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Merge branch 'tracing/core' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic...
[mirror_ubuntu-artful-kernel.git] / kernel / sys.c
1 /*
2 * linux/kernel/sys.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 */
6
7 #include <linux/module.h>
8 #include <linux/mm.h>
9 #include <linux/utsname.h>
10 #include <linux/mman.h>
11 #include <linux/notifier.h>
12 #include <linux/reboot.h>
13 #include <linux/prctl.h>
14 #include <linux/highuid.h>
15 #include <linux/fs.h>
16 #include <linux/perf_event.h>
17 #include <linux/resource.h>
18 #include <linux/kernel.h>
19 #include <linux/kexec.h>
20 #include <linux/workqueue.h>
21 #include <linux/capability.h>
22 #include <linux/device.h>
23 #include <linux/key.h>
24 #include <linux/times.h>
25 #include <linux/posix-timers.h>
26 #include <linux/security.h>
27 #include <linux/dcookies.h>
28 #include <linux/suspend.h>
29 #include <linux/tty.h>
30 #include <linux/signal.h>
31 #include <linux/cn_proc.h>
32 #include <linux/getcpu.h>
33 #include <linux/task_io_accounting_ops.h>
34 #include <linux/seccomp.h>
35 #include <linux/cpu.h>
36 #include <linux/ptrace.h>
37 #include <linux/fs_struct.h>
38
39 #include <linux/compat.h>
40 #include <linux/syscalls.h>
41 #include <linux/kprobes.h>
42 #include <linux/user_namespace.h>
43
44 #include <asm/uaccess.h>
45 #include <asm/io.h>
46 #include <asm/unistd.h>
47
48 #ifndef SET_UNALIGN_CTL
49 # define SET_UNALIGN_CTL(a,b) (-EINVAL)
50 #endif
51 #ifndef GET_UNALIGN_CTL
52 # define GET_UNALIGN_CTL(a,b) (-EINVAL)
53 #endif
54 #ifndef SET_FPEMU_CTL
55 # define SET_FPEMU_CTL(a,b) (-EINVAL)
56 #endif
57 #ifndef GET_FPEMU_CTL
58 # define GET_FPEMU_CTL(a,b) (-EINVAL)
59 #endif
60 #ifndef SET_FPEXC_CTL
61 # define SET_FPEXC_CTL(a,b) (-EINVAL)
62 #endif
63 #ifndef GET_FPEXC_CTL
64 # define GET_FPEXC_CTL(a,b) (-EINVAL)
65 #endif
66 #ifndef GET_ENDIAN
67 # define GET_ENDIAN(a,b) (-EINVAL)
68 #endif
69 #ifndef SET_ENDIAN
70 # define SET_ENDIAN(a,b) (-EINVAL)
71 #endif
72 #ifndef GET_TSC_CTL
73 # define GET_TSC_CTL(a) (-EINVAL)
74 #endif
75 #ifndef SET_TSC_CTL
76 # define SET_TSC_CTL(a) (-EINVAL)
77 #endif
78
79 /*
80 * this is where the system-wide overflow UID and GID are defined, for
81 * architectures that now have 32-bit UID/GID but didn't in the past
82 */
83
84 int overflowuid = DEFAULT_OVERFLOWUID;
85 int overflowgid = DEFAULT_OVERFLOWGID;
86
87 #ifdef CONFIG_UID16
88 EXPORT_SYMBOL(overflowuid);
89 EXPORT_SYMBOL(overflowgid);
90 #endif
91
92 /*
93 * the same as above, but for filesystems which can only store a 16-bit
94 * UID and GID. as such, this is needed on all architectures
95 */
96
97 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
98 int fs_overflowgid = DEFAULT_FS_OVERFLOWUID;
99
100 EXPORT_SYMBOL(fs_overflowuid);
101 EXPORT_SYMBOL(fs_overflowgid);
102
103 /*
104 * this indicates whether you can reboot with ctrl-alt-del: the default is yes
105 */
106
107 int C_A_D = 1;
108 struct pid *cad_pid;
109 EXPORT_SYMBOL(cad_pid);
110
111 /*
112 * If set, this is used for preparing the system to power off.
113 */
114
115 void (*pm_power_off_prepare)(void);
116
117 /*
118 * set the priority of a task
119 * - the caller must hold the RCU read lock
120 */
121 static int set_one_prio(struct task_struct *p, int niceval, int error)
122 {
123 const struct cred *cred = current_cred(), *pcred = __task_cred(p);
124 int no_nice;
125
126 if (pcred->uid != cred->euid &&
127 pcred->euid != cred->euid && !capable(CAP_SYS_NICE)) {
128 error = -EPERM;
129 goto out;
130 }
131 if (niceval < task_nice(p) && !can_nice(p, niceval)) {
132 error = -EACCES;
133 goto out;
134 }
135 no_nice = security_task_setnice(p, niceval);
136 if (no_nice) {
137 error = no_nice;
138 goto out;
139 }
140 if (error == -ESRCH)
141 error = 0;
142 set_user_nice(p, niceval);
143 out:
144 return error;
145 }
146
147 SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
148 {
149 struct task_struct *g, *p;
150 struct user_struct *user;
151 const struct cred *cred = current_cred();
152 int error = -EINVAL;
153 struct pid *pgrp;
154
155 if (which > PRIO_USER || which < PRIO_PROCESS)
156 goto out;
157
158 /* normalize: avoid signed division (rounding problems) */
159 error = -ESRCH;
160 if (niceval < -20)
161 niceval = -20;
162 if (niceval > 19)
163 niceval = 19;
164
165 rcu_read_lock();
166 read_lock(&tasklist_lock);
167 switch (which) {
168 case PRIO_PROCESS:
169 if (who)
170 p = find_task_by_vpid(who);
171 else
172 p = current;
173 if (p)
174 error = set_one_prio(p, niceval, error);
175 break;
176 case PRIO_PGRP:
177 if (who)
178 pgrp = find_vpid(who);
179 else
180 pgrp = task_pgrp(current);
181 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
182 error = set_one_prio(p, niceval, error);
183 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
184 break;
185 case PRIO_USER:
186 user = (struct user_struct *) cred->user;
187 if (!who)
188 who = cred->uid;
189 else if ((who != cred->uid) &&
190 !(user = find_user(who)))
191 goto out_unlock; /* No processes for this user */
192
193 do_each_thread(g, p) {
194 if (__task_cred(p)->uid == who)
195 error = set_one_prio(p, niceval, error);
196 } while_each_thread(g, p);
197 if (who != cred->uid)
198 free_uid(user); /* For find_user() */
199 break;
200 }
201 out_unlock:
202 read_unlock(&tasklist_lock);
203 rcu_read_unlock();
204 out:
205 return error;
206 }
207
208 /*
209 * Ugh. To avoid negative return values, "getpriority()" will
210 * not return the normal nice-value, but a negated value that
211 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
212 * to stay compatible.
