blob: e7998cf314986fd37adbf6ccf1aa65ea5cb3982d [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/kernel/sys.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 */
6
Linus Torvalds1da177e2005-04-16 15:20:36 -07007#include <linux/module.h>
8#include <linux/mm.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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/highuid.h>
16#include <linux/fs.h>
Daniel Walker3e88c552007-05-10 22:22:53 -070017#include <linux/resource.h>
Eric W. Biedermandc009d92005-06-25 14:57:52 -070018#include <linux/kernel.h>
19#include <linux/kexec.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <linux/workqueue.h>
Randy.Dunlapc59ede72006-01-11 12:17:46 -080021#include <linux/capability.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#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>
Jesper Juhl7ed20e12005-05-01 08:59:14 -070030#include <linux/signal.h>
Matt Helsley9f460802005-11-07 00:59:16 -080031#include <linux/cn_proc.h>
Andi Kleen3cfc3482006-09-26 10:52:28 +020032#include <linux/getcpu.h>
Eric Dumazet6eaeeab2007-05-10 22:22:37 -070033#include <linux/task_io_accounting_ops.h>
Andrea Arcangeli1d9d02f2007-07-15 23:41:32 -070034#include <linux/seccomp.h>
Mark Lord40477272007-10-01 01:20:10 -070035#include <linux/cpu.h>
Paul Mackerrase3d5a272009-01-06 14:41:02 -080036#include <linux/ptrace.h>
Al Viro5ad4e532009-03-29 19:50:06 -040037#include <linux/fs_struct.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070038
39#include <linux/compat.h>
40#include <linux/syscalls.h>
Keshavamurthy Anil S00d7c052005-12-12 00:37:33 -080041#include <linux/kprobes.h>
Cedric Le Goateracce2922007-07-15 23:40:59 -070042#include <linux/user_namespace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070043
44#include <asm/uaccess.h>
45#include <asm/io.h>
46#include <asm/unistd.h>
47
48#ifndef SET_UNALIGN_CTL
49# define SET_UNALIGN_CTL(a,b) (-EINVAL)
50#endif
51#ifndef GET_UNALIGN_CTL
52# define GET_UNALIGN_CTL(a,b) (-EINVAL)
53#endif
54#ifndef SET_FPEMU_CTL
55# define SET_FPEMU_CTL(a,b) (-EINVAL)
56#endif
57#ifndef GET_FPEMU_CTL
58# define GET_FPEMU_CTL(a,b) (-EINVAL)
59#endif
60#ifndef SET_FPEXC_CTL
61# define SET_FPEXC_CTL(a,b) (-EINVAL)
62#endif
63#ifndef GET_FPEXC_CTL
64# define GET_FPEXC_CTL(a,b) (-EINVAL)
65#endif
Anton Blanchard651d7652006-06-07 16:10:19 +100066#ifndef GET_ENDIAN
67# define GET_ENDIAN(a,b) (-EINVAL)
68#endif
69#ifndef SET_ENDIAN
70# define SET_ENDIAN(a,b) (-EINVAL)
71#endif
Erik Bosman8fb402b2008-04-11 18:54:17 +020072#ifndef GET_TSC_CTL
73# define GET_TSC_CTL(a) (-EINVAL)
74#endif
75#ifndef SET_TSC_CTL
76# define SET_TSC_CTL(a) (-EINVAL)
77#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070078
79/*
80 * this is where the system-wide overflow UID and GID are defined, for
81 * architectures that now have 32-bit UID/GID but didn't in the past
82 */
83
84int overflowuid = DEFAULT_OVERFLOWUID;
85int overflowgid = DEFAULT_OVERFLOWGID;
86
87#ifdef CONFIG_UID16
88EXPORT_SYMBOL(overflowuid);
89EXPORT_SYMBOL(overflowgid);
90#endif
91
92/*
93 * the same as above, but for filesystems which can only store a 16-bit
94 * UID and GID. as such, this is needed on all architectures
95 */
96
97int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
98int fs_overflowgid = DEFAULT_FS_OVERFLOWUID;
99
100EXPORT_SYMBOL(fs_overflowuid);
101EXPORT_SYMBOL(fs_overflowgid);
102
103/*
104 * this indicates whether you can reboot with ctrl-alt-del: the default is yes
105 */
106
107int C_A_D = 1;
Cedric Le Goater9ec52092006-10-02 02:19:00 -0700108struct pid *cad_pid;
109EXPORT_SYMBOL(cad_pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110
111/*
Rafael J. Wysockibd804eb2007-07-19 01:47:40 -0700112 * If set, this is used for preparing the system to power off.
113 */
114
115void (*pm_power_off_prepare)(void);
Rafael J. Wysockibd804eb2007-07-19 01:47:40 -0700116
David Howellsc69e8d92008-11-14 10:39:19 +1100117/*
118 * set the priority of a task
119 * - the caller must hold the RCU read lock
120 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121static int set_one_prio(struct task_struct *p, int niceval, int error)
122{
David Howellsc69e8d92008-11-14 10:39:19 +1100123 const struct cred *cred = current_cred(), *pcred = __task_cred(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124 int no_nice;
125
David Howellsc69e8d92008-11-14 10:39:19 +1100126 if (pcred->uid != cred->euid &&
127 pcred->euid != cred->euid && !capable(CAP_SYS_NICE)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 error = -EPERM;
129 goto out;
130 }
Matt Mackalle43379f2005-05-01 08:59:00 -0700131 if (niceval < task_nice(p) && !can_nice(p, niceval)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 error = -EACCES;
133 goto out;
134 }
135 no_nice = security_task_setnice(p, niceval);
136 if (no_nice) {
137 error = no_nice;
138 goto out;
139 }
140 if (error == -ESRCH)
141 error = 0;
142 set_user_nice(p, niceval);
143out:
144 return error;
145}
146
Heiko Carstens754fe8d2009-01-14 14:14:09 +0100147SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148{
149 struct task_struct *g, *p;
150 struct user_struct *user;
David Howells86a264a2008-11-14 10:39:18 +1100151 const struct cred *cred = current_cred();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 int error = -EINVAL;
Eric W. Biederman41487c62007-02-12 00:53:01 -0800153 struct pid *pgrp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154
Daniel Walker3e88c552007-05-10 22:22:53 -0700155 if (which > PRIO_USER || which < PRIO_PROCESS)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156 goto out;
157
158 /* normalize: avoid signed division (rounding problems) */
159 error = -ESRCH;
160 if (niceval < -20)
161 niceval = -20;
162 if (niceval > 19)
163 niceval = 19;
164
165 read_lock(&tasklist_lock);
166 switch (which) {
167 case PRIO_PROCESS:
Eric W. Biederman41487c62007-02-12 00:53:01 -0800168 if (who)
Pavel Emelyanov228ebcb2007-10-18 23:40:16 -0700169 p = find_task_by_vpid(who);
Eric W. Biederman41487c62007-02-12 00:53:01 -0800170 else
171 p = current;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 if (p)
173 error = set_one_prio(p, niceval, error);
174 break;
175 case PRIO_PGRP:
Eric W. Biederman41487c62007-02-12 00:53:01 -0800176 if (who)
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700177 pgrp = find_vpid(who);
Eric W. Biederman41487c62007-02-12 00:53:01 -0800178 else
179 pgrp = task_pgrp(current);
Ken Chen2d70b682008-08-20 14:09:17 -0700180 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 error = set_one_prio(p, niceval, error);
Ken Chen2d70b682008-08-20 14:09:17 -0700182 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 break;
184 case PRIO_USER:
David Howellsd84f4f92008-11-14 10:39:23 +1100185 user = (struct user_struct *) cred->user;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 if (!who)
David Howells86a264a2008-11-14 10:39:18 +1100187 who = cred->uid;
188 else if ((who != cred->uid) &&
189 !(user = find_user(who)))
190 goto out_unlock; /* No processes for this user */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191
192 do_each_thread(g, p)
David Howells86a264a2008-11-14 10:39:18 +1100193 if (__task_cred(p)->uid == who)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 error = set_one_prio(p, niceval, error);
195 while_each_thread(g, p);
David Howells86a264a2008-11-14 10:39:18 +1100196 if (who != cred->uid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 free_uid(user); /* For find_user() */
198 break;
199 }
200out_unlock:
201 read_unlock(&tasklist_lock);
202out:
203 return error;
204}
205
206/*
207 * Ugh. To avoid negative return values, "getpriority()" will
208 * not return the normal nice-value, but a negated value that
209 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
210 * to stay compatible.
211 */
Heiko Carstens754fe8d2009-01-14 14:14:09 +0100212SYSCALL_DEFINE2(getpriority, int, which, int, who)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213{
214 struct task_struct *g, *p;
215 struct user_struct *user;
David Howells86a264a2008-11-14 10:39:18 +1100216 const struct cred *cred = current_cred();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217 long niceval, retval = -ESRCH;
Eric W. Biederman41487c62007-02-12 00:53:01 -0800218 struct pid *pgrp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219
Daniel Walker3e88c552007-05-10 22:22:53 -0700220 if (which > PRIO_USER || which < PRIO_PROCESS)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 return -EINVAL;
222
223 read_lock(&tasklist_lock);
224 switch (which) {
225 case PRIO_PROCESS:
Eric W. Biederman41487c62007-02-12 00:53:01 -0800226 if (who)
Pavel Emelyanov228ebcb2007-10-18 23:40:16 -0700227 p = find_task_by_vpid(who);
Eric W. Biederman41487c62007-02-12 00:53:01 -0800228 else
229 p = current;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 if (p) {
231 niceval = 20 - task_nice(p);
232 if (niceval > retval)
233 retval = niceval;
234 }
235 break;
236 case PRIO_PGRP:
Eric W. Biederman41487c62007-02-12 00:53:01 -0800237 if (who)
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700238 pgrp = find_vpid(who);
Eric W. Biederman41487c62007-02-12 00:53:01 -0800239 else
240 pgrp = task_pgrp(current);
Ken Chen2d70b682008-08-20 14:09:17 -0700241 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242 niceval = 20 - task_nice(p);
243 if (niceval > retval)
244 retval = niceval;
Ken Chen2d70b682008-08-20 14:09:17 -0700245 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 break;
247 case PRIO_USER:
David Howells86a264a2008-11-14 10:39:18 +1100248 user = (struct user_struct *) cred->user;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249 if (!who)
David Howells86a264a2008-11-14 10:39:18 +1100250 who = cred->uid;
251 else if ((who != cred->uid) &&
252 !(user = find_user(who)))
253 goto out_unlock; /* No processes for this user */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254
255 do_each_thread(g, p)
David Howells86a264a2008-11-14 10:39:18 +1100256 if (__task_cred(p)->uid == who) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257 niceval = 20 - task_nice(p);
258 if (niceval > retval)
259 retval = niceval;
260 }
261 while_each_thread(g, p);
David Howells86a264a2008-11-14 10:39:18 +1100262 if (who != cred->uid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263 free_uid(user); /* for find_user() */
264 break;
265 }
266out_unlock:
267 read_unlock(&tasklist_lock);
268
269 return retval;
270}
271
Eric W. Biedermane4c94332005-09-22 21:43:45 -0700272/**
273 * emergency_restart - reboot the system
274 *
275 * Without shutting down any hardware or taking any locks
276 * reboot the system. This is called when we know we are in
277 * trouble so this is our best effort to reboot. This is
278 * safe to call in interrupt context.
