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initial commit with v2.6.9
[linux-2.6.9-moxart.git] / kernel / sys.c
blob571bba8c8989daf522b8744763092055a9b63a4a
1 /*
2 * linux/kernel/sys.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 */
6
7 #include <linux/config.h>
8 #include <linux/compat.h>
9 #include <linux/module.h>
10 #include <linux/mm.h>
11 #include <linux/utsname.h>
12 #include <linux/mman.h>
13 #include <linux/smp_lock.h>
14 #include <linux/notifier.h>
15 #include <linux/reboot.h>
16 #include <linux/prctl.h>
17 #include <linux/init.h>
18 #include <linux/highuid.h>
19 #include <linux/fs.h>
20 #include <linux/workqueue.h>
21 #include <linux/device.h>
22 #include <linux/times.h>
23 #include <linux/security.h>
24 #include <linux/dcookies.h>
25 #include <linux/suspend.h>
26
27 #include <asm/uaccess.h>
28 #include <asm/io.h>
29 #include <asm/unistd.h>
30
31 #ifndef SET_UNALIGN_CTL
32 # define SET_UNALIGN_CTL(a,b) (-EINVAL)
33 #endif
34 #ifndef GET_UNALIGN_CTL
35 # define GET_UNALIGN_CTL(a,b) (-EINVAL)
36 #endif
37 #ifndef SET_FPEMU_CTL
38 # define SET_FPEMU_CTL(a,b) (-EINVAL)
39 #endif
40 #ifndef GET_FPEMU_CTL
41 # define GET_FPEMU_CTL(a,b) (-EINVAL)
42 #endif
43 #ifndef SET_FPEXC_CTL
44 # define SET_FPEXC_CTL(a,b) (-EINVAL)
45 #endif
46 #ifndef GET_FPEXC_CTL
47 # define GET_FPEXC_CTL(a,b) (-EINVAL)
48 #endif
49
50 /*
51 * this is where the system-wide overflow UID and GID are defined, for
52 * architectures that now have 32-bit UID/GID but didn't in the past
53 */
54
55 int overflowuid = DEFAULT_OVERFLOWUID;
56 int overflowgid = DEFAULT_OVERFLOWGID;
57
58 #ifdef CONFIG_UID16
59 EXPORT_SYMBOL(overflowuid);
60 EXPORT_SYMBOL(overflowgid);
61 #endif
62
63 /*
64 * the same as above, but for filesystems which can only store a 16-bit
65 * UID and GID. as such, this is needed on all architectures
66 */
67
68 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
69 int fs_overflowgid = DEFAULT_FS_OVERFLOWUID;
70
71 EXPORT_SYMBOL(fs_overflowuid);
72 EXPORT_SYMBOL(fs_overflowgid);
73
74 /*
75 * this indicates whether you can reboot with ctrl-alt-del: the default is yes
76 */
77
78 int C_A_D = 1;
79 int cad_pid = 1;
80
81 /*
82 * Notifier list for kernel code which wants to be called
83 * at shutdown. This is used to stop any idling DMA operations
84 * and the like.
85 */
86
87 static struct notifier_block *reboot_notifier_list;
88 rwlock_t notifier_lock = RW_LOCK_UNLOCKED;
89
90 /**
91 * notifier_chain_register - Add notifier to a notifier chain
92 * @list: Pointer to root list pointer
93 * @n: New entry in notifier chain
94 *
95 * Adds a notifier to a notifier chain.
96 *
97 * Currently always returns zero.
98 */
99
100 int notifier_chain_register(struct notifier_block **list, struct notifier_block *n)
101 {
102 write_lock(&notifier_lock);
103 while(*list)
104 {
105 if(n->priority > (*list)->priority)
106 break;
107 list= &((*list)->next);
108 }
109 n->next = *list;
110 *list=n;
111 write_unlock(&notifier_lock);
112 return 0;
113 }
114
115 EXPORT_SYMBOL(notifier_chain_register);
116
117 /**
118 * notifier_chain_unregister - Remove notifier from a notifier chain
119 * @nl: Pointer to root list pointer
120 * @n: New entry in notifier chain
121 *
122 * Removes a notifier from a notifier chain.
123 *
124 * Returns zero on success, or %-ENOENT on failure.
125 */
126
127 int notifier_chain_unregister(struct notifier_block **nl, struct notifier_block *n)
128 {
129 write_lock(&notifier_lock);
130 while((*nl)!=NULL)
131 {
132 if((*nl)==n)
133 {
134 *nl=n->next;
135 write_unlock(&notifier_lock);
136 return 0;
137 }
138 nl=&((*nl)->next);
139 }
140 write_unlock(&notifier_lock);
141 return -ENOENT;
142 }
143
144 EXPORT_SYMBOL(notifier_chain_unregister);
145
146 /**
147 * notifier_call_chain - Call functions in a notifier chain
148 * @n: Pointer to root pointer of notifier chain
149 * @val: Value passed unmodified to notifier function
150 * @v: Pointer passed unmodified to notifier function
151 *
152 * Calls each function in a notifier chain in turn.
153 *
154 * If the return value of the notifier can be and'd
155 * with %NOTIFY_STOP_MASK, then notifier_call_chain
156 * will return immediately, with the return value of
157 * the notifier function which halted execution.
158 * Otherwise, the return value is the return value
159 * of the last notifier function called.
160 */
161
162 int notifier_call_chain(struct notifier_block **n, unsigned long val, void *v)
163 {
164 int ret=NOTIFY_DONE;
165 struct notifier_block *nb = *n;
166
167 while(nb)
168 {
169 ret=nb->notifier_call(nb,val,v);
170 if(ret&NOTIFY_STOP_MASK)
171 {
172 return ret;
173 }
174 nb=nb->next;
175 }
176 return ret;
177 }
178
179 EXPORT_SYMBOL(notifier_call_chain);
180
181 /**
182 * register_reboot_notifier - Register function to be called at reboot time
183 * @nb: Info about notifier function to be called
184 *
185 * Registers a function with the list of functions
186 * to be called at reboot time.
187 *
188 * Currently always returns zero, as notifier_chain_register
189 * always returns zero.
190 */
191
192 int register_reboot_notifier(struct notifier_block * nb)
193 {
194 return notifier_chain_register(&reboot_notifier_list, nb);
195 }
196
197 EXPORT_SYMBOL(register_reboot_notifier);
198
199 /**
200 * unregister_reboot_notifier - Unregister previously registered reboot notifier
201 * @nb: Hook to be unregistered
202 *
203 * Unregisters a previously registered reboot
204 * notifier function.
205 *
206 * Returns zero on success, or %-ENOENT on failure.