213 */
214 SYSCALL_DEFINE2(getpriority, int, which, int, who)
215 {
216 struct task_struct *g, *p;
217 struct user_struct *user;
218 const struct cred *cred = current_cred();
219 long niceval, retval = -ESRCH;
220 struct pid *pgrp;
221
222 if (which > PRIO_USER || which < PRIO_PROCESS)
223 return -EINVAL;
224
225 rcu_read_lock();
226 read_lock(&tasklist_lock);
227 switch (which) {
228 case PRIO_PROCESS:
229 if (who)
230 p = find_task_by_vpid(who);
231 else
232 p = current;
233 if (p) {
234 niceval = 20 - task_nice(p);
235 if (niceval > retval)
236 retval = niceval;
237 }
238 break;
239 case PRIO_PGRP:
240 if (who)
241 pgrp = find_vpid(who);
242 else
243 pgrp = task_pgrp(current);
244 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
245 niceval = 20 - task_nice(p);
246 if (niceval > retval)
247 retval = niceval;
248 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
249 break;
250 case PRIO_USER:
251 user = (struct user_struct *) cred->user;
252 if (!who)
253 who = cred->uid;
254 else if ((who != cred->uid) &&
255 !(user = find_user(who)))
256 goto out_unlock; /* No processes for this user */
257
258 do_each_thread(g, p) {
259 if (__task_cred(p)->uid == who) {
260 niceval = 20 - task_nice(p);
261 if (niceval > retval)
262 retval = niceval;
263 }
264 } while_each_thread(g, p);
265 if (who != cred->uid)
266 free_uid(user); /* for find_user() */
267 break;
268 }
269 out_unlock:
270 read_unlock(&tasklist_lock);
271 rcu_read_unlock();
272
273 return retval;
274 }
275
276 /**
277 * emergency_restart - reboot the system
278 *
279 * Without shutting down any hardware or taking any locks
280 * reboot the system. This is called when we know we are in
281 * trouble so this is our best effort to reboot. This is
282 * safe to call in interrupt context.
283 */
284 void emergency_restart(void)
285 {
286 machine_emergency_restart();
287 }
288 EXPORT_SYMBOL_GPL(emergency_restart);
289
290 void kernel_restart_prepare(char *cmd)
291 {
292 blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd);
293 system_state = SYSTEM_RESTART;
294 device_shutdown();
295 sysdev_shutdown();
296 }
297
298 /**
299 * kernel_restart - reboot the system
300 * @cmd: pointer to buffer containing command to execute for restart
301 * or %NULL
302 *
303 * Shutdown everything and perform a clean reboot.
304 * This is not safe to call in interrupt context.
305 */
306 void kernel_restart(char *cmd)
307 {
308 kernel_restart_prepare(cmd);
309 if (!cmd)
310 printk(KERN_EMERG "Restarting system.\n");
311 else
312 printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd);
313 machine_restart(cmd);
314 }
315 EXPORT_SYMBOL_GPL(kernel_restart);
316
317 static void kernel_shutdown_prepare(enum system_states state)
318 {
319 blocking_notifier_call_chain(&reboot_notifier_list,
320 (state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL);
321 system_state = state;
322 device_shutdown();
323 }
324 /**
325 * kernel_halt - halt the system
326 *
327 * Shutdown everything and perform a clean system halt.
328 */
329 void kernel_halt(void)
330 {
331 kernel_shutdown_prepare(SYSTEM_HALT);
332 sysdev_shutdown();
333 printk(KERN_EMERG "System halted.\n");
334 machine_halt();
335 }
336
337 EXPORT_SYMBOL_GPL(kernel_halt);
338
339 /**
340 * kernel_power_off - power_off the system
341 *
342 * Shutdown everything and perform a clean system power_off.
343 */
344 void kernel_power_off(void)
345 {
346 kernel_shutdown_prepare(SYSTEM_POWER_OFF);
347 if (pm_power_off_prepare)
348 pm_power_off_prepare();
349 disable_nonboot_cpus();
350 sysdev_shutdown();
351 printk(KERN_EMERG "Power down.\n");
352 machine_power_off();
353 }
354 EXPORT_SYMBOL_GPL(kernel_power_off);
355
356 static DEFINE_MUTEX(reboot_mutex);
357
358 /*
359 * Reboot system call: for obvious reasons only root may call it,
360 * and even root needs to set up some magic numbers in the registers
361 * so that some mistake won't make this reboot the whole machine.
362 * You can also set the meaning of the ctrl-alt-del-key here.
363 *
364 * reboot doesn't sync: do that yourself before calling this.
365 */
366 SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
367 void __user *, arg)
368 {
369 char buffer[256];
370 int ret = 0;
371
372 /* We only trust the superuser with rebooting the system. */
373 if (!capable(CAP_SYS_BOOT))
374 return -EPERM;
375
376 /* For safety, we require "magic" arguments. */
377 if (magic1 != LINUX_REBOOT_MAGIC1 ||
378 (magic2 != LINUX_REBOOT_MAGIC2 &&
379 magic2 != LINUX_REBOOT_MAGIC2A &&
380 magic2 != LINUX_REBOOT_MAGIC2B &&
381 magic2 != LINUX_REBOOT_MAGIC2C))
382 return -EINVAL;
383
384 /* Instead of trying to make the power_off code look like
385 * halt when pm_power_off is not set do it the easy way.