279 */
Eric W. Biederman7c903472005-07-26 11:29:55 -0600280void emergency_restart(void)
281{
282 machine_emergency_restart();
283}
284EXPORT_SYMBOL_GPL(emergency_restart);
285
Huang Yingca195b72008-08-15 00:40:24 -0700286void kernel_restart_prepare(char *cmd)
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600287{
Alan Sterne041c682006-03-27 01:16:30 -0800288 blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd);
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600289 system_state = SYSTEM_RESTART;
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600290 device_shutdown();
Rafael J. Wysocki58b3b712007-07-26 16:29:55 +0200291 sysdev_shutdown();
Eric W. Biedermane4c94332005-09-22 21:43:45 -0700292}
Randy Dunlap1e5d5332005-11-07 01:01:06 -0800293
294/**
295 * kernel_restart - reboot the system
296 * @cmd: pointer to buffer containing command to execute for restart
Randy Dunlapb8887e62005-11-07 01:01:07 -0800297 * or %NULL
Randy Dunlap1e5d5332005-11-07 01:01:06 -0800298 *
299 * Shutdown everything and perform a clean reboot.
300 * This is not safe to call in interrupt context.
301 */
Eric W. Biedermane4c94332005-09-22 21:43:45 -0700302void kernel_restart(char *cmd)
303{
304 kernel_restart_prepare(cmd);
Cal Peake756184b2006-09-30 23:27:24 -0700305 if (!cmd)
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600306 printk(KERN_EMERG "Restarting system.\n");
Cal Peake756184b2006-09-30 23:27:24 -0700307 else
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600308 printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd);
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600309 machine_restart(cmd);
310}
311EXPORT_SYMBOL_GPL(kernel_restart);
312
Adrian Bunk4ef72292008-02-04 22:30:06 -0800313static void kernel_shutdown_prepare(enum system_states state)
Alexey Starikovskiy729b4d42005-12-01 04:29:00 -0500314{
Alan Sterne041c682006-03-27 01:16:30 -0800315 blocking_notifier_call_chain(&reboot_notifier_list,
Alexey Starikovskiy729b4d42005-12-01 04:29:00 -0500316 (state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL);
317 system_state = state;
318 device_shutdown();
319}
Eric W. Biedermane4c94332005-09-22 21:43:45 -0700320/**
321 * kernel_halt - halt the system
322 *
323 * Shutdown everything and perform a clean system halt.
324 */
Eric W. Biedermane4c94332005-09-22 21:43:45 -0700325void kernel_halt(void)
326{
Alexey Starikovskiy729b4d42005-12-01 04:29:00 -0500327 kernel_shutdown_prepare(SYSTEM_HALT);
Rafael J. Wysocki58b3b712007-07-26 16:29:55 +0200328 sysdev_shutdown();
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600329 printk(KERN_EMERG "System halted.\n");
330 machine_halt();
331}
Alexey Starikovskiy729b4d42005-12-01 04:29:00 -0500332
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600333EXPORT_SYMBOL_GPL(kernel_halt);
334
Eric W. Biedermane4c94332005-09-22 21:43:45 -0700335/**
336 * kernel_power_off - power_off the system
337 *
338 * Shutdown everything and perform a clean system power_off.
339 */
Eric W. Biedermane4c94332005-09-22 21:43:45 -0700340void kernel_power_off(void)
341{
Alexey Starikovskiy729b4d42005-12-01 04:29:00 -0500342 kernel_shutdown_prepare(SYSTEM_POWER_OFF);
Rafael J. Wysockibd804eb2007-07-19 01:47:40 -0700343 if (pm_power_off_prepare)
344 pm_power_off_prepare();
Mark Lord40477272007-10-01 01:20:10 -0700345 disable_nonboot_cpus();
Rafael J. Wysocki58b3b712007-07-26 16:29:55 +0200346 sysdev_shutdown();
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600347 printk(KERN_EMERG "Power down.\n");
348 machine_power_off();
349}
350EXPORT_SYMBOL_GPL(kernel_power_off);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351/*
352 * Reboot system call: for obvious reasons only root may call it,
353 * and even root needs to set up some magic numbers in the registers
354 * so that some mistake won't make this reboot the whole machine.
355 * You can also set the meaning of the ctrl-alt-del-key here.
356 *
357 * reboot doesn't sync: do that yourself before calling this.
358 */
Heiko Carstens754fe8d2009-01-14 14:14:09 +0100359SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
360 void __user *, arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361{
362 char buffer[256];
Andi Kleen3d26dcf2009-04-13 14:40:08 -0700363 int ret = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364
365 /* We only trust the superuser with rebooting the system. */
366 if (!capable(CAP_SYS_BOOT))
367 return -EPERM;
368
369 /* For safety, we require "magic" arguments. */
370 if (magic1 != LINUX_REBOOT_MAGIC1 ||
371 (magic2 != LINUX_REBOOT_MAGIC2 &&
372 magic2 != LINUX_REBOOT_MAGIC2A &&
373 magic2 != LINUX_REBOOT_MAGIC2B &&
374 magic2 != LINUX_REBOOT_MAGIC2C))
375 return -EINVAL;
376
Eric W. Biederman5e382912006-01-08 01:03:46 -0800377 /* Instead of trying to make the power_off code look like
378 * halt when pm_power_off is not set do it the easy way.
379 */
380 if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off)
381 cmd = LINUX_REBOOT_CMD_HALT;
382
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383 lock_kernel();
384 switch (cmd) {
385 case LINUX_REBOOT_CMD_RESTART:
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600386 kernel_restart(NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 break;
388
389 case LINUX_REBOOT_CMD_CAD_ON:
390 C_A_D = 1;
391 break;
392
393 case LINUX_REBOOT_CMD_CAD_OFF:
394 C_A_D = 0;
395 break;
396
397 case LINUX_REBOOT_CMD_HALT:
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600398 kernel_halt();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399 unlock_kernel();
400 do_exit(0);
Andi Kleen3d26dcf2009-04-13 14:40:08 -0700401 panic("cannot halt");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402
403 case LINUX_REBOOT_CMD_POWER_OFF:
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600404 kernel_power_off();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405 unlock_kernel();
406 do_exit(0);
407 break;
408
409 case LINUX_REBOOT_CMD_RESTART2:
410 if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) {
411 unlock_kernel();
412 return -EFAULT;
413 }
414 buffer[sizeof(buffer) - 1] = '\0';
415
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600416 kernel_restart(buffer);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417 break;
418
Huang Ying3ab83522008-07-25 19:45:07 -0700419#ifdef CONFIG_KEXEC
Eric W. Biedermandc009d92005-06-25 14:57:52 -0700420 case LINUX_REBOOT_CMD_KEXEC:
Andi Kleen3d26dcf2009-04-13 14:40:08 -0700421 ret = kernel_kexec();
422 break;
Huang Ying3ab83522008-07-25 19:45:07 -0700423#endif
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600424
Rafael J. Wysockib0cb1a12007-07-29 23:24:36 +0200425#ifdef CONFIG_HIBERNATION
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426 case LINUX_REBOOT_CMD_SW_SUSPEND:
Andi Kleen3d26dcf2009-04-13 14:40:08 -0700427 ret = hibernate();
428 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429#endif
430
431 default:
Andi Kleen3d26dcf2009-04-13 14:40:08 -0700432 ret = -EINVAL;
433 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434 }
435 unlock_kernel();
Andi Kleen3d26dcf2009-04-13 14:40:08 -0700436 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437}
438
David Howells65f27f32006-11-22 14:55:48 +0000439static void deferred_cad(struct work_struct *dummy)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440{
Eric W. Biedermanabcd9e52005-07-26 11:27:34 -0600441 kernel_restart(NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442}
443
444/*
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.
448 */
449void ctrl_alt_del(void)
450{
David Howells65f27f32006-11-22 14:55:48 +0000451 static DECLARE_WORK(cad_work, deferred_cad);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452
453 if (C_A_D)
454 schedule_work(&cad_work);
455 else
Cedric Le Goater9ec52092006-10-02 02:19:00 -0700456 kill_cad_pid(SIGINT, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457}
458
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459/*
460 * Unprivileged users may change the real gid to the effective gid
461 * or vice versa. (BSD-style)
462 *
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.
465 *
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.
469 *
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.
473 *
474 * SMP: There are not races, the GIDs are checked only by filesystem
475 * operations (as far as semantic preservation is concerned).