207 */
208
209 int unregister_reboot_notifier(struct notifier_block * nb)
210 {
211 return notifier_chain_unregister(&reboot_notifier_list, nb);
212 }
213
214 EXPORT_SYMBOL(unregister_reboot_notifier);
215
216 asmlinkage long sys_ni_syscall(void)
217 {
218 return -ENOSYS;
219 }
220
221 cond_syscall(sys_nfsservctl)
222 cond_syscall(sys_quotactl)
223 cond_syscall(sys_acct)
224 cond_syscall(sys_lookup_dcookie)
225 cond_syscall(sys_swapon)
226 cond_syscall(sys_swapoff)
227 cond_syscall(sys_init_module)
228 cond_syscall(sys_delete_module)
229 cond_syscall(sys_socketpair)
230 cond_syscall(sys_bind)
231 cond_syscall(sys_listen)
232 cond_syscall(sys_accept)
233 cond_syscall(sys_connect)
234 cond_syscall(sys_getsockname)
235 cond_syscall(sys_getpeername)
236 cond_syscall(sys_sendto)
237 cond_syscall(sys_send)
238 cond_syscall(sys_recvfrom)
239 cond_syscall(sys_recv)
240 cond_syscall(sys_socket)
241 cond_syscall(sys_setsockopt)
242 cond_syscall(sys_getsockopt)
243 cond_syscall(sys_shutdown)
244 cond_syscall(sys_sendmsg)
245 cond_syscall(sys_recvmsg)
246 cond_syscall(sys_socketcall)
247 cond_syscall(sys_futex)
248 cond_syscall(compat_sys_futex)
249 cond_syscall(sys_epoll_create)
250 cond_syscall(sys_epoll_ctl)
251 cond_syscall(sys_epoll_wait)
252 cond_syscall(sys_semget)
253 cond_syscall(sys_semop)
254 cond_syscall(sys_semtimedop)
255 cond_syscall(sys_semctl)
256 cond_syscall(sys_msgget)
257 cond_syscall(sys_msgsnd)
258 cond_syscall(sys_msgrcv)
259 cond_syscall(sys_msgctl)
260 cond_syscall(sys_shmget)
261 cond_syscall(sys_shmdt)
262 cond_syscall(sys_shmctl)
263 cond_syscall(sys_mq_open)
264 cond_syscall(sys_mq_unlink)
265 cond_syscall(sys_mq_timedsend)
266 cond_syscall(sys_mq_timedreceive)
267 cond_syscall(sys_mq_notify)
268 cond_syscall(sys_mq_getsetattr)
269 cond_syscall(compat_sys_mq_open)
270 cond_syscall(compat_sys_mq_timedsend)
271 cond_syscall(compat_sys_mq_timedreceive)
272 cond_syscall(compat_sys_mq_notify)
273 cond_syscall(compat_sys_mq_getsetattr)
274 cond_syscall(sys_mbind)
275 cond_syscall(sys_get_mempolicy)
276 cond_syscall(sys_set_mempolicy)
277 cond_syscall(compat_mbind)
278 cond_syscall(compat_get_mempolicy)
279 cond_syscall(compat_set_mempolicy)
280
281 /* arch-specific weak syscall entries */
282 cond_syscall(sys_pciconfig_read)
283 cond_syscall(sys_pciconfig_write)
284 cond_syscall(sys_pciconfig_iobase)
285
286 static int set_one_prio(struct task_struct *p, int niceval, int error)
287 {
288 int no_nice;
289
290 if (p->uid != current->euid &&
291 p->uid != current->uid && !capable(CAP_SYS_NICE)) {
292 error = -EPERM;
293 goto out;
294 }
295 if (niceval < task_nice(p) && !capable(CAP_SYS_NICE)) {
296 error = -EACCES;
297 goto out;
298 }
299 no_nice = security_task_setnice(p, niceval);
300 if (no_nice) {
301 error = no_nice;
302 goto out;
303 }
304 if (error == -ESRCH)
305 error = 0;
306 set_user_nice(p, niceval);
307 out:
308 return error;
309 }
310
311 asmlinkage long sys_setpriority(int which, int who, int niceval)
312 {
313 struct task_struct *g, *p;
314 struct user_struct *user;
315 int error = -EINVAL;
316
317 if (which > 2 || which < 0)
318 goto out;
319
320 /* normalize: avoid signed division (rounding problems) */
321 error = -ESRCH;
322 if (niceval < -20)
323 niceval = -20;
324 if (niceval > 19)
325 niceval = 19;
326
327 read_lock(&tasklist_lock);
328 switch (which) {
329 case PRIO_PROCESS:
330 if (!who)
331 who = current->pid;
332 p = find_task_by_pid(who);
333 if (p)
334 error = set_one_prio(p, niceval, error);
335 break;
336 case PRIO_PGRP:
337 if (!who)
338 who = process_group(current);
339 do_each_task_pid(who, PIDTYPE_PGID, p) {
340 error = set_one_prio(p, niceval, error);
341 } while_each_task_pid(who, PIDTYPE_PGID, p);
342 break;
343 case PRIO_USER:
344 if (!who)
345 user = current->user;
346 else
347 user = find_user(who);
348
349 if (!user)
350 goto out_unlock;
351
352 do_each_thread(g, p)
353 if (p->uid == who)
354 error = set_one_prio(p, niceval, error);
355 while_each_thread(g, p);
356 if (who)
357 free_uid(user); /* For find_user() */
358 break;
359 }
360 out_unlock:
361 read_unlock(&tasklist_lock);
362 out:
363 return error;
364 }
365
366 /*
367 * Ugh. To avoid negative return values, "getpriority()" will
368 * not return the normal nice-value, but a negated value that
369 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
370 * to stay compatible.
371 */
372 asmlinkage long sys_getpriority(int which, int who)
373 {
374 struct task_struct *g, *p;
375 struct user_struct *user;
376 long niceval, retval = -ESRCH;
377
378 if (which > 2 || which < 0)
379 return -EINVAL;
380
381 read_lock(&tasklist_lock);
382 switch (which) {
383 case PRIO_PROCESS:
384 if (!who)
385 who = current->pid;
386 p = find_task_by_pid(who);
387 if (p) {
388 niceval = 20 - task_nice(p);
389 if (niceval > retval)
390 retval = niceval;
391 }
392 break;
393 case PRIO_PGRP:
394 if (!who)
395 who = process_group(current);
396 do_each_task_pid(who, PIDTYPE_PGID, p) {
397 niceval = 20 - task_nice(p);
398 if (niceval > retval)
399 retval = niceval;
400 } while_each_task_pid(who, PIDTYPE_PGID, p);
401 break;
402 case PRIO_USER:
403 if (!who)
404 user = current->user;
405 else
406 user = find_user(who);
407
408 if (!user)
409 goto out_unlock;
410
411 do_each_thread(g, p)
412 if (p->uid == who) {
413 niceval = 20 - task_nice(p);
414 if (niceval > retval)
415 retval = niceval;
416 }
417 while_each_thread(g, p);
418 if (who)
419 free_uid(user); /* for find_user() */
420 break;
421 }
422 out_unlock:
423 read_unlock(&tasklist_lock);
424
425 return retval;
426 }
427
428
429 /*
430 * Reboot system call: for obvious reasons only root may call it,
431 * and even root needs to set up some magic numbers in the registers
432 * so that some mistake won't make this reboot the whole machine.
433 * You can also set the meaning of the ctrl-alt-del-key here.
