xref: /linux/arch/s390/kernel/compat_linux.c (revision f2ee442115c9b6219083c019939a9cc0c9abb2f8)
1 /*
2  *  arch/s390x/kernel/linux32.c
3  *
4  *  S390 version
5  *    Copyright (C) 2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
6  *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
7  *               Gerhard Tonn (ton@de.ibm.com)
8  *               Thomas Spatzier (tspat@de.ibm.com)
9  *
10  *  Conversion between 31bit and 64bit native syscalls.
11  *
12  * Heavily inspired by the 32-bit Sparc compat code which is
13  * Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
14  * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
15  *
16  */
17 
18 
19 #include <linux/kernel.h>
20 #include <linux/sched.h>
21 #include <linux/fs.h>
22 #include <linux/mm.h>
23 #include <linux/file.h>
24 #include <linux/signal.h>
25 #include <linux/resource.h>
26 #include <linux/times.h>
27 #include <linux/smp.h>
28 #include <linux/sem.h>
29 #include <linux/msg.h>
30 #include <linux/shm.h>
31 #include <linux/uio.h>
32 #include <linux/quota.h>
33 #include <linux/module.h>
34 #include <linux/poll.h>
35 #include <linux/personality.h>
36 #include <linux/stat.h>
37 #include <linux/filter.h>
38 #include <linux/highmem.h>
39 #include <linux/highuid.h>
40 #include <linux/mman.h>
41 #include <linux/ipv6.h>
42 #include <linux/in.h>
43 #include <linux/icmpv6.h>
44 #include <linux/syscalls.h>
45 #include <linux/sysctl.h>
46 #include <linux/binfmts.h>
47 #include <linux/capability.h>
48 #include <linux/compat.h>
49 #include <linux/vfs.h>
50 #include <linux/ptrace.h>
51 #include <linux/fadvise.h>
52 #include <linux/ipc.h>
53 #include <linux/slab.h>
54 
55 #include <asm/types.h>
56 #include <asm/uaccess.h>
57 
58 #include <net/scm.h>
59 #include <net/sock.h>
60 
61 #include "compat_linux.h"
62 
63 u32 psw32_user_bits = PSW32_MASK_DAT | PSW32_MASK_IO | PSW32_MASK_EXT |
64 		      PSW32_DEFAULT_KEY | PSW32_MASK_BASE | PSW32_MASK_MCHECK |
65 		      PSW32_MASK_PSTATE | PSW32_ASC_HOME;
66 
67 /* For this source file, we want overflow handling. */
68 
69 #undef high2lowuid
70 #undef high2lowgid
71 #undef low2highuid
72 #undef low2highgid
73 #undef SET_UID16
74 #undef SET_GID16
75 #undef NEW_TO_OLD_UID
76 #undef NEW_TO_OLD_GID
77 #undef SET_OLDSTAT_UID
78 #undef SET_OLDSTAT_GID
79 #undef SET_STAT_UID
80 #undef SET_STAT_GID
81 
82 #define high2lowuid(uid) ((uid) > 65535) ? (u16)overflowuid : (u16)(uid)
83 #define high2lowgid(gid) ((gid) > 65535) ? (u16)overflowgid : (u16)(gid)
84 #define low2highuid(uid) ((uid) == (u16)-1) ? (uid_t)-1 : (uid_t)(uid)
85 #define low2highgid(gid) ((gid) == (u16)-1) ? (gid_t)-1 : (gid_t)(gid)
86 #define SET_UID16(var, uid)	var = high2lowuid(uid)
87 #define SET_GID16(var, gid)	var = high2lowgid(gid)
88 #define NEW_TO_OLD_UID(uid)	high2lowuid(uid)
89 #define NEW_TO_OLD_GID(gid)	high2lowgid(gid)
90 #define SET_OLDSTAT_UID(stat, uid)	(stat).st_uid = high2lowuid(uid)
91 #define SET_OLDSTAT_GID(stat, gid)	(stat).st_gid = high2lowgid(gid)
92 #define SET_STAT_UID(stat, uid)		(stat).st_uid = high2lowuid(uid)
93 #define SET_STAT_GID(stat, gid)		(stat).st_gid = high2lowgid(gid)
94 
95 asmlinkage long sys32_chown16(const char __user * filename, u16 user, u16 group)
96 {
97 	return sys_chown(filename, low2highuid(user), low2highgid(group));
98 }
99 
100 asmlinkage long sys32_lchown16(const char __user * filename, u16 user, u16 group)
101 {
102 	return sys_lchown(filename, low2highuid(user), low2highgid(group));
