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linux_file64.c revision 1.21.2.3
      1 /*	$NetBSD: linux_file64.c,v 1.21.2.3 2004/09/18 14:43:42 skrll 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 1.21.2.3 2004/09/18 14:43:42 skrll 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/vnode.h>
     59 #include <sys/tty.h>
     60 #include <sys/conf.h>
     61 
     62 #include <sys/sa.h>
     63 #include <sys/syscallargs.h>
     64 
     65 #include <compat/linux/common/linux_types.h>
     66 #include <compat/linux/common/linux_signal.h>
     67 #include <compat/linux/common/linux_fcntl.h>
     68 #include <compat/linux/common/linux_util.h>
     69 #include <compat/linux/common/linux_machdep.h>
     70 #include <compat/linux/common/linux_dirent.h>
     71 
     72 #include <compat/linux/linux_syscallargs.h>
     73 
     74 #ifndef alpha
     75 
     76 static void bsd_to_linux_stat __P((struct stat *, struct linux_stat64 *));
     77 static int linux_do_stat64 __P((struct lwp *, void *, register_t *, int));
     78 
     79 /*
     80  * Convert a NetBSD stat structure to a Linux stat structure.
     81  * Only the order of the fields and the padding in the structure
     82  * is different. linux_fakedev is a machine-dependent function
     83  * which optionally converts device driver major/minor numbers
     84  * (XXX horrible, but what can you do against code that compares
     85  * things against constant major device numbers? sigh)
     86  */
     87 static void
     88 bsd_to_linux_stat(bsp, lsp)
     89 	struct stat *bsp;
     90 	struct linux_stat64 *lsp;
     91 {
     92 	lsp->lst_dev     = linux_fakedev(bsp->st_dev, 0);
     93 	lsp->lst_ino     = bsp->st_ino;
     94 	lsp->lst_mode    = (linux_mode_t)bsp->st_mode;
     95 	if (bsp->st_nlink >= (1 << 15))
     96 		lsp->lst_nlink = (1 << 15) - 1;
     97 	else
     98 		lsp->lst_nlink = (linux_nlink_t)bsp->st_nlink;
     99 	lsp->lst_uid     = bsp->st_uid;
    100 	lsp->lst_gid     = bsp->st_gid;
    101 	lsp->lst_rdev    = linux_fakedev(bsp->st_rdev, 1);
    102 	lsp->lst_size    = bsp->st_size;
    103 	lsp->lst_blksize = bsp->st_blksize;
    104 	lsp->lst_blocks  = bsp->st_blocks;
    105 	lsp->lst_atime   = bsp->st_atime;
    106 	lsp->lst_mtime   = bsp->st_mtime;
    107 	lsp->lst_ctime   = bsp->st_ctime;
    108 #if LINUX_STAT64_HAS_BROKEN_ST_INO
    109 	lsp->__lst_ino   = (linux_ino_t) bsp->st_ino;
    110 #endif
    111 }
    112 
    113 /*
    114  * The stat functions below are plain sailing. stat and lstat are handled
    115  * by one function to avoid code duplication.
    116  */
    117 int
    118 linux_sys_fstat64(l, v, retval)
    119 	struct lwp *l;
    120 	void *v;
    121 	register_t *retval;
    122 {
    123 	struct linux_sys_fstat64_args /* {
    124 		syscallarg(int) fd;
    125 		syscallarg(struct linux_stat64 *) sp;
    126 	} */ *uap = v;
    127 	struct proc *p = l->l_proc;
    128 	struct sys___fstat13_args fsa;
    129 	struct linux_stat64 tmplst;
    130 	struct stat *st,tmpst;
    131 	caddr_t sg;
    132 	int error;
    133 
    134 	sg = stackgap_init(p, 0);
    135 
    136 	st = stackgap_alloc(p, &sg, sizeof (struct stat));
    137 
    138 	SCARG(&fsa, fd) = SCARG(uap, fd);
    139 	SCARG(&fsa, sb) = st;
    140 
    141 	if ((error = sys___fstat13(l, &fsa, retval)))
    142 		return error;
    143 
    144 	if ((error = copyin(st, &tmpst, sizeof tmpst)))
    145 		return error;
    146 
    147 	bsd_to_linux_stat(&tmpst, &tmplst);
    148 
    149 	if ((error = copyout(&tmplst, SCARG(uap, sp), sizeof tmplst)))
    150 		return error;
    151 
    152 	return 0;
    153 }
    154 