476 */
Heiko Carstensae1251a2009-01-14 14:14:05 +0100477SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478{
David Howellsd84f4f92008-11-14 10:39:23 +1100479 const struct cred *old;
480 struct cred *new;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481 int retval;
482
David Howellsd84f4f92008-11-14 10:39:23 +1100483 new = prepare_creds();
484 if (!new)
485 return -ENOMEM;
486 old = current_cred();
487
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488 retval = security_task_setgid(rgid, egid, (gid_t)-1, LSM_SETID_RE);
489 if (retval)
David Howellsd84f4f92008-11-14 10:39:23 +1100490 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491
David Howellsd84f4f92008-11-14 10:39:23 +1100492 retval = -EPERM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493 if (rgid != (gid_t) -1) {
David Howellsd84f4f92008-11-14 10:39:23 +1100494 if (old->gid == rgid ||
495 old->egid == rgid ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496 capable(CAP_SETGID))
David Howellsd84f4f92008-11-14 10:39:23 +1100497 new->gid = rgid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498 else
David Howellsd84f4f92008-11-14 10:39:23 +1100499 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500 }
501 if (egid != (gid_t) -1) {
David Howellsd84f4f92008-11-14 10:39:23 +1100502 if (old->gid == egid ||
503 old->egid == egid ||
504 old->sgid == egid ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505 capable(CAP_SETGID))
David Howellsd84f4f92008-11-14 10:39:23 +1100506 new->egid = egid;
Cal Peake756184b2006-09-30 23:27:24 -0700507 else
David Howellsd84f4f92008-11-14 10:39:23 +1100508 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509 }
David Howellsd84f4f92008-11-14 10:39:23 +1100510
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511 if (rgid != (gid_t) -1 ||
David Howellsd84f4f92008-11-14 10:39:23 +1100512 (egid != (gid_t) -1 && egid != old->gid))
513 new->sgid = new->egid;
514 new->fsgid = new->egid;
515
516 return commit_creds(new);
517
518error:
519 abort_creds(new);
520 return retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521}
522
523/*
524 * setgid() is implemented like SysV w/ SAVED_IDS
525 *
526 * SMP: Same implicit races as above.
527 */
Heiko Carstensae1251a2009-01-14 14:14:05 +0100528SYSCALL_DEFINE1(setgid, gid_t, gid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529{
David Howellsd84f4f92008-11-14 10:39:23 +1100530 const struct cred *old;
531 struct cred *new;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700532 int retval;
533
David Howellsd84f4f92008-11-14 10:39:23 +1100534 new = prepare_creds();
535 if (!new)
536 return -ENOMEM;
537 old = current_cred();
538
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539 retval = security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID);
540 if (retval)
David Howellsd84f4f92008-11-14 10:39:23 +1100541 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542
David Howellsd84f4f92008-11-14 10:39:23 +1100543 retval = -EPERM;
544 if (capable(CAP_SETGID))
545 new->gid = new->egid = new->sgid = new->fsgid = gid;
546 else if (gid == old->gid || gid == old->sgid)
547 new->egid = new->fsgid = gid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548 else
David Howellsd84f4f92008-11-14 10:39:23 +1100549 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550
David Howellsd84f4f92008-11-14 10:39:23 +1100551 return commit_creds(new);
552
553error:
554 abort_creds(new);
555 return retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556}
Dhaval Giani54e99122009-02-27 15:13:54 +0530557
David Howellsd84f4f92008-11-14 10:39:23 +1100558/*
559 * change the user struct in a credentials set to match the new UID
560 */
561static int set_user(struct cred *new)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562{
563 struct user_struct *new_user;
564
Serge Hallyn18b6e042008-10-15 16:38:45 -0500565 new_user = alloc_uid(current_user_ns(), new->uid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566 if (!new_user)
567 return -EAGAIN;
568
Dhaval Giani54e99122009-02-27 15:13:54 +0530569 if (!task_can_switch_user(new_user, current)) {
570 free_uid(new_user);
571 return -EINVAL;
572 }
573
Linus Torvalds1da177e2005-04-16 15:20:36 -0700574 if (atomic_read(&new_user->processes) >=
575 current->signal->rlim[RLIMIT_NPROC].rlim_cur &&
Serge Hallyn18b6e042008-10-15 16:38:45 -0500576 new_user != INIT_USER) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577 free_uid(new_user);
578 return -EAGAIN;
579 }
580
David Howellsd84f4f92008-11-14 10:39:23 +1100581 free_uid(new->user);
582 new->user = new_user;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583 return 0;
584}
585
586/*
587 * Unprivileged users may change the real uid to the effective uid
588 * or vice versa. (BSD-style)
589 *
590 * If you set the real uid at all, or set the effective uid to a value not
591 * equal to the real uid, then the saved uid is set to the new effective uid.
592 *
593 * This makes it possible for a setuid program to completely drop its
594 * privileges, which is often a useful assertion to make when you are doing
595 * a security audit over a program.
596 *
597 * The general idea is that a program which uses just setreuid() will be
598 * 100% compatible with BSD. A program which uses just setuid() will be
599 * 100% compatible with POSIX with saved IDs.
600 */
Heiko Carstensae1251a2009-01-14 14:14:05 +0100601SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602{
David Howellsd84f4f92008-11-14 10:39:23 +1100603 const struct cred *old;
604 struct cred *new;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605 int retval;
606
David Howellsd84f4f92008-11-14 10:39:23 +1100607 new = prepare_creds();
608 if (!new)
609 return -ENOMEM;
610 old = current_cred();
611
Linus Torvalds1da177e2005-04-16 15:20:36 -0700612 retval = security_task_setuid(ruid, euid, (uid_t)-1, LSM_SETID_RE);
613 if (retval)
David Howellsd84f4f92008-11-14 10:39:23 +1100614 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615
David Howellsd84f4f92008-11-14 10:39:23 +1100616 retval = -EPERM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617 if (ruid != (uid_t) -1) {
David Howellsd84f4f92008-11-14 10:39:23 +1100618 new->uid = ruid;
619 if (old->uid != ruid &&
620 old->euid != ruid &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621 !capable(CAP_SETUID))
David Howellsd84f4f92008-11-14 10:39:23 +1100622 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623 }
624
625 if (euid != (uid_t) -1) {
David Howellsd84f4f92008-11-14 10:39:23 +1100626 new->euid = euid;
627 if (old->uid != euid &&
628 old->euid != euid &&
629 old->suid != euid &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630 !capable(CAP_SETUID))
David Howellsd84f4f92008-11-14 10:39:23 +1100631 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632 }
633
Dhaval Giani54e99122009-02-27 15:13:54 +0530634 if (new->uid != old->uid) {
635 retval = set_user(new);
636 if (retval < 0)
637 goto error;
638 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639 if (ruid != (uid_t) -1 ||
David Howellsd84f4f92008-11-14 10:39:23 +1100640 (euid != (uid_t) -1 && euid != old->uid))
641 new->suid = new->euid;
642 new->fsuid = new->euid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643
David Howellsd84f4f92008-11-14 10:39:23 +1100644 retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
645 if (retval < 0)
646 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647
David Howellsd84f4f92008-11-14 10:39:23 +1100648 return commit_creds(new);
649
650error:
651 abort_creds(new);
652 return retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654
655/*
656 * setuid() is implemented like SysV with SAVED_IDS
657 *
658 * Note that SAVED_ID's is deficient in that a setuid root program
659 * like sendmail, for example, cannot set its uid to be a normal
660 * user and then switch back, because if you're root, setuid() sets
661 * the saved uid too. If you don't like this, blame the bright people
662 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
663 * will allow a root program to temporarily drop privileges and be able to
664 * regain them by swapping the real and effective uid.
665 */
Heiko Carstensae1251a2009-01-14 14:14:05 +0100666SYSCALL_DEFINE1(setuid, uid_t, uid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667{
David Howellsd84f4f92008-11-14 10:39:23 +1100668 const struct cred *old;
669 struct cred *new;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670 int retval;
671
David Howellsd84f4f92008-11-14 10:39:23 +1100672 new = prepare_creds();
673 if (!new)
674 return -ENOMEM;
675 old = current_cred();
676
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677 retval = security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_ID);
678 if (retval)
David Howellsd84f4f92008-11-14 10:39:23 +1100679 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680
David Howellsd84f4f92008-11-14 10:39:23 +1100681 retval = -EPERM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700682 if (capable(CAP_SETUID)) {
David Howellsd84f4f92008-11-14 10:39:23 +1100683 new->suid = new->uid = uid;
Dhaval Giani54e99122009-02-27 15:13:54 +0530684 if (uid != old->uid) {
685 retval = set_user(new);
686 if (retval < 0)
687 goto error;
David Howellsd84f4f92008-11-14 10:39:23 +1100688 }
689 } else if (uid != old->uid && uid != new->suid) {
690 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700691 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692
David Howellsd84f4f92008-11-14 10:39:23 +1100693 new->fsuid = new->euid = uid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694
David Howellsd84f4f92008-11-14 10:39:23 +1100695 retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
696 if (retval < 0)
697 goto error;
698
699 return commit_creds(new);
700
701error:
702 abort_creds(new);
703 return retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704}
705
706
707/*
708 * This function implements a generic ability to update ruid, euid,
709 * and suid. This allows you to implement the 4.4 compatible seteuid().
