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, resource, new_rlim); 1400 if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) { 1401 /* 1402 * The caller is asking for an immediate RLIMIT_CPU 1403 * expiry. But we use the zero value to mean "it was 1404 * never set". So let's cheat and make it one second 1405 * instead 1406 */ 1407 new_rlim->rlim_cur = 1; 1408 } 1409 } 1410 if (!retval) { 1411 if (old_rlim) 1412 *old_rlim = *rlim; 1413 if (new_rlim) 1414 *rlim = *new_rlim; 1415 } 1416 task_unlock(tsk->group_leader); 1417 1418 /* 1419 * RLIMIT_CPU handling. Note that the kernel fails to return an error 1420 * code if it rejected the user's attempt to set RLIMIT_CPU. This is a 1421 * very long-standing error, and fixing it now risks breakage of 1422 * applications, so we live with it 1423 */ 1424 if (!retval && new_rlim && resource == RLIMIT_CPU && 1425 new_rlim->rlim_cur != RLIM_INFINITY && 1426 IS_ENABLED(CONFIG_POSIX_TIMERS)) 1427 update_rlimit_cpu(tsk, new_rlim->rlim_cur); 1428 out: 1429 read_unlock(&tasklist_lock); 1430 return retval; 1431 } 1432 1433 /* rcu lock must be held */ 1434 static int check_prlimit_permission(struct task_struct *task, 1435 unsigned int flags) 1436 { 1437 const struct cred *cred = current_cred(), *tcred; 1438 bool id_match; 1439 1440 if (current == task) 1441 return 0; 1442 1443 tcred = __task_cred(task); 1444 id_match = (uid_eq(cred->uid, tcred->euid) && 1445 uid_eq(cred->uid, tcred->suid) && 1446 uid_eq(cred->uid, tcred->uid) && 1447 gid_eq(cred->gid, tcred->egid) && 1448 gid_eq(cred->gid, tcred->sgid) && 1449 gid_eq(cred->gid, tcred->gid)); 1450 if (!id_match && !ns_capable(tcred->user_ns, CAP_SYS_RESOURCE)) 1451 return -EPERM; 1452 1453 return security_task_prlimit(cred, tcred, flags); 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 unsigned int checkflags = 0; 1464 int ret; 1465 1466 if (old_rlim) 1467 checkflags |= LSM_PRLIMIT_READ; 1468 1469 if (new_rlim) { 1470 if (copy_from_user(&new64, new_rlim, sizeof(new64))) 1471 return -EFAULT; 1472 rlim64_to_rlim(&new64, &new); 1473 checkflags |= LSM_PRLIMIT_WRITE; 1474 } 1475 1476 rcu_read_lock(); 1477 tsk = pid ? find_task_by_vpid(pid) : current; 1478 if (!tsk) { 1479 rcu_read_unlock(); 1480 return -ESRCH; 1481 } 1482 ret = check_prlimit_permission(tsk, checkflags); 1483 if (ret) { 1484 rcu_read_unlock(); 1485 return ret; 1486 } 1487 get_task_struct(tsk); 1488 rcu_read_unlock(); 1489 1490 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL, 1491 old_rlim ? &old : NULL); 1492 1493 if (!ret && old_rlim) { 1494 rlim_to_rlim64(&old, &old64); 1495 if (copy_to_user(old_rlim, &old64, sizeof(old64))) 1496 ret = -EFAULT; 1497 } 1498 1499 put_task_struct(tsk); 1500 return ret; 1501 } 1502 1503 SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim) 1504 { 1505 struct rlimit new_rlim; 1506 1507 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim))) 1508 return -EFAULT; 1509 return do_prlimit(current, resource, &new_rlim, NULL); 1510 } 1511 1512 /* 1513 * It would make sense to put struct rusage in the task_struct, 1514 * except that would make the task_struct be *really big*. After 1515 * task_struct gets moved into malloc'ed memory, it would 1516 * make sense to do this. It will make moving the rest of the information 1517 * a lot simpler! (Which we're not doing right now because we're not 1518 * measuring them yet). 1519 * 1520 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have 1521 * races with threads incrementing their own counters. But since word 1522 * reads are atomic, we either get new values or old values and we don't 1523 * care which for the sums. We always take the siglock to protect reading 1524 * the c* fields from p->signal from races with exit.c updating those 1525 * fields when reaping, so a sample either gets all the additions of a 1526 * given child after it's reaped, or none so this sample is before reaping. 