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1 | /* | |
2 | * linux/kernel/sys.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | */ | |
6 | ||
7 | #include <linux/export.h> | |
8 | #include <linux/mm.h> | |
9 | #include <linux/utsname.h> | |
10 | #include <linux/mman.h> | |
11 | #include <linux/reboot.h> | |
12 | #include <linux/prctl.h> | |
13 | #include <linux/highuid.h> | |
14 | #include <linux/fs.h> | |
15 | #include <linux/kmod.h> | |
16 | #include <linux/perf_event.h> | |
17 | #include <linux/resource.h> | |
18 | #include <linux/kernel.h> | |
19 | #include <linux/workqueue.h> | |
20 | #include <linux/capability.h> | |
21 | #include <linux/device.h> | |
22 | #include <linux/key.h> | |
23 | #include <linux/times.h> | |
24 | #include <linux/posix-timers.h> | |
25 | #include <linux/security.h> | |
26 | #include <linux/dcookies.h> | |
27 | #include <linux/suspend.h> | |
28 | #include <linux/tty.h> | |
29 | #include <linux/signal.h> | |
30 | #include <linux/cn_proc.h> | |
31 | #include <linux/getcpu.h> | |
32 | #include <linux/task_io_accounting_ops.h> | |
33 | #include <linux/seccomp.h> | |
34 | #include <linux/cpu.h> | |
35 | #include <linux/personality.h> | |
36 | #include <linux/ptrace.h> | |
37 | #include <linux/fs_struct.h> | |
38 | #include <linux/file.h> | |
39 | #include <linux/mount.h> | |
40 | #include <linux/gfp.h> | |
41 | #include <linux/syscore_ops.h> | |
42 | #include <linux/version.h> | |
43 | #include <linux/ctype.h> | |
44 | ||
45 | #include <linux/compat.h> | |
46 | #include <linux/syscalls.h> | |
47 | #include <linux/kprobes.h> | |
48 | #include <linux/user_namespace.h> | |
49 | #include <linux/binfmts.h> | |
50 | ||
51 | #include <linux/sched.h> | |
52 | #include <linux/rcupdate.h> | |
53 | #include <linux/uidgid.h> | |
54 | #include <linux/cred.h> | |
55 | ||
56 | #include <linux/kmsg_dump.h> | |
57 | /* Move somewhere else to avoid recompiling? */ | |
58 | #include <generated/utsrelease.h> | |
59 | ||
60 | #include <asm/uaccess.h> | |
61 | #include <asm/io.h> | |
62 | #include <asm/unistd.h> | |
63 | ||
64 | #ifndef SET_UNALIGN_CTL | |
65 | # define SET_UNALIGN_CTL(a, b) (-EINVAL) | |
66 | #endif | |
67 | #ifndef GET_UNALIGN_CTL | |
68 | # define GET_UNALIGN_CTL(a, b) (-EINVAL) | |
69 | #endif | |
70 | #ifndef SET_FPEMU_CTL | |
71 | # define SET_FPEMU_CTL(a, b) (-EINVAL) | |
72 | #endif | |
73 | #ifndef GET_FPEMU_CTL | |
74 | # define GET_FPEMU_CTL(a, b) (-EINVAL) | |
75 | #endif | |
76 | #ifndef SET_FPEXC_CTL | |
77 | # define SET_FPEXC_CTL(a, b) (-EINVAL) | |
78 | #endif | |
79 | #ifndef GET_FPEXC_CTL | |
80 | # define GET_FPEXC_CTL(a, b) (-EINVAL) | |
81 | #endif | |
82 | #ifndef GET_ENDIAN | |
83 | # define GET_ENDIAN(a, b) (-EINVAL) | |
84 | #endif | |
85 | #ifndef SET_ENDIAN | |
86 | # define SET_ENDIAN(a, b) (-EINVAL) | |
87 | #endif | |
88 | #ifndef GET_TSC_CTL | |
89 | # define GET_TSC_CTL(a) (-EINVAL) | |
90 | #endif | |
91 | #ifndef SET_TSC_CTL | |
92 | # define SET_TSC_CTL(a) (-EINVAL) | |
93 | #endif | |
94 | #ifndef MPX_ENABLE_MANAGEMENT | |
95 | # define MPX_ENABLE_MANAGEMENT() (-EINVAL) | |
96 | #endif | |
97 | #ifndef MPX_DISABLE_MANAGEMENT | |
98 | # define MPX_DISABLE_MANAGEMENT() (-EINVAL) | |
99 | #endif | |
100 | #ifndef GET_FP_MODE | |
101 | # define GET_FP_MODE(a) (-EINVAL) | |
102 | #endif | |
103 | #ifndef SET_FP_MODE | |
104 | # define SET_FP_MODE(a,b) (-EINVAL) | |
105 | #endif | |
106 | ||
107 | /* | |
108 | * this is where the system-wide overflow UID and GID are defined, for | |
109 | * architectures that now have 32-bit UID/GID but didn't in the past | |
110 | */ | |
111 | ||
112 | int overflowuid = DEFAULT_OVERFLOWUID; | |
113 | int overflowgid = DEFAULT_OVERFLOWGID; | |
114 | ||
115 | EXPORT_SYMBOL(overflowuid); | |
116 | EXPORT_SYMBOL(overflowgid); | |
117 | ||
118 | /* | |
119 | * the same as above, but for filesystems which can only store a 16-bit | |
120 | * UID and GID. as such, this is needed on all architectures | |
121 | */ | |
122 | ||
123 | int fs_overflowuid = DEFAULT_FS_OVERFLOWUID; | |
124 | int fs_overflowgid = DEFAULT_FS_OVERFLOWUID; | |
125 | ||
126 | EXPORT_SYMBOL(fs_overflowuid); | |
127 | EXPORT_SYMBOL(fs_overflowgid); | |
128 | ||
129 | /* | |
130 | * Returns true if current's euid is same as p's uid or euid, | |
131 | * or has CAP_SYS_NICE to p's user_ns. | |
132 | * | |
133 | * Called with rcu_read_lock, creds are safe | |
134 | */ | |
135 | static bool set_one_prio_perm(struct task_struct *p) | |
136 | { | |
137 | const struct cred *cred = current_cred(), *pcred = __task_cred(p); | |
138 | ||
139 | if (uid_eq(pcred->uid, cred->euid) || | |
140 | uid_eq(pcred->euid, cred->euid)) | |
141 | return true; | |
142 | if (ns_capable(pcred->user_ns, CAP_SYS_NICE)) | |
143 | return true; | |
144 | return false; | |
145 | } | |
146 | ||
147 | /* | |
148 | * set the priority of a task | |
149 | * - the caller must hold the RCU read lock | |
150 | */ | |
151 | static int set_one_prio(struct task_struct *p, int niceval, int error) | |
152 | { | |
153 | int no_nice; | |
154 | ||
155 | if (!set_one_prio_perm(p)) { | |
156 | error = -EPERM; | |
157 | goto out; | |
158 | } | |
159 | if (niceval < task_nice(p) && !can_nice(p, niceval)) { | |
160 | error = -EACCES; | |
161 | goto out; | |
162 | } | |
163 | no_nice = security_task_setnice(p, niceval); | |
164 | if (no_nice) { | |
165 | error = no_nice; | |
166 | goto out; | |
167 | } | |
168 | if (error == -ESRCH) | |
169 | error = 0; | |
170 | set_user_nice(p, niceval); | |
171 | out: | |
172 | return error; | |
173 | } | |
174 | ||
175 | SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval) | |
176 | { | |
177 | struct task_struct *g, *p; | |
178 | struct user_struct *user; | |
179 | const struct cred *cred = current_cred(); | |
180 | int error = -EINVAL; | |
181 | struct pid *pgrp; | |
182 | kuid_t uid; | |
183 | ||
184 | if (which > PRIO_USER || which < PRIO_PROCESS) | |
185 | goto out; | |
186 | ||
187 | /* normalize: avoid signed division (rounding problems) */ | |
188 | error = -ESRCH; | |
189 | if (niceval < MIN_NICE) | |
190 | niceval = MIN_NICE; | |
191 | if (niceval > MAX_NICE) | |
192 | niceval = MAX_NICE; | |
193 | ||
194 | rcu_read_lock(); | |
195 | read_lock(&tasklist_lock); | |
196 | switch (which) { | |
197 | case PRIO_PROCESS: | |
198 | if (who) | |
199 | p = find_task_by_vpid(who); | |
200 | else | |
201 | p = current; | |
202 | if (p) | |
203 | error = set_one_prio(p, niceval, error); | |
204 | break; | |
205 | case PRIO_PGRP: | |
206 | if (who) | |
207 | pgrp = find_vpid(who); | |
208 | else | |
209 | pgrp = task_pgrp(current); | |
210 | do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { | |
211 | error = set_one_prio(p, niceval, error); | |
212 | } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); | |
213 | break; | |
214 | case PRIO_USER: | |
215 | uid = make_kuid(cred->user_ns, who); | |
216 | user = cred->user; | |
217 | if (!who) | |
218 | uid = cred->uid; | |
219 | else if (!uid_eq(uid, cred->uid)) { | |
220 | user = find_user(uid); | |
221 | if (!user) | |
222 | goto out_unlock; /* No processes for this user */ | |
223 | } | |
224 | do_each_thread(g, p) { | |
225 | if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) | |
226 | error = set_one_prio(p, niceval, error); | |
227 | } while_each_thread(g, p); | |
228 | if (!uid_eq(uid, cred->uid)) | |
229 | free_uid(user); /* For find_user() */ | |
230 | break; | |
231 | } | |
232 | out_unlock: | |
233 | read_unlock(&tasklist_lock); | |
234 | rcu_read_unlock(); | |
235 | out: | |
236 | return error; | |
237 | } | |
238 | ||
239 | /* | |
240 | * Ugh. To avoid negative return values, "getpriority()" will | |
241 | * not return the normal nice-value, but a negated value that | |
242 | * has been offset by 20 (ie it returns 40..1 instead of -20..19) | |
243 | * to stay compatible. | |
244 | */ | |
245 | SYSCALL_DEFINE2(getpriority, int, which, int, who) | |
246 | { | |
247 | struct task_struct *g, *p; | |
248 | struct user_struct *user; | |
249 | const struct cred *cred = current_cred(); | |
250 | long niceval, retval = -ESRCH; | |
251 | struct pid *pgrp; | |
252 | kuid_t uid; | |
253 | ||
254 | if (which > PRIO_USER || which < PRIO_PROCESS) | |
255 | return -EINVAL; | |
256 | ||
257 | rcu_read_lock(); | |
258 | read_lock(&tasklist_lock); | |
259 | switch (which) { | |
260 | case PRIO_PROCESS: | |
261 | if (who) | |
262 | p = find_task_by_vpid(who); | |
263 | else | |
264 | p = current; | |
265 | if (p) { | |
266 | niceval = nice_to_rlimit(task_nice(p)); | |
267 | if (niceval > retval) | |
268 | retval = niceval; | |
269 | } | |
270 | break; | |
271 | case PRIO_PGRP: | |
272 | if (who) | |
273 | pgrp = find_vpid(who); | |
274 | else | |
275 | pgrp = task_pgrp(current); | |
276 | do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { | |
277 | niceval = nice_to_rlimit(task_nice(p)); | |
278 | if (niceval > retval) | |
279 | retval = niceval; | |
280 | } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); | |
281 | break; | |
282 | case PRIO_USER: | |
283 | uid = make_kuid(cred->user_ns, who); | |
284 | user = cred->user; | |
285 | if (!who) | |
286 | uid = cred->uid; | |
287 | else if (!uid_eq(uid, cred->uid)) { | |
288 | user = find_user(uid); | |
289 | if (!user) | |
290 | goto out_unlock; /* No processes for this user */ | |
291 | } | |
292 | do_each_thread(g, p) { | |
293 | if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) { | |
294 | niceval = nice_to_rlimit(task_nice(p)); | |
295 | if (niceval > retval) | |
296 | retval = niceval; | |
297 | } | |
298 | } while_each_thread(g, p); | |
299 | if (!uid_eq(uid, cred->uid)) | |
300 | free_uid(user); /* for find_user() */ | |
301 | break; | |
302 | } | |
303 | out_unlock: | |
304 | read_unlock(&tasklist_lock); | |
305 | rcu_read_unlock(); | |
306 | ||
307 | return retval; | |
308 | } | |
309 | ||
310 | /* | |
311 | * Unprivileged users may change the real gid to the effective gid | |
312 | * or vice versa. (BSD-style) | |
313 | * | |
314 | * If you set the real gid at all, or set the effective gid to a value not | |