434 *
435 * reboot doesn't sync: do that yourself before calling this.
436 */
437 asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user * arg)
438 {
439 char buffer[256];
440
441 /* We only trust the superuser with rebooting the system. */
442 if (!capable(CAP_SYS_BOOT))
443 return -EPERM;
444
445 /* For safety, we require "magic" arguments. */
446 if (magic1 != LINUX_REBOOT_MAGIC1 ||
447 (magic2 != LINUX_REBOOT_MAGIC2 &&
448 magic2 != LINUX_REBOOT_MAGIC2A &&
449 magic2 != LINUX_REBOOT_MAGIC2B &&
450 magic2 != LINUX_REBOOT_MAGIC2C))
451 return -EINVAL;
452
453 lock_kernel();
454 switch (cmd) {
455 case LINUX_REBOOT_CMD_RESTART:
456 notifier_call_chain(&reboot_notifier_list, SYS_RESTART, NULL);
457 system_state = SYSTEM_RESTART;
458 device_shutdown();
459 printk(KERN_EMERG "Restarting system.\n");
460 machine_restart(NULL);
461 break;
462
463 case LINUX_REBOOT_CMD_CAD_ON:
464 C_A_D = 1;
465 break;
466
467 case LINUX_REBOOT_CMD_CAD_OFF:
468 C_A_D = 0;
469 break;
470
471 case LINUX_REBOOT_CMD_HALT:
472 notifier_call_chain(&reboot_notifier_list, SYS_HALT, NULL);
473 system_state = SYSTEM_HALT;
474 device_shutdown();
475 printk(KERN_EMERG "System halted.\n");
476 machine_halt();
477 unlock_kernel();
478 do_exit(0);
479 break;
480
481 case LINUX_REBOOT_CMD_POWER_OFF:
482 notifier_call_chain(&reboot_notifier_list, SYS_POWER_OFF, NULL);
483 system_state = SYSTEM_POWER_OFF;
484 device_shutdown();
485 printk(KERN_EMERG "Power down.\n");
486 machine_power_off();
487 unlock_kernel();
488 do_exit(0);
489 break;
490
491 case LINUX_REBOOT_CMD_RESTART2:
492 if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) {
493 unlock_kernel();
494 return -EFAULT;
495 }
496 buffer[sizeof(buffer) - 1] = '\0';
497
498 notifier_call_chain(&reboot_notifier_list, SYS_RESTART, buffer);
499 system_state = SYSTEM_RESTART;
500 device_shutdown();
501 printk(KERN_EMERG "Restarting system with command '%s'.\n", buffer);
502 machine_restart(buffer);
503 break;
504
505 #ifdef CONFIG_SOFTWARE_SUSPEND
506 case LINUX_REBOOT_CMD_SW_SUSPEND:
507 {
508 int ret = software_suspend();
509 unlock_kernel();
510 return ret;
511 }
512 #endif
513
514 default:
515 unlock_kernel();
516 return -EINVAL;
517 }
518 unlock_kernel();
519 return 0;
520 }
521
522 static void deferred_cad(void *dummy)
523 {
524 notifier_call_chain(&reboot_notifier_list, SYS_RESTART, NULL);
525 machine_restart(NULL);
526 }
527
528 /*
529 * This function gets called by ctrl-alt-del - ie the keyboard interrupt.
530 * As it's called within an interrupt, it may NOT sync: the only choice
531 * is whether to reboot at once, or just ignore the ctrl-alt-del.
532 */
533 void ctrl_alt_del(void)
534 {
535 static DECLARE_WORK(cad_work, deferred_cad, NULL);
536
537 if (C_A_D)
538 schedule_work(&cad_work);
539 else
540 kill_proc(cad_pid, SIGINT, 1);
541 }
542
543
544 /*
545 * Unprivileged users may change the real gid to the effective gid
546 * or vice versa. (BSD-style)
547 *
548 * If you set the real gid at all, or set the effective gid to a value not
549 * equal to the real gid, then the saved gid is set to the new effective gid.
550 *
551 * This makes it possible for a setgid program to completely drop its
552 * privileges, which is often a useful assertion to make when you are doing
553 * a security audit over a program.
554 *
555 * The general idea is that a program which uses just setregid() will be
556 * 100% compatible with BSD. A program which uses just setgid() will be
557 * 100% compatible with POSIX with saved IDs.
558 *
559 * SMP: There are not races, the GIDs are checked only by filesystem
560 * operations (as far as semantic preservation is concerned).
561 */
562 asmlinkage long sys_setregid(gid_t rgid, gid_t egid)
563 {
564 int old_rgid = current->gid;
565 int old_egid = current->egid;
566 int new_rgid = old_rgid;
567 int new_egid = old_egid;
568 int retval;
569
570 retval = security_task_setgid(rgid, egid, (gid_t)-1, LSM_SETID_RE);
571 if (retval)
572 return retval;
573
574 if (rgid != (gid_t) -1) {
575 if ((old_rgid == rgid) ||
576 (current->egid==rgid) ||
577 capable(CAP_SETGID))
578 new_rgid = rgid;
579 else
580 return -EPERM;
581 }
582 if (egid != (gid_t) -1) {
583 if ((old_rgid == egid) ||
584 (current->egid == egid) ||
585 (current->sgid == egid) ||
586 capable(CAP_SETGID))
587 new_egid = egid;
588 else {
589 return -EPERM;
590 }
591 }
592 if (new_egid != old_egid)
593 {
594 current->mm->dumpable = 0;
595 wmb();
596 }
597 if (rgid != (gid_t) -1 ||
598 (egid != (gid_t) -1 && egid != old_rgid))
599 current->sgid = new_egid;
600 current->fsgid = new_egid;
601 current->egid = new_egid;
602 current->gid = new_rgid;
603 return 0;
604 }
605
606 /*
607 * setgid() is implemented like SysV w/ SAVED_IDS
608 *
609 * SMP: Same implicit races as above.
610 */
611 asmlinkage long sys_setgid(gid_t gid)
612 {
613 int old_egid = current->egid;
614 int retval;
615
616 retval = security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID);
617 if (retval)
618 return retval;
619
620 if (capable(CAP_SETGID))
621 {
622 if(old_egid != gid)
623 {
624 current->mm->dumpable=0;
625 wmb();
626 }
627 current->gid = current->egid = current->sgid = current->fsgid = gid;
628 }
629 else if ((gid == current->gid) || (gid == current->sgid))
630 {
631 if(old_egid != gid)
632 {
633 current->mm->dumpable=0;
634 wmb();
635 }
636 current->egid = current->fsgid = gid;
637 }
638 else
639 return -EPERM;
640 return 0;
641 }
642
643 static int set_user(uid_t new_ruid, int dumpclear)
644 {
645 struct user_struct *new_user;
646
647 new_user = alloc_uid(new_ruid);
648 if (!new_user)
649 return -EAGAIN;
650
651 if (atomic_read(&new_user->processes) >=
652 current->rlim[RLIMIT_NPROC].rlim_cur &&
653 new_user != &root_user) {
654 free_uid(new_user);
655 return -EAGAIN;
656 }
657
658 switch_uid(new_user);
659
660 if(dumpclear)
661 {
662 current->mm->dumpable = 0;
663 wmb();
664 }
665 current->uid = new_ruid;
666 return 0;
667 }
668
669 /*
670 * Unprivileged users may change the real uid to the effective uid
671 * or vice versa. (BSD-style)
672 *
673 * If you set the real uid at all, or set the effective uid to a value not
674 * equal to the real uid, then the saved uid is set to the new effective uid.
