1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/kernel/sys.c 4 * 5 * Copyright (C) 1991, 1992 Linus Torvalds 6 */ 7 8 #include <linux/export.h> 9 #include <linux/mm.h> 10 #include <linux/utsname.h> 11 #include <linux/mman.h> 12 #include <linux/reboot.h> 13 #include <linux/prctl.h> 14 #include <linux/highuid.h> 15 #include <linux/fs.h> 16 #include <linux/kmod.h> 17 #include <linux/perf_event.h> 18 #include <linux/resource.h> 19 #include <linux/kernel.h> 20 #include <linux/workqueue.h> 21 #include <linux/capability.h> 22 #include <linux/device.h> 23 #include <linux/key.h> 24 #include <linux/times.h> 25 #include <linux/posix-timers.h> 26 #include <linux/security.h> 27 #include <linux/dcookies.h> 28 #include <linux/suspend.h> 29 #include <linux/tty.h> 30 #include <linux/signal.h> 31 #include <linux/cn_proc.h> 32 #include <linux/getcpu.h> 33 #include <linux/task_io_accounting_ops.h> 34 #include <linux/seccomp.h> 35 #include <linux/cpu.h> 36 #include <linux/personality.h> 37 #include <linux/ptrace.h> 38 #include <linux/fs_struct.h> 39 #include <linux/file.h> 40 #include <linux/mount.h> 41 #include <linux/gfp.h> 42 #include <linux/syscore_ops.h> 43 #include <linux/version.h> 44 #include <linux/ctype.h> 45 46 #include <linux/compat.h> 47 #include <linux/syscalls.h> 48 #include <linux/kprobes.h> 49 #include <linux/user_namespace.h> 50 #include <linux/binfmts.h> 51 52 #include <linux/sched.h> 53 #include <linux/sched/autogroup.h> 54 #include <linux/sched/loadavg.h> 55 #include <linux/sched/stat.h> 56 #include <linux/sched/mm.h> 57 #include <linux/sched/coredump.h> 58 #include <linux/sched/task.h> 59 #include <linux/sched/cputime.h> 60 #include <linux/rcupdate.h> 61 #include <linux/uidgid.h> 62 #include <linux/cred.h> 63 64 #include <linux/kmsg_dump.h> 65 /* Move somewhere else to avoid recompiling? */ 66 #include <generated/utsrelease.h> 67 68 #include <linux/uaccess.h> 69 #include <asm/io.h> 70 #include <asm/unistd.h> 71 72 #ifndef SET_UNALIGN_CTL 73 # define SET_UNALIGN_CTL(a, b) (-EINVAL) 74 #endif 75 #ifndef GET_UNALIGN_CTL 76 # define GET_UNALIGN_CTL(a, b) (-EINVAL) 77 #endif 78 #ifndef SET_FPEMU_CTL 79 # define SET_FPEMU_CTL(a, b) (-EINVAL) 80 #endif 81 #ifndef GET_FPEMU_CTL 82 # define GET_FPEMU_CTL(a, b) (-EINVAL) 83 #endif 84 #ifndef SET_FPEXC_CTL 85 # define SET_FPEXC_CTL(a, b) (-EINVAL) 86 #endif 87 #ifndef GET_FPEXC_CTL 88 # define GET_FPEXC_CTL(a, b) (-EINVAL) 89 #endif 90 #ifndef GET_ENDIAN 91 # define GET_ENDIAN(a, b) (-EINVAL) 92 #endif 93 #ifndef SET_ENDIAN 94 # define SET_ENDIAN(a, b) (-EINVAL) 95 #endif 96 #ifndef GET_TSC_CTL 97 # define GET_TSC_CTL(a) (-EINVAL) 98 #endif 99 #ifndef SET_TSC_CTL 100 # define SET_TSC_CTL(a) (-EINVAL) 101 #endif 102 #ifndef MPX_ENABLE_MANAGEMENT 103 # define MPX_ENABLE_MANAGEMENT() (-EINVAL) 104 #endif 105 #ifndef MPX_DISABLE_MANAGEMENT 106 # define MPX_DISABLE_MANAGEMENT() (-EINVAL) 107 #endif 108 #ifndef GET_FP_MODE 109 # define GET_FP_MODE(a) (-EINVAL) 110 #endif 111 #ifndef SET_FP_MODE 112 # define SET_FP_MODE(a,b) (-EINVAL) 113 #endif 114 #ifndef SVE_SET_VL 115 # define SVE_SET_VL(a) (-EINVAL) 116 #endif 117 #ifndef SVE_GET_VL 118 # define SVE_GET_VL() (-EINVAL) 119 #endif 120 121 /* 122 * this is where the system-wide overflow UID and GID are defined, for 123 * architectures that now have 32-bit UID/GID but didn't in the past 124 */ 125 126 int overflowuid = DEFAULT_OVERFLOWUID; 127 int overflowgid = DEFAULT_OVERFLOWGID; 128 129 EXPORT_SYMBOL(overflowuid); 130 EXPORT_SYMBOL(overflowgid); 131 132 /* 133 * the same as above, but for filesystems which can only store a 16-bit 134 * UID and GID. as such, this is needed on all architectures 135 */ 136 137 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID; 138 int fs_overflowgid = DEFAULT_FS_OVERFLOWUID; 139 140 EXPORT_SYMBOL(fs_overflowuid); 141 EXPORT_SYMBOL(fs_overflowgid); 142 143 /* 144 * Returns true if current's euid is same as p's uid or euid, 145 * or has CAP_SYS_NICE to p's user_ns. 146 * 147 * Called with rcu_read_lock, creds are safe 148 */ 149 static bool set_one_prio_perm(struct task_struct *p) 150 { 151 const struct cred *cred = current_cred(), *pcred = __task_cred(p); 152 153 if (uid_eq(pcred->uid, cred->euid) || 154 uid_eq(pcred->euid, cred->euid)) 155 return true; 156 if (ns_capable(pcred->user_ns, CAP_SYS_NICE)) 157 return true; 158 return false; 159 } 160 161 /* 162 * set the priority of a task 163 * - the caller must hold the RCU read lock 164 */ 165 static int set_one_prio(struct task_struct *p, int niceval, int error) 166 { 167 int no_nice; 168 169 if (!set_one_prio_perm(p)) { 170 error = -EPERM; 171 goto out; 172 } 173 if (niceval < task_nice(p) && !can_nice(p, niceval)) { 174 error = -EACCES; 175 goto out; 176 } 177 no_nice = security_task_setnice(p, niceval); 178 if (no_nice) { 179 error = no_nice; 180 goto out; 181 } 182 if (error == -ESRCH) 183 error = 0; 184 set_user_nice(p, niceval); 185 out: 186 return error; 187 } 188 189 SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval) 190 { 191 struct task_struct *g, *p; 192 struct user_struct *user; 193 const struct cred *cred = current_cred(); 194 int error = -EINVAL; 195 struct pid *pgrp; 196 kuid_t uid; 197 198 if (which > PRIO_USER || which < PRIO_PROCESS) 199 goto out; 200 201 /* normalize: avoid signed division (rounding problems) */ 202 error = -ESRCH; 203 if (niceval < MIN_NICE) 204 niceval = MIN_NICE; 205 if (niceval > MAX_NICE) 206 niceval = MAX_NICE; 207 208 rcu_read_lock(); 209 read_lock(&tasklist_lock); 210 switch (which) { 211 case PRIO_PROCESS: 212 if (who) 213 p = find_task_by_vpid(who); 214 else 215 p = current; 216 if (p) 217 error = set_one_prio(p, niceval, error); 218 break; 219 case PRIO_PGRP: 220 if (who) 221 pgrp = find_vpid(who); 222 else 223 pgrp = task_pgrp(current); 224 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { 225 error = set_one_prio(p, niceval, error); 226 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); 227 break; 228 case PRIO_USER: 229 uid = make_kuid(cred->user_ns, who); 230 user = cred->user; 231 if (!who) 232 uid = cred->uid; 233 else if (!uid_eq(uid, cred->uid)) { 234 user = find_user(uid); 235 if (!user) 236 goto out_unlock; /* No processes for this user */ 237 } 238 do_each_thread(g, p) { 239 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) 240 error = set_one_prio(p, niceval, error); 241 } while_each_thread(g, p); 242 if (!uid_eq(uid, cred->uid)) 243 free_uid(user); /* For find_user() */ 244 break; 245 } 246 out_unlock: 247 read_unlock(&tasklist_lock); 248 rcu_read_unlock(); 249 out: 250 return error; 251 } 252 253 /* 254 * Ugh. To avoid negative return values, "getpriority()" will 255 * not return the normal nice-value, but a negated value that 256 * has been offset by 20 (ie it returns 40..1 instead of -20..19) 257 * to stay compatible. 258 */ 259 SYSCALL_DEFINE2(getpriority, int, which, int, who) 260 { 261 struct task_struct *g, *p; 262 struct user_struct *user; 263 const struct cred *cred = current_cred(); 264 long niceval, retval = -ESRCH; 265 struct pid *pgrp; 266 kuid_t uid; 267 268 if (which > PRIO_USER || which < PRIO_PROCESS) 269 return -EINVAL; 270 271 rcu_read_lock(); 272 read_lock(&tasklist_lock); 273 switch (which) { 274 case PRIO_PROCESS: 275 if (who) 276 p = find_task_by_vpid(who); 277 else 278 p = current; 279 if (p) { 280 niceval = nice_to_rlimit(task_nice(p)); 281 if (niceval > retval) 282 retval = niceval; 283 } 284 break; 285 case PRIO_PGRP: 286 if (who) 287 pgrp = find_vpid(who); 288 else 289 pgrp = task_pgrp(current); 290 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { 291 niceval = nice_to_rlimit(task_nice(p)); 292 if (niceval > retval) 293 retval = niceval; 294 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); 295 break; 296 case PRIO_USER: 297 uid = make_kuid(cred->user_ns, who); 298 user = cred->user; 299 if (!who) 300 uid = cred->uid; 301 else if (!uid_eq(uid, cred->uid)) { 302 user = find_user(uid); 303 if (!user) 304 goto out_unlock; /* No processes for this user */ 305 } 306 do_each_thread(g, p) { 307 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) { 308 niceval = nice_to_rlimit(task_nice(p)); 309 if (niceval > retval) 310 retval = niceval; 311 } 312 } while_each_thread(g, p); 313 if (!uid_eq(uid, cred->uid)) 314 free_uid(user); /* for find_user() */ 315 break; 316 } 317 out_unlock: 318 read_unlock(&tasklist_lock); 319 rcu_read_unlock(); 320 321 return retval; 322 } 323 324 /* 325 * Unprivileged users may change the real gid to the effective gid 326 * or vice versa. (BSD-style) 327 * 328 * If you set the real gid at all, or set the effective gid to a value not 329 * equal to the real gid, then the saved gid is set to the new effective gid. 330 * 331 * This makes it possible for a setgid program to completely drop its 332 * privileges, which is often a useful assertion to make when you are doing 333 * a security audit over a program. 