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) 2000-2017 Nicholas Nethercote
  14       njn@valgrind.org
  15    Copyright (C) 2006-2017 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, see <http://www.gnu.org/licenses/>.
  30
  31    The GNU General Public License is contained in the file COPYING.
  32 */
  33
  34 #include "pub_core_aspacemgr.h"      // VG_(am_find_nsegment)
  35 #include "pub_core_signals.h"        // VG_(extend_stack)
  36 #include "pub_core_libcprint.h"      // VG_(umsg)
  37 #include "pub_core_tooliface.h"      // VG_TRACK
  38 #include "pub_core_machine.h"        // VG_STACK_REDZONE_SZB
  39 #include "priv_sigframe.h"           // self
  40
  41
  42 /* For tracking memory events, indicate the entire frame has been
  43    allocated.  Except, don't mess with the area which
  44    overlaps the previous frame's redzone. */
  45 static void track_frame_memory ( Addr addr, SizeT size, ThreadId tid )
  46 {
  47    VG_TRACK( new_mem_stack_signal, addr - VG_STACK_REDZONE_SZB, size, tid );
  48 }
  49
  50 #if defined(VGO_linux) || defined(VGO_solaris) || defined(VGO_freebsd)
  51
  52 /* Extend the stack segment downwards if needed so as to ensure the
  53    new signal frames are mapped to something.  Return a Bool
  54    indicating whether or not the operation was successful. */
  55 Bool ML_(sf_maybe_extend_stack) ( const ThreadState *tst, Addr addr,
  56                                   SizeT size, UInt flags )
  57 {
  58    ThreadId        tid = tst->tid;
  59    const NSegment *stackseg = NULL;
  60
  61    if (flags & VKI_SA_ONSTACK) {
  62       /* If the sigframe is allocated on an alternate stack, then we cannot
  63          extend that stack. Nothing to do here. */
  64       stackseg = VG_(am_find_nsegment)(addr);
  65    } else if (VG_(am_addr_is_in_extensible_client_stack)(addr)) {
  66       if (VG_(extend_stack)(tid, addr)) {
  67          stackseg = VG_(am_find_nsegment)(addr);
  68          if (0 && stackseg)
  69             VG_(printf)("frame=%#lx seg=%#lx-%#lx\n",
  70                         addr, stackseg->start, stackseg->end);
  71       }
  72    } else if ((stackseg = VG_(am_find_nsegment)(addr)) &&
  73               VG_(am_is_valid_for_client)(addr, 1,
  74                                           VKI_PROT_READ | VKI_PROT_WRITE)) {
  75       /* We come here for explicitly defined pthread-stacks which can be
  76          located in any client segment. */
  77    } else {
  78       /* Something unexpected */
  79       stackseg = NULL;
  80    }
  81
  82    if (stackseg == NULL || !stackseg->hasR || !stackseg->hasW) {
  83       VG_(umsg)("Can't extend stack to %#lx during signal delivery for "
  84                 "thread %u:\n", addr, tid);
  85       if (stackseg == NULL)
  86          VG_(umsg)("  no stack segment\n");
  87       else
  88          VG_(umsg)("  too small or bad protection modes\n");
  89
  90       /* set SIGSEGV to default handler */
  91       VG_(set_default_handler)(VKI_SIGSEGV);
  92       VG_(synth_fault_mapping)(tid, addr);
  93
  94       /* The whole process should be about to die, since the default
  95          action of SIGSEGV to kill the whole process. */
  96       return False;
  97    }
  98
  99    /* Tell the tool about the new memory */
 100    track_frame_memory(addr, size, tid);
 101
 102    return True;
 103 }
 104
 105 #elif defined(VGO_darwin)
 106
 107 /* Extend the stack segment downwards if needed so as to ensure the
 108    new signal frames are mapped to something.  Return a Bool
 109    indicating whether or not the operation was successful. */
 110 Bool ML_(sf_maybe_extend_stack) ( const ThreadState *tst, Addr addr,
 111                                   SizeT size, UInt flags )
 112 {
 113    /* Tell the tool about the new memory */
 114    track_frame_memory(addr, size, tst->tid);
 115    return True;
 116 }
 117
 118 #else
 119 #error unknown OS
 120 #endif
 121
 122 /*--------------------------------------------------------------------*/
 123 /*--- end                                                          ---*/
 124 /*--------------------------------------------------------------------*/