blob: 7de9c984f6968e9bf6816b90edd30223bb2fe93c [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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070036
37#include <linux/compat.h>
38#include <linux/syscalls.h>
Keshavamurthy Anil S00d7c052005-12-12 00:37:33 -080039#include <linux/kprobes.h>
Cedric Le Goateracce2922007-07-15 23:40:59 -070040#include <linux/user_namespace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070041
42#include <asm/uaccess.h>
43#include <asm/io.h>
44#include <asm/unistd.h>
45
46#ifndef SET_UNALIGN_CTL
47# define SET_UNALIGN_CTL(a,b) (-EINVAL)
48#endif
49#ifndef GET_UNALIGN_CTL
50# define GET_UNALIGN_CTL(a,b) (-EINVAL)
51#endif
52#ifndef SET_FPEMU_CTL
53# define SET_FPEMU_CTL(a,b) (-EINVAL)
54#endif
55#ifndef GET_FPEMU_CTL
56# define GET_FPEMU_CTL(a,b) (-EINVAL)
57#endif
58#ifndef SET_FPEXC_CTL
59# define SET_FPEXC_CTL(a,b) (-EINVAL)
60#endif
61#ifndef GET_FPEXC_CTL
62# define GET_FPEXC_CTL(a,b) (-EINVAL)
63#endif
Anton Blanchard651d7652006-06-07 16:10:19 +100064#ifndef GET_ENDIAN
65# define GET_ENDIAN(a,b) (-EINVAL)
66#endif
67#ifndef SET_ENDIAN
68# define SET_ENDIAN(a,b) (-EINVAL)
69#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070070
71/*
72 * this is where the system-wide overflow UID and GID are defined, for
73 * architectures that now have 32-bit UID/GID but didn't in the past
74 */
75
76int overflowuid = DEFAULT_OVERFLOWUID;
77int overflowgid = DEFAULT_OVERFLOWGID;
78
79#ifdef CONFIG_UID16
80EXPORT_SYMBOL(overflowuid);
81EXPORT_SYMBOL(overflowgid);
82#endif
83
84/*
85 * the same as above, but for filesystems which can only store a 16-bit
86 * UID and GID. as such, this is needed on all architectures
87 */
88
89int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
90int fs_overflowgid = DEFAULT_FS_OVERFLOWUID;
91
92EXPORT_SYMBOL(fs_overflowuid);
93EXPORT_SYMBOL(fs_overflowgid);
94
95/*
96 * this indicates whether you can reboot with ctrl-alt-del: the default is yes
97 */
98
99int C_A_D = 1;
Cedric Le Goater9ec52092006-10-02 02:19:00 -0700100struct pid *cad_pid;
101EXPORT_SYMBOL(cad_pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102
103/*
Rafael J. Wysockibd804eb2007-07-19 01:47:40 -0700104 * If set, this is used for preparing the system to power off.
105 */
106
107void (*pm_power_off_prepare)(void);
Rafael J. Wysockibd804eb2007-07-19 01:47:40 -0700108
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109static int set_one_prio(struct task_struct *p, int niceval, int error)
110{
111 int no_nice;
112
113 if (p->uid != current->euid &&
114 p->euid != current->euid && !capable(CAP_SYS_NICE)) {
115 error = -EPERM;
116 goto out;
117 }
Matt Mackalle43379f2005-05-01 08:59:00 -0700118 if (niceval < task_nice(p) && !can_nice(p, niceval)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119 error = -EACCES;
120 goto out;
121 }
122 no_nice = security_task_setnice(p, niceval);
123 if (no_nice) {
124 error = no_nice;
125 goto out;
126 }
127 if (error == -ESRCH)
128 error = 0;
129 set_user_nice(p, niceval);
130out:
131 return error;
132}
133
134asmlinkage long sys_setpriority(int which, int who, int niceval)
135{
136 struct task_struct *g, *p;
137 struct user_struct *user;
138 int error = -EINVAL;
Eric W. Biederman41487c62007-02-12 00:53:01 -0800139 struct pid *pgrp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140
Daniel Walker3e88c552007-05-10 22:22:53 -0700141 if (which > PRIO_USER || which < PRIO_PROCESS)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142 goto out;
143
144 /* normalize: avoid signed division (rounding problems) */
145 error = -ESRCH;
146 if (niceval < -20)
147 niceval = -20;
148 if (niceval > 19)
149 niceval = 19;
150
151 read_lock(&tasklist_lock);
152 switch (which) {
153 case PRIO_PROCESS:
Eric W. Biederman41487c62007-02-12 00:53:01 -0800154 if (who)
Pavel Emelyanov228ebcb2007-10-18 23:40:16 -0700155 p = find_task_by_vpid(who);
Eric W. Biederman41487c62007-02-12 00:53:01 -0800156 else
157 p = current;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 if (p)
159 error = set_one_prio(p, niceval, error);
160 break;
161 case PRIO_PGRP:
Eric W. Biederman41487c62007-02-12 00:53:01 -0800162 if (who)
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700163 pgrp = find_vpid(who);
Eric W. Biederman41487c62007-02-12 00:53:01 -0800164 else
165 pgrp = task_pgrp(current);
166 do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 error = set_one_prio(p, niceval, error);
Eric W. Biederman41487c62007-02-12 00:53:01 -0800168 } while_each_pid_task(pgrp, PIDTYPE_PGID, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169 break;
170 case PRIO_USER:
171 user = current->user;
172 if (!who)
173 who = current->uid;
174 else
175 if ((who != current->uid) && !(user = find_user(who)))
176 goto out_unlock; /* No processes for this user */
177
178 do_each_thread(g, p)
179 if (p->uid == who)
180 error = set_one_prio(p, niceval, error);
181 while_each_thread(g, p);
182 if (who != current->uid)
183 free_uid(user); /* For find_user() */
184 break;
185 }
186out_unlock:
187 read_unlock(&tasklist_lock);
188out:
189 return error;
190}
191
192/*
193 * Ugh. To avoid negative return values, "getpriority()" will
194 * not return the normal nice-value, but a negated value that
195 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
196 * to stay compatible.
197 */
198asmlinkage long sys_getpriority(int which, int who)
199{
200 struct task_struct *g, *p;
201 struct user_struct *user;
202 long niceval, retval = -ESRCH;
Eric W. Biederman41487c62007-02-12 00:53:01 -0800203 struct pid *pgrp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204
Daniel Walker3e88c552007-05-10 22:22:53 -0700205 if (which > PRIO_USER || which < PRIO_PROCESS)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 return -EINVAL;
207
208 read_lock(&tasklist_lock);
209 switch (which) {
210 case PRIO_PROCESS:
Eric W. Biederman41487c62007-02-12 00:53:01 -0800211 if (who)
Pavel Emelyanov228ebcb2007-10-18 23:40:16 -0700212 p = find_task_by_vpid(who);
Eric W. Biederman41487c62007-02-12 00:53:01 -0800213 else
214 p = current;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215 if (p) {
216 niceval = 20 - task_nice(p);
217 if (niceval > retval)
218 retval = niceval;
219 }
220 break;
221 case PRIO_PGRP:
Eric W. Biederman41487c62007-02-12 00:53:01 -0800222 if (who)
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700223 pgrp = find_vpid(who);
Eric W. Biederman41487c62007-02-12 00:53:01 -0800224 else
225 pgrp = task_pgrp(current);
226 do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 niceval = 20 - task_nice(p);
228 if (niceval > retval)
229 retval = niceval;
Eric W. Biederman41487c62007-02-12 00:53:01 -0800230 } while_each_pid_task(pgrp, PIDTYPE_PGID, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 break;
232 case PRIO_USER:
233 user = current->user;
234 if (!who)
235 who = current->uid;
236 else
237 if ((who != current->uid) && !(user = find_user(who)))
238 goto out_unlock; /* No processes for this user */
239
240 do_each_thread(g, p)
241 if (p->uid == who) {
242 niceval = 20 - task_nice(p);
243 if (niceval > retval)
244 retval = niceval;
245 }
246 while_each_thread(g, p);
247 if (who != current->uid)
248 free_uid(user); /* for find_user() */
249 break;
250 }
251out_unlock:
252 read_unlock(&tasklist_lock);
253
254 return retval;
255}
256
Eric W. Biedermane4c94332005-09-22 21:43:45 -0700257/**
258 * emergency_restart - reboot the system
259 *
260 * Without shutting down any hardware or taking any locks
261 * reboot the system. This is called when we know we are in
262 * trouble so this is our best effort to reboot. This is
263 * safe to call in interrupt context.