1527 * 1528 * Locking: 1529 * We need to take the siglock for CHILDEREN, SELF and BOTH 1530 * for the cases current multithreaded, non-current single threaded 1531 * non-current multithreaded. Thread traversal is now safe with 1532 * the siglock held. 1533 * Strictly speaking, we donot need to take the siglock if we are current and 1534 * single threaded, as no one else can take our signal_struct away, no one 1535 * else can reap the children to update signal->c* counters, and no one else 1536 * can race with the signal-> fields. If we do not take any lock, the 1537 * signal-> fields could be read out of order while another thread was just 1538 * exiting. So we should place a read memory barrier when we avoid the lock. 1539 * On the writer side, write memory barrier is implied in __exit_signal 1540 * as __exit_signal releases the siglock spinlock after updating the signal-> 1541 * fields. But we don't do this yet to keep things simple. 1542 * 1543 */ 1544 1545 static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r) 1546 { 1547 r->ru_nvcsw += t->nvcsw; 1548 r->ru_nivcsw += t->nivcsw; 1549 r->ru_minflt += t->min_flt; 1550 r->ru_majflt += t->maj_flt; 1551 r->ru_inblock += task_io_get_inblock(t); 1552 r->ru_oublock += task_io_get_oublock(t); 1553 } 1554 1555 static void k_getrusage(struct task_struct *p, int who, struct rusage *r) 1556 { 1557 struct task_struct *t; 1558 unsigned long flags; 1559 u64 tgutime, tgstime, utime, stime; 1560 unsigned long maxrss = 0; 1561 1562 memset((char *)r, 0, sizeof (*r)); 1563 utime = stime = 0; 1564 1565 if (who == RUSAGE_THREAD) { 1566 task_cputime_adjusted(current, &utime, &stime); 1567 accumulate_thread_rusage(p, r); 1568 maxrss = p->signal->maxrss; 1569 goto out; 1570 } 1571 1572 if (!lock_task_sighand(p, &flags)) 1573 return; 1574 1575 switch (who) { 1576 case RUSAGE_BOTH: 1577 case RUSAGE_CHILDREN: 1578 utime = p->signal->cutime; 1579 stime = p->signal->cstime; 1580 r->ru_nvcsw = p->signal->cnvcsw; 1581 r->ru_nivcsw = p->signal->cnivcsw; 1582 r->ru_minflt = p->signal->cmin_flt; 1583 r->ru_majflt = p->signal->cmaj_flt; 1584 r->ru_inblock = p->signal->cinblock; 1585 r->ru_oublock = p->signal->coublock; 1586 maxrss = p->signal->cmaxrss; 1587 1588 if (who == RUSAGE_CHILDREN) 1589 break; 1590 1591 case RUSAGE_SELF: 1592 thread_group_cputime_adjusted(p, &tgutime, &tgstime); 1593 utime += tgutime; 1594 stime += tgstime; 1595 r->ru_nvcsw += p->signal->nvcsw; 1596 r->ru_nivcsw += p->signal->nivcsw; 1597 r->ru_minflt += p->signal->min_flt; 1598 r->ru_majflt += p->signal->maj_flt; 1599 r->ru_inblock += p->signal->inblock; 1600 r->ru_oublock += p->signal->oublock; 1601 if (maxrss < p->signal->maxrss) 1602 maxrss = p->signal->maxrss; 1603 t = p; 1604 do { 1605 accumulate_thread_rusage(t, r); 1606 } while_each_thread(p, t); 1607 break; 1608 1609 default: 1610 BUG(); 1611 } 1612 unlock_task_sighand(p, &flags); 1613 1614 out: 1615 r->ru_utime = ns_to_timeval(utime); 1616 r->ru_stime = ns_to_timeval(stime); 1617 1618 if (who != RUSAGE_CHILDREN) { 1619 struct mm_struct *mm = get_task_mm(p); 1620 1621 if (mm) { 1622 setmax_mm_hiwater_rss(&maxrss, mm); 1623 mmput(mm); 1624 } 1625 } 1626 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ 1627 } 1628 1629 int getrusage(struct task_struct *p, int who, struct rusage __user *ru) 1630 { 1631 struct rusage r; 1632 1633 k_getrusage(p, who, &r); 1634 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0; 1635 } 1636 1637 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru) 1638 { 1639 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && 1640 who != RUSAGE_THREAD) 1641 return -EINVAL; 1642 return getrusage(current, who, ru); 1643 } 1644 1645 #ifdef