4 * Copyright (C) 1991, 1992 Linus Torvalds
7 #include <linux/export.h>
9 #include <linux/utsname.h>
10 #include <linux/mman.h>
11 #include <linux/reboot.h>
12 #include <linux/prctl.h>
13 #include <linux/highuid.h>
15 #include <linux/kmod.h>
16 #include <linux/perf_event.h>
17 #include <linux/resource.h>
18 #include <linux/kernel.h>
19 #include <linux/kexec.h>
20 #include <linux/workqueue.h>
21 #include <linux/capability.h>
22 #include <linux/device.h>
23 #include <linux/key.h>
24 #include <linux/times.h>
25 #include <linux/posix-timers.h>
26 #include <linux/security.h>
27 #include <linux/dcookies.h>
28 #include <linux/suspend.h>
29 #include <linux/tty.h>
30 #include <linux/signal.h>
31 #include <linux/cn_proc.h>
32 #include <linux/getcpu.h>
33 #include <linux/task_io_accounting_ops.h>
34 #include <linux/seccomp.h>
35 #include <linux/cpu.h>
36 #include <linux/personality.h>
37 #include <linux/ptrace.h>
38 #include <linux/fs_struct.h>
39 #include <linux/file.h>
40 #include <linux/mount.h>
41 #include <linux/gfp.h>
42 #include <linux/syscore_ops.h>
43 #include <linux/version.h>
44 #include <linux/ctype.h>
46 #include <linux/compat.h>
47 #include <linux/syscalls.h>
48 #include <linux/kprobes.h>
49 #include <linux/user_namespace.h>
50 #include <linux/binfmts.h>
52 #include <linux/kmsg_dump.h>
53 /* Move somewhere else to avoid recompiling? */
54 #include <generated/utsrelease.h>
56 #include <asm/uaccess.h>
58 #include <asm/unistd.h>
60 #ifndef SET_UNALIGN_CTL
61 # define SET_UNALIGN_CTL(a,b) (-EINVAL)
63 #ifndef GET_UNALIGN_CTL
64 # define GET_UNALIGN_CTL(a,b) (-EINVAL)
67 # define SET_FPEMU_CTL(a,b) (-EINVAL)
70 # define GET_FPEMU_CTL(a,b) (-EINVAL)
73 # define SET_FPEXC_CTL(a,b) (-EINVAL)
76 # define GET_FPEXC_CTL(a,b) (-EINVAL)
79 # define GET_ENDIAN(a,b) (-EINVAL)
82 # define SET_ENDIAN(a,b) (-EINVAL)
85 # define GET_TSC_CTL(a) (-EINVAL)
88 # define SET_TSC_CTL(a) (-EINVAL)
92 * this is where the system-wide overflow UID and GID are defined, for
93 * architectures that now have 32-bit UID/GID but didn't in the past
96 int overflowuid
= DEFAULT_OVERFLOWUID
;
97 int overflowgid
= DEFAULT_OVERFLOWGID
;
99 EXPORT_SYMBOL(overflowuid
);
100 EXPORT_SYMBOL(overflowgid
);
103 * the same as above, but for filesystems which can only store a 16-bit
104 * UID and GID. as such, this is needed on all architectures
107 int fs_overflowuid
= DEFAULT_FS_OVERFLOWUID
;
108 int fs_overflowgid
= DEFAULT_FS_OVERFLOWUID
;
110 EXPORT_SYMBOL(fs_overflowuid
);
111 EXPORT_SYMBOL(fs_overflowgid
);
114 * this indicates whether you can reboot with ctrl-alt-del: the default is yes
119 EXPORT_SYMBOL(cad_pid
);
122 * If set, this is used for preparing the system to power off.
125 void (*pm_power_off_prepare
)(void);
128 * Returns true if current's euid is same as p's uid or euid,
129 * or has CAP_SYS_NICE to p's user_ns.
131 * Called with rcu_read_lock, creds are safe
133 static bool set_one_prio_perm(struct task_struct
*p
)
135 const struct cred
*cred
= current_cred(), *pcred
= __task_cred(p
);
137 if (uid_eq(pcred
->uid
, cred
->euid
) ||
138 uid_eq(pcred
->euid
, cred
->euid
))
140 if (ns_capable(pcred
->user_ns
, CAP_SYS_NICE
))
146 * set the priority of a task
147 * - the caller must hold the RCU read lock
149 static int set_one_prio(struct task_struct
*p
, int niceval
, int error
)
153 if (!set_one_prio_perm(p
)) {
157 if (niceval
< task_nice(p
) && !can_nice(p
, niceval
)) {
161 no_nice
= security_task_setnice(p
, niceval
);
168 set_user_nice(p
, niceval
);
173 SYSCALL_DEFINE3(setpriority
, int, which
, int, who
, int, niceval
)
175 struct task_struct
*g
, *p
;
176 struct user_struct
*user
;
177 const struct cred
*cred
= current_cred();
182 if (which
> PRIO_USER
|| which
< PRIO_PROCESS
)
185 /* normalize: avoid signed division (rounding problems) */
193 read_lock(&tasklist_lock
);
197 p
= find_task_by_vpid(who
);
201 error
= set_one_prio(p
, niceval
, error
);
205 pgrp
= find_vpid(who
);
207 pgrp
= task_pgrp(current
);
208 do_each_pid_thread(pgrp
, PIDTYPE_PGID
, p
) {
209 error
= set_one_prio(p
, niceval
, error
);
210 } while_each_pid_thread(pgrp
, PIDTYPE_PGID
, p
);
213 uid
= make_kuid(cred
->user_ns
, who
);
217 else if (!uid_eq(uid
, cred
->uid
) &&
218 !(user
= find_user(uid
)))
219 goto out_unlock
; /* No processes for this user */
221 do_each_thread(g
, p
) {
222 if (uid_eq(task_uid(p
), uid
))
223 error
= set_one_prio(p
, niceval
, error
);
224 } while_each_thread(g
, p
);
225 if (!uid_eq(uid
, cred
->uid
))
226 free_uid(user
); /* For find_user() */
230 read_unlock(&tasklist_lock
);
237 * Ugh. To avoid negative return values, "getpriority()" will
238 * not return the normal nice-value, but a negated value that
239 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
240 * to stay compatible.
242 SYSCALL_DEFINE2(getpriority
, int, which
, int, who
)
244 struct task_struct
*g
, *p
;
245 struct user_struct
*user
;
246 const struct cred
*cred
= current_cred();
247 long niceval
, retval
= -ESRCH
;
251 if (which
> PRIO_USER
|| which
< PRIO_PROCESS
)
255 read_lock(&tasklist_lock
);
259 p
= find_task_by_vpid(who
);
263 niceval
= 20 - task_nice(p
);
264 if (niceval
> retval
)
270 pgrp
= find_vpid(who
);
272 pgrp
= task_pgrp(current
);
273 do_each_pid_thread(pgrp
, PIDTYPE_PGID
, p
) {
274 niceval
= 20 - task_nice(p
);
275 if (niceval
> retval
)
277 } while_each_pid_thread(pgrp
, PIDTYPE_PGID
, p
);
280 uid
= make_kuid(cred
->user_ns
, who
);
284 else if (!uid_eq(uid
, cred
->uid
) &&
285 !(user
= find_user(uid
)))
286 goto out_unlock
; /* No processes for this user */
288 do_each_thread(g
, p
) {
289 if (uid_eq(task_uid(p
), uid
)) {
290 niceval
= 20 - task_nice(p
);
291 if (niceval
> retval
)
294 } while_each_thread(g
, p
);
295 if (!uid_eq(uid
, cred
->uid
))
296 free_uid(user
); /* for find_user() */
300 read_unlock(&tasklist_lock
);
307 * emergency_restart - reboot the system
309 * Without shutting down any hardware or taking any locks
310 * reboot the system. This is called when we know we are in
311 * trouble so this is our best effort to reboot. This is
312 * safe to call in interrupt context.
