 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) { 301 niceval = nice_to_rlimit(task_nice(p)); 302 if (niceval > retval) 303 retval = niceval; 304 } 305 } while_each_thread(g, p); 306 if (!uid_eq(uid, cred->uid)) 307 free_uid(user); /* for find_user() */ 308 break; 309 } 310 out_unlock: 311 read_unlock(&tasklist_lock); 312 rcu_read_unlock(); 313 314 return retval; 315 } 316 317 /* 318 * Unprivileged users may change the real gid to the effective gid 319 * or vice versa. (BSD-style) 320 * 321 * If you set the real gid at all, or set the effective gid to a value not 322 * equal to the real gid, then the saved gid is set to the new effective gid. 323 * 324 * This makes it possible for a setgid program to completely drop its 325 * privileges, which is often a useful assertion to make when you are doing 326 * a security audit over a program. 327 * 328 * The general idea is that a program which uses just setregid() will be 329 * 100% compatible with BSD. A program which uses just setgid() will be 330 * 100% compatible with POSIX with saved IDs. 331 * 332 * SMP: There are not races, the GIDs are checked only by filesystem 333 * operations (as far as semantic preservation is concerned). 334 */ 335 #ifdef CONFIG_MULTIUSER 336 SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid) 337 { 338 struct user_namespace *ns = current_user_ns(); 339 const struct cred *old; 340 struct cred *new; 341 int retval; 342 kgid_t krgid, kegid; 343 344 krgid = make_kgid(ns, rgid); 345 kegid = make_kgid(ns, egid); 346 347 if ((rgid != (gid_t) -1) && !gid_valid(krgid)) 348 return -EINVAL; 349 if ((egid != (gid_t) -1) && !gid_valid(kegid)) 350 return -EINVAL; 351 352 new = prepare_creds(); 353 if (!new) 354 return -ENOMEM; 355 old = current_cred(); 356 357 retval = -EPERM; 358 if (rgid != (gid_t) -1) { 359 if (gid_eq(old->gid, krgid) || 360 gid_eq(old->egid, krgid) || 361 ns_capable(old->user_ns, CAP_SETGID)) 362 new->gid = krgid; 363 else 364 goto error; 365 } 366 if (egid != (gid_t) -1) { 367 if (gid_eq(old->gid, kegid) || 368 gid_eq(old->egid, kegid) || 369 gid_eq(old->sgid, kegid) || 370 ns_capable(old->user_ns, CAP_SETGID)) 371 new->egid = kegid; 372 else 373 goto error; 374 } 375 376 if (rgid != (gid_t) -1 || 377 (egid != (gid_t) -1 && !gid_eq(kegid, old->gid))) 378 new->sgid = new->egid; 379 new->fsgid = new->egid; 380 381 return commit_creds(new); 382 383 error: 384 abort_creds(new); 385 return retval; 386 } 387 388 /* 389 * setgid() is implemented like SysV w/ SAVED_IDS 390 * 391 * SMP: Same implicit races as above. 392 */ 393 SYSCALL_DEFINE1(setgid, gid_t, gid) 394 { 395 struct user_namespace *ns = current_user_ns(); 396 const struct cred *old; 397 struct cred *new; 398 int retval; 399 kgid_t kgid; 400 401 kgid = make_kgid(ns, gid); 402 if (!gid_valid(kgid)) 403 return -EINVAL; 404 405 new = prepare_creds(); 406 if (!new) 407 return -ENOMEM; 408 old = current_cred(); 409 410 retval = -EPERM; 411 if (ns_capable(old->user_ns, CAP_SETGID)) 412 new->gid = new->egid = new->sgid = new->fsgid = kgid; 413 else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid)) 414 new->egid = new->fsgid = kgid; 415 else 416 goto error; 417 418 return commit_creds(new); 419 420 error: 421 abort_creds(new); 422 return retval; 423 } 424 425 /* 426 * change the user struct in a credentials set to match the new UID 427 */ 428 static int set_user(struct cred *new) 429 { 430 struct user_struct *new_user; 431 432 new_user = alloc_uid(new->uid); 433 if (!new_user) 434 return -EAGAIN; 435 436 /* 437 * We don't fail in case of NPROC limit excess here because too many 438 * poorly written programs don't check set*uid() return code, assuming 439 * it never fails if called by root. We may still enforce NPROC limit 440 * for programs doing set*uid()+execve() by harmlessly deferring the 441 * failure to the execve() stage. 442 */ 443 if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) && 444 new_user != INIT_USER) 445 current->flags |= PF_NPROC_EXCEEDED; 446 else 447 current->flags &= ~PF_NPROC_EXCEEDED; 448 449 free_uid(new->user); 450 new->user = new_user; 451 return 0; 452 } 453 454 /* 455 * Unprivileged users may change the real uid to the effective uid 456 * or vice versa. (BSD-style) 457 * 458 * If you set the real uid at all, or set the effective uid to a value not 459 * equal to the real uid, then the saved uid is set to the new effective uid. 460 * 461 * This makes it possible for a setuid program to completely drop its 462 * privileges, which is often a useful assertion to make when you are doing 463 * a security audit over a program. 464 * 465 * The general idea is that a program which uses just setreuid() will be 466 * 100% compatible with BSD. A program which uses just setuid() will be 467 * 100% compatible with POSIX with saved IDs. 468 */ 469 SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid) 470 { 471 struct user_namespace *ns = current_user_ns(); 472 const struct cred *old; 473 struct cred *new; 474 int retval; 475 kuid_t kruid, keuid; 476 477 kruid = make_kuid(ns, ruid); 478 keuid = make_kuid(ns, euid); 479 480 if ((ruid != (uid_t) -1) && !uid_valid(kruid)) 481 return -EINVAL; 482 if ((euid != (uid_t) -1) && !uid_valid(keuid)) 483 return -EINVAL; 484 485 new = prepare_creds(); 486 if (!new) 487 return -ENOMEM; 488 old = current_cred(); 489 490 retval = -EPERM; 491 if (ruid != (uid_t) -1) { 492 new->uid = kruid; 493 if (!uid_eq(old->uid, kruid) && 494 !uid_eq(old->euid, kruid) && 495 !ns_capable(old->user_ns, CAP_SETUID)) 496 goto error; 497 } 498 499 if (euid != (uid_t) -1) { 500 new->euid = keuid; 501 if (!uid_eq(old->uid, keuid) && 502 !uid_eq(old->euid, keuid) && 503 !uid_eq(old->suid, keuid) && 504 !ns_capable(old->user_ns, CAP_SETUID)) 505 goto error; 506 } 507 508 if (!uid_eq(new->uid, old->uid)) { 509 retval = set_user(new); 510 if (retval < 0) 511 goto error; 512 } 513 if (ruid != (uid_t) -1 || 514 (euid != (uid_t) -1 && !uid_eq(keuid, old->uid))) 515 new->suid = new->euid; 516 new->fsuid = new->euid; 517 518 retval = security_task_fix_setuid(new, old, LSM_SETID_RE); 519 if (retval < 0) 520 goto error; 521 522 return commit_creds(new); 523 524 error: 525 abort_creds(new); 526 return retval; 527 } 528 529 /* 530 * setuid() is implemented like SysV with SAVED_IDS 531 * 532 * Note that SAVED_ID's is deficient in that a setuid root program 533 * like sendmail, for example, cannot set its uid to be a normal 534 * user and then switch back, because if you're root, setuid() sets 535 * the saved uid too. If you don't like this, blame the bright people 536 * in the POSIX committee and/or USG. Note that the BSD-style setreuid() 537 * will allow a root program to temporarily drop privileges and be able to 538 * regain them by swapping the real and effective uid. 539 */ 540 SYSCALL_DEFINE1(setuid, uid_t, uid) 541 { 542 struct user_namespace *ns = current_user_ns(); 543 const struct cred *old; 544 struct cred *new; 545 int retval; 546 kuid_t kuid; 547 548 kuid = make_kuid(ns, uid); 549 if (!uid_valid(kuid)) 550 return -EINVAL; 551 552 new = prepare_creds(); 553 if (!new) 554 return -ENOMEM; 555 old = current_cred(); 556 557 retval = -EPERM; 558 if (ns_capable(old->user_ns, CAP_SETUID)) { 559 new->suid = new->uid = kuid; 560 if (!uid_eq(kuid, old->uid)) { 561 retval = set_user(new); 562 if (retval < 0) 563 goto error; 564 } 565 } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) { 566 goto error; 567 } 568 569 new->fsuid = new->euid = kuid; 570 571 retval = security_task_fix_setuid(new, old, LSM_SETID_ID); 572 if (retval < 0) 573 goto error; 574 575 return commit_creds(new); 576 577 error: 578 abort_creds(new); 579 return retval; 580 } 581 582 583 /* 584 * This function implements a generic ability to update ruid, euid, 585 * and suid. This allows you to implement the 4.4 compatible seteuid(). 