264 */
Eric W. Biederman7c903472005-07-26 11:29:55 -0600265void emergency_restart(void)
266{
267 machine_emergency_restart();
268}
269EXPORT_SYMBOL_GPL(emergency_restart);
270
Adrian Bunk83cc5ed2006-06-25 05:47:41 -0700271static void kernel_restart_prepare(char *cmd)
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600272{
Alan Sterne041c682006-03-27 01:16:30 -0800273 blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd);
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600274 system_state = SYSTEM_RESTART;
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600275 device_shutdown();
Rafael J. Wysocki58b3b712007-07-26 16:29:55 +0200276 sysdev_shutdown();
Eric W. Biedermane4c94332005-09-22 21:43:45 -0700277}
Randy Dunlap1e5d5332005-11-07 01:01:06 -0800278
279/**
280 * kernel_restart - reboot the system
281 * @cmd: pointer to buffer containing command to execute for restart
Randy Dunlapb8887e62005-11-07 01:01:07 -0800282 * or %NULL
Randy Dunlap1e5d5332005-11-07 01:01:06 -0800283 *
284 * Shutdown everything and perform a clean reboot.
285 * This is not safe to call in interrupt context.
286 */
Eric W. Biedermane4c94332005-09-22 21:43:45 -0700287void kernel_restart(char *cmd)
288{
289 kernel_restart_prepare(cmd);
Cal Peake756184b2006-09-30 23:27:24 -0700290 if (!cmd)
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600291 printk(KERN_EMERG "Restarting system.\n");
Cal Peake756184b2006-09-30 23:27:24 -0700292 else
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600293 printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd);
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600294 machine_restart(cmd);
295}
296EXPORT_SYMBOL_GPL(kernel_restart);
297
Eric W. Biedermane4c94332005-09-22 21:43:45 -0700298/**
299 * kernel_kexec - reboot the system
300 *
301 * Move into place and start executing a preloaded standalone
302 * executable. If nothing was preloaded return an error.
303 */
Adrian Bunk83cc5ed2006-06-25 05:47:41 -0700304static void kernel_kexec(void)
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600305{
306#ifdef CONFIG_KEXEC
307 struct kimage *image;
Al Viro4bb80892006-02-01 05:57:32 -0500308 image = xchg(&kexec_image, NULL);
Cal Peake756184b2006-09-30 23:27:24 -0700309 if (!image)
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600310 return;
Eric W. Biedermane4c94332005-09-22 21:43:45 -0700311 kernel_restart_prepare(NULL);
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600312 printk(KERN_EMERG "Starting new kernel\n");
313 machine_shutdown();
314 machine_kexec(image);
315#endif
316}
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600317
Adrian Bunk4ef72292008-02-04 22:30:06 -0800318static void kernel_shutdown_prepare(enum system_states state)
Alexey Starikovskiy729b4d42005-12-01 04:29:00 -0500319{
Alan Sterne041c682006-03-27 01:16:30 -0800320 blocking_notifier_call_chain(&reboot_notifier_list,
Alexey Starikovskiy729b4d42005-12-01 04:29:00 -0500321 (state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL);
322 system_state = state;
323 device_shutdown();
324}
Eric W. Biedermane4c94332005-09-22 21:43:45 -0700325/**
326 * kernel_halt - halt the system
327 *
328 * Shutdown everything and perform a clean system halt.
329 */
Eric W. Biedermane4c94332005-09-22 21:43:45 -0700330void kernel_halt(void)
331{
Alexey Starikovskiy729b4d42005-12-01 04:29:00 -0500332 kernel_shutdown_prepare(SYSTEM_HALT);
Rafael J. Wysocki58b3b712007-07-26 16:29:55 +0200333 sysdev_shutdown();
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600334 printk(KERN_EMERG "System halted.\n");
335 machine_halt();
336}
Alexey Starikovskiy729b4d42005-12-01 04:29:00 -0500337
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600338EXPORT_SYMBOL_GPL(kernel_halt);
339
Eric W. Biedermane4c94332005-09-22 21:43:45 -0700340/**
341 * kernel_power_off - power_off the system
342 *
343 * Shutdown everything and perform a clean system power_off.
344 */
Eric W. Biedermane4c94332005-09-22 21:43:45 -0700345void kernel_power_off(void)
346{
Alexey Starikovskiy729b4d42005-12-01 04:29:00 -0500347 kernel_shutdown_prepare(SYSTEM_POWER_OFF);
Rafael J. Wysockibd804eb2007-07-19 01:47:40 -0700348 if (pm_power_off_prepare)
349 pm_power_off_prepare();
Mark Lord40477272007-10-01 01:20:10 -0700350 disable_nonboot_cpus();
Rafael J. Wysocki58b3b712007-07-26 16:29:55 +0200351 sysdev_shutdown();
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600352 printk(KERN_EMERG "Power down.\n");
353 machine_power_off();
354}
355EXPORT_SYMBOL_GPL(kernel_power_off);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356/*
357 * Reboot system call: for obvious reasons only root may call it,
358 * and even root needs to set up some magic numbers in the registers
359 * so that some mistake won't make this reboot the whole machine.
360 * You can also set the meaning of the ctrl-alt-del-key here.
361 *
362 * reboot doesn't sync: do that yourself before calling this.
363 */
364asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user * arg)
365{
366 char buffer[256];
367
368 /* We only trust the superuser with rebooting the system. */
369 if (!capable(CAP_SYS_BOOT))
370 return -EPERM;
371
372 /* For safety, we require "magic" arguments. */
373 if (magic1 != LINUX_REBOOT_MAGIC1 ||
374 (magic2 != LINUX_REBOOT_MAGIC2 &&
375 magic2 != LINUX_REBOOT_MAGIC2A &&
376 magic2 != LINUX_REBOOT_MAGIC2B &&
377 magic2 != LINUX_REBOOT_MAGIC2C))
378 return -EINVAL;
379
Eric W. Biederman5e382912006-01-08 01:03:46 -0800380 /* Instead of trying to make the power_off code look like
381 * halt when pm_power_off is not set do it the easy way.
382 */
383 if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off)
384 cmd = LINUX_REBOOT_CMD_HALT;
385
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386 lock_kernel();
387 switch (cmd) {
388 case LINUX_REBOOT_CMD_RESTART:
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600389 kernel_restart(NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390 break;
391
392 case LINUX_REBOOT_CMD_CAD_ON:
393 C_A_D = 1;
394 break;
395
396 case LINUX_REBOOT_CMD_CAD_OFF:
397 C_A_D = 0;
398 break;
399
400 case LINUX_REBOOT_CMD_HALT:
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600401 kernel_halt();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 unlock_kernel();
403 do_exit(0);
404 break;
405
406 case LINUX_REBOOT_CMD_POWER_OFF:
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600407 kernel_power_off();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408 unlock_kernel();
409 do_exit(0);
410 break;
411
412 case LINUX_REBOOT_CMD_RESTART2:
413 if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) {
414 unlock_kernel();
415 return -EFAULT;
416 }
417 buffer[sizeof(buffer) - 1] = '\0';
418
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600419 kernel_restart(buffer);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 break;
421
Eric W. Biedermandc009d92005-06-25 14:57:52 -0700422 case LINUX_REBOOT_CMD_KEXEC:
Eric W. Biederman4a00ea12005-07-26 11:24:14 -0600423 kernel_kexec();
424 unlock_kernel();
425 return -EINVAL;
426
Rafael J. Wysockib0cb1a12007-07-29 23:24:36 +0200427#ifdef CONFIG_HIBERNATION
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428 case LINUX_REBOOT_CMD_SW_SUSPEND:
429 {
Rafael J. Wysockia3d25c22007-05-09 02:33:18 -0700430 int ret = hibernate();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431 unlock_kernel();
432 return ret;
433 }
434#endif
435
436 default:
437 unlock_kernel();
438 return -EINVAL;
439 }
440 unlock_kernel();
441 return 0;
442}
443
David Howells65f27f32006-11-22 14:55:48 +0000444static void deferred_cad(struct work_struct *dummy)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445{
Eric W. Biedermanabcd9e52005-07-26 11:27:34 -0600446 kernel_restart(NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447}
448
449/*
450 * This function gets called by ctrl-alt-del - ie the keyboard interrupt.
451 * As it's called within an interrupt, it may NOT sync: the only choice
452 * is whether to reboot at once, or just ignore the ctrl-alt-del.
453 */
454void ctrl_alt_del(void)
455{
David Howells65f27f32006-11-22 14:55:48 +0000456 static DECLARE_WORK(cad_work, deferred_cad);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457
458 if (C_A_D)
459 schedule_work(&cad_work);
460 else
Cedric Le Goater9ec52092006-10-02 02:19:00 -0700461 kill_cad_pid(SIGINT, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462}
463
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464/*
465 * Unprivileged users may change the real gid to the effective gid
466 * or vice versa. (BSD-style)
467 *
468 * If you set the real gid at all, or set the effective gid to a value not
469 * equal to the real gid, then the saved gid is set to the new effective gid.
470 *
471 * This makes it possible for a setgid program to completely drop its
472 * privileges, which is often a useful assertion to make when you are doing
473 * a security audit over a program.
474 *
475 * The general idea is that a program which uses just setregid() will be
476 * 100% compatible with BSD. A program which uses just setgid() will be
477 * 100% compatible with POSIX with saved IDs.
478 *
479 * SMP: There are not races, the GIDs are checked only by filesystem
480 * operations (as far as semantic preservation is concerned).
