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[netdrvr] Fix register_netdev() races in older ISA net drivers
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / kernel / sys.c
blobf006632c2ba70c4493e1340db7c99bcad7ff38c0
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/posix-timers.h>
24 #include <linux/security.h>
25 #include <linux/dcookies.h>
26 #include <linux/suspend.h>
27 #include <linux/tty.h>
28 #include <linux/signal.h>
29
30 #include <linux/compat.h>
31 #include <linux/syscalls.h>
32
33 #include <asm/uaccess.h>
34 #include <asm/io.h>
35 #include <asm/unistd.h>
36
37 #ifndef SET_UNALIGN_CTL
38 # define SET_UNALIGN_CTL(a,b) (-EINVAL)
39 #endif
40 #ifndef GET_UNALIGN_CTL
41 # define GET_UNALIGN_CTL(a,b) (-EINVAL)
42 #endif
43 #ifndef SET_FPEMU_CTL
44 # define SET_FPEMU_CTL(a,b) (-EINVAL)
45 #endif
46 #ifndef GET_FPEMU_CTL
47 # define GET_FPEMU_CTL(a,b) (-EINVAL)
48 #endif
49 #ifndef SET_FPEXC_CTL
50 # define SET_FPEXC_CTL(a,b) (-EINVAL)
51 #endif
52 #ifndef GET_FPEXC_CTL
53 # define GET_FPEXC_CTL(a,b) (-EINVAL)
54 #endif
55
56 /*
57 * this is where the system-wide overflow UID and GID are defined, for
58 * architectures that now have 32-bit UID/GID but didn't in the past
59 */
60
61 int overflowuid = DEFAULT_OVERFLOWUID;
62 int overflowgid = DEFAULT_OVERFLOWGID;
63
64 #ifdef CONFIG_UID16
65 EXPORT_SYMBOL(overflowuid);
66 EXPORT_SYMBOL(overflowgid);
67 #endif
68
69 /*
70 * the same as above, but for filesystems which can only store a 16-bit
71 * UID and GID. as such, this is needed on all architectures
72 */
73
74 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
75 int fs_overflowgid = DEFAULT_FS_OVERFLOWUID;
76
77 EXPORT_SYMBOL(fs_overflowuid);
78 EXPORT_SYMBOL(fs_overflowgid);
79
80 /*
81 * this indicates whether you can reboot with ctrl-alt-del: the default is yes
82 */
83
84 int C_A_D = 1;
85 int cad_pid = 1;
86
87 /*
88 * Notifier list for kernel code which wants to be called
89 * at shutdown. This is used to stop any idling DMA operations
90 * and the like.
91 */
92
93 static struct notifier_block *reboot_notifier_list;
94 static DEFINE_RWLOCK(notifier_lock);
95
96 /**
97 * notifier_chain_register - Add notifier to a notifier chain
98 * @list: Pointer to root list pointer
99 * @n: New entry in notifier chain
100 *
101 * Adds a notifier to a notifier chain.
102 *
103 * Currently always returns zero.
104 */
105
106 int notifier_chain_register(struct notifier_block **list, struct notifier_block *n)
107 {
108 write_lock(&notifier_lock);
109 while(*list)
110 {
111 if(n->priority > (*list)->priority)
112 break;
113 list= &((*list)->next);
114 }
115 n->next = *list;
116 *list=n;
117 write_unlock(&notifier_lock);
118 return 0;
119 }
120
121 EXPORT_SYMBOL(notifier_chain_register);
122
123 /**
124 * notifier_chain_unregister - Remove notifier from a notifier chain
125 * @nl: Pointer to root list pointer
126 * @n: New entry in notifier chain
127 *
128 * Removes a notifier from a notifier chain.
129 *
130 * Returns zero on success, or %-ENOENT on failure.
131 */
132
133 int notifier_chain_unregister(struct notifier_block **nl, struct notifier_block *n)
134 {
135 write_lock(&notifier_lock);
136 while((*nl)!=NULL)
137 {
138 if((*nl)==n)
139 {
140 *nl=n->next;
141 write_unlock(&notifier_lock);
142 return 0;
143 }
144 nl=&((*nl)->next);
145 }
146 write_unlock(&notifier_lock);
147 return -ENOENT;
148 }
149
150 EXPORT_SYMBOL(notifier_chain_unregister);
151
152 /**
153 * notifier_call_chain - Call functions in a notifier chain
154 * @n: Pointer to root pointer of notifier chain
155 * @val: Value passed unmodified to notifier function
156 * @v: Pointer passed unmodified to notifier function
157 *
158 * Calls each function in a notifier chain in turn.
159 *
160 * If the return value of the notifier can be and'd
161 * with %NOTIFY_STOP_MASK, then notifier_call_chain
162 * will return immediately, with the return value of
163 * the notifier function which halted execution.
164 * Otherwise, the return value is the return value
165 * of the last notifier function called.
166 */
167
168 int notifier_call_chain(struct notifier_block **n, unsigned long val, void *v)
169 {
170 int ret=NOTIFY_DONE;
171 struct notifier_block *nb = *n;
172
173 while(nb)
174 {
175 ret=nb->notifier_call(nb,val,v);
176 if(ret&NOTIFY_STOP_MASK)
177 {
178 return ret;
179 }
180 nb=nb->next;
181 }
182 return ret;
183 }
184
185 EXPORT_SYMBOL(notifier_call_chain);
186
187 /**
188 * register_reboot_notifier - Register function to be called at reboot time
189 * @nb: Info about notifier function to be called
190 *
191 * Registers a function with the list of functions
192 * to be called at reboot time.
193 *
194 * Currently always returns zero, as notifier_chain_register
195 * always returns zero.
196 */
197
198 int register_reboot_notifier(struct notifier_block * nb)
199 {
200 return notifier_chain_register(&reboot_notifier_list, nb);
201 }
202
203 EXPORT_SYMBOL(register_reboot_notifier);
204
205 /**
206 * unregister_reboot_notifier - Unregister previously registered reboot notifier
207 * @nb: Hook to be unregistered
208 *
209 * Unregisters a previously registered reboot
210 * notifier function.
211 *
212 * Returns zero on success, or %-ENOENT on failure.