710 */
Heiko Carstensae1251a2009-01-14 14:14:05 +0100711SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712{
David Howellsd84f4f92008-11-14 10:39:23 +1100713 const struct cred *old;
714 struct cred *new;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715 int retval;
716
David Howellsd84f4f92008-11-14 10:39:23 +1100717 new = prepare_creds();
718 if (!new)
719 return -ENOMEM;
720
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721 retval = security_task_setuid(ruid, euid, suid, LSM_SETID_RES);
722 if (retval)
David Howellsd84f4f92008-11-14 10:39:23 +1100723 goto error;
724 old = current_cred();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725
David Howellsd84f4f92008-11-14 10:39:23 +1100726 retval = -EPERM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727 if (!capable(CAP_SETUID)) {
David Howellsd84f4f92008-11-14 10:39:23 +1100728 if (ruid != (uid_t) -1 && ruid != old->uid &&
729 ruid != old->euid && ruid != old->suid)
730 goto error;
731 if (euid != (uid_t) -1 && euid != old->uid &&
732 euid != old->euid && euid != old->suid)
733 goto error;
734 if (suid != (uid_t) -1 && suid != old->uid &&
735 suid != old->euid && suid != old->suid)
736 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737 }
David Howellsd84f4f92008-11-14 10:39:23 +1100738
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739 if (ruid != (uid_t) -1) {
David Howellsd84f4f92008-11-14 10:39:23 +1100740 new->uid = ruid;
Dhaval Giani54e99122009-02-27 15:13:54 +0530741 if (ruid != old->uid) {
742 retval = set_user(new);
743 if (retval < 0)
744 goto error;
745 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746 }
David Howellsd84f4f92008-11-14 10:39:23 +1100747 if (euid != (uid_t) -1)
748 new->euid = euid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700749 if (suid != (uid_t) -1)
David Howellsd84f4f92008-11-14 10:39:23 +1100750 new->suid = suid;
751 new->fsuid = new->euid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700752
David Howellsd84f4f92008-11-14 10:39:23 +1100753 retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
754 if (retval < 0)
755 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700756
David Howellsd84f4f92008-11-14 10:39:23 +1100757 return commit_creds(new);
758
759error:
760 abort_creds(new);
761 return retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700762}
763
Heiko Carstensdbf040d2009-01-14 14:14:04 +0100764SYSCALL_DEFINE3(getresuid, uid_t __user *, ruid, uid_t __user *, euid, uid_t __user *, suid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765{
David Howells86a264a2008-11-14 10:39:18 +1100766 const struct cred *cred = current_cred();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700767 int retval;
768
David Howells86a264a2008-11-14 10:39:18 +1100769 if (!(retval = put_user(cred->uid, ruid)) &&
770 !(retval = put_user(cred->euid, euid)))
David Howellsb6dff3e2008-11-14 10:39:16 +1100771 retval = put_user(cred->suid, suid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700772
773 return retval;
774}
775
776/*
777 * Same as above, but for rgid, egid, sgid.
778 */
Heiko Carstensae1251a2009-01-14 14:14:05 +0100779SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780{
David Howellsd84f4f92008-11-14 10:39:23 +1100781 const struct cred *old;
782 struct cred *new;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783 int retval;
784
David Howellsd84f4f92008-11-14 10:39:23 +1100785 new = prepare_creds();
786 if (!new)
787 return -ENOMEM;
788 old = current_cred();
789
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790 retval = security_task_setgid(rgid, egid, sgid, LSM_SETID_RES);
791 if (retval)
David Howellsd84f4f92008-11-14 10:39:23 +1100792 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793
David Howellsd84f4f92008-11-14 10:39:23 +1100794 retval = -EPERM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700795 if (!capable(CAP_SETGID)) {
David Howellsd84f4f92008-11-14 10:39:23 +1100796 if (rgid != (gid_t) -1 && rgid != old->gid &&
797 rgid != old->egid && rgid != old->sgid)
798 goto error;
799 if (egid != (gid_t) -1 && egid != old->gid &&
800 egid != old->egid && egid != old->sgid)
801 goto error;
802 if (sgid != (gid_t) -1 && sgid != old->gid &&
803 sgid != old->egid && sgid != old->sgid)
804 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700806
David Howellsd84f4f92008-11-14 10:39:23 +1100807 if (rgid != (gid_t) -1)
808 new->gid = rgid;
809 if (egid != (gid_t) -1)
810 new->egid = egid;
811 if (sgid != (gid_t) -1)
812 new->sgid = sgid;
813 new->fsgid = new->egid;
814
815 return commit_creds(new);
816
817error:
818 abort_creds(new);
819 return retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700820}
821
Heiko Carstensdbf040d2009-01-14 14:14:04 +0100822SYSCALL_DEFINE3(getresgid, gid_t __user *, rgid, gid_t __user *, egid, gid_t __user *, sgid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823{
David Howells86a264a2008-11-14 10:39:18 +1100824 const struct cred *cred = current_cred();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700825 int retval;
826
David Howells86a264a2008-11-14 10:39:18 +1100827 if (!(retval = put_user(cred->gid, rgid)) &&
828 !(retval = put_user(cred->egid, egid)))
David Howellsb6dff3e2008-11-14 10:39:16 +1100829 retval = put_user(cred->sgid, sgid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700830
831 return retval;
832}
833
834
835/*
836 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
837 * is used for "access()" and for the NFS daemon (letting nfsd stay at
838 * whatever uid it wants to). It normally shadows "euid", except when
839 * explicitly set by setfsuid() or for access..
840 */
Heiko Carstensae1251a2009-01-14 14:14:05 +0100841SYSCALL_DEFINE1(setfsuid, uid_t, uid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700842{
David Howellsd84f4f92008-11-14 10:39:23 +1100843 const struct cred *old;
844 struct cred *new;
845 uid_t old_fsuid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700846
David Howellsd84f4f92008-11-14 10:39:23 +1100847 new = prepare_creds();
848 if (!new)
849 return current_fsuid();
850 old = current_cred();
851 old_fsuid = old->fsuid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700852
David Howellsd84f4f92008-11-14 10:39:23 +1100853 if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS) < 0)
854 goto error;
855
856 if (uid == old->uid || uid == old->euid ||
857 uid == old->suid || uid == old->fsuid ||
Cal Peake756184b2006-09-30 23:27:24 -0700858 capable(CAP_SETUID)) {
859 if (uid != old_fsuid) {
David Howellsd84f4f92008-11-14 10:39:23 +1100860 new->fsuid = uid;
861 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
862 goto change_okay;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700863 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700864 }
865
David Howellsd84f4f92008-11-14 10:39:23 +1100866error:
867 abort_creds(new);
868 return old_fsuid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700869
David Howellsd84f4f92008-11-14 10:39:23 +1100870change_okay:
871 commit_creds(new);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700872 return old_fsuid;
873}
874
875/*
John Anthony Kazos Jrf42df9e2007-05-09 08:23:08 +0200876 * Samma på svenska..
Linus Torvalds1da177e2005-04-16 15:20:36 -0700877 */
Heiko Carstensae1251a2009-01-14 14:14:05 +0100878SYSCALL_DEFINE1(setfsgid, gid_t, gid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700879{
David Howellsd84f4f92008-11-14 10:39:23 +1100880 const struct cred *old;
881 struct cred *new;
882 gid_t old_fsgid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883
David Howellsd84f4f92008-11-14 10:39:23 +1100884 new = prepare_creds();
885 if (!new)
886 return current_fsgid();
887 old = current_cred();
888 old_fsgid = old->fsgid;
889
Linus Torvalds1da177e2005-04-16 15:20:36 -0700890 if (security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS))
David Howellsd84f4f92008-11-14 10:39:23 +1100891 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700892
David Howellsd84f4f92008-11-14 10:39:23 +1100893 if (gid == old->gid || gid == old->egid ||
894 gid == old->sgid || gid == old->fsgid ||
Cal Peake756184b2006-09-30 23:27:24 -0700895 capable(CAP_SETGID)) {
896 if (gid != old_fsgid) {
David Howellsd84f4f92008-11-14 10:39:23 +1100897 new->fsgid = gid;
898 goto change_okay;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700899 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700900 }
David Howellsd84f4f92008-11-14 10:39:23 +1100901
902error:
903 abort_creds(new);
904 return old_fsgid;
905
906change_okay:
907 commit_creds(new);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700908 return old_fsgid;
909}
910
Frank Mayharf06febc2008-09-12 09:54:39 -0700911void do_sys_times(struct tms *tms)
912{
913 struct task_cputime cputime;
914 cputime_t cutime, cstime;
915
Frank Mayharf06febc2008-09-12 09:54:39 -0700916 thread_group_cputime(current, &cputime);
Oleg Nesterov2b5fe6d2008-11-17 15:40:08 +0100917 spin_lock_irq(&current->sighand->siglock);
Frank Mayharf06febc2008-09-12 09:54:39 -0700918 cutime = current->signal->cutime;
919 cstime = current->signal->cstime;
920 spin_unlock_irq(&current->sighand->siglock);
921 tms->tms_utime = cputime_to_clock_t(cputime.utime);
922 tms->tms_stime = cputime_to_clock_t(cputime.stime);
923 tms->tms_cutime = cputime_to_clock_t(cutime);
924 tms->tms_cstime = cputime_to_clock_t(cstime);
925}
926
Heiko Carstens58fd3aa2009-01-14 14:14:03 +0100927SYSCALL_DEFINE1(times, struct tms __user *, tbuf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700928{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700929 if (tbuf) {
930 struct tms tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700931
Frank Mayharf06febc2008-09-12 09:54:39 -0700932 do_sys_times(&tmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700933 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
934 return -EFAULT;
935 }
Paul Mackerrase3d5a272009-01-06 14:41:02 -0800936 force_successful_syscall_return();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700937 return (long) jiffies_64_to_clock_t(get_jiffies_64());
938}
939
940/*
941 * This needs some heavy checking ...
942 * I just haven't the stomach for it. I also don't fully
943 * understand sessions/pgrp etc. Let somebody who does explain it.
