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Merge tag 'backlight-next-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/lee...
[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>
d7597f59 18#include <linux/ksm.h>
cdd6c482 19#include <linux/perf_event.h>
3e88c553 20#include <linux/resource.h>
dc009d92 21#include <linux/kernel.h>
1da177e4 22#include <linux/workqueue.h>
c59ede7b 23#include <linux/capability.h>
1da177e4
LT		 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>
37608ba3 29#include <linux/random.h>
1da177e4
LT		 30#include <linux/suspend.h>
31#include <linux/tty.h>
7ed20e1a 32#include <linux/signal.h>
9f46080c 33#include <linux/cn_proc.h>
3cfc348b 34#include <linux/getcpu.h>
6eaeeaba 35#include <linux/task_io_accounting_ops.h>
1d9d02fe 36#include <linux/seccomp.h>
4047727e 37#include <linux/cpu.h>
e28cbf22 38#include <linux/personality.h>
e3d5a27d 39#include <linux/ptrace.h>
5ad4e53b 40#include <linux/fs_struct.h>
b32dfe37
CG		 41#include <linux/file.h>
42#include <linux/mount.h>
5a0e3ad6 43#include <linux/gfp.h>
40dc166c 44#include <linux/syscore_ops.h>
be27425d
AK		 45#include <linux/version.h>
46#include <linux/ctype.h>
1446e1df 47#include <linux/syscall_user_dispatch.h>
1da177e4
LT		 48
49#include <linux/compat.h>
50#include <linux/syscalls.h>
00d7c05a 51#include <linux/kprobes.h>
acce292c 52#include <linux/user_namespace.h>
ecc421e0 53#include <linux/time_namespace.h>
7fe5e042 54#include <linux/binfmts.h>
1da177e4 55
4a22f166 56#include <linux/sched.h>
4eb5aaa3 57#include <linux/sched/autogroup.h>
4f17722c 58#include <linux/sched/loadavg.h>
03441a34 59#include <linux/sched/stat.h>
6e84f315 60#include <linux/sched/mm.h>
f7ccbae4 61#include <linux/sched/coredump.h>
29930025 62#include <linux/sched/task.h>
32ef5517 63#include <linux/sched/cputime.h>
4a22f166
SR		 64#include <linux/rcupdate.h>
65#include <linux/uidgid.h>
66#include <linux/cred.h>
67
b617cfc8
TG		 68#include <linux/nospec.h>
69
04c6862c 70#include <linux/kmsg_dump.h>
be27425d
AK		 71/* Move somewhere else to avoid recompiling? */
72#include <generated/utsrelease.h>
04c6862c 73
7c0f6ba6 74#include <linux/uaccess.h>
1da177e4
LT		 75#include <asm/io.h>
76#include <asm/unistd.h>
77
e530dca5
DB		 78#include "uid16.h"
79
1da177e4 80#ifndef SET_UNALIGN_CTL
ec94fc3d 81# define SET_UNALIGN_CTL(a, b) (-EINVAL)
1da177e4
LT		 82#endif
83#ifndef GET_UNALIGN_CTL
ec94fc3d 84# define GET_UNALIGN_CTL(a, b) (-EINVAL)
1da177e4
LT		 85#endif
86#ifndef SET_FPEMU_CTL
ec94fc3d 87# define SET_FPEMU_CTL(a, b) (-EINVAL)
1da177e4
LT		 88#endif
89#ifndef GET_FPEMU_CTL
ec94fc3d 90# define GET_FPEMU_CTL(a, b) (-EINVAL)
1da177e4
LT		 91#endif
92#ifndef SET_FPEXC_CTL
ec94fc3d 93# define SET_FPEXC_CTL(a, b) (-EINVAL)
1da177e4
LT		 94#endif
95#ifndef GET_FPEXC_CTL
ec94fc3d 96# define GET_FPEXC_CTL(a, b) (-EINVAL)
1da177e4 97#endif
651d765d 98#ifndef GET_ENDIAN
ec94fc3d 99# define GET_ENDIAN(a, b) (-EINVAL)
651d765d
AB		 100#endif
101#ifndef SET_ENDIAN
ec94fc3d 102# define SET_ENDIAN(a, b) (-EINVAL)
651d765d 103#endif
8fb402bc
EB		 104#ifndef GET_TSC_CTL
105# define GET_TSC_CTL(a) (-EINVAL)
106#endif
107#ifndef SET_TSC_CTL
108# define SET_TSC_CTL(a) (-EINVAL)
109#endif
9791554b
PB		 110#ifndef GET_FP_MODE
111# define GET_FP_MODE(a) (-EINVAL)
112#endif
113#ifndef SET_FP_MODE
114# define SET_FP_MODE(a,b) (-EINVAL)
115#endif
2d2123bc
DM		 116#ifndef SVE_SET_VL
117# define SVE_SET_VL(a) (-EINVAL)
118#endif
119#ifndef SVE_GET_VL
120# define SVE_GET_VL() (-EINVAL)
121#endif
9e4ab6c8
MB		 122#ifndef SME_SET_VL
123# define SME_SET_VL(a) (-EINVAL)
124#endif
125#ifndef SME_GET_VL
126# define SME_GET_VL() (-EINVAL)
127#endif
ba830885
KM		 128#ifndef PAC_RESET_KEYS
129# define PAC_RESET_KEYS(a, b) (-EINVAL)
130#endif
20169862
PC		 131#ifndef PAC_SET_ENABLED_KEYS
132# define PAC_SET_ENABLED_KEYS(a, b, c) (-EINVAL)
133#endif
134#ifndef PAC_GET_ENABLED_KEYS
135# define PAC_GET_ENABLED_KEYS(a) (-EINVAL)
136#endif
63f0c603
CM		 137#ifndef SET_TAGGED_ADDR_CTRL
138# define SET_TAGGED_ADDR_CTRL(a) (-EINVAL)
139#endif
140#ifndef GET_TAGGED_ADDR_CTRL
141# define GET_TAGGED_ADDR_CTRL() (-EINVAL)
142#endif
1da177e4
LT		 143
144/*
145 * this is where the system-wide overflow UID and GID are defined, for
146 * architectures that now have 32-bit UID/GID but didn't in the past
147 */
148
149int overflowuid = DEFAULT_OVERFLOWUID;
150int overflowgid = DEFAULT_OVERFLOWGID;
151
1da177e4
LT		 152EXPORT_SYMBOL(overflowuid);
153EXPORT_SYMBOL(overflowgid);
1da177e4
LT		 154
155/*
156 * the same as above, but for filesystems which can only store a 16-bit
157 * UID and GID. as such, this is needed on all architectures
158 */
159
160int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
8b2770a4 161int fs_overflowgid = DEFAULT_FS_OVERFLOWGID;
1da177e4
LT		 162
163EXPORT_SYMBOL(fs_overflowuid);
164EXPORT_SYMBOL(fs_overflowgid);
165
fc832ad3
SH		 166/*
167 * Returns true if current's euid is same as p's uid or euid,
168 * or has CAP_SYS_NICE to p's user_ns.
169 *
170 * Called with rcu_read_lock, creds are safe
171 */
172static bool set_one_prio_perm(struct task_struct *p)
173{
174 const struct cred *cred = current_cred(), *pcred = __task_cred(p);
175
5af66203
EB		 176 if (uid_eq(pcred->uid, cred->euid) ||
177 uid_eq(pcred->euid, cred->euid))
fc832ad3 178 return true;
c4a4d603 179 if (ns_capable(pcred->user_ns, CAP_SYS_NICE))
fc832ad3
SH		 180 return true;
181 return false;
182}
183
c69e8d9c
DH		 184/*
185 * set the priority of a task
186 * - the caller must hold the RCU read lock
187 */
1da177e4
LT		 188static int set_one_prio(struct task_struct *p, int niceval, int error)
189{
190 int no_nice;
191
fc832ad3 192 if (!set_one_prio_perm(p)) {
1da177e4
LT		 193 error = -EPERM;
194 goto out;
195 }
e43379f1 196 if (niceval < task_nice(p) && !can_nice(p, niceval)) {
1da177e4
LT		 197 error = -EACCES;
198 goto out;
199 }
200 no_nice = security_task_setnice(p, niceval);
201 if (no_nice) {
202 error = no_nice;
203 goto out;
204 }
205 if (error == -ESRCH)
206 error = 0;
207 set_user_nice(p, niceval);
208out:
209 return error;
210}
211
754fe8d2 212SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
1da177e4
LT		 213{
214 struct task_struct *g, *p;
215 struct user_struct *user;
86a264ab 216 const struct cred *cred = current_cred();
1da177e4 217 int error = -EINVAL;
41487c65 218 struct pid *pgrp;
7b44ab97 219 kuid_t uid;
1da177e4 220
3e88c553 221 if (which > PRIO_USER || which < PRIO_PROCESS)
1da177e4
LT		 222 goto out;
223
224 /* normalize: avoid signed division (rounding problems) */
225 error = -ESRCH;
c4a4d2f4
DY		 226 if (niceval < MIN_NICE)
227 niceval = MIN_NICE;
228 if (niceval > MAX_NICE)
229 niceval = MAX_NICE;
1da177e4 230
d4581a23 231 rcu_read_lock();
1da177e4 232 switch (which) {
ec94fc3d 233 case PRIO_PROCESS:
234 if (who)
235 p = find_task_by_vpid(who);
236 else
237 p = current;
238 if (p)
239 error = set_one_prio(p, niceval, error);
240 break;
241 case PRIO_PGRP:
242 if (who)
243 pgrp = find_vpid(who);
244 else
245 pgrp = task_pgrp(current);
7f8ca0ed 246 read_lock(&tasklist_lock);
ec94fc3d 247 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
248 error = set_one_prio(p, niceval, error);
249 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
7f8ca0ed 250 read_unlock(&tasklist_lock);
ec94fc3d 251 break;
252 case PRIO_USER:
253 uid = make_kuid(cred->user_ns, who);
254 user = cred->user;
255 if (!who)
256 uid = cred->uid;
257 else if (!uid_eq(uid, cred->uid)) {
258 user = find_user(uid);
259 if (!user)
86a264ab 260 goto out_unlock; /* No processes for this user */
ec94fc3d 261 }
7f8ca0ed 262 for_each_process_thread(g, p) {
8639b461 263 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p))
ec94fc3d 264 error = set_one_prio(p, niceval, error);
7f8ca0ed 265 }
ec94fc3d 266 if (!uid_eq(uid, cred->uid))
267 free_uid(user); /* For find_user() */
268 break;
1da177e4
LT		 269 }
270out_unlock:
d4581a23 271 rcu_read_unlock();
1da177e4
LT		 272out:
273 return error;
274}
275
276/*
277 * Ugh. To avoid negative return values, "getpriority()" will
278 * not return the normal nice-value, but a negated value that
279 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
280 * to stay compatible.
281 */
754fe8d2 282SYSCALL_DEFINE2(getpriority, int, which, int, who)
1da177e4
LT		 283{
284 struct task_struct *g, *p;
285 struct user_struct *user;
86a264ab 286 const struct cred *cred = current_cred();
1da177e4 287 long niceval, retval = -ESRCH;
41487c65 288 struct pid *pgrp;
7b44ab97 289 kuid_t uid;
1da177e4 290
3e88c553 291 if (which > PRIO_USER || which < PRIO_PROCESS)
1da177e4
LT		 292 return -EINVAL;
293
70118837 294 rcu_read_lock();
1da177e4 295 switch (which) {
ec94fc3d 296 case PRIO_PROCESS:
297 if (who)
298 p = find_task_by_vpid(who);
299 else
300 p = current;
301 if (p) {
302 niceval = nice_to_rlimit(task_nice(p));
303 if (niceval > retval)
304 retval = niceval;
305 }
306 break;
307 case PRIO_PGRP:
308 if (who)
309 pgrp = find_vpid(who);
310 else
311 pgrp = task_pgrp(current);
7f8ca0ed 312 read_lock(&tasklist_lock);
ec94fc3d 313 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
314 niceval = nice_to_rlimit(task_nice(p));
315 if (niceval > retval)
316 retval = niceval;
317 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
7f8ca0ed 318 read_unlock(&tasklist_lock);
ec94fc3d 319 break;
320 case PRIO_USER:
321 uid = make_kuid(cred->user_ns, who);
322 user = cred->user;
323 if (!who)
324 uid = cred->uid;
325 else if (!uid_eq(uid, cred->uid)) {
326 user = find_user(uid);
327 if (!user)
328 goto out_unlock; /* No processes for this user */
329 }
7f8ca0ed 330 for_each_process_thread(g, p) {
8639b461 331 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) {
7aa2c016 332 niceval = nice_to_rlimit(task_nice(p));
1da177e4
LT		 333 if (niceval > retval)
334 retval = niceval;
335 }
7f8ca0ed 336 }
ec94fc3d 337 if (!uid_eq(uid, cred->uid))
338 free_uid(user); /* for find_user() */
339 break;
1da177e4
LT		 340 }
341out_unlock:
70118837 342 rcu_read_unlock();
1da177e4
LT		 343
344 return retval;
345}
346
1da177e4
LT		 347/*
348 * Unprivileged users may change the real gid to the effective gid
349 * or vice versa. (BSD-style)
350 *
351 * If you set the real gid at all, or set the effective gid to a value not
352 * equal to the real gid, then the saved gid is set to the new effective gid.
353 *
354 * This makes it possible for a setgid program to completely drop its
355 * privileges, which is often a useful assertion to make when you are doing
356 * a security audit over a program.
357 *
358 * The general idea is that a program which uses just setregid() will be
359 * 100% compatible with BSD. A program which uses just setgid() will be
ec94fc3d 360 * 100% compatible with POSIX with saved IDs.
1da177e4
LT		 361 *
362 * SMP: There are not races, the GIDs are checked only by filesystem
363 * operations (as far as semantic preservation is concerned).