386 */
387 if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off)
388 cmd = LINUX_REBOOT_CMD_HALT;
389
390 mutex_lock(&reboot_mutex);
391 switch (cmd) {
392 case LINUX_REBOOT_CMD_RESTART:
393 kernel_restart(NULL);
394 break;
395
396 case LINUX_REBOOT_CMD_CAD_ON:
397 C_A_D = 1;
398 break;
399
400 case LINUX_REBOOT_CMD_CAD_OFF:
401 C_A_D = 0;
402 break;
403
404 case LINUX_REBOOT_CMD_HALT:
405 kernel_halt();
406 do_exit(0);
407 panic("cannot halt");
408
409 case LINUX_REBOOT_CMD_POWER_OFF:
410 kernel_power_off();
411 do_exit(0);
412 break;
413
414 case LINUX_REBOOT_CMD_RESTART2:
415 if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) {
416 ret = -EFAULT;
417 break;
418 }
419 buffer[sizeof(buffer) - 1] = '\0';
420
421 kernel_restart(buffer);
422 break;
423
424 #ifdef CONFIG_KEXEC
425 case LINUX_REBOOT_CMD_KEXEC:
426 ret = kernel_kexec();
427 break;
428 #endif
429
430 #ifdef CONFIG_HIBERNATION
431 case LINUX_REBOOT_CMD_SW_SUSPEND:
432 ret = hibernate();
433 break;
434 #endif
435
436 default:
437 ret = -EINVAL;
438 break;
439 }
440 mutex_unlock(&reboot_mutex);
441 return ret;
442 }
443
444 static void deferred_cad(struct work_struct *dummy)
445 {
446 kernel_restart(NULL);
447 }
448
449 /*
450 * This function gets called by ctrl-alt-del - ie the keyboard interrupt.
451 * As it's called within an interrupt, it may NOT sync: the only choice
452 * is whether to reboot at once, or just ignore the ctrl-alt-del.
453 */
454 void ctrl_alt_del(void)
455 {
456 static DECLARE_WORK(cad_work, deferred_cad);
457
458 if (C_A_D)
459 schedule_work(&cad_work);
460 else
461 kill_cad_pid(SIGINT, 1);
462 }
463
464 /*
465 * Unprivileged users may change the real gid to the effective gid
466 * or vice versa. (BSD-style)
467 *
468 * If you set the real gid at all, or set the effective gid to a value not
469 * equal to the real gid, then the saved gid is set to the new effective gid.
470 *
471 * This makes it possible for a setgid program to completely drop its
472 * privileges, which is often a useful assertion to make when you are doing
473 * a security audit over a program.
474 *
475 * The general idea is that a program which uses just setregid() will be
476 * 100% compatible with BSD. A program which uses just setgid() will be
477 * 100% compatible with POSIX with saved IDs.
478 *
479 * SMP: There are not races, the GIDs are checked only by filesystem
480 * operations (as far as semantic preservation is concerned).
481 */
482 SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
483 {
484 const struct cred *old;
485 struct cred *new;
486 int retval;
487
488 new = prepare_creds();
489 if (!new)
490 return -ENOMEM;
491 old = current_cred();
492
493 retval = security_task_setgid(rgid, egid, (gid_t)-1, LSM_SETID_RE);
494 if (retval)
495 goto error;
496
497 retval = -EPERM;
498 if (rgid != (gid_t) -1) {
499 if (old->gid == rgid ||
500 old->egid == rgid ||
501 capable(CAP_SETGID))
502 new->gid = rgid;
503 else
504 goto error;
505 }
506 if (egid != (gid_t) -1) {
507 if (old->gid == egid ||
508 old->egid == egid ||
509 old->sgid == egid ||
510 capable(CAP_SETGID))
511 new->egid = egid;
512 else
513 goto error;
514 }
515
516 if (rgid != (gid_t) -1 ||
517 (egid != (gid_t) -1 && egid != old->gid))
518 new->sgid = new->egid;
519 new->fsgid = new->egid;
520
521 return commit_creds(new);
522
523 error:
524 abort_creds(new);
525 return retval;
526 }
527
528 /*
529 * setgid() is implemented like SysV w/ SAVED_IDS
530 *
531 * SMP: Same implicit races as above.
532 */
533 SYSCALL_DEFINE1(setgid, gid_t, gid)
534 {
535 const struct cred *old;
536 struct cred *new;
537 int retval;
538
539 new = prepare_creds();
540 if (!new)
541 return -ENOMEM;
542 old = current_cred();
543
544 retval = security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID);
545 if (retval)
546 goto error;
547
548 retval = -EPERM;
549 if (capable(CAP_SETGID))
550 new->gid = new->egid = new->sgid = new->fsgid = gid;
551 else if (gid == old->gid || gid == old->sgid)
552 new->egid = new->fsgid = gid;
553 else
554 goto error;
555
556 return commit_creds(new);
557
558 error:
559 abort_creds(new);
560 return retval;
561 }
562
563 /*
564 * change the user struct in a credentials set to match the new UID
565 */
566 static int set_user(struct cred *new)
567 {
568 struct user_struct *new_user;
569
570 new_user = alloc_uid(current_user_ns(), new->uid);
571 if (!new_user)
572 return -EAGAIN;
573
574 if (!task_can_switch_user(new_user, current)) {
575 free_uid(new_user);
576 return -EINVAL;
577 }
578
579 if (atomic_read(&new_user->processes) >=
580 current->signal->rlim[RLIMIT_NPROC].rlim_cur &&
581 new_user != INIT_USER) {
582 free_uid(new_user);
583 return -EAGAIN;
584 }
585
586 free_uid(new->user);
587 new->user = new_user;
588 return 0;
589 }
590
591 /*
592 * Unprivileged users may change the real uid to the effective uid
593 * or vice versa. (BSD-style)
594 *
595 * If you set the real uid at all, or set the effective uid to a value not
596 * equal to the real uid, then the saved uid is set to the new effective uid.
597 *
598 * This makes it possible for a setuid program to completely drop its
599 * privileges, which is often a useful assertion to make when you are doing
600 * a security audit over a program.
601 *
602 * The general idea is that a program which uses just setreuid() will be
603 * 100% compatible with BSD. A program which uses just setuid() will be
604 * 100% compatible with POSIX with saved IDs.
