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/mm_inline.h> 11 #include <linux/utsname.h> 12 #include <linux/mman.h> 13 #include <linux/reboot.h> 14 #include <linux/prctl.h> 15 #include <linux/highuid.h> 16 #include <linux/fs.h> 17 #include <linux/kmod.h> 18 #include <linux/ksm.h> 19 #include <linux/perf_event.h> 20 #include <linux/resource.h> 21 #include <linux/kernel.h> 22 #include <linux/workqueue.h> 23 #include <linux/capability.h> 24 #include <linux/device.h> 25 #include <linux/key.h> 26 #include <linux/times.h> 27 #include <linux/posix-timers.h> 28 #include <linux/security.h> 29 #include <linux/random.h> 30 #include <linux/suspend.h> 31 #include <linux/tty.h> 32 #include <linux/signal.h> 33 #include <linux/cn_proc.h> 34 #include <linux/getcpu.h> 35 #include <linux/task_io_accounting_ops.h> 36 #include <linux/seccomp.h> 37 #include <linux/cpu.h> 38 #include <linux/personality.h> 39 #include <linux/ptrace.h> 40 #include <linux/fs_struct.h> 41 #include <linux/file.h> 42 #include <linux/mount.h> 43 #include <linux/gfp.h> 44 #include <linux/syscore_ops.h> 45 #include <linux/version.h> 46 #include <linux/ctype.h> 47 #include <linux/syscall_user_dispatch.h> 48 49 #include <linux/compat.h> 50 #include <linux/syscalls.h> 51 #include <linux/kprobes.h> 52 #include <linux/user_namespace.h> 53 #include <linux/time_namespace.h> 54 #include <linux/binfmts.h> 55 #include <linux/futex.h> 56 57 #include <linux/sched.h> 58 #include <linux/sched/autogroup.h> 59 #include <linux/sched/loadavg.h> 60 #include <linux/sched/stat.h> 61 #include <linux/sched/mm.h> 62 #include <linux/sched/coredump.h> 63 #include <linux/sched/task.h> 64 #include <linux/sched/cputime.h> 65 #include <linux/rcupdate.h> 66 #include <linux/uidgid.h> 67 #include <linux/cred.h> 68 69 #include <linux/nospec.h> 70 71 #include <linux/kmsg_dump.h> 72 /* Move somewhere else to avoid recompiling? */ 73 #include <generated/utsrelease.h> 74 75 #include <linux/uaccess.h> 76 #include <asm/io.h> 77 #include <asm/unistd.h> 78 79 #include <trace/events/task.h> 80 81 #include "uid16.h" 82 83 #ifndef SET_UNALIGN_CTL 84 # define SET_UNALIGN_CTL(a, b) (-EINVAL) 85 #endif 86 #ifndef GET_UNALIGN_CTL 87 # define GET_UNALIGN_CTL(a, b) (-EINVAL) 88 #endif 89 #ifndef SET_FPEMU_CTL 90 # define SET_FPEMU_CTL(a, b) (-EINVAL) 91 #endif 92 #ifndef GET_FPEMU_CTL 93 # define GET_FPEMU_CTL(a, b) (-EINVAL) 94 #endif 95 #ifndef SET_FPEXC_CTL 96 # define SET_FPEXC_CTL(a, b) (-EINVAL) 97 #endif 98 #ifndef GET_FPEXC_CTL 99 # define GET_FPEXC_CTL(a, b) (-EINVAL) 100 #endif 101 #ifndef GET_ENDIAN 102 # define GET_ENDIAN(a, b) (-EINVAL) 103 #endif 104 #ifndef SET_ENDIAN 105 # define SET_ENDIAN(a, b) (-EINVAL) 106 #endif 107 #ifndef GET_TSC_CTL 108 # define GET_TSC_CTL(a) (-EINVAL) 109 #endif 110 #ifndef SET_TSC_CTL 111 # define SET_TSC_CTL(a) (-EINVAL) 112 #endif 113 #ifndef GET_FP_MODE 114 # define GET_FP_MODE(a) (-EINVAL) 115 #endif 116 #ifndef SET_FP_MODE 117 # define SET_FP_MODE(a,b) (-EINVAL) 118 #endif 119 #ifndef SVE_SET_VL 120 # define SVE_SET_VL(a) (-EINVAL) 121 #endif 122 #ifndef SVE_GET_VL 123 # define SVE_GET_VL() (-EINVAL) 124 #endif 125 #ifndef SME_SET_VL 126 # define SME_SET_VL(a) (-EINVAL) 127 #endif 128 #ifndef SME_GET_VL 129 # define SME_GET_VL() (-EINVAL) 130 #endif 131 #ifndef PAC_RESET_KEYS 132 # define PAC_RESET_KEYS(a, b) (-EINVAL) 133 #endif 134 #ifndef PAC_SET_ENABLED_KEYS 135 # define PAC_SET_ENABLED_KEYS(a, b, c) (-EINVAL) 136 #endif 137 #ifndef PAC_GET_ENABLED_KEYS 138 # define PAC_GET_ENABLED_KEYS(a) (-EINVAL) 139 #endif 140 #ifndef SET_TAGGED_ADDR_CTRL 141 # define SET_TAGGED_ADDR_CTRL(a) (-EINVAL) 142 #endif 143 #ifndef GET_TAGGED_ADDR_CTRL 144 # define GET_TAGGED_ADDR_CTRL() (-EINVAL) 145 #endif 146 #ifndef RISCV_V_SET_CONTROL 147 # define RISCV_V_SET_CONTROL(a) (-EINVAL) 148 #endif 149 #ifndef RISCV_V_GET_CONTROL 150 # define RISCV_V_GET_CONTROL() (-EINVAL) 151 #endif 152 #ifndef RISCV_SET_ICACHE_FLUSH_CTX 153 # define RISCV_SET_ICACHE_FLUSH_CTX(a, b) (-EINVAL) 154 #endif 155 #ifndef PPC_GET_DEXCR_ASPECT 156 # define PPC_GET_DEXCR_ASPECT(a, b) (-EINVAL) 157 #endif 158 #ifndef PPC_SET_DEXCR_ASPECT 159 # define PPC_SET_DEXCR_ASPECT(a, b, c) (-EINVAL) 160 #endif 161 162 /* 163 * this is where the system-wide overflow UID and GID are defined, for 164 * architectures that now have 32-bit UID/GID but didn't in the past 165 */ 166 167 int overflowuid = DEFAULT_OVERFLOWUID; 168 int overflowgid = DEFAULT_OVERFLOWGID; 169 170 EXPORT_SYMBOL(overflowuid); 171 EXPORT_SYMBOL(overflowgid); 172 173 /* 174 * the same as above, but for filesystems which can only store a 16-bit 175 * UID and GID. as such, this is needed on all architectures 176 */ 177 178 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID; 179 int fs_overflowgid = DEFAULT_FS_OVERFLOWGID; 180 181 EXPORT_SYMBOL(fs_overflowuid); 182 EXPORT_SYMBOL(fs_overflowgid); 183 184 /* 185 * Returns true if current's euid is same as p's uid or euid, 186 * or has CAP_SYS_NICE to p's user_ns. 187 * 188 * Called with rcu_read_lock, creds are safe 189 */ 190 static bool set_one_prio_perm(struct task_struct *p) 191 { 192 const struct cred *cred = current_cred(), *pcred = __task_cred(p); 193 194 if (uid_eq(pcred->uid, cred->euid) || 195 uid_eq(pcred->euid, cred->euid)) 196 return true; 197 if (ns_capable(pcred->user_ns, CAP_SYS_NICE)) 198 return true; 199 return false; 200 } 201 202 /* 203 * set the priority of a task 204 * - the caller must hold the RCU read lock 205 */ 206 static int set_one_prio(struct task_struct *p, int niceval, int error) 207 { 208 int no_nice; 209 210 if (!set_one_prio_perm(p)) { 211 error = -EPERM; 212 goto out; 213 } 214 if (niceval < task_nice(p) && !can_nice(p, niceval)) { 215 error = -EACCES; 216 goto out; 217 } 218 no_nice = security_task_setnice(p, niceval); 219 if (no_nice) { 220 error = no_nice; 221 goto out; 222 } 223 if (error == -ESRCH) 224 error = 0; 225 set_user_nice(p, niceval); 226 out: 227 return error; 228 } 229 230 SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval) 231 { 232 struct task_struct *g, *p; 233 struct user_struct *user; 234 const struct cred *cred = current_cred(); 235 int error = -EINVAL; 236 struct pid *pgrp; 237 kuid_t uid; 238 239 if (which > PRIO_USER || which < PRIO_PROCESS) 240 goto out; 241 242 /* normalize: avoid signed division (rounding problems) */ 243 error = -ESRCH; 244 if (niceval < MIN_NICE) 245 niceval = MIN_NICE; 246 if (niceval > MAX_NICE) 247 niceval = MAX_NICE; 248 249 rcu_read_lock(); 250 switch (which) { 251 case PRIO_PROCESS: 252 if (who) 253 p = find_task_by_vpid(who); 254 else 255 p = current; 256 if (p) 257 error = set_one_prio(p, niceval, error); 258 break; 259 case PRIO_PGRP: 260 if (who) 261 pgrp = find_vpid(who); 262 else 263 pgrp = task_pgrp(current); 264 read_lock(&tasklist_lock); 265 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { 266 error = set_one_prio(p, niceval, error); 267 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); 268 read_unlock(&tasklist_lock); 269 break; 270 case PRIO_USER: 271 uid = make_kuid(cred->user_ns, who); 272 user = cred->user; 273 if (!who) 274 uid = cred->uid; 275 else if (!uid_eq(uid, cred->uid)) { 276 user = find_user(uid); 277 if (!user) 278 goto out_unlock; /* No processes for this user */ 279 } 280 for_each_process_thread(g, p) { 281 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) 282 error = set_one_prio(p, niceval, error); 283 } 284 if (!uid_eq(uid, cred->uid)) 285 free_uid(user); /* For find_user() */ 286 break; 287 } 288 out_unlock: 289 rcu_read_unlock(); 290 out: 291 return error; 292 } 293 294 /* 295 * Ugh. To avoid negative return values, "getpriority()" will 296 * not return the normal nice-value, but a negated value that 297 * has been offset by 20 (ie it returns 40..1 instead of -20..19) 298 * to stay compatible. 299 */ 300 SYSCALL_DEFINE2(getpriority, int, which, int, who) 301 { 302 struct task_struct *g, *p; 303 struct user_struct *user; 304 const struct cred *cred = current_cred(); 305 long niceval, retval = -ESRCH; 306 struct pid *pgrp; 307 kuid_t uid; 308 309 if (which > PRIO_USER || which < PRIO_PROCESS) 310 return -EINVAL; 311 312 rcu_read_lock(); 313 switch (which) { 314 case PRIO_PROCESS: 315 if (who) 316 p = find_task_by_vpid(who); 317 else 318 p = current; 319 if (p) { 320 niceval = nice_to_rlimit(task_nice(p)); 321 if (niceval > retval) 322 retval = niceval; 323 } 324 break; 325 case PRIO_PGRP: 326 if (who) 327 pgrp = find_vpid(who); 328 else 329 pgrp = task_pgrp(current); 330 read_lock(&tasklist_lock); 331 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { 332 niceval = nice_to_rlimit(task_nice(p)); 333 if (niceval > retval) 334 retval = niceval; 335 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); 336 read_unlock(&tasklist_lock); 337 break; 338 case PRIO_USER: 339 uid = make_kuid(cred->user_ns, who); 340 user = cred->user; 341 if (!who) 342 uid = cred->uid; 343 else if (!uid_eq(uid, cred->uid)) { 344 user = find_user(uid); 345 if (!user) 346 goto out_unlock; /* No processes for this user */ 347 } 348 for_each_process_thread(g, p) { 349 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) { 350 niceval = nice_to_rlimit(task_nice(p)); 351 if (niceval > retval) 352 retval = niceval; 353 } 354 } 355 if (!uid_eq(uid, cred->uid)) 356 free_uid(user); /* for find_user() */ 357 break; 358 } 359 out_unlock: 360 rcu_read_unlock(); 361 362 return retval; 363 } 364 365 /* 366 * Unprivileged users may change the real gid to the effective gid 367 * or vice versa. (BSD-style) 368 * 369 * If you set the real gid at all, or set the effective gid to a value not 370 * equal to the real gid, then the saved gid is set to the new effective gid. 371 * 372 * This makes it possible for a setgid program to completely drop its 373 * privileges, which is often a useful assertion to make when you are doing 374 * a security audit over a program. 375 * 376 * The general idea is that a program which uses just setregid() will be 377 * 100% compatible with BSD. A program which uses just setgid() will be 378 * 100% compatible with POSIX with saved IDs. 379 * 380 * SMP: There are not races, the GIDs are checked only by filesystem 381 * operations (as far as semantic preservation is concerned). 