4 * Copyright (C) 1991, 1992 Linus Torvalds
7 #include <linux/module.h>
9 #include <linux/utsname.h>
10 #include <linux/mman.h>
11 #include <linux/smp_lock.h>
12 #include <linux/notifier.h>
13 #include <linux/reboot.h>
14 #include <linux/prctl.h>
15 #include <linux/highuid.h>
17 #include <linux/resource.h>
18 #include <linux/kernel.h>
19 #include <linux/kexec.h>
20 #include <linux/workqueue.h>
21 #include <linux/capability.h>
22 #include <linux/device.h>
23 #include <linux/key.h>
24 #include <linux/times.h>
25 #include <linux/posix-timers.h>
26 #include <linux/security.h>
27 #include <linux/dcookies.h>
28 #include <linux/suspend.h>
29 #include <linux/tty.h>
30 #include <linux/signal.h>
31 #include <linux/cn_proc.h>
32 #include <linux/getcpu.h>
33 #include <linux/task_io_accounting_ops.h>
34 #include <linux/seccomp.h>
35 #include <linux/cpu.h>
37 #include <linux/compat.h>
38 #include <linux/syscalls.h>
39 #include <linux/kprobes.h>
40 #include <linux/user_namespace.h>
42 #include <asm/uaccess.h>
44 #include <asm/unistd.h>
46 #ifndef SET_UNALIGN_CTL
47 # define SET_UNALIGN_CTL(a,b) (-EINVAL)
49 #ifndef GET_UNALIGN_CTL
50 # define GET_UNALIGN_CTL(a,b) (-EINVAL)
53 # define SET_FPEMU_CTL(a,b) (-EINVAL)
56 # define GET_FPEMU_CTL(a,b) (-EINVAL)
59 # define SET_FPEXC_CTL(a,b) (-EINVAL)
62 # define GET_FPEXC_CTL(a,b) (-EINVAL)
65 # define GET_ENDIAN(a,b) (-EINVAL)
68 # define SET_ENDIAN(a,b) (-EINVAL)
71 # define GET_TSC_CTL(a) (-EINVAL)
74 # define SET_TSC_CTL(a) (-EINVAL)
78 * this is where the system-wide overflow UID and GID are defined, for
79 * architectures that now have 32-bit UID/GID but didn't in the past
82 int overflowuid
= DEFAULT_OVERFLOWUID
;
83 int overflowgid
= DEFAULT_OVERFLOWGID
;
86 EXPORT_SYMBOL(overflowuid
);
87 EXPORT_SYMBOL(overflowgid
);
91 * the same as above, but for filesystems which can only store a 16-bit
92 * UID and GID. as such, this is needed on all architectures
95 int fs_overflowuid
= DEFAULT_FS_OVERFLOWUID
;
96 int fs_overflowgid
= DEFAULT_FS_OVERFLOWUID
;
98 EXPORT_SYMBOL(fs_overflowuid
);
99 EXPORT_SYMBOL(fs_overflowgid
);
102 * this indicates whether you can reboot with ctrl-alt-del: the default is yes
107 EXPORT_SYMBOL(cad_pid
);
110 * If set, this is used for preparing the system to power off.
113 void (*pm_power_off_prepare
)(void);
115 static int set_one_prio(struct task_struct
*p
, int niceval
, int error
)
117 uid_t euid
= current_euid();
120 if (p
->cred
->uid
!= euid
&&
121 p
->cred
->euid
!= euid
&&
122 !capable(CAP_SYS_NICE
)) {
126 if (niceval
< task_nice(p
) && !can_nice(p
, niceval
)) {
130 no_nice
= security_task_setnice(p
, niceval
);
137 set_user_nice(p
, niceval
);
142 asmlinkage
long sys_setpriority(int which
, int who
, int niceval
)
144 struct task_struct
*g
, *p
;
145 struct user_struct
*user
;
146 const struct cred
*cred
= current_cred();
150 if (which
> PRIO_USER
|| which
< PRIO_PROCESS
)
153 /* normalize: avoid signed division (rounding problems) */
160 read_lock(&tasklist_lock
);
164 p
= find_task_by_vpid(who
);
168 error
= set_one_prio(p
, niceval
, error
);
172 pgrp
= find_vpid(who
);
174 pgrp
= task_pgrp(current
);
175 do_each_pid_thread(pgrp
, PIDTYPE_PGID
, p
) {
176 error
= set_one_prio(p
, niceval
, error
);
177 } while_each_pid_thread(pgrp
, PIDTYPE_PGID
, p
);
183 else if ((who
!= cred
->uid
) &&
184 !(user
= find_user(who
)))
185 goto out_unlock
; /* No processes for this user */
188 if (__task_cred(p
)->uid
== who
)
189 error
= set_one_prio(p
, niceval
, error
);
190 while_each_thread(g
, p
);
191 if (who
!= cred
->uid
)
192 free_uid(user
); /* For find_user() */
196 read_unlock(&tasklist_lock
);
202 * Ugh. To avoid negative return values, "getpriority()" will
203 * not return the normal nice-value, but a negated value that
204 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
205 * to stay compatible.
207 asmlinkage
long sys_getpriority(int which
, int who
)
209 struct task_struct
*g
, *p
;
210 struct user_struct
*user
;
211 const struct cred
*cred
= current_cred();
212 long niceval
, retval
= -ESRCH
;
215 if (which
> PRIO_USER
|| which
< PRIO_PROCESS
)
218 read_lock(&tasklist_lock
);
222 p
= find_task_by_vpid(who
);
226 niceval
= 20 - task_nice(p
);
227 if (niceval
> retval
)
233 pgrp
= find_vpid(who
);
235 pgrp
= task_pgrp(current
);
236 do_each_pid_thread(pgrp
, PIDTYPE_PGID
, p
) {
237 niceval
= 20 - task_nice(p
);
238 if (niceval
> retval
)
240 } while_each_pid_thread(pgrp
, PIDTYPE_PGID
, p
);
243 user
= (struct user_struct
*) cred
->user
;
246 else if ((who
!= cred
->uid
) &&
247 !(user
= find_user(who
)))
248 goto out_unlock
; /* No processes for this user */
251 if (__task_cred(p
)->uid
== who
) {
252 niceval
= 20 - task_nice(p
);
253 if (niceval
> retval
)
256 while_each_thread(g
, p
);
257 if (who
!= cred
->uid
)
258 free_uid(user
); /* for find_user() */
262 read_unlock(&tasklist_lock
);
268 * emergency_restart - reboot the system
270 * Without shutting down any hardware or taking any locks
271 * reboot the system. This is called when we know we are in
272 * trouble so this is our best effort to reboot. This is
273 * safe to call in interrupt context.