334 * 335 * The general idea is that a program which uses just setregid() will be 336 * 100% compatible with BSD. A program which uses just setgid() will be 337 * 100% compatible with POSIX with saved IDs. 338 * 339 * SMP: There are not races, the GIDs are checked only by filesystem 340 * operations (as far as semantic preservation is concerned). 341 */ 342 #ifdef CONFIG_MULTIUSER 343 SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid) 344 { 345 struct user_namespace *ns = current_user_ns(); 346 const struct cred *old; 347 struct cred *new; 348 int retval; 349 kgid_t krgid, kegid; 350 351 krgid = make_kgid(ns, rgid); 352 kegid = make_kgid(ns, egid); 353 354 if ((rgid != (gid_t) -1) && !gid_valid(krgid)) 355 return -EINVAL; 356 if ((egid != (gid_t) -1) && !gid_valid(kegid)) 357 return -EINVAL; 358 359 new = prepare_creds(); 360 if (!new) 361 return -ENOMEM; 362 old = current_cred(); 363 364 retval = -EPERM; 365 if (rgid != (gid_t) -1) { 366 if (gid_eq(old->gid, krgid) || 367 gid_eq(old->egid, krgid) || 368 ns_capable(old->user_ns, CAP_SETGID)) 369 new->gid = krgid; 370 else 371 goto error; 372 } 373 if (egid != (gid_t) -1) { 374 if (gid_eq(old->gid, kegid) || 375 gid_eq(old->egid, kegid) || 376 gid_eq(old->sgid, kegid) || 377 ns_capable(old->user_ns, CAP_SETGID)) 378 new->egid = kegid; 379 else 380 goto error; 381 } 382 383 if (rgid != (gid_t) -1 || 384 (egid != (gid_t) -1 && !gid_eq(kegid, old->gid))) 385 new->sgid = new->egid; 386 new->fsgid = new->egid; 387 388 return commit_creds(new); 389 390 error: 391 abort_creds(new); 392 return retval; 393 } 394 395 /* 396 * setgid() is implemented like SysV w/ SAVED_IDS 397 * 398 * SMP: Same implicit races as above. 399 */ 400 SYSCALL_DEFINE1(setgid, gid_t, gid) 401 { 402 struct user_namespace *ns = current_user_ns(); 403 const struct cred *old; 404 struct cred *new; 405 int retval; 406 kgid_t kgid; 407 408 kgid = make_kgid(ns, gid); 409 if (!gid_valid(kgid)) 410 return -EINVAL; 411 412 new = prepare_creds(); 413 if (!new) 414 return -ENOMEM; 415 old = current_cred(); 416 417 retval = -EPERM; 418 if (ns_capable(old->user_ns, CAP_SETGID)) 419 new->gid = new->egid = new->sgid = new->fsgid = kgid; 420 else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid)) 421 new->egid = new->fsgid = kgid; 422 else 423 goto error; 424 425 return commit_creds(new); 426 427 error: 428 abort_creds(new); 429 return retval; 430 } 431 432 /* 433 * change the user struct in a credentials set to match the new UID 434 */ 435 static int set_user(struct cred *new) 436 { 437 struct user_struct *new_user; 438 439 new_user = alloc_uid(new->uid); 440 if (!new_user) 441 return -EAGAIN; 442 443 /* 444 * We don't fail in case of NPROC limit excess here because too many 445 * poorly written programs don't check set*uid() return code, assuming 446 * it never fails if called by root. We may still enforce NPROC limit 447 * for programs doing set*uid()+execve() by harmlessly deferring the 448 * failure to the execve() stage. 449 */ 450 if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) && 451 new_user != INIT_USER) 452 current->flags |= PF_NPROC_EXCEEDED; 453 else 454 current->flags &= ~PF_NPROC_EXCEEDED; 455 456 free_uid(new->user); 457 new->user = new_user; 458 return 0; 459 } 460 461 /* 462 * Unprivileged users may change the real uid to the effective uid 463 * or vice versa. (BSD-style) 464 * 465 * If you set the real uid at all, or set the effective uid to a value not 466 * equal to the real uid, then the saved uid is set to the new effective uid. 467 * 468 * This makes it possible for a setuid program to completely drop its 469 * privileges, which is often a useful assertion to make when you are doing 470 * a security audit over a program. 471 * 472 * The general idea is that a program which uses just setreuid() will be 473 * 100% compatible with BSD. A program which uses just setuid() will be 474 * 100% compatible with POSIX with saved IDs. 475 */ 476 SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid) 477 { 478 struct user_namespace *ns = current_user_ns(); 479 const struct cred *old; 480 struct cred *new; 481 int retval; 482 kuid_t kruid, keuid; 483 484 kruid = make_kuid(ns, ruid); 485 keuid = make_kuid(ns, euid); 486 487 if ((ruid != (uid_t) -1) && !uid_valid(kruid)) 488 return -EINVAL; 489 if ((euid != (uid_t) -1) && !uid_valid(keuid)) 490 return -EINVAL; 491 492 new = prepare_creds(); 493 if (!new) 494 return -ENOMEM; 495 old = current_cred(); 496 497 retval = -EPERM; 498 if (ruid != (uid_t) -1) { 499 new->uid = kruid; 500 if (!uid_eq(old->uid, kruid) && 501 !uid_eq(old->euid, kruid) && 502 !ns_capable(old->user_ns, CAP_SETUID)) 503 goto error; 504 } 505 506 if (euid != (uid_t) -1) { 507 new->euid = keuid; 508 if (!uid_eq(old->uid, keuid) && 509 !uid_eq(old->euid, keuid) && 510 !uid_eq(old->suid, keuid) && 511 !ns_capable(old->user_ns, CAP_SETUID)) 512 goto error; 513 } 514 515 if (!uid_eq(new->uid, old->uid)) { 516 retval = set_user(new); 517 if (retval < 0) 518 goto error; 519 } 520 if (ruid != (uid_t) -1 || 521 (euid != (uid_t) -1 && !uid_eq(keuid, old->uid))) 522 new->suid = new->euid; 523 new->fsuid = new->euid; 524 525 retval = security_task_fix_setuid(new, old, LSM_SETID_RE); 526 if (retval < 0) 527 goto error; 528 529 return commit_creds(new); 530 531 error: 532 abort_creds(new); 533 return retval; 534 } 535 536 /* 537 * setuid() is implemented like SysV with SAVED_IDS 538 * 539 * Note that SAVED_ID's is deficient in that a setuid root program 540 * like sendmail, for example, cannot set its uid to be a normal 541 * user and then switch back, because if you're root, setuid() sets 542 * the saved uid too. If you don't like this, blame the bright people 543 * in the POSIX committee and/or USG. Note that the BSD-style setreuid() 544 * will allow a root program to temporarily drop privileges and be able to 545 * regain them by swapping the real and effective uid. 546 */ 547 SYSCALL_DEFINE1(setuid, uid_t, uid) 548 { 549 struct user_namespace *ns = current_user_ns(); 550 const struct cred *old; 551 struct cred *new; 552 int retval; 553 kuid_t kuid; 554 555 kuid = make_kuid(ns, uid); 556 if (!uid_valid(kuid)) 557 return -EINVAL; 558 559 new = prepare_creds(); 560 if (!new) 561 return -ENOMEM; 562 old = current_cred(); 563 564 retval = -EPERM; 565 if (ns_capable(old->user_ns, CAP_SETUID)) { 566 new->suid = new->uid = kuid; 567 if (!uid_eq(kuid, old->uid)) { 568 retval = set_user(new); 569 if (retval < 0) 570 goto error; 571 } 572 } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) { 573 goto error; 574 } 575 576 new->fsuid = new->euid = kuid; 577 578 retval = security_task_fix_setuid(new, old, LSM_SETID_ID); 579 if (retval < 0) 580 goto error; 581 582 return commit_creds(new); 583 584 error: 585 abort_creds(new); 586 return retval; 587 } 588 589 590 /* 591 * This function implements a generic ability to update ruid, euid, 592 * and suid. This allows you to implement the 4.4 compatible seteuid(). 593 */ 594 SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid) 595 { 596 struct user_namespace *ns = current_user_ns(); 597 const struct cred *old; 598 struct cred *new; 599 int retval; 600 kuid_t kruid, keuid, ksuid; 601 602 kruid = make_kuid(ns, ruid); 603 keuid = make_kuid(ns, euid); 604 ksuid = make_kuid(ns, suid); 605 606 if ((ruid != (uid_t) -1) && !uid_valid(kruid)) 607 return -EINVAL; 608 609 if ((euid != (uid_t) -1) && !uid_valid(keuid)) 610 return -EINVAL; 611 612 if ((suid != (uid_t) -1) && !uid_valid(ksuid)) 613 return -EINVAL; 614 615 new = prepare_creds(); 616 if (!new) 617 return -ENOMEM; 618 619 old = current_cred(); 620 621 retval = -EPERM; 622 if (!ns_capable(old->user_ns, CAP_SETUID)) { 623 if (ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) && 624 !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid)) 625 goto error; 626 if (euid != (uid_t) -1 && !uid_eq(keuid, old->uid) && 627 !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid)) 628 goto error; 629 if (suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) && 630 !