364 */
2813893f 365#ifdef CONFIG_MULTIUSER
e530dca5 366long __sys_setregid(gid_t rgid, gid_t egid)
1da177e4 367{
a29c33f4 368 struct user_namespace *ns = current_user_ns();
d84f4f99
DH		 369 const struct cred *old;
370 struct cred *new;
1da177e4 371 int retval;
a29c33f4
EB		 372 kgid_t krgid, kegid;
373
374 krgid = make_kgid(ns, rgid);
375 kegid = make_kgid(ns, egid);
376
377 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
378 return -EINVAL;
379 if ((egid != (gid_t) -1) && !gid_valid(kegid))
380 return -EINVAL;
1da177e4 381
d84f4f99
DH		 382 new = prepare_creds();
383 if (!new)
384 return -ENOMEM;
385 old = current_cred();
386
d84f4f99 387 retval = -EPERM;
1da177e4 388 if (rgid != (gid_t) -1) {
a29c33f4
EB		 389 if (gid_eq(old->gid, krgid) ||
390 gid_eq(old->egid, krgid) ||
111767c1 391 ns_capable_setid(old->user_ns, CAP_SETGID))
a29c33f4 392 new->gid = krgid;
1da177e4 393 else
d84f4f99 394 goto error;
1da177e4
LT		 395 }
396 if (egid != (gid_t) -1) {
a29c33f4
EB		 397 if (gid_eq(old->gid, kegid) ||
398 gid_eq(old->egid, kegid) ||
399 gid_eq(old->sgid, kegid) ||
111767c1 400 ns_capable_setid(old->user_ns, CAP_SETGID))
a29c33f4 401 new->egid = kegid;
756184b7 402 else
d84f4f99 403 goto error;
1da177e4 404 }
d84f4f99 405
1da177e4 406 if (rgid != (gid_t) -1 ||
a29c33f4 407 (egid != (gid_t) -1 && !gid_eq(kegid, old->gid)))
d84f4f99
DH		 408 new->sgid = new->egid;
409 new->fsgid = new->egid;
410
39030e13
TC		 411 retval = security_task_fix_setgid(new, old, LSM_SETID_RE);
412 if (retval < 0)
413 goto error;
414
d84f4f99
DH		 415 return commit_creds(new);
416
417error:
418 abort_creds(new);
419 return retval;
1da177e4
LT		 420}
421
e530dca5
DB		 422SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
423{
424 return __sys_setregid(rgid, egid);
425}
426
1da177e4 427/*
ec94fc3d 428 * setgid() is implemented like SysV w/ SAVED_IDS
1da177e4
LT		 429 *
430 * SMP: Same implicit races as above.
431 */
e530dca5 432long __sys_setgid(gid_t gid)
1da177e4 433{
a29c33f4 434 struct user_namespace *ns = current_user_ns();
d84f4f99
DH		 435 const struct cred *old;
436 struct cred *new;
1da177e4 437 int retval;
a29c33f4
EB		 438 kgid_t kgid;
439
440 kgid = make_kgid(ns, gid);
441 if (!gid_valid(kgid))
442 return -EINVAL;
1da177e4 443
d84f4f99
DH		 444 new = prepare_creds();
445 if (!new)
446 return -ENOMEM;
447 old = current_cred();
448
d84f4f99 449 retval = -EPERM;
111767c1 450 if (ns_capable_setid(old->user_ns, CAP_SETGID))
a29c33f4
EB		 451 new->gid = new->egid = new->sgid = new->fsgid = kgid;
452 else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid))
453 new->egid = new->fsgid = kgid;
1da177e4 454 else
d84f4f99 455 goto error;
1da177e4 456
39030e13
TC		 457 retval = security_task_fix_setgid(new, old, LSM_SETID_ID);
458 if (retval < 0)
459 goto error;
460
d84f4f99
DH		 461 return commit_creds(new);
462
463error:
464 abort_creds(new);
465 return retval;
1da177e4 466}
54e99124 467
e530dca5
DB		 468SYSCALL_DEFINE1(setgid, gid_t, gid)
469{
470 return __sys_setgid(gid);
471}
472
d84f4f99
DH		 473/*
474 * change the user struct in a credentials set to match the new UID
475 */
476static int set_user(struct cred *new)
1da177e4
LT		 477{
478 struct user_struct *new_user;
479
078de5f7 480 new_user = alloc_uid(new->uid);
1da177e4
LT		 481 if (!new_user)
482 return -EAGAIN;
483
c923a8e7
EB		 484 free_uid(new->user);
485 new->user = new_user;
486 return 0;
487}
488
489static void flag_nproc_exceeded(struct cred *new)
490{
491 if (new->ucounts == current_ucounts())
492 return;
493
72fa5997
VK		 494 /*
495 * We don't fail in case of NPROC limit excess here because too many
496 * poorly written programs don't check set*uid() return code, assuming
497 * it never fails if called by root. We may still enforce NPROC limit
498 * for programs doing set*uid()+execve() by harmlessly deferring the
499 * failure to the execve() stage.
500 */
de399236 501 if (is_rlimit_overlimit(new->ucounts, UCOUNT_RLIMIT_NPROC, rlimit(RLIMIT_NPROC)) &&
c923a8e7 502 new->user != INIT_USER)
72fa5997
VK		 503 current->flags |= PF_NPROC_EXCEEDED;
504 else
505 current->flags &= ~PF_NPROC_EXCEEDED;
1da177e4
LT		 506}
507
508/*
509 * Unprivileged users may change the real uid to the effective uid
510 * or vice versa. (BSD-style)
511 *
512 * If you set the real uid at all, or set the effective uid to a value not
513 * equal to the real uid, then the saved uid is set to the new effective uid.
514 *
515 * This makes it possible for a setuid program to completely drop its
516 * privileges, which is often a useful assertion to make when you are doing
517 * a security audit over a program.
518 *
519 * The general idea is that a program which uses just setreuid() will be
520 * 100% compatible with BSD. A program which uses just setuid() will be
ec94fc3d 521 * 100% compatible with POSIX with saved IDs.
1da177e4 522 */
e530dca5 523long __sys_setreuid(uid_t ruid, uid_t euid)
1da177e4 524{
a29c33f4 525 struct user_namespace *ns = current_user_ns();
d84f4f99
DH		 526 const struct cred *old;
527 struct cred *new;
1da177e4 528 int retval;
a29c33f4
EB		 529 kuid_t kruid, keuid;
530
531 kruid = make_kuid(ns, ruid);
532 keuid = make_kuid(ns, euid);
533
534 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
535 return -EINVAL;
536 if ((euid != (uid_t) -1) && !uid_valid(keuid))
537 return -EINVAL;
1da177e4 538
d84f4f99
DH		 539 new = prepare_creds();
540 if (!new)
541 return -ENOMEM;
542 old = current_cred();
543
d84f4f99 544 retval = -EPERM;
1da177e4 545 if (ruid != (uid_t) -1) {
a29c33f4
EB		 546 new->uid = kruid;
547 if (!uid_eq(old->uid, kruid) &&
548 !uid_eq(old->euid, kruid) &&
40852275 549 !ns_capable_setid(old->user_ns, CAP_SETUID))
d84f4f99 550 goto error;
1da177e4
LT		 551 }
552
553 if (euid != (uid_t) -1) {
a29c33f4
EB		 554 new->euid = keuid;
555 if (!uid_eq(old->uid, keuid) &&
556 !uid_eq(old->euid, keuid) &&
557 !uid_eq(old->suid, keuid) &&
40852275 558 !ns_capable_setid(old->user_ns, CAP_SETUID))
d84f4f99 559 goto error;
1da177e4
LT		 560 }
561
a29c33f4 562 if (!uid_eq(new->uid, old->uid)) {
54e99124
DG		 563 retval = set_user(new);
564 if (retval < 0)
565 goto error;
566 }
1da177e4 567 if (ruid != (uid_t) -1 ||
a29c33f4 568 (euid != (uid_t) -1 && !uid_eq(keuid, old->uid)))
d84f4f99
DH		 569 new->suid = new->euid;
570 new->fsuid = new->euid;
1da177e4 571
d84f4f99
DH		 572 retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
573 if (retval < 0)
574 goto error;
1da177e4 575
905ae01c
AG		 576 retval = set_cred_ucounts(new);
577 if (retval < 0)
578 goto error;
579
c923a8e7 580 flag_nproc_exceeded(new);
d84f4f99 581 return commit_creds(new);
1da177e4 582
d84f4f99
DH		 583error:
584 abort_creds(new);
585 return retval;
586}
ec94fc3d 587
e530dca5
DB		 588SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
589{
590 return __sys_setreuid(ruid, euid);
591}
592
1da177e4 593/*
ec94fc3d 594 * setuid() is implemented like SysV with SAVED_IDS
595 *
1da177e4 596 * Note that SAVED_ID's is deficient in that a setuid root program
ec94fc3d 597 * like sendmail, for example, cannot set its uid to be a normal
1da177e4
LT		 598 * user and then switch back, because if you're root, setuid() sets
599 * the saved uid too. If you don't like this, blame the bright people
600 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
601 * will allow a root program to temporarily drop privileges and be able to
ec94fc3d 602 * regain them by swapping the real and effective uid.
1da177e4 603 */
e530dca5 604long __sys_setuid(uid_t uid)
1da177e4 605{
a29c33f4 606 struct user_namespace *ns = current_user_ns();
d84f4f99
DH		 607 const struct cred *old;
608 struct cred *new;
1da177e4 609 int retval;
a29c33f4
EB		 610 kuid_t kuid;
611
612 kuid = make_kuid(ns, uid);
613 if (!uid_valid(kuid))
614 return -EINVAL;
1da177e4 615
d84f4f99
DH		 616 new = prepare_creds();
617 if (!new)
618 return -ENOMEM;
619 old = current_cred();
620
d84f4f99 621 retval = -EPERM;
40852275 622 if (ns_capable_setid(old->user_ns, CAP_SETUID)) {
a29c33f4
EB		 623 new->suid = new->uid = kuid;
624 if (!uid_eq(kuid, old->uid)) {
54e99124
DG		 625 retval = set_user(new);
626 if (retval < 0)
627 goto error;
d84f4f99 628 }
a29c33f4 629 } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) {
d84f4f99 630 goto error;
1da177e4 631 }
1da177e4 632
a29c33f4 633 new->fsuid = new->euid = kuid;
d84f4f99
DH		 634
635 retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
636 if (retval < 0)
637 goto error;
1da177e4 638
905ae01c
AG		 639 retval = set_cred_ucounts(new);
640 if (retval < 0)
641 goto error;
642
c923a8e7 643 flag_nproc_exceeded(new);
d84f4f99 644 return commit_creds(new);
1da177e4 645
d84f4f99
DH		 646error:
647 abort_creds(new);
648 return retval;
1da177e4
LT		 649}
650
e530dca5
DB		 651SYSCALL_DEFINE1(setuid, uid_t, uid)
652{
653 return __sys_setuid(uid);
654}
655
1da177e4
LT		 656
657/*
658 * This function implements a generic ability to update ruid, euid,
659 * and suid. This allows you to implement the 4.4 compatible seteuid().
660 */
e530dca5 661long __sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
1da177e4 662{
a29c33f4 663 struct user_namespace *ns = current_user_ns();
d84f4f99
DH		 664 const struct cred *old;
665 struct cred *new;
1da177e4 666 int retval;
a29c33f4 667 kuid_t kruid, keuid, ksuid;
659c0ce1 668 bool ruid_new, euid_new, suid_new;
a29c33f4
EB		 669
670 kruid = make_kuid(ns, ruid);
671 keuid = make_kuid(ns, euid);
672 ksuid = make_kuid(ns, suid);
673
674 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
675 return -EINVAL;
676
677 if ((euid != (uid_t) -1) && !uid_valid(keuid))
678 return -EINVAL;
679
680 if ((suid != (uid_t) -1) && !uid_valid(ksuid))
681 return -EINVAL;
1da177e4 682
659c0ce1
OM		 683 old = current_cred();
684
685 /* check for no-op */
686 if ((ruid == (uid_t) -1 || uid_eq(kruid, old->uid)) &&
687 (euid == (uid_t) -1 || (uid_eq(keuid, old->euid) &&
688 uid_eq(keuid, old->fsuid))) &&
689 (suid == (uid_t) -1 || uid_eq(ksuid, old->suid)))
690 return 0;
691
692 ruid_new = ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) &&
693 !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid);
694 euid_new = euid != (uid_t) -1 && !uid_eq(keuid, old->uid) &&
695 !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid);
696 suid_new = suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) &&
697 !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid);
698 if ((ruid_new || euid_new || suid_new) &&
699 !ns_capable_setid(old->user_ns, CAP_SETUID))
700 return -EPERM;
701
d84f4f99
DH		 702 new = prepare_creds();
703 if (!new)
704 return -ENOMEM;
705
1da177e4 706 if (ruid != (uid_t) -1) {
a29c33f4
EB		 707 new->uid = kruid;
708 if (!uid_eq(kruid, old->uid)) {
54e99124
DG		 709 retval = set_user(new);
710 if (retval < 0)
711 goto error;
712 }
1da177e4 713 }
d84f4f99 714 if (euid != (uid_t) -1)
a29c33f4 715 new->euid = keuid;
1da177e4 716 if (suid != (uid_t) -1)
a29c33f4 717 new->suid = ksuid;
d84f4f99 718 new->fsuid = new->euid;
1da177e4 719
d84f4f99
DH		 720 retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
721 if (retval < 0)
722 goto error;
1da177e4 723
905ae01c
AG		 724 retval = set_cred_ucounts(new);
725 if (retval < 0)
726 goto error;
727
c923a8e7 728 flag_nproc_exceeded(new);
d84f4f99 729 return commit_creds(new);
1da177e4 730
d84f4f99
DH		 731error:
732 abort_creds(new);
733 return retval;
1da177e4
LT		 734}
735
e530dca5
DB		 736SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
737{
738 return __sys_setresuid(ruid, euid, suid);
739}
740
a29c33f4 741SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp)
1da177e4 742{
86a264ab 743 const struct cred *cred = current_cred();
1da177e4 744 int retval;
a29c33f4
EB		 745 uid_t ruid, euid, suid;
746
747 ruid = from_kuid_munged(cred->user_ns, cred->uid);
748 euid = from_kuid_munged(cred->user_ns, cred->euid);
749 suid = from_kuid_munged(cred->user_ns, cred->suid);
1da177e4 750
ec94fc3d 751 retval = put_user(ruid, ruidp);
752 if (!retval) {
753 retval = put_user(euid, euidp);
754 if (!retval)
755 return put_user(suid, suidp);
756 }
1da177e4
LT		 757 return retval;
758}
759
760/*
761 * Same as above, but for rgid, egid, sgid.