275 void emergency_restart(void)
277 machine_emergency_restart();
279 EXPORT_SYMBOL_GPL(emergency_restart
);
281 void kernel_restart_prepare(char *cmd
)
283 blocking_notifier_call_chain(&reboot_notifier_list
, SYS_RESTART
, cmd
);
284 system_state
= SYSTEM_RESTART
;
290 * kernel_restart - reboot the system
291 * @cmd: pointer to buffer containing command to execute for restart
294 * Shutdown everything and perform a clean reboot.
295 * This is not safe to call in interrupt context.
297 void kernel_restart(char *cmd
)
299 kernel_restart_prepare(cmd
);
301 printk(KERN_EMERG
"Restarting system.\n");
303 printk(KERN_EMERG
"Restarting system with command '%s'.\n", cmd
);
304 machine_restart(cmd
);
306 EXPORT_SYMBOL_GPL(kernel_restart
);
308 static void kernel_shutdown_prepare(enum system_states state
)
310 blocking_notifier_call_chain(&reboot_notifier_list
,
311 (state
== SYSTEM_HALT
)?SYS_HALT
:SYS_POWER_OFF
, NULL
);
312 system_state
= state
;
316 * kernel_halt - halt the system
318 * Shutdown everything and perform a clean system halt.
320 void kernel_halt(void)
322 kernel_shutdown_prepare(SYSTEM_HALT
);
324 printk(KERN_EMERG
"System halted.\n");
328 EXPORT_SYMBOL_GPL(kernel_halt
);
331 * kernel_power_off - power_off the system
333 * Shutdown everything and perform a clean system power_off.
335 void kernel_power_off(void)
337 kernel_shutdown_prepare(SYSTEM_POWER_OFF
);
338 if (pm_power_off_prepare
)
339 pm_power_off_prepare();
340 disable_nonboot_cpus();
342 printk(KERN_EMERG
"Power down.\n");
345 EXPORT_SYMBOL_GPL(kernel_power_off
);
347 * Reboot system call: for obvious reasons only root may call it,
348 * and even root needs to set up some magic numbers in the registers
349 * so that some mistake won't make this reboot the whole machine.
350 * You can also set the meaning of the ctrl-alt-del-key here.
352 * reboot doesn't sync: do that yourself before calling this.
354 asmlinkage
long sys_reboot(int magic1
, int magic2
, unsigned int cmd
, void __user
* arg
)
358 /* We only trust the superuser with rebooting the system. */
359 if (!capable(CAP_SYS_BOOT
))
362 /* For safety, we require "magic" arguments. */
363 if (magic1
!= LINUX_REBOOT_MAGIC1
||
364 (magic2
!= LINUX_REBOOT_MAGIC2
&&
365 magic2
!= LINUX_REBOOT_MAGIC2A
&&
366 magic2
!= LINUX_REBOOT_MAGIC2B
&&
367 magic2
!= LINUX_REBOOT_MAGIC2C
))
370 /* Instead of trying to make the power_off code look like
371 * halt when pm_power_off is not set do it the easy way.
373 if ((cmd
== LINUX_REBOOT_CMD_POWER_OFF
) && !pm_power_off
)
374 cmd
= LINUX_REBOOT_CMD_HALT
;
378 case LINUX_REBOOT_CMD_RESTART
:
379 kernel_restart(NULL
);
382 case LINUX_REBOOT_CMD_CAD_ON
:
386 case LINUX_REBOOT_CMD_CAD_OFF
:
390 case LINUX_REBOOT_CMD_HALT
:
396 case LINUX_REBOOT_CMD_POWER_OFF
:
402 case LINUX_REBOOT_CMD_RESTART2
:
403 if (strncpy_from_user(&buffer
[0], arg
, sizeof(buffer
) - 1) < 0) {
407 buffer
[sizeof(buffer
) - 1] = '\0';
409 kernel_restart(buffer
);
413 case LINUX_REBOOT_CMD_KEXEC
:
416 ret
= kernel_kexec();
422 #ifdef CONFIG_HIBERNATION
423 case LINUX_REBOOT_CMD_SW_SUSPEND
:
425 int ret
= hibernate();
439 static void deferred_cad(struct work_struct
*dummy
)
441 kernel_restart(NULL
);
445 * This function gets called by ctrl-alt-del - ie the keyboard interrupt.
446 * As it's called within an interrupt, it may NOT sync: the only choice
447 * is whether to reboot at once, or just ignore the ctrl-alt-del.
449 void ctrl_alt_del(void)
451 static DECLARE_WORK(cad_work
, deferred_cad
);
454 schedule_work(&cad_work
);
456 kill_cad_pid(SIGINT
, 1);
460 * Unprivileged users may change the real gid to the effective gid
461 * or vice versa. (BSD-style)
463 * If you set the real gid at all, or set the effective gid to a value not
464 * equal to the real gid, then the saved gid is set to the new effective gid.
466 * This makes it possible for a setgid program to completely drop its
467 * privileges, which is often a useful assertion to make when you are doing
468 * a security audit over a program.
470 * The general idea is that a program which uses just setregid() will be
471 * 100% compatible with BSD. A program which uses just setgid() will be
472 * 100% compatible with POSIX with saved IDs.
474 * SMP: There are not races, the GIDs are checked only by filesystem
475 * operations (as far as semantic preservation is concerned).