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid)) 631 goto error; 632 } 633 634 if (ruid != (uid_t) -1) { 635 new->uid = kruid; 636 if (!uid_eq(kruid, old->uid)) { 637 retval = set_user(new); 638 if (retval < 0) 639 goto error; 640 } 641 } 642 if (euid != (uid_t) -1) 643 new->euid = keuid; 644 if (suid != (uid_t) -1) 645 new->suid = ksuid; 646 new->fsuid = new->euid; 647 648 retval = security_task_fix_setuid(new, old, LSM_SETID_RES); 649 if (retval < 0) 650 goto error; 651 652 return commit_creds(new); 653 654 error: 655 abort_creds(new); 656 return retval; 657 } 658 659 SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp) 660 { 661 const struct cred *cred = current_cred(); 662 int retval; 663 uid_t ruid, euid, suid; 664 665 ruid = from_kuid_munged(cred->user_ns, cred->uid); 666 euid = from_kuid_munged(cred->user_ns, cred->euid); 667 suid = from_kuid_munged(cred->user_ns, cred->suid); 668 669 retval = put_user(ruid, ruidp); 670 if (!retval) { 671 retval = put_user(euid, euidp); 672 if (!retval) 673 return put_user(suid, suidp); 674 } 675 return retval; 676 } 677 678 /* 679 * Same as above, but for rgid, egid, sgid. 680 */ 681 SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid) 682 { 683 struct user_namespace *ns = current_user_ns(); 684 const struct cred *old; 685 struct cred *new; 686 int retval; 687 kgid_t krgid, kegid, ksgid; 688 689 krgid = make_kgid(ns, rgid); 690 kegid = make_kgid(ns, egid); 691 ksgid = make_kgid(ns, sgid); 692 693 if ((rgid != (gid_t) -1) && !gid_valid(krgid)) 694 return -EINVAL; 695 if ((egid != (gid_t) -1) && !gid_valid(kegid)) 696 return -EINVAL; 697 if ((sgid != (gid_t) -1) && !gid_valid(ksgid)) 698 return -EINVAL; 699 700 new = prepare_creds(); 701 if (!new) 702 return -ENOMEM; 703 old = current_cred(); 704 705 retval = -EPERM; 706 if (!ns_capable(old->user_ns, CAP_SETGID)) { 707 if (rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) && 708 !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid)) 709 goto error; 710 if (egid != (gid_t) -1 && !gid_eq(kegid, old->gid) && 711 !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid)) 712 goto error; 713 if (sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) && 714 !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid)) 715 goto error; 716 } 717 718 if (rgid != (gid_t) -1) 719 new->gid = krgid; 720 if (egid != (gid_t) -1) 721 new->egid = kegid; 722 if (sgid != (gid_t) -1) 723 new->sgid = ksgid; 724 new->fsgid = new->egid; 725 726 return commit_creds(new); 727 728 error: 729 abort_creds(new); 730 return retval; 731 } 732 733 SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp) 734 { 735 const struct cred *cred = current_cred(); 736 int retval; 737 gid_t rgid, egid, sgid; 738 739 rgid = from_kgid_munged(cred->user_ns, cred->gid); 740 egid = from_kgid_munged(cred->user_ns, cred->egid); 741 sgid = from_kgid_munged(cred->user_ns, cred->sgid); 742 743 retval = put_user(rgid, rgidp); 744 if (!retval) { 745 retval = put_user(egid, egidp); 746 if (!retval) 747 retval = put_user(sgid, sgidp); 748 } 749 750 return retval; 751 } 752 753 754 /* 755 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This 756 * is used for "access()" and for the NFS daemon (letting nfsd stay at 757 * whatever uid it wants to). It normally shadows "euid", except when 758 * explicitly set by setfsuid() or for access.. 759 */ 760 SYSCALL_DEFINE1(setfsuid, uid_t, uid) 761 { 762 const struct cred *old; 763 struct cred *new; 764 uid_t old_fsuid; 765 kuid_t kuid; 766 767 old = current_cred(); 768 old_fsuid = from_kuid_munged(old->user_ns, old->fsuid); 769 770 kuid = make_kuid(old->user_ns, uid); 771 if (!uid_valid(kuid)) 772 return old_fsuid; 773 774 new = prepare_creds(); 775 if (!new) 776 return old_fsuid; 777 778 if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) || 779 uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) || 780 ns_capable(old->user_ns, CAP_SETUID)) { 781 if (!uid_eq(kuid, old->fsuid)) { 782 new->fsuid = kuid; 783 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0) 784 goto change_okay; 785 } 786 } 787 788 abort_creds(new); 789 return old_fsuid; 790 791 change_okay: 792 commit_creds(new); 793 return old_fsuid; 794 } 795 796 /* 797 * Samma på svenska.. 798 */ 799 SYSCALL_DEFINE1(setfsgid, gid_t, gid) 800 { 801 const struct cred *old; 802 struct cred *new; 803 gid_t old_fsgid; 804 kgid_t kgid; 805 806 old = current_cred(); 807 old_fsgid = from_kgid_munged(old->user_ns, old->fsgid); 808 809 kgid = make_kgid(old->user_ns, gid); 810 if (!gid_valid(kgid)) 811 return old_fsgid; 812 813 new = prepare_creds(); 814 if (!new) 815 return old_fsgid; 816 817 if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) || 818 gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) || 819 ns_capable(old->user_ns, CAP_SETGID)) { 820 if (!gid_eq(kgid, old->fsgid)) { 821 new->fsgid = kgid; 822 goto change_okay; 823 } 824 } 825 826 abort_creds(new); 827 return old_fsgid; 828 829 change_okay: 830 commit_creds(new); 831 return old_fsgid; 832 } 833 #endif /* CONFIG_MULTIUSER */ 834 835 /** 836 * sys_getpid - return the thread group id of the current process 837 * 838 * Note, despite the name, this returns the tgid not the pid. The tgid and 839 * the pid are identical unless CLONE_THREAD was specified on clone() in 840 * which case the tgid is the same in all threads of the same group. 841 * 842 * This is SMP safe as current->tgid does not change. 843 */ 844 SYSCALL_DEFINE0(getpid) 845 { 846 return task_tgid_vnr(current); 847 } 848 849 /* Thread ID - the internal kernel "pid" */ 850 SYSCALL_DEFINE0(gettid) 851 { 852 return task_pid_vnr(current); 853 } 854 855 /* 856 * Accessing ->real_parent is not SMP-safe, it could 857 * change from under us. However, we can use a stale 858 * value of ->real_parent under rcu_read_lock(), see 859 * release_task()->call_rcu(delayed_put_task_struct). 860 */ 861 SYSCALL_DEFINE0(getppid) 862 { 863 int pid; 864 865 rcu_read_lock(); 866 pid = task_tgid_vnr(rcu_dereference(current->real_parent)); 867 rcu_read_unlock(); 868 869 return pid; 870 } 871 872 SYSCALL_DEFINE0(getuid) 873 { 874 /* Only we change this so SMP safe */ 875 return from_kuid_munged(current_user_ns(), current_uid()); 876 } 877 878 SYSCALL_DEFINE0(geteuid) 879 { 880 /* Only we change this so SMP safe */ 881 return from_kuid_munged(current_user_ns(), current_euid()); 882 } 883 884 SYSCALL_DEFINE0(getgid) 885 { 886 /* Only we change this so SMP safe */ 887 return from_kgid_munged(current_user_ns(), current_gid()); 888 } 889 890 SYSCALL_DEFINE0(getegid) 891 { 892 /* Only we change this so SMP safe */ 893 return from_kgid_munged(current_user_ns(), current_egid()); 894 } 895 896 static void do_sys_times(struct tms *tms) 897 { 898 u64 tgutime, tgstime, cutime, cstime; 899 900 thread_group_cputime_adjusted(current, &tgutime, &tgstime); 901 cutime = current->signal->cutime; 902 cstime = current->signal->cstime; 903 tms->tms_utime = nsec_to_clock_t(tgutime); 904 tms->tms_stime = nsec_to_clock_t(tgstime); 905 tms->tms_cutime = nsec_to_clock_t(cutime); 906 tms->tms_cstime = nsec_to_clock_t(cstime); 907 } 908 909 SYSCALL_DEFINE1(times, struct tms __user *, tbuf) 910 { 911 if (tbuf) { 912 struct tms tmp; 913 914 do_sys_times(&tmp); 915 if (copy_to_user(tbuf, &tmp, sizeof(struct tms))) 916 return -EFAULT; 917 } 918 force_successful_syscall_return(); 919 return (long) jiffies_64_to_clock_t(get_jiffies_64()); 920 } 921 922 #ifdef CONFIG_COMPAT 923 static compat_clock_t clock_t_to_compat_clock_t(clock_t x) 924 { 925 return compat_jiffies_to_clock_t(clock_t_to_jiffies(x)); 926 } 927 928 COMPAT_SYSCALL_DEFINE1(times, struct compat_tms __user *, tbuf) 929 { 930 if (tbuf) { 931 struct tms tms; 932 struct compat_tms tmp; 933 934 do_sys_times(&tms); 935 /* Convert our struct tms to the compat version. */ 936 tmp.tms_utime = clock_t_to_compat_clock_t(tms.tms_utime); 937 tmp.tms_stime = clock_t_to_compat_clock_t(tms.tms_stime); 938 tmp.tms_cutime = clock_t_to_compat_clock_t(tms.tms_cutime); 939 tmp.tms_cstime = clock_t_to_compat_clock_t(tms.tms_cstime); 940 if (copy_to_user(tbuf, &tmp, sizeof(tmp))) 941 return -EFAULT; 942 } 943 force_successful_syscall_return(); 944 return compat_jiffies_to_clock_t(jiffies); 945 } 946 #endif 947 948 /* 949 * This needs some heavy checking ... 950 * I just haven't the stomach for it. I also don't fully 951 * understand sessions/pgrp etc. Let somebody who does explain it. 952 * 953 * OK, I think I have the protection semantics right.... this is really 954 * only important on a multi-user system anyway, to make sure one user 955 * can't send a signal to a process owned by another. -TYT, 12/12/91 956 * 957 * !PF_FORKNOEXEC check to conform completely to POSIX. 958 */ 959 SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid) 960 { 961 struct task_struct *p; 962 struct task_struct *group_leader = current->group_leader; 963 struct pid *pgrp; 964 int err; 965 966 if (!pid) 967 pid = task_pid_vnr(group_leader); 968 if (!pgid) 969 pgid = pid; 970 if (pgid < 0) 971 return -EINVAL; 972 rcu_read_lock(); 973 974 /* From this point forward we keep holding onto the tasklist lock 975 * so that our parent does not change from under us. -DaveM 976 */ 977 write_lock_irq(&tasklist_lock); 978 979 err = -ESRCH; 980 p = find_task_by_vpid(pid); 981 if (!p) 982 goto out; 983 984 err = -EINVAL; 985 if (!thread_group_leader(p)) 986 goto out; 987 988 if (same_thread_group(p->real_parent, group_leader)) { 989 err = -EPERM; 990 if (task_session(p) != task_session(group_leader)) 991 goto out; 992 err = -EACCES; 993 if (!