315 | * equal to the real gid, then the saved gid is set to the new effective gid. | |
316 | * | |
317 | * This makes it possible for a setgid program to completely drop its | |
318 | * privileges, which is often a useful assertion to make when you are doing | |
319 | * a security audit over a program. | |
320 | * | |
321 | * The general idea is that a program which uses just setregid() will be | |
322 | * 100% compatible with BSD. A program which uses just setgid() will be | |
323 | * 100% compatible with POSIX with saved IDs. | |
324 | * | |
325 | * SMP: There are not races, the GIDs are checked only by filesystem | |
326 | * operations (as far as semantic preservation is concerned). | |
327 | */ | |
328 | #ifdef CONFIG_MULTIUSER | |
329 | SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid) | |
330 | { | |
331 | struct user_namespace *ns = current_user_ns(); | |
332 | const struct cred *old; | |
333 | struct cred *new; | |
334 | int retval; | |
335 | kgid_t krgid, kegid; | |
336 | ||
337 | krgid = make_kgid(ns, rgid); | |
338 | kegid = make_kgid(ns, egid); | |
339 | ||
340 | if ((rgid != (gid_t) -1) && !gid_valid(krgid)) | |
341 | return -EINVAL; | |
342 | if ((egid != (gid_t) -1) && !gid_valid(kegid)) | |
343 | return -EINVAL; | |
344 | ||
345 | new = prepare_creds(); | |
346 | if (!new) | |
347 | return -ENOMEM; | |
348 | old = current_cred(); | |
349 | ||
350 | retval = -EPERM; | |
351 | if (rgid != (gid_t) -1) { | |
352 | if (gid_eq(old->gid, krgid) || | |
353 | gid_eq(old->egid, krgid) || | |
354 | ns_capable(old->user_ns, CAP_SETGID)) | |
355 | new->gid = krgid; | |
356 | else | |
357 | goto error; | |
358 | } | |
359 | if (egid != (gid_t) -1) { | |
360 | if (gid_eq(old->gid, kegid) || | |
361 | gid_eq(old->egid, kegid) || | |
362 | gid_eq(old->sgid, kegid) || | |
363 | ns_capable(old->user_ns, CAP_SETGID)) | |
364 | new->egid = kegid; | |
365 | else | |
366 | goto error; | |
367 | } | |
368 | ||
369 | if (rgid != (gid_t) -1 || | |
370 | (egid != (gid_t) -1 && !gid_eq(kegid, old->gid))) | |
371 | new->sgid = new->egid; | |
372 | new->fsgid = new->egid; | |
373 | ||
374 | return commit_creds(new); | |
375 | ||
376 | error: | |
377 | abort_creds(new); | |
378 | return retval; | |
379 | } | |
380 | ||
381 | /* | |
382 | * setgid() is implemented like SysV w/ SAVED_IDS | |
383 | * | |
384 | * SMP: Same implicit races as above. | |
385 | */ | |
386 | SYSCALL_DEFINE1(setgid, gid_t, gid) | |
387 | { | |
388 | struct user_namespace *ns = current_user_ns(); | |
389 | const struct cred *old; | |
390 | struct cred *new; | |
391 | int retval; | |
392 | kgid_t kgid; | |
393 | ||
394 | kgid = make_kgid(ns, gid); | |
395 | if (!gid_valid(kgid)) | |
396 | return -EINVAL; | |
397 | ||
398 | new = prepare_creds(); | |
399 | if (!new) | |
400 | return -ENOMEM; | |
401 | old = current_cred(); | |
402 | ||
403 | retval = -EPERM; | |
404 | if (ns_capable(old->user_ns, CAP_SETGID)) | |
405 | new->gid = new->egid = new->sgid = new->fsgid = kgid; | |
406 | else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid)) | |
407 | new->egid = new->fsgid = kgid; | |
408 | else | |
409 | goto error; | |
410 | ||
411 | return commit_creds(new); | |
412 | ||
413 | error: | |
414 | abort_creds(new); | |
415 | return retval; | |
416 | } | |
417 | ||
418 | /* | |
419 | * change the user struct in a credentials set to match the new UID | |
420 | */ | |
421 | static int set_user(struct cred *new) | |
422 | { | |
423 | struct user_struct *new_user; | |
424 | ||
425 | new_user = alloc_uid(new->uid); | |
426 | if (!new_user) | |
427 | return -EAGAIN; | |
428 | ||
429 | /* | |
430 | * We don't fail in case of NPROC limit excess here because too many | |
431 | * poorly written programs don't check set*uid() return code, assuming | |
432 | * it never fails if called by root. We may still enforce NPROC limit | |
433 | * for programs doing set*uid()+execve() by harmlessly deferring the | |
434 | * failure to the execve() stage. | |
435 | */ | |
436 | if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) && | |
437 | new_user != INIT_USER) | |
438 | current->flags |= PF_NPROC_EXCEEDED; | |
439 | else | |
440 | current->flags &= ~PF_NPROC_EXCEEDED; | |
441 | ||
442 | free_uid(new->user); | |
443 | new->user = new_user; | |
444 | return 0; | |
445 | } | |
446 | ||
447 | /* | |
448 | * Unprivileged users may change the real uid to the effective uid | |
449 | * or vice versa. (BSD-style) | |
450 | * | |
451 | * If you set the real uid at all, or set the effective uid to a value not | |
452 | * equal to the real uid, then the saved uid is set to the new effective uid. | |
453 | * | |
454 | * This makes it possible for a setuid program to completely drop its | |
455 | * privileges, which is often a useful assertion to make when you are doing | |
456 | * a security audit over a program. | |
457 | * | |
458 | * The general idea is that a program which uses just setreuid() will be | |
459 | * 100% compatible with BSD. A program which uses just setuid() will be | |
460 | * 100% compatible with POSIX with saved IDs. | |
461 | */ | |
462 | SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid) | |
463 | { | |
464 | struct user_namespace *ns = current_user_ns(); | |
465 | const struct cred *old; | |
466 | struct cred *new; | |
467 | int retval; | |
468 | kuid_t kruid, keuid; | |
469 | ||
470 | kruid = make_kuid(ns, ruid); | |
471 | keuid = make_kuid(ns, euid); | |
472 | ||
473 | if ((ruid != (uid_t) -1) && !uid_valid(kruid)) | |
474 | return -EINVAL; | |
475 | if ((euid != (uid_t) -1) && !uid_valid(keuid)) | |
476 | return -EINVAL; | |
477 | ||
478 | new = prepare_creds(); | |
479 | if (!new) | |
480 | return -ENOMEM; | |
481 | old = current_cred(); | |
482 | ||
483 | retval = -EPERM; | |
484 | if (ruid != (uid_t) -1) { | |
485 | new->uid = kruid; | |
486 | if (!uid_eq(old->uid, kruid) && | |
487 | !uid_eq(old->euid, kruid) && | |
488 | !ns_capable(old->user_ns, CAP_SETUID)) | |
489 | goto error; | |
490 | } | |
491 | ||
492 | if (euid != (uid_t) -1) { | |
493 | new->euid = keuid; | |
494 | if (!uid_eq(old->uid, keuid) && | |
495 | !uid_eq(old->euid, keuid) && | |
496 | !uid_eq(old->suid, keuid) && | |
497 | !ns_capable(old->user_ns, CAP_SETUID)) | |
498 | goto error; | |
499 | } | |
500 | ||
501 | if (!uid_eq(new->uid, old->uid)) { | |
502 | retval = set_user(new); | |
503 | if (retval < 0) | |
504 | goto error; | |
505 | } | |
506 | if (ruid != (uid_t) -1 || | |
507 | (euid != (uid_t) -1 && !uid_eq(keuid, old->uid))) | |
508 | new->suid = new->euid; | |
509 | new->fsuid = new->euid; | |
510 | ||
511 | retval = security_task_fix_setuid(new, old, LSM_SETID_RE); | |
512 | if (retval < 0) | |
513 | goto error; | |
514 | ||
515 | return commit_creds(new); | |
516 | ||
517 | error: | |
518 | abort_creds(new); | |
519 | return retval; | |
520 | } | |
521 | ||
522 | /* | |
523 | * setuid() is implemented like SysV with SAVED_IDS | |
524 | * | |
525 | * Note that SAVED_ID's is deficient in that a setuid root program | |
526 | * like sendmail, for example, cannot set its uid to be a normal | |
527 | * user and then switch back, because if you're root, setuid() sets | |
528 | * the saved uid too. If you don't like this, blame the bright people | |
529 | * in the POSIX committee and/or USG. Note that the BSD-style setreuid() | |
530 | * will allow a root program to temporarily drop privileges and be able to | |
531 | * regain them by swapping the real and effective uid. | |
532 | */ | |
533 | SYSCALL_DEFINE1(setuid, uid_t, uid) | |
534 | { | |
535 | struct user_namespace *ns = current_user_ns(); | |
536 | const struct cred *old; | |
537 | struct cred *new; | |
538 | int retval; | |
539 | kuid_t kuid; | |
540 | ||
541 | kuid = make_kuid(ns, uid); | |
542 | if (!uid_valid(kuid)) | |
543 | return -EINVAL; | |
544 | ||
545 | new = prepare_creds(); | |
546 | if (!new) | |
547 | return -ENOMEM; | |
548 | old = current_cred(); | |
549 | ||
550 | retval = -EPERM; | |
551 | if (ns_capable(old->user_ns, CAP_SETUID)) { | |
552 | new->suid = new->uid = kuid; | |
553 | if (!uid_eq(kuid, old->uid)) { | |
554 | retval = set_user(new); | |
555 | if (retval < 0) | |
556 | goto error; | |
557 | } | |
558 | } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) { | |
559 | goto error; | |
560 | } | |
561 | ||
562 | new->fsuid = new->euid = kuid; | |
563 | ||
564 | retval = security_task_fix_setuid(new, old, LSM_SETID_ID); | |
565 | if (retval < 0) | |
566 | goto error; | |
567 | ||
568 | return commit_creds(new); | |
569 | ||
570 | error: | |
571 | abort_creds(new); | |
572 | return retval; | |
573 | } | |
574 | ||
575 | ||
576 | /* | |
577 | * This function implements a generic ability to update ruid, euid, | |
578 | * and suid. This allows you to implement the 4.4 compatible seteuid(). | |
579 | */ | |
580 | SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid) | |
581 | { | |
582 | struct user_namespace *ns = current_user_ns(); | |
583 | const struct cred *old; | |
584 | struct cred *new; | |
585 | int retval; | |
586 | kuid_t kruid, keuid, ksuid; | |
587 | ||
588 | kruid = make_kuid(ns, ruid); | |
589 | keuid = make_kuid(ns, euid); | |
590 | ksuid = make_kuid(ns, suid); | |
591 | ||
592 | if ((ruid != (uid_t) -1) && !uid_valid(kruid)) | |
593 | return -EINVAL; | |
594 | ||
595 | if ((euid != (uid_t) -1) && !uid_valid(keuid)) | |
596 | return -EINVAL; | |
597 | ||
598 | if ((suid != (uid_t) -1) && !uid_valid(ksuid)) | |
599 | return -EINVAL; | |
600 | ||
601 | new = prepare_creds(); | |
602 | if (!new) | |
603 | return -ENOMEM; | |
604 | ||
605 | old = current_cred(); | |
606 | ||
607 | retval = -EPERM; | |
608 | if (!ns_capable(old->user_ns, CAP_SETUID)) { | |
609 | if (ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) && | |
610 | !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid)) | |
611 | goto error; | |
612 | if (euid != (uid_t) -1 && !uid_eq(keuid, old->uid) && | |
613 | !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid)) | |
614 | goto error; | |
615 | if (suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) && | |