586 */ 587 SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid) 588 { 589 struct user_namespace *ns = current_user_ns(); 590 const struct cred *old; 591 struct cred *new; 592 int retval; 593 kuid_t kruid, keuid, ksuid; 594 595 kruid = make_kuid(ns, ruid); 596 keuid = make_kuid(ns, euid); 597 ksuid = make_kuid(ns, suid); 598 599 if ((ruid != (uid_t) -1) && !uid_valid(kruid)) 600 return -EINVAL; 601 602 if ((euid != (uid_t) -1) && !uid_valid(keuid)) 603 return -EINVAL; 604 605 if ((suid != (uid_t) -1) && !uid_valid(ksuid)) 606 return -EINVAL; 607 608 new = prepare_creds(); 609 if (!new) 610 return -ENOMEM; 611 612 old = current_cred(); 613 614 retval = -EPERM; 615 if (!ns_capable(old->user_ns, CAP_SETUID)) { 616 if (ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) && 617 !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid)) 618 goto error; 619 if (euid != (uid_t) -1 && !uid_eq(keuid, old->uid) && 620 !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid)) 621 goto error; 622 if (suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) && 623 !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid)) 624 goto error; 625 } 626 627 if (ruid != (uid_t) -1) { 628 new->uid = kruid; 629 if (!uid_eq(kruid, old->uid)) { 630 retval = set_user(new); 631 if (retval < 0) 632 goto error; 633 } 634 } 635 if (euid != (uid_t) -1) 636 new->euid = keuid; 637 if (suid != (uid_t) -1) 638 new->suid = ksuid; 639 new->fsuid = new->euid; 640 641 retval = security_task_fix_setuid(new, old, LSM_SETID_RES); 642 if (retval < 0) 643 goto error; 644 645 return commit_creds(new); 646 647 error: 648 abort_creds(new); 649 return retval; 650 } 651 652 SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp) 653 { 654 const struct cred *cred = current_cred(); 655 int retval; 656 uid_t ruid, euid, suid; 657 658 ruid = from_kuid_munged(cred->user_ns, cred->uid); 659 euid = from_kuid_munged(cred->user_ns, cred->euid); 660 suid = from_kuid_munged(cred->user_ns, cred->suid); 661 662 retval = put_user(ruid, ruidp); 663 if (!retval) { 664 retval = put_user(euid, euidp); 665 if (!retval) 666 return put_user(suid, suidp); 667 } 668 return retval; 669 } 670 671 /* 672 * Same as above, but for rgid, egid, sgid. 673 */ 674 SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid) 675 { 676 struct user_namespace *ns = current_user_ns(); 677 const struct cred *old; 678 struct cred *new; 679 int retval; 680 kgid_t krgid, kegid, ksgid; 681 682 krgid = make_kgid(ns, rgid); 683 kegid = make_kgid(ns, egid); 684 ksgid = make_kgid(ns, sgid); 685 686 if ((rgid != (gid_t) -1) && !gid_valid(krgid)) 687 return -EINVAL; 688 if ((egid != (gid_t) -1) && !gid_valid(kegid)) 689 return -EINVAL; 690 if ((sgid != (gid_t) -1) && !gid_valid(ksgid)) 691 return -EINVAL; 692 693 new = prepare_creds(); 694 if (!new) 695 return -ENOMEM; 696 old = current_cred(); 697 698 retval = -EPERM; 699 if (!ns_capable(old->user_ns, CAP_SETGID)) { 700 if (rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) && 701 !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid)) 702 goto error; 703 if (egid != (gid_t) -1 && !gid_eq(kegid, old->gid) && 704 !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid)) 705 goto error; 706 if (sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) && 707 !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid)) 708 goto error; 709 } 710 711 if (rgid != (gid_t) -1) 712 new->gid = krgid; 713 if (egid != (gid_t) -1) 714 new->egid = kegid; 715 if (sgid != (gid_t) -1) 716 new->sgid = ksgid; 717 new->fsgid = new->egid; 718 719 return commit_creds(new); 720 721 error: 722 abort_creds(new); 723 return retval; 724 } 725 726 SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp) 727 { 728 const struct cred *cred = current_cred(); 729 int retval; 730 gid_t rgid, egid, sgid; 731 732 rgid = from_kgid_munged(cred->user_ns, cred->gid); 733 egid = from_kgid_munged(cred->user_ns, cred->egid); 734 sgid = from_kgid_munged(cred->user_ns, cred->sgid); 735 736 retval = put_user(rgid, rgidp); 737 if (!retval) { 738 retval = put_user(egid, egidp); 739 if (!retval) 740 retval = put_user(sgid, sgidp); 741 } 742 743 return retval; 744 } 745 746 747 /* 748 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This 749 * is used for "access()" and for the NFS daemon (letting nfsd stay at 750 * whatever uid it wants to). It normally shadows "euid", except when 751 * explicitly set by setfsuid() or for access.. 752 */ 753 SYSCALL_DEFINE1(setfsuid, uid_t, uid) 754 { 755 const struct cred *old; 756 struct cred *new; 757 uid_t old_fsuid; 758 kuid_t kuid; 759 760 old = current_cred(); 761 old_fsuid = from_kuid_munged(old->user_ns, old->fsuid); 762 763 kuid = make_kuid(old->user_ns, uid); 764 if (!uid_valid(kuid)) 765 return old_fsuid; 766 767 new = prepare_creds(); 768 if (!new) 769 return old_fsuid; 770 771 if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) || 772 uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) || 773 ns_capable(old->user_ns, CAP_SETUID)) { 774 if (!uid_eq(kuid, old->fsuid)) { 775 new->fsuid = kuid; 776 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0) 777 goto change_okay; 778 } 779 } 780 781 abort_creds(new); 782 return old_fsuid; 783 784 change_okay: 785 commit_creds(new); 786 return old_fsuid; 787 } 788 789 /* 790 * Samma på svenska.. 791 */ 792 SYSCALL_DEFINE1(setfsgid, gid_t, gid) 793 { 794 const struct cred *old; 795 struct cred *new; 796 gid_t old_fsgid; 797 kgid_t kgid; 798 799 old = current_cred(); 800 old_fsgid = from_kgid_munged(old->user_ns, old->fsgid); 801 802 kgid = make_kgid(old->user_ns, gid); 803 if (!gid_valid(kgid)) 804 return old_fsgid; 805 806 new = prepare_creds(); 807 if (!new) 808 return old_fsgid; 809 810 if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) || 811 gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) || 812 ns_capable(old->user_ns, CAP_SETGID)) { 813 if (!gid_eq(kgid, old->fsgid)) { 814 new->fsgid = kgid; 815 goto change_okay; 816 } 817 } 818 819 abort_creds(new); 820 return old_fsgid; 821 822 change_okay: 823 commit_creds(new); 824 return old_fsgid; 825 } 826 #endif /* CONFIG_MULTIUSER */ 827 828 /** 829 * sys_getpid - return the thread group id of the current process 830 * 831 * Note, despite the name, this returns the tgid not the pid. The tgid and 832 * the pid are identical unless CLONE_THREAD was specified on clone() in 833 * which case the tgid is the same in all threads of the same group. 834 * 835 * This is SMP safe as current->tgid does not change. 836 */ 837 SYSCALL_DEFINE0(getpid) 838 { 839 return task_tgid_vnr(current); 840 } 841 842 /* Thread ID - the internal kernel "pid" */ 843 SYSCALL_DEFINE0(gettid) 844 { 845 return task_pid_vnr(current); 846 } 847 848 /* 849 * Accessing ->real_parent is not SMP-safe, it could 850 * change from under us. However, we can use a stale 851 * value of ->real_parent under rcu_read_lock(), see 852 * release_task()->call_rcu(delayed_put_task_struct). 