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mm: fix exec activate_mm vs TLB shootdown and lazy tlb switching race
[linux/fpc-iii.git] / arch / arm / kernel / sys_oabi-compat.c
bloba87684532327b2959899cf618cd7d72ca480d790
1 /*
2 * arch/arm/kernel/sys_oabi-compat.c
3 *
4 * Compatibility wrappers for syscalls that are used from
5 * old ABI user space binaries with an EABI kernel.
6 *
7 * Author: Nicolas Pitre
8 * Created: Oct 7, 2005
9 * Copyright: MontaVista Software, Inc.
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
14 */
15
16 /*
17 * The legacy ABI and the new ARM EABI have different rules making some
18 * syscalls incompatible especially with structure arguments.
19 * Most notably, Eabi says 64-bit members should be 64-bit aligned instead of
20 * simply word aligned. EABI also pads structures to the size of the largest
21 * member it contains instead of the invariant 32-bit.
22 *
23 * The following syscalls are affected:
24 *
25 * sys_stat64:
26 * sys_lstat64:
27 * sys_fstat64:
28 * sys_fstatat64:
29 *
30 * struct stat64 has different sizes and some members are shifted
31 * Compatibility wrappers are needed for them and provided below.
32 *
33 * sys_fcntl64:
34 *
35 * struct flock64 has different sizes and some members are shifted
36 * A compatibility wrapper is needed and provided below.
37 *
38 * sys_statfs64:
39 * sys_fstatfs64:
40 *
41 * struct statfs64 has extra padding with EABI growing its size from
42 * 84 to 88. This struct is now __attribute__((packed,aligned(4)))
43 * with a small assembly wrapper to force the sz argument to 84 if it is 88
44 * to avoid copying the extra padding over user space unexpecting it.
45 *
46 * sys_newuname:
47 *
48 * struct new_utsname has no padding with EABI. No problem there.
49 *
50 * sys_epoll_ctl:
51 * sys_epoll_wait:
52 *
53 * struct epoll_event has its second member shifted also affecting the
54 * structure size. Compatibility wrappers are needed and provided below.
55 *
56 * sys_ipc:
57 * sys_semop:
58 * sys_semtimedop:
59 *
60 * struct sembuf loses its padding with EABI. Since arrays of them are
61 * used they have to be copyed to remove the padding. Compatibility wrappers
62 * provided below.
63 *
64 * sys_bind:
65 * sys_connect:
66 * sys_sendmsg:
67 * sys_sendto:
68 * sys_socketcall:
69 *
70 * struct sockaddr_un loses its padding with EABI. Since the size of the
71 * structure is used as a validation test in unix_mkname(), we need to
72 * change the length argument to 110 whenever it is 112. Compatibility
73 * wrappers provided below.
74 */
75
76 #include <linux/syscalls.h>
77 #include <linux/errno.h>
78 #include <linux/fs.h>
79 #include <linux/cred.h>
80 #include <linux/fcntl.h>
81 #include <linux/eventpoll.h>
82 #include <linux/sem.h>
83 #include <linux/socket.h>
84 #include <linux/net.h>
85 #include <linux/ipc.h>
86 #include <linux/uaccess.h>
87 #include <linux/slab.h>
88
89 struct oldabi_stat64 {
90 unsigned long long st_dev;
91 unsigned int __pad1;
92 unsigned long __st_ino;
93 unsigned int st_mode;
94 unsigned int st_nlink;
95
96 unsigned long st_uid;
97 unsigned long st_gid;
98
99 unsigned long long st_rdev;
100 unsigned int __pad2;
101
102 long long st_size;
103 unsigned long st_blksize;
104 unsigned long long st_blocks;
105
106 unsigned long st_atime;
107 unsigned long st_atime_nsec;
108
109 unsigned long st_mtime;
