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io_uring: complete request via task work in case of DEFER_TASKRUN
[linux-block.git] / kernel / sys.c
CommitLineData
b2441318 1// SPDX-License-Identifier: GPL-2.0
1da177e4
LT		 2/*
3 * linux/kernel/sys.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 */
7
9984de1a 8#include <linux/export.h>
1da177e4 9#include <linux/mm.h>
5c26f6ac 10#include <linux/mm_inline.h>
1da177e4
LT		 11#include <linux/utsname.h>
12#include <linux/mman.h>
1da177e4
LT		 13#include <linux/reboot.h>
14#include <linux/prctl.h>
1da177e4
LT		 15#include <linux/highuid.h>
16#include <linux/fs.h>
74da1ff7 17#include <linux/kmod.h>
cdd6c482 18#include <linux/perf_event.h>
3e88c553 19#include <linux/resource.h>
dc009d92 20#include <linux/kernel.h>
1da177e4 21#include <linux/workqueue.h>
c59ede7b 22#include <linux/capability.h>
1da177e4
LT		 23#include <linux/device.h>
24#include <linux/key.h>
25#include <linux/times.h>
26#include <linux/posix-timers.h>
27#include <linux/security.h>
37608ba3 28#include <linux/random.h>
1da177e4
LT		 29#include <linux/suspend.h>
30#include <linux/tty.h>
7ed20e1a 31#include <linux/signal.h>
9f46080c 32#include <linux/cn_proc.h>
3cfc348b 33#include <linux/getcpu.h>
6eaeeaba 34#include <linux/task_io_accounting_ops.h>
1d9d02fe 35#include <linux/seccomp.h>
4047727e 36#include <linux/cpu.h>
e28cbf22 37#include <linux/personality.h>
e3d5a27d 38#include <linux/ptrace.h>
5ad4e53b 39#include <linux/fs_struct.h>
b32dfe37
CG		 40#include <linux/file.h>
41#include <linux/mount.h>
5a0e3ad6 42#include <linux/gfp.h>
40dc166c 43#include <linux/syscore_ops.h>
be27425d
AK		 44#include <linux/version.h>
45#include <linux/ctype.h>
1446e1df 46#include <linux/syscall_user_dispatch.h>
1da177e4
LT		 47
48#include <linux/compat.h>
49#include <linux/syscalls.h>
00d7c05a 50#include <linux/kprobes.h>
acce292c 51#include <linux/user_namespace.h>
ecc421e0 52#include <linux/time_namespace.h>
7fe5e042 53#include <linux/binfmts.h>
1da177e4 54
4a22f166 55#include <linux/sched.h>
4eb5aaa3 56#include <linux/sched/autogroup.h>
4f17722c 57#include <linux/sched/loadavg.h>
03441a34 58#include <linux/sched/stat.h>
6e84f315 59#include <linux/sched/mm.h>
f7ccbae4 60#include <linux/sched/coredump.h>
29930025 61#include <linux/sched/task.h>
32ef5517 62#include <linux/sched/cputime.h>
4a22f166
SR		 63#include <linux/rcupdate.h>
64#include <linux/uidgid.h>
65#include <linux/cred.h>
66
b617cfc8
TG		 67#include <linux/nospec.h>
68
04c6862c 69#include <linux/kmsg_dump.h>
be27425d
AK		 70/* Move somewhere else to avoid recompiling? */
71#include <generated/utsrelease.h>
04c6862c 72
7c0f6ba6 73#include <linux/uaccess.h>
1da177e4
LT		 74#include <asm/io.h>
75#include <asm/unistd.h>
76
e530dca5
DB		 77#include "uid16.h"
78
1da177e4 79#ifndef SET_UNALIGN_CTL
ec94fc3d 80# define SET_UNALIGN_CTL(a, b) (-EINVAL)
1da177e4
LT		 81#endif
82#ifndef GET_UNALIGN_CTL
ec94fc3d 83# define GET_UNALIGN_CTL(a, b) (-EINVAL)
1da177e4
LT		 84#endif
85#ifndef SET_FPEMU_CTL
ec94fc3d 86# define SET_FPEMU_CTL(a, b) (-EINVAL)
1da177e4
LT		 87#endif
88#ifndef GET_FPEMU_CTL
ec94fc3d 89# define GET_FPEMU_CTL(a, b) (-EINVAL)
1da177e4
LT		 90#endif
91#ifndef SET_FPEXC_CTL
ec94fc3d 92# define SET_FPEXC_CTL(a, b) (-EINVAL)
1da177e4
LT		 93#endif
94#ifndef GET_FPEXC_CTL
ec94fc3d 95# define GET_FPEXC_CTL(a, b) (-EINVAL)
1da177e4 96#endif
651d765d 97#ifndef GET_ENDIAN
ec94fc3d 98# define GET_ENDIAN(a, b) (-EINVAL)
651d765d
AB		 99#endif
100#ifndef SET_ENDIAN
ec94fc3d 101# define SET_ENDIAN(a, b) (-EINVAL)
651d765d 102#endif
8fb402bc
EB		 103#ifndef GET_TSC_CTL
104# define GET_TSC_CTL(a) (-EINVAL)
105#endif
106#ifndef SET_TSC_CTL
107# define SET_TSC_CTL(a) (-EINVAL)
108#endif
9791554b
PB		 109#ifndef GET_FP_MODE
110# define GET_FP_MODE(a) (-EINVAL)
111#endif
112#ifndef SET_FP_MODE
113# define SET_FP_MODE(a,b) (-EINVAL)
114#endif
2d2123bc
DM		 115#ifndef SVE_SET_VL
116# define SVE_SET_VL(a) (-EINVAL)
117#endif
118#ifndef SVE_GET_VL
119# define SVE_GET_VL() (-EINVAL)
120#endif
9e4ab6c8
MB		 121#ifndef SME_SET_VL
122# define SME_SET_VL(a) (-EINVAL)
123#endif
124#ifndef SME_GET_VL
125# define SME_GET_VL() (-EINVAL)
126#endif
ba830885
KM		 127#ifndef PAC_RESET_KEYS
128# define PAC_RESET_KEYS(a, b) (-EINVAL)
129#endif
20169862
PC		 130#ifndef PAC_SET_ENABLED_KEYS
131# define PAC_SET_ENABLED_KEYS(a, b, c) (-EINVAL)
132#endif
133#ifndef PAC_GET_ENABLED_KEYS
134# define PAC_GET_ENABLED_KEYS(a) (-EINVAL)
135#endif
63f0c603
CM		 136#ifndef SET_TAGGED_ADDR_CTRL
137# define SET_TAGGED_ADDR_CTRL(a) (-EINVAL)
138#endif
139#ifndef GET_TAGGED_ADDR_CTRL
140# define GET_TAGGED_ADDR_CTRL() (-EINVAL)
141#endif
1da177e4
LT		 142
143/*
144 * this is where the system-wide overflow UID and GID are defined, for
145 * architectures that now have 32-bit UID/GID but didn't in the past
146 */
147
148int overflowuid = DEFAULT_OVERFLOWUID;
149int overflowgid = DEFAULT_OVERFLOWGID;
150
1da177e4
LT		 151EXPORT_SYMBOL(overflowuid);
152EXPORT_SYMBOL(overflowgid);
1da177e4
LT		 153
154/*
155 * the same as above, but for filesystems which can only store a 16-bit
156 * UID and GID. as such, this is needed on all architectures
157 */
158
159int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
8b2770a4 160int fs_overflowgid = DEFAULT_FS_OVERFLOWGID;
1da177e4
LT		 161
162EXPORT_SYMBOL(fs_overflowuid);
163EXPORT_SYMBOL(fs_overflowgid);
164
fc832ad3
SH		 165/*
166 * Returns true if current's euid is same as p's uid or euid,
167 * or has CAP_SYS_NICE to p's user_ns.
168 *
169 * Called with rcu_read_lock, creds are safe
170 */
171static bool set_one_prio_perm(struct task_struct *p)
172{
173 const struct cred *cred = current_cred(), *pcred = __task_cred(p);
174
5af66203
EB		 175 if (uid_eq(pcred->uid, cred->euid) ||
176 uid_eq(pcred->euid, cred->euid))
fc832ad3 177 return true;
c4a4d603 178 if (ns_capable(pcred->user_ns, CAP_SYS_NICE))
fc832ad3
SH		 179 return true;
180 return false;
181}
182
c69e8d9c
DH		 183/*
184 * set the priority of a task
185 * - the caller must hold the RCU read lock
186 */
1da177e4
LT		 187static int set_one_prio(struct task_struct *p, int niceval, int error)
188{
189 int no_nice;
190
fc832ad3 191 if (!set_one_prio_perm(p)) {
1da177e4
LT		 192 error = -EPERM;
193 goto out;
194 }
e43379f1 195 if (niceval < task_nice(p) && !can_nice(p, niceval)) {
1da177e4
LT		 196 error = -EACCES;
197 goto out;
198 }
199 no_nice = security_task_setnice(p, niceval);
200 if (no_nice) {
201 error = no_nice;
202 goto out;
203 }
204 if (error == -ESRCH)
205 error = 0;
206 set_user_nice(p, niceval);
207out:
208 return error;
209}
210
754fe8d2 211SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
1da177e4
LT		 212{
213 struct task_struct *g, *p;
214 struct user_struct *user;
86a264ab 215 const struct cred *cred = current_cred();
1da177e4 216 int error = -EINVAL;
41487c65 217 struct pid *pgrp;
7b44ab97 218 kuid_t uid;
1da177e4 219
3e88c553 220 if (which > PRIO_USER || which < PRIO_PROCESS)
1da177e4
LT		 221 goto out;
222
223 /* normalize: avoid signed division (rounding problems) */
224 error = -ESRCH;
c4a4d2f4
DY		 225 if (niceval < MIN_NICE)
226 niceval = MIN_NICE;
227 if (niceval > MAX_NICE)
228 niceval = MAX_NICE;
1da177e4 229
d4581a23 230 rcu_read_lock();
1da177e4 231 switch (which) {
ec94fc3d 232 case PRIO_PROCESS:
233 if (who)
234 p = find_task_by_vpid(who);
235 else
236 p = current;
237 if (p)
238 error = set_one_prio(p, niceval, error);
239 break;
240 case PRIO_PGRP:
241 if (who)
242 pgrp = find_vpid(who);
243 else
244 pgrp = task_pgrp(current);
7f8ca0ed 245 read_lock(&tasklist_lock);
ec94fc3d 246 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
247 error = set_one_prio(p, niceval, error);
248 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
7f8ca0ed 249 read_unlock(&tasklist_lock);
ec94fc3d 250 break;
251 case PRIO_USER:
252 uid = make_kuid(cred->user_ns, who);
253 user = cred->user;
254 if (!who)
255 uid = cred->uid;
256 else if (!uid_eq(uid, cred->uid)) {
257 user = find_user(uid);
258 if (!user)
86a264ab 259 goto out_unlock; /* No processes for this user */
ec94fc3d 260 }
7f8ca0ed 261 for_each_process_thread(g, p) {
8639b461 262 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p))
ec94fc3d 263 error = set_one_prio(p, niceval, error);
7f8ca0ed 264 }
ec94fc3d 265 if (!uid_eq(uid, cred->uid))
266 free_uid(user); /* For find_user() */
267 break;
1da177e4
LT		 268 }
269out_unlock:
d4581a23 270 rcu_read_unlock();
1da177e4
LT		 271out:
272 return error;
273}
274
275/*
276 * Ugh. To avoid negative return values, "getpriority()" will
277 * not return the normal nice-value, but a negated value that
278 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
279 * to stay compatible.
280 */
754fe8d2 281SYSCALL_DEFINE2(getpriority, int, which, int, who)
1da177e4
LT		 282{
283 struct task_struct *g, *p;
284 struct user_struct *user;
86a264ab 285 const struct cred *cred = current_cred();
1da177e4 286 long niceval, retval = -ESRCH;
41487c65 287 struct pid *pgrp;
7b44ab97 288 kuid_t uid;
1da177e4 289
3e88c553 290 if (which > PRIO_USER || which < PRIO_PROCESS)
1da177e4
LT		 291 return -EINVAL;
292
70118837 293 rcu_read_lock();
1da177e4 294 switch (which) {
ec94fc3d 295 case PRIO_PROCESS:
296 if (who)
297 p = find_task_by_vpid(who);
298 else
299 p = current;
300 if (p) {
301 niceval = nice_to_rlimit(task_nice(p));
302 if (niceval > retval)
303 retval = niceval;
304 }
305 break;
306 case PRIO_PGRP:
307 if (who)
308 pgrp = find_vpid(who);
309 else
310 pgrp = task_pgrp(current);
7f8ca0ed 311 read_lock(&tasklist_lock);
ec94fc3d 312 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
313 niceval = nice_to_rlimit(task_nice(p));
314 if (niceval > retval)
315 retval = niceval;
316 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
7f8ca0ed 317 read_unlock(&tasklist_lock);
ec94fc3d 318 break;
319 case PRIO_USER:
320 uid = make_kuid(cred->user_ns, who);
321 user = cred->user;
322 if (!who)
323 uid = cred->uid;
324 else if (!uid_eq(uid, cred->uid)) {
325 user = find_user(uid);
326 if (!user)
327 goto out_unlock; /* No processes for this user */
328 }
7f8ca0ed 329 for_each_process_thread(g, p) {
8639b461 330 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) {
7aa2c016 331 niceval = nice_to_rlimit(task_nice(p));
1da177e4
LT		 332 if (niceval > retval)
333 retval = niceval;
334 }
7f8ca0ed 335 }
ec94fc3d 336 if (!uid_eq(uid, cred->uid))
337 free_uid(user); /* for find_user() */
338 break;
1da177e4
LT		 339 }
340out_unlock:
70118837 341 rcu_read_unlock();
1da177e4
LT		 342
343 return retval;
344}
345
1da177e4
LT		 346/*
347 * Unprivileged users may change the real gid to the effective gid
348 * or vice versa. (BSD-style)
349 *
350 * If you set the real gid at all, or set the effective gid to a value not
351 * equal to the real gid, then the saved gid is set to the new effective gid.