CONFIG_COMPAT 1646 COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru) 1647 { 1648 struct rusage r; 1649 1650 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && 1651 who != RUSAGE_THREAD) 1652 return -EINVAL; 1653 1654 k_getrusage(current, who, &r); 1655 return put_compat_rusage(&r, ru); 1656 } 1657 #endif 1658 1659 SYSCALL_DEFINE1(umask, int, mask) 1660 { 1661 mask = xchg(¤t->fs->umask, mask & S_IRWXUGO); 1662 return mask; 1663 } 1664 1665 static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd) 1666 { 1667 struct fd exe; 1668 struct file *old_exe, *exe_file; 1669 struct inode *inode; 1670 int err; 1671 1672 exe = fdget(fd); 1673 if (!exe.file) 1674 return -EBADF; 1675 1676 inode = file_inode(exe.file); 1677 1678 /* 1679 * Because the original mm->exe_file points to executable file, make 1680 * sure that this one is executable as well, to avoid breaking an 1681 * overall picture. 1682 */ 1683 err = -EACCES; 1684 if (!S_ISREG(inode->i_mode) || path_noexec(&exe.file->f_path)) 1685 goto exit; 1686 1687 err = inode_permission(inode, MAY_EXEC); 1688 if (err) 1689 goto exit; 1690 1691 /* 1692 * Forbid mm->exe_file change if old file still mapped. 1693 */ 1694 exe_file = get_mm_exe_file(mm); 1695 err = -EBUSY; 1696 if (exe_file) { 1697 struct vm_area_struct *vma; 1698 1699 down_read(&mm->mmap_sem); 1700 for (vma = mm->mmap; vma; vma = vma->vm_next) { 1701 if (!vma->vm_file) 1702 continue; 1703 if (path_equal(&vma->vm_file->f_path, 1704 &exe_file->f_path)) 1705 goto exit_err; 1706 } 1707 1708 up_read(&mm->mmap_sem); 1709 fput(exe_file); 1710 } 1711 1712 err = 0; 1713 /* set the new file, lockless */ 1714 get_file(exe.file); 1715 old_exe = xchg(&mm->exe_file, exe.file); 1716 if (old_exe) 1717 fput(old_exe); 1718 exit: 1719 fdput(exe); 1720 return err; 1721 exit_err: 1722 up_read(&mm->mmap_sem); 1723 fput(exe_file); 1724 goto exit; 1725 } 1726 1727 /* 1728 * WARNING: we don't require any capability here so be very careful 1729 * in what is allowed for modification from userspace. 1730 */ 1731 static int validate_prctl_map(struct prctl_mm_map *prctl_map) 1732 { 1733 unsigned long mmap_max_addr = TASK_SIZE; 1734 struct mm_struct *mm = current->mm; 1735 int error = -EINVAL, i; 1736 1737 static const unsigned char offsets[] = { 1738 offsetof(struct prctl_mm_map, start_code), 1739 offsetof(struct prctl_mm_map, end_code), 1740 offsetof(struct prctl_mm_map, start_data), 1741 offsetof(struct prctl_mm_map, end_data), 1742 offsetof(struct prctl_mm_map, start_brk), 1743 offsetof(struct prctl_mm_map, brk), 1744 offsetof(struct prctl_mm_map, start_stack), 1745 offsetof(struct prctl_mm_map, arg_start), 1746 offsetof(struct prctl_mm_map, arg_end), 1747 offsetof(struct prctl_mm_map, env_start), 1748 offsetof(struct prctl_mm_map, env_end), 1749 }; 1750 1751 /* 1752 * Make sure the members are not somewhere outside 1753 * of allowed address space. 1754 */ 1755 for (i = 0; i < ARRAY_SIZE(offsets); i++) { 1756 u64 val = *(u64 *)((char *)prctl_map + offsets[i]); 1757 1758 if ((unsigned long)val >= mmap_max_addr || 1759 (unsigned long)val < mmap_min_addr) 1760 goto out; 1761 } 1762 1763 /* 1764 * Make sure the pairs are ordered. 1765 */ 1766 #define __prctl_check_order(__m1, __op, __m2) \ 1767 ((unsigned long)prctl_map->__m1 __op \ 1768 (unsigned long)prctl_map->__m2) ? 0 : -EINVAL 1769 error = __prctl_check_order(start_code, <, end_code); 1770 error |= __prctl_check_order(start_data, <, end_data); 1771 error |= __prctl_check_order(start_brk, <=, brk); 1772 error |= __prctl_check_order(arg_start, <=, arg_end); 1773 error |= __prctl_check_order(env_start, <=, env_end); 1774 if (error) 1775 goto out; 1776 #undef __prctl_check_order 1777 1778 error = -EINVAL; 1779 1780 /* 1781 * @brk should be after @end_data in traditional maps. 1782 */ 1783 if (prctl_map->start_brk <= prctl_map->end_data || 1784 prctl_map->brk <= prctl_map->end_data) 1785 goto out; 1786 1787 /* 1788 * Neither we should allow to override limits if they set. 1789 */ 1790 if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk, 1791 prctl_map->start_brk, prctl_map->end_data, 1792 prctl_map->start_data)) 1793 goto out; 1794 1795 /* 1796 * Someone is trying to cheat the auxv vector. 