110 unsigned long st_mtime_nsec;
111
112 unsigned long st_ctime;
113 unsigned long st_ctime_nsec;
114
115 unsigned long long st_ino;
116 } __attribute__ ((packed,aligned(4)));
117
118 static long cp_oldabi_stat64(struct kstat *stat,
119 struct oldabi_stat64 __user *statbuf)
120 {
121 struct oldabi_stat64 tmp;
122
123 tmp.st_dev = huge_encode_dev(stat->dev);
124 tmp.__pad1 = 0;
125 tmp.__st_ino = stat->ino;
126 tmp.st_mode = stat->mode;
127 tmp.st_nlink = stat->nlink;
128 tmp.st_uid = from_kuid_munged(current_user_ns(), stat->uid);
129 tmp.st_gid = from_kgid_munged(current_user_ns(), stat->gid);
130 tmp.st_rdev = huge_encode_dev(stat->rdev);
131 tmp.st_size = stat->size;
132 tmp.st_blocks = stat->blocks;
133 tmp.__pad2 = 0;
134 tmp.st_blksize = stat->blksize;
135 tmp.st_atime = stat->atime.tv_sec;
136 tmp.st_atime_nsec = stat->atime.tv_nsec;
137 tmp.st_mtime = stat->mtime.tv_sec;
138 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
139 tmp.st_ctime = stat->ctime.tv_sec;
140 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
141 tmp.st_ino = stat->ino;
142 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
143 }
144
145 asmlinkage long sys_oabi_stat64(const char __user * filename,
146 struct oldabi_stat64 __user * statbuf)
147 {
148 struct kstat stat;
149 int error = vfs_stat(filename, &stat);
150 if (!error)
151 error = cp_oldabi_stat64(&stat, statbuf);
152 return error;
153 }
154
155 asmlinkage long sys_oabi_lstat64(const char __user * filename,
156 struct oldabi_stat64 __user * statbuf)
157 {
158 struct kstat stat;
159 int error = vfs_lstat(filename, &stat);
160 if (!error)
161 error = cp_oldabi_stat64(&stat, statbuf);
162 return error;
163 }
164
165 asmlinkage long sys_oabi_fstat64(unsigned long fd,
166 struct oldabi_stat64 __user * statbuf)
167 {
168 struct kstat stat;
169 int error = vfs_fstat(fd, &stat);
170 if (!error)
171 error = cp_oldabi_stat64(&stat, statbuf);
172 return error;
173 }
174
175 asmlinkage long sys_oabi_fstatat64(int dfd,
176 const char __user *filename,
177 struct oldabi_stat64 __user *statbuf,
178 int flag)
179 {
180 struct kstat stat;
181 int error;
182
183 error = vfs_fstatat(dfd, filename, &stat, flag);
184 if (error)
185 return error;
186 return cp_oldabi_stat64(&stat, statbuf);
187 }
188
189 struct oabi_flock64 {
190 short l_type;
191 short l_whence;
192 loff_t l_start;
193 loff_t l_len;
194 pid_t l_pid;
195 } __attribute__ ((packed,aligned(4)));
196
197 static long do_locks(unsigned int fd, unsigned int cmd,
198 unsigned long arg)
199 {
200 struct flock64 kernel;
201 struct oabi_flock64 user;
202 mm_segment_t fs;
203 long ret;
204
205 if (copy_from_user(&user, (struct oabi_flock64 __user *)arg,
206 sizeof(user)))
207 return -EFAULT;
208 kernel.l_type = user.l_type;
209 kernel.l_whence = user.l_whence;
210 kernel.l_start = user.l_start;
211 kernel.l_len = user.l_len;
212 kernel.l_pid = user.l_pid;
213
214 fs = get_fs();
215 set_fs(KERNEL_DS);
216 ret = sys_fcntl64(fd, cmd, (unsigned long)&kernel);
217 set_fs(fs);
218
219 if (!ret && (cmd == F_GETLK64 || cmd == F_OFD_GETLK)) {
220 user.l_type = kernel.l_type;
221 user.l_whence = kernel.l_whence;
222 user.l_start = kernel.l_start;
223 user.l_len = kernel.l_len;
224 user.l_pid = kernel.l_pid;
225 if (copy_to_user((struct oabi_flock64 __user *)arg,
226 &user, sizeof(user)))
227 ret = -EFAULT;
228 }