605 */
606 SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
607 {
608 const struct cred *old;
609 struct cred *new;
610 int retval;
611
612 new = prepare_creds();
613 if (!new)
614 return -ENOMEM;
615 old = current_cred();
616
617 retval = security_task_setuid(ruid, euid, (uid_t)-1, LSM_SETID_RE);
618 if (retval)
619 goto error;
620
621 retval = -EPERM;
622 if (ruid != (uid_t) -1) {
623 new->uid = ruid;
624 if (old->uid != ruid &&
625 old->euid != ruid &&
626 !capable(CAP_SETUID))
627 goto error;
628 }
629
630 if (euid != (uid_t) -1) {
631 new->euid = euid;
632 if (old->uid != euid &&
633 old->euid != euid &&
634 old->suid != euid &&
635 !capable(CAP_SETUID))
636 goto error;
637 }
638
639 if (new->uid != old->uid) {
640 retval = set_user(new);
641 if (retval < 0)
642 goto error;
643 }
644 if (ruid != (uid_t) -1 ||
645 (euid != (uid_t) -1 && euid != old->uid))
646 new->suid = new->euid;
647 new->fsuid = new->euid;
648
649 retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
650 if (retval < 0)
651 goto error;
652
653 return commit_creds(new);
654
655 error:
656 abort_creds(new);
657 return retval;
658 }
659
660 /*
661 * setuid() is implemented like SysV with SAVED_IDS
662 *
663 * Note that SAVED_ID's is deficient in that a setuid root program
664 * like sendmail, for example, cannot set its uid to be a normal
665 * user and then switch back, because if you're root, setuid() sets
666 * the saved uid too. If you don't like this, blame the bright people
667 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
668 * will allow a root program to temporarily drop privileges and be able to
669 * regain them by swapping the real and effective uid.
670 */
671 SYSCALL_DEFINE1(setuid, uid_t, uid)
672 {
673 const struct cred *old;
674 struct cred *new;
675 int retval;
676
677 new = prepare_creds();
678 if (!new)
679 return -ENOMEM;
680 old = current_cred();
681
682 retval = security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_ID);
683 if (retval)
684 goto error;
685
686 retval = -EPERM;
687 if (capable(CAP_SETUID)) {
688 new->suid = new->uid = uid;
689 if (uid != old->uid) {
690 retval = set_user(new);
691 if (retval < 0)
692 goto error;
693 }
694 } else if (uid != old->uid && uid != new->suid) {
695 goto error;
696 }
697
698 new->fsuid = new->euid = uid;
699
700 retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
701 if (retval < 0)
702 goto error;
703
704 return commit_creds(new);
705
706 error:
707 abort_creds(new);
708 return retval;
709 }
710
711
712 /*
713 * This function implements a generic ability to update ruid, euid,
714 * and suid. This allows you to implement the 4.4 compatible seteuid().
715 */
716 SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
717 {
718 const struct cred *old;
719 struct cred *new;
720 int retval;
721
722 new = prepare_creds();
723 if (!new)
724 return -ENOMEM;
725
726 retval = security_task_setuid(ruid, euid, suid, LSM_SETID_RES);
727 if (retval)
728 goto error;
729 old = current_cred();
730
731 retval = -EPERM;
732 if (!capable(CAP_SETUID)) {
733 if (ruid != (uid_t) -1 && ruid != old->uid &&
734 ruid != old->euid && ruid != old->suid)
735 goto error;
736 if (euid != (uid_t) -1 && euid != old->uid &&
737 euid != old->euid && euid != old->suid)
738 goto error;
739 if (suid != (uid_t) -1 && suid != old->uid &&
740 suid != old->euid && suid != old->suid)
741 goto error;
742 }
743
744 if (ruid != (uid_t) -1) {
745 new->uid = ruid;
746 if (ruid != old->uid) {
747 retval = set_user(new);
748 if (retval < 0)
749 goto error;
750 }
751 }
752 if (euid != (uid_t) -1)
753 new->euid = euid;
754 if (suid != (uid_t) -1)
755 new->suid = suid;
756 new->fsuid = new->euid;
757
758 retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
759 if (retval < 0)
760 goto error;
761
762 return commit_creds(new);
763
764 error:
765 abort_creds(new);
766 return retval;
767 }
768
769 SYSCALL_DEFINE3(getresuid, uid_t __user *, ruid, uid_t __user *, euid, uid_t __user *, suid)
770 {
771 const struct cred *cred = current_cred();
772 int retval;
773
774 if (!(retval = put_user(cred->uid, ruid)) &&
775 !(retval = put_user(cred->euid, euid)))
776 retval = put_user(cred->suid, suid);
777
778 return retval;
779 }
780
781 /*
782 * Same as above, but for rgid, egid, sgid.
783 */
784 SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
785 {
786 const struct cred *old;
787 struct cred *new;
788 int retval;
789
790 new = prepare_creds();
791 if (!new)
792 return -ENOMEM;
793 old = current_cred();
794
795 retval = security_task_setgid(rgid, egid, sgid, LSM_SETID_RES);
796 if (retval)
797 goto error;
798
799 retval = -EPERM;
800 if (!capable(CAP_SETGID)) {
801 if (rgid != (gid_t) -1 && rgid != old->gid &&
802 rgid != old->egid && rgid != old->sgid)
803 goto error;
804 if (egid != (gid_t) -1 && egid != old->gid &&
805 egid != old->egid && egid != old->sgid)
806 goto error;
807 if (sgid != (gid_t) -1 && sgid != old->gid &&
808 sgid != old->egid && sgid != old->sgid)
809 goto error;
810 }
811
812 if (rgid != (gid_t) -1)
813 new->gid = rgid;
814 if (egid != (gid_t) -1)
815 new->egid = egid;
816 if (sgid != (gid_t) -1)
817 new->sgid = sgid;
818 new->fsgid = new->egid;
819
820 return commit_creds(new);
821
822 error:
823 abort_creds(new);
824 return retval;
825 }
826
827 SYSCALL_DEFINE3(getresgid, gid_t __user *, rgid, gid_t __user *, egid, gid_t __user *, sgid)
828 {
829 const struct cred *cred = current_cred();
830 int retval;
831
832 if (!(retval = put_user(cred->gid, rgid)) &&
833 !(retval = put_user(cred->egid, egid)))
834 retval = put_user(cred->sgid, sgid);
835
836 return retval;
837 }
838
839
840 /*
841 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
842 * is used for "access()" and for the NFS daemon (letting nfsd stay at
843 * whatever uid it wants to). It normally shadows "euid", except when
844 * explicitly set by setfsuid() or for access..
845 */
846 SYSCALL_DEFINE1(setfsuid, uid_t, uid)
847 {
848 const struct cred *old;
849 struct cred *new;
850 uid_t old_fsuid;
851
852 new = prepare_creds();
853 if (!new)
854 return current_fsuid();
855 old = current_cred();
856 old_fsuid = old->fsuid;
857
858 if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS) < 0)
859 goto error;
860
861 if (uid == old->uid || uid == old->euid ||
862 uid == old->suid || uid == old->fsuid ||
863 capable(CAP_SETUID)) {
864 if (uid != old_fsuid) {
865 new->fsuid = uid;
866 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
867 goto change_okay;
868 }
869 }
870
871 error:
872 abort_creds(new);
873 return old_fsuid;
874
875 change_okay:
876 commit_creds(new);
877 return old_fsuid;
878 }
879
880 /*
881 * Samma på svenska..
