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Revert "hwmon: (sch56xx-common) Add DMI override table"
[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
1fd96a3e
AC		 143#ifndef RISCV_V_SET_CONTROL
144# define RISCV_V_SET_CONTROL(a) (-EINVAL)
145#endif
146#ifndef RISCV_V_GET_CONTROL
147# define RISCV_V_GET_CONTROL() (-EINVAL)
148#endif
1da177e4
LT		 149
150/*
151 * this is where the system-wide overflow UID and GID are defined, for
152 * architectures that now have 32-bit UID/GID but didn't in the past
153 */
154
155int overflowuid = DEFAULT_OVERFLOWUID;
156int overflowgid = DEFAULT_OVERFLOWGID;
157
1da177e4
LT		 158EXPORT_SYMBOL(overflowuid);
159EXPORT_SYMBOL(overflowgid);
1da177e4
LT		 160
161/*
162 * the same as above, but for filesystems which can only store a 16-bit
163 * UID and GID. as such, this is needed on all architectures
164 */
165
166int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
8b2770a4 167int fs_overflowgid = DEFAULT_FS_OVERFLOWGID;
1da177e4
LT		 168
169EXPORT_SYMBOL(fs_overflowuid);
170EXPORT_SYMBOL(fs_overflowgid);
171
fc832ad3
SH		 172/*
173 * Returns true if current's euid is same as p's uid or euid,
174 * or has CAP_SYS_NICE to p's user_ns.
175 *
176 * Called with rcu_read_lock, creds are safe
177 */
178static bool set_one_prio_perm(struct task_struct *p)
179{
180 const struct cred *cred = current_cred(), *pcred = __task_cred(p);
181
5af66203
EB		 182 if (uid_eq(pcred->uid, cred->euid) ||
183 uid_eq(pcred->euid, cred->euid))
fc832ad3 184 return true;
c4a4d603 185 if (ns_capable(pcred->user_ns, CAP_SYS_NICE))
fc832ad3
SH		 186 return true;
187 return false;
188}
189
c69e8d9c
DH		 190/*
191 * set the priority of a task
192 * - the caller must hold the RCU read lock
193 */
1da177e4
LT		 194static int set_one_prio(struct task_struct *p, int niceval, int error)
195{
196 int no_nice;
197
fc832ad3 198 if (!set_one_prio_perm(p)) {
1da177e4
LT		 199 error = -EPERM;
200 goto out;
201 }
e43379f1 202 if (niceval < task_nice(p) && !can_nice(p, niceval)) {
1da177e4
LT		 203 error = -EACCES;
204 goto out;
205 }
206 no_nice = security_task_setnice(p, niceval);
207 if (no_nice) {
208 error = no_nice;
209 goto out;
210 }
211 if (error == -ESRCH)
212 error = 0;
213 set_user_nice(p, niceval);
214out:
215 return error;
216}
217
754fe8d2 218SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
1da177e4
LT		 219{
220 struct task_struct *g, *p;
221 struct user_struct *user;
86a264ab 222 const struct cred *cred = current_cred();
1da177e4 223 int error = -EINVAL;
41487c65 224 struct pid *pgrp;
7b44ab97 225 kuid_t uid;
1da177e4 226
3e88c553 227 if (which > PRIO_USER || which < PRIO_PROCESS)
1da177e4
LT		 228 goto out;
229
230 /* normalize: avoid signed division (rounding problems) */
231 error = -ESRCH;
c4a4d2f4
DY		 232 if (niceval < MIN_NICE)
233 niceval = MIN_NICE;
234 if (niceval > MAX_NICE)
235 niceval = MAX_NICE;
1da177e4 236
d4581a23 237 rcu_read_lock();
1da177e4 238 switch (which) {
ec94fc3d 239 case PRIO_PROCESS:
240 if (who)
241 p = find_task_by_vpid(who);
242 else
243 p = current;
244 if (p)
245 error = set_one_prio(p, niceval, error);
246 break;
247 case PRIO_PGRP:
248 if (who)
249 pgrp = find_vpid(who);
250 else
251 pgrp = task_pgrp(current);
7f8ca0ed 252 read_lock(&tasklist_lock);
ec94fc3d 253 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
254 error = set_one_prio(p, niceval, error);
255 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
7f8ca0ed 256 read_unlock(&tasklist_lock);
ec94fc3d 257 break;
258 case PRIO_USER:
259 uid = make_kuid(cred->user_ns, who);
260 user = cred->user;
261 if (!who)
262 uid = cred->uid;
263 else if (!uid_eq(uid, cred->uid)) {
264 user = find_user(uid);
265 if (!user)
86a264ab 266 goto out_unlock; /* No processes for this user */
ec94fc3d 267 }
7f8ca0ed 268 for_each_process_thread(g, p) {
8639b461 269 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p))
ec94fc3d 270 error = set_one_prio(p, niceval, error);
7f8ca0ed 271 }
ec94fc3d 272 if (!uid_eq(uid, cred->uid))
273 free_uid(user); /* For find_user() */
274 break;
1da177e4
LT		 275 }
276out_unlock:
d4581a23 277 rcu_read_unlock();
1da177e4
LT		 278out:
279 return error;
280}
281
282/*
283 * Ugh. To avoid negative return values, "getpriority()" will
284 * not return the normal nice-value, but a negated value that
285 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
286 * to stay compatible.
287 */
754fe8d2 288SYSCALL_DEFINE2(getpriority, int, which, int, who)
1da177e4
LT		 289{
290 struct task_struct *g, *p;
291 struct user_struct *user;
86a264ab 292 const struct cred *cred = current_cred();
1da177e4 293 long niceval, retval = -ESRCH;
41487c65 294 struct pid *pgrp;
7b44ab97 295 kuid_t uid;
1da177e4 296
3e88c553 297 if (which > PRIO_USER || which < PRIO_PROCESS)
1da177e4
LT		 298 return -EINVAL;
299
70118837 300 rcu_read_lock();
1da177e4 301 switch (which) {
ec94fc3d 302 case PRIO_PROCESS:
303 if (who)
304 p = find_task_by_vpid(who);
305 else
306 p = current;
307 if (p) {
308 niceval = nice_to_rlimit(task_nice(p));
309 if (niceval > retval)
310 retval = niceval;
311 }
312 break;
313 case PRIO_PGRP:
314 if (who)
315 pgrp = find_vpid(who);
316 else
317 pgrp = task_pgrp(current);
7f8ca0ed 318 read_lock(&tasklist_lock);
ec94fc3d 319 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
320 niceval = nice_to_rlimit(task_nice(p));
321 if (niceval > retval)
322 retval = niceval;
323 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
7f8ca0ed 324 read_unlock(&tasklist_lock);
ec94fc3d 325 break;
326 case PRIO_USER:
327 uid = make_kuid(cred->user_ns, who);
328 user = cred->user;
329 if (!who)
330 uid = cred->uid;
331 else if (!uid_eq(uid, cred->uid)) {
332 user = find_user(uid);
333 if (!user)
334 goto out_unlock; /* No processes for this user */
335 }
7f8ca0ed 336 for_each_process_thread(g, p) {
8639b461 337 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) {
7aa2c016 338 niceval = nice_to_rlimit(task_nice(p));
1da177e4
LT		 339 if (niceval > retval)
340 retval = niceval;
341 }
7f8ca0ed 342 }
ec94fc3d 343 if (!uid_eq(uid, cred->uid))
344 free_uid(user); /* for find_user() */
345 break;
1da177e4
LT		 346 }
347out_unlock:
70118837 348 rcu_read_unlock();
1da177e4
LT		 349
350 return retval;
351}
352
1da177e4
LT		 353/*
354 * Unprivileged users may change the real gid to the effective gid
355 * or vice versa. (BSD-style)
356 *
357 * If you set the real gid at all, or set the effective gid to a value not
358 * equal to the real gid, then the saved gid is set to the new effective gid.
359 *
360 * This makes it possible for a setgid program to completely drop its
361 * privileges, which is often a useful assertion to make when you are doing
362 * a security audit over a program.
363 *
364 * The general idea is that a program which uses just setregid() will be
365 * 100% compatible with BSD. A program which uses just setgid() will be
ec94fc3d 366 * 100% compatible with POSIX with saved IDs.
1da177e4
LT		 367 *
368 * SMP: There are not races, the GIDs are checked only by filesystem
369 * operations (as far as semantic preservation is concerned).
370 */
2813893f 371#ifdef CONFIG_MULTIUSER
e530dca5 372long __sys_setregid(gid_t rgid, gid_t egid)
1da177e4 373{
a29c33f4 374 struct user_namespace *ns = current_user_ns();
d84f4f99
DH		 375 const struct cred *old;
376 struct cred *new;
1da177e4 377 int retval;
a29c33f4
EB		 378 kgid_t krgid, kegid;
379
380 krgid = make_kgid(ns, rgid);
381 kegid = make_kgid(ns, egid);
382
383 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
384 return -EINVAL;
385 if ((egid != (gid_t) -1) && !gid_valid(kegid))
386 return -EINVAL;
1da177e4 387
d84f4f99
DH		 388 new = prepare_creds();
389 if (!new)
390 return -ENOMEM;
391 old = current_cred();
392
d84f4f99 393 retval = -EPERM;
1da177e4 394 if (rgid != (gid_t) -1) {
a29c33f4
EB		 395 if (gid_eq(old->gid, krgid) ||
396 gid_eq(old->egid, krgid) ||
111767c1 397 ns_capable_setid(old->user_ns, CAP_SETGID))
a29c33f4 398 new->gid = krgid;
1da177e4 399 else
d84f4f99 400 goto error;
1da177e4
LT		 401 }
402 if (egid != (gid_t) -1) {
a29c33f4
EB		 403 if (gid_eq(old->gid, kegid) ||
404 gid_eq(old->egid, kegid) ||
405 gid_eq(old->sgid, kegid) ||
111767c1 406 ns_capable_setid(old->user_ns, CAP_SETGID))
a29c33f4 407 new->egid = kegid;
756184b7 408 else
d84f4f99 409 goto error;
1da177e4 410 }
d84f4f99 411
1da177e4 412 if (rgid != (gid_t) -1 ||
a29c33f4 413 (egid != (gid_t) -1 && !gid_eq(kegid, old->gid)))
d84f4f99
DH		 414 new->sgid = new->egid;
415 new->fsgid = new->egid;
416
39030e13
TC		 417 retval = security_task_fix_setgid(new, old, LSM_SETID_RE);
418 if (retval < 0)
419 goto error;
420
d84f4f99
DH		 421 return commit_creds(new);
422
423error:
424 abort_creds(new);
425 return retval;
1da177e4
LT		 426}
427
e530dca5
DB		 428SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
429{
430 return __sys_setregid(rgid, egid);
431}
432
1da177e4 433/*
ec94fc3d 434 * setgid() is implemented like SysV w/ SAVED_IDS
1da177e4
LT		 435 *
436 * SMP: Same implicit races as above.
437 */
e530dca5 438long __sys_setgid(gid_t gid)
1da177e4 439{
a29c33f4 440 struct user_namespace *ns = current_user_ns();
d84f4f99
DH		 441 const struct cred *old;
442 struct cred *new;
1da177e4 443 int retval;
a29c33f4
EB		 444 kgid_t kgid;
445
446 kgid = make_kgid(ns, gid);
447 if (!gid_valid(kgid))
448 return -EINVAL;
1da177e4 449
d84f4f99
DH		 450 new = prepare_creds();
451 if (!new)
452 return -ENOMEM;
453 old = current_cred();
454
d84f4f99 455 retval = -EPERM;
111767c1 456 if (ns_capable_setid(old->user_ns, CAP_SETGID))
a29c33f4
EB		 457 new->gid = new->egid = new->sgid = new->fsgid = kgid;
458 else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid))
459 new->egid = new->fsgid = kgid;
1da177e4 460 else
d84f4f99 461 goto error;
1da177e4 462
39030e13
TC		 463 retval = security_task_fix_setgid(new, old, LSM_SETID_ID);
464 if (retval < 0)
465 goto error;
466
d84f4f99
DH		 467 return commit_creds(new);
468
469error:
470 abort_creds(new);
471 return retval;
1da177e4 472}
54e99124 473
e530dca5
DB		 474SYSCALL_DEFINE1(setgid, gid_t, gid)
475{
476 return __sys_setgid(gid);
477}
478
d84f4f99
DH		 479/*
480 * change the user struct in a credentials set to match the new UID
481 */
482static int set_user(struct cred *new)
1da177e4
LT		 483{
484 struct user_struct *new_user;
485
078de5f7 486 new_user = alloc_uid(new->uid);
1da177e4
LT		 487 if (!new_user)
488 return -EAGAIN;
489
c923a8e7
EB		 490 free_uid(new->user);
491 new->user = new_user;
492 return 0;
493}
494
495static void flag_nproc_exceeded(struct cred *new)
496{
497 if (new->ucounts == current_ucounts())
498 return;
499
72fa5997
VK		 500 /*
501 * We don't fail in case of NPROC limit excess here because too many
502 * poorly written programs don't check set*uid() return code, assuming
503 * it never fails if called by root. We may still enforce NPROC limit
504 * for programs doing set*uid()+execve() by harmlessly deferring the
505 * failure to the execve() stage.