477 asmlinkage
long sys_setregid(gid_t rgid
, gid_t egid
)
479 struct cred
*cred
= current
->cred
;
480 int old_rgid
= cred
->gid
;
481 int old_egid
= cred
->egid
;
482 int new_rgid
= old_rgid
;
483 int new_egid
= old_egid
;
486 retval
= security_task_setgid(rgid
, egid
, (gid_t
)-1, LSM_SETID_RE
);
490 if (rgid
!= (gid_t
) -1) {
491 if ((old_rgid
== rgid
) ||
492 (cred
->egid
== rgid
) ||
498 if (egid
!= (gid_t
) -1) {
499 if ((old_rgid
== egid
) ||
500 (cred
->egid
== egid
) ||
501 (cred
->sgid
== egid
) ||
507 if (new_egid
!= old_egid
) {
508 set_dumpable(current
->mm
, suid_dumpable
);
511 if (rgid
!= (gid_t
) -1 ||
512 (egid
!= (gid_t
) -1 && egid
!= old_rgid
))
513 cred
->sgid
= new_egid
;
514 cred
->fsgid
= new_egid
;
515 cred
->egid
= new_egid
;
516 cred
->gid
= new_rgid
;
517 key_fsgid_changed(current
);
518 proc_id_connector(current
, PROC_EVENT_GID
);
523 * setgid() is implemented like SysV w/ SAVED_IDS
525 * SMP: Same implicit races as above.
527 asmlinkage
long sys_setgid(gid_t gid
)
529 struct cred
*cred
= current
->cred
;
530 int old_egid
= cred
->egid
;
533 retval
= security_task_setgid(gid
, (gid_t
)-1, (gid_t
)-1, LSM_SETID_ID
);
537 if (capable(CAP_SETGID
)) {
538 if (old_egid
!= gid
) {
539 set_dumpable(current
->mm
, suid_dumpable
);
542 cred
->gid
= cred
->egid
= cred
->sgid
= cred
->fsgid
= gid
;
543 } else if ((gid
== cred
->gid
) || (gid
== cred
->sgid
)) {
544 if (old_egid
!= gid
) {
545 set_dumpable(current
->mm
, suid_dumpable
);
548 cred
->egid
= cred
->fsgid
= gid
;
553 key_fsgid_changed(current
);
554 proc_id_connector(current
, PROC_EVENT_GID
);
558 static int set_user(uid_t new_ruid
, int dumpclear
)
560 struct user_struct
*new_user
;
562 new_user
= alloc_uid(current
->nsproxy
->user_ns
, new_ruid
);
566 if (atomic_read(&new_user
->processes
) >=
567 current
->signal
->rlim
[RLIMIT_NPROC
].rlim_cur
&&
568 new_user
!= current
->nsproxy
->user_ns
->root_user
) {
573 switch_uid(new_user
);
576 set_dumpable(current
->mm
, suid_dumpable
);
579 current
->cred
->uid
= new_ruid
;
584 * Unprivileged users may change the real uid to the effective uid
585 * or vice versa. (BSD-style)
587 * If you set the real uid at all, or set the effective uid to a value not
588 * equal to the real uid, then the saved uid is set to the new effective uid.
590 * This makes it possible for a setuid program to completely drop its
591 * privileges, which is often a useful assertion to make when you are doing
592 * a security audit over a program.
594 * The general idea is that a program which uses just setreuid() will be
595 * 100% compatible with BSD. A program which uses just setuid() will be
596 * 100% compatible with POSIX with saved IDs.
598 asmlinkage
long sys_setreuid(uid_t ruid
, uid_t euid
)
600 struct cred
*cred
= current
->cred
;
601 int old_ruid
, old_euid
, old_suid
, new_ruid
, new_euid
;
604 retval
= security_task_setuid(ruid
, euid
, (uid_t
)-1, LSM_SETID_RE
);
608 new_ruid
= old_ruid
= cred
->uid
;
609 new_euid
= old_euid
= cred
->euid
;
610 old_suid
= cred
->suid
;
612 if (ruid
!= (uid_t
) -1) {
614 if ((old_ruid
!= ruid
) &&
615 (cred
->euid
!= ruid
) &&
616 !capable(CAP_SETUID
))
620 if (euid
!= (uid_t
) -1) {
622 if ((old_ruid
!= euid
) &&
623 (cred
->euid
!= euid
) &&
624 (cred
->suid
!= euid
) &&
625 !capable(CAP_SETUID
))
629 if (new_ruid
!= old_ruid
&& set_user(new_ruid
, new_euid
!= old_euid
) < 0)
632 if (new_euid
!= old_euid
) {
633 set_dumpable(current
->mm
, suid_dumpable
);
636 cred
->fsuid
= cred
->euid
= new_euid
;
637 if (ruid
!= (uid_t
) -1 ||
638 (euid
!= (uid_t
) -1 && euid
!= old_ruid
))
639 cred
->suid
= cred
->euid
;
640 cred
->fsuid
= cred
->euid
;
642 key_fsuid_changed(current
);
643 proc_id_connector(current
, PROC_EVENT_UID
);
645 return security_task_post_setuid(old_ruid
, old_euid
, old_suid
, LSM_SETID_RE
);
651 * setuid() is implemented like SysV with SAVED_IDS
653 * Note that SAVED_ID's is deficient in that a setuid root program
654 * like sendmail, for example, cannot set its uid to be a normal
655 * user and then switch back, because if you're root, setuid() sets
656 * the saved uid too. If you don't like this, blame the bright people
657 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
658 * will allow a root program to temporarily drop privileges and be able to
659 * regain them by swapping the real and effective uid.
661 asmlinkage
long sys_setuid(uid_t uid
)
663 struct cred
*cred
= current
->cred
;
664 int old_euid
= cred
->euid
;
665 int old_ruid
, old_suid
, new_suid
;
668 retval
= security_task_setuid(uid
, (uid_t
)-1, (uid_t
)-1, LSM_SETID_ID
);
672 old_ruid
= cred
->uid
;
673 old_suid
= cred
->suid
;
676 if (capable(CAP_SETUID
)) {
677 if (uid
!= old_ruid
&& set_user(uid
, old_euid
!= uid
) < 0)
680 } else if ((uid
!= cred
->uid
) && (uid
!= new_suid
))
683 if (old_euid
!= uid
) {
684 set_dumpable(current
->mm
, suid_dumpable
);
687 cred
->fsuid
= cred
->euid
= uid
;
688 cred
->suid
= new_suid
;
690 key_fsuid_changed(current
);
691 proc_id_connector(current
, PROC_EVENT_UID
);
693 return security_task_post_setuid(old_ruid
, old_euid
, old_suid
, LSM_SETID_ID
);
698 * This function implements a generic ability to update ruid, euid,
699 * and suid. This allows you to implement the 4.4 compatible seteuid().
