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:
29 * struct stat64 has different sizes and some members are shifted
30 * Compatibility wrappers are needed for them and provided below.
34 * struct flock64 has different sizes and some members are shifted
35 * A compatibility wrapper is needed and provided below.
40 * struct statfs64 has extra padding with EABI growing its size from
41 * 84 to 88. This struct is now __attribute__((packed,aligned(4)))
42 * with a small assembly wrapper to force the sz argument to 84 if it is 88
43 * to avoid copying the extra padding over user space unexpecting it.
47 * struct new_utsname has no padding with EABI. No problem there.
52 * struct epoll_event has its second member shifted also affecting the
53 * structure size. Compatibility wrappers are needed and provided below.
59 * struct sembuf loses its padding with EABI. Since arrays of them are
60 * used they have to be copyed to remove the padding. Compatibility wrappers
68 * struct sockaddr_un loses its padding with EABI. Since the size of the
69 * structure is used as a validation test in unix_mkname(), we need to
70 * change the length argument to 110 whenever it is 112. Compatibility
71 * wrappers provided below.
74 #include <linux/syscalls.h>
75 #include <linux/errno.h>
77 #include <linux/fcntl.h>
78 #include <linux/eventpoll.h>
79 #include <linux/sem.h>
80 #include <linux/socket.h>
82 #include <asm/uaccess.h>
84 struct oldabi_stat64 {
85 unsigned long long st_dev;
87 unsigned long __st_ino;
89 unsigned int st_nlink;
94 unsigned long long st_rdev;
98 unsigned long st_blksize;
99 unsigned long long st_blocks;
101 unsigned long st_atime;
102 unsigned long st_atime_nsec;
104 unsigned long st_mtime;
105 unsigned long st_mtime_nsec;
107 unsigned long st_ctime;
108 unsigned long st_ctime_nsec;
110 unsigned long long st_ino;
111 } __attribute__ ((packed,aligned(4)));
113 static long cp_oldabi_stat64(struct kstat *stat,
114 struct oldabi_stat64 __user *statbuf)
116 struct oldabi_stat64 tmp;
118 tmp.st_dev = huge_encode_dev(stat->dev);
120 tmp.__st_ino = stat->ino;
121 tmp.st_mode = stat->mode;
122 tmp.st_nlink = stat->nlink;
123 tmp.st_uid = stat->uid;
124 tmp.st_gid = stat->gid;
125 tmp.st_rdev = huge_encode_dev(stat->rdev);
126 tmp.st_size = stat->size;
127 tmp.st_blocks = stat->blocks;
129 tmp.st_blksize = stat->blksize;
130 tmp.st_atime = stat->atime.tv_sec;
131 tmp.st_atime_nsec = stat->atime.tv_nsec;
132 tmp.st_mtime = stat->mtime.tv_sec;
133 tmp.st_mtime_nsec = stat->mtime.tv_nsec;
134 tmp.st_ctime = stat->ctime.tv_sec;
135 tmp.st_ctime_nsec = stat->ctime.tv_nsec;
136 tmp.st_ino = stat->ino;
137 return copy_to_user(statbuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
140 asmlinkage long sys_oabi_stat64(char __user * filename,
141 struct oldabi_stat64 __user * statbuf)
144 int error = vfs_stat(filename, &stat);
146 error = cp_oldabi_stat64(&stat, statbuf);
150 asmlinkage long sys_oabi_lstat64(char __user * filename,
151 struct oldabi_stat64 __user * statbuf)
154 int error = vfs_lstat(filename, &stat);
156 error = cp_oldabi_stat64(&stat, statbuf);
160 asmlinkage long sys_oabi_fstat64(unsigned long fd,
161 struct oldabi_stat64 __user * statbuf)
164 int error = vfs_fstat(fd, &stat);
166 error = cp_oldabi_stat64(&stat, statbuf);
170 struct oabi_flock64 {
176 } __attribute__ ((packed,aligned(4)));
178 asmlinkage long sys_oabi_fcntl64(unsigned int fd, unsigned int cmd,
181 struct oabi_flock64 user;
182 struct flock64 kernel;
183 mm_segment_t fs = USER_DS; /* initialized to kill a warning */
184 unsigned long local_arg = arg;
191 if (copy_from_user(&user, (struct oabi_flock64 __user *)arg,
194 kernel.l_type = user.l_type;
195 kernel.l_whence = user.l_whence;
196 kernel.l_start = user.l_start;
197 kernel.l_len = user.l_len;
198 kernel.l_pid = user.l_pid;
199 local_arg = (unsigned long)&kernel;
204 ret = sys_fcntl64(fd, cmd, local_arg);
209 user.l_type = kernel.l_type;
210 user.l_whence = kernel.l_whence;
211 user.l_start = kernel.l_start;
212 user.l_len = kernel.l_len;
213 user.l_pid = kernel.l_pid;
214 if (copy_to_user((struct oabi_flock64 __user *)arg,