382 */ 383 #ifdef CONFIG_MULTIUSER 384 long __sys_setregid(gid_t rgid, gid_t egid) 385 { 386 struct user_namespace *ns = current_user_ns(); 387 const struct cred *old; 388 struct cred *new; 389 int retval; 390 kgid_t krgid, kegid; 391 392 krgid = make_kgid(ns, rgid); 393 kegid = make_kgid(ns, egid); 394 395 if ((rgid != (gid_t) -1) && !gid_valid(krgid)) 396 return -EINVAL; 397 if ((egid != (gid_t) -1) && !gid_valid(kegid)) 398 return -EINVAL; 399 400 new = prepare_creds(); 401 if (!new) 402 return -ENOMEM; 403 old = current_cred(); 404 405 retval = -EPERM; 406 if (rgid != (gid_t) -1) { 407 if (gid_eq(old->gid, krgid) || 408 gid_eq(old->egid, krgid) || 409 ns_capable_setid(old->user_ns, CAP_SETGID)) 410 new->gid = krgid; 411 else 412 goto error; 413 } 414 if (egid != (gid_t) -1) { 415 if (gid_eq(old->gid, kegid) || 416 gid_eq(old->egid, kegid) || 417 gid_eq(old->sgid, kegid) || 418 ns_capable_setid(old->user_ns, CAP_SETGID)) 419 new->egid = kegid; 420 else 421 goto error; 422 } 423 424 if (rgid != (gid_t) -1 || 425 (egid != (gid_t) -1 && !gid_eq(kegid, old->gid))) 426 new->sgid = new->egid; 427 new->fsgid = new->egid; 428 429 retval = security_task_fix_setgid(new, old, LSM_SETID_RE); 430 if (retval < 0) 431 goto error; 432 433 return commit_creds(new); 434 435 error: 436 abort_creds(new); 437 return retval; 438 } 439 440 SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid) 441 { 442 return __sys_setregid(rgid, egid); 443 } 444 445 /* 446 * setgid() is implemented like SysV w/ SAVED_IDS 447 * 448 * SMP: Same implicit races as above. 449 */ 450 long __sys_setgid(gid_t gid) 451 { 452 struct user_namespace *ns = current_user_ns(); 453 const struct cred *old; 454 struct cred *new; 455 int retval; 456 kgid_t kgid; 457 458 kgid = make_kgid(ns, gid); 459 if (!gid_valid(kgid)) 460 return -EINVAL; 461 462 new = prepare_creds(); 463 if (!new) 464 return -ENOMEM; 465 old = current_cred(); 466 467 retval = -EPERM; 468 if (ns_capable_setid(old->user_ns, CAP_SETGID)) 469 new->gid = new->egid = new->sgid = new->fsgid = kgid; 470 else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid)) 471 new->egid = new->fsgid = kgid; 472 else 473 goto error; 474 475 retval = security_task_fix_setgid(new, old, LSM_SETID_ID); 476 if (retval < 0) 477 goto error; 478 479 return commit_creds(new); 480 481 error: 482 abort_creds(new); 483 return retval; 484 } 485 486 SYSCALL_DEFINE1(setgid, gid_t, gid) 487 { 488 return __sys_setgid(gid); 489 } 490 491 /* 492 * change the user struct in a credentials set to match the new UID 493 */ 494 static int set_user(struct cred *new) 495 { 496 struct user_struct *new_user; 497 498 new_user = alloc_uid(new->uid); 499 if (!new_user) 500 return -EAGAIN; 501 502 free_uid(new->user); 503 new->user = new_user; 504 return 0; 505 } 506 507 static void flag_nproc_exceeded(struct cred *new) 508 { 509 if (new->ucounts == current_ucounts()) 510 return; 511 512 /* 513 * We don't fail in case of NPROC limit excess here because too many 514 * poorly written programs don't check set*uid() return code, assuming 515 * it never fails if called by root. We may still enforce NPROC limit 516 * for programs doing set*uid()+execve() by harmlessly deferring the 517 * failure to the execve() stage. 518 */ 519 if (is_rlimit_overlimit(new->ucounts, UCOUNT_RLIMIT_NPROC, rlimit(RLIMIT_NPROC)) && 520 new->user != INIT_USER) 521 current->flags |= PF_NPROC_EXCEEDED; 522 else 523 current->flags &= ~PF_NPROC_EXCEEDED; 524 } 525 526 /* 527 * Unprivileged users may change the real uid to the effective uid 528 * or vice versa. (BSD-style) 529 * 530 * If you set the real uid at all, or set the effective uid to a value not 531 * equal to the real uid, then the saved uid is set to the new effective uid. 532 * 533 * This makes it possible for a setuid program to completely drop its 534 * privileges, which is often a useful assertion to make when you are doing 535 * a security audit over a program. 536 * 537 * The general idea is that a program which uses just setreuid() will be 538 * 100% compatible with BSD. A program which uses just setuid() will be 539 * 100% compatible with POSIX with saved IDs. 540 */ 541 long __sys_setreuid(uid_t ruid, uid_t euid) 542 { 543 struct user_namespace *ns = current_user_ns(); 544 const struct cred *old; 545 struct cred *new; 546 int retval; 547 kuid_t kruid, keuid; 548 549 kruid = make_kuid(ns, ruid); 550 keuid = make_kuid(ns, euid); 551 552 if ((ruid != (uid_t) -1) && !uid_valid(kruid)) 553 return -EINVAL; 554 if ((euid != (uid_t) -1) && !uid_valid(keuid)) 555 return -EINVAL; 556 557 new = prepare_creds(); 558 if (!new) 559 return -ENOMEM; 560 old = current_cred(); 561 562 retval = -EPERM; 563 if (ruid != (uid_t) -1) { 564 new->uid = kruid; 565 if (!uid_eq(old->uid, kruid) && 566 !uid_eq(old->euid, kruid) && 567 !ns_capable_setid(old->user_ns, CAP_SETUID)) 568 goto error; 569 } 570 571 if (euid != (uid_t) -1) { 572 new->euid = keuid; 573 if (!uid_eq(old->uid, keuid) && 574 !uid_eq(old->euid, keuid) && 575 !uid_eq(old->suid, keuid) && 576 !ns_capable_setid(old->user_ns, CAP_SETUID)) 577 goto error; 578 } 579 580 if (!uid_eq(new->uid, old->uid)) { 581 retval = set_user(new); 582 if (retval < 0) 583 goto error; 584 } 585 if (ruid != (uid_t) -1 || 586 (euid != (uid_t) -1 && !uid_eq(keuid, old->uid))) 587 new->suid = new->euid; 588 new->fsuid = new->euid; 589 590 retval = security_task_fix_setuid(new, old, LSM_SETID_RE); 591 if (retval < 0) 592 goto error; 593 594 retval = set_cred_ucounts(new); 595 if (retval < 0) 596 goto error; 597 598 flag_nproc_exceeded(new); 599 return commit_creds(new); 600 601 error: 602 abort_creds(new); 603 return retval; 604 } 605 606 SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid) 607 { 608 return __sys_setreuid(ruid, euid); 609 } 610 611 /* 612 * setuid() is implemented like SysV with SAVED_IDS 613 * 614 * Note that SAVED_ID's is deficient in that a setuid root program 615 * like sendmail, for example, cannot set its uid to be a normal 616 * user and then switch back, because if you're root, setuid() sets 617 * the saved uid too. If you don't like this, blame the bright people 618 * in the POSIX committee and/or USG. Note that the BSD-style setreuid() 619 * will allow a root program to temporarily drop privileges and be able to 620 * regain them by swapping the real and effective uid. 621 */ 622 long __sys_setuid(uid_t uid) 623 { 624 struct user_namespace *ns = current_user_ns(); 625 const struct cred *old; 626 struct cred *new; 627 int retval; 628 kuid_t kuid; 629 630 kuid = make_kuid(ns, uid); 631 if (!uid_valid(kuid)) 632 return -EINVAL; 633 634 new = prepare_creds(); 635 if (!new) 636 return -ENOMEM; 637 old = current_cred(); 638 639 retval = -EPERM; 640 if (ns_capable_setid(old->user_ns, CAP_SETUID)) { 641 new->suid = new->uid = kuid; 642 if (!uid_eq(kuid, old->uid)) { 643 retval = set_user(new); 644 if (retval < 0) 645 goto error; 646 } 647 } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) { 648 goto error; 649 } 650 651 new->fsuid = new->euid = kuid; 652 653 retval = security_task_fix_setuid(new, old, LSM_SETID_ID); 654 if (retval < 0) 655 goto error; 656 657 retval = set_cred_ucounts(new); 658 if (retval < 0) 659 goto error; 660 661 flag_nproc_exceeded(new); 662 return commit_creds(new); 663 664 error: 665 abort_creds(new); 666 return retval; 667 } 668 669 SYSCALL_DEFINE1(setuid, uid_t, uid) 670 { 671 return __sys_setuid(uid); 672 } 673 674 675 /* 676 * This function implements a generic ability to update ruid, euid, 677 * and suid. This allows you to implement the 4.4 compatible seteuid(). 678 */ 679 long __sys_setresuid(uid_t ruid, uid_t euid, uid_t suid) 680 { 681 struct user_namespace *ns = current_user_ns(); 682 const struct cred *old; 683 struct cred *new; 684 int retval; 685 kuid_t kruid, keuid, ksuid; 686 bool ruid_new, euid_new, suid_new; 687 688 kruid = make_kuid(ns, ruid); 689 keuid = make_kuid(ns, euid); 690 ksuid = make_kuid(ns, suid); 691 692 if ((ruid != (uid_t) -1) && !uid_valid(kruid)) 693 return -EINVAL; 694 695 if ((euid != (uid_t) -1) && !uid_valid(keuid)) 696 return -EINVAL; 697 698 if ((suid != (uid_t) -1) && !uid_valid(ksuid)) 699 return -EINVAL; 700 701 old = current_cred(); 702 703 /* check for no-op */ 704 if ((ruid == (uid_t) -1 || uid_eq(kruid, old->uid)) && 705 (euid == (uid_t) -1 || (uid_eq(keuid, old->euid) && 706 uid_eq(keuid, old->fsuid))) && 707 (suid == (uid_t) -1 || uid_eq(ksuid, old->suid))) 708 return 0; 709 710 ruid_new = ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) && 711 !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid); 712 euid_new = euid != (uid_t) -1 && !uid_eq(keuid, old->uid) && 713 !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid); 714 suid_new = suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) && 715 !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid); 716 if ((ruid_new || euid_new || suid_new) && 717 !ns_capable_setid(old->user_ns, CAP_SETUID)) 718 return -EPERM; 719 720 new = prepare_creds(); 721 if (!new) 722 return -ENOMEM; 723 724 if (ruid != (uid_t) -1) { 725 new->uid = kruid; 726 if (!uid_eq(kruid, old->uid)) { 727 retval = set_user(new); 728 if (retval < 0) 729 goto error; 730 } 731 } 732 if (euid != (uid_t) -1) 733 new->euid = keuid; 734 if (suid != (uid_t) -1) 735 new->suid = ksuid; 736 new->fsuid = new->euid; 737 738 retval = security_task_fix_setuid(new, old, LSM_SETID_RES); 739 if (retval < 0) 740 goto error; 741 742 retval = set_cred_ucounts(new); 743 if (retval < 0) 744 goto error; 745 746 flag_nproc_exceeded(new); 747 return commit_creds(new); 748 749 error: 750 abort_creds(new); 751 return retval; 752 } 753 754 SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid) 755 { 756 return __sys_setresuid(ruid, euid, suid); 757 } 758 759 SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp) 760 { 761 const struct cred *cred = current_cred(); 762 int retval; 763 uid_t ruid, euid, suid; 764 765 ruid = from_kuid_munged(cred->user_ns, cred->uid); 766 euid = from_kuid_munged(cred->user_ns, cred->euid); 767 suid = from_kuid_munged(cred->user_ns, cred->suid); 768 769 retval = put_user(ruid, ruidp); 770 if (!retval) { 771 retval = put_user(euid, euidp); 772 if (!retval) 773 return put_user(suid, suidp); 774 } 775 return retval; 776 } 777 778 /* 779 * Same as above, but for rgid, egid, sgid. 780 */ 781 long __sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid) 782 { 783 struct user_namespace *ns = current_user_ns(); 784 const struct cred *old; 785 struct cred *new; 786 int retval; 787 kgid_t krgid, kegid, ksgid; 788 bool rgid_new, egid_new, sgid_new; 789 790 krgid = make_kgid(ns, rgid); 791 kegid = make_kgid(ns, egid); 792 ksgid = make_kgid(ns, sgid); 793 794 if ((rgid != (gid_t) -1) && !gid_valid(krgid)) 795 return -EINVAL; 796 if ((egid != (gid_t) -1) && !gid_valid(kegid)) 797 return -EINVAL; 798 if ((sgid != (gid_t) -1) && !gid_valid(ksgid)) 799 return -EINVAL; 800 801 old = current_cred(); 802 803 /* check for no-op */ 804 if ((rgid == (gid_t) -1 || gid_eq(krgid, old->gid)) && 805 (egid == (gid_t) -1 || (gid_eq(kegid, old->egid) && 806 gid_eq(kegid, old->fsgid))) && 807 (sgid == (gid_t) -1 || gid_eq(ksgid, old->sgid))) 808 return 0; 809 810 rgid_new = rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) && 811 !