103 }
104 
105 asmlinkage long sys32_fchown16(unsigned int fd, u16 user, u16 group)
106 {
107 	return sys_fchown(fd, low2highuid(user), low2highgid(group));
108 }
109 
110 asmlinkage long sys32_setregid16(u16 rgid, u16 egid)
111 {
112 	return sys_setregid(low2highgid(rgid), low2highgid(egid));
113 }
114 
115 asmlinkage long sys32_setgid16(u16 gid)
116 {
117 	return sys_setgid((gid_t)gid);
118 }
119 
120 asmlinkage long sys32_setreuid16(u16 ruid, u16 euid)
121 {
122 	return sys_setreuid(low2highuid(ruid), low2highuid(euid));
123 }
124 
125 asmlinkage long sys32_setuid16(u16 uid)
126 {
127 	return sys_setuid((uid_t)uid);
128 }
129 
130 asmlinkage long sys32_setresuid16(u16 ruid, u16 euid, u16 suid)
131 {
132 	return sys_setresuid(low2highuid(ruid), low2highuid(euid),
133 		low2highuid(suid));
134 }
135 
136 asmlinkage long sys32_getresuid16(u16 __user *ruid, u16 __user *euid, u16 __user *suid)
137 {
138 	int retval;
139 
140 	if (!(retval = put_user(high2lowuid(current->cred->uid), ruid)) &&
141 	    !(retval = put_user(high2lowuid(current->cred->euid), euid)))
142 		retval = put_user(high2lowuid(current->cred->suid), suid);
143 
144 	return retval;
145 }
146 
147 asmlinkage long sys32_setresgid16(u16 rgid, u16 egid, u16 sgid)
148 {
149 	return sys_setresgid(low2highgid(rgid), low2highgid(egid),
150 		low2highgid(sgid));
151 }
152 
153 asmlinkage long sys32_getresgid16(u16 __user *rgid, u16 __user *egid, u16 __user *sgid)
154 {
155 	int retval;
156 
157 	if (!(retval = put_user(high2lowgid(current->cred->gid), rgid)) &&
158 	    !(retval = put_user(high2lowgid(current->cred->egid), egid)))
159 		retval = put_user(high2lowgid(current->cred->sgid), sgid);
160 
161 	return retval;
162 }
163 
164 asmlinkage long sys32_setfsuid16(u16 uid)
165 {
166 	return sys_setfsuid((uid_t)uid);
167 }
168 
169 asmlinkage long sys32_setfsgid16(u16 gid)
170 {
171 	return sys_setfsgid((gid_t)gid);
172 }
173 
174 static int groups16_to_user(u16 __user *grouplist, struct group_info *group_info)
175 {
176 	int i;
177 	u16 group;
178 
179 	for (i = 0; i < group_info->ngroups; i++) {
180 		group = (u16)GROUP_AT(group_info, i);
181 		if (put_user(group, grouplist+i))
182 			return -EFAULT;
183 	}
184 
185 	return 0;
186 }
187 
188 static int groups16_from_user(struct group_info *group_info, u16 __user *grouplist)
189 {
190 	int i;
191 	u16 group;
192 
193 	for (i = 0; i < group_info->ngroups; i++) {
194 		if (get_user(group, grouplist+i))
195 			return  -EFAULT;
196 		GROUP_AT(group_info, i) = (gid_t)group;
197 	}
198 
199 	return 0;
200 }
201 
202 asmlinkage long sys32_getgroups16(int gidsetsize, u16 __user *grouplist)
203 {
204 	int i;
205 
206 	if (gidsetsize < 0)
207 		return -EINVAL;
208 
209 	get_group_info(current->cred->group_info);
210 	i = current->cred->group_info->ngroups;
211 	if (gidsetsize) {
212 		if (i > gidsetsize) {
213 			i = -EINVAL;
214 			goto out;
215 		}
216 		if (groups16_to_user(grouplist, current->cred->group_info)) {
217 			i = -EFAULT;
218 			goto out;
219 		}
220 	}
221 out:
222 	put_group_info(current->cred->group_info);
223 	return i;
224 }
225 
226 asmlinkage long sys32_setgroups16(int gidsetsize, u16 __user *grouplist)
227 {
228 	struct group_info *group_info;
229 	int retval;
230 
231 	if (!capable(CAP_SETGID))
232 		return -EPERM;
233 	if ((unsigned)gidsetsize > NGROUPS_MAX)
234 		return -EINVAL;
235 
236 	group_info = groups_alloc(gidsetsize);
