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linux_file64.c revision 1.40
      1 /*	$NetBSD: linux_file64.c,v 1.40 2007/10/19 18:52:11 njoly Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1995, 1998, 2000 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Frank van der Linden and Eric Haszlakiewicz.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *	This product includes software developed by the NetBSD
     21  *	Foundation, Inc. and its contributors.
     22  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  *    contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  * POSSIBILITY OF SUCH DAMAGE.
     37  */
     38 
     39 /*
     40  * Linux 64bit filesystem calls. Used on 32bit archs, not used on 64bit ones.
     41  */
     42 
     43 #include <sys/cdefs.h>
     44 __KERNEL_RCSID(0, "$NetBSD: linux_file64.c,v 1.40 2007/10/19 18:52:11 njoly Exp $");
     45 
     46 #include <sys/param.h>
     47 #include <sys/systm.h>
     48 #include <sys/namei.h>
     49 #include <sys/proc.h>
     50 #include <sys/dirent.h>
     51 #include <sys/file.h>
     52 #include <sys/stat.h>
     53 #include <sys/filedesc.h>
     54 #include <sys/ioctl.h>
     55 #include <sys/kernel.h>
     56 #include <sys/mount.h>
     57 #include <sys/malloc.h>
     58 #include <sys/namei.h>
     59 #include <sys/vfs_syscalls.h>
     60 #include <sys/vnode.h>
     61 #include <sys/tty.h>
     62 #include <sys/conf.h>
     63 
     64 #include <sys/syscallargs.h>
     65 
     66 #include <compat/linux/common/linux_types.h>
     67 #include <compat/linux/common/linux_signal.h>
     68 #include <compat/linux/common/linux_fcntl.h>
     69 #include <compat/linux/common/linux_util.h>
     70 #include <compat/linux/common/linux_machdep.h>
     71 #include <compat/linux/common/linux_dirent.h>
     72 #include <compat/linux/common/linux_ipc.h>
     73 #include <compat/linux/common/linux_sem.h>
     74 
     75 #include <compat/linux/linux_syscallargs.h>
     76 
     77 #ifndef alpha
     78 
     79 # ifndef COMPAT_LINUX32
     80 
     81 static void bsd_to_linux_stat __P((struct stat *, struct linux_stat64 *));
     82 static int linux_do_stat64 __P((struct lwp *, void *, register_t *, int));
     83 
     84 /*
     85  * Convert a NetBSD stat structure to a Linux stat structure.
     86  * Only the order of the fields and the padding in the structure
     87  * is different. linux_fakedev is a machine-dependent function
     88  * which optionally converts device driver major/minor numbers
     89  * (XXX horrible, but what can you do against code that compares
     90  * things against constant major device numbers? sigh)
     91  */
     92 static void
     93 bsd_to_linux_stat(bsp, lsp)
     94 	struct stat *bsp;
     95 	struct linux_stat64 *lsp;
     96 {
     97 	lsp->lst_dev     = linux_fakedev(bsp->st_dev, 0);
     98 	lsp->lst_ino     = bsp->st_ino;
     99 	lsp->lst_mode    = (linux_mode_t)bsp->st_mode;
    100 	if (bsp->st_nlink >= (1 << 15))
    101 		lsp->lst_nlink = (1 << 15) - 1;
    102 	else
    103 		lsp->lst_nlink = (linux_nlink_t)bsp->st_nlink;
    104 	lsp->lst_uid     = bsp->st_uid;
    105 	lsp->lst_gid     = bsp->st_gid;
    106 	lsp->lst_rdev    = linux_fakedev(bsp->st_rdev, 1);
    107 	lsp->lst_size    = bsp->st_size;
    108 	lsp->lst_blksize = bsp->st_blksize;
    109 	lsp->lst_blocks  = bsp->st_blocks;
    110 	lsp->lst_atime   = bsp->st_atime;
    111 	lsp->lst_mtime   = bsp->st_mtime;
    112 	lsp->lst_ctime   = bsp->st_ctime;
    113 #  ifdef LINUX_STAT64_HAS_NSEC
    114 	lsp->lst_atime_nsec   = bsp->st_atimensec;
    115 	lsp->lst_mtime_nsec   = bsp->st_mtimensec;
    116 	lsp->lst_ctime_nsec   = bsp->st_ctimensec;
    117 #  endif
    118 #  if LINUX_STAT64_HAS_BROKEN_ST_INO
    119 	lsp->__lst_ino   = (linux_ino_t) bsp->st_ino;
    120 #  endif
    121 }
    122 
    123 /*
    124  * The stat functions below are plain sailing. stat and lstat are handled
    125  * by one function to avoid code duplication.