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid); 812 egid_new = egid != (gid_t) -1 && !gid_eq(kegid, old->gid) && 813 !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid); 814 sgid_new = sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) && 815 !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid); 816 if ((rgid_new || egid_new || sgid_new) && 817 !ns_capable_setid(old->user_ns, CAP_SETGID)) 818 return -EPERM; 819 820 new = prepare_creds(); 821 if (!new) 822 return -ENOMEM; 823 824 if (rgid != (gid_t) -1) 825 new->gid = krgid; 826 if (egid != (gid_t) -1) 827 new->egid = kegid; 828 if (sgid != (gid_t) -1) 829 new->sgid = ksgid; 830 new->fsgid = new->egid; 831 832 retval = security_task_fix_setgid(new, old, LSM_SETID_RES); 833 if (retval < 0) 834 goto error; 835 836 return commit_creds(new); 837 838 error: 839 abort_creds(new); 840 return retval; 841 } 842 843 SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid) 844 { 845 return __sys_setresgid(rgid, egid, sgid); 846 } 847 848 SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp) 849 { 850 const struct cred *cred = current_cred(); 851 int retval; 852 gid_t rgid, egid, sgid; 853 854 rgid = from_kgid_munged(cred->user_ns, cred->gid); 855 egid = from_kgid_munged(cred->user_ns, cred->egid); 856 sgid = from_kgid_munged(cred->user_ns, cred->sgid); 857 858 retval = put_user(rgid, rgidp); 859 if (!retval) { 860 retval = put_user(egid, egidp); 861 if (!retval) 862 retval = put_user(sgid, sgidp); 863 } 864 865 return retval; 866 } 867 868 869 /* 870 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This 871 * is used for "access()" and for the NFS daemon (letting nfsd stay at 872 * whatever uid it wants to). It normally shadows "euid", except when 873 * explicitly set by setfsuid() or for access.. 874 */ 875 long __sys_setfsuid(uid_t uid) 876 { 877 const struct cred *old; 878 struct cred *new; 879 uid_t old_fsuid; 880 kuid_t kuid; 881 882 old = current_cred(); 883 old_fsuid = from_kuid_munged(old->user_ns, old->fsuid); 884 885 kuid = make_kuid(old->user_ns, uid); 886 if (!uid_valid(kuid)) 887 return old_fsuid; 888 889 new = prepare_creds(); 890 if (!new) 891 return old_fsuid; 892 893 if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) || 894 uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) || 895 ns_capable_setid(old->user_ns, CAP_SETUID)) { 896 if (!uid_eq(kuid, old->fsuid)) { 897 new->fsuid = kuid; 898 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0) 899 goto change_okay; 900 } 901 } 902 903 abort_creds(new); 904 return old_fsuid; 905 906 change_okay: 907 commit_creds(new); 908 return old_fsuid; 909 } 910 911 SYSCALL_DEFINE1(setfsuid, uid_t, uid) 912 { 913 return __sys_setfsuid(uid); 914 } 915 916 /* 917 * Samma på svenska.. 918 */ 919 long __sys_setfsgid(gid_t gid) 920 { 921 const struct cred *old; 922 struct cred *new; 923 gid_t old_fsgid; 924 kgid_t kgid; 925 926 old = current_cred(); 927 old_fsgid = from_kgid_munged(old->user_ns, old->fsgid); 928 929 kgid = make_kgid(old->user_ns, gid); 930 if (!gid_valid(kgid)) 931 return old_fsgid; 932 933 new = prepare_creds(); 934 if (!new) 935 return old_fsgid; 936 937 if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) || 938 gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) || 939 ns_capable_setid(old->user_ns, CAP_SETGID)) { 940 if (!gid_eq(kgid, old->fsgid)) { 941 new->fsgid = kgid; 942 if (security_task_fix_setgid(new,old,LSM_SETID_FS) == 0) 943 goto change_okay; 944 } 945 } 946 947 abort_creds(new); 948 return old_fsgid; 949 950 change_okay: 951 commit_creds(new); 952 return old_fsgid; 953 } 954 955 SYSCALL_DEFINE1(setfsgid, gid_t, gid) 956 { 957 return __sys_setfsgid(gid); 958 } 959 #endif /* CONFIG_MULTIUSER */ 960 961 /** 962 * sys_getpid - return the thread group id of the current process 963 * 964 * Note, despite the name, this returns the tgid not the pid. The tgid and 965 * the pid are identical unless CLONE_THREAD was specified on clone() in 966 * which case the tgid is the same in all threads of the same group. 967 * 968 * This is SMP safe as current->tgid does not change. 969 */ 970 SYSCALL_DEFINE0(getpid) 971 { 972 return task_tgid_vnr(current); 973 } 974 975 /* Thread ID - the internal kernel "pid" */ 976 SYSCALL_DEFINE0(gettid) 977 { 978 return task_pid_vnr(current); 979 } 980 981 /* 982 * Accessing ->real_parent is not SMP-safe, it could 983 * change from under us. However, we can use a stale 984 * value of ->real_parent under rcu_read_lock(), see 985 * release_task()->call_rcu(delayed_put_task_struct). 986 */ 987 SYSCALL_DEFINE0(getppid) 988 { 989 int pid; 990 991 rcu_read_lock(); 992 pid = task_tgid_vnr(rcu_dereference(current->real_parent)); 993 rcu_read_unlock(); 994 995 return pid; 996 } 997 998 SYSCALL_DEFINE0(getuid) 999 { 1000 /* Only we change this so SMP safe */ 1001 return from_kuid_munged(current_user_ns(), current_uid()); 1002 } 1003 1004 SYSCALL_DEFINE0(geteuid) 1005 { 1006 /* Only we change this so SMP safe */ 1007 return from_kuid_munged(current_user_ns(), current_euid()); 1008 } 1009 1010 SYSCALL_DEFINE0(getgid) 1011 { 1012 /* Only we change this so SMP safe */ 1013 return from_kgid_munged(current_user_ns(), current_gid()); 1014 } 1015 1016 SYSCALL_DEFINE0(getegid) 1017 { 1018 /* Only we change this so SMP safe */ 1019 return from_kgid_munged(current_user_ns(), current_egid()); 1020 } 1021 1022 static void do_sys_times(struct tms *tms) 1023 { 1024 u64 tgutime, tgstime, cutime, cstime; 1025 1026 thread_group_cputime_adjusted(current, &tgutime, &tgstime); 1027 cutime = current->signal->cutime; 1028 cstime = current->signal->cstime; 1029 tms->tms_utime = nsec_to_clock_t(tgutime); 1030 tms->tms_stime = nsec_to_clock_t(tgstime); 1031 tms->tms_cutime = nsec_to_clock_t(cutime); 1032 tms->tms_cstime = nsec_to_clock_t(cstime); 1033 } 1034 1035 SYSCALL_DEFINE1(times, struct tms __user *, tbuf) 1036 { 1037 if (tbuf) { 1038 struct tms tmp; 1039 1040 do_sys_times(&tmp); 1041 if (copy_to_user(tbuf, &tmp, sizeof(struct tms))) 1042 return -EFAULT; 1043 } 1044 force_successful_syscall_return(); 1045 return (long) jiffies_64_to_clock_t(get_jiffies_64()); 1046 } 1047 1048 #ifdef CONFIG_COMPAT 1049 static compat_clock_t clock_t_to_compat_clock_t(clock_t x) 1050 { 1051 return compat_jiffies_to_clock_t(clock_t_to_jiffies(x)); 1052 } 1053 1054 COMPAT_SYSCALL_DEFINE1(times, struct compat_tms __user *, tbuf) 1055 { 1056 if (tbuf) { 1057 struct tms tms; 1058 struct compat_tms tmp; 1059 1060 do_sys_times(&tms); 1061 /* Convert our struct tms to the compat version. */ 1062 tmp.tms_utime = clock_t_to_compat_clock_t(tms.tms_utime); 1063 tmp.tms_stime = clock_t_to_compat_clock_t(tms.tms_stime); 1064 tmp.tms_cutime = clock_t_to_compat_clock_t(tms.tms_cutime); 1065 tmp.tms_cstime = clock_t_to_compat_clock_t(tms.tms_cstime); 1066 if (copy_to_user(tbuf, &tmp, sizeof(tmp))) 1067 return -EFAULT; 1068 } 1069 force_successful_syscall_return(); 1070 return compat_jiffies_to_clock_t(jiffies); 1071 } 1072 #endif 1073 1074 /* 1075 * This needs some heavy checking ... 1076 * I just haven't the stomach for it. I also don't fully 1077 * understand sessions/pgrp etc. Let somebody who does explain it. 1078 * 1079 * OK, I think I have the protection semantics right.... this is really 1080 * only important on a multi-user system anyway, to make sure one user 1081 * can't send a signal to a process owned by another. -TYT, 12/12/91 1082 * 1083 * !PF_FORKNOEXEC check to conform completely to POSIX. 1084 */ 1085 SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid) 1086 { 1087 struct task_struct *p; 1088 struct task_struct *group_leader = current->group_leader; 1089 struct pid *pids[PIDTYPE_MAX] = { 0 }; 1090 struct pid *pgrp; 1091 int err; 1092 1093 if (!pid) 1094 pid = task_pid_vnr(group_leader); 1095 if (!pgid) 1096 pgid = pid; 1097 if (pgid < 0) 1098 return -EINVAL; 1099 rcu_read_lock(); 1100 1101 /* From this point forward we keep holding onto the tasklist lock 1102 * so that our parent does not change from under us. -DaveM 1103 */ 1104 write_lock_irq(&tasklist_lock); 1105 1106 err = -ESRCH; 1107 p = find_task_by_vpid(pid); 1108 if (!p) 1109 goto out; 1110 1111 err = -EINVAL; 1112 if (!thread_group_leader(p)) 1113 goto out; 1114 1115 if (same_thread_group(p->real_parent, group_leader)) { 1116 err = -EPERM; 1117 if (task_session(p) != task_session(group_leader)) 1118 goto out; 1119 err = -EACCES; 1120 if (!