853 */ 854 SYSCALL_DEFINE0(getppid) 855 { 856 int pid; 857 858 rcu_read_lock(); 859 pid = task_tgid_vnr(rcu_dereference(current->real_parent)); 860 rcu_read_unlock(); 861 862 return pid; 863 } 864 865 SYSCALL_DEFINE0(getuid) 866 { 867 /* Only we change this so SMP safe */ 868 return from_kuid_munged(current_user_ns(), current_uid()); 869 } 870 871 SYSCALL_DEFINE0(geteuid) 872 { 873 /* Only we change this so SMP safe */ 874 return from_kuid_munged(current_user_ns(), current_euid()); 875 } 876 877 SYSCALL_DEFINE0(getgid) 878 { 879 /* Only we change this so SMP safe */ 880 return from_kgid_munged(current_user_ns(), current_gid()); 881 } 882 883 SYSCALL_DEFINE0(getegid) 884 { 885 /* Only we change this so SMP safe */ 886 return from_kgid_munged(current_user_ns(), current_egid()); 887 } 888 889 void do_sys_times(struct tms *tms) 890 { 891 u64 tgutime, tgstime, cutime, cstime; 892 893 thread_group_cputime_adjusted(current, &tgutime, &tgstime); 894 cutime = current->signal->cutime; 895 cstime = current->signal->cstime; 896 tms->tms_utime = nsec_to_clock_t(tgutime); 897 tms->tms_stime = nsec_to_clock_t(tgstime); 898 tms->tms_cutime = nsec_to_clock_t(cutime); 899 tms->tms_cstime = nsec_to_clock_t(cstime); 900 } 901 902 SYSCALL_DEFINE1(times, struct tms __user *, tbuf) 903 { 904 if (tbuf) { 905 struct tms tmp; 906 907 do_sys_times(&tmp); 908 if (copy_to_user(tbuf, &tmp, sizeof(struct tms))) 909 return -EFAULT; 910 } 911 force_successful_syscall_return(); 912 return (long) jiffies_64_to_clock_t(get_jiffies_64()); 913 } 914 915 /* 916 * This needs some heavy checking ... 917 * I just haven't the stomach for it. I also don't fully 918 * understand sessions/pgrp etc. Let somebody who does explain it. 919 * 920 * OK, I think I have the protection semantics right.... this is really 921 * only important on a multi-user system anyway, to make sure one user 922 * can't send a signal to a process owned by another. -TYT, 12/12/91 923 * 924 * !PF_FORKNOEXEC check to conform completely to POSIX. 925 */ 926 SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid) 927 { 928 struct task_struct *p; 929 struct task_struct *group_leader = current->group_leader; 930 struct pid *pgrp; 931 int err; 932 933 if (!pid) 934 pid = task_pid_vnr(group_leader); 935 if (!pgid) 936 pgid = pid; 937 if (pgid < 0) 938 return -EINVAL; 939 rcu_read_lock(); 940 941 /* From this point forward we keep holding onto the tasklist lock 942 * so that our parent does not change from under us. -DaveM 943 */ 944 write_lock_irq(&tasklist_lock); 945 946 err = -ESRCH; 947 p = find_task_by_vpid(pid); 948 if (!p) 949 goto out; 950 951 err = -EINVAL; 952 if (!thread_group_leader(p)) 953 goto out; 954 955 if (same_thread_group(p->real_parent, group_leader)) { 956 err = -EPERM; 957 if (task_session(p) != task_session(group_leader)) 958 goto out; 959 err = -EACCES; 960 if (!(p->flags & PF_FORKNOEXEC)) 961 goto out; 962 } else { 963 err = -ESRCH; 964 if (p != group_leader) 965 goto out; 966 } 967 968 err = -EPERM; 969 if (p->signal->leader) 970 goto out; 971 972 pgrp = task_pid(p); 973 if (pgid != pid) { 974 struct task_struct *g; 975 976 pgrp = find_vpid(pgid); 977 g = pid_task(pgrp, PIDTYPE_PGID); 978 if (!g || task_session(g) != task_session(group_leader)) 979 goto out; 980 } 981 982 err = security_task_setpgid(p, pgid); 983 if (err) 984 goto out; 985 986 if (task_pgrp(p) != pgrp) 987 change_pid(p, PIDTYPE_PGID, pgrp); 988 989 err = 0; 990 out: 991 /* All paths lead to here, thus we are safe. -DaveM */ 992 write_unlock_irq(&tasklist_lock); 993 rcu_read_unlock(); 994 return err; 995 } 996 997 SYSCALL_DEFINE1(getpgid, pid_t, pid) 998 { 999 struct task_struct *p; 1000 struct pid *grp; 1001 int retval; 1002 1003 rcu_read_lock(); 1004 if (!pid) 1005 grp = task_pgrp(current); 1006 else { 1007 retval = -ESRCH; 1008 p = find_task_by_vpid(pid); 1009 if (!p) 1010 goto out; 1011 grp = task_pgrp(p); 1012 if (!grp) 1013 goto out; 1014 1015 retval = security_task_getpgid(p); 1016 if (retval) 1017 goto out; 1018 } 1019 retval = pid_vnr(grp); 1020 out: 1021 rcu_read_unlock(); 1022 return retval; 1023 } 1024 1025 #ifdef __ARCH_WANT_SYS_GETPGRP 1026 1027 SYSCALL_DEFINE0(getpgrp) 1028 { 1029 return sys_getpgid(0); 1030 } 1031 1032 #endif 1033 1034 SYSCALL_DEFINE1(getsid, pid_t, pid) 1035 { 1036 struct task_struct *p; 1037 struct pid *sid; 1038 int retval; 1039 1040 rcu_read_lock(); 1041 if (!pid) 1042 sid = task_session(current); 1043 else { 1044 retval = -ESRCH; 1045 p = find_task_by_vpid(pid); 1046 if (!p) 1047 goto out; 1048 sid = task_session(p); 1049 if (!sid) 1050 goto out; 1051 1052 retval = security_task_getsid(p); 1053 if (retval) 1054 goto out; 1055 } 1056 retval = pid_vnr(sid); 1057 out: 1058 rcu_read_unlock(); 1059 return retval; 1060 } 1061 1062 static void set_special_pids(struct pid *pid) 1063 { 1064 struct task_struct *curr = current->group_leader; 1065 1066 if (task_session(curr) != pid) 1067 change_pid(curr, PIDTYPE_SID, pid); 1068 1069 if (task_pgrp(curr) != pid) 1070 change_pid(curr, PIDTYPE_PGID, pid); 1071 } 1072 1073 SYSCALL_DEFINE0(setsid) 1074 { 1075 struct task_struct *group_leader = current->group_leader; 1076 struct pid *sid = task_pid(group_leader); 1077 pid_t session = pid_vnr(sid); 1078 int err = -EPERM; 1079 1080 write_lock_irq(&tasklist_lock); 1081 /* Fail if I am already a session leader */ 1082 if (group_leader->signal->leader) 1083 goto out; 1084 1085 /* Fail if a process group id already exists that equals the 1086 * proposed session id. 1087 */ 1088 if (pid_task(sid, PIDTYPE_PGID)) 1089 goto out; 1090 1091 group_leader->signal->leader = 1; 1092 set_special_pids(sid); 1093 1094 proc_clear_tty(group_leader); 1095 1096 err = session; 1097 out: 1098 write_unlock_irq(&tasklist_lock); 1099 if (err > 0) { 1100 proc_sid_connector(group_leader); 1101 sched_autogroup_create_attach(group_leader); 1102 } 1103 return err; 1104 } 1105 1106 DECLARE_RWSEM(uts_sem); 1107 1108 #ifdef COMPAT_UTS_MACHINE 1109 #define override_architecture(name) \ 1110 (personality(current->personality) == PER_LINUX32 && \ 1111 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \ 1112 sizeof(COMPAT_UTS_MACHINE))) 1113 #else 1114 #define override_architecture(name) 0 1115 #endif 1116 1117 /* 1118 * Work around broken programs that cannot handle "Linux 3.0". 1119 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40 1120 * And we map 4.x to 2.6.60+x, so 4.0 would be 2.6.60. 1121 */ 1122 static int override_release(char __user *release, size_t len) 1123 { 1124 int ret = 0; 1125 1126 if (current->personality & UNAME26) { 1127 const char *rest = UTS_RELEASE; 1128 char buf[65] = { 0 }; 1129 int ndots = 0; 1130 unsigned v; 1131 size_t copy; 1132 1133 while (*rest) { 1134 if (*rest == '.' && ++ndots >= 3) 1135 break; 1136 if (!isdigit(*rest) && *rest != '.') 1137 break; 1138 rest++; 1139 } 1140 v = ((LINUX_VERSION_CODE >> 8) & 0xff) + 60; 1141 copy = clamp_t(size_t, len, 1, sizeof(buf)); 1142 copy = scnprintf(buf, copy, "2.6.