projects/linux·blob v4.20 · refs

446 lines · 11.9 KiB

1/*
2 * linux/kernel/compat.c
3 *
4 * Kernel compatibililty routines for e.g. 32 bit syscall support
5 * on 64 bit kernels.
6 *
7 * Copyright (C) 2002-2003 Stephen Rothwell, IBM Corporation
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 */
13
14#include <linux/linkage.h>
15#include <linux/compat.h>
16#include <linux/errno.h>
17#include <linux/time.h>
18#include <linux/signal.h>
19#include <linux/sched.h> /* for MAX_SCHEDULE_TIMEOUT */
20#include <linux/syscalls.h>
21#include <linux/unistd.h>
22#include <linux/security.h>
23#include <linux/timex.h>
24#include <linux/export.h>
25#include <linux/migrate.h>
26#include <linux/posix-timers.h>
27#include <linux/times.h>
28#include <linux/ptrace.h>
29#include <linux/gfp.h>
30
31#include <linux/uaccess.h>
32
33int compat_get_timex(struct timex *txc, const struct compat_timex __user *utp)
34{
35 struct compat_timex tx32;
36
37 memset(txc, 0, sizeof(struct timex));
38 if (copy_from_user(&tx32, utp, sizeof(struct compat_timex)))
39 return -EFAULT;
40
41 txc->modes = tx32.modes;
42 txc->offset = tx32.offset;
43 txc->freq = tx32.freq;
44 txc->maxerror = tx32.maxerror;
45 txc->esterror = tx32.esterror;
46 txc->status = tx32.status;
47 txc->constant = tx32.constant;
48 txc->precision = tx32.precision;
49 txc->tolerance = tx32.tolerance;
50 txc->time.tv_sec = tx32.time.tv_sec;
51 txc->time.tv_usec = tx32.time.tv_usec;
52 txc->tick = tx32.tick;
53 txc->ppsfreq = tx32.ppsfreq;
54 txc->jitter = tx32.jitter;
55 txc->shift = tx32.shift;
56 txc->stabil = tx32.stabil;
57 txc->jitcnt = tx32.jitcnt;
58 txc->calcnt = tx32.calcnt;
59 txc->errcnt = tx32.errcnt;
60 txc->stbcnt = tx32.stbcnt;
61
62 return 0;
63}
64
65int compat_put_timex(struct compat_timex __user *utp, const struct timex *txc)
66{
67 struct compat_timex tx32;
68
69 memset(&tx32, 0, sizeof(struct compat_timex));
70 tx32.modes = txc->modes;
71 tx32.offset = txc->offset;
72 tx32.freq = txc->freq;
73 tx32.maxerror = txc->maxerror;
74 tx32.esterror = txc->esterror;
75 tx32.status = txc->status;
76 tx32.constant = txc->constant;
77 tx32.precision = txc->precision;
78 tx32.tolerance = txc->tolerance;
79 tx32.time.tv_sec = txc->time.tv_sec;
80 tx32.time.tv_usec = txc->time.tv_usec;
81 tx32.tick = txc->tick;
82 tx32.ppsfreq = txc->ppsfreq;
83 tx32.jitter = txc->jitter;
84 tx32.shift = txc->shift;
85 tx32.stabil = txc->stabil;
86 tx32.jitcnt = txc->jitcnt;
87 tx32.calcnt = txc->calcnt;
88 tx32.errcnt = txc->errcnt;
89 tx32.stbcnt = txc->stbcnt;
90 tx32.tai = txc->tai;
91 if (copy_to_user(utp, &tx32, sizeof(struct compat_timex)))
92 return -EFAULT;
93 return 0;
94}
95
96static int __compat_get_timeval(struct timeval *tv, const struct old_timeval32 __user *ctv)
97{
98 return (!access_ok(VERIFY_READ, ctv, sizeof(*ctv)) ||
99 __get_user(tv->tv_sec, &ctv->tv_sec) ||
100 __get_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0;
101}
102
103static int __compat_put_timeval(const struct timeval *tv, struct old_timeval32 __user *ctv)
104{
105 return (!access_ok(VERIFY_WRITE, ctv, sizeof(*ctv)) ||
106 __put_user(tv->tv_sec, &ctv->tv_sec) ||
107 __put_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0;
