Object-elf.h

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/*
 * See the dyninst/COPYRIGHT file for copyright information.
 * 
 * We provide the Paradyn Tools (below described as "Paradyn")
 * on an AS IS basis, and do not warrant its validity or performance.
 * We reserve the right to update, modify, or discontinue this
 * software at any time.  We shall have no obligation to supply such
 * updates or modifications or any other form of support to you.
 * 
 * By your use of Paradyn, you understand and agree that we (or any
 * other person or entity with proprietary rights in Paradyn) are
 * under no obligation to provide either maintenance services,
 * update services, notices of latent defects, or correction of
 * defects for Paradyn.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/************************************************************************
 * $Id: Object-elf.h,v 1.21 2008/06/23 18:45:42 legendre Exp $
 * Object-elf.h: Object class for ELF file format
************************************************************************/


#if !defined(_Object_elf_h_)
#define _Object_elf_h_

#if defined(USES_DWARF_DEBUG)
//#include "dwarf.h"
#include "libdwarf.h"
#include "dwarf/h/dwarfHandle.h"
#endif

#include<vector>
#include "common/h/headers.h"
#include "common/h/Types.h"
#include "common/h/MappedFile.h"
#include "common/h/IntervalTree.h"

#if 0
#include "symtabAPI/h/Symbol.h"
#include "symtabAPI/h/Symtab.h"
#endif


#include <elf.h>
#include <libelf.h>
#include <string>

#include "elf/h/Elf_X.h"

#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>
#include <set>
#include <sys/types.h>
#include <sys/mman.h>
#include <sys/stat.h>


namespace Dyninst{

namespace Dwarf {
   class DwarfFrameParser;
   typedef boost::shared_ptr<DwarfFrameParser> DwarfFrameParserPtr;
}

namespace SymtabAPI{
/*
 * The standard symbol table in an elf file is the .symtab section. This section does
 * not have information to find the module to which a global symbol belongs, so we must
 * also read the .stab section to get this info.
 */

// Declarations for the .stab section.
// These are not declared in any system header files, so we must provide our own
// declarations. The declarations below were taken from:
//       SPARCWorks 3.0.x Debugger Interface, July 1994
// 
struct stab32 {
    unsigned int name;  // stabstr table index for this symbol
    unsigned char type; // type of this symbol
    unsigned char other;
    unsigned short desc;
    unsigned int val;   // value of this symbol -- usually zero. The real value must
            // be obtained from the symtab section
};
struct stab64 {
    // XXX ELF stabs are currently not implementing actual 64-bit support
    //     on AMD-64, for which this separation was introduced. Until we
    //     start seeing stab records with fields of the appropriate length,
    //     we should assume the smaller records.
    //unsigned long name; // stabstr table index for this symbol
    unsigned int name; // stabstr table index for this symbol
    unsigned char type; // type of this symbol
    unsigned char other;
    unsigned short desc;
    //unsigned long val;
    unsigned int val;  // value of this symbol -- usually zero. The real value must
            // be obtained from the symtab section
};

// 
// Extended to a class for 32/64-bit stab entries at runtime. - Ray
// 
class stab_entry {
  public:
    stab_entry(void *_stabptr = 0, const char *_stabstr = 0, long _nsyms = 0)
    : stabptr(_stabptr), stabstr(_stabstr), nsyms(_nsyms) { }
    virtual ~stab_entry() {};

    virtual const char *name(int i) = 0;
    virtual unsigned long nameIdx(int i) = 0;
    virtual unsigned char type(int i) = 0;
    virtual unsigned char other(int i) = 0;
    virtual unsigned short desc(int i) = 0;
    virtual unsigned long val(int i) = 0;

    unsigned long count() { return nsyms; }
    void setStringBase(const char *ptr) { stabstr = const_cast<char *>(ptr); }
    const char *getStringBase() { return stabstr; }

  protected:
    void *stabptr;
    const char *stabstr;
    long nsyms;
};

class stab_entry_32 : public stab_entry {
  public:
    stab_entry_32(void *_stabptr = 0, const char *_stabstr = 0, long _nsyms = 0)
    : stab_entry(_stabptr, _stabstr, _nsyms) { }
    virtual ~stab_entry_32() {};