237 	if (!group_info)
238 		return -ENOMEM;
239 	retval = groups16_from_user(group_info, grouplist);
240 	if (retval) {
241 		put_group_info(group_info);
242 		return retval;
243 	}
244 
245 	retval = set_current_groups(group_info);
246 	put_group_info(group_info);
247 
248 	return retval;
249 }
250 
251 asmlinkage long sys32_getuid16(void)
252 {
253 	return high2lowuid(current->cred->uid);
254 }
255 
256 asmlinkage long sys32_geteuid16(void)
257 {
258 	return high2lowuid(current->cred->euid);
259 }
260 
261 asmlinkage long sys32_getgid16(void)
262 {
263 	return high2lowgid(current->cred->gid);
264 }
265 
266 asmlinkage long sys32_getegid16(void)
267 {
268 	return high2lowgid(current->cred->egid);
269 }
270 
271 /*
272  * sys32_ipc() is the de-multiplexer for the SysV IPC calls in 32bit emulation.
273  *
274  * This is really horribly ugly.
275  */
276 #ifdef CONFIG_SYSVIPC
277 asmlinkage long sys32_ipc(u32 call, int first, int second, int third, u32 ptr)
278 {
279 	if (call >> 16)		/* hack for backward compatibility */
280 		return -EINVAL;
281 
282 	call &= 0xffff;
283 
284 	switch (call) {
285 	case SEMTIMEDOP:
286 		return compat_sys_semtimedop(first, compat_ptr(ptr),
287 					     second, compat_ptr(third));
288 	case SEMOP:
289 		/* struct sembuf is the same on 32 and 64bit :)) */
290 		return sys_semtimedop(first, compat_ptr(ptr),
291 				      second, NULL);
292 	case SEMGET:
293 		return sys_semget(first, second, third);
294 	case SEMCTL:
295 		return compat_sys_semctl(first, second, third,
296 					 compat_ptr(ptr));
297 	case MSGSND:
298 		return compat_sys_msgsnd(first, second, third,
299 					 compat_ptr(ptr));
300 	case MSGRCV:
301 		return compat_sys_msgrcv(first, second, 0, third,
302 					 0, compat_ptr(ptr));
303 	case MSGGET:
304 		return sys_msgget((key_t) first, second);
305 	case MSGCTL:
306 		return compat_sys_msgctl(first, second, compat_ptr(ptr));
307 	case SHMAT:
308 		return compat_sys_shmat(first, second, third,
309 					0, compat_ptr(ptr));
310 	case SHMDT:
311 		return sys_shmdt(compat_ptr(ptr));
312 	case SHMGET:
313 		return sys_shmget(first, (unsigned)second, third);
314 	case SHMCTL:
315 		return compat_sys_shmctl(first, second, compat_ptr(ptr));
316 	}
317 
318 	return -ENOSYS;
319 }
320 #endif
321 
322 asmlinkage long sys32_truncate64(const char __user * path, unsigned long high, unsigned long low)
323 {
324 	if ((int)high < 0)
325 		return -EINVAL;
326 	else
327 		return sys_truncate(path, (high << 32) | low);
328 }
329 
330 asmlinkage long sys32_ftruncate64(unsigned int fd, unsigned long high, unsigned long low)
331 {
332 	if ((int)high < 0)
333 		return -EINVAL;
334 	else
335 		return sys_ftruncate(fd, (high << 32) | low);
336 }
337 
338 asmlinkage long sys32_sched_rr_get_interval(compat_pid_t pid,
339 				struct compat_timespec __user *interval)
340 {
341 	struct timespec t;
342 	int ret;
343 	mm_segment_t old_fs = get_fs ();
344 
345 	set_fs (KERNEL_DS);
346 	ret = sys_sched_rr_get_interval(pid,
347 					(struct timespec __force __user *) &t);
348 	set_fs (old_fs);
349 	if (put_compat_timespec(&t, interval))
350 		return -EFAULT;
351 	return ret;
352 }
353 
354 asmlinkage long sys32_rt_sigprocmask(int how, compat_sigset_t __user *set,
355 			compat_sigset_t __user *oset, size_t sigsetsize)
356 {
357 	sigset_t s;
358 	compat_sigset_t s32;
359 	int ret;
360 	mm_segment_t old_fs = get_fs();
361 
362 	if (set) {