675 *
676 * This makes it possible for a setuid program to completely drop its
677 * privileges, which is often a useful assertion to make when you are doing
678 * a security audit over a program.
679 *
680 * The general idea is that a program which uses just setreuid() will be
681 * 100% compatible with BSD. A program which uses just setuid() will be
682 * 100% compatible with POSIX with saved IDs.
683 */
684 asmlinkage long sys_setreuid(uid_t ruid, uid_t euid)
685 {
686 int old_ruid, old_euid, old_suid, new_ruid, new_euid;
687 int retval;
688
689 retval = security_task_setuid(ruid, euid, (uid_t)-1, LSM_SETID_RE);
690 if (retval)
691 return retval;
692
693 new_ruid = old_ruid = current->uid;
694 new_euid = old_euid = current->euid;
695 old_suid = current->suid;
696
697 if (ruid != (uid_t) -1) {
698 new_ruid = ruid;
699 if ((old_ruid != ruid) &&
700 (current->euid != ruid) &&
701 !capable(CAP_SETUID))
702 return -EPERM;
703 }
704
705 if (euid != (uid_t) -1) {
706 new_euid = euid;
707 if ((old_ruid != euid) &&
708 (current->euid != euid) &&
709 (current->suid != euid) &&
710 !capable(CAP_SETUID))
711 return -EPERM;
712 }
713
714 if (new_ruid != old_ruid && set_user(new_ruid, new_euid != old_euid) < 0)
715 return -EAGAIN;
716
717 if (new_euid != old_euid)
718 {
719 current->mm->dumpable=0;
720 wmb();
721 }
722 current->fsuid = current->euid = new_euid;
723 if (ruid != (uid_t) -1 ||
724 (euid != (uid_t) -1 && euid != old_ruid))
725 current->suid = current->euid;
726 current->fsuid = current->euid;
727
728 return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RE);
729 }
730
731
732
733 /*
734 * setuid() is implemented like SysV with SAVED_IDS
735 *
736 * Note that SAVED_ID's is deficient in that a setuid root program
737 * like sendmail, for example, cannot set its uid to be a normal
738 * user and then switch back, because if you're root, setuid() sets
739 * the saved uid too. If you don't like this, blame the bright people
740 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
741 * will allow a root program to temporarily drop privileges and be able to
742 * regain them by swapping the real and effective uid.
743 */
744 asmlinkage long sys_setuid(uid_t uid)
745 {
746 int old_euid = current->euid;
747 int old_ruid, old_suid, new_ruid, new_suid;
748 int retval;
749
750 retval = security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_ID);
751 if (retval)
752 return retval;
753
754 old_ruid = new_ruid = current->uid;
755 old_suid = current->suid;
756 new_suid = old_suid;
757
758 if (capable(CAP_SETUID)) {
759 if (uid != old_ruid && set_user(uid, old_euid != uid) < 0)
760 return -EAGAIN;
761 new_suid = uid;
762 } else if ((uid != current->uid) && (uid != new_suid))
763 return -EPERM;
764
765 if (old_euid != uid)
766 {
767 current->mm->dumpable = 0;
768 wmb();
769 }
770 current->fsuid = current->euid = uid;
771 current->suid = new_suid;
772
773 return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_ID);
774 }
775
776
777 /*
778 * This function implements a generic ability to update ruid, euid,
779 * and suid. This allows you to implement the 4.4 compatible seteuid().
780 */
781 asmlinkage long sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
782 {
783 int old_ruid = current->uid;
784 int old_euid = current->euid;
785 int old_suid = current->suid;
786 int retval;
787
788 retval = security_task_setuid(ruid, euid, suid, LSM_SETID_RES);
789 if (retval)
790 return retval;
791
792 if (!capable(CAP_SETUID)) {
793 if ((ruid != (uid_t) -1) && (ruid != current->uid) &&
794 (ruid != current->euid) && (ruid != current->suid))
795 return -EPERM;
796 if ((euid != (uid_t) -1) && (euid != current->uid) &&
797 (euid != current->euid) && (euid != current->suid))
798 return -EPERM;
799 if ((suid != (uid_t) -1) && (suid != current->uid) &&
800 (suid != current->euid) && (suid != current->suid))
801 return -EPERM;
802 }
803 if (ruid != (uid_t) -1) {
804 if (ruid != current->uid && set_user(ruid, euid != current->euid) < 0)
805 return -EAGAIN;
806 }
807 if (euid != (uid_t) -1) {
808 if (euid != current->euid)
809 {
810 current->mm->dumpable = 0;
811 wmb();
812 }
813 current->euid = euid;
814 }
815 current->fsuid = current->euid;
816 if (suid != (uid_t) -1)
817 current->suid = suid;
818
819 return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RES);
820 }
821
822 asmlinkage long sys_getresuid(uid_t __user *ruid, uid_t __user *euid, uid_t __user *suid)
823 {
824 int retval;
825
826 if (!(retval = put_user(current->uid, ruid)) &&
827 !(retval = put_user(current->euid, euid)))
828 retval = put_user(current->suid, suid);
829
830 return retval;
831 }
832
833 /*
834 * Same as above, but for rgid, egid, sgid.
835 */
836 asmlinkage long sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
837 {
838 int retval;
839
840 retval = security_task_setgid(rgid, egid, sgid, LSM_SETID_RES);
841 if (retval)
842 return retval;
843
844 if (!capable(CAP_SETGID)) {
845 if ((rgid != (gid_t) -1) && (rgid != current->gid) &&
846 (rgid != current->egid) && (rgid != current->sgid))
847 return -EPERM;
848 if ((egid != (gid_t) -1) && (egid != current->gid) &&
849 (egid != current->egid) && (egid != current->sgid))
850 return -EPERM;
851 if ((sgid != (gid_t) -1) && (sgid != current->gid) &&
852 (sgid != current->egid) && (sgid != current->sgid))
853 return -EPERM;
854 }
855 if (egid != (gid_t) -1) {
856 if (egid != current->egid)
857 {
858 current->mm->dumpable = 0;
859 wmb();
860 }
861 current->egid = egid;
862 }
863 current->fsgid = current->egid;
864 if (rgid != (gid_t) -1)
865 current->gid = rgid;
866 if (sgid != (gid_t) -1)
867 current->sgid = sgid;
868 return 0;
869 }
870
871 asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __user *sgid)
872 {
873 int retval;
874
875 if (!(retval = put_user(current->gid, rgid)) &&
876 !(retval = put_user(current->egid, egid)))
877 retval = put_user(current->sgid, sgid);
878
879 return retval;
880 }
881
882
883 /*
884 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
885 * is used for "access()" and for the NFS daemon (letting nfsd stay at
886 * whatever uid it wants to). It normally shadows "euid", except when
887 * explicitly set by setfsuid() or for access..