506 */
de399236 507 if (is_rlimit_overlimit(new->ucounts, UCOUNT_RLIMIT_NPROC, rlimit(RLIMIT_NPROC)) &&
c923a8e7 508 new->user != INIT_USER)
72fa5997
VK		 509 current->flags |= PF_NPROC_EXCEEDED;
510 else
511 current->flags &= ~PF_NPROC_EXCEEDED;
1da177e4
LT		 512}
513
514/*
515 * Unprivileged users may change the real uid to the effective uid
516 * or vice versa. (BSD-style)
517 *
518 * If you set the real uid at all, or set the effective uid to a value not
519 * equal to the real uid, then the saved uid is set to the new effective uid.
520 *
521 * This makes it possible for a setuid program to completely drop its
522 * privileges, which is often a useful assertion to make when you are doing
523 * a security audit over a program.
524 *
525 * The general idea is that a program which uses just setreuid() will be
526 * 100% compatible with BSD. A program which uses just setuid() will be
ec94fc3d 527 * 100% compatible with POSIX with saved IDs.
1da177e4 528 */
e530dca5 529long __sys_setreuid(uid_t ruid, uid_t euid)
1da177e4 530{
a29c33f4 531 struct user_namespace *ns = current_user_ns();
d84f4f99
DH		 532 const struct cred *old;
533 struct cred *new;
1da177e4 534 int retval;
a29c33f4
EB		 535 kuid_t kruid, keuid;
536
537 kruid = make_kuid(ns, ruid);
538 keuid = make_kuid(ns, euid);
539
540 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
541 return -EINVAL;
542 if ((euid != (uid_t) -1) && !uid_valid(keuid))
543 return -EINVAL;
1da177e4 544
d84f4f99
DH		 545 new = prepare_creds();
546 if (!new)
547 return -ENOMEM;
548 old = current_cred();
549
d84f4f99 550 retval = -EPERM;
1da177e4 551 if (ruid != (uid_t) -1) {
a29c33f4
EB		 552 new->uid = kruid;
553 if (!uid_eq(old->uid, kruid) &&
554 !uid_eq(old->euid, kruid) &&
40852275 555 !ns_capable_setid(old->user_ns, CAP_SETUID))
d84f4f99 556 goto error;
1da177e4
LT		 557 }
558
559 if (euid != (uid_t) -1) {
a29c33f4
EB		 560 new->euid = keuid;
561 if (!uid_eq(old->uid, keuid) &&
562 !uid_eq(old->euid, keuid) &&
563 !uid_eq(old->suid, keuid) &&
40852275 564 !ns_capable_setid(old->user_ns, CAP_SETUID))
d84f4f99 565 goto error;
1da177e4
LT		 566 }
567
a29c33f4 568 if (!uid_eq(new->uid, old->uid)) {
54e99124
DG		 569 retval = set_user(new);
570 if (retval < 0)
571 goto error;
572 }
1da177e4 573 if (ruid != (uid_t) -1 ||
a29c33f4 574 (euid != (uid_t) -1 && !uid_eq(keuid, old->uid)))
d84f4f99
DH		 575 new->suid = new->euid;
576 new->fsuid = new->euid;
1da177e4 577
d84f4f99
DH		 578 retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
579 if (retval < 0)
580 goto error;
1da177e4 581
905ae01c
AG		 582 retval = set_cred_ucounts(new);
583 if (retval < 0)
584 goto error;
585
c923a8e7 586 flag_nproc_exceeded(new);
d84f4f99 587 return commit_creds(new);
1da177e4 588
d84f4f99
DH		 589error:
590 abort_creds(new);
591 return retval;
592}
ec94fc3d 593
e530dca5
DB		 594SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
595{
596 return __sys_setreuid(ruid, euid);
597}
598
1da177e4 599/*
ec94fc3d 600 * setuid() is implemented like SysV with SAVED_IDS
601 *
1da177e4 602 * Note that SAVED_ID's is deficient in that a setuid root program
ec94fc3d 603 * like sendmail, for example, cannot set its uid to be a normal
1da177e4
LT		 604 * user and then switch back, because if you're root, setuid() sets
605 * the saved uid too. If you don't like this, blame the bright people
606 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
607 * will allow a root program to temporarily drop privileges and be able to
ec94fc3d 608 * regain them by swapping the real and effective uid.
1da177e4 609 */
e530dca5 610long __sys_setuid(uid_t uid)
1da177e4 611{
a29c33f4 612 struct user_namespace *ns = current_user_ns();
d84f4f99
DH		 613 const struct cred *old;
614 struct cred *new;
1da177e4 615 int retval;
a29c33f4
EB		 616 kuid_t kuid;
617
618 kuid = make_kuid(ns, uid);
619 if (!uid_valid(kuid))
620 return -EINVAL;
1da177e4 621
d84f4f99
DH		 622 new = prepare_creds();
623 if (!new)
624 return -ENOMEM;
625 old = current_cred();
626
d84f4f99 627 retval = -EPERM;
40852275 628 if (ns_capable_setid(old->user_ns, CAP_SETUID)) {
a29c33f4
EB		 629 new->suid = new->uid = kuid;
630 if (!uid_eq(kuid, old->uid)) {
54e99124
DG		 631 retval = set_user(new);
632 if (retval < 0)
633 goto error;
d84f4f99 634 }
a29c33f4 635 } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) {
d84f4f99 636 goto error;
1da177e4 637 }
1da177e4 638
a29c33f4 639 new->fsuid = new->euid = kuid;
d84f4f99
DH		 640
641 retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
642 if (retval < 0)
643 goto error;
1da177e4 644
905ae01c
AG		 645 retval = set_cred_ucounts(new);
646 if (retval < 0)
647 goto error;
648
c923a8e7 649 flag_nproc_exceeded(new);
d84f4f99 650 return commit_creds(new);
1da177e4 651
d84f4f99
DH		 652error:
653 abort_creds(new);
654 return retval;
1da177e4
LT		 655}
656
e530dca5
DB		 657SYSCALL_DEFINE1(setuid, uid_t, uid)
658{
659 return __sys_setuid(uid);
660}
661
1da177e4
LT		 662
663/*
664 * This function implements a generic ability to update ruid, euid,
665 * and suid. This allows you to implement the 4.4 compatible seteuid().
666 */
e530dca5 667long __sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
1da177e4 668{
a29c33f4 669 struct user_namespace *ns = current_user_ns();
d84f4f99
DH		 670 const struct cred *old;
671 struct cred *new;
1da177e4 672 int retval;
a29c33f4 673 kuid_t kruid, keuid, ksuid;
659c0ce1 674 bool ruid_new, euid_new, suid_new;
a29c33f4
EB		 675
676 kruid = make_kuid(ns, ruid);
677 keuid = make_kuid(ns, euid);
678 ksuid = make_kuid(ns, suid);
679
680 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
681 return -EINVAL;
682
683 if ((euid != (uid_t) -1) && !uid_valid(keuid))
684 return -EINVAL;
685
686 if ((suid != (uid_t) -1) && !uid_valid(ksuid))
687 return -EINVAL;
1da177e4 688
659c0ce1
OM		 689 old = current_cred();
690
691 /* check for no-op */
692 if ((ruid == (uid_t) -1 || uid_eq(kruid, old->uid)) &&
693 (euid == (uid_t) -1 || (uid_eq(keuid, old->euid) &&
694 uid_eq(keuid, old->fsuid))) &&
695 (suid == (uid_t) -1 || uid_eq(ksuid, old->suid)))
696 return 0;
697
698 ruid_new = ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) &&
699 !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid);
700 euid_new = euid != (uid_t) -1 && !uid_eq(keuid, old->uid) &&
701 !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid);
702 suid_new = suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) &&
703 !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid);
704 if ((ruid_new || euid_new || suid_new) &&
705 !ns_capable_setid(old->user_ns, CAP_SETUID))
706 return -EPERM;
707
d84f4f99
DH		 708 new = prepare_creds();
709 if (!new)
710 return -ENOMEM;
711
1da177e4 712 if (ruid != (uid_t) -1) {
a29c33f4
EB		 713 new->uid = kruid;
714 if (!uid_eq(kruid, old->uid)) {
54e99124
DG		 715 retval = set_user(new);
716 if (retval < 0)
717 goto error;
718 }
1da177e4 719 }
d84f4f99 720 if (euid != (uid_t) -1)
a29c33f4 721 new->euid = keuid;
1da177e4 722 if (suid != (uid_t) -1)
a29c33f4 723 new->suid = ksuid;
d84f4f99 724 new->fsuid = new->euid;
1da177e4 725
d84f4f99
DH		 726 retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
727 if (retval < 0)
728 goto error;
1da177e4 729
905ae01c
AG		 730 retval = set_cred_ucounts(new);
731 if (retval < 0)
732 goto error;
733
c923a8e7 734 flag_nproc_exceeded(new);
d84f4f99 735 return commit_creds(new);
1da177e4 736
d84f4f99
DH		 737error:
738 abort_creds(new);
739 return retval;
1da177e4
LT		 740}
741
e530dca5
DB		 742SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
743{
744 return __sys_setresuid(ruid, euid, suid);
745}
746
a29c33f4 747SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp)
1da177e4 748{
86a264ab 749 const struct cred *cred = current_cred();
1da177e4 750 int retval;
a29c33f4
EB		 751 uid_t ruid, euid, suid;
752
753 ruid = from_kuid_munged(cred->user_ns, cred->uid);
754 euid = from_kuid_munged(cred->user_ns, cred->euid);
755 suid = from_kuid_munged(cred->user_ns, cred->suid);
1da177e4 756
ec94fc3d 757 retval = put_user(ruid, ruidp);
758 if (!retval) {
759 retval = put_user(euid, euidp);
760 if (!retval)
761 return put_user(suid, suidp);
762 }
1da177e4
LT		 763 return retval;
764}
765
766/*
767 * Same as above, but for rgid, egid, sgid.
768 */
e530dca5 769long __sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
1da177e4 770{
a29c33f4 771 struct user_namespace *ns = current_user_ns();
d84f4f99
DH		 772 const struct cred *old;
773 struct cred *new;
1da177e4 774 int retval;
a29c33f4 775 kgid_t krgid, kegid, ksgid;
659c0ce1 776 bool rgid_new, egid_new, sgid_new;
a29c33f4
EB		 777
778 krgid = make_kgid(ns, rgid);
779 kegid = make_kgid(ns, egid);
780 ksgid = make_kgid(ns, sgid);
781
782 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
783 return -EINVAL;
784 if ((egid != (gid_t) -1) && !gid_valid(kegid))
785 return -EINVAL;
786 if ((sgid != (gid_t) -1) && !gid_valid(ksgid))
787 return -EINVAL;
1da177e4 788
659c0ce1
OM		 789 old = current_cred();
790
791 /* check for no-op */
792 if ((rgid == (gid_t) -1 || gid_eq(krgid, old->gid)) &&
793 (egid == (gid_t) -1 || (gid_eq(kegid, old->egid) &&
794 gid_eq(kegid, old->fsgid))) &&
795 (sgid == (gid_t) -1 || gid_eq(ksgid, old->sgid)))
796 return 0;
797
798 rgid_new = rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) &&
799 !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid);
800 egid_new = egid != (gid_t) -1 && !gid_eq(kegid, old->gid) &&
801 !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid);
802 sgid_new = sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) &&
803 !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid);
804 if ((rgid_new || egid_new || sgid_new) &&
805 !ns_capable_setid(old->user_ns, CAP_SETGID))
806 return -EPERM;
807
d84f4f99
DH		 808 new = prepare_creds();
809 if (!new)
810 return -ENOMEM;
d84f4f99 811
1da177e4 812 if (rgid != (gid_t) -1)
a29c33f4 813 new->gid = krgid;
d84f4f99 814 if (egid != (gid_t) -1)
a29c33f4 815 new->egid = kegid;
1da177e4 816 if (sgid != (gid_t) -1)
a29c33f4 817 new->sgid = ksgid;
d84f4f99 818 new->fsgid = new->egid;
1da177e4 819
39030e13
TC		 820 retval = security_task_fix_setgid(new, old, LSM_SETID_RES);
821 if (retval < 0)
822 goto error;
823
d84f4f99
DH		 824 return commit_creds(new);
825
826error:
827 abort_creds(new);
828 return retval;
1da177e4
LT		 829}
830
e530dca5
DB		 831SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
832{
833 return __sys_setresgid(rgid, egid, sgid);
834}
835
a29c33f4 836SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp)
1da177e4 837{
86a264ab 838 const struct cred *cred = current_cred();
1da177e4 839 int retval;
a29c33f4
EB		 840 gid_t rgid, egid, sgid;
841
842 rgid = from_kgid_munged(cred->user_ns, cred->gid);
843 egid = from_kgid_munged(cred->user_ns, cred->egid);
844 sgid = from_kgid_munged(cred->user_ns, cred->sgid);
1da177e4 845
ec94fc3d 846 retval = put_user(rgid, rgidp);
847 if (!retval) {
848 retval = put_user(egid, egidp);
849 if (!retval)
850 retval = put_user(sgid, sgidp);
851 }
1da177e4
LT		 852
853 return retval;
854}
855
856
857/*
858 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
859 * is used for "access()" and for the NFS daemon (letting nfsd stay at
860 * whatever uid it wants to). It normally shadows "euid", except when
861 * explicitly set by setfsuid() or for access..