882 */
883 SYSCALL_DEFINE1(setfsgid, gid_t, gid)
884 {
885 const struct cred *old;
886 struct cred *new;
887 gid_t old_fsgid;
888
889 new = prepare_creds();
890 if (!new)
891 return current_fsgid();
892 old = current_cred();
893 old_fsgid = old->fsgid;
894
895 if (security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS))
896 goto error;
897
898 if (gid == old->gid || gid == old->egid ||
899 gid == old->sgid || gid == old->fsgid ||
900 capable(CAP_SETGID)) {
901 if (gid != old_fsgid) {
902 new->fsgid = gid;
903 goto change_okay;
904 }
905 }
906
907 error:
908 abort_creds(new);
909 return old_fsgid;
910
911 change_okay:
912 commit_creds(new);
913 return old_fsgid;
914 }
915
916 void do_sys_times(struct tms *tms)
917 {
918 cputime_t tgutime, tgstime, cutime, cstime;
919
920 spin_lock_irq(&current->sighand->siglock);
921 thread_group_times(current, &tgutime, &tgstime);
922 cutime = current->signal->cutime;
923 cstime = current->signal->cstime;
924 spin_unlock_irq(&current->sighand->siglock);
925 tms->tms_utime = cputime_to_clock_t(tgutime);
926 tms->tms_stime = cputime_to_clock_t(tgstime);
927 tms->tms_cutime = cputime_to_clock_t(cutime);
928 tms->tms_cstime = cputime_to_clock_t(cstime);
929 }
930
931 SYSCALL_DEFINE1(times, struct tms __user *, tbuf)
932 {
933 if (tbuf) {
934 struct tms tmp;
935
936 do_sys_times(&tmp);
937 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
938 return -EFAULT;
939 }
940 force_successful_syscall_return();
941 return (long) jiffies_64_to_clock_t(get_jiffies_64());
942 }
943
944 /*
945 * This needs some heavy checking ...
946 * I just haven't the stomach for it. I also don't fully
947 * understand sessions/pgrp etc. Let somebody who does explain it.
948 *
949 * OK, I think I have the protection semantics right.... this is really
950 * only important on a multi-user system anyway, to make sure one user
951 * can't send a signal to a process owned by another. -TYT, 12/12/91
952 *
953 * Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
954 * LBT 04.03.94
955 */
956 SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
957 {
958 struct task_struct *p;
959 struct task_struct *group_leader = current->group_leader;
960 struct pid *pgrp;
961 int err;
962
963 if (!pid)
964 pid = task_pid_vnr(group_leader);
965 if (!pgid)
966 pgid = pid;
967 if (pgid < 0)
968 return -EINVAL;
969
970 /* From this point forward we keep holding onto the tasklist lock
971 * so that our parent does not change from under us. -DaveM
972 */
973 write_lock_irq(&tasklist_lock);
974
975 err = -ESRCH;
976 p = find_task_by_vpid(pid);
977 if (!p)
978 goto out;
979
980 err = -EINVAL;
981 if (!thread_group_leader(p))
982 goto out;
983
984 if (same_thread_group(p->real_parent, group_leader)) {
985 err = -EPERM;
986 if (task_session(p) != task_session(group_leader))
987 goto out;
988 err = -EACCES;
989 if (p->did_exec)
990 goto out;
991 } else {
992 err = -ESRCH;
993 if (p != group_leader)
994 goto out;
995 }
996
997 err = -EPERM;
998 if (p->signal->leader)
999 goto out;
1000
1001 pgrp = task_pid(p);
1002 if (pgid != pid) {
1003 struct task_struct *g;
1004
1005 pgrp = find_vpid(pgid);
1006 g = pid_task(pgrp, PIDTYPE_PGID);
1007 if (!g || task_session(g) != task_session(group_leader))
1008 goto out;
1009 }
1010
1011 err = security_task_setpgid(p, pgid);
1012 if (err)
1013 goto out;
1014
1015 if (task_pgrp(p) != pgrp)
1016 change_pid(p, PIDTYPE_PGID, pgrp);
1017
1018 err = 0;
1019 out:
1020 /* All paths lead to here, thus we are safe. -DaveM */
1021 write_unlock_irq(&tasklist_lock);
1022 return err;
1023 }
1024
1025 SYSCALL_DEFINE1(getpgid, pid_t, pid)
1026 {
1027 struct task_struct *p;
1028 struct pid *grp;
1029 int retval;
1030
1031 rcu_read_lock();
1032 if (!pid)
1033 grp = task_pgrp(current);
1034 else {
1035 retval = -ESRCH;
1036 p = find_task_by_vpid(pid);
1037 if (!p)
1038 goto out;
1039 grp = task_pgrp(p);
1040 if (!grp)
1041 goto out;
1042
1043 retval = security_task_getpgid(p);
1044 if (retval)
1045 goto out;
1046 }
1047 retval = pid_vnr(grp);
1048 out:
1049 rcu_read_unlock();
1050 return retval;
1051 }
1052
1053 #ifdef __ARCH_WANT_SYS_GETPGRP
1054
1055 SYSCALL_DEFINE0(getpgrp)
1056 {
1057 return sys_getpgid(0);
1058 }
1059
1060 #endif
1061
1062 SYSCALL_DEFINE1(getsid, pid_t, pid)
1063 {
1064 struct task_struct *p;
1065 struct pid *sid;
1066 int retval;
1067
1068 rcu_read_lock();
1069 if (!pid)
1070 sid = task_session(current);
1071 else {
1072 retval = -ESRCH;
1073 p = find_task_by_vpid(pid);
1074 if (!p)
1075 goto out;
1076 sid = task_session(p);
1077 if (!sid)
1078 goto out;
1079
1080 retval = security_task_getsid(p);
1081 if (retval)
1082 goto out;
1083 }
1084 retval = pid_vnr(sid);
1085 out:
1086 rcu_read_unlock();
1087 return retval;
1088 }
1089
1090 SYSCALL_DEFINE0(setsid)
1091 {
1092 struct task_struct *group_leader = current->group_leader;
1093 struct pid *sid = task_pid(group_leader);
1094 pid_t session = pid_vnr(sid);
1095 int err = -EPERM;
1096
1097 write_lock_irq(&tasklist_lock);
1098 /* Fail if I am already a session leader */
1099 if (group_leader->signal->leader)
1100 goto out;
1101
1102 /* Fail if a process group id already exists that equals the
1103 * proposed session id.
