nptl/sem_unlink.c

   1 /* Copyright (C) 2002, 2004 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <errno.h>
  21 #include <semaphore.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <unistd.h>
  25 #include "semaphoreP.h"
  26
  27
  28 int
  29 sem_unlink (name)
  30      const char *name;
  31 {
  32   char *fname;
  33   size_t namelen;
  34
  35   /* Determine where the shmfs is mounted.  */
  36   INTUSE(__pthread_once) (&__namedsem_once, __where_is_shmfs);
  37
  38   /* If we don't know the mount points there is nothing we can do.  Ever.  */
  39   if (mountpoint.dir == NULL)
  40     {
  41       __set_errno (ENOSYS);
  42       return -1;
  43     }
  44
  45   /* Construct the filename.  */
  46   while (name[0] == '/')
  47     ++name;
  48
  49   if (name[0] == '\0')
  50     {
  51       /* The name "/" is not supported.  */
  52       __set_errno (ENOENT);
  53       return -1;
  54     }
  55   namelen = strlen (name);
  56
  57   /* Create the name of the file.  */
  58   fname = (char *) alloca (mountpoint.dirlen + namelen + 1);
  59   __mempcpy (__mempcpy (fname, mountpoint.dir, mountpoint.dirlen),
  60              name, namelen + 1);
  61
  62   /* Now try removing it.  */
  63   int ret = unlink (fname);
  64   if (ret < 0 && errno == EPERM)
  65     __set_errno (EACCES);
  66   return ret;
  67 }