862 */
e530dca5 863long __sys_setfsuid(uid_t uid)
1da177e4 864{
d84f4f99
DH		 865 const struct cred *old;
866 struct cred *new;
867 uid_t old_fsuid;
a29c33f4
EB		 868 kuid_t kuid;
869
870 old = current_cred();
871 old_fsuid = from_kuid_munged(old->user_ns, old->fsuid);
872
873 kuid = make_kuid(old->user_ns, uid);
874 if (!uid_valid(kuid))
875 return old_fsuid;
1da177e4 876
d84f4f99
DH		 877 new = prepare_creds();
878 if (!new)
a29c33f4 879 return old_fsuid;
1da177e4 880
a29c33f4
EB		 881 if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) ||
882 uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) ||
40852275 883 ns_capable_setid(old->user_ns, CAP_SETUID)) {
a29c33f4
EB		 884 if (!uid_eq(kuid, old->fsuid)) {
885 new->fsuid = kuid;
d84f4f99
DH		 886 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
887 goto change_okay;
1da177e4 888 }
1da177e4
LT		 889 }
890
d84f4f99
DH		 891 abort_creds(new);
892 return old_fsuid;
1da177e4 893
d84f4f99
DH		 894change_okay:
895 commit_creds(new);
1da177e4
LT		 896 return old_fsuid;
897}
898
e530dca5
DB		 899SYSCALL_DEFINE1(setfsuid, uid_t, uid)
900{
901 return __sys_setfsuid(uid);
902}
903
1da177e4 904/*
f42df9e6 905 * Samma på svenska..
1da177e4 906 */
e530dca5 907long __sys_setfsgid(gid_t gid)
1da177e4 908{
d84f4f99
DH		 909 const struct cred *old;
910 struct cred *new;
911 gid_t old_fsgid;
a29c33f4
EB		 912 kgid_t kgid;
913
914 old = current_cred();
915 old_fsgid = from_kgid_munged(old->user_ns, old->fsgid);
916
917 kgid = make_kgid(old->user_ns, gid);
918 if (!gid_valid(kgid))
919 return old_fsgid;
d84f4f99
DH		 920
921 new = prepare_creds();
922 if (!new)
a29c33f4 923 return old_fsgid;
1da177e4 924
a29c33f4
EB		 925 if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) ||
926 gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) ||
111767c1 927 ns_capable_setid(old->user_ns, CAP_SETGID)) {
a29c33f4
EB		 928 if (!gid_eq(kgid, old->fsgid)) {
929 new->fsgid = kgid;
39030e13
TC		 930 if (security_task_fix_setgid(new,old,LSM_SETID_FS) == 0)
931 goto change_okay;
1da177e4 932 }
1da177e4 933 }
d84f4f99 934
d84f4f99
DH		 935 abort_creds(new);
936 return old_fsgid;
937
938change_okay:
939 commit_creds(new);
1da177e4
LT		 940 return old_fsgid;
941}
e530dca5
DB		 942
943SYSCALL_DEFINE1(setfsgid, gid_t, gid)
944{
945 return __sys_setfsgid(gid);
946}
2813893f 947#endif /* CONFIG_MULTIUSER */
1da177e4 948
4a22f166
SR		 949/**
950 * sys_getpid - return the thread group id of the current process
951 *
952 * Note, despite the name, this returns the tgid not the pid. The tgid and
953 * the pid are identical unless CLONE_THREAD was specified on clone() in
954 * which case the tgid is the same in all threads of the same group.
955 *
956 * This is SMP safe as current->tgid does not change.
957 */
958SYSCALL_DEFINE0(getpid)
959{
960 return task_tgid_vnr(current);
961}
962
963/* Thread ID - the internal kernel "pid" */
964SYSCALL_DEFINE0(gettid)
965{
966 return task_pid_vnr(current);
967}
968
969/*
970 * Accessing ->real_parent is not SMP-safe, it could
971 * change from under us. However, we can use a stale
972 * value of ->real_parent under rcu_read_lock(), see
973 * release_task()->call_rcu(delayed_put_task_struct).
974 */
975SYSCALL_DEFINE0(getppid)
976{
977 int pid;
978
979 rcu_read_lock();
980 pid = task_tgid_vnr(rcu_dereference(current->real_parent));
981 rcu_read_unlock();
982
983 return pid;
984}
985
986SYSCALL_DEFINE0(getuid)
987{
988 /* Only we change this so SMP safe */
989 return from_kuid_munged(current_user_ns(), current_uid());
990}
991
992SYSCALL_DEFINE0(geteuid)
993{
994 /* Only we change this so SMP safe */
995 return from_kuid_munged(current_user_ns(), current_euid());
996}
997
998SYSCALL_DEFINE0(getgid)
999{
1000 /* Only we change this so SMP safe */
1001 return from_kgid_munged(current_user_ns(), current_gid());
1002}
1003
1004SYSCALL_DEFINE0(getegid)
1005{
1006 /* Only we change this so SMP safe */
1007 return from_kgid_munged(current_user_ns(), current_egid());
1008}
1009
ca2406ed 1010static void do_sys_times(struct tms *tms)
f06febc9 1011{
5613fda9 1012 u64 tgutime, tgstime, cutime, cstime;
f06febc9 1013
e80d0a1a 1014 thread_group_cputime_adjusted(current, &tgutime, &tgstime);
f06febc9
FM		 1015 cutime = current->signal->cutime;
1016 cstime = current->signal->cstime;
5613fda9
FW		 1017 tms->tms_utime = nsec_to_clock_t(tgutime);
1018 tms->tms_stime = nsec_to_clock_t(tgstime);
1019 tms->tms_cutime = nsec_to_clock_t(cutime);
1020 tms->tms_cstime = nsec_to_clock_t(cstime);
f06febc9
FM		 1021}
1022
58fd3aa2 1023SYSCALL_DEFINE1(times, struct tms __user *, tbuf)
1da177e4 1024{
1da177e4
LT		 1025 if (tbuf) {
1026 struct tms tmp;
f06febc9
FM		 1027
1028 do_sys_times(&tmp);
1da177e4
LT		 1029 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
1030 return -EFAULT;
1031 }
e3d5a27d 1032 force_successful_syscall_return();
1da177e4
LT		 1033 return (long) jiffies_64_to_clock_t(get_jiffies_64());
1034}
1035
ca2406ed
AV		 1036#ifdef CONFIG_COMPAT
1037static compat_clock_t clock_t_to_compat_clock_t(clock_t x)
1038{
1039 return compat_jiffies_to_clock_t(clock_t_to_jiffies(x));
1040}
1041
1042COMPAT_SYSCALL_DEFINE1(times, struct compat_tms __user *, tbuf)
1043{
1044 if (tbuf) {
1045 struct tms tms;
1046 struct compat_tms tmp;
1047
1048 do_sys_times(&tms);
1049 /* Convert our struct tms to the compat version. */
1050 tmp.tms_utime = clock_t_to_compat_clock_t(tms.tms_utime);
1051 tmp.tms_stime = clock_t_to_compat_clock_t(tms.tms_stime);
1052 tmp.tms_cutime = clock_t_to_compat_clock_t(tms.tms_cutime);
1053 tmp.tms_cstime = clock_t_to_compat_clock_t(tms.tms_cstime);
1054 if (copy_to_user(tbuf, &tmp, sizeof(tmp)))
1055 return -EFAULT;
1056 }
1057 force_successful_syscall_return();
1058 return compat_jiffies_to_clock_t(jiffies);
1059}
1060#endif
1061
1da177e4
LT		 1062/*
1063 * This needs some heavy checking ...
1064 * I just haven't the stomach for it. I also don't fully
1065 * understand sessions/pgrp etc. Let somebody who does explain it.
1066 *
1067 * OK, I think I have the protection semantics right.... this is really
1068 * only important on a multi-user system anyway, to make sure one user
1069 * can't send a signal to a process owned by another. -TYT, 12/12/91
1070 *
98611e4e 1071 * !PF_FORKNOEXEC check to conform completely to POSIX.
1da177e4 1072 */
b290ebe2 1073SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
1da177e4
LT		 1074{
1075 struct task_struct *p;
ee0acf90 1076 struct task_struct *group_leader = current->group_leader;
4e021306
ON		 1077 struct pid *pgrp;
1078 int err;
1da177e4
LT		 1079
1080 if (!pid)
b488893a 1081 pid = task_pid_vnr(group_leader);
1da177e4
LT		 1082 if (!pgid)
1083 pgid = pid;
1084 if (pgid < 0)
1085 return -EINVAL;
950eaaca 1086 rcu_read_lock();
1da177e4
LT		 1087
1088 /* From this point forward we keep holding onto the tasklist lock
1089 * so that our parent does not change from under us. -DaveM
1090 */
1091 write_lock_irq(&tasklist_lock);
1092
1093 err = -ESRCH;
4e021306 1094 p = find_task_by_vpid(pid);
1da177e4
LT		 1095 if (!p)
1096 goto out;
1097
1098 err = -EINVAL;
1099 if (!thread_group_leader(p))
1100 goto out;
1101
4e021306 1102 if (same_thread_group(p->real_parent, group_leader)) {
1da177e4 1103 err = -EPERM;
41487c65 1104 if (task_session(p) != task_session(group_leader))
1da177e4
LT		 1105 goto out;
1106 err = -EACCES;
98611e4e 1107 if (!(p->flags & PF_FORKNOEXEC))
1da177e4
LT		 1108 goto out;
1109 } else {
1110 err = -ESRCH;
ee0acf90 1111 if (p != group_leader)
1da177e4
LT		 1112 goto out;
1113 }
1114
1115 err = -EPERM;
1116 if (p->signal->leader)
1117 goto out;
1118
4e021306 1119 pgrp = task_pid(p);
1da177e4 1120 if (pgid != pid) {
b488893a 1121 struct task_struct *g;
1da177e4 1122
4e021306
ON		 1123 pgrp = find_vpid(pgid);
1124 g = pid_task(pgrp, PIDTYPE_PGID);
41487c65 1125 if (!g || task_session(g) != task_session(group_leader))
f020bc46 1126 goto out;
1da177e4
LT		 1127 }
1128
1da177e4
LT		 1129 err = security_task_setpgid(p, pgid);
1130 if (err)
1131 goto out;
1132
1b0f7ffd 1133 if (task_pgrp(p) != pgrp)
83beaf3c 1134 change_pid(p, PIDTYPE_PGID, pgrp);
1da177e4
LT		 1135
1136 err = 0;
1137out:
1138 /* All paths lead to here, thus we are safe. -DaveM */
1139 write_unlock_irq(&tasklist_lock);
950eaaca 1140 rcu_read_unlock();
1da177e4
LT		 1141 return err;
1142}
1143
192c5807 1144static int do_getpgid(pid_t pid)
1da177e4 1145{
12a3de0a
ON		 1146 struct task_struct *p;
1147 struct pid *grp;
1148 int retval;
1149
1150 rcu_read_lock();
756184b7 1151 if (!pid)
12a3de0a 1152 grp = task_pgrp(current);
756184b7 1153 else {
1da177e4 1154 retval = -ESRCH;
12a3de0a
ON		 1155 p = find_task_by_vpid(pid);
1156 if (!p)
1157 goto out;
1158 grp = task_pgrp(p);
1159 if (!grp)
1160 goto out;
1161
1162 retval = security_task_getpgid(p);
1163 if (retval)
1164 goto out;
1da177e4 1165 }
12a3de0a
ON		 1166 retval = pid_vnr(grp);
1167out:
1168 rcu_read_unlock();
1169 return retval;
1da177e4
LT		 1170}
1171
192c5807
DB		 1172SYSCALL_DEFINE1(getpgid, pid_t, pid)
1173{
1174 return do_getpgid(pid);
1175}
1176
1da177e4
LT		 1177#ifdef __ARCH_WANT_SYS_GETPGRP
1178
dbf040d9 1179SYSCALL_DEFINE0(getpgrp)
1da177e4 1180{
192c5807 1181 return do_getpgid(0);
1da177e4
LT		 1182}
1183
1184#endif
1185
dbf040d9 1186SYSCALL_DEFINE1(getsid, pid_t, pid)
1da177e4 1187{
1dd768c0
ON		 1188 struct task_struct *p;
1189 struct pid *sid;
1190 int retval;
1191
1192 rcu_read_lock();
756184b7 1193 if (!pid)
1dd768c0 1194 sid = task_session(current);
756184b7 1195 else {
1da177e4 1196 retval = -ESRCH;
1dd768c0
ON		 1197 p = find_task_by_vpid(pid);
1198 if (!p)
1199 goto out;
1200 sid = task_session(p);
1201 if (!sid)
1202 goto out;
1203
1204 retval = security_task_getsid(p);
1205 if (retval)
1206 goto out;
1da177e4 1207 }
1dd768c0
ON		 1208 retval = pid_vnr(sid);
1209out:
1210 rcu_read_unlock();
1211 return retval;
1da177e4
LT		 1212}
1213
81dabb46
ON		 1214static void set_special_pids(struct pid *pid)
1215{
1216 struct task_struct *curr = current->group_leader;
1217
1218 if (task_session(curr) != pid)
1219 change_pid(curr, PIDTYPE_SID, pid);
1220
1221 if (task_pgrp(curr) != pid)
1222 change_pid(curr, PIDTYPE_PGID, pid);
1223}
1224
e2aaa9f4 1225int ksys_setsid(void)
1da177e4 1226{
e19f247a 1227 struct task_struct *group_leader = current->group_leader;
e4cc0a9c
ON		 1228 struct pid *sid = task_pid(group_leader);
1229 pid_t session = pid_vnr(sid);
1da177e4
LT		 1230 int err = -EPERM;
1231
1da177e4 1232 write_lock_irq(&tasklist_lock);
390e2ff0
EB		 1233 /* Fail if I am already a session leader */
1234 if (group_leader->signal->leader)
1235 goto out;
1236
430c6231
ON		 1237 /* Fail if a process group id already exists that equals the
1238 * proposed session id.
