1 /*
2 * linux/kernel/sys.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 */
6
7 #include <linux/config.h>
8 #include <linux/module.h>
9 #include <linux/mm.h>
10 #include <linux/utsname.h>
11 #include <linux/mman.h>
12 #include <linux/smp_lock.h>
13 #include <linux/notifier.h>
14 #include <linux/reboot.h>
15 #include <linux/prctl.h>
16 #include <linux/init.h>
17 #include <linux/highuid.h>
18 #include <linux/fs.h>
19 #include <linux/workqueue.h>
20 #include <linux/device.h>
21 #include <linux/key.h>
22 #include <linux/times.h>
23 #include <linux/security.h>
24 #include <linux/dcookies.h>
25 #include <linux/suspend.h>
26 #include <linux/tty.h>
27
28 #include <linux/compat.h>
29 #include <linux/syscalls.h>
30
31 #include <asm/uaccess.h>
32 #include <asm/io.h>
33 #include <asm/unistd.h>
34
35 #ifndef SET_UNALIGN_CTL
36 # define SET_UNALIGN_CTL(a,b) (-EINVAL)
37 #endif
38 #ifndef GET_UNALIGN_CTL
39 # define GET_UNALIGN_CTL(a,b) (-EINVAL)
40 #endif
41 #ifndef SET_FPEMU_CTL
42 # define SET_FPEMU_CTL(a,b) (-EINVAL)
43 #endif
44 #ifndef GET_FPEMU_CTL
45 # define GET_FPEMU_CTL(a,b) (-EINVAL)
46 #endif
47 #ifndef SET_FPEXC_CTL
48 # define SET_FPEXC_CTL(a,b) (-EINVAL)
49 #endif
50 #ifndef GET_FPEXC_CTL
51 # define GET_FPEXC_CTL(a,b) (-EINVAL)
52 #endif
53
54 /*
55 * this is where the system-wide overflow UID and GID are defined, for
56 * architectures that now have 32-bit UID/GID but didn't in the past
57 */
58
59 int overflowuid = DEFAULT_OVERFLOWUID;
60 int overflowgid = DEFAULT_OVERFLOWGID;
61
62 #ifdef CONFIG_UID16
63 EXPORT_SYMBOL(overflowuid);
64 EXPORT_SYMBOL(overflowgid);
65 #endif
66
67 /*
68 * the same as above, but for filesystems which can only store a 16-bit
69 * UID and GID. as such, this is needed on all architectures
70 */
71
72 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
73 int fs_overflowgid = DEFAULT_FS_OVERFLOWUID;
74
75 EXPORT_SYMBOL(fs_overflowuid);
76 EXPORT_SYMBOL(fs_overflowgid);
77
78 /*
79 * this indicates whether you can reboot with ctrl-alt-del: the default is yes
80 */
81
82 int C_A_D = 1;
83 int cad_pid = 1;
84
85 /*
86 * Notifier list for kernel code which wants to be called
87 * at shutdown. This is used to stop any idling DMA operations
88 * and the like.
89 */
90
91 static struct notifier_block *reboot_notifier_list;
92 DEFINE_RWLOCK(notifier_lock);
93
94 /**
95 * notifier_chain_register - Add notifier to a notifier chain
96 * @list: Pointer to root list pointer
97 * @n: New entry in notifier chain
98 *
99 * Adds a notifier to a notifier chain.
100 *
101 * Currently always returns zero.
102 */
103
104 int notifier_chain_register(struct notifier_block **list, struct notifier_block *n)
105 {
106 write_lock(¬ifier_lock);
107 while(*list)
108 {
109 if(n->priority > (*list)->priority)
110 break;
111 list= &((*list)->next);
112 }
113 n->next = *list;
114 *list=n;
115 write_unlock(¬ifier_lock);
116 return 0;
117 }
118
119 EXPORT_SYMBOL(notifier_chain_register);
120
121 /**
122 * notifier_chain_unregister - Remove notifier from a notifier chain
123 * @nl: Pointer to root list pointer
124 * @n: New entry in notifier chain
125 *
126 * Removes a notifier from a notifier chain.
127 *
128 * Returns zero on success, or %-ENOENT on failure.
129 */
130
131 int notifier_chain_unregister(struct notifier_block **nl, struct notifier_block *n)
132 {
133 write_lock(¬ifier_lock);
134 while((*nl)!=NULL)
135 {
136 if((*nl)==n)
137 {
138 *nl=n->next;
139 write_unlock(¬ifier_lock);
140 return 0;
141 }
142 nl=&((*nl)->next);
143 }
144 write_unlock(¬ifier_lock);
145 return -ENOENT;
146 }
147
148 EXPORT_SYMBOL(notifier_chain_unregister);
149
150 /**
151 * notifier_call_chain - Call functions in a notifier chain
152 * @n: Pointer to root pointer of notifier chain
153 * @val: Value passed unmodified to notifier function
154 * @v: Pointer passed unmodified to notifier function
155 *
156 * Calls each function in a notifier chain in turn.
157 *
158 * If the return value of the notifier can be and'd
159 * with %NOTIFY_STOP_MASK, then notifier_call_chain
160 * will return immediately, with the return value of
161 * the notifier function which halted execution.
162 * Otherwise, the return value is the return value
163 * of the last notifier function called.
164 */
165
166 int notifier_call_chain(struct notifier_block **n, unsigned long val, void *v)
167 {
168 int ret=NOTIFY_DONE;
169 struct notifier_block *nb = *n;
170
171 while(nb)
172 {
173 ret=nb->notifier_call(nb,val,v);
174 if(ret&NOTIFY_STOP_MASK)
175 {
176 return ret;
177 }
178 nb=nb->next;
179 }
180 return ret;
181 }
182
183 EXPORT_SYMBOL(notifier_call_chain);
184
185 /**
186 * register_reboot_notifier - Register function to be called at reboot time
187 * @nb: Info about notifier function to be called
188 *
189 * Registers a function with the list of functions
190 * to be called at reboot time.
191 *
192 * Currently always returns zero, as notifier_chain_register
193 * always returns zero.
194 */
195
196 int register_reboot_notifier(struct notifier_block * nb)
197 {
198 return notifier_chain_register(&reboot_notifier_list, nb);
199 }
200
201 EXPORT_SYMBOL(register_reboot_notifier);
202
203 /**
204 * unregister_reboot_notifier - Unregister previously registered reboot notifier
205 * @nb: Hook to be unregistered
206 *
207 * Unregisters a previously registered reboot
208 * notifier function.
209 *
210 * Returns zero on success, or %-ENOENT on failure.