944 *
945 * OK, I think I have the protection semantics right.... this is really
946 * only important on a multi-user system anyway, to make sure one user
947 * can't send a signal to a process owned by another. -TYT, 12/12/91
948 *
949 * Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
950 * LBT 04.03.94
951 */
Heiko Carstensb290ebe2009-01-14 14:14:06 +0100952SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700953{
954 struct task_struct *p;
Oleg Nesterovee0acf92006-01-08 01:03:53 -0800955 struct task_struct *group_leader = current->group_leader;
Oleg Nesterov4e021302008-02-08 04:19:08 -0800956 struct pid *pgrp;
957 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700958
959 if (!pid)
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700960 pid = task_pid_vnr(group_leader);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700961 if (!pgid)
962 pgid = pid;
963 if (pgid < 0)
964 return -EINVAL;
965
966 /* From this point forward we keep holding onto the tasklist lock
967 * so that our parent does not change from under us. -DaveM
968 */
969 write_lock_irq(&tasklist_lock);
970
971 err = -ESRCH;
Oleg Nesterov4e021302008-02-08 04:19:08 -0800972 p = find_task_by_vpid(pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700973 if (!p)
974 goto out;
975
976 err = -EINVAL;
977 if (!thread_group_leader(p))
978 goto out;
979
Oleg Nesterov4e021302008-02-08 04:19:08 -0800980 if (same_thread_group(p->real_parent, group_leader)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700981 err = -EPERM;
Eric W. Biederman41487c62007-02-12 00:53:01 -0800982 if (task_session(p) != task_session(group_leader))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700983 goto out;
984 err = -EACCES;
985 if (p->did_exec)
986 goto out;
987 } else {
988 err = -ESRCH;
Oleg Nesterovee0acf92006-01-08 01:03:53 -0800989 if (p != group_leader)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700990 goto out;
991 }
992
993 err = -EPERM;
994 if (p->signal->leader)
995 goto out;
996
Oleg Nesterov4e021302008-02-08 04:19:08 -0800997 pgrp = task_pid(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700998 if (pgid != pid) {
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700999 struct task_struct *g;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001000
Oleg Nesterov4e021302008-02-08 04:19:08 -08001001 pgrp = find_vpid(pgid);
1002 g = pid_task(pgrp, PIDTYPE_PGID);
Eric W. Biederman41487c62007-02-12 00:53:01 -08001003 if (!g || task_session(g) != task_session(group_leader))
Oleg Nesterovf020bc42006-12-08 02:38:02 -08001004 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001005 }
1006
Linus Torvalds1da177e2005-04-16 15:20:36 -07001007 err = security_task_setpgid(p, pgid);
1008 if (err)
1009 goto out;
1010
Oleg Nesterov1b0f7ff2009-04-02 16:58:39 -07001011 if (task_pgrp(p) != pgrp)
Oleg Nesterov83beaf32008-04-30 00:54:27 -07001012 change_pid(p, PIDTYPE_PGID, pgrp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001013
1014 err = 0;
1015out:
1016 /* All paths lead to here, thus we are safe. -DaveM */
1017 write_unlock_irq(&tasklist_lock);
1018 return err;
1019}
1020
Heiko Carstensdbf040d2009-01-14 14:14:04 +01001021SYSCALL_DEFINE1(getpgid, pid_t, pid)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001022{
Oleg Nesterov12a3de0a2008-04-30 00:54:29 -07001023 struct task_struct *p;
1024 struct pid *grp;
1025 int retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001026
Oleg Nesterov12a3de0a2008-04-30 00:54:29 -07001027 rcu_read_lock();
1028 if (!pid)
1029 grp = task_pgrp(current);
1030 else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001031 retval = -ESRCH;
Oleg Nesterov12a3de0a2008-04-30 00:54:29 -07001032 p = find_task_by_vpid(pid);
1033 if (!p)
1034 goto out;
1035 grp = task_pgrp(p);
1036 if (!grp)
1037 goto out;
1038
1039 retval = security_task_getpgid(p);
1040 if (retval)
1041 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001042 }
Oleg Nesterov12a3de0a2008-04-30 00:54:29 -07001043 retval = pid_vnr(grp);
1044out:
1045 rcu_read_unlock();
1046 return retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001047}
1048
1049#ifdef __ARCH_WANT_SYS_GETPGRP
1050
Heiko Carstensdbf040d2009-01-14 14:14:04 +01001051SYSCALL_DEFINE0(getpgrp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001052{
Oleg Nesterov12a3de0a2008-04-30 00:54:29 -07001053 return sys_getpgid(0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001054}
1055
1056#endif
1057
Heiko Carstensdbf040d2009-01-14 14:14:04 +01001058SYSCALL_DEFINE1(getsid, pid_t, pid)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001059{
Oleg Nesterov1dd768c02008-04-30 00:54:28 -07001060 struct task_struct *p;
1061 struct pid *sid;
1062 int retval;
Pavel Emelyanovb4888932007-10-18 23:40:14 -07001063
Oleg Nesterov1dd768c02008-04-30 00:54:28 -07001064 rcu_read_lock();
1065 if (!pid)
1066 sid = task_session(current);
1067 else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001068 retval = -ESRCH;
Oleg Nesterov1dd768c02008-04-30 00:54:28 -07001069 p = find_task_by_vpid(pid);
1070 if (!p)
1071 goto out;
1072 sid = task_session(p);
1073 if (!sid)
1074 goto out;
1075
1076 retval = security_task_getsid(p);
1077 if (retval)
1078 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001079 }
Oleg Nesterov1dd768c02008-04-30 00:54:28 -07001080 retval = pid_vnr(sid);
1081out:
1082 rcu_read_unlock();
1083 return retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001084}
1085
Heiko Carstensb290ebe2009-01-14 14:14:06 +01001086SYSCALL_DEFINE0(setsid)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001087{
Oren Laadane19f2472006-01-08 01:03:58 -08001088 struct task_struct *group_leader = current->group_leader;
Oleg Nesterove4cc0a92008-02-08 04:19:09 -08001089 struct pid *sid = task_pid(group_leader);
1090 pid_t session = pid_vnr(sid);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001091 int err = -EPERM;
1092
Linus Torvalds1da177e2005-04-16 15:20:36 -07001093 write_lock_irq(&tasklist_lock);
Eric W. Biederman390e2ff2006-03-31 02:31:33 -08001094 /* Fail if I am already a session leader */
1095 if (group_leader->signal->leader)
1096 goto out;
1097
Oleg Nesterov430c6232008-02-08 04:19:11 -08001098 /* Fail if a process group id already exists that equals the
1099 * proposed session id.
Eric W. Biederman390e2ff2006-03-31 02:31:33 -08001100 */
Oleg Nesterov6806aac2008-02-08 04:19:12 -08001101 if (pid_task(sid, PIDTYPE_PGID))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001102 goto out;
1103
Oren Laadane19f2472006-01-08 01:03:58 -08001104 group_leader->signal->leader = 1;
Oleg Nesterov8520d7c2008-02-08 04:19:09 -08001105 __set_special_pids(sid);
Peter Zijlstra24ec8392006-12-08 02:36:04 -08001106
Alan Cox9c9f4de2008-10-13 10:37:26 +01001107 proc_clear_tty(group_leader);
Peter Zijlstra24ec8392006-12-08 02:36:04 -08001108
Oleg Nesterove4cc0a92008-02-08 04:19:09 -08001109 err = session;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001110out:
1111 write_unlock_irq(&tasklist_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001112 return err;
1113}
1114
1115/*
1116 * Supplementary group IDs
1117 */
1118
1119/* init to 2 - one for init_task, one to ensure it is never freed */
1120struct group_info init_groups = { .usage = ATOMIC_INIT(2) };
1121
1122struct group_info *groups_alloc(int gidsetsize)
1123{
1124 struct group_info *group_info;
1125 int nblocks;
1126 int i;
1127
1128 nblocks = (gidsetsize + NGROUPS_PER_BLOCK - 1) / NGROUPS_PER_BLOCK;
1129 /* Make sure we always allocate at least one indirect block pointer */
1130 nblocks = nblocks ? : 1;
1131 group_info = kmalloc(sizeof(*group_info) + nblocks*sizeof(gid_t *), GFP_USER);
1132 if (!group_info)
1133 return NULL;
1134 group_info->ngroups = gidsetsize;
1135 group_info->nblocks = nblocks;
1136 atomic_set(&group_info->usage, 1);
1137
Cal Peake756184b2006-09-30 23:27:24 -07001138 if (gidsetsize <= NGROUPS_SMALL)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001139 group_info->blocks[0] = group_info->small_block;
Cal Peake756184b2006-09-30 23:27:24 -07001140 else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001141 for (i = 0; i < nblocks; i++) {
1142 gid_t *b;
1143 b = (void *)__get_free_page(GFP_USER);
1144 if (!b)
1145 goto out_undo_partial_alloc;
1146 group_info->blocks[i] = b;
1147 }
1148 }
1149 return group_info;
1150
1151out_undo_partial_alloc:
1152 while (--i >= 0) {
1153 free_page((unsigned long)group_info->blocks[i]);
1154 }
1155 kfree(group_info);
1156 return NULL;
1157}
1158
1159EXPORT_SYMBOL(groups_alloc);
1160
1161void groups_free(struct group_info *group_info)
1162{
1163 if (group_info->blocks[0] != group_info->small_block) {
1164 int i;
1165 for (i = 0; i < group_info->nblocks; i++)
1166 free_page((unsigned long)group_info->blocks[i]);
1167 }
1168 kfree(group_info);
1169}
1170
1171EXPORT_SYMBOL(groups_free);
1172
1173/* export the group_info to a user-space array */
1174static int groups_to_user(gid_t __user *grouplist,
David Howellsd84f4f92008-11-14 10:39:23 +11001175 const struct group_info *group_info)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001176{
1177 int i;
Eric Dumazet1bf47342008-02-06 01:37:56 -08001178 unsigned int count = group_info->ngroups;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001179
1180 for (i = 0; i < group_info->nblocks; i++) {
Eric Dumazet1bf47342008-02-06 01:37:56 -08001181 unsigned int cp_count = min(NGROUPS_PER_BLOCK, count);
1182 unsigned int len = cp_count * sizeof(*grouplist);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001183
Eric Dumazet1bf47342008-02-06 01:37:56 -08001184 if (copy_to_user(grouplist, group_info->blocks[i], len))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001185 return -EFAULT;
1186
Eric Dumazet1bf47342008-02-06 01:37:56 -08001187 grouplist += NGROUPS_PER_BLOCK;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001188 count -= cp_count;
1189 }
1190 return 0;
1191}
1192
1193/* fill a group_info from a user-space array - it must be allocated already */
1194static int groups_from_user(struct group_info *group_info,
1195 gid_t __user *grouplist)
Cal Peake756184b2006-09-30 23:27:24 -07001196{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001197 int i;
Eric Dumazet1bf47342008-02-06 01:37:56 -08001198 unsigned int count = group_info->ngroups;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001199
1200 for (i = 0; i < group_info->nblocks; i++) {
Eric Dumazet1bf47342008-02-06 01:37:56 -08001201 unsigned int cp_count = min(NGROUPS_PER_BLOCK, count);
1202 unsigned int len = cp_count * sizeof(*grouplist);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001203
Eric Dumazet1bf47342008-02-06 01:37:56 -08001204 if (copy_from_user(group_info->blocks[i], grouplist, len))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001205 return -EFAULT;
1206
Eric Dumazet1bf47342008-02-06 01:37:56 -08001207 grouplist += NGROUPS_PER_BLOCK;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001208 count -= cp_count;
1209 }
1210 return 0;
1211}
1212
Domen Puncerebe8b542005-05-05 16:16:19 -07001213/* a simple Shell sort */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001214static void groups_sort(struct group_info *group_info)
1215{
1216 int base, max, stride;
1217 int gidsetsize = group_info->ngroups;
1218
1219 for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1)
1220 ; /* nothing */
1221 stride /= 3;
1222
1223 while (stride) {
1224 max = gidsetsize - stride;
1225 for (base = 0; base < max; base++) {
1226 int left = base;
1227 int right = left + stride;
1228 gid_t tmp = GROUP_AT(group_info, right);
1229
1230 while (left >= 0 && GROUP_AT(group_info, left) > tmp) {
1231 GROUP_AT(group_info, right) =
1232 GROUP_AT(group_info, left);
1233 right = left;
1234 left -= stride;
1235 }
1236 GROUP_AT(group_info, right) = tmp;
1237 }
1238 stride /= 3;
1239 }
1240}
1241
1242/* a simple bsearch */
David Howells86a264a2008-11-14 10:39:18 +11001243int groups_search(const struct group_info *group_info, gid_t grp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001244{
Eric Dumazetd74beb9f2006-03-25 03:08:19 -08001245 unsigned int left, right;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001246
1247 if (!group_info)
1248 return 0;
1249
1250 left = 0;
1251 right = group_info->ngroups;
1252 while (left < right) {
Eric Dumazetd74beb9f2006-03-25 03:08:19 -08001253 unsigned int mid = (left+right)/2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001254 int cmp = grp - GROUP_AT(group_info, mid);
1255 if (cmp > 0)
1256 left = mid + 1;
1257 else if (cmp < 0)
1258 right = mid;
1259 else
1260 return 1;
1261 }
1262 return 0;
1263}
1264
David Howellsb6dff3e2008-11-14 10:39:16 +11001265/**
David Howellsd84f4f92008-11-14 10:39:23 +11001266 * set_groups - Change a group subscription in a set of credentials
1267 * @new: The newly prepared set of credentials to alter
1268 * @group_info: The group list to install
David Howellsb6dff3e2008-11-14 10:39:16 +11001269 *
David Howellsd84f4f92008-11-14 10:39:23 +11001270 * Validate a group subscription and, if valid, insert it into a set
1271 * of credentials.