1797 */ 1798 if (prctl_map->auxv_size) { 1799 if (!prctl_map->auxv || prctl_map->auxv_size > sizeof(mm->saved_auxv)) 1800 goto out; 1801 } 1802 1803 /* 1804 * Finally, make sure the caller has the rights to 1805 * change /proc/pid/exe link: only local root should 1806 * be allowed to. 1807 */ 1808 if (prctl_map->exe_fd != (u32)-1) { 1809 struct user_namespace *ns = current_user_ns(); 1810 const struct cred *cred = current_cred(); 1811 1812 if (!uid_eq(cred->uid, make_kuid(ns, 0)) || 1813 !gid_eq(cred->gid, make_kgid(ns, 0))) 1814 goto out; 1815 } 1816 1817 error = 0; 1818 out: 1819 return error; 1820 } 1821 1822 #ifdef CONFIG_CHECKPOINT_RESTORE 1823 static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size) 1824 { 1825 struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, }; 1826 unsigned long user_auxv[AT_VECTOR_SIZE]; 1827 struct mm_struct *mm = current->mm; 1828 int error; 1829 1830 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv)); 1831 BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256); 1832 1833 if (opt == PR_SET_MM_MAP_SIZE) 1834 return put_user((unsigned int)sizeof(prctl_map), 1835 (unsigned int __user *)addr); 1836 1837 if (data_size != sizeof(prctl_map)) 1838 return -EINVAL; 1839 1840 if (copy_from_user(&prctl_map, addr, sizeof(prctl_map))) 1841 return -EFAULT; 1842 1843 error = validate_prctl_map(&prctl_map); 1844 if (error) 1845 return error; 1846 1847 if (prctl_map.auxv_size) { 1848 memset(user_auxv, 0, sizeof(user_auxv)); 1849 if (copy_from_user(user_auxv, 1850 (const void __user *)prctl_map.auxv, 1851 prctl_map.auxv_size)) 1852 return -EFAULT; 1853 1854 /* Last entry must be AT_NULL as specification requires */ 1855 user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL; 1856 user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL; 1857 } 1858 1859 if (prctl_map.exe_fd != (u32)-1) { 1860 error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd); 1861 if (error) 1862 return error; 1863 } 1864 1865 down_write(&mm->mmap_sem); 1866 1867 /* 1868 * We don't validate if these members are pointing to 1869 * real present VMAs because application may have correspond 1870 * VMAs already unmapped and kernel uses these members for statistics 1871 * output in procfs mostly, except 1872 * 1873 * - @start_brk/@brk which are used in do_brk but kernel lookups 1874 * for VMAs when updating these memvers so anything wrong written 1875 * here cause kernel to swear at userspace program but won't lead 1876 * to any problem in kernel itself 1877 */ 1878 1879 mm->start_code = prctl_map.start_code; 1880 mm->end_code = prctl_map.end_code; 1881 mm->start_data = prctl_map.start_data; 1882 mm->end_data = prctl_map.end_data; 1883 mm->start_brk = prctl_map.start_brk; 1884 mm->brk = prctl_map.brk; 1885 mm->start_stack = prctl_map.start_stack; 1886 mm->arg_start = prctl_map.arg_start; 1887 mm->arg_end = prctl_map.arg_end; 1888 mm->env_start = prctl_map.env_start; 1889 mm->env_end = prctl_map.env_end; 1890 1891 /* 1892 * Note this update of @saved_auxv is lockless thus 1893 * if someone reads this member in procfs while we're 1894 * updating -- it may get partly updated results. It's 1895 * known and acceptable trade off: we leave it as is to 1896 * not introduce additional locks here making the kernel 1897 * more complex. 