314 void emergency_restart(void)
316 kmsg_dump(KMSG_DUMP_EMERG
);
317 machine_emergency_restart();
319 EXPORT_SYMBOL_GPL(emergency_restart
);
321 void kernel_restart_prepare(char *cmd
)
323 blocking_notifier_call_chain(&reboot_notifier_list
, SYS_RESTART
, cmd
);
324 system_state
= SYSTEM_RESTART
;
325 usermodehelper_disable();
330 * register_reboot_notifier - Register function to be called at reboot time
331 * @nb: Info about notifier function to be called
333 * Registers a function with the list of functions
334 * to be called at reboot time.
336 * Currently always returns zero, as blocking_notifier_chain_register()
337 * always returns zero.
339 int register_reboot_notifier(struct notifier_block
*nb
)
341 return blocking_notifier_chain_register(&reboot_notifier_list
, nb
);
343 EXPORT_SYMBOL(register_reboot_notifier
);
346 * unregister_reboot_notifier - Unregister previously registered reboot notifier
347 * @nb: Hook to be unregistered
349 * Unregisters a previously registered reboot
352 * Returns zero on success, or %-ENOENT on failure.
354 int unregister_reboot_notifier(struct notifier_block
*nb
)
356 return blocking_notifier_chain_unregister(&reboot_notifier_list
, nb
);
358 EXPORT_SYMBOL(unregister_reboot_notifier
);
361 * kernel_restart - reboot the system
362 * @cmd: pointer to buffer containing command to execute for restart
365 * Shutdown everything and perform a clean reboot.
366 * This is not safe to call in interrupt context.
368 void kernel_restart(char *cmd
)
370 kernel_restart_prepare(cmd
);
371 disable_nonboot_cpus();
374 printk(KERN_EMERG
"Restarting system.\n");
376 printk(KERN_EMERG
"Restarting system with command '%s'.\n", cmd
);
377 kmsg_dump(KMSG_DUMP_RESTART
);
378 machine_restart(cmd
);
380 EXPORT_SYMBOL_GPL(kernel_restart
);
382 static void kernel_shutdown_prepare(enum system_states state
)
384 blocking_notifier_call_chain(&reboot_notifier_list
,
385 (state
== SYSTEM_HALT
)?SYS_HALT
:SYS_POWER_OFF
, NULL
);
386 system_state
= state
;
387 usermodehelper_disable();
391 * kernel_halt - halt the system
393 * Shutdown everything and perform a clean system halt.
395 void kernel_halt(void)
397 kernel_shutdown_prepare(SYSTEM_HALT
);
398 disable_nonboot_cpus();
400 printk(KERN_EMERG
"System halted.\n");
401 kmsg_dump(KMSG_DUMP_HALT
);
405 EXPORT_SYMBOL_GPL(kernel_halt
);
408 * kernel_power_off - power_off the system
410 * Shutdown everything and perform a clean system power_off.
412 void kernel_power_off(void)
414 kernel_shutdown_prepare(SYSTEM_POWER_OFF
);
415 if (pm_power_off_prepare
)
416 pm_power_off_prepare();
417 disable_nonboot_cpus();
419 printk(KERN_EMERG
"Power down.\n");
420 kmsg_dump(KMSG_DUMP_POWEROFF
);
423 EXPORT_SYMBOL_GPL(kernel_power_off
);
425 static DEFINE_MUTEX(reboot_mutex
);
428 * Reboot system call: for obvious reasons only root may call it,
429 * and even root needs to set up some magic numbers in the registers
430 * so that some mistake won't make this reboot the whole machine.
431 * You can also set the meaning of the ctrl-alt-del-key here.
433 * reboot doesn't sync: do that yourself before calling this.
435 SYSCALL_DEFINE4(reboot
, int, magic1
, int, magic2
, unsigned int, cmd
,
438 struct pid_namespace
*pid_ns
= task_active_pid_ns(current
);
442 /* We only trust the superuser with rebooting the system. */
443 if (!ns_capable(pid_ns
->user_ns
, CAP_SYS_BOOT
))
446 /* For safety, we require "magic" arguments. */
447 if (magic1
!= LINUX_REBOOT_MAGIC1
||
448 (magic2
!= LINUX_REBOOT_MAGIC2
&&
449 magic2
!= LINUX_REBOOT_MAGIC2A
&&
450 magic2
!= LINUX_REBOOT_MAGIC2B
&&
451 magic2
!= LINUX_REBOOT_MAGIC2C
))
455 * If pid namespaces are enabled and the current task is in a child
456 * pid_namespace, the command is handled by reboot_pid_ns() which will
459 ret
= reboot_pid_ns(pid_ns
, cmd
);
463 /* Instead of trying to make the power_off code look like
464 * halt when pm_power_off is not set do it the easy way.
466 if ((cmd
== LINUX_REBOOT_CMD_POWER_OFF
) && !pm_power_off
)
467 cmd
= LINUX_REBOOT_CMD_HALT
;
469 mutex_lock(&reboot_mutex
);
471 case LINUX_REBOOT_CMD_RESTART
:
472 kernel_restart(NULL
);
475 case LINUX_REBOOT_CMD_CAD_ON
:
479 case LINUX_REBOOT_CMD_CAD_OFF
:
483 case LINUX_REBOOT_CMD_HALT
:
486 panic("cannot halt");
488 case LINUX_REBOOT_CMD_POWER_OFF
:
493 case LINUX_REBOOT_CMD_RESTART2
:
494 if (strncpy_from_user(&buffer
[0], arg
, sizeof(buffer
) - 1) < 0) {
498 buffer
[sizeof(buffer
) - 1] = '\0';
500 kernel_restart(buffer
);
504 case LINUX_REBOOT_CMD_KEXEC
:
505 ret
= kernel_kexec();
509 #ifdef CONFIG_HIBERNATION
510 case LINUX_REBOOT_CMD_SW_SUSPEND
:
519 mutex_unlock(&reboot_mutex
);
523 static void deferred_cad(struct work_struct
*dummy
)
525 kernel_restart(NULL
);
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.
533 void ctrl_alt_del(void)
535 static DECLARE_WORK(cad_work
, deferred_cad
);
538 schedule_work(&cad_work
);
540 kill_cad_pid(SIGINT
, 1);
544 * Unprivileged users may change the real gid to the effective gid
545 * or vice versa. (BSD-style)
547 * If you set the real gid at all, or set the effective gid to a value not
548 * equal to the real gid, then the saved gid is set to the new effective gid.
550 * This makes it possible for a setgid program to completely drop its
551 * privileges, which is often a useful assertion to make when you are doing
552 * a security audit over a program.
554 * The general idea is that a program which uses just setregid() will be
555 * 100% compatible with BSD. A program which uses just setgid() will be
556 * 100% compatible with POSIX with saved IDs.
558 * SMP: There are not races, the GIDs are checked only by filesystem
559 * operations (as far as semantic preservation is concerned).
561 SYSCALL_DEFINE2(setregid
, gid_t
, rgid
, gid_t
, egid
)
563 struct user_namespace
*ns
= current_user_ns();
564 const struct cred
*old
;
569 krgid
= make_kgid(ns
, rgid
);
570 kegid
= make_kgid(ns
, egid
);
572 if ((rgid
!= (gid_t
) -1) && !gid_valid(krgid
))
574 if ((egid
!= (gid_t
) -1) && !gid_valid(kegid
))
577 new = prepare_creds();
580 old
= current_cred();
583 if (rgid
!= (gid_t
) -1) {
584 if (gid_eq(old
->gid
, krgid
) ||
585 gid_eq(old
->egid
, krgid
) ||
586 nsown_capable(CAP_SETGID
))
591 if (egid
!= (gid_t
) -1) {
592 if (gid_eq(old
->gid
, kegid
) ||
593 gid_eq(old
->egid
, kegid
) ||
594 gid_eq(old
->sgid
, kegid
) ||
595 nsown_capable(CAP_SETGID
))
601 if (rgid
!= (gid_t
) -1 ||
602 (egid
!= (gid_t
) -1 && !gid_eq(kegid
, old
->gid
)))
603 new->sgid
= new->egid
;
604 new->fsgid
= new->egid
;
606 return commit_creds(new);
614 * setgid() is implemented like SysV w/ SAVED_IDS
616 * SMP: Same implicit races as above.
