nptl/pthread_attr_getaffinity.c

   1 /* Copyright (C) 2003-2018 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 <errno.h>
  20 #include <pthreadP.h>
  21 #include <string.h>
  22 #include <sysdep.h>
  23 #include <sys/types.h>
  24 #include <sys/param.h>
  25 #include <shlib-compat.h>
  26
  27
  28 int
  29 __pthread_attr_getaffinity_new (const pthread_attr_t *attr, size_t cpusetsize,
  30                                 cpu_set_t *cpuset)
  31 {
  32   const struct pthread_attr *iattr;
  33
  34   iattr = (const struct pthread_attr *) attr;
  35
  36   if (iattr->cpuset != NULL)
  37     {
  38       /* Check whether there are any bits set beyond the limits
  39          the user requested.  */
  40       for (size_t cnt = cpusetsize; cnt < iattr->cpusetsize; ++cnt)
  41         if (((char *) iattr->cpuset)[cnt] != 0)
  42           return EINVAL;
  43
  44       /* Copy over the cpuset from the thread attribute object.  Limit the copy
  45          to the minimum of the source and destination sizes to prevent a buffer
  46          overrun.  If the destination is larger, fill the remaining space with
  47          zeroes.  */
  48       void *p = mempcpy (cpuset, iattr->cpuset,
  49                          MIN (iattr->cpusetsize, cpusetsize));
  50       if (cpusetsize > iattr->cpusetsize)
  51         memset (p, '\0', cpusetsize - iattr->cpusetsize);
  52     }
  53   else
  54     /* We have no information.  */
  55     memset (cpuset, -1, cpusetsize);
  56
  57   return 0;
  58 }
  59 versioned_symbol (libpthread, __pthread_attr_getaffinity_new,
  60                   pthread_attr_getaffinity_np, GLIBC_2_3_4);
  61
  62
  63 #if SHLIB_COMPAT (libpthread, GLIBC_2_3_3, GLIBC_2_3_4)
  64 int
  65 __pthread_attr_getaffinity_old (const pthread_attr_t *attr, cpu_set_t *cpuset)
  66 {
  67   /* The old interface by default assumed a 1024 processor bitmap.  */
  68   return __pthread_attr_getaffinity_new (attr, 128, cpuset);
  69 }
  70 compat_symbol (libpthread, __pthread_attr_getaffinity_old,
  71                pthread_attr_getaffinity_np, GLIBC_2_3_3);
  72 #endif