(p->flags & PF_FORKNOEXEC)) 1121 goto out; 1122 } else { 1123 err = -ESRCH; 1124 if (p != group_leader) 1125 goto out; 1126 } 1127 1128 err = -EPERM; 1129 if (p->signal->leader) 1130 goto out; 1131 1132 pgrp = task_pid(p); 1133 if (pgid != pid) { 1134 struct task_struct *g; 1135 1136 pgrp = find_vpid(pgid); 1137 g = pid_task(pgrp, PIDTYPE_PGID); 1138 if (!g || task_session(g) != task_session(group_leader)) 1139 goto out; 1140 } 1141 1142 err = security_task_setpgid(p, pgid); 1143 if (err) 1144 goto out; 1145 1146 if (task_pgrp(p) != pgrp) 1147 change_pid(pids, p, PIDTYPE_PGID, pgrp); 1148 1149 err = 0; 1150 out: 1151 /* All paths lead to here, thus we are safe. -DaveM */ 1152 write_unlock_irq(&tasklist_lock); 1153 rcu_read_unlock(); 1154 free_pids(pids); 1155 return err; 1156 } 1157 1158 static int do_getpgid(pid_t pid) 1159 { 1160 struct task_struct *p; 1161 struct pid *grp; 1162 int retval; 1163 1164 rcu_read_lock(); 1165 if (!pid) 1166 grp = task_pgrp(current); 1167 else { 1168 retval = -ESRCH; 1169 p = find_task_by_vpid(pid); 1170 if (!p) 1171 goto out; 1172 grp = task_pgrp(p); 1173 if (!grp) 1174 goto out; 1175 1176 retval = security_task_getpgid(p); 1177 if (retval) 1178 goto out; 1179 } 1180 retval = pid_vnr(grp); 1181 out: 1182 rcu_read_unlock(); 1183 return retval; 1184 } 1185 1186 SYSCALL_DEFINE1(getpgid, pid_t, pid) 1187 { 1188 return do_getpgid(pid); 1189 } 1190 1191 #ifdef __ARCH_WANT_SYS_GETPGRP 1192 1193 SYSCALL_DEFINE0(getpgrp) 1194 { 1195 return do_getpgid(0); 1196 } 1197 1198 #endif 1199 1200 SYSCALL_DEFINE1(getsid, pid_t, pid) 1201 { 1202 struct task_struct *p; 1203 struct pid *sid; 1204 int retval; 1205 1206 rcu_read_lock(); 1207 if (!pid) 1208 sid = task_session(current); 1209 else { 1210 retval = -ESRCH; 1211 p = find_task_by_vpid(pid); 1212 if (!p) 1213 goto out; 1214 sid = task_session(p); 1215 if (!sid) 1216 goto out; 1217 1218 retval = security_task_getsid(p); 1219 if (retval) 1220 goto out; 1221 } 1222 retval = pid_vnr(sid); 1223 out: 1224 rcu_read_unlock(); 1225 return retval; 1226 } 1227 1228 static void set_special_pids(struct pid **pids, struct pid *pid) 1229 { 1230 struct task_struct *curr = current->group_leader; 1231 1232 if (task_session(curr) != pid) 1233 change_pid(pids, curr, PIDTYPE_SID, pid); 1234 1235 if (task_pgrp(curr) != pid) 1236 change_pid(pids, curr, PIDTYPE_PGID, pid); 1237 } 1238 1239 int ksys_setsid(void) 1240 { 1241 struct task_struct *group_leader = current->group_leader; 1242 struct pid *sid = task_pid(group_leader); 1243 struct pid *pids[PIDTYPE_MAX] = { 0 }; 1244 pid_t session = pid_vnr(sid); 1245 int err = -EPERM; 1246 1247 write_lock_irq(&tasklist_lock); 1248 /* Fail if I am already a session leader */ 1249 if (group_leader->signal->leader) 1250 goto out; 1251 1252 /* Fail if a process group id already exists that equals the 1253 * proposed session id. 1254 */ 1255 if (pid_task(sid, PIDTYPE_PGID)) 1256 goto out; 1257 1258 group_leader->signal->leader = 1; 1259 set_special_pids(pids, sid); 1260 1261 proc_clear_tty(group_leader); 1262 1263 err = session; 1264 out: 1265 write_unlock_irq(&tasklist_lock); 1266 free_pids(pids); 1267 if (err > 0) { 1268 proc_sid_connector(group_leader); 1269 sched_autogroup_create_attach(group_leader); 1270 } 1271 return err; 1272 } 1273 1274 SYSCALL_DEFINE0(setsid) 1275 { 1276 return ksys_setsid(); 1277 } 1278 1279 DECLARE_RWSEM(uts_sem); 1280 1281 #ifdef COMPAT_UTS_MACHINE 1282 #define override_architecture(name) \ 1283 (personality(current->personality) == PER_LINUX32 && \ 1284 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \ 1285 sizeof(COMPAT_UTS_MACHINE))) 1286 #else 1287 #define override_architecture(name) 0 1288 #endif 1289 1290 /* 1291 * Work around broken programs that cannot handle "Linux 3.0". 1292 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40 1293 * And we map 4.x and later versions to 2.6.60+x, so 4.0/5.0/6.0/... would be 1294 * 2.6.60. 1295 */ 1296 static int override_release(char __user *release, size_t len) 1297 { 1298 int ret = 0; 1299 1300 if (current->personality & UNAME26) { 1301 const char *rest = UTS_RELEASE; 1302 char buf[65] = { 0 }; 1303 int ndots = 0; 1304 unsigned v; 1305 size_t copy; 1306 1307 while (*rest) { 1308 if (*rest == '.' && ++ndots >= 3) 1309 break; 1310 if (!isdigit(*rest) && *rest != '.') 1311 break; 1312 rest++; 1313 } 1314 v = LINUX_VERSION_PATCHLEVEL + 60; 1315 copy = clamp_t(size_t, len, 1, sizeof(buf)); 1316 copy = scnprintf(buf, copy, "2.6.%u%s", v, rest); 1317 ret = copy_to_user(release, buf, copy + 1); 1318 } 1319 return ret; 1320 } 1321 1322 SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name) 1323 { 1324 struct new_utsname tmp; 1325 1326 down_read(&uts_sem); 1327 memcpy(&tmp, utsname(), sizeof(tmp)); 1328 up_read(&uts_sem); 1329 if (copy_to_user(name, &tmp, sizeof(tmp))) 1330 return -EFAULT; 1331 1332 if (override_release(name->release, sizeof(name->release))) 1333 return -EFAULT; 1334 if (override_architecture(name)) 1335 return -EFAULT; 1336 return 0; 1337 } 1338 1339 #ifdef __ARCH_WANT_SYS_OLD_UNAME 1340 /* 1341 * Old cruft 1342 */ 1343 SYSCALL_DEFINE1(uname, struct old_utsname __user *, name) 1344 { 1345 struct old_utsname tmp; 1346 1347 if (!name) 1348 return -EFAULT; 1349 1350 down_read(&uts_sem); 1351 memcpy(&tmp, utsname(), sizeof(tmp)); 1352 up_read(&uts_sem); 1353 if (copy_to_user(name, &tmp, sizeof(tmp))) 1354 return -EFAULT; 1355 1356 if (override_release(name->release, sizeof(name->release))) 1357 return -EFAULT; 1358 if (override_architecture(name)) 1359 return -EFAULT; 1360 return 0; 1361 } 1362 1363 SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name) 1364 { 1365 struct oldold_utsname tmp; 1366 1367 if (!name) 1368 return -EFAULT; 1369 1370 memset(&tmp, 0, sizeof(tmp)); 1371 1372 down_read(&uts_sem); 1373 memcpy(&tmp.sysname, &utsname()->sysname, __OLD_UTS_LEN); 1374 memcpy(&tmp.nodename, &utsname()->nodename, __OLD_UTS_LEN); 1375 memcpy(&tmp.release, &utsname()->release, __OLD_UTS_LEN); 1376 memcpy(&tmp.version, &utsname()->version, __OLD_UTS_LEN); 1377 memcpy(&tmp.machine, &utsname()->machine, __OLD_UTS_LEN); 1378 up_read(&uts_sem); 1379 if (copy_to_user(name, &tmp, sizeof(tmp))) 1380 return -EFAULT; 1381 1382 if (override_architecture(name)) 1383 return -EFAULT; 1384 if (override_release(name->release, sizeof(name->release))) 1385 return -EFAULT; 1386 return 0; 1387 } 1388 #endif 1389 1390 SYSCALL_DEFINE2(sethostname, char __user *, name, int, len) 1391 { 1392 int errno; 1393 char tmp[__NEW_UTS_LEN]; 1394 1395 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) 1396 return -EPERM; 1397 1398 if (len < 0 || len > __NEW_UTS_LEN) 1399 return -EINVAL; 1400 errno = -EFAULT; 1401 if (!copy_from_user(tmp, name, len)) { 1402 struct new_utsname *u; 1403 1404 add_device_randomness(tmp, len); 1405 down_write(&uts_sem); 1406 u = utsname(); 1407 memcpy(u->nodename, tmp, len); 1408 memset(u->nodename + len, 0, sizeof(u->nodename) - len); 1409 errno = 0; 1410 uts_proc_notify(UTS_PROC_HOSTNAME); 1411 up_write(&uts_sem); 1412 } 1413 return errno; 1414 } 1415 1416 #ifdef __ARCH_WANT_SYS_GETHOSTNAME 1417 1418 SYSCALL_DEFINE2(gethostname, char __user *, name, int, len) 1419 { 1420 int i; 1421 struct new_utsname *u; 1422 char tmp[__NEW_UTS_LEN + 1]; 1423 1424 if (len < 0) 1425 return -EINVAL; 1426 down_read(&uts_sem); 1427 u = utsname(); 1428 i = 1 + strlen(u->nodename); 1429 if (i > len) 1430 i = len; 1431 memcpy(tmp, u->nodename, i); 1432 up_read(&uts_sem); 1433 if (copy_to_user(name, tmp, i)) 1434 return -EFAULT; 1435 return 0; 1436 } 1437 1438 #endif 1439 1440 /* 1441 * Only setdomainname; getdomainname can be implemented by calling 1442 * uname() 1443 */ 1444 SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len) 1445 { 1446 int errno; 1447 char tmp[__NEW_UTS_LEN]; 1448 1449 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) 1450 return -EPERM; 1451 if (len < 0 || len > __NEW_UTS_LEN) 1452 return -EINVAL; 1453 1454 errno = -EFAULT; 1455 if (!copy_from_user(tmp, name, len)) { 1456 struct new_utsname *u; 1457 1458 add_device_randomness(tmp, len); 1459 down_write(&uts_sem); 1460 u = utsname(); 1461 memcpy(u->domainname, tmp, len); 1462 memset(u->domainname + len, 0, sizeof(u->domainname) - len); 1463 errno = 0; 1464 uts_proc_notify(UTS_PROC_DOMAINNAME); 1465 up_write(&uts_sem); 1466 } 1467 return errno; 1468 } 1469 1470 /* make sure you are allowed to change @tsk limits before calling this */ 1471 static int do_prlimit(struct task_struct *tsk, unsigned int resource, 1472 struct rlimit *new_rlim, struct rlimit *old_rlim) 1473 { 1474 struct rlimit *rlim; 1475 int retval = 0; 1476 1477 if (resource >= RLIM_NLIMITS) 1478 return -EINVAL; 1479 resource = array_index_nospec(resource, RLIM_NLIMITS); 1480 1481 if (new_rlim) { 1482 if (new_rlim->rlim_cur > new_rlim->rlim_max) 1483 return -EINVAL; 1484 if (resource == RLIMIT_NOFILE && 1485 new_rlim->rlim_max > sysctl_nr_open) 1486 return -EPERM; 1487 } 1488 1489 /* Holding a refcount on tsk protects tsk->signal from disappearing. */ 1490 rlim = tsk->signal->rlim + resource; 1491 task_lock(tsk->group_leader); 1492 if (new_rlim) { 1493 /* 1494 * Keep the capable check against init_user_ns until cgroups can 1495 * contain all limits. 1496 */ 1497 if (new_rlim->rlim_max > rlim->rlim_max && 1498 !capable(CAP_SYS_RESOURCE)) 1499 retval = -EPERM; 1500 if (!retval) 1501 retval = security_task_setrlimit(tsk, resource, new_rlim); 1502 } 1503 if (!retval) { 1504 if (old_rlim) 1505 *old_rlim = *rlim; 1506 if (new_rlim) 1507 *rlim = *new_rlim; 1508 } 1509 task_unlock(tsk->group_leader); 1510 1511 /* 1512 * RLIMIT_CPU handling. Arm the posix CPU timer if the limit is not 1513 * infinite. In case of RLIM_INFINITY the posix CPU timer code 1514 * ignores the rlimit. 1515 */ 1516 if (!retval && new_rlim && resource == RLIMIT_CPU && 1517 new_rlim->rlim_cur != RLIM_INFINITY && 1518 IS_ENABLED(CONFIG_POSIX_TIMERS)) { 1519 /* 1520 * update_rlimit_cpu can fail if the task is exiting, but there 1521 * may be other tasks in the thread group that are not exiting, 1522 * and they need their cpu timers adjusted. 