%u%s", v, rest); 1143 ret = copy_to_user(release, buf, copy + 1); 1144 } 1145 return ret; 1146 } 1147 1148 SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name) 1149 { 1150 int errno = 0; 1151 1152 down_read(&uts_sem); 1153 if (copy_to_user(name, utsname(), sizeof *name)) 1154 errno = -EFAULT; 1155 up_read(&uts_sem); 1156 1157 if (!errno && override_release(name->release, sizeof(name->release))) 1158 errno = -EFAULT; 1159 if (!errno && override_architecture(name)) 1160 errno = -EFAULT; 1161 return errno; 1162 } 1163 1164 #ifdef __ARCH_WANT_SYS_OLD_UNAME 1165 /* 1166 * Old cruft 1167 */ 1168 SYSCALL_DEFINE1(uname, struct old_utsname __user *, name) 1169 { 1170 int error = 0; 1171 1172 if (!name) 1173 return -EFAULT; 1174 1175 down_read(&uts_sem); 1176 if (copy_to_user(name, utsname(), sizeof(*name))) 1177 error = -EFAULT; 1178 up_read(&uts_sem); 1179 1180 if (!error && override_release(name->release, sizeof(name->release))) 1181 error = -EFAULT; 1182 if (!error && override_architecture(name)) 1183 error = -EFAULT; 1184 return error; 1185 } 1186 1187 SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name) 1188 { 1189 int error; 1190 1191 if (!name) 1192 return -EFAULT; 1193 if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname))) 1194 return -EFAULT; 1195 1196 down_read(&uts_sem); 1197 error = __copy_to_user(&name->sysname, &utsname()->sysname, 1198 __OLD_UTS_LEN); 1199 error |= __put_user(0, name->sysname + __OLD_UTS_LEN); 1200 error |= __copy_to_user(&name->nodename, &utsname()->nodename, 1201 __OLD_UTS_LEN); 1202 error |= __put_user(0, name->nodename + __OLD_UTS_LEN); 1203 error |= __copy_to_user(&name->release, &utsname()->release, 1204 __OLD_UTS_LEN); 1205 error |= __put_user(0, name->release + __OLD_UTS_LEN); 1206 error |= __copy_to_user(&name->version, &utsname()->version, 1207 __OLD_UTS_LEN); 1208 error |= __put_user(0, name->version + __OLD_UTS_LEN); 1209 error |= __copy_to_user(&name->machine, &utsname()->machine, 1210 __OLD_UTS_LEN); 1211 error |= __put_user(0, name->machine + __OLD_UTS_LEN); 1212 up_read(&uts_sem); 1213 1214 if (!error && override_architecture(name)) 1215 error = -EFAULT; 1216 if (!error && override_release(name->release, sizeof(name->release))) 1217 error = -EFAULT; 1218 return error ? -EFAULT : 0; 1219 } 1220 #endif 1221 1222 SYSCALL_DEFINE2(sethostname, char __user *, name, int, len) 1223 { 1224 int errno; 1225 char tmp[__NEW_UTS_LEN]; 1226 1227 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) 1228 return -EPERM; 1229 1230 if (len < 0 || len > __NEW_UTS_LEN) 1231 return -EINVAL; 1232 down_write(&uts_sem); 1233 errno = -EFAULT; 1234 if (!copy_from_user(tmp, name, len)) { 1235 struct new_utsname *u = utsname(); 1236 1237 memcpy(u->nodename, tmp, len); 1238 memset(u->nodename + len, 0, sizeof(u->nodename) - len); 1239 errno = 0; 1240 uts_proc_notify(UTS_PROC_HOSTNAME); 1241 } 1242 up_write(&uts_sem); 1243 return errno; 1244 } 1245 1246 #ifdef __ARCH_WANT_SYS_GETHOSTNAME 1247 1248 SYSCALL_DEFINE2(gethostname, char __user *, name, int, len) 1249 { 1250 int i, errno; 1251 struct new_utsname *u; 1252 1253 if (len < 0) 1254 return -EINVAL; 1255 down_read(&uts_sem); 1256 u = utsname(); 1257 i = 1 + strlen(u->nodename); 1258 if (i > len) 1259 i = len; 1260 errno = 0; 1261 if (copy_to_user(name, u->nodename, i)) 1262 errno = -EFAULT; 1263 up_read(&uts_sem); 1264 return errno; 1265 } 1266 1267 #endif 1268 1269 /* 1270 * Only setdomainname; getdomainname can be implemented by calling 1271 * uname() 1272 */ 1273 SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len) 1274 { 1275 int errno; 1276 char tmp[__NEW_UTS_LEN]; 1277 1278 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) 1279 return -EPERM; 1280 if (len < 0 || len > __NEW_UTS_LEN) 1281 return -EINVAL; 1282 1283 down_write(&uts_sem); 1284 errno = -EFAULT; 1285 if (!copy_from_user(tmp, name, len)) { 1286 struct new_utsname *u = utsname(); 1287 1288 memcpy(u->domainname, tmp, len); 1289 memset(u->domainname + len, 0, sizeof(u->domainname) - len); 1290 errno = 0; 1291 uts_proc_notify(UTS_PROC_DOMAINNAME); 1292 } 1293 up_write(&uts_sem); 1294 return errno; 1295 } 1296 1297 SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim) 1298 { 1299 struct rlimit value; 1300 int ret; 1301 1302 ret = do_prlimit(current, resource, NULL, &value); 1303 if (!ret) 1304 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0; 1305 1306 return ret; 1307 } 1308 1309 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT 1310 1311 /* 1312 * Back compatibility for getrlimit. Needed for some apps. 1313 */ 1314 SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource, 1315 struct rlimit __user *, rlim) 1316 { 1317 struct rlimit x; 1318 if (resource >= RLIM_NLIMITS) 1319 return -EINVAL; 1320 1321 task_lock(current->group_leader); 1322 x = current->signal->rlim[resource]; 1323 task_unlock(current->group_leader); 1324 if (x.rlim_cur > 0x7FFFFFFF) 1325 x.rlim_cur = 0x7FFFFFFF; 1326 if (x.rlim_max > 0x7FFFFFFF) 1327 x.rlim_max = 0x7FFFFFFF; 1328 return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0; 1329 } 1330 1331 #endif 1332 1333 static inline bool rlim64_is_infinity(__u64 rlim64) 1334 { 1335 #if BITS_PER_LONG < 64 1336 return rlim64 >= ULONG_MAX; 1337 #else 1338 return rlim64 == RLIM64_INFINITY; 1339 #endif 1340 } 1341 1342 static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64) 1343 { 1344 if (rlim->rlim_cur == RLIM_INFINITY) 1345 rlim64->rlim_cur = RLIM64_INFINITY; 1346 else 1347 rlim64->rlim_cur = rlim->rlim_cur; 1348 if (rlim->rlim_max == RLIM_INFINITY) 1349 rlim64->rlim_max = RLIM64_INFINITY; 1350 else 1351 rlim64->rlim_max = rlim->rlim_max; 1352 } 1353 1354 static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim) 1355 { 1356 if (rlim64_is_infinity(rlim64->rlim_cur)) 1357 rlim->rlim_cur = RLIM_INFINITY; 1358 else 1359 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur; 1360 if (rlim64_is_infinity(rlim64->rlim_max)) 1361 rlim->rlim_max = RLIM_INFINITY; 1362 else 1363 rlim->rlim_max = (unsigned long)rlim64->rlim_max; 1364 } 1365 1366 /* make sure you are allowed to change @tsk limits before calling this */ 1367 int do_prlimit(struct task_struct *tsk, unsigned int resource, 1368 struct rlimit *new_rlim, struct rlimit *old_rlim) 1369 { 1370 struct rlimit *rlim; 1371 int retval = 0; 1372 1373 if (resource >= RLIM_NLIMITS) 1374 return -EINVAL; 1375 if (new_rlim) { 1376 if (new_rlim->rlim_cur > new_rlim->rlim_max) 1377 return -EINVAL; 1378 if (resource == RLIMIT_NOFILE && 1379 new_rlim->rlim_max > sysctl_nr_open) 1380 return -EPERM; 1381 } 1382 1383 /* protect tsk->signal and tsk->sighand from disappearing */ 1384 read_lock(&tasklist_lock); 1385 if (!tsk->sighand) { 1386 retval = -ESRCH; 1387 goto out; 1388 } 1389 1390 rlim = tsk->signal->rlim + resource; 1391 task_lock(tsk->group_leader); 1392 if (new_rlim) { 1393 /* Keep the capable check against init_user_ns until 1394 cgroups can contain all limits */ 1395 if (new_rlim->rlim_max > rlim->rlim_max && 1396 !capable(CAP_SYS_RESOURCE)) 1397 retval = -EPERM; 1398 if (!retval) 1399 retval = security_task_setrlimit(tsk->group_leader, 1400 resource, new_rlim); 1401 if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) { 1402 /* 1403 * The caller is asking for an immediate RLIMIT_CPU 1404 * expiry. But we use the zero value to mean "it was 1405 * never set". So let's cheat and make it one second 1406 * instead 1407 */ 1408 new_rlim->rlim_cur = 1; 1409 } 1410 } 1411 if (!retval) { 1412 if (old_rlim) 1413 *old_rlim = *rlim; 1414 if (new_rlim) 1415 *rlim = *new_rlim; 1416 } 1417 task_unlock(tsk->group_leader); 1418 1419 /* 1420 * RLIMIT_CPU handling. Note that the kernel fails to return an error 1421 * code if it rejected the user's attempt to set RLIMIT_CPU. This is a 1422 * very long-standing error, and fixing it now risks breakage of 1423 * applications, so we live with it 1424 */ 1425 if (!retval && new_rlim && resource == RLIMIT_CPU && 1426 new_rlim->rlim_cur != RLIM_INFINITY && 1427 IS_ENABLED(CONFIG_POSIX_TIMERS)) 1428 update_rlimit_cpu(tsk, new_rlim->rlim_cur); 1429 out: 1430 read_unlock(&tasklist_lock); 1431 return retval; 1432 } 1433 1434 /* rcu lock must be held */ 1435 static int check_prlimit_permission(struct task_struct *task) 1436 { 1437 const struct cred *cred = current_cred(), *tcred; 1438 1439 if (current == task) 1440 return 0; 1441 1442 tcred = __task_cred(task); 1443 if (uid_eq(cred->uid, tcred->euid) && 1444 uid_eq(cred->uid, tcred->suid) && 1445 uid_eq(cred->uid, tcred->uid) && 1446 gid_eq(cred->gid, tcred->egid) && 1447 gid_eq(cred->gid, tcred->sgid) && 1448 gid_eq(cred->gid, tcred->gid)) 1449 return 0; 1450 if (ns_capable(tcred->user_ns, CAP_SYS_RESOURCE)) 1451 return 0; 1452 1453 return -EPERM; 1454 } 1455 1456 SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource, 1457 const struct rlimit64 __user *, new_rlim, 1458 struct rlimit64 __user *, old_rlim) 1459 { 1460 struct rlimit64 old64, new64; 1461 struct rlimit old, new; 1462 struct task_struct *tsk; 1463 int ret; 1464 1465 if (new_rlim) { 1466 if (copy_from_user(&new64, new_rlim, sizeof(new64))) 1467 return -EFAULT; 1468 rlim64_to_rlim(&new64, &new); 1469 } 1470 1471 rcu_read_lock(); 1472 tsk = pid ? find_task_by_vpid(pid) : current; 1473 if (!tsk) { 1474 rcu_read_unlock(); 1475 return -ESRCH; 1476 } 1477 ret = check_prlimit_permission(tsk); 1478 if (ret) { 1479 rcu_read_unlock(); 1480 return ret; 1481 } 1482 get_task_struct(tsk); 1483 rcu_read_unlock(); 1484 1485 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL, 1486 old_rlim ? &old : NULL); 1487 1488 if (!ret && old_rlim) { 1489 rlim_to_rlim64(&old, &old64); 1490 if (copy_to_user(old_rlim, &old64, sizeof(old64))) 1491 ret = -EFAULT; 1492 } 1493 1494 put_task_struct(tsk); 1495 return ret; 1496 } 1497 1498 SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim) 1499 { 1500 struct rlimit new_rlim; 1501 1502 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim))) 1503 return -EFAULT; 1504 return do_prlimit(current, resource, &new_rlim, NULL); 1505 } 1506 1507 /* 1508 * It would make sense to put struct rusage in the task_struct, 1509 * except that would make the task_struct be *really big*. After 1510 * task_struct gets moved into malloc'ed memory, it would 1511 * make sense to do this. It will make moving the rest of the information 1512 * a lot simpler! (Which we're not doing right now because we're not 1513 * measuring them yet). 1514 * 1515 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have 1516 * races with threads incrementing their own counters. But since word 1517 * reads are atomic, we either get new values or old values and we don't 1518 * care which for the sums. We always take the siglock to protect reading 1519 * the c* fields from p->signal from races with exit.c updating those 1520 * fields when reaping, so a sample either gets all the additions of a 1521 * given child after it's reaped, or none so this sample is before reaping. 1522 * 1523 * Locking: 1524 * We need to take the siglock for CHILDEREN, SELF and BOTH 1525 * for the cases current multithreaded, non-current single threaded 1526 * non-current multithreaded. Thread traversal is now safe with 1527 * the siglock held. 1528 * Strictly speaking, we donot need to take the siglock if we are current and 1529 * single threaded, as no one else can take our signal_struct away, no one 1530 * else can reap the children to update signal->c* counters, and no one else 1531 * can race with the signal-> fields. If we do not take any lock, the 1532 * signal-> fields could be read out of order while another thread was just 1533 * exiting. So we should place a read memory barrier when we avoid the lock. 1534 * On the writer side, write memory barrier is implied in __exit_signal 1535 * as __exit_signal releases the siglock spinlock after updating the signal-> 1536 * fields. But we don't do this yet to keep things simple. 1537 * 1538 */ 1539 1540 static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r) 1541 { 1542 r->ru_nvcsw += t->nvcsw; 1543 r->ru_nivcsw += t->nivcsw; 1544 r->ru_minflt += t->min_flt; 1545 r->ru_majflt += t->maj_flt; 1546 r->ru_inblock += task_io_get_inblock(t); 1547 r->ru_oublock += task_io_get_oublock(t); 1548 } 1549 1550 static void k_getrusage(struct task_struct *p, int who, struct rusage *r) 1551 { 1552 struct task_struct *t; 1553 unsigned long flags; 1554 u64 tgutime, tgstime, utime, stime; 1555 unsigned long maxrss = 0; 1556 1557 memset((char *)r, 0, sizeof (*r)); 1558 utime = stime = 0; 1559 1560 if (who == RUSAGE_THREAD) { 1561 task_cputime_adjusted(current, &utime, &stime); 1562 accumulate_thread_rusage(p, r); 1563 maxrss = p->signal->maxrss; 1564 goto out; 1565 } 1566 1567 if (!lock_task_sighand(p, &flags)) 1568 return; 1569 1570 switch (who) { 1571 case RUSAGE_BOTH: 1572 case RUSAGE_CHILDREN: 1573 utime = p->signal->cutime; 1574 stime = p->signal->cstime; 1575 r->ru_nvcsw = p->signal->cnvcsw; 1576 r->ru_nivcsw = p->signal->cnivcsw; 1577 r->ru_minflt = p->signal->cmin_flt; 1578 r->ru_majflt = p->signal->cmaj_flt; 1579 r->ru_inblock = p->signal->cinblock; 1580 r->ru_oublock = p->signal->coublock; 1581 maxrss = p->signal->cmaxrss; 1582 1583 if (who == RUSAGE_CHILDREN) 1584 break; 1585 1586 case RUSAGE_SELF: 1587 thread_group_cputime_adjusted(p, &tgutime, &tgstime); 1588 utime += tgutime; 1589 stime += tgstime; 1590 r->ru_nvcsw += p->signal->nvcsw; 1591 r->ru_nivcsw += p->signal->nivcsw; 1592 r->ru_minflt += p->signal->min_flt; 1593 r->ru_majflt += p->signal->maj_flt; 1594 r->ru_inblock += p->signal->inblock; 1595 r->ru_oublock += p->signal->oublock; 1596 if (maxrss < p->signal->maxrss) 1597 maxrss = p->signal->maxrss; 1598 t = p; 1599 do { 1600 accumulate_thread_rusage(t, r); 1601 } while_each_thread(p, t); 1602 break; 1603 1604 default: 1605 BUG(); 1606 } 1607 unlock_task_sighand(p, &flags); 1608 1609 out: 1610 r->ru_utime = ns_to_timeval(utime); 1611 r->ru_stime = ns_to_timeval(stime); 1612 1613 if (who != RUSAGE_CHILDREN) { 1614 struct mm_struct *mm = get_task_mm(p); 1615 1616 if (mm) { 1617 setmax_mm_hiwater_rss(&maxrss, mm); 1618 mmput(mm); 1619 } 1620 } 1621 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ 1622 } 1623 1624 int getrusage(struct task_struct *p, int who, struct rusage __user *ru) 1625 { 1626 struct rusage r; 1627 1628 k_getrusage(p, who, &r); 1629 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0; 1630 } 1631 1632 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru) 1633 { 1634 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && 1635 who != RUSAGE_THREAD) 1636 return -EINVAL; 1637 return getrusage(current, who, ru); 1638 } 1639 1640 #ifdef CONFIG_COMPAT 1641 COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru) 1642 { 1643 struct rusage r; 1644 1645 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && 1646 who != RUSAGE_THREAD) 1647 return -EINVAL; 1648 1649 k_getrusage(current, who, &r); 1650 return put_compat_rusage(&r, ru); 1651 } 1652 #endif 1653 1654 SYSCALL_DEFINE1(umask, int, mask) 1655 { 1656 mask = xchg(¤t->fs->umask, mask & S_IRWXUGO); 1657 return mask; 1658 } 1659 1660 static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd) 1661 { 1662 struct fd exe; 1663 struct file *old_exe, *exe_file; 1664 struct inode *inode; 1665 int err; 1666 1667 exe = fdget(fd); 1668 if (!exe.file) 1669 return -EBADF; 1670 1671 inode = file_inode(exe.file); 1672 1673 /* 1674 * Because the original mm->exe_file points to executable file, make 1675 * sure that this one is executable as well, to avoid breaking an 1676 * overall picture. 