213 */
214
215 int unregister_reboot_notifier(struct notifier_block * nb)
216 {
217 return notifier_chain_unregister(&reboot_notifier_list, nb);
218 }
219
220 EXPORT_SYMBOL(unregister_reboot_notifier);
221
222 static int set_one_prio(struct task_struct *p, int niceval, int error)
223 {
224 int no_nice;
225
226 if (p->uid != current->euid &&
227 p->euid != current->euid && !capable(CAP_SYS_NICE)) {
228 error = -EPERM;
229 goto out;
230 }
231 if (niceval < task_nice(p) && !can_nice(p, niceval)) {
232 error = -EACCES;
233 goto out;
234 }
235 no_nice = security_task_setnice(p, niceval);
236 if (no_nice) {
237 error = no_nice;
238 goto out;
239 }
240 if (error == -ESRCH)
241 error = 0;
242 set_user_nice(p, niceval);
243 out:
244 return error;
245 }
246
247 asmlinkage long sys_setpriority(int which, int who, int niceval)
248 {
249 struct task_struct *g, *p;
250 struct user_struct *user;
251 int error = -EINVAL;
252
253 if (which > 2 || which < 0)
254 goto out;
255
256 /* normalize: avoid signed division (rounding problems) */
257 error = -ESRCH;
258 if (niceval < -20)
259 niceval = -20;
260 if (niceval > 19)
261 niceval = 19;
262
263 read_lock(&tasklist_lock);
264 switch (which) {
265 case PRIO_PROCESS:
266 if (!who)
267 who = current->pid;
268 p = find_task_by_pid(who);
269 if (p)
270 error = set_one_prio(p, niceval, error);
271 break;
272 case PRIO_PGRP:
273 if (!who)
274 who = process_group(current);
275 do_each_task_pid(who, PIDTYPE_PGID, p) {
276 error = set_one_prio(p, niceval, error);
277 } while_each_task_pid(who, PIDTYPE_PGID, p);
278 break;
279 case PRIO_USER:
280 user = current->user;
281 if (!who)
282 who = current->uid;
283 else
284 if ((who != current->uid) && !(user = find_user(who)))
285 goto out_unlock; /* No processes for this user */
286
287 do_each_thread(g, p)
288 if (p->uid == who)
289 error = set_one_prio(p, niceval, error);
290 while_each_thread(g, p);
291 if (who != current->uid)
292 free_uid(user); /* For find_user() */
293 break;
294 }
295 out_unlock:
296 read_unlock(&tasklist_lock);
297 out:
298 return error;
299 }
300
301 /*
302 * Ugh. To avoid negative return values, "getpriority()" will
303 * not return the normal nice-value, but a negated value that
304 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
305 * to stay compatible.
306 */
307 asmlinkage long sys_getpriority(int which, int who)
308 {
309 struct task_struct *g, *p;
310 struct user_struct *user;
311 long niceval, retval = -ESRCH;
312
313 if (which > 2 || which < 0)
314 return -EINVAL;
315
316 read_lock(&tasklist_lock);
317 switch (which) {
318 case PRIO_PROCESS:
319 if (!who)
320 who = current->pid;
321 p = find_task_by_pid(who);
322 if (p) {
323 niceval = 20 - task_nice(p);
324 if (niceval > retval)
325 retval = niceval;
326 }
327 break;
328 case PRIO_PGRP:
329 if (!who)
330 who = process_group(current);
331 do_each_task_pid(who, PIDTYPE_PGID, p) {
332 niceval = 20 - task_nice(p);
333 if (niceval > retval)
334 retval = niceval;
335 } while_each_task_pid(who, PIDTYPE_PGID, p);
336 break;
337 case PRIO_USER:
338 user = current->user;
339 if (!who)
340 who = current->uid;
341 else
342 if ((who != current->uid) && !(user = find_user(who)))
343 goto out_unlock; /* No processes for this user */
344
345 do_each_thread(g, p)
346 if (p->uid == who) {
347 niceval = 20 - task_nice(p);
348 if (niceval > retval)
349 retval = niceval;
350 }
351 while_each_thread(g, p);
352 if (who != current->uid)
353 free_uid(user); /* for find_user() */
354 break;
355 }
356 out_unlock:
357 read_unlock(&tasklist_lock);
358
359 return retval;
360 }
361
362
363 /*
364 * Reboot system call: for obvious reasons only root may call it,
365 * and even root needs to set up some magic numbers in the registers
366 * so that some mistake won't make this reboot the whole machine.
367 * You can also set the meaning of the ctrl-alt-del-key here.
368 *
369 * reboot doesn't sync: do that yourself before calling this.
370 */
371 asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user * arg)
372 {
373 char buffer[256];
374
375 /* We only trust the superuser with rebooting the system. */
376 if (!capable(CAP_SYS_BOOT))
377 return -EPERM;
378
379 /* For safety, we require "magic" arguments. */
380 if (magic1 != LINUX_REBOOT_MAGIC1 ||
381 (magic2 != LINUX_REBOOT_MAGIC2 &&
382 magic2 != LINUX_REBOOT_MAGIC2A &&
383 magic2 != LINUX_REBOOT_MAGIC2B &&
384 magic2 != LINUX_REBOOT_MAGIC2C))
385 return -EINVAL;
386
387 lock_kernel();
388 switch (cmd) {
389 case LINUX_REBOOT_CMD_RESTART:
390 notifier_call_chain(&reboot_notifier_list, SYS_RESTART, NULL);
391 system_state = SYSTEM_RESTART;
392 device_shutdown();
393 printk(KERN_EMERG "Restarting system.\n");
394 machine_restart(NULL);
395 break;
396
397 case LINUX_REBOOT_CMD_CAD_ON:
398 C_A_D = 1;
399 break;
400
401 case LINUX_REBOOT_CMD_CAD_OFF:
402 C_A_D = 0;
403 break;
404
405 case LINUX_REBOOT_CMD_HALT:
406 notifier_call_chain(&reboot_notifier_list, SYS_HALT, NULL);
407 system_state = SYSTEM_HALT;
408 device_shutdown();
409 printk(KERN_EMERG "System halted.\n");
410 machine_halt();
411 unlock_kernel();
412 do_exit(0);
413 break;
414
415 case LINUX_REBOOT_CMD_POWER_OFF:
416 notifier_call_chain(&reboot_notifier_list, SYS_POWER_OFF, NULL);
417 system_state = SYSTEM_POWER_OFF;
418 device_shutdown();
419 printk(KERN_EMERG "Power down.\n");
420 machine_power_off();
421 unlock_kernel();
422 do_exit(0);
423 break;
424
425 case LINUX_REBOOT_CMD_RESTART2:
426 if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) {
427 unlock_kernel();
428 return -EFAULT;
429 }
430 buffer[sizeof(buffer) - 1] = '\0';
431
432 notifier_call_chain(&reboot_notifier_list, SYS_RESTART, buffer);
433 system_state = SYSTEM_RESTART;
434 device_shutdown();
435 printk(KERN_EMERG "Restarting system with command '%s'.\n", buffer);
436 machine_restart(buffer);
437 break;
438
439 #ifdef CONFIG_SOFTWARE_SUSPEND
440 case LINUX_REBOOT_CMD_SW_SUSPEND:
441 {
442 int ret = software_suspend();
443 unlock_kernel();
444 return ret;
445 }
446 #endif
447
448 default:
449 unlock_kernel();
450 return -EINVAL;
451 }
452 unlock_kernel();
453 return 0;
454 }
455
456 static void deferred_cad(void *dummy)
457 {
458 notifier_call_chain(&reboot_notifier_list, SYS_RESTART, NULL);
459 machine_restart(NULL);
460 }
461
462 /*
463 * This function gets called by ctrl-alt-del - ie the keyboard interrupt.