888 */
889 asmlinkage long sys_setfsuid(uid_t uid)
890 {
891 int old_fsuid;
892
893 old_fsuid = current->fsuid;
894 if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS))
895 return old_fsuid;
896
897 if (uid == current->uid || uid == current->euid ||
898 uid == current->suid || uid == current->fsuid ||
899 capable(CAP_SETUID))
900 {
901 if (uid != old_fsuid)
902 {
903 current->mm->dumpable = 0;
904 wmb();
905 }
906 current->fsuid = uid;
907 }
908
909 security_task_post_setuid(old_fsuid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS);
910
911 return old_fsuid;
912 }
913
914 /*
915 * Samma på svenska..
916 */
917 asmlinkage long sys_setfsgid(gid_t gid)
918 {
919 int old_fsgid;
920
921 old_fsgid = current->fsgid;
922 if (security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS))
923 return old_fsgid;
924
925 if (gid == current->gid || gid == current->egid ||
926 gid == current->sgid || gid == current->fsgid ||
927 capable(CAP_SETGID))
928 {
929 if (gid != old_fsgid)
930 {
931 current->mm->dumpable = 0;
932 wmb();
933 }
934 current->fsgid = gid;
935 }
936 return old_fsgid;
937 }
938
939 asmlinkage long sys_times(struct tms __user * tbuf)
940 {
941 /*
942 * In the SMP world we might just be unlucky and have one of
943 * the times increment as we use it. Since the value is an
944 * atomically safe type this is just fine. Conceptually its
945 * as if the syscall took an instant longer to occur.
946 */
947 if (tbuf) {
948 struct tms tmp;
949 struct task_struct *tsk = current;
950 struct task_struct *t;
951 unsigned long utime, stime, cutime, cstime;
952
953 read_lock(&tasklist_lock);
954 utime = tsk->signal->utime;
955 stime = tsk->signal->stime;
956 t = tsk;
957 do {
958 utime += t->utime;
959 stime += t->stime;
960 t = next_thread(t);
961 } while (t != tsk);
962
963 /*
964 * While we have tasklist_lock read-locked, no dying thread
965 * can be updating current->signal->[us]time. Instead,
966 * we got their counts included in the live thread loop.
967 * However, another thread can come in right now and
968 * do a wait call that updates current->signal->c[us]time.
969 * To make sure we always see that pair updated atomically,
970 * we take the siglock around fetching them.
971 */
972 spin_lock_irq(&tsk->sighand->siglock);
973 cutime = tsk->signal->cutime;
974 cstime = tsk->signal->cstime;
975 spin_unlock_irq(&tsk->sighand->siglock);
976 read_unlock(&tasklist_lock);
977
978 tmp.tms_utime = jiffies_to_clock_t(utime);
979 tmp.tms_stime = jiffies_to_clock_t(stime);
980 tmp.tms_cutime = jiffies_to_clock_t(cutime);
981 tmp.tms_cstime = jiffies_to_clock_t(cstime);
982 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
983 return -EFAULT;
984 }
985 return (long) jiffies_64_to_clock_t(get_jiffies_64());
986 }
987
988 /*
989 * This needs some heavy checking ...
990 * I just haven't the stomach for it. I also don't fully
991 * understand sessions/pgrp etc. Let somebody who does explain it.
992 *
993 * OK, I think I have the protection semantics right.... this is really
994 * only important on a multi-user system anyway, to make sure one user
995 * can't send a signal to a process owned by another. -TYT, 12/12/91
996 *
997 * Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
998 * LBT 04.03.94
999 */
1000
1001 asmlinkage long sys_setpgid(pid_t pid, pid_t pgid)
1002 {
1003 struct task_struct *p;
1004 int err = -EINVAL;
1005
1006 if (!pid)
1007 pid = current->pid;
1008 if (!pgid)
1009 pgid = pid;
1010 if (pgid < 0)
1011 return -EINVAL;
1012
1013 /* From this point forward we keep holding onto the tasklist lock
1014 * so that our parent does not change from under us. -DaveM
1015 */
1016 write_lock_irq(&tasklist_lock);
1017
1018 err = -ESRCH;
1019 p = find_task_by_pid(pid);
1020 if (!p)
1021 goto out;
1022
1023 err = -EINVAL;
1024 if (!thread_group_leader(p))
1025 goto out;
1026
1027 if (p->parent == current || p->real_parent == current) {
1028 err = -EPERM;
1029 if (p->signal->session != current->signal->session)
1030 goto out;
1031 err = -EACCES;
1032 if (p->did_exec)
1033 goto out;
1034 } else {
1035 err = -ESRCH;
1036 if (p != current)
1037 goto out;
1038 }
1039
1040 err = -EPERM;
1041 if (p->signal->leader)
1042 goto out;
1043
1044 if (pgid != pid) {
1045 struct task_struct *p;
1046
1047 do_each_task_pid(pgid, PIDTYPE_PGID, p) {
1048 if (p->signal->session == current->signal->session)
1049 goto ok_pgid;
1050 } while_each_task_pid(pgid, PIDTYPE_PGID, p);
1051 goto out;
1052 }
1053
1054 ok_pgid:
1055 err = security_task_setpgid(p, pgid);
1056 if (err)
1057 goto out;
1058
1059 if (process_group(p) != pgid) {
1060 detach_pid(p, PIDTYPE_PGID);
1061 p->signal->pgrp = pgid;
1062 attach_pid(p, PIDTYPE_PGID, pgid);
1063 }
1064
1065 err = 0;
1066 out:
1067 /* All paths lead to here, thus we are safe. -DaveM */
1068 write_unlock_irq(&tasklist_lock);
1069 return err;
1070 }
1071
1072 asmlinkage long sys_getpgid(pid_t pid)
1073 {
1074 if (!pid) {
1075 return process_group(current);
1076 } else {
1077 int retval;
1078 struct task_struct *p;
1079
1080 read_lock(&tasklist_lock);
1081 p = find_task_by_pid(pid);
1082
1083 retval = -ESRCH;
1084 if (p) {
1085 retval = security_task_getpgid(p);
1086 if (!retval)
1087 retval = process_group(p);
1088 }
1089 read_unlock(&tasklist_lock);
1090 return retval;
1091 }
1092 }
1093
1094 #ifdef __ARCH_WANT_SYS_GETPGRP
1095
1096 asmlinkage long sys_getpgrp(void)
1097 {
1098 /* SMP - assuming writes are word atomic this is fine */
1099 return process_group(current);
1100 }
1101
1102 #endif
1103
1104 asmlinkage long sys_getsid(pid_t pid)
1105 {
1106 if (!pid) {
1107 return current->signal->session;