390e2ff0 1239 */
6806aac6 1240 if (pid_task(sid, PIDTYPE_PGID))
1da177e4
LT		 1241 goto out;
1242
e19f247a 1243 group_leader->signal->leader = 1;
81dabb46 1244 set_special_pids(sid);
24ec839c 1245
9c9f4ded 1246 proc_clear_tty(group_leader);
24ec839c 1247
e4cc0a9c 1248 err = session;
1da177e4
LT		 1249out:
1250 write_unlock_irq(&tasklist_lock);
5091faa4 1251 if (err > 0) {
0d0df599 1252 proc_sid_connector(group_leader);
5091faa4
MG		 1253 sched_autogroup_create_attach(group_leader);
1254 }
1da177e4
LT		 1255 return err;
1256}
1257
e2aaa9f4
DB		 1258SYSCALL_DEFINE0(setsid)
1259{
1260 return ksys_setsid();
1261}
1262
1da177e4
LT		 1263DECLARE_RWSEM(uts_sem);
1264
e28cbf22
CH		 1265#ifdef COMPAT_UTS_MACHINE
1266#define override_architecture(name) \
46da2766 1267 (personality(current->personality) == PER_LINUX32 && \
e28cbf22
CH		 1268 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \
1269 sizeof(COMPAT_UTS_MACHINE)))
1270#else
1271#define override_architecture(name) 0
1272#endif
1273
be27425d
AK		 1274/*
1275 * Work around broken programs that cannot handle "Linux 3.0".
1276 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40
b7285b42
JN		 1277 * And we map 4.x and later versions to 2.6.60+x, so 4.0/5.0/6.0/... would be
1278 * 2.6.60.
be27425d 1279 */
2702b152 1280static int override_release(char __user *release, size_t len)
be27425d
AK		 1281{
1282 int ret = 0;
be27425d
AK		 1283
1284 if (current->personality & UNAME26) {
2702b152
KC		 1285 const char *rest = UTS_RELEASE;
1286 char buf[65] = { 0 };
be27425d
AK		 1287 int ndots = 0;
1288 unsigned v;
2702b152 1289 size_t copy;
be27425d
AK		 1290
1291 while (*rest) {
1292 if (*rest == '.' && ++ndots >= 3)
1293 break;
1294 if (!isdigit(*rest) && *rest != '.')
1295 break;
1296 rest++;
1297 }
88a68672 1298 v = LINUX_VERSION_PATCHLEVEL + 60;
31fd84b9 1299 copy = clamp_t(size_t, len, 1, sizeof(buf));
2702b152
KC		 1300 copy = scnprintf(buf, copy, "2.6.%u%s", v, rest);
1301 ret = copy_to_user(release, buf, copy + 1);
be27425d
AK		 1302 }
1303 return ret;
1304}
1305
e48fbb69 1306SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
1da177e4 1307{
42a0cc34 1308 struct new_utsname tmp;
1da177e4
LT		 1309
1310 down_read(&uts_sem);
42a0cc34 1311 memcpy(&tmp, utsname(), sizeof(tmp));
1da177e4 1312 up_read(&uts_sem);
42a0cc34
JH		 1313 if (copy_to_user(name, &tmp, sizeof(tmp)))
1314 return -EFAULT;
e28cbf22 1315
42a0cc34
JH		 1316 if (override_release(name->release, sizeof(name->release)))
1317 return -EFAULT;
1318 if (override_architecture(name))
1319 return -EFAULT;
1320 return 0;
1da177e4
LT		 1321}
1322
5cacdb4a
CH		 1323#ifdef __ARCH_WANT_SYS_OLD_UNAME
1324/*
1325 * Old cruft
1326 */
1327SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
1328{
42a0cc34 1329 struct old_utsname tmp;
5cacdb4a
CH		 1330
1331 if (!name)
1332 return -EFAULT;
1333
1334 down_read(&uts_sem);
42a0cc34 1335 memcpy(&tmp, utsname(), sizeof(tmp));
5cacdb4a 1336 up_read(&uts_sem);
42a0cc34
JH		 1337 if (copy_to_user(name, &tmp, sizeof(tmp)))
1338 return -EFAULT;
5cacdb4a 1339
42a0cc34
JH		 1340 if (override_release(name->release, sizeof(name->release)))
1341 return -EFAULT;
1342 if (override_architecture(name))
1343 return -EFAULT;
1344 return 0;
5cacdb4a
CH		 1345}
1346
1347SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
1348{
5e1aada0 1349 struct oldold_utsname tmp;
5cacdb4a
CH		 1350
1351 if (!name)
1352 return -EFAULT;
5cacdb4a 1353
5e1aada0
JP		 1354 memset(&tmp, 0, sizeof(tmp));
1355
5cacdb4a 1356 down_read(&uts_sem);
42a0cc34
JH		 1357 memcpy(&tmp.sysname, &utsname()->sysname, __OLD_UTS_LEN);
1358 memcpy(&tmp.nodename, &utsname()->nodename, __OLD_UTS_LEN);
1359 memcpy(&tmp.release, &utsname()->release, __OLD_UTS_LEN);
1360 memcpy(&tmp.version, &utsname()->version, __OLD_UTS_LEN);
1361 memcpy(&tmp.machine, &utsname()->machine, __OLD_UTS_LEN);
5cacdb4a 1362 up_read(&uts_sem);
42a0cc34
JH		 1363 if (copy_to_user(name, &tmp, sizeof(tmp)))
1364 return -EFAULT;
5cacdb4a 1365
42a0cc34
JH		 1366 if (override_architecture(name))
1367 return -EFAULT;
1368 if (override_release(name->release, sizeof(name->release)))
1369 return -EFAULT;
1370 return 0;
5cacdb4a
CH		 1371}
1372#endif
1373
5a8a82b1 1374SYSCALL_DEFINE2(sethostname, char __user *, name, int, len)
1da177e4
LT		 1375{
1376 int errno;
1377 char tmp[__NEW_UTS_LEN];
1378
bb96a6f5 1379 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1da177e4 1380 return -EPERM;
fc832ad3 1381
1da177e4
LT		 1382 if (len < 0 || len > __NEW_UTS_LEN)
1383 return -EINVAL;
1da177e4
LT		 1384 errno = -EFAULT;
1385 if (!copy_from_user(tmp, name, len)) {
42a0cc34 1386 struct new_utsname *u;
9679e4dd 1387
37608ba3 1388 add_device_randomness(tmp, len);
42a0cc34
JH		 1389 down_write(&uts_sem);
1390 u = utsname();
9679e4dd
AM		 1391 memcpy(u->nodename, tmp, len);
1392 memset(u->nodename + len, 0, sizeof(u->nodename) - len);
1da177e4 1393 errno = 0;
499eea6b 1394 uts_proc_notify(UTS_PROC_HOSTNAME);
42a0cc34 1395 up_write(&uts_sem);
1da177e4 1396 }
1da177e4
LT		 1397 return errno;
1398}
1399
1400#ifdef __ARCH_WANT_SYS_GETHOSTNAME
1401
5a8a82b1 1402SYSCALL_DEFINE2(gethostname, char __user *, name, int, len)
1da177e4 1403{
42a0cc34 1404 int i;
9679e4dd 1405 struct new_utsname *u;
42a0cc34 1406 char tmp[__NEW_UTS_LEN + 1];
1da177e4
LT		 1407
1408 if (len < 0)
1409 return -EINVAL;
1410 down_read(&uts_sem);
9679e4dd
AM		 1411 u = utsname();
1412 i = 1 + strlen(u->nodename);
1da177e4
LT		 1413 if (i > len)
1414 i = len;
42a0cc34 1415 memcpy(tmp, u->nodename, i);
1da177e4 1416 up_read(&uts_sem);
42a0cc34
JH		 1417 if (copy_to_user(name, tmp, i))
1418 return -EFAULT;
1419 return 0;
1da177e4
LT		 1420}
1421
1422#endif
1423
1424/*
1425 * Only setdomainname; getdomainname can be implemented by calling
1426 * uname()
1427 */
5a8a82b1 1428SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
1da177e4
LT		 1429{
1430 int errno;
1431 char tmp[__NEW_UTS_LEN];
1432
fc832ad3 1433 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1da177e4
LT		 1434 return -EPERM;
1435 if (len < 0 || len > __NEW_UTS_LEN)
1436 return -EINVAL;
1437
1da177e4
LT		 1438 errno = -EFAULT;
1439 if (!copy_from_user(tmp, name, len)) {
42a0cc34 1440 struct new_utsname *u;
9679e4dd 1441
37608ba3 1442 add_device_randomness(tmp, len);
42a0cc34
JH		 1443 down_write(&uts_sem);
1444 u = utsname();
9679e4dd
AM		 1445 memcpy(u->domainname, tmp, len);
1446 memset(u->domainname + len, 0, sizeof(u->domainname) - len);
1da177e4 1447 errno = 0;
499eea6b 1448 uts_proc_notify(UTS_PROC_DOMAINNAME);
42a0cc34 1449 up_write(&uts_sem);
1da177e4 1450 }
1da177e4
LT		 1451 return errno;
1452}
1453
c57bef02
BR		 1454/* make sure you are allowed to change @tsk limits before calling this */
1455static int do_prlimit(struct task_struct *tsk, unsigned int resource,
1456 struct rlimit *new_rlim, struct rlimit *old_rlim)
1457{
1458 struct rlimit *rlim;
1459 int retval = 0;
1460
1461 if (resource >= RLIM_NLIMITS)
1462 return -EINVAL;
73979060
GKH		 1463 resource = array_index_nospec(resource, RLIM_NLIMITS);
1464
c57bef02
BR		 1465 if (new_rlim) {
1466 if (new_rlim->rlim_cur > new_rlim->rlim_max)
1467 return -EINVAL;
1468 if (resource == RLIMIT_NOFILE &&
1469 new_rlim->rlim_max > sysctl_nr_open)
1470 return -EPERM;
1471 }
1472
18c91bb2 1473 /* Holding a refcount on tsk protects tsk->signal from disappearing. */
c57bef02
BR		 1474 rlim = tsk->signal->rlim + resource;
1475 task_lock(tsk->group_leader);
1476 if (new_rlim) {
1477 /*
1478 * Keep the capable check against init_user_ns until cgroups can
1479 * contain all limits.
1480 */
1481 if (new_rlim->rlim_max > rlim->rlim_max &&
1482 !capable(CAP_SYS_RESOURCE))
1483 retval = -EPERM;
1484 if (!retval)
1485 retval = security_task_setrlimit(tsk, resource, new_rlim);
1486 }
1487 if (!retval) {
1488 if (old_rlim)
1489 *old_rlim = *rlim;
1490 if (new_rlim)
1491 *rlim = *new_rlim;
1492 }
1493 task_unlock(tsk->group_leader);
1494
1495 /*
1496 * RLIMIT_CPU handling. Arm the posix CPU timer if the limit is not
1497 * infinite. In case of RLIM_INFINITY the posix CPU timer code
1498 * ignores the rlimit.
1499 */
1500 if (!retval && new_rlim && resource == RLIMIT_CPU &&
1501 new_rlim->rlim_cur != RLIM_INFINITY &&
18c91bb2
BR		 1502 IS_ENABLED(CONFIG_POSIX_TIMERS)) {
1503 /*
1504 * update_rlimit_cpu can fail if the task is exiting, but there
1505 * may be other tasks in the thread group that are not exiting,
1506 * and they need their cpu timers adjusted.
1507 *
1508 * The group_leader is the last task to be released, so if we
1509 * cannot update_rlimit_cpu on it, then the entire process is
1510 * exiting and we do not need to update at all.
1511 */
1512 update_rlimit_cpu(tsk->group_leader, new_rlim->rlim_cur);
1513 }
1514
c57bef02
BR		 1515 return retval;
1516}
1517
e48fbb69 1518SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1da177e4 1519{
b9518345
JS		 1520 struct rlimit value;
1521 int ret;
1522
1523 ret = do_prlimit(current, resource, NULL, &value);
1524 if (!ret)
1525 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1526
1527 return ret;
1da177e4
LT		 1528}
1529
d9e968cb
AV		 1530#ifdef CONFIG_COMPAT
1531
1532COMPAT_SYSCALL_DEFINE2(setrlimit, unsigned int, resource,
1533 struct compat_rlimit __user *, rlim)
1534{
1535 struct rlimit r;
1536 struct compat_rlimit r32;
1537
1538 if (copy_from_user(&r32, rlim, sizeof(struct compat_rlimit)))
1539 return -EFAULT;
1540
1541 if (r32.rlim_cur == COMPAT_RLIM_INFINITY)
1542 r.rlim_cur = RLIM_INFINITY;
1543 else
1544 r.rlim_cur = r32.rlim_cur;
1545 if (r32.rlim_max == COMPAT_RLIM_INFINITY)
1546 r.rlim_max = RLIM_INFINITY;
1547 else
1548 r.rlim_max = r32.rlim_max;
1549 return do_prlimit(current, resource, &r, NULL);
1550}
1551
1552COMPAT_SYSCALL_DEFINE2(getrlimit, unsigned int, resource,
1553 struct compat_rlimit __user *, rlim)
1554{
1555 struct rlimit r;
1556 int ret;
1557
1558 ret = do_prlimit(current, resource, NULL, &r);
1559 if (!ret) {
58c7ffc0 1560 struct compat_rlimit r32;
d9e968cb
AV		 1561 if (r.rlim_cur > COMPAT_RLIM_INFINITY)
1562 r32.rlim_cur = COMPAT_RLIM_INFINITY;
1563 else
1564 r32.rlim_cur = r.rlim_cur;
1565 if (r.rlim_max > COMPAT_RLIM_INFINITY)
1566 r32.rlim_max = COMPAT_RLIM_INFINITY;
1567 else
1568 r32.rlim_max = r.rlim_max;
1569
1570 if (copy_to_user(rlim, &r32, sizeof(struct compat_rlimit)))
1571 return -EFAULT;
1572 }
1573 return ret;
1574}
1575
1576#endif
1577
1da177e4
LT		 1578#ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1579
1580/*
1581 * Back compatibility for getrlimit. Needed for some apps.