464 * As it's called within an interrupt, it may NOT sync: the only choice
465 * is whether to reboot at once, or just ignore the ctrl-alt-del.
466 */
467 void ctrl_alt_del(void)
468 {
469 static DECLARE_WORK(cad_work, deferred_cad, NULL);
470
471 if (C_A_D)
472 schedule_work(&cad_work);
473 else
474 kill_proc(cad_pid, SIGINT, 1);
475 }
476
477
478 /*
479 * Unprivileged users may change the real gid to the effective gid
480 * or vice versa. (BSD-style)
481 *
482 * If you set the real gid at all, or set the effective gid to a value not
483 * equal to the real gid, then the saved gid is set to the new effective gid.
484 *
485 * This makes it possible for a setgid program to completely drop its
486 * privileges, which is often a useful assertion to make when you are doing
487 * a security audit over a program.
488 *
489 * The general idea is that a program which uses just setregid() will be
490 * 100% compatible with BSD. A program which uses just setgid() will be
491 * 100% compatible with POSIX with saved IDs.
492 *
493 * SMP: There are not races, the GIDs are checked only by filesystem
494 * operations (as far as semantic preservation is concerned).
495 */
496 asmlinkage long sys_setregid(gid_t rgid, gid_t egid)
497 {
498 int old_rgid = current->gid;
499 int old_egid = current->egid;
500 int new_rgid = old_rgid;
501 int new_egid = old_egid;
502 int retval;
503
504 retval = security_task_setgid(rgid, egid, (gid_t)-1, LSM_SETID_RE);
505 if (retval)
506 return retval;
507
508 if (rgid != (gid_t) -1) {
509 if ((old_rgid == rgid) ||
510 (current->egid==rgid) ||
511 capable(CAP_SETGID))
512 new_rgid = rgid;
513 else
514 return -EPERM;
515 }
516 if (egid != (gid_t) -1) {
517 if ((old_rgid == egid) ||
518 (current->egid == egid) ||
519 (current->sgid == egid) ||
520 capable(CAP_SETGID))
521 new_egid = egid;
522 else {
523 return -EPERM;
524 }
525 }
526 if (new_egid != old_egid)
527 {
528 current->mm->dumpable = 0;
529 smp_wmb();
530 }
531 if (rgid != (gid_t) -1 ||
532 (egid != (gid_t) -1 && egid != old_rgid))
533 current->sgid = new_egid;
534 current->fsgid = new_egid;
535 current->egid = new_egid;
536 current->gid = new_rgid;
537 key_fsgid_changed(current);
538 return 0;
539 }
540
541 /*
542 * setgid() is implemented like SysV w/ SAVED_IDS
543 *
544 * SMP: Same implicit races as above.
545 */
546 asmlinkage long sys_setgid(gid_t gid)
547 {
548 int old_egid = current->egid;
549 int retval;
550
551 retval = security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID);
552 if (retval)
553 return retval;
554
555 if (capable(CAP_SETGID))
556 {
557 if(old_egid != gid)
558 {
559 current->mm->dumpable=0;
560 smp_wmb();
561 }
562 current->gid = current->egid = current->sgid = current->fsgid = gid;
563 }
564 else if ((gid == current->gid) || (gid == current->sgid))
565 {
566 if(old_egid != gid)
567 {
568 current->mm->dumpable=0;
569 smp_wmb();
570 }
571 current->egid = current->fsgid = gid;
572 }
573 else
574 return -EPERM;
575
576 key_fsgid_changed(current);
577 return 0;
578 }
579
580 static int set_user(uid_t new_ruid, int dumpclear)
581 {
582 struct user_struct *new_user;
583
584 new_user = alloc_uid(new_ruid);
585 if (!new_user)
586 return -EAGAIN;
587
588 if (atomic_read(&new_user->processes) >=
589 current->signal->rlim[RLIMIT_NPROC].rlim_cur &&
590 new_user != &root_user) {
591 free_uid(new_user);
592 return -EAGAIN;
593 }
594
595 switch_uid(new_user);
596
597 if(dumpclear)
598 {
599 current->mm->dumpable = 0;
600 smp_wmb();
601 }
602 current->uid = new_ruid;
603 return 0;
604 }
605
606 /*
607 * Unprivileged users may change the real uid to the effective uid
608 * or vice versa. (BSD-style)
609 *
610 * If you set the real uid at all, or set the effective uid to a value not
611 * equal to the real uid, then the saved uid is set to the new effective uid.
612 *
613 * This makes it possible for a setuid program to completely drop its
614 * privileges, which is often a useful assertion to make when you are doing
615 * a security audit over a program.
616 *
617 * The general idea is that a program which uses just setreuid() will be
618 * 100% compatible with BSD. A program which uses just setuid() will be
619 * 100% compatible with POSIX with saved IDs.
620 */
621 asmlinkage long sys_setreuid(uid_t ruid, uid_t euid)
622 {
623 int old_ruid, old_euid, old_suid, new_ruid, new_euid;
624 int retval;
625
626 retval = security_task_setuid(ruid, euid, (uid_t)-1, LSM_SETID_RE);
627 if (retval)
628 return retval;
629
630 new_ruid = old_ruid = current->uid;
631 new_euid = old_euid = current->euid;
632 old_suid = current->suid;
633
634 if (ruid != (uid_t) -1) {
635 new_ruid = ruid;
636 if ((old_ruid != ruid) &&
637 (current->euid != ruid) &&
638 !capable(CAP_SETUID))
639 return -EPERM;
640 }
641
642 if (euid != (uid_t) -1) {
643 new_euid = euid;
644 if ((old_ruid != euid) &&
645 (current->euid != euid) &&
646 (current->suid != euid) &&
647 !capable(CAP_SETUID))
648 return -EPERM;
649 }
650
651 if (new_ruid != old_ruid && set_user(new_ruid, new_euid != old_euid) < 0)
652 return -EAGAIN;
653
654 if (new_euid != old_euid)
655 {
656 current->mm->dumpable=0;
657 smp_wmb();
658 }
659 current->fsuid = current->euid = new_euid;
660 if (ruid != (uid_t) -1 ||
661 (euid != (uid_t) -1 && euid != old_ruid))
662 current->suid = current->euid;
663 current->fsuid = current->euid;
664
665 key_fsuid_changed(current);
666
667 return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RE);
668 }
669
670
671
672 /*
673 * setuid() is implemented like SysV with SAVED_IDS
674 *
675 * Note that SAVED_ID's is deficient in that a setuid root program
676 * like sendmail, for example, cannot set its uid to be a normal
677 * user and then switch back, because if you're root, setuid() sets
678 * the saved uid too. If you don't like this, blame the bright people
679 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
680 * will allow a root program to temporarily drop privileges and be able to
681 * regain them by swapping the real and effective uid.