1108 } else {
1109 int retval;
1110 struct task_struct *p;
1111
1112 read_lock(&tasklist_lock);
1113 p = find_task_by_pid(pid);
1114
1115 retval = -ESRCH;
1116 if(p) {
1117 retval = security_task_getsid(p);
1118 if (!retval)
1119 retval = p->signal->session;
1120 }
1121 read_unlock(&tasklist_lock);
1122 return retval;
1123 }
1124 }
1125
1126 asmlinkage long sys_setsid(void)
1127 {
1128 struct pid *pid;
1129 int err = -EPERM;
1130
1131 if (!thread_group_leader(current))
1132 return -EINVAL;
1133
1134 write_lock_irq(&tasklist_lock);
1135
1136 pid = find_pid(PIDTYPE_PGID, current->pid);
1137 if (pid)
1138 goto out;
1139
1140 current->signal->leader = 1;
1141 __set_special_pids(current->pid, current->pid);
1142 current->signal->tty = NULL;
1143 current->signal->tty_old_pgrp = 0;
1144 err = process_group(current);
1145 out:
1146 write_unlock_irq(&tasklist_lock);
1147 return err;
1148 }
1149
1150 /*
1151 * Supplementary group IDs
1152 */
1153
1154 /* init to 2 - one for init_task, one to ensure it is never freed */
1155 struct group_info init_groups = { .usage = ATOMIC_INIT(2) };
1156
1157 struct group_info *groups_alloc(int gidsetsize)
1158 {
1159 struct group_info *group_info;
1160 int nblocks;
1161 int i;
1162
1163 nblocks = (gidsetsize + NGROUPS_PER_BLOCK - 1) / NGROUPS_PER_BLOCK;
1164 /* Make sure we always allocate at least one indirect block pointer */
1165 nblocks = nblocks ? : 1;
1166 group_info = kmalloc(sizeof(*group_info) + nblocks*sizeof(gid_t *), GFP_USER);
1167 if (!group_info)
1168 return NULL;
1169 group_info->ngroups = gidsetsize;
1170 group_info->nblocks = nblocks;
1171 atomic_set(&group_info->usage, 1);
1172
1173 if (gidsetsize <= NGROUPS_SMALL) {
1174 group_info->blocks[0] = group_info->small_block;
1175 } else {
1176 for (i = 0; i < nblocks; i++) {
1177 gid_t *b;
1178 b = (void *)__get_free_page(GFP_USER);
1179 if (!b)
1180 goto out_undo_partial_alloc;
1181 group_info->blocks[i] = b;
1182 }
1183 }
1184 return group_info;
1185
1186 out_undo_partial_alloc:
1187 while (--i >= 0) {
1188 free_page((unsigned long)group_info->blocks[i]);
1189 }
1190 kfree(group_info);
1191 return NULL;
1192 }
1193
1194 EXPORT_SYMBOL(groups_alloc);
1195
1196 void groups_free(struct group_info *group_info)
1197 {
1198 if (group_info->blocks[0] != group_info->small_block) {
1199 int i;
1200 for (i = 0; i < group_info->nblocks; i++)
1201 free_page((unsigned long)group_info->blocks[i]);
1202 }
1203 kfree(group_info);
1204 }
1205
1206 EXPORT_SYMBOL(groups_free);
1207
1208 /* export the group_info to a user-space array */
1209 static int groups_to_user(gid_t __user *grouplist,
1210 struct group_info *group_info)
1211 {
1212 int i;
1213 int count = group_info->ngroups;
1214
1215 for (i = 0; i < group_info->nblocks; i++) {
1216 int cp_count = min(NGROUPS_PER_BLOCK, count);
1217 int off = i * NGROUPS_PER_BLOCK;
1218 int len = cp_count * sizeof(*grouplist);
1219
1220 if (copy_to_user(grouplist+off, group_info->blocks[i], len))
1221 return -EFAULT;
1222
1223 count -= cp_count;
1224 }
1225 return 0;
1226 }
1227
1228 /* fill a group_info from a user-space array - it must be allocated already */
1229 static int groups_from_user(struct group_info *group_info,
1230 gid_t __user *grouplist)
1231 {
1232 int i;
1233 int count = group_info->ngroups;
1234
1235 for (i = 0; i < group_info->nblocks; i++) {
1236 int cp_count = min(NGROUPS_PER_BLOCK, count);
1237 int off = i * NGROUPS_PER_BLOCK;
1238 int len = cp_count * sizeof(*grouplist);
1239
1240 if (copy_from_user(group_info->blocks[i], grouplist+off, len))
1241 return -EFAULT;
1242
1243 count -= cp_count;
1244 }
1245 return 0;
1246 }
1247
1248 /* a simple shell-metzner sort */
1249 static void groups_sort(struct group_info *group_info)
1250 {
1251 int base, max, stride;
1252 int gidsetsize = group_info->ngroups;
1253
1254 for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1)
1255 ; /* nothing */
1256 stride /= 3;
1257
1258 while (stride) {
1259 max = gidsetsize - stride;
1260 for (base = 0; base < max; base++) {
1261 int left = base;
1262 int right = left + stride;
1263 gid_t tmp = GROUP_AT(group_info, right);
1264
1265 while (left >= 0 && GROUP_AT(group_info, left) > tmp) {
1266 GROUP_AT(group_info, right) =
1267 GROUP_AT(group_info, left);
1268 right = left;
1269 left -= stride;
1270 }
1271 GROUP_AT(group_info, right) = tmp;
1272 }
1273 stride /= 3;
1274 }
1275 }
1276
1277 /* a simple bsearch */
1278 static int groups_search(struct group_info *group_info, gid_t grp)
1279 {
1280 int left, right;
1281
1282 if (!group_info)
1283 return 0;
1284
1285 left = 0;
1286 right = group_info->ngroups;
1287 while (left < right) {
1288 int mid = (left+right)/2;
1289 int cmp = grp - GROUP_AT(group_info, mid);
1290 if (cmp > 0)
1291 left = mid + 1;
1292 else if (cmp < 0)
1293 right = mid;
1294 else
1295 return 1;
1296 }
1297 return 0;
1298 }
1299
1300 /* validate and set current->group_info */
1301 int set_current_groups(struct group_info *group_info)
1302 {
1303 int retval;
1304 struct group_info *old_info;
1305
1306 retval = security_task_setgroups(group_info);
1307 if (retval)
1308 return retval;
1309
1310 groups_sort(group_info);
1311 get_group_info(group_info);
1312
1313 task_lock(current);
1314 old_info = current->group_info;
1315 current->group_info = group_info;
1316 task_unlock(current);
1317
1318 put_group_info(old_info);
1319
1320 return 0;
1321 }
1322
1323 EXPORT_SYMBOL(set_current_groups);
1324
1325 asmlinkage long sys_getgroups(int gidsetsize, gid_t __user *grouplist)
1326 {
1327 int i = 0;
1328
1329 /*
1330 * SMP: Nobody else can change our grouplist. Thus we are
1331 * safe.