616 | !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid)) | |
617 | goto error; | |
618 | } | |
619 | ||
620 | if (ruid != (uid_t) -1) { | |
621 | new->uid = kruid; | |
622 | if (!uid_eq(kruid, old->uid)) { | |
623 | retval = set_user(new); | |
624 | if (retval < 0) | |
625 | goto error; | |
626 | } | |
627 | } | |
628 | if (euid != (uid_t) -1) | |
629 | new->euid = keuid; | |
630 | if (suid != (uid_t) -1) | |
631 | new->suid = ksuid; | |
632 | new->fsuid = new->euid; | |
633 | ||
634 | retval = security_task_fix_setuid(new, old, LSM_SETID_RES); | |
635 | if (retval < 0) | |
636 | goto error; | |
637 | ||
638 | return commit_creds(new); | |
639 | ||
640 | error: | |
641 | abort_creds(new); | |
642 | return retval; | |
643 | } | |
644 | ||
645 | SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp) | |
646 | { | |
647 | const struct cred *cred = current_cred(); | |
648 | int retval; | |
649 | uid_t ruid, euid, suid; | |
650 | ||
651 | ruid = from_kuid_munged(cred->user_ns, cred->uid); | |
652 | euid = from_kuid_munged(cred->user_ns, cred->euid); | |
653 | suid = from_kuid_munged(cred->user_ns, cred->suid); | |
654 | ||
655 | retval = put_user(ruid, ruidp); | |
656 | if (!retval) { | |
657 | retval = put_user(euid, euidp); | |
658 | if (!retval) | |
659 | return put_user(suid, suidp); | |
660 | } | |
661 | return retval; | |
662 | } | |
663 | ||
664 | /* | |
665 | * Same as above, but for rgid, egid, sgid. | |
666 | */ | |
667 | SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid) | |
668 | { | |
669 | struct user_namespace *ns = current_user_ns(); | |
670 | const struct cred *old; | |
671 | struct cred *new; | |
672 | int retval; | |
673 | kgid_t krgid, kegid, ksgid; | |
674 | ||
675 | krgid = make_kgid(ns, rgid); | |
676 | kegid = make_kgid(ns, egid); | |
677 | ksgid = make_kgid(ns, sgid); | |
678 | ||
679 | if ((rgid != (gid_t) -1) && !gid_valid(krgid)) | |
680 | return -EINVAL; | |
681 | if ((egid != (gid_t) -1) && !gid_valid(kegid)) | |
682 | return -EINVAL; | |
683 | if ((sgid != (gid_t) -1) && !gid_valid(ksgid)) | |
684 | return -EINVAL; | |
685 | ||
686 | new = prepare_creds(); | |
687 | if (!new) | |
688 | return -ENOMEM; | |
689 | old = current_cred(); | |
690 | ||
691 | retval = -EPERM; | |
692 | if (!ns_capable(old->user_ns, CAP_SETGID)) { | |
693 | if (rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) && | |
694 | !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid)) | |
695 | goto error; | |
696 | if (egid != (gid_t) -1 && !gid_eq(kegid, old->gid) && | |
697 | !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid)) | |
698 | goto error; | |
699 | if (sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) && | |
700 | !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid)) | |
701 | goto error; | |
702 | } | |
703 | ||
704 | if (rgid != (gid_t) -1) | |
705 | new->gid = krgid; | |
706 | if (egid != (gid_t) -1) | |
707 | new->egid = kegid; | |
708 | if (sgid != (gid_t) -1) | |
709 | new->sgid = ksgid; | |
710 | new->fsgid = new->egid; | |
711 | ||
712 | return commit_creds(new); | |
713 | ||
714 | error: | |
715 | abort_creds(new); | |
716 | return retval; | |
717 | } | |
718 | ||
719 | SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp) | |
720 | { | |
721 | const struct cred *cred = current_cred(); | |
722 | int retval; | |
723 | gid_t rgid, egid, sgid; | |
724 | ||
725 | rgid = from_kgid_munged(cred->user_ns, cred->gid); | |
726 | egid = from_kgid_munged(cred->user_ns, cred->egid); | |
727 | sgid = from_kgid_munged(cred->user_ns, cred->sgid); | |
728 | ||
729 | retval = put_user(rgid, rgidp); | |
730 | if (!retval) { | |
731 | retval = put_user(egid, egidp); | |
732 | if (!retval) | |
733 | retval = put_user(sgid, sgidp); | |
734 | } | |
735 | ||
736 | return retval; | |
737 | } | |
738 | ||
739 | ||
740 | /* | |
741 | * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This | |
742 | * is used for "access()" and for the NFS daemon (letting nfsd stay at | |
743 | * whatever uid it wants to). It normally shadows "euid", except when | |
744 | * explicitly set by setfsuid() or for access.. | |
745 | */ | |
746 | SYSCALL_DEFINE1(setfsuid, uid_t, uid) | |
747 | { | |
748 | const struct cred *old; | |
749 | struct cred *new; | |
750 | uid_t old_fsuid; | |
751 | kuid_t kuid; | |
752 | ||
753 | old = current_cred(); | |
754 | old_fsuid = from_kuid_munged(old->user_ns, old->fsuid); | |
755 | ||
756 | kuid = make_kuid(old->user_ns, uid); | |
757 | if (!uid_valid(kuid)) | |
758 | return old_fsuid; | |
759 | ||
760 | new = prepare_creds(); | |
761 | if (!new) | |
762 | return old_fsuid; | |
763 | ||
764 | if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) || | |
765 | uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) || | |
766 | ns_capable(old->user_ns, CAP_SETUID)) { | |
767 | if (!uid_eq(kuid, old->fsuid)) { | |
768 | new->fsuid = kuid; | |
769 | if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0) | |
770 | goto change_okay; | |
771 | } | |
772 | } | |
773 | ||
774 | abort_creds(new); | |
775 | return old_fsuid; | |
776 | ||
777 | change_okay: | |
778 | commit_creds(new); | |
779 | return old_fsuid; | |
780 | } | |
781 | ||
782 | /* | |
783 | * Samma på svenska.. | |
784 | */ | |
785 | SYSCALL_DEFINE1(setfsgid, gid_t, gid) | |
786 | { | |
787 | const struct cred *old; | |
788 | struct cred *new; | |
789 | gid_t old_fsgid; | |
790 | kgid_t kgid; | |
791 | ||
792 | old = current_cred(); | |
793 | old_fsgid = from_kgid_munged(old->user_ns, old->fsgid); | |
794 | ||
795 | kgid = make_kgid(old->user_ns, gid); | |
796 | if (!gid_valid(kgid)) | |
797 | return old_fsgid; | |
798 | ||
799 | new = prepare_creds(); | |
800 | if (!new) | |
801 | return old_fsgid; | |
802 | ||
803 | if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) || | |
804 | gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) || | |
805 | ns_capable(old->user_ns, CAP_SETGID)) { | |
806 | if (!gid_eq(kgid, old->fsgid)) { | |
807 | new->fsgid = kgid; | |
808 | goto change_okay; | |
809 | } | |
810 | } | |
811 | ||
812 | abort_creds(new); | |
813 | return old_fsgid; | |
814 | ||
815 | change_okay: | |
816 | commit_creds(new); | |
817 | return old_fsgid; | |
818 | } | |
819 | #endif /* CONFIG_MULTIUSER */ | |
820 | ||
821 | /** | |
822 | * sys_getpid - return the thread group id of the current process | |
823 | * | |
824 | * Note, despite the name, this returns the tgid not the pid. The tgid and | |
825 | * the pid are identical unless CLONE_THREAD was specified on clone() in | |
826 | * which case the tgid is the same in all threads of the same group. | |
827 | * | |
828 | * This is SMP safe as current->tgid does not change. | |
829 | */ | |
830 | SYSCALL_DEFINE0(getpid) | |
831 | { | |
832 | return task_tgid_vnr(current); | |
833 | } | |
834 | ||
835 | /* Thread ID - the internal kernel "pid" */ | |
836 | SYSCALL_DEFINE0(gettid) | |
837 | { | |
838 | return task_pid_vnr(current); | |
839 | } | |
840 | ||
841 | /* | |
842 | * Accessing ->real_parent is not SMP-safe, it could | |
843 | * change from under us. However, we can use a stale | |
844 | * value of ->real_parent under rcu_read_lock(), see | |
845 | * release_task()->call_rcu(delayed_put_task_struct). | |
846 | */ | |
847 | SYSCALL_DEFINE0(getppid) | |
848 | { | |
849 | int pid; | |
850 | ||
851 | rcu_read_lock(); | |
852 | pid = task_tgid_vnr(rcu_dereference(current->real_parent)); | |
853 | rcu_read_unlock(); | |
854 | ||
855 | return pid; | |
856 | } | |
857 | ||
858 | SYSCALL_DEFINE0(getuid) | |
859 | { | |
860 | /* Only we change this so SMP safe */ | |
861 | return from_kuid_munged(current_user_ns(), current_uid()); | |
862 | } | |
863 | ||
864 | SYSCALL_DEFINE0(geteuid) | |
865 | { | |
866 | /* Only we change this so SMP safe */ | |
867 | return from_kuid_munged(current_user_ns(), current_euid()); | |
868 | } | |
869 | ||
870 | SYSCALL_DEFINE0(getgid) | |
871 | { | |
872 | /* Only we change this so SMP safe */ | |
873 | return from_kgid_munged(current_user_ns(), current_gid()); | |
874 | } | |
875 | ||
876 | SYSCALL_DEFINE0(getegid) | |
877 | { | |
878 | /* Only we change this so SMP safe */ | |
879 | return from_kgid_munged(current_user_ns(), current_egid()); | |
880 | } | |
881 | ||
882 | void do_sys_times(struct tms *tms) | |
883 | { | |
884 | cputime_t tgutime, tgstime, cutime, cstime; | |
885 | ||
886 | thread_group_cputime_adjusted(current, &tgutime, &tgstime); | |
887 | cutime = current->signal->cutime; | |
888 | cstime = current->signal->cstime; | |
889 | tms->tms_utime = cputime_to_clock_t(tgutime); | |
890 | tms->tms_stime = cputime_to_clock_t(tgstime); | |
891 | tms->tms_cutime = cputime_to_clock_t(cutime); | |
892 | tms->tms_cstime = cputime_to_clock_t(cstime); | |
893 | } | |
894 | ||
895 | SYSCALL_DEFINE1(times, struct tms __user *, tbuf) | |
896 | { | |
897 | if (tbuf) { | |
898 | struct tms tmp; | |
899 | ||
900 | do_sys_times(&tmp); | |
901 | if (copy_to_user(tbuf, &tmp, sizeof(struct tms))) | |
902 | return -EFAULT; | |
903 | } | |
904 | force_successful_syscall_return(); | |
905 | return (long) jiffies_64_to_clock_t(get_jiffies_64()); | |
906 | } | |
907 | ||
908 | /* | |
909 | * This needs some heavy checking ... | |
910 | * I just haven't the stomach for it. I also don't fully | |
911 | * understand sessions/pgrp etc. Let somebody who does explain it. | |
912 | * | |
913 | * OK, I think I have the protection semantics right.... this is really | |
914 | * only important on a multi-user system anyway, to make sure one user | |
915 | * can't send a signal to a process owned by another. -TYT, 12/12/91 | |
916 | * | |
917 | * !PF_FORKNOEXEC check to conform completely to POSIX. | |
918 | */ | |
919 | SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid) | |
920 | { | |
921 | struct task_struct *p; | |
922 | struct task_struct *group_leader = current->group_leader; | |
923 | struct pid *pgrp; | |
924 | int err; | |
925 | ||
926 | if (!pid) | |
927 | pid = task_pid_vnr(group_leader); | |
928 | if (!pgid) | |
929 | pgid = pid; | |
930 | if (pgid < 0) | |
931 | return -EINVAL; | |
932 | rcu_read_lock(); | |
933 | ||