211 */
212
213 int unregister_reboot_notifier(struct notifier_block * nb)
214 {
215 return notifier_chain_unregister(&reboot_notifier_list, nb);
216 }
217
218 EXPORT_SYMBOL(unregister_reboot_notifier);
219 static int set_one_prio(struct task_struct *p, int niceval, int error)
220 {
221 int no_nice;
222
223 if (p->uid != current->euid &&
224 p->uid != current->uid && !capable(CAP_SYS_NICE)) {
225 error = -EPERM;
226 goto out;
227 }
228 if (niceval < task_nice(p) && !capable(CAP_SYS_NICE)) {
229 error = -EACCES;
230 goto out;
231 }
232 no_nice = security_task_setnice(p, niceval);
233 if (no_nice) {
234 error = no_nice;
235 goto out;
236 }
237 if (error == -ESRCH)
238 error = 0;
239 set_user_nice(p, niceval);
240 out:
241 return error;
242 }
243
244 asmlinkage long sys_setpriority(int which, int who, int niceval)
245 {
246 struct task_struct *g, *p;
247 struct user_struct *user;
248 int error = -EINVAL;
249
250 if (which > 2 || which < 0)
251 goto out;
252
253 /* normalize: avoid signed division (rounding problems) */
254 error = -ESRCH;
255 if (niceval < -20)
256 niceval = -20;
257 if (niceval > 19)
258 niceval = 19;
259
260 read_lock(&tasklist_lock);
261 switch (which) {
262 case PRIO_PROCESS:
263 if (!who)
264 who = current->pid;
265 p = find_task_by_pid(who);
266 if (p)
267 error = set_one_prio(p, niceval, error);
268 break;
269 case PRIO_PGRP:
270 if (!who)
271 who = process_group(current);
272 do_each_task_pid(who, PIDTYPE_PGID, p) {
273 error = set_one_prio(p, niceval, error);
274 } while_each_task_pid(who, PIDTYPE_PGID, p);
275 break;
276 case PRIO_USER:
277 user = current->user;
278 if (!who)
279 who = current->uid;
280 else
281 if ((who != current->uid) && !(user = find_user(who)))
282 goto out_unlock; /* No processes for this user */
283
284 do_each_thread(g, p)
285 if (p->uid == who)
286 error = set_one_prio(p, niceval, error);
287 while_each_thread(g, p);
288 if (who != current->uid)
289 free_uid(user); /* For find_user() */
290 break;
291 }
292 out_unlock:
293 read_unlock(&tasklist_lock);
294 out:
295 return error;
296 }
297
298 /*
299 * Ugh. To avoid negative return values, "getpriority()" will
300 * not return the normal nice-value, but a negated value that
301 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
302 * to stay compatible.
303 */
304 asmlinkage long sys_getpriority(int which, int who)
305 {
306 struct task_struct *g, *p;
307 struct user_struct *user;
308 long niceval, retval = -ESRCH;
309
310 if (which > 2 || which < 0)
311 return -EINVAL;
312
313 read_lock(&tasklist_lock);
314 switch (which) {
315 case PRIO_PROCESS:
316 if (!who)
317 who = current->pid;
318 p = find_task_by_pid(who);
319 if (p) {
320 niceval = 20 - task_nice(p);
321 if (niceval > retval)
322 retval = niceval;
323 }
324 break;
325 case PRIO_PGRP:
326 if (!who)
327 who = process_group(current);
328 do_each_task_pid(who, PIDTYPE_PGID, p) {
329 niceval = 20 - task_nice(p);
330 if (niceval > retval)
331 retval = niceval;
332 } while_each_task_pid(who, PIDTYPE_PGID, p);
333 break;
334 case PRIO_USER:
335 user = current->user;
336 if (!who)
337 who = current->uid;
338 else
339 if ((who != current->uid) && !(user = find_user(who)))
340 goto out_unlock; /* No processes for this user */
341
342 do_each_thread(g, p)
343 if (p->uid == who) {
344 niceval = 20 - task_nice(p);
345 if (niceval > retval)
346 retval = niceval;
347 }
348 while_each_thread(g, p);
349 if (who != current->uid)
350 free_uid(user); /* for find_user() */
351 break;
352 }
353 out_unlock:
354 read_unlock(&tasklist_lock);
355
356 return retval;
357 }
358
359
360 /*
361 * Reboot system call: for obvious reasons only root may call it,
362 * and even root needs to set up some magic numbers in the registers
363 * so that some mistake won't make this reboot the whole machine.
364 * You can also set the meaning of the ctrl-alt-del-key here.
365 *
366 * reboot doesn't sync: do that yourself before calling this.
367 */
368 asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user * arg)
369 {
370 char buffer[256];
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 lock_kernel();
385 switch (cmd) {
386 case LINUX_REBOOT_CMD_RESTART:
387 notifier_call_chain(&reboot_notifier_list, SYS_RESTART, NULL);
388 system_state = SYSTEM_RESTART;
389 device_shutdown();
390 printk(KERN_EMERG "Restarting system.\n");
391 machine_restart(NULL);
392 break;
393
394 case LINUX_REBOOT_CMD_CAD_ON:
395 C_A_D = 1;
396 break;
397
398 case LINUX_REBOOT_CMD_CAD_OFF:
399 C_A_D = 0;
400 break;
401
402 case LINUX_REBOOT_CMD_HALT:
403 notifier_call_chain(&reboot_notifier_list, SYS_HALT, NULL);
404 system_state = SYSTEM_HALT;
405 device_shutdown();
406 printk(KERN_EMERG "System halted.\n");
407 machine_halt();
408 unlock_kernel();
409 do_exit(0);
410 break;
411
412 case LINUX_REBOOT_CMD_POWER_OFF:
413 notifier_call_chain(&reboot_notifier_list, SYS_POWER_OFF, NULL);
414 system_state = SYSTEM_POWER_OFF;
415 device_shutdown();
416 printk(KERN_EMERG "Power down.\n");
417 machine_power_off();
418 unlock_kernel();
419 do_exit(0);
420 break;
421
422 case LINUX_REBOOT_CMD_RESTART2:
423 if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) {
424 unlock_kernel();
425 return -EFAULT;
426 }
427 buffer[sizeof(buffer) - 1] = '\0';
428
429 notifier_call_chain(&reboot_notifier_list, SYS_RESTART, buffer);
430 system_state = SYSTEM_RESTART;
431 device_shutdown();
432 printk(KERN_EMERG "Restarting system with command '%s'.\n", buffer);
433 machine_restart(buffer);
434 break;
435
436 #ifdef CONFIG_SOFTWARE_SUSPEND
437 case LINUX_REBOOT_CMD_SW_SUSPEND:
438 {
439 int ret = software_suspend();
440 unlock_kernel();
441 return ret;
442 }
443 #endif
444
445 default:
446 unlock_kernel();
447 return -EINVAL;
448 }
449 unlock_kernel();
450 return 0;
451 }
452
453 static void deferred_cad(void *dummy)
454 {
455 notifier_call_chain(&reboot_notifier_list, SYS_RESTART, NULL);
456 machine_restart(NULL);
457 }
458
459 /*
460 * This function gets called by ctrl-alt-del - ie the keyboard interrupt.