701 asmlinkage
long sys_setresuid(uid_t ruid
, uid_t euid
, uid_t suid
)
703 struct cred
*cred
= current
->cred
;
704 int old_ruid
= cred
->uid
;
705 int old_euid
= cred
->euid
;
706 int old_suid
= cred
->suid
;
709 retval
= security_task_setuid(ruid
, euid
, suid
, LSM_SETID_RES
);
713 if (!capable(CAP_SETUID
)) {
714 if ((ruid
!= (uid_t
) -1) && (ruid
!= cred
->uid
) &&
715 (ruid
!= cred
->euid
) && (ruid
!= cred
->suid
))
717 if ((euid
!= (uid_t
) -1) && (euid
!= cred
->uid
) &&
718 (euid
!= cred
->euid
) && (euid
!= cred
->suid
))
720 if ((suid
!= (uid_t
) -1) && (suid
!= cred
->uid
) &&
721 (suid
!= cred
->euid
) && (suid
!= cred
->suid
))
724 if (ruid
!= (uid_t
) -1) {
725 if (ruid
!= cred
->uid
&&
726 set_user(ruid
, euid
!= cred
->euid
) < 0)
729 if (euid
!= (uid_t
) -1) {
730 if (euid
!= cred
->euid
) {
731 set_dumpable(current
->mm
, suid_dumpable
);
736 cred
->fsuid
= cred
->euid
;
737 if (suid
!= (uid_t
) -1)
740 key_fsuid_changed(current
);
741 proc_id_connector(current
, PROC_EVENT_UID
);
743 return security_task_post_setuid(old_ruid
, old_euid
, old_suid
, LSM_SETID_RES
);
746 asmlinkage
long sys_getresuid(uid_t __user
*ruid
, uid_t __user
*euid
, uid_t __user
*suid
)
748 const struct cred
*cred
= current_cred();
751 if (!(retval
= put_user(cred
->uid
, ruid
)) &&
752 !(retval
= put_user(cred
->euid
, euid
)))
753 retval
= put_user(cred
->suid
, suid
);
759 * Same as above, but for rgid, egid, sgid.
761 asmlinkage
long sys_setresgid(gid_t rgid
, gid_t egid
, gid_t sgid
)
763 struct cred
*cred
= current
->cred
;
766 retval
= security_task_setgid(rgid
, egid
, sgid
, LSM_SETID_RES
);
770 if (!capable(CAP_SETGID
)) {
771 if ((rgid
!= (gid_t
) -1) && (rgid
!= cred
->gid
) &&
772 (rgid
!= cred
->egid
) && (rgid
!= cred
->sgid
))
774 if ((egid
!= (gid_t
) -1) && (egid
!= cred
->gid
) &&
775 (egid
!= cred
->egid
) && (egid
!= cred
->sgid
))
777 if ((sgid
!= (gid_t
) -1) && (sgid
!= cred
->gid
) &&
778 (sgid
!= cred
->egid
) && (sgid
!= cred
->sgid
))
781 if (egid
!= (gid_t
) -1) {
782 if (egid
!= cred
->egid
) {
783 set_dumpable(current
->mm
, suid_dumpable
);
788 cred
->fsgid
= cred
->egid
;
789 if (rgid
!= (gid_t
) -1)
791 if (sgid
!= (gid_t
) -1)
794 key_fsgid_changed(current
);
795 proc_id_connector(current
, PROC_EVENT_GID
);
799 asmlinkage
long sys_getresgid(gid_t __user
*rgid
, gid_t __user
*egid
, gid_t __user
*sgid
)
801 const struct cred
*cred
= current_cred();
804 if (!(retval
= put_user(cred
->gid
, rgid
)) &&
805 !(retval
= put_user(cred
->egid
, egid
)))
806 retval
= put_user(cred
->sgid
, sgid
);
813 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
814 * is used for "access()" and for the NFS daemon (letting nfsd stay at
815 * whatever uid it wants to). It normally shadows "euid", except when
816 * explicitly set by setfsuid() or for access..
818 asmlinkage
long sys_setfsuid(uid_t uid
)
820 struct cred
*cred
= current
->cred
;
823 old_fsuid
= cred
->fsuid
;
824 if (security_task_setuid(uid
, (uid_t
)-1, (uid_t
)-1, LSM_SETID_FS
))
827 if (uid
== cred
->uid
|| uid
== cred
->euid
||
828 uid
== cred
->suid
|| uid
== cred
->fsuid
||
829 capable(CAP_SETUID
)) {
830 if (uid
!= old_fsuid
) {
831 set_dumpable(current
->mm
, suid_dumpable
);
837 key_fsuid_changed(current
);
838 proc_id_connector(current
, PROC_EVENT_UID
);
840 security_task_post_setuid(old_fsuid
, (uid_t
)-1, (uid_t
)-1, LSM_SETID_FS
);
846 * Samma på svenska..
848 asmlinkage
long sys_setfsgid(gid_t gid
)
850 struct cred
*cred
= current
->cred
;
853 old_fsgid
= cred
->fsgid
;
854 if (security_task_setgid(gid
, (gid_t
)-1, (gid_t
)-1, LSM_SETID_FS
))
857 if (gid
== cred
->gid
|| gid
== cred
->egid
||
858 gid
== cred
->sgid
|| gid
== cred
->fsgid
||
859 capable(CAP_SETGID
)) {
860 if (gid
!= old_fsgid
) {
861 set_dumpable(current
->mm
, suid_dumpable
);
865 key_fsgid_changed(current
);
866 proc_id_connector(current
, PROC_EVENT_GID
);
871 void do_sys_times(struct tms
*tms
)
873 struct task_cputime cputime
;
874 cputime_t cutime
, cstime
;
876 spin_lock_irq(¤t
->sighand
->siglock
);
877 thread_group_cputime(current
, &cputime
);
878 cutime
= current
->signal
->cutime
;
879 cstime
= current
->signal
->cstime
;
880 spin_unlock_irq(¤t
->sighand
->siglock
);
881 tms
->tms_utime
= cputime_to_clock_t(cputime
.utime
);
882 tms
->tms_stime
= cputime_to_clock_t(cputime
.stime
);
883 tms
->tms_cutime
= cputime_to_clock_t(cutime
);
884 tms
->tms_cstime
= cputime_to_clock_t(cstime
);
887 asmlinkage
long sys_times(struct tms __user
* tbuf
)
893 if (copy_to_user(tbuf
, &tmp
, sizeof(struct tms
)))
896 return (long) jiffies_64_to_clock_t(get_jiffies_64());
900 * This needs some heavy checking ...