    126  */
    127 int
    128 linux_sys_fstat64(l, v, retval)
    129 	struct lwp *l;
    130 	void *v;
    131 	register_t *retval;
    132 {
    133 	struct linux_sys_fstat64_args /* {
    134 		syscallarg(int) fd;
    135 		syscallarg(struct linux_stat64 *) sp;
    136 	} */ *uap = v;
    137 	struct linux_stat64 tmplst;
    138 	struct stat tmpst;
    139 	int error;
    140 
    141 	error = do_sys_fstat(l,  SCARG(uap, fd), &tmpst);
    142 	if (error != 0)
    143 		return error;
    144 
    145 	bsd_to_linux_stat(&tmpst, &tmplst);
    146 
    147 	return copyout(&tmplst, SCARG(uap, sp), sizeof tmplst);
    148 }
    149 
    150 static int
    151 linux_do_stat64(l, v, retval, flags)
    152 	struct lwp *l;
    153 	void *v;
    154 	register_t *retval;
    155 	int flags;
    156 {
    157 	struct linux_stat64 tmplst;
    158 	struct stat tmpst;
    159 	int error;
    160 	struct linux_sys_stat64_args *uap = v;
    161 
    162 	error = do_sys_stat(l, SCARG(uap, path), flags, &tmpst);
    163 	if (error != 0)
    164 		return error;
    165 
    166 	bsd_to_linux_stat(&tmpst, &tmplst);
    167 
    168 	return copyout(&tmplst, SCARG(uap, sp), sizeof tmplst);
    169 }
    170 
    171 int
    172 linux_sys_stat64(l, v, retval)
    173 	struct lwp *l;
    174 	void *v;
    175 	register_t *retval;
    176 {
    177 	struct linux_sys_stat64_args /* {
    178 		syscallarg(const char *) path;
    179 		syscallarg(struct linux_stat64 *) sp;
    180 	} */ *uap = v;
    181 
    182 	return linux_do_stat64(l, uap, retval, FOLLOW);
    183 }
    184 
    185 int
    186 linux_sys_lstat64(l, v, retval)
    187 	struct lwp *l;
    188 	void *v;
    189 	register_t *retval;
    190 {
    191 	struct linux_sys_lstat64_args /* {
    192 		syscallarg(const char *) path;
    193 		syscallarg(struct linux_stat64 *) sp;
    194 	} */ *uap = v;
    195 
    196 	return linux_do_stat64(l, uap, retval, NOFOLLOW);
    197 }
    198 
    199 int
    200 linux_sys_truncate64(l, v, retval)
    201 	struct lwp *l;
    202 	void *v;
    203 	register_t *retval;
    204 {
    205 	struct linux_sys_truncate64_args /* {
    206 		syscallarg(const char *) path;
    207 		syscallarg(off_t) length;
    208 	} */ *uap = v;
    209 	struct sys_truncate_args ta;
    210 
    211 	/* Linux doesn't have the 'pad' pseudo-parameter */
    212 	SCARG(&ta, path) = SCARG(uap, path);
    213 	SCARG(&ta, pad) = 0;
    214 	SCARG(&ta, length) = SCARG(uap, length);
    215 
    216 	return sys_truncate(l, &ta, retval);
    217 }
    218 
    219 int
    220 linux_sys_ftruncate64(l, v, retval)
    221 	struct lwp *l;
    222 	void *v;
    223 	register_t *retval;
    224 {
    225 	struct linux_sys_ftruncate64_args /* {
    226 		syscallarg(unsigned int) fd;
    227 		syscallarg(off_t) length;
    228 	} */ *uap = v;
    229 	struct sys_ftruncate_args ta;
    230 
    231 	/* Linux doesn't have the 'pad' pseudo-parameter */
    232 	SCARG(&ta, fd) = SCARG(uap, fd);
    233 	SCARG(&ta, pad) = 0;
    234 	SCARG(&ta, length) = SCARG(uap, length);
    235 
    236 	return sys_ftruncate(l, &ta, retval);
    237 }
    238 # endif /* !COMPAT_LINUX32 */
    239 
    240 # if !defined(__m68k__) && (!defined(__amd64__) || defined(COMPAT_LINUX32))
    241 static void bsd_to_linux_flock64 __P((struct linux_flock64 *,
    242     const struct flock *));