(p->flags & PF_FORKNOEXEC)) 994 goto out; 995 } else { 996 err = -ESRCH; 997 if (p != group_leader) 998 goto out; 999 } 1000 1001 err = -EPERM; 1002 if (p->signal->leader) 1003 goto out; 1004 1005 pgrp = task_pid(p); 1006 if (pgid != pid) { 1007 struct task_struct *g; 1008 1009 pgrp = find_vpid(pgid); 1010 g = pid_task(pgrp, PIDTYPE_PGID); 1011 if (!g || task_session(g) != task_session(group_leader)) 1012 goto out; 1013 } 1014 1015 err = security_task_setpgid(p, pgid); 1016 if (err) 1017 goto out; 1018 1019 if (task_pgrp(p) != pgrp) 1020 change_pid(p, PIDTYPE_PGID, pgrp); 1021 1022 err = 0; 1023 out: 1024 /* All paths lead to here, thus we are safe. -DaveM */ 1025 write_unlock_irq(&tasklist_lock); 1026 rcu_read_unlock(); 1027 return err; 1028 } 1029 1030 SYSCALL_DEFINE1(getpgid, pid_t, pid) 1031 { 1032 struct task_struct *p; 1033 struct pid *grp; 1034 int retval; 1035 1036 rcu_read_lock(); 1037 if (!pid) 1038 grp = task_pgrp(current); 1039 else { 1040 retval = -ESRCH; 1041 p = find_task_by_vpid(pid); 1042 if (!p) 1043 goto out; 1044 grp = task_pgrp(p); 1045 if (!grp) 1046 goto out; 1047 1048 retval = security_task_getpgid(p); 1049 if (retval) 1050 goto out; 1051 } 1052 retval = pid_vnr(grp); 1053 out: 1054 rcu_read_unlock(); 1055 return retval; 1056 } 1057 1058 #ifdef __ARCH_WANT_SYS_GETPGRP 1059 1060 SYSCALL_DEFINE0(getpgrp) 1061 { 1062 return sys_getpgid(0); 1063 } 1064 1065 #endif 1066 1067 SYSCALL_DEFINE1(getsid, pid_t, pid) 1068 { 1069 struct task_struct *p; 1070 struct pid *sid; 1071 int retval; 1072 1073 rcu_read_lock(); 1074 if (!pid) 1075 sid = task_session(current); 1076 else { 1077 retval = -ESRCH; 1078 p = find_task_by_vpid(pid); 1079 if (!p) 1080 goto out; 1081 sid = task_session(p); 1082 if (!sid) 1083 goto out; 1084 1085 retval = security_task_getsid(p); 1086 if (retval) 1087 goto out; 1088 } 1089 retval = pid_vnr(sid); 1090 out: 1091 rcu_read_unlock(); 1092 return retval; 1093 } 1094 1095 static void set_special_pids(struct pid *pid) 1096 { 1097 struct task_struct *curr = current->group_leader; 1098 1099 if (task_session(curr) != pid) 1100 change_pid(curr, PIDTYPE_SID, pid); 1101 1102 if (task_pgrp(curr) != pid) 1103 change_pid(curr, PIDTYPE_PGID, pid); 1104 } 1105 1106 SYSCALL_DEFINE0(setsid) 1107 { 1108 struct task_struct *group_leader = current->group_leader; 1109 struct pid *sid = task_pid(group_leader); 1110 pid_t session = pid_vnr(sid); 1111 int err = -EPERM; 1112 1113 write_lock_irq(&tasklist_lock); 1114 /* Fail if I am already a session leader */ 1115 if (group_leader->signal->leader) 1116 goto out; 1117 1118 /* Fail if a process group id already exists that equals the 1119 * proposed session id. 1120 */ 1121 if (pid_task(sid, PIDTYPE_PGID)) 1122 goto out; 1123 1124 group_leader->signal->leader = 1; 1125 set_special_pids(sid); 1126 1127 proc_clear_tty(group_leader); 1128 1129 err = session; 1130 out: 1131 write_unlock_irq(&tasklist_lock); 1132 if (err > 0) { 1133 proc_sid_connector(group_leader); 1134 sched_autogroup_create_attach(group_leader); 1135 } 1136 return err; 1137 } 1138 1139 DECLARE_RWSEM(uts_sem); 1140 1141 #ifdef COMPAT_UTS_MACHINE 1142 #define override_architecture(name) \ 1143 (personality(current->personality) == PER_LINUX32 && \ 1144 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \ 1145 sizeof(COMPAT_UTS_MACHINE))) 1146 #else 1147 #define override_architecture(name) 0 1148 #endif 1149 1150 /* 1151 * Work around broken programs that cannot handle "Linux 3.0". 1152 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40 1153 * And we map 4.x to 2.6.60+x, so 4.0 would be 2.6.60. 1154 */ 1155 static int override_release(char __user *release, size_t len) 1156 { 1157 int ret = 0; 1158 1159 if (current->personality & UNAME26) { 1160 const char *rest = UTS_RELEASE; 1161 char buf[65] = { 0 }; 1162 int ndots = 0; 1163 unsigned v; 1164 size_t copy; 1165 1166 while (*rest) { 1167 if (*rest == '.' && ++ndots >= 3) 1168 break; 1169 if (!isdigit(*rest) && *rest != '.') 1170 break; 1171 rest++; 1172 } 1173 v = ((LINUX_VERSION_CODE >> 8) & 0xff) + 60; 1174 copy = clamp_t(size_t, len, 1, sizeof(buf)); 1175 copy = scnprintf(buf, copy, "2.6.%u%s", v, rest); 1176 ret = copy_to_user(release, buf, copy + 1); 1177 } 1178 return ret; 1179 } 1180 1181 SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name) 1182 { 1183 int errno = 0; 1184 1185 down_read(&uts_sem); 1186 if (copy_to_user(name, utsname(), sizeof *name)) 1187 errno = -EFAULT; 1188 up_read(&uts_sem); 1189 1190 if (!errno && override_release(name->release, sizeof(name->release))) 1191 errno = -EFAULT; 1192 if (!errno && override_architecture(name)) 1193 errno = -EFAULT; 1194 return errno; 1195 } 1196 1197 #ifdef __ARCH_WANT_SYS_OLD_UNAME 1198 /* 1199 * Old cruft 1200 */ 1201 SYSCALL_DEFINE1(uname, struct old_utsname __user *, name) 1202 { 1203 int error = 0; 1204 1205 if (!name) 1206 return -EFAULT; 1207 1208 down_read(&uts_sem); 1209 if (copy_to_user(name, utsname(), sizeof(*name))) 1210 error = -EFAULT; 1211 up_read(&uts_sem); 1212 1213 if (!error && override_release(name->release, sizeof(name->release))) 1214 error = -EFAULT; 1215 if (!error && override_architecture(name)) 1216 error = -EFAULT; 1217 return error; 1218 } 1219 1220 SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name) 1221 { 1222 int error; 1223 1224 if (!name) 1225 return -EFAULT; 1226 if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname))) 1227 return -EFAULT; 1228 1229 down_read(&uts_sem); 1230 error = __copy_to_user(&name->sysname, &utsname()->sysname, 1231 __OLD_UTS_LEN); 1232 error |= __put_user(0, name->sysname + __OLD_UTS_LEN); 1233 error |= __copy_to_user(&name->nodename, &utsname()->nodename, 1234 __OLD_UTS_LEN); 1235 error |= __put_user(0, name->nodename + __OLD_UTS_LEN); 1236 error |= __copy_to_user(&name->release, &utsname()->release, 1237 __OLD_UTS_LEN); 1238 error |= __put_user(0, name->release + __OLD_UTS_LEN); 1239 error |= __copy_to_user(&name->version, &utsname()->version, 1240 __OLD_UTS_LEN); 1241 error |= __put_user(0, name->version + __OLD_UTS_LEN); 1242 error |= __copy_to_user(&name->machine, &utsname()->machine, 1243 __OLD_UTS_LEN); 1244 error |= __put_user(0, name->machine + __OLD_UTS_LEN); 1245 up_read(&uts_sem); 1246 1247 if (!error && override_architecture(name)) 1248 error = -EFAULT; 1249 if (!error && override_release(name->release, sizeof(name->release))) 1250 error = -EFAULT; 1251 return error ? -EFAULT : 0; 1252 } 1253 #endif 1254 1255 SYSCALL_DEFINE2(sethostname, char __user *, name, int, len) 1256 { 1257 int errno; 1258 char tmp[__NEW_UTS_LEN]; 1259 1260 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) 1261 return -EPERM; 1262 1263 if (len < 0 || len > __NEW_UTS_LEN) 1264 return -EINVAL; 1265 down_write(&uts_sem); 1266 errno = -EFAULT; 1267 if (!copy_from_user(tmp, name, len)) { 1268 struct new_utsname *u = utsname(); 1269 1270 memcpy(u->nodename, tmp, len); 1271 memset(u->nodename + len, 0, sizeof(u->nodename) - len); 1272 errno = 0; 1273 uts_proc_notify(UTS_PROC_HOSTNAME); 1274 } 1275 up_write(&uts_sem); 1276 return errno; 1277 } 1278 1279 #ifdef __ARCH_WANT_SYS_GETHOSTNAME 1280 1281 SYSCALL_DEFINE2(gethostname, char __user *, name, int, len) 1282 { 1283 int i, errno; 1284 struct new_utsname *u; 1285 1286 if (len < 0) 1287 return -EINVAL; 1288 down_read(&uts_sem); 1289 u = utsname(); 1290 i = 1 + strlen(u->nodename); 1291 if (i > len) 1292 i = len; 1293 errno = 0; 1294 if (copy_to_user(name, u->nodename, i)) 1295 errno = -EFAULT; 1296 up_read(&uts_sem); 1297 return errno; 1298 } 1299 1300 #endif 1301 1302 /* 1303 * Only setdomainname; getdomainname can be implemented by calling 1304 * uname() 1305 */ 1306 SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len) 1307 { 1308 int errno; 1309 char tmp[__NEW_UTS_LEN]; 1310 1311 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) 1312 return -EPERM; 1313 if (len < 0 || len > __NEW_UTS_LEN) 1314 return -EINVAL; 1315 1316 down_write(&uts_sem); 1317 errno = -EFAULT; 1318 if (!copy_from_user(tmp, name, len)) { 1319 struct new_utsname *u = utsname(); 1320 1321 memcpy(u->domainname, tmp, len); 1322 memset(u->domainname + len, 0, sizeof(u->domainname) - len); 1323 errno = 0; 1324 uts_proc_notify(UTS_PROC_DOMAINNAME); 1325 } 1326 up_write(&uts_sem); 1327 return errno; 1328 } 1329 1330 SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim) 1331 { 1332 struct rlimit value; 1333 int ret; 1334 1335 ret = do_prlimit(current, resource, NULL, &value); 1336 if (!ret) 1337 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0; 