352 *
353 * This makes it possible for a setgid program to completely drop its
354 * privileges, which is often a useful assertion to make when you are doing
355 * a security audit over a program.
356 *
357 * The general idea is that a program which uses just setregid() will be
358 * 100% compatible with BSD. A program which uses just setgid() will be
ec94fc3d 359 * 100% compatible with POSIX with saved IDs.
1da177e4
LT		 360 *
361 * SMP: There are not races, the GIDs are checked only by filesystem
362 * operations (as far as semantic preservation is concerned).
363 */
2813893f 364#ifdef CONFIG_MULTIUSER
e530dca5 365long __sys_setregid(gid_t rgid, gid_t egid)
1da177e4 366{
a29c33f4 367 struct user_namespace *ns = current_user_ns();
d84f4f99
DH		 368 const struct cred *old;
369 struct cred *new;
1da177e4 370 int retval;
a29c33f4
EB		 371 kgid_t krgid, kegid;
372
373 krgid = make_kgid(ns, rgid);
374 kegid = make_kgid(ns, egid);
375
376 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
377 return -EINVAL;
378 if ((egid != (gid_t) -1) && !gid_valid(kegid))
379 return -EINVAL;
1da177e4 380
d84f4f99
DH		 381 new = prepare_creds();
382 if (!new)
383 return -ENOMEM;
384 old = current_cred();
385
d84f4f99 386 retval = -EPERM;
1da177e4 387 if (rgid != (gid_t) -1) {
a29c33f4
EB		 388 if (gid_eq(old->gid, krgid) ||
389 gid_eq(old->egid, krgid) ||
111767c1 390 ns_capable_setid(old->user_ns, CAP_SETGID))
a29c33f4 391 new->gid = krgid;
1da177e4 392 else
d84f4f99 393 goto error;
1da177e4
LT		 394 }
395 if (egid != (gid_t) -1) {
a29c33f4
EB		 396 if (gid_eq(old->gid, kegid) ||
397 gid_eq(old->egid, kegid) ||
398 gid_eq(old->sgid, kegid) ||
111767c1 399 ns_capable_setid(old->user_ns, CAP_SETGID))
a29c33f4 400 new->egid = kegid;
756184b7 401 else
d84f4f99 402 goto error;
1da177e4 403 }
d84f4f99 404
1da177e4 405 if (rgid != (gid_t) -1 ||
a29c33f4 406 (egid != (gid_t) -1 && !gid_eq(kegid, old->gid)))
d84f4f99
DH		 407 new->sgid = new->egid;
408 new->fsgid = new->egid;
409
39030e13
TC		 410 retval = security_task_fix_setgid(new, old, LSM_SETID_RE);
411 if (retval < 0)
412 goto error;
413
d84f4f99
DH		 414 return commit_creds(new);
415
416error:
417 abort_creds(new);
418 return retval;
1da177e4
LT		 419}
420
e530dca5
DB		 421SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
422{
423 return __sys_setregid(rgid, egid);
424}
425
1da177e4 426/*
ec94fc3d 427 * setgid() is implemented like SysV w/ SAVED_IDS
1da177e4
LT		 428 *
429 * SMP: Same implicit races as above.
430 */
e530dca5 431long __sys_setgid(gid_t gid)
1da177e4 432{
a29c33f4 433 struct user_namespace *ns = current_user_ns();
d84f4f99
DH		 434 const struct cred *old;
435 struct cred *new;
1da177e4 436 int retval;
a29c33f4
EB		 437 kgid_t kgid;
438
439 kgid = make_kgid(ns, gid);
440 if (!gid_valid(kgid))
441 return -EINVAL;
1da177e4 442
d84f4f99
DH		 443 new = prepare_creds();
444 if (!new)
445 return -ENOMEM;
446 old = current_cred();
447
d84f4f99 448 retval = -EPERM;
111767c1 449 if (ns_capable_setid(old->user_ns, CAP_SETGID))
a29c33f4
EB		 450 new->gid = new->egid = new->sgid = new->fsgid = kgid;
451 else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid))
452 new->egid = new->fsgid = kgid;
1da177e4 453 else
d84f4f99 454 goto error;
1da177e4 455
39030e13
TC		 456 retval = security_task_fix_setgid(new, old, LSM_SETID_ID);
457 if (retval < 0)
458 goto error;
459
d84f4f99
DH		 460 return commit_creds(new);
461
462error:
463 abort_creds(new);
464 return retval;
1da177e4 465}
54e99124 466
e530dca5
DB		 467SYSCALL_DEFINE1(setgid, gid_t, gid)
468{
469 return __sys_setgid(gid);
470}
471
d84f4f99
DH		 472/*
473 * change the user struct in a credentials set to match the new UID
474 */
475static int set_user(struct cred *new)
1da177e4
LT		 476{
477 struct user_struct *new_user;
478
078de5f7 479 new_user = alloc_uid(new->uid);
1da177e4
LT		 480 if (!new_user)
481 return -EAGAIN;
482
c923a8e7
EB		 483 free_uid(new->user);
484 new->user = new_user;
485 return 0;
486}
487
488static void flag_nproc_exceeded(struct cred *new)
489{
490 if (new->ucounts == current_ucounts())
491 return;
492
72fa5997
VK		 493 /*
494 * We don't fail in case of NPROC limit excess here because too many
495 * poorly written programs don't check set*uid() return code, assuming
496 * it never fails if called by root. We may still enforce NPROC limit
497 * for programs doing set*uid()+execve() by harmlessly deferring the
498 * failure to the execve() stage.
499 */
de399236 500 if (is_rlimit_overlimit(new->ucounts, UCOUNT_RLIMIT_NPROC, rlimit(RLIMIT_NPROC)) &&
c923a8e7 501 new->user != INIT_USER)
72fa5997
VK		 502 current->flags |= PF_NPROC_EXCEEDED;
503 else
504 current->flags &= ~PF_NPROC_EXCEEDED;
1da177e4
LT		 505}
506
507/*
508 * Unprivileged users may change the real uid to the effective uid
509 * or vice versa. (BSD-style)
510 *
511 * If you set the real uid at all, or set the effective uid to a value not
512 * equal to the real uid, then the saved uid is set to the new effective uid.
513 *
514 * This makes it possible for a setuid program to completely drop its
515 * privileges, which is often a useful assertion to make when you are doing
516 * a security audit over a program.
517 *
518 * The general idea is that a program which uses just setreuid() will be
519 * 100% compatible with BSD. A program which uses just setuid() will be
ec94fc3d 520 * 100% compatible with POSIX with saved IDs.
1da177e4 521 */
e530dca5 522long __sys_setreuid(uid_t ruid, uid_t euid)
1da177e4 523{
a29c33f4 524 struct user_namespace *ns = current_user_ns();
d84f4f99
DH		 525 const struct cred *old;
526 struct cred *new;
1da177e4 527 int retval;
a29c33f4
EB		 528 kuid_t kruid, keuid;
529
530 kruid = make_kuid(ns, ruid);
531 keuid = make_kuid(ns, euid);
532
533 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
534 return -EINVAL;
535 if ((euid != (uid_t) -1) && !uid_valid(keuid))
536 return -EINVAL;
1da177e4 537
d84f4f99
DH		 538 new = prepare_creds();
539 if (!new)
540 return -ENOMEM;
541 old = current_cred();
542
d84f4f99 543 retval = -EPERM;
1da177e4 544 if (ruid != (uid_t) -1) {
a29c33f4
EB		 545 new->uid = kruid;
546 if (!uid_eq(old->uid, kruid) &&
547 !uid_eq(old->euid, kruid) &&
40852275 548 !ns_capable_setid(old->user_ns, CAP_SETUID))
d84f4f99 549 goto error;
1da177e4
LT		 550 }
551
552 if (euid != (uid_t) -1) {
a29c33f4
EB		 553 new->euid = keuid;
554 if (!uid_eq(old->uid, keuid) &&
555 !uid_eq(old->euid, keuid) &&
556 !uid_eq(old->suid, keuid) &&
40852275 557 !ns_capable_setid(old->user_ns, CAP_SETUID))
d84f4f99 558 goto error;
1da177e4
LT		 559 }
560
a29c33f4 561 if (!uid_eq(new->uid, old->uid)) {
54e99124
DG		 562 retval = set_user(new);
563 if (retval < 0)
564 goto error;
565 }
1da177e4 566 if (ruid != (uid_t) -1 ||
a29c33f4 567 (euid != (uid_t) -1 && !uid_eq(keuid, old->uid)))
d84f4f99
DH		 568 new->suid = new->euid;
569 new->fsuid = new->euid;
1da177e4 570
d84f4f99
DH		 571 retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
572 if (retval < 0)
573 goto error;
1da177e4 574
905ae01c
AG		 575 retval = set_cred_ucounts(new);
576 if (retval < 0)
577 goto error;
578
c923a8e7 579 flag_nproc_exceeded(new);
d84f4f99 580 return commit_creds(new);
1da177e4 581
d84f4f99
DH		 582error:
583 abort_creds(new);
584 return retval;
585}
ec94fc3d 586
e530dca5
DB		 587SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
588{
589 return __sys_setreuid(ruid, euid);
590}
591
1da177e4 592/*
ec94fc3d 593 * setuid() is implemented like SysV with SAVED_IDS
594 *
1da177e4 595 * Note that SAVED_ID's is deficient in that a setuid root program
ec94fc3d 596 * like sendmail, for example, cannot set its uid to be a normal
1da177e4
LT		 597 * user and then switch back, because if you're root, setuid() sets
598 * the saved uid too. If you don't like this, blame the bright people
599 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
600 * will allow a root program to temporarily drop privileges and be able to
ec94fc3d 601 * regain them by swapping the real and effective uid.
1da177e4 602 */
e530dca5 603long __sys_setuid(uid_t uid)
1da177e4 604{
a29c33f4 605 struct user_namespace *ns = current_user_ns();
d84f4f99
DH		 606 const struct cred *old;
607 struct cred *new;
1da177e4 608 int retval;
a29c33f4
EB		 609 kuid_t kuid;
610
611 kuid = make_kuid(ns, uid);
612 if (!uid_valid(kuid))
613 return -EINVAL;
1da177e4 614
d84f4f99
DH		 615 new = prepare_creds();
616 if (!new)
617 return -ENOMEM;
618 old = current_cred();
619
d84f4f99 620 retval = -EPERM;
40852275 621 if (ns_capable_setid(old->user_ns, CAP_SETUID)) {
a29c33f4
EB		 622 new->suid = new->uid = kuid;
623 if (!uid_eq(kuid, old->uid)) {
54e99124
DG		 624 retval = set_user(new);
625 if (retval < 0)
626 goto error;
d84f4f99 627 }
a29c33f4 628 } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) {
d84f4f99 629 goto error;
1da177e4 630 }
1da177e4 631
a29c33f4 632 new->fsuid = new->euid = kuid;
d84f4f99
DH		 633
634 retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
635 if (retval < 0)
636 goto error;
1da177e4 637
905ae01c
AG		 638 retval = set_cred_ucounts(new);
639 if (retval < 0)
640 goto error;
641
c923a8e7 642 flag_nproc_exceeded(new);
d84f4f99 643 return commit_creds(new);
1da177e4 644
d84f4f99
DH		 645error:
646 abort_creds(new);
647 return retval;
1da177e4
LT		 648}
649
e530dca5
DB		 650SYSCALL_DEFINE1(setuid, uid_t, uid)
651{
652 return __sys_setuid(uid);
653}
654
1da177e4
LT		 655
656/*
657 * This function implements a generic ability to update ruid, euid,
658 * and suid. This allows you to implement the 4.4 compatible seteuid().
659 */
e530dca5 660long __sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
1da177e4 661{
a29c33f4 662 struct user_namespace *ns = current_user_ns();
d84f4f99
DH		 663 const struct cred *old;
664 struct cred *new;
1da177e4 665 int retval;
a29c33f4
EB		 666 kuid_t kruid, keuid, ksuid;
667
668 kruid = make_kuid(ns, ruid);
669 keuid = make_kuid(ns, euid);
670 ksuid = make_kuid(ns, suid);
671
672 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
673 return -EINVAL;
674
675 if ((euid != (uid_t) -1) && !uid_valid(keuid))
676 return -EINVAL;
677
678 if ((suid != (uid_t) -1) && !uid_valid(ksuid))
679 return -EINVAL;
1da177e4 680
d84f4f99
DH		 681 new = prepare_creds();
682 if (!new)
683 return -ENOMEM;
684
d84f4f99 685 old = current_cred();
1da177e4 686
d84f4f99 687 retval = -EPERM;
40852275 688 if (!ns_capable_setid(old->user_ns, CAP_SETUID)) {
a29c33f4
EB		 689 if (ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) &&
690 !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid))
d84f4f99 691 goto error;
a29c33f4
EB		 692 if (euid != (uid_t) -1 && !uid_eq(keuid, old->uid) &&
693 !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid))
d84f4f99 694 goto error;
a29c33f4
EB		 695 if (suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) &&
696 !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid))
d84f4f99 697 goto error;
1da177e4 698 }
d84f4f99 699
1da177e4 700 if (ruid != (uid_t) -1) {
a29c33f4
EB		 701 new->uid = kruid;
702 if (!uid_eq(kruid, old->uid)) {
54e99124
DG		 703 retval = set_user(new);
704 if (retval < 0)
705 goto error;
706 }
1da177e4 707 }
d84f4f99 708 if (euid != (uid_t) -1)
a29c33f4 709 new->euid = keuid;
1da177e4 710 if (suid != (uid_t) -1)
a29c33f4 711 new->suid = ksuid;
d84f4f99 712 new->fsuid = new->euid;
1da177e4 713
d84f4f99
DH		 714 retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
715 if (retval < 0)
716 goto error;
1da177e4 717
905ae01c
AG		 718 retval = set_cred_ucounts(new);
719 if (retval < 0)
720 goto error;
721
c923a8e7 722 flag_nproc_exceeded(new);
d84f4f99 723 return commit_creds(new);
1da177e4 724
d84f4f99
DH		 725error:
726 abort_creds(new);
727 return retval;
1da177e4
LT		 728}
729
e530dca5
DB		 730SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
731{
732 return __sys_setresuid(ruid, euid, suid);
733}
734
a29c33f4 735SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp)
1da177e4 736{
86a264ab 737 const struct cred *cred = current_cred();
1da177e4 738 int retval;
a29c33f4
EB		 739 uid_t ruid, euid, suid;
740
741 ruid = from_kuid_munged(cred->user_ns, cred->uid);
742 euid = from_kuid_munged(cred->user_ns, cred->euid);
743 suid = from_kuid_munged(cred->user_ns, cred->suid);
1da177e4 744
ec94fc3d 745 retval = put_user(ruid, ruidp);
746 if (!retval) {
747 retval = put_user(euid, euidp);
748 if (!retval)
749 return put_user(suid, suidp);
750 }
1da177e4
LT		 751 return retval;
752}
753
754/*
755 * Same as above, but for rgid, egid, sgid.