461 * As it's called within an interrupt, it may NOT sync: the only choice
462 * is whether to reboot at once, or just ignore the ctrl-alt-del.
463 */
464 void ctrl_alt_del(void)
465 {
466 static DECLARE_WORK(cad_work, deferred_cad, NULL);
467
468 if (C_A_D)
469 schedule_work(&cad_work);
470 else
471 kill_proc(cad_pid, SIGINT, 1);
472 }
473
474
475 /*
476 * Unprivileged users may change the real gid to the effective gid
477 * or vice versa. (BSD-style)
478 *
479 * If you set the real gid at all, or set the effective gid to a value not
480 * equal to the real gid, then the saved gid is set to the new effective gid.
481 *
482 * This makes it possible for a setgid program to completely drop its
483 * privileges, which is often a useful assertion to make when you are doing
484 * a security audit over a program.
485 *
486 * The general idea is that a program which uses just setregid() will be
487 * 100% compatible with BSD. A program which uses just setgid() will be
488 * 100% compatible with POSIX with saved IDs.
489 *
490 * SMP: There are not races, the GIDs are checked only by filesystem
491 * operations (as far as semantic preservation is concerned).
492 */
493 asmlinkage long sys_setregid(gid_t rgid, gid_t egid)
494 {
495 int old_rgid = current->gid;
496 int old_egid = current->egid;
497 int new_rgid = old_rgid;
498 int new_egid = old_egid;
499 int retval;
500
501 retval = security_task_setgid(rgid, egid, (gid_t)-1, LSM_SETID_RE);
502 if (retval)
503 return retval;
504
505 if (rgid != (gid_t) -1) {
506 if ((old_rgid == rgid) ||
507 (current->egid==rgid) ||
508 capable(CAP_SETGID))
509 new_rgid = rgid;
510 else
511 return -EPERM;
512 }
513 if (egid != (gid_t) -1) {
514 if ((old_rgid == egid) ||
515 (current->egid == egid) ||
516 (current->sgid == egid) ||
517 capable(CAP_SETGID))
518 new_egid = egid;
519 else {
520 return -EPERM;
521 }
522 }
523 if (new_egid != old_egid)
524 {
525 current->mm->dumpable = 0;
526 wmb();
527 }
528 if (rgid != (gid_t) -1 ||
529 (egid != (gid_t) -1 && egid != old_rgid))
530 current->sgid = new_egid;
531 current->fsgid = new_egid;
532 current->egid = new_egid;
533 current->gid = new_rgid;
534 key_fsgid_changed(current);
535 return 0;
536 }
537
538 /*
539 * setgid() is implemented like SysV w/ SAVED_IDS
540 *
541 * SMP: Same implicit races as above.
542 */
543 asmlinkage long sys_setgid(gid_t gid)
544 {
545 int old_egid = current->egid;
546 int retval;
547
548 retval = security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID);
549 if (retval)
550 return retval;
551
552 if (capable(CAP_SETGID))
553 {
554 if(old_egid != gid)
555 {
556 current->mm->dumpable=0;
557 wmb();
558 }
559 current->gid = current->egid = current->sgid = current->fsgid = gid;
560 }
561 else if ((gid == current->gid) || (gid == current->sgid))
562 {
563 if(old_egid != gid)
564 {
565 current->mm->dumpable=0;
566 wmb();
567 }
568 current->egid = current->fsgid = gid;
569 }
570 else
571 return -EPERM;
572
573 key_fsgid_changed(current);
574 return 0;
575 }
576
577 static int set_user(uid_t new_ruid, int dumpclear)
578 {
579 struct user_struct *new_user;
580
581 new_user = alloc_uid(new_ruid);
582 if (!new_user)
583 return -EAGAIN;
584
585 if (atomic_read(&new_user->processes) >=
586 current->signal->rlim[RLIMIT_NPROC].rlim_cur &&
587 new_user != &root_user) {
588 free_uid(new_user);
589 return -EAGAIN;
590 }
591
592 switch_uid(new_user);
593
594 if(dumpclear)
595 {
596 current->mm->dumpable = 0;
597 wmb();
598 }
599 current->uid = new_ruid;
600 return 0;
601 }
602
603 /*
604 * Unprivileged users may change the real uid to the effective uid
605 * or vice versa. (BSD-style)
606 *
607 * If you set the real uid at all, or set the effective uid to a value not
608 * equal to the real uid, then the saved uid is set to the new effective uid.
609 *
610 * This makes it possible for a setuid program to completely drop its
611 * privileges, which is often a useful assertion to make when you are doing
612 * a security audit over a program.
613 *
614 * The general idea is that a program which uses just setreuid() will be
615 * 100% compatible with BSD. A program which uses just setuid() will be
616 * 100% compatible with POSIX with saved IDs.
617 */
618 asmlinkage long sys_setreuid(uid_t ruid, uid_t euid)
619 {
620 int old_ruid, old_euid, old_suid, new_ruid, new_euid;
621 int retval;
622
623 retval = security_task_setuid(ruid, euid, (uid_t)-1, LSM_SETID_RE);
624 if (retval)
625 return retval;
626
627 new_ruid = old_ruid = current->uid;
628 new_euid = old_euid = current->euid;
629 old_suid = current->suid;
630
631 if (ruid != (uid_t) -1) {
632 new_ruid = ruid;
633 if ((old_ruid != ruid) &&
634 (current->euid != ruid) &&
635 !capable(CAP_SETUID))
636 return -EPERM;
637 }
638
639 if (euid != (uid_t) -1) {
640 new_euid = euid;
641 if ((old_ruid != euid) &&
642 (current->euid != euid) &&
643 (current->suid != euid) &&
644 !capable(CAP_SETUID))
645 return -EPERM;
646 }
647
648 if (new_ruid != old_ruid && set_user(new_ruid, new_euid != old_euid) < 0)
649 return -EAGAIN;
650
651 if (new_euid != old_euid)
652 {
653 current->mm->dumpable=0;
654 wmb();
655 }
656 current->fsuid = current->euid = new_euid;
657 if (ruid != (uid_t) -1 ||
658 (euid != (uid_t) -1 && euid != old_ruid))
659 current->suid = current->euid;
660 current->fsuid = current->euid;
661
662 key_fsuid_changed(current);
663
664 return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RE);
665 }
666
667
668
669 /*
670 * setuid() is implemented like SysV with SAVED_IDS
671 *
672 * Note that SAVED_ID's is deficient in that a setuid root program
673 * like sendmail, for example, cannot set its uid to be a normal
674 * user and then switch back, because if you're root, setuid() sets
675 * the saved uid too. If you don't like this, blame the bright people
676 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
677 * will allow a root program to temporarily drop privileges and be able to
678 * regain them by swapping the real and effective uid.