901 * I just haven't the stomach for it. I also don't fully
902 * understand sessions/pgrp etc. Let somebody who does explain it.
904 * OK, I think I have the protection semantics right.... this is really
905 * only important on a multi-user system anyway, to make sure one user
906 * can't send a signal to a process owned by another. -TYT, 12/12/91
908 * Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
911 asmlinkage
long sys_setpgid(pid_t pid
, pid_t pgid
)
913 struct task_struct
*p
;
914 struct task_struct
*group_leader
= current
->group_leader
;
919 pid
= task_pid_vnr(group_leader
);
925 /* From this point forward we keep holding onto the tasklist lock
926 * so that our parent does not change from under us. -DaveM
928 write_lock_irq(&tasklist_lock
);
931 p
= find_task_by_vpid(pid
);
936 if (!thread_group_leader(p
))
939 if (same_thread_group(p
->real_parent
, group_leader
)) {
941 if (task_session(p
) != task_session(group_leader
))
948 if (p
!= group_leader
)
953 if (p
->signal
->leader
)
958 struct task_struct
*g
;
960 pgrp
= find_vpid(pgid
);
961 g
= pid_task(pgrp
, PIDTYPE_PGID
);
962 if (!g
|| task_session(g
) != task_session(group_leader
))
966 err
= security_task_setpgid(p
, pgid
);
970 if (task_pgrp(p
) != pgrp
) {
971 change_pid(p
, PIDTYPE_PGID
, pgrp
);
972 set_task_pgrp(p
, pid_nr(pgrp
));
977 /* All paths lead to here, thus we are safe. -DaveM */
978 write_unlock_irq(&tasklist_lock
);
982 asmlinkage
long sys_getpgid(pid_t pid
)
984 struct task_struct
*p
;
990 grp
= task_pgrp(current
);
993 p
= find_task_by_vpid(pid
);
1000 retval
= security_task_getpgid(p
);
1004 retval
= pid_vnr(grp
);
1010 #ifdef __ARCH_WANT_SYS_GETPGRP
1012 asmlinkage
long sys_getpgrp(void)
1014 return sys_getpgid(0);
1019 asmlinkage
long sys_getsid(pid_t pid
)
1021 struct task_struct
*p
;
1027 sid
= task_session(current
);
1030 p
= find_task_by_vpid(pid
);
1033 sid
= task_session(p
);
1037 retval
= security_task_getsid(p
);
1041 retval
= pid_vnr(sid
);
1047 asmlinkage
long sys_setsid(void)
1049 struct task_struct
*group_leader
= current
->group_leader
;
1050 struct pid
*sid
= task_pid(group_leader
);
1051 pid_t session
= pid_vnr(sid
);
1054 write_lock_irq(&tasklist_lock
);
1055 /* Fail if I am already a session leader */
1056 if (group_leader
->signal
->leader
)
1059 /* Fail if a process group id already exists that equals the
1060 * proposed session id.
1062 if (pid_task(sid
, PIDTYPE_PGID
))
1065 group_leader
->signal
->leader
= 1;
1066 __set_special_pids(sid
);
1068 proc_clear_tty(group_leader
);
1072 write_unlock_irq(&tasklist_lock
);
1077 * Supplementary group IDs
1080 /* init to 2 - one for init_task, one to ensure it is never freed */
1081 struct group_info init_groups
= { .usage
= ATOMIC_INIT(2) };
1083 struct group_info
*groups_alloc(int gidsetsize
)
1085 struct group_info
*group_info
;
1089 nblocks
= (gidsetsize
+ NGROUPS_PER_BLOCK
- 1) / NGROUPS_PER_BLOCK
;
1090 /* Make sure we always allocate at least one indirect block pointer */
1091 nblocks
= nblocks
? : 1;
1092 group_info
= kmalloc(sizeof(*group_info
) + nblocks
*sizeof(gid_t
*), GFP_USER
);
1095 group_info
->ngroups
= gidsetsize
;
1096 group_info
->nblocks
= nblocks
;
1097 atomic_set(&group_info
->usage
, 1);
1099 if (gidsetsize
<= NGROUPS_SMALL
)
1100 group_info
->blocks
[0] = group_info
->small_block
;
1102 for (i
= 0; i
< nblocks
; i
++) {
1104 b
= (void *)__get_free_page(GFP_USER
);
1106 goto out_undo_partial_alloc
;
1107 group_info
->blocks
[i
] = b
;
1112 out_undo_partial_alloc
:
1114 free_page((unsigned long)group_info
->blocks
[i
]);
1120 EXPORT_SYMBOL(groups_alloc
);
1122 void groups_free(struct group_info
*group_info
)
1124 if (group_info
->blocks
[0] != group_info
->small_block
) {
1126 for (i
= 0; i
< group_info
->nblocks
; i
++)
1127 free_page((unsigned long)group_info
->blocks
[i
]);
1132 EXPORT_SYMBOL(groups_free
);
1134 /* export the group_info to a user-space array */
1135 static int groups_to_user(gid_t __user
*grouplist
,
1136 struct group_info
*group_info
)
1139 unsigned int count
= group_info
->ngroups
;
1141 for (i
= 0; i
< group_info
->nblocks
; i
++) {
1142 unsigned int cp_count
= min(NGROUPS_PER_BLOCK
, count
);
1143 unsigned int len
= cp_count
* sizeof(*grouplist
);
1145 if (copy_to_user(grouplist
, group_info
->blocks
[i
], len
))
1148 grouplist
+= NGROUPS_PER_BLOCK
;
1154 /* fill a group_info from a user-space array - it must be allocated already */
1155 static int groups_from_user(struct group_info
*group_info
,
1156 gid_t __user
*grouplist
)
1159 unsigned int count
= group_info
->ngroups
;
1161 for (i
= 0; i
< group_info
->nblocks
; i
++) {
1162 unsigned int cp_count
= min(NGROUPS_PER_BLOCK
, count
);
1163 unsigned int len
= cp_count
* sizeof(*grouplist
);
1165 if (copy_from_user(group_info
->blocks
[i
], grouplist
, len
))
1168 grouplist
+= NGROUPS_PER_BLOCK
;
1174 /* a simple Shell sort */
1175 static void groups_sort(struct group_info