682 */
683 asmlinkage long sys_setuid(uid_t uid)
684 {
685 int old_euid = current->euid;
686 int old_ruid, old_suid, new_ruid, new_suid;
687 int retval;
688
689 retval = security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_ID);
690 if (retval)
691 return retval;
692
693 old_ruid = new_ruid = current->uid;
694 old_suid = current->suid;
695 new_suid = old_suid;
696
697 if (capable(CAP_SETUID)) {
698 if (uid != old_ruid && set_user(uid, old_euid != uid) < 0)
699 return -EAGAIN;
700 new_suid = uid;
701 } else if ((uid != current->uid) && (uid != new_suid))
702 return -EPERM;
703
704 if (old_euid != uid)
705 {
706 current->mm->dumpable = 0;
707 smp_wmb();
708 }
709 current->fsuid = current->euid = uid;
710 current->suid = new_suid;
711
712 key_fsuid_changed(current);
713
714 return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_ID);
715 }
716
717
718 /*
719 * This function implements a generic ability to update ruid, euid,
720 * and suid. This allows you to implement the 4.4 compatible seteuid().
721 */
722 asmlinkage long sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
723 {
724 int old_ruid = current->uid;
725 int old_euid = current->euid;
726 int old_suid = current->suid;
727 int retval;
728
729 retval = security_task_setuid(ruid, euid, suid, LSM_SETID_RES);
730 if (retval)
731 return retval;
732
733 if (!capable(CAP_SETUID)) {
734 if ((ruid != (uid_t) -1) && (ruid != current->uid) &&
735 (ruid != current->euid) && (ruid != current->suid))
736 return -EPERM;
737 if ((euid != (uid_t) -1) && (euid != current->uid) &&
738 (euid != current->euid) && (euid != current->suid))
739 return -EPERM;
740 if ((suid != (uid_t) -1) && (suid != current->uid) &&
741 (suid != current->euid) && (suid != current->suid))
742 return -EPERM;
743 }
744 if (ruid != (uid_t) -1) {
745 if (ruid != current->uid && set_user(ruid, euid != current->euid) < 0)
746 return -EAGAIN;
747 }
748 if (euid != (uid_t) -1) {
749 if (euid != current->euid)
750 {
751 current->mm->dumpable = 0;
752 smp_wmb();
753 }
754 current->euid = euid;
755 }
756 current->fsuid = current->euid;
757 if (suid != (uid_t) -1)
758 current->suid = suid;
759
760 key_fsuid_changed(current);
761
762 return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RES);
763 }
764
765 asmlinkage long sys_getresuid(uid_t __user *ruid, uid_t __user *euid, uid_t __user *suid)
766 {
767 int retval;
768
769 if (!(retval = put_user(current->uid, ruid)) &&
770 !(retval = put_user(current->euid, euid)))
771 retval = put_user(current->suid, suid);
772
773 return retval;
774 }
775
776 /*
777 * Same as above, but for rgid, egid, sgid.
778 */
779 asmlinkage long sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
780 {
781 int retval;
782
783 retval = security_task_setgid(rgid, egid, sgid, LSM_SETID_RES);
784 if (retval)
785 return retval;
786
787 if (!capable(CAP_SETGID)) {
788 if ((rgid != (gid_t) -1) && (rgid != current->gid) &&
789 (rgid != current->egid) && (rgid != current->sgid))
790 return -EPERM;
791 if ((egid != (gid_t) -1) && (egid != current->gid) &&
792 (egid != current->egid) && (egid != current->sgid))
793 return -EPERM;
794 if ((sgid != (gid_t) -1) && (sgid != current->gid) &&
795 (sgid != current->egid) && (sgid != current->sgid))
796 return -EPERM;
797 }
798 if (egid != (gid_t) -1) {
799 if (egid != current->egid)
800 {
801 current->mm->dumpable = 0;
802 smp_wmb();
803 }
804 current->egid = egid;
805 }
806 current->fsgid = current->egid;
807 if (rgid != (gid_t) -1)
808 current->gid = rgid;
809 if (sgid != (gid_t) -1)
810 current->sgid = sgid;
811
812 key_fsgid_changed(current);
813 return 0;
814 }
815
816 asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __user *sgid)
817 {
818 int retval;
819
820 if (!(retval = put_user(current->gid, rgid)) &&
821 !(retval = put_user(current->egid, egid)))
822 retval = put_user(current->sgid, sgid);
823
824 return retval;
825 }
826
827
828 /*
829 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
830 * is used for "access()" and for the NFS daemon (letting nfsd stay at
831 * whatever uid it wants to). It normally shadows "euid", except when
832 * explicitly set by setfsuid() or for access..
833 */
834 asmlinkage long sys_setfsuid(uid_t uid)
835 {
836 int old_fsuid;
837
838 old_fsuid = current->fsuid;
839 if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS))
840 return old_fsuid;
841
842 if (uid == current->uid || uid == current->euid ||
843 uid == current->suid || uid == current->fsuid ||
844 capable(CAP_SETUID))
845 {
846 if (uid != old_fsuid)
847 {
848 current->mm->dumpable = 0;
849 smp_wmb();
850 }
851 current->fsuid = uid;
852 }
853
854 key_fsuid_changed(current);
855
856 security_task_post_setuid(old_fsuid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS);
857
858 return old_fsuid;
859 }
860
861 /*
862 * Samma på svenska..
863 */
864 asmlinkage long sys_setfsgid(gid_t gid)
865 {
866 int old_fsgid;
867
868 old_fsgid = current->fsgid;
869 if (security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS))
870 return old_fsgid;
871
872 if (gid == current->gid || gid == current->egid ||
873 gid == current->sgid || gid == current->fsgid ||
874 capable(CAP_SETGID))
875 {
876 if (gid != old_fsgid)
877 {
878 current->mm->dumpable = 0;
879 smp_wmb();
880 }
881 current->fsgid = gid;
882 key_fsgid_changed(current);
883 }
884 return old_fsgid;
885 }
886
887 asmlinkage long sys_times(struct tms __user * tbuf)
888 {
889 /*
890 * In the SMP world we might just be unlucky and have one of
891 * the times increment as we use it. Since the value is an
892 * atomically safe type this is just fine. Conceptually its
893 * as if the syscall took an instant longer to occur.
