2 * arch/arm/kernel/sys_oabi-compat.c
4 * Compatibility wrappers for syscalls that are used from
5 * old ABI user space binaries with an EABI kernel.
7 * Author: Nicolas Pitre
9 * Copyright: MontaVista Software, Inc.
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.
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.
23 * The following syscalls are affected:
30 * struct stat64 has different sizes and some members are shifted
31 * Compatibility wrappers are needed for them and provided below.
35 * struct flock64 has different sizes and some members are shifted
36 * A compatibility wrapper is needed and provided below.
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.
48 * struct new_utsname has no padding with EABI. No problem there.
53 * struct epoll_event has its second member shifted also affecting the
54 * structure size. Compatibility wrappers are needed and provided below.
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
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.
76 #include <linux/syscalls.h>
77 #include <linux/errno.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>
89 struct oldabi_stat64 {
90 unsigned long long st_dev;
92 unsigned long __st_ino;
94 unsigned int st_nlink;
99 unsigned long long st_rdev;
103 unsigned long st_blksize;
104 unsigned long long st_blocks;
106 unsigned long st_atime;
107 unsigned long st_atime_nsec;
109 unsigned long st_mtime;
110 unsigned long st_mtime_nsec;
112 unsigned long st_ctime;
113 unsigned long st_ctime_nsec;
115 unsigned long long st_ino;
116 } __attribute__ ((packed,aligned(4)));
118 static long cp_oldabi_stat64(struct kstat *stat,
119 struct oldabi_stat64 __user *statbuf)
121 struct oldabi_stat64 tmp;
123 tmp.st_dev = huge_encode_dev(stat->dev);
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;
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;
145 asmlinkage long sys_oabi_stat64(const char __user * filename,
146 struct oldabi_stat64 __user * statbuf)
149 int error = vfs_stat(filename, &stat);
151 error = cp_oldabi_stat64(&stat, statbuf);
155 asmlinkage long sys_oabi_lstat64(const char __user * filename,
156 struct oldabi_stat64 __user * statbuf)
159 int error = vfs_lstat(filename, &stat);
161 error = cp_oldabi_stat64(&stat, statbuf);
165 asmlinkage long sys_oabi_fstat64(unsigned long fd,
166 struct oldabi_stat64 __user * statbuf)
169 int error = vfs_fstat(fd, &stat);
171 error = cp_oldabi_stat64(&stat, statbuf);
175 asmlinkage long sys_oabi_fstatat64(int dfd,
176 const char __user *filename,
177 struct oldabi_stat64 __user *statbuf,
183 error = vfs_fstatat(dfd, filename, &stat, flag);
186 return cp_oldabi_stat64(&stat, statbuf);
189 struct oabi_flock64 {
195 } __attribute__ ((packed,aligned(4)));
197 static long do_locks(unsigned int fd, unsigned int cmd,
200 struct flock64 kernel;
201 struct oabi_flock64 user;
205 if (copy_from_user(&user, (struct oabi_flock64 __user *)arg,
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;
216 ret = sys_fcntl64(fd, cmd, (unsigned long)&kernel);
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)))
232 asmlinkage long sys_oabi_fcntl64(unsigned int fd, unsigned int cmd,
242 return do_locks(fd, cmd, arg);
245 return sys_fcntl64(fd, cmd, arg);
249 struct oabi_epoll_event {
252 } __attribute__ ((packed,aligned(4)));
254 asmlinkage long sys_oabi_epoll_ctl(int epfd, int op, int fd,
255 struct oabi_epoll_event __user *event)
257 struct oabi_epoll_event user;
258 struct epoll_event kernel;
262 if (op == EPOLL_CTL_DEL)
263 return sys_epoll_ctl(epfd, op, fd, NULL);
264 if (copy_from_user(&user, event, sizeof(user)))
266 kernel.events = user.events;
267 kernel.data = user.data;
270 ret = sys_epoll_ctl(epfd, op, fd, &kernel);
275 asmlinkage long sys_oabi_epoll_wait(int epfd,
276 struct oabi_epoll_event __user *events,
277 int maxevents, int timeout)
279 struct epoll_event *kbuf;
283 if (maxevents <= 0 ||
284 maxevents > (INT_MAX/sizeof(*kbuf)) ||
285 maxevents > (INT_MAX/sizeof(*events)))
287 if (!access_ok(VERIFY_WRITE, events, sizeof(*events) * maxevents))