1523 * 1524 * The group_leader is the last task to be released, so if we 1525 * cannot update_rlimit_cpu on it, then the entire process is 1526 * exiting and we do not need to update at all. 1527 */ 1528 update_rlimit_cpu(tsk->group_leader, new_rlim->rlim_cur); 1529 } 1530 1531 return retval; 1532 } 1533 1534 SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim) 1535 { 1536 struct rlimit value; 1537 int ret; 1538 1539 ret = do_prlimit(current, resource, NULL, &value); 1540 if (!ret) 1541 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0; 1542 1543 return ret; 1544 } 1545 1546 #ifdef CONFIG_COMPAT 1547 1548 COMPAT_SYSCALL_DEFINE2(setrlimit, unsigned int, resource, 1549 struct compat_rlimit __user *, rlim) 1550 { 1551 struct rlimit r; 1552 struct compat_rlimit r32; 1553 1554 if (copy_from_user(&r32, rlim, sizeof(struct compat_rlimit))) 1555 return -EFAULT; 1556 1557 if (r32.rlim_cur == COMPAT_RLIM_INFINITY) 1558 r.rlim_cur = RLIM_INFINITY; 1559 else 1560 r.rlim_cur = r32.rlim_cur; 1561 if (r32.rlim_max == COMPAT_RLIM_INFINITY) 1562 r.rlim_max = RLIM_INFINITY; 1563 else 1564 r.rlim_max = r32.rlim_max; 1565 return do_prlimit(current, resource, &r, NULL); 1566 } 1567 1568 COMPAT_SYSCALL_DEFINE2(getrlimit, unsigned int, resource, 1569 struct compat_rlimit __user *, rlim) 1570 { 1571 struct rlimit r; 1572 int ret; 1573 1574 ret = do_prlimit(current, resource, NULL, &r); 1575 if (!ret) { 1576 struct compat_rlimit r32; 1577 if (r.rlim_cur > COMPAT_RLIM_INFINITY) 1578 r32.rlim_cur = COMPAT_RLIM_INFINITY; 1579 else 1580 r32.rlim_cur = r.rlim_cur; 1581 if (r.rlim_max > COMPAT_RLIM_INFINITY) 1582 r32.rlim_max = COMPAT_RLIM_INFINITY; 1583 else 1584 r32.rlim_max = r.rlim_max; 1585 1586 if (copy_to_user(rlim, &r32, sizeof(struct compat_rlimit))) 1587 return -EFAULT; 1588 } 1589 return ret; 1590 } 1591 1592 #endif 1593 1594 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT 1595 1596 /* 1597 * Back compatibility for getrlimit. Needed for some apps. 1598 */ 1599 SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource, 1600 struct rlimit __user *, rlim) 1601 { 1602 struct rlimit x; 1603 if (resource >= RLIM_NLIMITS) 1604 return -EINVAL; 1605 1606 resource = array_index_nospec(resource, RLIM_NLIMITS); 1607 task_lock(current->group_leader); 1608 x = current->signal->rlim[resource]; 1609 task_unlock(current->group_leader); 1610 if (x.rlim_cur > 0x7FFFFFFF) 1611 x.rlim_cur = 0x7FFFFFFF; 1612 if (x.rlim_max > 0x7FFFFFFF) 1613 x.rlim_max = 0x7FFFFFFF; 1614 return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0; 1615 } 1616 1617 #ifdef CONFIG_COMPAT 1618 COMPAT_SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource, 1619 struct compat_rlimit __user *, rlim) 1620 { 1621 struct rlimit r; 1622 1623 if (resource >= RLIM_NLIMITS) 1624 return -EINVAL; 1625 1626 resource = array_index_nospec(resource, RLIM_NLIMITS); 1627 task_lock(current->group_leader); 1628 r = current->signal->rlim[resource]; 1629 task_unlock(current->group_leader); 1630 if (r.rlim_cur > 0x7FFFFFFF) 1631 r.rlim_cur = 0x7FFFFFFF; 1632 if (r.rlim_max > 0x7FFFFFFF) 1633 r.rlim_max = 0x7FFFFFFF; 1634 1635 if (put_user(r.rlim_cur, &rlim->rlim_cur) || 1636 put_user(r.rlim_max, &rlim->rlim_max)) 1637 return -EFAULT; 1638 return 0; 1639 } 1640 #endif 1641 1642 #endif 1643 1644 static inline bool rlim64_is_infinity(__u64 rlim64) 1645 { 1646 #if BITS_PER_LONG < 64 1647 return rlim64 >= ULONG_MAX; 1648 #else 1649 return rlim64 == RLIM64_INFINITY; 1650 #endif 1651 } 1652 1653 static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64) 1654 { 1655 if (rlim->rlim_cur == RLIM_INFINITY) 1656 rlim64->rlim_cur = RLIM64_INFINITY; 1657 else 1658 rlim64->rlim_cur = rlim->rlim_cur; 1659 if (rlim->rlim_max == RLIM_INFINITY) 1660 rlim64->rlim_max = RLIM64_INFINITY; 1661 else 1662 rlim64->rlim_max = rlim->rlim_max; 1663 } 1664 1665 static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim) 1666 { 1667 if (rlim64_is_infinity(rlim64->rlim_cur)) 1668 rlim->rlim_cur = RLIM_INFINITY; 1669 else 1670 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur; 1671 if (rlim64_is_infinity(rlim64->rlim_max)) 1672 rlim->rlim_max = RLIM_INFINITY; 1673 else 1674 rlim->rlim_max = (unsigned long)rlim64->rlim_max; 1675 } 1676 1677 /* rcu lock must be held */ 1678 static int check_prlimit_permission(struct task_struct *task, 1679 unsigned int flags) 1680 { 1681 const struct cred *cred = current_cred(), *tcred; 1682 bool id_match; 1683 1684 if (current == task) 1685 return 0; 1686 1687 tcred = __task_cred(task); 1688 id_match = (uid_eq(cred->uid, tcred->euid) && 1689 uid_eq(cred->uid, tcred->suid) && 1690 uid_eq(cred->uid, tcred->uid) && 1691 gid_eq(cred->gid, tcred->egid) && 1692 gid_eq(cred->gid, tcred->sgid) && 1693 gid_eq(cred->gid, tcred->gid)); 1694 if (!id_match && !ns_capable(tcred->user_ns, CAP_SYS_RESOURCE)) 1695 return -EPERM; 1696 1697 return security_task_prlimit(cred, tcred, flags); 1698 } 1699 1700 SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource, 1701 const struct rlimit64 __user *, new_rlim, 1702 struct rlimit64 __user *, old_rlim) 1703 { 1704 struct rlimit64 old64, new64; 1705 struct rlimit old, new; 1706 struct task_struct *tsk; 1707 unsigned int checkflags = 0; 1708 int ret; 1709 1710 if (old_rlim) 1711 checkflags |= LSM_PRLIMIT_READ; 1712 1713 if (new_rlim) { 1714 if (copy_from_user(&new64, new_rlim, sizeof(new64))) 1715 return -EFAULT; 1716 rlim64_to_rlim(&new64, &new); 1717 checkflags |= LSM_PRLIMIT_WRITE; 1718 } 1719 1720 rcu_read_lock(); 1721 tsk = pid ? find_task_by_vpid(pid) : current; 1722 if (!tsk) { 1723 rcu_read_unlock(); 1724 return -ESRCH; 1725 } 1726 ret = check_prlimit_permission(tsk, checkflags); 1727 if (ret) { 1728 rcu_read_unlock(); 1729 return ret; 1730 } 1731 get_task_struct(tsk); 1732 rcu_read_unlock(); 1733 1734 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL, 1735 old_rlim ? &old : NULL); 1736 1737 if (!ret && old_rlim) { 1738 rlim_to_rlim64(&old, &old64); 1739 if (copy_to_user(old_rlim, &old64, sizeof(old64))) 1740 ret = -EFAULT; 1741 } 1742 1743 put_task_struct(tsk); 1744 return ret; 1745 } 1746 1747 SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim) 1748 { 1749 struct rlimit new_rlim; 1750 1751 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim))) 1752 return -EFAULT; 1753 return do_prlimit(current, resource, &new_rlim, NULL); 1754 } 1755 1756 /* 1757 * It would make sense to put struct rusage in the task_struct, 1758 * except that would make the task_struct be *really big*. After 1759 * task_struct gets moved into malloc'ed memory, it would 1760 * make sense to do this. It will make moving the rest of the information 1761 * a lot simpler! (Which we're not doing right now because we're not 1762 * measuring them yet). 1763 * 1764 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have 1765 * races with threads incrementing their own counters. But since word 1766 * reads are atomic, we either get new values or old values and we don't 1767 * care which for the sums. We always take the siglock to protect reading 1768 * the c* fields from p->signal from races with exit.c updating those 1769 * fields when reaping, so a sample either gets all the additions of a 1770 * given child after it's reaped, or none so this sample is before reaping. 1771 * 1772 * Locking: 1773 * We need to take the siglock for CHILDEREN, SELF and BOTH 1774 * for the cases current multithreaded, non-current single threaded 1775 * non-current multithreaded. Thread traversal is now safe with 1776 * the siglock held. 1777 * Strictly speaking, we donot need to take the siglock if we are current and 1778 * single threaded, as no one else can take our signal_struct away, no one 1779 * else can reap the children to update signal->c* counters, and no one else 1780 * can race with the signal-> fields. If we do not take any lock, the 1781 * signal-> fields could be read out of order while another thread was just 1782 * exiting. So we should place a read memory barrier when we avoid the lock. 1783 * On the writer side, write memory barrier is implied in __exit_signal 1784 * as __exit_signal releases the siglock spinlock after updating the signal-> 1785 * fields. But we don't do this yet to keep things simple. 1786 * 1787 */ 1788 1789 static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r) 1790 { 1791 r->ru_nvcsw += t->nvcsw; 1792 r->ru_nivcsw += t->nivcsw; 1793 r->ru_minflt += t->min_flt; 1794 r->ru_majflt += t->maj_flt; 1795 r->ru_inblock += task_io_get_inblock(t); 1796 r->ru_oublock += task_io_get_oublock(t); 1797 } 1798 1799 void getrusage(struct task_struct *p, int who, struct rusage *r) 1800 { 1801 struct task_struct *t; 1802 unsigned long flags; 1803 u64 tgutime, tgstime, utime, stime; 1804 unsigned long maxrss; 1805 struct mm_struct *mm; 1806 struct signal_struct *sig = p->signal; 1807 unsigned int seq = 0; 1808 1809 retry: 1810 memset(r, 0, sizeof(*r)); 1811 utime = stime = 0; 1812 maxrss = 0; 1813 1814 if (who == RUSAGE_THREAD) { 1815 task_cputime_adjusted(current, &utime, &stime); 1816 accumulate_thread_rusage(p, r); 1817 maxrss = sig->maxrss; 1818 goto out_thread; 1819 } 1820 1821 flags = read_seqbegin_or_lock_irqsave(&sig->stats_lock, &seq); 1822 1823 switch (who) { 1824 case RUSAGE_BOTH: 1825 case RUSAGE_CHILDREN: 1826 utime = sig->cutime; 1827 stime = sig->cstime; 1828 r->ru_nvcsw = sig->cnvcsw; 1829 r->ru_nivcsw = sig->cnivcsw; 1830 r->ru_minflt = sig->cmin_flt; 1831 r->ru_majflt = sig->cmaj_flt; 1832 r->ru_inblock = sig->cinblock; 1833 r->ru_oublock = sig->coublock; 1834 maxrss = sig->cmaxrss; 1835 1836 if (who == RUSAGE_CHILDREN) 1837 break; 1838 fallthrough; 1839 1840 case RUSAGE_SELF: 1841 r->ru_nvcsw += sig->nvcsw; 1842 r->ru_nivcsw += sig->nivcsw; 1843 r->ru_minflt += sig->min_flt; 1844 r->ru_majflt += sig->maj_flt; 1845 r->ru_inblock += sig->inblock; 1846 r->ru_oublock += sig->oublock; 1847 if (maxrss < sig->maxrss) 1848 maxrss = sig->maxrss; 1849 1850 rcu_read_lock(); 1851 __for_each_thread(sig, t) 1852 accumulate_thread_rusage(t, r); 1853 rcu_read_unlock(); 1854 1855 break; 1856 1857 default: 1858 BUG(); 1859 } 1860 1861 if (need_seqretry(&sig->stats_lock, seq)) { 1862 seq = 1; 1863 goto retry; 1864 } 1865 done_seqretry_irqrestore(&sig->stats_lock, seq, flags); 1866 1867 if (who == RUSAGE_CHILDREN) 1868 goto out_children; 1869 1870 thread_group_cputime_adjusted(p, &tgutime, &tgstime); 1871 utime += tgutime; 1872 stime += tgstime; 1873 1874 out_thread: 1875 mm = get_task_mm(p); 1876 if (mm) { 1877 setmax_mm_hiwater_rss(&maxrss, mm); 1878 mmput(mm); 1879 } 1880 1881 out_children: 1882 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ 1883 r->ru_utime = ns_to_kernel_old_timeval(utime); 1884 r->ru_stime = ns_to_kernel_old_timeval(stime); 1885 } 1886 1887 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru) 1888 { 1889 struct rusage r; 1890 1891 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && 1892 who != RUSAGE_THREAD) 1893 return -EINVAL; 1894 1895 getrusage(current, who, &r); 1896 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0; 1897 } 1898 1899 #ifdef CONFIG_COMPAT 1900 COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru) 1901 { 1902 struct rusage r; 1903 1904 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && 1905 who != RUSAGE_THREAD) 1906 return -EINVAL; 1907 1908 getrusage(current, who, &r); 1909 return put_compat_rusage(&r, ru); 1910 } 1911 #endif 1912 1913 SYSCALL_DEFINE1(umask, int, mask) 1914 { 1915 mask = xchg(¤t->fs->umask, mask & S_IRWXUGO); 1916 return mask; 1917 } 1918 1919 static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd) 1920 { 1921 CLASS(fd, exe)(fd); 1922 struct inode *inode; 1923 int err; 1924 1925 if (fd_empty(exe)) 1926 return -EBADF; 1927 1928 inode = file_inode(fd_file(exe)); 1929 1930 /* 1931 * Because the original mm->exe_file points to executable file, make 1932 * sure that this one is executable as well, to avoid breaking an 1933 * overall picture. 