363 		if (copy_from_user (&s32, set, sizeof(compat_sigset_t)))
364 			return -EFAULT;
365 		s.sig[0] = s32.sig[0] | (((long)s32.sig[1]) << 32);
366 	}
367 	set_fs (KERNEL_DS);
368 	ret = sys_rt_sigprocmask(how,
369 				 set ? (sigset_t __force __user *) &s : NULL,
370 				 oset ? (sigset_t __force __user *) &s : NULL,
371 				 sigsetsize);
372 	set_fs (old_fs);
373 	if (ret) return ret;
374 	if (oset) {
375 		s32.sig[1] = (s.sig[0] >> 32);
376 		s32.sig[0] = s.sig[0];
377 		if (copy_to_user (oset, &s32, sizeof(compat_sigset_t)))
378 			return -EFAULT;
379 	}
380 	return 0;
381 }
382 
383 asmlinkage long sys32_rt_sigpending(compat_sigset_t __user *set,
384 				size_t sigsetsize)
385 {
386 	sigset_t s;
387 	compat_sigset_t s32;
388 	int ret;
389 	mm_segment_t old_fs = get_fs();
390 
391 	set_fs (KERNEL_DS);
392 	ret = sys_rt_sigpending((sigset_t __force __user *) &s, sigsetsize);
393 	set_fs (old_fs);
394 	if (!ret) {
395 		s32.sig[1] = (s.sig[0] >> 32);
396 		s32.sig[0] = s.sig[0];
397 		if (copy_to_user (set, &s32, sizeof(compat_sigset_t)))
398 			return -EFAULT;
399 	}
400 	return ret;
401 }
402 
403 asmlinkage long
404 sys32_rt_sigqueueinfo(int pid, int sig, compat_siginfo_t __user *uinfo)
405 {
406 	siginfo_t info;
407 	int ret;
408 	mm_segment_t old_fs = get_fs();
409 
410 	if (copy_siginfo_from_user32(&info, uinfo))
411 		return -EFAULT;
412 	set_fs (KERNEL_DS);
413 	ret = sys_rt_sigqueueinfo(pid, sig, (siginfo_t __force __user *) &info);
414 	set_fs (old_fs);
415 	return ret;
416 }
417 
418 /*
419  * sys32_execve() executes a new program after the asm stub has set
420  * things up for us.  This should basically do what I want it to.
421  */
422 asmlinkage long sys32_execve(const char __user *name, compat_uptr_t __user *argv,
423 			     compat_uptr_t __user *envp)
424 {
425 	struct pt_regs *regs = task_pt_regs(current);
426 	char *filename;
427 	long rc;
428 
429 	filename = getname(name);
430 	rc = PTR_ERR(filename);
431 	if (IS_ERR(filename))
432 		return rc;
433 	rc = compat_do_execve(filename, argv, envp, regs);
434 	if (rc)
435 		goto out;
436 	current->thread.fp_regs.fpc=0;
437 	asm volatile("sfpc %0,0" : : "d" (0));
438 	rc = regs->gprs[2];
439 out:
440 	putname(filename);
441 	return rc;
442 }
443 
444 asmlinkage long sys32_pread64(unsigned int fd, char __user *ubuf,
445 				size_t count, u32 poshi, u32 poslo)
446 {
447 	if ((compat_ssize_t) count < 0)
448 		return -EINVAL;
449 	return sys_pread64(fd, ubuf, count, ((loff_t)AA(poshi) << 32) | AA(poslo));
450 }
451 
452 asmlinkage long sys32_pwrite64(unsigned int fd, const char __user *ubuf,
453 				size_t count, u32 poshi, u32 poslo)
454 {
455 	if ((compat_ssize_t) count < 0)
456 		return -EINVAL;
457 	return sys_pwrite64(fd, ubuf, count, ((loff_t)AA(poshi) << 32) | AA(poslo));
458 }
459 
460 asmlinkage compat_ssize_t sys32_readahead(int fd, u32 offhi, u32 offlo, s32 count)
461 {
462 	return sys_readahead(fd, ((loff_t)AA(offhi) << 32) | AA(offlo), count);
463 }
464 
465 asmlinkage long sys32_sendfile(int out_fd, int in_fd, compat_off_t __user *offset, size_t count)
466 {
467 	mm_segment_t old_fs = get_fs();
468 	int ret;
469 	off_t of;
470 
471 	if (offset && get_user(of, offset))
472 		return -EFAULT;
473 
474 	set_fs(KERNEL_DS);
475 	ret = sys_sendfile(out_fd, in_fd,
476 			   offset ? (off_t __force __user *) &of : NULL, count);
477 	set_fs(old_fs);
478 
479 	if (offset && put_user(of, offset))
480 		return -EFAULT;
481 
482 	return ret;