762 */
e530dca5 763long __sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
1da177e4 764{
a29c33f4 765 struct user_namespace *ns = current_user_ns();
d84f4f99
DH		 766 const struct cred *old;
767 struct cred *new;
1da177e4 768 int retval;
a29c33f4 769 kgid_t krgid, kegid, ksgid;
659c0ce1 770 bool rgid_new, egid_new, sgid_new;
a29c33f4
EB		 771
772 krgid = make_kgid(ns, rgid);
773 kegid = make_kgid(ns, egid);
774 ksgid = make_kgid(ns, sgid);
775
776 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
777 return -EINVAL;
778 if ((egid != (gid_t) -1) && !gid_valid(kegid))
779 return -EINVAL;
780 if ((sgid != (gid_t) -1) && !gid_valid(ksgid))
781 return -EINVAL;
1da177e4 782
659c0ce1
OM		 783 old = current_cred();
784
785 /* check for no-op */
786 if ((rgid == (gid_t) -1 || gid_eq(krgid, old->gid)) &&
787 (egid == (gid_t) -1 || (gid_eq(kegid, old->egid) &&
788 gid_eq(kegid, old->fsgid))) &&
789 (sgid == (gid_t) -1 || gid_eq(ksgid, old->sgid)))
790 return 0;
791
792 rgid_new = rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) &&
793 !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid);
794 egid_new = egid != (gid_t) -1 && !gid_eq(kegid, old->gid) &&
795 !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid);
796 sgid_new = sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) &&
797 !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid);
798 if ((rgid_new || egid_new || sgid_new) &&
799 !ns_capable_setid(old->user_ns, CAP_SETGID))
800 return -EPERM;
801
d84f4f99
DH		 802 new = prepare_creds();
803 if (!new)
804 return -ENOMEM;
d84f4f99 805
1da177e4 806 if (rgid != (gid_t) -1)
a29c33f4 807 new->gid = krgid;
d84f4f99 808 if (egid != (gid_t) -1)
a29c33f4 809 new->egid = kegid;
1da177e4 810 if (sgid != (gid_t) -1)
a29c33f4 811 new->sgid = ksgid;
d84f4f99 812 new->fsgid = new->egid;
1da177e4 813
39030e13
TC		 814 retval = security_task_fix_setgid(new, old, LSM_SETID_RES);
815 if (retval < 0)
816 goto error;
817
d84f4f99
DH		 818 return commit_creds(new);
819
820error:
821 abort_creds(new);
822 return retval;
1da177e4
LT		 823}
824
e530dca5
DB		 825SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
826{
827 return __sys_setresgid(rgid, egid, sgid);
828}
829
a29c33f4 830SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp)
1da177e4 831{
86a264ab 832 const struct cred *cred = current_cred();
1da177e4 833 int retval;
a29c33f4
EB		 834 gid_t rgid, egid, sgid;
835
836 rgid = from_kgid_munged(cred->user_ns, cred->gid);
837 egid = from_kgid_munged(cred->user_ns, cred->egid);
838 sgid = from_kgid_munged(cred->user_ns, cred->sgid);
1da177e4 839
ec94fc3d 840 retval = put_user(rgid, rgidp);
841 if (!retval) {
842 retval = put_user(egid, egidp);
843 if (!retval)
844 retval = put_user(sgid, sgidp);
845 }
1da177e4
LT		 846
847 return retval;
848}
849
850
851/*
852 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
853 * is used for "access()" and for the NFS daemon (letting nfsd stay at
854 * whatever uid it wants to). It normally shadows "euid", except when
855 * explicitly set by setfsuid() or for access..
856 */
e530dca5 857long __sys_setfsuid(uid_t uid)
1da177e4 858{
d84f4f99
DH		 859 const struct cred *old;
860 struct cred *new;
861 uid_t old_fsuid;
a29c33f4
EB		 862 kuid_t kuid;
863
864 old = current_cred();
865 old_fsuid = from_kuid_munged(old->user_ns, old->fsuid);
866
867 kuid = make_kuid(old->user_ns, uid);
868 if (!uid_valid(kuid))
869 return old_fsuid;
1da177e4 870
d84f4f99
DH		 871 new = prepare_creds();
872 if (!new)
a29c33f4 873 return old_fsuid;
1da177e4 874
a29c33f4
EB		 875 if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) ||
876 uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) ||
40852275 877 ns_capable_setid(old->user_ns, CAP_SETUID)) {
a29c33f4
EB		 878 if (!uid_eq(kuid, old->fsuid)) {
879 new->fsuid = kuid;
d84f4f99
DH		 880 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
881 goto change_okay;
1da177e4 882 }
1da177e4
LT		 883 }
884
d84f4f99
DH		 885 abort_creds(new);
886 return old_fsuid;
1da177e4 887
d84f4f99
DH		 888change_okay:
889 commit_creds(new);
1da177e4
LT		 890 return old_fsuid;
891}
892
e530dca5
DB		 893SYSCALL_DEFINE1(setfsuid, uid_t, uid)
894{
895 return __sys_setfsuid(uid);
896}
897
1da177e4 898/*
f42df9e6 899 * Samma på svenska..
1da177e4 900 */
e530dca5 901long __sys_setfsgid(gid_t gid)
1da177e4 902{
d84f4f99
DH		 903 const struct cred *old;
904 struct cred *new;
905 gid_t old_fsgid;
a29c33f4
EB		 906 kgid_t kgid;
907
908 old = current_cred();
909 old_fsgid = from_kgid_munged(old->user_ns, old->fsgid);
910
911 kgid = make_kgid(old->user_ns, gid);
912 if (!gid_valid(kgid))
913 return old_fsgid;
d84f4f99
DH		 914
915 new = prepare_creds();
916 if (!new)
a29c33f4 917 return old_fsgid;
1da177e4 918
a29c33f4
EB		 919 if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) ||
920 gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) ||
111767c1 921 ns_capable_setid(old->user_ns, CAP_SETGID)) {
a29c33f4
EB		 922 if (!gid_eq(kgid, old->fsgid)) {
923 new->fsgid = kgid;
39030e13
TC		 924 if (security_task_fix_setgid(new,old,LSM_SETID_FS) == 0)
925 goto change_okay;
1da177e4 926 }
1da177e4 927 }
d84f4f99 928
d84f4f99
DH		 929 abort_creds(new);
930 return old_fsgid;
931
932change_okay:
933 commit_creds(new);
1da177e4
LT		 934 return old_fsgid;
935}
e530dca5
DB		 936
937SYSCALL_DEFINE1(setfsgid, gid_t, gid)
938{
939 return __sys_setfsgid(gid);
940}
2813893f 941#endif /* CONFIG_MULTIUSER */
1da177e4 942
4a22f166
SR		 943/**
944 * sys_getpid - return the thread group id of the current process
945 *
946 * Note, despite the name, this returns the tgid not the pid. The tgid and
947 * the pid are identical unless CLONE_THREAD was specified on clone() in
948 * which case the tgid is the same in all threads of the same group.
949 *
950 * This is SMP safe as current->tgid does not change.
951 */
952SYSCALL_DEFINE0(getpid)
953{
954 return task_tgid_vnr(current);
955}
956
957/* Thread ID - the internal kernel "pid" */
958SYSCALL_DEFINE0(gettid)
959{
960 return task_pid_vnr(current);
961}
962
963/*
964 * Accessing ->real_parent is not SMP-safe, it could
965 * change from under us. However, we can use a stale
966 * value of ->real_parent under rcu_read_lock(), see
967 * release_task()->call_rcu(delayed_put_task_struct).
968 */
969SYSCALL_DEFINE0(getppid)
970{
971 int pid;
972
973 rcu_read_lock();
974 pid = task_tgid_vnr(rcu_dereference(current->real_parent));
975 rcu_read_unlock();
976
977 return pid;
978}
979
980SYSCALL_DEFINE0(getuid)
981{
982 /* Only we change this so SMP safe */
983 return from_kuid_munged(current_user_ns(), current_uid());
984}
985
986SYSCALL_DEFINE0(geteuid)
987{
988 /* Only we change this so SMP safe */
989 return from_kuid_munged(current_user_ns(), current_euid());
990}
991
992SYSCALL_DEFINE0(getgid)
993{
994 /* Only we change this so SMP safe */
995 return from_kgid_munged(current_user_ns(), current_gid());
996}
997
998SYSCALL_DEFINE0(getegid)
999{
1000 /* Only we change this so SMP safe */
1001 return from_kgid_munged(current_user_ns(), current_egid());
1002}
1003
ca2406ed 1004static void do_sys_times(struct tms *tms)
f06febc9 1005{
5613fda9 1006 u64 tgutime, tgstime, cutime, cstime;
f06febc9 1007
e80d0a1a 1008 thread_group_cputime_adjusted(current, &tgutime, &tgstime);
f06febc9
FM		 1009 cutime = current->signal->cutime;
1010 cstime = current->signal->cstime;
5613fda9
FW		 1011 tms->tms_utime = nsec_to_clock_t(tgutime);
1012 tms->tms_stime = nsec_to_clock_t(tgstime);
1013 tms->tms_cutime = nsec_to_clock_t(cutime);
1014 tms->tms_cstime = nsec_to_clock_t(cstime);
f06febc9
FM		 1015}
1016
58fd3aa2 1017SYSCALL_DEFINE1(times, struct tms __user *, tbuf)
1da177e4 1018{
1da177e4
LT		 1019 if (tbuf) {
1020 struct tms tmp;
f06febc9
FM		 1021
1022 do_sys_times(&tmp);
1da177e4
LT		 1023 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
1024 return -EFAULT;
1025 }
e3d5a27d 1026 force_successful_syscall_return();
1da177e4
LT		 1027 return (long) jiffies_64_to_clock_t(get_jiffies_64());
1028}
1029
ca2406ed
AV		 1030#ifdef CONFIG_COMPAT
1031static compat_clock_t clock_t_to_compat_clock_t(clock_t x)
1032{
1033 return compat_jiffies_to_clock_t(clock_t_to_jiffies(x));
1034}
1035
1036COMPAT_SYSCALL_DEFINE1(times, struct compat_tms __user *, tbuf)
1037{
1038 if (tbuf) {
1039 struct tms tms;
1040 struct compat_tms tmp;
1041
1042 do_sys_times(&tms);
1043 /* Convert our struct tms to the compat version. */
1044 tmp.tms_utime = clock_t_to_compat_clock_t(tms.tms_utime);
1045 tmp.tms_stime = clock_t_to_compat_clock_t(tms.tms_stime);
1046 tmp.tms_cutime = clock_t_to_compat_clock_t(tms.tms_cutime);
1047 tmp.tms_cstime = clock_t_to_compat_clock_t(tms.tms_cstime);
1048 if (copy_to_user(tbuf, &tmp, sizeof(tmp)))
1049 return -EFAULT;
1050 }
1051 force_successful_syscall_return();
1052 return compat_jiffies_to_clock_t(jiffies);
1053}
1054#endif
1055
1da177e4
LT		 1056/*
1057 * This needs some heavy checking ...
1058 * I just haven't the stomach for it. I also don't fully
1059 * understand sessions/pgrp etc. Let somebody who does explain it.
1060 *
1061 * OK, I think I have the protection semantics right.... this is really
1062 * only important on a multi-user system anyway, to make sure one user
1063 * can't send a signal to a process owned by another. -TYT, 12/12/91
1064 *
98611e4e 1065 * !PF_FORKNOEXEC check to conform completely to POSIX.