    155 static int
    156 linux_do_stat64(l, v, retval, dolstat)
    157 	struct lwp *l;
    158 	void *v;
    159 	register_t *retval;
    160 	int dolstat;
    161 {
    162 	struct proc *p = l->l_proc;
    163 	struct sys___stat13_args sa;
    164 	struct linux_stat64 tmplst;
    165 	struct stat *st, tmpst;
    166 	caddr_t sg;
    167 	int error;
    168 	struct linux_sys_stat64_args *uap = v;
    169 
    170 	sg = stackgap_init(p, 0);
    171 	st = stackgap_alloc(p, &sg, sizeof (struct stat));
    172 	CHECK_ALT_EXIST(p, &sg, SCARG(uap, path));
    173 
    174 	SCARG(&sa, ub) = st;
    175 	SCARG(&sa, path) = SCARG(uap, path);
    176 
    177 	if ((error = (dolstat ? sys___lstat13(l, &sa, retval) :
    178 				sys___stat13(l, &sa, retval))))
    179 		return error;
    180 
    181 	if ((error = copyin(st, &tmpst, sizeof tmpst)))
    182 		return error;
    183 
    184 	bsd_to_linux_stat(&tmpst, &tmplst);
    185 
    186 	if ((error = copyout(&tmplst, SCARG(uap, sp), sizeof tmplst)))
    187 		return error;
    188 
    189 	return 0;
    190 }
    191 
    192 int
    193 linux_sys_stat64(l, v, retval)
    194 	struct lwp *l;
    195 	void *v;
    196 	register_t *retval;
    197 {
    198 	struct linux_sys_stat64_args /* {
    199 		syscallarg(const char *) path;
    200 		syscallarg(struct linux_stat64 *) sp;
    201 	} */ *uap = v;
    202 
    203 	return linux_do_stat64(l, uap, retval, 0);
    204 }
    205 
    206 int
    207 linux_sys_lstat64(l, v, retval)
    208 	struct lwp *l;
    209 	void *v;
    210 	register_t *retval;
    211 {
    212 	struct linux_sys_lstat64_args /* {
    213 		syscallarg(const char *) path;
    214 		syscallarg(struct linux_stat64 *) sp;
    215 	} */ *uap = v;
    216 
    217 	return linux_do_stat64(l, uap, retval, 1);
    218 }
    219 
    220 int
    221 linux_sys_truncate64(l, v, retval)
    222 	struct lwp *l;
    223 	void *v;
    224 	register_t *retval;
    225 {
    226 	struct linux_sys_truncate64_args /* {
    227 		syscallarg(const char *) path;
    228 		syscallarg(off_t) length;
    229 	} */ *uap = v;
    230 	struct sys_truncate_args ta;
    231 	struct proc *p = l->l_proc;
    232 	caddr_t sg = stackgap_init(p, 0);
    233 
    234 	CHECK_ALT_EXIST(p, &sg, SCARG(uap, path));
    235 
    236 	/* Linux doesn't have the 'pad' pseudo-parameter */
    237 	SCARG(&ta, path) = SCARG(uap, path);
    238 	SCARG(&ta, pad) = 0;
    239 	SCARG(&ta, length) = SCARG(uap, length);
    240 
    241 	return sys_truncate(l, &ta, retval);
    242 }
    243 
    244 int
    245 linux_sys_ftruncate64(l, v, retval)
    246 	struct lwp *l;
    247 	void *v;
    248 	register_t *retval;
    249 {
    250 	struct linux_sys_ftruncate64_args /* {
    251 		syscallarg(unsigned int) fd;
    252 		syscallarg(off_t) length;
    253 	} */ *uap = v;
    254 	struct sys_ftruncate_args ta;
    255 
    256 	/* Linux doesn't have the 'pad' pseudo-parameter */
    257 	SCARG(&ta, fd) = SCARG(uap, fd);
    258 	SCARG(&ta, pad) = 0;
    259 	SCARG(&ta, length) = SCARG(uap, length);
    260 
    261 	return sys_ftruncate(l, &ta, retval);
    262 }
    263 
    264 #if !defined(__m68k__)
    265 static void bsd_to_linux_flock64 __P((struct linux_flock64 *,
    266     const struct flock *));
    267 static void linux_to_bsd_flock64 __P((struct flock *,
    268     const struct linux_flock64 *));
    269 
    270 static void
    271 bsd_to_linux_flock64(lfp, bfp)
    272 	struct linux_flock64 *lfp;
    273 	const struct flock *bfp;
    274 {
    275 
    276 	lfp->l_start = bfp->l_start;
    277 	lfp->l_len = bfp->l_len;
    278 	lfp->l_pid = bfp->l_pid;