*group_info
)
1177 int base
, max
, stride
;
1178 int gidsetsize
= group_info
->ngroups
;
1180 for (stride
= 1; stride
< gidsetsize
; stride
= 3 * stride
+ 1)
1185 max
= gidsetsize
- stride
;
1186 for (base
= 0; base
< max
; base
++) {
1188 int right
= left
+ stride
;
1189 gid_t tmp
= GROUP_AT(group_info
, right
);
1191 while (left
>= 0 && GROUP_AT(group_info
, left
) > tmp
) {
1192 GROUP_AT(group_info
, right
) =
1193 GROUP_AT(group_info
, left
);
1197 GROUP_AT(group_info
, right
) = tmp
;
1203 /* a simple bsearch */
1204 int groups_search(const struct group_info
*group_info
, gid_t grp
)
1206 unsigned int left
, right
;
1212 right
= group_info
->ngroups
;
1213 while (left
< right
) {
1214 unsigned int mid
= (left
+right
)/2;
1215 int cmp
= grp
- GROUP_AT(group_info
, mid
);
1227 * set_groups - Change a group subscription in a security record
1228 * @sec: The security record to alter
1229 * @group_info: The group list to impose
1231 * Validate a group subscription and, if valid, impose it upon a task security
1234 int set_groups(struct cred
*cred
, struct group_info
*group_info
)
1237 struct group_info
*old_info
;
1239 retval
= security_task_setgroups(group_info
);
1243 groups_sort(group_info
);
1244 get_group_info(group_info
);
1246 spin_lock(&cred
->lock
);
1247 old_info
= cred
->group_info
;
1248 cred
->group_info
= group_info
;
1249 spin_unlock(&cred
->lock
);
1251 put_group_info(old_info
);
1255 EXPORT_SYMBOL(set_groups
);
1258 * set_current_groups - Change current's group subscription
1259 * @group_info: The group list to impose
1261 * Validate a group subscription and, if valid, impose it upon current's task
1264 int set_current_groups(struct group_info
*group_info
)
1266 return set_groups(current
->cred
, group_info
);
1269 EXPORT_SYMBOL(set_current_groups
);
1271 asmlinkage
long sys_getgroups(int gidsetsize
, gid_t __user
*grouplist
)
1273 const struct cred
*cred
= current_cred();
1279 /* no need to grab task_lock here; it cannot change */
1280 i
= cred
->group_info
->ngroups
;
1282 if (i
> gidsetsize
) {
1286 if (groups_to_user(grouplist
, cred
->group_info
)) {
1296 * SMP: Our groups are copy-on-write. We can set them safely
1297 * without another task interfering.
1300 asmlinkage
long sys_setgroups(int gidsetsize
, gid_t __user
*grouplist
)
1302 struct group_info
*group_info
;
1305 if (!capable(CAP_SETGID
))
1307 if ((unsigned)gidsetsize
> NGROUPS_MAX
)
1310 group_info
= groups_alloc(gidsetsize
);
1313 retval
= groups_from_user(group_info
, grouplist
);
1315 put_group_info(group_info
);
1319 retval
= set_current_groups(group_info
);
1320 put_group_info(group_info
);
1326 * Check whether we're fsgid/egid or in the supplemental group..
1328 int in_group_p(gid_t grp
)
1330 const struct cred
*cred
= current_cred();
1333 if (grp
!= cred
->fsgid
)
1334 retval
= groups_search(cred
->group_info
, grp
);
1338 EXPORT_SYMBOL(in_group_p
);
1340 int in_egroup_p(gid_t grp
)
1342 const struct cred
*cred
= current_cred();
1345 if (grp
!= cred
->egid
)
1346 retval
= groups_search(cred
->group_info
, grp
);
1350 EXPORT_SYMBOL(in_egroup_p
);
1352 DECLARE_RWSEM(uts_sem
);
1354 asmlinkage
long sys_newuname(struct new_utsname __user
* name
)
1358 down_read(&uts_sem
);
1359 if (copy_to_user(name
, utsname(), sizeof *name
))
1365 asmlinkage
long sys_sethostname(char __user
*name
, int len
)
1368 char tmp
[__NEW_UTS_LEN
];
1370 if (!capable(CAP_SYS_ADMIN
))
1372 if (len
< 0 || len
> __NEW_UTS_LEN
)
1374 down_write(&uts_sem
);
1376 if (!copy_from_user(tmp
, name
, len
)) {
1377 struct new_utsname
*u
= utsname();
1379 memcpy(u
->nodename
, tmp
, len
);
1380 memset(u
->nodename
+ len
, 0, sizeof(u
->nodename
) - len
);
1387 #ifdef __ARCH_WANT_SYS_GETHOSTNAME
1389 asmlinkage
long sys_gethostname(char __user
*name
, int len
)
1392 struct new_utsname
*u
;
1396 down_read(&uts_sem
);
1398 i
= 1 + strlen(u
->nodename
);
1402 if (copy_to_user(name
, u
->nodename
, i
))
1411 * Only setdomainname; getdomainname can be implemented by calling
1414 asmlinkage
long sys_setdomainname(char __user
*name
, int len
)
1417 char tmp
[__NEW_UTS_LEN
];
1419 if (!capable(CAP_SYS_ADMIN
))
1421 if (len
< 0 || len
> __NEW_UTS_LEN
)
1424 down_write(&uts_sem
);
1426 if (!copy_from_user(tmp
, name
, len
)) {
1427 struct new_utsname
*u
= utsname();
1429 memcpy(u
->domainname
, tmp
, len
);
1430 memset(u
->domainname
+ len
, 0, sizeof(u
->domainname
) - len
);
1437 asmlinkage
long sys_getrlimit(unsigned int resource
, struct rlimit __user
*rlim
)
1439 if (resource
>= RLIM_NLIMITS
)
1442 struct rlimit value
;
1443 task_lock(current
->group_leader
);
1444 value
= current
->signal
->rlim
[resource
];
1445 task_unlock(current
->group_leader
);
1446 return copy_to_user(rlim
, &value
, sizeof(*rlim
)) ? -EFAULT
: 0;
1450 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1453 * Back compatibility for getrlimit. Needed for some apps.