1934 */ 1935 if (!S_ISREG(inode->i_mode) || path_noexec(&fd_file(exe)->f_path)) 1936 return -EACCES; 1937 1938 err = file_permission(fd_file(exe), MAY_EXEC); 1939 if (err) 1940 return err; 1941 1942 return replace_mm_exe_file(mm, fd_file(exe)); 1943 } 1944 1945 /* 1946 * Check arithmetic relations of passed addresses. 1947 * 1948 * WARNING: we don't require any capability here so be very careful 1949 * in what is allowed for modification from userspace. 1950 */ 1951 static int validate_prctl_map_addr(struct prctl_mm_map *prctl_map) 1952 { 1953 unsigned long mmap_max_addr = TASK_SIZE; 1954 int error = -EINVAL, i; 1955 1956 static const unsigned char offsets[] = { 1957 offsetof(struct prctl_mm_map, start_code), 1958 offsetof(struct prctl_mm_map, end_code), 1959 offsetof(struct prctl_mm_map, start_data), 1960 offsetof(struct prctl_mm_map, end_data), 1961 offsetof(struct prctl_mm_map, start_brk), 1962 offsetof(struct prctl_mm_map, brk), 1963 offsetof(struct prctl_mm_map, start_stack), 1964 offsetof(struct prctl_mm_map, arg_start), 1965 offsetof(struct prctl_mm_map, arg_end), 1966 offsetof(struct prctl_mm_map, env_start), 1967 offsetof(struct prctl_mm_map, env_end), 1968 }; 1969 1970 /* 1971 * Make sure the members are not somewhere outside 1972 * of allowed address space. 1973 */ 1974 for (i = 0; i < ARRAY_SIZE(offsets); i++) { 1975 u64 val = *(u64 *)((char *)prctl_map + offsets[i]); 1976 1977 if ((unsigned long)val >= mmap_max_addr || 1978 (unsigned long)val < mmap_min_addr) 1979 goto out; 1980 } 1981 1982 /* 1983 * Make sure the pairs are ordered. 1984 */ 1985 #define __prctl_check_order(__m1, __op, __m2) \ 1986 ((unsigned long)prctl_map->__m1 __op \ 1987 (unsigned long)prctl_map->__m2) ? 0 : -EINVAL 1988 error = __prctl_check_order(start_code, <, end_code); 1989 error |= __prctl_check_order(start_data,<=, end_data); 1990 error |= __prctl_check_order(start_brk, <=, brk); 1991 error |= __prctl_check_order(arg_start, <=, arg_end); 1992 error |= __prctl_check_order(env_start, <=, env_end); 1993 if (error) 1994 goto out; 1995 #undef __prctl_check_order 1996 1997 error = -EINVAL; 1998 1999 /* 2000 * Neither we should allow to override limits if they set. 2001 */ 2002 if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk, 2003 prctl_map->start_brk, prctl_map->end_data, 2004 prctl_map->start_data)) 2005 goto out; 2006 2007 error = 0; 2008 out: 2009 return error; 2010 } 2011 2012 #ifdef CONFIG_CHECKPOINT_RESTORE 2013 static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size) 2014 { 2015 struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, }; 2016 unsigned long user_auxv[AT_VECTOR_SIZE]; 2017 struct mm_struct *mm = current->mm; 2018 int error; 2019 2020 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv)); 2021 BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256); 2022 2023 if (opt == PR_SET_MM_MAP_SIZE) 2024 return put_user((unsigned int)sizeof(prctl_map), 2025 (unsigned int __user *)addr); 2026 2027 if (data_size != sizeof(prctl_map)) 2028 return -EINVAL; 2029 2030 if (copy_from_user(&prctl_map, addr, sizeof(prctl_map))) 2031 return -EFAULT; 2032 2033 error = validate_prctl_map_addr(&prctl_map); 2034 if (error) 2035 return error; 2036 2037 if (prctl_map.auxv_size) { 2038 /* 2039 * Someone is trying to cheat the auxv vector. 2040 */ 2041 if (!prctl_map.auxv || 2042 prctl_map.auxv_size > sizeof(mm->saved_auxv)) 2043 return -EINVAL; 2044 2045 memset(user_auxv, 0, sizeof(user_auxv)); 2046 if (copy_from_user(user_auxv, 2047 (const void __user *)prctl_map.auxv, 2048 prctl_map.auxv_size)) 2049 return -EFAULT; 2050 2051 /* Last entry must be AT_NULL as specification requires */ 2052 user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL; 2053 user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL; 2054 } 2055 2056 if (prctl_map.exe_fd != (u32)-1) { 2057 /* 2058 * Check if the current user is checkpoint/restore capable. 2059 * At the time of this writing, it checks for CAP_SYS_ADMIN 2060 * or CAP_CHECKPOINT_RESTORE. 2061 * Note that a user with access to ptrace can masquerade an 2062 * arbitrary program as any executable, even setuid ones. 2063 * This may have implications in the tomoyo subsystem. 2064 */ 2065 if (!checkpoint_restore_ns_capable(current_user_ns())) 2066 return -EPERM; 2067 2068 error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd); 2069 if (error) 2070 return error; 2071 } 2072 2073 /* 2074 * arg_lock protects concurrent updates but we still need mmap_lock for 2075 * read to exclude races with sys_brk. 2076 */ 2077 mmap_read_lock(mm); 2078 2079 /* 2080 * We don't validate if these members are pointing to 2081 * real present VMAs because application may have correspond 2082 * VMAs already unmapped and kernel uses these members for statistics 2083 * output in procfs mostly, except 2084 * 2085 * - @start_brk/@brk which are used in do_brk_flags but kernel lookups 2086 * for VMAs when updating these members so anything wrong written 2087 * here cause kernel to swear at userspace program but won't lead 2088 * to any problem in kernel itself 2089 */ 2090 2091 spin_lock(&mm->arg_lock); 2092 mm->start_code = prctl_map.start_code; 2093 mm->end_code = prctl_map.end_code; 2094 mm->start_data = prctl_map.start_data; 2095 mm->end_data = prctl_map.end_data; 2096 mm->start_brk = prctl_map.start_brk; 2097 mm->brk = prctl_map.brk; 2098 mm->start_stack = prctl_map.start_stack; 2099 mm->arg_start = prctl_map.arg_start; 2100 mm->arg_end = prctl_map.arg_end; 2101 mm->env_start = prctl_map.env_start; 2102 mm->env_end = prctl_map.env_end; 2103 spin_unlock(&mm->arg_lock); 2104 2105 /* 2106 * Note this update of @saved_auxv is lockless thus 2107 * if someone reads this member in procfs while we're 2108 * updating -- it may get partly updated results. It's 2109 * known and acceptable trade off: we leave it as is to 2110 * not introduce additional locks here making the kernel 2111 * more complex. 2112 */ 2113 if (prctl_map.auxv_size) 2114 memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv)); 2115 2116 mmap_read_unlock(mm); 2117 return 0; 2118 } 2119 #endif /* CONFIG_CHECKPOINT_RESTORE */ 2120 2121 static int prctl_set_auxv(struct mm_struct *mm, unsigned long addr, 2122 unsigned long len) 2123 { 2124 /* 2125 * This doesn't move the auxiliary vector itself since it's pinned to 2126 * mm_struct, but it permits filling the vector with new values. It's 2127 * up to the caller to provide sane values here, otherwise userspace 2128 * tools which use this vector might be unhappy. 2129 */ 2130 unsigned long user_auxv[AT_VECTOR_SIZE] = {}; 2131 2132 if (len > sizeof(user_auxv)) 2133 return -EINVAL; 2134 2135 if (copy_from_user(user_auxv, (const void __user *)addr, len)) 2136 return -EFAULT; 2137 2138 /* Make sure the last entry is always AT_NULL */ 2139 user_auxv[AT_VECTOR_SIZE - 2] = 0; 2140 user_auxv[AT_VECTOR_SIZE - 1] = 0; 2141 2142 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv)); 2143 2144 task_lock(current); 2145 memcpy(mm->saved_auxv, user_auxv, len); 2146 task_unlock(current); 2147 2148 return 0; 2149 } 2150 2151 static int prctl_set_mm(int opt, unsigned long addr, 2152 unsigned long arg4, unsigned long arg5) 2153 { 2154 struct mm_struct *mm = current->mm; 2155 struct prctl_mm_map prctl_map = { 2156 .auxv = NULL, 2157 .auxv_size = 0, 2158 .exe_fd = -1, 2159 }; 2160 struct vm_area_struct *vma; 2161 int error; 2162 2163 if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV && 2164 opt != PR_SET_MM_MAP && 2165 opt != PR_SET_MM_MAP_SIZE))) 2166 return -EINVAL; 2167 2168 #ifdef CONFIG_CHECKPOINT_RESTORE 2169 if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE) 2170 return prctl_set_mm_map(opt, (const void __user *)addr, arg4); 2171 #endif 2172 2173 if (!capable(CAP_SYS_RESOURCE)) 2174 return -EPERM; 2175 2176 if (opt == PR_SET_MM_EXE_FILE) 2177 return prctl_set_mm_exe_file(mm, (unsigned int)addr); 2178 2179 if (opt == PR_SET_MM_AUXV) 2180 return prctl_set_auxv(mm, addr, arg4); 2181 2182 if (addr >= TASK_SIZE || addr < mmap_min_addr) 2183 return -EINVAL; 2184 2185 error = -EINVAL; 2186 2187 /* 2188 * arg_lock protects concurrent updates of arg boundaries, we need 2189 * mmap_lock for a) concurrent sys_brk, b) finding VMA for addr 2190 * validation. 2191 */ 2192 mmap_read_lock(mm); 2193 vma = find_vma(mm, addr); 2194 2195 spin_lock(&mm->arg_lock); 2196 prctl_map.start_code = mm->start_code; 2197 prctl_map.end_code = mm->end_code; 2198 prctl_map.start_data = mm->start_data; 2199 prctl_map.end_data = mm->end_data; 2200 prctl_map.start_brk = mm->start_brk; 2201 prctl_map.brk = mm->brk; 2202 prctl_map.start_stack = mm->start_stack; 2203 prctl_map.arg_start = mm->arg_start; 2204 prctl_map.arg_end = mm->arg_end; 2205 prctl_map.env_start = mm->env_start; 2206 prctl_map.env_end = mm->env_end; 2207 2208 switch (opt) { 2209 case PR_SET_MM_START_CODE: 2210 prctl_map.start_code = addr; 2211 break; 2212 case PR_SET_MM_END_CODE: 2213 prctl_map.end_code = addr; 2214 break; 2215 case PR_SET_MM_START_DATA: 2216 prctl_map.start_data = addr; 2217 break; 2218 case PR_SET_MM_END_DATA: 2219 prctl_map.end_data = addr; 2220 break; 2221 case PR_SET_MM_START_STACK: 2222 prctl_map.start_stack = addr; 2223 break; 2224 case PR_SET_MM_START_BRK: 2225 prctl_map.start_brk = addr; 2226 break; 2227 case PR_SET_MM_BRK: 2228 prctl_map.brk = addr; 2229 break; 2230 case PR_SET_MM_ARG_START: 2231 prctl_map.arg_start = addr; 2232 break; 2233 case PR_SET_MM_ARG_END: 2234 prctl_map.arg_end = addr; 2235 break; 2236 case PR_SET_MM_ENV_START: 2237 prctl_map.env_start = addr; 2238 break; 2239 case PR_SET_MM_ENV_END: 2240 prctl_map.env_end = addr; 2241 break; 2242 default: 2243 goto out; 2244 } 2245 2246 error = validate_prctl_map_addr(&prctl_map); 2247 if (error) 2248 goto out; 2249 2250 switch (opt) { 2251 /* 2252 * If command line arguments and environment 2253 * are placed somewhere else on stack, we can 2254 * set them up here, ARG_START/END to setup 2255 * command line arguments and ENV_START/END 2256 * for environment. 