1104 */
1105 if (pid_task(sid, PIDTYPE_PGID))
1106 goto out;
1107
1108 group_leader->signal->leader = 1;
1109 __set_special_pids(sid);
1110
1111 proc_clear_tty(group_leader);
1112
1113 err = session;
1114 out:
1115 write_unlock_irq(&tasklist_lock);
1116 if (err > 0)
1117 proc_sid_connector(group_leader);
1118 return err;
1119 }
1120
1121 DECLARE_RWSEM(uts_sem);
1122
1123 SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
1124 {
1125 int errno = 0;
1126
1127 down_read(&uts_sem);
1128 if (copy_to_user(name, utsname(), sizeof *name))
1129 errno = -EFAULT;
1130 up_read(&uts_sem);
1131 return errno;
1132 }
1133
1134 SYSCALL_DEFINE2(sethostname, char __user *, name, int, len)
1135 {
1136 int errno;
1137 char tmp[__NEW_UTS_LEN];
1138
1139 if (!capable(CAP_SYS_ADMIN))
1140 return -EPERM;
1141 if (len < 0 || len > __NEW_UTS_LEN)
1142 return -EINVAL;
1143 down_write(&uts_sem);
1144 errno = -EFAULT;
1145 if (!copy_from_user(tmp, name, len)) {
1146 struct new_utsname *u = utsname();
1147
1148 memcpy(u->nodename, tmp, len);
1149 memset(u->nodename + len, 0, sizeof(u->nodename) - len);
1150 errno = 0;
1151 }
1152 up_write(&uts_sem);
1153 return errno;
1154 }
1155
1156 #ifdef __ARCH_WANT_SYS_GETHOSTNAME
1157
1158 SYSCALL_DEFINE2(gethostname, char __user *, name, int, len)
1159 {
1160 int i, errno;
1161 struct new_utsname *u;
1162
1163 if (len < 0)
1164 return -EINVAL;
1165 down_read(&uts_sem);
1166 u = utsname();
1167 i = 1 + strlen(u->nodename);
1168 if (i > len)
1169 i = len;
1170 errno = 0;
1171 if (copy_to_user(name, u->nodename, i))
1172 errno = -EFAULT;
1173 up_read(&uts_sem);
1174 return errno;
1175 }
1176
1177 #endif
1178
1179 /*
1180 * Only setdomainname; getdomainname can be implemented by calling
1181 * uname()
1182 */
1183 SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
1184 {
1185 int errno;
1186 char tmp[__NEW_UTS_LEN];
1187
1188 if (!capable(CAP_SYS_ADMIN))
1189 return -EPERM;
1190 if (len < 0 || len > __NEW_UTS_LEN)
1191 return -EINVAL;
1192
1193 down_write(&uts_sem);
1194 errno = -EFAULT;
1195 if (!copy_from_user(tmp, name, len)) {
1196 struct new_utsname *u = utsname();
1197
1198 memcpy(u->domainname, tmp, len);
1199 memset(u->domainname + len, 0, sizeof(u->domainname) - len);
1200 errno = 0;
1201 }
1202 up_write(&uts_sem);
1203 return errno;
1204 }
1205
1206 SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1207 {
1208 if (resource >= RLIM_NLIMITS)
1209 return -EINVAL;
1210 else {
1211 struct rlimit value;
1212 task_lock(current->group_leader);
1213 value = current->signal->rlim[resource];
1214 task_unlock(current->group_leader);
1215 return copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1216 }
1217 }
1218
1219 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1220
1221 /*
1222 * Back compatibility for getrlimit. Needed for some apps.
1223 */
1224
1225 SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1226 struct rlimit __user *, rlim)
1227 {
1228 struct rlimit x;
1229 if (resource >= RLIM_NLIMITS)
1230 return -EINVAL;
1231
1232 task_lock(current->group_leader);
1233 x = current->signal->rlim[resource];
1234 task_unlock(current->group_leader);
1235 if (x.rlim_cur > 0x7FFFFFFF)
1236 x.rlim_cur = 0x7FFFFFFF;
1237 if (x.rlim_max > 0x7FFFFFFF)
1238 x.rlim_max = 0x7FFFFFFF;
1239 return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0;
1240 }
1241
1242 #endif
1243
1244 SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1245 {
1246 struct rlimit new_rlim, *old_rlim;
1247 int retval;
1248
1249 if (resource >= RLIM_NLIMITS)
1250 return -EINVAL;
1251 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1252 return -EFAULT;
1253 if (new_rlim.rlim_cur > new_rlim.rlim_max)
1254 return -EINVAL;
1255 old_rlim = current->signal->rlim + resource;
1256 if ((new_rlim.rlim_max > old_rlim->rlim_max) &&
1257 !capable(CAP_SYS_RESOURCE))
1258 return -EPERM;
1259 if (resource == RLIMIT_NOFILE && new_rlim.rlim_max > sysctl_nr_open)
1260 return -EPERM;
1261
1262 retval = security_task_setrlimit(resource, &new_rlim);
1263 if (retval)
1264 return retval;
1265
1266 if (resource == RLIMIT_CPU && new_rlim.rlim_cur == 0) {
1267 /*
1268 * The caller is asking for an immediate RLIMIT_CPU
1269 * expiry. But we use the zero value to mean "it was
1270 * never set". So let's cheat and make it one second
1271 * instead
1272 */
1273 new_rlim.rlim_cur = 1;
1274 }
1275
1276 task_lock(current->group_leader);
1277 *old_rlim = new_rlim;
1278 task_unlock(current->group_leader);
1279
1280 if (resource != RLIMIT_CPU)
1281 goto out;
1282
1283 /*
1284 * RLIMIT_CPU handling. Note that the kernel fails to return an error
1285 * code if it rejected the user's attempt to set RLIMIT_CPU. This is a
1286 * very long-standing error, and fixing it now risks breakage of
1287 * applications, so we live with it
1288 */
1289 if (new_rlim.rlim_cur == RLIM_INFINITY)
1290 goto out;
1291
1292 update_rlimit_cpu(new_rlim.rlim_cur);
1293 out:
1294 return 0;
1295 }
1296
1297 /*
1298 * It would make sense to put struct rusage in the task_struct,
1299 * except that would make the task_struct be *really big*. After
1300 * task_struct gets moved into malloc'ed memory, it would
1301 * make sense to do this. It will make moving the rest of the information
1302 * a lot simpler! (Which we're not doing right now because we're not
1303 * measuring them yet).