1456 asmlinkage
long sys_old_getrlimit(unsigned int resource
, struct rlimit __user
*rlim
)
1459 if (resource
>= RLIM_NLIMITS
)
1462 task_lock(current
->group_leader
);
1463 x
= current
->signal
->rlim
[resource
];
1464 task_unlock(current
->group_leader
);
1465 if (x
.rlim_cur
> 0x7FFFFFFF)
1466 x
.rlim_cur
= 0x7FFFFFFF;
1467 if (x
.rlim_max
> 0x7FFFFFFF)
1468 x
.rlim_max
= 0x7FFFFFFF;
1469 return copy_to_user(rlim
, &x
, sizeof(x
))?-EFAULT
:0;
1474 asmlinkage
long sys_setrlimit(unsigned int resource
, struct rlimit __user
*rlim
)
1476 struct rlimit new_rlim
, *old_rlim
;
1479 if (resource
>= RLIM_NLIMITS
)
1481 if (copy_from_user(&new_rlim
, rlim
, sizeof(*rlim
)))
1483 old_rlim
= current
->signal
->rlim
+ resource
;
1484 if ((new_rlim
.rlim_max
> old_rlim
->rlim_max
) &&
1485 !capable(CAP_SYS_RESOURCE
))
1488 if (resource
== RLIMIT_NOFILE
) {
1489 if (new_rlim
.rlim_max
== RLIM_INFINITY
)
1490 new_rlim
.rlim_max
= sysctl_nr_open
;
1491 if (new_rlim
.rlim_cur
== RLIM_INFINITY
)
1492 new_rlim
.rlim_cur
= sysctl_nr_open
;
1493 if (new_rlim
.rlim_max
> sysctl_nr_open
)
1497 if (new_rlim
.rlim_cur
> new_rlim
.rlim_max
)
1500 retval
= security_task_setrlimit(resource
, &new_rlim
);
1504 if (resource
== RLIMIT_CPU
&& new_rlim
.rlim_cur
== 0) {
1506 * The caller is asking for an immediate RLIMIT_CPU
1507 * expiry. But we use the zero value to mean "it was
1508 * never set". So let's cheat and make it one second
1511 new_rlim
.rlim_cur
= 1;
1514 task_lock(current
->group_leader
);
1515 *old_rlim
= new_rlim
;
1516 task_unlock(current
->group_leader
);
1518 if (resource
!= RLIMIT_CPU
)
1522 * RLIMIT_CPU handling. Note that the kernel fails to return an error
1523 * code if it rejected the user's attempt to set RLIMIT_CPU. This is a
1524 * very long-standing error, and fixing it now risks breakage of
1525 * applications, so we live with it
1527 if (new_rlim
.rlim_cur
== RLIM_INFINITY
)
1530 update_rlimit_cpu(new_rlim
.rlim_cur
);
1536 * It would make sense to put struct rusage in the task_struct,
1537 * except that would make the task_struct be *really big*. After
1538 * task_struct gets moved into malloc'ed memory, it would
1539 * make sense to do this. It will make moving the rest of the information
1540 * a lot simpler! (Which we're not doing right now because we're not
1541 * measuring them yet).
1543 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1544 * races with threads incrementing their own counters. But since word
1545 * reads are atomic, we either get new values or old values and we don't
1546 * care which for the sums. We always take the siglock to protect reading
1547 * the c* fields from p->signal from races with exit.c updating those
1548 * fields when reaping, so a sample either gets all the additions of a
1549 * given child after it's reaped, or none so this sample is before reaping.
1552 * We need to take the siglock for CHILDEREN, SELF and BOTH
1553 * for the cases current multithreaded, non-current single threaded
1554 * non-current multithreaded. Thread traversal is now safe with
1556 * Strictly speaking, we donot need to take the siglock if we are current and
1557 * single threaded, as no one else can take our signal_struct away, no one
1558 * else can reap the children to update signal->c* counters, and no one else
1559 * can race with the signal-> fields. If we do not take any lock, the
1560 * signal-> fields could be read out of order while another thread was just
1561 * exiting. So we should place a read memory barrier when we avoid the lock.
1562 * On the writer side, write memory barrier is implied in __exit_signal
1563 * as __exit_signal releases the siglock spinlock after updating the signal->
1564 * fields. But we don't do this yet to keep things simple.