1332 */
1333
1334 if (gidsetsize < 0)
1335 return -EINVAL;
1336
1337 /* no need to grab task_lock here; it cannot change */
1338 get_group_info(current->group_info);
1339 i = current->group_info->ngroups;
1340 if (gidsetsize) {
1341 if (i > gidsetsize) {
1342 i = -EINVAL;
1343 goto out;
1344 }
1345 if (groups_to_user(grouplist, current->group_info)) {
1346 i = -EFAULT;
1347 goto out;
1348 }
1349 }
1350 out:
1351 put_group_info(current->group_info);
1352 return i;
1353 }
1354
1355 /*
1356 * SMP: Our groups are copy-on-write. We can set them safely
1357 * without another task interfering.
1358 */
1359
1360 asmlinkage long sys_setgroups(int gidsetsize, gid_t __user *grouplist)
1361 {
1362 struct group_info *group_info;
1363 int retval;
1364
1365 if (!capable(CAP_SETGID))
1366 return -EPERM;
1367 if ((unsigned)gidsetsize > NGROUPS_MAX)
1368 return -EINVAL;
1369
1370 group_info = groups_alloc(gidsetsize);
1371 if (!group_info)
1372 return -ENOMEM;
1373 retval = groups_from_user(group_info, grouplist);
1374 if (retval) {
1375 put_group_info(group_info);
1376 return retval;
1377 }
1378
1379 retval = set_current_groups(group_info);
1380 put_group_info(group_info);
1381
1382 return retval;
1383 }
1384
1385 /*
1386 * Check whether we're fsgid/egid or in the supplemental group..
1387 */
1388 int in_group_p(gid_t grp)
1389 {
1390 int retval = 1;
1391 if (grp != current->fsgid) {
1392 get_group_info(current->group_info);
1393 retval = groups_search(current->group_info, grp);
1394 put_group_info(current->group_info);
1395 }
1396 return retval;
1397 }
1398
1399 EXPORT_SYMBOL(in_group_p);
1400
1401 int in_egroup_p(gid_t grp)
1402 {
1403 int retval = 1;
1404 if (grp != current->egid) {
1405 get_group_info(current->group_info);
1406 retval = groups_search(current->group_info, grp);
1407 put_group_info(current->group_info);
1408 }
1409 return retval;
1410 }
1411
1412 EXPORT_SYMBOL(in_egroup_p);
1413
1414 DECLARE_RWSEM(uts_sem);
1415
1416 EXPORT_SYMBOL(uts_sem);
1417
1418 asmlinkage long sys_newuname(struct new_utsname __user * name)
1419 {
1420 int errno = 0;
1421
1422 down_read(&uts_sem);
1423 if (copy_to_user(name,&system_utsname,sizeof *name))
1424 errno = -EFAULT;
1425 up_read(&uts_sem);
1426 return errno;
1427 }
1428
1429 asmlinkage long sys_sethostname(char __user *name, int len)
1430 {
1431 int errno;
1432 char tmp[__NEW_UTS_LEN];
1433
1434 if (!capable(CAP_SYS_ADMIN))
1435 return -EPERM;
1436 if (len < 0 || len > __NEW_UTS_LEN)
1437 return -EINVAL;
1438 down_write(&uts_sem);
1439 errno = -EFAULT;
1440 if (!copy_from_user(tmp, name, len)) {
1441 memcpy(system_utsname.nodename, tmp, len);
1442 system_utsname.nodename[len] = 0;
1443 errno = 0;
1444 }
1445 up_write(&uts_sem);
1446 return errno;
1447 }
1448
1449 #ifdef __ARCH_WANT_SYS_GETHOSTNAME
1450
1451 asmlinkage long sys_gethostname(char __user *name, int len)
1452 {
1453 int i, errno;
1454
1455 if (len < 0)
1456 return -EINVAL;
1457 down_read(&uts_sem);
1458 i = 1 + strlen(system_utsname.nodename);
1459 if (i > len)
1460 i = len;
1461 errno = 0;
1462 if (copy_to_user(name, system_utsname.nodename, i))
1463 errno = -EFAULT;
1464 up_read(&uts_sem);
1465 return errno;
1466 }
1467
1468 #endif
1469
1470 /*
1471 * Only setdomainname; getdomainname can be implemented by calling
1472 * uname()
1473 */
1474 asmlinkage long sys_setdomainname(char __user *name, int len)
1475 {
1476 int errno;
1477 char tmp[__NEW_UTS_LEN];
1478
1479 if (!capable(CAP_SYS_ADMIN))
1480 return -EPERM;
1481 if (len < 0 || len > __NEW_UTS_LEN)
1482 return -EINVAL;
1483
1484 down_write(&uts_sem);
1485 errno = -EFAULT;
1486 if (!copy_from_user(tmp, name, len)) {
1487 memcpy(system_utsname.domainname, tmp, len);
1488 system_utsname.domainname[len] = 0;
1489 errno = 0;
1490 }
1491 up_write(&uts_sem);
1492 return errno;
1493 }
1494
1495 asmlinkage long sys_getrlimit(unsigned int resource, struct rlimit __user *rlim)
1496 {
1497 if (resource >= RLIM_NLIMITS)
1498 return -EINVAL;
1499 else
1500 return copy_to_user(rlim, current->rlim + resource, sizeof(*rlim))
1501 ? -EFAULT : 0;
1502 }
1503
1504 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1505
1506 /*
1507 * Back compatibility for getrlimit. Needed for some apps.
1508 */
1509
1510 asmlinkage long sys_old_getrlimit(unsigned int resource, struct rlimit __user *rlim)
1511 {
1512 struct rlimit x;
1513 if (resource >= RLIM_NLIMITS)
1514 return -EINVAL;
1515
1516 memcpy(&x, current->rlim + resource, sizeof(*rlim));
1517 if(x.rlim_cur > 0x7FFFFFFF)
1518 x.rlim_cur = 0x7FFFFFFF;
1519 if(x.rlim_max > 0x7FFFFFFF)
1520 x.rlim_max = 0x7FFFFFFF;
1521 return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0;
1522 }
1523
1524 #endif
1525
1526 asmlinkage long sys_setrlimit(unsigned int resource, struct rlimit __user *rlim)
1527 {
1528 struct rlimit new_rlim, *old_rlim;
1529 int retval;
1530
1531 if (resource >= RLIM_NLIMITS)
1532 return -EINVAL;
1533 if(copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1534 return -EFAULT;
1535 if (new_rlim.rlim_cur > new_rlim.rlim_max)
1536 return -EINVAL;
1537 old_rlim = current->rlim + resource;
1538 if (((new_rlim.rlim_cur > old_rlim->rlim_max) ||
1539 (new_rlim.rlim_max > old_rlim->rlim_max)) &&
1540 !capable(CAP_SYS_RESOURCE))
1541 return -EPERM;
1542 if (resource == RLIMIT_NOFILE) {
1543 if (new_rlim.rlim_cur > NR_OPEN || new_rlim.rlim_max > NR_OPEN)
1544 return -EPERM;
1545 }
1546
1547 retval = security_task_setrlimit(resource, &new_rlim);
1548 if (retval)
1549 return retval;
1550
1551 *old_rlim = new_rlim;
1552 return 0;
1553 }
1554
1555 /*
1556 * It would make sense to put struct rusage in the task_struct,
1557 * except that would make the task_struct be *really big*. After
1558 * task_struct gets moved into malloc'ed memory, it would
1559 * make sense to do this. It will make moving the rest of the information
1560 * a lot simpler! (Which we're not doing right now because we're not
1561 * measuring them yet).