894 */
895 if (tbuf) {
896 struct tms tmp;
897 struct task_struct *tsk = current;
898 struct task_struct *t;
899 cputime_t utime, stime, cutime, cstime;
900
901 read_lock(&tasklist_lock);
902 utime = tsk->signal->utime;
903 stime = tsk->signal->stime;
904 t = tsk;
905 do {
906 utime = cputime_add(utime, t->utime);
907 stime = cputime_add(stime, t->stime);
908 t = next_thread(t);
909 } while (t != tsk);
910
911 /*
912 * While we have tasklist_lock read-locked, no dying thread
913 * can be updating current->signal->[us]time. Instead,
914 * we got their counts included in the live thread loop.
915 * However, another thread can come in right now and
916 * do a wait call that updates current->signal->c[us]time.
917 * To make sure we always see that pair updated atomically,
918 * we take the siglock around fetching them.
919 */
920 spin_lock_irq(&tsk->sighand->siglock);
921 cutime = tsk->signal->cutime;
922 cstime = tsk->signal->cstime;
923 spin_unlock_irq(&tsk->sighand->siglock);
924 read_unlock(&tasklist_lock);
925
926 tmp.tms_utime = cputime_to_clock_t(utime);
927 tmp.tms_stime = cputime_to_clock_t(stime);
928 tmp.tms_cutime = cputime_to_clock_t(cutime);
929 tmp.tms_cstime = cputime_to_clock_t(cstime);
930 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
931 return -EFAULT;
932 }
933 return (long) jiffies_64_to_clock_t(get_jiffies_64());
934 }
935
936 /*
937 * This needs some heavy checking ...
938 * I just haven't the stomach for it. I also don't fully
939 * understand sessions/pgrp etc. Let somebody who does explain it.
940 *
941 * OK, I think I have the protection semantics right.... this is really
942 * only important on a multi-user system anyway, to make sure one user
943 * can't send a signal to a process owned by another. -TYT, 12/12/91
944 *
945 * Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
946 * LBT 04.03.94
947 */
948
949 asmlinkage long sys_setpgid(pid_t pid, pid_t pgid)
950 {
951 struct task_struct *p;
952 int err = -EINVAL;
953
954 if (!pid)
955 pid = current->pid;
956 if (!pgid)
957 pgid = pid;
958 if (pgid < 0)
959 return -EINVAL;
960
961 /* From this point forward we keep holding onto the tasklist lock
962 * so that our parent does not change from under us. -DaveM
963 */
964 write_lock_irq(&tasklist_lock);
965
966 err = -ESRCH;
967 p = find_task_by_pid(pid);
968 if (!p)
969 goto out;
970
971 err = -EINVAL;
972 if (!thread_group_leader(p))
973 goto out;
974
975 if (p->parent == current || p->real_parent == current) {
976 err = -EPERM;
977 if (p->signal->session != current->signal->session)
978 goto out;
979 err = -EACCES;
980 if (p->did_exec)
981 goto out;
982 } else {
983 err = -ESRCH;
984 if (p != current)
985 goto out;
986 }
987
988 err = -EPERM;
989 if (p->signal->leader)
990 goto out;
991
992 if (pgid != pid) {
993 struct task_struct *p;
994
995 do_each_task_pid(pgid, PIDTYPE_PGID, p) {
996 if (p->signal->session == current->signal->session)
997 goto ok_pgid;
998 } while_each_task_pid(pgid, PIDTYPE_PGID, p);
999 goto out;
1000 }
1001
1002 ok_pgid:
1003 err = security_task_setpgid(p, pgid);
1004 if (err)
1005 goto out;
1006
1007 if (process_group(p) != pgid) {
1008 detach_pid(p, PIDTYPE_PGID);
1009 p->signal->pgrp = pgid;
1010 attach_pid(p, PIDTYPE_PGID, pgid);
1011 }
1012
1013 err = 0;
1014 out:
1015 /* All paths lead to here, thus we are safe. -DaveM */
1016 write_unlock_irq(&tasklist_lock);
1017 return err;
1018 }
1019
1020 asmlinkage long sys_getpgid(pid_t pid)
1021 {
1022 if (!pid) {
1023 return process_group(current);
1024 } else {
1025 int retval;
1026 struct task_struct *p;
1027
1028 read_lock(&tasklist_lock);
1029 p = find_task_by_pid(pid);
1030
1031 retval = -ESRCH;
1032 if (p) {
1033 retval = security_task_getpgid(p);
1034 if (!retval)
1035 retval = process_group(p);
1036 }
1037 read_unlock(&tasklist_lock);
1038 return retval;
1039 }
1040 }
1041
1042 #ifdef __ARCH_WANT_SYS_GETPGRP
1043
1044 asmlinkage long sys_getpgrp(void)
1045 {
1046 /* SMP - assuming writes are word atomic this is fine */
1047 return process_group(current);
1048 }
1049
1050 #endif
1051
1052 asmlinkage long sys_getsid(pid_t pid)
1053 {
1054 if (!pid) {
1055 return current->signal->session;
1056 } else {
1057 int retval;
1058 struct task_struct *p;
1059
1060 read_lock(&tasklist_lock);
1061 p = find_task_by_pid(pid);
1062
1063 retval = -ESRCH;
1064 if(p) {
1065 retval = security_task_getsid(p);
1066 if (!retval)
1067 retval = p->signal->session;
1068 }
1069 read_unlock(&tasklist_lock);
1070 return retval;
1071 }
1072 }
1073
1074 asmlinkage long sys_setsid(void)
1075 {
1076 struct pid *pid;
1077 int err = -EPERM;
1078
1079 if (!thread_group_leader(current))
1080 return -EINVAL;
1081
1082 down(&tty_sem);
1083 write_lock_irq(&tasklist_lock);
1084
1085 pid = find_pid(PIDTYPE_PGID, current->pid);
1086 if (pid)
1087 goto out;
1088
1089 current->signal->leader = 1;
1090 __set_special_pids(current->pid, current->pid);
1091 current->signal->tty = NULL;
1092 current->signal->tty_old_pgrp = 0;
1093 err = process_group(current);
1094 out:
1095 write_unlock_irq(&tasklist_lock);
1096 up(&tty_sem);
1097 return err;
1098 }
1099
1100 /*
1101 * Supplementary group IDs
1102 */
1103
1104 /* init to 2 - one for init_task, one to ensure it is never freed */
1105 struct group_info init_groups = { .usage = ATOMIC_INIT(2) };
1106
1107 struct group_info *groups_alloc(int gidsetsize)
1108 {
1109 struct group_info *group_info;
1110 int nblocks;
1111 int i;
1112
1113 nblocks = (gidsetsize + NGROUPS_PER_BLOCK - 1) / NGROUPS_PER_BLOCK;