934 | /* From this point forward we keep holding onto the tasklist lock | |
935 | * so that our parent does not change from under us. -DaveM | |
936 | */ | |
937 | write_lock_irq(&tasklist_lock); | |
938 | ||
939 | err = -ESRCH; | |
940 | p = find_task_by_vpid(pid); | |
941 | if (!p) | |
942 | goto out; | |
943 | ||
944 | err = -EINVAL; | |
945 | if (!thread_group_leader(p)) | |
946 | goto out; | |
947 | ||
948 | if (same_thread_group(p->real_parent, group_leader)) { | |
949 | err = -EPERM; | |
950 | if (task_session(p) != task_session(group_leader)) | |
951 | goto out; | |
952 | err = -EACCES; | |
953 | if (!(p->flags & PF_FORKNOEXEC)) | |
954 | goto out; | |
955 | } else { | |
956 | err = -ESRCH; | |
957 | if (p != group_leader) | |
958 | goto out; | |
959 | } | |
960 | ||
961 | err = -EPERM; | |
962 | if (p->signal->leader) | |
963 | goto out; | |
964 | ||
965 | pgrp = task_pid(p); | |
966 | if (pgid != pid) { | |
967 | struct task_struct *g; | |
968 | ||
969 | pgrp = find_vpid(pgid); | |
970 | g = pid_task(pgrp, PIDTYPE_PGID); | |
971 | if (!g || task_session(g) != task_session(group_leader)) | |
972 | goto out; | |
973 | } | |
974 | ||
975 | err = security_task_setpgid(p, pgid); | |
976 | if (err) | |
977 | goto out; | |
978 | ||
979 | if (task_pgrp(p) != pgrp) | |
980 | change_pid(p, PIDTYPE_PGID, pgrp); | |
981 | ||
982 | err = 0; | |
983 | out: | |
984 | /* All paths lead to here, thus we are safe. -DaveM */ | |
985 | write_unlock_irq(&tasklist_lock); | |
986 | rcu_read_unlock(); | |
987 | return err; | |
988 | } | |
989 | ||
990 | SYSCALL_DEFINE1(getpgid, pid_t, pid) | |
991 | { | |
992 | struct task_struct *p; | |
993 | struct pid *grp; | |
994 | int retval; | |
995 | ||
996 | rcu_read_lock(); | |
997 | if (!pid) | |
998 | grp = task_pgrp(current); | |
999 | else { | |
1000 | retval = -ESRCH; | |
1001 | p = find_task_by_vpid(pid); | |
1002 | if (!p) | |
1003 | goto out; | |
1004 | grp = task_pgrp(p); | |
1005 | if (!grp) | |
1006 | goto out; | |
1007 | ||
1008 | retval = security_task_getpgid(p); | |
1009 | if (retval) | |
1010 | goto out; | |
1011 | } | |
1012 | retval = pid_vnr(grp); | |
1013 | out: | |
1014 | rcu_read_unlock(); | |
1015 | return retval; | |
1016 | } | |
1017 | ||
1018 | #ifdef __ARCH_WANT_SYS_GETPGRP | |
1019 | ||
1020 | SYSCALL_DEFINE0(getpgrp) | |
1021 | { | |
1022 | return sys_getpgid(0); | |
1023 | } | |
1024 | ||
1025 | #endif | |
1026 | ||
1027 | SYSCALL_DEFINE1(getsid, pid_t, pid) | |
1028 | { | |
1029 | struct task_struct *p; | |
1030 | struct pid *sid; | |
1031 | int retval; | |
1032 | ||
1033 | rcu_read_lock(); | |
1034 | if (!pid) | |
1035 | sid = task_session(current); | |
1036 | else { | |
1037 | retval = -ESRCH; | |
1038 | p = find_task_by_vpid(pid); | |
1039 | if (!p) | |
1040 | goto out; | |
1041 | sid = task_session(p); | |
1042 | if (!sid) | |
1043 | goto out; | |
1044 | ||
1045 | retval = security_task_getsid(p); | |
1046 | if (retval) | |
1047 | goto out; | |
1048 | } | |
1049 | retval = pid_vnr(sid); | |
1050 | out: | |
1051 | rcu_read_unlock(); | |
1052 | return retval; | |
1053 | } | |
1054 | ||
1055 | static void set_special_pids(struct pid *pid) | |
1056 | { | |
1057 | struct task_struct *curr = current->group_leader; | |
1058 | ||
1059 | if (task_session(curr) != pid) | |
1060 | change_pid(curr, PIDTYPE_SID, pid); | |
1061 | ||
1062 | if (task_pgrp(curr) != pid) | |
1063 | change_pid(curr, PIDTYPE_PGID, pid); | |
1064 | } | |
1065 | ||
1066 | SYSCALL_DEFINE0(setsid) | |
1067 | { | |
1068 | struct task_struct *group_leader = current->group_leader; | |
1069 | struct pid *sid = task_pid(group_leader); | |
1070 | pid_t session = pid_vnr(sid); | |
1071 | int err = -EPERM; | |
1072 | ||
1073 | write_lock_irq(&tasklist_lock); | |
1074 | /* Fail if I am already a session leader */ | |
1075 | if (group_leader->signal->leader) | |
1076 | goto out; | |
1077 | ||
1078 | /* Fail if a process group id already exists that equals the | |
1079 | * proposed session id. | |
1080 | */ | |
1081 | if (pid_task(sid, PIDTYPE_PGID)) | |
1082 | goto out; | |
1083 | ||
1084 | group_leader->signal->leader = 1; | |
1085 | set_special_pids(sid); | |
1086 | ||
1087 | proc_clear_tty(group_leader); | |
1088 | ||
1089 | err = session; | |
1090 | out: | |
1091 | write_unlock_irq(&tasklist_lock); | |
1092 | if (err > 0) { | |
1093 | proc_sid_connector(group_leader); | |
1094 | sched_autogroup_create_attach(group_leader); | |
1095 | } | |
1096 | return err; | |
1097 | } | |
1098 | ||
1099 | DECLARE_RWSEM(uts_sem); | |
1100 | ||
1101 | #ifdef COMPAT_UTS_MACHINE | |
1102 | #define override_architecture(name) \ | |
1103 | (personality(current->personality) == PER_LINUX32 && \ | |
1104 | copy_to_user(name->machine, COMPAT_UTS_MACHINE, \ | |
1105 | sizeof(COMPAT_UTS_MACHINE))) | |
1106 | #else | |
1107 | #define override_architecture(name) 0 | |
1108 | #endif | |
1109 | ||
1110 | /* | |
1111 | * Work around broken programs that cannot handle "Linux 3.0". | |
1112 | * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40 | |
1113 | * And we map 4.x to 2.6.60+x, so 4.0 would be 2.6.60. | |
1114 | */ | |
1115 | static int override_release(char __user *release, size_t len) | |
1116 | { | |
1117 | int ret = 0; | |
1118 | ||
1119 | if (current->personality & UNAME26) { | |
1120 | const char *rest = UTS_RELEASE; | |
1121 | char buf[65] = { 0 }; | |
1122 | int ndots = 0; | |
1123 | unsigned v; | |
1124 | size_t copy; | |
1125 | ||
1126 | while (*rest) { | |
1127 | if (*rest == '.' && ++ndots >= 3) | |
1128 | break; | |
1129 | if (!isdigit(*rest) && *rest != '.') | |
1130 | break; | |
1131 | rest++; | |
1132 | } | |
1133 | v = ((LINUX_VERSION_CODE >> 8) & 0xff) + 60; | |
1134 | copy = clamp_t(size_t, len, 1, sizeof(buf)); | |
1135 | copy = scnprintf(buf, copy, "2.6.%u%s", v, rest); | |
1136 | ret = copy_to_user(release, buf, copy + 1); | |
1137 | } | |
1138 | return ret; | |
1139 | } | |
1140 | ||
1141 | SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name) | |
1142 | { | |
1143 | int errno = 0; | |
1144 | ||
1145 | down_read(&uts_sem); | |
1146 | if (copy_to_user(name, utsname(), sizeof *name)) | |
1147 | errno = -EFAULT; | |
1148 | up_read(&uts_sem); | |
1149 | ||
1150 | if (!errno && override_release(name->release, sizeof(name->release))) | |
1151 | errno = -EFAULT; | |
1152 | if (!errno && override_architecture(name)) | |
1153 | errno = -EFAULT; | |
1154 | return errno; | |
1155 | } | |
1156 | ||
1157 | #ifdef __ARCH_WANT_SYS_OLD_UNAME | |
1158 | /* | |
1159 | * Old cruft | |
1160 | */ | |
1161 | SYSCALL_DEFINE1(uname, struct old_utsname __user *, name) | |
1162 | { | |
1163 | int error = 0; | |
1164 | ||
1165 | if (!name) | |
1166 | return -EFAULT; | |
1167 | ||
1168 | down_read(&uts_sem); | |
1169 | if (copy_to_user(name, utsname(), sizeof(*name))) | |
1170 | error = -EFAULT; | |
1171 | up_read(&uts_sem); | |
1172 | ||
1173 | if (!error && override_release(name->release, sizeof(name->release))) | |
1174 | error = -EFAULT; | |
1175 | if (!error && override_architecture(name)) | |
1176 | error = -EFAULT; | |
1177 | return error; | |
1178 | } | |
1179 | ||
1180 | SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name) | |
1181 | { | |
1182 | int error; | |
1183 | ||
1184 | if (!name) | |
1185 | return -EFAULT; | |
1186 | if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname))) | |
1187 | return -EFAULT; | |
1188 | ||
1189 | down_read(&uts_sem); | |
1190 | error = __copy_to_user(&name->sysname, &utsname()->sysname, | |
1191 | __OLD_UTS_LEN); | |
1192 | error |= __put_user(0, name->sysname + __OLD_UTS_LEN); | |
1193 | error |= __copy_to_user(&name->nodename, &utsname()->nodename, | |
1194 | __OLD_UTS_LEN); | |
1195 | error |= __put_user(0, name->nodename + __OLD_UTS_LEN); | |
1196 | error |= __copy_to_user(&name->release, &utsname()->release, | |
1197 | __OLD_UTS_LEN); | |
1198 | error |= __put_user(0, name->release + __OLD_UTS_LEN); | |
1199 | error |= __copy_to_user(&name->version, &utsname()->version, | |
1200 | __OLD_UTS_LEN); | |
1201 | error |= __put_user(0, name->version + __OLD_UTS_LEN); | |
1202 | error |= __copy_to_user(&name->machine, &utsname()->machine, | |
1203 | __OLD_UTS_LEN); | |
1204 | error |= __put_user(0, name->machine + __OLD_UTS_LEN); | |
1205 | up_read(&uts_sem); | |
1206 | ||
1207 | if (!error && override_architecture(name)) | |
1208 | error = -EFAULT; | |
1209 | if (!error && override_release(name->release, sizeof(name->release))) | |
1210 | error = -EFAULT; | |
1211 | return error ? -EFAULT : 0; | |
1212 | } | |
1213 | #endif | |
1214 | ||
1215 | SYSCALL_DEFINE2(sethostname, char __user *, name, int, len) | |
1216 | { | |
1217 | int errno; | |
1218 | char tmp[__NEW_UTS_LEN]; | |
1219 | ||
1220 | if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) | |
1221 | return -EPERM; | |
1222 | ||
1223 | if (len < 0 || len > __NEW_UTS_LEN) | |
1224 | return -EINVAL; | |
1225 | down_write(&uts_sem); | |
1226 | errno = -EFAULT; | |
1227 | if (!copy_from_user(tmp, name, len)) { | |
1228 | struct new_utsname *u = utsname(); | |
1229 | ||
1230 | memcpy(u->nodename, tmp, len); | |
1231 | memset(u->nodename + len, 0, sizeof(u->nodename) - len); | |
1232 | errno = 0; | |
1233 | uts_proc_notify(UTS_PROC_HOSTNAME); | |
1234 | } | |
1235 | up_write(&uts_sem); | |
1236 | return errno; | |
1237 | } | |
1238 | ||
1239 | #ifdef __ARCH_WANT_SYS_GETHOSTNAME | |
1240 | ||
1241 | SYSCALL_DEFINE2(gethostname, char __user *, name, int, len) | |
1242 | { | |
1243 | int i, errno; | |
1244 | struct new_utsname *u; | |
1245 | ||
1246 | if (len < 0) | |
1247 | return -EINVAL; | |
1248 | down_read(&uts_sem); | |
1249 | u = utsname(); | |
1250 | i = 1 + strlen(u->nodename); | |
1251 | if (i > len) | |
1252 | i = len; | |
1253 | errno = 0; | |
1254 | if (copy_to_user(name, u->nodename, i)) | |
1255 | errno = -EFAULT; | |
1256 | up_read(&uts_sem); | |
1257 | return errno; | |
1258 | } | |
1259 | ||
1260 | #endif | |
1261 | ||
1262 | /* | |
1263 | * Only setdomainname; getdomainname can be implemented by calling | |
1264 | * uname() | |
1265 | */ | |
1266 | SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len) | |