618 SYSCALL_DEFINE1(setgid
, gid_t
, gid
)
620 struct user_namespace
*ns
= current_user_ns();
621 const struct cred
*old
;
626 kgid
= make_kgid(ns
, gid
);
627 if (!gid_valid(kgid
))
630 new = prepare_creds();
633 old
= current_cred();
636 if (nsown_capable(CAP_SETGID
))
637 new->gid
= new->egid
= new->sgid
= new->fsgid
= kgid
;
638 else if (gid_eq(kgid
, old
->gid
) || gid_eq(kgid
, old
->sgid
))
639 new->egid
= new->fsgid
= kgid
;
643 return commit_creds(new);
651 * change the user struct in a credentials set to match the new UID
653 static int set_user(struct cred
*new)
655 struct user_struct
*new_user
;
657 new_user
= alloc_uid(new->uid
);
662 * We don't fail in case of NPROC limit excess here because too many
663 * poorly written programs don't check set*uid() return code, assuming
664 * it never fails if called by root. We may still enforce NPROC limit
665 * for programs doing set*uid()+execve() by harmlessly deferring the
666 * failure to the execve() stage.
668 if (atomic_read(&new_user
->processes
) >= rlimit(RLIMIT_NPROC
) &&
669 new_user
!= INIT_USER
)
670 current
->flags
|= PF_NPROC_EXCEEDED
;
672 current
->flags
&= ~PF_NPROC_EXCEEDED
;
675 new->user
= new_user
;
680 * Unprivileged users may change the real uid to the effective uid
681 * or vice versa. (BSD-style)
683 * If you set the real uid at all, or set the effective uid to a value not
684 * equal to the real uid, then the saved uid is set to the new effective uid.
686 * This makes it possible for a setuid program to completely drop its
687 * privileges, which is often a useful assertion to make when you are doing
688 * a security audit over a program.
690 * The general idea is that a program which uses just setreuid() will be
691 * 100% compatible with BSD. A program which uses just setuid() will be
692 * 100% compatible with POSIX with saved IDs.
694 SYSCALL_DEFINE2(setreuid
, uid_t
, ruid
, uid_t
, euid
)
696 struct user_namespace
*ns
= current_user_ns();
697 const struct cred
*old
;
702 kruid
= make_kuid(ns
, ruid
);
703 keuid
= make_kuid(ns
, euid
);
705 if ((ruid
!= (uid_t
) -1) && !uid_valid(kruid
))
707 if ((euid
!= (uid_t
) -1) && !uid_valid(keuid
))
710 new = prepare_creds();
713 old
= current_cred();
716 if (ruid
!= (uid_t
) -1) {
718 if (!uid_eq(old
->uid
, kruid
) &&
719 !uid_eq(old
->euid
, kruid
) &&
720 !nsown_capable(CAP_SETUID
))
724 if (euid
!= (uid_t
) -1) {
726 if (!uid_eq(old
->uid
, keuid
) &&
727 !uid_eq(old
->euid
, keuid
) &&
728 !uid_eq(old
->suid
, keuid
) &&
729 !nsown_capable(CAP_SETUID
))
733 if (!uid_eq(new->uid
, old
->uid
)) {
734 retval
= set_user(new);
738 if (ruid
!= (uid_t
) -1 ||
739 (euid
!= (uid_t
) -1 && !uid_eq(keuid
, old
->uid
)))
740 new->suid
= new->euid
;
741 new->fsuid
= new->euid
;
743 retval
= security_task_fix_setuid(new, old
, LSM_SETID_RE
);
747 return commit_creds(new);
755 * setuid() is implemented like SysV with SAVED_IDS
757 * Note that SAVED_ID's is deficient in that a setuid root program
758 * like sendmail, for example, cannot set its uid to be a normal
759 * user and then switch back, because if you're root, setuid() sets
760 * the saved uid too. If you don't like this, blame the bright people
761 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
762 * will allow a root program to temporarily drop privileges and be able to
763 * regain them by swapping the real and effective uid.
765 SYSCALL_DEFINE1(setuid
, uid_t
, uid
)
767 struct user_namespace
*ns
= current_user_ns();
768 const struct cred
*old
;
773 kuid
= make_kuid(ns
, uid
);
774 if (!uid_valid(kuid
))
777 new = prepare_creds();
780 old
= current_cred();
783 if (nsown_capable(CAP_SETUID
)) {
784 new->suid
= new->uid
= kuid
;
785 if (!uid_eq(kuid
, old
->uid
)) {
786 retval
= set_user(new);
790 } else if (!uid_eq(kuid
, old
->uid
) && !uid_eq(kuid
, new->suid
)) {
794 new->fsuid
= new->euid
= kuid
;
796 retval
= security_task_fix_setuid(new, old
, LSM_SETID_ID
);
800 return commit_creds(new);
809 * This function implements a generic ability to update ruid, euid,
810 * and suid. This allows you to implement the 4.4 compatible seteuid().
812 SYSCALL_DEFINE3(setresuid
, uid_t
, ruid
, uid_t
, euid
, uid_t
, suid
)
814 struct user_namespace
*ns
= current_user_ns();
815 const struct cred
*old
;
818 kuid_t kruid
, keuid
, ksuid
;
820 kruid
= make_kuid(ns
, ruid
);
821 keuid
= make_kuid(ns
, euid
);
822 ksuid
= make_kuid(ns
, suid
);
824 if ((ruid
!= (uid_t
) -1) && !uid_valid(kruid
))
827 if ((euid
!= (uid_t
) -1) && !uid_valid(keuid
))
830 if ((suid
!= (uid_t
) -1) && !uid_valid(ksuid
))
833 new = prepare_creds();
837 old
= current_cred();
840 if (!nsown_capable(CAP_SETUID
)) {
841 if (ruid
!= (uid_t
) -1 && !uid_eq(kruid
, old
->uid
) &&
842 !uid_eq(kruid
, old
->euid
) && !uid_eq(kruid
, old
->suid
))
844 if (euid
!= (uid_t
) -1 && !uid_eq(keuid
, old
->uid
) &&
845 !uid_eq(keuid
, old
->euid
) && !uid_eq(keuid
, old
->suid
))
847 if (suid
!= (uid_t
) -1 && !uid_eq(ksuid
, old
->uid
) &&
848 !uid_eq(ksuid
, old
->euid
) && !uid_eq(ksuid
, old
->suid
))
852 if (ruid
!= (uid_t
) -1) {
854 if (!uid_eq(kruid
, old
->uid
)) {
855 retval
= set_user(new);
860 if (euid
!= (uid_t
) -1)
862 if (suid
!= (uid_t
) -1)
864 new->fsuid
= new->euid
;
866 retval
= security_task_fix_setuid(new, old
, LSM_SETID_RES
);
870 return commit_creds(new);
877 SYSCALL_DEFINE3(getresuid
, uid_t __user
*, ruidp
, uid_t __user
*, euidp
, uid_t __user
*, suidp
)
879 const struct cred
*cred
= current_cred();
881 uid_t ruid
, euid
, suid
;
883 ruid
= from_kuid_munged(cred
->user_ns
, cred
->uid
);
884 euid
= from_kuid_munged(cred
->user_ns
, cred
->euid
);
885 suid
= from_kuid_munged(cred
->user_ns
, cred
->suid
);
887 if (!(retval
= put_user(ruid
, ruidp
)) &&
888 !(retval
= put_user(euid
, euidp
)))
889 retval
= put_user(suid
, suidp
);
895 * Same as above, but for rgid, egid, sgid.