1304 *
1305 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1306 * races with threads incrementing their own counters. But since word
1307 * reads are atomic, we either get new values or old values and we don't
1308 * care which for the sums. We always take the siglock to protect reading
1309 * the c* fields from p->signal from races with exit.c updating those
1310 * fields when reaping, so a sample either gets all the additions of a
1311 * given child after it's reaped, or none so this sample is before reaping.
1312 *
1313 * Locking:
1314 * We need to take the siglock for CHILDEREN, SELF and BOTH
1315 * for the cases current multithreaded, non-current single threaded
1316 * non-current multithreaded. Thread traversal is now safe with
1317 * the siglock held.
1318 * Strictly speaking, we donot need to take the siglock if we are current and
1319 * single threaded, as no one else can take our signal_struct away, no one
1320 * else can reap the children to update signal->c* counters, and no one else
1321 * can race with the signal-> fields. If we do not take any lock, the
1322 * signal-> fields could be read out of order while another thread was just
1323 * exiting. So we should place a read memory barrier when we avoid the lock.
1324 * On the writer side, write memory barrier is implied in __exit_signal
1325 * as __exit_signal releases the siglock spinlock after updating the signal->
1326 * fields. But we don't do this yet to keep things simple.
1327 *
1328 */
1329
1330 static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
1331 {
1332 r->ru_nvcsw += t->nvcsw;
1333 r->ru_nivcsw += t->nivcsw;
1334 r->ru_minflt += t->min_flt;
1335 r->ru_majflt += t->maj_flt;
1336 r->ru_inblock += task_io_get_inblock(t);
1337 r->ru_oublock += task_io_get_oublock(t);
1338 }
1339
1340 static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
1341 {
1342 struct task_struct *t;
1343 unsigned long flags;
1344 cputime_t tgutime, tgstime, utime, stime;
1345 unsigned long maxrss = 0;
1346
1347 memset((char *) r, 0, sizeof *r);
1348 utime = stime = cputime_zero;
1349
1350 if (who == RUSAGE_THREAD) {
1351 task_times(current, &utime, &stime);
1352 accumulate_thread_rusage(p, r);
1353 maxrss = p->signal->maxrss;
1354 goto out;
1355 }
1356
1357 if (!lock_task_sighand(p, &flags))
1358 return;
1359
1360 switch (who) {
1361 case RUSAGE_BOTH:
1362 case RUSAGE_CHILDREN:
1363 utime = p->signal->cutime;
1364 stime = p->signal->cstime;
1365 r->ru_nvcsw = p->signal->cnvcsw;
1366 r->ru_nivcsw = p->signal->cnivcsw;
1367 r->ru_minflt = p->signal->cmin_flt;
1368 r->ru_majflt = p->signal->cmaj_flt;
1369 r->ru_inblock = p->signal->cinblock;
1370 r->ru_oublock = p->signal->coublock;
1371 maxrss = p->signal->cmaxrss;
1372
1373 if (who == RUSAGE_CHILDREN)
1374 break;
1375
1376 case RUSAGE_SELF:
1377 thread_group_times(p, &tgutime, &tgstime);
1378 utime = cputime_add(utime, tgutime);
1379 stime = cputime_add(stime, tgstime);
1380 r->ru_nvcsw += p->signal->nvcsw;
1381 r->ru_nivcsw += p->signal->nivcsw;
1382 r->ru_minflt += p->signal->min_flt;
1383 r->ru_majflt += p->signal->maj_flt;
1384 r->ru_inblock += p->signal->inblock;
1385 r->ru_oublock += p->signal->oublock;
1386 if (maxrss < p->signal->maxrss)
1387 maxrss = p->signal->maxrss;
1388 t = p;
1389 do {
1390 accumulate_thread_rusage(t, r);
1391 t = next_thread(t);
1392 } while (t != p);
1393 break;
1394
1395 default:
1396 BUG();
1397 }
1398 unlock_task_sighand(p, &flags);
1399
1400 out:
1401 cputime_to_timeval(utime, &r->ru_utime);
1402 cputime_to_timeval(stime, &r->ru_stime);
1403
1404 if (who != RUSAGE_CHILDREN) {
1405 struct mm_struct *mm = get_task_mm(p);
1406 if (mm) {
1407 setmax_mm_hiwater_rss(&maxrss, mm);
1408 mmput(mm);
1409 }
1410 }
1411 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
1412 }
1413
1414 int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
1415 {
1416 struct rusage r;
1417 k_getrusage(p, who, &r);
1418 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1419 }
1420
1421 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
1422 {
1423 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1424 who != RUSAGE_THREAD)
1425 return -EINVAL;
1426 return getrusage(current, who, ru);
1427 }
1428
1429 SYSCALL_DEFINE1(umask, int, mask)
1430 {
1431 mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1432 return mask;
1433 }
1434
1435 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
1436 unsigned long, arg4, unsigned long, arg5)
1437 {
1438 struct task_struct *me = current;
1439 unsigned char comm[sizeof(me->comm)];
1440 long error;
1441
1442 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
1443 if (error != -ENOSYS)
1444 return error;
1445
1446 error = 0;
1447 switch (option) {
1448 case PR_SET_PDEATHSIG:
1449 if (!valid_signal(arg2)) {
1450 error = -EINVAL;
1451 break;
1452 }
1453 me->pdeath_signal = arg2;
1454 error = 0;
1455 break;
1456 case PR_GET_PDEATHSIG:
1457 error = put_user(me->pdeath_signal, (int __user *)arg2);
1458 break;
1459 case PR_GET_DUMPABLE:
1460 error = get_dumpable(me->mm);
1461 break;