David Howellsb6dff3e2008-11-14 10:39:16 +11001272 */
David Howellsd84f4f92008-11-14 10:39:23 +11001273int set_groups(struct cred *new, struct group_info *group_info)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001274{
1275 int retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001276
1277 retval = security_task_setgroups(group_info);
1278 if (retval)
1279 return retval;
1280
David Howellsd84f4f92008-11-14 10:39:23 +11001281 put_group_info(new->group_info);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001282 groups_sort(group_info);
1283 get_group_info(group_info);
David Howellsd84f4f92008-11-14 10:39:23 +11001284 new->group_info = group_info;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001285 return 0;
1286}
1287
David Howellsb6dff3e2008-11-14 10:39:16 +11001288EXPORT_SYMBOL(set_groups);
1289
1290/**
1291 * set_current_groups - Change current's group subscription
1292 * @group_info: The group list to impose
1293 *
1294 * Validate a group subscription and, if valid, impose it upon current's task
1295 * security record.
1296 */
1297int set_current_groups(struct group_info *group_info)
1298{
David Howellsd84f4f92008-11-14 10:39:23 +11001299 struct cred *new;
1300 int ret;
1301
1302 new = prepare_creds();
1303 if (!new)
1304 return -ENOMEM;
1305
1306 ret = set_groups(new, group_info);
1307 if (ret < 0) {
1308 abort_creds(new);
1309 return ret;
1310 }
1311
1312 return commit_creds(new);
David Howellsb6dff3e2008-11-14 10:39:16 +11001313}
1314
Linus Torvalds1da177e2005-04-16 15:20:36 -07001315EXPORT_SYMBOL(set_current_groups);
1316
Heiko Carstensae1251a2009-01-14 14:14:05 +01001317SYSCALL_DEFINE2(getgroups, int, gidsetsize, gid_t __user *, grouplist)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001318{
David Howells86a264a2008-11-14 10:39:18 +11001319 const struct cred *cred = current_cred();
1320 int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001321
1322 if (gidsetsize < 0)
1323 return -EINVAL;
1324
1325 /* no need to grab task_lock here; it cannot change */
David Howellsb6dff3e2008-11-14 10:39:16 +11001326 i = cred->group_info->ngroups;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001327 if (gidsetsize) {
1328 if (i > gidsetsize) {
1329 i = -EINVAL;
1330 goto out;
1331 }
David Howellsb6dff3e2008-11-14 10:39:16 +11001332 if (groups_to_user(grouplist, cred->group_info)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001333 i = -EFAULT;
1334 goto out;
1335 }
1336 }
1337out:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001338 return i;
1339}
1340
1341/*
1342 * SMP: Our groups are copy-on-write. We can set them safely
1343 * without another task interfering.
1344 */
1345
Heiko Carstensb290ebe2009-01-14 14:14:06 +01001346SYSCALL_DEFINE2(setgroups, int, gidsetsize, gid_t __user *, grouplist)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001347{
1348 struct group_info *group_info;
1349 int retval;
1350
1351 if (!capable(CAP_SETGID))
1352 return -EPERM;
1353 if ((unsigned)gidsetsize > NGROUPS_MAX)
1354 return -EINVAL;
1355
1356 group_info = groups_alloc(gidsetsize);
1357 if (!group_info)
1358 return -ENOMEM;
1359 retval = groups_from_user(group_info, grouplist);
1360 if (retval) {
1361 put_group_info(group_info);
1362 return retval;
1363 }
1364
1365 retval = set_current_groups(group_info);
1366 put_group_info(group_info);
1367
1368 return retval;
1369}
1370
1371/*
1372 * Check whether we're fsgid/egid or in the supplemental group..
1373 */
1374int in_group_p(gid_t grp)
1375{
David Howells86a264a2008-11-14 10:39:18 +11001376 const struct cred *cred = current_cred();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001377 int retval = 1;
David Howells86a264a2008-11-14 10:39:18 +11001378
David Howellsb6dff3e2008-11-14 10:39:16 +11001379 if (grp != cred->fsgid)
1380 retval = groups_search(cred->group_info, grp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001381 return retval;
1382}
1383
1384EXPORT_SYMBOL(in_group_p);
1385
1386int in_egroup_p(gid_t grp)
1387{
David Howells86a264a2008-11-14 10:39:18 +11001388 const struct cred *cred = current_cred();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001389 int retval = 1;
David Howells86a264a2008-11-14 10:39:18 +11001390
David Howellsb6dff3e2008-11-14 10:39:16 +11001391 if (grp != cred->egid)
1392 retval = groups_search(cred->group_info, grp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001393 return retval;
1394}
1395
1396EXPORT_SYMBOL(in_egroup_p);
1397
1398DECLARE_RWSEM(uts_sem);
1399
Heiko Carstense48fbb62009-01-14 14:14:26 +01001400SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001401{
1402 int errno = 0;
1403
1404 down_read(&uts_sem);
Serge E. Hallyne9ff3992006-10-02 02:18:11 -07001405 if (copy_to_user(name, utsname(), sizeof *name))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001406 errno = -EFAULT;
1407 up_read(&uts_sem);
1408 return errno;
1409}
1410
Heiko Carstens5a8a82b2009-01-14 14:14:25 +01001411SYSCALL_DEFINE2(sethostname, char __user *, name, int, len)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001412{
1413 int errno;
1414 char tmp[__NEW_UTS_LEN];
1415
1416 if (!capable(CAP_SYS_ADMIN))
1417 return -EPERM;
1418 if (len < 0 || len > __NEW_UTS_LEN)
1419 return -EINVAL;
1420 down_write(&uts_sem);
1421 errno = -EFAULT;
1422 if (!copy_from_user(tmp, name, len)) {
Andrew Morton9679e4d2008-10-15 22:01:51 -07001423 struct new_utsname *u = utsname();
1424
1425 memcpy(u->nodename, tmp, len);
1426 memset(u->nodename + len, 0, sizeof(u->nodename) - len);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001427 errno = 0;
1428 }
1429 up_write(&uts_sem);
1430 return errno;
1431}
1432
1433#ifdef __ARCH_WANT_SYS_GETHOSTNAME
1434
Heiko Carstens5a8a82b2009-01-14 14:14:25 +01001435SYSCALL_DEFINE2(gethostname, char __user *, name, int, len)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001436{
1437 int i, errno;
Andrew Morton9679e4d2008-10-15 22:01:51 -07001438 struct new_utsname *u;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001439
1440 if (len < 0)
1441 return -EINVAL;
1442 down_read(&uts_sem);
Andrew Morton9679e4d2008-10-15 22:01:51 -07001443 u = utsname();
1444 i = 1 + strlen(u->nodename);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001445 if (i > len)
1446 i = len;
1447 errno = 0;
Andrew Morton9679e4d2008-10-15 22:01:51 -07001448 if (copy_to_user(name, u->nodename, i))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001449 errno = -EFAULT;
1450 up_read(&uts_sem);
1451 return errno;
1452}
1453
1454#endif
1455
1456/*
1457 * Only setdomainname; getdomainname can be implemented by calling
1458 * uname()
1459 */
Heiko Carstens5a8a82b2009-01-14 14:14:25 +01001460SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001461{
1462 int errno;
1463 char tmp[__NEW_UTS_LEN];
1464
1465 if (!capable(CAP_SYS_ADMIN))
1466 return -EPERM;
1467 if (len < 0 || len > __NEW_UTS_LEN)
1468 return -EINVAL;
1469
1470 down_write(&uts_sem);
1471 errno = -EFAULT;
1472 if (!copy_from_user(tmp, name, len)) {
Andrew Morton9679e4d2008-10-15 22:01:51 -07001473 struct new_utsname *u = utsname();
1474
1475 memcpy(u->domainname, tmp, len);
1476 memset(u->domainname + len, 0, sizeof(u->domainname) - len);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001477 errno = 0;
1478 }
1479 up_write(&uts_sem);
1480 return errno;
1481}
1482
Heiko Carstense48fbb62009-01-14 14:14:26 +01001483SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001484{
1485 if (resource >= RLIM_NLIMITS)
1486 return -EINVAL;
1487 else {
1488 struct rlimit value;
1489 task_lock(current->group_leader);
1490 value = current->signal->rlim[resource];
1491 task_unlock(current->group_leader);
1492 return copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1493 }
1494}
1495
1496#ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1497
1498/*
1499 * Back compatibility for getrlimit. Needed for some apps.