897 SYSCALL_DEFINE3(setresgid
, gid_t
, rgid
, gid_t
, egid
, gid_t
, sgid
)
899 struct user_namespace
*ns
= current_user_ns();
900 const struct cred
*old
;
903 kgid_t krgid
, kegid
, ksgid
;
905 krgid
= make_kgid(ns
, rgid
);
906 kegid
= make_kgid(ns
, egid
);
907 ksgid
= make_kgid(ns
, sgid
);
909 if ((rgid
!= (gid_t
) -1) && !gid_valid(krgid
))
911 if ((egid
!= (gid_t
) -1) && !gid_valid(kegid
))
913 if ((sgid
!= (gid_t
) -1) && !gid_valid(ksgid
))
916 new = prepare_creds();
919 old
= current_cred();
922 if (!nsown_capable(CAP_SETGID
)) {
923 if (rgid
!= (gid_t
) -1 && !gid_eq(krgid
, old
->gid
) &&
924 !gid_eq(krgid
, old
->egid
) && !gid_eq(krgid
, old
->sgid
))
926 if (egid
!= (gid_t
) -1 && !gid_eq(kegid
, old
->gid
) &&
927 !gid_eq(kegid
, old
->egid
) && !gid_eq(kegid
, old
->sgid
))
929 if (sgid
!= (gid_t
) -1 && !gid_eq(ksgid
, old
->gid
) &&
930 !gid_eq(ksgid
, old
->egid
) && !gid_eq(ksgid
, old
->sgid
))
934 if (rgid
!= (gid_t
) -1)
936 if (egid
!= (gid_t
) -1)
938 if (sgid
!= (gid_t
) -1)
940 new->fsgid
= new->egid
;
942 return commit_creds(new);
949 SYSCALL_DEFINE3(getresgid
, gid_t __user
*, rgidp
, gid_t __user
*, egidp
, gid_t __user
*, sgidp
)
951 const struct cred
*cred
= current_cred();
953 gid_t rgid
, egid
, sgid
;
955 rgid
= from_kgid_munged(cred
->user_ns
, cred
->gid
);
956 egid
= from_kgid_munged(cred
->user_ns
, cred
->egid
);
957 sgid
= from_kgid_munged(cred
->user_ns
, cred
->sgid
);
959 if (!(retval
= put_user(rgid
, rgidp
)) &&
960 !(retval
= put_user(egid
, egidp
)))
961 retval
= put_user(sgid
, sgidp
);
968 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
969 * is used for "access()" and for the NFS daemon (letting nfsd stay at
970 * whatever uid it wants to). It normally shadows "euid", except when
971 * explicitly set by setfsuid() or for access..
973 SYSCALL_DEFINE1(setfsuid
, uid_t
, uid
)
975 const struct cred
*old
;
980 old
= current_cred();
981 old_fsuid
= from_kuid_munged(old
->user_ns
, old
->fsuid
);
983 kuid
= make_kuid(old
->user_ns
, uid
);
984 if (!uid_valid(kuid
))
987 new = prepare_creds();
991 if (uid_eq(kuid
, old
->uid
) || uid_eq(kuid
, old
->euid
) ||
992 uid_eq(kuid
, old
->suid
) || uid_eq(kuid
, old
->fsuid
) ||
993 nsown_capable(CAP_SETUID
)) {
994 if (!uid_eq(kuid
, old
->fsuid
)) {
996 if (security_task_fix_setuid(new, old
, LSM_SETID_FS
) == 0)
1010 * Samma på svenska..
1012 SYSCALL_DEFINE1(setfsgid
, gid_t
, gid
)
1014 const struct cred
*old
;
1019 old
= current_cred();
1020 old_fsgid
= from_kgid_munged(old
->user_ns
, old
->fsgid
);
1022 kgid
= make_kgid(old
->user_ns
, gid
);
1023 if (!gid_valid(kgid
))
1026 new = prepare_creds();
1030 if (gid_eq(kgid
, old
->gid
) || gid_eq(kgid
, old
->egid
) ||
1031 gid_eq(kgid
, old
->sgid
) || gid_eq(kgid
, old
->fsgid
) ||
1032 nsown_capable(CAP_SETGID
)) {
1033 if (!gid_eq(kgid
, old
->fsgid
)) {
1047 void do_sys_times(struct tms
*tms
)
1049 cputime_t tgutime
, tgstime
, cutime
, cstime
;
1051 spin_lock_irq(¤t
->sighand
->siglock
);
1052 thread_group_cputime_adjusted(current
, &tgutime
, &tgstime
);
1053 cutime
= current
->signal
->cutime
;
1054 cstime
= current
->signal
->cstime
;
1055 spin_unlock_irq(¤t
->sighand
->siglock
);
1056 tms
->tms_utime
= cputime_to_clock_t(tgutime
);
1057 tms
->tms_stime
= cputime_to_clock_t(tgstime
);
1058 tms
->tms_cutime
= cputime_to_clock_t(cutime
);
1059 tms
->tms_cstime
= cputime_to_clock_t(cstime
);
1062 SYSCALL_DEFINE1(times
, struct tms __user
*, tbuf
)
1068 if (copy_to_user(tbuf
, &tmp
, sizeof(struct tms
)))
1071 force_successful_syscall_return();
1072 return (long) jiffies_64_to_clock_t(get_jiffies_64());
1076 * This needs some heavy checking ...
1077 * I just haven't the stomach for it. I also don't fully
1078 * understand sessions/pgrp etc. Let somebody who does explain it.
1080 * OK, I think I have the protection semantics right.... this is really
1081 * only important on a multi-user system anyway, to make sure one user
1082 * can't send a signal to a process owned by another. -TYT, 12/12/91
1084 * Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
1087 SYSCALL_DEFINE2(setpgid
, pid_t
, pid
, pid_t
, pgid
)
1089 struct task_struct
*p
;
1090 struct task_struct
*group_leader
= current
->group_leader
;
1095 pid
= task_pid_vnr(group_leader
);
1102 /* From this point forward we keep holding onto the tasklist lock
1103 * so that our parent does not change from under us. -DaveM
1105 write_lock_irq(&tasklist_lock
);
1108 p
= find_task_by_vpid(pid
);
1113 if (!thread_group_leader(p
))
1116 if (same_thread_group(p
->real_parent
, group_leader
)) {
1118 if (task_session(p
) != task_session(group_leader
))
1125 if (p
!= group_leader
)
1130 if (p
->signal
->leader
)
1135 struct task_struct
*g
;
1137 pgrp
= find_vpid(pgid
);
1138 g
= pid_task(pgrp
, PIDTYPE_PGID
);
1139 if (!g
|| task_session(g
) != task_session(group_leader
))
1143 err
= security_task_setpgid(p
, pgid
);
1147 if (task_pgrp(p
) != pgrp
)
1148 change_pid(p
, PIDTYPE_PGID
, pgrp
);
1152 /* All paths lead to here, thus we are safe. -DaveM */
1153 write_unlock_irq(&tasklist_lock
);
1158 SYSCALL_DEFINE1(getpgid
, pid_t
, pid
)
1160 struct task_struct
*p
;
1166 grp
= task_pgrp(current
);
1169 p
= find_task_by_vpid(pid
);
1176 retval
= security_task_getpgid(p
);
1180 retval
= pid_vnr(grp
);
1186 #ifdef __ARCH_WANT_SYS_GETPGRP
1188 SYSCALL_DEFINE0(getpgrp
)
1190 return sys_getpgid(0);
1195 SYSCALL_DEFINE1(getsid
, pid_t
, pid
)
1197 struct task_struct
*p
;
1203 sid
= task_session(current
);
1206 p
= find_task_by_vpid(pid
);
1209 sid
= task_session(p
);
1213 retval
= security_task_getsid(p
);
1217 retval
= pid_vnr(sid
);
1223 SYSCALL_DEFINE0(setsid
)
1225 struct task_struct
*group_leader
= current
->group_leader
;
1226 struct pid
*sid
= task_pid(group_leader
);
1227 pid_t session
= pid_vnr(sid
);
1230 write_lock_irq(&tasklist_lock
);
1231 /* Fail if I am already a session leader */
1232 if (group_leader
->signal
->leader
)
1235 /* Fail if a process group id already exists that equals the
1236 * proposed session id.