1582 */
e48fbb69
HC		 1583SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1584 struct rlimit __user *, rlim)
1da177e4
LT		 1585{
1586 struct rlimit x;
1587 if (resource >= RLIM_NLIMITS)
1588 return -EINVAL;
1589
23d6aef7 1590 resource = array_index_nospec(resource, RLIM_NLIMITS);
1da177e4
LT		 1591 task_lock(current->group_leader);
1592 x = current->signal->rlim[resource];
1593 task_unlock(current->group_leader);
756184b7 1594 if (x.rlim_cur > 0x7FFFFFFF)
1da177e4 1595 x.rlim_cur = 0x7FFFFFFF;
756184b7 1596 if (x.rlim_max > 0x7FFFFFFF)
1da177e4 1597 x.rlim_max = 0x7FFFFFFF;
ec94fc3d 1598 return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0;
1da177e4
LT		 1599}
1600
613763a1
AV		 1601#ifdef CONFIG_COMPAT
1602COMPAT_SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1603 struct compat_rlimit __user *, rlim)
1604{
1605 struct rlimit r;
1606
1607 if (resource >= RLIM_NLIMITS)
1608 return -EINVAL;
1609
23d6aef7 1610 resource = array_index_nospec(resource, RLIM_NLIMITS);
613763a1
AV		 1611 task_lock(current->group_leader);
1612 r = current->signal->rlim[resource];
1613 task_unlock(current->group_leader);
1614 if (r.rlim_cur > 0x7FFFFFFF)
1615 r.rlim_cur = 0x7FFFFFFF;
1616 if (r.rlim_max > 0x7FFFFFFF)
1617 r.rlim_max = 0x7FFFFFFF;
1618
1619 if (put_user(r.rlim_cur, &rlim->rlim_cur) ||
1620 put_user(r.rlim_max, &rlim->rlim_max))
1621 return -EFAULT;
1622 return 0;
1623}
1624#endif
1625
1da177e4
LT		 1626#endif
1627
c022a0ac
JS		 1628static inline bool rlim64_is_infinity(__u64 rlim64)
1629{
1630#if BITS_PER_LONG < 64
1631 return rlim64 >= ULONG_MAX;
1632#else
1633 return rlim64 == RLIM64_INFINITY;
1634#endif
1635}
1636
1637static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64)
1638{
1639 if (rlim->rlim_cur == RLIM_INFINITY)
1640 rlim64->rlim_cur = RLIM64_INFINITY;
1641 else
1642 rlim64->rlim_cur = rlim->rlim_cur;
1643 if (rlim->rlim_max == RLIM_INFINITY)
1644 rlim64->rlim_max = RLIM64_INFINITY;
1645 else
1646 rlim64->rlim_max = rlim->rlim_max;
1647}
1648
1649static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim)
1650{
1651 if (rlim64_is_infinity(rlim64->rlim_cur))
1652 rlim->rlim_cur = RLIM_INFINITY;
1653 else
1654 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur;
1655 if (rlim64_is_infinity(rlim64->rlim_max))
1656 rlim->rlim_max = RLIM_INFINITY;
1657 else
1658 rlim->rlim_max = (unsigned long)rlim64->rlim_max;
1659}
1660
c022a0ac 1661/* rcu lock must be held */
791ec491
SS		 1662static int check_prlimit_permission(struct task_struct *task,
1663 unsigned int flags)
c022a0ac
JS		 1664{
1665 const struct cred *cred = current_cred(), *tcred;
791ec491 1666 bool id_match;
c022a0ac 1667
fc832ad3
SH		 1668 if (current == task)
1669 return 0;
c022a0ac 1670
fc832ad3 1671 tcred = __task_cred(task);
791ec491
SS		 1672 id_match = (uid_eq(cred->uid, tcred->euid) &&
1673 uid_eq(cred->uid, tcred->suid) &&
1674 uid_eq(cred->uid, tcred->uid) &&
1675 gid_eq(cred->gid, tcred->egid) &&
1676 gid_eq(cred->gid, tcred->sgid) &&
1677 gid_eq(cred->gid, tcred->gid));
1678 if (!id_match && !ns_capable(tcred->user_ns, CAP_SYS_RESOURCE))
1679 return -EPERM;
fc832ad3 1680
791ec491 1681 return security_task_prlimit(cred, tcred, flags);
c022a0ac
JS		 1682}
1683
1684SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource,
1685 const struct rlimit64 __user *, new_rlim,
1686 struct rlimit64 __user *, old_rlim)
1687{
1688 struct rlimit64 old64, new64;
1689 struct rlimit old, new;
1690 struct task_struct *tsk;
791ec491 1691 unsigned int checkflags = 0;
c022a0ac
JS		 1692 int ret;
1693
791ec491
SS		 1694 if (old_rlim)
1695 checkflags |= LSM_PRLIMIT_READ;
1696
c022a0ac
JS		 1697 if (new_rlim) {
1698 if (copy_from_user(&new64, new_rlim, sizeof(new64)))
1699 return -EFAULT;
1700 rlim64_to_rlim(&new64, &new);
791ec491 1701 checkflags |= LSM_PRLIMIT_WRITE;
c022a0ac
JS		 1702 }
1703
1704 rcu_read_lock();
1705 tsk = pid ? find_task_by_vpid(pid) : current;
1706 if (!tsk) {
1707 rcu_read_unlock();
1708 return -ESRCH;
1709 }
791ec491 1710 ret = check_prlimit_permission(tsk, checkflags);
c022a0ac
JS		 1711 if (ret) {
1712 rcu_read_unlock();
1713 return ret;
1714 }
1715 get_task_struct(tsk);
1716 rcu_read_unlock();
1717
1718 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL,
1719 old_rlim ? &old : NULL);
1720
1721 if (!ret && old_rlim) {
1722 rlim_to_rlim64(&old, &old64);
1723 if (copy_to_user(old_rlim, &old64, sizeof(old64)))
1724 ret = -EFAULT;
1725 }
1726
1727 put_task_struct(tsk);
1728 return ret;
1729}
1730
7855c35d
JS		 1731SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1732{
1733 struct rlimit new_rlim;
1734
1735 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1736 return -EFAULT;
5b41535a 1737 return do_prlimit(current, resource, &new_rlim, NULL);
7855c35d
JS		 1738}
1739
1da177e4
LT		 1740/*
1741 * It would make sense to put struct rusage in the task_struct,
1742 * except that would make the task_struct be *really big*. After
1743 * task_struct gets moved into malloc'ed memory, it would
1744 * make sense to do this. It will make moving the rest of the information
1745 * a lot simpler! (Which we're not doing right now because we're not
1746 * measuring them yet).
1747 *
1da177e4
LT		 1748 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1749 * races with threads incrementing their own counters. But since word
1750 * reads are atomic, we either get new values or old values and we don't
1751 * care which for the sums. We always take the siglock to protect reading
1752 * the c* fields from p->signal from races with exit.c updating those
1753 * fields when reaping, so a sample either gets all the additions of a
1754 * given child after it's reaped, or none so this sample is before reaping.
2dd0ebcd 1755 *
de047c1b
RT		 1756 * Locking:
1757 * We need to take the siglock for CHILDEREN, SELF and BOTH
1758 * for the cases current multithreaded, non-current single threaded
1759 * non-current multithreaded. Thread traversal is now safe with
1760 * the siglock held.
1761 * Strictly speaking, we donot need to take the siglock if we are current and
1762 * single threaded, as no one else can take our signal_struct away, no one
1763 * else can reap the children to update signal->c* counters, and no one else
1764 * can race with the signal-> fields. If we do not take any lock, the
1765 * signal-> fields could be read out of order while another thread was just
1766 * exiting. So we should place a read memory barrier when we avoid the lock.
1767 * On the writer side, write memory barrier is implied in __exit_signal
1768 * as __exit_signal releases the siglock spinlock after updating the signal->
1769 * fields. But we don't do this yet to keep things simple.
2dd0ebcd 1770 *
1da177e4
LT		 1771 */
1772
f06febc9 1773static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
679c9cd4 1774{
679c9cd4
SK		 1775 r->ru_nvcsw += t->nvcsw;
1776 r->ru_nivcsw += t->nivcsw;
1777 r->ru_minflt += t->min_flt;
1778 r->ru_majflt += t->maj_flt;
1779 r->ru_inblock += task_io_get_inblock(t);
1780 r->ru_oublock += task_io_get_oublock(t);
1781}
1782
ce72a16f 1783void getrusage(struct task_struct *p, int who, struct rusage *r)
1da177e4
LT		 1784{
1785 struct task_struct *t;
1786 unsigned long flags;
5613fda9 1787 u64 tgutime, tgstime, utime, stime;
1f10206c 1788 unsigned long maxrss = 0;
1da177e4 1789
ec94fc3d 1790 memset((char *)r, 0, sizeof (*r));
64861634 1791 utime = stime = 0;
1da177e4 1792
679c9cd4 1793 if (who == RUSAGE_THREAD) {
e80d0a1a 1794 task_cputime_adjusted(current, &utime, &stime);
f06febc9 1795 accumulate_thread_rusage(p, r);
1f10206c 1796 maxrss = p->signal->maxrss;
679c9cd4
SK		 1797 goto out;
1798 }
1799
d6cf723a 1800 if (!lock_task_sighand(p, &flags))
de047c1b 1801 return;
0f59cc4a 1802
1da177e4 1803 switch (who) {
ec94fc3d 1804 case RUSAGE_BOTH:
1805 case RUSAGE_CHILDREN:
1806 utime = p->signal->cutime;
1807 stime = p->signal->cstime;
1808 r->ru_nvcsw = p->signal->cnvcsw;
1809 r->ru_nivcsw = p->signal->cnivcsw;
1810 r->ru_minflt = p->signal->cmin_flt;
1811 r->ru_majflt = p->signal->cmaj_flt;
1812 r->ru_inblock = p->signal->cinblock;
1813 r->ru_oublock = p->signal->coublock;
1814 maxrss = p->signal->cmaxrss;
1815
1816 if (who == RUSAGE_CHILDREN)
1da177e4 1817 break;
df561f66 1818 fallthrough;
0f59cc4a 1819
ec94fc3d 1820 case RUSAGE_SELF:
1821 thread_group_cputime_adjusted(p, &tgutime, &tgstime);
1822 utime += tgutime;
1823 stime += tgstime;
1824 r->ru_nvcsw += p->signal->nvcsw;
1825 r->ru_nivcsw += p->signal->nivcsw;
1826 r->ru_minflt += p->signal->min_flt;
1827 r->ru_majflt += p->signal->maj_flt;
1828 r->ru_inblock += p->signal->inblock;
1829 r->ru_oublock += p->signal->oublock;
1830 if (maxrss < p->signal->maxrss)
1831 maxrss = p->signal->maxrss;
1832 t = p;
1833 do {
1834 accumulate_thread_rusage(t, r);
1835 } while_each_thread(p, t);
1836 break;
1837
1838 default:
1839 BUG();
1da177e4 1840 }
de047c1b 1841 unlock_task_sighand(p, &flags);
de047c1b 1842
679c9cd4 1843out:
bdd565f8
AB		 1844 r->ru_utime = ns_to_kernel_old_timeval(utime);
1845 r->ru_stime = ns_to_kernel_old_timeval(stime);
1f10206c
JP		 1846
1847 if (who != RUSAGE_CHILDREN) {
1848 struct mm_struct *mm = get_task_mm(p);
ec94fc3d 1849
1f10206c
JP		 1850 if (mm) {
1851 setmax_mm_hiwater_rss(&maxrss, mm);
1852 mmput(mm);
1853 }
1854 }
1855 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
1da177e4
LT		 1856}
1857
ce72a16f 1858SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
1da177e4
LT		 1859{
1860 struct rusage r;
ec94fc3d 1861
679c9cd4
SK		 1862 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1863 who != RUSAGE_THREAD)
1da177e4 1864 return -EINVAL;
ce72a16f
AV		 1865
1866 getrusage(current, who, &r);
1867 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1da177e4
LT		 1868}
1869
8d2d5c4a
AV		 1870#ifdef CONFIG_COMPAT
1871COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru)
1872{
1873 struct rusage r;
1874
1875 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1876 who != RUSAGE_THREAD)
1877 return -EINVAL;
1878
ce72a16f 1879 getrusage(current, who, &r);
8d2d5c4a
AV		 1880 return put_compat_rusage(&r, ru);
1881}
1882#endif
1883
e48fbb69 1884SYSCALL_DEFINE1(umask, int, mask)
1da177e4
LT		 1885{
1886 mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1887 return mask;
1888}
3b7391de 1889
6e399cd1 1890static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
b32dfe37 1891{
2903ff01 1892 struct fd exe;
496ad9aa 1893 struct inode *inode;
2903ff01 1894 int err;
b32dfe37 1895
2903ff01
AV		 1896 exe = fdget(fd);
1897 if (!exe.file)
b32dfe37
CG		 1898 return -EBADF;
1899
496ad9aa 1900 inode = file_inode(exe.file);
b32dfe37
CG		 1901
1902 /*
1903 * Because the original mm->exe_file points to executable file, make
1904 * sure that this one is executable as well, to avoid breaking an
1905 * overall picture.
