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
);