1da177e4 1066 */
b290ebe2 1067SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
1da177e4
LT		 1068{
1069 struct task_struct *p;
ee0acf90 1070 struct task_struct *group_leader = current->group_leader;
4e021306
ON		 1071 struct pid *pgrp;
1072 int err;
1da177e4
LT		 1073
1074 if (!pid)
b488893a 1075 pid = task_pid_vnr(group_leader);
1da177e4
LT		 1076 if (!pgid)
1077 pgid = pid;
1078 if (pgid < 0)
1079 return -EINVAL;
950eaaca 1080 rcu_read_lock();
1da177e4
LT		 1081
1082 /* From this point forward we keep holding onto the tasklist lock
1083 * so that our parent does not change from under us. -DaveM
1084 */
1085 write_lock_irq(&tasklist_lock);
1086
1087 err = -ESRCH;
4e021306 1088 p = find_task_by_vpid(pid);
1da177e4
LT		 1089 if (!p)
1090 goto out;
1091
1092 err = -EINVAL;
1093 if (!thread_group_leader(p))
1094 goto out;
1095
4e021306 1096 if (same_thread_group(p->real_parent, group_leader)) {
1da177e4 1097 err = -EPERM;
41487c65 1098 if (task_session(p) != task_session(group_leader))
1da177e4
LT		 1099 goto out;
1100 err = -EACCES;
98611e4e 1101 if (!(p->flags & PF_FORKNOEXEC))
1da177e4
LT		 1102 goto out;
1103 } else {
1104 err = -ESRCH;
ee0acf90 1105 if (p != group_leader)
1da177e4
LT		 1106 goto out;
1107 }
1108
1109 err = -EPERM;
1110 if (p->signal->leader)
1111 goto out;
1112
4e021306 1113 pgrp = task_pid(p);
1da177e4 1114 if (pgid != pid) {
b488893a 1115 struct task_struct *g;
1da177e4 1116
4e021306
ON		 1117 pgrp = find_vpid(pgid);
1118 g = pid_task(pgrp, PIDTYPE_PGID);
41487c65 1119 if (!g || task_session(g) != task_session(group_leader))
f020bc46 1120 goto out;
1da177e4
LT		 1121 }
1122
1da177e4
LT		 1123 err = security_task_setpgid(p, pgid);
1124 if (err)
1125 goto out;
1126
1b0f7ffd 1127 if (task_pgrp(p) != pgrp)
83beaf3c 1128 change_pid(p, PIDTYPE_PGID, pgrp);
1da177e4
LT		 1129
1130 err = 0;
1131out:
1132 /* All paths lead to here, thus we are safe. -DaveM */
1133 write_unlock_irq(&tasklist_lock);
950eaaca 1134 rcu_read_unlock();
1da177e4
LT		 1135 return err;
1136}
1137
192c5807 1138static int do_getpgid(pid_t pid)
1da177e4 1139{
12a3de0a
ON		 1140 struct task_struct *p;
1141 struct pid *grp;
1142 int retval;
1143
1144 rcu_read_lock();
756184b7 1145 if (!pid)
12a3de0a 1146 grp = task_pgrp(current);
756184b7 1147 else {
1da177e4 1148 retval = -ESRCH;
12a3de0a
ON		 1149 p = find_task_by_vpid(pid);
1150 if (!p)
1151 goto out;
1152 grp = task_pgrp(p);
1153 if (!grp)
1154 goto out;
1155
1156 retval = security_task_getpgid(p);
1157 if (retval)
1158 goto out;
1da177e4 1159 }
12a3de0a
ON		 1160 retval = pid_vnr(grp);
1161out:
1162 rcu_read_unlock();
1163 return retval;
1da177e4
LT		 1164}
1165
192c5807
DB		 1166SYSCALL_DEFINE1(getpgid, pid_t, pid)
1167{
1168 return do_getpgid(pid);
1169}
1170
1da177e4
LT		 1171#ifdef __ARCH_WANT_SYS_GETPGRP
1172
dbf040d9 1173SYSCALL_DEFINE0(getpgrp)
1da177e4 1174{
192c5807 1175 return do_getpgid(0);
1da177e4
LT		 1176}
1177
1178#endif
1179
dbf040d9 1180SYSCALL_DEFINE1(getsid, pid_t, pid)
1da177e4 1181{
1dd768c0
ON		 1182 struct task_struct *p;
1183 struct pid *sid;
1184 int retval;
1185
1186 rcu_read_lock();
756184b7 1187 if (!pid)
1dd768c0 1188 sid = task_session(current);
756184b7 1189 else {
1da177e4 1190 retval = -ESRCH;
1dd768c0
ON		 1191 p = find_task_by_vpid(pid);
1192 if (!p)
1193 goto out;
1194 sid = task_session(p);
1195 if (!sid)
1196 goto out;
1197
1198 retval = security_task_getsid(p);
1199 if (retval)
1200 goto out;
1da177e4 1201 }
1dd768c0
ON		 1202 retval = pid_vnr(sid);
1203out:
1204 rcu_read_unlock();
1205 return retval;
1da177e4
LT		 1206}
1207
81dabb46
ON		 1208static void set_special_pids(struct pid *pid)
1209{
1210 struct task_struct *curr = current->group_leader;
1211
1212 if (task_session(curr) != pid)
1213 change_pid(curr, PIDTYPE_SID, pid);
1214
1215 if (task_pgrp(curr) != pid)
1216 change_pid(curr, PIDTYPE_PGID, pid);
1217}
1218
e2aaa9f4 1219int ksys_setsid(void)
1da177e4 1220{
e19f247a 1221 struct task_struct *group_leader = current->group_leader;
e4cc0a9c
ON		 1222 struct pid *sid = task_pid(group_leader);
1223 pid_t session = pid_vnr(sid);
1da177e4
LT		 1224 int err = -EPERM;
1225
1da177e4 1226 write_lock_irq(&tasklist_lock);
390e2ff0
EB		 1227 /* Fail if I am already a session leader */
1228 if (group_leader->signal->leader)
1229 goto out;
1230
430c6231
ON		 1231 /* Fail if a process group id already exists that equals the
1232 * proposed session id.
390e2ff0 1233 */
6806aac6 1234 if (pid_task(sid, PIDTYPE_PGID))
1da177e4
LT		 1235 goto out;
1236
e19f247a 1237 group_leader->signal->leader = 1;
81dabb46 1238 set_special_pids(sid);
24ec839c 1239
9c9f4ded 1240 proc_clear_tty(group_leader);
24ec839c 1241
e4cc0a9c 1242 err = session;
1da177e4
LT		 1243out:
1244 write_unlock_irq(&tasklist_lock);
5091faa4 1245 if (err > 0) {
0d0df599 1246 proc_sid_connector(group_leader);
5091faa4
MG		 1247 sched_autogroup_create_attach(group_leader);
1248 }
1da177e4
LT		 1249 return err;
1250}
1251
e2aaa9f4
DB		 1252SYSCALL_DEFINE0(setsid)
1253{
1254 return ksys_setsid();
1255}
1256
1da177e4
LT		 1257DECLARE_RWSEM(uts_sem);
1258
e28cbf22
CH		 1259#ifdef COMPAT_UTS_MACHINE
1260#define override_architecture(name) \
46da2766 1261 (personality(current->personality) == PER_LINUX32 && \
e28cbf22
CH		 1262 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \
1263 sizeof(COMPAT_UTS_MACHINE)))
1264#else
1265#define override_architecture(name) 0
1266#endif
1267
be27425d
AK		 1268/*
1269 * Work around broken programs that cannot handle "Linux 3.0".
1270 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40
b7285b42
JN		 1271 * And we map 4.x and later versions to 2.6.60+x, so 4.0/5.0/6.0/... would be
1272 * 2.6.60.
be27425d 1273 */
2702b152 1274static int override_release(char __user *release, size_t len)
be27425d
AK		 1275{
1276 int ret = 0;
be27425d
AK		 1277
1278 if (current->personality & UNAME26) {
2702b152
KC		 1279 const char *rest = UTS_RELEASE;
1280 char buf[65] = { 0 };
be27425d
AK		 1281 int ndots = 0;
1282 unsigned v;
2702b152 1283 size_t copy;
be27425d
AK		 1284
1285 while (*rest) {
1286 if (*rest == '.' && ++ndots >= 3)
1287 break;
1288 if (!isdigit(*rest) && *rest != '.')
1289 break;
1290 rest++;
1291 }
88a68672 1292 v = LINUX_VERSION_PATCHLEVEL + 60;
31fd84b9 1293 copy = clamp_t(size_t, len, 1, sizeof(buf));
2702b152
KC		 1294 copy = scnprintf(buf, copy, "2.6.%u%s", v, rest);
1295 ret = copy_to_user(release, buf, copy + 1);
be27425d
AK		 1296 }
1297 return ret;
1298}
1299
e48fbb69 1300SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
1da177e4 1301{
42a0cc34 1302 struct new_utsname tmp;
1da177e4
LT		 1303
1304 down_read(&uts_sem);
42a0cc34 1305 memcpy(&tmp, utsname(), sizeof(tmp));
1da177e4 1306 up_read(&uts_sem);
42a0cc34
JH		 1307 if (copy_to_user(name, &tmp, sizeof(tmp)))
1308 return -EFAULT;
e28cbf22 1309
42a0cc34
JH		 1310 if (override_release(name->release, sizeof(name->release)))
1311 return -EFAULT;
1312 if (override_architecture(name))
1313 return -EFAULT;
1314 return 0;
1da177e4
LT		 1315}
1316
5cacdb4a
CH		 1317#ifdef __ARCH_WANT_SYS_OLD_UNAME
1318/*
1319 * Old cruft
1320 */
1321SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
1322{
42a0cc34 1323 struct old_utsname tmp;
5cacdb4a
CH		 1324
1325 if (!name)
1326 return -EFAULT;
1327
1328 down_read(&uts_sem);
42a0cc34 1329 memcpy(&tmp, utsname(), sizeof(tmp));
5cacdb4a 1330 up_read(&uts_sem);
42a0cc34
JH		 1331 if (copy_to_user(name, &tmp, sizeof(tmp)))
1332 return -EFAULT;
5cacdb4a 1333
42a0cc34
JH		 1334 if (override_release(name->release, sizeof(name->release)))
1335 return -EFAULT;
1336 if (override_architecture(name))
1337 return -EFAULT;
1338 return 0;
5cacdb4a
CH		 1339}
1340
1341SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
1342{
5e1aada0 1343 struct oldold_utsname tmp;
5cacdb4a
CH		 1344
1345 if (!name)
1346 return -EFAULT;
5cacdb4a 1347
5e1aada0
JP		 1348 memset(&tmp, 0, sizeof(tmp));
1349
5cacdb4a 1350 down_read(&uts_sem);
42a0cc34
JH		 1351 memcpy(&tmp.sysname, &utsname()->sysname, __OLD_UTS_LEN);
1352 memcpy(&tmp.nodename, &utsname()->nodename, __OLD_UTS_LEN);
1353 memcpy(&tmp.release, &utsname()->release, __OLD_UTS_LEN);
1354 memcpy(&tmp.version, &utsname()->version, __OLD_UTS_LEN);
1355 memcpy(&tmp.machine, &utsname()->machine, __OLD_UTS_LEN);
5cacdb4a 1356 up_read(&uts_sem);
42a0cc34
JH		 1357 if (copy_to_user(name, &tmp, sizeof(tmp)))
1358 return -EFAULT;
5cacdb4a 1359
42a0cc34
JH		 1360 if (override_architecture(name))
1361 return -EFAULT;
1362 if (override_release(name->release, sizeof(name->release)))
1363 return -EFAULT;
1364 return 0;
5cacdb4a
CH		 1365}
1366#endif
1367
5a8a82b1 1368SYSCALL_DEFINE2(sethostname, char __user *, name, int, len)
1da177e4
LT		 1369{
1370 int errno;
1371 char tmp[__NEW_UTS_LEN];
1372
bb96a6f5 1373 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1da177e4 1374 return -EPERM;
fc832ad3 1375
1da177e4
LT		 1376 if (len < 0 || len > __NEW_UTS_LEN)
1377 return -EINVAL;
1da177e4
LT		 1378 errno = -EFAULT;
1379 if (!copy_from_user(tmp, name, len)) {
42a0cc34 1380 struct new_utsname *u;
9679e4dd 1381
37608ba3 1382 add_device_randomness(tmp, len);
42a0cc34
JH		 1383 down_write(&uts_sem);
1384 u = utsname();
9679e4dd
AM		 1385 memcpy(u->nodename, tmp, len);
1386 memset(u->nodename + len, 0, sizeof(u->nodename) - len);
1da177e4 1387 errno = 0;
499eea6b 1388 uts_proc_notify(UTS_PROC_HOSTNAME);
42a0cc34 1389 up_write(&uts_sem);
1da177e4 1390 }
1da177e4
LT		 1391 return errno;
1392}
1393
1394#ifdef __ARCH_WANT_SYS_GETHOSTNAME
1395
5a8a82b1 1396SYSCALL_DEFINE2(gethostname, char __user *, name, int, len)
1da177e4 1397{
42a0cc34 1398 int i;
9679e4dd 1399 struct new_utsname *u;
42a0cc34 1400 char tmp[__NEW_UTS_LEN + 1];
1da177e4
LT		 1401
1402 if (len < 0)
1403 return -EINVAL;
1404 down_read(&uts_sem);
9679e4dd
AM		 1405 u = utsname();
1406 i = 1 + strlen(u->nodename);
1da177e4
LT		 1407 if (i > len)
1408 i = len;
42a0cc34 1409 memcpy(tmp, u->nodename, i);
1da177e4 1410 up_read(&uts_sem);
42a0cc34
JH		 1411 if (copy_to_user(name, tmp, i))
1412 return -EFAULT;
1413 return 0;
1da177e4
LT		 1414}
1415
1416#endif
1417
1418/*
1419 * Only setdomainname; getdomainname can be implemented by calling
1420 * uname()
1421 */
5a8a82b1 1422SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
1da177e4
LT		 1423{
1424 int errno;
1425 char tmp[__NEW_UTS_LEN];
1426
fc832ad3 1427 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1da177e4
LT		 1428 return -EPERM;
1429 if (len < 0 || len > __NEW_UTS_LEN)
1430 return -EINVAL;
1431
1da177e4
LT		 1432 errno = -EFAULT;
1433 if (!copy_from_user(tmp, name, len)) {
42a0cc34 1434 struct new_utsname *u;
9679e4dd 1435
37608ba3 1436 add_device_randomness(tmp, len);
42a0cc34
JH		 1437 down_write(&uts_sem);
1438 u = utsname();
9679e4dd
AM		 1439 memcpy(u->domainname, tmp, len);
1440 memset(u->domainname + len, 0, sizeof(u->domainname) - len);
1da177e4 1441 errno = 0;
499eea6b 1442 uts_proc_notify(UTS_PROC_DOMAINNAME);
42a0cc34 1443 up_write(&uts_sem);
1da177e4 1444 }
1da177e4
LT		 1445 return errno;
1446}
1447
c57bef02
BR		 1448/* make sure you are allowed to change @tsk limits before calling this */
1449static int do_prlimit(struct task_struct *tsk, unsigned int resource,
1450 struct rlimit *new_rlim, struct rlimit *old_rlim)
1451{
1452 struct rlimit *rlim;
1453 int retval = 0;
1454
1455 if (resource >= RLIM_NLIMITS)
1456 return -EINVAL;
73979060
GKH		 1457 resource = array_index_nospec(resource, RLIM_NLIMITS);
1458
c57bef02
BR		 1459 if (new_rlim) {
1460 if (new_rlim->rlim_cur > new_rlim->rlim_max)
1461 return -EINVAL;
1462 if (resource == RLIMIT_NOFILE &&
1463 new_rlim->rlim_max > sysctl_nr_open)
1464 return -EPERM;
1465 }
1466
18c91bb2 1467 /* Holding a refcount on tsk protects tsk->signal from disappearing. */
c57bef02
BR		 1468 rlim = tsk->signal->rlim + resource;
1469 task_lock(tsk->group_leader);
1470 if (new_rlim) {
1471 /*
1472 * Keep the capable check against init_user_ns until cgroups can
1473 * contain all limits.
1474 */
1475 if (new_rlim->rlim_max > rlim->rlim_max &&
1476 !capable(CAP_SYS_RESOURCE))
1477 retval = -EPERM;
1478 if (!retval)
1479 retval = security_task_setrlimit(tsk, resource, new_rlim);
1480 }
1481 if (!retval) {
1482 if (old_rlim)
1483 *old_rlim = *rlim;
1484 if (new_rlim)
1485 *rlim = *new_rlim;
1486 }
1487 task_unlock(tsk->group_leader);
1488
1489 /*
1490 * RLIMIT_CPU handling. Arm the posix CPU timer if the limit is not
1491 * infinite. In case of RLIM_INFINITY the posix CPU timer code
1492 * ignores the rlimit.