1906 */
1907 err = -EACCES;
90f8572b 1908 if (!S_ISREG(inode->i_mode) || path_noexec(&exe.file->f_path))
b32dfe37
CG		 1909 goto exit;
1910
02f92b38 1911 err = file_permission(exe.file, MAY_EXEC);
b32dfe37
CG		 1912 if (err)
1913 goto exit;
1914
35d7bdc8 1915 err = replace_mm_exe_file(mm, exe.file);
b32dfe37 1916exit:
2903ff01 1917 fdput(exe);
b32dfe37
CG		 1918 return err;
1919}
1920
f606b77f 1921/*
11bbd8b4
MK		 1922 * Check arithmetic relations of passed addresses.
1923 *
f606b77f
CG		 1924 * WARNING: we don't require any capability here so be very careful
1925 * in what is allowed for modification from userspace.
1926 */
11bbd8b4 1927static int validate_prctl_map_addr(struct prctl_mm_map *prctl_map)
f606b77f
CG		 1928{
1929 unsigned long mmap_max_addr = TASK_SIZE;
f606b77f
CG		 1930 int error = -EINVAL, i;
1931
1932 static const unsigned char offsets[] = {
1933 offsetof(struct prctl_mm_map, start_code),
1934 offsetof(struct prctl_mm_map, end_code),
1935 offsetof(struct prctl_mm_map, start_data),
1936 offsetof(struct prctl_mm_map, end_data),
1937 offsetof(struct prctl_mm_map, start_brk),
1938 offsetof(struct prctl_mm_map, brk),
1939 offsetof(struct prctl_mm_map, start_stack),
1940 offsetof(struct prctl_mm_map, arg_start),
1941 offsetof(struct prctl_mm_map, arg_end),
1942 offsetof(struct prctl_mm_map, env_start),
1943 offsetof(struct prctl_mm_map, env_end),
1944 };
1945
1946 /*
1947 * Make sure the members are not somewhere outside
1948 * of allowed address space.
1949 */
1950 for (i = 0; i < ARRAY_SIZE(offsets); i++) {
1951 u64 val = *(u64 *)((char *)prctl_map + offsets[i]);
1952
1953 if ((unsigned long)val >= mmap_max_addr ||
1954 (unsigned long)val < mmap_min_addr)
1955 goto out;
1956 }
1957
1958 /*
1959 * Make sure the pairs are ordered.
1960 */
1961#define __prctl_check_order(__m1, __op, __m2) \
1962 ((unsigned long)prctl_map->__m1 __op \
1963 (unsigned long)prctl_map->__m2) ? 0 : -EINVAL
1964 error = __prctl_check_order(start_code, <, end_code);
a9e73998 1965 error |= __prctl_check_order(start_data,<=, end_data);
f606b77f
CG		 1966 error |= __prctl_check_order(start_brk, <=, brk);
1967 error |= __prctl_check_order(arg_start, <=, arg_end);
1968 error |= __prctl_check_order(env_start, <=, env_end);
1969 if (error)
1970 goto out;
1971#undef __prctl_check_order
1972
1973 error = -EINVAL;
1974
f606b77f
CG		 1975 /*
1976 * Neither we should allow to override limits if they set.
1977 */
1978 if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk,
1979 prctl_map->start_brk, prctl_map->end_data,
1980 prctl_map->start_data))
1981 goto out;
1982
f606b77f
CG		 1983 error = 0;
1984out:
1985 return error;
1986}
1987
4a00e9df 1988#ifdef CONFIG_CHECKPOINT_RESTORE
f606b77f
CG		 1989static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size)
1990{
1991 struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, };
1992 unsigned long user_auxv[AT_VECTOR_SIZE];
1993 struct mm_struct *mm = current->mm;
1994 int error;
1995
1996 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
1997 BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256);
1998
1999 if (opt == PR_SET_MM_MAP_SIZE)
2000 return put_user((unsigned int)sizeof(prctl_map),
2001 (unsigned int __user *)addr);
2002
2003 if (data_size != sizeof(prctl_map))
2004 return -EINVAL;
2005
2006 if (copy_from_user(&prctl_map, addr, sizeof(prctl_map)))
2007 return -EFAULT;
2008
11bbd8b4 2009 error = validate_prctl_map_addr(&prctl_map);
f606b77f
CG		 2010 if (error)
2011 return error;
2012
2013 if (prctl_map.auxv_size) {
11bbd8b4
MK		 2014 /*
2015 * Someone is trying to cheat the auxv vector.
2016 */
2017 if (!prctl_map.auxv ||
2018 prctl_map.auxv_size > sizeof(mm->saved_auxv))
2019 return -EINVAL;
2020
f606b77f
CG		 2021 memset(user_auxv, 0, sizeof(user_auxv));
2022 if (copy_from_user(user_auxv,
2023 (const void __user *)prctl_map.auxv,
2024 prctl_map.auxv_size))
2025 return -EFAULT;
2026
2027 /* Last entry must be AT_NULL as specification requires */
2028 user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL;
2029 user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL;
2030 }
2031
ddf1d398 2032 if (prctl_map.exe_fd != (u32)-1) {
11bbd8b4 2033 /*
ebd6de68
NV		 2034 * Check if the current user is checkpoint/restore capable.
2035 * At the time of this writing, it checks for CAP_SYS_ADMIN
2036 * or CAP_CHECKPOINT_RESTORE.
2037 * Note that a user with access to ptrace can masquerade an
2038 * arbitrary program as any executable, even setuid ones.
2039 * This may have implications in the tomoyo subsystem.
11bbd8b4 2040 */
ebd6de68 2041 if (!checkpoint_restore_ns_capable(current_user_ns()))
227175b2 2042 return -EPERM;
11bbd8b4 2043
6e399cd1 2044 error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd);
ddf1d398
MG		 2045 if (error)
2046 return error;
2047 }
2048
88aa7cc6 2049 /*
5afe69c2 2050 * arg_lock protects concurrent updates but we still need mmap_lock for
88aa7cc6
YS		 2051 * read to exclude races with sys_brk.
2052 */
d8ed45c5 2053 mmap_read_lock(mm);
f606b77f
CG		 2054
2055 /*
2056 * We don't validate if these members are pointing to
2057 * real present VMAs because application may have correspond
2058 * VMAs already unmapped and kernel uses these members for statistics
2059 * output in procfs mostly, except
2060 *
15ec0fcf 2061 * - @start_brk/@brk which are used in do_brk_flags but kernel lookups
5afe69c2 2062 * for VMAs when updating these members so anything wrong written
f606b77f
CG		 2063 * here cause kernel to swear at userspace program but won't lead
2064 * to any problem in kernel itself
2065 */
2066
88aa7cc6 2067 spin_lock(&mm->arg_lock);
f606b77f
CG		 2068 mm->start_code = prctl_map.start_code;
2069 mm->end_code = prctl_map.end_code;
2070 mm->start_data = prctl_map.start_data;
2071 mm->end_data = prctl_map.end_data;
2072 mm->start_brk = prctl_map.start_brk;
2073 mm->brk = prctl_map.brk;
2074 mm->start_stack = prctl_map.start_stack;
2075 mm->arg_start = prctl_map.arg_start;
2076 mm->arg_end = prctl_map.arg_end;
2077 mm->env_start = prctl_map.env_start;
2078 mm->env_end = prctl_map.env_end;
88aa7cc6 2079 spin_unlock(&mm->arg_lock);
f606b77f
CG		 2080
2081 /*
2082 * Note this update of @saved_auxv is lockless thus
2083 * if someone reads this member in procfs while we're
2084 * updating -- it may get partly updated results. It's
2085 * known and acceptable trade off: we leave it as is to
2086 * not introduce additional locks here making the kernel
2087 * more complex.
2088 */
2089 if (prctl_map.auxv_size)
2090 memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv));
2091
d8ed45c5 2092 mmap_read_unlock(mm);
ddf1d398 2093 return 0;
f606b77f
CG		 2094}
2095#endif /* CONFIG_CHECKPOINT_RESTORE */
2096
4a00e9df
AD		 2097static int prctl_set_auxv(struct mm_struct *mm, unsigned long addr,
2098 unsigned long len)
2099{
2100 /*
2101 * This doesn't move the auxiliary vector itself since it's pinned to
2102 * mm_struct, but it permits filling the vector with new values. It's
2103 * up to the caller to provide sane values here, otherwise userspace
2104 * tools which use this vector might be unhappy.
2105 */
c995f12a 2106 unsigned long user_auxv[AT_VECTOR_SIZE] = {};
4a00e9df
AD		 2107
2108 if (len > sizeof(user_auxv))
2109 return -EINVAL;
2110
2111 if (copy_from_user(user_auxv, (const void __user *)addr, len))
2112 return -EFAULT;
2113
2114 /* Make sure the last entry is always AT_NULL */
2115 user_auxv[AT_VECTOR_SIZE - 2] = 0;
2116 user_auxv[AT_VECTOR_SIZE - 1] = 0;
2117
2118 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
2119
2120 task_lock(current);
2121 memcpy(mm->saved_auxv, user_auxv, len);
2122 task_unlock(current);
2123
2124 return 0;
2125}
2126
028ee4be
CG		 2127static int prctl_set_mm(int opt, unsigned long addr,
2128 unsigned long arg4, unsigned long arg5)
2129{
028ee4be 2130 struct mm_struct *mm = current->mm;
11bbd8b4
MK		 2131 struct prctl_mm_map prctl_map = {
2132 .auxv = NULL,
2133 .auxv_size = 0,
2134 .exe_fd = -1,
2135 };
fe8c7f5c
CG		 2136 struct vm_area_struct *vma;
2137 int error;
028ee4be 2138
f606b77f
CG		 2139 if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV &&
2140 opt != PR_SET_MM_MAP &&
2141 opt != PR_SET_MM_MAP_SIZE)))
028ee4be
CG		 2142 return -EINVAL;
2143
f606b77f
CG		 2144#ifdef CONFIG_CHECKPOINT_RESTORE
2145 if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE)
2146 return prctl_set_mm_map(opt, (const void __user *)addr, arg4);
2147#endif
2148
79f0713d 2149 if (!capable(CAP_SYS_RESOURCE))
028ee4be
CG		 2150 return -EPERM;
2151
6e399cd1
DB		 2152 if (opt == PR_SET_MM_EXE_FILE)
2153 return prctl_set_mm_exe_file(mm, (unsigned int)addr);
b32dfe37 2154
4a00e9df
AD		 2155 if (opt == PR_SET_MM_AUXV)
2156 return prctl_set_auxv(mm, addr, arg4);
2157
1ad75b9e 2158 if (addr >= TASK_SIZE || addr < mmap_min_addr)
028ee4be
CG		 2159 return -EINVAL;
2160
fe8c7f5c
CG		 2161 error = -EINVAL;
2162
bc81426f 2163 /*
5afe69c2 2164 * arg_lock protects concurrent updates of arg boundaries, we need
c1e8d7c6 2165 * mmap_lock for a) concurrent sys_brk, b) finding VMA for addr
bc81426f
MK		 2166 * validation.
2167 */
d8ed45c5 2168 mmap_read_lock(mm);
028ee4be
CG		 2169 vma = find_vma(mm, addr);
2170
bc81426f 2171 spin_lock(&mm->arg_lock);
4a00e9df
AD		 2172 prctl_map.start_code = mm->start_code;
2173 prctl_map.end_code = mm->end_code;
2174 prctl_map.start_data = mm->start_data;
2175 prctl_map.end_data = mm->end_data;
2176 prctl_map.start_brk = mm->start_brk;
2177 prctl_map.brk = mm->brk;
2178 prctl_map.start_stack = mm->start_stack;
2179 prctl_map.arg_start = mm->arg_start;
2180 prctl_map.arg_end = mm->arg_end;
2181 prctl_map.env_start = mm->env_start;
2182 prctl_map.env_end = mm->env_end;
4a00e9df 2183
028ee4be
CG		 2184 switch (opt) {
2185 case PR_SET_MM_START_CODE:
4a00e9df 2186 prctl_map.start_code = addr;
fe8c7f5c 2187 break;
028ee4be 2188 case PR_SET_MM_END_CODE:
4a00e9df 2189 prctl_map.end_code = addr;
028ee4be 2190 break;
028ee4be 2191 case PR_SET_MM_START_DATA:
4a00e9df 2192 prctl_map.start_data = addr;
028ee4be 2193 break;
fe8c7f5c 2194 case PR_SET_MM_END_DATA:
4a00e9df
AD		 2195 prctl_map.end_data = addr;
2196 break;
2197 case PR_SET_MM_START_STACK:
2198 prctl_map.start_stack = addr;
028ee4be 2199 break;
028ee4be 2200 case PR_SET_MM_START_BRK:
4a00e9df 2201 prctl_map.start_brk = addr;
028ee4be 2202 break;
028ee4be 2203 case PR_SET_MM_BRK:
4a00e9df 2204 prctl_map.brk = addr;
028ee4be 2205 break;
4a00e9df
AD		 2206 case PR_SET_MM_ARG_START:
2207 prctl_map.arg_start = addr;
2208 break;
2209 case PR_SET_MM_ARG_END:
2210 prctl_map.arg_end = addr;
2211 break;
2212 case PR_SET_MM_ENV_START:
2213 prctl_map.env_start = addr;
2214 break;
2215 case PR_SET_MM_ENV_END:
2216 prctl_map.env_end = addr;
2217 break;
2218 default:
2219 goto out;
2220 }
2221
11bbd8b4 2222 error = validate_prctl_map_addr(&prctl_map);
4a00e9df
AD		 2223 if (error)
2224 goto out;
028ee4be 2225
4a00e9df 2226 switch (opt) {
fe8c7f5c
CG		 2227 /*
2228 * If command line arguments and environment
2229 * are placed somewhere else on stack, we can
2230 * set them up here, ARG_START/END to setup
5afe69c2 2231 * command line arguments and ENV_START/END
fe8c7f5c
CG		 2232 * for environment.