108}
109
110static int __compat_get_timespec(struct timespec *ts, const struct old_timespec32 __user *cts)
111{
112 return (!access_ok(VERIFY_READ, cts, sizeof(*cts)) ||
113 __get_user(ts->tv_sec, &cts->tv_sec) ||
114 __get_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
115}
116
117static int __compat_put_timespec(const struct timespec *ts, struct old_timespec32 __user *cts)
118{
119 return (!access_ok(VERIFY_WRITE, cts, sizeof(*cts)) ||
120 __put_user(ts->tv_sec, &cts->tv_sec) ||
121 __put_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
122}
123
124int compat_get_timeval(struct timeval *tv, const void __user *utv)
125{
126 if (COMPAT_USE_64BIT_TIME)
127 return copy_from_user(tv, utv, sizeof(*tv)) ? -EFAULT : 0;
128 else
129 return __compat_get_timeval(tv, utv);
130}
131EXPORT_SYMBOL_GPL(compat_get_timeval);
132
133int compat_put_timeval(const struct timeval *tv, void __user *utv)
134{
135 if (COMPAT_USE_64BIT_TIME)
136 return copy_to_user(utv, tv, sizeof(*tv)) ? -EFAULT : 0;
137 else
138 return __compat_put_timeval(tv, utv);
139}
140EXPORT_SYMBOL_GPL(compat_put_timeval);
141
142int compat_get_timespec(struct timespec *ts, const void __user *uts)
143{
144 if (COMPAT_USE_64BIT_TIME)
145 return copy_from_user(ts, uts, sizeof(*ts)) ? -EFAULT : 0;
146 else
147 return __compat_get_timespec(ts, uts);
148}
149EXPORT_SYMBOL_GPL(compat_get_timespec);
150
151int compat_put_timespec(const struct timespec *ts, void __user *uts)
152{
153 if (COMPAT_USE_64BIT_TIME)
154 return copy_to_user(uts, ts, sizeof(*ts)) ? -EFAULT : 0;
155 else
156 return __compat_put_timespec(ts, uts);
157}
158EXPORT_SYMBOL_GPL(compat_put_timespec);
159
160int get_compat_itimerval(struct itimerval *o, const struct compat_itimerval __user *i)
161{
162 struct compat_itimerval v32;
163
164 if (copy_from_user(&v32, i, sizeof(struct compat_itimerval)))
165 return -EFAULT;
166 o->it_interval.tv_sec = v32.it_interval.tv_sec;
167 o->it_interval.tv_usec = v32.it_interval.tv_usec;
168 o->it_value.tv_sec = v32.it_value.tv_sec;
169 o->it_value.tv_usec = v32.it_value.tv_usec;
170 return 0;
171}
172
173int put_compat_itimerval(struct compat_itimerval __user *o, const struct itimerval *i)
174{
175 struct compat_itimerval v32;
176
177 v32.it_interval.tv_sec = i->it_interval.tv_sec;
178 v32.it_interval.tv_usec = i->it_interval.tv_usec;
179 v32.it_value.tv_sec = i->it_value.tv_sec;
180 v32.it_value.tv_usec = i->it_value.tv_usec;
181 return copy_to_user(o, &v32, sizeof(struct compat_itimerval)) ? -EFAULT : 0;
182}
183
184#ifdef __ARCH_WANT_SYS_SIGPROCMASK
185
186/*
187 * sys_sigprocmask SIG_SETMASK sets the first (compat) word of the
188 * blocked set of signals to the supplied signal set
189 */
190static inline void compat_sig_setmask(sigset_t *blocked, compat_sigset_word set)
191{
192 memcpy(blocked->sig, &set, sizeof(set));
193}
194
195COMPAT_SYSCALL_DEFINE3(sigprocmask, int, how,
196 compat_old_sigset_t __user *, nset,
197 compat_old_sigset_t __user *, oset)
198{
199 old_sigset_t old_set, new_set;
200 sigset_t new_blocked;
201
202 old_set = current->blocked.sig[0];
203
204 if (nset) {
205 if (get_user(new_set, nset))
206 return -EFAULT;
