coregrind/m_sigframe/sigframe-common.c

   1 /* -*- mode: C; c-basic-offset: 3; -*- */
   2
   3 /*--------------------------------------------------------------------*/
   4 /*--- Signal frames handling: stuff common to most/all platforms   ---*/
   5 /*---                                                              ---*/
   6 /*---                                            sigframe-common.c ---*/
   7 /*--------------------------------------------------------------------*/
   8
   9 /*
  10    This file is part of Valgrind, a dynamic binary instrumentation
  11    framework.
  12
  13    Copyright (C) 2000-2013 Nicholas Nethercote
  14       njn@valgrind.org
  15    Copyright (C) 2006-2013 OpenWorks Ltd
  16       info@open-works.co.uk
  17
  18    This program is free software; you can redistribute it and/or
  19    modify it under the terms of the GNU General Public License as
  20    published by the Free Software Foundation; either version 2 of the
  21    License, or (at your option) any later version.
  22
  23    This program is distributed in the hope that it will be useful, but
  24    WITHOUT ANY WARRANTY; without even the implied warranty of
  25    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  26    General Public License for more details.
  27
  28    You should have received a copy of the GNU General Public License
  29    along with this program; if not, write to the Free Software
  30    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  31    02111-1307, USA.
  32
  33    The GNU General Public License is contained in the file COPYING.
  34 */
  35
  36 #include "pub_core_aspacemgr.h"      // VG_(am_find_nsegment)
  37 #include "pub_core_signals.h"        // VG_(extend_stack)
  38 #include "pub_core_libcprint.h"      // VG_(umsg)
  39 #include "pub_core_tooliface.h"      // VG_TRACK
  40 #include "pub_core_machine.h"        // VG_STACK_REDZONE_SZB
  41 #include "priv_sigframe.h"           // self
  42
  43
  44 /* For tracking memory events, indicate the entire frame has been
  45    allocated.  Except, don't mess with the area which
  46    overlaps the previous frame's redzone. */
  47 static void track_frame_memory ( Addr addr, SizeT size, ThreadId tid )
  48 {
  49    VG_TRACK( new_mem_stack_signal, addr - VG_STACK_REDZONE_SZB, size, tid );
  50 }
  51
  52 #if defined(VGO_linux) || defined(VGO_solaris)
  53
  54 /* Extend the stack segment downwards if needed so as to ensure the
  55    new signal frames are mapped to something.  Return a Bool
  56    indicating whether or not the operation was successful. */
  57 Bool ML_(sf_maybe_extend_stack) ( const ThreadState *tst, Addr addr,
  58                                   SizeT size, UInt flags )
  59 {
  60    ThreadId        tid = tst->tid;
  61    const NSegment *stackseg = NULL;
  62
  63    if (flags & VKI_SA_ONSTACK) {
  64       /* If the sigframe is allocated on an alternate stack, then we cannot
  65          extend that stack. Nothing to do here. */
  66       stackseg = VG_(am_find_nsegment)(addr);
  67    } else if (VG_(am_addr_is_in_extensible_client_stack)(addr)) {
  68       if (VG_(extend_stack)(tid, addr)) {
  69          stackseg = VG_(am_find_nsegment)(addr);
  70          if (0 && stackseg)
  71             VG_(printf)("frame=%#lx seg=%#lx-%#lx\n",
  72                         addr, stackseg->start, stackseg->end);
  73       }
  74    } else if ((stackseg = VG_(am_find_nsegment)(addr)) &&
  75               VG_(am_is_valid_for_client)(addr, 1,
  76                                           VKI_PROT_READ | VKI_PROT_WRITE)) {
  77       /* We come here for explicitly defined pthread-stacks which can be
  78          located in any client segment. */
  79    } else {
  80       /* Something unexpected */
  81       stackseg = NULL;
  82    }
  83
  84    if (stackseg == NULL || !stackseg->hasR || !stackseg->hasW) {
  85       VG_(umsg)("Can't extend stack to %#lx during signal delivery for "
  86                 "thread %d:\n", addr, tid);
  87       if (stackseg == NULL)
  88          VG_(umsg)("  no stack segment\n");
  89       else
  90          VG_(umsg)("  too small or bad protection modes\n");
  91
  92       /* set SIGSEGV to default handler */
  93       VG_(set_default_handler)(VKI_SIGSEGV);
  94       VG_(synth_fault_mapping)(tid, addr);
  95
  96       /* The whole process should be about to die, since the default
  97          action of SIGSEGV to kill the whole process. */
  98       return False;
  99    }
 100
 101    /* Tell the tool about the new memory */
 102    track_frame_memory(addr, size, tid);
 103
 104    return True;
 105 }
 106
 107 #elif defined(VGO_darwin)
 108
 109 /* Extend the stack segment downwards if needed so as to ensure the
 110    new signal frames are mapped to something.  Return a Bool
 111    indicating whether or not the operation was successful. */
 112 Bool ML_(sf_maybe_extend_stack) ( const ThreadState *tst, Addr addr,
 113                                   SizeT size, UInt flags )
 114 {
 115    /* Tell the tool about the new memory */
 116    track_frame_memory(addr, size, tst->tid);
 117    return True;
 118 }
 119
 120 #else
 121 #error unknown OS
 122 #endif
 123
 124 /*--------------------------------------------------------------------*/
 125 /*--- end                                                          ---*/
 126 /*--------------------------------------------------------------------*/