481 */
482asmlinkage long sys_setregid(gid_t rgid, gid_t egid)
483{
484 int old_rgid = current->gid;
485 int old_egid = current->egid;
486 int new_rgid = old_rgid;
487 int new_egid = old_egid;
488 int retval;
489
490 retval = security_task_setgid(rgid, egid, (gid_t)-1, LSM_SETID_RE);
491 if (retval)
492 return retval;
493
494 if (rgid != (gid_t) -1) {
495 if ((old_rgid == rgid) ||
496 (current->egid==rgid) ||
497 capable(CAP_SETGID))
498 new_rgid = rgid;
499 else
500 return -EPERM;
501 }
502 if (egid != (gid_t) -1) {
503 if ((old_rgid == egid) ||
504 (current->egid == egid) ||
505 (current->sgid == egid) ||
506 capable(CAP_SETGID))
507 new_egid = egid;
Cal Peake756184b2006-09-30 23:27:24 -0700508 else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509 return -EPERM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510 }
Cal Peake756184b2006-09-30 23:27:24 -0700511 if (new_egid != old_egid) {
Kawai, Hidehiro6c5d5232007-07-19 01:48:27 -0700512 set_dumpable(current->mm, suid_dumpable);
akpm@osdl.orgd59dd462005-05-01 08:58:47 -0700513 smp_wmb();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514 }
515 if (rgid != (gid_t) -1 ||
516 (egid != (gid_t) -1 && egid != old_rgid))
517 current->sgid = new_egid;
518 current->fsgid = new_egid;
519 current->egid = new_egid;
520 current->gid = new_rgid;
521 key_fsgid_changed(current);
Matt Helsley9f460802005-11-07 00:59:16 -0800522 proc_id_connector(current, PROC_EVENT_GID);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523 return 0;
524}
525
526/*
527 * setgid() is implemented like SysV w/ SAVED_IDS
528 *
529 * SMP: Same implicit races as above.
530 */
531asmlinkage long sys_setgid(gid_t gid)
532{
533 int old_egid = current->egid;
534 int retval;
535
536 retval = security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID);
537 if (retval)
538 return retval;
539
Cal Peake756184b2006-09-30 23:27:24 -0700540 if (capable(CAP_SETGID)) {
541 if (old_egid != gid) {
Kawai, Hidehiro6c5d5232007-07-19 01:48:27 -0700542 set_dumpable(current->mm, suid_dumpable);
akpm@osdl.orgd59dd462005-05-01 08:58:47 -0700543 smp_wmb();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544 }
545 current->gid = current->egid = current->sgid = current->fsgid = gid;
Cal Peake756184b2006-09-30 23:27:24 -0700546 } else if ((gid == current->gid) || (gid == current->sgid)) {
547 if (old_egid != gid) {
Kawai, Hidehiro6c5d5232007-07-19 01:48:27 -0700548 set_dumpable(current->mm, suid_dumpable);
akpm@osdl.orgd59dd462005-05-01 08:58:47 -0700549 smp_wmb();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550 }
551 current->egid = current->fsgid = gid;
552 }
553 else
554 return -EPERM;
555
556 key_fsgid_changed(current);
Matt Helsley9f460802005-11-07 00:59:16 -0800557 proc_id_connector(current, PROC_EVENT_GID);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558 return 0;
559}
560
561static int set_user(uid_t new_ruid, int dumpclear)
562{
563 struct user_struct *new_user;
564
Cedric Le Goateracce2922007-07-15 23:40:59 -0700565 new_user = alloc_uid(current->nsproxy->user_ns, new_ruid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566 if (!new_user)
567 return -EAGAIN;
568
569 if (atomic_read(&new_user->processes) >=
570 current->signal->rlim[RLIMIT_NPROC].rlim_cur &&
Cedric Le Goateracce2922007-07-15 23:40:59 -0700571 new_user != current->nsproxy->user_ns->root_user) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700572 free_uid(new_user);
573 return -EAGAIN;
574 }
575
576 switch_uid(new_user);
577
Cal Peake756184b2006-09-30 23:27:24 -0700578 if (dumpclear) {
Kawai, Hidehiro6c5d5232007-07-19 01:48:27 -0700579 set_dumpable(current->mm, suid_dumpable);
akpm@osdl.orgd59dd462005-05-01 08:58:47 -0700580 smp_wmb();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700581 }
582 current->uid = new_ruid;
583 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 */
601asmlinkage long sys_setreuid(uid_t ruid, uid_t euid)
602{
603 int old_ruid, old_euid, old_suid, new_ruid, new_euid;
604 int retval;
605
606 retval = security_task_setuid(ruid, euid, (uid_t)-1, LSM_SETID_RE);
607 if (retval)
608 return retval;
609
610 new_ruid = old_ruid = current->uid;
611 new_euid = old_euid = current->euid;
612 old_suid = current->suid;
613
614 if (ruid != (uid_t) -1) {
615 new_ruid = ruid;
616 if ((old_ruid != ruid) &&
617 (current->euid != ruid) &&
618 !capable(CAP_SETUID))
619 return -EPERM;
620 }
621
622 if (euid != (uid_t) -1) {
623 new_euid = euid;
624 if ((old_ruid != euid) &&
625 (current->euid != euid) &&
626 (current->suid != euid) &&
627 !capable(CAP_SETUID))
628 return -EPERM;
629 }
630
631 if (new_ruid != old_ruid && set_user(new_ruid, new_euid != old_euid) < 0)
632 return -EAGAIN;
633
Cal Peake756184b2006-09-30 23:27:24 -0700634 if (new_euid != old_euid) {
Kawai, Hidehiro6c5d5232007-07-19 01:48:27 -0700635 set_dumpable(current->mm, suid_dumpable);
akpm@osdl.orgd59dd462005-05-01 08:58:47 -0700636 smp_wmb();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637 }
638 current->fsuid = current->euid = new_euid;
639 if (ruid != (uid_t) -1 ||
640 (euid != (uid_t) -1 && euid != old_ruid))
641 current->suid = current->euid;
642 current->fsuid = current->euid;
643
644 key_fsuid_changed(current);
Matt Helsley9f460802005-11-07 00:59:16 -0800645 proc_id_connector(current, PROC_EVENT_UID);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700646
647 return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RE);
648}
649
650
651
652/*
653 * setuid() is implemented like SysV with SAVED_IDS
654 *
655 * Note that SAVED_ID's is deficient in that a setuid root program
656 * like sendmail, for example, cannot set its uid to be a normal
657 * user and then switch back, because if you're root, setuid() sets
658 * the saved uid too. If you don't like this, blame the bright people
659 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
660 * will allow a root program to temporarily drop privileges and be able to
661 * regain them by swapping the real and effective uid.
662 */
663asmlinkage long sys_setuid(uid_t uid)
664{
665 int old_euid = current->euid;
David Rientjesa09c17a2006-12-06 20:40:18 -0800666 int old_ruid, old_suid, new_suid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667 int retval;
668
669 retval = security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_ID);
670 if (retval)
671 return retval;
672
David Rientjesa09c17a2006-12-06 20:40:18 -0800673 old_ruid = current->uid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700674 old_suid = current->suid;
675 new_suid = old_suid;
676
677 if (capable(CAP_SETUID)) {
678 if (uid != old_ruid && set_user(uid, old_euid != uid) < 0)
679 return -EAGAIN;
680 new_suid = uid;
681 } else if ((uid != current->uid) && (uid != new_suid))
682 return -EPERM;
683
Cal Peake756184b2006-09-30 23:27:24 -0700684 if (old_euid != uid) {
Kawai, Hidehiro6c5d5232007-07-19 01:48:27 -0700685 set_dumpable(current->mm, suid_dumpable);
akpm@osdl.orgd59dd462005-05-01 08:58:47 -0700686 smp_wmb();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687 }
688 current->fsuid = current->euid = uid;
689 current->suid = new_suid;
690
691 key_fsuid_changed(current);
Matt Helsley9f460802005-11-07 00:59:16 -0800692 proc_id_connector(current, PROC_EVENT_UID);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693
694 return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_ID);
695}
696
697
698/*
699 * This function implements a generic ability to update ruid, euid,
700 * and suid. This allows you to implement the 4.4 compatible seteuid().
