sysdeps/unix/sysv/linux/powerpc/dl-sysdep.c

   1 /* Operating system support for run-time dynamic linker.  Linux/PPC version.
   2    Copyright (C) 1997, 1998, 2001, 2003 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   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
  21 #include "config.h"
  22 #include "kernel-features.h"
  23 #include <ldsodefs.h>
  24
  25 extern int __cache_line_size;
  26 weak_extern (__cache_line_size)
  27
  28 /* Scan the Aux Vector for the "Data Cache Block Size" entry.  If found
  29    verify that the static extern __cache_line_size is defined by checking
  30    for not NULL.  If it is defined then assign the cache block size
  31    value to __cache_line_size.  */
  32 #define DL_PLATFORM_AUXV                                                      \
  33       case AT_DCACHEBSIZE:                                                    \
  34         {                                                                     \
  35           int *cls = & __cache_line_size;                                     \
  36           if (cls != NULL)                                                    \
  37             *cls = av->a_un.a_val;                                            \
  38         }                                                                     \
  39       break;
  40
  41 #ifndef __ASSUME_STD_AUXV
  42
  43 /* The PowerPC's auxiliary argument block gets aligned to a 16-byte
  44    boundary.  This is history and impossible to change compatibly.  */
  45
  46 #define DL_FIND_ARG_COMPONENTS(cookie, argc, argv, envp, auxp) \
  47   do {                                                                        \
  48     char **_tmp;                                                              \
  49     size_t _test;                                                             \
  50     (argc) = *(long int *) cookie;                                            \
  51     (argv) = (char **) cookie + 1;                                            \
  52     (envp) = (argv) + (argc) + 1;                                             \
  53     for (_tmp = (envp); *_tmp; ++_tmp)                                        \
  54       continue;                                                               \
  55     /* The following '++' is important!  */                                   \
  56     ++_tmp;                                                                   \
  57                                                                               \
  58     _test = (size_t)_tmp;                                                     \
  59     _test = (_test + 0xf) & ~0xf;                                             \
  60     /* Under some circumstances, MkLinux (up to at least DR3a5)               \
  61        omits the padding.  To work around this, we make a                     \
  62        basic sanity check of the argument vector.  Of                         \
  63        course, this means that in future, the argument                        \
  64        vector will have to be laid out to allow for this                      \
  65        test :-(.  */                                                          \
  66      if (((ElfW(auxv_t) *)_test)->a_type <= 0x10)                             \
  67        _tmp = (char **)_test;                                                 \
  68     (auxp) = (ElfW(auxv_t) *) _tmp;                                           \
  69   } while (0)
  70 #endif
  71
  72 #include_next <sysdeps/unix/sysv/linux/dl-sysdep.c>