1238 if (pid_task(sid
, PIDTYPE_PGID
))
1241 group_leader
->signal
->leader
= 1;
1242 __set_special_pids(sid
);
1244 proc_clear_tty(group_leader
);
1248 write_unlock_irq(&tasklist_lock
);
1250 proc_sid_connector(group_leader
);
1251 sched_autogroup_create_attach(group_leader
);
1256 DECLARE_RWSEM(uts_sem
);
1258 #ifdef COMPAT_UTS_MACHINE
1259 #define override_architecture(name) \
1260 (personality(current->personality) == PER_LINUX32 && \
1261 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \
1262 sizeof(COMPAT_UTS_MACHINE)))
1264 #define override_architecture(name) 0
1268 * Work around broken programs that cannot handle "Linux 3.0".
1269 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40
1271 static int override_release(char __user
*release
, size_t len
)
1275 if (current
->personality
& UNAME26
) {
1276 const char *rest
= UTS_RELEASE
;
1277 char buf
[65] = { 0 };
1283 if (*rest
== '.' && ++ndots
>= 3)
1285 if (!isdigit(*rest
) && *rest
!= '.')
1289 v
= ((LINUX_VERSION_CODE
>> 8) & 0xff) + 40;
1290 copy
= clamp_t(size_t, len
, 1, sizeof(buf
));
1291 copy
= scnprintf(buf
, copy
, "2.6.%u%s", v
, rest
);
1292 ret
= copy_to_user(release
, buf
, copy
+ 1);
1297 SYSCALL_DEFINE1(newuname
, struct new_utsname __user
*, name
)
1301 down_read(&uts_sem
);
1302 if (copy_to_user(name
, utsname(), sizeof *name
))
1306 if (!errno
&& override_release(name
->release
, sizeof(name
->release
)))
1308 if (!errno
&& override_architecture(name
))
1313 #ifdef __ARCH_WANT_SYS_OLD_UNAME
1317 SYSCALL_DEFINE1(uname
, struct old_utsname __user
*, name
)
1324 down_read(&uts_sem
);
1325 if (copy_to_user(name
, utsname(), sizeof(*name
)))
1329 if (!error
&& override_release(name
->release
, sizeof(name
->release
)))
1331 if (!error
&& override_architecture(name
))
1336 SYSCALL_DEFINE1(olduname
, struct oldold_utsname __user
*, name
)
1342 if (!access_ok(VERIFY_WRITE
, name
, sizeof(struct oldold_utsname
)))
1345 down_read(&uts_sem
);
1346 error
= __copy_to_user(&name
->sysname
, &utsname()->sysname
,
1348 error
|= __put_user(0, name
->sysname
+ __OLD_UTS_LEN
);
1349 error
|= __copy_to_user(&name
->nodename
, &utsname()->nodename
,
1351 error
|= __put_user(0, name
->nodename
+ __OLD_UTS_LEN
);
1352 error
|= __copy_to_user(&name
->release
, &utsname()->release
,
1354 error
|= __put_user(0, name
->release
+ __OLD_UTS_LEN
);
1355 error
|= __copy_to_user(&name
->version
, &utsname()->version
,
1357 error
|= __put_user(0, name
->version
+ __OLD_UTS_LEN
);
1358 error
|= __copy_to_user(&name
->machine
, &utsname()->machine
,
1360 error
|= __put_user(0, name
->machine
+ __OLD_UTS_LEN
);
1363 if (!error
&& override_architecture(name
))
1365 if (!error
&& override_release(name
->release
, sizeof(name
->release
)))
1367 return error
? -EFAULT
: 0;
1371 SYSCALL_DEFINE2(sethostname
, char __user
*, name
, int, len
)
1374 char tmp
[__NEW_UTS_LEN
];
1376 if (!ns_capable(current
->nsproxy
->uts_ns
->user_ns
, CAP_SYS_ADMIN
))
1379 if (len
< 0 || len
> __NEW_UTS_LEN
)
1381 down_write(&uts_sem
);
1383 if (!copy_from_user(tmp
, name
, len
)) {
1384 struct new_utsname
*u
= utsname();
1386 memcpy(u
->nodename
, tmp
, len
);
1387 memset(u
->nodename
+ len
, 0, sizeof(u
->nodename
) - len
);
1389 uts_proc_notify(UTS_PROC_HOSTNAME
);
1395 #ifdef __ARCH_WANT_SYS_GETHOSTNAME
1397 SYSCALL_DEFINE2(gethostname
, char __user
*, name
, int, len
)
1400 struct new_utsname
*u
;
1404 down_read(&uts_sem
);
1406 i
= 1 + strlen(u
->nodename
);
1410 if (copy_to_user(name
, u
->nodename
, i
))
1419 * Only setdomainname; getdomainname can be implemented by calling
1422 SYSCALL_DEFINE2(setdomainname
, char __user
*, name
, int, len
)
1425 char tmp
[__NEW_UTS_LEN
];
1427 if (!ns_capable(current
->nsproxy
->uts_ns
->user_ns
, CAP_SYS_ADMIN
))
1429 if (len
< 0 || len
> __NEW_UTS_LEN
)
1432 down_write(&uts_sem
);
1434 if (!copy_from_user(tmp
, name
, len
)) {
1435 struct new_utsname
*u
= utsname();
1437 memcpy(u
->domainname
, tmp
, len
);
1438 memset(u
->domainname
+ len
, 0, sizeof(u
->domainname
) - len
);
1440 uts_proc_notify(UTS_PROC_DOMAINNAME
);
1446 SYSCALL_DEFINE2(getrlimit
, unsigned int, resource
, struct rlimit __user
*, rlim
)
1448 struct rlimit value
;
1451 ret
= do_prlimit(current
, resource
, NULL
, &value
);
1453 ret
= copy_to_user(rlim
, &value
, sizeof(*rlim
)) ? -EFAULT
: 0;
1458 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1461 * Back compatibility for getrlimit. Needed for some apps.