2233 */
2234 case PR_SET_MM_START_STACK:
2235 case PR_SET_MM_ARG_START:
2236 case PR_SET_MM_ARG_END:
2237 case PR_SET_MM_ENV_START:
2238 case PR_SET_MM_ENV_END:
2239 if (!vma) {
2240 error = -EFAULT;
2241 goto out;
2242 }
028ee4be
CG		 2243 }
2244
4a00e9df
AD		 2245 mm->start_code = prctl_map.start_code;
2246 mm->end_code = prctl_map.end_code;
2247 mm->start_data = prctl_map.start_data;
2248 mm->end_data = prctl_map.end_data;
2249 mm->start_brk = prctl_map.start_brk;
2250 mm->brk = prctl_map.brk;
2251 mm->start_stack = prctl_map.start_stack;
2252 mm->arg_start = prctl_map.arg_start;
2253 mm->arg_end = prctl_map.arg_end;
2254 mm->env_start = prctl_map.env_start;
2255 mm->env_end = prctl_map.env_end;
2256
028ee4be 2257 error = 0;
028ee4be 2258out:
bc81426f 2259 spin_unlock(&mm->arg_lock);
d8ed45c5 2260 mmap_read_unlock(mm);
028ee4be
CG		 2261 return error;
2262}
300f786b 2263
52b36941 2264#ifdef CONFIG_CHECKPOINT_RESTORE
986b9eac 2265static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr)
300f786b
CG		 2266{
2267 return put_user(me->clear_child_tid, tid_addr);
2268}
52b36941 2269#else
986b9eac 2270static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr)
300f786b
CG		 2271{
2272 return -EINVAL;
2273}
028ee4be
CG		 2274#endif
2275
749860ce
PT		 2276static int propagate_has_child_subreaper(struct task_struct *p, void *data)
2277{
2278 /*
5afe69c2
XC		 2279 * If task has has_child_subreaper - all its descendants
2280 * already have these flag too and new descendants will
749860ce
PT		 2281 * inherit it on fork, skip them.
2282 *
2283 * If we've found child_reaper - skip descendants in
2284 * it's subtree as they will never get out pidns.
2285 */
2286 if (p->signal->has_child_subreaper ||
2287 is_child_reaper(task_pid(p)))
2288 return 0;
2289
2290 p->signal->has_child_subreaper = 1;
2291 return 1;
2292}
2293
7bbf1373 2294int __weak arch_prctl_spec_ctrl_get(struct task_struct *t, unsigned long which)
b617cfc8
TG		 2295{
2296 return -EINVAL;
2297}
2298
7bbf1373
KC		 2299int __weak arch_prctl_spec_ctrl_set(struct task_struct *t, unsigned long which,
2300 unsigned long ctrl)
b617cfc8
TG		 2301{
2302 return -EINVAL;
2303}
2304
a37b0715 2305#define PR_IO_FLUSHER (PF_MEMALLOC_NOIO | PF_LOCAL_THROTTLE)
8d19f1c8 2306
9a10064f
CC		 2307#ifdef CONFIG_ANON_VMA_NAME
2308
2309#define ANON_VMA_NAME_MAX_LEN 80
2310#define ANON_VMA_NAME_INVALID_CHARS "\\`$[]"
2311
2312static inline bool is_valid_name_char(char ch)
2313{
2314 /* printable ascii characters, excluding ANON_VMA_NAME_INVALID_CHARS */
2315 return ch > 0x1f && ch < 0x7f &&
2316 !strchr(ANON_VMA_NAME_INVALID_CHARS, ch);
2317}
2318
2319static int prctl_set_vma(unsigned long opt, unsigned long addr,
2320 unsigned long size, unsigned long arg)
2321{
2322 struct mm_struct *mm = current->mm;
2323 const char __user *uname;
5c26f6ac 2324 struct anon_vma_name *anon_name = NULL;
9a10064f
CC		 2325 int error;
2326
2327 switch (opt) {
2328 case PR_SET_VMA_ANON_NAME:
2329 uname = (const char __user *)arg;
2330 if (uname) {
5c26f6ac 2331 char *name, *pch;
9a10064f 2332
5c26f6ac 2333 name = strndup_user(uname, ANON_VMA_NAME_MAX_LEN);
9a10064f
CC		 2334 if (IS_ERR(name))
2335 return PTR_ERR(name);
2336
2337 for (pch = name; *pch != '\0'; pch++) {
2338 if (!is_valid_name_char(*pch)) {
2339 kfree(name);
2340 return -EINVAL;
2341 }
2342 }
5c26f6ac
SB		 2343 /* anon_vma has its own copy */
2344 anon_name = anon_vma_name_alloc(name);
2345 kfree(name);
2346 if (!anon_name)
2347 return -ENOMEM;
2348
9a10064f
CC		 2349 }
2350
2351 mmap_write_lock(mm);
5c26f6ac 2352 error = madvise_set_anon_name(mm, addr, size, anon_name);
9a10064f 2353 mmap_write_unlock(mm);
5c26f6ac 2354 anon_vma_name_put(anon_name);
9a10064f
CC		 2355 break;
2356 default:
2357 error = -EINVAL;
2358 }
2359
2360 return error;
2361}
2362
2363#else /* CONFIG_ANON_VMA_NAME */
2364static int prctl_set_vma(unsigned long opt, unsigned long start,
2365 unsigned long size, unsigned long arg)
2366{
2367 return -EINVAL;
2368}
2369#endif /* CONFIG_ANON_VMA_NAME */
2370
b507808e
JG		 2371static inline int prctl_set_mdwe(unsigned long bits, unsigned long arg3,
2372 unsigned long arg4, unsigned long arg5)
2373{
2374 if (arg3 || arg4 || arg5)
2375 return -EINVAL;
2376
2377 if (bits & ~(PR_MDWE_REFUSE_EXEC_GAIN))
2378 return -EINVAL;
2379
2380 if (bits & PR_MDWE_REFUSE_EXEC_GAIN)
2381 set_bit(MMF_HAS_MDWE, &current->mm->flags);
2382 else if (test_bit(MMF_HAS_MDWE, &current->mm->flags))
2383 return -EPERM; /* Cannot unset the flag */
2384
2385 return 0;
2386}
2387
2388static inline int prctl_get_mdwe(unsigned long arg2, unsigned long arg3,
2389 unsigned long arg4, unsigned long arg5)
2390{
2391 if (arg2 || arg3 || arg4 || arg5)
2392 return -EINVAL;
2393
2394 return test_bit(MMF_HAS_MDWE, &current->mm->flags) ?
2395 PR_MDWE_REFUSE_EXEC_GAIN : 0;
2396}
2397
ddc65971
JT		 2398static int prctl_get_auxv(void __user *addr, unsigned long len)
2399{
2400 struct mm_struct *mm = current->mm;
2401 unsigned long size = min_t(unsigned long, sizeof(mm->saved_auxv), len);
2402
2403 if (size && copy_to_user(addr, mm->saved_auxv, size))
2404 return -EFAULT;
2405 return sizeof(mm->saved_auxv);
2406}
2407
c4ea37c2
HC		 2408SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
2409 unsigned long, arg4, unsigned long, arg5)
1da177e4 2410{
b6dff3ec
DH		 2411 struct task_struct *me = current;
2412 unsigned char comm[sizeof(me->comm)];
2413 long error;
1da177e4 2414
d84f4f99
DH		 2415 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
2416 if (error != -ENOSYS)
1da177e4
LT		 2417 return error;
2418
d84f4f99 2419 error = 0;
1da177e4 2420 switch (option) {
f3cbd435
AM		 2421 case PR_SET_PDEATHSIG:
2422 if (!valid_signal(arg2)) {
2423 error = -EINVAL;
1da177e4 2424 break;
f3cbd435
AM		 2425 }
2426 me->pdeath_signal = arg2;
2427 break;
2428 case PR_GET_PDEATHSIG:
2429 error = put_user(me->pdeath_signal, (int __user *)arg2);
2430 break;
2431 case PR_GET_DUMPABLE:
2432 error = get_dumpable(me->mm);
2433 break;
2434 case PR_SET_DUMPABLE:
2435 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) {
2436 error = -EINVAL;
1da177e4 2437 break;
f3cbd435
AM		 2438 }
2439 set_dumpable(me->mm, arg2);
2440 break;
1da177e4 2441
f3cbd435
AM		 2442 case PR_SET_UNALIGN:
2443 error = SET_UNALIGN_CTL(me, arg2);
2444 break;
2445 case PR_GET_UNALIGN:
2446 error = GET_UNALIGN_CTL(me, arg2);
2447 break;
2448 case PR_SET_FPEMU:
2449 error = SET_FPEMU_CTL(me, arg2);
2450 break;
2451 case PR_GET_FPEMU:
2452 error = GET_FPEMU_CTL(me, arg2);
2453 break;
2454 case PR_SET_FPEXC:
2455 error = SET_FPEXC_CTL(me, arg2);
2456 break;
2457 case PR_GET_FPEXC:
2458 error = GET_FPEXC_CTL(me, arg2);
2459 break;
2460 case PR_GET_TIMING:
2461 error = PR_TIMING_STATISTICAL;
2462 break;
2463 case PR_SET_TIMING:
2464 if (arg2 != PR_TIMING_STATISTICAL)
2465 error = -EINVAL;
2466 break;
2467 case PR_SET_NAME:
2468 comm[sizeof(me->comm) - 1] = 0;
2469 if (strncpy_from_user(comm, (char __user *)arg2,
2470 sizeof(me->comm) - 1) < 0)
2471 return -EFAULT;
2472 set_task_comm(me, comm);
2473 proc_comm_connector(me);
2474 break;
2475 case PR_GET_NAME:
2476 get_task_comm(comm, me);
2477 if (copy_to_user((char __user *)arg2, comm, sizeof(comm)))
2478 return -EFAULT;
2479 break;
2480 case PR_GET_ENDIAN:
2481 error = GET_ENDIAN(me, arg2);
2482 break;
2483 case PR_SET_ENDIAN:
2484 error = SET_ENDIAN(me, arg2);
2485 break;
2486 case PR_GET_SECCOMP:
2487 error = prctl_get_seccomp();
2488 break;
2489 case PR_SET_SECCOMP:
2490 error = prctl_set_seccomp(arg2, (char __user *)arg3);
2491 break;
2492 case PR_GET_TSC:
2493 error = GET_TSC_CTL(arg2);
2494 break;
2495 case PR_SET_TSC:
2496 error = SET_TSC_CTL(arg2);
2497 break;
2498 case PR_TASK_PERF_EVENTS_DISABLE:
2499 error = perf_event_task_disable();
2500 break;
2501 case PR_TASK_PERF_EVENTS_ENABLE:
2502 error = perf_event_task_enable();
2503 break;
2504 case PR_GET_TIMERSLACK:
da8b44d5
JS		 2505 if (current->timer_slack_ns > ULONG_MAX)
2506 error = ULONG_MAX;
2507 else
2508 error = current->timer_slack_ns;
f3cbd435
AM		 2509 break;
2510 case PR_SET_TIMERSLACK:
2511 if (arg2 <= 0)
2512 current->timer_slack_ns =
6976675d 2513 current->default_timer_slack_ns;
f3cbd435
AM		 2514 else
2515 current->timer_slack_ns = arg2;
2516 break;
2517 case PR_MCE_KILL:
2518 if (arg4 | arg5)
2519 return -EINVAL;
2520 switch (arg2) {
2521 case PR_MCE_KILL_CLEAR:
2522 if (arg3 != 0)
4db96cf0 2523 return -EINVAL;
f3cbd435 2524 current->flags &= ~PF_MCE_PROCESS;
4db96cf0 2525 break;
f3cbd435
AM		 2526 case PR_MCE_KILL_SET:
2527 current->flags |= PF_MCE_PROCESS;
2528 if (arg3 == PR_MCE_KILL_EARLY)
2529 current->flags |= PF_MCE_EARLY;
2530 else if (arg3 == PR_MCE_KILL_LATE)
2531 current->flags &= ~PF_MCE_EARLY;
2532 else if (arg3 == PR_MCE_KILL_DEFAULT)
2533 current->flags &=
2534 ~(PF_MCE_EARLY|PF_MCE_PROCESS);
1087e9b4 2535 else
259e5e6c 2536 return -EINVAL;
259e5e6c 2537 break;
1da177e4 2538 default:
f3cbd435
AM		 2539 return -EINVAL;
2540 }
2541 break;
2542 case PR_MCE_KILL_GET:
2543 if (arg2 | arg3 | arg4 | arg5)
2544 return -EINVAL;
2545 if (current->flags & PF_MCE_PROCESS)
2546 error = (current->flags & PF_MCE_EARLY) ?