    279 	lfp->l_whence = bfp->l_whence;
    280 	switch (bfp->l_type) {
    281 	case F_RDLCK:
    282 		lfp->l_type = LINUX_F_RDLCK;
    283 		break;
    284 	case F_UNLCK:
    285 		lfp->l_type = LINUX_F_UNLCK;
    286 		break;
    287 	case F_WRLCK:
    288 		lfp->l_type = LINUX_F_WRLCK;
    289 		break;
    290 	}
    291 }
    292 
    293 static void
    294 linux_to_bsd_flock64(bfp, lfp)
    295 	struct flock *bfp;
    296 	const struct linux_flock64 *lfp;
    297 {
    298 
    299 	bfp->l_start = lfp->l_start;
    300 	bfp->l_len = lfp->l_len;
    301 	bfp->l_pid = lfp->l_pid;
    302 	bfp->l_whence = lfp->l_whence;
    303 	switch (lfp->l_type) {
    304 	case LINUX_F_RDLCK:
    305 		bfp->l_type = F_RDLCK;
    306 		break;
    307 	case LINUX_F_UNLCK:
    308 		bfp->l_type = F_UNLCK;
    309 		break;
    310 	case LINUX_F_WRLCK:
    311 		bfp->l_type = F_WRLCK;
    312 		break;
    313 	}
    314 }
    315 
    316 int
    317 linux_sys_fcntl64(l, v, retval)
    318 	struct lwp *l;
    319 	void *v;
    320 	register_t *retval;
    321 {
    322 	struct linux_sys_fcntl64_args /* {
    323 		syscallarg(int) fd;
    324 		syscallarg(int) cmd;
    325 		syscallarg(void *) arg;
    326 	} */ *uap = v;
    327 	struct proc *p = l->l_proc;
    328 	struct sys_fcntl_args fca;
    329 	struct linux_flock64 lfl;
    330 	struct flock bfl, *bfp;
    331 	int error;
    332 	caddr_t sg;
    333 	void *arg = SCARG(uap, arg);
    334 	int cmd = SCARG(uap, cmd);
    335 	int fd = SCARG(uap, fd);
    336 
    337 	switch (cmd) {
    338 	case LINUX_F_GETLK64:
    339 		sg = stackgap_init(p, 0);
    340 		bfp = (struct flock *) stackgap_alloc(p, &sg, sizeof *bfp);
    341 		if ((error = copyin(arg, &lfl, sizeof lfl)) != 0)
    342 			return error;
    343 		linux_to_bsd_flock64(&bfl, &lfl);
    344 		if ((error = copyout(&bfl, bfp, sizeof bfl)) != 0)
    345 			return error;
    346 		SCARG(&fca, fd) = fd;
    347 		SCARG(&fca, cmd) = F_GETLK;
    348 		SCARG(&fca, arg) = bfp;
    349 		if ((error = sys_fcntl(l, &fca, retval)) != 0)
    350 			return error;
    351 		if ((error = copyin(bfp, &bfl, sizeof bfl)) != 0)
    352 			return error;
    353 		bsd_to_linux_flock64(&lfl, &bfl);
    354 		return copyout(&lfl, arg, sizeof lfl);
    355 	case LINUX_F_SETLK64:
    356 	case LINUX_F_SETLKW64:
    357 		cmd = (cmd == LINUX_F_SETLK64 ? F_SETLK : F_SETLKW);
    358 		if ((error = copyin(arg, &lfl, sizeof lfl)) != 0)
    359 			return error;
    360 		linux_to_bsd_flock64(&bfl, &lfl);
    361 		sg = stackgap_init(p, 0);
    362 		bfp = (struct flock *) stackgap_alloc(p, &sg, sizeof *bfp);
    363 		if ((error = copyout(&bfl, bfp, sizeof bfl)) != 0)
    364 			return error;
    365 		SCARG(&fca, fd) = fd;
    366 		SCARG(&fca, cmd) = cmd;
    367 		SCARG(&fca, arg) = bfp;
    368 		return sys_fcntl(l, &fca, retval);
    369 	default:
    370 		return linux_sys_fcntl(l, v, retval);
    371 	}
    372 }
    373 #endif /* !m68k */
    374 
    375 #endif /* !alpha */
    376 
    377 /*
    378  * Linux 'readdir' call. This code is mostly taken from the
    379  * SunOS getdents call (see compat/sunos/sunos_misc.c), though
    380  * an attempt has been made to keep it a little cleaner.
    381  *
    382  * The d_off field contains the offset of the next valid entry,
    383  * unless the older Linux getdents(2), which used to have it set
    384  * to the offset of the entry itself. This function also doesn't
    385  * need to deal with the old count == 1 glibc problem.
    386  *
    387  * Read in BSD-style entries, convert them, and copy them out.
    388  *
    389  * Note that this doesn't handle union-mounted filesystems.