1562 *
1563 * This expects to be called with tasklist_lock read-locked or better,
1564 * and the siglock not locked. It may momentarily take the siglock.
1565 *
1566 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1567 * races with threads incrementing their own counters. But since word
1568 * reads are atomic, we either get new values or old values and we don't
1569 * care which for the sums. We always take the siglock to protect reading
1570 * the c* fields from p->signal from races with exit.c updating those
1571 * fields when reaping, so a sample either gets all the additions of a
1572 * given child after it's reaped, or none so this sample is before reaping.
1573 */
1574
1575 void k_getrusage(struct task_struct *p, int who, struct rusage *r)
1576 {
1577 struct task_struct *t;
1578 unsigned long flags;
1579 unsigned long utime, stime;
1580
1581 memset((char *) r, 0, sizeof *r);
1582
1583 if (unlikely(!p->signal))
1584 return;
1585
1586 switch (who) {
1587 case RUSAGE_CHILDREN:
1588 spin_lock_irqsave(&p->sighand->siglock, flags);
1589 utime = p->signal->cutime;
1590 stime = p->signal->cstime;
1591 r->ru_nvcsw = p->signal->cnvcsw;
1592 r->ru_nivcsw = p->signal->cnivcsw;
1593 r->ru_minflt = p->signal->cmin_flt;
1594 r->ru_majflt = p->signal->cmaj_flt;
1595 spin_unlock_irqrestore(&p->sighand->siglock, flags);
1596 jiffies_to_timeval(utime, &r->ru_utime);
1597 jiffies_to_timeval(stime, &r->ru_stime);
1598 break;
1599 case RUSAGE_SELF:
1600 spin_lock_irqsave(&p->sighand->siglock, flags);
1601 utime = stime = 0;
1602 goto sum_group;
1603 case RUSAGE_BOTH:
1604 spin_lock_irqsave(&p->sighand->siglock, flags);
1605 utime = p->signal->cutime;
1606 stime = p->signal->cstime;
1607 r->ru_nvcsw = p->signal->cnvcsw;
1608 r->ru_nivcsw = p->signal->cnivcsw;
1609 r->ru_minflt = p->signal->cmin_flt;
1610 r->ru_majflt = p->signal->cmaj_flt;
1611 sum_group:
1612 utime += p->signal->utime;
1613 stime += p->signal->stime;
1614 r->ru_nvcsw += p->signal->nvcsw;
1615 r->ru_nivcsw += p->signal->nivcsw;
1616 r->ru_minflt += p->signal->min_flt;
1617 r->ru_majflt += p->signal->maj_flt;
1618 t = p;
1619 do {
1620 utime += t->utime;
1621 stime += t->stime;
1622 r->ru_nvcsw += t->nvcsw;
1623 r->ru_nivcsw += t->nivcsw;
1624 r->ru_minflt += t->min_flt;
1625 r->ru_majflt += t->maj_flt;
1626 t = next_thread(t);
1627 } while (t != p);
1628 spin_unlock_irqrestore(&p->sighand->siglock, flags);
1629 jiffies_to_timeval(utime, &r->ru_utime);
1630 jiffies_to_timeval(stime, &r->ru_stime);
1631 break;
1632 default:
1633 BUG();
1634 }
1635 }
1636
1637 int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
1638 {
1639 struct rusage r;
1640 read_lock(&tasklist_lock);
1641 k_getrusage(p, who, &r);
1642 read_unlock(&tasklist_lock);
1643 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1644 }
1645
1646 asmlinkage long sys_getrusage(int who, struct rusage __user *ru)
1647 {
1648 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN)
1649 return -EINVAL;
1650 return getrusage(current, who, ru);
1651 }
1652
1653 asmlinkage long sys_umask(int mask)
1654 {
1655 mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1656 return mask;
1657 }
1658
1659 asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3,
1660 unsigned long arg4, unsigned long arg5)
1661 {
1662 int error;
1663 int sig;
1664
1665 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
1666 if (error)
1667 return error;
1668
1669 switch (option) {
1670 case PR_SET_PDEATHSIG:
1671 sig = arg2;
1672 if (sig < 0 || sig > _NSIG) {
1673 error = -EINVAL;
1674 break;
1675 }
1676 current->pdeath_signal = sig;
1677 break;
1678 case PR_GET_PDEATHSIG:
1679 error = put_user(current->pdeath_signal, (int __user *)arg2);
1680 break;
1681 case PR_GET_DUMPABLE:
1682 if (current->mm->dumpable)
1683 error = 1;
1684 break;
1685 case PR_SET_DUMPABLE:
1686 if (arg2 != 0 && arg2 != 1) {
1687 error = -EINVAL;
1688 break;
1689 }
1690 current->mm->dumpable = arg2;
1691 break;
1692
1693 case PR_SET_UNALIGN:
1694 error = SET_UNALIGN_CTL(current, arg2);
1695 break;
1696 case PR_GET_UNALIGN:
1697 error = GET_UNALIGN_CTL(current, arg2);
1698 break;
1699 case PR_SET_FPEMU:
1700 error = SET_FPEMU_CTL(current, arg2);
1701 break;
1702 case PR_GET_FPEMU:
1703 error = GET_FPEMU_CTL(current, arg2);
1704 break;
1705 case PR_SET_FPEXC:
1706 error = SET_FPEXC_CTL(current, arg2);
1707 break;
1708 case PR_GET_FPEXC:
1709 error = GET_FPEXC_CTL(current, arg2);
1710 break;
1711 case PR_GET_TIMING:
1712 error = PR_TIMING_STATISTICAL;
1713 break;
1714 case PR_SET_TIMING:
1715 if (arg2 == PR_TIMING_STATISTICAL)
1716 error = 0;
1717 else
1718 error = -EINVAL;
1719 break;
1720
1721 case PR_GET_KEEPCAPS:
1722 if (current->keep_capabilities)
1723 error = 1;
1724 break;
1725 case PR_SET_KEEPCAPS:
1726 if (arg2 != 0 && arg2 != 1) {
1727 error = -EINVAL;
1728 break;
1729 }
1730 current->keep_capabilities = arg2;
1731 break;
1732 case PR_SET_NAME: {
1733 struct task_struct *me = current;
1734 unsigned char ncomm[sizeof(me->comm)];
1735
1736 ncomm[sizeof(me->comm)-1] = 0;
1737 if (strncpy_from_user(ncomm, (char __user *)arg2,
1738 sizeof(me->comm)-1) < 0)
1739 return -EFAULT;
1740 set_task_comm(me, ncomm);
1741 return 0;
1742 }
1743 default:
1744 error = -EINVAL;
1745 break;
1746 }
1747 return error;
1748 }
MOXA 2.6.9 from sdlinux-moxaart.tgz