679 */
680 asmlinkage long sys_setuid(uid_t uid)
681 {
682 int old_euid = current->euid;
683 int old_ruid, old_suid, new_ruid, new_suid;
684 int retval;
685
686 retval = security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_ID);
687 if (retval)
688 return retval;
689
690 old_ruid = new_ruid = current->uid;
691 old_suid = current->suid;
692 new_suid = old_suid;
693
694 if (capable(CAP_SETUID)) {
695 if (uid != old_ruid && set_user(uid, old_euid != uid) < 0)
696 return -EAGAIN;
697 new_suid = uid;
698 } else if ((uid != current->uid) && (uid != new_suid))
699 return -EPERM;
700
701 if (old_euid != uid)
702 {
703 current->mm->dumpable = 0;
704 wmb();
705 }
706 current->fsuid = current->euid = uid;
707 current->suid = new_suid;
708
709 key_fsuid_changed(current);
710
711 return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_ID);
712 }
713
714
715 /*
716 * This function implements a generic ability to update ruid, euid,
717 * and suid. This allows you to implement the 4.4 compatible seteuid().
718 */
719 asmlinkage long sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
720 {
721 int old_ruid = current->uid;
722 int old_euid = current->euid;
723 int old_suid = current->suid;
724 int retval;
725
726 retval = security_task_setuid(ruid, euid, suid, LSM_SETID_RES);
727 if (retval)
728 return retval;
729
730 if (!capable(CAP_SETUID)) {
731 if ((ruid != (uid_t) -1) && (ruid != current->uid) &&
732 (ruid != current->euid) && (ruid != current->suid))
733 return -EPERM;
734 if ((euid != (uid_t) -1) && (euid != current->uid) &&
735 (euid != current->euid) && (euid != current->suid))
736 return -EPERM;
737 if ((suid != (uid_t) -1) && (suid != current->uid) &&
738 (suid != current->euid) && (suid != current->suid))
739 return -EPERM;
740 }
741 if (ruid != (uid_t) -1) {
742 if (ruid != current->uid && set_user(ruid, euid != current->euid) < 0)
743 return -EAGAIN;
744 }
745 if (euid != (uid_t) -1) {
746 if (euid != current->euid)
747 {
748 current->mm->dumpable = 0;
749 wmb();
750 }
751 current->euid = euid;
752 }
753 current->fsuid = current->euid;
754 if (suid != (uid_t) -1)
755 current->suid = suid;
756
757 key_fsuid_changed(current);
758
759 return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RES);
760 }
761
762 asmlinkage long sys_getresuid(uid_t __user *ruid, uid_t __user *euid, uid_t __user *suid)
763 {
764 int retval;
765
766 if (!(retval = put_user(current->uid, ruid)) &&
767 !(retval = put_user(current->euid, euid)))
768 retval = put_user(current->suid, suid);
769
770 return retval;
771 }
772
773 /*
774 * Same as above, but for rgid, egid, sgid.
775 */
776 asmlinkage long sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
777 {
778 int retval;
779
780 retval = security_task_setgid(rgid, egid, sgid, LSM_SETID_RES);
781 if (retval)
782 return retval;
783
784 if (!capable(CAP_SETGID)) {
785 if ((rgid != (gid_t) -1) && (rgid != current->gid) &&
786 (rgid != current->egid) && (rgid != current->sgid))
787 return -EPERM;
788 if ((egid != (gid_t) -1) && (egid != current->gid) &&
789 (egid != current->egid) && (egid != current->sgid))
790 return -EPERM;
791 if ((sgid != (gid_t) -1) && (sgid != current->gid) &&
792 (sgid != current->egid) && (sgid != current->sgid))
793 return -EPERM;
794 }
795 if (egid != (gid_t) -1) {
796 if (egid != current->egid)
797 {
798 current->mm->dumpable = 0;
799 wmb();
800 }
801 current->egid = egid;
802 }
803 current->fsgid = current->egid;
804 if (rgid != (gid_t) -1)
805 current->gid = rgid;
806 if (sgid != (gid_t) -1)
807 current->sgid = sgid;
808
809 key_fsgid_changed(current);
810 return 0;
811 }
812
813 asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __user *sgid)
814 {
815 int retval;
816
817 if (!(retval = put_user(current->gid, rgid)) &&
818 !(retval = put_user(current->egid, egid)))
819 retval = put_user(current->sgid, sgid);
820
821 return retval;
822 }
823
824
825 /*
826 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
827 * is used for "access()" and for the NFS daemon (letting nfsd stay at
828 * whatever uid it wants to). It normally shadows "euid", except when
829 * explicitly set by setfsuid() or for access..
830 */
831 asmlinkage long sys_setfsuid(uid_t uid)
832 {
833 int old_fsuid;
834
835 old_fsuid = current->fsuid;
836 if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS))
837 return old_fsuid;
838
839 if (uid == current->uid || uid == current->euid ||
840 uid == current->suid || uid == current->fsuid ||
841 capable(CAP_SETUID))
842 {
843 if (uid != old_fsuid)
844 {
845 current->mm->dumpable = 0;
846 wmb();
847 }
848 current->fsuid = uid;
849 }
850
851 key_fsuid_changed(current);
852
853 security_task_post_setuid(old_fsuid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS);
854
855 return old_fsuid;
856 }
857
858 /*
859 * Samma på svenska..
860 */
861 asmlinkage long sys_setfsgid(gid_t gid)
862 {
863 int old_fsgid;
864
865 old_fsgid = current->fsgid;
866 if (security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS))
867 return old_fsgid;
868
869 if (gid == current->gid || gid == current->egid ||
870 gid == current->sgid || gid == current->fsgid ||
871 capable(CAP_SETGID))
872 {
873 if (gid != old_fsgid)
874 {
875 current->mm->dumpable = 0;
876 wmb();
877 }
878 current->fsgid = gid;
879 key_fsgid_changed(current);
880 }
881 return old_fsgid;
882 }
883
884 asmlinkage long sys_times(struct tms __user * tbuf)
885 {
886 /*
887 * In the SMP world we might just be unlucky and have one of
888 * the times increment as we use it. Since the value is an
889 * atomically safe type this is just fine. Conceptually its
890 * as if the syscall took an instant longer to occur.