1464 SYSCALL_DEFINE2(old_getrlimit
, unsigned int, resource
,
1465 struct rlimit __user
*, rlim
)
1468 if (resource
>= RLIM_NLIMITS
)
1471 task_lock(current
->group_leader
);
1472 x
= current
->signal
->rlim
[resource
];
1473 task_unlock(current
->group_leader
);
1474 if (x
.rlim_cur
> 0x7FFFFFFF)
1475 x
.rlim_cur
= 0x7FFFFFFF;
1476 if (x
.rlim_max
> 0x7FFFFFFF)
1477 x
.rlim_max
= 0x7FFFFFFF;
1478 return copy_to_user(rlim
, &x
, sizeof(x
))?-EFAULT
:0;
1483 static inline bool rlim64_is_infinity(__u64 rlim64
)
1485 #if BITS_PER_LONG < 64
1486 return rlim64
>= ULONG_MAX
;
1488 return rlim64
== RLIM64_INFINITY
;
1492 static void rlim_to_rlim64(const struct rlimit
*rlim
, struct rlimit64
*rlim64
)
1494 if (rlim
->rlim_cur
== RLIM_INFINITY
)
1495 rlim64
->rlim_cur
= RLIM64_INFINITY
;
1497 rlim64
->rlim_cur
= rlim
->rlim_cur
;
1498 if (rlim
->rlim_max
== RLIM_INFINITY
)
1499 rlim64
->rlim_max
= RLIM64_INFINITY
;
1501 rlim64
->rlim_max
= rlim
->rlim_max
;
1504 static void rlim64_to_rlim(const struct rlimit64
*rlim64
, struct rlimit
*rlim
)
1506 if (rlim64_is_infinity(rlim64
->rlim_cur
))
1507 rlim
->rlim_cur
= RLIM_INFINITY
;
1509 rlim
->rlim_cur
= (unsigned long)rlim64
->rlim_cur
;
1510 if (rlim64_is_infinity(rlim64
->rlim_max
))
1511 rlim
->rlim_max
= RLIM_INFINITY
;
1513 rlim
->rlim_max
= (unsigned long)rlim64
->rlim_max
;
1516 /* make sure you are allowed to change @tsk limits before calling this */
1517 int do_prlimit(struct task_struct
*tsk
, unsigned int resource
,
1518 struct rlimit
*new_rlim
, struct rlimit
*old_rlim
)
1520 struct rlimit
*rlim
;
1523 if (resource
>= RLIM_NLIMITS
)
1526 if (new_rlim
->rlim_cur
> new_rlim
->rlim_max
)
1528 if (resource
== RLIMIT_NOFILE
&&
1529 new_rlim
->rlim_max
> sysctl_nr_open
)
1533 /* protect tsk->signal and tsk->sighand from disappearing */
1534 read_lock(&tasklist_lock
);
1535 if (!tsk
->sighand
) {
1540 rlim
= tsk
->signal
->rlim
+ resource
;
1541 task_lock(tsk
->group_leader
);
1543 /* Keep the capable check against init_user_ns until
1544 cgroups can contain all limits */
1545 if (new_rlim
->rlim_max
> rlim
->rlim_max
&&
1546 !capable(CAP_SYS_RESOURCE
))
1549 retval
= security_task_setrlimit(tsk
->group_leader
,
1550 resource
, new_rlim
);
1551 if (resource
== RLIMIT_CPU
&& new_rlim
->rlim_cur
== 0) {
1553 * The caller is asking for an immediate RLIMIT_CPU
1554 * expiry. But we use the zero value to mean "it was
1555 * never set". So let's cheat and make it one second
1558 new_rlim
->rlim_cur
= 1;
1567 task_unlock(tsk
->group_leader
);
1570 * RLIMIT_CPU handling. Note that the kernel fails to return an error
1571 * code if it rejected the user's attempt to set RLIMIT_CPU. This is a
1572 * very long-standing error, and fixing it now risks breakage of
1573 * applications, so we live with it
1575 if (!retval
&& new_rlim
&& resource
== RLIMIT_CPU
&&
1576 new_rlim
->rlim_cur
!= RLIM_INFINITY
)
1577 update_rlimit_cpu(tsk
, new_rlim
->rlim_cur
);
1579 read_unlock(&tasklist_lock
);
1583 /* rcu lock must be held */
1584 static int check_prlimit_permission(struct task_struct
*task
)
1586 const struct cred
*cred
= current_cred(), *tcred
;
1588 if (current
== task
)
1591 tcred
= __task_cred(task
);
1592 if (uid_eq(cred
->uid
, tcred
->euid
) &&
1593 uid_eq(cred
->uid
, tcred
->suid
) &&
1594 uid_eq(cred
->uid
, tcred
->uid
) &&
1595 gid_eq(cred
->gid
, tcred
->egid
) &&
1596 gid_eq(cred
->gid
, tcred
->sgid
) &&
1597 gid_eq(cred
->gid
, tcred
->gid
))
1599 if (ns_capable(tcred
->user_ns
, CAP_SYS_RESOURCE
))
1605 SYSCALL_DEFINE4(prlimit64
, pid_t
, pid
, unsigned int, resource
,
1606 const struct rlimit64 __user
*, new_rlim
,
1607 struct rlimit64 __user
*, old_rlim
)
1609 struct rlimit64 old64
, new64
;
1610 struct rlimit old
, new;
1611 struct task_struct
*tsk
;
1615 if (copy_from_user(&new64
, new_rlim
, sizeof(new64
)))
1617 rlim64_to_rlim(&new64
, &new);
1621 tsk
= pid
? find_task_by_vpid(pid
) : current
;
1626 ret
= check_prlimit_permission(tsk
);
1631 get_task_struct(tsk
);
1634 ret
= do_prlimit(tsk
, resource
, new_rlim
? &new : NULL
,
1635 old_rlim
? &old
: NULL
);
1637 if (!ret
&& old_rlim
) {
1638 rlim_to_rlim64(&old
, &old64
);
1639 if (copy_to_user(old_rlim
, &old64
, sizeof(old64
)))
1643 put_task_struct(tsk
);
1647 SYSCALL_DEFINE2(setrlimit
, unsigned int, resource
, struct rlimit __user
*, rlim
)
1649 struct rlimit new_rlim
;
1651 if (copy_from_user(&new_rlim
, rlim
, sizeof(*rlim
)))
1653 return do_prlimit(current
, resource
, &new_rlim
, NULL
);
1657 * It would make sense to put struct rusage in the task_struct,
1658 * except that would make the task_struct be *really big*. After
1659 * task_struct gets moved into malloc'ed memory, it would
1660 * make sense to do this. It will make moving the rest of the information
1661 * a lot simpler! (Which we're not doing right now because we're not
1662 * measuring them yet).
1664 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1665 * races with threads incrementing their own counters. But since word
1666 * reads are atomic, we either get new values or old values and we don't
1667 * care which for the sums. We always take the siglock to protect reading
1668 * the c* fields from p->signal from races with exit.c updating those
1669 * fields when reaping, so a sample either gets all the additions of a
1670 * given child after it's reaped, or none so this sample is before reaping.
1673 * We need to take the siglock for CHILDEREN, SELF and BOTH
1674 * for the cases current multithreaded, non-current single threaded
1675 * non-current multithreaded. Thread traversal is now safe with
1677 * Strictly speaking, we donot need to take the siglock if we are current and
1678 * single threaded, as no one else can take our signal_struct away, no one
1679 * else can reap the children to update signal->c* counters, and no one else
1680 * can race with the signal-> fields. If we do not take any lock, the
1681 * signal-> fields could be read out of order while another thread was just
1682 * exiting. So we should place a read memory barrier when we avoid the lock.
1683 * On the writer side, write memory barrier is implied in __exit_signal
1684 * as __exit_signal releases the siglock spinlock after updating the signal->
1685 * fields. But we don't do this yet to keep things simple.