1898 */ 1899 if (prctl_map.auxv_size) 1900 memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv)); 1901 1902 up_write(&mm->mmap_sem); 1903 return 0; 1904 } 1905 #endif /* CONFIG_CHECKPOINT_RESTORE */ 1906 1907 static int prctl_set_auxv(struct mm_struct *mm, unsigned long addr, 1908 unsigned long len) 1909 { 1910 /* 1911 * This doesn't move the auxiliary vector itself since it's pinned to 1912 * mm_struct, but it permits filling the vector with new values. It's 1913 * up to the caller to provide sane values here, otherwise userspace 1914 * tools which use this vector might be unhappy. 1915 */ 1916 unsigned long user_auxv[AT_VECTOR_SIZE]; 1917 1918 if (len > sizeof(user_auxv)) 1919 return -EINVAL; 1920 1921 if (copy_from_user(user_auxv, (const void __user *)addr, len)) 1922 return -EFAULT; 1923 1924 /* Make sure the last entry is always AT_NULL */ 1925 user_auxv[AT_VECTOR_SIZE - 2] = 0; 1926 user_auxv[AT_VECTOR_SIZE - 1] = 0; 1927 1928 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv)); 1929 1930 task_lock(current); 1931 memcpy(mm->saved_auxv, user_auxv, len); 1932 task_unlock(current); 1933 1934 return 0; 1935 } 1936 1937 static int prctl_set_mm(int opt, unsigned long addr, 1938 unsigned long arg4, unsigned long arg5) 1939 { 1940 struct mm_struct *mm = current->mm; 1941 struct prctl_mm_map prctl_map; 1942 struct vm_area_struct *vma; 1943 int error; 1944 1945 if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV && 1946 opt != PR_SET_MM_MAP && 1947 opt != PR_SET_MM_MAP_SIZE))) 1948 return -EINVAL; 1949 1950 #ifdef CONFIG_CHECKPOINT_RESTORE 1951 if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE) 1952 return prctl_set_mm_map(opt, (const void __user *)addr, arg4); 1953 #endif 1954 1955 if (!capable(CAP_SYS_RESOURCE)) 1956 return -EPERM; 1957 1958 if (opt == PR_SET_MM_EXE_FILE) 1959 return prctl_set_mm_exe_file(mm, (unsigned int)addr); 1960 1961 if (opt == PR_SET_MM_AUXV) 1962 return prctl_set_auxv(mm, addr, arg4); 1963 1964 if (addr >= TASK_SIZE || addr < mmap_min_addr) 1965 return -EINVAL; 1966 1967 error = -EINVAL; 1968 1969 down_write(&mm->mmap_sem); 1970 vma = find_vma(mm, addr); 1971 1972 prctl_map.start_code = mm->start_code; 1973 prctl_map.end_code = mm->end_code; 1974 prctl_map.start_data = mm->start_data; 1975 prctl_map.end_data = mm->end_data; 1976 prctl_map.start_brk = mm->start_brk; 1977 prctl_map.brk = mm->brk; 1978 prctl_map.start_stack = mm->start_stack; 1979 prctl_map.arg_start = mm->arg_start; 1980 prctl_map.arg_end = mm->arg_end; 1981 prctl_map.env_start = mm->env_start; 1982 prctl_map.env_end = mm->env_end; 1983 prctl_map.auxv = NULL; 1984 prctl_map.auxv_size = 0; 1985 prctl_map.exe_fd = -1; 1986 1987 switch (opt) { 1988 case PR_SET_MM_START_CODE: 1989 prctl_map.start_code = addr; 1990 break; 1991 case PR_SET_MM_END_CODE: 1992 prctl_map.end_code = addr; 1993 break; 1994 case PR_SET_MM_START_DATA: 1995 prctl_map.start_data = addr; 1996 break; 1997 case PR_SET_MM_END_DATA: 1998 prctl_map.end_data = addr; 1999 break; 2000 case PR_SET_MM_START_STACK: 2001 prctl_map.start_stack = addr; 2002 break; 2003 case PR_SET_MM_START_BRK: 2004 prctl_map.start_brk = addr; 2005 break; 2006 case PR_SET_MM_BRK: 2007 prctl_map.brk = addr; 2008 break; 2009 case PR_SET_MM_ARG_START: 2010 prctl_map.arg_start = addr; 2011 break; 2012 case PR_SET_MM_ARG_END: 2013 prctl_map.arg_end = addr; 2014 break; 2015 case PR_SET_MM_ENV_START: 2016 prctl_map.env_start = addr; 2017 break; 2018 case PR_SET_MM_ENV_END: 2019 prctl_map.env_end = addr; 2020 break; 2021 default: 2022 goto out; 2023 } 2024 2025 error = validate_prctl_map(&prctl_map); 2026 if (error) 2027 goto out; 2028 2029 switch (opt) { 2030 /* 2031 * If command line arguments and environment 2032 * are placed somewhere else on stack, we can 2033 * set them up here, ARG_START/END to setup 2034 * command line argumets and ENV_START/END 2035 * for environment. 