701 */
702asmlinkage long sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
703{
704 int old_ruid = current->uid;
705 int old_euid = current->euid;
706 int old_suid = current->suid;
707 int retval;
708
709 retval = security_task_setuid(ruid, euid, suid, LSM_SETID_RES);
710 if (retval)
711 return retval;
712
713 if (!capable(CAP_SETUID)) {
714 if ((ruid != (uid_t) -1) && (ruid != current->uid) &&
715 (ruid != current->euid) && (ruid != current->suid))
716 return -EPERM;
717 if ((euid != (uid_t) -1) && (euid != current->uid) &&
718 (euid != current->euid) && (euid != current->suid))
719 return -EPERM;
720 if ((suid != (uid_t) -1) && (suid != current->uid) &&
721 (suid != current->euid) && (suid != current->suid))
722 return -EPERM;
723 }
724 if (ruid != (uid_t) -1) {
725 if (ruid != current->uid && set_user(ruid, euid != current->euid) < 0)
726 return -EAGAIN;
727 }
728 if (euid != (uid_t) -1) {
Cal Peake756184b2006-09-30 23:27:24 -0700729 if (euid != current->euid) {
Kawai, Hidehiro6c5d5232007-07-19 01:48:27 -0700730 set_dumpable(current->mm, suid_dumpable);
akpm@osdl.orgd59dd462005-05-01 08:58:47 -0700731 smp_wmb();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700732 }
733 current->euid = euid;
734 }
735 current->fsuid = current->euid;
736 if (suid != (uid_t) -1)
737 current->suid = suid;
738
739 key_fsuid_changed(current);
Matt Helsley9f460802005-11-07 00:59:16 -0800740 proc_id_connector(current, PROC_EVENT_UID);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700741
742 return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RES);
743}
744
745asmlinkage long sys_getresuid(uid_t __user *ruid, uid_t __user *euid, uid_t __user *suid)
746{
747 int retval;
748
749 if (!(retval = put_user(current->uid, ruid)) &&
750 !(retval = put_user(current->euid, euid)))
751 retval = put_user(current->suid, suid);
752
753 return retval;
754}
755
756/*
757 * Same as above, but for rgid, egid, sgid.
758 */
759asmlinkage long sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
760{
761 int retval;
762
763 retval = security_task_setgid(rgid, egid, sgid, LSM_SETID_RES);
764 if (retval)
765 return retval;
766
767 if (!capable(CAP_SETGID)) {
768 if ((rgid != (gid_t) -1) && (rgid != current->gid) &&
769 (rgid != current->egid) && (rgid != current->sgid))
770 return -EPERM;
771 if ((egid != (gid_t) -1) && (egid != current->gid) &&
772 (egid != current->egid) && (egid != current->sgid))
773 return -EPERM;
774 if ((sgid != (gid_t) -1) && (sgid != current->gid) &&
775 (sgid != current->egid) && (sgid != current->sgid))
776 return -EPERM;
777 }
778 if (egid != (gid_t) -1) {
Cal Peake756184b2006-09-30 23:27:24 -0700779 if (egid != current->egid) {
Kawai, Hidehiro6c5d5232007-07-19 01:48:27 -0700780 set_dumpable(current->mm, suid_dumpable);
akpm@osdl.orgd59dd462005-05-01 08:58:47 -0700781 smp_wmb();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782 }
783 current->egid = egid;
784 }
785 current->fsgid = current->egid;
786 if (rgid != (gid_t) -1)
787 current->gid = rgid;
788 if (sgid != (gid_t) -1)
789 current->sgid = sgid;
790
791 key_fsgid_changed(current);
Matt Helsley9f460802005-11-07 00:59:16 -0800792 proc_id_connector(current, PROC_EVENT_GID);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793 return 0;
794}
795
796asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __user *sgid)
797{
798 int retval;
799
800 if (!(retval = put_user(current->gid, rgid)) &&
801 !(retval = put_user(current->egid, egid)))
802 retval = put_user(current->sgid, sgid);
803
804 return retval;
805}
806
807
808/*
809 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
810 * is used for "access()" and for the NFS daemon (letting nfsd stay at
811 * whatever uid it wants to). It normally shadows "euid", except when
812 * explicitly set by setfsuid() or for access..
813 */
814asmlinkage long sys_setfsuid(uid_t uid)
815{
816 int old_fsuid;
817
818 old_fsuid = current->fsuid;
819 if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS))
820 return old_fsuid;
821
822 if (uid == current->uid || uid == current->euid ||
823 uid == current->suid || uid == current->fsuid ||
Cal Peake756184b2006-09-30 23:27:24 -0700824 capable(CAP_SETUID)) {
825 if (uid != old_fsuid) {
Kawai, Hidehiro6c5d5232007-07-19 01:48:27 -0700826 set_dumpable(current->mm, suid_dumpable);
akpm@osdl.orgd59dd462005-05-01 08:58:47 -0700827 smp_wmb();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700828 }
829 current->fsuid = uid;
830 }
831
832 key_fsuid_changed(current);
Matt Helsley9f460802005-11-07 00:59:16 -0800833 proc_id_connector(current, PROC_EVENT_UID);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700834
835 security_task_post_setuid(old_fsuid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS);
836
837 return old_fsuid;
838}
839
840/*
John Anthony Kazos Jrf42df9e2007-05-09 08:23:08 +0200841 * Samma på svenska..
Linus Torvalds1da177e2005-04-16 15:20:36 -0700842 */
843asmlinkage long sys_setfsgid(gid_t gid)
844{
845 int old_fsgid;
846
847 old_fsgid = current->fsgid;
848 if (security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS))
849 return old_fsgid;
850
851 if (gid == current->gid || gid == current->egid ||
852 gid == current->sgid || gid == current->fsgid ||
Cal Peake756184b2006-09-30 23:27:24 -0700853 capable(CAP_SETGID)) {
854 if (gid != old_fsgid) {
Kawai, Hidehiro6c5d5232007-07-19 01:48:27 -0700855 set_dumpable(current->mm, suid_dumpable);
akpm@osdl.orgd59dd462005-05-01 08:58:47 -0700856 smp_wmb();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700857 }
858 current->fsgid = gid;
859 key_fsgid_changed(current);
Matt Helsley9f460802005-11-07 00:59:16 -0800860 proc_id_connector(current, PROC_EVENT_GID);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700861 }
862 return old_fsgid;
863}
864
865asmlinkage long sys_times(struct tms __user * tbuf)
866{
867 /*
868 * In the SMP world we might just be unlucky and have one of
869 * the times increment as we use it. Since the value is an
870 * atomically safe type this is just fine. Conceptually its
871 * as if the syscall took an instant longer to occur.
872 */
873 if (tbuf) {
874 struct tms tmp;
Oleg Nesterov35f5cad2006-03-28 16:11:19 -0800875 struct task_struct *tsk = current;
876 struct task_struct *t;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700877 cputime_t utime, stime, cutime, cstime;
878
Oleg Nesterov7d7185c2006-03-28 16:11:21 -0800879 spin_lock_irq(&tsk->sighand->siglock);
Oleg Nesterov35f5cad2006-03-28 16:11:19 -0800880 utime = tsk->signal->utime;
881 stime = tsk->signal->stime;
882 t = tsk;
883 do {
884 utime = cputime_add(utime, t->utime);
885 stime = cputime_add(stime, t->stime);
886 t = next_thread(t);
887 } while (t != tsk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700888
Oleg Nesterov35f5cad2006-03-28 16:11:19 -0800889 cutime = tsk->signal->cutime;
890 cstime = tsk->signal->cstime;
891 spin_unlock_irq(&tsk->sighand->siglock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700892
893 tmp.tms_utime = cputime_to_clock_t(utime);
894 tmp.tms_stime = cputime_to_clock_t(stime);
895 tmp.tms_cutime = cputime_to_clock_t(cutime);
896 tmp.tms_cstime = cputime_to_clock_t(cstime);
897 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
898 return -EFAULT;
899 }
900 return (long) jiffies_64_to_clock_t(get_jiffies_64());
901}
902
903/*
904 * This needs some heavy checking ...
905 * I just haven't the stomach for it. I also don't fully
906 * understand sessions/pgrp etc. Let somebody who does explain it.
