sysdeps/unix/sysv/linux/i386/setrlimit.c

   1 /* Copyright (C) 1999, 2000, 2003, 2006 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/param.h>
  21 #include <sys/resource.h>
  22
  23 #include <sysdep.h>
  24 #include <sys/syscall.h>
  25 #include <shlib-compat.h>
  26 #include <bp-checks.h>
  27
  28 #include <kernel-features.h>
  29
  30 extern int __new_setrlimit (enum __rlimit_resource resource,
  31                             const struct rlimit *__unboundedrlimits);
  32
  33 /* Linux 2.3.25 introduced a new system call since the types used for
  34    the limits are now unsigned.  */
  35 #if defined __NR_ugetrlimit && !defined __ASSUME_NEW_GETRLIMIT_SYSCALL
  36 extern int __have_no_new_getrlimit; /* from getrlimit.c */
  37 #endif
  38
  39 int
  40 __new_setrlimit (enum __rlimit_resource resource, const struct rlimit *rlimits)
  41 {
  42 #ifdef __ASSUME_NEW_GETRLIMIT_SYSCALL
  43   return INLINE_SYSCALL (setrlimit, 2, resource, CHECK_1 (rlimits));
  44 #else
  45   struct rlimit rlimits_small;
  46
  47 # ifdef __NR_ugetrlimit
  48   if (__have_no_new_getrlimit == 0)
  49     {
  50       /* Check if the new ugetrlimit syscall exists.  We must do this
  51          first because older kernels don't reject negative rlimit
  52          values in setrlimit.  */
  53       int result = INLINE_SYSCALL (ugetrlimit, 2, resource, __ptrvalue (&rlimits_small));
  54       if (result != -1 || errno != ENOSYS)
  55         /* The syscall exists.  */
  56         __have_no_new_getrlimit = -1;
  57       else
  58         /* The syscall does not exist.  */
  59         __have_no_new_getrlimit = 1;
  60     }
  61   if (__have_no_new_getrlimit < 0)
  62     return INLINE_SYSCALL (setrlimit, 2, resource, CHECK_1 (rlimits));
  63 # endif
  64
  65   /* We might have to correct the limits values.  Since the old values
  66      were signed the new values might be too large.  */
  67   rlimits_small.rlim_cur = MIN ((unsigned long int) rlimits->rlim_cur,
  68                                 RLIM_INFINITY >> 1);
  69   rlimits_small.rlim_max = MIN ((unsigned long int) rlimits->rlim_max,
  70                                 RLIM_INFINITY >> 1);
  71
  72   /* Use the adjusted values.  */
  73   return INLINE_SYSCALL (setrlimit, 2, resource, __ptrvalue (&rlimits_small));
  74 #endif
  75 }
  76
  77 weak_alias (__new_setrlimit, __setrlimit);
  78 versioned_symbol (libc, __new_setrlimit, setrlimit, GLIBC_2_2);