2257 */ 2258 case PR_SET_MM_START_STACK: 2259 case PR_SET_MM_ARG_START: 2260 case PR_SET_MM_ARG_END: 2261 case PR_SET_MM_ENV_START: 2262 case PR_SET_MM_ENV_END: 2263 if (!vma) { 2264 error = -EFAULT; 2265 goto out; 2266 } 2267 } 2268 2269 mm->start_code = prctl_map.start_code; 2270 mm->end_code = prctl_map.end_code; 2271 mm->start_data = prctl_map.start_data; 2272 mm->end_data = prctl_map.end_data; 2273 mm->start_brk = prctl_map.start_brk; 2274 mm->brk = prctl_map.brk; 2275 mm->start_stack = prctl_map.start_stack; 2276 mm->arg_start = prctl_map.arg_start; 2277 mm->arg_end = prctl_map.arg_end; 2278 mm->env_start = prctl_map.env_start; 2279 mm->env_end = prctl_map.env_end; 2280 2281 error = 0; 2282 out: 2283 spin_unlock(&mm->arg_lock); 2284 mmap_read_unlock(mm); 2285 return error; 2286 } 2287 2288 #ifdef CONFIG_CHECKPOINT_RESTORE 2289 static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr) 2290 { 2291 return put_user(me->clear_child_tid, tid_addr); 2292 } 2293 #else 2294 static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr) 2295 { 2296 return -EINVAL; 2297 } 2298 #endif 2299 2300 static int propagate_has_child_subreaper(struct task_struct *p, void *data) 2301 { 2302 /* 2303 * If task has has_child_subreaper - all its descendants 2304 * already have these flag too and new descendants will 2305 * inherit it on fork, skip them. 2306 * 2307 * If we've found child_reaper - skip descendants in 2308 * it's subtree as they will never get out pidns. 2309 */ 2310 if (p->signal->has_child_subreaper || 2311 is_child_reaper(task_pid(p))) 2312 return 0; 2313 2314 p->signal->has_child_subreaper = 1; 2315 return 1; 2316 } 2317 2318 int __weak arch_prctl_spec_ctrl_get(struct task_struct *t, unsigned long which) 2319 { 2320 return -EINVAL; 2321 } 2322 2323 int __weak arch_prctl_spec_ctrl_set(struct task_struct *t, unsigned long which, 2324 unsigned long ctrl) 2325 { 2326 return -EINVAL; 2327 } 2328 2329 int __weak arch_get_shadow_stack_status(struct task_struct *t, unsigned long __user *status) 2330 { 2331 return -EINVAL; 2332 } 2333 2334 int __weak arch_set_shadow_stack_status(struct task_struct *t, unsigned long status) 2335 { 2336 return -EINVAL; 2337 } 2338 2339 int __weak arch_lock_shadow_stack_status(struct task_struct *t, unsigned long status) 2340 { 2341 return -EINVAL; 2342 } 2343 2344 #define PR_IO_FLUSHER (PF_MEMALLOC_NOIO | PF_LOCAL_THROTTLE) 2345 2346 #ifdef CONFIG_ANON_VMA_NAME 2347 2348 #define ANON_VMA_NAME_MAX_LEN 80 2349 #define ANON_VMA_NAME_INVALID_CHARS "\\`$[]" 2350 2351 static inline bool is_valid_name_char(char ch) 2352 { 2353 /* printable ascii characters, excluding ANON_VMA_NAME_INVALID_CHARS */ 2354 return ch > 0x1f && ch < 0x7f && 2355 !strchr(ANON_VMA_NAME_INVALID_CHARS, ch); 2356 } 2357 2358 static int prctl_set_vma(unsigned long opt, unsigned long addr, 2359 unsigned long size, unsigned long arg) 2360 { 2361 struct mm_struct *mm = current->mm; 2362 const char __user *uname; 2363 struct anon_vma_name *anon_name = NULL; 2364 int error; 2365 2366 switch (opt) { 2367 case PR_SET_VMA_ANON_NAME: 2368 uname = (const char __user *)arg; 2369 if (uname) { 2370 char *name, *pch; 2371 2372 name = strndup_user(uname, ANON_VMA_NAME_MAX_LEN); 2373 if (IS_ERR(name)) 2374 return PTR_ERR(name); 2375 2376 for (pch = name; *pch != '\0'; pch++) { 2377 if (!is_valid_name_char(*pch)) { 2378 kfree(name); 2379 return -EINVAL; 2380 } 2381 } 2382 /* anon_vma has its own copy */ 2383 anon_name = anon_vma_name_alloc(name); 2384 kfree(name); 2385 if (!anon_name) 2386 return -ENOMEM; 2387 2388 } 2389 2390 mmap_write_lock(mm); 2391 error = madvise_set_anon_name(mm, addr, size, anon_name); 2392 mmap_write_unlock(mm); 2393 anon_vma_name_put(anon_name); 2394 break; 2395 default: 2396 error = -EINVAL; 2397 } 2398 2399 return error; 2400 } 2401 2402 #else /* CONFIG_ANON_VMA_NAME */ 2403 static int prctl_set_vma(unsigned long opt, unsigned long start, 2404 unsigned long size, unsigned long arg) 2405 { 2406 return -EINVAL; 2407 } 2408 #endif /* CONFIG_ANON_VMA_NAME */ 2409 2410 static inline unsigned long get_current_mdwe(void) 2411 { 2412 unsigned long ret = 0; 2413 2414 if (test_bit(MMF_HAS_MDWE, ¤t->mm->flags)) 2415 ret |= PR_MDWE_REFUSE_EXEC_GAIN; 2416 if (test_bit(MMF_HAS_MDWE_NO_INHERIT, ¤t->mm->flags)) 2417 ret |= PR_MDWE_NO_INHERIT; 2418 2419 return ret; 2420 } 2421 2422 static inline int prctl_set_mdwe(unsigned long bits, unsigned long arg3, 2423 unsigned long arg4, unsigned long arg5) 2424 { 2425 unsigned long current_bits; 2426 2427 if (arg3 || arg4 || arg5) 2428 return -EINVAL; 2429 2430 if (bits & ~(PR_MDWE_REFUSE_EXEC_GAIN | PR_MDWE_NO_INHERIT)) 2431 return -EINVAL; 2432 2433 /* NO_INHERIT only makes sense with REFUSE_EXEC_GAIN */ 2434 if (bits & PR_MDWE_NO_INHERIT && !(bits & PR_MDWE_REFUSE_EXEC_GAIN)) 2435 return -EINVAL; 2436 2437 /* 2438 * EOPNOTSUPP might be more appropriate here in principle, but 2439 * existing userspace depends on EINVAL specifically. 2440 */ 2441 if (!arch_memory_deny_write_exec_supported()) 2442 return -EINVAL; 2443 2444 current_bits = get_current_mdwe(); 2445 if (current_bits && current_bits != bits) 2446 return -EPERM; /* Cannot unset the flags */ 2447 2448 if (bits & PR_MDWE_NO_INHERIT) 2449 set_bit(MMF_HAS_MDWE_NO_INHERIT, ¤t->mm->flags); 2450 if (bits & PR_MDWE_REFUSE_EXEC_GAIN) 2451 set_bit(MMF_HAS_MDWE, ¤t->mm->flags); 2452 2453 return 0; 2454 } 2455 2456 static inline int prctl_get_mdwe(unsigned long arg2, unsigned long arg3, 2457 unsigned long arg4, unsigned long arg5) 2458 { 2459 if (arg2 || arg3 || arg4 || arg5) 2460 return -EINVAL; 2461 return get_current_mdwe(); 2462 } 2463 2464 static int prctl_get_auxv(void __user *addr, unsigned long len) 2465 { 2466 struct mm_struct *mm = current->mm; 2467 unsigned long size = min_t(unsigned long, sizeof(mm->saved_auxv), len); 2468 2469 if (size && copy_to_user(addr, mm->saved_auxv, size)) 2470 return -EFAULT; 2471 return sizeof(mm->saved_auxv); 2472 } 2473 2474 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, 2475 unsigned long, arg4, unsigned long, arg5) 2476 { 2477 struct task_struct *me = current; 2478 unsigned char comm[sizeof(me->comm)]; 2479 long error; 2480 2481 error = security_task_prctl(option, arg2, arg3, arg4, arg5); 2482 if (error != -ENOSYS) 2483 return error; 2484 2485 error = 0; 2486 switch (option) { 2487 case PR_SET_PDEATHSIG: 2488 if (!valid_signal(arg2)) { 2489 error = -EINVAL; 2490 break; 2491 } 2492 me->pdeath_signal = arg2; 2493 break; 2494 case PR_GET_PDEATHSIG: 2495 error = put_user(me->pdeath_signal, (int __user *)arg2); 2496 break; 2497 case PR_GET_DUMPABLE: 2498 error = get_dumpable(me->mm); 2499 break; 2500 case PR_SET_DUMPABLE: 2501 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) { 2502 error = -EINVAL; 2503 break; 2504 } 2505 set_dumpable(me->mm, arg2); 2506 break; 2507 2508 case PR_SET_UNALIGN: 2509 error = SET_UNALIGN_CTL(me, arg2); 2510 break; 2511 case PR_GET_UNALIGN: 2512 error = GET_UNALIGN_CTL(me, arg2); 2513 break; 2514 case PR_SET_FPEMU: 2515 error = SET_FPEMU_CTL(me, arg2); 2516 break; 2517 case PR_GET_FPEMU: 2518 error = GET_FPEMU_CTL(me, arg2); 2519 break; 2520 case PR_SET_FPEXC: 2521 error = SET_FPEXC_CTL(me, arg2); 2522 break; 2523 case PR_GET_FPEXC: 2524 error = GET_FPEXC_CTL(me, arg2); 2525 break; 2526 case PR_GET_TIMING: 2527 error = PR_TIMING_STATISTICAL; 2528 break; 2529 case PR_SET_TIMING: 2530 if (arg2 != PR_TIMING_STATISTICAL) 2531 error = -EINVAL; 2532 break; 2533 case PR_SET_NAME: 2534 comm[sizeof(me->comm) - 1] = 0; 2535 if (strncpy_from_user(comm, (char __user *)arg2, 2536 sizeof(me->comm) - 1) < 0) 2537 return -EFAULT; 2538 set_task_comm(me, comm); 2539 proc_comm_connector(me); 2540 break; 2541 case PR_GET_NAME: 2542 get_task_comm(comm, me); 2543 if (copy_to_user((char __user *)arg2, comm, sizeof(comm))) 2544 return -EFAULT; 2545 break; 2546 case PR_GET_ENDIAN: 2547 error = GET_ENDIAN(me, arg2); 2548 break; 2549 case PR_SET_ENDIAN: 2550 error = SET_ENDIAN(me, arg2); 2551 break; 2552 case PR_GET_SECCOMP: 2553 error = prctl_get_seccomp(); 2554 break; 2555 case PR_SET_SECCOMP: 2556 error = prctl_set_seccomp(arg2, (char __user *)arg3); 2557 break; 2558 case PR_GET_TSC: 2559 error = GET_TSC_CTL(arg2); 2560 break; 2561 case PR_SET_TSC: 2562 error = SET_TSC_CTL(arg2); 2563 break; 2564 case PR_TASK_PERF_EVENTS_DISABLE: 2565 error = perf_event_task_disable(); 2566 break; 2567 case PR_TASK_PERF_EVENTS_ENABLE: 2568 error = perf_event_task_enable(); 2569 break; 2570 case PR_GET_TIMERSLACK: 2571 if (current->timer_slack_ns > ULONG_MAX) 2572 error = ULONG_MAX; 2573 else 2574 error = current->timer_slack_ns; 2575 break; 2576 case PR_SET_TIMERSLACK: 2577 if (rt_or_dl_task_policy(current)) 2578 break; 2579 if (arg2 <= 0) 2580 current->timer_slack_ns = 2581 current->default_timer_slack_ns; 2582 else 2583 current->timer_slack_ns = arg2; 2584 break; 2585 case PR_MCE_KILL: 2586 if (arg4 | arg5) 2587 return -EINVAL; 2588 switch (arg2) { 2589 case PR_MCE_KILL_CLEAR: 2590 if (arg3 != 0) 2591 return -EINVAL; 2592 current->flags &= ~PF_MCE_PROCESS; 2593 break; 2594 case PR_MCE_KILL_SET: 2595 current->flags |= PF_MCE_PROCESS; 2596 if (arg3 == PR_MCE_KILL_EARLY) 2597 current->flags |= PF_MCE_EARLY; 2598 else if (arg3 == PR_MCE_KILL_LATE) 2599 current->flags &= ~PF_MCE_EARLY; 2600 else if (arg3 == PR_MCE_KILL_DEFAULT) 2601 current->flags &= 2602 ~(PF_MCE_EARLY|PF_MCE_PROCESS); 2603 else 2604 return -EINVAL; 2605 break; 2606 default: 2607 return -EINVAL; 2608 } 2609 break; 2610 case PR_MCE_KILL_GET: 2611 if (arg2 | arg3 | arg4 | arg5) 2612 return -EINVAL; 2613 if (current->flags & PF_MCE_PROCESS) 2614 error = (current->flags & PF_MCE_EARLY) ? 