1493 */
1494 if (!retval && new_rlim && resource == RLIMIT_CPU &&
1495 new_rlim->rlim_cur != RLIM_INFINITY &&
18c91bb2
BR		 1496 IS_ENABLED(CONFIG_POSIX_TIMERS)) {
1497 /*
1498 * update_rlimit_cpu can fail if the task is exiting, but there
1499 * may be other tasks in the thread group that are not exiting,
1500 * and they need their cpu timers adjusted.
1501 *
1502 * The group_leader is the last task to be released, so if we
1503 * cannot update_rlimit_cpu on it, then the entire process is
1504 * exiting and we do not need to update at all.
1505 */
1506 update_rlimit_cpu(tsk->group_leader, new_rlim->rlim_cur);
1507 }
1508
c57bef02
BR		 1509 return retval;
1510}
1511
e48fbb69 1512SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1da177e4 1513{
b9518345
JS		 1514 struct rlimit value;
1515 int ret;
1516
1517 ret = do_prlimit(current, resource, NULL, &value);
1518 if (!ret)
1519 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1520
1521 return ret;
1da177e4
LT		 1522}
1523
d9e968cb
AV		 1524#ifdef CONFIG_COMPAT
1525
1526COMPAT_SYSCALL_DEFINE2(setrlimit, unsigned int, resource,
1527 struct compat_rlimit __user *, rlim)
1528{
1529 struct rlimit r;
1530 struct compat_rlimit r32;
1531
1532 if (copy_from_user(&r32, rlim, sizeof(struct compat_rlimit)))
1533 return -EFAULT;
1534
1535 if (r32.rlim_cur == COMPAT_RLIM_INFINITY)
1536 r.rlim_cur = RLIM_INFINITY;
1537 else
1538 r.rlim_cur = r32.rlim_cur;
1539 if (r32.rlim_max == COMPAT_RLIM_INFINITY)
1540 r.rlim_max = RLIM_INFINITY;
1541 else
1542 r.rlim_max = r32.rlim_max;
1543 return do_prlimit(current, resource, &r, NULL);
1544}
1545
1546COMPAT_SYSCALL_DEFINE2(getrlimit, unsigned int, resource,
1547 struct compat_rlimit __user *, rlim)
1548{
1549 struct rlimit r;
1550 int ret;
1551
1552 ret = do_prlimit(current, resource, NULL, &r);
1553 if (!ret) {
58c7ffc0 1554 struct compat_rlimit r32;
d9e968cb
AV		 1555 if (r.rlim_cur > COMPAT_RLIM_INFINITY)
1556 r32.rlim_cur = COMPAT_RLIM_INFINITY;
1557 else
1558 r32.rlim_cur = r.rlim_cur;
1559 if (r.rlim_max > COMPAT_RLIM_INFINITY)
1560 r32.rlim_max = COMPAT_RLIM_INFINITY;
1561 else
1562 r32.rlim_max = r.rlim_max;
1563
1564 if (copy_to_user(rlim, &r32, sizeof(struct compat_rlimit)))
1565 return -EFAULT;
1566 }
1567 return ret;
1568}
1569
1570#endif
1571
1da177e4
LT		 1572#ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1573
1574/*
1575 * Back compatibility for getrlimit. Needed for some apps.
1576 */
e48fbb69
HC		 1577SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1578 struct rlimit __user *, rlim)
1da177e4
LT		 1579{
1580 struct rlimit x;
1581 if (resource >= RLIM_NLIMITS)
1582 return -EINVAL;
1583
23d6aef7 1584 resource = array_index_nospec(resource, RLIM_NLIMITS);
1da177e4
LT		 1585 task_lock(current->group_leader);
1586 x = current->signal->rlim[resource];
1587 task_unlock(current->group_leader);
756184b7 1588 if (x.rlim_cur > 0x7FFFFFFF)
1da177e4 1589 x.rlim_cur = 0x7FFFFFFF;
756184b7 1590 if (x.rlim_max > 0x7FFFFFFF)
1da177e4 1591 x.rlim_max = 0x7FFFFFFF;
ec94fc3d 1592 return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0;
1da177e4
LT		 1593}
1594
613763a1
AV		 1595#ifdef CONFIG_COMPAT
1596COMPAT_SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1597 struct compat_rlimit __user *, rlim)
1598{
1599 struct rlimit r;
1600
1601 if (resource >= RLIM_NLIMITS)
1602 return -EINVAL;
1603
23d6aef7 1604 resource = array_index_nospec(resource, RLIM_NLIMITS);
613763a1
AV		 1605 task_lock(current->group_leader);
1606 r = current->signal->rlim[resource];
1607 task_unlock(current->group_leader);
1608 if (r.rlim_cur > 0x7FFFFFFF)
1609 r.rlim_cur = 0x7FFFFFFF;
1610 if (r.rlim_max > 0x7FFFFFFF)
1611 r.rlim_max = 0x7FFFFFFF;
1612
1613 if (put_user(r.rlim_cur, &rlim->rlim_cur) ||
1614 put_user(r.rlim_max, &rlim->rlim_max))
1615 return -EFAULT;
1616 return 0;
1617}
1618#endif
1619
1da177e4
LT		 1620#endif
1621
c022a0ac
JS		 1622static inline bool rlim64_is_infinity(__u64 rlim64)
1623{
1624#if BITS_PER_LONG < 64
1625 return rlim64 >= ULONG_MAX;
1626#else
1627 return rlim64 == RLIM64_INFINITY;
1628#endif
1629}
1630
1631static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64)
1632{
1633 if (rlim->rlim_cur == RLIM_INFINITY)
1634 rlim64->rlim_cur = RLIM64_INFINITY;
1635 else
1636 rlim64->rlim_cur = rlim->rlim_cur;
1637 if (rlim->rlim_max == RLIM_INFINITY)
1638 rlim64->rlim_max = RLIM64_INFINITY;
1639 else
1640 rlim64->rlim_max = rlim->rlim_max;
1641}
1642
1643static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim)
1644{
1645 if (rlim64_is_infinity(rlim64->rlim_cur))
1646 rlim->rlim_cur = RLIM_INFINITY;
1647 else
1648 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur;
1649 if (rlim64_is_infinity(rlim64->rlim_max))
1650 rlim->rlim_max = RLIM_INFINITY;
1651 else
1652 rlim->rlim_max = (unsigned long)rlim64->rlim_max;
1653}
1654
c022a0ac 1655/* rcu lock must be held */
791ec491
SS		 1656static int check_prlimit_permission(struct task_struct *task,
1657 unsigned int flags)
c022a0ac
JS		 1658{
1659 const struct cred *cred = current_cred(), *tcred;
791ec491 1660 bool id_match;
c022a0ac 1661
fc832ad3
SH		 1662 if (current == task)
1663 return 0;
c022a0ac 1664
fc832ad3 1665 tcred = __task_cred(task);
791ec491
SS		 1666 id_match = (uid_eq(cred->uid, tcred->euid) &&
1667 uid_eq(cred->uid, tcred->suid) &&
1668 uid_eq(cred->uid, tcred->uid) &&
1669 gid_eq(cred->gid, tcred->egid) &&
1670 gid_eq(cred->gid, tcred->sgid) &&
1671 gid_eq(cred->gid, tcred->gid));
1672 if (!id_match && !ns_capable(tcred->user_ns, CAP_SYS_RESOURCE))
1673 return -EPERM;
fc832ad3 1674
791ec491 1675 return security_task_prlimit(cred, tcred, flags);
c022a0ac
JS		 1676}
1677
1678SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource,
1679 const struct rlimit64 __user *, new_rlim,
1680 struct rlimit64 __user *, old_rlim)
1681{
1682 struct rlimit64 old64, new64;
1683 struct rlimit old, new;
1684 struct task_struct *tsk;
791ec491 1685 unsigned int checkflags = 0;
c022a0ac
JS		 1686 int ret;
1687
791ec491
SS		 1688 if (old_rlim)
1689 checkflags |= LSM_PRLIMIT_READ;
1690
c022a0ac
JS		 1691 if (new_rlim) {
1692 if (copy_from_user(&new64, new_rlim, sizeof(new64)))
1693 return -EFAULT;
1694 rlim64_to_rlim(&new64, &new);
791ec491 1695 checkflags |= LSM_PRLIMIT_WRITE;
c022a0ac
JS		 1696 }
1697
1698 rcu_read_lock();
1699 tsk = pid ? find_task_by_vpid(pid) : current;
1700 if (!tsk) {
1701 rcu_read_unlock();
1702 return -ESRCH;
1703 }
791ec491 1704 ret = check_prlimit_permission(tsk, checkflags);
c022a0ac
JS		 1705 if (ret) {
1706 rcu_read_unlock();
1707 return ret;
1708 }
1709 get_task_struct(tsk);
1710 rcu_read_unlock();
1711
1712 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL,
1713 old_rlim ? &old : NULL);
1714
1715 if (!ret && old_rlim) {
1716 rlim_to_rlim64(&old, &old64);
1717 if (copy_to_user(old_rlim, &old64, sizeof(old64)))
1718 ret = -EFAULT;
1719 }
1720
1721 put_task_struct(tsk);
1722 return ret;
1723}
1724
7855c35d
JS		 1725SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1726{
1727 struct rlimit new_rlim;
1728
1729 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1730 return -EFAULT;
5b41535a 1731 return do_prlimit(current, resource, &new_rlim, NULL);
7855c35d
JS		 1732}
1733
1da177e4
LT		 1734/*
1735 * It would make sense to put struct rusage in the task_struct,
1736 * except that would make the task_struct be *really big*. After
1737 * task_struct gets moved into malloc'ed memory, it would
1738 * make sense to do this. It will make moving the rest of the information
1739 * a lot simpler! (Which we're not doing right now because we're not
1740 * measuring them yet).
1741 *
1da177e4
LT		 1742 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1743 * races with threads incrementing their own counters. But since word
1744 * reads are atomic, we either get new values or old values and we don't
1745 * care which for the sums. We always take the siglock to protect reading
1746 * the c* fields from p->signal from races with exit.c updating those
1747 * fields when reaping, so a sample either gets all the additions of a
1748 * given child after it's reaped, or none so this sample is before reaping.
2dd0ebcd 1749 *
de047c1b
RT		 1750 * Locking:
1751 * We need to take the siglock for CHILDEREN, SELF and BOTH
1752 * for the cases current multithreaded, non-current single threaded
1753 * non-current multithreaded. Thread traversal is now safe with
1754 * the siglock held.
1755 * Strictly speaking, we donot need to take the siglock if we are current and
1756 * single threaded, as no one else can take our signal_struct away, no one
1757 * else can reap the children to update signal->c* counters, and no one else
1758 * can race with the signal-> fields. If we do not take any lock, the
1759 * signal-> fields could be read out of order while another thread was just
1760 * exiting. So we should place a read memory barrier when we avoid the lock.
1761 * On the writer side, write memory barrier is implied in __exit_signal
1762 * as __exit_signal releases the siglock spinlock after updating the signal->
1763 * fields. But we don't do this yet to keep things simple.
2dd0ebcd 1764 *
1da177e4
LT		 1765 */
1766
f06febc9 1767static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
679c9cd4 1768{
679c9cd4
SK		 1769 r->ru_nvcsw += t->nvcsw;
1770 r->ru_nivcsw += t->nivcsw;
1771 r->ru_minflt += t->min_flt;
1772 r->ru_majflt += t->maj_flt;
1773 r->ru_inblock += task_io_get_inblock(t);
1774 r->ru_oublock += task_io_get_oublock(t);
1775}
1776
ce72a16f 1777void getrusage(struct task_struct *p, int who, struct rusage *r)
1da177e4
LT		 1778{
1779 struct task_struct *t;
1780 unsigned long flags;
5613fda9 1781 u64 tgutime, tgstime, utime, stime;
1f10206c 1782 unsigned long maxrss = 0;
1da177e4 1783
ec94fc3d 1784 memset((char *)r, 0, sizeof (*r));
64861634 1785 utime = stime = 0;
1da177e4 1786
679c9cd4 1787 if (who == RUSAGE_THREAD) {
e80d0a1a 1788 task_cputime_adjusted(current, &utime, &stime);
f06febc9 1789 accumulate_thread_rusage(p, r);
1f10206c 1790 maxrss = p->signal->maxrss;
679c9cd4
SK		 1791 goto out;
1792 }
1793
d6cf723a 1794 if (!lock_task_sighand(p, &flags))
de047c1b 1795 return;
0f59cc4a 1796
1da177e4 1797 switch (who) {
ec94fc3d 1798 case RUSAGE_BOTH:
1799 case RUSAGE_CHILDREN:
1800 utime = p->signal->cutime;
1801 stime = p->signal->cstime;
1802 r->ru_nvcsw = p->signal->cnvcsw;
1803 r->ru_nivcsw = p->signal->cnivcsw;
1804 r->ru_minflt = p->signal->cmin_flt;
1805 r->ru_majflt = p->signal->cmaj_flt;
1806 r->ru_inblock = p->signal->cinblock;
1807 r->ru_oublock = p->signal->coublock;
1808 maxrss = p->signal->cmaxrss;
1809
1810 if (who == RUSAGE_CHILDREN)
1da177e4 1811 break;
df561f66 1812 fallthrough;
0f59cc4a 1813
ec94fc3d 1814 case RUSAGE_SELF:
1815 thread_group_cputime_adjusted(p, &tgutime, &tgstime);
1816 utime += tgutime;
1817 stime += tgstime;
1818 r->ru_nvcsw += p->signal->nvcsw;
1819 r->ru_nivcsw += p->signal->nivcsw;
1820 r->ru_minflt += p->signal->min_flt;
1821 r->ru_majflt += p->signal->maj_flt;
1822 r->ru_inblock += p->signal->inblock;
1823 r->ru_oublock += p->signal->oublock;
1824 if (maxrss < p->signal->maxrss)
1825 maxrss = p->signal->maxrss;
1826 t = p;
1827 do {
1828 accumulate_thread_rusage(t, r);
1829 } while_each_thread(p, t);
1830 break;
1831
1832 default:
1833 BUG();
1da177e4 1834 }
de047c1b 1835 unlock_task_sighand(p, &flags);
de047c1b 1836
679c9cd4 1837out:
bdd565f8
AB		 1838 r->ru_utime = ns_to_kernel_old_timeval(utime);
1839 r->ru_stime = ns_to_kernel_old_timeval(stime);
1f10206c
JP		 1840
1841 if (who != RUSAGE_CHILDREN) {
1842 struct mm_struct *mm = get_task_mm(p);
ec94fc3d 1843
1f10206c
JP		 1844 if (mm) {
1845 setmax_mm_hiwater_rss(&maxrss, mm);
1846 mmput(mm);
1847 }
1848 }
1849 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
1da177e4
LT		 1850}
1851
ce72a16f 1852SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
1da177e4
LT		 1853{
1854 struct rusage r;
ec94fc3d 1855
679c9cd4
SK		 1856 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1857 who != RUSAGE_THREAD)
1da177e4 1858 return -EINVAL;
ce72a16f
AV		 1859
1860 getrusage(current, who, &r);
1861 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1da177e4
LT		 1862}
1863
8d2d5c4a
AV		 1864#ifdef CONFIG_COMPAT
1865COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru)
1866{
1867 struct rusage r;
1868
1869 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1870 who != RUSAGE_THREAD)
1871 return -EINVAL;
1872
ce72a16f 1873 getrusage(current, who, &r);
8d2d5c4a
AV		 1874 return put_compat_rusage(&r, ru);
1875}
1876#endif
1877
e48fbb69 1878SYSCALL_DEFINE1(umask, int, mask)
1da177e4
LT		 1879{
1880 mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1881 return mask;
1882}
3b7391de 1883
6e399cd1 1884static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
b32dfe37 1885{
2903ff01 1886 struct fd exe;
496ad9aa 1887 struct inode *inode;
2903ff01 1888 int err;
b32dfe37 1889
2903ff01
AV		 1890 exe = fdget(fd);
1891 if (!exe.file)
b32dfe37
CG		 1892 return -EBADF;
1893
496ad9aa 1894 inode = file_inode(exe.file);
b32dfe37
CG		 1895
1896 /*
1897 * Because the original mm->exe_file points to executable file, make
1898 * sure that this one is executable as well, to avoid breaking an
1899 * overall picture.