229 return ret;
230 }
231
232 asmlinkage long sys_oabi_fcntl64(unsigned int fd, unsigned int cmd,
233 unsigned long arg)
234 {
235 switch (cmd) {
236 case F_OFD_GETLK:
237 case F_OFD_SETLK:
238 case F_OFD_SETLKW:
239 case F_GETLK64:
240 case F_SETLK64:
241 case F_SETLKW64:
242 return do_locks(fd, cmd, arg);
243
244 default:
245 return sys_fcntl64(fd, cmd, arg);
246 }
247 }
248
249 struct oabi_epoll_event {
250 __u32 events;
251 __u64 data;
252 } __attribute__ ((packed,aligned(4)));
253
254 asmlinkage long sys_oabi_epoll_ctl(int epfd, int op, int fd,
255 struct oabi_epoll_event __user *event)
256 {
257 struct oabi_epoll_event user;
258 struct epoll_event kernel;
259 mm_segment_t fs;
260 long ret;
261
262 if (op == EPOLL_CTL_DEL)
263 return sys_epoll_ctl(epfd, op, fd, NULL);
264 if (copy_from_user(&user, event, sizeof(user)))
265 return -EFAULT;
266 kernel.events = user.events;
267 kernel.data = user.data;
268 fs = get_fs();
269 set_fs(KERNEL_DS);
270 ret = sys_epoll_ctl(epfd, op, fd, &kernel);
271 set_fs(fs);
272 return ret;
273 }
274
275 asmlinkage long sys_oabi_epoll_wait(int epfd,
276 struct oabi_epoll_event __user *events,
277 int maxevents, int timeout)
278 {
279 struct epoll_event *kbuf;
280 struct oabi_epoll_event e;
281 mm_segment_t fs;
282 long ret, err, i;
283
284 if (maxevents <= 0 ||
285 maxevents > (INT_MAX/sizeof(*kbuf)) ||
286 maxevents > (INT_MAX/sizeof(*events)))
287 return -EINVAL;
288 if (!access_ok(VERIFY_WRITE, events, sizeof(*events) * maxevents))
289 return -EFAULT;
290 kbuf = kmalloc(sizeof(*kbuf) * maxevents, GFP_KERNEL);
291 if (!kbuf)
292 return -ENOMEM;
293 fs = get_fs();
294 set_fs(KERNEL_DS);
295 ret = sys_epoll_wait(epfd, kbuf, maxevents, timeout);
296 set_fs(fs);
297 err = 0;
298 for (i = 0; i < ret; i++) {
299 e.events = kbuf[i].events;
300 e.data = kbuf[i].data;
301 err = __copy_to_user(events, &e, sizeof(e));
302 if (err)
303 break;
304 events++;
305 }
306 kfree(kbuf);
307 return err ? -EFAULT : ret;
308 }
309
310 struct oabi_sembuf {
311 unsigned short sem_num;
312 short sem_op;
313 short sem_flg;
314 unsigned short __pad;
315 };
316
317 asmlinkage long sys_oabi_semtimedop(int semid,
318 struct oabi_sembuf __user *tsops,
319 unsigned nsops,
320 const struct timespec __user *timeout)
321 {
322 struct sembuf *sops;
323 struct timespec local_timeout;
324 long err;
325 int i;
326
327 if (nsops < 1 || nsops > SEMOPM)
328 return -EINVAL;
329 if (!access_ok(VERIFY_READ, tsops, sizeof(*tsops) * nsops))
330 return -EFAULT;
331 sops = kmalloc(sizeof(*sops) * nsops, GFP_KERNEL);
332 if (!sops)
333 return -ENOMEM;
334 err = 0;
335 for (i = 0; i < nsops; i++) {
336 struct oabi_sembuf osb;
337 err |= __copy_from_user(&osb, tsops, sizeof(osb));
338 sops[i].sem_num = osb.sem_num;
339 sops[i].sem_op = osb.sem_op;
340 sops[i].sem_flg = osb.sem_flg;
341 tsops++;
342 }
343 if (timeout) {
344 /* copy this as well before changing domain protection */
345 err |= copy_from_user(&local_timeout, timeout, sizeof(*timeout));
346 timeout = &local_timeout;
347 }
348 if (err) {
349 err = -EFAULT;
350 } else {
351 mm_segment_t fs = get_fs();
352 set_fs(KERNEL_DS);
353 err = sys_semtimedop(semid, sops, nsops, timeout);
354 set_fs(fs);
355 }
356 kfree(sops);
357 return err;
358 }
359
360 asmlinkage long sys_oabi_semop(int semid, struct oabi_sembuf __user *tsops,
361 unsigned nsops)
362 {