1500 */
1501
Heiko Carstense48fbb62009-01-14 14:14:26 +01001502SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1503 struct rlimit __user *, rlim)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001504{
1505 struct rlimit x;
1506 if (resource >= RLIM_NLIMITS)
1507 return -EINVAL;
1508
1509 task_lock(current->group_leader);
1510 x = current->signal->rlim[resource];
1511 task_unlock(current->group_leader);
Cal Peake756184b2006-09-30 23:27:24 -07001512 if (x.rlim_cur > 0x7FFFFFFF)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001513 x.rlim_cur = 0x7FFFFFFF;
Cal Peake756184b2006-09-30 23:27:24 -07001514 if (x.rlim_max > 0x7FFFFFFF)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001515 x.rlim_max = 0x7FFFFFFF;
1516 return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0;
1517}
1518
1519#endif
1520
Heiko Carstense48fbb62009-01-14 14:14:26 +01001521SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001522{
1523 struct rlimit new_rlim, *old_rlim;
1524 int retval;
1525
1526 if (resource >= RLIM_NLIMITS)
1527 return -EINVAL;
Andrew Mortonec9e16b2006-03-24 03:18:34 -08001528 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001529 return -EFAULT;
Andrew Morton60fd7602009-02-04 15:12:06 -08001530 if (new_rlim.rlim_cur > new_rlim.rlim_max)
1531 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001532 old_rlim = current->signal->rlim + resource;
1533 if ((new_rlim.rlim_max > old_rlim->rlim_max) &&
1534 !capable(CAP_SYS_RESOURCE))
1535 return -EPERM;
Andrew Morton60fd7602009-02-04 15:12:06 -08001536 if (resource == RLIMIT_NOFILE && new_rlim.rlim_max > sysctl_nr_open)
1537 return -EPERM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001538
1539 retval = security_task_setrlimit(resource, &new_rlim);
1540 if (retval)
1541 return retval;
1542
Tom Alsberg9926e4c2007-05-08 00:30:31 -07001543 if (resource == RLIMIT_CPU && new_rlim.rlim_cur == 0) {
1544 /*
1545 * The caller is asking for an immediate RLIMIT_CPU
1546 * expiry. But we use the zero value to mean "it was
1547 * never set". So let's cheat and make it one second
1548 * instead
1549 */
1550 new_rlim.rlim_cur = 1;
1551 }
1552
Linus Torvalds1da177e2005-04-16 15:20:36 -07001553 task_lock(current->group_leader);
1554 *old_rlim = new_rlim;
1555 task_unlock(current->group_leader);
1556
Andrew Mortonec9e16b2006-03-24 03:18:34 -08001557 if (resource != RLIMIT_CPU)
1558 goto out;
Andrew Mortond3561f72006-03-24 03:18:36 -08001559
1560 /*
1561 * RLIMIT_CPU handling. Note that the kernel fails to return an error
1562 * code if it rejected the user's attempt to set RLIMIT_CPU. This is a
1563 * very long-standing error, and fixing it now risks breakage of
1564 * applications, so we live with it
1565 */
Andrew Mortonec9e16b2006-03-24 03:18:34 -08001566 if (new_rlim.rlim_cur == RLIM_INFINITY)
1567 goto out;
1568
Frank Mayharf06febc2008-09-12 09:54:39 -07001569 update_rlimit_cpu(new_rlim.rlim_cur);
Andrew Mortonec9e16b2006-03-24 03:18:34 -08001570out:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001571 return 0;
1572}
1573
1574/*
1575 * It would make sense to put struct rusage in the task_struct,
1576 * except that would make the task_struct be *really big*. After
1577 * task_struct gets moved into malloc'ed memory, it would
1578 * make sense to do this. It will make moving the rest of the information
1579 * a lot simpler! (Which we're not doing right now because we're not
1580 * measuring them yet).
1581 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001582 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1583 * races with threads incrementing their own counters. But since word
1584 * reads are atomic, we either get new values or old values and we don't
1585 * care which for the sums. We always take the siglock to protect reading
1586 * the c* fields from p->signal from races with exit.c updating those
1587 * fields when reaping, so a sample either gets all the additions of a
1588 * given child after it's reaped, or none so this sample is before reaping.
Ravikiran G Thirumalai2dd0ebc2006-03-23 03:00:13 -08001589 *
Ravikiran G Thirumalaide047c12006-06-22 14:47:26 -07001590 * Locking:
1591 * We need to take the siglock for CHILDEREN, SELF and BOTH
1592 * for the cases current multithreaded, non-current single threaded
1593 * non-current multithreaded. Thread traversal is now safe with
1594 * the siglock held.
1595 * Strictly speaking, we donot need to take the siglock if we are current and
1596 * single threaded, as no one else can take our signal_struct away, no one
1597 * else can reap the children to update signal->c* counters, and no one else
1598 * can race with the signal-> fields. If we do not take any lock, the
1599 * signal-> fields could be read out of order while another thread was just
1600 * exiting. So we should place a read memory barrier when we avoid the lock.
1601 * On the writer side, write memory barrier is implied in __exit_signal
1602 * as __exit_signal releases the siglock spinlock after updating the signal->
1603 * fields. But we don't do this yet to keep things simple.
Ravikiran G Thirumalai2dd0ebc2006-03-23 03:00:13 -08001604 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001605 */
1606
Frank Mayharf06febc2008-09-12 09:54:39 -07001607static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
Sripathi Kodi679c9cd2008-04-29 00:58:42 -07001608{
Sripathi Kodi679c9cd2008-04-29 00:58:42 -07001609 r->ru_nvcsw += t->nvcsw;
1610 r->ru_nivcsw += t->nivcsw;
1611 r->ru_minflt += t->min_flt;
1612 r->ru_majflt += t->maj_flt;
1613 r->ru_inblock += task_io_get_inblock(t);
1614 r->ru_oublock += task_io_get_oublock(t);
1615}
1616
Linus Torvalds1da177e2005-04-16 15:20:36 -07001617static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
1618{
1619 struct task_struct *t;
1620 unsigned long flags;
1621 cputime_t utime, stime;
Frank Mayharf06febc2008-09-12 09:54:39 -07001622 struct task_cputime cputime;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001623
1624 memset((char *) r, 0, sizeof *r);
Oleg Nesterov0f59cc42006-01-08 01:05:15 -08001625 utime = stime = cputime_zero;
1626
Sripathi Kodi679c9cd2008-04-29 00:58:42 -07001627 if (who == RUSAGE_THREAD) {
KOSAKI Motohiro8916ede2009-01-04 05:40:37 +09001628 utime = task_utime(current);
1629 stime = task_stime(current);
Frank Mayharf06febc2008-09-12 09:54:39 -07001630 accumulate_thread_rusage(p, r);
Sripathi Kodi679c9cd2008-04-29 00:58:42 -07001631 goto out;
1632 }
1633
Oleg Nesterovd6cf7232008-04-30 00:52:38 -07001634 if (!lock_task_sighand(p, &flags))
Ravikiran G Thirumalaide047c12006-06-22 14:47:26 -07001635 return;
Ravikiran G Thirumalai2dd0ebc2006-03-23 03:00:13 -08001636
Linus Torvalds1da177e2005-04-16 15:20:36 -07001637 switch (who) {
Oleg Nesterov0f59cc42006-01-08 01:05:15 -08001638 case RUSAGE_BOTH:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001639 case RUSAGE_CHILDREN:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001640 utime = p->signal->cutime;
1641 stime = p->signal->cstime;
1642 r->ru_nvcsw = p->signal->cnvcsw;
1643 r->ru_nivcsw = p->signal->cnivcsw;
1644 r->ru_minflt = p->signal->cmin_flt;
1645 r->ru_majflt = p->signal->cmaj_flt;
Eric Dumazet6eaeeab2007-05-10 22:22:37 -07001646 r->ru_inblock = p->signal->cinblock;
1647 r->ru_oublock = p->signal->coublock;
Oleg Nesterov0f59cc42006-01-08 01:05:15 -08001648
1649 if (who == RUSAGE_CHILDREN)
1650 break;
1651
Linus Torvalds1da177e2005-04-16 15:20:36 -07001652 case RUSAGE_SELF:
Frank Mayharf06febc2008-09-12 09:54:39 -07001653 thread_group_cputime(p, &cputime);
1654 utime = cputime_add(utime, cputime.utime);
1655 stime = cputime_add(stime, cputime.stime);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001656 r->ru_nvcsw += p->signal->nvcsw;
1657 r->ru_nivcsw += p->signal->nivcsw;
1658 r->ru_minflt += p->signal->min_flt;
1659 r->ru_majflt += p->signal->maj_flt;
Eric Dumazet6eaeeab2007-05-10 22:22:37 -07001660 r->ru_inblock += p->signal->inblock;
1661 r->ru_oublock += p->signal->oublock;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001662 t = p;
1663 do {
Frank Mayharf06febc2008-09-12 09:54:39 -07001664 accumulate_thread_rusage(t, r);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001665 t = next_thread(t);
1666 } while (t != p);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001667 break;
Oleg Nesterov0f59cc42006-01-08 01:05:15 -08001668
Linus Torvalds1da177e2005-04-16 15:20:36 -07001669 default:
1670 BUG();
1671 }
Ravikiran G Thirumalaide047c12006-06-22 14:47:26 -07001672 unlock_task_sighand(p, &flags);
Ravikiran G Thirumalaide047c12006-06-22 14:47:26 -07001673
Sripathi Kodi679c9cd2008-04-29 00:58:42 -07001674out:
Oleg Nesterov0f59cc42006-01-08 01:05:15 -08001675 cputime_to_timeval(utime, &r->ru_utime);