907 *
908 * OK, I think I have the protection semantics right.... this is really
909 * only important on a multi-user system anyway, to make sure one user
910 * can't send a signal to a process owned by another. -TYT, 12/12/91
911 *
912 * Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
913 * LBT 04.03.94
914 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700915asmlinkage long sys_setpgid(pid_t pid, pid_t pgid)
916{
917 struct task_struct *p;
Oleg Nesterovee0acf92006-01-08 01:03:53 -0800918 struct task_struct *group_leader = current->group_leader;
Oleg Nesterov4e021302008-02-08 04:19:08 -0800919 struct pid *pgrp;
920 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700921
922 if (!pid)
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700923 pid = task_pid_vnr(group_leader);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700924 if (!pgid)
925 pgid = pid;
926 if (pgid < 0)
927 return -EINVAL;
928
929 /* From this point forward we keep holding onto the tasklist lock
930 * so that our parent does not change from under us. -DaveM
931 */
932 write_lock_irq(&tasklist_lock);
933
934 err = -ESRCH;
Oleg Nesterov4e021302008-02-08 04:19:08 -0800935 p = find_task_by_vpid(pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700936 if (!p)
937 goto out;
938
939 err = -EINVAL;
940 if (!thread_group_leader(p))
941 goto out;
942
Oleg Nesterov4e021302008-02-08 04:19:08 -0800943 if (same_thread_group(p->real_parent, group_leader)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700944 err = -EPERM;
Eric W. Biederman41487c62007-02-12 00:53:01 -0800945 if (task_session(p) != task_session(group_leader))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700946 goto out;
947 err = -EACCES;
948 if (p->did_exec)
949 goto out;
950 } else {
951 err = -ESRCH;
Oleg Nesterovee0acf92006-01-08 01:03:53 -0800952 if (p != group_leader)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700953 goto out;
954 }
955
956 err = -EPERM;
957 if (p->signal->leader)
958 goto out;
959
Oleg Nesterov4e021302008-02-08 04:19:08 -0800960 pgrp = task_pid(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700961 if (pgid != pid) {
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700962 struct task_struct *g;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700963
Oleg Nesterov4e021302008-02-08 04:19:08 -0800964 pgrp = find_vpid(pgid);
965 g = pid_task(pgrp, PIDTYPE_PGID);
Eric W. Biederman41487c62007-02-12 00:53:01 -0800966 if (!g || task_session(g) != task_session(group_leader))
Oleg Nesterovf020bc42006-12-08 02:38:02 -0800967 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700968 }
969
Linus Torvalds1da177e2005-04-16 15:20:36 -0700970 err = security_task_setpgid(p, pgid);
971 if (err)
972 goto out;
973
Oleg Nesterov4e021302008-02-08 04:19:08 -0800974 if (task_pgrp(p) != pgrp) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700975 detach_pid(p, PIDTYPE_PGID);
Oleg Nesterov4e021302008-02-08 04:19:08 -0800976 attach_pid(p, PIDTYPE_PGID, pgrp);
977 set_task_pgrp(p, pid_nr(pgrp));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700978 }
979
980 err = 0;
981out:
982 /* All paths lead to here, thus we are safe. -DaveM */
983 write_unlock_irq(&tasklist_lock);
984 return err;
985}
986
987asmlinkage long sys_getpgid(pid_t pid)
988{
Cal Peake756184b2006-09-30 23:27:24 -0700989 if (!pid)
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700990 return task_pgrp_vnr(current);
Cal Peake756184b2006-09-30 23:27:24 -0700991 else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700992 int retval;
993 struct task_struct *p;
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700994 struct pid_namespace *ns;
995
996 ns = current->nsproxy->pid_ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700997
998 read_lock(&tasklist_lock);
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700999 p = find_task_by_pid_ns(pid, ns);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001000 retval = -ESRCH;
1001 if (p) {
1002 retval = security_task_getpgid(p);
1003 if (!retval)
Pavel Emelyanovb4888932007-10-18 23:40:14 -07001004 retval = task_pgrp_nr_ns(p, ns);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001005 }
1006 read_unlock(&tasklist_lock);
1007 return retval;
1008 }
1009}
1010
1011#ifdef __ARCH_WANT_SYS_GETPGRP
1012
1013asmlinkage long sys_getpgrp(void)
1014{
1015 /* SMP - assuming writes are word atomic this is fine */
Pavel Emelyanovb4888932007-10-18 23:40:14 -07001016 return task_pgrp_vnr(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001017}
1018
1019#endif
1020
1021asmlinkage long sys_getsid(pid_t pid)
1022{
Cal Peake756184b2006-09-30 23:27:24 -07001023 if (!pid)
Pavel Emelyanovb4888932007-10-18 23:40:14 -07001024 return task_session_vnr(current);
Cal Peake756184b2006-09-30 23:27:24 -07001025 else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001026 int retval;
1027 struct task_struct *p;
Pavel Emelyanovb4888932007-10-18 23:40:14 -07001028 struct pid_namespace *ns;
1029
1030 ns = current->nsproxy->pid_ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001031
1032 read_lock(&tasklist_lock);
Pavel Emelyanovb4888932007-10-18 23:40:14 -07001033 p = find_task_by_pid_ns(pid, ns);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001034 retval = -ESRCH;
Cal Peake756184b2006-09-30 23:27:24 -07001035 if (p) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001036 retval = security_task_getsid(p);
1037 if (!retval)
Pavel Emelyanovb4888932007-10-18 23:40:14 -07001038 retval = task_session_nr_ns(p, ns);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001039 }
1040 read_unlock(&tasklist_lock);
1041 return retval;
1042 }
1043}
1044
1045asmlinkage long sys_setsid(void)
1046{
Oren Laadane19f2472006-01-08 01:03:58 -08001047 struct task_struct *group_leader = current->group_leader;
Oleg Nesterove4cc0a92008-02-08 04:19:09 -08001048 struct pid *sid = task_pid(group_leader);
1049 pid_t session = pid_vnr(sid);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001050 int err = -EPERM;
1051
Linus Torvalds1da177e2005-04-16 15:20:36 -07001052 write_lock_irq(&tasklist_lock);
Eric W. Biederman390e2ff2006-03-31 02:31:33 -08001053 /* Fail if I am already a session leader */
1054 if (group_leader->signal->leader)
1055 goto out;
1056
Oleg Nesterov430c6232008-02-08 04:19:11 -08001057 /* Fail if a process group id already exists that equals the
1058 * proposed session id.
Eric W. Biederman390e2ff2006-03-31 02:31:33 -08001059 *
Oleg Nesterov430c6232008-02-08 04:19:11 -08001060 * Don't check if session == 1, clone(CLONE_NEWPID) creates
1061 * this group/session beforehand.
Eric W. Biederman390e2ff2006-03-31 02:31:33 -08001062 */
Oleg Nesterove4cc0a92008-02-08 04:19:09 -08001063 if (session != 1 && pid_task(sid, PIDTYPE_PGID))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001064 goto out;
1065
Oren Laadane19f2472006-01-08 01:03:58 -08001066 group_leader->signal->leader = 1;
Oleg Nesterov8520d7c2008-02-08 04:19:09 -08001067 __set_special_pids(sid);
Peter Zijlstra24ec8392006-12-08 02:36:04 -08001068
1069 spin_lock(&group_leader->sighand->siglock);
Oren Laadane19f2472006-01-08 01:03:58 -08001070 group_leader->signal->tty = NULL;
Peter Zijlstra24ec8392006-12-08 02:36:04 -08001071 spin_unlock(&group_leader->sighand->siglock);
1072
Oleg Nesterove4cc0a92008-02-08 04:19:09 -08001073 err = session;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001074out:
1075 write_unlock_irq(&tasklist_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001076 return err;
1077}
1078
1079/*
1080 * Supplementary group IDs
1081 */
1082
1083/* init to 2 - one for init_task, one to ensure it is never freed */
1084struct group_info init_groups = { .usage = ATOMIC_INIT(2) };
1085
1086struct group_info *groups_alloc(int gidsetsize)
1087{
1088 struct group_info *group_info;
1089 int nblocks;
1090 int i;
1091
1092 nblocks = (gidsetsize + NGROUPS_PER_BLOCK - 1) / NGROUPS_PER_BLOCK;
1093 /* Make sure we always allocate at least one indirect block pointer */
1094 nblocks = nblocks ? : 1;
1095 group_info = kmalloc(sizeof(*group_info) + nblocks*sizeof(gid_t *), GFP_USER);
1096 if (!group_info)
1097 return NULL;
1098 group_info->ngroups = gidsetsize;
1099 group_info->nblocks = nblocks;
1100 atomic_set(&group_info->usage, 1);
1101
Cal Peake756184b2006-09-30 23:27:24 -07001102 if (gidsetsize <= NGROUPS_SMALL)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001103 group_info->blocks[0] = group_info->small_block;
Cal Peake756184b2006-09-30 23:27:24 -07001104 else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001105 for (i = 0; i < nblocks; i++) {
1106 gid_t *b;
1107 b = (void *)__get_free_page(GFP_USER);
1108 if (!b)
1109 goto out_undo_partial_alloc;
1110 group_info->blocks[i] = b;
1111 }
1112 }
1113 return group_info;
1114
1115out_undo_partial_alloc:
1116 while (--i >= 0) {
1117 free_page((unsigned long)group_info->blocks[i]);
1118 }
1119 kfree(group_info);
1120 return NULL;
1121}
1122
1123EXPORT_SYMBOL(groups_alloc);
1124
1125void groups_free(struct group_info *group_info)
1126{
1127 if (group_info->blocks[0] != group_info->small_block) {
1128 int i;
1129 for (i = 0; i < group_info->nblocks; i++)
1130 free_page((unsigned long)group_info->blocks[i]);
1131 }
1132 kfree(group_info);
1133}
1134
1135EXPORT_SYMBOL(groups_free);
1136
1137/* export the group_info to a user-space array */