363 return sys_oabi_semtimedop(semid, tsops, nsops, NULL);
364 }
365
366 asmlinkage int sys_oabi_ipc(uint call, int first, int second, int third,
367 void __user *ptr, long fifth)
368 {
369 switch (call & 0xffff) {
370 case SEMOP:
371 return sys_oabi_semtimedop(first,
372 (struct oabi_sembuf __user *)ptr,
373 second, NULL);
374 case SEMTIMEDOP:
375 return sys_oabi_semtimedop(first,
376 (struct oabi_sembuf __user *)ptr,
377 second,
378 (const struct timespec __user *)fifth);
379 default:
380 return sys_ipc(call, first, second, third, ptr, fifth);
381 }
382 }
383
384 asmlinkage long sys_oabi_bind(int fd, struct sockaddr __user *addr, int addrlen)
385 {
386 sa_family_t sa_family;
387 if (addrlen == 112 &&
388 get_user(sa_family, &addr->sa_family) == 0 &&
389 sa_family == AF_UNIX)
390 addrlen = 110;
391 return sys_bind(fd, addr, addrlen);
392 }
393
394 asmlinkage long sys_oabi_connect(int fd, struct sockaddr __user *addr, int addrlen)
395 {
396 sa_family_t sa_family;
397 if (addrlen == 112 &&
398 get_user(sa_family, &addr->sa_family) == 0 &&
399 sa_family == AF_UNIX)
400 addrlen = 110;
401 return sys_connect(fd, addr, addrlen);
402 }
403
404 asmlinkage long sys_oabi_sendto(int fd, void __user *buff,
405 size_t len, unsigned flags,
406 struct sockaddr __user *addr,
407 int addrlen)
408 {
409 sa_family_t sa_family;
410 if (addrlen == 112 &&
411 get_user(sa_family, &addr->sa_family) == 0 &&
412 sa_family == AF_UNIX)
413 addrlen = 110;
414 return sys_sendto(fd, buff, len, flags, addr, addrlen);
415 }
416
417 asmlinkage long sys_oabi_sendmsg(int fd, struct user_msghdr __user *msg, unsigned flags)
418 {
419 struct sockaddr __user *addr;
420 int msg_namelen;
421 sa_family_t sa_family;
422 if (msg &&
423 get_user(msg_namelen, &msg->msg_namelen) == 0 &&
424 msg_namelen == 112 &&
425 get_user(addr, &msg->msg_name) == 0 &&
426 get_user(sa_family, &addr->sa_family) == 0 &&
427 sa_family == AF_UNIX)
428 {
429 /*
430 * HACK ALERT: there is a limit to how much backward bending
431 * we should do for what is actually a transitional
432 * compatibility layer. This already has known flaws with
433 * a few ioctls that we don't intend to fix. Therefore
434 * consider this blatent hack as another one... and take care
435 * to run for cover. In most cases it will "just work fine".
436 * If it doesn't, well, tough.
437 */
438 put_user(110, &msg->msg_namelen);
439 }
440 return sys_sendmsg(fd, msg, flags);
441 }
442
443 asmlinkage long sys_oabi_socketcall(int call, unsigned long __user *args)
444 {
445 unsigned long r = -EFAULT, a[6];
446
447 switch (call) {
448 case SYS_BIND:
449 if (copy_from_user(a, args, 3 * sizeof(long)) == 0)
450 r = sys_oabi_bind(a[0], (struct sockaddr __user *)a[1], a[2]);
451 break;
452 case SYS_CONNECT:
453 if (copy_from_user(a, args, 3 * sizeof(long)) == 0)
454 r = sys_oabi_connect(a[0], (struct sockaddr __user *)a[1], a[2]);
455 break;
456 case SYS_SENDTO:
457 if (copy_from_user(a, args, 6 * sizeof(long)) == 0)
458 r = sys_oabi_sendto(a[0], (void __user *)a[1], a[2], a[3],
459 (struct sockaddr __user *)a[4], a[5]);
460 break;
461 case SYS_SENDMSG:
462 if (copy_from_user(a, args, 3 * sizeof(long)) == 0)
463 r = sys_oabi_sendmsg(a[0], (struct user_msghdr __user *)a[1], a[2]);
464 break;
465 default:
466 r = sys_socketcall(call, args);
467 }
468
469 return r;
470 }
Linux with added FPC-III support