sysdeps/unix/sysv/linux/prlimit.c

   1 /* Copyright (C) 2010, 2012 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <errno.h>
  20 #include <sys/resource.h>
  21 #include <sys/syscall.h>
  22
  23
  24 #ifdef __NR_prlimit64
  25 int
  26 prlimit (__pid_t pid, enum __rlimit_resource resource,
  27          const struct rlimit *new_rlimit, struct rlimit *old_rlimit)
  28 {
  29   struct rlimit64 new_rlimit64_mem;
  30   struct rlimit64 *new_rlimit64 = NULL;
  31   struct rlimit64 old_rlimit64_mem;
  32   struct rlimit64 *old_rlimit64 = (old_rlimit != NULL
  33                                    ? &old_rlimit64_mem : NULL);
  34
  35   if (new_rlimit != NULL)
  36     {
  37       if (new_rlimit->rlim_cur == RLIM_INFINITY)
  38         new_rlimit64_mem.rlim_cur = RLIM64_INFINITY;
  39       else
  40         new_rlimit64_mem.rlim_cur = new_rlimit->rlim_cur;
  41       if (new_rlimit->rlim_max == RLIM_INFINITY)
  42         new_rlimit64_mem.rlim_max = RLIM64_INFINITY;
  43       else
  44         new_rlimit64_mem.rlim_max = new_rlimit->rlim_max;
  45       new_rlimit64 = &new_rlimit64_mem;
  46     }
  47
  48   int res = INLINE_SYSCALL (prlimit64, 4, pid, resource, new_rlimit64,
  49                             old_rlimit64);
  50
  51   if (res == 0 && old_rlimit != NULL)
  52     {
  53       /* The prlimit64 syscall is ill-designed for 32-bit machines.
  54          We have to provide a 32-bit variant since otherwise the LFS
  55          system would not work.  But what shall we do if the syscall
  56          succeeds but the old values do not fit into a rlimit
  57          structure?  We cannot return an error because the operation
  58          itself worked.  Best is perhaps to return RLIM_INFINITY.  */
  59       old_rlimit->rlim_cur = old_rlimit64_mem.rlim_cur;
  60       if (old_rlimit->rlim_cur != old_rlimit64_mem.rlim_cur)
  61         {
  62           if (new_rlimit == NULL)
  63             {
  64               __set_errno (EOVERFLOW);
  65               return -1;
  66             }
  67           old_rlimit->rlim_cur = RLIM_INFINITY;
  68         }
  69       old_rlimit->rlim_max = old_rlimit64_mem.rlim_max;
  70       if (old_rlimit->rlim_max != old_rlimit64_mem.rlim_max)
  71         {
  72           if (new_rlimit == NULL)
  73             {
  74               __set_errno (EOVERFLOW);
  75               return -1;
  76             }
  77           old_rlimit->rlim_max = RLIM_INFINITY;
  78         }
  79     }
  80
  81   return res;
  82 }
  83 #else
  84 int
  85 prlimit (__pid_t pid, enum __rlimit_resource resource,
  86          const struct rlimit *new_rlimit, struct rlimit *old_rlimit)
  87 {
  88   __set_errno (ENOSYS);
  89   return -1;
  90 }
  91 stub_warning (prlimit)
  92 #endif