1676 cputime_to_timeval(stime, &r->ru_stime);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001677}
1678
1679int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
1680{
1681 struct rusage r;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001682 k_getrusage(p, who, &r);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001683 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1684}
1685
Heiko Carstense48fbb62009-01-14 14:14:26 +01001686SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001687{
Sripathi Kodi679c9cd2008-04-29 00:58:42 -07001688 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1689 who != RUSAGE_THREAD)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001690 return -EINVAL;
1691 return getrusage(current, who, ru);
1692}
1693
Heiko Carstense48fbb62009-01-14 14:14:26 +01001694SYSCALL_DEFINE1(umask, int, mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001695{
1696 mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1697 return mask;
1698}
Serge E. Hallyn3b7391d2008-02-04 22:29:45 -08001699
Heiko Carstensc4ea37c2009-01-14 14:14:28 +01001700SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
1701 unsigned long, arg4, unsigned long, arg5)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001702{
David Howellsb6dff3e2008-11-14 10:39:16 +11001703 struct task_struct *me = current;
1704 unsigned char comm[sizeof(me->comm)];
1705 long error;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001706
David Howellsd84f4f92008-11-14 10:39:23 +11001707 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
1708 if (error != -ENOSYS)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001709 return error;
1710
David Howellsd84f4f92008-11-14 10:39:23 +11001711 error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001712 switch (option) {
1713 case PR_SET_PDEATHSIG:
Jesper Juhl0730ded2005-09-06 15:17:37 -07001714 if (!valid_signal(arg2)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001715 error = -EINVAL;
1716 break;
1717 }
David Howellsb6dff3e2008-11-14 10:39:16 +11001718 me->pdeath_signal = arg2;
1719 error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001720 break;
1721 case PR_GET_PDEATHSIG:
David Howellsb6dff3e2008-11-14 10:39:16 +11001722 error = put_user(me->pdeath_signal, (int __user *)arg2);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001723 break;
1724 case PR_GET_DUMPABLE:
David Howellsb6dff3e2008-11-14 10:39:16 +11001725 error = get_dumpable(me->mm);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001726 break;
1727 case PR_SET_DUMPABLE:
Marcel Holtmannabf75a52006-07-12 13:12:00 +02001728 if (arg2 < 0 || arg2 > 1) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001729 error = -EINVAL;
1730 break;
1731 }
David Howellsb6dff3e2008-11-14 10:39:16 +11001732 set_dumpable(me->mm, arg2);
1733 error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001734 break;
1735
1736 case PR_SET_UNALIGN:
David Howellsb6dff3e2008-11-14 10:39:16 +11001737 error = SET_UNALIGN_CTL(me, arg2);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001738 break;
1739 case PR_GET_UNALIGN:
David Howellsb6dff3e2008-11-14 10:39:16 +11001740 error = GET_UNALIGN_CTL(me, arg2);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001741 break;
1742 case PR_SET_FPEMU:
David Howellsb6dff3e2008-11-14 10:39:16 +11001743 error = SET_FPEMU_CTL(me, arg2);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001744 break;
1745 case PR_GET_FPEMU:
David Howellsb6dff3e2008-11-14 10:39:16 +11001746 error = GET_FPEMU_CTL(me, arg2);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001747 break;
1748 case PR_SET_FPEXC:
David Howellsb6dff3e2008-11-14 10:39:16 +11001749 error = SET_FPEXC_CTL(me, arg2);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001750 break;
1751 case PR_GET_FPEXC:
David Howellsb6dff3e2008-11-14 10:39:16 +11001752 error = GET_FPEXC_CTL(me, arg2);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001753 break;
1754 case PR_GET_TIMING:
1755 error = PR_TIMING_STATISTICAL;
1756 break;
1757 case PR_SET_TIMING:
Shi Weihua7b266552008-05-23 13:04:59 -07001758 if (arg2 != PR_TIMING_STATISTICAL)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001759 error = -EINVAL;
David Howellsb6dff3e2008-11-14 10:39:16 +11001760 else
1761 error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001762 break;
1763
David Howellsb6dff3e2008-11-14 10:39:16 +11001764 case PR_SET_NAME:
1765 comm[sizeof(me->comm)-1] = 0;
1766 if (strncpy_from_user(comm, (char __user *)arg2,
1767 sizeof(me->comm) - 1) < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001768 return -EFAULT;
David Howellsb6dff3e2008-11-14 10:39:16 +11001769 set_task_comm(me, comm);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001770 return 0;
David Howellsb6dff3e2008-11-14 10:39:16 +11001771 case PR_GET_NAME:
1772 get_task_comm(comm, me);
1773 if (copy_to_user((char __user *)arg2, comm,
1774 sizeof(comm)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001775 return -EFAULT;
1776 return 0;
Anton Blanchard651d7652006-06-07 16:10:19 +10001777 case PR_GET_ENDIAN:
David Howellsb6dff3e2008-11-14 10:39:16 +11001778 error = GET_ENDIAN(me, arg2);
Anton Blanchard651d7652006-06-07 16:10:19 +10001779 break;
1780 case PR_SET_ENDIAN:
David Howellsb6dff3e2008-11-14 10:39:16 +11001781 error = SET_ENDIAN(me, arg2);
Anton Blanchard651d7652006-06-07 16:10:19 +10001782 break;
1783
Andrea Arcangeli1d9d02f2007-07-15 23:41:32 -07001784 case PR_GET_SECCOMP:
1785 error = prctl_get_seccomp();
1786 break;
1787 case PR_SET_SECCOMP:
1788 error = prctl_set_seccomp(arg2);
1789 break;
Erik Bosman8fb402b2008-04-11 18:54:17 +02001790 case PR_GET_TSC:
1791 error = GET_TSC_CTL(arg2);
1792 break;
1793 case PR_SET_TSC:
1794 error = SET_TSC_CTL(arg2);
1795 break;
Arjan van de Ven69766752008-09-01 15:52:40 -07001796 case PR_GET_TIMERSLACK:
1797 error = current->timer_slack_ns;
1798 break;
1799 case PR_SET_TIMERSLACK:
1800 if (arg2 <= 0)
1801 current->timer_slack_ns =
1802 current->default_timer_slack_ns;
1803 else
1804 current->timer_slack_ns = arg2;
David Howellsb6dff3e2008-11-14 10:39:16 +11001805 error = 0;
Arjan van de Ven69766752008-09-01 15:52:40 -07001806 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001807 default:
1808 error = -EINVAL;
1809 break;
1810 }
1811 return error;
1812}
Andi Kleen3cfc3482006-09-26 10:52:28 +02001813
Heiko Carstens836f92a2009-01-14 14:14:33 +01001814SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
1815 struct getcpu_cache __user *, unused)
Andi Kleen3cfc3482006-09-26 10:52:28 +02001816{
1817 int err = 0;
1818 int cpu = raw_smp_processor_id();
1819 if (cpup)
1820 err |= put_user(cpu, cpup);
1821 if (nodep)
1822 err |= put_user(cpu_to_node(cpu), nodep);
Andi Kleen3cfc3482006-09-26 10:52:28 +02001823 return err ? -EFAULT : 0;
1824}
Jeremy Fitzhardinge10a0a8d2007-07-17 18:37:02 -07001825
1826char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff";
1827
1828static void argv_cleanup(char **argv, char **envp)
1829{
1830 argv_free(argv);
1831}
1832
1833/**
1834 * orderly_poweroff - Trigger an orderly system poweroff
1835 * @force: force poweroff if command execution fails
1836 *
1837 * This may be called from any context to trigger a system shutdown.
1838 * If the orderly shutdown fails, it will force an immediate shutdown.
1839 */
1840int orderly_poweroff(bool force)
1841{
1842 int argc;
1843 char **argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc);
1844 static char *envp[] = {
1845 "HOME=/",
1846 "PATH=/sbin:/bin:/usr/sbin:/usr/bin",
1847 NULL
1848 };
1849 int ret = -ENOMEM;
1850 struct subprocess_info *info;
1851
1852 if (argv == NULL) {
1853 printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n",
1854 __func__, poweroff_cmd);
1855 goto out;
1856 }
1857
KOSAKI Motohiroac331d12008-07-25 01:45:38 -07001858 info = call_usermodehelper_setup(argv[0], argv, envp, GFP_ATOMIC);
Jeremy Fitzhardinge10a0a8d2007-07-17 18:37:02 -07001859 if (info == NULL) {
1860 argv_free(argv);
1861 goto out;
1862 }
1863
1864 call_usermodehelper_setcleanup(info, argv_cleanup);
1865
Jeremy Fitzhardinge86313c42007-07-17 18:37:03 -07001866 ret = call_usermodehelper_exec(info, UMH_NO_WAIT);
Jeremy Fitzhardinge10a0a8d2007-07-17 18:37:02 -07001867
1868 out:
1869 if (ret && force) {
1870 printk(KERN_WARNING "Failed to start orderly shutdown: "
1871 "forcing the issue\n");
1872
1873 /* I guess this should try to kick off some daemon to
1874 sync and poweroff asap. Or not even bother syncing
1875 if we're doing an emergency shutdown? */
1876 emergency_sync();
1877 kernel_power_off();
1878 }
1879
1880 return ret;
1881}
1882EXPORT_SYMBOL_GPL(orderly_poweroff);