2036 */ 2037 case PR_SET_MM_START_STACK: 2038 case PR_SET_MM_ARG_START: 2039 case PR_SET_MM_ARG_END: 2040 case PR_SET_MM_ENV_START: 2041 case PR_SET_MM_ENV_END: 2042 if (!vma) { 2043 error = -EFAULT; 2044 goto out; 2045 } 2046 } 2047 2048 mm->start_code = prctl_map.start_code; 2049 mm->end_code = prctl_map.end_code; 2050 mm->start_data = prctl_map.start_data; 2051 mm->end_data = prctl_map.end_data; 2052 mm->start_brk = prctl_map.start_brk; 2053 mm->brk = prctl_map.brk; 2054 mm->start_stack = prctl_map.start_stack; 2055 mm->arg_start = prctl_map.arg_start; 2056 mm->arg_end = prctl_map.arg_end; 2057 mm->env_start = prctl_map.env_start; 2058 mm->env_end = prctl_map.env_end; 2059 2060 error = 0; 2061 out: 2062 up_write(&mm->mmap_sem); 2063 return error; 2064 } 2065 2066 #ifdef CONFIG_CHECKPOINT_RESTORE 2067 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr) 2068 { 2069 return put_user(me->clear_child_tid, tid_addr); 2070 } 2071 #else 2072 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr) 2073 { 2074 return -EINVAL; 2075 } 2076 #endif 2077 2078 static int propagate_has_child_subreaper(struct task_struct *p, void *data) 2079 { 2080 /* 2081 * If task has has_child_subreaper - all its decendants 2082 * already have these flag too and new decendants will 2083 * inherit it on fork, skip them. 2084 * 2085 * If we've found child_reaper - skip descendants in 2086 * it's subtree as they will never get out pidns. 2087 */ 2088 if (p->signal->has_child_subreaper || 2089 is_child_reaper(task_pid(p))) 2090 return 0; 2091 2092 p->signal->has_child_subreaper = 1; 2093 return 1; 2094 } 2095 2096 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, 2097 unsigned long, arg4, unsigned long, arg5) 2098 { 2099 struct task_struct *me = current; 2100 unsigned char comm[sizeof(me->comm)]; 2101 long error; 2102 2103 error = security_task_prctl(option, arg2, arg3, arg4, arg5); 2104 if (error != -ENOSYS) 2105 return error; 2106 2107 error = 0; 2108 switch (option) { 2109 case PR_SET_PDEATHSIG: 2110 if (!valid_signal(arg2)) { 2111 error = -EINVAL; 2112 break; 2113 } 2114 me->pdeath_signal = arg2; 2115 break; 2116 case PR_GET_PDEATHSIG: 2117 error = put_user(me->pdeath_signal, (int __user *)arg2); 2118 break; 2119 case PR_GET_DUMPABLE: 2120 error = get_dumpable(me->mm); 2121 break; 2122 case PR_SET_DUMPABLE: 2123 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) { 2124 error = -EINVAL; 2125 break; 2126 } 2127 set_dumpable(me->mm, arg2); 2128 break; 2129 2130 case PR_SET_UNALIGN: 2131 error = SET_UNALIGN_CTL(me, arg2); 2132 break; 2133 case PR_GET_UNALIGN: 2134 error = GET_UNALIGN_CTL(me, arg2); 2135 break; 2136 case PR_SET_FPEMU: 2137 error = SET_FPEMU_CTL(me, arg2); 2138 break; 2139 case PR_GET_FPEMU: 2140 error = GET_FPEMU_CTL(me, arg2); 2141 break; 2142 case PR_SET_FPEXC: 2143 error = SET_FPEXC_CTL(me, arg2); 2144 break; 2145 case PR_GET_FPEXC: 2146 error = GET_FPEXC_CTL(me, arg2); 2147 break; 2148 case PR_GET_TIMING: 2149 error = PR_TIMING_STATISTICAL; 2150 break; 2151 case PR_SET_TIMING: 2152 if (arg2 != PR_TIMING_STATISTICAL) 2153 error = -EINVAL; 2154 break; 2155 case PR_SET_NAME: 2156 comm[sizeof(me->comm) - 1] = 0; 2157 if (strncpy_from_user(comm, (char __user *)arg2, 2158 sizeof(me->comm) - 1) < 0) 2159 return -EFAULT; 2160 set_task_comm(me, comm); 2161 proc_comm_connector(me); 2162 break; 2163 case PR_GET_NAME: 2164 get_task_comm(comm, me); 2165 if (copy_to_user((char __user *)arg2, comm, sizeof(comm))) 2166 return -EFAULT; 2167 break; 2168 case PR_GET_ENDIAN: 2169 error = GET_ENDIAN(me, arg2); 2170 break; 2171 case PR_SET_ENDIAN: 2172 error = SET_ENDIAN(me, arg2); 2173 break; 2174 case PR_GET_SECCOMP: 2175 error = prctl_get_seccomp(); 2176 break; 2177 case PR_SET_SECCOMP: 2178 error = prctl_set_seccomp(arg2, (char __user *)arg3); 2179 