1900 */
1901 err = -EACCES;
90f8572b 1902 if (!S_ISREG(inode->i_mode) || path_noexec(&exe.file->f_path))
b32dfe37
CG		 1903 goto exit;
1904
02f92b38 1905 err = file_permission(exe.file, MAY_EXEC);
b32dfe37
CG		 1906 if (err)
1907 goto exit;
1908
35d7bdc8 1909 err = replace_mm_exe_file(mm, exe.file);
b32dfe37 1910exit:
2903ff01 1911 fdput(exe);
b32dfe37
CG		 1912 return err;
1913}
1914
f606b77f 1915/*
11bbd8b4
MK		 1916 * Check arithmetic relations of passed addresses.
1917 *
f606b77f
CG		 1918 * WARNING: we don't require any capability here so be very careful
1919 * in what is allowed for modification from userspace.
1920 */
11bbd8b4 1921static int validate_prctl_map_addr(struct prctl_mm_map *prctl_map)
f606b77f
CG		 1922{
1923 unsigned long mmap_max_addr = TASK_SIZE;
f606b77f
CG		 1924 int error = -EINVAL, i;
1925
1926 static const unsigned char offsets[] = {
1927 offsetof(struct prctl_mm_map, start_code),
1928 offsetof(struct prctl_mm_map, end_code),
1929 offsetof(struct prctl_mm_map, start_data),
1930 offsetof(struct prctl_mm_map, end_data),
1931 offsetof(struct prctl_mm_map, start_brk),
1932 offsetof(struct prctl_mm_map, brk),
1933 offsetof(struct prctl_mm_map, start_stack),
1934 offsetof(struct prctl_mm_map, arg_start),
1935 offsetof(struct prctl_mm_map, arg_end),
1936 offsetof(struct prctl_mm_map, env_start),
1937 offsetof(struct prctl_mm_map, env_end),
1938 };
1939
1940 /*
1941 * Make sure the members are not somewhere outside
1942 * of allowed address space.
1943 */
1944 for (i = 0; i < ARRAY_SIZE(offsets); i++) {
1945 u64 val = *(u64 *)((char *)prctl_map + offsets[i]);
1946
1947 if ((unsigned long)val >= mmap_max_addr ||
1948 (unsigned long)val < mmap_min_addr)
1949 goto out;
1950 }
1951
1952 /*
1953 * Make sure the pairs are ordered.
1954 */
1955#define __prctl_check_order(__m1, __op, __m2) \
1956 ((unsigned long)prctl_map->__m1 __op \
1957 (unsigned long)prctl_map->__m2) ? 0 : -EINVAL
1958 error = __prctl_check_order(start_code, <, end_code);
a9e73998 1959 error |= __prctl_check_order(start_data,<=, end_data);
f606b77f
CG		 1960 error |= __prctl_check_order(start_brk, <=, brk);
1961 error |= __prctl_check_order(arg_start, <=, arg_end);
1962 error |= __prctl_check_order(env_start, <=, env_end);
1963 if (error)
1964 goto out;
1965#undef __prctl_check_order
1966
1967 error = -EINVAL;
1968
f606b77f
CG		 1969 /*
1970 * Neither we should allow to override limits if they set.
1971 */
1972 if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk,
1973 prctl_map->start_brk, prctl_map->end_data,
1974 prctl_map->start_data))
1975 goto out;
1976
f606b77f
CG		 1977 error = 0;
1978out:
1979 return error;
1980}
1981
4a00e9df 1982#ifdef CONFIG_CHECKPOINT_RESTORE
f606b77f
CG		 1983static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size)
1984{
1985 struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, };
1986 unsigned long user_auxv[AT_VECTOR_SIZE];
1987 struct mm_struct *mm = current->mm;
1988 int error;
1989
1990 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
1991 BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256);
1992
1993 if (opt == PR_SET_MM_MAP_SIZE)
1994 return put_user((unsigned int)sizeof(prctl_map),
1995 (unsigned int __user *)addr);
1996
1997 if (data_size != sizeof(prctl_map))
1998 return -EINVAL;
1999
2000 if (copy_from_user(&prctl_map, addr, sizeof(prctl_map)))
2001 return -EFAULT;
2002
11bbd8b4 2003 error = validate_prctl_map_addr(&prctl_map);
f606b77f
CG		 2004 if (error)
2005 return error;
2006
2007 if (prctl_map.auxv_size) {
11bbd8b4
MK		 2008 /*
2009 * Someone is trying to cheat the auxv vector.
2010 */
2011 if (!prctl_map.auxv ||
2012 prctl_map.auxv_size > sizeof(mm->saved_auxv))
2013 return -EINVAL;
2014
f606b77f
CG		 2015 memset(user_auxv, 0, sizeof(user_auxv));
2016 if (copy_from_user(user_auxv,
2017 (const void __user *)prctl_map.auxv,
2018 prctl_map.auxv_size))
2019 return -EFAULT;
2020
2021 /* Last entry must be AT_NULL as specification requires */
2022 user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL;
2023 user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL;
2024 }
2025
ddf1d398 2026 if (prctl_map.exe_fd != (u32)-1) {
11bbd8b4 2027 /*
ebd6de68
NV		 2028 * Check if the current user is checkpoint/restore capable.
2029 * At the time of this writing, it checks for CAP_SYS_ADMIN
2030 * or CAP_CHECKPOINT_RESTORE.
2031 * Note that a user with access to ptrace can masquerade an
2032 * arbitrary program as any executable, even setuid ones.
2033 * This may have implications in the tomoyo subsystem.
11bbd8b4 2034 */
ebd6de68 2035 if (!checkpoint_restore_ns_capable(current_user_ns()))
227175b2 2036 return -EPERM;
11bbd8b4 2037
6e399cd1 2038 error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd);
ddf1d398
MG		 2039 if (error)
2040 return error;
2041 }
2042
88aa7cc6 2043 /*
5afe69c2 2044 * arg_lock protects concurrent updates but we still need mmap_lock for
88aa7cc6
YS		 2045 * read to exclude races with sys_brk.
2046 */
d8ed45c5 2047 mmap_read_lock(mm);
f606b77f
CG		 2048
2049 /*
2050 * We don't validate if these members are pointing to
2051 * real present VMAs because application may have correspond
2052 * VMAs already unmapped and kernel uses these members for statistics
2053 * output in procfs mostly, except
2054 *
15ec0fcf 2055 * - @start_brk/@brk which are used in do_brk_flags but kernel lookups
5afe69c2 2056 * for VMAs when updating these members so anything wrong written
f606b77f
CG		 2057 * here cause kernel to swear at userspace program but won't lead
2058 * to any problem in kernel itself
2059 */
2060
88aa7cc6 2061 spin_lock(&mm->arg_lock);
f606b77f
CG		 2062 mm->start_code = prctl_map.start_code;
2063 mm->end_code = prctl_map.end_code;
2064 mm->start_data = prctl_map.start_data;
2065 mm->end_data = prctl_map.end_data;
2066 mm->start_brk = prctl_map.start_brk;
2067 mm->brk = prctl_map.brk;
2068 mm->start_stack = prctl_map.start_stack;
2069 mm->arg_start = prctl_map.arg_start;
2070 mm->arg_end = prctl_map.arg_end;
2071 mm->env_start = prctl_map.env_start;
2072 mm->env_end = prctl_map.env_end;
88aa7cc6 2073 spin_unlock(&mm->arg_lock);
f606b77f
CG		 2074
2075 /*
2076 * Note this update of @saved_auxv is lockless thus
2077 * if someone reads this member in procfs while we're
2078 * updating -- it may get partly updated results. It's
2079 * known and acceptable trade off: we leave it as is to
2080 * not introduce additional locks here making the kernel
2081 * more complex.
2082 */
2083 if (prctl_map.auxv_size)
2084 memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv));
2085
d8ed45c5 2086 mmap_read_unlock(mm);
ddf1d398 2087 return 0;
f606b77f
CG		 2088}
2089#endif /* CONFIG_CHECKPOINT_RESTORE */
2090
4a00e9df
AD		 2091static int prctl_set_auxv(struct mm_struct *mm, unsigned long addr,
2092 unsigned long len)
2093{
2094 /*
2095 * This doesn't move the auxiliary vector itself since it's pinned to
2096 * mm_struct, but it permits filling the vector with new values. It's
2097 * up to the caller to provide sane values here, otherwise userspace
2098 * tools which use this vector might be unhappy.
2099 */
c995f12a 2100 unsigned long user_auxv[AT_VECTOR_SIZE] = {};
4a00e9df
AD		 2101
2102 if (len > sizeof(user_auxv))
2103 return -EINVAL;
2104
2105 if (copy_from_user(user_auxv, (const void __user *)addr, len))
2106 return -EFAULT;
2107
2108 /* Make sure the last entry is always AT_NULL */
2109 user_auxv[AT_VECTOR_SIZE - 2] = 0;
2110 user_auxv[AT_VECTOR_SIZE - 1] = 0;
2111
2112 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
2113
2114 task_lock(current);
2115 memcpy(mm->saved_auxv, user_auxv, len);
2116 task_unlock(current);
2117
2118 return 0;
2119}
2120
028ee4be
CG		 2121static int prctl_set_mm(int opt, unsigned long addr,
2122 unsigned long arg4, unsigned long arg5)
2123{
028ee4be 2124 struct mm_struct *mm = current->mm;
11bbd8b4
MK		 2125 struct prctl_mm_map prctl_map = {
2126 .auxv = NULL,
2127 .auxv_size = 0,
2128 .exe_fd = -1,
2129 };
fe8c7f5c
CG		 2130 struct vm_area_struct *vma;
2131 int error;
028ee4be 2132
f606b77f
CG		 2133 if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV &&
2134 opt != PR_SET_MM_MAP &&
2135 opt != PR_SET_MM_MAP_SIZE)))
028ee4be
CG		 2136 return -EINVAL;
2137
f606b77f
CG		 2138#ifdef CONFIG_CHECKPOINT_RESTORE
2139 if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE)
2140 return prctl_set_mm_map(opt, (const void __user *)addr, arg4);
2141#endif
2142
79f0713d 2143 if (!capable(CAP_SYS_RESOURCE))
028ee4be
CG		 2144 return -EPERM;
2145
6e399cd1
DB		 2146 if (opt == PR_SET_MM_EXE_FILE)
2147 return prctl_set_mm_exe_file(mm, (unsigned int)addr);
b32dfe37 2148
4a00e9df
AD		 2149 if (opt == PR_SET_MM_AUXV)
2150 return prctl_set_auxv(mm, addr, arg4);
2151
1ad75b9e 2152 if (addr >= TASK_SIZE || addr < mmap_min_addr)
028ee4be
CG		 2153 return -EINVAL;
2154
fe8c7f5c
CG		 2155 error = -EINVAL;
2156
bc81426f 2157 /*
5afe69c2 2158 * arg_lock protects concurrent updates of arg boundaries, we need
c1e8d7c6 2159 * mmap_lock for a) concurrent sys_brk, b) finding VMA for addr
bc81426f
MK		 2160 * validation.