891 */
892 if (tbuf) {
893 struct tms tmp;
894 struct task_struct *tsk = current;
895 struct task_struct *t;
896 cputime_t utime, stime, cutime, cstime;
897
898 read_lock(&tasklist_lock);
899 utime = tsk->signal->utime;
900 stime = tsk->signal->stime;
901 t = tsk;
902 do {
903 utime = cputime_add(utime, t->utime);
904 stime = cputime_add(stime, t->stime);
905 t = next_thread(t);
906 } while (t != tsk);
907
908 /*
909 * While we have tasklist_lock read-locked, no dying thread
910 * can be updating current->signal->[us]time. Instead,
911 * we got their counts included in the live thread loop.
912 * However, another thread can come in right now and
913 * do a wait call that updates current->signal->c[us]time.
914 * To make sure we always see that pair updated atomically,
915 * we take the siglock around fetching them.
916 */
917 spin_lock_irq(&tsk->sighand->siglock);
918 cutime = tsk->signal->cutime;
919 cstime = tsk->signal->cstime;
920 spin_unlock_irq(&tsk->sighand->siglock);
921 read_unlock(&tasklist_lock);
922
923 tmp.tms_utime = cputime_to_clock_t(utime);
924 tmp.tms_stime = cputime_to_clock_t(stime);
925 tmp.tms_cutime = cputime_to_clock_t(cutime);
926 tmp.tms_cstime = cputime_to_clock_t(cstime);
927 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
928 return -EFAULT;
929 }
930 return (long) jiffies_64_to_clock_t(get_jiffies_64());
931 }
932
933 /*
934 * This needs some heavy checking ...
935 * I just haven't the stomach for it. I also don't fully
936 * understand sessions/pgrp etc. Let somebody who does explain it.
937 *
938 * OK, I think I have the protection semantics right.... this is really
939 * only important on a multi-user system anyway, to make sure one user
940 * can't send a signal to a process owned by another. -TYT, 12/12/91
941 *
942 * Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
943 * LBT 04.03.94
944 */
945
946 asmlinkage long sys_setpgid(pid_t pid, pid_t pgid)
947 {
948 struct task_struct *p;
949 int err = -EINVAL;
950
951 if (!pid)
952 pid = current->pid;
953 if (!pgid)
954 pgid = pid;
955 if (pgid < 0)
956 return -EINVAL;
957
958 /* From this point forward we keep holding onto the tasklist lock
959 * so that our parent does not change from under us. -DaveM
960 */
961 write_lock_irq(&tasklist_lock);
962
963 err = -ESRCH;
964 p = find_task_by_pid(pid);
965 if (!p)
966 goto out;
967
968 err = -EINVAL;
969 if (!thread_group_leader(p))
970 goto out;
971
972 if (p->parent == current || p->real_parent == current) {
973 err = -EPERM;
974 if (p->signal->session != current->signal->session)
975 goto out;
976 err = -EACCES;
977 if (p->did_exec)
978 goto out;
979 } else {
980 err = -ESRCH;
981 if (p != current)
982 goto out;
983 }
984
985 err = -EPERM;
986 if (p->signal->leader)
987 goto out;
988
989 if (pgid != pid) {
990 struct task_struct *p;
991
992 do_each_task_pid(pgid, PIDTYPE_PGID, p) {
993 if (p->signal->session == current->signal->session)
994 goto ok_pgid;
995 } while_each_task_pid(pgid, PIDTYPE_PGID, p);
996 goto out;
997 }
998
999 ok_pgid:
1000 err = security_task_setpgid(p, pgid);
1001 if (err)
1002 goto out;
1003
1004 if (process_group(p) != pgid) {
1005 detach_pid(p, PIDTYPE_PGID);
1006 p->signal->pgrp = pgid;
1007 attach_pid(p, PIDTYPE_PGID, pgid);
1008 }
1009
1010 err = 0;
1011 out:
1012 /* All paths lead to here, thus we are safe. -DaveM */
1013 write_unlock_irq(&tasklist_lock);
1014 return err;
1015 }
1016
1017 asmlinkage long sys_getpgid(pid_t pid)
1018 {
1019 if (!pid) {
1020 return process_group(current);
1021 } else {
1022 int retval;
1023 struct task_struct *p;
1024
1025 read_lock(&tasklist_lock);
1026 p = find_task_by_pid(pid);
1027
1028 retval = -ESRCH;
1029 if (p) {
1030 retval = security_task_getpgid(p);
1031 if (!retval)
1032 retval = process_group(p);
1033 }
1034 read_unlock(&tasklist_lock);
1035 return retval;
1036 }
1037 }
1038
1039 #ifdef __ARCH_WANT_SYS_GETPGRP
1040
1041 asmlinkage long sys_getpgrp(void)
1042 {
1043 /* SMP - assuming writes are word atomic this is fine */
1044 return process_group(current);
1045 }
1046
1047 #endif
1048
1049 asmlinkage long sys_getsid(pid_t pid)
1050 {
1051 if (!pid) {
1052 return current->signal->session;
1053 } else {
1054 int retval;
1055 struct task_struct *p;
1056
1057 read_lock(&tasklist_lock);
1058 p = find_task_by_pid(pid);
1059
1060 retval = -ESRCH;
1061 if(p) {
1062 retval = security_task_getsid(p);
1063 if (!retval)
1064 retval = p->signal->session;
1065 }
1066 read_unlock(&tasklist_lock);
1067 return retval;
1068 }
1069 }
1070
1071 asmlinkage long sys_setsid(void)
1072 {
1073 struct pid *pid;
1074 int err = -EPERM;
1075
1076 if (!thread_group_leader(current))
1077 return -EINVAL;
1078
1079 down(&tty_sem);
1080 write_lock_irq(&tasklist_lock);
1081
1082 pid = find_pid(PIDTYPE_PGID, current->pid);
1083 if (pid)
1084 goto out;
1085
1086 current->signal->leader = 1;
1087 __set_special_pids(current->pid, current->pid);
1088 current->signal->tty = NULL;
1089 current->signal->tty_old_pgrp = 0;
1090 err = process_group(current);
1091 out:
1092 write_unlock_irq(&tasklist_lock);
1093 up(&tty_sem);
1094 return err;
1095 }
1096
1097 /*
1098 * Supplementary group IDs
1099 */
1100
1101 /* init to 2 - one for init_task, one to ensure it is never freed */
1102 struct group_info init_groups = { .usage = ATOMIC_INIT(2) };
1103
1104 struct group_info *groups_alloc(int gidsetsize)
1105 {
1106 struct group_info *group_info;
1107 int nblocks;
1108 int i;
1109
1110 nblocks = (gidsetsize + NGROUPS_PER_BLOCK - 1) / NGROUPS_PER_BLOCK;
1111 /* Make sure we always allocate at least one indirect block pointer */
