projects/linux·blob v5.2-rc4 · refs

383 lines · 10.1 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/export.h>
24#include <linux/migrate.h>
25#include <linux/posix-timers.h>
26#include <linux/times.h>
27#include <linux/ptrace.h>
28#include <linux/gfp.h>
29
30#include <linux/uaccess.h>
31
32static int __compat_get_timeval(struct timeval *tv, const struct old_timeval32 __user *ctv)
33{
34 return (!access_ok(ctv, sizeof(*ctv)) ||
35 __get_user(tv->tv_sec, &ctv->tv_sec) ||
36 __get_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0;
37}
38
39static int __compat_put_timeval(const struct timeval *tv, struct old_timeval32 __user *ctv)
40{
41 return (!access_ok(ctv, sizeof(*ctv)) ||
42 __put_user(tv->tv_sec, &ctv->tv_sec) ||
43 __put_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0;
44}
45
46static int __compat_get_timespec(struct timespec *ts, const struct old_timespec32 __user *cts)
47{
48 return (!access_ok(cts, sizeof(*cts)) ||
49 __get_user(ts->tv_sec, &cts->tv_sec) ||
50 __get_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
51}
52
53static int __compat_put_timespec(const struct timespec *ts, struct old_timespec32 __user *cts)
54{
55 return (!access_ok(cts, sizeof(*cts)) ||
56 __put_user(ts->tv_sec, &cts->tv_sec) ||
57 __put_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
58}
59
60int compat_get_timeval(struct timeval *tv, const void __user *utv)
61{
62 if (COMPAT_USE_64BIT_TIME)
63 return copy_from_user(tv, utv, sizeof(*tv)) ? -EFAULT : 0;
64 else
65 return __compat_get_timeval(tv, utv);
66}
67EXPORT_SYMBOL_GPL(compat_get_timeval);
68
69int compat_put_timeval(const struct timeval *tv, void __user *utv)
70{
71 if (COMPAT_USE_64BIT_TIME)
72 return copy_to_user(utv, tv, sizeof(*tv)) ? -EFAULT : 0;
73 else
74 return __compat_put_timeval(tv, utv);
75}
76EXPORT_SYMBOL_GPL(compat_put_timeval);
77
78int compat_get_timespec(struct timespec *ts, const void __user *uts)
79{
80 if (COMPAT_USE_64BIT_TIME)
81 return copy_from_user(ts, uts, sizeof(*ts)) ? -EFAULT : 0;
82 else
83 return __compat_get_timespec(ts, uts);
84}
85EXPORT_SYMBOL_GPL(compat_get_timespec);
86
87int compat_put_timespec(const struct timespec *ts, void __user *uts)
88{
89 if (COMPAT_USE_64BIT_TIME)
90 return copy_to_user(uts, ts, sizeof(*ts)) ? -EFAULT : 0;
91 else
92 return __compat_put_timespec(ts, uts);
93}
94EXPORT_SYMBOL_GPL(compat_put_timespec);
95
96int get_compat_itimerval(struct itimerval *o, const struct compat_itimerval __user *i)
97{
98 struct compat_itimerval v32;
99
100 if (copy_from_user(&v32, i, sizeof(struct compat_itimerval)))
101 return -EFAULT;
102 o->it_interval.tv_sec = v32.it_interval.tv_sec;
103 o->it_interval.tv_usec = v32.it_interval.tv_usec;
104 o->it_value.tv_sec = v32.it_value.tv_sec;
105 o->it_value.tv_usec = v32.it_value.tv_usec;
106 return 0;
107}
108
109int put_compat_itimerval(struct compat_itimerval __user *o, const struct itimerval *i)
110{
111 struct compat_itimerval v32;
112
113 v32.it_interval.tv_sec = i->it_interval.tv_sec;
114 v32.it_interval.tv_usec = i->it_interval.tv_usec;
115 v32.it_value.tv_sec = i->it_value.tv_sec;
116 v32.it_value.tv_usec = i->it_value.tv_usec;
117 return copy_to_user(o, &v32, sizeof(struct compat_itimerval)) ? -EFAULT : 0;
118}
119
120#ifdef __ARCH_WANT_SYS_SIGPROCMASK
121
122/*
123 * sys_sigprocmask SIG_SETMASK sets the first (compat) word of the
124 * blocked set of signals to the supplied signal set
125 */
126static inline void compat_sig_setmask(sigset_t *blocked, compat_sigset_word set)
127{
128 memcpy(blocked->sig, &set, sizeof(set));