756 */
e530dca5 757long __sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
1da177e4 758{
a29c33f4 759 struct user_namespace *ns = current_user_ns();
d84f4f99
DH		 760 const struct cred *old;
761 struct cred *new;
1da177e4 762 int retval;
a29c33f4
EB		 763 kgid_t krgid, kegid, ksgid;
764
765 krgid = make_kgid(ns, rgid);
766 kegid = make_kgid(ns, egid);
767 ksgid = make_kgid(ns, sgid);
768
769 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
770 return -EINVAL;
771 if ((egid != (gid_t) -1) && !gid_valid(kegid))
772 return -EINVAL;
773 if ((sgid != (gid_t) -1) && !gid_valid(ksgid))
774 return -EINVAL;
1da177e4 775
d84f4f99
DH		 776 new = prepare_creds();
777 if (!new)
778 return -ENOMEM;
779 old = current_cred();
780
d84f4f99 781 retval = -EPERM;
111767c1 782 if (!ns_capable_setid(old->user_ns, CAP_SETGID)) {
a29c33f4
EB		 783 if (rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) &&
784 !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid))
d84f4f99 785 goto error;
a29c33f4
EB		 786 if (egid != (gid_t) -1 && !gid_eq(kegid, old->gid) &&
787 !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid))
d84f4f99 788 goto error;
a29c33f4
EB		 789 if (sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) &&
790 !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid))
d84f4f99 791 goto error;
1da177e4 792 }
d84f4f99 793
1da177e4 794 if (rgid != (gid_t) -1)
a29c33f4 795 new->gid = krgid;
d84f4f99 796 if (egid != (gid_t) -1)
a29c33f4 797 new->egid = kegid;
1da177e4 798 if (sgid != (gid_t) -1)
a29c33f4 799 new->sgid = ksgid;
d84f4f99 800 new->fsgid = new->egid;
1da177e4 801
39030e13
TC		 802 retval = security_task_fix_setgid(new, old, LSM_SETID_RES);
803 if (retval < 0)
804 goto error;
805
d84f4f99
DH		 806 return commit_creds(new);
807
808error:
809 abort_creds(new);
810 return retval;
1da177e4
LT		 811}
812
e530dca5
DB		 813SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
814{
815 return __sys_setresgid(rgid, egid, sgid);
816}
817
a29c33f4 818SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp)
1da177e4 819{
86a264ab 820 const struct cred *cred = current_cred();
1da177e4 821 int retval;
a29c33f4
EB		 822 gid_t rgid, egid, sgid;
823
824 rgid = from_kgid_munged(cred->user_ns, cred->gid);
825 egid = from_kgid_munged(cred->user_ns, cred->egid);
826 sgid = from_kgid_munged(cred->user_ns, cred->sgid);
1da177e4 827
ec94fc3d 828 retval = put_user(rgid, rgidp);
829 if (!retval) {
830 retval = put_user(egid, egidp);
831 if (!retval)
832 retval = put_user(sgid, sgidp);
833 }
1da177e4
LT		 834
835 return retval;
836}
837
838
839/*
840 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
841 * is used for "access()" and for the NFS daemon (letting nfsd stay at
842 * whatever uid it wants to). It normally shadows "euid", except when
843 * explicitly set by setfsuid() or for access..
844 */
e530dca5 845long __sys_setfsuid(uid_t uid)
1da177e4 846{
d84f4f99
DH		 847 const struct cred *old;
848 struct cred *new;
849 uid_t old_fsuid;
a29c33f4
EB		 850 kuid_t kuid;
851
852 old = current_cred();
853 old_fsuid = from_kuid_munged(old->user_ns, old->fsuid);
854
855 kuid = make_kuid(old->user_ns, uid);
856 if (!uid_valid(kuid))
857 return old_fsuid;
1da177e4 858
d84f4f99
DH		 859 new = prepare_creds();
860 if (!new)
a29c33f4 861 return old_fsuid;
1da177e4 862
a29c33f4
EB		 863 if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) ||
864 uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) ||
40852275 865 ns_capable_setid(old->user_ns, CAP_SETUID)) {
a29c33f4
EB		 866 if (!uid_eq(kuid, old->fsuid)) {
867 new->fsuid = kuid;
d84f4f99
DH		 868 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
869 goto change_okay;
1da177e4 870 }
1da177e4
LT		 871 }
872
d84f4f99
DH		 873 abort_creds(new);
874 return old_fsuid;
1da177e4 875
d84f4f99
DH		 876change_okay:
877 commit_creds(new);
1da177e4
LT		 878 return old_fsuid;
879}
880
e530dca5
DB		 881SYSCALL_DEFINE1(setfsuid, uid_t, uid)
882{
883 return __sys_setfsuid(uid);
884}
885
1da177e4 886/*
f42df9e6 887 * Samma på svenska..
1da177e4 888 */
e530dca5 889long __sys_setfsgid(gid_t gid)
1da177e4 890{
d84f4f99
DH		 891 const struct cred *old;
892 struct cred *new;
893 gid_t old_fsgid;
a29c33f4
EB		 894 kgid_t kgid;
895
896 old = current_cred();
897 old_fsgid = from_kgid_munged(old->user_ns, old->fsgid);
898
899 kgid = make_kgid(old->user_ns, gid);
900 if (!gid_valid(kgid))
901 return old_fsgid;
d84f4f99
DH		 902
903 new = prepare_creds();
904 if (!new)
a29c33f4 905 return old_fsgid;
1da177e4 906
a29c33f4
EB		 907 if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) ||
908 gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) ||
111767c1 909 ns_capable_setid(old->user_ns, CAP_SETGID)) {
a29c33f4
EB		 910 if (!gid_eq(kgid, old->fsgid)) {
911 new->fsgid = kgid;
39030e13
TC		 912 if (security_task_fix_setgid(new,old,LSM_SETID_FS) == 0)
913 goto change_okay;
1da177e4 914 }
1da177e4 915 }
d84f4f99 916
d84f4f99
DH		 917 abort_creds(new);
918 return old_fsgid;
919
920change_okay:
921 commit_creds(new);
1da177e4
LT		 922 return old_fsgid;
923}
e530dca5
DB		 924
925SYSCALL_DEFINE1(setfsgid, gid_t, gid)
926{
927 return __sys_setfsgid(gid);
928}
2813893f 929#endif /* CONFIG_MULTIUSER */
1da177e4 930
4a22f166
SR		 931/**
932 * sys_getpid - return the thread group id of the current process
933 *
934 * Note, despite the name, this returns the tgid not the pid. The tgid and
935 * the pid are identical unless CLONE_THREAD was specified on clone() in
936 * which case the tgid is the same in all threads of the same group.
937 *
938 * This is SMP safe as current->tgid does not change.
939 */
940SYSCALL_DEFINE0(getpid)
941{
942 return task_tgid_vnr(current);
943}
944
945/* Thread ID - the internal kernel "pid" */
946SYSCALL_DEFINE0(gettid)
947{
948 return task_pid_vnr(current);
949}
950
951/*
952 * Accessing ->real_parent is not SMP-safe, it could
953 * change from under us. However, we can use a stale
954 * value of ->real_parent under rcu_read_lock(), see
955 * release_task()->call_rcu(delayed_put_task_struct).
956 */
957SYSCALL_DEFINE0(getppid)
958{
959 int pid;
960
961 rcu_read_lock();
962 pid = task_tgid_vnr(rcu_dereference(current->real_parent));
963 rcu_read_unlock();
964
965 return pid;
966}
967
968SYSCALL_DEFINE0(getuid)
969{
970 /* Only we change this so SMP safe */
971 return from_kuid_munged(current_user_ns(), current_uid());
972}
973
974SYSCALL_DEFINE0(geteuid)
975{
976 /* Only we change this so SMP safe */
977 return from_kuid_munged(current_user_ns(), current_euid());
978}
979
980SYSCALL_DEFINE0(getgid)
981{
982 /* Only we change this so SMP safe */
983 return from_kgid_munged(current_user_ns(), current_gid());
984}
985
986SYSCALL_DEFINE0(getegid)
987{
988 /* Only we change this so SMP safe */
989 return from_kgid_munged(current_user_ns(), current_egid());
990}
991
ca2406ed 992static void do_sys_times(struct tms *tms)
f06febc9 993{
5613fda9 994 u64 tgutime, tgstime, cutime, cstime;
f06febc9 995
e80d0a1a 996 thread_group_cputime_adjusted(current, &tgutime, &tgstime);
f06febc9
FM		 997 cutime = current->signal->cutime;
998 cstime = current->signal->cstime;
5613fda9
FW		 999 tms->tms_utime = nsec_to_clock_t(tgutime);
1000 tms->tms_stime = nsec_to_clock_t(tgstime);
1001 tms->tms_cutime = nsec_to_clock_t(cutime);
1002 tms->tms_cstime = nsec_to_clock_t(cstime);
f06febc9
FM		 1003}
1004
58fd3aa2 1005SYSCALL_DEFINE1(times, struct tms __user *, tbuf)
1da177e4 1006{
1da177e4
LT		 1007 if (tbuf) {
1008 struct tms tmp;
f06febc9
FM		 1009
1010 do_sys_times(&tmp);
1da177e4
LT		 1011 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
1012 return -EFAULT;
1013 }
e3d5a27d 1014 force_successful_syscall_return();
1da177e4
LT		 1015 return (long) jiffies_64_to_clock_t(get_jiffies_64());
1016}
1017
ca2406ed
AV		 1018#ifdef CONFIG_COMPAT
1019static compat_clock_t clock_t_to_compat_clock_t(clock_t x)
1020{
1021 return compat_jiffies_to_clock_t(clock_t_to_jiffies(x));
1022}
1023
1024COMPAT_SYSCALL_DEFINE1(times, struct compat_tms __user *, tbuf)
1025{
1026 if (tbuf) {
1027 struct tms tms;
1028 struct compat_tms tmp;
1029
1030 do_sys_times(&tms);
1031 /* Convert our struct tms to the compat version. */
1032 tmp.tms_utime = clock_t_to_compat_clock_t(tms.tms_utime);
1033 tmp.tms_stime = clock_t_to_compat_clock_t(tms.tms_stime);
1034 tmp.tms_cutime = clock_t_to_compat_clock_t(tms.tms_cutime);
1035 tmp.tms_cstime = clock_t_to_compat_clock_t(tms.tms_cstime);
1036 if (copy_to_user(tbuf, &tmp, sizeof(tmp)))
1037 return -EFAULT;
1038 }
1039 force_successful_syscall_return();
1040 return compat_jiffies_to_clock_t(jiffies);
1041}
1042#endif
1043
1da177e4
LT		 1044/*
1045 * This needs some heavy checking ...
1046 * I just haven't the stomach for it. I also don't fully
1047 * understand sessions/pgrp etc. Let somebody who does explain it.
1048 *
1049 * OK, I think I have the protection semantics right.... this is really
1050 * only important on a multi-user system anyway, to make sure one user
1051 * can't send a signal to a process owned by another. -TYT, 12/12/91
1052 *
98611e4e 1053 * !PF_FORKNOEXEC check to conform completely to POSIX.