1677 */ 1678 err = -EACCES; 1679 if (!S_ISREG(inode->i_mode) || path_noexec(&exe.file->f_path)) 1680 goto exit; 1681 1682 err = inode_permission(inode, MAY_EXEC); 1683 if (err) 1684 goto exit; 1685 1686 /* 1687 * Forbid mm->exe_file change if old file still mapped. 1688 */ 1689 exe_file = get_mm_exe_file(mm); 1690 err = -EBUSY; 1691 if (exe_file) { 1692 struct vm_area_struct *vma; 1693 1694 down_read(&mm->mmap_sem); 1695 for (vma = mm->mmap; vma; vma = vma->vm_next) { 1696 if (!vma->vm_file) 1697 continue; 1698 if (path_equal(&vma->vm_file->f_path, 1699 &exe_file->f_path)) 1700 goto exit_err; 1701 } 1702 1703 up_read(&mm->mmap_sem); 1704 fput(exe_file); 1705 } 1706 1707 err = 0; 1708 /* set the new file, lockless */ 1709 get_file(exe.file); 1710 old_exe = xchg(&mm->exe_file, exe.file); 1711 if (old_exe) 1712 fput(old_exe); 1713 exit: 1714 fdput(exe); 1715 return err; 1716 exit_err: 1717 up_read(&mm->mmap_sem); 1718 fput(exe_file); 1719 goto exit; 1720 } 1721 1722 /* 1723 * WARNING: we don't require any capability here so be very careful 1724 * in what is allowed for modification from userspace. 1725 */ 1726 static int validate_prctl_map(struct prctl_mm_map *prctl_map) 1727 { 1728 unsigned long mmap_max_addr = TASK_SIZE; 1729 struct mm_struct *mm = current->mm; 1730 int error = -EINVAL, i; 1731 1732 static const unsigned char offsets[] = { 1733 offsetof(struct prctl_mm_map, start_code), 1734 offsetof(struct prctl_mm_map, end_code), 1735 offsetof(struct prctl_mm_map, start_data), 1736 offsetof(struct prctl_mm_map, end_data), 1737 offsetof(struct prctl_mm_map, start_brk), 1738 offsetof(struct prctl_mm_map, brk), 1739 offsetof(struct prctl_mm_map, start_stack), 1740 offsetof(struct prctl_mm_map, arg_start), 1741 offsetof(struct prctl_mm_map, arg_end), 1742 offsetof(struct prctl_mm_map, env_start), 1743 offsetof(struct prctl_mm_map, env_end), 1744 }; 1745 1746 /* 1747 * Make sure the members are not somewhere outside 1748 * of allowed address space. 1749 */ 1750 for (i = 0; i < ARRAY_SIZE(offsets); i++) { 1751 u64 val = *(u64 *)((char *)prctl_map + offsets[i]); 1752 1753 if ((unsigned long)val >= mmap_max_addr || 1754 (unsigned long)val < mmap_min_addr) 1755 goto out; 1756 } 1757 1758 /* 1759 * Make sure the pairs are ordered. 1760 */ 1761 #define __prctl_check_order(__m1, __op, __m2) \ 1762 ((unsigned long)prctl_map->__m1 __op \ 1763 (unsigned long)prctl_map->__m2) ? 0 : -EINVAL 1764 error = __prctl_check_order(start_code, <, end_code); 1765 error |= __prctl_check_order(start_data, <, end_data); 1766 error |= __prctl_check_order(start_brk, <=, brk); 1767 error |= __prctl_check_order(arg_start, <=, arg_end); 1768 error |= __prctl_check_order(env_start, <=, env_end); 1769 if (error) 1770 goto out; 1771 #undef __prctl_check_order 1772 1773 error = -EINVAL; 1774 1775 /* 1776 * @brk should be after @end_data in traditional maps. 1777 */ 1778 if (prctl_map->start_brk <= prctl_map->end_data || 1779 prctl_map->brk <= prctl_map->end_data) 1780 goto out; 1781 1782 /* 1783 * Neither we should allow to override limits if they set. 1784 */ 1785 if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk, 1786 prctl_map->start_brk, prctl_map->end_data, 1787 prctl_map->start_data)) 1788 goto out; 1789 1790 /* 1791 * Someone is trying to cheat the auxv vector. 1792 */ 1793 if (prctl_map->auxv_size) { 1794 if (!prctl_map->auxv || prctl_map->auxv_size > sizeof(mm->saved_auxv)) 1795 goto out; 1796 } 1797 1798 /* 1799 * Finally, make sure the caller has the rights to 1800 * change /proc/pid/exe link: only local root should 1801 * be allowed to. 1802 */ 1803 if (prctl_map->exe_fd != (u32)-1) { 1804 struct user_namespace *ns = current_user_ns(); 1805 const struct cred *cred = current_cred(); 1806 1807 if (!uid_eq(cred->uid, make_kuid(ns, 0)) || 1808 !gid_eq(cred->gid, make_kgid(ns, 0))) 1809 goto out; 1810 } 1811 1812 error = 0; 1813 out: 1814 return error; 1815 } 1816 1817 #ifdef CONFIG_CHECKPOINT_RESTORE 1818 static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size) 1819 { 1820 struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, }; 1821 unsigned long user_auxv[AT_VECTOR_SIZE]; 1822 struct mm_struct *mm = current->mm; 1823 int error; 1824 1825 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv)); 1826 BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256); 1827 1828 if (opt == PR_SET_MM_MAP_SIZE) 1829 return put_user((unsigned int)sizeof(prctl_map), 1830 (unsigned int __user *)addr); 1831 1832 if (data_size != sizeof(prctl_map)) 1833 return -EINVAL; 1834 1835 if (copy_from_user(&prctl_map, addr, sizeof(prctl_map))) 1836 return -EFAULT; 1837 1838 error = validate_prctl_map(&prctl_map); 1839 if (error) 1840 return error; 1841 1842 if (prctl_map.auxv_size) { 1843 memset(user_auxv, 0, sizeof(user_auxv)); 1844 if (copy_from_user(user_auxv, 1845 (const void __user *)prctl_map.auxv, 1846 prctl_map.auxv_size)) 1847 return -EFAULT; 1848 1849 /* Last entry must be AT_NULL as specification requires */ 1850 user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL; 1851 user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL; 1852 } 1853 1854 if (prctl_map.exe_fd != (u32)-1) { 1855 error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd); 1856 if (error) 1857 return error; 1858 } 1859 1860 down_write(&mm->mmap_sem); 1861 1862 /* 1863 * We don't validate if these members are pointing to 1864 * real present VMAs because application may have correspond 1865 * VMAs already unmapped and kernel uses these members for statistics 1866 * output in procfs mostly, except 1867 * 1868 * - @start_brk/@brk which are used in do_brk but kernel lookups 1869 * for VMAs when updating these memvers so anything wrong written 1870 * here cause kernel to swear at userspace program but won't lead 1871 * to any problem in kernel itself 1872 */ 1873 1874 mm->start_code = prctl_map.start_code; 1875 mm->end_code = prctl_map.end_code; 1876 mm->start_data = prctl_map.start_data; 1877 mm->end_data = prctl_map.end_data; 1878 mm->start_brk = prctl_map.start_brk; 1879 mm->brk = prctl_map.brk; 1880 mm->start_stack = prctl_map.start_stack; 1881 mm->arg_start = prctl_map.arg_start; 1882 mm->arg_end = prctl_map.arg_end; 1883 mm->env_start = prctl_map.env_start; 1884 mm->env_end = prctl_map.env_end; 1885 1886 /* 1887 * Note this update of @saved_auxv is lockless thus 1888 * if someone reads this member in procfs while we're 1889 * updating -- it may get partly updated results. It's 1890 * known and acceptable trade off: we leave it as is to 1891 * not introduce additional locks here making the kernel 1892 * more complex. 1893 */ 1894 if (prctl_map.auxv_size) 1895 memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv)); 1896 1897 up_write(&mm->mmap_sem); 1898 return 0; 1899 } 1900 #endif /* CONFIG_CHECKPOINT_RESTORE */ 1901 1902 static int prctl_set_auxv(struct mm_struct *mm, unsigned long addr, 1903 unsigned long len) 1904 { 1905 /* 1906 * This doesn't move the auxiliary vector itself since it's pinned to 1907 * mm_struct, but it permits filling the vector with new values. It's 1908 * up to the caller to provide sane values here, otherwise userspace 1909 * tools which use this vector might be unhappy. 