483 }
484 
485 asmlinkage long sys32_sendfile64(int out_fd, int in_fd,
486 				compat_loff_t __user *offset, s32 count)
487 {
488 	mm_segment_t old_fs = get_fs();
489 	int ret;
490 	loff_t lof;
491 
492 	if (offset && get_user(lof, offset))
493 		return -EFAULT;
494 
495 	set_fs(KERNEL_DS);
496 	ret = sys_sendfile64(out_fd, in_fd,
497 			     offset ? (loff_t __force __user *) &lof : NULL,
498 			     count);
499 	set_fs(old_fs);
500 
501 	if (offset && put_user(lof, offset))
502 		return -EFAULT;
503 
504 	return ret;
505 }
506 
507 struct stat64_emu31 {
508 	unsigned long long  st_dev;
509 	unsigned int    __pad1;
510 #define STAT64_HAS_BROKEN_ST_INO        1
511 	u32             __st_ino;
512 	unsigned int    st_mode;
513 	unsigned int    st_nlink;
514 	u32             st_uid;
515 	u32             st_gid;
516 	unsigned long long  st_rdev;
517 	unsigned int    __pad3;
518 	long            st_size;
519 	u32             st_blksize;
520 	unsigned char   __pad4[4];
521 	u32             __pad5;     /* future possible st_blocks high bits */
522 	u32             st_blocks;  /* Number 512-byte blocks allocated. */
523 	u32             st_atime;
524 	u32             __pad6;
525 	u32             st_mtime;
526 	u32             __pad7;
527 	u32             st_ctime;
528 	u32             __pad8;     /* will be high 32 bits of ctime someday */
529 	unsigned long   st_ino;
530 };
531 
532 static int cp_stat64(struct stat64_emu31 __user *ubuf, struct kstat *stat)
533 {
534 	struct stat64_emu31 tmp;
535 
536 	memset(&tmp, 0, sizeof(tmp));
537 
538 	tmp.st_dev = huge_encode_dev(stat->dev);
539 	tmp.st_ino = stat->ino;
540 	tmp.__st_ino = (u32)stat->ino;
541 	tmp.st_mode = stat->mode;
542 	tmp.st_nlink = (unsigned int)stat->nlink;
543 	tmp.st_uid = stat->uid;
544 	tmp.st_gid = stat->gid;
545 	tmp.st_rdev = huge_encode_dev(stat->rdev);
546 	tmp.st_size = stat->size;
547 	tmp.st_blksize = (u32)stat->blksize;
548 	tmp.st_blocks = (u32)stat->blocks;
549 	tmp.st_atime = (u32)stat->atime.tv_sec;
550 	tmp.st_mtime = (u32)stat->mtime.tv_sec;
551 	tmp.st_ctime = (u32)stat->ctime.tv_sec;
552 
553 	return copy_to_user(ubuf,&tmp,sizeof(tmp)) ? -EFAULT : 0;
554 }
555 
556 asmlinkage long sys32_stat64(const char __user * filename, struct stat64_emu31 __user * statbuf)
557 {
558 	struct kstat stat;
559 	int ret = vfs_stat(filename, &stat);
560 	if (!ret)
561 		ret = cp_stat64(statbuf, &stat);
562 	return ret;
563 }
564 
565 asmlinkage long sys32_lstat64(const char __user * filename, struct stat64_emu31 __user * statbuf)
566 {
567 	struct kstat stat;
568 	int ret = vfs_lstat(filename, &stat);
569 	if (!ret)
570 		ret = cp_stat64(statbuf, &stat);
571 	return ret;
572 }
573 
574 asmlinkage long sys32_fstat64(unsigned long fd, struct stat64_emu31 __user * statbuf)
575 {
576 	struct kstat stat;
577 	int ret = vfs_fstat(fd, &stat);
578 	if (!ret)
579 		ret = cp_stat64(statbuf, &stat);
580 	return ret;
581 }
582 
583 asmlinkage long sys32_fstatat64(unsigned int dfd, const char __user *filename,
584 				struct stat64_emu31 __user* statbuf, int flag)
585 {
586 	struct kstat stat;
587 	int error;
588 
589 	error = vfs_fstatat(dfd, filename, &stat, flag);
590 	if (error)
591 		return error;
592 	return cp_stat64(statbuf, &stat);
593 }
594 
595 /*
596  * Linux/i386 didn't use to be able to handle more than
597  * 4 system call parameters, so these system calls used a memory
598  * block for parameter passing..