1462 case PR_SET_DUMPABLE:
1463 if (arg2 < 0 || arg2 > 1) {
1464 error = -EINVAL;
1465 break;
1466 }
1467 set_dumpable(me->mm, arg2);
1468 error = 0;
1469 break;
1470
1471 case PR_SET_UNALIGN:
1472 error = SET_UNALIGN_CTL(me, arg2);
1473 break;
1474 case PR_GET_UNALIGN:
1475 error = GET_UNALIGN_CTL(me, arg2);
1476 break;
1477 case PR_SET_FPEMU:
1478 error = SET_FPEMU_CTL(me, arg2);
1479 break;
1480 case PR_GET_FPEMU:
1481 error = GET_FPEMU_CTL(me, arg2);
1482 break;
1483 case PR_SET_FPEXC:
1484 error = SET_FPEXC_CTL(me, arg2);
1485 break;
1486 case PR_GET_FPEXC:
1487 error = GET_FPEXC_CTL(me, arg2);
1488 break;
1489 case PR_GET_TIMING:
1490 error = PR_TIMING_STATISTICAL;
1491 break;
1492 case PR_SET_TIMING:
1493 if (arg2 != PR_TIMING_STATISTICAL)
1494 error = -EINVAL;
1495 else
1496 error = 0;
1497 break;
1498
1499 case PR_SET_NAME:
1500 comm[sizeof(me->comm)-1] = 0;
1501 if (strncpy_from_user(comm, (char __user *)arg2,
1502 sizeof(me->comm) - 1) < 0)
1503 return -EFAULT;
1504 set_task_comm(me, comm);
1505 return 0;
1506 case PR_GET_NAME:
1507 get_task_comm(comm, me);
1508 if (copy_to_user((char __user *)arg2, comm,
1509 sizeof(comm)))
1510 return -EFAULT;
1511 return 0;
1512 case PR_GET_ENDIAN:
1513 error = GET_ENDIAN(me, arg2);
1514 break;
1515 case PR_SET_ENDIAN:
1516 error = SET_ENDIAN(me, arg2);
1517 break;
1518
1519 case PR_GET_SECCOMP:
1520 error = prctl_get_seccomp();
1521 break;
1522 case PR_SET_SECCOMP:
1523 error = prctl_set_seccomp(arg2);
1524 break;
1525 case PR_GET_TSC:
1526 error = GET_TSC_CTL(arg2);
1527 break;
1528 case PR_SET_TSC:
1529 error = SET_TSC_CTL(arg2);
1530 break;
1531 case PR_TASK_PERF_EVENTS_DISABLE:
1532 error = perf_event_task_disable();
1533 break;
1534 case PR_TASK_PERF_EVENTS_ENABLE:
1535 error = perf_event_task_enable();
1536 break;
1537 case PR_GET_TIMERSLACK:
1538 error = current->timer_slack_ns;
1539 break;
1540 case PR_SET_TIMERSLACK:
1541 if (arg2 <= 0)
1542 current->timer_slack_ns =
1543 current->default_timer_slack_ns;
1544 else
1545 current->timer_slack_ns = arg2;
1546 error = 0;
1547 break;
1548 case PR_MCE_KILL:
1549 if (arg4 | arg5)
1550 return -EINVAL;
1551 switch (arg2) {
1552 case PR_MCE_KILL_CLEAR:
1553 if (arg3 != 0)
1554 return -EINVAL;
1555 current->flags &= ~PF_MCE_PROCESS;
1556 break;
1557 case PR_MCE_KILL_SET:
1558 current->flags |= PF_MCE_PROCESS;
1559 if (arg3 == PR_MCE_KILL_EARLY)
1560 current->flags |= PF_MCE_EARLY;
1561 else if (arg3 == PR_MCE_KILL_LATE)
1562 current->flags &= ~PF_MCE_EARLY;
1563 else if (arg3 == PR_MCE_KILL_DEFAULT)
1564 current->flags &=
1565 ~(PF_MCE_EARLY|PF_MCE_PROCESS);
1566 else
1567 return -EINVAL;
1568 break;
1569 default:
1570 return -EINVAL;
1571 }
1572 error = 0;
1573 break;
1574 case PR_MCE_KILL_GET:
1575 if (arg2 | arg3 | arg4 | arg5)
1576 return -EINVAL;
1577 if (current->flags & PF_MCE_PROCESS)
1578 error = (current->flags & PF_MCE_EARLY) ?
1579 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
1580 else
1581 error = PR_MCE_KILL_DEFAULT;
1582 break;
1583 default:
1584 error = -EINVAL;
1585 break;
1586 }
1587 return error;
1588 }
1589
1590 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
1591 struct getcpu_cache __user *, unused)
1592 {
1593 int err = 0;
1594 int cpu = raw_smp_processor_id();
1595 if (cpup)
1596 err |= put_user(cpu, cpup);
1597 if (nodep)
1598 err |= put_user(cpu_to_node(cpu), nodep);
1599 return err ? -EFAULT : 0;
1600 }
1601
1602 char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff";
1603
1604 static void argv_cleanup(char **argv, char **envp)
1605 {
1606 argv_free(argv);
1607 }
1608
1609 /**
1610 * orderly_poweroff - Trigger an orderly system poweroff
1611 * @force: force poweroff if command execution fails
1612 *
1613 * This may be called from any context to trigger a system shutdown.
1614 * If the orderly shutdown fails, it will force an immediate shutdown.
1615 */
1616 int orderly_poweroff(bool force)
1617 {
1618 int argc;
1619 char **argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc);
1620 static char *envp[] = {
1621 "HOME=/",
1622 "PATH=/sbin:/bin:/usr/sbin:/usr/bin",
1623 NULL
1624 };
1625 int ret = -ENOMEM;
1626 struct subprocess_info *info;
1627
1628 if (argv == NULL) {
1629 printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n",
1630 __func__, poweroff_cmd);
1631 goto out;
1632 }
1633
1634 info = call_usermodehelper_setup(argv[0], argv, envp, GFP_ATOMIC);
1635 if (info == NULL) {
1636 argv_free(argv);
1637 goto out;
1638 }
1639
1640 call_usermodehelper_setcleanup(info, argv_cleanup);
1641
1642 ret = call_usermodehelper_exec(info, UMH_NO_WAIT);
1643
1644 out:
1645 if (ret && force) {
1646 printk(KERN_WARNING "Failed to start orderly shutdown: "
1647 "forcing the issue\n");
1648
1649 /* I guess this should try to kick off some daemon to
1650 sync and poweroff asap. Or not even bother syncing
1651 if we're doing an emergency shutdown? */
1652 emergency_sync();
1653 kernel_power_off();
1654 }
1655
1656 return ret;
1657 }
1658 EXPORT_SYMBOL_GPL(orderly_poweroff);
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