2161 */
d8ed45c5 2162 mmap_read_lock(mm);
028ee4be
CG		 2163 vma = find_vma(mm, addr);
2164
bc81426f 2165 spin_lock(&mm->arg_lock);
4a00e9df
AD		 2166 prctl_map.start_code = mm->start_code;
2167 prctl_map.end_code = mm->end_code;
2168 prctl_map.start_data = mm->start_data;
2169 prctl_map.end_data = mm->end_data;
2170 prctl_map.start_brk = mm->start_brk;
2171 prctl_map.brk = mm->brk;
2172 prctl_map.start_stack = mm->start_stack;
2173 prctl_map.arg_start = mm->arg_start;
2174 prctl_map.arg_end = mm->arg_end;
2175 prctl_map.env_start = mm->env_start;
2176 prctl_map.env_end = mm->env_end;
4a00e9df 2177
028ee4be
CG		 2178 switch (opt) {
2179 case PR_SET_MM_START_CODE:
4a00e9df 2180 prctl_map.start_code = addr;
fe8c7f5c 2181 break;
028ee4be 2182 case PR_SET_MM_END_CODE:
4a00e9df 2183 prctl_map.end_code = addr;
028ee4be 2184 break;
028ee4be 2185 case PR_SET_MM_START_DATA:
4a00e9df 2186 prctl_map.start_data = addr;
028ee4be 2187 break;
fe8c7f5c 2188 case PR_SET_MM_END_DATA:
4a00e9df
AD		 2189 prctl_map.end_data = addr;
2190 break;
2191 case PR_SET_MM_START_STACK:
2192 prctl_map.start_stack = addr;
028ee4be 2193 break;
028ee4be 2194 case PR_SET_MM_START_BRK:
4a00e9df 2195 prctl_map.start_brk = addr;
028ee4be 2196 break;
028ee4be 2197 case PR_SET_MM_BRK:
4a00e9df 2198 prctl_map.brk = addr;
028ee4be 2199 break;
4a00e9df
AD		 2200 case PR_SET_MM_ARG_START:
2201 prctl_map.arg_start = addr;
2202 break;
2203 case PR_SET_MM_ARG_END:
2204 prctl_map.arg_end = addr;
2205 break;
2206 case PR_SET_MM_ENV_START:
2207 prctl_map.env_start = addr;
2208 break;
2209 case PR_SET_MM_ENV_END:
2210 prctl_map.env_end = addr;
2211 break;
2212 default:
2213 goto out;
2214 }
2215
11bbd8b4 2216 error = validate_prctl_map_addr(&prctl_map);
4a00e9df
AD		 2217 if (error)
2218 goto out;
028ee4be 2219
4a00e9df 2220 switch (opt) {
fe8c7f5c
CG		 2221 /*
2222 * If command line arguments and environment
2223 * are placed somewhere else on stack, we can
2224 * set them up here, ARG_START/END to setup
5afe69c2 2225 * command line arguments and ENV_START/END
fe8c7f5c
CG		 2226 * for environment.
2227 */
2228 case PR_SET_MM_START_STACK:
2229 case PR_SET_MM_ARG_START:
2230 case PR_SET_MM_ARG_END:
2231 case PR_SET_MM_ENV_START:
2232 case PR_SET_MM_ENV_END:
2233 if (!vma) {
2234 error = -EFAULT;
2235 goto out;
2236 }
028ee4be
CG		 2237 }
2238
4a00e9df
AD		 2239 mm->start_code = prctl_map.start_code;
2240 mm->end_code = prctl_map.end_code;
2241 mm->start_data = prctl_map.start_data;
2242 mm->end_data = prctl_map.end_data;
2243 mm->start_brk = prctl_map.start_brk;
2244 mm->brk = prctl_map.brk;
2245 mm->start_stack = prctl_map.start_stack;
2246 mm->arg_start = prctl_map.arg_start;
2247 mm->arg_end = prctl_map.arg_end;
2248 mm->env_start = prctl_map.env_start;
2249 mm->env_end = prctl_map.env_end;
2250
028ee4be 2251 error = 0;
028ee4be 2252out:
bc81426f 2253 spin_unlock(&mm->arg_lock);
d8ed45c5 2254 mmap_read_unlock(mm);
028ee4be
CG		 2255 return error;
2256}
300f786b 2257
52b36941 2258#ifdef CONFIG_CHECKPOINT_RESTORE
986b9eac 2259static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr)
300f786b
CG		 2260{
2261 return put_user(me->clear_child_tid, tid_addr);
2262}
52b36941 2263#else
986b9eac 2264static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr)
300f786b
CG		 2265{
2266 return -EINVAL;
2267}
028ee4be
CG		 2268#endif
2269
749860ce
PT		 2270static int propagate_has_child_subreaper(struct task_struct *p, void *data)
2271{
2272 /*
5afe69c2
XC		 2273 * If task has has_child_subreaper - all its descendants
2274 * already have these flag too and new descendants will
749860ce
PT		 2275 * inherit it on fork, skip them.
2276 *
2277 * If we've found child_reaper - skip descendants in
2278 * it's subtree as they will never get out pidns.
2279 */
2280 if (p->signal->has_child_subreaper ||
2281 is_child_reaper(task_pid(p)))
2282 return 0;
2283
2284 p->signal->has_child_subreaper = 1;
2285 return 1;
2286}
2287
7bbf1373 2288int __weak arch_prctl_spec_ctrl_get(struct task_struct *t, unsigned long which)
b617cfc8
TG		 2289{
2290 return -EINVAL;
2291}
2292
7bbf1373
KC		 2293int __weak arch_prctl_spec_ctrl_set(struct task_struct *t, unsigned long which,
2294 unsigned long ctrl)
b617cfc8
TG		 2295{
2296 return -EINVAL;
2297}
2298
a37b0715 2299#define PR_IO_FLUSHER (PF_MEMALLOC_NOIO | PF_LOCAL_THROTTLE)
8d19f1c8 2300
9a10064f
CC		 2301#ifdef CONFIG_ANON_VMA_NAME
2302
2303#define ANON_VMA_NAME_MAX_LEN 80
2304#define ANON_VMA_NAME_INVALID_CHARS "\\`$[]"
2305
2306static inline bool is_valid_name_char(char ch)
2307{
2308 /* printable ascii characters, excluding ANON_VMA_NAME_INVALID_CHARS */
2309 return ch > 0x1f && ch < 0x7f &&
2310 !strchr(ANON_VMA_NAME_INVALID_CHARS, ch);
2311}
2312
2313static int prctl_set_vma(unsigned long opt, unsigned long addr,
2314 unsigned long size, unsigned long arg)
2315{
2316 struct mm_struct *mm = current->mm;
2317 const char __user *uname;
5c26f6ac 2318 struct anon_vma_name *anon_name = NULL;
9a10064f
CC		 2319 int error;
2320
2321 switch (opt) {
2322 case PR_SET_VMA_ANON_NAME:
2323 uname = (const char __user *)arg;
2324 if (uname) {
5c26f6ac 2325 char *name, *pch;
9a10064f 2326
5c26f6ac 2327 name = strndup_user(uname, ANON_VMA_NAME_MAX_LEN);
9a10064f
CC		 2328 if (IS_ERR(name))
2329 return PTR_ERR(name);
2330
2331 for (pch = name; *pch != '\0'; pch++) {
2332 if (!is_valid_name_char(*pch)) {
2333 kfree(name);
2334 return -EINVAL;
2335 }
2336 }
5c26f6ac
SB		 2337 /* anon_vma has its own copy */
2338 anon_name = anon_vma_name_alloc(name);
2339 kfree(name);
2340 if (!anon_name)
2341 return -ENOMEM;
2342
9a10064f
CC		 2343 }
2344
2345 mmap_write_lock(mm);
5c26f6ac 2346 error = madvise_set_anon_name(mm, addr, size, anon_name);
9a10064f 2347 mmap_write_unlock(mm);
5c26f6ac 2348 anon_vma_name_put(anon_name);
9a10064f
CC		 2349 break;
2350 default:
2351 error = -EINVAL;
2352 }
2353
2354 return error;
2355}
2356
2357#else /* CONFIG_ANON_VMA_NAME */
2358static int prctl_set_vma(unsigned long opt, unsigned long start,
2359 unsigned long size, unsigned long arg)
2360{
2361 return -EINVAL;
2362}
2363#endif /* CONFIG_ANON_VMA_NAME */
2364
b507808e
JG		 2365static inline int prctl_set_mdwe(unsigned long bits, unsigned long arg3,
2366 unsigned long arg4, unsigned long arg5)
2367{
2368 if (arg3 || arg4 || arg5)
2369 return -EINVAL;
2370
2371 if (bits & ~(PR_MDWE_REFUSE_EXEC_GAIN))
2372 return -EINVAL;
2373
2374 if (bits & PR_MDWE_REFUSE_EXEC_GAIN)
2375 set_bit(MMF_HAS_MDWE, &current->mm->flags);
2376 else if (test_bit(MMF_HAS_MDWE, &current->mm->flags))
2377 return -EPERM; /* Cannot unset the flag */
2378
2379 return 0;
2380}
2381
2382static inline int prctl_get_mdwe(unsigned long arg2, unsigned long arg3,
2383 unsigned long arg4, unsigned long arg5)
2384{
2385 if (arg2 || arg3 || arg4 || arg5)
2386 return -EINVAL;
2387
2388 return test_bit(MMF_HAS_MDWE, &current->mm->flags) ?
2389 PR_MDWE_REFUSE_EXEC_GAIN : 0;
2390}
2391
ddc65971
JT		 2392static int prctl_get_auxv(void __user *addr, unsigned long len)
2393{
2394 struct mm_struct *mm = current->mm;
2395 unsigned long size = min_t(unsigned long, sizeof(mm->saved_auxv), len);
2396
2397 if (size && copy_to_user(addr, mm->saved_auxv, size))
2398 return -EFAULT;
2399 return sizeof(mm->saved_auxv);
2400}
2401
c4ea37c2
HC		 2402SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
2403 unsigned long, arg4, unsigned long, arg5)
1da177e4 2404{
b6dff3ec
DH		 2405 struct task_struct *me = current;
2406 unsigned char comm[sizeof(me->comm)];
2407 long error;
1da177e4 2408
d84f4f99
DH		 2409 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
2410 if (error != -ENOSYS)
1da177e4
LT		 2411 return error;
2412
d84f4f99 2413 error = 0;
1da177e4 2414 switch (option) {
f3cbd435
AM		 2415 case PR_SET_PDEATHSIG:
2416 if (!valid_signal(arg2)) {
2417 error = -EINVAL;
1da177e4 2418 break;
f3cbd435
AM		 2419 }
2420 me->pdeath_signal = arg2;
2421 break;
2422 case PR_GET_PDEATHSIG:
2423 error = put_user(me->pdeath_signal, (int __user *)arg2);
2424 break;
2425 case PR_GET_DUMPABLE:
2426 error = get_dumpable(me->mm);
2427 break;
2428 case PR_SET_DUMPABLE:
2429 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) {
2430 error = -EINVAL;
1da177e4 2431 break;
f3cbd435
AM		 2432 }
2433 set_dumpable(me->mm, arg2);
2434 break;
1da177e4 2435
f3cbd435
AM		 2436 case PR_SET_UNALIGN:
2437 error = SET_UNALIGN_CTL(me, arg2);
2438 break;
2439 case PR_GET_UNALIGN:
2440 error = GET_UNALIGN_CTL(me, arg2);
2441 break;
2442 case PR_SET_FPEMU:
2443 error = SET_FPEMU_CTL(me, arg2);
2444 break;
2445 case PR_GET_FPEMU:
2446 error = GET_FPEMU_CTL(me, arg2);
2447 break;
2448 case PR_SET_FPEXC:
2449 error = SET_FPEXC_CTL(me, arg2);
2450 break;
2451 case PR_GET_FPEXC:
2452 error = GET_FPEXC_CTL(me, arg2);
2453 break;
2454 case PR_GET_TIMING:
2455 error = PR_TIMING_STATISTICAL;
2456 break;
2457 case PR_SET_TIMING:
2458 if (arg2 != PR_TIMING_STATISTICAL)
2459 error = -EINVAL;
2460 break;
2461 case PR_SET_NAME:
2462 comm[sizeof(me->comm) - 1] = 0;
2463 if (strncpy_from_user(comm, (char __user *)arg2,
2464 sizeof(me->comm) - 1) < 0)
2465 return -EFAULT;
2466 set_task_comm(me, comm);
2467 proc_comm_connector(me);
2468 break;
2469 case PR_GET_NAME:
2470 get_task_comm(comm, me);
2471 if (copy_to_user((char __user *)arg2, comm, sizeof(comm)))
2472 return -EFAULT;
2473 break;
2474 case PR_GET_ENDIAN:
2475 error = GET_ENDIAN(me, arg2);
2476 break;
2477 case PR_SET_ENDIAN:
2478 error = SET_ENDIAN(me, arg2);
2479 break;
2480 case PR_GET_SECCOMP:
2481 error = prctl_get_seccomp();
2482 break;
2483 case PR_SET_SECCOMP:
2484 error = prctl_set_seccomp(arg2, (char __user *)arg3);
2485 break;
2486 case PR_GET_TSC:
2487 error = GET_TSC_CTL(arg2);
2488 break;
2489 case PR_SET_TSC:
2490 error = SET_TSC_CTL(arg2);
2491 break;
2492 case PR_TASK_PERF_EVENTS_DISABLE:
2493 error = perf_event_task_disable();
2494 break;
2495 case PR_TASK_PERF_EVENTS_ENABLE:
2496 error = perf_event_task_enable();
2497 break;
2498 case PR_GET_TIMERSLACK:
da8b44d5
JS		 2499 if (current->timer_slack_ns > ULONG_MAX)
2500 error = ULONG_MAX;
2501 else
2502 error = current->timer_slack_ns;
f3cbd435
AM		 2503 break;
2504 case PR_SET_TIMERSLACK:
2505 if (arg2 <= 0)
2506 current->timer_slack_ns =
6976675d 2507 current->default_timer_slack_ns;
f3cbd435
AM		 2508 else
2509 current->timer_slack_ns = arg2;
2510 break;
2511 case PR_MCE_KILL:
2512 if (arg4 | arg5)
2513 return -EINVAL;
2514 switch (arg2) {
2515 case PR_MCE_KILL_CLEAR:
2516 if (arg3 != 0)
4db96cf0 2517 return -EINVAL;
f3cbd435 2518 current->flags &= ~PF_MCE_PROCESS;
4db96cf0 2519 break;
f3cbd435
AM		 2520 case PR_MCE_KILL_SET:
2521 current->flags |= PF_MCE_PROCESS;
2522 if (arg3 == PR_MCE_KILL_EARLY)
2523 current->flags |= PF_MCE_EARLY;
2524 else if (arg3 == PR_MCE_KILL_LATE)
2525 current->flags &= ~PF_MCE_EARLY;
2526 else if (arg3 == PR_MCE_KILL_DEFAULT)
2527 current->flags &=
2528 ~(PF_MCE_EARLY|PF_MCE_PROCESS);
1087e9b4 2529 else
259e5e6c 2530 return -EINVAL;
259e5e6c 2531 break;
ddc65971
JT		 2532 case PR_GET_AUXV:
2533 if (arg4 || arg5)
2534 return -EINVAL;
2535 error = prctl_get_auxv((void __user *)arg2, arg3);
2536 break;
1da177e4 2537 default:
f3cbd435
AM		 2538 return -EINVAL;
2539 }
2540 break;
2541 case PR_MCE_KILL_GET:
2542 if (arg2 | arg3 | arg4 | arg5)
2543 return -EINVAL;
2544 if (current->flags & PF_MCE_PROCESS)
2545 error = (current->flags & PF_MCE_EARLY) ?