2615 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE; 2616 else 2617 error = PR_MCE_KILL_DEFAULT; 2618 break; 2619 case PR_SET_MM: 2620 error = prctl_set_mm(arg2, arg3, arg4, arg5); 2621 break; 2622 case PR_GET_TID_ADDRESS: 2623 error = prctl_get_tid_address(me, (int __user * __user *)arg2); 2624 break; 2625 case PR_SET_CHILD_SUBREAPER: 2626 me->signal->is_child_subreaper = !!arg2; 2627 if (!arg2) 2628 break; 2629 2630 walk_process_tree(me, propagate_has_child_subreaper, NULL); 2631 break; 2632 case PR_GET_CHILD_SUBREAPER: 2633 error = put_user(me->signal->is_child_subreaper, 2634 (int __user *)arg2); 2635 break; 2636 case PR_SET_NO_NEW_PRIVS: 2637 if (arg2 != 1 || arg3 || arg4 || arg5) 2638 return -EINVAL; 2639 2640 task_set_no_new_privs(current); 2641 break; 2642 case PR_GET_NO_NEW_PRIVS: 2643 if (arg2 || arg3 || arg4 || arg5) 2644 return -EINVAL; 2645 return task_no_new_privs(current) ? 1 : 0; 2646 case PR_GET_THP_DISABLE: 2647 if (arg2 || arg3 || arg4 || arg5) 2648 return -EINVAL; 2649 error = !!test_bit(MMF_DISABLE_THP, &me->mm->flags); 2650 break; 2651 case PR_SET_THP_DISABLE: 2652 if (arg3 || arg4 || arg5) 2653 return -EINVAL; 2654 if (mmap_write_lock_killable(me->mm)) 2655 return -EINTR; 2656 if (arg2) 2657 set_bit(MMF_DISABLE_THP, &me->mm->flags); 2658 else 2659 clear_bit(MMF_DISABLE_THP, &me->mm->flags); 2660 mmap_write_unlock(me->mm); 2661 break; 2662 case PR_MPX_ENABLE_MANAGEMENT: 2663 case PR_MPX_DISABLE_MANAGEMENT: 2664 /* No longer implemented: */ 2665 return -EINVAL; 2666 case PR_SET_FP_MODE: 2667 error = SET_FP_MODE(me, arg2); 2668 break; 2669 case PR_GET_FP_MODE: 2670 error = GET_FP_MODE(me); 2671 break; 2672 case PR_SVE_SET_VL: 2673 error = SVE_SET_VL(arg2); 2674 break; 2675 case PR_SVE_GET_VL: 2676 error = SVE_GET_VL(); 2677 break; 2678 case PR_SME_SET_VL: 2679 error = SME_SET_VL(arg2); 2680 break; 2681 case PR_SME_GET_VL: 2682 error = SME_GET_VL(); 2683 break; 2684 case PR_GET_SPECULATION_CTRL: 2685 if (arg3 || arg4 || arg5) 2686 return -EINVAL; 2687 error = arch_prctl_spec_ctrl_get(me, arg2); 2688 break; 2689 case PR_SET_SPECULATION_CTRL: 2690 if (arg4 || arg5) 2691 return -EINVAL; 2692 error = arch_prctl_spec_ctrl_set(me, arg2, arg3); 2693 break; 2694 case PR_PAC_RESET_KEYS: 2695 if (arg3 || arg4 || arg5) 2696 return -EINVAL; 2697 error = PAC_RESET_KEYS(me, arg2); 2698 break; 2699 case PR_PAC_SET_ENABLED_KEYS: 2700 if (arg4 || arg5) 2701 return -EINVAL; 2702 error = PAC_SET_ENABLED_KEYS(me, arg2, arg3); 2703 break; 2704 case PR_PAC_GET_ENABLED_KEYS: 2705 if (arg2 || arg3 || arg4 || arg5) 2706 return -EINVAL; 2707 error = PAC_GET_ENABLED_KEYS(me); 2708 break; 2709 case PR_SET_TAGGED_ADDR_CTRL: 2710 if (arg3 || arg4 || arg5) 2711 return -EINVAL; 2712 error = SET_TAGGED_ADDR_CTRL(arg2); 2713 break; 2714 case PR_GET_TAGGED_ADDR_CTRL: 2715 if (arg2 || arg3 || arg4 || arg5) 2716 return -EINVAL; 2717 error = GET_TAGGED_ADDR_CTRL(); 2718 break; 2719 case PR_SET_IO_FLUSHER: 2720 if (!capable(CAP_SYS_RESOURCE)) 2721 return -EPERM; 2722 2723 if (arg3 || arg4 || arg5) 2724 return -EINVAL; 2725 2726 if (arg2 == 1) 2727 current->flags |= PR_IO_FLUSHER; 2728 else if (!arg2) 2729 current->flags &= ~PR_IO_FLUSHER; 2730 else 2731 return -EINVAL; 2732 break; 2733 case PR_GET_IO_FLUSHER: 2734 if (!capable(CAP_SYS_RESOURCE)) 2735 return -EPERM; 2736 2737 if (arg2 || arg3 || arg4 || arg5) 2738 return -EINVAL; 2739 2740 error = (current->flags & PR_IO_FLUSHER) == PR_IO_FLUSHER; 2741 break; 2742 case PR_SET_SYSCALL_USER_DISPATCH: 2743 error = set_syscall_user_dispatch(arg2, arg3, arg4, 2744 (char __user *) arg5); 2745 break; 2746 #ifdef CONFIG_SCHED_CORE 2747 case PR_SCHED_CORE: 2748 error = sched_core_share_pid(arg2, arg3, arg4, arg5); 2749 break; 2750 #endif 2751 case PR_SET_MDWE: 2752 error = prctl_set_mdwe(arg2, arg3, arg4, arg5); 2753 break; 2754 case PR_GET_MDWE: 2755 error = prctl_get_mdwe(arg2, arg3, arg4, arg5); 2756 break; 2757 case PR_PPC_GET_DEXCR: 2758 if (arg3 || arg4 || arg5) 2759 return -EINVAL; 2760 error = PPC_GET_DEXCR_ASPECT(me, arg2); 2761 break; 2762 case PR_PPC_SET_DEXCR: 2763 if (arg4 || arg5) 2764 return -EINVAL; 2765 error = PPC_SET_DEXCR_ASPECT(me, arg2, arg3); 2766 break; 2767 case PR_SET_VMA: 2768 error = prctl_set_vma(arg2, arg3, arg4, arg5); 2769 break; 2770 case PR_GET_AUXV: 2771 if (arg4 || arg5) 2772 return -EINVAL; 2773 error = prctl_get_auxv((void __user *)arg2, arg3); 2774 break; 2775 #ifdef CONFIG_KSM 2776 case PR_SET_MEMORY_MERGE: 2777 if (arg3 || arg4 || arg5) 2778 return -EINVAL; 2779 if (mmap_write_lock_killable(me->mm)) 2780 return -EINTR; 2781 2782 if (arg2) 2783 error = ksm_enable_merge_any(me->mm); 2784 else 2785 error = ksm_disable_merge_any(me->mm); 2786 mmap_write_unlock(me->mm); 2787 break; 2788 case PR_GET_MEMORY_MERGE: 2789 if (arg2 || arg3 || arg4 || arg5) 2790 return -EINVAL; 2791 2792 error = !!test_bit(MMF_VM_MERGE_ANY, &me->mm->flags); 2793 break; 2794 #endif 2795 case PR_RISCV_V_SET_CONTROL: 2796 error = RISCV_V_SET_CONTROL(arg2); 2797 break; 2798 case PR_RISCV_V_GET_CONTROL: 2799 error = RISCV_V_GET_CONTROL(); 2800 break; 2801 case PR_RISCV_SET_ICACHE_FLUSH_CTX: 2802 error = RISCV_SET_ICACHE_FLUSH_CTX(arg2, arg3); 2803 break; 2804 case PR_GET_SHADOW_STACK_STATUS: 2805 if (arg3 || arg4 || arg5) 2806 return -EINVAL; 2807 error = arch_get_shadow_stack_status(me, (unsigned long __user *) arg2); 2808 break; 2809 case PR_SET_SHADOW_STACK_STATUS: 2810 if (arg3 || arg4 || arg5) 2811 return -EINVAL; 2812 error = arch_set_shadow_stack_status(me, arg2); 2813 break; 2814 case PR_LOCK_SHADOW_STACK_STATUS: 2815 if (arg3 || arg4 || arg5) 2816 return -EINVAL; 2817 error = arch_lock_shadow_stack_status(me, arg2); 2818 break; 2819 case PR_TIMER_CREATE_RESTORE_IDS: 2820 if (arg3 || arg4 || arg5) 2821 return -EINVAL; 2822 error = posixtimer_create_prctl(arg2); 2823 break; 2824 case PR_FUTEX_HASH: 2825 error = futex_hash_prctl(arg2, arg3, arg4); 2826 break; 2827 default: 2828 trace_task_prctl_unknown(option, arg2, arg3, arg4, arg5); 2829 error = -EINVAL; 2830 break; 2831 } 2832 return error; 2833 } 2834 2835 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep, 2836 struct getcpu_cache __user *, unused) 2837 { 2838 int err = 0; 2839 int cpu = raw_smp_processor_id(); 2840 2841 if (cpup) 2842 err |= put_user(cpu, cpup); 2843 if (nodep) 2844 err |= put_user(cpu_to_node(cpu), nodep); 2845 return err ? -EFAULT : 0; 2846 } 2847 2848 /** 2849 * do_sysinfo - fill in sysinfo struct 2850 * @info: pointer to buffer to fill 2851 */ 2852 static int do_sysinfo(struct sysinfo *info) 2853 { 2854 unsigned long mem_total, sav_total; 2855 unsigned int mem_unit, bitcount; 2856 struct timespec64 tp; 2857 2858 memset(info, 0, sizeof(struct sysinfo)); 2859 2860 ktime_get_boottime_ts64(&tp); 2861 timens_add_boottime(&tp); 2862 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0); 2863 2864 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT); 2865 2866 info->procs = nr_threads; 2867 2868 si_meminfo(info); 2869 si_swapinfo(info); 2870 2871 /* 2872 * If the sum of all the available memory (i.e. ram + swap) 2873 * is less than can be stored in a 32 bit unsigned long then 2874 * we can be binary compatible with 2.2.x kernels. If not, 2875 * well, in that case 2.2.x was broken anyways... 2876 * 2877 * -Erik Andersen <andersee@debian.org> 2878 */ 2879 2880 mem_total = info->totalram + info->totalswap; 2881 if (mem_total < info->totalram || mem_total < info->totalswap) 2882 goto out; 2883 bitcount = 0; 2884 mem_unit = info->mem_unit; 2885 while (mem_unit > 1) { 2886 bitcount++; 2887 mem_unit >>= 1; 2888 sav_total = mem_total; 2889 mem_total <<= 1; 2890 if (mem_total < sav_total) 2891 goto out; 2892 } 2893 2894 /* 2895 * If mem_total did not overflow, multiply all memory values by 2896 * info->mem_unit and set it to 1. This leaves things compatible 2897 * with 2.2.x, and also retains compatibility with earlier 2.4.x 2898 * kernels... 2899 */ 2900 2901 info->mem_unit = 1; 2902 info->totalram <<= bitcount; 2903 info->freeram <<= bitcount; 2904 info->sharedram <<= bitcount; 2905 info->bufferram <<= bitcount; 2906 info->totalswap <<= bitcount; 2907 info->freeswap <<= bitcount; 2908 info->totalhigh <<= bitcount; 2909 info->freehigh <<= bitcount; 2910 2911 out: 2912 return 0; 2913 } 2914 2915 SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info) 2916 { 2917 struct sysinfo val; 2918 2919 do_sysinfo(&val); 2920 2921 if (copy_to_user(info, &val, sizeof(struct sysinfo))) 2922 return -EFAULT; 2923 2924 return 0; 2925 } 2926 2927 #ifdef CONFIG_COMPAT 2928 struct compat_sysinfo { 2929 s32 uptime; 2930 u32 loads[3]; 2931 u32 totalram; 2932 u32 freeram; 2933 u32 sharedram; 2934 u32 bufferram; 2935 u32 totalswap; 2936 u32 freeswap; 2937 u16 procs; 2938 u16 pad; 2939 u32 totalhigh; 2940 u32 freehigh; 2941 u32 mem_unit; 2942 char _f[20-2*sizeof(u32)-sizeof(int)]; 2943 }; 2944 2945 COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info) 2946 { 2947 struct sysinfo s; 2948 struct compat_sysinfo s_32; 2949 2950 do_sysinfo(&s); 2951 2952 /* Check to see if any memory value is too large for 32-bit and scale 2953 * down if needed 2954 */ 2955 if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) { 2956 int bitcount = 0; 2957 2958 while (s.mem_unit < PAGE_SIZE) { 2959 s.mem_unit <<= 1; 2960 bitcount++; 2961 } 2962 2963 s.totalram >>= bitcount; 2964 s.freeram >>= bitcount; 2965 s.sharedram >>= bitcount; 2966 s.bufferram >>= bitcount; 2967 s.totalswap >>= bitcount; 2968 s.freeswap >>= bitcount; 2969 s.totalhigh >>= bitcount; 2970 s.freehigh >>= bitcount; 2971 } 2972 2973 memset(&s_32, 0, sizeof(s_32)); 2974 s_32.uptime = s.uptime; 2975 s_32.loads[0] = s.loads[0]; 2976 s_32.loads[1] = s.loads[1]; 2977 s_32.loads[2] = s.loads[2]; 2978 s_32.totalram = s.totalram; 2979 s_32.freeram = s.freeram; 2980 s_32.sharedram = s.sharedram; 2981 s_32.bufferram = s.bufferram; 2982 s_32.totalswap = s.totalswap; 2983 s_32.freeswap = s.freeswap; 2984 s_32.procs = s.procs; 2985 s_32.totalhigh = s.totalhigh; 2986 s_32.freehigh = s.freehigh; 2987 s_32.mem_unit = s.mem_unit; 2988 if (copy_to_user(info, &s_32, sizeof(s_32))) 2989 return -EFAULT; 2990 return 0; 2991 } 2992 #endif /* CONFIG_COMPAT */ 2993