sys/emulation/linux/linux_getcwd.c

   1 /* $FreeBSD: src/sys/compat/linux/linux_getcwd.c,v 1.2.2.3 2001/11/05 19:08:22 marcel Exp $ */
   2 /* $DragonFly: src/sys/emulation/linux/linux_getcwd.c,v 1.23 2006/12/23 00:27:02 swildner Exp $ */
   3 /* $OpenBSD: linux_getcwd.c,v 1.2 2001/05/16 12:50:21 ho Exp $ */
   4 /* $NetBSD: vfs_getcwd.c,v 1.3.2.3 1999/07/11 10:24:09 sommerfeld Exp $ */
   5
   6 /*-
   7  * Copyright (c) 1999 The NetBSD Foundation, Inc.
   8  * All rights reserved.
   9  *
  10  * This code is derived from software contributed to The NetBSD Foundation
  11  * by Bill Sommerfeld.
  12  *
  13  * Redistribution and use in source and binary forms, with or without
  14  * modification, are permitted provided that the following conditions
  15  * are met:
  16  * 1. Redistributions of source code must retain the above copyright
  17  *    notice, this list of conditions and the following disclaimer.
  18  * 2. Redistributions in binary form must reproduce the above copyright
  19  *    notice, this list of conditions and the following disclaimer in the
  20  *    documentation and/or other materials provided with the distribution.
  21  * 3. All advertising materials mentioning features or use of this software
  22  *    must display the following acknowledgement:
  23  *        This product includes software developed by the NetBSD
  24  *        Foundation, Inc. and its contributors.
  25  * 4. Neither the name of The NetBSD Foundation nor the names of its
  26  *    contributors may be used to endorse or promote products derived
  27  *    from this software without specific prior written permission.
  28  *
  29  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  30  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  31  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  32  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  33  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  34  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  35  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  36  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  37  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  38  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  39  * POSSIBILITY OF SUCH DAMAGE.
  40  */
  41 #include "opt_compat.h"
  42
  43 #include <sys/param.h>
  44 #include <sys/systm.h>
  45 #include <sys/sysproto.h>
  46 #include <sys/filedesc.h>
  47 #include <sys/kernel.h>
  48 #include <sys/file.h>
  49 #include <sys/stat.h>
  50 #include <sys/vnode.h>
  51 #include <sys/mount.h>
  52 #include <sys/proc.h>
  53 #include <sys/namei.h>
  54 #include <sys/uio.h>
  55 #include <sys/malloc.h>
  56 #include <sys/dirent.h>
  57 #include <sys/kern_syscall.h>
  58 #include <vfs/ufs/dir.h>        /* XXX only for DIRBLKSIZ */
  59
  60 #include <sys/mplock2.h>
  61
  62 #include <arch_linux/linux.h>
  63 #include <arch_linux/linux_proto.h>
  64 #include "linux_util.h"
  65
  66 /*
  67  * Find pathname of process's current directory.
  68  *
  69  * Use vfs vnode-to-name reverse cache; if that fails, fall back
  70  * to reading directory contents.
  71  *
  72  * MPALMOSTSAFE
  73  */
  74 int
  75 sys_linux_getcwd(struct linux_getcwd_args *args)
  76 {
  77         int buflen;
  78         int error;
  79         char *buf;
  80         char *bp;
  81
  82 #ifdef DEBUG
  83         kprintf("Linux-emul(%d): getcwd(%p, %d)\n",
  84             (curthread->td_proc ? (int)curthread->td_proc->p_pid : -1),
  85             args->buf, args->bufsize);
  86 #endif
  87         buflen = args->bufsize;
  88         if (buflen < 2)
  89                 return (EINVAL);
  90         if (buflen > MAXPATHLEN)
  91                 buflen = MAXPATHLEN;
  92
  93         buf = kmalloc(buflen, M_TEMP, M_WAITOK);
  94         get_mplock();
  95         bp = kern_getcwd(buf, buflen, &error);
  96         rel_mplock();
  97         if (error == 0) {
  98                 buflen = strlen(bp) + 1;
  99                 error = copyout(bp, args->buf, buflen);
 100                 args->sysmsg_result = buflen;
 101         }
 102         kfree(buf, M_TEMP);
 103         return (error);
 104 }
 105