289 kbuf = kmalloc(sizeof(*kbuf) * maxevents, GFP_KERNEL);
294 ret = sys_epoll_wait(epfd, kbuf, maxevents, timeout);
297 for (i = 0; i < ret; i++) {
298 __put_user_error(kbuf[i].events, &events->events, err);
299 __put_user_error(kbuf[i].data, &events->data, err);
303 return err ? -EFAULT : ret;
307 unsigned short sem_num;
310 unsigned short __pad;
313 asmlinkage long sys_oabi_semtimedop(int semid,
314 struct oabi_sembuf __user *tsops,
316 const struct timespec __user *timeout)
319 struct timespec local_timeout;
323 if (nsops < 1 || nsops > SEMOPM)
325 if (!access_ok(VERIFY_READ, tsops, sizeof(*tsops) * nsops))
327 sops = kmalloc(sizeof(*sops) * nsops, GFP_KERNEL);
331 for (i = 0; i < nsops; i++) {
332 __get_user_error(sops[i].sem_num, &tsops->sem_num, err);
333 __get_user_error(sops[i].sem_op, &tsops->sem_op, err);
334 __get_user_error(sops[i].sem_flg, &tsops->sem_flg, err);
338 /* copy this as well before changing domain protection */
339 err |= copy_from_user(&local_timeout, timeout, sizeof(*timeout));
340 timeout = &local_timeout;
345 mm_segment_t fs = get_fs();
347 err = sys_semtimedop(semid, sops, nsops, timeout);
354 asmlinkage long sys_oabi_semop(int semid, struct oabi_sembuf __user *tsops,
357 return sys_oabi_semtimedop(semid, tsops, nsops, NULL);
360 asmlinkage int sys_oabi_ipc(uint call, int first, int second, int third,
361 void __user *ptr, long fifth)
363 switch (call & 0xffff) {
365 return sys_oabi_semtimedop(first,
366 (struct oabi_sembuf __user *)ptr,
369 return sys_oabi_semtimedop(first,
370 (struct oabi_sembuf __user *)ptr,
372 (const struct timespec __user *)fifth);
374 return sys_ipc(call, first, second, third, ptr, fifth);
378 asmlinkage long sys_oabi_bind(int fd, struct sockaddr __user *addr, int addrlen)
380 sa_family_t sa_family;
381 if (addrlen == 112 &&
382 get_user(sa_family, &addr->sa_family) == 0 &&
383 sa_family == AF_UNIX)
385 return sys_bind(fd, addr, addrlen);
388 asmlinkage long sys_oabi_connect(int fd, struct sockaddr __user *addr, int addrlen)
390 sa_family_t sa_family;
391 if (addrlen == 112 &&
392 get_user(sa_family, &addr->sa_family) == 0 &&
393 sa_family == AF_UNIX)
395 return sys_connect(fd, addr, addrlen);
398 asmlinkage long sys_oabi_sendto(int fd, void __user *buff,
399 size_t len, unsigned flags,
400 struct sockaddr __user *addr,
403 sa_family_t sa_family;
404 if (addrlen == 112 &&
405 get_user(sa_family, &addr->sa_family) == 0 &&
406 sa_family == AF_UNIX)
408 return sys_sendto(fd, buff, len, flags, addr, addrlen);
411 asmlinkage long sys_oabi_sendmsg(int fd, struct user_msghdr __user *msg, unsigned flags)
413 struct sockaddr __user *addr;
415 sa_family_t sa_family;
417 get_user(msg_namelen, &msg->msg_namelen) == 0 &&
418 msg_namelen == 112 &&
419 get_user(addr, &msg->msg_name) == 0 &&
420 get_user(sa_family, &addr->sa_family) == 0 &&
421 sa_family == AF_UNIX)
424 * HACK ALERT: there is a limit to how much backward bending
425 * we should do for what is actually a transitional
426 * compatibility layer. This already has known flaws with
427 * a few ioctls that we don't intend to fix. Therefore
428 * consider this blatent hack as another one... and take care
429 * to run for cover. In most cases it will "just work fine".
430 * If it doesn't, well, tough.
432 put_user(110, &msg->msg_namelen);
434 return sys_sendmsg(fd, msg, flags);
437 asmlinkage long sys_oabi_socketcall(int call, unsigned long __user *args)
439 unsigned long r = -EFAULT, a[6];
443 if (copy_from_user(a, args, 3 * sizeof(long)) == 0)
444 r = sys_oabi_bind(a[0], (struct sockaddr __user *)a[1], a[2]);
447 if (copy_from_user(a, args, 3 * sizeof(long)) == 0)
448 r = sys_oabi_connect(a[0], (struct sockaddr __user *)a[1], a[2]);
451 if (copy_from_user(a, args, 6 * sizeof(long)) == 0)
452 r = sys_oabi_sendto(a[0], (void __user *)a[1], a[2], a[3],
453 (struct sockaddr __user *)a[4], a[5]);
456 if (copy_from_user(a, args, 3 * sizeof(long)) == 0)
457 r = sys_oabi_sendmsg(a[0], (struct user_msghdr __user *)a[1], a[2]);
460 r = sys_socketcall(call, args);