1267 | { | |
1268 | int errno; | |
1269 | char tmp[__NEW_UTS_LEN]; | |
1270 | ||
1271 | if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) | |
1272 | return -EPERM; | |
1273 | if (len < 0 || len > __NEW_UTS_LEN) | |
1274 | return -EINVAL; | |
1275 | ||
1276 | down_write(&uts_sem); | |
1277 | errno = -EFAULT; | |
1278 | if (!copy_from_user(tmp, name, len)) { | |
1279 | struct new_utsname *u = utsname(); | |
1280 | ||
1281 | memcpy(u->domainname, tmp, len); | |
1282 | memset(u->domainname + len, 0, sizeof(u->domainname) - len); | |
1283 | errno = 0; | |
1284 | uts_proc_notify(UTS_PROC_DOMAINNAME); | |
1285 | } | |
1286 | up_write(&uts_sem); | |
1287 | return errno; | |
1288 | } | |
1289 | ||
1290 | SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim) | |
1291 | { | |
1292 | struct rlimit value; | |
1293 | int ret; | |
1294 | ||
1295 | ret = do_prlimit(current, resource, NULL, &value); | |
1296 | if (!ret) | |
1297 | ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0; | |
1298 | ||
1299 | return ret; | |
1300 | } | |
1301 | ||
1302 | #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT | |
1303 | ||
1304 | /* | |
1305 | * Back compatibility for getrlimit. Needed for some apps. | |
1306 | */ | |
1307 | SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource, | |
1308 | struct rlimit __user *, rlim) | |
1309 | { | |
1310 | struct rlimit x; | |
1311 | if (resource >= RLIM_NLIMITS) | |
1312 | return -EINVAL; | |
1313 | ||
1314 | task_lock(current->group_leader); | |
1315 | x = current->signal->rlim[resource]; | |
1316 | task_unlock(current->group_leader); | |
1317 | if (x.rlim_cur > 0x7FFFFFFF) | |
1318 | x.rlim_cur = 0x7FFFFFFF; | |
1319 | if (x.rlim_max > 0x7FFFFFFF) | |
1320 | x.rlim_max = 0x7FFFFFFF; | |
1321 | return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0; | |
1322 | } | |
1323 | ||
1324 | #endif | |
1325 | ||
1326 | static inline bool rlim64_is_infinity(__u64 rlim64) | |
1327 | { | |
1328 | #if BITS_PER_LONG < 64 | |
1329 | return rlim64 >= ULONG_MAX; | |
1330 | #else | |
1331 | return rlim64 == RLIM64_INFINITY; | |
1332 | #endif | |
1333 | } | |
1334 | ||
1335 | static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64) | |
1336 | { | |
1337 | if (rlim->rlim_cur == RLIM_INFINITY) | |
1338 | rlim64->rlim_cur = RLIM64_INFINITY; | |
1339 | else | |
1340 | rlim64->rlim_cur = rlim->rlim_cur; | |
1341 | if (rlim->rlim_max == RLIM_INFINITY) | |
1342 | rlim64->rlim_max = RLIM64_INFINITY; | |
1343 | else | |
1344 | rlim64->rlim_max = rlim->rlim_max; | |
1345 | } | |
1346 | ||
1347 | static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim) | |
1348 | { | |
1349 | if (rlim64_is_infinity(rlim64->rlim_cur)) | |
1350 | rlim->rlim_cur = RLIM_INFINITY; | |
1351 | else | |
1352 | rlim->rlim_cur = (unsigned long)rlim64->rlim_cur; | |
1353 | if (rlim64_is_infinity(rlim64->rlim_max)) | |
1354 | rlim->rlim_max = RLIM_INFINITY; | |
1355 | else | |
1356 | rlim->rlim_max = (unsigned long)rlim64->rlim_max; | |
1357 | } | |
1358 | ||
1359 | /* make sure you are allowed to change @tsk limits before calling this */ | |
1360 | int do_prlimit(struct task_struct *tsk, unsigned int resource, | |
1361 | struct rlimit *new_rlim, struct rlimit *old_rlim) | |
1362 | { | |
1363 | struct rlimit *rlim; | |
1364 | int retval = 0; | |
1365 | ||
1366 | if (resource >= RLIM_NLIMITS) | |
1367 | return -EINVAL; | |
1368 | if (new_rlim) { | |
1369 | if (new_rlim->rlim_cur > new_rlim->rlim_max) | |
1370 | return -EINVAL; | |
1371 | if (resource == RLIMIT_NOFILE && | |
1372 | new_rlim->rlim_max > sysctl_nr_open) | |
1373 | return -EPERM; | |
1374 | } | |
1375 | ||
1376 | /* protect tsk->signal and tsk->sighand from disappearing */ | |
1377 | read_lock(&tasklist_lock); | |
1378 | if (!tsk->sighand) { | |
1379 | retval = -ESRCH; | |
1380 | goto out; | |
1381 | } | |
1382 | ||
1383 | rlim = tsk->signal->rlim + resource; | |
1384 | task_lock(tsk->group_leader); | |
1385 | if (new_rlim) { | |
1386 | /* Keep the capable check against init_user_ns until | |
1387 | cgroups can contain all limits */ | |
1388 | if (new_rlim->rlim_max > rlim->rlim_max && | |
1389 | !capable(CAP_SYS_RESOURCE)) | |
1390 | retval = -EPERM; | |
1391 | if (!retval) | |
1392 | retval = security_task_setrlimit(tsk->group_leader, | |
1393 | resource, new_rlim); | |
1394 | if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) { | |
1395 | /* | |
1396 | * The caller is asking for an immediate RLIMIT_CPU | |
1397 | * expiry. But we use the zero value to mean "it was | |
1398 | * never set". So let's cheat and make it one second | |
1399 | * instead | |
1400 | */ | |
1401 | new_rlim->rlim_cur = 1; | |
1402 | } | |
1403 | } | |
1404 | if (!retval) { | |
1405 | if (old_rlim) | |
1406 | *old_rlim = *rlim; | |
1407 | if (new_rlim) | |
1408 | *rlim = *new_rlim; | |
1409 | } | |
1410 | task_unlock(tsk->group_leader); | |
1411 | ||
1412 | /* | |
1413 | * RLIMIT_CPU handling. Note that the kernel fails to return an error | |
1414 | * code if it rejected the user's attempt to set RLIMIT_CPU. This is a | |
1415 | * very long-standing error, and fixing it now risks breakage of | |
1416 | * applications, so we live with it | |
1417 | */ | |
1418 | if (!retval && new_rlim && resource == RLIMIT_CPU && | |
1419 | new_rlim->rlim_cur != RLIM_INFINITY) | |
1420 | update_rlimit_cpu(tsk, new_rlim->rlim_cur); | |
1421 | out: | |
1422 | read_unlock(&tasklist_lock); | |
1423 | return retval; | |
1424 | } | |
1425 | ||
1426 | /* rcu lock must be held */ | |
1427 | static int check_prlimit_permission(struct task_struct *task) | |
1428 | { | |
1429 | const struct cred *cred = current_cred(), *tcred; | |
1430 | ||
1431 | if (current == task) | |
1432 | return 0; | |
1433 | ||
1434 | tcred = __task_cred(task); | |
1435 | if (uid_eq(cred->uid, tcred->euid) && | |
1436 | uid_eq(cred->uid, tcred->suid) && | |
1437 | uid_eq(cred->uid, tcred->uid) && | |
1438 | gid_eq(cred->gid, tcred->egid) && | |
1439 | gid_eq(cred->gid, tcred->sgid) && | |
1440 | gid_eq(cred->gid, tcred->gid)) | |
1441 | return 0; | |
1442 | if (ns_capable(tcred->user_ns, CAP_SYS_RESOURCE)) | |
1443 | return 0; | |
1444 | ||
1445 | return -EPERM; | |
1446 | } | |
1447 | ||
1448 | SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource, | |
1449 | const struct rlimit64 __user *, new_rlim, | |
1450 | struct rlimit64 __user *, old_rlim) | |
1451 | { | |
1452 | struct rlimit64 old64, new64; | |
1453 | struct rlimit old, new; | |
1454 | struct task_struct *tsk; | |
1455 | int ret; | |
1456 | ||
1457 | if (new_rlim) { | |
1458 | if (copy_from_user(&new64, new_rlim, sizeof(new64))) | |
1459 | return -EFAULT; | |
1460 | rlim64_to_rlim(&new64, &new); | |
1461 | } | |
1462 | ||
1463 | rcu_read_lock(); | |
1464 | tsk = pid ? find_task_by_vpid(pid) : current; | |
1465 | if (!tsk) { | |
1466 | rcu_read_unlock(); | |
1467 | return -ESRCH; | |
1468 | } | |
1469 | ret = check_prlimit_permission(tsk); | |
1470 | if (ret) { | |
1471 | rcu_read_unlock(); | |
1472 | return ret; | |
1473 | } | |
1474 | get_task_struct(tsk); | |
1475 | rcu_read_unlock(); | |
1476 | ||
1477 | ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL, | |
1478 | old_rlim ? &old : NULL); | |
1479 | ||
1480 | if (!ret && old_rlim) { | |
1481 | rlim_to_rlim64(&old, &old64); | |
1482 | if (copy_to_user(old_rlim, &old64, sizeof(old64))) | |
1483 | ret = -EFAULT; | |
1484 | } | |
1485 | ||
1486 | put_task_struct(tsk); | |
1487 | return ret; | |
1488 | } | |
1489 | ||
1490 | SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim) | |
1491 | { | |
1492 | struct rlimit new_rlim; | |
1493 | ||
1494 | if (copy_from_user(&new_rlim, rlim, sizeof(*rlim))) | |
1495 | return -EFAULT; | |
1496 | return do_prlimit(current, resource, &new_rlim, NULL); | |
1497 | } | |
1498 | ||
1499 | /* | |
1500 | * It would make sense to put struct rusage in the task_struct, | |
1501 | * except that would make the task_struct be *really big*. After | |
1502 | * task_struct gets moved into malloc'ed memory, it would | |
1503 | * make sense to do this. It will make moving the rest of the information | |
1504 | * a lot simpler! (Which we're not doing right now because we're not | |
1505 | * measuring them yet). | |
1506 | * | |
1507 | * When sampling multiple threads for RUSAGE_SELF, under SMP we might have | |
1508 | * races with threads incrementing their own counters. But since word | |
1509 | * reads are atomic, we either get new values or old values and we don't | |
1510 | * care which for the sums. We always take the siglock to protect reading | |
1511 | * the c* fields from p->signal from races with exit.c updating those | |
1512 | * fields when reaping, so a sample either gets all the additions of a | |
1513 | * given child after it's reaped, or none so this sample is before reaping. | |
1514 | * | |
1515 | * Locking: | |
1516 | * We need to take the siglock for CHILDEREN, SELF and BOTH | |
1517 | * for the cases current multithreaded, non-current single threaded | |
1518 | * non-current multithreaded. Thread traversal is now safe with | |
1519 | * the siglock held. | |
1520 | * Strictly speaking, we donot need to take the siglock if we are current and | |
1521 | * single threaded, as no one else can take our signal_struct away, no one | |
1522 | * else can reap the children to update signal->c* counters, and no one else | |
1523 | * can race with the signal-> fields. If we do not take any lock, the | |
1524 | * signal-> fields could be read out of order while another thread was just | |
1525 | * exiting. So we should place a read memory barrier when we avoid the lock. | |
1526 | * On the writer side, write memory barrier is implied in __exit_signal | |
1527 | * as __exit_signal releases the siglock spinlock after updating the signal-> | |
1528 | * fields. But we don't do this yet to keep things simple. | |
1529 | * | |
1530 | */ | |
1531 | ||
1532 | static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r) | |
1533 | { | |
1534 | r->ru_nvcsw += t->nvcsw; | |
1535 | r->ru_nivcsw += t->nivcsw; | |
1536 | r->ru_minflt += t->min_flt; | |