1568 static void accumulate_thread_rusage(struct task_struct
*t
, struct rusage
*r
)
1570 r
->ru_nvcsw
+= t
->nvcsw
;
1571 r
->ru_nivcsw
+= t
->nivcsw
;
1572 r
->ru_minflt
+= t
->min_flt
;
1573 r
->ru_majflt
+= t
->maj_flt
;
1574 r
->ru_inblock
+= task_io_get_inblock(t
);
1575 r
->ru_oublock
+= task_io_get_oublock(t
);
1578 static void k_getrusage(struct task_struct
*p
, int who
, struct rusage
*r
)
1580 struct task_struct
*t
;
1581 unsigned long flags
;
1582 cputime_t utime
, stime
;
1583 struct task_cputime cputime
;
1585 memset((char *) r
, 0, sizeof *r
);
1586 utime
= stime
= cputime_zero
;
1588 if (who
== RUSAGE_THREAD
) {
1589 accumulate_thread_rusage(p
, r
);
1593 if (!lock_task_sighand(p
, &flags
))
1598 case RUSAGE_CHILDREN
:
1599 utime
= p
->signal
->cutime
;
1600 stime
= p
->signal
->cstime
;
1601 r
->ru_nvcsw
= p
->signal
->cnvcsw
;
1602 r
->ru_nivcsw
= p
->signal
->cnivcsw
;
1603 r
->ru_minflt
= p
->signal
->cmin_flt
;
1604 r
->ru_majflt
= p
->signal
->cmaj_flt
;
1605 r
->ru_inblock
= p
->signal
->cinblock
;
1606 r
->ru_oublock
= p
->signal
->coublock
;
1608 if (who
== RUSAGE_CHILDREN
)
1612 thread_group_cputime(p
, &cputime
);
1613 utime
= cputime_add(utime
, cputime
.utime
);
1614 stime
= cputime_add(stime
, cputime
.stime
);
1615 r
->ru_nvcsw
+= p
->signal
->nvcsw
;
1616 r
->ru_nivcsw
+= p
->signal
->nivcsw
;
1617 r
->ru_minflt
+= p
->signal
->min_flt
;
1618 r
->ru_majflt
+= p
->signal
->maj_flt
;
1619 r
->ru_inblock
+= p
->signal
->inblock
;
1620 r
->ru_oublock
+= p
->signal
->oublock
;
1623 accumulate_thread_rusage(t
, r
);
1631 unlock_task_sighand(p
, &flags
);
1634 cputime_to_timeval(utime
, &r
->ru_utime
);
1635 cputime_to_timeval(stime
, &r
->ru_stime
);
1638 int getrusage(struct task_struct
*p
, int who
, struct rusage __user
*ru
)
1641 k_getrusage(p
, who
, &r
);
1642 return copy_to_user(ru
, &r
, sizeof(r
)) ? -EFAULT
: 0;
1645 asmlinkage
long sys_getrusage(int who
, struct rusage __user
*ru
)
1647 if (who
!= RUSAGE_SELF
&& who
!= RUSAGE_CHILDREN
&&
1648 who
!= RUSAGE_THREAD
)
1650 return getrusage(current
, who
, ru
);
1653 asmlinkage
long sys_umask(int mask
)
1655 mask
= xchg(¤t
->fs
->umask
, mask
& S_IRWXUGO
);
1659 asmlinkage
long sys_prctl(int option
, unsigned long arg2
, unsigned long arg3
,
1660 unsigned long arg4
, unsigned long arg5
)
1662 struct task_struct
*me
= current
;
1663 unsigned char comm
[sizeof(me
->comm
)];
1666 if (security_task_prctl(option
, arg2
, arg3
, arg4
, arg5
, &error
))
1670 case PR_SET_PDEATHSIG
:
1671 if (!valid_signal(arg2
)) {
1675 me
->pdeath_signal
= arg2
;
1678 case PR_GET_PDEATHSIG
:
1679 error
= put_user(me
->pdeath_signal
, (int __user
*)arg2
);
1681 case PR_GET_DUMPABLE
:
1682 error
= get_dumpable(me
->mm
);
1684 case PR_SET_DUMPABLE
:
1685 if (arg2
< 0 || arg2
> 1) {
1689 set_dumpable(me
->mm
, arg2
);
1693 case PR_SET_UNALIGN
:
1694 error
= SET_UNALIGN_CTL(me
, arg2
);
1696 case PR_GET_UNALIGN
:
1697 error
= GET_UNALIGN_CTL(me
, arg2
);
1700 error
= SET_FPEMU_CTL(me
, arg2
);
1703 error
= GET_FPEMU_CTL(me
, arg2
);
1706 error
= SET_FPEXC_CTL(me
, arg2
);
1709 error
= GET_FPEXC_CTL(me
, arg2
);
1712 error
= PR_TIMING_STATISTICAL
;
1715 if (arg2
!= PR_TIMING_STATISTICAL
)
1722 comm
[sizeof(me
->comm
)-1] = 0;
1723 if (strncpy_from_user(comm
, (char __user
*)arg2
,
1724 sizeof(me
->comm
) - 1) < 0)
1726 set_task_comm(me
, comm
);
1729 get_task_comm(comm
, me
);
1730 if (copy_to_user((char __user
*)arg2
, comm
,
1735 error
= GET_ENDIAN(me
, arg2
);
1738 error
= SET_ENDIAN(me
, arg2
);
1741 case PR_GET_SECCOMP
:
1742 error
= prctl_get_seccomp();
1744 case PR_SET_SECCOMP
:
1745 error
= prctl_set_seccomp(arg2
);
1748 error
= GET_TSC_CTL(arg2
);
1751 error
= SET_TSC_CTL(arg2
);
1753 case PR_GET_TIMERSLACK
:
1754 error
= current
->timer_slack_ns
;
1756 case PR_SET_TIMERSLACK
:
1758 current
->timer_slack_ns
=
1759 current
->default_timer_slack_ns
;
1761 current
->timer_slack_ns
= arg2
;
1771 asmlinkage
long sys_getcpu(unsigned __user
*cpup
, unsigned __user
*nodep
,
1772 struct getcpu_cache __user
*unused
)
1775 int cpu
= raw_smp_processor_id();
1777 err
|= put_user(cpu
, cpup
);
1779 err
|= put_user(cpu_to_node(cpu
), nodep
);
1780 return err
? -EFAULT
: 0;
1783 char poweroff_cmd
[POWEROFF_CMD_PATH_LEN
] = "/sbin/poweroff";
1785 static void argv_cleanup(char **argv
, char **envp
)
1791 * orderly_poweroff - Trigger an orderly system poweroff
1792 * @force: force poweroff if command execution fails
1794 * This may be called from any context to trigger a system shutdown.
1795 * If the orderly shutdown fails, it will force an immediate shutdown.
1797 int orderly_poweroff(bool force
)
1800 char **argv
= argv_split(GFP_ATOMIC
, poweroff_cmd
, &argc
);
1801 static char *envp
[] = {
1803 "PATH=/sbin:/bin:/usr/sbin:/usr/bin",
1807 struct subprocess_info
*info
;
1810 printk(KERN_WARNING
"%s failed to allocate memory for \"%s\"\n",
1811 __func__
, poweroff_cmd
);
1815 info
= call_usermodehelper_setup(argv
[0], argv
, envp
, GFP_ATOMIC
);
1821 call_usermodehelper_setcleanup(info
, argv_cleanup
);
1823 ret
= call_usermodehelper_exec(info
, UMH_NO_WAIT
);
1827 printk(KERN_WARNING
"Failed to start orderly shutdown: "
1828 "forcing the issue\n");
1830 /* I guess this should try to kick off some daemon to
1831 sync and poweroff asap. Or not even bother syncing
1832 if we're doing an emergency shutdown? */
1839 EXPORT_SYMBOL_GPL(orderly_poweroff
);