129}
130
131COMPAT_SYSCALL_DEFINE3(sigprocmask, int, how,
132 compat_old_sigset_t __user *, nset,
133 compat_old_sigset_t __user *, oset)
134{
135 old_sigset_t old_set, new_set;
136 sigset_t new_blocked;
137
138 old_set = current->blocked.sig[0];
139
140 if (nset) {
141 if (get_user(new_set, nset))
142 return -EFAULT;
143 new_set &= ~(sigmask(SIGKILL) | sigmask(SIGSTOP));
144
145 new_blocked = current->blocked;
146
147 switch (how) {
148 case SIG_BLOCK:
149 sigaddsetmask(&new_blocked, new_set);
150 break;
151 case SIG_UNBLOCK:
152 sigdelsetmask(&new_blocked, new_set);
153 break;
154 case SIG_SETMASK:
155 compat_sig_setmask(&new_blocked, new_set);
156 break;
157 default:
158 return -EINVAL;
159 }
160
161 set_current_blocked(&new_blocked);
162 }
163
164 if (oset) {
165 if (put_user(old_set, oset))
166 return -EFAULT;
167 }
168
169 return 0;
170}
171
172#endif
173
174int put_compat_rusage(const struct rusage *r, struct compat_rusage __user *ru)
175{
176 struct compat_rusage r32;
177 memset(&r32, 0, sizeof(r32));
178 r32.ru_utime.tv_sec = r->ru_utime.tv_sec;
179 r32.ru_utime.tv_usec = r->ru_utime.tv_usec;
180 r32.ru_stime.tv_sec = r->ru_stime.tv_sec;
181 r32.ru_stime.tv_usec = r->ru_stime.tv_usec;
182 r32.ru_maxrss = r->ru_maxrss;
183 r32.ru_ixrss = r->ru_ixrss;
184 r32.ru_idrss = r->ru_idrss;
185 r32.ru_isrss = r->ru_isrss;
186 r32.ru_minflt = r->ru_minflt;
187 r32.ru_majflt = r->ru_majflt;
188 r32.ru_nswap = r->ru_nswap;
189 r32.ru_inblock = r->ru_inblock;
190 r32.ru_oublock = r->ru_oublock;
191 r32.ru_msgsnd = r->ru_msgsnd;
192 r32.ru_msgrcv = r->ru_msgrcv;
193 r32.ru_nsignals = r->ru_nsignals;
194 r32.ru_nvcsw = r->ru_nvcsw;
195 r32.ru_nivcsw = r->ru_nivcsw;
196 if (copy_to_user(ru, &r32, sizeof(r32)))
197 return -EFAULT;
198 return 0;
199}
200
201static int compat_get_user_cpu_mask(compat_ulong_t __user *user_mask_ptr,
202 unsigned len, struct cpumask *new_mask)
203{
204 unsigned long *k;
205
206 if (len < cpumask_size())
207 memset(new_mask, 0, cpumask_size());
208 else if (len > cpumask_size())
209 len = cpumask_size();
210
211 k = cpumask_bits(new_mask);
212 return compat_get_bitmap(k, user_mask_ptr, len * 8);
213}
214
215COMPAT_SYSCALL_DEFINE3(sched_setaffinity, compat_pid_t, pid,
216 unsigned int, len,
217 compat_ulong_t __user *, user_mask_ptr)
218{
219 cpumask_var_t new_mask;
220 int retval;
221
222 if (!alloc_cpumask_var(&new_mask, GFP_KERNEL))
223 return -ENOMEM;
224
225 retval = compat_get_user_cpu_mask(user_mask_ptr, len, new_mask);
226 if (retval)
227 goto out;
228
229 retval = sched_setaffinity(pid, new_mask);
230out:
231 free_cpumask_var(new_mask);
232 return retval;
233}
234
235COMPAT_SYSCALL_DEFINE3(sched_getaffinity, compat_pid_t, pid, unsigned int, len,
236 compat_ulong_t __user *, user_mask_ptr)
237{
238 int ret;
239 cpumask_var_t mask;
240
241 if ((len * BITS_PER_BYTE) < nr_cpu_ids)
242 return -EINVAL;
243 if (len & (sizeof(compat_ulong_t)-1))
244 return -EINVAL;
245
246 if (!alloc_cpumask_var(&mask, GFP_KERNEL))
247 return -ENOMEM;
248
249 ret = sched_getaffinity(pid, mask);
250 if (ret == 0) {
251 unsigned int retlen = min(len, cpumask_size());
252
253 if (compat_put_bitmap(user_mask_ptr, cpumask_bits(mask), retlen * 8))
254 ret = -EFAULT;
255 else
256 ret = retlen;
257 }
258 free_cpumask_var(mask);
259
260 return ret;
261}
262
263/*
264 * We currently only need the following fields from the sigevent
265 * structure: sigev_value, sigev_signo, sig_notify and (sometimes
266 * sigev_notify_thread_id). The others are handled in user mode.