1537 | r->ru_majflt += t->maj_flt; | |
1538 | r->ru_inblock += task_io_get_inblock(t); | |
1539 | r->ru_oublock += task_io_get_oublock(t); | |
1540 | } | |
1541 | ||
1542 | static void k_getrusage(struct task_struct *p, int who, struct rusage *r) | |
1543 | { | |
1544 | struct task_struct *t; | |
1545 | unsigned long flags; | |
1546 | cputime_t tgutime, tgstime, utime, stime; | |
1547 | unsigned long maxrss = 0; | |
1548 | ||
1549 | memset((char *)r, 0, sizeof (*r)); | |
1550 | utime = stime = 0; | |
1551 | ||
1552 | if (who == RUSAGE_THREAD) { | |
1553 | task_cputime_adjusted(current, &utime, &stime); | |
1554 | accumulate_thread_rusage(p, r); | |
1555 | maxrss = p->signal->maxrss; | |
1556 | goto out; | |
1557 | } | |
1558 | ||
1559 | if (!lock_task_sighand(p, &flags)) | |
1560 | return; | |
1561 | ||
1562 | switch (who) { | |
1563 | case RUSAGE_BOTH: | |
1564 | case RUSAGE_CHILDREN: | |
1565 | utime = p->signal->cutime; | |
1566 | stime = p->signal->cstime; | |
1567 | r->ru_nvcsw = p->signal->cnvcsw; | |
1568 | r->ru_nivcsw = p->signal->cnivcsw; | |
1569 | r->ru_minflt = p->signal->cmin_flt; | |
1570 | r->ru_majflt = p->signal->cmaj_flt; | |
1571 | r->ru_inblock = p->signal->cinblock; | |
1572 | r->ru_oublock = p->signal->coublock; | |
1573 | maxrss = p->signal->cmaxrss; | |
1574 | ||
1575 | if (who == RUSAGE_CHILDREN) | |
1576 | break; | |
1577 | ||
1578 | case RUSAGE_SELF: | |
1579 | thread_group_cputime_adjusted(p, &tgutime, &tgstime); | |
1580 | utime += tgutime; | |
1581 | stime += tgstime; | |
1582 | r->ru_nvcsw += p->signal->nvcsw; | |
1583 | r->ru_nivcsw += p->signal->nivcsw; | |
1584 | r->ru_minflt += p->signal->min_flt; | |
1585 | r->ru_majflt += p->signal->maj_flt; | |
1586 | r->ru_inblock += p->signal->inblock; | |
1587 | r->ru_oublock += p->signal->oublock; | |
1588 | if (maxrss < p->signal->maxrss) | |
1589 | maxrss = p->signal->maxrss; | |
1590 | t = p; | |
1591 | do { | |
1592 | accumulate_thread_rusage(t, r); | |
1593 | } while_each_thread(p, t); | |
1594 | break; | |
1595 | ||
1596 | default: | |
1597 | BUG(); | |
1598 | } | |
1599 | unlock_task_sighand(p, &flags); | |
1600 | ||
1601 | out: | |
1602 | cputime_to_timeval(utime, &r->ru_utime); | |
1603 | cputime_to_timeval(stime, &r->ru_stime); | |
1604 | ||
1605 | if (who != RUSAGE_CHILDREN) { | |
1606 | struct mm_struct *mm = get_task_mm(p); | |
1607 | ||
1608 | if (mm) { | |
1609 | setmax_mm_hiwater_rss(&maxrss, mm); | |
1610 | mmput(mm); | |
1611 | } | |
1612 | } | |
1613 | r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ | |
1614 | } | |
1615 | ||
1616 | int getrusage(struct task_struct *p, int who, struct rusage __user *ru) | |
1617 | { | |
1618 | struct rusage r; | |
1619 | ||
1620 | k_getrusage(p, who, &r); | |
1621 | return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0; | |
1622 | } | |
1623 | ||
1624 | SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru) | |
1625 | { | |
1626 | if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && | |
1627 | who != RUSAGE_THREAD) | |
1628 | return -EINVAL; | |
1629 | return getrusage(current, who, ru); | |
1630 | } | |
1631 | ||
1632 | #ifdef CONFIG_COMPAT | |
1633 | COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru) | |
1634 | { | |
1635 | struct rusage r; | |
1636 | ||
1637 | if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && | |
1638 | who != RUSAGE_THREAD) | |
1639 | return -EINVAL; | |
1640 | ||
1641 | k_getrusage(current, who, &r); | |
1642 | return put_compat_rusage(&r, ru); | |
1643 | } | |
1644 | #endif | |
1645 | ||
1646 | SYSCALL_DEFINE1(umask, int, mask) | |
1647 | { | |
1648 | mask = xchg(¤t->fs->umask, mask & S_IRWXUGO); | |
1649 | return mask; | |
1650 | } | |
1651 | ||
1652 | static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd) | |
1653 | { | |
1654 | struct fd exe; | |
1655 | struct file *old_exe, *exe_file; | |
1656 | struct inode *inode; | |
1657 | int err; | |
1658 | ||
1659 | exe = fdget(fd); | |
1660 | if (!exe.file) | |
1661 | return -EBADF; | |
1662 | ||
1663 | inode = file_inode(exe.file); | |
1664 | ||
1665 | /* | |
1666 | * Because the original mm->exe_file points to executable file, make | |
1667 | * sure that this one is executable as well, to avoid breaking an | |
1668 | * overall picture. | |
1669 | */ | |
1670 | err = -EACCES; | |
1671 | if (!S_ISREG(inode->i_mode) || path_noexec(&exe.file->f_path)) | |
1672 | goto exit; | |
1673 | ||
1674 | err = inode_permission(inode, MAY_EXEC); | |
1675 | if (err) | |
1676 | goto exit; | |
1677 | ||
1678 | /* | |
1679 | * Forbid mm->exe_file change if old file still mapped. | |
1680 | */ | |
1681 | exe_file = get_mm_exe_file(mm); | |
1682 | err = -EBUSY; | |
1683 | if (exe_file) { | |
1684 | struct vm_area_struct *vma; | |
1685 | ||
1686 | down_read(&mm->mmap_sem); | |
1687 | for (vma = mm->mmap; vma; vma = vma->vm_next) { | |
1688 | if (!vma->vm_file) | |
1689 | continue; | |
1690 | if (path_equal(&vma->vm_file->f_path, | |
1691 | &exe_file->f_path)) | |
1692 | goto exit_err; | |
1693 | } | |
1694 | ||
1695 | up_read(&mm->mmap_sem); | |
1696 | fput(exe_file); | |
1697 | } | |
1698 | ||
1699 | /* | |
1700 | * The symlink can be changed only once, just to disallow arbitrary | |
1701 | * transitions malicious software might bring in. This means one | |
1702 | * could make a snapshot over all processes running and monitor | |
1703 | * /proc/pid/exe changes to notice unusual activity if needed. | |
1704 | */ | |
1705 | err = -EPERM; | |
1706 | if (test_and_set_bit(MMF_EXE_FILE_CHANGED, &mm->flags)) | |
1707 | goto exit; | |
1708 | ||
1709 | err = 0; | |
1710 | /* set the new file, lockless */ | |
1711 | get_file(exe.file); | |
1712 | old_exe = xchg(&mm->exe_file, exe.file); | |
1713 | if (old_exe) | |
1714 | fput(old_exe); | |
1715 | exit: | |
1716 | fdput(exe); | |
1717 | return err; | |
1718 | exit_err: | |
1719 | up_read(&mm->mmap_sem); | |
1720 | fput(exe_file); | |
1721 | goto exit; | |
1722 | } | |
1723 | ||
1724 | /* | |
1725 | * WARNING: we don't require any capability here so be very careful | |
1726 | * in what is allowed for modification from userspace. | |
1727 | */ | |
1728 | static int validate_prctl_map(struct prctl_mm_map *prctl_map) | |
1729 | { | |
1730 | unsigned long mmap_max_addr = TASK_SIZE; | |
1731 | struct mm_struct *mm = current->mm; | |
1732 | int error = -EINVAL, i; | |
1733 | ||
1734 | static const unsigned char offsets[] = { | |
1735 | offsetof(struct prctl_mm_map, start_code), | |
1736 | offsetof(struct prctl_mm_map, end_code), | |
1737 | offsetof(struct prctl_mm_map, start_data), | |
1738 | offsetof(struct prctl_mm_map, end_data), | |
1739 | offsetof(struct prctl_mm_map, start_brk), | |
1740 | offsetof(struct prctl_mm_map, brk), | |
1741 | offsetof(struct prctl_mm_map, start_stack), | |
1742 | offsetof(struct prctl_mm_map, arg_start), | |
1743 | offsetof(struct prctl_mm_map, arg_end), | |
1744 | offsetof(struct prctl_mm_map, env_start), | |
1745 | offsetof(struct prctl_mm_map, env_end), | |
1746 | }; | |
1747 | ||
1748 | /* | |
1749 | * Make sure the members are not somewhere outside | |
1750 | * of allowed address space. | |
1751 | */ | |
1752 | for (i = 0; i < ARRAY_SIZE(offsets); i++) { | |
1753 | u64 val = *(u64 *)((char *)prctl_map + offsets[i]); | |
1754 | ||
1755 | if ((unsigned long)val >= mmap_max_addr || | |
1756 | (unsigned long)val < mmap_min_addr) | |
1757 | goto out; | |
1758 | } | |
1759 | ||
1760 | /* | |
1761 | * Make sure the pairs are ordered. | |
1762 | */ | |
1763 | #define __prctl_check_order(__m1, __op, __m2) \ | |
1764 | ((unsigned long)prctl_map->__m1 __op \ | |
1765 | (unsigned long)prctl_map->__m2) ? 0 : -EINVAL | |
1766 | error = __prctl_check_order(start_code, <, end_code); | |
1767 | error |= __prctl_check_order(start_data, <, end_data); | |
1768 | error |= __prctl_check_order(start_brk, <=, brk); | |
1769 | error |= __prctl_check_order(arg_start, <=, arg_end); | |
1770 | error |= __prctl_check_order(env_start, <=, env_end); | |
1771 | if (error) | |
1772 | goto out; | |
1773 | #undef __prctl_check_order | |
1774 | ||
1775 | error = -EINVAL; | |
1776 | ||
1777 | /* | |
1778 | * @brk should be after @end_data in traditional maps. | |
1779 | */ | |
1780 | if (prctl_map->start_brk <= prctl_map->end_data || | |
1781 | prctl_map->brk <= prctl_map->end_data) | |
1782 | goto out; | |
1783 | ||
1784 | /* | |
1785 | * Neither we should allow to override limits if they set. | |
1786 | */ | |
1787 | if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk, | |
1788 | prctl_map->start_brk, prctl_map->end_data, | |
1789 | prctl_map->start_data)) | |
1790 | goto out; | |
1791 | ||
1792 | /* | |
1793 | * Someone is trying to cheat the auxv vector. | |
1794 | */ | |
1795 | if (prctl_map->auxv_size) { | |
1796 | if (!prctl_map->auxv || prctl_map->auxv_size > sizeof(mm->saved_auxv)) | |
1797 | goto out; | |
1798 | } | |
1799 | ||
1800 | /* | |
1801 | * Finally, make sure the caller has the rights to | |
1802 | * change /proc/pid/exe link: only local root should | |
1803 | * be allowed to. | |
1804 | */ | |
1805 | if (prctl_map->exe_fd != (u32)-1) { | |
1806 | struct user_namespace *ns = current_user_ns(); | |
1807 | const struct cred *cred = current_cred(); | |
1808 | ||
1809 | if (!uid_eq(cred->uid, make_kuid(ns, 0)) || | |
1810 | !gid_eq(cred->gid, make_kgid(ns, 0))) | |
1811 | goto out; | |
1812 | } | |
1813 | ||
1814 | error = 0; | |
1815 | out: | |
1816 | return error; | |
1817 | } | |
1818 | ||
1819 | #ifdef CONFIG_CHECKPOINT_RESTORE | |
1820 | static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size) | |
1821 | { | |
1822 | struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, }; | |
1823 | unsigned long user_auxv[AT_VECTOR_SIZE]; | |
1824 | struct mm_struct *mm = current->mm; | |
1825 | int error; | |
1826 | ||
1827 | BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv)); | |
1828 | BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256); | |
1829 | ||
1830 | if (opt == PR_SET_MM_MAP_SIZE) | |
1831 | return put_user((unsigned int)sizeof(prctl_map), | |
1832 | (unsigned int __user *)addr); | |
1833 | ||