1338 1339 return ret; 1340 } 1341 1342 #ifdef CONFIG_COMPAT 1343 1344 COMPAT_SYSCALL_DEFINE2(setrlimit, unsigned int, resource, 1345 struct compat_rlimit __user *, rlim) 1346 { 1347 struct rlimit r; 1348 struct compat_rlimit r32; 1349 1350 if (copy_from_user(&r32, rlim, sizeof(struct compat_rlimit))) 1351 return -EFAULT; 1352 1353 if (r32.rlim_cur == COMPAT_RLIM_INFINITY) 1354 r.rlim_cur = RLIM_INFINITY; 1355 else 1356 r.rlim_cur = r32.rlim_cur; 1357 if (r32.rlim_max == COMPAT_RLIM_INFINITY) 1358 r.rlim_max = RLIM_INFINITY; 1359 else 1360 r.rlim_max = r32.rlim_max; 1361 return do_prlimit(current, resource, &r, NULL); 1362 } 1363 1364 COMPAT_SYSCALL_DEFINE2(getrlimit, unsigned int, resource, 1365 struct compat_rlimit __user *, rlim) 1366 { 1367 struct rlimit r; 1368 int ret; 1369 1370 ret = do_prlimit(current, resource, NULL, &r); 1371 if (!ret) { 1372 struct compat_rlimit r32; 1373 if (r.rlim_cur > COMPAT_RLIM_INFINITY) 1374 r32.rlim_cur = COMPAT_RLIM_INFINITY; 1375 else 1376 r32.rlim_cur = r.rlim_cur; 1377 if (r.rlim_max > COMPAT_RLIM_INFINITY) 1378 r32.rlim_max = COMPAT_RLIM_INFINITY; 1379 else 1380 r32.rlim_max = r.rlim_max; 1381 1382 if (copy_to_user(rlim, &r32, sizeof(struct compat_rlimit))) 1383 return -EFAULT; 1384 } 1385 return ret; 1386 } 1387 1388 #endif 1389 1390 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT 1391 1392 /* 1393 * Back compatibility for getrlimit. Needed for some apps. 1394 */ 1395 SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource, 1396 struct rlimit __user *, rlim) 1397 { 1398 struct rlimit x; 1399 if (resource >= RLIM_NLIMITS) 1400 return -EINVAL; 1401 1402 task_lock(current->group_leader); 1403 x = current->signal->rlim[resource]; 1404 task_unlock(current->group_leader); 1405 if (x.rlim_cur > 0x7FFFFFFF) 1406 x.rlim_cur = 0x7FFFFFFF; 1407 if (x.rlim_max > 0x7FFFFFFF) 1408 x.rlim_max = 0x7FFFFFFF; 1409 return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0; 1410 } 1411 1412 #ifdef CONFIG_COMPAT 1413 COMPAT_SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource, 1414 struct compat_rlimit __user *, rlim) 1415 { 1416 struct rlimit r; 1417 1418 if (resource >= RLIM_NLIMITS) 1419 return -EINVAL; 1420 1421 task_lock(current->group_leader); 1422 r = current->signal->rlim[resource]; 1423 task_unlock(current->group_leader); 1424 if (r.rlim_cur > 0x7FFFFFFF) 1425 r.rlim_cur = 0x7FFFFFFF; 1426 if (r.rlim_max > 0x7FFFFFFF) 1427 r.rlim_max = 0x7FFFFFFF; 1428 1429 if (put_user(r.rlim_cur, &rlim->rlim_cur) || 1430 put_user(r.rlim_max, &rlim->rlim_max)) 1431 return -EFAULT; 1432 return 0; 1433 } 1434 #endif 1435 1436 #endif 1437 1438 static inline bool rlim64_is_infinity(__u64 rlim64) 1439 { 1440 #if BITS_PER_LONG < 64 1441 return rlim64 >= ULONG_MAX; 1442 #else 1443 return rlim64 == RLIM64_INFINITY; 1444 #endif 1445 } 1446 1447 static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64) 1448 { 1449 if (rlim->rlim_cur == RLIM_INFINITY) 1450 rlim64->rlim_cur = RLIM64_INFINITY; 1451 else 1452 rlim64->rlim_cur = rlim->rlim_cur; 1453 if (rlim->rlim_max == RLIM_INFINITY) 1454 rlim64->rlim_max = RLIM64_INFINITY; 1455 else 1456 rlim64->rlim_max = rlim->rlim_max; 1457 } 1458 1459 static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim) 1460 { 1461 if (rlim64_is_infinity(rlim64->rlim_cur)) 1462 rlim->rlim_cur = RLIM_INFINITY; 1463 else 1464 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur; 1465 if (rlim64_is_infinity(rlim64->rlim_max)) 1466 rlim->rlim_max = RLIM_INFINITY; 1467 else 1468 rlim->rlim_max = (unsigned long)rlim64->rlim_max; 1469 } 1470 1471 /* make sure you are allowed to change @tsk limits before calling this */ 1472 int do_prlimit(struct task_struct *tsk, unsigned int resource, 1473 struct rlimit *new_rlim, struct rlimit *old_rlim) 1474 { 1475 struct rlimit *rlim; 1476 int retval = 0; 1477 1478 if (resource >= RLIM_NLIMITS) 1479 return -EINVAL; 1480 if (new_rlim) { 1481 if (new_rlim->rlim_cur > new_rlim->rlim_max) 1482 return -EINVAL; 1483 if (resource == RLIMIT_NOFILE && 1484 new_rlim->rlim_max > sysctl_nr_open) 1485 return -EPERM; 1486 } 1487 1488 /* protect tsk->signal and tsk->sighand from disappearing */ 1489 read_lock(&tasklist_lock); 1490 if (!tsk->sighand) { 1491 retval = -ESRCH; 1492 goto out; 1493 } 1494 1495 rlim = tsk->signal->rlim + resource; 1496 task_lock(tsk->group_leader); 1497 if (new_rlim) { 1498 /* Keep the capable check against init_user_ns until 1499 cgroups can contain all limits */ 1500 if (new_rlim->rlim_max > rlim->rlim_max && 1501 !capable(CAP_SYS_RESOURCE)) 1502 retval = -EPERM; 1503 if (!retval) 1504 retval = security_task_setrlimit(tsk, resource, new_rlim); 1505 if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) { 1506 /* 1507 * The caller is asking for an immediate RLIMIT_CPU 1508 * expiry. But we use the zero value to mean "it was 1509 * never set". So let's cheat and make it one second 1510 * instead 1511 */ 1512 new_rlim->rlim_cur = 1; 1513 } 1514 } 1515 if (!retval) { 1516 if (old_rlim) 1517 *old_rlim = *rlim; 1518 if (new_rlim) 1519 *rlim = *new_rlim; 1520 } 1521 task_unlock(tsk->group_leader); 1522 1523 /* 1524 * RLIMIT_CPU handling. Note that the kernel fails to return an error 1525 * code if it rejected the user's attempt to set RLIMIT_CPU. This is a 1526 * very long-standing error, and fixing it now risks breakage of 1527 * applications, so we live with it 1528 */ 1529 if (!retval && new_rlim && resource == RLIMIT_CPU && 1530 new_rlim->rlim_cur != RLIM_INFINITY && 1531 IS_ENABLED(CONFIG_POSIX_TIMERS)) 1532 update_rlimit_cpu(tsk, new_rlim->rlim_cur); 1533 out: 1534 read_unlock(&tasklist_lock); 1535 return retval; 1536 } 1537 1538 /* rcu lock must be held */ 1539 static int check_prlimit_permission(struct task_struct *task, 1540 unsigned int flags) 1541 { 1542 const struct cred *cred = current_cred(), *tcred; 1543 bool id_match; 1544 1545 if (current == task) 1546 return 0; 1547 1548 tcred = __task_cred(task); 1549 id_match = (uid_eq(cred->uid, tcred->euid) && 1550 uid_eq(cred->uid, tcred->suid) && 1551 uid_eq(cred->uid, tcred->uid) && 1552 gid_eq(cred->gid, tcred->egid) && 1553 gid_eq(cred->gid, tcred->sgid) && 1554 gid_eq(cred->gid, tcred->gid)); 1555 if (!id_match && !ns_capable(tcred->user_ns, CAP_SYS_RESOURCE)) 1556 return -EPERM; 1557 1558 return security_task_prlimit(cred, tcred, flags); 1559 } 1560 1561 SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource, 1562 const struct rlimit64 __user *, new_rlim, 1563 struct rlimit64 __user *, old_rlim) 1564 { 1565 struct rlimit64 old64, new64; 1566 struct rlimit old, new; 1567 struct task_struct *tsk; 1568 unsigned int checkflags = 0; 1569 int ret; 1570 1571 if (old_rlim) 1572 checkflags |= LSM_PRLIMIT_READ; 1573 1574 if (new_rlim) { 1575 if (copy_from_user(&new64, new_rlim, sizeof(new64))) 1576 return -EFAULT; 1577 rlim64_to_rlim(&new64, &new); 1578 checkflags |= LSM_PRLIMIT_WRITE; 1579 } 1580 1581 rcu_read_lock(); 1582 tsk = pid ? find_task_by_vpid(pid) : current; 1583 if (!tsk) { 1584 rcu_read_unlock(); 1585 return -ESRCH; 1586 } 1587 ret = check_prlimit_permission(tsk, checkflags); 1588 if (ret) { 1589 rcu_read_unlock(); 1590 return ret; 1591 } 1592 get_task_struct(tsk); 1593 rcu_read_unlock(); 1594 1595 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL, 1596 old_rlim ? &old : NULL); 1597 1598 if (!ret && old_rlim) { 1599 rlim_to_rlim64(&old, &old64); 1600 if (copy_to_user(old_rlim, &old64, sizeof(old64))) 1601 ret = -EFAULT; 1602 } 1603 1604 put_task_struct(tsk); 1605 return ret; 1606 } 1607 1608 SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim) 1609 { 1610 struct rlimit new_rlim; 1611 1612 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim))) 1613 return -EFAULT; 1614 return do_prlimit(current, resource, &new_rlim, NULL); 1615 } 1616 1617 /* 1618 * It would make sense to put struct rusage in the task_struct, 1619 * except that would make the task_struct be *really big*. After 1620 * task_struct gets moved into malloc'ed memory, it would 1621 * make sense to do this. It will make moving the rest of the information 1622 * a lot simpler! (Which we're not doing right now because we're not 1623 * measuring them yet). 1624 * 1625 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have 1626 * races with threads incrementing their own counters. But since word 1627 * reads are atomic, we either get new values or old values and we don't 1628 * care which for the sums. We always take the siglock to protect reading 1629 * the c* fields from p->signal from races with exit.c updating those 1630 * fields when reaping, so a sample either gets all the additions of a 1631 * given child after it's reaped, or none so this sample is before reaping. 