break; 2180 case PR_GET_TSC: 2181 error = GET_TSC_CTL(arg2); 2182 break; 2183 case PR_SET_TSC: 2184 error = SET_TSC_CTL(arg2); 2185 break; 2186 case PR_TASK_PERF_EVENTS_DISABLE: 2187 error = perf_event_task_disable(); 2188 break; 2189 case PR_TASK_PERF_EVENTS_ENABLE: 2190 error = perf_event_task_enable(); 2191 break; 2192 case PR_GET_TIMERSLACK: 2193 if (current->timer_slack_ns > ULONG_MAX) 2194 error = ULONG_MAX; 2195 else 2196 error = current->timer_slack_ns; 2197 break; 2198 case PR_SET_TIMERSLACK: 2199 if (arg2 <= 0) 2200 current->timer_slack_ns = 2201 current->default_timer_slack_ns; 2202 else 2203 current->timer_slack_ns = arg2; 2204 break; 2205 case PR_MCE_KILL: 2206 if (arg4 | arg5) 2207 return -EINVAL; 2208 switch (arg2) { 2209 case PR_MCE_KILL_CLEAR: 2210 if (arg3 != 0) 2211 return -EINVAL; 2212 current->flags &= ~PF_MCE_PROCESS; 2213 break; 2214 case PR_MCE_KILL_SET: 2215 current->flags |= PF_MCE_PROCESS; 2216 if (arg3 == PR_MCE_KILL_EARLY) 2217 current->flags |= PF_MCE_EARLY; 2218 else if (arg3 == PR_MCE_KILL_LATE) 2219 current->flags &= ~PF_MCE_EARLY; 2220 else if (arg3 == PR_MCE_KILL_DEFAULT) 2221 current->flags &= 2222 ~(PF_MCE_EARLY|PF_MCE_PROCESS); 2223 else 2224 return -EINVAL; 2225 break; 2226 default: 2227 return -EINVAL; 2228 } 2229 break; 2230 case PR_MCE_KILL_GET: 2231 if (arg2 | arg3 | arg4 | arg5) 2232 return -EINVAL; 2233 if (current->flags & PF_MCE_PROCESS) 2234 error = (current->flags & PF_MCE_EARLY) ? 2235 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE; 2236 else 2237 error = PR_MCE_KILL_DEFAULT; 2238 break; 2239 case PR_SET_MM: 2240 error = prctl_set_mm(arg2, arg3, arg4, arg5); 2241 break; 2242 case PR_GET_TID_ADDRESS: 2243 error = prctl_get_tid_address(me, (int __user **)arg2); 2244 break; 2245 case PR_SET_CHILD_SUBREAPER: 2246 me->signal->is_child_subreaper = !!arg2; 2247 if (!arg2) 2248 break; 2249 2250 walk_process_tree(me, propagate_has_child_subreaper, NULL); 2251 break; 2252 case PR_GET_CHILD_SUBREAPER: 2253 error = put_user(me->signal->is_child_subreaper, 2254 (int __user *)arg2); 2255 break; 2256 case PR_SET_NO_NEW_PRIVS: 2257 if (arg2 != 1 || arg3 || arg4 || arg5) 2258 return -EINVAL; 2259 2260 task_set_no_new_privs(current); 2261 break; 2262 case PR_GET_NO_NEW_PRIVS: 2263 if (arg2 || arg3 || arg4 || arg5) 2264 return -EINVAL; 2265 return task_no_new_privs(current) ? 1 : 0; 2266 case PR_GET_THP_DISABLE: 2267 if (arg2 || arg3 || arg4 || arg5) 2268 return -EINVAL; 2269 error = !!(me->mm->def_flags & VM_NOHUGEPAGE); 2270 break; 2271 case PR_SET_THP_DISABLE: 2272 if (arg3 || arg4 || arg5) 2273 return -EINVAL; 2274 if (down_write_killable(&me->mm->mmap_sem)) 2275 return -EINTR; 2276 if (arg2) 2277 me->mm->def_flags |= VM_NOHUGEPAGE; 2278 else 2279 me->mm->def_flags &= ~VM_NOHUGEPAGE; 2280 up_write(&me->mm->mmap_sem); 2281 break; 2282 case PR_MPX_ENABLE_MANAGEMENT: 2283 if (arg2 || arg3 || arg4 || arg5) 2284 return -EINVAL; 2285 error = MPX_ENABLE_MANAGEMENT(); 2286 break; 2287 case PR_MPX_DISABLE_MANAGEMENT: 2288 if (arg2 || arg3 || arg4 || arg5) 2289 return -EINVAL; 2290 error = MPX_DISABLE_MANAGEMENT(); 2291 break; 2292 case PR_SET_FP_MODE: 2293 error = SET_FP_MODE(me, arg2); 2294 break; 2295 case PR_GET_FP_MODE: 2296 error = GET_FP_MODE(me); 2297 break; 2298 default: 2299 error = -EINVAL; 2300 break; 2301 } 2302 return error; 2303 } 2304 2305 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep, 2306 struct getcpu_cache __user *, unused) 2307 { 2308 int err = 0; 2309 int cpu = raw_smp_processor_id(); 2310 2311 if (cpup) 2312 err |= put_user(cpu, cpup); 2313 if (nodep) 2314 err |= put_user(cpu_to_node(cpu), nodep); 2315 return err ? -EFAULT : 0; 2316 } 2317 2318 /** 2319 * do_sysinfo - fill in sysinfo struct 2320 * @info: pointer to buffer to fill 2321 */ 2322 static int do_sysinfo(struct