1da177e4 1054 */
b290ebe2 1055SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
1da177e4
LT		 1056{
1057 struct task_struct *p;
ee0acf90 1058 struct task_struct *group_leader = current->group_leader;
4e021306
ON		 1059 struct pid *pgrp;
1060 int err;
1da177e4
LT		 1061
1062 if (!pid)
b488893a 1063 pid = task_pid_vnr(group_leader);
1da177e4
LT		 1064 if (!pgid)
1065 pgid = pid;
1066 if (pgid < 0)
1067 return -EINVAL;
950eaaca 1068 rcu_read_lock();
1da177e4
LT		 1069
1070 /* From this point forward we keep holding onto the tasklist lock
1071 * so that our parent does not change from under us. -DaveM
1072 */
1073 write_lock_irq(&tasklist_lock);
1074
1075 err = -ESRCH;
4e021306 1076 p = find_task_by_vpid(pid);
1da177e4
LT		 1077 if (!p)
1078 goto out;
1079
1080 err = -EINVAL;
1081 if (!thread_group_leader(p))
1082 goto out;
1083
4e021306 1084 if (same_thread_group(p->real_parent, group_leader)) {
1da177e4 1085 err = -EPERM;
41487c65 1086 if (task_session(p) != task_session(group_leader))
1da177e4
LT		 1087 goto out;
1088 err = -EACCES;
98611e4e 1089 if (!(p->flags & PF_FORKNOEXEC))
1da177e4
LT		 1090 goto out;
1091 } else {
1092 err = -ESRCH;
ee0acf90 1093 if (p != group_leader)
1da177e4
LT		 1094 goto out;
1095 }
1096
1097 err = -EPERM;
1098 if (p->signal->leader)
1099 goto out;
1100
4e021306 1101 pgrp = task_pid(p);
1da177e4 1102 if (pgid != pid) {
b488893a 1103 struct task_struct *g;
1da177e4 1104
4e021306
ON		 1105 pgrp = find_vpid(pgid);
1106 g = pid_task(pgrp, PIDTYPE_PGID);
41487c65 1107 if (!g || task_session(g) != task_session(group_leader))
f020bc46 1108 goto out;
1da177e4
LT		 1109 }
1110
1da177e4
LT		 1111 err = security_task_setpgid(p, pgid);
1112 if (err)
1113 goto out;
1114
1b0f7ffd 1115 if (task_pgrp(p) != pgrp)
83beaf3c 1116 change_pid(p, PIDTYPE_PGID, pgrp);
1da177e4
LT		 1117
1118 err = 0;
1119out:
1120 /* All paths lead to here, thus we are safe. -DaveM */
1121 write_unlock_irq(&tasklist_lock);
950eaaca 1122 rcu_read_unlock();
1da177e4
LT		 1123 return err;
1124}
1125
192c5807 1126static int do_getpgid(pid_t pid)
1da177e4 1127{
12a3de0a
ON		 1128 struct task_struct *p;
1129 struct pid *grp;
1130 int retval;
1131
1132 rcu_read_lock();
756184b7 1133 if (!pid)
12a3de0a 1134 grp = task_pgrp(current);
756184b7 1135 else {
1da177e4 1136 retval = -ESRCH;
12a3de0a
ON		 1137 p = find_task_by_vpid(pid);
1138 if (!p)
1139 goto out;
1140 grp = task_pgrp(p);
1141 if (!grp)
1142 goto out;
1143
1144 retval = security_task_getpgid(p);
1145 if (retval)
1146 goto out;
1da177e4 1147 }
12a3de0a
ON		 1148 retval = pid_vnr(grp);
1149out:
1150 rcu_read_unlock();
1151 return retval;
1da177e4
LT		 1152}
1153
192c5807
DB		 1154SYSCALL_DEFINE1(getpgid, pid_t, pid)
1155{
1156 return do_getpgid(pid);
1157}
1158
1da177e4
LT		 1159#ifdef __ARCH_WANT_SYS_GETPGRP
1160
dbf040d9 1161SYSCALL_DEFINE0(getpgrp)
1da177e4 1162{
192c5807 1163 return do_getpgid(0);
1da177e4
LT		 1164}
1165
1166#endif
1167
dbf040d9 1168SYSCALL_DEFINE1(getsid, pid_t, pid)
1da177e4 1169{
1dd768c0
ON		 1170 struct task_struct *p;
1171 struct pid *sid;
1172 int retval;
1173
1174 rcu_read_lock();
756184b7 1175 if (!pid)
1dd768c0 1176 sid = task_session(current);
756184b7 1177 else {
1da177e4 1178 retval = -ESRCH;
1dd768c0
ON		 1179 p = find_task_by_vpid(pid);
1180 if (!p)
1181 goto out;
1182 sid = task_session(p);
1183 if (!sid)
1184 goto out;
1185
1186 retval = security_task_getsid(p);
1187 if (retval)
1188 goto out;
1da177e4 1189 }
1dd768c0
ON		 1190 retval = pid_vnr(sid);
1191out:
1192 rcu_read_unlock();
1193 return retval;
1da177e4
LT		 1194}
1195
81dabb46
ON		 1196static void set_special_pids(struct pid *pid)
1197{
1198 struct task_struct *curr = current->group_leader;
1199
1200 if (task_session(curr) != pid)
1201 change_pid(curr, PIDTYPE_SID, pid);
1202
1203 if (task_pgrp(curr) != pid)
1204 change_pid(curr, PIDTYPE_PGID, pid);
1205}
1206
e2aaa9f4 1207int ksys_setsid(void)
1da177e4 1208{
e19f247a 1209 struct task_struct *group_leader = current->group_leader;
e4cc0a9c
ON		 1210 struct pid *sid = task_pid(group_leader);
1211 pid_t session = pid_vnr(sid);
1da177e4
LT		 1212 int err = -EPERM;
1213
1da177e4 1214 write_lock_irq(&tasklist_lock);
390e2ff0
EB		 1215 /* Fail if I am already a session leader */
1216 if (group_leader->signal->leader)
1217 goto out;
1218
430c6231
ON		 1219 /* Fail if a process group id already exists that equals the
1220 * proposed session id.
390e2ff0 1221 */
6806aac6 1222 if (pid_task(sid, PIDTYPE_PGID))
1da177e4
LT		 1223 goto out;
1224
e19f247a 1225 group_leader->signal->leader = 1;
81dabb46 1226 set_special_pids(sid);
24ec839c 1227
9c9f4ded 1228 proc_clear_tty(group_leader);
24ec839c 1229
e4cc0a9c 1230 err = session;
1da177e4
LT		 1231out:
1232 write_unlock_irq(&tasklist_lock);
5091faa4 1233 if (err > 0) {
0d0df599 1234 proc_sid_connector(group_leader);
5091faa4
MG		 1235 sched_autogroup_create_attach(group_leader);
1236 }
1da177e4
LT		 1237 return err;
1238}
1239
e2aaa9f4
DB		 1240SYSCALL_DEFINE0(setsid)
1241{
1242 return ksys_setsid();
1243}
1244
1da177e4
LT		 1245DECLARE_RWSEM(uts_sem);
1246
e28cbf22
CH		 1247#ifdef COMPAT_UTS_MACHINE
1248#define override_architecture(name) \
46da2766 1249 (personality(current->personality) == PER_LINUX32 && \
e28cbf22
CH		 1250 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \
1251 sizeof(COMPAT_UTS_MACHINE)))
1252#else
1253#define override_architecture(name) 0
1254#endif
1255
be27425d
AK		 1256/*
1257 * Work around broken programs that cannot handle "Linux 3.0".
1258 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40
b7285b42
JN		 1259 * And we map 4.x and later versions to 2.6.60+x, so 4.0/5.0/6.0/... would be
1260 * 2.6.60.
be27425d 1261 */
2702b152 1262static int override_release(char __user *release, size_t len)
be27425d
AK		 1263{
1264 int ret = 0;
be27425d
AK		 1265
1266 if (current->personality & UNAME26) {
2702b152
KC		 1267 const char *rest = UTS_RELEASE;
1268 char buf[65] = { 0 };
be27425d
AK		 1269 int ndots = 0;
1270 unsigned v;
2702b152 1271 size_t copy;
be27425d
AK		 1272
1273 while (*rest) {
1274 if (*rest == '.' && ++ndots >= 3)
1275 break;
1276 if (!isdigit(*rest) && *rest != '.')
1277 break;
1278 rest++;
1279 }
88a68672 1280 v = LINUX_VERSION_PATCHLEVEL + 60;
31fd84b9 1281 copy = clamp_t(size_t, len, 1, sizeof(buf));
2702b152
KC		 1282 copy = scnprintf(buf, copy, "2.6.%u%s", v, rest);
1283 ret = copy_to_user(release, buf, copy + 1);
be27425d
AK		 1284 }
1285 return ret;
1286}
1287
e48fbb69 1288SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
1da177e4 1289{
42a0cc34 1290 struct new_utsname tmp;
1da177e4
LT		 1291
1292 down_read(&uts_sem);
42a0cc34 1293 memcpy(&tmp, utsname(), sizeof(tmp));
1da177e4 1294 up_read(&uts_sem);
42a0cc34
JH		 1295 if (copy_to_user(name, &tmp, sizeof(tmp)))
1296 return -EFAULT;
e28cbf22 1297
42a0cc34
JH		 1298 if (override_release(name->release, sizeof(name->release)))
1299 return -EFAULT;
1300 if (override_architecture(name))
1301 return -EFAULT;
1302 return 0;
1da177e4
LT		 1303}
1304
5cacdb4a
CH		 1305#ifdef __ARCH_WANT_SYS_OLD_UNAME
1306/*
1307 * Old cruft
1308 */
1309SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
1310{
42a0cc34 1311 struct old_utsname tmp;
5cacdb4a
CH		 1312
1313 if (!name)
1314 return -EFAULT;
1315
1316 down_read(&uts_sem);
42a0cc34 1317 memcpy(&tmp, utsname(), sizeof(tmp));
5cacdb4a 1318 up_read(&uts_sem);
42a0cc34
JH		 1319 if (copy_to_user(name, &tmp, sizeof(tmp)))
1320 return -EFAULT;
5cacdb4a 1321
42a0cc34
JH		 1322 if (override_release(name->release, sizeof(name->release)))
1323 return -EFAULT;
1324 if (override_architecture(name))
1325 return -EFAULT;
1326 return 0;
5cacdb4a
CH		 1327}
1328
1329SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
1330{
5e1aada0 1331 struct oldold_utsname tmp;
5cacdb4a
CH		 1332
1333 if (!name)
1334 return -EFAULT;
5cacdb4a 1335
5e1aada0
JP		 1336 memset(&tmp, 0, sizeof(tmp));
1337
5cacdb4a 1338 down_read(&uts_sem);
42a0cc34
JH		 1339 memcpy(&tmp.sysname, &utsname()->sysname, __OLD_UTS_LEN);
1340 memcpy(&tmp.nodename, &utsname()->nodename, __OLD_UTS_LEN);
1341 memcpy(&tmp.release, &utsname()->release, __OLD_UTS_LEN);
1342 memcpy(&tmp.version, &utsname()->version, __OLD_UTS_LEN);
1343 memcpy(&tmp.machine, &utsname()->machine, __OLD_UTS_LEN);
5cacdb4a 1344 up_read(&uts_sem);
42a0cc34
JH		 1345 if (copy_to_user(name, &tmp, sizeof(tmp)))
1346 return -EFAULT;
5cacdb4a 1347
42a0cc34
JH		 1348 if (override_architecture(name))
1349 return -EFAULT;
1350 if (override_release(name->release, sizeof(name->release)))
1351 return -EFAULT;
1352 return 0;
5cacdb4a
CH		 1353}
1354#endif
1355
5a8a82b1 1356SYSCALL_DEFINE2(sethostname, char __user *, name, int, len)
1da177e4
LT		 1357{
1358 int errno;
1359 char tmp[__NEW_UTS_LEN];
1360
bb96a6f5 1361 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1da177e4 1362 return -EPERM;
fc832ad3 1363
1da177e4
LT		 1364 if (len < 0 || len > __NEW_UTS_LEN)
1365 return -EINVAL;
1da177e4
LT		 1366 errno = -EFAULT;
1367 if (!copy_from_user(tmp, name, len)) {
42a0cc34 1368 struct new_utsname *u;
9679e4dd 1369
37608ba3 1370 add_device_randomness(tmp, len);
42a0cc34
JH		 1371 down_write(&uts_sem);
1372 u = utsname();
9679e4dd
AM		 1373 memcpy(u->nodename, tmp, len);
1374 memset(u->nodename + len, 0, sizeof(u->nodename) - len);
1da177e4 1375 errno = 0;
499eea6b 1376 uts_proc_notify(UTS_PROC_HOSTNAME);
42a0cc34 1377 up_write(&uts_sem);
1da177e4 1378 }
1da177e4
LT		 1379 return errno;
1380}
1381
1382#ifdef __ARCH_WANT_SYS_GETHOSTNAME
1383
5a8a82b1 1384SYSCALL_DEFINE2(gethostname, char __user *, name, int, len)
1da177e4 1385{
42a0cc34 1386 int i;
9679e4dd 1387 struct new_utsname *u;
42a0cc34 1388 char tmp[__NEW_UTS_LEN + 1];
1da177e4
LT		 1389
1390 if (len < 0)
1391 return -EINVAL;
1392 down_read(&uts_sem);
9679e4dd
AM		 1393 u = utsname();
1394 i = 1 + strlen(u->nodename);
1da177e4
LT		 1395 if (i > len)
1396 i = len;
42a0cc34 1397 memcpy(tmp, u->nodename, i);
1da177e4 1398 up_read(&uts_sem);
42a0cc34
JH		 1399 if (copy_to_user(name, tmp, i))
1400 return -EFAULT;
1401 return 0;
1da177e4
LT		 1402}
1403
1404#endif
1405
1406/*
1407 * Only setdomainname; getdomainname can be implemented by calling
1408 * uname()
1409 */
5a8a82b1 1410SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
1da177e4
LT		 1411{
1412 int errno;
1413 char tmp[__NEW_UTS_LEN];
1414
fc832ad3 1415 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1da177e4
LT		 1416 return -EPERM;
1417 if (len < 0 || len > __NEW_UTS_LEN)
1418 return -EINVAL;
1419
1da177e4
LT		 1420 errno = -EFAULT;
1421 if (!copy_from_user(tmp, name, len)) {
42a0cc34 1422 struct new_utsname *u;
9679e4dd 1423
37608ba3 1424 add_device_randomness(tmp, len);
42a0cc34
JH		 1425 down_write(&uts_sem);
1426 u = utsname();
9679e4dd
AM		 1427 memcpy(u->domainname, tmp, len);
1428 memset(u->domainname + len, 0, sizeof(u->domainname) - len);
1da177e4 1429 errno = 0;
499eea6b 1430 uts_proc_notify(UTS_PROC_DOMAINNAME);
42a0cc34 1431 up_write(&uts_sem);
1da177e4 1432 }
1da177e4
LT		 1433 return errno;
1434}
1435
c57bef02
BR		 1436/* make sure you are allowed to change @tsk limits before calling this */
1437static int do_prlimit(struct task_struct *tsk, unsigned int resource,
1438 struct rlimit *new_rlim, struct rlimit *old_rlim)
1439{
1440 struct rlimit *rlim;
1441 int retval = 0;
1442
1443 if (resource >= RLIM_NLIMITS)
1444 return -EINVAL;
73979060
GKH		 1445 resource = array_index_nospec(resource, RLIM_NLIMITS);
1446
c57bef02
BR		 1447 if (new_rlim) {
1448 if (new_rlim->rlim_cur > new_rlim->rlim_max)
1449 return -EINVAL;
1450 if (resource == RLIMIT_NOFILE &&
1451 new_rlim->rlim_max > sysctl_nr_open)
1452 return -EPERM;
1453 }
1454
18c91bb2 1455 /* Holding a refcount on tsk protects tsk->signal from disappearing. */
c57bef02
BR		 1456 rlim = tsk->signal->rlim + resource;
1457 task_lock(tsk->group_leader);
1458 if (new_rlim) {
1459 /*
1460 * Keep the capable check against init_user_ns until cgroups can
1461 * contain all limits.