2547 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
2548 else
2549 error = PR_MCE_KILL_DEFAULT;
2550 break;
2551 case PR_SET_MM:
2552 error = prctl_set_mm(arg2, arg3, arg4, arg5);
2553 break;
2554 case PR_GET_TID_ADDRESS:
986b9eac 2555 error = prctl_get_tid_address(me, (int __user * __user *)arg2);
f3cbd435
AM		 2556 break;
2557 case PR_SET_CHILD_SUBREAPER:
2558 me->signal->is_child_subreaper = !!arg2;
749860ce
PT		 2559 if (!arg2)
2560 break;
2561
2562 walk_process_tree(me, propagate_has_child_subreaper, NULL);
f3cbd435
AM		 2563 break;
2564 case PR_GET_CHILD_SUBREAPER:
2565 error = put_user(me->signal->is_child_subreaper,
2566 (int __user *)arg2);
2567 break;
2568 case PR_SET_NO_NEW_PRIVS:
2569 if (arg2 != 1 || arg3 || arg4 || arg5)
2570 return -EINVAL;
2571
1d4457f9 2572 task_set_no_new_privs(current);
f3cbd435
AM		 2573 break;
2574 case PR_GET_NO_NEW_PRIVS:
2575 if (arg2 || arg3 || arg4 || arg5)
2576 return -EINVAL;
1d4457f9 2577 return task_no_new_privs(current) ? 1 : 0;
a0715cc2
AT		 2578 case PR_GET_THP_DISABLE:
2579 if (arg2 || arg3 || arg4 || arg5)
2580 return -EINVAL;
18600332 2581 error = !!test_bit(MMF_DISABLE_THP, &me->mm->flags);
a0715cc2
AT		 2582 break;
2583 case PR_SET_THP_DISABLE:
2584 if (arg3 || arg4 || arg5)
2585 return -EINVAL;
d8ed45c5 2586 if (mmap_write_lock_killable(me->mm))
17b0573d 2587 return -EINTR;
a0715cc2 2588 if (arg2)
18600332 2589 set_bit(MMF_DISABLE_THP, &me->mm->flags);
a0715cc2 2590 else
18600332 2591 clear_bit(MMF_DISABLE_THP, &me->mm->flags);
d8ed45c5 2592 mmap_write_unlock(me->mm);
a0715cc2 2593 break;
fe3d197f 2594 case PR_MPX_ENABLE_MANAGEMENT:
fe3d197f 2595 case PR_MPX_DISABLE_MANAGEMENT:
f240652b
DH		 2596 /* No longer implemented: */
2597 return -EINVAL;
9791554b
PB		 2598 case PR_SET_FP_MODE:
2599 error = SET_FP_MODE(me, arg2);
2600 break;
2601 case PR_GET_FP_MODE:
2602 error = GET_FP_MODE(me);
2603 break;
2d2123bc
DM		 2604 case PR_SVE_SET_VL:
2605 error = SVE_SET_VL(arg2);
2606 break;
2607 case PR_SVE_GET_VL:
2608 error = SVE_GET_VL();
2609 break;
9e4ab6c8
MB		 2610 case PR_SME_SET_VL:
2611 error = SME_SET_VL(arg2);
2612 break;
2613 case PR_SME_GET_VL:
2614 error = SME_GET_VL();
2615 break;
b617cfc8
TG		 2616 case PR_GET_SPECULATION_CTRL:
2617 if (arg3 || arg4 || arg5)
2618 return -EINVAL;
7bbf1373 2619 error = arch_prctl_spec_ctrl_get(me, arg2);
b617cfc8
TG		 2620 break;
2621 case PR_SET_SPECULATION_CTRL:
2622 if (arg4 || arg5)
2623 return -EINVAL;
7bbf1373 2624 error = arch_prctl_spec_ctrl_set(me, arg2, arg3);
b617cfc8 2625 break;
ba830885
KM		 2626 case PR_PAC_RESET_KEYS:
2627 if (arg3 || arg4 || arg5)
2628 return -EINVAL;
2629 error = PAC_RESET_KEYS(me, arg2);
2630 break;
20169862
PC		 2631 case PR_PAC_SET_ENABLED_KEYS:
2632 if (arg4 || arg5)
2633 return -EINVAL;
2634 error = PAC_SET_ENABLED_KEYS(me, arg2, arg3);
2635 break;
2636 case PR_PAC_GET_ENABLED_KEYS:
2637 if (arg2 || arg3 || arg4 || arg5)
2638 return -EINVAL;
2639 error = PAC_GET_ENABLED_KEYS(me);
2640 break;
63f0c603 2641 case PR_SET_TAGGED_ADDR_CTRL:
3e91ec89
CM		 2642 if (arg3 || arg4 || arg5)
2643 return -EINVAL;
63f0c603
CM		 2644 error = SET_TAGGED_ADDR_CTRL(arg2);
2645 break;
2646 case PR_GET_TAGGED_ADDR_CTRL:
3e91ec89
CM		 2647 if (arg2 || arg3 || arg4 || arg5)
2648 return -EINVAL;
63f0c603
CM		 2649 error = GET_TAGGED_ADDR_CTRL();
2650 break;
8d19f1c8
MC		 2651 case PR_SET_IO_FLUSHER:
2652 if (!capable(CAP_SYS_RESOURCE))
2653 return -EPERM;
2654
2655 if (arg3 || arg4 || arg5)
2656 return -EINVAL;
2657
2658 if (arg2 == 1)
2659 current->flags |= PR_IO_FLUSHER;
2660 else if (!arg2)
2661 current->flags &= ~PR_IO_FLUSHER;
2662 else
2663 return -EINVAL;
2664 break;
2665 case PR_GET_IO_FLUSHER:
2666 if (!capable(CAP_SYS_RESOURCE))
2667 return -EPERM;
2668
2669 if (arg2 || arg3 || arg4 || arg5)
2670 return -EINVAL;
2671
2672 error = (current->flags & PR_IO_FLUSHER) == PR_IO_FLUSHER;
2673 break;
1446e1df
GKB		 2674 case PR_SET_SYSCALL_USER_DISPATCH:
2675 error = set_syscall_user_dispatch(arg2, arg3, arg4,
2676 (char __user *) arg5);
2677 break;
7ac592aa
CH		 2678#ifdef CONFIG_SCHED_CORE
2679 case PR_SCHED_CORE:
2680 error = sched_core_share_pid(arg2, arg3, arg4, arg5);
2681 break;
2682#endif
b507808e
JG		 2683 case PR_SET_MDWE:
2684 error = prctl_set_mdwe(arg2, arg3, arg4, arg5);
2685 break;
2686 case PR_GET_MDWE:
2687 error = prctl_get_mdwe(arg2, arg3, arg4, arg5);
2688 break;
9a10064f
CC		 2689 case PR_SET_VMA:
2690 error = prctl_set_vma(arg2, arg3, arg4, arg5);
2691 break;
636e3483
MO		 2692 case PR_GET_AUXV:
2693 if (arg4 || arg5)
2694 return -EINVAL;
2695 error = prctl_get_auxv((void __user *)arg2, arg3);
2696 break;
d7597f59
SR		 2697#ifdef CONFIG_KSM
2698 case PR_SET_MEMORY_MERGE:
2699 if (arg3 || arg4 || arg5)
2700 return -EINVAL;
2701 if (mmap_write_lock_killable(me->mm))
2702 return -EINTR;
2703
24139c07 2704 if (arg2)
d7597f59 2705 error = ksm_enable_merge_any(me->mm);
24139c07
DH		 2706 else
2707 error = ksm_disable_merge_any(me->mm);
d7597f59
SR		 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
1fd96a3e
AC		 2717 case PR_RISCV_V_SET_CONTROL:
2718 error = RISCV_V_SET_CONTROL(arg2);
2719 break;
2720 case PR_RISCV_V_GET_CONTROL:
2721 error = RISCV_V_GET_CONTROL();
2722 break;
f3cbd435
AM		 2723 default:
2724 error = -EINVAL;
2725 break;
1da177e4
LT		 2726 }
2727 return error;
2728}
3cfc348b 2729
836f92ad
HC		 2730SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
2731 struct getcpu_cache __user *, unused)
3cfc348b
AK		 2732{
2733 int err = 0;
2734 int cpu = raw_smp_processor_id();
ec94fc3d 2735
3cfc348b
AK		 2736 if (cpup)
2737 err |= put_user(cpu, cpup);
2738 if (nodep)
2739 err |= put_user(cpu_to_node(cpu), nodep);
3cfc348b
AK		 2740 return err ? -EFAULT : 0;
2741}
10a0a8d4 2742
4a22f166
SR		 2743/**
2744 * do_sysinfo - fill in sysinfo struct
2745 * @info: pointer to buffer to fill
2746 */
2747static int do_sysinfo(struct sysinfo *info)
2748{
2749 unsigned long mem_total, sav_total;
2750 unsigned int mem_unit, bitcount;
dc1b7b6c 2751 struct timespec64 tp;
4a22f166
SR		 2752
2753 memset(info, 0, sizeof(struct sysinfo));
2754
dc1b7b6c 2755 ktime_get_boottime_ts64(&tp);
ecc421e0 2756 timens_add_boottime(&tp);
4a22f166
SR		 2757 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
2758
2759 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT);
2760
2761 info->procs = nr_threads;
2762
2763 si_meminfo(info);
2764 si_swapinfo(info);
2765
2766 /*
2767 * If the sum of all the available memory (i.e. ram + swap)
2768 * is less than can be stored in a 32 bit unsigned long then
2769 * we can be binary compatible with 2.2.x kernels. If not,
2770 * well, in that case 2.2.x was broken anyways...
2771 *
2772 * -Erik Andersen <andersee@debian.org>
2773 */
2774
2775 mem_total = info->totalram + info->totalswap;
2776 if (mem_total < info->totalram || mem_total < info->totalswap)
2777 goto out;
2778 bitcount = 0;
2779 mem_unit = info->mem_unit;
2780 while (mem_unit > 1) {
2781 bitcount++;
2782 mem_unit >>= 1;
2783 sav_total = mem_total;
2784 mem_total <<= 1;
2785 if (mem_total < sav_total)
2786 goto out;
2787 }
2788
2789 /*
2790 * If mem_total did not overflow, multiply all memory values by
2791 * info->mem_unit and set it to 1. This leaves things compatible
2792 * with 2.2.x, and also retains compatibility with earlier 2.4.x
2793 * kernels...
2794 */
2795
2796 info->mem_unit = 1;
2797 info->totalram <<= bitcount;
2798 info->freeram <<= bitcount;
2799 info->sharedram <<= bitcount;
2800 info->bufferram <<= bitcount;
2801 info->totalswap <<= bitcount;
2802 info->freeswap <<= bitcount;
2803 info->totalhigh <<= bitcount;
2804 info->freehigh <<= bitcount;
2805
2806out:
2807 return 0;
2808}
2809
2810SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info)
2811{
2812 struct sysinfo val;
2813
2814 do_sysinfo(&val);
2815
2816 if (copy_to_user(info, &val, sizeof(struct sysinfo)))
2817 return -EFAULT;
2818
2819 return 0;
2820}
2821
2822#ifdef CONFIG_COMPAT
2823struct compat_sysinfo {
2824 s32 uptime;
2825 u32 loads[3];
2826 u32 totalram;
2827 u32 freeram;
2828 u32 sharedram;
2829 u32 bufferram;
2830 u32 totalswap;
2831 u32 freeswap;
2832 u16 procs;
2833 u16 pad;
2834 u32 totalhigh;
2835 u32 freehigh;
2836 u32 mem_unit;
2837 char _f[20-2*sizeof(u32)-sizeof(int)];
2838};
2839
2840COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info)
2841{
2842 struct sysinfo s;
ce5155c4 2843 struct compat_sysinfo s_32;
4a22f166
SR		 2844
2845 do_sysinfo(&s);
2846
2847 /* Check to see if any memory value is too large for 32-bit and scale
2848 * down if needed
2849 */
0baae41e 2850 if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) {
4a22f166
SR		 2851 int bitcount = 0;
2852
2853 while (s.mem_unit < PAGE_SIZE) {
2854 s.mem_unit <<= 1;
2855 bitcount++;
2856 }
2857
2858 s.totalram >>= bitcount;
2859 s.freeram >>= bitcount;
2860 s.sharedram >>= bitcount;
2861 s.bufferram >>= bitcount;
2862 s.totalswap >>= bitcount;
2863 s.freeswap >>= bitcount;
2864 s.totalhigh >>= bitcount;
2865 s.freehigh >>= bitcount;
2866 }
2867
ce5155c4
AV		 2868 memset(&s_32, 0, sizeof(s_32));
2869 s_32.uptime = s.uptime;
2870 s_32.loads[0] = s.loads[0];
2871 s_32.loads[1] = s.loads[1];
2872 s_32.loads[2] = s.loads[2];
2873 s_32.totalram = s.totalram;
2874 s_32.freeram = s.freeram;
2875 s_32.sharedram = s.sharedram;
2876 s_32.bufferram = s.bufferram;
2877 s_32.totalswap = s.totalswap;
2878 s_32.freeswap = s.freeswap;
2879 s_32.procs = s.procs;
2880 s_32.totalhigh = s.totalhigh;
2881 s_32.freehigh = s.freehigh;
2882 s_32.mem_unit = s.mem_unit;
2883 if (copy_to_user(info, &s_32, sizeof(s_32)))
4a22f166 2884 return -EFAULT;
4a22f166
SR		 2885 return 0;
2886}
2887#endif /* CONFIG_COMPAT */
Linux 6.x block layer and io_uring tree(s)