1632 * 1633 * Locking: 1634 * We need to take the siglock for CHILDEREN, SELF and BOTH 1635 * for the cases current multithreaded, non-current single threaded 1636 * non-current multithreaded. Thread traversal is now safe with 1637 * the siglock held. 1638 * Strictly speaking, we donot need to take the siglock if we are current and 1639 * single threaded, as no one else can take our signal_struct away, no one 1640 * else can reap the children to update signal->c* counters, and no one else 1641 * can race with the signal-> fields. If we do not take any lock, the 1642 * signal-> fields could be read out of order while another thread was just 1643 * exiting. So we should place a read memory barrier when we avoid the lock. 1644 * On the writer side, write memory barrier is implied in __exit_signal 1645 * as __exit_signal releases the siglock spinlock after updating the signal-> 1646 * fields. But we don't do this yet to keep things simple. 1647 * 1648 */ 1649 1650 static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r) 1651 { 1652 r->ru_nvcsw += t->nvcsw; 1653 r->ru_nivcsw += t->nivcsw; 1654 r->ru_minflt += t->min_flt; 1655 r->ru_majflt += t->maj_flt; 1656 r->ru_inblock += task_io_get_inblock(t); 1657 r->ru_oublock += task_io_get_oublock(t); 1658 } 1659 1660 void getrusage(struct task_struct *p, int who, struct rusage *r) 1661 { 1662 struct task_struct *t; 1663 unsigned long flags; 1664 u64 tgutime, tgstime, utime, stime; 1665 unsigned long maxrss = 0; 1666 1667 memset((char *)r, 0, sizeof (*r)); 1668 utime = stime = 0; 1669 1670 if (who == RUSAGE_THREAD) { 1671 task_cputime_adjusted(current, &utime, &stime); 1672 accumulate_thread_rusage(p, r); 1673 maxrss = p->signal->maxrss; 1674 goto out; 1675 } 1676 1677 if (!lock_task_sighand(p, &flags)) 1678 return; 1679 1680 switch (who) { 1681 case RUSAGE_BOTH: 1682 case RUSAGE_CHILDREN: 1683 utime = p->signal->cutime; 1684 stime = p->signal->cstime; 1685 r->ru_nvcsw = p->signal->cnvcsw; 1686 r->ru_nivcsw = p->signal->cnivcsw; 1687 r->ru_minflt = p->signal->cmin_flt; 1688 r->ru_majflt = p->signal->cmaj_flt; 1689 r->ru_inblock = p->signal->cinblock; 1690 r->ru_oublock = p->signal->coublock; 1691 maxrss = p->signal->cmaxrss; 1692 1693 if (who == RUSAGE_CHILDREN) 1694 break; 1695 1696 case RUSAGE_SELF: 1697 thread_group_cputime_adjusted(p, &tgutime, &tgstime); 1698 utime += tgutime; 1699 stime += tgstime; 1700 r->ru_nvcsw += p->signal->nvcsw; 1701 r->ru_nivcsw += p->signal->nivcsw; 1702 r->ru_minflt += p->signal->min_flt; 1703 r->ru_majflt += p->signal->maj_flt; 1704 r->ru_inblock += p->signal->inblock; 1705 r->ru_oublock += p->signal->oublock; 1706 if (maxrss < p->signal->maxrss) 1707 maxrss = p->signal->maxrss; 1708 t = p; 1709 do { 1710 accumulate_thread_rusage(t, r); 1711 } while_each_thread(p, t); 1712 break; 1713 1714 default: 1715 BUG(); 1716 } 1717 unlock_task_sighand(p, &flags); 1718 1719 out: 1720 r->ru_utime = ns_to_timeval(utime); 1721 r->ru_stime = ns_to_timeval(stime); 1722 1723 if (who != RUSAGE_CHILDREN) { 1724 struct mm_struct *mm = get_task_mm(p); 1725 1726 if (mm) { 1727 setmax_mm_hiwater_rss(&maxrss, mm); 1728 mmput(mm); 1729 } 1730 } 1731 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ 1732 } 1733 1734 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru) 1735 { 1736 struct rusage r; 1737 1738 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && 1739 who != RUSAGE_THREAD) 1740 return -EINVAL; 1741 1742 getrusage(current, who, &r); 1743 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0; 1744 } 1745 1746 #ifdef CONFIG_COMPAT 1747 COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru) 1748 { 1749 struct rusage r; 1750 1751 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && 1752 who != RUSAGE_THREAD) 1753 return -EINVAL; 1754 1755 getrusage(current, who, &r); 1756 return put_compat_rusage(&r, ru); 1757 } 1758 #endif 1759 1760 SYSCALL_DEFINE1(umask, int, mask) 1761 { 1762 mask = xchg(¤t->fs->umask, mask & S_IRWXUGO); 1763 return mask; 1764 } 1765 1766 static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd) 1767 { 1768 struct fd exe; 1769 struct file *old_exe, *exe_file; 1770 struct inode *inode; 1771 int err; 1772 1773 exe = fdget(fd); 1774 if (!exe.file) 1775 return -EBADF; 1776 1777 inode = file_inode(exe.file); 1778 1779 /* 1780 * Because the original mm->exe_file points to executable file, make 1781 * sure that this one is executable as well, to avoid breaking an 1782 * overall picture. 1783 */ 1784 err = -EACCES; 1785 if (!S_ISREG(inode->i_mode) || path_noexec(&exe.file->f_path)) 1786 goto exit; 1787 1788 err = inode_permission(inode, MAY_EXEC); 1789 if (err) 1790 goto exit; 1791 1792 /* 1793 * Forbid mm->exe_file change if old file still mapped. 1794 */ 1795 exe_file = get_mm_exe_file(mm); 1796 err = -EBUSY; 1797 if (exe_file) { 1798 struct vm_area_struct *vma; 1799 1800 down_read(&mm->mmap_sem); 1801 for (vma = mm->mmap; vma; vma = vma->vm_next) { 1802 if (!vma->vm_file) 1803 continue; 1804 if (path_equal(&vma->vm_file->f_path, 1805 &exe_file->f_path)) 1806 goto exit_err; 1807 } 1808 1809 up_read(&mm->mmap_sem); 1810 fput(exe_file); 1811 } 1812 1813 err = 0; 1814 /* set the new file, lockless */ 1815 get_file(exe.file); 1816 old_exe = xchg(&mm->exe_file, exe.file); 1817 if (old_exe) 1818 fput(old_exe); 1819 exit: 1820 fdput(exe); 1821 return err; 1822 exit_err: 1823 up_read(&mm->mmap_sem); 1824 fput(exe_file); 1825 goto exit; 1826 } 1827 1828 /* 1829 * WARNING: we don't require any capability here so be very careful 1830 * in what is allowed for modification from userspace. 1831 */ 1832 static int validate_prctl_map(struct prctl_mm_map *prctl_map) 1833 { 1834 unsigned long mmap_max_addr = TASK_SIZE; 1835 struct mm_struct *mm = current->mm; 1836 int error = -EINVAL, i; 1837 1838 static const unsigned char offsets[] = { 1839 offsetof(struct prctl_mm_map, start_code), 1840 offsetof(struct prctl_mm_map, end_code), 1841 offsetof(struct prctl_mm_map, start_data), 1842 offsetof(struct prctl_mm_map, end_data), 1843 offsetof(struct prctl_mm_map, start_brk), 1844 offsetof(struct prctl_mm_map, brk), 1845 offsetof(struct prctl_mm_map, start_stack), 1846 offsetof(struct prctl_mm_map, arg_start), 1847 offsetof(struct prctl_mm_map, arg_end), 1848 offsetof(struct prctl_mm_map, env_start), 1849 offsetof(struct prctl_mm_map, env_end), 1850 }; 1851 1852 /* 1853 * Make sure the members are not somewhere outside 1854 * of allowed address space. 1855 */ 1856 for (i = 0; i < ARRAY_SIZE(offsets); i++) { 1857 u64 val = *(u64 *)((char *)prctl_map + offsets[i]); 1858 1859 if ((unsigned long)val >= mmap_max_addr || 1860 (unsigned long)val < mmap_min_addr) 1861 goto out; 1862 } 1863 1864 /* 1865 * Make sure the pairs are ordered. 1866 */ 1867 #define __prctl_check_order(__m1, __op, __m2) \ 1868 ((unsigned long)prctl_map->__m1 __op \ 1869 (unsigned long)prctl_map->__m2) ? 0 : -EINVAL 1870 error = __prctl_check_order(start_code, <, end_code); 1871 error |= __prctl_check_order(start_data, <, end_data); 1872 error |= __prctl_check_order(start_brk, <=, brk); 1873 error |= __prctl_check_order(arg_start, <=, arg_end); 1874 error |= __prctl_check_order(env_start, <=, env_end); 1875 if (error) 1876 goto out; 1877 #undef __prctl_check_order 1878 1879 error = -EINVAL; 1880 1881 /* 1882 * @brk should be after @end_data in traditional maps. 1883 */ 1884 if (prctl_map->start_brk <= prctl_map->end_data || 1885 prctl_map->brk <= prctl_map->end_data) 1886 goto out; 1887 1888 /* 1889 * Neither we should allow to override limits if they set. 1890 */ 1891 if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk, 1892 prctl_map->start_brk, prctl_map->end_data, 1893 prctl_map->start_data)) 1894 goto out; 1895 1896 /* 1897 * Someone is trying to cheat the auxv vector. 