1138static int groups_to_user(gid_t __user *grouplist,
1139 struct group_info *group_info)
1140{
1141 int i;
Eric Dumazet1bf47342008-02-06 01:37:56 -08001142 unsigned int count = group_info->ngroups;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001143
1144 for (i = 0; i < group_info->nblocks; i++) {
Eric Dumazet1bf47342008-02-06 01:37:56 -08001145 unsigned int cp_count = min(NGROUPS_PER_BLOCK, count);
1146 unsigned int len = cp_count * sizeof(*grouplist);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001147
Eric Dumazet1bf47342008-02-06 01:37:56 -08001148 if (copy_to_user(grouplist, group_info->blocks[i], len))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001149 return -EFAULT;
1150
Eric Dumazet1bf47342008-02-06 01:37:56 -08001151 grouplist += NGROUPS_PER_BLOCK;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001152 count -= cp_count;
1153 }
1154 return 0;
1155}
1156
1157/* fill a group_info from a user-space array - it must be allocated already */
1158static int groups_from_user(struct group_info *group_info,
1159 gid_t __user *grouplist)
Cal Peake756184b2006-09-30 23:27:24 -07001160{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001161 int i;
Eric Dumazet1bf47342008-02-06 01:37:56 -08001162 unsigned int count = group_info->ngroups;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001163
1164 for (i = 0; i < group_info->nblocks; i++) {
Eric Dumazet1bf47342008-02-06 01:37:56 -08001165 unsigned int cp_count = min(NGROUPS_PER_BLOCK, count);
1166 unsigned int len = cp_count * sizeof(*grouplist);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001167
Eric Dumazet1bf47342008-02-06 01:37:56 -08001168 if (copy_from_user(group_info->blocks[i], grouplist, len))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001169 return -EFAULT;
1170
Eric Dumazet1bf47342008-02-06 01:37:56 -08001171 grouplist += NGROUPS_PER_BLOCK;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001172 count -= cp_count;
1173 }
1174 return 0;
1175}
1176
Domen Puncerebe8b542005-05-05 16:16:19 -07001177/* a simple Shell sort */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001178static void groups_sort(struct group_info *group_info)
1179{
1180 int base, max, stride;
1181 int gidsetsize = group_info->ngroups;
1182
1183 for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1)
1184 ; /* nothing */
1185 stride /= 3;
1186
1187 while (stride) {
1188 max = gidsetsize - stride;
1189 for (base = 0; base < max; base++) {
1190 int left = base;
1191 int right = left + stride;
1192 gid_t tmp = GROUP_AT(group_info, right);
1193
1194 while (left >= 0 && GROUP_AT(group_info, left) > tmp) {
1195 GROUP_AT(group_info, right) =
1196 GROUP_AT(group_info, left);
1197 right = left;
1198 left -= stride;
1199 }
1200 GROUP_AT(group_info, right) = tmp;
1201 }
1202 stride /= 3;
1203 }
1204}
1205
1206/* a simple bsearch */
David Howells3e301482005-06-23 22:00:56 -07001207int groups_search(struct group_info *group_info, gid_t grp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001208{
Eric Dumazetd74beb9f2006-03-25 03:08:19 -08001209 unsigned int left, right;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001210
1211 if (!group_info)
1212 return 0;
1213
1214 left = 0;
1215 right = group_info->ngroups;
1216 while (left < right) {
Eric Dumazetd74beb9f2006-03-25 03:08:19 -08001217 unsigned int mid = (left+right)/2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001218 int cmp = grp - GROUP_AT(group_info, mid);
1219 if (cmp > 0)
1220 left = mid + 1;
1221 else if (cmp < 0)
1222 right = mid;
1223 else
1224 return 1;
1225 }
1226 return 0;
1227}
1228
1229/* validate and set current->group_info */
1230int set_current_groups(struct group_info *group_info)
1231{
1232 int retval;
1233 struct group_info *old_info;
1234
1235 retval = security_task_setgroups(group_info);
1236 if (retval)
1237 return retval;
1238
1239 groups_sort(group_info);
1240 get_group_info(group_info);
1241
1242 task_lock(current);
1243 old_info = current->group_info;
1244 current->group_info = group_info;
1245 task_unlock(current);
1246
1247 put_group_info(old_info);
1248
1249 return 0;
1250}
1251
1252EXPORT_SYMBOL(set_current_groups);
1253
1254asmlinkage long sys_getgroups(int gidsetsize, gid_t __user *grouplist)
1255{
1256 int i = 0;
1257
1258 /*
1259 * SMP: Nobody else can change our grouplist. Thus we are
1260 * safe.
1261 */
1262
1263 if (gidsetsize < 0)
1264 return -EINVAL;
1265
1266 /* no need to grab task_lock here; it cannot change */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001267 i = current->group_info->ngroups;
1268 if (gidsetsize) {
1269 if (i > gidsetsize) {
1270 i = -EINVAL;
1271 goto out;
1272 }
1273 if (groups_to_user(grouplist, current->group_info)) {
1274 i = -EFAULT;
1275 goto out;
1276 }
1277 }
1278out:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001279 return i;
1280}
1281
1282/*
1283 * SMP: Our groups are copy-on-write. We can set them safely
1284 * without another task interfering.
1285 */
1286
1287asmlinkage long sys_setgroups(int gidsetsize, gid_t __user *grouplist)
1288{
1289 struct group_info *group_info;
1290 int retval;
1291
1292 if (!capable(CAP_SETGID))
1293 return -EPERM;
1294 if ((unsigned)gidsetsize > NGROUPS_MAX)
1295 return -EINVAL;
1296
1297 group_info = groups_alloc(gidsetsize);
1298 if (!group_info)
1299 return -ENOMEM;
1300 retval = groups_from_user(group_info, grouplist);
1301 if (retval) {
1302 put_group_info(group_info);
1303 return retval;
1304 }
1305
1306 retval = set_current_groups(group_info);
1307 put_group_info(group_info);
1308
1309 return retval;
1310}
1311
1312/*
1313 * Check whether we're fsgid/egid or in the supplemental group..
1314 */
1315int in_group_p(gid_t grp)
1316{
1317 int retval = 1;
Cal Peake756184b2006-09-30 23:27:24 -07001318 if (grp != current->fsgid)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001319 retval = groups_search(current->group_info, grp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001320 return retval;
1321}
1322
1323EXPORT_SYMBOL(in_group_p);
1324
1325int in_egroup_p(gid_t grp)
1326{
1327 int retval = 1;
Cal Peake756184b2006-09-30 23:27:24 -07001328 if (grp != current->egid)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001329 retval = groups_search(current->group_info, grp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001330 return retval;
1331}
1332
1333EXPORT_SYMBOL(in_egroup_p);
1334
1335DECLARE_RWSEM(uts_sem);
1336
David S. Miller393b0722005-11-10 12:47:50 -08001337EXPORT_SYMBOL(uts_sem);
1338
Linus Torvalds1da177e2005-04-16 15:20:36 -07001339asmlinkage long sys_newuname(struct new_utsname __user * name)
1340{
1341 int errno = 0;
1342
1343 down_read(&uts_sem);
Serge E. Hallyne9ff3992006-10-02 02:18:11 -07001344 if (copy_to_user(name, utsname(), sizeof *name))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001345 errno = -EFAULT;
1346 up_read(&uts_sem);
1347 return errno;
1348}
1349
1350asmlinkage long sys_sethostname(char __user *name, int len)
1351{
1352 int errno;
1353 char tmp[__NEW_UTS_LEN];
1354
1355 if (!capable(CAP_SYS_ADMIN))
1356 return -EPERM;
1357 if (len < 0 || len > __NEW_UTS_LEN)
1358 return -EINVAL;
1359 down_write(&uts_sem);
1360 errno = -EFAULT;
1361 if (!copy_from_user(tmp, name, len)) {
Serge E. Hallyne9ff3992006-10-02 02:18:11 -07001362 memcpy(utsname()->nodename, tmp, len);
1363 utsname()->nodename[len] = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001364 errno = 0;
1365 }
1366 up_write(&uts_sem);
1367 return errno;
1368}
1369
1370#ifdef __ARCH_WANT_SYS_GETHOSTNAME
1371
1372asmlinkage long sys_gethostname(char __user *name, int len)
1373{
1374 int i, errno;
1375
1376 if (len < 0)
1377 return -EINVAL;
1378 down_read(&uts_sem);
Serge E. Hallyne9ff3992006-10-02 02:18:11 -07001379 i = 1 + strlen(utsname()->nodename);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001380 if (i > len)
1381 i = len;
1382 errno = 0;
Serge E. Hallyne9ff3992006-10-02 02:18:11 -07001383 if (copy_to_user(name, utsname()->nodename, i))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001384 errno = -EFAULT;
1385 up_read(&uts_sem);
1386 return errno;
1387}
1388
1389#endif
1390
1391/*
1392 * Only setdomainname; getdomainname can be implemented by calling
1393 * uname()
1394 */
1395asmlinkage long sys_setdomainname(char __user *name, int len)
1396{
1397 int errno;
1398 char tmp[__NEW_UTS_LEN];
1399
1400 if (!capable(CAP_SYS_ADMIN))
1401 return -EPERM;
1402 if (len < 0 || len > __NEW_UTS_LEN)
1403 return -EINVAL;
1404
1405 down_write(&uts_sem);
1406 errno = -EFAULT;
1407 if (!copy_from_user(tmp, name, len)) {
Serge E. Hallyne9ff3992006-10-02 02:18:11 -07001408 memcpy(utsname()->domainname, tmp, len);
1409 utsname()->domainname[len] = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001410 errno = 0;
1411 }
1412 up_write(&uts_sem);
1413 return errno;
1414}
1415
1416asmlinkage long sys_getrlimit(unsigned int resource, struct rlimit __user *rlim)
1417{
1418 if (resource >= RLIM_NLIMITS)
1419 return -EINVAL;
1420 else {
1421 struct rlimit value;
1422 task_lock(current->group_leader);
1423 value = current->signal->rlim[resource];
1424 task_unlock(current->group_leader);
1425 return copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1426 }
1427}
1428
1429#ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1430
1431/*
1432 * Back compatibility for getrlimit. Needed for some apps.