1112 nblocks = nblocks ? : 1;
1113 group_info = kmalloc(sizeof(*group_info) + nblocks*sizeof(gid_t *), GFP_USER);
1114 if (!group_info)
1115 return NULL;
1116 group_info->ngroups = gidsetsize;
1117 group_info->nblocks = nblocks;
1118 atomic_set(&group_info->usage, 1);
1119
1120 if (gidsetsize <= NGROUPS_SMALL) {
1121 group_info->blocks[0] = group_info->small_block;
1122 } else {
1123 for (i = 0; i < nblocks; i++) {
1124 gid_t *b;
1125 b = (void *)__get_free_page(GFP_USER);
1126 if (!b)
1127 goto out_undo_partial_alloc;
1128 group_info->blocks[i] = b;
1129 }
1130 }
1131 return group_info;
1132
1133 out_undo_partial_alloc:
1134 while (--i >= 0) {
1135 free_page((unsigned long)group_info->blocks[i]);
1136 }
1137 kfree(group_info);
1138 return NULL;
1139 }
1140
1141 EXPORT_SYMBOL(groups_alloc);
1142
1143 void groups_free(struct group_info *group_info)
1144 {
1145 if (group_info->blocks[0] != group_info->small_block) {
1146 int i;
1147 for (i = 0; i < group_info->nblocks; i++)
1148 free_page((unsigned long)group_info->blocks[i]);
1149 }
1150 kfree(group_info);
1151 }
1152
1153 EXPORT_SYMBOL(groups_free);
1154
1155 /* export the group_info to a user-space array */
1156 static int groups_to_user(gid_t __user *grouplist,
1157 struct group_info *group_info)
1158 {
1159 int i;
1160 int count = group_info->ngroups;
1161
1162 for (i = 0; i < group_info->nblocks; i++) {
1163 int cp_count = min(NGROUPS_PER_BLOCK, count);
1164 int off = i * NGROUPS_PER_BLOCK;
1165 int len = cp_count * sizeof(*grouplist);
1166
1167 if (copy_to_user(grouplist+off, group_info->blocks[i], len))
1168 return -EFAULT;
1169
1170 count -= cp_count;
1171 }
1172 return 0;
1173 }
1174
1175 /* fill a group_info from a user-space array - it must be allocated already */
1176 static int groups_from_user(struct group_info *group_info,
1177 gid_t __user *grouplist)
1178 {
1179 int i;
1180 int count = group_info->ngroups;
1181
1182 for (i = 0; i < group_info->nblocks; i++) {
1183 int cp_count = min(NGROUPS_PER_BLOCK, count);
1184 int off = i * NGROUPS_PER_BLOCK;
1185 int len = cp_count * sizeof(*grouplist);
1186
1187 if (copy_from_user(group_info->blocks[i], grouplist+off, len))
1188 return -EFAULT;
1189
1190 count -= cp_count;
1191 }
1192 return 0;
1193 }
1194
1195 /* a simple shell-metzner sort */
1196 static void groups_sort(struct group_info *group_info)
1197 {
1198 int base, max, stride;
1199 int gidsetsize = group_info->ngroups;
1200
1201 for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1)
1202 ; /* nothing */
1203 stride /= 3;
1204
1205 while (stride) {
1206 max = gidsetsize - stride;
1207 for (base = 0; base < max; base++) {
1208 int left = base;
1209 int right = left + stride;
1210 gid_t tmp = GROUP_AT(group_info, right);
1211
1212 while (left >= 0 && GROUP_AT(group_info, left) > tmp) {
1213 GROUP_AT(group_info, right) =
1214 GROUP_AT(group_info, left);
1215 right = left;
1216 left -= stride;
1217 }
1218 GROUP_AT(group_info, right) = tmp;
1219 }
1220 stride /= 3;
1221 }
1222 }
1223
1224 /* a simple bsearch */
1225 static int groups_search(struct group_info *group_info, gid_t grp)
1226 {
1227 int left, right;
1228
1229 if (!group_info)
1230 return 0;
1231
1232 left = 0;
1233 right = group_info->ngroups;
1234 while (left < right) {
1235 int mid = (left+right)/2;
1236 int cmp = grp - GROUP_AT(group_info, mid);
1237 if (cmp > 0)
1238 left = mid + 1;
1239 else if (cmp < 0)
1240 right = mid;
1241 else
1242 return 1;
1243 }
1244 return 0;
1245 }
1246
1247 /* validate and set current->group_info */
1248 int set_current_groups(struct group_info *group_info)
1249 {
1250 int retval;
1251 struct group_info *old_info;
1252
1253 retval = security_task_setgroups(group_info);
1254 if (retval)
1255 return retval;
1256
1257 groups_sort(group_info);
1258 get_group_info(group_info);
1259
1260 task_lock(current);
1261 old_info = current->group_info;
1262 current->group_info = group_info;
1263 task_unlock(current);
1264
1265 put_group_info(old_info);
1266
1267 return 0;
1268 }
1269
1270 EXPORT_SYMBOL(set_current_groups);
1271
1272 asmlinkage long sys_getgroups(int gidsetsize, gid_t __user *grouplist)
1273 {
1274 int i = 0;
1275
1276 /*
1277 * SMP: Nobody else can change our grouplist. Thus we are
1278 * safe.
1279 */
1280
1281 if (gidsetsize < 0)
1282 return -EINVAL;
1283
1284 /* no need to grab task_lock here; it cannot change */
1285 get_group_info(current->group_info);
1286 i = current->group_info->ngroups;
1287 if (gidsetsize) {
1288 if (i > gidsetsize) {
1289 i = -EINVAL;
1290 goto out;
1291 }
1292 if (groups_to_user(grouplist, current->group_info)) {
1293 i = -EFAULT;
1294 goto out;
1295 }
1296 }
1297 out:
1298 put_group_info(current->group_info);
1299 return i;
1300 }
1301
1302 /*
1303 * SMP: Our groups are copy-on-write. We can set them safely
1304 * without another task interfering.
1305 */
1306
1307 asmlinkage long sys_setgroups(int gidsetsize, gid_t __user *grouplist)
1308 {
1309 struct group_info *group_info;
1310 int retval;
1311
1312 if (!capable(CAP_SETGID))
1313 return -EPERM;
1314 if ((unsigned)gidsetsize > NGROUPS_MAX)
1315 return -EINVAL;
1316
1317 group_info = groups_alloc(gidsetsize);
1318 if (!group_info)
1319 return -ENOMEM;
1320 retval = groups_from_user(group_info, grouplist);
1321 if (retval) {
1322 put_group_info(group_info);
1323 return retval;
1324 }
1325
1326 retval = set_current_groups(group_info);
1327 put_group_info(group_info);
1328
1329 return retval;
1330 }
1331
1332 /*
1333 * Check whether we're fsgid/egid or in the supplemental group..