1898 */ 1899 if (prctl_map->auxv_size) { 1900 if (!prctl_map->auxv || prctl_map->auxv_size > sizeof(mm->saved_auxv)) 1901 goto out; 1902 } 1903 1904 /* 1905 * Finally, make sure the caller has the rights to 1906 * change /proc/pid/exe link: only local sys admin should 1907 * be allowed to. 1908 */ 1909 if (prctl_map->exe_fd != (u32)-1) { 1910 if (!ns_capable(current_user_ns(), CAP_SYS_ADMIN)) 1911 goto out; 1912 } 1913 1914 error = 0; 1915 out: 1916 return error; 1917 } 1918 1919 #ifdef CONFIG_CHECKPOINT_RESTORE 1920 static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size) 1921 { 1922 struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, }; 1923 unsigned long user_auxv[AT_VECTOR_SIZE]; 1924 struct mm_struct *mm = current->mm; 1925 int error; 1926 1927 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv)); 1928 BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256); 1929 1930 if (opt == PR_SET_MM_MAP_SIZE) 1931 return put_user((unsigned int)sizeof(prctl_map), 1932 (unsigned int __user *)addr); 1933 1934 if (data_size != sizeof(prctl_map)) 1935 return -EINVAL; 1936 1937 if (copy_from_user(&prctl_map, addr, sizeof(prctl_map))) 1938 return -EFAULT; 1939 1940 error = validate_prctl_map(&prctl_map); 1941 if (error) 1942 return error; 1943 1944 if (prctl_map.auxv_size) { 1945 memset(user_auxv, 0, sizeof(user_auxv)); 1946 if (copy_from_user(user_auxv, 1947 (const void __user *)prctl_map.auxv, 1948 prctl_map.auxv_size)) 1949 return -EFAULT; 1950 1951 /* Last entry must be AT_NULL as specification requires */ 1952 user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL; 1953 user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL; 1954 } 1955 1956 if (prctl_map.exe_fd != (u32)-1) { 1957 error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd); 1958 if (error) 1959 return error; 1960 } 1961 1962 down_write(&mm->mmap_sem); 1963 1964 /* 1965 * We don't validate if these members are pointing to 1966 * real present VMAs because application may have correspond 1967 * VMAs already unmapped and kernel uses these members for statistics 1968 * output in procfs mostly, except 1969 * 1970 * - @start_brk/@brk which are used in do_brk but kernel lookups 1971 * for VMAs when updating these memvers so anything wrong written 1972 * here cause kernel to swear at userspace program but won't lead 1973 * to any problem in kernel itself 1974 */ 1975 1976 mm->start_code = prctl_map.start_code; 1977 mm->end_code = prctl_map.end_code; 1978 mm->start_data = prctl_map.start_data; 1979 mm->end_data = prctl_map.end_data; 1980 mm->start_brk = prctl_map.start_brk; 1981 mm->brk = prctl_map.brk; 1982 mm->start_stack = prctl_map.start_stack; 1983 mm->arg_start = prctl_map.arg_start; 1984 mm->arg_end = prctl_map.arg_end; 1985 mm->env_start = prctl_map.env_start; 1986 mm->env_end = prctl_map.env_end; 1987 1988 /* 1989 * Note this update of @saved_auxv is lockless thus 1990 * if someone reads this member in procfs while we're 1991 * updating -- it may get partly updated results. It's 1992 * known and acceptable trade off: we leave it as is to 1993 * not introduce additional locks here making the kernel 1994 * more complex. 1995 */ 1996 if (prctl_map.auxv_size) 1997 memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv)); 1998 1999 up_write(&mm->mmap_sem); 2000 return 0; 2001 } 2002 #endif /* CONFIG_CHECKPOINT_RESTORE */ 2003 2004 static int prctl_set_auxv(struct mm_struct *mm, unsigned long addr, 2005 unsigned long len) 2006 { 2007 /* 2008 * This doesn't move the auxiliary vector itself since it's pinned to 2009 * mm_struct, but it permits filling the vector with new values. It's 2010 * up to the caller to provide sane values here, otherwise userspace 2011 * tools which use this vector might be unhappy. 2012 */ 2013 unsigned long user_auxv[AT_VECTOR_SIZE]; 2014 2015 if (len > sizeof(user_auxv)) 2016 return -EINVAL; 2017 2018 if (copy_from_user(user_auxv, (const void __user *)addr, len)) 2019 return -EFAULT; 2020 2021 /* Make sure the last entry is always AT_NULL */ 2022 user_auxv[AT_VECTOR_SIZE - 2] = 0; 2023 user_auxv[AT_VECTOR_SIZE - 1] = 0; 2024 2025 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv)); 2026 2027 task_lock(current); 2028 memcpy(mm->saved_auxv, user_auxv, len); 2029 task_unlock(current); 2030 2031 return 0; 2032 } 2033 2034 static int prctl_set_mm(int opt, unsigned long addr, 2035 unsigned long arg4, unsigned long arg5) 2036 { 2037 struct mm_struct *mm = current->mm; 2038 struct prctl_mm_map prctl_map; 2039 struct vm_area_struct *vma; 2040 int error; 2041 2042 if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV && 2043 opt != PR_SET_MM_MAP && 2044 opt != PR_SET_MM_MAP_SIZE))) 2045 return -EINVAL; 2046 2047 #ifdef CONFIG_CHECKPOINT_RESTORE 2048 if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE) 2049 return prctl_set_mm_map(opt, (const void __user *)addr, arg4); 2050 #endif 2051 2052 if (!capable(CAP_SYS_RESOURCE)) 2053 return -EPERM; 2054 2055 if (opt == PR_SET_MM_EXE_FILE) 2056 return prctl_set_mm_exe_file(mm, (unsigned int)addr); 2057 2058 if (opt == PR_SET_MM_AUXV) 2059 return prctl_set_auxv(mm, addr, arg4); 2060 2061 if (addr >= TASK_SIZE || addr < mmap_min_addr) 2062 return -EINVAL; 2063 2064 error = -EINVAL; 2065 2066 down_write(&mm->mmap_sem); 2067 vma = find_vma(mm, addr); 2068 2069 prctl_map.start_code = mm->start_code; 2070 prctl_map.end_code = mm->end_code; 2071 prctl_map.start_data = mm->start_data; 2072 prctl_map.end_data = mm->end_data; 2073 prctl_map.start_brk = mm->start_brk; 2074 prctl_map.brk = mm->brk; 2075 prctl_map.start_stack = mm->start_stack; 2076 prctl_map.arg_start = mm->arg_start; 2077 prctl_map.arg_end = mm->arg_end; 2078 prctl_map.env_start = mm->env_start; 2079 prctl_map.env_end = mm->env_end; 2080 prctl_map.auxv = NULL; 2081 prctl_map.auxv_size = 0; 2082 prctl_map.exe_fd = -1; 2083 2084 switch (opt) { 2085 case PR_SET_MM_START_CODE: 2086 prctl_map.start_code = addr; 2087 break; 2088 case PR_SET_MM_END_CODE: 2089 prctl_map.end_code = addr; 2090 break; 2091 case PR_SET_MM_START_DATA: 2092 prctl_map.start_data = addr; 2093 break; 2094 case PR_SET_MM_END_DATA: 2095 prctl_map.end_data = addr; 2096 break; 2097 case PR_SET_MM_START_STACK: 2098 prctl_map.start_stack = addr; 2099 break; 2100 case PR_SET_MM_START_BRK: 2101 prctl_map.start_brk = addr; 2102 break; 2103 case PR_SET_MM_BRK: 2104 prctl_map.brk = addr; 2105 break; 2106 case PR_SET_MM_ARG_START: 2107 prctl_map.arg_start = addr; 2108 break; 2109 case PR_SET_MM_ARG_END: 2110 prctl_map.arg_end = addr; 2111 break; 2112 case PR_SET_MM_ENV_START: 2113 prctl_map.env_start = addr; 2114 break; 2115 case PR_SET_MM_ENV_END: 2116 prctl_map.env_end = addr; 2117 break; 2118 default: 2119 goto out; 2120 } 2121 2122 error = validate_prctl_map(&prctl_map); 2123 if (error) 2124 goto out; 2125 2126 switch (opt) { 2127 /* 2128 * If command line arguments and environment 2129 * are placed somewhere else on stack, we can 2130 * set them up here, ARG_START/END to setup 2131 * command line argumets and ENV_START/END 2132 * for environment. 2133 */ 2134 case PR_SET_MM_START_STACK: 2135 case PR_SET_MM_ARG_START: 2136 case PR_SET_MM_ARG_END: 2137 case PR_SET_MM_ENV_START: 2138 case PR_SET_MM_ENV_END: 2139 if (!vma) { 2140 error = -EFAULT; 2141 goto out; 2142 } 2143 } 2144 2145 mm->start_code = prctl_map.start_code; 2146 mm->end_code = prctl_map.end_code; 2147 mm->start_data = prctl_map.start_data; 2148 mm->end_data = prctl_map.end_data; 2149 mm->start_brk = prctl_map.start_brk; 2150 mm->brk = prctl_map.brk; 2151 mm->start_stack = prctl_map.start_stack; 2152 mm->arg_start = prctl_map.arg_start; 2153 mm->arg_end = prctl_map.arg_end; 2154 mm->env_start = prctl_map.env_start; 2155 mm->env_end = prctl_map.env_end; 2156 2157 error = 0; 2158 out: 2159 up_write(&mm->mmap_sem); 2160 return error; 2161 } 2162 2163 #ifdef CONFIG_CHECKPOINT_RESTORE 2164 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr) 2165 { 2166 return put_user(me->clear_child_tid, tid_addr); 2167 } 2168 #else 2169 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr) 2170 { 2171 return -EINVAL; 2172 } 2173 #endif 2174 2175 static int propagate_has_child_subreaper(struct task_struct *p, void *data) 2176 { 2177 /* 2178 * If task has has_child_subreaper - all its decendants 2179 * already have these flag too and new decendants will 2180 * inherit it on fork, skip them. 2181 * 2182 * If we've found child_reaper - skip descendants in 2183 * it's subtree as they will never get out pidns. 2184 */ 2185 if (p->signal->has_child_subreaper || 2186 is_child_reaper(task_pid(p))) 2187 return 0; 2188 2189 p->signal->has_child_subreaper = 1; 2190 return 1; 2191 } 2192 2193 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, 2194 unsigned long, arg4, unsigned long, arg5) 2195 { 2196 struct task_struct *me = current; 2197 unsigned char comm[sizeof(me->comm)]; 2198 long error; 2199 2200 error = security_task_prctl(option, arg2, arg3, arg4, arg5); 2201 if (error != -ENOSYS) 2202 return error; 2203 2204 error = 0; 2205 switch (option) { 2206 case PR_SET_PDEATHSIG: 2207 if (!valid_signal(arg2)) { 2208 error = -EINVAL; 2209 break; 2210 } 2211 me->pdeath_signal = arg2; 2212 break; 2213 case PR_GET_PDEATHSIG: 2214 error = put_user(me->pdeath_signal, (int __user *)arg2); 2215 break; 2216 case PR_GET_DUMPABLE: 2217 error = get_dumpable(me->mm); 2218 break; 2219 case PR_SET_DUMPABLE: 2220 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) { 2221 error = -EINVAL; 2222 break; 2223 } 2224 set_dumpable(me->mm, arg2); 2225 break; 2226 2227 case PR_SET_UNALIGN: 2228 error = SET_UNALIGN_CTL(me, arg2); 2229 break; 2230 case PR_GET_UNALIGN: 2231 error = GET_UNALIGN_CTL(me, arg2); 2232 break; 2233 case PR_SET_FPEMU: 2234 error = SET_FPEMU_CTL(me, arg2); 2235 break; 2236 case PR_GET_FPEMU: 2237 error = GET_FPEMU_CTL(me, arg2); 2238 break; 2239 