1689 static void accumulate_thread_rusage(struct task_struct
*t
, struct rusage
*r
)
1691 r
->ru_nvcsw
+= t
->nvcsw
;
1692 r
->ru_nivcsw
+= t
->nivcsw
;
1693 r
->ru_minflt
+= t
->min_flt
;
1694 r
->ru_majflt
+= t
->maj_flt
;
1695 r
->ru_inblock
+= task_io_get_inblock(t
);
1696 r
->ru_oublock
+= task_io_get_oublock(t
);
1699 static void k_getrusage(struct task_struct
*p
, int who
, struct rusage
*r
)
1701 struct task_struct
*t
;
1702 unsigned long flags
;
1703 cputime_t tgutime
, tgstime
, utime
, stime
;
1704 unsigned long maxrss
= 0;
1706 memset((char *) r
, 0, sizeof *r
);
1709 if (who
== RUSAGE_THREAD
) {
1710 task_cputime_adjusted(current
, &utime
, &stime
);
1711 accumulate_thread_rusage(p
, r
);
1712 maxrss
= p
->signal
->maxrss
;
1716 if (!lock_task_sighand(p
, &flags
))
1721 case RUSAGE_CHILDREN
:
1722 utime
= p
->signal
->cutime
;
1723 stime
= p
->signal
->cstime
;
1724 r
->ru_nvcsw
= p
->signal
->cnvcsw
;
1725 r
->ru_nivcsw
= p
->signal
->cnivcsw
;
1726 r
->ru_minflt
= p
->signal
->cmin_flt
;
1727 r
->ru_majflt
= p
->signal
->cmaj_flt
;
1728 r
->ru_inblock
= p
->signal
->cinblock
;
1729 r
->ru_oublock
= p
->signal
->coublock
;
1730 maxrss
= p
->signal
->cmaxrss
;
1732 if (who
== RUSAGE_CHILDREN
)
1736 thread_group_cputime_adjusted(p
, &tgutime
, &tgstime
);
1739 r
->ru_nvcsw
+= p
->signal
->nvcsw
;
1740 r
->ru_nivcsw
+= p
->signal
->nivcsw
;
1741 r
->ru_minflt
+= p
->signal
->min_flt
;
1742 r
->ru_majflt
+= p
->signal
->maj_flt
;
1743 r
->ru_inblock
+= p
->signal
->inblock
;
1744 r
->ru_oublock
+= p
->signal
->oublock
;
1745 if (maxrss
< p
->signal
->maxrss
)
1746 maxrss
= p
->signal
->maxrss
;
1749 accumulate_thread_rusage(t
, r
);
1757 unlock_task_sighand(p
, &flags
);
1760 cputime_to_timeval(utime
, &r
->ru_utime
);
1761 cputime_to_timeval(stime
, &r
->ru_stime
);
1763 if (who
!= RUSAGE_CHILDREN
) {
1764 struct mm_struct
*mm
= get_task_mm(p
);
1766 setmax_mm_hiwater_rss(&maxrss
, mm
);
1770 r
->ru_maxrss
= maxrss
* (PAGE_SIZE
/ 1024); /* convert pages to KBs */
1773 int getrusage(struct task_struct
*p
, int who
, struct rusage __user
*ru
)
1776 k_getrusage(p
, who
, &r
);
1777 return copy_to_user(ru
, &r
, sizeof(r
)) ? -EFAULT
: 0;
1780 SYSCALL_DEFINE2(getrusage
, int, who
, struct rusage __user
*, ru
)
1782 if (who
!= RUSAGE_SELF
&& who
!= RUSAGE_CHILDREN
&&
1783 who
!= RUSAGE_THREAD
)
1785 return getrusage(current
, who
, ru
);
1788 SYSCALL_DEFINE1(umask
, int, mask
)
1790 mask
= xchg(¤t
->fs
->umask
, mask
& S_IRWXUGO
);
1794 #ifdef CONFIG_CHECKPOINT_RESTORE
1795 static int prctl_set_mm_exe_file(struct mm_struct
*mm
, unsigned int fd
)
1798 struct inode
*inode
;
1805 inode
= file_inode(exe
.file
);
1808 * Because the original mm->exe_file points to executable file, make
1809 * sure that this one is executable as well, to avoid breaking an
1813 if (!S_ISREG(inode
->i_mode
) ||
1814 exe
.file
->f_path
.mnt
->mnt_flags
& MNT_NOEXEC
)
1817 err
= inode_permission(inode
, MAY_EXEC
);
1821 down_write(&mm
->mmap_sem
);
1824 * Forbid mm->exe_file change if old file still mapped.
1828 struct vm_area_struct
*vma
;
1830 for (vma
= mm
->mmap
; vma
; vma
= vma
->vm_next
)
1832 path_equal(&vma
->vm_file
->f_path
,
1833 &mm
->exe_file
->f_path
))
1838 * The symlink can be changed only once, just to disallow arbitrary
1839 * transitions malicious software might bring in. This means one
1840 * could make a snapshot over all processes running and monitor
1841 * /proc/pid/exe changes to notice unusual activity if needed.
1844 if (test_and_set_bit(MMF_EXE_FILE_CHANGED
, &mm
->flags
))
1848 set_mm_exe_file(mm
, exe
.file
); /* this grabs a reference to exe.file */
1850 up_write(&mm
->mmap_sem
);
1857 static int prctl_set_mm(int opt
, unsigned long addr
,
1858 unsigned long arg4
, unsigned long arg5
)
1860 unsigned long rlim
= rlimit(RLIMIT_DATA
);
1861 struct mm_struct
*mm
= current
->mm
;
1862 struct vm_area_struct
*vma
;
1865 if (arg5
|| (arg4
&& opt
!= PR_SET_MM_AUXV
))
1868 if (!capable(CAP_SYS_RESOURCE
))
1871 if (opt
== PR_SET_MM_EXE_FILE
)
1872 return prctl_set_mm_exe_file(mm
, (unsigned int)addr
);
1874 if (addr
>= TASK_SIZE
|| addr
< mmap_min_addr
)
1879 down_read(&mm
->mmap_sem
);
1880 vma
= find_vma(mm
, addr
);
1883 case PR_SET_MM_START_CODE
:
1884 mm
->start_code
= addr
;
1886 case PR_SET_MM_END_CODE
:
1887 mm
->end_code
= addr
;
1889 case PR_SET_MM_START_DATA
:
1890 mm
->start_data
= addr
;
1892 case PR_SET_MM_END_DATA
:
1893 mm
->end_data
= addr
;
1896 case PR_SET_MM_START_BRK
:
1897 if (addr
<= mm
->end_data
)
1900 if (rlim
< RLIM_INFINITY
&&
1902 (mm
->end_data
- mm
->start_data
) > rlim
)
1905 mm
->start_brk
= addr
;
1909 if (addr
<= mm
->end_data
)
1912 if (rlim
< RLIM_INFINITY
&&
1913 (addr
- mm
->start_brk
) +
1914 (mm
->end_data
- mm
->start_data
) > rlim
)
1921 * If command line arguments and environment
1922 * are placed somewhere else on stack, we can
1923 * set them up here, ARG_START/END to setup
1924 * command line argumets and ENV_START/END
1927 case PR_SET_MM_START_STACK
:
1928 case PR_SET_MM_ARG_START
:
1929 case PR_SET_MM_ARG_END
:
1930 case PR_SET_MM_ENV_START
:
1931 case PR_SET_MM_ENV_END
:
1936 if (opt
== PR_SET_MM_START_STACK
)
1937 mm
->start_stack
= addr
;
1938 else if (opt
== PR_SET_MM_ARG_START
)
1939 mm
->arg_start
= addr
;
1940 else if (opt
== PR_SET_MM_ARG_END
)
1942 else if (opt
== PR_SET_MM_ENV_START
)
1943 mm
->env_start
= addr
;
1944 else if (opt
== PR_SET_MM_ENV_END
)
1949 * This doesn't move auxiliary vector itself
1950 * since it's pinned to mm_struct, but allow
1951 * to fill vector with new values. It's up
1952 * to a caller to provide sane values here
1953 * otherwise user space tools which use this
1954 * vector might be unhappy.