1910 */ 1911 unsigned long user_auxv[AT_VECTOR_SIZE]; 1912 1913 if (len > sizeof(user_auxv)) 1914 return -EINVAL; 1915 1916 if (copy_from_user(user_auxv, (const void __user *)addr, len)) 1917 return -EFAULT; 1918 1919 /* Make sure the last entry is always AT_NULL */ 1920 user_auxv[AT_VECTOR_SIZE - 2] = 0; 1921 user_auxv[AT_VECTOR_SIZE - 1] = 0; 1922 1923 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv)); 1924 1925 task_lock(current); 1926 memcpy(mm->saved_auxv, user_auxv, len); 1927 task_unlock(current); 1928 1929 return 0; 1930 } 1931 1932 static int prctl_set_mm(int opt, unsigned long addr, 1933 unsigned long arg4, unsigned long arg5) 1934 { 1935 struct mm_struct *mm = current->mm; 1936 struct prctl_mm_map prctl_map; 1937 struct vm_area_struct *vma; 1938 int error; 1939 1940 if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV && 1941 opt != PR_SET_MM_MAP && 1942 opt != PR_SET_MM_MAP_SIZE))) 1943 return -EINVAL; 1944 1945 #ifdef CONFIG_CHECKPOINT_RESTORE 1946 if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE) 1947 return prctl_set_mm_map(opt, (const void __user *)addr, arg4); 1948 #endif 1949 1950 if (!capable(CAP_SYS_RESOURCE)) 1951 return -EPERM; 1952 1953 if (opt == PR_SET_MM_EXE_FILE) 1954 return prctl_set_mm_exe_file(mm, (unsigned int)addr); 1955 1956 if (opt == PR_SET_MM_AUXV) 1957 return prctl_set_auxv(mm, addr, arg4); 1958 1959 if (addr >= TASK_SIZE || addr < mmap_min_addr) 1960 return -EINVAL; 1961 1962 error = -EINVAL; 1963 1964 down_write(&mm->mmap_sem); 1965 vma = find_vma(mm, addr); 1966 1967 prctl_map.start_code = mm->start_code; 1968 prctl_map.end_code = mm->end_code; 1969 prctl_map.start_data = mm->start_data; 1970 prctl_map.end_data = mm->end_data; 1971 prctl_map.start_brk = mm->start_brk; 1972 prctl_map.brk = mm->brk; 1973 prctl_map.start_stack = mm->start_stack; 1974 prctl_map.arg_start = mm->arg_start; 1975 prctl_map.arg_end = mm->arg_end; 1976 prctl_map.env_start = mm->env_start; 1977 prctl_map.env_end = mm->env_end; 1978 prctl_map.auxv = NULL; 1979 prctl_map.auxv_size = 0; 1980 prctl_map.exe_fd = -1; 1981 1982 switch (opt) { 1983 case PR_SET_MM_START_CODE: 1984 prctl_map.start_code = addr; 1985 break; 1986 case PR_SET_MM_END_CODE: 1987 prctl_map.end_code = addr; 1988 break; 1989 case PR_SET_MM_START_DATA: 1990 prctl_map.start_data = addr; 1991 break; 1992 case PR_SET_MM_END_DATA: 1993 prctl_map.end_data = addr; 1994 break; 1995 case PR_SET_MM_START_STACK: 1996 prctl_map.start_stack = addr; 1997 break; 1998 case PR_SET_MM_START_BRK: 1999 prctl_map.start_brk = addr; 2000 break; 2001 case PR_SET_MM_BRK: 2002 prctl_map.brk = addr; 2003 break; 2004 case PR_SET_MM_ARG_START: 2005 prctl_map.arg_start = addr; 2006 break; 2007 case PR_SET_MM_ARG_END: 2008 prctl_map.arg_end = addr; 2009 break; 2010 case PR_SET_MM_ENV_START: 2011 prctl_map.env_start = addr; 2012 break; 2013 case PR_SET_MM_ENV_END: 2014 prctl_map.env_end = addr; 2015 break; 2016 default: 2017 goto out; 2018 } 2019 2020 error = validate_prctl_map(&prctl_map); 2021 if (error) 2022 goto out; 2023 2024 switch (opt) { 2025 /* 2026 * If command line arguments and environment 2027 * are placed somewhere else on stack, we can 2028 * set them up here, ARG_START/END to setup 2029 * command line argumets and ENV_START/END 2030 * for environment. 2031 */ 2032 case PR_SET_MM_START_STACK: 2033 case PR_SET_MM_ARG_START: 2034 case PR_SET_MM_ARG_END: 2035 case PR_SET_MM_ENV_START: 2036 case PR_SET_MM_ENV_END: 2037 if (!vma) { 2038 error = -EFAULT; 2039 goto out; 2040 } 2041 } 2042 2043 mm->start_code = prctl_map.start_code; 2044 mm->end_code = prctl_map.end_code; 2045 mm->start_data = prctl_map.start_data; 2046 mm->end_data = prctl_map.end_data; 2047 mm->start_brk = prctl_map.start_brk; 2048 mm->brk = prctl_map.brk; 2049 mm->start_stack = prctl_map.start_stack; 2050 mm->arg_start = prctl_map.arg_start; 2051 mm->arg_end = prctl_map.arg_end; 2052 mm->env_start = prctl_map.env_start; 2053 mm->env_end = prctl_map.env_end; 2054 2055 error = 0; 2056 out: 2057 up_write(&mm->mmap_sem); 2058 return error; 2059 } 2060 2061 #ifdef CONFIG_CHECKPOINT_RESTORE 2062 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr) 2063 { 2064 return put_user(me->clear_child_tid, tid_addr); 2065 } 2066 #else 2067 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr) 2068 { 2069 return -EINVAL; 2070 } 2071 #endif 2072 2073 static int propagate_has_child_subreaper(struct task_struct *p, void *data) 2074 { 2075 /* 2076 * If task has has_child_subreaper - all its decendants 2077 * already have these flag too and new decendants will 2078 * inherit it on fork, skip them. 2079 * 2080 * If we've found child_reaper - skip descendants in 2081 * it's subtree as they will never get out pidns. 2082 */ 2083 if (p->signal->has_child_subreaper || 2084 is_child_reaper(task_pid(p))) 2085 return 0; 2086 2087 p->signal->has_child_subreaper = 1; 2088 return 1; 2089 } 2090 2091 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, 2092 unsigned long, arg4, unsigned long, arg5) 2093 { 2094 struct task_struct *me = current; 2095 unsigned char comm[sizeof(me->comm)]; 2096 long error; 2097 2098 error = security_task_prctl(option, arg2, arg3, arg4, arg5); 2099 if (error != -ENOSYS) 2100 return error; 2101 2102 error = 0; 2103 switch (option) { 2104 case PR_SET_PDEATHSIG: 2105 if (!valid_signal(arg2)) { 2106 error = -EINVAL; 2107 break; 2108 } 2109 me->pdeath_signal = arg2; 2110 break; 2111 case PR_GET_PDEATHSIG: 2112 error = put_user(me->pdeath_signal, (int __user *)arg2); 2113 break; 2114 case PR_GET_DUMPABLE: 2115 error = get_dumpable(me->mm); 2116 break; 2117 case PR_SET_DUMPABLE: 2118 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) { 2119 error = -EINVAL; 2120 break; 2121 } 2122 set_dumpable(me->mm, arg2); 2123 break; 2124 2125 case PR_SET_UNALIGN: 2126 error = SET_UNALIGN_CTL(me, arg2); 2127 break; 2128 case PR_GET_UNALIGN: 2129 error = GET_UNALIGN_CTL(me, arg2); 2130 break; 2131 case PR_SET_FPEMU: 2132 error = SET_FPEMU_CTL(me, arg2); 2133 break; 2134 case PR_GET_FPEMU: 2135 error = GET_FPEMU_CTL(me, arg2); 2136 break; 2137 case PR_SET_FPEXC: 2138 error = SET_FPEXC_CTL(me, arg2); 2139 break; 2140 case PR_GET_FPEXC: 2141 error = GET_FPEXC_CTL(me, arg2); 2142 break; 2143 case PR_GET_TIMING: 2144 error = PR_TIMING_STATISTICAL; 2145 break; 2146 case PR_SET_TIMING: 2147 if (arg2 != PR_TIMING_STATISTICAL) 2148 error = -EINVAL; 2149 break; 2150 case PR_SET_NAME: 2151 comm[sizeof(me->comm) - 1] = 0; 2152 if (strncpy_from_user(comm, (char __user *)arg2, 2153 sizeof(me->comm) - 1) < 0) 2154 return -EFAULT; 2155 set_task_comm(me, comm); 2156 proc_comm_connector(me); 2157 break; 2158 case PR_GET_NAME: 2159 get_task_comm(comm, me); 2160 if (copy_to_user((char __user *)arg2, comm, sizeof(comm))) 2161 return -EFAULT; 2162 break; 2163 case PR_GET_ENDIAN: 2164 error = GET_ENDIAN(me, arg2); 2165 break; 2166 case PR_SET_ENDIAN: 2167 error = SET_ENDIAN(me, arg2); 2168 break; 2169 case PR_GET_SECCOMP: 2170 error = prctl_get_seccomp(); 2171 break; 2172 case PR_SET_SECCOMP: 2173 error = prctl_set_seccomp(arg2, (char __user *)arg3); 2174 break; 2175 case PR_GET_TSC: 2176 error = GET_TSC_CTL(arg2); 2177 break; 2178 case PR_SET_TSC: 2179 error = SET_TSC_CTL(arg2); 2180 break; 2181 case PR_TASK_PERF_EVENTS_DISABLE: 2182 error = perf_event_task_disable(); 2183 break; 2184 case PR_TASK_PERF_EVENTS_ENABLE: 2185 error = perf_event_task_enable(); 2186 break; 2187 case PR_GET_TIMERSLACK: 2188 if (current->timer_slack_ns > ULONG_MAX) 2189 error = ULONG_MAX; 2190 else 2191 error = current->timer_slack_ns; 2192 break; 2193 case PR_SET_TIMERSLACK: 2194 if (arg2 <= 0) 2195 current->timer_slack_ns = 2196 current->default_timer_slack_ns; 2197 else 2198 current->timer_slack_ns = arg2; 2199 break; 2200 case PR_MCE_KILL: 2201 if (arg4 | arg5) 2202 return -EINVAL; 2203 switch (arg2) { 2204 case PR_MCE_KILL_CLEAR: 2205 if (arg3 != 0) 2206 return -EINVAL; 2207 current->flags &= ~PF_MCE_PROCESS; 2208 break; 2209 case PR_MCE_KILL_SET: 2210 current->flags |= PF_MCE_PROCESS; 2211 if (arg3 == PR_MCE_KILL_EARLY) 2212 current->flags |= PF_MCE_EARLY; 2213 else if (arg3 == PR_MCE_KILL_LATE) 2214 current->flags &= ~PF_MCE_EARLY; 2215 else if (arg3 == PR_MCE_KILL_DEFAULT) 2216 current->flags &= 2217 ~(PF_MCE_EARLY|PF_MCE_PROCESS); 2218 else 2219 return -EINVAL; 2220 break; 2221 default: 2222 return -EINVAL; 2223 } 2224 break; 2225 case PR_MCE_KILL_GET: 2226 if (arg2 | arg3 | arg4 | arg5) 2227 return -EINVAL; 2228 if (current->flags & PF_MCE_PROCESS) 2229 error = (current->flags & PF_MCE_EARLY) ? 2230 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE; 2231 else 2232 error = PR_MCE_KILL_DEFAULT; 2233 break; 2234 case PR_SET_MM: 2235 error = prctl_set_mm(arg2, arg3, arg4, arg5); 2236 break; 2237 case PR_GET_TID_ADDRESS: 2238 error = prctl_get_tid_address(me, (int __user **)arg2); 2239 break; 2240 case PR_SET_CHILD_SUBREAPER: 2241 me->signal->is_child_subreaper = !!arg2; 2242 if (!arg2) 2243 break; 2244 2245 walk_process_tree(me, propagate_has_child_subreaper, NULL); 2246 break; 2247 case PR_GET_CHILD_SUBREAPER: 2248 error = put_user(me->signal->is_child_subreaper, 2249 (int __user *)arg2); 2250 break; 2251 case PR_SET_NO_NEW_PRIVS: 2252 if (arg2 != 1 || arg3 || arg4 || arg5) 2253 return -EINVAL; 2254 2255 task_set_no_new_privs(current); 2256 break; 2257 case PR_GET_NO_NEW_PRIVS: 2258 if (arg2 || arg3 || arg4 || arg5) 2259 return -EINVAL; 2260 return task_no_new_privs(current) ? 1 : 0; 2261 case PR_GET_THP_DISABLE: 2262 if (arg2 || arg3 || arg4 || arg5) 2263 return -EINVAL; 2264 error = !!(me->mm->def_flags & VM_NOHUGEPAGE); 2265 break; 2266 case PR_SET_THP_DISABLE: 2267 if (arg3 || arg4 || arg5) 2268 return -EINVAL; 2269 if (down_write_killable(&me->mm->mmap_sem)) 2270 return -EINTR; 2271 if (arg2) 2272 me->mm->def_flags |= VM_NOHUGEPAGE; 2273 else 2274 me->mm->def_flags &= ~VM_NOHUGEPAGE; 2275 up_write(&me->mm->mmap_sem); 2276 break; 2277 case PR_MPX_ENABLE_MANAGEMENT: 2278 if (arg2 || arg3 || arg4 || arg5) 2279 return -EINVAL; 2280 error = MPX_ENABLE_MANAGEMENT(); 2281 break; 2282 case PR_MPX_DISABLE_MANAGEMENT: 2283 if (arg2 || arg3 || arg4 || arg5) 2284 return -EINVAL; 2285 error = MPX_DISABLE_MANAGEMENT(); 2286 break; 2287 case PR_SET_FP_MODE: 2288 error = SET_FP_MODE(me, arg2); 2289 break; 2290 case PR_GET_FP_MODE: 2291 error = GET_FP_MODE(me); 2292 break; 2293 default: 2294 error = -EINVAL; 2295 break; 2296 } 2297 return error; 2298 } 2299 2300 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep, 2301 struct getcpu_cache __user *, unused) 2302 { 2303 int err = 0; 2304 int cpu = raw_smp_processor_id(); 2305 2306 if (cpup) 2307 err |= put_user(cpu, cpup); 2308 if (nodep) 2309 err |= put_user(cpu_to_node(cpu), nodep); 2310 return err ? -EFAULT : 0; 2311 } 2312 2313 /** 2314 * do_sysinfo - fill in sysinfo struct 2315 * @info: pointer to buffer to fill 2316 */ 2317 static int do_sysinfo(struct sysinfo *info) 2318 { 2319 unsigned long mem_total, sav_total; 2320 unsigned int mem_unit, bitcount; 2321 struct timespec tp; 2322 2323 memset(info, 0, sizeof(struct sysinfo)); 2324 2325 get_monotonic_boottime(&tp); 2326 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0); 2327 2328 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT); 2329 2330 info->procs = nr_threads; 2331 2332 si_meminfo(info); 2333 si_swapinfo(info); 2334 2335 /* 2336 * If the sum of all the available memory (i.e. ram + swap) 2337 * is less than can be stored in a 32 bit unsigned long then 2338 * we can be binary compatible with 2.2.x kernels. If not, 2339 * well, in that case 2.2.x was broken anyways... 2340 * 2341 * -Erik Andersen <andersee@debian.org> 2342 */ 2343 2344 mem_total = info->totalram + info->totalswap; 2345 if (mem_total < info->totalram || mem_total < info->totalswap) 2346 goto out; 2347 bitcount = 0; 2348 mem_unit = info->mem_unit; 2349 while (mem_unit > 1) { 2350 bitcount++; 2351 mem_unit >>= 1; 2352 sav_total = mem_total; 2353 mem_total <<= 1; 2354 if (mem_total < sav_total) 2355 goto out; 2356 } 2357 2358 /* 2359 * If mem_total did not overflow, multiply all memory values by 2360 * info->mem_unit and set it to 1. This leaves things compatible 2361 * with 2.2.x, and also retains compatibility with earlier 2.4.x 2362 * kernels... 2363 */ 2364 2365 info->mem_unit = 1; 2366 info->totalram <<= bitcount; 2367 info->freeram <<= bitcount; 2368 info->sharedram <<= bitcount; 2369 info->bufferram <<= bitcount; 2370 info->totalswap <<= bitcount; 2371 info->freeswap <<= bitcount; 2372 info->totalhigh <<= bitcount; 2373 info->freehigh <<= bitcount; 2374 2375 out: 2376 return 0; 2377 } 2378 2379 SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info) 2380 { 2381 struct sysinfo val; 2382 2383 do_sysinfo(&val); 2384 2385 if (copy_to_user(info, &val, sizeof(struct sysinfo))) 2386 return -EFAULT; 2387 2388 return 0; 2389 } 2390 2391 #ifdef CONFIG_COMPAT 2392 struct compat_sysinfo { 2393 s32 uptime; 2394 u32 loads[3]; 2395 u32 totalram; 2396 u32 freeram; 2397 u32 sharedram; 2398 u32 bufferram; 2399 u32 totalswap; 2400 u32 freeswap; 2401 u16 procs; 2402 u16 pad; 2403 u32 totalhigh; 2404 u32 freehigh; 2405 u32 mem_unit; 2406 char _f[20-2*sizeof(u32)-sizeof(int)]; 2407 }; 2408 2409 COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info) 2410 { 2411 struct sysinfo s; 2412 2413 do_sysinfo(&s); 2414 2415 /* Check to see if any memory value is too large for 32-bit and scale 2416 * down if needed 2417 */ 2418 if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) { 2419 int bitcount = 0; 2420 2421 while (s.mem_unit < PAGE_SIZE) { 2422 s.mem_unit <<= 1; 2423 bitcount++; 2424 } 2425 2426 s.totalram >>= bitcount; 2427 s.freeram >>= bitcount; 2428 s.sharedram >>= bitcount; 2429 s.bufferram >>= bitcount; 2430 s.totalswap >>= bitcount; 2431 s.freeswap >>= bitcount; 2432 s.totalhigh >>= bitcount; 2433 s.freehigh >>= bitcount; 2434 } 2435 2436 if (!access_ok(VERIFY_WRITE, info, sizeof(struct compat_sysinfo)) || 2437 __put_user(s.uptime, &info->uptime) || 2438 __put_user(s.loads[0], &info->loads[0]) || 2439 __put_user(s.loads[1], &info->loads[1]) || 2440 __put_user(s.loads[2], &info->loads[2]) || 2441 __put_user(s.totalram, &info->totalram) || 2442 __put_user(s.freeram, &info->freeram) || 2443 __put_user(s.sharedram, &info->sharedram) || 2444 __put_user(s.bufferram, &info->bufferram) || 2445 __put_user(s.totalswap, &info->totalswap) || 2446 __put_user(s.freeswap, &info->freeswap) || 2447 __put_user(s.procs, &info->procs) || 2448 __put_user(s.totalhigh, &info->totalhigh) || 2449 __put_user(s.freehigh, &info->freehigh) || 2450 __put_user(s.mem_unit, &info->mem_unit)) 2451 return -EFAULT; 2452 2453 return 0; 2454 } 2455 #endif /* CONFIG_COMPAT */ 2456