1114 /* Make sure we always allocate at least one indirect block pointer */
1115 nblocks = nblocks ? : 1;
1116 group_info = kmalloc(sizeof(*group_info) + nblocks*sizeof(gid_t *), GFP_USER);
1117 if (!group_info)
1118 return NULL;
1119 group_info->ngroups = gidsetsize;
1120 group_info->nblocks = nblocks;
1121 atomic_set(&group_info->usage, 1);
1122
1123 if (gidsetsize <= NGROUPS_SMALL) {
1124 group_info->blocks[0] = group_info->small_block;
1125 } else {
1126 for (i = 0; i < nblocks; i++) {
1127 gid_t *b;
1128 b = (void *)__get_free_page(GFP_USER);
1129 if (!b)
1130 goto out_undo_partial_alloc;
1131 group_info->blocks[i] = b;
1132 }
1133 }
1134 return group_info;
1135
1136 out_undo_partial_alloc:
1137 while (--i >= 0) {
1138 free_page((unsigned long)group_info->blocks[i]);
1139 }
1140 kfree(group_info);
1141 return NULL;
1142 }
1143
1144 EXPORT_SYMBOL(groups_alloc);
1145
1146 void groups_free(struct group_info *group_info)
1147 {
1148 if (group_info->blocks[0] != group_info->small_block) {
1149 int i;
1150 for (i = 0; i < group_info->nblocks; i++)
1151 free_page((unsigned long)group_info->blocks[i]);
1152 }
1153 kfree(group_info);
1154 }
1155
1156 EXPORT_SYMBOL(groups_free);
1157
1158 /* export the group_info to a user-space array */
1159 static int groups_to_user(gid_t __user *grouplist,
1160 struct group_info *group_info)
1161 {
1162 int i;
1163 int count = group_info->ngroups;
1164
1165 for (i = 0; i < group_info->nblocks; i++) {
1166 int cp_count = min(NGROUPS_PER_BLOCK, count);
1167 int off = i * NGROUPS_PER_BLOCK;
1168 int len = cp_count * sizeof(*grouplist);
1169
1170 if (copy_to_user(grouplist+off, group_info->blocks[i], len))
1171 return -EFAULT;
1172
1173 count -= cp_count;
1174 }
1175 return 0;
1176 }
1177
1178 /* fill a group_info from a user-space array - it must be allocated already */
1179 static int groups_from_user(struct group_info *group_info,
1180 gid_t __user *grouplist)
1181 {
1182 int i;
1183 int count = group_info->ngroups;
1184
1185 for (i = 0; i < group_info->nblocks; i++) {
1186 int cp_count = min(NGROUPS_PER_BLOCK, count);
1187 int off = i * NGROUPS_PER_BLOCK;
1188 int len = cp_count * sizeof(*grouplist);
1189
1190 if (copy_from_user(group_info->blocks[i], grouplist+off, len))
1191 return -EFAULT;
1192
1193 count -= cp_count;
1194 }
1195 return 0;
1196 }
1197
1198 /* a simple Shell sort */
1199 static void groups_sort(struct group_info *group_info)
1200 {
1201 int base, max, stride;
1202 int gidsetsize = group_info->ngroups;
1203
1204 for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1)
1205 ; /* nothing */
1206 stride /= 3;
1207
1208 while (stride) {
1209 max = gidsetsize - stride;
1210 for (base = 0; base < max; base++) {
1211 int left = base;
1212 int right = left + stride;
1213 gid_t tmp = GROUP_AT(group_info, right);
1214
1215 while (left >= 0 && GROUP_AT(group_info, left) > tmp) {
1216 GROUP_AT(group_info, right) =
1217 GROUP_AT(group_info, left);
1218 right = left;
1219 left -= stride;
1220 }
1221 GROUP_AT(group_info, right) = tmp;
1222 }
1223 stride /= 3;
1224 }
1225 }
1226
1227 /* a simple bsearch */
1228 static int groups_search(struct group_info *group_info, gid_t grp)
1229 {
1230 int left, right;
1231
1232 if (!group_info)
1233 return 0;
1234
1235 left = 0;
1236 right = group_info->ngroups;
1237 while (left < right) {
1238 int mid = (left+right)/2;
1239 int cmp = grp - GROUP_AT(group_info, mid);
1240 if (cmp > 0)
1241 left = mid + 1;
1242 else if (cmp < 0)
1243 right = mid;
1244 else
1245 return 1;
1246 }
1247 return 0;
1248 }
1249
1250 /* validate and set current->group_info */
1251 int set_current_groups(struct group_info *group_info)
1252 {
1253 int retval;
1254 struct group_info *old_info;
1255
1256 retval = security_task_setgroups(group_info);
1257 if (retval)
1258 return retval;
1259
1260 groups_sort(group_info);
1261 get_group_info(group_info);
1262
1263 task_lock(current);
1264 old_info = current->group_info;
1265 current->group_info = group_info;
1266 task_unlock(current);
1267
1268 put_group_info(old_info);
1269
1270 return 0;
1271 }
1272
1273 EXPORT_SYMBOL(set_current_groups);
1274
1275 asmlinkage long sys_getgroups(int gidsetsize, gid_t __user *grouplist)
1276 {
1277 int i = 0;
1278
1279 /*
1280 * SMP: Nobody else can change our grouplist. Thus we are
1281 * safe.
1282 */
1283
1284 if (gidsetsize < 0)
1285 return -EINVAL;
1286
1287 /* no need to grab task_lock here; it cannot change */
1288 get_group_info(current->group_info);
1289 i = current->group_info->ngroups;
1290 if (gidsetsize) {
1291 if (i > gidsetsize) {
1292 i = -EINVAL;
1293 goto out;
1294 }
1295 if (groups_to_user(grouplist, current->group_info)) {
1296 i = -EFAULT;
1297 goto out;
1298 }
1299 }
1300 out:
1301 put_group_info(current->group_info);
1302 return i;
1303 }
1304
1305 /*
1306 * SMP: Our groups are copy-on-write. We can set them safely
1307 * without another task interfering.
1308 */
1309
1310 asmlinkage long sys_setgroups(int gidsetsize, gid_t __user *grouplist)
1311 {
1312 struct group_info *group_info;
1313 int retval;
1314
1315 if (!capable(CAP_SETGID))
1316 return -EPERM;
1317 if ((unsigned)gidsetsize > NGROUPS_MAX)
1318 return -EINVAL;
1319
1320 group_info = groups_alloc(gidsetsize);
1321 if (!group_info)
1322 return -ENOMEM;
1323 retval = groups_from_user(group_info, grouplist);
1324 if (retval) {
1325 put_group_info(group_info);
1326 return retval;
1327 }
1328
1329 retval = set_current_groups(group_info);
1330 put_group_info(group_info);
1331
1332 return retval;
1333 }
1334
1335 /*
1336 * Check whether we're fsgid/egid or in the supplemental group..
