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, write to the Free Software
  25    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  26    02111-1307, USA.
  27
  28    The GNU General Public License is contained in the file COPYING.
  29 */
  30
  31 #ifndef __PUB_CORE_REDIR_H
  32 #define __PUB_CORE_REDIR_H
  33
  34 //--------------------------------------------------------------------
  35 // PURPOSE: This module deals with:
  36 //
  37 // - code replacement: intercepting calls to client functions, and
  38 //   pointing them to a different piece of code.
  39 //
  40 // - loading notification: telling the core where certain client-space
  41 //   functions are when they get loaded.
  42 //
  43 // - function wrapping: add calls to code before and after client
  44 //   functions execute, for inspection and/or modification.
  45 //
  46 // - checking of --require-text-symbol= specifications: when a new
  47 //   object is loaded, its symbol table is examined, and if a symbol
  48 //   (as required by the specifications) is not found then the run
  49 //   is aborted.  See comment by VG_(clo_n_req_tsyms) in
  50 //   pub_core_options.h for background.  This doesn't have anything
  51 //   to do with function intercepting or wrapping, but it does have
  52 //   to do with examining all symbols at object load time, so this
  53 //   module seems like a logical place to put it.
  54 //
  55 //--------------------------------------------------------------------
  56
  57 #include "pub_tool_redir.h"
  58 #include "pub_core_basics.h"      // Addr
  59 #include "pub_core_debuginfo.h"   // DebugInfo
  60
  61 //--------------------------------------------------------------------
  62 // Notifications - by which we are told of state changes
  63 //--------------------------------------------------------------------
  64
  65 /* Notify the module of a new DebugInfo (called from m_debuginfo). */
  66 extern void VG_(redir_notify_new_DebugInfo)( const DebugInfo* );
  67
  68 /* Notify the module of the disappearance of a DebugInfo (also called
  69    from m_debuginfo). */
  70 extern void VG_(redir_notify_delete_DebugInfo)( const DebugInfo* );
  71
  72 /* Initialise the module, and load initial "hardwired" redirects. */
  73 extern void VG_(redir_initialise)( void );
  74
  75 /* Notify the module of a new target for an indirect function. */
  76 extern void VG_(redir_add_ifunc_target)( Addr old_from, Addr new_from );
  77
  78 //--------------------------------------------------------------------
  79 // Queries
  80 //--------------------------------------------------------------------
  81
  82 /* This is the crucial redirection function.  It answers the question:
  83    should this code address be redirected somewhere else?  It's used
  84    just before translating a basic block.  If a redir is found,
  85    *isWrap allows to distinguish wrap- from replace- style
  86    redirections. */
  87 extern Addr VG_(redir_do_lookup) ( Addr orig, Bool* isWrap );
  88
  89
  90 //--------------------------------------------------------------------
  91 // Loading notification
  92 //--------------------------------------------------------------------
  93
  94 /* Functions named with this macro have the property that the core will
  95    be told what their address is when they are loaded.  This can be useful
  96    if the core wants to call them at some point, and so needs to know their
  97    address.  This is a weaker but more general mechanism than code
  98    replacement.
  99
 100    Functions named with this macro should be in client space, ie. in
 101    vgpreload_<tool>.h or vgpreload_core.h. */
 102
 103 #define VG_NOTIFY_ON_LOAD(name)           _vgnU_##name
 104 #define VG_NOTIFY_ON_LOAD_PREFIX          "_vgnU_"
 105 #define VG_NOTIFY_ON_LOAD_PREFIX_LEN      6
 106
 107
 108 //--------------------------------------------------------------------
 109 // Function wrapping
 110 //--------------------------------------------------------------------
 111
 112 // This is currently not working(?) --njn
 113
 114 /* Wrapping machinery */
 115 //enum return_type {
 116   //   RT_RETURN,
 117    //   RT_LONGJMP,
 118    //   RT_EXIT,
 119    //};
 120 //
 121 //typedef struct _FuncWrapper FuncWrapper;
 122 //struct _FuncWrapper {
 123   //   void *(*before)(va_list args);
 124   //   void  (*after) (void *nonce, enum return_type, Word retval);
 125   //};
 126 //
 127 //extern void VG_(wrap_function)(Addr eip, const FuncWrapper *wrapper);
 128 //extern const FuncWrapper *VG_(is_wrapped)(Addr eip);
 129 //extern Bool VG_(is_wrapper_return)(Addr eip);
 130
 131 /* Primary interface for adding wrappers for client-side functions. */
 132 //extern CodeRedirect *VG_(add_wrapper)(const HChar *from_lib, const HChar *from_sym,
 133 //                                    const FuncWrapper *wrapper);
 134 //
 135 //extern Bool VG_(is_resolved)(const CodeRedirect *redir);
 136
 137 #endif   // __PUB_CORE_REDIR_H
 138
 139 /*--------------------------------------------------------------------*/
 140 /*--- end                                                          ---*/
 141 /*--------------------------------------------------------------------*/