    243 static void linux_to_bsd_flock64 __P((struct flock *,
    244     const struct linux_flock64 *));
    245 
    246 static void
    247 bsd_to_linux_flock64(lfp, bfp)
    248 	struct linux_flock64 *lfp;
    249 	const struct flock *bfp;
    250 {
    251 
    252 	lfp->l_start = bfp->l_start;
    253 	lfp->l_len = bfp->l_len;
    254 	lfp->l_pid = bfp->l_pid;
    255 	lfp->l_whence = bfp->l_whence;
    256 	switch (bfp->l_type) {
    257 	case F_RDLCK:
    258 		lfp->l_type = LINUX_F_RDLCK;
    259 		break;
    260 	case F_UNLCK:
    261 		lfp->l_type = LINUX_F_UNLCK;
    262 		break;
    263 	case F_WRLCK:
    264 		lfp->l_type = LINUX_F_WRLCK;
    265 		break;
    266 	}
    267 }
    268 
    269 static void
    270 linux_to_bsd_flock64(bfp, lfp)
    271 	struct flock *bfp;
    272 	const struct linux_flock64 *lfp;
    273 {
    274 
    275 	bfp->l_start = lfp->l_start;
    276 	bfp->l_len = lfp->l_len;
    277 	bfp->l_pid = lfp->l_pid;
    278 	bfp->l_whence = lfp->l_whence;
    279 	switch (lfp->l_type) {
    280 	case LINUX_F_RDLCK:
    281 		bfp->l_type = F_RDLCK;
    282 		break;
    283 	case LINUX_F_UNLCK:
    284 		bfp->l_type = F_UNLCK;
    285 		break;
    286 	case LINUX_F_WRLCK:
    287 		bfp->l_type = F_WRLCK;
    288 		break;
    289 	}
    290 }
    291 
    292 int
    293 linux_sys_fcntl64(l, v, retval)
    294 	struct lwp *l;
    295 	void *v;
    296 	register_t *retval;
    297 {
    298 	struct linux_sys_fcntl64_args /* {
    299 		syscallarg(int) fd;
    300 		syscallarg(int) cmd;
    301 		syscallarg(void *) arg;
    302 	} */ *uap = v;
    303 	struct linux_flock64 lfl;
    304 	struct flock bfl;
    305 	int error;
    306 	void *arg = SCARG(uap, arg);
    307 	int cmd = SCARG(uap, cmd);
    308 	int fd = SCARG(uap, fd);
    309 
    310 	switch (cmd) {
    311 	case LINUX_F_GETLK64:
    312 		if ((error = copyin(arg, &lfl, sizeof lfl)) != 0)
    313 			return error;
    314 		linux_to_bsd_flock64(&bfl, &lfl);
    315 		error = do_fcntl_lock(l, fd, F_GETLK, &bfl);
    316 		if (error != 0)
    317 			return error;
    318 		bsd_to_linux_flock64(&lfl, &bfl);
    319 		return copyout(&lfl, arg, sizeof lfl);
    320 	case LINUX_F_SETLK64:
    321 	case LINUX_F_SETLKW64:
    322 		cmd = (cmd == LINUX_F_SETLK64 ? F_SETLK : F_SETLKW);
    323 		if ((error = copyin(arg, &lfl, sizeof lfl)) != 0)
    324 			return error;
    325 		linux_to_bsd_flock64(&bfl, &lfl);
    326 		return do_fcntl_lock(l, fd, cmd, &bfl);
    327 	default:
    328 		return linux_sys_fcntl(l, v, retval);
    329 	}
    330 }
    331 # endif /* !m69k && !amd64  && !COMPAT_LINUX32 */
    332 
    333 #endif /* !alpha */
    334 
    335 /*
    336  * Linux 'readdir' call. This code is mostly taken from the
    337  * SunOS getdents call (see compat/sunos/sunos_misc.c), though
    338  * an attempt has been made to keep it a little cleaner.
    339  *
    340  * The d_off field contains the offset of the next valid entry,
    341  * unless the older Linux getdents(2), which used to have it set
    342  * to the offset of the entry itself. This function also doesn't
    343  * need to deal with the old count == 1 glibc problem.
    344  *
    345  * Read in BSD-style entries, convert them, and copy them out.
    346  *
    347  * Note that this doesn't handle union-mounted filesystems.