1462 */
1463 if (new_rlim->rlim_max > rlim->rlim_max &&
1464 !capable(CAP_SYS_RESOURCE))
1465 retval = -EPERM;
1466 if (!retval)
1467 retval = security_task_setrlimit(tsk, resource, new_rlim);
1468 }
1469 if (!retval) {
1470 if (old_rlim)
1471 *old_rlim = *rlim;
1472 if (new_rlim)
1473 *rlim = *new_rlim;
1474 }
1475 task_unlock(tsk->group_leader);
1476
1477 /*
1478 * RLIMIT_CPU handling. Arm the posix CPU timer if the limit is not
1479 * infinite. In case of RLIM_INFINITY the posix CPU timer code
1480 * ignores the rlimit.
1481 */
1482 if (!retval && new_rlim && resource == RLIMIT_CPU &&
1483 new_rlim->rlim_cur != RLIM_INFINITY &&
18c91bb2
BR		 1484 IS_ENABLED(CONFIG_POSIX_TIMERS)) {
1485 /*
1486 * update_rlimit_cpu can fail if the task is exiting, but there
1487 * may be other tasks in the thread group that are not exiting,
1488 * and they need their cpu timers adjusted.
1489 *
1490 * The group_leader is the last task to be released, so if we
1491 * cannot update_rlimit_cpu on it, then the entire process is
1492 * exiting and we do not need to update at all.
1493 */
1494 update_rlimit_cpu(tsk->group_leader, new_rlim->rlim_cur);
1495 }
1496
c57bef02
BR		 1497 return retval;
1498}
1499
e48fbb69 1500SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1da177e4 1501{
b9518345
JS		 1502 struct rlimit value;
1503 int ret;
1504
1505 ret = do_prlimit(current, resource, NULL, &value);
1506 if (!ret)
1507 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1508
1509 return ret;
1da177e4
LT		 1510}
1511
d9e968cb
AV		 1512#ifdef CONFIG_COMPAT
1513
1514COMPAT_SYSCALL_DEFINE2(setrlimit, unsigned int, resource,
1515 struct compat_rlimit __user *, rlim)
1516{
1517 struct rlimit r;
1518 struct compat_rlimit r32;
1519
1520 if (copy_from_user(&r32, rlim, sizeof(struct compat_rlimit)))
1521 return -EFAULT;
1522
1523 if (r32.rlim_cur == COMPAT_RLIM_INFINITY)
1524 r.rlim_cur = RLIM_INFINITY;
1525 else
1526 r.rlim_cur = r32.rlim_cur;
1527 if (r32.rlim_max == COMPAT_RLIM_INFINITY)
1528 r.rlim_max = RLIM_INFINITY;
1529 else
1530 r.rlim_max = r32.rlim_max;
1531 return do_prlimit(current, resource, &r, NULL);
1532}
1533
1534COMPAT_SYSCALL_DEFINE2(getrlimit, unsigned int, resource,
1535 struct compat_rlimit __user *, rlim)
1536{
1537 struct rlimit r;
1538 int ret;
1539
1540 ret = do_prlimit(current, resource, NULL, &r);
1541 if (!ret) {
58c7ffc0 1542 struct compat_rlimit r32;
d9e968cb
AV		 1543 if (r.rlim_cur > COMPAT_RLIM_INFINITY)
1544 r32.rlim_cur = COMPAT_RLIM_INFINITY;
1545 else
1546 r32.rlim_cur = r.rlim_cur;
1547 if (r.rlim_max > COMPAT_RLIM_INFINITY)
1548 r32.rlim_max = COMPAT_RLIM_INFINITY;
1549 else
1550 r32.rlim_max = r.rlim_max;
1551
1552 if (copy_to_user(rlim, &r32, sizeof(struct compat_rlimit)))
1553 return -EFAULT;
1554 }
1555 return ret;
1556}
1557
1558#endif
1559
1da177e4
LT		 1560#ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1561
1562/*
1563 * Back compatibility for getrlimit. Needed for some apps.
1564 */
e48fbb69
HC		 1565SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1566 struct rlimit __user *, rlim)
1da177e4
LT		 1567{
1568 struct rlimit x;
1569 if (resource >= RLIM_NLIMITS)
1570 return -EINVAL;
1571
23d6aef7 1572 resource = array_index_nospec(resource, RLIM_NLIMITS);
1da177e4
LT		 1573 task_lock(current->group_leader);
1574 x = current->signal->rlim[resource];
1575 task_unlock(current->group_leader);
756184b7 1576 if (x.rlim_cur > 0x7FFFFFFF)
1da177e4 1577 x.rlim_cur = 0x7FFFFFFF;
756184b7 1578 if (x.rlim_max > 0x7FFFFFFF)
1da177e4 1579 x.rlim_max = 0x7FFFFFFF;
ec94fc3d 1580 return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0;
1da177e4
LT		 1581}
1582
613763a1
AV		 1583#ifdef CONFIG_COMPAT
1584COMPAT_SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1585 struct compat_rlimit __user *, rlim)
1586{
1587 struct rlimit r;
1588
1589 if (resource >= RLIM_NLIMITS)
1590 return -EINVAL;
1591
23d6aef7 1592 resource = array_index_nospec(resource, RLIM_NLIMITS);
613763a1
AV		 1593 task_lock(current->group_leader);
1594 r = current->signal->rlim[resource];
1595 task_unlock(current->group_leader);
1596 if (r.rlim_cur > 0x7FFFFFFF)
1597 r.rlim_cur = 0x7FFFFFFF;
1598 if (r.rlim_max > 0x7FFFFFFF)
1599 r.rlim_max = 0x7FFFFFFF;
1600
1601 if (put_user(r.rlim_cur, &rlim->rlim_cur) ||
1602 put_user(r.rlim_max, &rlim->rlim_max))
1603 return -EFAULT;
1604 return 0;
1605}
1606#endif
1607
1da177e4
LT		 1608#endif
1609
c022a0ac
JS		 1610static inline bool rlim64_is_infinity(__u64 rlim64)
1611{
1612#if BITS_PER_LONG < 64
1613 return rlim64 >= ULONG_MAX;
1614#else
1615 return rlim64 == RLIM64_INFINITY;
1616#endif
1617}
1618
1619static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64)
1620{
1621 if (rlim->rlim_cur == RLIM_INFINITY)
1622 rlim64->rlim_cur = RLIM64_INFINITY;
1623 else
1624 rlim64->rlim_cur = rlim->rlim_cur;
1625 if (rlim->rlim_max == RLIM_INFINITY)
1626 rlim64->rlim_max = RLIM64_INFINITY;
1627 else
1628 rlim64->rlim_max = rlim->rlim_max;
1629}
1630
1631static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim)
1632{
1633 if (rlim64_is_infinity(rlim64->rlim_cur))
1634 rlim->rlim_cur = RLIM_INFINITY;
1635 else
1636 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur;
1637 if (rlim64_is_infinity(rlim64->rlim_max))
1638 rlim->rlim_max = RLIM_INFINITY;
1639 else
1640 rlim->rlim_max = (unsigned long)rlim64->rlim_max;
1641}
1642
c022a0ac 1643/* rcu lock must be held */
791ec491
SS		 1644static int check_prlimit_permission(struct task_struct *task,
1645 unsigned int flags)
c022a0ac
JS		 1646{
1647 const struct cred *cred = current_cred(), *tcred;
791ec491 1648 bool id_match;
c022a0ac 1649
fc832ad3
SH		 1650 if (current == task)
1651 return 0;
c022a0ac 1652
fc832ad3 1653 tcred = __task_cred(task);
791ec491
SS		 1654 id_match = (uid_eq(cred->uid, tcred->euid) &&
1655 uid_eq(cred->uid, tcred->suid) &&
1656 uid_eq(cred->uid, tcred->uid) &&
1657 gid_eq(cred->gid, tcred->egid) &&
1658 gid_eq(cred->gid, tcred->sgid) &&
1659 gid_eq(cred->gid, tcred->gid));
1660 if (!id_match && !ns_capable(tcred->user_ns, CAP_SYS_RESOURCE))
1661 return -EPERM;
fc832ad3 1662
791ec491 1663 return security_task_prlimit(cred, tcred, flags);
c022a0ac
JS		 1664}
1665
1666SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource,
1667 const struct rlimit64 __user *, new_rlim,
1668 struct rlimit64 __user *, old_rlim)
1669{
1670 struct rlimit64 old64, new64;
1671 struct rlimit old, new;
1672 struct task_struct *tsk;
791ec491 1673 unsigned int checkflags = 0;
c022a0ac
JS		 1674 int ret;
1675
791ec491
SS		 1676 if (old_rlim)
1677 checkflags |= LSM_PRLIMIT_READ;
1678
c022a0ac
JS		 1679 if (new_rlim) {
1680 if (copy_from_user(&new64, new_rlim, sizeof(new64)))
1681 return -EFAULT;
1682 rlim64_to_rlim(&new64, &new);
791ec491 1683 checkflags |= LSM_PRLIMIT_WRITE;
c022a0ac
JS		 1684 }
1685
1686 rcu_read_lock();
1687 tsk = pid ? find_task_by_vpid(pid) : current;
1688 if (!tsk) {
1689 rcu_read_unlock();
1690 return -ESRCH;
1691 }
791ec491 1692 ret = check_prlimit_permission(tsk, checkflags);
c022a0ac
JS		 1693 if (ret) {
1694 rcu_read_unlock();
1695 return ret;
1696 }
1697 get_task_struct(tsk);
1698 rcu_read_unlock();
1699
1700 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL,
1701 old_rlim ? &old : NULL);
1702
1703 if (!ret && old_rlim) {
1704 rlim_to_rlim64(&old, &old64);
1705 if (copy_to_user(old_rlim, &old64, sizeof(old64)))
1706 ret = -EFAULT;
1707 }
1708
1709 put_task_struct(tsk);
1710 return ret;
1711}
1712
7855c35d
JS		 1713SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1714{
1715 struct rlimit new_rlim;
1716
1717 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1718 return -EFAULT;
5b41535a 1719 return do_prlimit(current, resource, &new_rlim, NULL);
7855c35d
JS		 1720}
1721
1da177e4
LT		 1722/*
1723 * It would make sense to put struct rusage in the task_struct,
1724 * except that would make the task_struct be *really big*. After
1725 * task_struct gets moved into malloc'ed memory, it would
1726 * make sense to do this. It will make moving the rest of the information
1727 * a lot simpler! (Which we're not doing right now because we're not
1728 * measuring them yet).
1729 *
1da177e4
LT		 1730 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1731 * races with threads incrementing their own counters. But since word
1732 * reads are atomic, we either get new values or old values and we don't
1733 * care which for the sums. We always take the siglock to protect reading
1734 * the c* fields from p->signal from races with exit.c updating those
1735 * fields when reaping, so a sample either gets all the additions of a
1736 * given child after it's reaped, or none so this sample is before reaping.
2dd0ebcd 1737 *
de047c1b
RT		 1738 * Locking:
1739 * We need to take the siglock for CHILDEREN, SELF and BOTH
1740 * for the cases current multithreaded, non-current single threaded
1741 * non-current multithreaded. Thread traversal is now safe with
1742 * the siglock held.
1743 * Strictly speaking, we donot need to take the siglock if we are current and
1744 * single threaded, as no one else can take our signal_struct away, no one
1745 * else can reap the children to update signal->c* counters, and no one else
1746 * can race with the signal-> fields. If we do not take any lock, the
1747 * signal-> fields could be read out of order while another thread was just
1748 * exiting. So we should place a read memory barrier when we avoid the lock.
1749 * On the writer side, write memory barrier is implied in __exit_signal
1750 * as __exit_signal releases the siglock spinlock after updating the signal->
1751 * fields. But we don't do this yet to keep things simple.