1956 case PR_SET_MM_AUXV
: {
1957 unsigned long user_auxv
[AT_VECTOR_SIZE
];
1959 if (arg4
> sizeof(user_auxv
))
1961 up_read(&mm
->mmap_sem
);
1963 if (copy_from_user(user_auxv
, (const void __user
*)addr
, arg4
))
1966 /* Make sure the last entry is always AT_NULL */
1967 user_auxv
[AT_VECTOR_SIZE
- 2] = 0;
1968 user_auxv
[AT_VECTOR_SIZE
- 1] = 0;
1970 BUILD_BUG_ON(sizeof(user_auxv
) != sizeof(mm
->saved_auxv
));
1973 memcpy(mm
->saved_auxv
, user_auxv
, arg4
);
1974 task_unlock(current
);
1984 up_read(&mm
->mmap_sem
);
1988 static int prctl_get_tid_address(struct task_struct
*me
, int __user
**tid_addr
)
1990 return put_user(me
->clear_child_tid
, tid_addr
);
1993 #else /* CONFIG_CHECKPOINT_RESTORE */
1994 static int prctl_set_mm(int opt
, unsigned long addr
,
1995 unsigned long arg4
, unsigned long arg5
)
1999 static int prctl_get_tid_address(struct task_struct
*me
, int __user
**tid_addr
)
2005 SYSCALL_DEFINE5(prctl
, int, option
, unsigned long, arg2
, unsigned long, arg3
,
2006 unsigned long, arg4
, unsigned long, arg5
)
2008 struct task_struct
*me
= current
;
2009 unsigned char comm
[sizeof(me
->comm
)];
2012 error
= security_task_prctl(option
, arg2
, arg3
, arg4
, arg5
);
2013 if (error
!= -ENOSYS
)
2018 case PR_SET_PDEATHSIG
:
2019 if (!valid_signal(arg2
)) {
2023 me
->pdeath_signal
= arg2
;
2025 case PR_GET_PDEATHSIG
:
2026 error
= put_user(me
->pdeath_signal
, (int __user
*)arg2
);
2028 case PR_GET_DUMPABLE
:
2029 error
= get_dumpable(me
->mm
);
2031 case PR_SET_DUMPABLE
:
2032 if (arg2
!= SUID_DUMP_DISABLE
&& arg2
!= SUID_DUMP_USER
) {
2036 set_dumpable(me
->mm
, arg2
);
2039 case PR_SET_UNALIGN
:
2040 error
= SET_UNALIGN_CTL(me
, arg2
);
2042 case PR_GET_UNALIGN
:
2043 error
= GET_UNALIGN_CTL(me
, arg2
);
2046 error
= SET_FPEMU_CTL(me
, arg2
);
2049 error
= GET_FPEMU_CTL(me
, arg2
);
2052 error
= SET_FPEXC_CTL(me
, arg2
);
2055 error
= GET_FPEXC_CTL(me
, arg2
);
2058 error
= PR_TIMING_STATISTICAL
;
2061 if (arg2
!= PR_TIMING_STATISTICAL
)
2065 comm
[sizeof(me
->comm
) - 1] = 0;
2066 if (strncpy_from_user(comm
, (char __user
*)arg2
,
2067 sizeof(me
->comm
) - 1) < 0)
2069 set_task_comm(me
, comm
);
2070 proc_comm_connector(me
);
2073 get_task_comm(comm
, me
);
2074 if (copy_to_user((char __user
*)arg2
, comm
, sizeof(comm
)))
2078 error
= GET_ENDIAN(me
, arg2
);
2081 error
= SET_ENDIAN(me
, arg2
);
2083 case PR_GET_SECCOMP
:
2084 error
= prctl_get_seccomp();
2086 case PR_SET_SECCOMP
:
2087 error
= prctl_set_seccomp(arg2
, (char __user
*)arg3
);
2090 error
= GET_TSC_CTL(arg2
);
2093 error
= SET_TSC_CTL(arg2
);
2095 case PR_TASK_PERF_EVENTS_DISABLE
:
2096 error
= perf_event_task_disable();
2098 case PR_TASK_PERF_EVENTS_ENABLE
:
2099 error
= perf_event_task_enable();
2101 case PR_GET_TIMERSLACK
:
2102 error
= current
->timer_slack_ns
;
2104 case PR_SET_TIMERSLACK
:
2106 current
->timer_slack_ns
=
2107 current
->default_timer_slack_ns
;
2109 current
->timer_slack_ns
= arg2
;
2115 case PR_MCE_KILL_CLEAR
:
2118 current
->flags
&= ~PF_MCE_PROCESS
;
2120 case PR_MCE_KILL_SET
:
2121 current
->flags
|= PF_MCE_PROCESS
;
2122 if (arg3
== PR_MCE_KILL_EARLY
)
2123 current
->flags
|= PF_MCE_EARLY
;
2124 else if (arg3
== PR_MCE_KILL_LATE
)
2125 current
->flags
&= ~PF_MCE_EARLY
;
2126 else if (arg3
== PR_MCE_KILL_DEFAULT
)
2128 ~(PF_MCE_EARLY
|PF_MCE_PROCESS
);
2136 case PR_MCE_KILL_GET
:
2137 if (arg2
| arg3
| arg4
| arg5
)
2139 if (current
->flags
& PF_MCE_PROCESS
)
2140 error
= (current
->flags
& PF_MCE_EARLY
) ?
2141 PR_MCE_KILL_EARLY
: PR_MCE_KILL_LATE
;
2143 error
= PR_MCE_KILL_DEFAULT
;
2146 error
= prctl_set_mm(arg2
, arg3
, arg4
, arg5
);
2148 case PR_GET_TID_ADDRESS
:
2149 error
= prctl_get_tid_address(me
, (int __user
**)arg2
);
2151 case PR_SET_CHILD_SUBREAPER
:
2152 me
->signal
->is_child_subreaper
= !!arg2
;
2154 case PR_GET_CHILD_SUBREAPER
:
2155 error
= put_user(me
->signal
->is_child_subreaper
,
2156 (int __user
*)arg2
);
2158 case PR_SET_NO_NEW_PRIVS
:
2159 if (arg2
!= 1 || arg3
|| arg4
|| arg5
)
2162 current
->no_new_privs
= 1;
2164 case PR_GET_NO_NEW_PRIVS
:
2165 if (arg2
|| arg3
|| arg4
|| arg5
)
2167 return current
->no_new_privs
? 1 : 0;
2175 SYSCALL_DEFINE3(getcpu
, unsigned __user
*, cpup
, unsigned __user
*, nodep
,
2176 struct getcpu_cache __user
*, unused
)
2179 int cpu
= raw_smp_processor_id();
2181 err
|= put_user(cpu
, cpup
);
2183 err
|= put_user(cpu_to_node(cpu
), nodep
);
2184 return err
? -EFAULT
: 0;
2187 char poweroff_cmd
[POWEROFF_CMD_PATH_LEN
] = "/sbin/poweroff";
2189 static int __orderly_poweroff(bool force
)
2192 static char *envp
[] = {
2194 "PATH=/sbin:/bin:/usr/sbin:/usr/bin",
2199 argv
= argv_split(GFP_KERNEL
, poweroff_cmd
, NULL
);
2201 ret
= call_usermodehelper(argv
[0], argv
, envp
, UMH_WAIT_EXEC
);
2204 printk(KERN_WARNING
"%s failed to allocate memory for \"%s\"\n",
2205 __func__
, poweroff_cmd
);
2210 printk(KERN_WARNING
"Failed to start orderly shutdown: "
2211 "forcing the issue\n");
2213 * I guess this should try to kick off some daemon to sync and
2214 * poweroff asap. Or not even bother syncing if we're doing an
2215 * emergency shutdown?
2224 static bool poweroff_force
;
2226 static void poweroff_work_func(struct work_struct
*work
)
2228 __orderly_poweroff(poweroff_force
);
2231 static DECLARE_WORK(poweroff_work
, poweroff_work_func
);
2234 * orderly_poweroff - Trigger an orderly system poweroff
2235 * @force: force poweroff if command execution fails
2237 * This may be called from any context to trigger a system shutdown.
2238 * If the orderly shutdown fails, it will force an immediate shutdown.
2240 int orderly_poweroff(bool force
)
2242 if (force
) /* do not override the pending "true" */
2243 poweroff_force
= true;
2244 schedule_work(&poweroff_work
);
2247 EXPORT_SYMBOL_GPL(orderly_poweroff
);