    390  */
    391 int
    392 linux_sys_getdents64(l, v, retval)
    393 	struct lwp *l;
    394 	void *v;
    395 	register_t *retval;
    396 {
    397 	struct linux_sys_getdents_args /* {
    398 		syscallarg(int) fd;
    399 		syscallarg(struct linux_dirent64 *) dent;
    400 		syscallarg(unsigned int) count;
    401 	} */ *uap = v;
    402 	struct proc *p = l->l_proc;
    403 	struct dirent *bdp;
    404 	struct vnode *vp;
    405 	caddr_t	inp, buf;		/* BSD-format */
    406 	int len, reclen;		/* BSD-format */
    407 	caddr_t outp;			/* Linux-format */
    408 	int resid, linux_reclen = 0;	/* Linux-format */
    409 	struct file *fp;
    410 	struct uio auio;
    411 	struct iovec aiov;
    412 	struct linux_dirent64 idb;
    413 	off_t off;		/* true file offset */
    414 	int buflen, error, eofflag, nbytes;
    415 	struct vattr va;
    416 	off_t *cookiebuf = NULL, *cookie;
    417 	int ncookies;
    418 
    419 	/* getvnode() will use the descriptor for us */
    420 	if ((error = getvnode(p->p_fd, SCARG(uap, fd), &fp)) != 0)
    421 		return (error);
    422 
    423 	if ((fp->f_flag & FREAD) == 0) {
    424 		error = EBADF;
    425 		goto out1;
    426 	}
    427 
    428 	vp = (struct vnode *)fp->f_data;
    429 	if (vp->v_type != VDIR) {
    430 		error = EINVAL;
    431 		goto out1;
    432 	}
    433 
    434 	if ((error = VOP_GETATTR(vp, &va, p->p_ucred, p)))
    435 		goto out1;
    436 
    437 	nbytes = SCARG(uap, count);
    438 	buflen = min(MAXBSIZE, nbytes);
    439 	if (buflen < va.va_blocksize)
    440 		buflen = va.va_blocksize;
    441 	buf = malloc(buflen, M_TEMP, M_WAITOK);
    442 
    443 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
    444 	off = fp->f_offset;
    445 again:
    446 	aiov.iov_base = buf;
    447 	aiov.iov_len = buflen;
    448 	auio.uio_iov = &aiov;
    449 	auio.uio_iovcnt = 1;
    450 	auio.uio_rw = UIO_READ;
    451 	auio.uio_segflg = UIO_SYSSPACE;
    452 	auio.uio_procp = NULL;
    453 	auio.uio_resid = buflen;
    454 	auio.uio_offset = off;
    455 	/*
    456          * First we read into the malloc'ed buffer, then
    457          * we massage it into user space, one record at a time.
    458          */
    459 	error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, &cookiebuf,
    460 	    &ncookies);
    461 	if (error)
    462 		goto out;
    463 
    464 	inp = buf;
    465 	outp = (caddr_t)SCARG(uap, dent);
    466 	resid = nbytes;
    467 	if ((len = buflen - auio.uio_resid) == 0)
    468 		goto eof;
    469 
    470 	for (cookie = cookiebuf; len > 0; len -= reclen) {
    471 		bdp = (struct dirent *)inp;
    472 		reclen = bdp->d_reclen;
    473 		if (reclen & 3)
    474 			panic("linux_readdir");
    475 		if (bdp->d_fileno == 0) {
    476 			inp += reclen;	/* it is a hole; squish it out */
    477 			off = *cookie++;
    478 			continue;
    479 		}
    480 		linux_reclen = LINUX_RECLEN(&idb, bdp->d_namlen);
    481 		if (reclen > len || resid < linux_reclen) {
    482 			/* entry too big for buffer, so just stop */
    483 			outp++;
    484 			break;
    485 		}
    486 		off = *cookie++;	/* each entry points to next */
    487 		/*
    488 		 * Massage in place to make a Linux-shaped dirent (otherwise
    489 		 * we have to worry about touching user memory outside of
    490 		 * the copyout() call).
    491 		 */
    492 		idb.d_ino = bdp->d_fileno;
    493 		idb.d_type = bdp->d_type;
    494 		idb.d_off = off;
    495 		idb.d_reclen = (u_short)linux_reclen;
    496 		strcpy(idb.d_name, bdp->d_name);
    497 		if ((error = copyout((caddr_t)&idb, outp, linux_reclen)))
    498 			goto out;
    499 		/* advance past this real entry */
    500 		inp += reclen;
    501 		/* advance output past Linux-shaped entry */
    502 		outp += linux_reclen;
    503 		resid -= linux_reclen;
    504 	}
    505 
    506 	/* if we squished out the whole block, try again */
    507 	if (outp == (caddr_t)SCARG(uap, dent))
    508 		goto again;
    509 	fp->f_offset = off;	/* update the vnode offset */
    510 
    511 eof:
    512 	*retval = nbytes - resid;
    513 out:
    514 	VOP_UNLOCK(vp, 0);
    515 	if (cookiebuf)
    516 		free(cookiebuf, M_TEMP);
    517 	free(buf, M_TEMP);
    518 out1:
    519 	FILE_UNUSE(fp, p);
    520 	return error;
    521 }
    522