    348  */
    349 #ifndef COMPAT_LINUX32
    350 int
    351 linux_sys_getdents64(l, v, retval)
    352 	struct lwp *l;
    353 	void *v;
    354 	register_t *retval;
    355 {
    356 	struct linux_sys_getdents_args /* {
    357 		syscallarg(int) fd;
    358 		syscallarg(struct linux_dirent64 *) dent;
    359 		syscallarg(unsigned int) count;
    360 	} */ *uap = v;
    361 	struct dirent *bdp;
    362 	struct vnode *vp;
    363 	char *inp, *tbuf;		/* BSD-format */
    364 	int len, reclen;		/* BSD-format */
    365 	char *outp;			/* Linux-format */
    366 	int resid, linux_reclen = 0;	/* Linux-format */
    367 	struct file *fp;
    368 	struct uio auio;
    369 	struct iovec aiov;
    370 	struct linux_dirent64 idb;
    371 	off_t off;		/* true file offset */
    372 	int buflen, error, eofflag, nbytes;
    373 	struct vattr va;
    374 	off_t *cookiebuf = NULL, *cookie;
    375 	int ncookies;
    376 
    377 	/* getvnode() will use the descriptor for us */
    378 	if ((error = getvnode(l->l_proc->p_fd, SCARG(uap, fd), &fp)) != 0)
    379 		return (error);
    380 
    381 	if ((fp->f_flag & FREAD) == 0) {
    382 		error = EBADF;
    383 		goto out1;
    384 	}
    385 
    386 	vp = (struct vnode *)fp->f_data;
    387 	if (vp->v_type != VDIR) {
    388 		error = EINVAL;
    389 		goto out1;
    390 	}
    391 
    392 	if ((error = VOP_GETATTR(vp, &va, l->l_cred, l)))
    393 		goto out1;
    394 
    395 	nbytes = SCARG(uap, count);
    396 	buflen = min(MAXBSIZE, nbytes);
    397 	if (buflen < va.va_blocksize)
    398 		buflen = va.va_blocksize;
    399 	tbuf = malloc(buflen, M_TEMP, M_WAITOK);
    400 
    401 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
    402 	off = fp->f_offset;
    403 again:
    404 	aiov.iov_base = tbuf;
    405 	aiov.iov_len = buflen;
    406 	auio.uio_iov = &aiov;
    407 	auio.uio_iovcnt = 1;
    408 	auio.uio_rw = UIO_READ;
    409 	auio.uio_resid = buflen;
    410 	auio.uio_offset = off;
    411 	UIO_SETUP_SYSSPACE(&auio);
    412 	/*
    413          * First we read into the malloc'ed buffer, then
    414          * we massage it into user space, one record at a time.
    415          */
    416 	error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, &cookiebuf,
    417 	    &ncookies);
    418 	if (error)
    419 		goto out;
    420 
    421 	inp = tbuf;
    422 	outp = (void *)SCARG(uap, dent);
    423 	resid = nbytes;
    424 	if ((len = buflen - auio.uio_resid) == 0)
    425 		goto eof;
    426 
    427 	for (cookie = cookiebuf; len > 0; len -= reclen) {
    428 		bdp = (struct dirent *)inp;
    429 		reclen = bdp->d_reclen;
    430 		if (reclen & 3)
    431 			panic("linux_readdir");
    432 		if (bdp->d_fileno == 0) {
    433 			inp += reclen;	/* it is a hole; squish it out */
    434 			if (cookie)
    435 				off = *cookie++;
    436 			else
    437 				off += reclen;
    438 			continue;
    439 		}
    440 		linux_reclen = LINUX_RECLEN(&idb, bdp->d_namlen);
    441 		if (reclen > len || resid < linux_reclen) {
    442 			/* entry too big for buffer, so just stop */
    443 			outp++;
    444 			break;
    445 		}
    446 		if (cookie)
    447 			off = *cookie++;	/* each entry points to next */
    448 		else
    449 			off += reclen;
    450 		/*
    451 		 * Massage in place to make a Linux-shaped dirent (otherwise
    452 		 * we have to worry about touching user memory outside of
    453 		 * the copyout() call).
    454 		 */
    455 		idb.d_ino = bdp->d_fileno;
    456 		idb.d_type = bdp->d_type;
    457 		idb.d_off = off;
    458 		idb.d_reclen = (u_short)linux_reclen;
    459 		strcpy(idb.d_name, bdp->d_name);
    460 		if ((error = copyout((void *)&idb, outp, linux_reclen)))
    461 			goto out;
    462 		/* advance past this real entry */
    463 		inp += reclen;
    464 		/* advance output past Linux-shaped entry */
    465 		outp += linux_reclen;
    466 		resid -= linux_reclen;
    467 	}
    468 
    469 	/* if we squished out the whole block, try again */
    470 	if (outp == (void *)SCARG(uap, dent))
    471 		goto again;
    472 	fp->f_offset = off;	/* update the vnode offset */
    473 
    474 eof:
    475 	*retval = nbytes - resid;
    476 out:
    477 	VOP_UNLOCK(vp, 0);
    478 	if (cookiebuf)
    479 		free(cookiebuf, M_TEMP);
    480 	free(tbuf, M_TEMP);
    481 out1:
    482 	FILE_UNUSE(fp, l);
    483 	return error;
    484 }
    485 #endif /* !COMPAT_LINUX32 */
    486