1433 */
1434
1435asmlinkage long sys_old_getrlimit(unsigned int resource, struct rlimit __user *rlim)
1436{
1437 struct rlimit x;
1438 if (resource >= RLIM_NLIMITS)
1439 return -EINVAL;
1440
1441 task_lock(current->group_leader);
1442 x = current->signal->rlim[resource];
1443 task_unlock(current->group_leader);
Cal Peake756184b2006-09-30 23:27:24 -07001444 if (x.rlim_cur > 0x7FFFFFFF)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001445 x.rlim_cur = 0x7FFFFFFF;
Cal Peake756184b2006-09-30 23:27:24 -07001446 if (x.rlim_max > 0x7FFFFFFF)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001447 x.rlim_max = 0x7FFFFFFF;
1448 return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0;
1449}
1450
1451#endif
1452
1453asmlinkage long sys_setrlimit(unsigned int resource, struct rlimit __user *rlim)
1454{
1455 struct rlimit new_rlim, *old_rlim;
Andrew Mortonec9e16b2006-03-24 03:18:34 -08001456 unsigned long it_prof_secs;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001457 int retval;
1458
1459 if (resource >= RLIM_NLIMITS)
1460 return -EINVAL;
Andrew Mortonec9e16b2006-03-24 03:18:34 -08001461 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001462 return -EFAULT;
Andrew Mortonec9e16b2006-03-24 03:18:34 -08001463 if (new_rlim.rlim_cur > new_rlim.rlim_max)
1464 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001465 old_rlim = current->signal->rlim + resource;
1466 if ((new_rlim.rlim_max > old_rlim->rlim_max) &&
1467 !capable(CAP_SYS_RESOURCE))
1468 return -EPERM;
Eric Dumazet9cfe0152008-02-06 01:37:16 -08001469 if (resource == RLIMIT_NOFILE && new_rlim.rlim_max > sysctl_nr_open)
Andrew Mortonec9e16b2006-03-24 03:18:34 -08001470 return -EPERM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001471
1472 retval = security_task_setrlimit(resource, &new_rlim);
1473 if (retval)
1474 return retval;
1475
Tom Alsberg9926e4c2007-05-08 00:30:31 -07001476 if (resource == RLIMIT_CPU && new_rlim.rlim_cur == 0) {
1477 /*
1478 * The caller is asking for an immediate RLIMIT_CPU
1479 * expiry. But we use the zero value to mean "it was
1480 * never set". So let's cheat and make it one second
1481 * instead
1482 */
1483 new_rlim.rlim_cur = 1;
1484 }
1485
Linus Torvalds1da177e2005-04-16 15:20:36 -07001486 task_lock(current->group_leader);
1487 *old_rlim = new_rlim;
1488 task_unlock(current->group_leader);
1489
Andrew Mortonec9e16b2006-03-24 03:18:34 -08001490 if (resource != RLIMIT_CPU)
1491 goto out;
Andrew Mortond3561f72006-03-24 03:18:36 -08001492
1493 /*
1494 * RLIMIT_CPU handling. Note that the kernel fails to return an error
1495 * code if it rejected the user's attempt to set RLIMIT_CPU. This is a
1496 * very long-standing error, and fixing it now risks breakage of
1497 * applications, so we live with it
1498 */
Andrew Mortonec9e16b2006-03-24 03:18:34 -08001499 if (new_rlim.rlim_cur == RLIM_INFINITY)
1500 goto out;
1501
1502 it_prof_secs = cputime_to_secs(current->signal->it_prof_expires);
1503 if (it_prof_secs == 0 || new_rlim.rlim_cur <= it_prof_secs) {
Andrew Mortone0661112006-03-24 03:18:35 -08001504 unsigned long rlim_cur = new_rlim.rlim_cur;
1505 cputime_t cputime;
Andrew Mortonec9e16b2006-03-24 03:18:34 -08001506
Andrew Mortone0661112006-03-24 03:18:35 -08001507 cputime = secs_to_cputime(rlim_cur);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001508 read_lock(&tasklist_lock);
1509 spin_lock_irq(&current->sighand->siglock);
Andrew Mortonec9e16b2006-03-24 03:18:34 -08001510 set_process_cpu_timer(current, CPUCLOCK_PROF, &cputime, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001511 spin_unlock_irq(&current->sighand->siglock);
1512 read_unlock(&tasklist_lock);
1513 }
Andrew Mortonec9e16b2006-03-24 03:18:34 -08001514out:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001515 return 0;
1516}
1517
1518/*
1519 * It would make sense to put struct rusage in the task_struct,
1520 * except that would make the task_struct be *really big*. After
1521 * task_struct gets moved into malloc'ed memory, it would
1522 * make sense to do this. It will make moving the rest of the information
1523 * a lot simpler! (Which we're not doing right now because we're not
1524 * measuring them yet).
1525 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001526 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1527 * races with threads incrementing their own counters. But since word
1528 * reads are atomic, we either get new values or old values and we don't
1529 * care which for the sums. We always take the siglock to protect reading
1530 * the c* fields from p->signal from races with exit.c updating those
1531 * fields when reaping, so a sample either gets all the additions of a
1532 * given child after it's reaped, or none so this sample is before reaping.
Ravikiran G Thirumalai2dd0ebc2006-03-23 03:00:13 -08001533 *
Ravikiran G Thirumalaide047c12006-06-22 14:47:26 -07001534 * Locking:
1535 * We need to take the siglock for CHILDEREN, SELF and BOTH
1536 * for the cases current multithreaded, non-current single threaded
1537 * non-current multithreaded. Thread traversal is now safe with
1538 * the siglock held.
1539 * Strictly speaking, we donot need to take the siglock if we are current and
1540 * single threaded, as no one else can take our signal_struct away, no one
1541 * else can reap the children to update signal->c* counters, and no one else
1542 * can race with the signal-> fields. If we do not take any lock, the
1543 * signal-> fields could be read out of order while another thread was just
1544 * exiting. So we should place a read memory barrier when we avoid the lock.
1545 * On the writer side, write memory barrier is implied in __exit_signal
1546 * as __exit_signal releases the siglock spinlock after updating the signal->
1547 * fields. But we don't do this yet to keep things simple.