case PR_SET_FPEXC: 2240 error = SET_FPEXC_CTL(me, arg2); 2241 break; 2242 case PR_GET_FPEXC: 2243 error = GET_FPEXC_CTL(me, arg2); 2244 break; 2245 case PR_GET_TIMING: 2246 error = PR_TIMING_STATISTICAL; 2247 break; 2248 case PR_SET_TIMING: 2249 if (arg2 != PR_TIMING_STATISTICAL) 2250 error = -EINVAL; 2251 break; 2252 case PR_SET_NAME: 2253 comm[sizeof(me->comm) - 1] = 0; 2254 if (strncpy_from_user(comm, (char __user *)arg2, 2255 sizeof(me->comm) - 1) < 0) 2256 return -EFAULT; 2257 set_task_comm(me, comm); 2258 proc_comm_connector(me); 2259 break; 2260 case PR_GET_NAME: 2261 get_task_comm(comm, me); 2262 if (copy_to_user((char __user *)arg2, comm, sizeof(comm))) 2263 return -EFAULT; 2264 break; 2265 case PR_GET_ENDIAN: 2266 error = GET_ENDIAN(me, arg2); 2267 break; 2268 case PR_SET_ENDIAN: 2269 error = SET_ENDIAN(me, arg2); 2270 break; 2271 case PR_GET_SECCOMP: 2272 error = prctl_get_seccomp(); 2273 break; 2274 case PR_SET_SECCOMP: 2275 error = prctl_set_seccomp(arg2, (char __user *)arg3); 2276 break; 2277 case PR_GET_TSC: 2278 error = GET_TSC_CTL(arg2); 2279 break; 2280 case PR_SET_TSC: 2281 error = SET_TSC_CTL(arg2); 2282 break; 2283 case PR_TASK_PERF_EVENTS_DISABLE: 2284 error = perf_event_task_disable(); 2285 break; 2286 case PR_TASK_PERF_EVENTS_ENABLE: 2287 error = perf_event_task_enable(); 2288 break; 2289 case PR_GET_TIMERSLACK: 2290 if (current->timer_slack_ns > ULONG_MAX) 2291 error = ULONG_MAX; 2292 else 2293 error = current->timer_slack_ns; 2294 break; 2295 case PR_SET_TIMERSLACK: 2296 if (arg2 <= 0) 2297 current->timer_slack_ns = 2298 current->default_timer_slack_ns; 2299 else 2300 current->timer_slack_ns = arg2; 2301 break; 2302 case PR_MCE_KILL: 2303 if (arg4 | arg5) 2304 return -EINVAL; 2305 switch (arg2) { 2306 case PR_MCE_KILL_CLEAR: 2307 if (arg3 != 0) 2308 return -EINVAL; 2309 current->flags &= ~PF_MCE_PROCESS; 2310 break; 2311 case PR_MCE_KILL_SET: 2312 current->flags |= PF_MCE_PROCESS; 2313 if (arg3 == PR_MCE_KILL_EARLY) 2314 current->flags |= PF_MCE_EARLY; 2315 else if (arg3 == PR_MCE_KILL_LATE) 2316 current->flags &= ~PF_MCE_EARLY; 2317 else if (arg3 == PR_MCE_KILL_DEFAULT) 2318 current->flags &= 2319 ~(PF_MCE_EARLY|PF_MCE_PROCESS); 2320 else 2321 return -EINVAL; 2322 break; 2323 default: 2324 return -EINVAL; 2325 } 2326 break; 2327 case PR_MCE_KILL_GET: 2328 if (arg2 | arg3 | arg4 | arg5) 2329 return -EINVAL; 2330 if (current->flags & PF_MCE_PROCESS) 2331 error = (current->flags & PF_MCE_EARLY) ? 2332 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE; 2333 else 2334 error = PR_MCE_KILL_DEFAULT; 2335 break; 2336 case PR_SET_MM: 2337 error = prctl_set_mm(arg2, arg3, arg4, arg5); 2338 break; 2339 case PR_GET_TID_ADDRESS: 2340 error = prctl_get_tid_address(me, (int __user **)arg2); 2341 break; 2342 case PR_SET_CHILD_SUBREAPER: 2343 me->signal->is_child_subreaper = !!arg2; 2344 if (!arg2) 2345 break; 2346 2347 walk_process_tree(me, propagate_has_child_subreaper, NULL); 2348 break; 2349 case PR_GET_CHILD_SUBREAPER: 2350 error = put_user(me->signal->is_child_subreaper, 2351 (int __user *)arg2); 2352 break; 2353 case PR_SET_NO_NEW_PRIVS: 2354 if (arg2 != 1 || arg3 || arg4 || arg5) 2355 return -EINVAL; 2356 2357 task_set_no_new_privs(current); 2358 break; 2359 case PR_GET_NO_NEW_PRIVS: 2360 if (arg2 || arg3 || arg4 || arg5) 2361 return -EINVAL; 2362 return task_no_new_privs(current) ? 1 : 0; 2363 case PR_GET_THP_DISABLE: 2364 if (arg2 || arg3 || arg4 || arg5) 2365 return -EINVAL; 2366 error = !!test_bit(MMF_DISABLE_THP, &me->mm->flags); 2367 break; 2368 case PR_SET_THP_DISABLE: 2369 if (arg3 || arg4 || arg5) 2370 return -EINVAL; 2371 if (down_write_killable(&me->mm->mmap_sem)) 2372 return -EINTR; 2373 if (arg2) 2374 set_bit(MMF_DISABLE_THP, &me->mm->flags); 2375 else 2376 clear_bit(MMF_DISABLE_THP, &me->mm->flags); 2377 up_write(&me->mm->mmap_sem); 2378 break; 2379 case PR_MPX_ENABLE_MANAGEMENT: 2380 if (arg2 || arg3 || arg4 || arg5) 2381 return -EINVAL; 2382 error = MPX_ENABLE_MANAGEMENT(); 2383 break; 2384 case PR_MPX_DISABLE_MANAGEMENT: 2385 if (arg2 || arg3 || arg4 || arg5) 2386 return -EINVAL; 2387 error = MPX_DISABLE_MANAGEMENT(); 2388 break; 2389 case PR_SET_FP_MODE: 2390 error = SET_FP_MODE(me, arg2); 2391 break; 2392 case PR_GET_FP_MODE: 2393 error = GET_FP_MODE(me); 2394 break; 2395 case PR_SVE_SET_VL: 2396 error = SVE_SET_VL(arg2); 2397 break; 2398 case PR_SVE_GET_VL: 2399 error = SVE_GET_VL(); 2400 break; 2401 default: 2402 error = -EINVAL; 2403 break; 2404 } 2405 return error; 2406 } 2407 2408 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep, 2409 struct getcpu_cache __user *, unused) 2410 { 2411 int err = 0; 2412 int cpu = raw_smp_processor_id(); 2413 2414 if (cpup) 2415 err |= put_user(cpu, cpup); 2416 if (nodep) 2417 err |= put_user(cpu_to_node(cpu), nodep); 2418 return err ? -EFAULT : 0; 2419 } 2420 2421 /** 2422 * do_sysinfo - fill in sysinfo struct 2423 * @info: pointer to buffer to fill 2424 */ 2425 static int do_sysinfo(struct sysinfo *info) 2426 { 2427 unsigned long mem_total, sav_total; 2428 unsigned int mem_unit, bitcount; 2429 struct timespec tp; 2430 2431 memset(info, 0, sizeof(struct sysinfo)); 2432 2433 get_monotonic_boottime(&tp); 2434 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0); 2435 2436 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT); 2437 2438 info->procs = nr_threads; 2439 2440 si_meminfo(info); 2441 si_swapinfo(info); 2442 2443 /* 2444 * If the sum of all the available memory (i.e. ram + swap) 2445 * is less than can be stored in a 32 bit unsigned long then 2446 * we can be binary compatible with 2.2.x kernels. If not, 2447 * well, in that case 2.2.x was broken anyways... 2448 * 2449 * -Erik Andersen <andersee@debian.org> 2450 */ 2451 2452 mem_total = info->totalram + info->totalswap; 2453 if (mem_total < info->totalram || mem_total < info->totalswap) 2454 goto out; 2455 bitcount = 0; 2456 mem_unit = info->mem_unit; 2457 while (mem_unit > 1) { 2458 bitcount++; 2459 mem_unit >>= 1; 2460 sav_total = mem_total; 2461 mem_total <<= 1; 2462 if (mem_total < sav_total) 2463 goto out; 2464 } 2465 2466 /* 2467 * If mem_total did not overflow, multiply all memory values by 2468 * info->mem_unit and set it to 1. This leaves things compatible 2469 * with 2.2.x, and also retains compatibility with earlier 2.4.x 2470 * kernels... 2471 */ 2472 2473 info->mem_unit = 1; 2474 info->totalram <<= bitcount; 2475 info->freeram <<= bitcount; 2476 info->sharedram <<= bitcount; 2477 info->bufferram <<= bitcount; 2478 info->totalswap <<= bitcount; 2479 info->freeswap <<= bitcount; 2480 info->totalhigh <<= bitcount; 2481 info->freehigh <<= bitcount; 2482 2483 out: 2484 return 0; 2485 } 2486 2487 SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info) 2488 { 2489 struct sysinfo val; 2490 2491 do_sysinfo(&val); 2492 2493 if (copy_to_user(info, &val, sizeof(struct sysinfo))) 2494 return -EFAULT; 2495 2496 return 0; 2497 } 2498 2499 #ifdef CONFIG_COMPAT 2500 struct compat_sysinfo { 2501 s32 uptime; 2502 u32 loads[3]; 2503 u32 totalram; 2504 u32 freeram; 2505 u32 sharedram; 2506 u32 bufferram; 2507 u32 totalswap; 2508 u32 freeswap; 2509 u16 procs; 2510 u16 pad; 2511 u32 totalhigh; 2512 u32 freehigh; 2513 u32 mem_unit; 2514 char _f[20-2*sizeof(u32)-sizeof(int)]; 2515 }; 2516 2517 COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info) 2518 { 2519 struct sysinfo s; 2520 2521 do_sysinfo(&s); 2522 2523 /* Check to see if any memory value is too large for 32-bit and scale 2524 * down if needed 2525 */ 2526 if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) { 2527 int bitcount = 0; 2528 2529 while (s.mem_unit < PAGE_SIZE) { 2530 s.mem_unit <<= 1; 2531 bitcount++; 2532 } 2533 2534 s.totalram >>= bitcount; 2535 s.freeram >>= bitcount; 2536 s.sharedram >>= bitcount; 2537 s.bufferram >>= bitcount; 2538 s.totalswap >>= bitcount; 2539 s.freeswap >>= bitcount; 2540 s.totalhigh >>= bitcount; 2541 s.freehigh >>= bitcount; 2542 } 2543 2544 if (!access_ok(VERIFY_WRITE, info, sizeof(struct compat_sysinfo)) || 2545 __put_user(s.uptime, &info->uptime) || 2546 __put_user(s.loads[0], &info->loads[0]) || 2547 __put_user(s.loads[1], &info->loads[1]) || 2548 __put_user(s.loads[2], &info->loads[2]) || 2549 __put_user(s.totalram, &info->totalram) || 2550 __put_user(s.freeram, &info->freeram) || 2551 __put_user(s.sharedram, &info->sharedram) || 2552 __put_user(s.bufferram, &info->bufferram) || 2553 __put_user(s.totalswap, &info->totalswap) || 2554 __put_user(s.freeswap, &info->freeswap) || 2555 __put_user(s.procs, &info->procs) || 2556 __put_user(s.totalhigh, &info->totalhigh) || 2557 __put_user(s.freehigh, &info->freehigh) || 2558 __put_user(s.mem_unit, &info->mem_unit)) 2559 return -EFAULT; 2560 2561 return 0; 2562 } 2563 #endif /* CONFIG_COMPAT */ 2564