1834 | if (data_size != sizeof(prctl_map)) | |
1835 | return -EINVAL; | |
1836 | ||
1837 | if (copy_from_user(&prctl_map, addr, sizeof(prctl_map))) | |
1838 | return -EFAULT; | |
1839 | ||
1840 | error = validate_prctl_map(&prctl_map); | |
1841 | if (error) | |
1842 | return error; | |
1843 | ||
1844 | if (prctl_map.auxv_size) { | |
1845 | memset(user_auxv, 0, sizeof(user_auxv)); | |
1846 | if (copy_from_user(user_auxv, | |
1847 | (const void __user *)prctl_map.auxv, | |
1848 | prctl_map.auxv_size)) | |
1849 | return -EFAULT; | |
1850 | ||
1851 | /* Last entry must be AT_NULL as specification requires */ | |
1852 | user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL; | |
1853 | user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL; | |
1854 | } | |
1855 | ||
1856 | if (prctl_map.exe_fd != (u32)-1) | |
1857 | error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd); | |
1858 | down_read(&mm->mmap_sem); | |
1859 | if (error) | |
1860 | goto out; | |
1861 | ||
1862 | /* | |
1863 | * We don't validate if these members are pointing to | |
1864 | * real present VMAs because application may have correspond | |
1865 | * VMAs already unmapped and kernel uses these members for statistics | |
1866 | * output in procfs mostly, except | |
1867 | * | |
1868 | * - @start_brk/@brk which are used in do_brk but kernel lookups | |
1869 | * for VMAs when updating these memvers so anything wrong written | |
1870 | * here cause kernel to swear at userspace program but won't lead | |
1871 | * to any problem in kernel itself | |
1872 | */ | |
1873 | ||
1874 | mm->start_code = prctl_map.start_code; | |
1875 | mm->end_code = prctl_map.end_code; | |
1876 | mm->start_data = prctl_map.start_data; | |
1877 | mm->end_data = prctl_map.end_data; | |
1878 | mm->start_brk = prctl_map.start_brk; | |
1879 | mm->brk = prctl_map.brk; | |
1880 | mm->start_stack = prctl_map.start_stack; | |
1881 | mm->arg_start = prctl_map.arg_start; | |
1882 | mm->arg_end = prctl_map.arg_end; | |
1883 | mm->env_start = prctl_map.env_start; | |
1884 | mm->env_end = prctl_map.env_end; | |
1885 | ||
1886 | /* | |
1887 | * Note this update of @saved_auxv is lockless thus | |
1888 | * if someone reads this member in procfs while we're | |
1889 | * updating -- it may get partly updated results. It's | |
1890 | * known and acceptable trade off: we leave it as is to | |
1891 | * not introduce additional locks here making the kernel | |
1892 | * more complex. | |
1893 | */ | |
1894 | if (prctl_map.auxv_size) | |
1895 | memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv)); | |
1896 | ||
1897 | error = 0; | |
1898 | out: | |
1899 | up_read(&mm->mmap_sem); | |
1900 | return error; | |
1901 | } | |
1902 | #endif /* CONFIG_CHECKPOINT_RESTORE */ | |
1903 | ||
1904 | static int prctl_set_auxv(struct mm_struct *mm, unsigned long addr, | |
1905 | unsigned long len) | |
1906 | { | |
1907 | /* | |
1908 | * This doesn't move the auxiliary vector itself since it's pinned to | |
1909 | * mm_struct, but it permits filling the vector with new values. It's | |
1910 | * up to the caller to provide sane values here, otherwise userspace | |
1911 | * tools which use this vector might be unhappy. | |
1912 | */ | |
1913 | unsigned long user_auxv[AT_VECTOR_SIZE]; | |
1914 | ||
1915 | if (len > sizeof(user_auxv)) | |
1916 | return -EINVAL; | |
1917 | ||
1918 | if (copy_from_user(user_auxv, (const void __user *)addr, len)) | |
1919 | return -EFAULT; | |
1920 | ||
1921 | /* Make sure the last entry is always AT_NULL */ | |
1922 | user_auxv[AT_VECTOR_SIZE - 2] = 0; | |
1923 | user_auxv[AT_VECTOR_SIZE - 1] = 0; | |
1924 | ||
1925 | BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv)); | |
1926 | ||
1927 | task_lock(current); | |
1928 | memcpy(mm->saved_auxv, user_auxv, len); | |
1929 | task_unlock(current); | |
1930 | ||
1931 | return 0; | |
1932 | } | |
1933 | ||
1934 | static int prctl_set_mm(int opt, unsigned long addr, | |
1935 | unsigned long arg4, unsigned long arg5) | |
1936 | { | |
1937 | struct mm_struct *mm = current->mm; | |
1938 | struct prctl_mm_map prctl_map; | |
1939 | struct vm_area_struct *vma; | |
1940 | int error; | |
1941 | ||
1942 | if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV && | |
1943 | opt != PR_SET_MM_MAP && | |
1944 | opt != PR_SET_MM_MAP_SIZE))) | |
1945 | return -EINVAL; | |
1946 | ||
1947 | #ifdef CONFIG_CHECKPOINT_RESTORE | |
1948 | if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE) | |
1949 | return prctl_set_mm_map(opt, (const void __user *)addr, arg4); | |
1950 | #endif | |
1951 | ||
1952 | if (!capable(CAP_SYS_RESOURCE)) | |
1953 | return -EPERM; | |
1954 | ||
1955 | if (opt == PR_SET_MM_EXE_FILE) | |
1956 | return prctl_set_mm_exe_file(mm, (unsigned int)addr); | |
1957 | ||
1958 | if (opt == PR_SET_MM_AUXV) | |
1959 | return prctl_set_auxv(mm, addr, arg4); | |
1960 | ||
1961 | if (addr >= TASK_SIZE || addr < mmap_min_addr) | |
1962 | return -EINVAL; | |
1963 | ||
1964 | error = -EINVAL; | |
1965 | ||
1966 | down_read(&mm->mmap_sem); | |
1967 | vma = find_vma(mm, addr); | |
1968 | ||
1969 | prctl_map.start_code = mm->start_code; | |
1970 | prctl_map.end_code = mm->end_code; | |
1971 | prctl_map.start_data = mm->start_data; | |
1972 | prctl_map.end_data = mm->end_data; | |
1973 | prctl_map.start_brk = mm->start_brk; | |
1974 | prctl_map.brk = mm->brk; | |
1975 | prctl_map.start_stack = mm->start_stack; | |
1976 | prctl_map.arg_start = mm->arg_start; | |
1977 | prctl_map.arg_end = mm->arg_end; | |
1978 | prctl_map.env_start = mm->env_start; | |
1979 | prctl_map.env_end = mm->env_end; | |
1980 | prctl_map.auxv = NULL; | |
1981 | prctl_map.auxv_size = 0; | |
1982 | prctl_map.exe_fd = -1; | |
1983 | ||
1984 | switch (opt) { | |
1985 | case PR_SET_MM_START_CODE: | |
1986 | prctl_map.start_code = addr; | |
1987 | break; | |
1988 | case PR_SET_MM_END_CODE: | |
1989 | prctl_map.end_code = addr; | |
1990 | break; | |
1991 | case PR_SET_MM_START_DATA: | |
1992 | prctl_map.start_data = addr; | |
1993 | break; | |
1994 | case PR_SET_MM_END_DATA: | |
1995 | prctl_map.end_data = addr; | |
1996 | break; | |
1997 | case PR_SET_MM_START_STACK: | |
1998 | prctl_map.start_stack = addr; | |
1999 | break; | |
2000 | case PR_SET_MM_START_BRK: | |
2001 | prctl_map.start_brk = addr; | |
2002 | break; | |
2003 | case PR_SET_MM_BRK: | |
2004 | prctl_map.brk = addr; | |
2005 | break; | |
2006 | case PR_SET_MM_ARG_START: | |
2007 | prctl_map.arg_start = addr; | |
2008 | break; | |
2009 | case PR_SET_MM_ARG_END: | |
2010 | prctl_map.arg_end = addr; | |
2011 | break; | |
2012 | case PR_SET_MM_ENV_START: | |
2013 | prctl_map.env_start = addr; | |
2014 | break; | |
2015 | case PR_SET_MM_ENV_END: | |
2016 | prctl_map.env_end = addr; | |
2017 | break; | |
2018 | default: | |
2019 | goto out; | |
2020 | } | |
2021 | ||
2022 | error = validate_prctl_map(&prctl_map); | |
2023 | if (error) | |
2024 | goto out; | |
2025 | ||
2026 | switch (opt) { | |
2027 | /* | |
2028 | * If command line arguments and environment | |
2029 | * are placed somewhere else on stack, we can | |
2030 | * set them up here, ARG_START/END to setup | |
2031 | * command line argumets and ENV_START/END | |
2032 | * for environment. | |
2033 | */ | |
2034 | case PR_SET_MM_START_STACK: | |
2035 | case PR_SET_MM_ARG_START: | |
2036 | case PR_SET_MM_ARG_END: | |
2037 | case PR_SET_MM_ENV_START: | |
2038 | case PR_SET_MM_ENV_END: | |
2039 | if (!vma) { | |
2040 | error = -EFAULT; | |
2041 | goto out; | |
2042 | } | |
2043 | } | |
2044 | ||
2045 | mm->start_code = prctl_map.start_code; | |
2046 | mm->end_code = prctl_map.end_code; | |
2047 | mm->start_data = prctl_map.start_data; | |
2048 | mm->end_data = prctl_map.end_data; | |
2049 | mm->start_brk = prctl_map.start_brk; | |
2050 | mm->brk = prctl_map.brk; | |
2051 | mm->start_stack = prctl_map.start_stack; | |
2052 | mm->arg_start = prctl_map.arg_start; | |
2053 | mm->arg_end = prctl_map.arg_end; | |
2054 | mm->env_start = prctl_map.env_start; | |
2055 | mm->env_end = prctl_map.env_end; | |
2056 | ||
2057 | error = 0; | |
2058 | out: | |
2059 | up_read(&mm->mmap_sem); | |
2060 | return error; | |
2061 | } | |
2062 | ||
2063 | #ifdef CONFIG_CHECKPOINT_RESTORE | |
2064 | static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr) | |
2065 | { | |
2066 | return put_user(me->clear_child_tid, tid_addr); | |
2067 | } | |
2068 | #else | |
2069 | static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr) | |
2070 | { | |
2071 | return -EINVAL; | |
2072 | } | |
2073 | #endif | |
2074 | ||
2075 | SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, | |
2076 | unsigned long, arg4, unsigned long, arg5) | |
2077 | { | |
2078 | struct task_struct *me = current; | |
2079 | unsigned char comm[sizeof(me->comm)]; | |
2080 | long error; | |
2081 | ||
2082 | error = security_task_prctl(option, arg2, arg3, arg4, arg5); | |
2083 | if (error != -ENOSYS) | |
2084 | return error; | |
2085 | ||
2086 | error = 0; | |
2087 | switch (option) { | |
2088 | case PR_SET_PDEATHSIG: | |
2089 | if (!valid_signal(arg2)) { | |
2090 | error = -EINVAL; | |
2091 | break; | |
2092 | } | |
2093 | me->pdeath_signal = arg2; | |
2094 | break; | |
2095 | case PR_GET_PDEATHSIG: | |
2096 | error = put_user(me->pdeath_signal, (int __user *)arg2); | |
2097 | break; | |
2098 | case PR_GET_DUMPABLE: | |
2099 | error = get_dumpable(me->mm); | |
2100 | break; | |
2101 | case PR_SET_DUMPABLE: | |
2102 | if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) { | |
2103 | error = -EINVAL; | |
2104 | break; | |
2105 | } | |
2106 | set_dumpable(me->mm, arg2); | |
2107 | break; | |
2108 | ||
2109 | case PR_SET_UNALIGN: | |
2110 | error = SET_UNALIGN_CTL(me, arg2); | |
2111 | break; | |
2112 | case PR_GET_UNALIGN: | |
2113 | error = GET_UNALIGN_CTL(me, arg2); | |
2114 | break; | |
2115 | case PR_SET_FPEMU: | |
2116 | error = SET_FPEMU_CTL(me, arg2); | |
2117 | break; | |
2118 | case PR_GET_FPEMU: | |
2119 | error = GET_FPEMU_CTL(me, arg2); | |
2120 | break; | |
2121 | case PR_SET_FPEXC: | |
2122 | error = SET_FPEXC_CTL(me, arg2); | |
2123 | break; | |
2124 | case PR_GET_FPEXC: | |
2125 | error = GET_FPEXC_CTL(me, arg2); | |