Ravikiran G Thirumalai2dd0ebc2006-03-23 03:00:13 -08001548 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001549 */
1550
1551static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
1552{
1553 struct task_struct *t;
1554 unsigned long flags;
1555 cputime_t utime, stime;
1556
1557 memset((char *) r, 0, sizeof *r);
Oleg Nesterov0f59cc42006-01-08 01:05:15 -08001558 utime = stime = cputime_zero;
1559
Ravikiran G Thirumalaide047c12006-06-22 14:47:26 -07001560 rcu_read_lock();
1561 if (!lock_task_sighand(p, &flags)) {
1562 rcu_read_unlock();
1563 return;
1564 }
Ravikiran G Thirumalai2dd0ebc2006-03-23 03:00:13 -08001565
Linus Torvalds1da177e2005-04-16 15:20:36 -07001566 switch (who) {
Oleg Nesterov0f59cc42006-01-08 01:05:15 -08001567 case RUSAGE_BOTH:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001568 case RUSAGE_CHILDREN:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001569 utime = p->signal->cutime;
1570 stime = p->signal->cstime;
1571 r->ru_nvcsw = p->signal->cnvcsw;
1572 r->ru_nivcsw = p->signal->cnivcsw;
1573 r->ru_minflt = p->signal->cmin_flt;
1574 r->ru_majflt = p->signal->cmaj_flt;
Eric Dumazet6eaeeab2007-05-10 22:22:37 -07001575 r->ru_inblock = p->signal->cinblock;
1576 r->ru_oublock = p->signal->coublock;
Oleg Nesterov0f59cc42006-01-08 01:05:15 -08001577
1578 if (who == RUSAGE_CHILDREN)
1579 break;
1580
Linus Torvalds1da177e2005-04-16 15:20:36 -07001581 case RUSAGE_SELF:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001582 utime = cputime_add(utime, p->signal->utime);
1583 stime = cputime_add(stime, p->signal->stime);
1584 r->ru_nvcsw += p->signal->nvcsw;
1585 r->ru_nivcsw += p->signal->nivcsw;
1586 r->ru_minflt += p->signal->min_flt;
1587 r->ru_majflt += p->signal->maj_flt;
Eric Dumazet6eaeeab2007-05-10 22:22:37 -07001588 r->ru_inblock += p->signal->inblock;
1589 r->ru_oublock += p->signal->oublock;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001590 t = p;
1591 do {
1592 utime = cputime_add(utime, t->utime);
1593 stime = cputime_add(stime, t->stime);
1594 r->ru_nvcsw += t->nvcsw;
1595 r->ru_nivcsw += t->nivcsw;
1596 r->ru_minflt += t->min_flt;
1597 r->ru_majflt += t->maj_flt;
Eric Dumazet6eaeeab2007-05-10 22:22:37 -07001598 r->ru_inblock += task_io_get_inblock(t);
1599 r->ru_oublock += task_io_get_oublock(t);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001600 t = next_thread(t);
1601 } while (t != p);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001602 break;
Oleg Nesterov0f59cc42006-01-08 01:05:15 -08001603
Linus Torvalds1da177e2005-04-16 15:20:36 -07001604 default:
1605 BUG();
1606 }
Oleg Nesterov0f59cc42006-01-08 01:05:15 -08001607
Ravikiran G Thirumalaide047c12006-06-22 14:47:26 -07001608 unlock_task_sighand(p, &flags);
1609 rcu_read_unlock();
1610
Oleg Nesterov0f59cc42006-01-08 01:05:15 -08001611 cputime_to_timeval(utime, &r->ru_utime);
1612 cputime_to_timeval(stime, &r->ru_stime);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001613}
1614
1615int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
1616{
1617 struct rusage r;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001618 k_getrusage(p, who, &r);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001619 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1620}
1621
1622asmlinkage long sys_getrusage(int who, struct rusage __user *ru)
1623{
1624 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN)
1625 return -EINVAL;
1626 return getrusage(current, who, ru);
1627}
1628
1629asmlinkage long sys_umask(int mask)
1630{
1631 mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1632 return mask;
1633}
Serge E. Hallyn3b7391d2008-02-04 22:29:45 -08001634
Linus Torvalds1da177e2005-04-16 15:20:36 -07001635asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3,
1636 unsigned long arg4, unsigned long arg5)
1637{
1638 long error;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001639
1640 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
1641 if (error)
1642 return error;
1643
1644 switch (option) {
1645 case PR_SET_PDEATHSIG:
Jesper Juhl0730ded2005-09-06 15:17:37 -07001646 if (!valid_signal(arg2)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001647 error = -EINVAL;
1648 break;
1649 }
Jesper Juhl0730ded2005-09-06 15:17:37 -07001650 current->pdeath_signal = arg2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001651 break;
1652 case PR_GET_PDEATHSIG:
1653 error = put_user(current->pdeath_signal, (int __user *)arg2);
1654 break;
1655 case PR_GET_DUMPABLE:
Kawai, Hidehiro6c5d5232007-07-19 01:48:27 -07001656 error = get_dumpable(current->mm);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001657 break;
1658 case PR_SET_DUMPABLE:
Marcel Holtmannabf75a52006-07-12 13:12:00 +02001659 if (arg2 < 0 || arg2 > 1) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001660 error = -EINVAL;
1661 break;
1662 }
Kawai, Hidehiro6c5d5232007-07-19 01:48:27 -07001663 set_dumpable(current->mm, arg2);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001664 break;
1665
1666 case PR_SET_UNALIGN:
1667 error = SET_UNALIGN_CTL(current, arg2);
1668 break;
1669 case PR_GET_UNALIGN:
1670 error = GET_UNALIGN_CTL(current, arg2);
1671 break;
1672 case PR_SET_FPEMU:
1673 error = SET_FPEMU_CTL(current, arg2);
1674 break;
1675 case PR_GET_FPEMU:
1676 error = GET_FPEMU_CTL(current, arg2);
1677 break;
1678 case PR_SET_FPEXC:
1679 error = SET_FPEXC_CTL(current, arg2);
1680 break;
1681 case PR_GET_FPEXC:
1682 error = GET_FPEXC_CTL(current, arg2);
1683 break;
1684 case PR_GET_TIMING:
1685 error = PR_TIMING_STATISTICAL;
1686 break;
1687 case PR_SET_TIMING:
1688 if (arg2 == PR_TIMING_STATISTICAL)
1689 error = 0;
1690 else
1691 error = -EINVAL;
1692 break;
1693
1694 case PR_GET_KEEPCAPS:
1695 if (current->keep_capabilities)
1696 error = 1;
1697 break;
1698 case PR_SET_KEEPCAPS:
1699 if (arg2 != 0 && arg2 != 1) {
1700 error = -EINVAL;
1701 break;
1702 }
1703 current->keep_capabilities = arg2;
1704 break;
1705 case PR_SET_NAME: {
1706 struct task_struct *me = current;
1707 unsigned char ncomm[sizeof(me->comm)];
1708
1709 ncomm[sizeof(me->comm)-1] = 0;
1710 if (strncpy_from_user(ncomm, (char __user *)arg2,
1711 sizeof(me->comm)-1) < 0)
1712 return -EFAULT;
1713 set_task_comm(me, ncomm);
1714 return 0;
1715 }
1716 case PR_GET_NAME: {
1717 struct task_struct *me = current;
1718 unsigned char tcomm[sizeof(me->comm)];
1719
1720 get_task_comm(tcomm, me);
1721 if (copy_to_user((char __user *)arg2, tcomm, sizeof(tcomm)))
1722 return -EFAULT;
1723 return 0;
1724 }
Anton Blanchard651d7652006-06-07 16:10:19 +10001725 case PR_GET_ENDIAN:
1726 error = GET_ENDIAN(current, arg2);
1727 break;
1728 case PR_SET_ENDIAN:
1729 error = SET_ENDIAN(current, arg2);
1730 break;
1731
Andrea Arcangeli1d9d02f2007-07-15 23:41:32 -07001732 case PR_GET_SECCOMP:
1733 error = prctl_get_seccomp();
1734 break;
1735 case PR_SET_SECCOMP:
1736 error = prctl_set_seccomp(arg2);
1737 break;
1738
Serge E. Hallyn3b7391d2008-02-04 22:29:45 -08001739 case PR_CAPBSET_READ:
1740 if (!cap_valid(arg2))
1741 return -EINVAL;
1742 return !!cap_raised(current->cap_bset, arg2);
1743 case PR_CAPBSET_DROP:
1744#ifdef CONFIG_SECURITY_FILE_CAPABILITIES
1745 return cap_prctl_drop(arg2);
1746#else
1747 return -EINVAL;
1748#endif
1749
Linus Torvalds1da177e2005-04-16 15:20:36 -07001750 default:
1751 error = -EINVAL;
1752 break;
1753 }
1754 return error;
1755}
Andi Kleen3cfc3482006-09-26 10:52:28 +02001756
1757asmlinkage long sys_getcpu(unsigned __user *cpup, unsigned __user *nodep,
Ingo Molnar4307d1e2007-11-07 18:37:48 +01001758 struct getcpu_cache __user *unused)
Andi Kleen3cfc3482006-09-26 10:52:28 +02001759{
1760 int err = 0;
1761 int cpu = raw_smp_processor_id();
1762 if (cpup)
1763 err |= put_user(cpu, cpup);
1764 if (nodep)
1765 err |= put_user(cpu_to_node(cpu), nodep);
Andi Kleen3cfc3482006-09-26 10:52:28 +02001766 return err ? -EFAULT : 0;
1767}
Jeremy Fitzhardinge10a0a8d2007-07-17 18:37:02 -07001768
1769char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff";
1770
1771static void argv_cleanup(char **argv, char **envp)
1772{
1773 argv_free(argv);
1774}
1775
1776/**
1777 * orderly_poweroff - Trigger an orderly system poweroff
1778 * @force: force poweroff if command execution fails
1779 *
1780 * This may be called from any context to trigger a system shutdown.
1781 * If the orderly shutdown fails, it will force an immediate shutdown.
1782 */
1783int orderly_poweroff(bool force)
1784{
1785 int argc;
1786 char **argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc);
1787 static char *envp[] = {
1788 "HOME=/",
1789 "PATH=/sbin:/bin:/usr/sbin:/usr/bin",
1790 NULL
1791 };
1792 int ret = -ENOMEM;
1793 struct subprocess_info *info;
1794
1795 if (argv == NULL) {
1796 printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n",
1797 __func__, poweroff_cmd);
1798 goto out;
1799 }
1800
1801 info = call_usermodehelper_setup(argv[0], argv, envp);
1802 if (info == NULL) {
1803 argv_free(argv);
1804 goto out;
1805 }
1806
1807 call_usermodehelper_setcleanup(info, argv_cleanup);
1808
Jeremy Fitzhardinge86313c42007-07-17 18:37:03 -07001809 ret = call_usermodehelper_exec(info, UMH_NO_WAIT);
Jeremy Fitzhardinge10a0a8d2007-07-17 18:37:02 -07001810
1811 out:
1812 if (ret && force) {
1813 printk(KERN_WARNING "Failed to start orderly shutdown: "
1814 "forcing the issue\n");
1815
1816 /* I guess this should try to kick off some daemon to
1817 sync and poweroff asap. Or not even bother syncing
1818 if we're doing an emergency shutdown? */
1819 emergency_sync();
1820 kernel_power_off();
1821 }
1822
1823 return ret;
1824}
1825EXPORT_SYMBOL_GPL(orderly_poweroff);