215 &user, sizeof(user)))
226 struct oabi_epoll_event {
229 } __attribute__ ((packed,aligned(4)));
231 asmlinkage long sys_oabi_epoll_ctl(int epfd, int op, int fd,
232 struct oabi_epoll_event __user *event)
234 struct oabi_epoll_event user;
235 struct epoll_event kernel;
239 if (op == EPOLL_CTL_DEL)
240 return sys_epoll_ctl(epfd, op, fd, NULL);
241 if (copy_from_user(&user, event, sizeof(user)))
243 kernel.events = user.events;
244 kernel.data = user.data;
247 ret = sys_epoll_ctl(epfd, op, fd, &kernel);
252 asmlinkage long sys_oabi_epoll_wait(int epfd,
253 struct oabi_epoll_event __user *events,
254 int maxevents, int timeout)
256 struct epoll_event *kbuf;
260 if (maxevents <= 0 || maxevents > (INT_MAX/sizeof(struct epoll_event)))
262 kbuf = kmalloc(sizeof(*kbuf) * maxevents, GFP_KERNEL);
267 ret = sys_epoll_wait(epfd, kbuf, maxevents, timeout);
270 for (i = 0; i < ret; i++) {
271 __put_user_error(kbuf[i].events, &events->events, err);
272 __put_user_error(kbuf[i].data, &events->data, err);
276 return err ? -EFAULT : ret;
280 unsigned short sem_num;
283 unsigned short __pad;
286 asmlinkage long sys_oabi_semtimedop(int semid,
287 struct oabi_sembuf __user *tsops,
289 const struct timespec __user *timeout)
292 struct timespec local_timeout;
298 sops = kmalloc(sizeof(*sops) * nsops, GFP_KERNEL);
302 for (i = 0; i < nsops; i++) {
303 __get_user_error(sops[i].sem_num, &tsops->sem_num, err);
304 __get_user_error(sops[i].sem_op, &tsops->sem_op, err);
305 __get_user_error(sops[i].sem_flg, &tsops->sem_flg, err);
309 /* copy this as well before changing domain protection */
310 err |= copy_from_user(&local_timeout, timeout, sizeof(*timeout));
311 timeout = &local_timeout;
316 mm_segment_t fs = get_fs();
318 err = sys_semtimedop(semid, sops, nsops, timeout);
325 asmlinkage long sys_oabi_semop(int semid, struct oabi_sembuf __user *tsops,
328 return sys_oabi_semtimedop(semid, tsops, nsops, NULL);
331 extern asmlinkage int sys_ipc(uint call, int first, int second, int third,
332 void __user *ptr, long fifth);
334 asmlinkage int sys_oabi_ipc(uint call, int first, int second, int third,
335 void __user *ptr, long fifth)
337 switch (call & 0xffff) {
339 return sys_oabi_semtimedop(first,
340 (struct oabi_sembuf __user *)ptr,
343 return sys_oabi_semtimedop(first,
344 (struct oabi_sembuf __user *)ptr,
346 (const struct timespec __user *)fifth);
348 return sys_ipc(call, first, second, third, ptr, fifth);
352 asmlinkage long sys_oabi_bind(int fd, struct sockaddr __user *addr, int addrlen)
354 sa_family_t sa_family;
355 if (addrlen == 112 &&
356 get_user(sa_family, &addr->sa_family) == 0 &&
357 sa_family == AF_UNIX)
359 return sys_bind(fd, addr, addrlen);
362 asmlinkage long sys_oabi_connect(int fd, struct sockaddr __user *addr, int addrlen)
364 sa_family_t sa_family;
365 if (addrlen == 112 &&
366 get_user(sa_family, &addr->sa_family) == 0 &&
367 sa_family == AF_UNIX)
369 return sys_connect(fd, addr, addrlen);
372 asmlinkage long sys_oabi_sendto(int fd, void __user *buff,
373 size_t len, unsigned flags,
374 struct sockaddr __user *addr,
377 sa_family_t sa_family;
378 if (addrlen == 112 &&
379 get_user(sa_family, &addr->sa_family) == 0 &&
380 sa_family == AF_UNIX)
382 return sys_sendto(fd, buff, len, flags, addr, addrlen);
385 asmlinkage long sys_oabi_sendmsg(int fd, struct msghdr __user *msg, unsigned flags)
387 struct sockaddr __user *addr;
389 sa_family_t sa_family;
391 get_user(msg_namelen, &msg->msg_namelen) == 0 &&
392 msg_namelen == 112 &&
393 get_user(addr, &msg->msg_name) == 0 &&
394 get_user(sa_family, &addr->sa_family) == 0 &&
395 sa_family == AF_UNIX)
398 * HACK ALERT: there is a limit to how much backward bending
399 * we should do for what is actually a transitional
400 * compatibility layer. This already has known flaws with
401 * a few ioctls that we don't intend to fix. Therefore
402 * consider this blatent hack as another one... and take care
403 * to run for cover. In most cases it will "just work fine".
404 * If it doesn't, well, tough.
406 put_user(110, &msg->msg_namelen);
408 return sys_sendmsg(fd, msg, flags);