207 new_set &= ~(sigmask(SIGKILL) | sigmask(SIGSTOP));
208
209 new_blocked = current->blocked;
210
211 switch (how) {
212 case SIG_BLOCK:
213 sigaddsetmask(&new_blocked, new_set);
214 break;
215 case SIG_UNBLOCK:
216 sigdelsetmask(&new_blocked, new_set);
217 break;
218 case SIG_SETMASK:
219 compat_sig_setmask(&new_blocked, new_set);
220 break;
221 default:
222 return -EINVAL;
223 }
224
225 set_current_blocked(&new_blocked);
226 }
227
228 if (oset) {
229 if (put_user(old_set, oset))
230 return -EFAULT;
231 }
232
233 return 0;
234}
235
236#endif
237
238int put_compat_rusage(const struct rusage *r, struct compat_rusage __user *ru)
239{
240 struct compat_rusage r32;
241 memset(&r32, 0, sizeof(r32));
242 r32.ru_utime.tv_sec = r->ru_utime.tv_sec;
243 r32.ru_utime.tv_usec = r->ru_utime.tv_usec;
244 r32.ru_stime.tv_sec = r->ru_stime.tv_sec;
245 r32.ru_stime.tv_usec = r->ru_stime.tv_usec;
246 r32.ru_maxrss = r->ru_maxrss;
247 r32.ru_ixrss = r->ru_ixrss;
248 r32.ru_idrss = r->ru_idrss;
249 r32.ru_isrss = r->ru_isrss;
250 r32.ru_minflt = r->ru_minflt;
251 r32.ru_majflt = r->ru_majflt;
252 r32.ru_nswap = r->ru_nswap;
253 r32.ru_inblock = r->ru_inblock;
254 r32.ru_oublock = r->ru_oublock;
255 r32.ru_msgsnd = r->ru_msgsnd;
256 r32.ru_msgrcv = r->ru_msgrcv;
257 r32.ru_nsignals = r->ru_nsignals;
258 r32.ru_nvcsw = r->ru_nvcsw;
259 r32.ru_nivcsw = r->ru_nivcsw;
260 if (copy_to_user(ru, &r32, sizeof(r32)))
261 return -EFAULT;
262 return 0;
263}
264
265static int compat_get_user_cpu_mask(compat_ulong_t __user *user_mask_ptr,
266 unsigned len, struct cpumask *new_mask)
267{
268 unsigned long *k;
269
270 if (len < cpumask_size())
271 memset(new_mask, 0, cpumask_size());
272 else if (len > cpumask_size())
273 len = cpumask_size();
274
275 k = cpumask_bits(new_mask);
276 return compat_get_bitmap(k, user_mask_ptr, len * 8);
277}
278
279COMPAT_SYSCALL_DEFINE3(sched_setaffinity, compat_pid_t, pid,
280 unsigned int, len,
281 compat_ulong_t __user *, user_mask_ptr)
282{
283 cpumask_var_t new_mask;
284 int retval;
285
286 if (!alloc_cpumask_var(&new_mask, GFP_KERNEL))
287 return -ENOMEM;
288
289 retval = compat_get_user_cpu_mask(user_mask_ptr, len, new_mask);
290 if (retval)
291 goto out;
292
293 retval = sched_setaffinity(pid, new_mask);
294out:
295 free_cpumask_var(new_mask);
296 return retval;
297}
298
299COMPAT_SYSCALL_DEFINE3(sched_getaffinity, compat_pid_t, pid, unsigned int, len,
300 compat_ulong_t __user *, user_mask_ptr)
301{
302 int ret;
303 cpumask_var_t mask;
304
305 if ((len * BITS_PER_BYTE) < nr_cpu_ids)
306 return -EINVAL;
307 if (len & (sizeof(compat_ulong_t)-1))
308 return -EINVAL;
309
310 if (!alloc_cpumask_var(&mask, GFP_KERNEL))
311 return -ENOMEM;
312
313 ret = sched_getaffinity(pid, mask);
314 if (ret == 0) {
315 unsigned int retlen = min(len, cpumask_size());
316
317 if (compat_put_bitmap(user_mask_ptr, cpumask_bits(mask), retlen * 8))
318 ret = -EFAULT;
319 else
320 ret = retlen;
321 }
322 free_cpumask_var(mask);
323
324 return ret;
325}
326
327/*
328 * We currently only need the following fields from the sigevent
329 * structure: sigev_value, sigev_signo, sig_notify and (sometimes
330 * sigev_notify_thread_id). The others are handled in user mode.