1334 */
1335 int in_group_p(gid_t grp)
1336 {
1337 int retval = 1;
1338 if (grp != current->fsgid) {
1339 get_group_info(current->group_info);
1340 retval = groups_search(current->group_info, grp);
1341 put_group_info(current->group_info);
1342 }
1343 return retval;
1344 }
1345
1346 EXPORT_SYMBOL(in_group_p);
1347
1348 int in_egroup_p(gid_t grp)
1349 {
1350 int retval = 1;
1351 if (grp != current->egid) {
1352 get_group_info(current->group_info);
1353 retval = groups_search(current->group_info, grp);
1354 put_group_info(current->group_info);
1355 }
1356 return retval;
1357 }
1358
1359 EXPORT_SYMBOL(in_egroup_p);
1360
1361 DECLARE_RWSEM(uts_sem);
1362
1363 EXPORT_SYMBOL(uts_sem);
1364
1365 asmlinkage long sys_newuname(struct new_utsname __user * name)
1366 {
1367 int errno = 0;
1368
1369 down_read(&uts_sem);
1370 if (copy_to_user(name,&system_utsname,sizeof *name))
1371 errno = -EFAULT;
1372 up_read(&uts_sem);
1373 return errno;
1374 }
1375
1376 asmlinkage long sys_sethostname(char __user *name, int len)
1377 {
1378 int errno;
1379 char tmp[__NEW_UTS_LEN];
1380
1381 if (!capable(CAP_SYS_ADMIN))
1382 return -EPERM;
1383 if (len < 0 || len > __NEW_UTS_LEN)
1384 return -EINVAL;
1385 down_write(&uts_sem);
1386 errno = -EFAULT;
1387 if (!copy_from_user(tmp, name, len)) {
1388 memcpy(system_utsname.nodename, tmp, len);
1389 system_utsname.nodename[len] = 0;
1390 errno = 0;
1391 }
1392 up_write(&uts_sem);
1393 return errno;
1394 }
1395
1396 #ifdef __ARCH_WANT_SYS_GETHOSTNAME
1397
1398 asmlinkage long sys_gethostname(char __user *name, int len)
1399 {
1400 int i, errno;
1401
1402 if (len < 0)
1403 return -EINVAL;
1404 down_read(&uts_sem);
1405 i = 1 + strlen(system_utsname.nodename);
1406 if (i > len)
1407 i = len;
1408 errno = 0;
1409 if (copy_to_user(name, system_utsname.nodename, i))
1410 errno = -EFAULT;
1411 up_read(&uts_sem);
1412 return errno;
1413 }
1414
1415 #endif
1416
1417 /*
1418 * Only setdomainname; getdomainname can be implemented by calling
1419 * uname()
1420 */
1421 asmlinkage long sys_setdomainname(char __user *name, int len)
1422 {
1423 int errno;
1424 char tmp[__NEW_UTS_LEN];
1425
1426 if (!capable(CAP_SYS_ADMIN))
1427 return -EPERM;
1428 if (len < 0 || len > __NEW_UTS_LEN)
1429 return -EINVAL;
1430
1431 down_write(&uts_sem);
1432 errno = -EFAULT;
1433 if (!copy_from_user(tmp, name, len)) {
1434 memcpy(system_utsname.domainname, tmp, len);
1435 system_utsname.domainname[len] = 0;
1436 errno = 0;
1437 }
1438 up_write(&uts_sem);
1439 return errno;
1440 }
1441
1442 asmlinkage long sys_getrlimit(unsigned int resource, struct rlimit __user *rlim)
1443 {
1444 if (resource >= RLIM_NLIMITS)
1445 return -EINVAL;
1446 else {
1447 struct rlimit value;
1448 task_lock(current->group_leader);
1449 value = current->signal->rlim[resource];
1450 task_unlock(current->group_leader);
1451 return copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1452 }
1453 }
1454
1455 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1456
1457 /*
1458 * Back compatibility for getrlimit. Needed for some apps.
1459 */
1460
1461 asmlinkage long sys_old_getrlimit(unsigned int resource, struct rlimit __user *rlim)
1462 {
1463 struct rlimit x;
1464 if (resource >= RLIM_NLIMITS)
1465 return -EINVAL;
1466
1467 task_lock(current->group_leader);
1468 x = current->signal->rlim[resource];
1469 task_unlock(current->group_leader);
1470 if(x.rlim_cur > 0x7FFFFFFF)
1471 x.rlim_cur = 0x7FFFFFFF;
1472 if(x.rlim_max > 0x7FFFFFFF)
1473 x.rlim_max = 0x7FFFFFFF;
1474 return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0;
1475 }
1476
1477 #endif
1478
1479 asmlinkage long sys_setrlimit(unsigned int resource, struct rlimit __user *rlim)
1480 {
1481 struct rlimit new_rlim, *old_rlim;
1482 int retval;
1483
1484 if (resource >= RLIM_NLIMITS)
1485 return -EINVAL;
1486 if(copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1487 return -EFAULT;
1488 if (new_rlim.rlim_cur > new_rlim.rlim_max)
1489 return -EINVAL;
1490 old_rlim = current->signal->rlim + resource;
1491 if ((new_rlim.rlim_max > old_rlim->rlim_max) &&
1492 !capable(CAP_SYS_RESOURCE))
1493 return -EPERM;
1494 if (resource == RLIMIT_NOFILE && new_rlim.rlim_max > NR_OPEN)
1495 return -EPERM;
1496
1497 retval = security_task_setrlimit(resource, &new_rlim);
1498 if (retval)
1499 return retval;
1500
1501 task_lock(current->group_leader);
1502 *old_rlim = new_rlim;
1503 task_unlock(current->group_leader);
1504 return 0;
1505 }
1506
1507 /*
1508 * It would make sense to put struct rusage in the task_struct,
1509 * except that would make the task_struct be *really big*. After
1510 * task_struct gets moved into malloc'ed memory, it would
1511 * make sense to do this. It will make moving the rest of the information
1512 * a lot simpler! (Which we're not doing right now because we're not
1513 * measuring them yet).
1514 *
1515 * This expects to be called with tasklist_lock read-locked or better,
1516 * and the siglock not locked. It may momentarily take the siglock.
1517 *
1518 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1519 * races with threads incrementing their own counters. But since word
1520 * reads are atomic, we either get new values or old values and we don't
1521 * care which for the sums. We always take the siglock to protect reading
1522 * the c* fields from p->signal from races with exit.c updating those
1523 * fields when reaping, so a sample either gets all the additions of a
1524 * given child after it's reaped, or none so this sample is before reaping.