2dd0ebcd 1752 *
1da177e4
LT		 1753 */
1754
f06febc9 1755static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
679c9cd4 1756{
679c9cd4
SK		 1757 r->ru_nvcsw += t->nvcsw;
1758 r->ru_nivcsw += t->nivcsw;
1759 r->ru_minflt += t->min_flt;
1760 r->ru_majflt += t->maj_flt;
1761 r->ru_inblock += task_io_get_inblock(t);
1762 r->ru_oublock += task_io_get_oublock(t);
1763}
1764
ce72a16f 1765void getrusage(struct task_struct *p, int who, struct rusage *r)
1da177e4
LT		 1766{
1767 struct task_struct *t;
1768 unsigned long flags;
5613fda9 1769 u64 tgutime, tgstime, utime, stime;
1f10206c 1770 unsigned long maxrss = 0;
1da177e4 1771
ec94fc3d 1772 memset((char *)r, 0, sizeof (*r));
64861634 1773 utime = stime = 0;
1da177e4 1774
679c9cd4 1775 if (who == RUSAGE_THREAD) {
e80d0a1a 1776 task_cputime_adjusted(current, &utime, &stime);
f06febc9 1777 accumulate_thread_rusage(p, r);
1f10206c 1778 maxrss = p->signal->maxrss;
679c9cd4
SK		 1779 goto out;
1780 }
1781
d6cf723a 1782 if (!lock_task_sighand(p, &flags))
de047c1b 1783 return;
0f59cc4a 1784
1da177e4 1785 switch (who) {
ec94fc3d 1786 case RUSAGE_BOTH:
1787 case RUSAGE_CHILDREN:
1788 utime = p->signal->cutime;
1789 stime = p->signal->cstime;
1790 r->ru_nvcsw = p->signal->cnvcsw;
1791 r->ru_nivcsw = p->signal->cnivcsw;
1792 r->ru_minflt = p->signal->cmin_flt;
1793 r->ru_majflt = p->signal->cmaj_flt;
1794 r->ru_inblock = p->signal->cinblock;
1795 r->ru_oublock = p->signal->coublock;
1796 maxrss = p->signal->cmaxrss;
1797
1798 if (who == RUSAGE_CHILDREN)
1da177e4 1799 break;
df561f66 1800 fallthrough;
0f59cc4a 1801
ec94fc3d 1802 case RUSAGE_SELF:
1803 thread_group_cputime_adjusted(p, &tgutime, &tgstime);
1804 utime += tgutime;
1805 stime += tgstime;
1806 r->ru_nvcsw += p->signal->nvcsw;
1807 r->ru_nivcsw += p->signal->nivcsw;
1808 r->ru_minflt += p->signal->min_flt;
1809 r->ru_majflt += p->signal->maj_flt;
1810 r->ru_inblock += p->signal->inblock;
1811 r->ru_oublock += p->signal->oublock;
1812 if (maxrss < p->signal->maxrss)
1813 maxrss = p->signal->maxrss;
1814 t = p;
1815 do {
1816 accumulate_thread_rusage(t, r);
1817 } while_each_thread(p, t);
1818 break;
1819
1820 default:
1821 BUG();
1da177e4 1822 }
de047c1b 1823 unlock_task_sighand(p, &flags);
de047c1b 1824
679c9cd4 1825out:
bdd565f8
AB		 1826 r->ru_utime = ns_to_kernel_old_timeval(utime);
1827 r->ru_stime = ns_to_kernel_old_timeval(stime);
1f10206c
JP		 1828
1829 if (who != RUSAGE_CHILDREN) {
1830 struct mm_struct *mm = get_task_mm(p);
ec94fc3d 1831
1f10206c
JP		 1832 if (mm) {
1833 setmax_mm_hiwater_rss(&maxrss, mm);
1834 mmput(mm);
1835 }
1836 }
1837 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
1da177e4
LT		 1838}
1839
ce72a16f 1840SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
1da177e4
LT		 1841{
1842 struct rusage r;
ec94fc3d 1843
679c9cd4
SK		 1844 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1845 who != RUSAGE_THREAD)
1da177e4 1846 return -EINVAL;
ce72a16f
AV		 1847
1848 getrusage(current, who, &r);
1849 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1da177e4
LT		 1850}
1851
8d2d5c4a
AV		 1852#ifdef CONFIG_COMPAT
1853COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru)
1854{
1855 struct rusage r;
1856
1857 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1858 who != RUSAGE_THREAD)
1859 return -EINVAL;
1860
ce72a16f 1861 getrusage(current, who, &r);
8d2d5c4a
AV		 1862 return put_compat_rusage(&r, ru);
1863}
1864#endif
1865
e48fbb69 1866SYSCALL_DEFINE1(umask, int, mask)
1da177e4
LT		 1867{
1868 mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1869 return mask;
1870}
3b7391de 1871
6e399cd1 1872static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
b32dfe37 1873{
2903ff01 1874 struct fd exe;
496ad9aa 1875 struct inode *inode;
2903ff01 1876 int err;
b32dfe37 1877
2903ff01
AV		 1878 exe = fdget(fd);
1879 if (!exe.file)
b32dfe37
CG		 1880 return -EBADF;
1881
496ad9aa 1882 inode = file_inode(exe.file);
b32dfe37
CG		 1883
1884 /*
1885 * Because the original mm->exe_file points to executable file, make
1886 * sure that this one is executable as well, to avoid breaking an
1887 * overall picture.
1888 */
1889 err = -EACCES;
90f8572b 1890 if (!S_ISREG(inode->i_mode) || path_noexec(&exe.file->f_path))
b32dfe37
CG		 1891 goto exit;
1892
02f92b38 1893 err = file_permission(exe.file, MAY_EXEC);
b32dfe37
CG		 1894 if (err)
1895 goto exit;
1896
35d7bdc8 1897 err = replace_mm_exe_file(mm, exe.file);
b32dfe37 1898exit:
2903ff01 1899 fdput(exe);
b32dfe37
CG		 1900 return err;
1901}
1902
f606b77f 1903/*
11bbd8b4
MK		 1904 * Check arithmetic relations of passed addresses.
1905 *
f606b77f
CG		 1906 * WARNING: we don't require any capability here so be very careful
1907 * in what is allowed for modification from userspace.
1908 */
11bbd8b4 1909static int validate_prctl_map_addr(struct prctl_mm_map *prctl_map)
f606b77f
CG		 1910{
1911 unsigned long mmap_max_addr = TASK_SIZE;
f606b77f
CG		 1912 int error = -EINVAL, i;
1913
1914 static const unsigned char offsets[] = {
1915 offsetof(struct prctl_mm_map, start_code),
1916 offsetof(struct prctl_mm_map, end_code),
1917 offsetof(struct prctl_mm_map, start_data),
1918 offsetof(struct prctl_mm_map, end_data),
1919 offsetof(struct prctl_mm_map, start_brk),
1920 offsetof(struct prctl_mm_map, brk),
1921 offsetof(struct prctl_mm_map, start_stack),
1922 offsetof(struct prctl_mm_map, arg_start),
1923 offsetof(struct prctl_mm_map, arg_end),
1924 offsetof(struct prctl_mm_map, env_start),
1925 offsetof(struct prctl_mm_map, env_end),
1926 };
1927
1928 /*
1929 * Make sure the members are not somewhere outside
1930 * of allowed address space.
1931 */
1932 for (i = 0; i < ARRAY_SIZE(offsets); i++) {
1933 u64 val = *(u64 *)((char *)prctl_map + offsets[i]);
1934
1935 if ((unsigned long)val >= mmap_max_addr ||
1936 (unsigned long)val < mmap_min_addr)
1937 goto out;
1938 }
1939
1940 /*
1941 * Make sure the pairs are ordered.
1942 */
1943#define __prctl_check_order(__m1, __op, __m2) \
1944 ((unsigned long)prctl_map->__m1 __op \
1945 (unsigned long)prctl_map->__m2) ? 0 : -EINVAL
1946 error = __prctl_check_order(start_code, <, end_code);
a9e73998 1947 error |= __prctl_check_order(start_data,<=, end_data);
f606b77f
CG		 1948 error |= __prctl_check_order(start_brk, <=, brk);
1949 error |= __prctl_check_order(arg_start, <=, arg_end);
1950 error |= __prctl_check_order(env_start, <=, env_end);
1951 if (error)
1952 goto out;
1953#undef __prctl_check_order
1954
1955 error = -EINVAL;
1956
f606b77f
CG		 1957 /*
1958 * Neither we should allow to override limits if they set.
1959 */
1960 if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk,
1961 prctl_map->start_brk, prctl_map->end_data,
1962 prctl_map->start_data))
1963 goto out;
1964
f606b77f
CG		 1965 error = 0;
1966out:
1967 return error;
1968}
1969
4a00e9df 1970#ifdef CONFIG_CHECKPOINT_RESTORE
f606b77f
CG		 1971static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size)
1972{
1973 struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, };
1974 unsigned long user_auxv[AT_VECTOR_SIZE];
1975 struct mm_struct *mm = current->mm;
1976 int error;
1977
1978 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
1979 BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256);
1980
1981 if (opt == PR_SET_MM_MAP_SIZE)
1982 return put_user((unsigned int)sizeof(prctl_map),
1983 (unsigned int __user *)addr);
1984
1985 if (data_size != sizeof(prctl_map))
1986 return -EINVAL;
1987
1988 if (copy_from_user(&prctl_map, addr, sizeof(prctl_map)))
1989 return -EFAULT;
1990
11bbd8b4 1991 error = validate_prctl_map_addr(&prctl_map);
f606b77f
CG		 1992 if (error)
1993 return error;
1994
1995 if (prctl_map.auxv_size) {
11bbd8b4
MK		 1996 /*
1997 * Someone is trying to cheat the auxv vector.
1998 */
1999 if (!prctl_map.auxv ||
2000 prctl_map.auxv_size > sizeof(mm->saved_auxv))
2001 return -EINVAL;
2002
f606b77f
CG		 2003 memset(user_auxv, 0, sizeof(user_auxv));
2004 if (copy_from_user(user_auxv,
2005 (const void __user *)prctl_map.auxv,
2006 prctl_map.auxv_size))
2007 return -EFAULT;
2008
2009 /* Last entry must be AT_NULL as specification requires */
2010 user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL;
2011 user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL;
2012 }
2013
ddf1d398 2014 if (prctl_map.exe_fd != (u32)-1) {
11bbd8b4 2015 /*
ebd6de68
NV		 2016 * Check if the current user is checkpoint/restore capable.
2017 * At the time of this writing, it checks for CAP_SYS_ADMIN
2018 * or CAP_CHECKPOINT_RESTORE.
2019 * Note that a user with access to ptrace can masquerade an
2020 * arbitrary program as any executable, even setuid ones.
2021 * This may have implications in the tomoyo subsystem.
11bbd8b4 2022 */
ebd6de68 2023 if (!checkpoint_restore_ns_capable(current_user_ns()))
227175b2 2024 return -EPERM;
11bbd8b4 2025
6e399cd1 2026 error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd);
ddf1d398
MG		 2027 if (error)
2028 return error;
2029 }
2030
88aa7cc6 2031 /*
5afe69c2 2032 * arg_lock protects concurrent updates but we still need mmap_lock for
88aa7cc6
YS		 2033 * read to exclude races with sys_brk.
2034 */
d8ed45c5 2035 mmap_read_lock(mm);
f606b77f
CG		 2036
2037 /*
2038 * We don't validate if these members are pointing to
2039 * real present VMAs because application may have correspond
2040 * VMAs already unmapped and kernel uses these members for statistics
2041 * output in procfs mostly, except
2042 *
15ec0fcf 2043 * - @start_brk/@brk which are used in do_brk_flags but kernel lookups
5afe69c2 2044 * for VMAs when updating these members so anything wrong written
f606b77f
CG		 2045 * here cause kernel to swear at userspace program but won't lead
2046 * to any problem in kernel itself
2047 */
2048
88aa7cc6 2049 spin_lock(&mm->arg_lock);
f606b77f
CG		 2050 mm->start_code = prctl_map.start_code;
2051 mm->end_code = prctl_map.end_code;
2052 mm->start_data = prctl_map.start_data;
2053 mm->end_data = prctl_map.end_data;
2054 mm->start_brk = prctl_map.start_brk;
2055 mm->brk = prctl_map.brk;
2056 mm->start_stack = prctl_map.start_stack;
2057 mm->arg_start = prctl_map.arg_start;
2058 mm->arg_end = prctl_map.arg_end;
2059 mm->env_start = prctl_map.env_start;
2060 mm->env_end = prctl_map.env_end;
88aa7cc6 2061 spin_unlock(&mm->arg_lock);
f606b77f
CG		 2062
2063 /*
2064 * Note this update of @saved_auxv is lockless thus
2065 * if someone reads this member in procfs while we're
2066 * updating -- it may get partly updated results. It's
2067 * known and acceptable trade off: we leave it as is to
2068 * not introduce additional locks here making the kernel
2069 * more complex.
2070 */
2071 if (prctl_map.auxv_size)
2072 memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv));
2073
d8ed45c5 2074 mmap_read_unlock(mm);
ddf1d398 2075 return 0;
f606b77f
CG		 2076}
2077#endif /* CONFIG_CHECKPOINT_RESTORE */
2078
4a00e9df
AD		 2079static int prctl_set_auxv(struct mm_struct *mm, unsigned long addr,
2080 unsigned long len)
2081{
2082 /*
2083 * This doesn't move the auxiliary vector itself since it's pinned to
2084 * mm_struct, but it permits filling the vector with new values. It's
2085 * up to the caller to provide sane values here, otherwise userspace
2086 * tools which use this vector might be unhappy.
2087 */
c995f12a 2088 unsigned long user_auxv[AT_VECTOR_SIZE] = {};
4a00e9df
AD		 2089
2090 if (len > sizeof(user_auxv))
2091 return -EINVAL;
2092
2093 if (copy_from_user(user_auxv, (const void __user *)addr, len))
2094 return -EFAULT;
2095
2096 /* Make sure the last entry is always AT_NULL */
2097 user_auxv[AT_VECTOR_SIZE - 2] = 0;
2098 user_auxv[AT_VECTOR_SIZE - 1] = 0;
2099
2100 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
2101
2102 task_lock(current);
2103 memcpy(mm->saved_auxv, user_auxv, len);
2104 task_unlock(current);
2105
2106 return 0;
2107}
2108
028ee4be
CG		 2109static int prctl_set_mm(int opt, unsigned long addr,
2110 unsigned long arg4, unsigned long arg5)
2111{
028ee4be 2112 struct mm_struct *mm = current->mm;
11bbd8b4
MK		 2113 struct prctl_mm_map prctl_map = {
2114 .auxv = NULL,
2115 .auxv_size = 0,
2116 .exe_fd = -1,
2117 };
fe8c7f5c
CG		 2118 struct vm_area_struct *vma;
2119 int error;
028ee4be 2120
f606b77f
CG		 2121 if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV &&
2122 opt != PR_SET_MM_MAP &&
2123 opt != PR_SET_MM_MAP_SIZE)))
028ee4be
CG		 2124 return -EINVAL;
2125
f606b77f
CG		 2126#ifdef CONFIG_CHECKPOINT_RESTORE
2127 if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE)
2128 return prctl_set_mm_map(opt, (const void __user *)addr, arg4);
2129#endif
2130
79f0713d 2131 if (!capable(CAP_SYS_RESOURCE))
028ee4be
CG		 2132 return -EPERM;
2133
6e399cd1
DB		 2134 if (opt == PR_SET_MM_EXE_FILE)
2135 return prctl_set_mm_exe_file(mm, (unsigned int)addr);
b32dfe37 2136
4a00e9df
AD		 2137 if (opt == PR_SET_MM_AUXV)
2138 return prctl_set_auxv(mm, addr, arg4);
2139
1ad75b9e 2140 if (addr >= TASK_SIZE || addr < mmap_min_addr)
028ee4be
CG		 2141 return -EINVAL;
2142
fe8c7f5c
CG		 2143 error = -EINVAL;
2144
bc81426f 2145 /*
5afe69c2 2146 * arg_lock protects concurrent updates of arg boundaries, we need
c1e8d7c6 2147 * mmap_lock for a) concurrent sys_brk, b) finding VMA for addr
bc81426f
MK		 2148 * validation.