sysinfo *info) 2323 { 2324 unsigned long mem_total, sav_total; 2325 unsigned int mem_unit, bitcount; 2326 struct timespec tp; 2327 2328 memset(info, 0, sizeof(struct sysinfo)); 2329 2330 get_monotonic_boottime(&tp); 2331 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0); 2332 2333 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT); 2334 2335 info->procs = nr_threads; 2336 2337 si_meminfo(info); 2338 si_swapinfo(info); 2339 2340 /* 2341 * If the sum of all the available memory (i.e. ram + swap) 2342 * is less than can be stored in a 32 bit unsigned long then 2343 * we can be binary compatible with 2.2.x kernels. If not, 2344 * well, in that case 2.2.x was broken anyways... 2345 * 2346 * -Erik Andersen <andersee@debian.org> 2347 */ 2348 2349 mem_total = info->totalram + info->totalswap; 2350 if (mem_total < info->totalram || mem_total < info->totalswap) 2351 goto out; 2352 bitcount = 0; 2353 mem_unit = info->mem_unit; 2354 while (mem_unit > 1) { 2355 bitcount++; 2356 mem_unit >>= 1; 2357 sav_total = mem_total; 2358 mem_total <<= 1; 2359 if (mem_total < sav_total) 2360 goto out; 2361 } 2362 2363 /* 2364 * If mem_total did not overflow, multiply all memory values by 2365 * info->mem_unit and set it to 1. This leaves things compatible 2366 * with 2.2.x, and also retains compatibility with earlier 2.4.x 2367 * kernels... 2368 */ 2369 2370 info->mem_unit = 1; 2371 info->totalram <<= bitcount; 2372 info->freeram <<= bitcount; 2373 info->sharedram <<= bitcount; 2374 info->bufferram <<= bitcount; 2375 info->totalswap <<= bitcount; 2376 info->freeswap <<= bitcount; 2377 info->totalhigh <<= bitcount; 2378 info->freehigh <<= bitcount; 2379 2380 out: 2381 return 0; 2382 } 2383 2384 SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info) 2385 { 2386 struct sysinfo val; 2387 2388 do_sysinfo(&val); 2389 2390 if (copy_to_user(info, &val, sizeof(struct sysinfo))) 2391 return -EFAULT; 2392 2393 return 0; 2394 } 2395 2396 #ifdef CONFIG_COMPAT 2397 struct compat_sysinfo { 2398 s32 uptime; 2399 u32 loads[3]; 2400 u32 totalram; 2401 u32 freeram; 2402 u32 sharedram; 2403 u32 bufferram; 2404 u32 totalswap; 2405 u32 freeswap; 2406 u16 procs; 2407 u16 pad; 2408 u32 totalhigh; 2409 u32 freehigh; 2410 u32 mem_unit; 2411 char _f[20-2*sizeof(u32)-sizeof(int)]; 2412 }; 2413 2414 COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info) 2415 { 2416 struct sysinfo s; 2417 2418 do_sysinfo(&s); 2419 2420 /* Check to see if any memory value is too large for 32-bit and scale 2421 * down if needed 2422 */ 2423 if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) { 2424 int bitcount = 0; 2425 2426 while (s.mem_unit < PAGE_SIZE) { 2427 s.mem_unit <<= 1; 2428 bitcount++; 2429 } 2430 2431 s.totalram >>= bitcount; 2432 s.freeram >>= bitcount; 2433 s.sharedram >>= bitcount; 2434 s.bufferram >>= bitcount; 2435 s.totalswap >>= bitcount; 2436 s.freeswap >>= bitcount; 2437 s.totalhigh >>= bitcount; 2438 s.freehigh >>= bitcount; 2439 } 2440 2441 if (!access_ok(VERIFY_WRITE, info, sizeof(struct compat_sysinfo)) || 2442 __put_user(s.uptime, &info->uptime) || 2443 __put_user(s.loads[0], &info->loads[0]) || 2444 __put_user(s.loads[1], &info->loads[1]) || 2445 __put_user(s.loads[2], &info->loads[2]) || 2446 __put_user(s.totalram, &info->totalram) || 2447 __put_user(s.freeram, &info->freeram) || 2448 __put_user(s.sharedram, &info->sharedram) || 2449 __put_user(s.bufferram, &info->bufferram) || 2450 __put_user(s.totalswap, &info->totalswap) || 2451 __put_user(s.freeswap, &info->freeswap) || 2452 __put_user(s.procs, &info->procs) || 2453 __put_user(s.totalhigh, &info->totalhigh) || 2454 __put_user(s.freehigh, &info->freehigh) || 2455 __put_user(s.mem_unit, &info->mem_unit)) 2456 return -EFAULT; 2457 2458 return 0; 2459 } 2460 #endif /* CONFIG_COMPAT */ 2461