331 * We also assume that copying sigev_value.sival_int is sufficient
332 * to keep all the bits of sigev_value.sival_ptr intact.
333 */
334int get_compat_sigevent(struct sigevent *event,
335 const struct compat_sigevent __user *u_event)
336{
337 memset(event, 0, sizeof(*event));
338 return (!access_ok(VERIFY_READ, u_event, sizeof(*u_event)) ||
339 __get_user(event->sigev_value.sival_int,
340 &u_event->sigev_value.sival_int) ||
341 __get_user(event->sigev_signo, &u_event->sigev_signo) ||
342 __get_user(event->sigev_notify, &u_event->sigev_notify) ||
343 __get_user(event->sigev_notify_thread_id,
344 &u_event->sigev_notify_thread_id))
345 ? -EFAULT : 0;
346}
347
348long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask,
349 unsigned long bitmap_size)
350{
351 unsigned long nr_compat_longs;
352
353 /* align bitmap up to nearest compat_long_t boundary */
354 bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
355 nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
356
357 if (!access_ok(VERIFY_READ, umask, bitmap_size / 8))
358 return -EFAULT;
359
360 user_access_begin();
361 while (nr_compat_longs > 1) {
362 compat_ulong_t l1, l2;
363 unsafe_get_user(l1, umask++, Efault);
364 unsafe_get_user(l2, umask++, Efault);
365 *mask++ = ((unsigned long)l2 << BITS_PER_COMPAT_LONG) | l1;
366 nr_compat_longs -= 2;
367 }
368 if (nr_compat_longs)
369 unsafe_get_user(*mask, umask++, Efault);
370 user_access_end();
371 return 0;
372
373Efault:
374 user_access_end();
375 return -EFAULT;
376}
377
378long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask,
379 unsigned long bitmap_size)
380{
381 unsigned long nr_compat_longs;
382
383 /* align bitmap up to nearest compat_long_t boundary */
384 bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
385 nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
386
387 if (!access_ok(VERIFY_WRITE, umask, bitmap_size / 8))
388 return -EFAULT;
389
390 user_access_begin();
391 while (nr_compat_longs > 1) {
392 unsigned long m = *mask++;
393 unsafe_put_user((compat_ulong_t)m, umask++, Efault);
394 unsafe_put_user(m >> BITS_PER_COMPAT_LONG, umask++, Efault);
395 nr_compat_longs -= 2;
396 }
397 if (nr_compat_longs)
398 unsafe_put_user((compat_ulong_t)*mask, umask++, Efault);
399 user_access_end();
400 return 0;
401Efault:
402 user_access_end();
403 return -EFAULT;
404}
405
406int
407get_compat_sigset(sigset_t *set, const compat_sigset_t __user *compat)
408{
409#ifdef __BIG_ENDIAN
410 compat_sigset_t v;
411 if (copy_from_user(&v, compat, sizeof(compat_sigset_t)))
412 return -EFAULT;
413 switch (_NSIG_WORDS) {
414 case 4: set->sig[3] = v.sig[6] | (((long)v.sig[7]) << 32 );
415 case 3: set->sig[2] = v.sig[4] | (((long)v.sig[5]) << 32 );
416 case 2: set->sig[1] = v.sig[2] | (((long)v.sig[3]) << 32 );
417 case 1: set->sig[0] = v.sig[0] | (((long)v.sig[1]) << 32 );
418 }
419#else
420 if (copy_from_user(set, compat, sizeof(compat_sigset_t)))
421 return -EFAULT;
422#endif
423 return 0;
424}
425EXPORT_SYMBOL_GPL(get_compat_sigset);
426
427/*
428 * Allocate user-space memory for the duration of a single system call,
429 * in order to marshall parameters inside a compat thunk.
430 */
431void __user *compat_alloc_user_space(unsigned long len)
432{
433 void __user *ptr;
434
435 /* If len would occupy more than half of the entire compat space... */
436 if (unlikely(len > (((compat_uptr_t)~0) >> 1)))
437 return NULL;
438
439 ptr = arch_compat_alloc_user_space(len);
440
441 if (unlikely(!access_ok(VERIFY_WRITE, ptr, len)))
442 return NULL;
443
444 return ptr;
445}
446EXPORT_SYMBOL_GPL(compat_alloc_user_space);