2149 */
d8ed45c5 2150 mmap_read_lock(mm);
028ee4be
CG		 2151 vma = find_vma(mm, addr);
2152
bc81426f 2153 spin_lock(&mm->arg_lock);
4a00e9df
AD		 2154 prctl_map.start_code = mm->start_code;
2155 prctl_map.end_code = mm->end_code;
2156 prctl_map.start_data = mm->start_data;
2157 prctl_map.end_data = mm->end_data;
2158 prctl_map.start_brk = mm->start_brk;
2159 prctl_map.brk = mm->brk;
2160 prctl_map.start_stack = mm->start_stack;
2161 prctl_map.arg_start = mm->arg_start;
2162 prctl_map.arg_end = mm->arg_end;
2163 prctl_map.env_start = mm->env_start;
2164 prctl_map.env_end = mm->env_end;
4a00e9df 2165
028ee4be
CG		 2166 switch (opt) {
2167 case PR_SET_MM_START_CODE:
4a00e9df 2168 prctl_map.start_code = addr;
fe8c7f5c 2169 break;
028ee4be 2170 case PR_SET_MM_END_CODE:
4a00e9df 2171 prctl_map.end_code = addr;
028ee4be 2172 break;
028ee4be 2173 case PR_SET_MM_START_DATA:
4a00e9df 2174 prctl_map.start_data = addr;
028ee4be 2175 break;
fe8c7f5c 2176 case PR_SET_MM_END_DATA:
4a00e9df
AD		 2177 prctl_map.end_data = addr;
2178 break;
2179 case PR_SET_MM_START_STACK:
2180 prctl_map.start_stack = addr;
028ee4be 2181 break;
028ee4be 2182 case PR_SET_MM_START_BRK:
4a00e9df 2183 prctl_map.start_brk = addr;
028ee4be 2184 break;
028ee4be 2185 case PR_SET_MM_BRK:
4a00e9df 2186 prctl_map.brk = addr;
028ee4be 2187 break;
4a00e9df
AD		 2188 case PR_SET_MM_ARG_START:
2189 prctl_map.arg_start = addr;
2190 break;
2191 case PR_SET_MM_ARG_END:
2192 prctl_map.arg_end = addr;
2193 break;
2194 case PR_SET_MM_ENV_START:
2195 prctl_map.env_start = addr;
2196 break;
2197 case PR_SET_MM_ENV_END:
2198 prctl_map.env_end = addr;
2199 break;
2200 default:
2201 goto out;
2202 }
2203
11bbd8b4 2204 error = validate_prctl_map_addr(&prctl_map);
4a00e9df
AD		 2205 if (error)
2206 goto out;
028ee4be 2207
4a00e9df 2208 switch (opt) {
fe8c7f5c
CG		 2209 /*
2210 * If command line arguments and environment
2211 * are placed somewhere else on stack, we can
2212 * set them up here, ARG_START/END to setup
5afe69c2 2213 * command line arguments and ENV_START/END
fe8c7f5c
CG		 2214 * for environment.
2215 */
2216 case PR_SET_MM_START_STACK:
2217 case PR_SET_MM_ARG_START:
2218 case PR_SET_MM_ARG_END:
2219 case PR_SET_MM_ENV_START:
2220 case PR_SET_MM_ENV_END:
2221 if (!vma) {
2222 error = -EFAULT;
2223 goto out;
2224 }
028ee4be
CG		 2225 }
2226
4a00e9df
AD		 2227 mm->start_code = prctl_map.start_code;
2228 mm->end_code = prctl_map.end_code;
2229 mm->start_data = prctl_map.start_data;
2230 mm->end_data = prctl_map.end_data;
2231 mm->start_brk = prctl_map.start_brk;
2232 mm->brk = prctl_map.brk;
2233 mm->start_stack = prctl_map.start_stack;
2234 mm->arg_start = prctl_map.arg_start;
2235 mm->arg_end = prctl_map.arg_end;
2236 mm->env_start = prctl_map.env_start;
2237 mm->env_end = prctl_map.env_end;
2238
028ee4be 2239 error = 0;
028ee4be 2240out:
bc81426f 2241 spin_unlock(&mm->arg_lock);
d8ed45c5 2242 mmap_read_unlock(mm);
028ee4be
CG		 2243 return error;
2244}
300f786b 2245
52b36941 2246#ifdef CONFIG_CHECKPOINT_RESTORE
986b9eac 2247static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr)
300f786b
CG		 2248{
2249 return put_user(me->clear_child_tid, tid_addr);
2250}
52b36941 2251#else
986b9eac 2252static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr)
300f786b
CG		 2253{
2254 return -EINVAL;
2255}
028ee4be
CG		 2256#endif
2257
749860ce
PT		 2258static int propagate_has_child_subreaper(struct task_struct *p, void *data)
2259{
2260 /*
5afe69c2
XC		 2261 * If task has has_child_subreaper - all its descendants
2262 * already have these flag too and new descendants will
749860ce
PT		 2263 * inherit it on fork, skip them.
2264 *
2265 * If we've found child_reaper - skip descendants in
2266 * it's subtree as they will never get out pidns.
2267 */
2268 if (p->signal->has_child_subreaper ||
2269 is_child_reaper(task_pid(p)))
2270 return 0;
2271
2272 p->signal->has_child_subreaper = 1;
2273 return 1;
2274}
2275
7bbf1373 2276int __weak arch_prctl_spec_ctrl_get(struct task_struct *t, unsigned long which)
b617cfc8
TG		 2277{
2278 return -EINVAL;
2279}
2280
7bbf1373
KC		 2281int __weak arch_prctl_spec_ctrl_set(struct task_struct *t, unsigned long which,
2282 unsigned long ctrl)
b617cfc8
TG		 2283{
2284 return -EINVAL;
2285}
2286
a37b0715 2287#define PR_IO_FLUSHER (PF_MEMALLOC_NOIO | PF_LOCAL_THROTTLE)
8d19f1c8 2288
9a10064f
CC		 2289#ifdef CONFIG_ANON_VMA_NAME
2290
2291#define ANON_VMA_NAME_MAX_LEN 80
2292#define ANON_VMA_NAME_INVALID_CHARS "\\`$[]"
2293
2294static inline bool is_valid_name_char(char ch)
2295{
2296 /* printable ascii characters, excluding ANON_VMA_NAME_INVALID_CHARS */
2297 return ch > 0x1f && ch < 0x7f &&
2298 !strchr(ANON_VMA_NAME_INVALID_CHARS, ch);
2299}
2300
2301static int prctl_set_vma(unsigned long opt, unsigned long addr,
2302 unsigned long size, unsigned long arg)
2303{
2304 struct mm_struct *mm = current->mm;
2305 const char __user *uname;
5c26f6ac 2306 struct anon_vma_name *anon_name = NULL;
9a10064f
CC		 2307 int error;
2308
2309 switch (opt) {
2310 case PR_SET_VMA_ANON_NAME:
2311 uname = (const char __user *)arg;
2312 if (uname) {
5c26f6ac 2313 char *name, *pch;
9a10064f 2314
5c26f6ac 2315 name = strndup_user(uname, ANON_VMA_NAME_MAX_LEN);
9a10064f
CC		 2316 if (IS_ERR(name))
2317 return PTR_ERR(name);
2318
2319 for (pch = name; *pch != '\0'; pch++) {
2320 if (!is_valid_name_char(*pch)) {
2321 kfree(name);
2322 return -EINVAL;
2323 }
2324 }
5c26f6ac
SB		 2325 /* anon_vma has its own copy */
2326 anon_name = anon_vma_name_alloc(name);
2327 kfree(name);
2328 if (!anon_name)
2329 return -ENOMEM;
2330
9a10064f
CC		 2331 }
2332
2333 mmap_write_lock(mm);
5c26f6ac 2334 error = madvise_set_anon_name(mm, addr, size, anon_name);
9a10064f 2335 mmap_write_unlock(mm);
5c26f6ac 2336 anon_vma_name_put(anon_name);
9a10064f
CC		 2337 break;
2338 default:
2339 error = -EINVAL;
2340 }
2341
2342 return error;
2343}
2344
2345#else /* CONFIG_ANON_VMA_NAME */
2346static int prctl_set_vma(unsigned long opt, unsigned long start,
2347 unsigned long size, unsigned long arg)
2348{
2349 return -EINVAL;
2350}
2351#endif /* CONFIG_ANON_VMA_NAME */
2352
b507808e
JG		 2353static inline int prctl_set_mdwe(unsigned long bits, unsigned long arg3,
2354 unsigned long arg4, unsigned long arg5)
2355{
2356 if (arg3 || arg4 || arg5)
2357 return -EINVAL;
2358
2359 if (bits & ~(PR_MDWE_REFUSE_EXEC_GAIN))
2360 return -EINVAL;
2361
2362 if (bits & PR_MDWE_REFUSE_EXEC_GAIN)
2363 set_bit(MMF_HAS_MDWE, &current->mm->flags);
2364 else if (test_bit(MMF_HAS_MDWE, &current->mm->flags))
2365 return -EPERM; /* Cannot unset the flag */
2366
2367 return 0;
2368}
2369
2370static inline int prctl_get_mdwe(unsigned long arg2, unsigned long arg3,
2371 unsigned long arg4, unsigned long arg5)
2372{
2373 if (arg2 || arg3 || arg4 || arg5)
2374 return -EINVAL;
2375
2376 return test_bit(MMF_HAS_MDWE, &current->mm->flags) ?
2377 PR_MDWE_REFUSE_EXEC_GAIN : 0;
2378}
2379
c4ea37c2
HC		 2380SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
2381 unsigned long, arg4, unsigned long, arg5)
1da177e4 2382{
b6dff3ec
DH		 2383 struct task_struct *me = current;
2384 unsigned char comm[sizeof(me->comm)];
2385 long error;
1da177e4 2386
d84f4f99
DH		 2387 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
2388 if (error != -ENOSYS)
1da177e4
LT		 2389 return error;
2390
d84f4f99 2391 error = 0;
1da177e4 2392 switch (option) {
f3cbd435
AM		 2393 case PR_SET_PDEATHSIG:
2394 if (!valid_signal(arg2)) {
2395 error = -EINVAL;
1da177e4 2396 break;
f3cbd435
AM		 2397 }
2398 me->pdeath_signal = arg2;
2399 break;
2400 case PR_GET_PDEATHSIG:
2401 error = put_user(me->pdeath_signal, (int __user *)arg2);
2402 break;
2403 case PR_GET_DUMPABLE:
2404 error = get_dumpable(me->mm);
2405 break;
2406 case PR_SET_DUMPABLE:
2407 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) {
2408 error = -EINVAL;
1da177e4 2409 break;
f3cbd435
AM		 2410 }
2411 set_dumpable(me->mm, arg2);
2412 break;
1da177e4 2413
f3cbd435
AM		 2414 case PR_SET_UNALIGN:
2415 error = SET_UNALIGN_CTL(me, arg2);
2416 break;
2417 case PR_GET_UNALIGN:
2418 error = GET_UNALIGN_CTL(me, arg2);
2419 break;
2420 case PR_SET_FPEMU:
2421 error = SET_FPEMU_CTL(me, arg2);
2422 break;
2423 case PR_GET_FPEMU:
2424 error = GET_FPEMU_CTL(me, arg2);
2425 break;
2426 case PR_SET_FPEXC:
2427 error = SET_FPEXC_CTL(me, arg2);
2428 break;
2429 case PR_GET_FPEXC:
2430 error = GET_FPEXC_CTL(me, arg2);
2431 break;
2432 case PR_GET_TIMING:
2433 error = PR_TIMING_STATISTICAL;
2434 break;
2435 case PR_SET_TIMING:
2436 if (arg2 != PR_TIMING_STATISTICAL)
2437 error = -EINVAL;
2438 break;
2439 case PR_SET_NAME:
2440 comm[sizeof(me->comm) - 1] = 0;
2441 if (strncpy_from_user(comm, (char __user *)arg2,
2442 sizeof(me->comm) - 1) < 0)
2443 return -EFAULT;
2444 set_task_comm(me, comm);
2445 proc_comm_connector(me);
2446 break;
2447 case PR_GET_NAME:
2448 get_task_comm(comm, me);
2449 if (copy_to_user((char __user *)arg2, comm, sizeof(comm)))
2450 return -EFAULT;
2451 break;
2452 case PR_GET_ENDIAN:
2453 error = GET_ENDIAN(me, arg2);
2454 break;
2455 case PR_SET_ENDIAN:
2456 error = SET_ENDIAN(me, arg2);
2457 break;
2458 case PR_GET_SECCOMP:
2459 error = prctl_get_seccomp();
2460 break;
2461 case PR_SET_SECCOMP:
2462 error = prctl_set_seccomp(arg2, (char __user *)arg3);
2463 break;
2464 case PR_GET_TSC:
2465 error = GET_TSC_CTL(arg2);
2466 break;
2467 case PR_SET_TSC:
2468 error = SET_TSC_CTL(arg2);
2469 break;
2470 case PR_TASK_PERF_EVENTS_DISABLE:
2471 error = perf_event_task_disable();
2472 break;
2473 case PR_TASK_PERF_EVENTS_ENABLE:
2474 error = perf_event_task_enable();
2475 break;
2476 case PR_GET_TIMERSLACK:
da8b44d5
JS		 2477 if (current->timer_slack_ns > ULONG_MAX)
2478 error = ULONG_MAX;
2479 else
2480 error = current->timer_slack_ns;
f3cbd435
AM		 2481 break;
2482 case PR_SET_TIMERSLACK:
2483 if (arg2 <= 0)
2484 current->timer_slack_ns =
6976675d 2485 current->default_timer_slack_ns;
f3cbd435
AM		 2486 else
2487 current->timer_slack_ns = arg2;
2488 break;
2489 case PR_MCE_KILL:
2490 if (arg4 | arg5)
2491 return -EINVAL;
2492 switch (arg2) {
2493 case PR_MCE_KILL_CLEAR:
2494 if (arg3 != 0)
4db96cf0 2495 return -EINVAL;
f3cbd435 2496 current->flags &= ~PF_MCE_PROCESS;
4db96cf0 2497 break;
f3cbd435
AM		 2498 case PR_MCE_KILL_SET:
2499 current->flags |= PF_MCE_PROCESS;
2500 if (arg3 == PR_MCE_KILL_EARLY)
2501 current->flags |= PF_MCE_EARLY;
2502 else if (arg3 == PR_MCE_KILL_LATE)
2503 current->flags &= ~PF_MCE_EARLY;
2504 else if (arg3 == PR_MCE_KILL_DEFAULT)
2505 current->flags &=
2506 ~(PF_MCE_EARLY|PF_MCE_PROCESS);
1087e9b4 2507 else
259e5e6c 2508 return -EINVAL;
259e5e6c 2509 break;
1da177e4 2510 default:
f3cbd435
AM		 2511 return -EINVAL;
2512 }
2513 break;
2514 case PR_MCE_KILL_GET:
2515 if (arg2 | arg3 | arg4 | arg5)
2516 return -EINVAL;
2517 if (current->flags & PF_MCE_PROCESS)
2518 error = (current->flags & PF_MCE_EARLY) ?