1525 */
1526
1527 void k_getrusage(struct task_struct *p, int who, struct rusage *r)
1528 {
1529 struct task_struct *t;
1530 unsigned long flags;
1531 cputime_t utime, stime;
1532
1533 memset((char *) r, 0, sizeof *r);
1534
1535 if (unlikely(!p->signal))
1536 return;
1537
1538 switch (who) {
1539 case RUSAGE_CHILDREN:
1540 spin_lock_irqsave(&p->sighand->siglock, flags);
1541 utime = p->signal->cutime;
1542 stime = p->signal->cstime;
1543 r->ru_nvcsw = p->signal->cnvcsw;
1544 r->ru_nivcsw = p->signal->cnivcsw;
1545 r->ru_minflt = p->signal->cmin_flt;
1546 r->ru_majflt = p->signal->cmaj_flt;
1547 spin_unlock_irqrestore(&p->sighand->siglock, flags);
1548 cputime_to_timeval(utime, &r->ru_utime);
1549 cputime_to_timeval(stime, &r->ru_stime);
1550 break;
1551 case RUSAGE_SELF:
1552 spin_lock_irqsave(&p->sighand->siglock, flags);
1553 utime = stime = cputime_zero;
1554 goto sum_group;
1555 case RUSAGE_BOTH:
1556 spin_lock_irqsave(&p->sighand->siglock, flags);
1557 utime = p->signal->cutime;
1558 stime = p->signal->cstime;
1559 r->ru_nvcsw = p->signal->cnvcsw;
1560 r->ru_nivcsw = p->signal->cnivcsw;
1561 r->ru_minflt = p->signal->cmin_flt;
1562 r->ru_majflt = p->signal->cmaj_flt;
1563 sum_group:
1564 utime = cputime_add(utime, p->signal->utime);
1565 stime = cputime_add(stime, p->signal->stime);
1566 r->ru_nvcsw += p->signal->nvcsw;
1567 r->ru_nivcsw += p->signal->nivcsw;
1568 r->ru_minflt += p->signal->min_flt;
1569 r->ru_majflt += p->signal->maj_flt;
1570 t = p;
1571 do {
1572 utime = cputime_add(utime, t->utime);
1573 stime = cputime_add(stime, t->stime);
1574 r->ru_nvcsw += t->nvcsw;
1575 r->ru_nivcsw += t->nivcsw;
1576 r->ru_minflt += t->min_flt;
1577 r->ru_majflt += t->maj_flt;
1578 t = next_thread(t);
1579 } while (t != p);
1580 spin_unlock_irqrestore(&p->sighand->siglock, flags);
1581 cputime_to_timeval(utime, &r->ru_utime);
1582 cputime_to_timeval(stime, &r->ru_stime);
1583 break;
1584 default:
1585 BUG();
1586 }
1587 }
1588
1589 int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
1590 {
1591 struct rusage r;
1592 read_lock(&tasklist_lock);
1593 k_getrusage(p, who, &r);
1594 read_unlock(&tasklist_lock);
1595 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1596 }
1597
1598 asmlinkage long sys_getrusage(int who, struct rusage __user *ru)
1599 {
1600 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN)
1601 return -EINVAL;
1602 return getrusage(current, who, ru);
1603 }
1604
1605 asmlinkage long sys_umask(int mask)
1606 {
1607 mask = xchg(¤t->fs->umask, mask & S_IRWXUGO);
1608 return mask;
1609 }
1610
1611 asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3,
1612 unsigned long arg4, unsigned long arg5)
1613 {
1614 long error;
1615 int sig;
1616
1617 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
1618 if (error)
1619 return error;
1620
1621 switch (option) {
1622 case PR_SET_PDEATHSIG:
1623 sig = arg2;
1624 if (sig < 0 || sig > _NSIG) {
1625 error = -EINVAL;
1626 break;
1627 }
1628 current->pdeath_signal = sig;
1629 break;
1630 case PR_GET_PDEATHSIG:
1631 error = put_user(current->pdeath_signal, (int __user *)arg2);
1632 break;
1633 case PR_GET_DUMPABLE:
1634 if (current->mm->dumpable)
1635 error = 1;
1636 break;
1637 case PR_SET_DUMPABLE:
1638 if (arg2 != 0 && arg2 != 1) {
1639 error = -EINVAL;
1640 break;
1641 }
1642 current->mm->dumpable = arg2;
1643 break;
1644
1645 case PR_SET_UNALIGN:
1646 error = SET_UNALIGN_CTL(current, arg2);
1647 break;
1648 case PR_GET_UNALIGN:
1649 error = GET_UNALIGN_CTL(current, arg2);
1650 break;
1651 case PR_SET_FPEMU:
1652 error = SET_FPEMU_CTL(current, arg2);
1653 break;
1654 case PR_GET_FPEMU:
1655 error = GET_FPEMU_CTL(current, arg2);
1656 break;
1657 case PR_SET_FPEXC:
1658 error = SET_FPEXC_CTL(current, arg2);
1659 break;
1660 case PR_GET_FPEXC:
1661 error = GET_FPEXC_CTL(current, arg2);
1662 break;
1663 case PR_GET_TIMING:
1664 error = PR_TIMING_STATISTICAL;
1665 break;
1666 case PR_SET_TIMING:
1667 if (arg2 == PR_TIMING_STATISTICAL)
1668 error = 0;
1669 else
1670 error = -EINVAL;
1671 break;
1672
1673 case PR_GET_KEEPCAPS:
1674 if (current->keep_capabilities)
1675 error = 1;
1676 break;
1677 case PR_SET_KEEPCAPS:
1678 if (arg2 != 0 && arg2 != 1) {
1679 error = -EINVAL;
1680 break;
1681 }
1682 current->keep_capabilities = arg2;
1683 break;
1684 case PR_SET_NAME: {
1685 struct task_struct *me = current;
1686 unsigned char ncomm[sizeof(me->comm)];
1687
1688 ncomm[sizeof(me->comm)-1] = 0;
1689 if (strncpy_from_user(ncomm, (char __user *)arg2,
1690 sizeof(me->comm)-1) < 0)
1691 return -EFAULT;
1692 set_task_comm(me, ncomm);
1693 return 0;
1694 }
1695 case PR_GET_NAME: {
1696 struct task_struct *me = current;
1697 unsigned char tcomm[sizeof(me->comm)];
1698
1699 get_task_comm(tcomm, me);
1700 if (copy_to_user((char __user *)arg2, tcomm, sizeof(tcomm)))
1701 return -EFAULT;
1702 return 0;
1703 }
1704 default:
1705 error = -EINVAL;
1706 break;
1707 }
1708 return error;
1709 }
1710
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