1337 */
1338 int in_group_p(gid_t grp)
1339 {
1340 int retval = 1;
1341 if (grp != current->fsgid) {
1342 get_group_info(current->group_info);
1343 retval = groups_search(current->group_info, grp);
1344 put_group_info(current->group_info);
1345 }
1346 return retval;
1347 }
1348
1349 EXPORT_SYMBOL(in_group_p);
1350
1351 int in_egroup_p(gid_t grp)
1352 {
1353 int retval = 1;
1354 if (grp != current->egid) {
1355 get_group_info(current->group_info);
1356 retval = groups_search(current->group_info, grp);
1357 put_group_info(current->group_info);
1358 }
1359 return retval;
1360 }
1361
1362 EXPORT_SYMBOL(in_egroup_p);
1363
1364 DECLARE_RWSEM(uts_sem);
1365
1366 EXPORT_SYMBOL(uts_sem);
1367
1368 asmlinkage long sys_newuname(struct new_utsname __user * name)
1369 {
1370 int errno = 0;
1371
1372 down_read(&uts_sem);
1373 if (copy_to_user(name,&system_utsname,sizeof *name))
1374 errno = -EFAULT;
1375 up_read(&uts_sem);
1376 return errno;
1377 }
1378
1379 asmlinkage long sys_sethostname(char __user *name, int len)
1380 {
1381 int errno;
1382 char tmp[__NEW_UTS_LEN];
1383
1384 if (!capable(CAP_SYS_ADMIN))
1385 return -EPERM;
1386 if (len < 0 || len > __NEW_UTS_LEN)
1387 return -EINVAL;
1388 down_write(&uts_sem);
1389 errno = -EFAULT;
1390 if (!copy_from_user(tmp, name, len)) {
1391 memcpy(system_utsname.nodename, tmp, len);
1392 system_utsname.nodename[len] = 0;
1393 errno = 0;
1394 }
1395 up_write(&uts_sem);
1396 return errno;
1397 }
1398
1399 #ifdef __ARCH_WANT_SYS_GETHOSTNAME
1400
1401 asmlinkage long sys_gethostname(char __user *name, int len)
1402 {
1403 int i, errno;
1404
1405 if (len < 0)
1406 return -EINVAL;
1407 down_read(&uts_sem);
1408 i = 1 + strlen(system_utsname.nodename);
1409 if (i > len)
1410 i = len;
1411 errno = 0;
1412 if (copy_to_user(name, system_utsname.nodename, i))
1413 errno = -EFAULT;
1414 up_read(&uts_sem);
1415 return errno;
1416 }
1417
1418 #endif
1419
1420 /*
1421 * Only setdomainname; getdomainname can be implemented by calling
1422 * uname()
1423 */
1424 asmlinkage long sys_setdomainname(char __user *name, int len)
1425 {
1426 int errno;
1427 char tmp[__NEW_UTS_LEN];
1428
1429 if (!capable(CAP_SYS_ADMIN))
1430 return -EPERM;
1431 if (len < 0 || len > __NEW_UTS_LEN)
1432 return -EINVAL;
1433
1434 down_write(&uts_sem);
1435 errno = -EFAULT;
1436 if (!copy_from_user(tmp, name, len)) {
1437 memcpy(system_utsname.domainname, tmp, len);
1438 system_utsname.domainname[len] = 0;
1439 errno = 0;
1440 }
1441 up_write(&uts_sem);
1442 return errno;
1443 }
1444
1445 asmlinkage long sys_getrlimit(unsigned int resource, struct rlimit __user *rlim)
1446 {
1447 if (resource >= RLIM_NLIMITS)
1448 return -EINVAL;
1449 else {
1450 struct rlimit value;
1451 task_lock(current->group_leader);
1452 value = current->signal->rlim[resource];
1453 task_unlock(current->group_leader);
1454 return copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1455 }
1456 }
1457
1458 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1459
1460 /*
1461 * Back compatibility for getrlimit. Needed for some apps.
1462 */
1463
1464 asmlinkage long sys_old_getrlimit(unsigned int resource, struct rlimit __user *rlim)
1465 {
1466 struct rlimit x;
1467 if (resource >= RLIM_NLIMITS)
1468 return -EINVAL;
1469
1470 task_lock(current->group_leader);
1471 x = current->signal->rlim[resource];
1472 task_unlock(current->group_leader);
1473 if(x.rlim_cur > 0x7FFFFFFF)
1474 x.rlim_cur = 0x7FFFFFFF;
1475 if(x.rlim_max > 0x7FFFFFFF)
1476 x.rlim_max = 0x7FFFFFFF;
1477 return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0;
1478 }
1479
1480 #endif
1481
1482 asmlinkage long sys_setrlimit(unsigned int resource, struct rlimit __user *rlim)
1483 {
1484 struct rlimit new_rlim, *old_rlim;
1485 int retval;
1486
1487 if (resource >= RLIM_NLIMITS)
1488 return -EINVAL;
1489 if(copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1490 return -EFAULT;
1491 if (new_rlim.rlim_cur > new_rlim.rlim_max)
1492 return -EINVAL;
1493 old_rlim = current->signal->rlim + resource;
1494 if ((new_rlim.rlim_max > old_rlim->rlim_max) &&
1495 !capable(CAP_SYS_RESOURCE))
1496 return -EPERM;
1497 if (resource == RLIMIT_NOFILE && new_rlim.rlim_max > NR_OPEN)
1498 return -EPERM;
1499
1500 retval = security_task_setrlimit(resource, &new_rlim);
1501 if (retval)
1502 return retval;
1503
1504 task_lock(current->group_leader);
1505 *old_rlim = new_rlim;
1506 task_unlock(current->group_leader);
1507
1508 if (resource == RLIMIT_CPU && new_rlim.rlim_cur != RLIM_INFINITY &&
1509 (cputime_eq(current->signal->it_prof_expires, cputime_zero) ||
1510 new_rlim.rlim_cur <= cputime_to_secs(
1511 current->signal->it_prof_expires))) {
1512 cputime_t cputime = secs_to_cputime(new_rlim.rlim_cur);
1513 read_lock(&tasklist_lock);
1514 spin_lock_irq(&current->sighand->siglock);
1515 set_process_cpu_timer(current, CPUCLOCK_PROF,
1516 &cputime, NULL);
1517 spin_unlock_irq(&current->sighand->siglock);
1518 read_unlock(&tasklist_lock);
1519 }
1520
1521 return 0;
1522 }
1523
1524 /*
1525 * It would make sense to put struct rusage in the task_struct,
1526 * except that would make the task_struct be *really big*. After
1527 * task_struct gets moved into malloc'ed memory, it would
1528 * make sense to do this. It will make moving the rest of the information
1529 * a lot simpler! (Which we're not doing right now because we're not
1530 * measuring them yet).
1531 *
1532 * This expects to be called with tasklist_lock read-locked or better,
1533 * and the siglock not locked. It may momentarily take the siglock.