2546 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
2547 else
2548 error = PR_MCE_KILL_DEFAULT;
2549 break;
2550 case PR_SET_MM:
2551 error = prctl_set_mm(arg2, arg3, arg4, arg5);
2552 break;
2553 case PR_GET_TID_ADDRESS:
986b9eac 2554 error = prctl_get_tid_address(me, (int __user * __user *)arg2);
f3cbd435
AM		 2555 break;
2556 case PR_SET_CHILD_SUBREAPER:
2557 me->signal->is_child_subreaper = !!arg2;
749860ce
PT		 2558 if (!arg2)
2559 break;
2560
2561 walk_process_tree(me, propagate_has_child_subreaper, NULL);
f3cbd435
AM		 2562 break;
2563 case PR_GET_CHILD_SUBREAPER:
2564 error = put_user(me->signal->is_child_subreaper,
2565 (int __user *)arg2);
2566 break;
2567 case PR_SET_NO_NEW_PRIVS:
2568 if (arg2 != 1 || arg3 || arg4 || arg5)
2569 return -EINVAL;
2570
1d4457f9 2571 task_set_no_new_privs(current);
f3cbd435
AM		 2572 break;
2573 case PR_GET_NO_NEW_PRIVS:
2574 if (arg2 || arg3 || arg4 || arg5)
2575 return -EINVAL;
1d4457f9 2576 return task_no_new_privs(current) ? 1 : 0;
a0715cc2
AT		 2577 case PR_GET_THP_DISABLE:
2578 if (arg2 || arg3 || arg4 || arg5)
2579 return -EINVAL;
18600332 2580 error = !!test_bit(MMF_DISABLE_THP, &me->mm->flags);
a0715cc2
AT		 2581 break;
2582 case PR_SET_THP_DISABLE:
2583 if (arg3 || arg4 || arg5)
2584 return -EINVAL;
d8ed45c5 2585 if (mmap_write_lock_killable(me->mm))
17b0573d 2586 return -EINTR;
a0715cc2 2587 if (arg2)
18600332 2588 set_bit(MMF_DISABLE_THP, &me->mm->flags);
a0715cc2 2589 else
18600332 2590 clear_bit(MMF_DISABLE_THP, &me->mm->flags);
d8ed45c5 2591 mmap_write_unlock(me->mm);
a0715cc2 2592 break;
fe3d197f 2593 case PR_MPX_ENABLE_MANAGEMENT:
fe3d197f 2594 case PR_MPX_DISABLE_MANAGEMENT:
f240652b
DH		 2595 /* No longer implemented: */
2596 return -EINVAL;
9791554b
PB		 2597 case PR_SET_FP_MODE:
2598 error = SET_FP_MODE(me, arg2);
2599 break;
2600 case PR_GET_FP_MODE:
2601 error = GET_FP_MODE(me);
2602 break;
2d2123bc
DM		 2603 case PR_SVE_SET_VL:
2604 error = SVE_SET_VL(arg2);
2605 break;
2606 case PR_SVE_GET_VL:
2607 error = SVE_GET_VL();
2608 break;
9e4ab6c8
MB		 2609 case PR_SME_SET_VL:
2610 error = SME_SET_VL(arg2);
2611 break;
2612 case PR_SME_GET_VL:
2613 error = SME_GET_VL();
2614 break;
b617cfc8
TG		 2615 case PR_GET_SPECULATION_CTRL:
2616 if (arg3 || arg4 || arg5)
2617 return -EINVAL;
7bbf1373 2618 error = arch_prctl_spec_ctrl_get(me, arg2);
b617cfc8
TG		 2619 break;
2620 case PR_SET_SPECULATION_CTRL:
2621 if (arg4 || arg5)
2622 return -EINVAL;
7bbf1373 2623 error = arch_prctl_spec_ctrl_set(me, arg2, arg3);
b617cfc8 2624 break;
ba830885
KM		 2625 case PR_PAC_RESET_KEYS:
2626 if (arg3 || arg4 || arg5)
2627 return -EINVAL;
2628 error = PAC_RESET_KEYS(me, arg2);
2629 break;
20169862
PC		 2630 case PR_PAC_SET_ENABLED_KEYS:
2631 if (arg4 || arg5)
2632 return -EINVAL;
2633 error = PAC_SET_ENABLED_KEYS(me, arg2, arg3);
2634 break;
2635 case PR_PAC_GET_ENABLED_KEYS:
2636 if (arg2 || arg3 || arg4 || arg5)
2637 return -EINVAL;
2638 error = PAC_GET_ENABLED_KEYS(me);
2639 break;
63f0c603 2640 case PR_SET_TAGGED_ADDR_CTRL:
3e91ec89
CM		 2641 if (arg3 || arg4 || arg5)
2642 return -EINVAL;
63f0c603
CM		 2643 error = SET_TAGGED_ADDR_CTRL(arg2);
2644 break;
2645 case PR_GET_TAGGED_ADDR_CTRL:
3e91ec89
CM		 2646 if (arg2 || arg3 || arg4 || arg5)
2647 return -EINVAL;
63f0c603
CM		 2648 error = GET_TAGGED_ADDR_CTRL();
2649 break;
8d19f1c8
MC		 2650 case PR_SET_IO_FLUSHER:
2651 if (!capable(CAP_SYS_RESOURCE))
2652 return -EPERM;
2653
2654 if (arg3 || arg4 || arg5)
2655 return -EINVAL;
2656
2657 if (arg2 == 1)
2658 current->flags |= PR_IO_FLUSHER;
2659 else if (!arg2)
2660 current->flags &= ~PR_IO_FLUSHER;
2661 else
2662 return -EINVAL;
2663 break;
2664 case PR_GET_IO_FLUSHER:
2665 if (!capable(CAP_SYS_RESOURCE))
2666 return -EPERM;
2667
2668 if (arg2 || arg3 || arg4 || arg5)
2669 return -EINVAL;
2670
2671 error = (current->flags & PR_IO_FLUSHER) == PR_IO_FLUSHER;
2672 break;
1446e1df
GKB		 2673 case PR_SET_SYSCALL_USER_DISPATCH:
2674 error = set_syscall_user_dispatch(arg2, arg3, arg4,
2675 (char __user *) arg5);
2676 break;
7ac592aa
CH		 2677#ifdef CONFIG_SCHED_CORE
2678 case PR_SCHED_CORE:
2679 error = sched_core_share_pid(arg2, arg3, arg4, arg5);
2680 break;
2681#endif
b507808e
JG		 2682 case PR_SET_MDWE:
2683 error = prctl_set_mdwe(arg2, arg3, arg4, arg5);
2684 break;
2685 case PR_GET_MDWE:
2686 error = prctl_get_mdwe(arg2, arg3, arg4, arg5);
2687 break;
9a10064f
CC		 2688 case PR_SET_VMA:
2689 error = prctl_set_vma(arg2, arg3, arg4, arg5);
2690 break;
d7597f59
SR		 2691#ifdef CONFIG_KSM
2692 case PR_SET_MEMORY_MERGE:
2693 if (arg3 || arg4 || arg5)
2694 return -EINVAL;
2695 if (mmap_write_lock_killable(me->mm))
2696 return -EINTR;
2697
2698 if (arg2) {
2699 error = ksm_enable_merge_any(me->mm);
2700 } else {
2701 /*
2702 * TODO: we might want disable KSM on all VMAs and
2703 * trigger unsharing to completely disable KSM.
2704 */
2705 clear_bit(MMF_VM_MERGE_ANY, &me->mm->flags);
2706 error = 0;
2707 }
2708 mmap_write_unlock(me->mm);
2709 break;
2710 case PR_GET_MEMORY_MERGE:
2711 if (arg2 || arg3 || arg4 || arg5)
2712 return -EINVAL;
2713
2714 error = !!test_bit(MMF_VM_MERGE_ANY, &me->mm->flags);
2715 break;
2716#endif
f3cbd435
AM		 2717 default:
2718 error = -EINVAL;
2719 break;
1da177e4
LT		 2720 }
2721 return error;
2722}
3cfc348b 2723
836f92ad
HC		 2724SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
2725 struct getcpu_cache __user *, unused)
3cfc348b
AK		 2726{
2727 int err = 0;
2728 int cpu = raw_smp_processor_id();
ec94fc3d 2729
3cfc348b
AK		 2730 if (cpup)
2731 err |= put_user(cpu, cpup);
2732 if (nodep)
2733 err |= put_user(cpu_to_node(cpu), nodep);
3cfc348b
AK		 2734 return err ? -EFAULT : 0;
2735}
10a0a8d4 2736
4a22f166
SR		 2737/**
2738 * do_sysinfo - fill in sysinfo struct
2739 * @info: pointer to buffer to fill
2740 */
2741static int do_sysinfo(struct sysinfo *info)
2742{
2743 unsigned long mem_total, sav_total;
2744 unsigned int mem_unit, bitcount;
dc1b7b6c 2745 struct timespec64 tp;
4a22f166
SR		 2746
2747 memset(info, 0, sizeof(struct sysinfo));
2748
dc1b7b6c 2749 ktime_get_boottime_ts64(&tp);
ecc421e0 2750 timens_add_boottime(&tp);
4a22f166
SR		 2751 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
2752
2753 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT);
2754
2755 info->procs = nr_threads;
2756
2757 si_meminfo(info);
2758 si_swapinfo(info);
2759
2760 /*
2761 * If the sum of all the available memory (i.e. ram + swap)
2762 * is less than can be stored in a 32 bit unsigned long then
2763 * we can be binary compatible with 2.2.x kernels. If not,
2764 * well, in that case 2.2.x was broken anyways...
2765 *
2766 * -Erik Andersen <andersee@debian.org>
2767 */
2768
2769 mem_total = info->totalram + info->totalswap;
2770 if (mem_total < info->totalram || mem_total < info->totalswap)
2771 goto out;
2772 bitcount = 0;
2773 mem_unit = info->mem_unit;
2774 while (mem_unit > 1) {
2775 bitcount++;
2776 mem_unit >>= 1;
2777 sav_total = mem_total;
2778 mem_total <<= 1;
2779 if (mem_total < sav_total)
2780 goto out;
2781 }
2782
2783 /*
2784 * If mem_total did not overflow, multiply all memory values by
2785 * info->mem_unit and set it to 1. This leaves things compatible
2786 * with 2.2.x, and also retains compatibility with earlier 2.4.x
2787 * kernels...
2788 */
2789
2790 info->mem_unit = 1;
2791 info->totalram <<= bitcount;
2792 info->freeram <<= bitcount;
2793 info->sharedram <<= bitcount;
2794 info->bufferram <<= bitcount;
2795 info->totalswap <<= bitcount;
2796 info->freeswap <<= bitcount;
2797 info->totalhigh <<= bitcount;
2798 info->freehigh <<= bitcount;
2799
2800out:
2801 return 0;
2802}
2803
2804SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info)
2805{
2806 struct sysinfo val;
2807
2808 do_sysinfo(&val);
2809
2810 if (copy_to_user(info, &val, sizeof(struct sysinfo)))
2811 return -EFAULT;
2812
2813 return 0;
2814}
2815
2816#ifdef CONFIG_COMPAT
2817struct compat_sysinfo {
2818 s32 uptime;
2819 u32 loads[3];
2820 u32 totalram;
2821 u32 freeram;
2822 u32 sharedram;
2823 u32 bufferram;
2824 u32 totalswap;
2825 u32 freeswap;
2826 u16 procs;
2827 u16 pad;
2828 u32 totalhigh;
2829 u32 freehigh;
2830 u32 mem_unit;
2831 char _f[20-2*sizeof(u32)-sizeof(int)];
2832};
2833
2834COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info)
2835{
2836 struct sysinfo s;
ce5155c4 2837 struct compat_sysinfo s_32;
4a22f166
SR		 2838
2839 do_sysinfo(&s);
2840
2841 /* Check to see if any memory value is too large for 32-bit and scale
2842 * down if needed
2843 */
0baae41e 2844 if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) {
4a22f166
SR		 2845 int bitcount = 0;
2846
2847 while (s.mem_unit < PAGE_SIZE) {
2848 s.mem_unit <<= 1;
2849 bitcount++;
2850 }
2851
2852 s.totalram >>= bitcount;
2853 s.freeram >>= bitcount;
2854 s.sharedram >>= bitcount;
2855 s.bufferram >>= bitcount;
2856 s.totalswap >>= bitcount;
2857 s.freeswap >>= bitcount;
2858 s.totalhigh >>= bitcount;
2859 s.freehigh >>= bitcount;
2860 }
2861
ce5155c4
AV		 2862 memset(&s_32, 0, sizeof(s_32));
2863 s_32.uptime = s.uptime;
2864 s_32.loads[0] = s.loads[0];
2865 s_32.loads[1] = s.loads[1];
2866 s_32.loads[2] = s.loads[2];
2867 s_32.totalram = s.totalram;
2868 s_32.freeram = s.freeram;
2869 s_32.sharedram = s.sharedram;
2870 s_32.bufferram = s.bufferram;
2871 s_32.totalswap = s.totalswap;
2872 s_32.freeswap = s.freeswap;
2873 s_32.procs = s.procs;
2874 s_32.totalhigh = s.totalhigh;
2875 s_32.freehigh = s.freehigh;
2876 s_32.mem_unit = s.mem_unit;
2877 if (copy_to_user(info, &s_32, sizeof(s_32)))
4a22f166 2878 return -EFAULT;
4a22f166
SR		 2879 return 0;
2880}
2881#endif /* CONFIG_COMPAT */
Linux 6.x block layer and io_uring tree(s)