2126 | break; | |
2127 | case PR_GET_TIMING: | |
2128 | error = PR_TIMING_STATISTICAL; | |
2129 | break; | |
2130 | case PR_SET_TIMING: | |
2131 | if (arg2 != PR_TIMING_STATISTICAL) | |
2132 | error = -EINVAL; | |
2133 | break; | |
2134 | case PR_SET_NAME: | |
2135 | comm[sizeof(me->comm) - 1] = 0; | |
2136 | if (strncpy_from_user(comm, (char __user *)arg2, | |
2137 | sizeof(me->comm) - 1) < 0) | |
2138 | return -EFAULT; | |
2139 | set_task_comm(me, comm); | |
2140 | proc_comm_connector(me); | |
2141 | break; | |
2142 | case PR_GET_NAME: | |
2143 | get_task_comm(comm, me); | |
2144 | if (copy_to_user((char __user *)arg2, comm, sizeof(comm))) | |
2145 | return -EFAULT; | |
2146 | break; | |
2147 | case PR_GET_ENDIAN: | |
2148 | error = GET_ENDIAN(me, arg2); | |
2149 | break; | |
2150 | case PR_SET_ENDIAN: | |
2151 | error = SET_ENDIAN(me, arg2); | |
2152 | break; | |
2153 | case PR_GET_SECCOMP: | |
2154 | error = prctl_get_seccomp(); | |
2155 | break; | |
2156 | case PR_SET_SECCOMP: | |
2157 | error = prctl_set_seccomp(arg2, (char __user *)arg3); | |
2158 | break; | |
2159 | case PR_GET_TSC: | |
2160 | error = GET_TSC_CTL(arg2); | |
2161 | break; | |
2162 | case PR_SET_TSC: | |
2163 | error = SET_TSC_CTL(arg2); | |
2164 | break; | |
2165 | case PR_TASK_PERF_EVENTS_DISABLE: | |
2166 | error = perf_event_task_disable(); | |
2167 | break; | |
2168 | case PR_TASK_PERF_EVENTS_ENABLE: | |
2169 | error = perf_event_task_enable(); | |
2170 | break; | |
2171 | case PR_GET_TIMERSLACK: | |
2172 | error = current->timer_slack_ns; | |
2173 | break; | |
2174 | case PR_SET_TIMERSLACK: | |
2175 | if (arg2 <= 0) | |
2176 | current->timer_slack_ns = | |
2177 | current->default_timer_slack_ns; | |
2178 | else | |
2179 | current->timer_slack_ns = arg2; | |
2180 | break; | |
2181 | case PR_MCE_KILL: | |
2182 | if (arg4 | arg5) | |
2183 | return -EINVAL; | |
2184 | switch (arg2) { | |
2185 | case PR_MCE_KILL_CLEAR: | |
2186 | if (arg3 != 0) | |
2187 | return -EINVAL; | |
2188 | current->flags &= ~PF_MCE_PROCESS; | |
2189 | break; | |
2190 | case PR_MCE_KILL_SET: | |
2191 | current->flags |= PF_MCE_PROCESS; | |
2192 | if (arg3 == PR_MCE_KILL_EARLY) | |
2193 | current->flags |= PF_MCE_EARLY; | |
2194 | else if (arg3 == PR_MCE_KILL_LATE) | |
2195 | current->flags &= ~PF_MCE_EARLY; | |
2196 | else if (arg3 == PR_MCE_KILL_DEFAULT) | |
2197 | current->flags &= | |
2198 | ~(PF_MCE_EARLY|PF_MCE_PROCESS); | |
2199 | else | |
2200 | return -EINVAL; | |
2201 | break; | |
2202 | default: | |
2203 | return -EINVAL; | |
2204 | } | |
2205 | break; | |
2206 | case PR_MCE_KILL_GET: | |
2207 | if (arg2 | arg3 | arg4 | arg5) | |
2208 | return -EINVAL; | |
2209 | if (current->flags & PF_MCE_PROCESS) | |
2210 | error = (current->flags & PF_MCE_EARLY) ? | |
2211 | PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE; | |
2212 | else | |
2213 | error = PR_MCE_KILL_DEFAULT; | |
2214 | break; | |
2215 | case PR_SET_MM: | |
2216 | error = prctl_set_mm(arg2, arg3, arg4, arg5); | |
2217 | break; | |
2218 | case PR_GET_TID_ADDRESS: | |
2219 | error = prctl_get_tid_address(me, (int __user **)arg2); | |
2220 | break; | |
2221 | case PR_SET_CHILD_SUBREAPER: | |
2222 | me->signal->is_child_subreaper = !!arg2; | |
2223 | break; | |
2224 | case PR_GET_CHILD_SUBREAPER: | |
2225 | error = put_user(me->signal->is_child_subreaper, | |
2226 | (int __user *)arg2); | |
2227 | break; | |
2228 | case PR_SET_NO_NEW_PRIVS: | |
2229 | if (arg2 != 1 || arg3 || arg4 || arg5) | |
2230 | return -EINVAL; | |
2231 | ||
2232 | task_set_no_new_privs(current); | |
2233 | break; | |
2234 | case PR_GET_NO_NEW_PRIVS: | |
2235 | if (arg2 || arg3 || arg4 || arg5) | |
2236 | return -EINVAL; | |
2237 | return task_no_new_privs(current) ? 1 : 0; | |
2238 | case PR_GET_THP_DISABLE: | |
2239 | if (arg2 || arg3 || arg4 || arg5) | |
2240 | return -EINVAL; | |
2241 | error = !!(me->mm->def_flags & VM_NOHUGEPAGE); | |
2242 | break; | |
2243 | case PR_SET_THP_DISABLE: | |
2244 | if (arg3 || arg4 || arg5) | |
2245 | return -EINVAL; | |
2246 | down_write(&me->mm->mmap_sem); | |
2247 | if (arg2) | |
2248 | me->mm->def_flags |= VM_NOHUGEPAGE; | |
2249 | else | |
2250 | me->mm->def_flags &= ~VM_NOHUGEPAGE; | |
2251 | up_write(&me->mm->mmap_sem); | |
2252 | break; | |
2253 | case PR_MPX_ENABLE_MANAGEMENT: | |
2254 | if (arg2 || arg3 || arg4 || arg5) | |
2255 | return -EINVAL; | |
2256 | error = MPX_ENABLE_MANAGEMENT(); | |
2257 | break; | |
2258 | case PR_MPX_DISABLE_MANAGEMENT: | |
2259 | if (arg2 || arg3 || arg4 || arg5) | |
2260 | return -EINVAL; | |
2261 | error = MPX_DISABLE_MANAGEMENT(); | |
2262 | break; | |
2263 | case PR_SET_FP_MODE: | |
2264 | error = SET_FP_MODE(me, arg2); | |
2265 | break; | |
2266 | case PR_GET_FP_MODE: | |
2267 | error = GET_FP_MODE(me); | |
2268 | break; | |
2269 | default: | |
2270 | error = -EINVAL; | |
2271 | break; | |
2272 | } | |
2273 | return error; | |
2274 | } | |
2275 | ||
2276 | SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep, | |
2277 | struct getcpu_cache __user *, unused) | |
2278 | { | |
2279 | int err = 0; | |
2280 | int cpu = raw_smp_processor_id(); | |
2281 | ||
2282 | if (cpup) | |
2283 | err |= put_user(cpu, cpup); | |
2284 | if (nodep) | |
2285 | err |= put_user(cpu_to_node(cpu), nodep); | |
2286 | return err ? -EFAULT : 0; | |
2287 | } | |
2288 | ||
2289 | /** | |
2290 | * do_sysinfo - fill in sysinfo struct | |
2291 | * @info: pointer to buffer to fill | |
2292 | */ | |
2293 | static int do_sysinfo(struct sysinfo *info) | |
2294 | { | |
2295 | unsigned long mem_total, sav_total; | |
2296 | unsigned int mem_unit, bitcount; | |
2297 | struct timespec tp; | |
2298 | ||
2299 | memset(info, 0, sizeof(struct sysinfo)); | |
2300 | ||
2301 | get_monotonic_boottime(&tp); | |
2302 | info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0); | |
2303 | ||
2304 | get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT); | |
2305 | ||
2306 | info->procs = nr_threads; | |
2307 | ||
2308 | si_meminfo(info); | |
2309 | si_swapinfo(info); | |
2310 | ||
2311 | /* | |
2312 | * If the sum of all the available memory (i.e. ram + swap) | |
2313 | * is less than can be stored in a 32 bit unsigned long then | |
2314 | * we can be binary compatible with 2.2.x kernels. If not, | |
2315 | * well, in that case 2.2.x was broken anyways... | |
2316 | * | |
2317 | * -Erik Andersen <andersee@debian.org> | |
2318 | */ | |
2319 | ||
2320 | mem_total = info->totalram + info->totalswap; | |
2321 | if (mem_total < info->totalram || mem_total < info->totalswap) | |
2322 | goto out; | |
2323 | bitcount = 0; | |
2324 | mem_unit = info->mem_unit; | |
2325 | while (mem_unit > 1) { | |
2326 | bitcount++; | |
2327 | mem_unit >>= 1; | |
2328 | sav_total = mem_total; | |
2329 | mem_total <<= 1; | |
2330 | if (mem_total < sav_total) | |
2331 | goto out; | |
2332 | } | |
2333 | ||
2334 | /* | |
2335 | * If mem_total did not overflow, multiply all memory values by | |
2336 | * info->mem_unit and set it to 1. This leaves things compatible | |
2337 | * with 2.2.x, and also retains compatibility with earlier 2.4.x | |
2338 | * kernels... | |
2339 | */ | |
2340 | ||
2341 | info->mem_unit = 1; | |
2342 | info->totalram <<= bitcount; | |
2343 | info->freeram <<= bitcount; | |
2344 | info->sharedram <<= bitcount; | |
2345 | info->bufferram <<= bitcount; | |
2346 | info->totalswap <<= bitcount; | |
2347 | info->freeswap <<= bitcount; | |
2348 | info->totalhigh <<= bitcount; | |
2349 | info->freehigh <<= bitcount; | |
2350 | ||
2351 | out: | |
2352 | return 0; | |
2353 | } | |
2354 | ||
2355 | SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info) | |
2356 | { | |
2357 | struct sysinfo val; | |
2358 | ||
2359 | do_sysinfo(&val); | |
2360 | ||
2361 | if (copy_to_user(info, &val, sizeof(struct sysinfo))) | |
2362 | return -EFAULT; | |
2363 | ||
2364 | return 0; | |
2365 | } | |
2366 | ||
2367 | #ifdef CONFIG_COMPAT | |
2368 | struct compat_sysinfo { | |
2369 | s32 uptime; | |
2370 | u32 loads[3]; | |
2371 | u32 totalram; | |
2372 | u32 freeram; | |
2373 | u32 sharedram; | |
2374 | u32 bufferram; | |
2375 | u32 totalswap; | |
2376 | u32 freeswap; | |
2377 | u16 procs; | |
2378 | u16 pad; | |
2379 | u32 totalhigh; | |
2380 | u32 freehigh; | |
2381 | u32 mem_unit; | |
2382 | char _f[20-2*sizeof(u32)-sizeof(int)]; | |
2383 | }; | |
2384 | ||
2385 | COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info) | |
2386 | { | |
2387 | struct sysinfo s; | |
2388 | ||
2389 | do_sysinfo(&s); | |
2390 | ||
2391 | /* Check to see if any memory value is too large for 32-bit and scale | |
2392 | * down if needed | |
2393 | */ | |
2394 | if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) { | |
2395 | int bitcount = 0; | |
2396 | ||
2397 | while (s.mem_unit < PAGE_SIZE) { | |
2398 | s.mem_unit <<= 1; | |
2399 | bitcount++; | |
2400 | } | |
2401 | ||
2402 | s.totalram >>= bitcount; | |
2403 | s.freeram >>= bitcount; | |
2404 | s.sharedram >>= bitcount; | |
2405 | s.bufferram >>= bitcount; | |
2406 | s.totalswap >>= bitcount; | |
2407 | s.freeswap >>= bitcount; | |
2408 | s.totalhigh >>= bitcount; | |
2409 | s.freehigh >>= bitcount; | |
2410 | } | |
2411 | ||
2412 | if (!access_ok(VERIFY_WRITE, info, sizeof(struct compat_sysinfo)) || | |
2413 | __put_user(s.uptime, &info->uptime) || | |
2414 | __put_user(s.loads[0], &info->loads[0]) || | |
2415 | __put_user(s.loads[1], &info->loads[1]) || | |
2416 | __put_user(s.loads[2], &info->loads[2]) || | |
2417 | __put_user(s.totalram, &info->totalram) || | |
2418 | __put_user(s.freeram, &info->freeram) || | |
2419 | __put_user(s.sharedram, &info->sharedram) || | |
2420 | __put_user(s.bufferram, &info->bufferram) || | |
2421 | __put_user(s.totalswap, &info->totalswap) || | |
2422 | __put_user(s.freeswap, &info->freeswap) || | |
2423 | __put_user(s.procs, &info->procs) || | |
2424 | __put_user(s.totalhigh, &info->totalhigh) || | |
2425 | __put_user(s.freehigh, &info->freehigh) || | |
2426 | __put_user(s.mem_unit, &info->mem_unit)) | |
2427 | return -EFAULT; | |
2428 | ||
2429 | return 0; | |
2430 | } | |
2431 | #endif /* CONFIG_COMPAT */ |