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      1 
      2 /*--------------------------------------------------------------------*/
      3 /*--- Notional "implementation" for m_vki.                         ---*/
      4 /*---                                                      m_vki.c ---*/
      5 /*--------------------------------------------------------------------*/
      6 
      7 /*
      8    This file is part of Valgrind, a dynamic binary instrumentation
      9    framework.
     10 
     11    Copyright (C) 2006-2012 OpenWorks LLP
     12       info (at) open-works.co.uk
     13 
     14    This program is free software; you can redistribute it and/or
     15    modify it under the terms of the GNU General Public License as
     16    published by the Free Software Foundation; either version 2 of the
     17    License, or (at your option) any later version.
     18 
     19    This program is distributed in the hope that it will be useful, but
     20    WITHOUT ANY WARRANTY; without even the implied warranty of
     21    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     22    General Public License for more details.
     23 
     24    You should have received a copy of the GNU General Public License
     25    along with this program; if not, write to the Free Software
     26    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
     27    02111-1307, USA.
     28 
     29    The GNU General Public License is contained in the file COPYING.
     30 */
     31 
     32 #include "pub_core_basics.h"
     33 #include "pub_core_libcassert.h"
     34 #include "pub_core_vki.h"     /* self */
     35 
     36 /* We have pub_{core,tool}_vki.h.  This is the matching implementation
     37    for that interface.  In fact there is no implementation, as the
     38    sole purpose of the module is to export types and constants
     39    describing the kernel interface, so this file is nearly empty. */
     40 
     41 
     42 /* ppc32/64-linux determines page size at startup, hence m_vki is
     43    the logical place to store that info. */
     44 
     45 #if defined(VGP_ppc32_linux) || defined(VGP_ppc64_linux)
     46 unsigned long VKI_PAGE_SHIFT = 12;
     47 unsigned long VKI_PAGE_SIZE  = 1UL << 12;
     48 #endif
     49 
     50 
     51 /* Do initial consistency checks on some of the definitions to do with
     52    signals (vki_sigset_t and vki_sigaction_{toK,fromK}_t).  This stuff
     53    is fragile enough that it's important to check at startup that
     54    the world looks like what we expect it to look like.
     55 
     56    The most important thing is to check that the definition of signal
     57    sets for this platform is right.  A signal set consists of some
     58    number _VKI_NSIG_WORDS of 32- or 64-bit words.  Because the kernel
     59    itself has some indexing scheme to set/clear individual bits in the
     60    set, we must make sure we use the same layout/scheme: where this
     61    requirement bites us is in the VG_(sigfillset) etc functions in
     62    m_libcsignal.c.  So we check carefully here that it's all sensible.
     63 */
     64 void VG_(vki_do_initial_consistency_checks) ( void )
     65 {
     66    /* --- Platform-independent checks on signal sets --- */
     67 
     68    vki_sigset_t set;
     69    // Set's size must agree with _VKI_NSIG
     70    vg_assert( 8 * sizeof(set) == _VKI_NSIG );
     71    // Set's word size must agree with _VKI_NSIG_BPW
     72    vg_assert( 8 * sizeof(set.sig[0]) == _VKI_NSIG_BPW );
     73    // The set elements are 32- or 64-bit
     74    vg_assert( _VKI_NSIG_BPW == 32 || _VKI_NSIG_BPW == 64 );
     75 
     76    /* --- Platform-specific checks on signal sets --- */
     77 
     78 #  if defined(VGO_linux)
     79    /* nothing to check */
     80 #  elif defined(VGP_x86_darwin) || defined(VGP_amd64_darwin)
     81    vg_assert(_VKI_NSIG == NSIG);
     82    vg_assert(_VKI_NSIG == 32);
     83    vg_assert(_VKI_NSIG_WORDS == 1);
     84    vg_assert(sizeof(sigset_t) /* defined by Darwin */
     85              == sizeof(vki_sigset_t) /* what we actually use */);
     86 #  else
     87 #    error "Unknown plat"
     88 #  endif
     89 
     90    /* --- Platform-specific checks on sigactions --- */
     91 
     92 #  if defined(VGO_linux)
     93    /* the toK- and fromK- forms are identical */
     94    vg_assert( sizeof(vki_sigaction_toK_t)
     95               == sizeof(vki_sigaction_fromK_t) );
     96 #  elif defined(VGO_darwin)
     97    /* the toK- and fromK- forms differ by one function-pointer field
     98       (sa_tramp) */
     99    vg_assert( sizeof(vki_sigaction_toK_t)
    100               == sizeof(vki_sigaction_fromK_t) + sizeof(void*) );
    101 
    102    vg_assert(sizeof(struct sigaction) == sizeof(vki_sigaction_fromK_t));
    103    vg_assert(sizeof(struct __sigaction) == sizeof(vki_sigaction_toK_t));
    104    { struct __sigaction    t1;
    105      vki_sigaction_toK_t   t2;
    106      struct sigaction      f1;
    107      vki_sigaction_fromK_t f2;
    108      vg_assert(sizeof(t1.sa_handler) == sizeof(t2.ksa_handler));
    109      vg_assert(sizeof(t1.sa_tramp)   == sizeof(t2.sa_tramp));
    110      vg_assert(sizeof(t1.sa_mask)    == sizeof(t2.sa_mask));
    111      vg_assert(sizeof(t1.sa_flags)   == sizeof(t2.sa_flags));
    112      vg_assert(sizeof(f1.sa_handler) == sizeof(f2.ksa_handler));
    113      vg_assert(sizeof(f1.sa_mask)    == sizeof(f2.sa_mask));
    114      vg_assert(sizeof(f1.sa_flags)   == sizeof(f2.sa_flags));
    115 #    if 0
    116      vg_assert(offsetof(t1,sa_handler) == offsetof(t2.ksa_handler));
    117      vg_assert(offsetof(t1.sa_tramp)   == offsetof(t2.sa_tramp));
    118      vg_assert(offsetof(t1.sa_mask)    == offsetof(t2.sa_mask));
    119      vg_assert(offsetof(t1.sa_flags)   == offsetof(t2.sa_flags));
    120      vg_assert(offsetof(f1.sa_handler) == offsetof(f2.ksa_handler));
    121      vg_assert(offsetof(f1.sa_mask)    == offsetof(f2.sa_mask));
    122      vg_assert(offsetof(f1.sa_flags)   == offsetof(f2.sa_flags));
    123 #    endif
    124    }
    125    /* also .. */
    126    /* VKI_SET_SIGMASK is hardwired into syscall-x86-darwin.S and
    127       syscall-amd64-darwin.S */
    128    vg_assert(VKI_SIG_SETMASK == 3);
    129 
    130 #  else
    131 #     error "Unknown OS"
    132 #  endif
    133 }
    134 
    135 
    136 /*--------------------------------------------------------------------*/
    137 /*--- end                                                  m_vki.c ---*/
    138 /*--------------------------------------------------------------------*/
    139