1534 *
1535 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1536 * races with threads incrementing their own counters. But since word
1537 * reads are atomic, we either get new values or old values and we don't
1538 * care which for the sums. We always take the siglock to protect reading
1539 * the c* fields from p->signal from races with exit.c updating those
1540 * fields when reaping, so a sample either gets all the additions of a
1541 * given child after it's reaped, or none so this sample is before reaping.
1542 */
1543
1544 static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
1545 {
1546 struct task_struct *t;
1547 unsigned long flags;
1548 cputime_t utime, stime;
1549
1550 memset((char *) r, 0, sizeof *r);
1551
1552 if (unlikely(!p->signal))
1553 return;
1554
1555 switch (who) {
1556 case RUSAGE_CHILDREN:
1557 spin_lock_irqsave(&p->sighand->siglock, flags);
1558 utime = p->signal->cutime;
1559 stime = p->signal->cstime;
1560 r->ru_nvcsw = p->signal->cnvcsw;
1561 r->ru_nivcsw = p->signal->cnivcsw;
1562 r->ru_minflt = p->signal->cmin_flt;
1563 r->ru_majflt = p->signal->cmaj_flt;
1564 spin_unlock_irqrestore(&p->sighand->siglock, flags);
1565 cputime_to_timeval(utime, &r->ru_utime);
1566 cputime_to_timeval(stime, &r->ru_stime);
1567 break;
1568 case RUSAGE_SELF:
1569 spin_lock_irqsave(&p->sighand->siglock, flags);
1570 utime = stime = cputime_zero;
1571 goto sum_group;
1572 case RUSAGE_BOTH:
1573 spin_lock_irqsave(&p->sighand->siglock, flags);
1574 utime = p->signal->cutime;
1575 stime = p->signal->cstime;
1576 r->ru_nvcsw = p->signal->cnvcsw;
1577 r->ru_nivcsw = p->signal->cnivcsw;
1578 r->ru_minflt = p->signal->cmin_flt;
1579 r->ru_majflt = p->signal->cmaj_flt;
1580 sum_group:
1581 utime = cputime_add(utime, p->signal->utime);
1582 stime = cputime_add(stime, p->signal->stime);
1583 r->ru_nvcsw += p->signal->nvcsw;
1584 r->ru_nivcsw += p->signal->nivcsw;
1585 r->ru_minflt += p->signal->min_flt;
1586 r->ru_majflt += p->signal->maj_flt;
1587 t = p;
1588 do {
1589 utime = cputime_add(utime, t->utime);
1590 stime = cputime_add(stime, t->stime);
1591 r->ru_nvcsw += t->nvcsw;
1592 r->ru_nivcsw += t->nivcsw;
1593 r->ru_minflt += t->min_flt;
1594 r->ru_majflt += t->maj_flt;
1595 t = next_thread(t);
1596 } while (t != p);
1597 spin_unlock_irqrestore(&p->sighand->siglock, flags);
1598 cputime_to_timeval(utime, &r->ru_utime);
1599 cputime_to_timeval(stime, &r->ru_stime);
1600 break;
1601 default:
1602 BUG();
1603 }
1604 }
1605
1606 int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
1607 {
1608 struct rusage r;
1609 read_lock(&tasklist_lock);
1610 k_getrusage(p, who, &r);
1611 read_unlock(&tasklist_lock);
1612 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1613 }
1614
1615 asmlinkage long sys_getrusage(int who, struct rusage __user *ru)
1616 {
1617 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN)
1618 return -EINVAL;
1619 return getrusage(current, who, ru);
1620 }
1621
1622 asmlinkage long sys_umask(int mask)
1623 {
1624 mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1625 return mask;
1626 }
1627
1628 asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3,
1629 unsigned long arg4, unsigned long arg5)
1630 {
1631 long error;
1632 int sig;
1633
1634 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
1635 if (error)
1636 return error;
1637
1638 switch (option) {
1639 case PR_SET_PDEATHSIG:
1640 sig = arg2;
1641 if (!valid_signal(sig)) {
1642 error = -EINVAL;
1643 break;
1644 }
1645 current->pdeath_signal = sig;
1646 break;
1647 case PR_GET_PDEATHSIG:
1648 error = put_user(current->pdeath_signal, (int __user *)arg2);
1649 break;
1650 case PR_GET_DUMPABLE:
1651 if (current->mm->dumpable)
1652 error = 1;
1653 break;
1654 case PR_SET_DUMPABLE:
1655 if (arg2 != 0 && arg2 != 1) {
1656 error = -EINVAL;
1657 break;
1658 }
1659 current->mm->dumpable = arg2;
1660 break;
1661
1662 case PR_SET_UNALIGN:
1663 error = SET_UNALIGN_CTL(current, arg2);
1664 break;
1665 case PR_GET_UNALIGN:
1666 error = GET_UNALIGN_CTL(current, arg2);
1667 break;
1668 case PR_SET_FPEMU:
1669 error = SET_FPEMU_CTL(current, arg2);
1670 break;
1671 case PR_GET_FPEMU:
1672 error = GET_FPEMU_CTL(current, arg2);
1673 break;
1674 case PR_SET_FPEXC:
1675 error = SET_FPEXC_CTL(current, arg2);
1676 break;
1677 case PR_GET_FPEXC:
1678 error = GET_FPEXC_CTL(current, arg2);
1679 break;
1680 case PR_GET_TIMING:
1681 error = PR_TIMING_STATISTICAL;
1682 break;
1683 case PR_SET_TIMING:
1684 if (arg2 == PR_TIMING_STATISTICAL)
1685 error = 0;
1686 else
1687 error = -EINVAL;
1688 break;
1689
1690 case PR_GET_KEEPCAPS:
1691 if (current->keep_capabilities)
1692 error = 1;
1693 break;
1694 case PR_SET_KEEPCAPS:
1695 if (arg2 != 0 && arg2 != 1) {
1696 error = -EINVAL;
1697 break;
1698 }
1699 current->keep_capabilities = arg2;
1700 break;
1701 case PR_SET_NAME: {
1702 struct task_struct *me = current;
1703 unsigned char ncomm[sizeof(me->comm)];
1704
1705 ncomm[sizeof(me->comm)-1] = 0;
1706 if (strncpy_from_user(ncomm, (char __user *)arg2,
1707 sizeof(me->comm)-1) < 0)
1708 return -EFAULT;
1709 set_task_comm(me, ncomm);
1710 return 0;
1711 }
1712 case PR_GET_NAME: {
1713 struct task_struct *me = current;
1714 unsigned char tcomm[sizeof(me->comm)];
1715
1716 get_task_comm(tcomm, me);
1717 if (copy_to_user((char __user *)arg2, tcomm, sizeof(tcomm)))
1718 return -EFAULT;
1719 return 0;
1720 }
1721 default:
1722 error = -EINVAL;
1723 break;
1724 }
1725 return error;
1726 }
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree