nptl/pthread_attr_getaffinity.c

   1 /* Copyright (C) 2003-2017 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@redhat.com>, 2003.
   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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <assert.h>
  20 #include <errno.h>
  21 #include <pthreadP.h>
  22 #include <string.h>
  23 #include <sysdep.h>
  24 #include <sys/types.h>
  25 #include <sys/param.h>
  26 #include <shlib-compat.h>
  27
  28
  29 int
  30 __pthread_attr_getaffinity_new (const pthread_attr_t *attr, size_t cpusetsize,
  31                                 cpu_set_t *cpuset)
  32 {
  33   const struct pthread_attr *iattr;
  34
  35   assert (sizeof (*attr) >= sizeof (struct pthread_attr));
  36   iattr = (const struct pthread_attr *) attr;
  37
  38   if (iattr->cpuset != NULL)
  39     {
  40       /* Check whether there are any bits set beyond the limits
  41          the user requested.  */
  42       for (size_t cnt = cpusetsize; cnt < iattr->cpusetsize; ++cnt)
  43         if (((char *) iattr->cpuset)[cnt] != 0)
  44           return EINVAL;
  45
  46       /* Copy over the cpuset from the thread attribute object.  Limit the copy
  47          to the minimum of the source and destination sizes to prevent a buffer
  48          overrun.  If the destination is larger, fill the remaining space with
  49          zeroes.  */
  50       void *p = mempcpy (cpuset, iattr->cpuset,
  51                          MIN (iattr->cpusetsize, cpusetsize));
  52       if (cpusetsize > iattr->cpusetsize)
  53         memset (p, '\0', cpusetsize - iattr->cpusetsize);
  54     }
  55   else
  56     /* We have no information.  */
  57     memset (cpuset, -1, cpusetsize);
  58
  59   return 0;
  60 }
  61 versioned_symbol (libpthread, __pthread_attr_getaffinity_new,
  62                   pthread_attr_getaffinity_np, GLIBC_2_3_4);
  63
  64
  65 #if SHLIB_COMPAT (libpthread, GLIBC_2_3_3, GLIBC_2_3_4)
  66 int
  67 __pthread_attr_getaffinity_old (const pthread_attr_t *attr, cpu_set_t *cpuset)
  68 {
  69   /* The old interface by default assumed a 1024 processor bitmap.  */
  70   return __pthread_attr_getaffinity_new (attr, 128, cpuset);
  71 }
  72 compat_symbol (libpthread, __pthread_attr_getaffinity_old,
  73                pthread_attr_getaffinity_np, GLIBC_2_3_3);
  74 #endif