2519 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
2520 else
2521 error = PR_MCE_KILL_DEFAULT;
2522 break;
2523 case PR_SET_MM:
2524 error = prctl_set_mm(arg2, arg3, arg4, arg5);
2525 break;
2526 case PR_GET_TID_ADDRESS:
986b9eac 2527 error = prctl_get_tid_address(me, (int __user * __user *)arg2);
f3cbd435
AM		 2528 break;
2529 case PR_SET_CHILD_SUBREAPER:
2530 me->signal->is_child_subreaper = !!arg2;
749860ce
PT		 2531 if (!arg2)
2532 break;
2533
2534 walk_process_tree(me, propagate_has_child_subreaper, NULL);
f3cbd435
AM		 2535 break;
2536 case PR_GET_CHILD_SUBREAPER:
2537 error = put_user(me->signal->is_child_subreaper,
2538 (int __user *)arg2);
2539 break;
2540 case PR_SET_NO_NEW_PRIVS:
2541 if (arg2 != 1 || arg3 || arg4 || arg5)
2542 return -EINVAL;
2543
1d4457f9 2544 task_set_no_new_privs(current);
f3cbd435
AM		 2545 break;
2546 case PR_GET_NO_NEW_PRIVS:
2547 if (arg2 || arg3 || arg4 || arg5)
2548 return -EINVAL;
1d4457f9 2549 return task_no_new_privs(current) ? 1 : 0;
a0715cc2
AT		 2550 case PR_GET_THP_DISABLE:
2551 if (arg2 || arg3 || arg4 || arg5)
2552 return -EINVAL;
18600332 2553 error = !!test_bit(MMF_DISABLE_THP, &me->mm->flags);
a0715cc2
AT		 2554 break;
2555 case PR_SET_THP_DISABLE:
2556 if (arg3 || arg4 || arg5)
2557 return -EINVAL;
d8ed45c5 2558 if (mmap_write_lock_killable(me->mm))
17b0573d 2559 return -EINTR;
a0715cc2 2560 if (arg2)
18600332 2561 set_bit(MMF_DISABLE_THP, &me->mm->flags);
a0715cc2 2562 else
18600332 2563 clear_bit(MMF_DISABLE_THP, &me->mm->flags);
d8ed45c5 2564 mmap_write_unlock(me->mm);
a0715cc2 2565 break;
fe3d197f 2566 case PR_MPX_ENABLE_MANAGEMENT:
fe3d197f 2567 case PR_MPX_DISABLE_MANAGEMENT:
f240652b
DH		 2568 /* No longer implemented: */
2569 return -EINVAL;
9791554b
PB		 2570 case PR_SET_FP_MODE:
2571 error = SET_FP_MODE(me, arg2);
2572 break;
2573 case PR_GET_FP_MODE:
2574 error = GET_FP_MODE(me);
2575 break;
2d2123bc
DM		 2576 case PR_SVE_SET_VL:
2577 error = SVE_SET_VL(arg2);
2578 break;
2579 case PR_SVE_GET_VL:
2580 error = SVE_GET_VL();
2581 break;
9e4ab6c8
MB		 2582 case PR_SME_SET_VL:
2583 error = SME_SET_VL(arg2);
2584 break;
2585 case PR_SME_GET_VL:
2586 error = SME_GET_VL();
2587 break;
b617cfc8
TG		 2588 case PR_GET_SPECULATION_CTRL:
2589 if (arg3 || arg4 || arg5)
2590 return -EINVAL;
7bbf1373 2591 error = arch_prctl_spec_ctrl_get(me, arg2);
b617cfc8
TG		 2592 break;
2593 case PR_SET_SPECULATION_CTRL:
2594 if (arg4 || arg5)
2595 return -EINVAL;
7bbf1373 2596 error = arch_prctl_spec_ctrl_set(me, arg2, arg3);
b617cfc8 2597 break;
ba830885
KM		 2598 case PR_PAC_RESET_KEYS:
2599 if (arg3 || arg4 || arg5)
2600 return -EINVAL;
2601 error = PAC_RESET_KEYS(me, arg2);
2602 break;
20169862
PC		 2603 case PR_PAC_SET_ENABLED_KEYS:
2604 if (arg4 || arg5)
2605 return -EINVAL;
2606 error = PAC_SET_ENABLED_KEYS(me, arg2, arg3);
2607 break;
2608 case PR_PAC_GET_ENABLED_KEYS:
2609 if (arg2 || arg3 || arg4 || arg5)
2610 return -EINVAL;
2611 error = PAC_GET_ENABLED_KEYS(me);
2612 break;
63f0c603 2613 case PR_SET_TAGGED_ADDR_CTRL:
3e91ec89
CM		 2614 if (arg3 || arg4 || arg5)
2615 return -EINVAL;
63f0c603
CM		 2616 error = SET_TAGGED_ADDR_CTRL(arg2);
2617 break;
2618 case PR_GET_TAGGED_ADDR_CTRL:
3e91ec89
CM		 2619 if (arg2 || arg3 || arg4 || arg5)
2620 return -EINVAL;
63f0c603
CM		 2621 error = GET_TAGGED_ADDR_CTRL();
2622 break;
8d19f1c8
MC		 2623 case PR_SET_IO_FLUSHER:
2624 if (!capable(CAP_SYS_RESOURCE))
2625 return -EPERM;
2626
2627 if (arg3 || arg4 || arg5)
2628 return -EINVAL;
2629
2630 if (arg2 == 1)
2631 current->flags |= PR_IO_FLUSHER;
2632 else if (!arg2)
2633 current->flags &= ~PR_IO_FLUSHER;
2634 else
2635 return -EINVAL;
2636 break;
2637 case PR_GET_IO_FLUSHER:
2638 if (!capable(CAP_SYS_RESOURCE))
2639 return -EPERM;
2640
2641 if (arg2 || arg3 || arg4 || arg5)
2642 return -EINVAL;
2643
2644 error = (current->flags & PR_IO_FLUSHER) == PR_IO_FLUSHER;
2645 break;
1446e1df
GKB		 2646 case PR_SET_SYSCALL_USER_DISPATCH:
2647 error = set_syscall_user_dispatch(arg2, arg3, arg4,
2648 (char __user *) arg5);
2649 break;
7ac592aa
CH		 2650#ifdef CONFIG_SCHED_CORE
2651 case PR_SCHED_CORE:
2652 error = sched_core_share_pid(arg2, arg3, arg4, arg5);
2653 break;
2654#endif
b507808e
JG		 2655 case PR_SET_MDWE:
2656 error = prctl_set_mdwe(arg2, arg3, arg4, arg5);
2657 break;
2658 case PR_GET_MDWE:
2659 error = prctl_get_mdwe(arg2, arg3, arg4, arg5);
2660 break;
9a10064f
CC		 2661 case PR_SET_VMA:
2662 error = prctl_set_vma(arg2, arg3, arg4, arg5);
2663 break;
f3cbd435
AM		 2664 default:
2665 error = -EINVAL;
2666 break;
1da177e4
LT		 2667 }
2668 return error;
2669}
3cfc348b 2670
836f92ad
HC		 2671SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
2672 struct getcpu_cache __user *, unused)
3cfc348b
AK		 2673{
2674 int err = 0;
2675 int cpu = raw_smp_processor_id();
ec94fc3d 2676
3cfc348b
AK		 2677 if (cpup)
2678 err |= put_user(cpu, cpup);
2679 if (nodep)
2680 err |= put_user(cpu_to_node(cpu), nodep);
3cfc348b
AK		 2681 return err ? -EFAULT : 0;
2682}
10a0a8d4 2683
4a22f166
SR		 2684/**
2685 * do_sysinfo - fill in sysinfo struct
2686 * @info: pointer to buffer to fill
2687 */
2688static int do_sysinfo(struct sysinfo *info)
2689{
2690 unsigned long mem_total, sav_total;
2691 unsigned int mem_unit, bitcount;
dc1b7b6c 2692 struct timespec64 tp;
4a22f166
SR		 2693
2694 memset(info, 0, sizeof(struct sysinfo));
2695
dc1b7b6c 2696 ktime_get_boottime_ts64(&tp);
ecc421e0 2697 timens_add_boottime(&tp);
4a22f166
SR		 2698 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
2699
2700 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT);
2701
2702 info->procs = nr_threads;
2703
2704 si_meminfo(info);
2705 si_swapinfo(info);
2706
2707 /*
2708 * If the sum of all the available memory (i.e. ram + swap)
2709 * is less than can be stored in a 32 bit unsigned long then
2710 * we can be binary compatible with 2.2.x kernels. If not,
2711 * well, in that case 2.2.x was broken anyways...
2712 *
2713 * -Erik Andersen <andersee@debian.org>
2714 */
2715
2716 mem_total = info->totalram + info->totalswap;
2717 if (mem_total < info->totalram || mem_total < info->totalswap)
2718 goto out;
2719 bitcount = 0;
2720 mem_unit = info->mem_unit;
2721 while (mem_unit > 1) {
2722 bitcount++;
2723 mem_unit >>= 1;
2724 sav_total = mem_total;
2725 mem_total <<= 1;
2726 if (mem_total < sav_total)
2727 goto out;
2728 }
2729
2730 /*
2731 * If mem_total did not overflow, multiply all memory values by
2732 * info->mem_unit and set it to 1. This leaves things compatible
2733 * with 2.2.x, and also retains compatibility with earlier 2.4.x
2734 * kernels...
2735 */
2736
2737 info->mem_unit = 1;
2738 info->totalram <<= bitcount;
2739 info->freeram <<= bitcount;
2740 info->sharedram <<= bitcount;
2741 info->bufferram <<= bitcount;
2742 info->totalswap <<= bitcount;
2743 info->freeswap <<= bitcount;
2744 info->totalhigh <<= bitcount;
2745 info->freehigh <<= bitcount;
2746
2747out:
2748 return 0;
2749}
2750
2751SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info)
2752{
2753 struct sysinfo val;
2754
2755 do_sysinfo(&val);
2756
2757 if (copy_to_user(info, &val, sizeof(struct sysinfo)))
2758 return -EFAULT;
2759
2760 return 0;
2761}
2762
2763#ifdef CONFIG_COMPAT
2764struct compat_sysinfo {
2765 s32 uptime;
2766 u32 loads[3];
2767 u32 totalram;
2768 u32 freeram;
2769 u32 sharedram;
2770 u32 bufferram;
2771 u32 totalswap;
2772 u32 freeswap;
2773 u16 procs;
2774 u16 pad;
2775 u32 totalhigh;
2776 u32 freehigh;
2777 u32 mem_unit;
2778 char _f[20-2*sizeof(u32)-sizeof(int)];
2779};
2780
2781COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info)
2782{
2783 struct sysinfo s;
ce5155c4 2784 struct compat_sysinfo s_32;
4a22f166
SR		 2785
2786 do_sysinfo(&s);
2787
2788 /* Check to see if any memory value is too large for 32-bit and scale
2789 * down if needed
2790 */
0baae41e 2791 if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) {
4a22f166
SR		 2792 int bitcount = 0;
2793
2794 while (s.mem_unit < PAGE_SIZE) {
2795 s.mem_unit <<= 1;
2796 bitcount++;
2797 }
2798
2799 s.totalram >>= bitcount;
2800 s.freeram >>= bitcount;
2801 s.sharedram >>= bitcount;
2802 s.bufferram >>= bitcount;
2803 s.totalswap >>= bitcount;
2804 s.freeswap >>= bitcount;
2805 s.totalhigh >>= bitcount;
2806 s.freehigh >>= bitcount;
2807 }
2808
ce5155c4
AV		 2809 memset(&s_32, 0, sizeof(s_32));
2810 s_32.uptime = s.uptime;
2811 s_32.loads[0] = s.loads[0];
2812 s_32.loads[1] = s.loads[1];
2813 s_32.loads[2] = s.loads[2];
2814 s_32.totalram = s.totalram;
2815 s_32.freeram = s.freeram;
2816 s_32.sharedram = s.sharedram;
2817 s_32.bufferram = s.bufferram;
2818 s_32.totalswap = s.totalswap;
2819 s_32.freeswap = s.freeswap;
2820 s_32.procs = s.procs;
2821 s_32.totalhigh = s.totalhigh;
2822 s_32.freehigh = s.freehigh;
2823 s_32.mem_unit = s.mem_unit;
2824 if (copy_to_user(info, &s_32, sizeof(s_32)))
4a22f166 2825 return -EFAULT;
4a22f166
SR		 2826 return 0;
2827}
2828#endif /* CONFIG_COMPAT */
Linux 6.x block layer and io_uring tree(s)