599  */
600 
601 struct mmap_arg_struct_emu31 {
602 	compat_ulong_t addr;
603 	compat_ulong_t len;
604 	compat_ulong_t prot;
605 	compat_ulong_t flags;
606 	compat_ulong_t fd;
607 	compat_ulong_t offset;
608 };
609 
610 asmlinkage unsigned long old32_mmap(struct mmap_arg_struct_emu31 __user *arg)
611 {
612 	struct mmap_arg_struct_emu31 a;
613 
614 	if (copy_from_user(&a, arg, sizeof(a)))
615 		return -EFAULT;
616 	if (a.offset & ~PAGE_MASK)
617 		return -EINVAL;
618 	a.addr = (unsigned long) compat_ptr(a.addr);
619 	return sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd,
620 			      a.offset >> PAGE_SHIFT);
621 }
622 
623 asmlinkage long sys32_mmap2(struct mmap_arg_struct_emu31 __user *arg)
624 {
625 	struct mmap_arg_struct_emu31 a;
626 
627 	if (copy_from_user(&a, arg, sizeof(a)))
628 		return -EFAULT;
629 	a.addr = (unsigned long) compat_ptr(a.addr);
630 	return sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset);
631 }
632 
633 asmlinkage long sys32_read(unsigned int fd, char __user * buf, size_t count)
634 {
635 	if ((compat_ssize_t) count < 0)
636 		return -EINVAL;
637 
638 	return sys_read(fd, buf, count);
639 }
640 
641 asmlinkage long sys32_write(unsigned int fd, const char __user * buf, size_t count)
642 {
643 	if ((compat_ssize_t) count < 0)
644 		return -EINVAL;
645 
646 	return sys_write(fd, buf, count);
647 }
648 
649 /*
650  * 31 bit emulation wrapper functions for sys_fadvise64/fadvise64_64.
651  * These need to rewrite the advise values for POSIX_FADV_{DONTNEED,NOREUSE}
652  * because the 31 bit values differ from the 64 bit values.
653  */
654 
655 asmlinkage long
656 sys32_fadvise64(int fd, loff_t offset, size_t len, int advise)
657 {
658 	if (advise == 4)
659 		advise = POSIX_FADV_DONTNEED;
660 	else if (advise == 5)
661 		advise = POSIX_FADV_NOREUSE;
662 	return sys_fadvise64(fd, offset, len, advise);
663 }
664 
665 struct fadvise64_64_args {
666 	int fd;
667 	long long offset;
668 	long long len;
669 	int advice;
670 };
671 
672 asmlinkage long
673 sys32_fadvise64_64(struct fadvise64_64_args __user *args)
674 {
675 	struct fadvise64_64_args a;
676 
677 	if ( copy_from_user(&a, args, sizeof(a)) )
678 		return -EFAULT;
679 	if (a.advice == 4)
680 		a.advice = POSIX_FADV_DONTNEED;
681 	else if (a.advice == 5)
682 		a.advice = POSIX_FADV_NOREUSE;
683 	return sys_fadvise64_64(a.fd, a.offset, a.len, a.advice);
684 }
685