coregrind/pub_core_redir.h

   1
   2 /*--------------------------------------------------------------------*/
   3 /*--- Function replacement and wrapping.          pub_core_redir.h ---*/
   4 /*--------------------------------------------------------------------*/
   5
   6 /*
   7    This file is part of Valgrind, a dynamic binary instrumentation
   8    framework.
   9
  10    Copyright (C) 2000-2017 Julian Seward
  11       jseward@acm.org
  12
  13    This program is free software; you can redistribute it and/or
  14    modify it under the terms of the GNU General Public License as
  15    published by the Free Software Foundation; either version 2 of the
  16    License, or (at your option) any later version.
  17
  18    This program is distributed in the hope that it will be useful, but
  19    WITHOUT ANY WARRANTY; without even the implied warranty of
  20    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  21    General Public License for more details.
  22
  23    You should have received a copy of the GNU General Public License
  24    along with this program; if not, see <http://www.gnu.org/licenses/>.
  25
  26    The GNU General Public License is contained in the file COPYING.
  27 */
  28
  29 #ifndef __PUB_CORE_REDIR_H
  30 #define __PUB_CORE_REDIR_H
  31
  32 //--------------------------------------------------------------------
  33 // PURPOSE: This module deals with:
  34 //
  35 // - code replacement: intercepting calls to client functions, and
  36 //   pointing them to a different piece of code.
  37 //
  38 // - loading notification: telling the core where certain client-space
  39 //   functions are when they get loaded.
  40 //
  41 // - function wrapping: add calls to code before and after client
  42 //   functions execute, for inspection and/or modification.
  43 //
  44 // - checking of --require-text-symbol= specifications: when a new
  45 //   object is loaded, its symbol table is examined, and if a symbol
  46 //   (as required by the specifications) is not found then the run
  47 //   is aborted.  See comment by VG_(clo_n_req_tsyms) in
  48 //   pub_core_options.h for background.  This doesn't have anything
  49 //   to do with function intercepting or wrapping, but it does have
  50 //   to do with examining all symbols at object load time, so this
  51 //   module seems like a logical place to put it.
  52 //
  53 //--------------------------------------------------------------------
  54
  55 #include "pub_tool_redir.h"
  56 #include "pub_core_basics.h"      // Addr
  57 #include "pub_core_debuginfo.h"   // DebugInfo
  58
  59 //--------------------------------------------------------------------
  60 // Notifications - by which we are told of state changes
  61 //--------------------------------------------------------------------
  62
  63 /* Notify the module of a new DebugInfo (called from m_debuginfo). */
  64 extern void VG_(redir_notify_new_DebugInfo)( DebugInfo* );
  65
  66 /* Notify the module of the disappearance of a DebugInfo (also called
  67    from m_debuginfo). */
  68 extern void VG_(redir_notify_delete_DebugInfo)( const DebugInfo* );
  69
  70 /* Initialise the module, and load initial "hardwired" redirects. */
  71 extern void VG_(redir_initialise)( void );
  72
  73 /* Notify the module of a new target for an indirect function. */
  74 extern void VG_(redir_add_ifunc_target)( Addr old_from, Addr new_from );
  75
  76 //--------------------------------------------------------------------
  77 // Queries
  78 //--------------------------------------------------------------------
  79
  80 /* This is the crucial redirection function.  It answers the question:
  81    should this code address be redirected somewhere else?  It's used
  82    just before translating a basic block.  If a redir is found,
  83    *isWrap allows to distinguish wrap- from replace- style
  84    redirections. */
  85 extern Addr VG_(redir_do_lookup) ( Addr orig, Bool* isWrap );
  86
  87
  88 //--------------------------------------------------------------------
  89 // Loading notification
  90 //--------------------------------------------------------------------
  91
  92 /* Functions named with this macro have the property that the core will
  93    be told what their address is when they are loaded.  This can be useful
  94    if the core wants to call them at some point, and so needs to know their
  95    address.  This is a weaker but more general mechanism than code
  96    replacement.
  97
  98    Functions named with this macro should be in client space, ie. in
  99    vgpreload_<tool>.h or vgpreload_core.h. */
 100
 101 #define VG_NOTIFY_ON_LOAD(name)           _vgnU_##name
 102 #define VG_NOTIFY_ON_LOAD_PREFIX          "_vgnU_"
 103 #define VG_NOTIFY_ON_LOAD_PREFIX_LEN      6
 104
 105
 106 //--------------------------------------------------------------------
 107 // Function wrapping
 108 //--------------------------------------------------------------------
 109
 110 // This is currently not working(?) --njn
 111
 112 /* Wrapping machinery */
 113 //enum return_type {
 114   //   RT_RETURN,
 115    //   RT_LONGJMP,
 116    //   RT_EXIT,
 117    //};
 118 //
 119 //typedef struct _FuncWrapper FuncWrapper;
 120 //struct _FuncWrapper {
 121   //   void *(*before)(va_list args);
 122   //   void  (*after) (void *nonce, enum return_type, Word retval);
 123   //};
 124 //
 125 //extern void VG_(wrap_function)(Addr eip, const FuncWrapper *wrapper);
 126 //extern const FuncWrapper *VG_(is_wrapped)(Addr eip);
 127 //extern Bool VG_(is_wrapper_return)(Addr eip);
 128
 129 /* Primary interface for adding wrappers for client-side functions. */
 130 //extern CodeRedirect *VG_(add_wrapper)(const HChar *from_lib, const HChar *from_sym,
 131 //                                    const FuncWrapper *wrapper);
 132 //
 133 //extern Bool VG_(is_resolved)(const CodeRedirect *redir);
 134
 135 #endif   // __PUB_CORE_REDIR_H
 136
 137 /*--------------------------------------------------------------------*/
 138 /*--- end                                                          ---*/
 139 /*--------------------------------------------------------------------*/