267 * We also assume that copying sigev_value.sival_int is sufficient
268 * to keep all the bits of sigev_value.sival_ptr intact.
269 */
270int get_compat_sigevent(struct sigevent *event,
271 const struct compat_sigevent __user *u_event)
272{
273 memset(event, 0, sizeof(*event));
274 return (!access_ok(u_event, sizeof(*u_event)) ||
275 __get_user(event->sigev_value.sival_int,
276 &u_event->sigev_value.sival_int) ||
277 __get_user(event->sigev_signo, &u_event->sigev_signo) ||
278 __get_user(event->sigev_notify, &u_event->sigev_notify) ||
279 __get_user(event->sigev_notify_thread_id,
280 &u_event->sigev_notify_thread_id))
281 ? -EFAULT : 0;
282}
283
284long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask,
285 unsigned long bitmap_size)
286{
287 unsigned long nr_compat_longs;
288
289 /* align bitmap up to nearest compat_long_t boundary */
290 bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
291 nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
292
293 if (!user_access_begin(umask, bitmap_size / 8))
294 return -EFAULT;
295
296 while (nr_compat_longs > 1) {
297 compat_ulong_t l1, l2;
298 unsafe_get_user(l1, umask++, Efault);
299 unsafe_get_user(l2, umask++, Efault);
300 *mask++ = ((unsigned long)l2 << BITS_PER_COMPAT_LONG) | l1;
301 nr_compat_longs -= 2;
302 }
303 if (nr_compat_longs)
304 unsafe_get_user(*mask, umask++, Efault);
305 user_access_end();
306 return 0;
307
308Efault:
309 user_access_end();
310 return -EFAULT;
311}
312
313long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask,
314 unsigned long bitmap_size)
315{
316 unsigned long nr_compat_longs;
317
318 /* align bitmap up to nearest compat_long_t boundary */
319 bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
320 nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
321
322 if (!user_access_begin(umask, bitmap_size / 8))
323 return -EFAULT;
324
325 while (nr_compat_longs > 1) {
326 unsigned long m = *mask++;
327 unsafe_put_user((compat_ulong_t)m, umask++, Efault);
328 unsafe_put_user(m >> BITS_PER_COMPAT_LONG, umask++, Efault);
329 nr_compat_longs -= 2;
330 }
331 if (nr_compat_longs)
332 unsafe_put_user((compat_ulong_t)*mask, umask++, Efault);
333 user_access_end();
334 return 0;
335Efault:
336 user_access_end();
337 return -EFAULT;
338}
339
340int
341get_compat_sigset(sigset_t *set, const compat_sigset_t __user *compat)
342{
343#ifdef __BIG_ENDIAN
344 compat_sigset_t v;
345 if (copy_from_user(&v, compat, sizeof(compat_sigset_t)))
346 return -EFAULT;
347 switch (_NSIG_WORDS) {
348 case 4: set->sig[3] = v.sig[6] | (((long)v.sig[7]) << 32 );
349 /* fall through */
350 case 3: set->sig[2] = v.sig[4] | (((long)v.sig[5]) << 32 );
351 /* fall through */
352 case 2: set->sig[1] = v.sig[2] | (((long)v.sig[3]) << 32 );
353 /* fall through */
354 case 1: set->sig[0] = v.sig[0] | (((long)v.sig[1]) << 32 );
355 }
356#else
357 if (copy_from_user(set, compat, sizeof(compat_sigset_t)))
358 return -EFAULT;
359#endif
360 return 0;
361}
362EXPORT_SYMBOL_GPL(get_compat_sigset);
363
364/*
365 * Allocate user-space memory for the duration of a single system call,
366 * in order to marshall parameters inside a compat thunk.
367 */
368void __user *compat_alloc_user_space(unsigned long len)
369{
370 void __user *ptr;
371
372 /* If len would occupy more than half of the entire compat space... */
373 if (unlikely(len > (((compat_uptr_t)~0) >> 1)))
374 return NULL;
375
376 ptr = arch_compat_alloc_user_space(len);
377
378 if (unlikely(!access_ok(ptr, len)))
379 return NULL;
380
381 return ptr;
382}
383EXPORT_SYMBOL_GPL(compat_alloc_user_space);