    const char *name(int i = 0) { 
       if (!stabptr) {
          fprintf(stderr, "%s[%d]:  warning, accessing uninitialized stab_entry\n",
                FILE__, __LINE__);
          return "bad_name";
       }
       return stabstr + ((stab32 *)stabptr)[i].name; 
    }
    unsigned long nameIdx(int i = 0) {
       if (!stabptr) {
          fprintf(stderr, "%s[%d]:  warning, accessing uninitialized stab_entry\n",
                FILE__, __LINE__);
          return 0L;
       }
       return ((stab32 *)stabptr)[i].name; 
    }
    unsigned char type(int i = 0) {
       if (!stabptr) {
          fprintf(stderr, "%s[%d]:  warning, accessing uninitialized stab_entry\n",
                FILE__, __LINE__);
          return 0;
       }
       return ((stab32 *)stabptr)[i].type; 
    }
    unsigned char other(int i = 0) {
       if (!stabptr) {
          fprintf(stderr, "%s[%d]:  warning, accessing uninitialized stab_entry\n",
                FILE__, __LINE__);
          return 0;
       }
       return ((stab32 *)stabptr)[i].other; 
    }
    unsigned short desc(int i = 0) { 
       if (!stabptr) {
          fprintf(stderr, "%s[%d]:  warning, accessing uninitialized stab_entry\n",
                FILE__, __LINE__);
          return 0;
       }
       return ((stab32 *)stabptr)[i].desc; 
    }
    unsigned long val(int i = 0) { 
       if (!stabptr) {
          fprintf(stderr, "%s[%d]:  warning, accessing uninitialized stab_entry\n",
                FILE__, __LINE__);
          return 0L;
       }
       return ((stab32 *)stabptr)[i].val; 
    }
};

class stab_entry_64 : public stab_entry {
  public:
    stab_entry_64(void *_stabptr = 0, const char *_stabstr = 0, long _nsyms = 0)
    : stab_entry(_stabptr, _stabstr, _nsyms) { }
    virtual ~stab_entry_64() {};

    const char *name(int i = 0) { 
       if (!stabptr) {
          fprintf(stderr, "%s[%d]:  warning, accessing uninitialized stab_entry\n",
                FILE__, __LINE__);
          return "bad_name";
       }
       return stabstr + ((stab64 *)stabptr)[i].name; 
    }
    unsigned long nameIdx(int i = 0) {
       if (!stabptr) {
          fprintf(stderr, "%s[%d]:  warning, accessing uninitialized stab_entry\n",
                FILE__, __LINE__);
          return 0L;
       }
       return ((stab64 *)stabptr)[i].name; 
    }
    unsigned char type(int i = 0) {
       if (!stabptr) {
          fprintf(stderr, "%s[%d]:  warning, accessing uninitialized stab_entry\n",
                FILE__, __LINE__);
          return 0;
       }
       return ((stab64 *)stabptr)[i].type; 
    }
    unsigned char other(int i = 0) { 
       if (!stabptr) {
          fprintf(stderr, "%s[%d]:  warning, accessing uninitialized stab_entry\n",
                FILE__, __LINE__);
          return 0;
       }
       return ((stab64 *)stabptr)[i].other; 
    }
    unsigned short desc(int i = 0) { 
       if (!stabptr) {
          fprintf(stderr, "%s[%d]:  warning, accessing uninitialized stab_entry\n",
                FILE__, __LINE__);
          return 0;
       }
       return ((stab64 *)stabptr)[i].desc; 
    }
    unsigned long val(int i = 0) { 
       if (!stabptr) {
          fprintf(stderr, "%s[%d]:  warning, accessing uninitialized stab_entry\n",
                FILE__, __LINE__);
          return 0L;
       }
       return ((stab64 *)stabptr)[i].val; 
    }
};

// Types 
#define N_UNDF  0x00 /* start of object file */
#define N_GSYM  0x20 /* global symbol */
#define N_FUN   0x24 /* function or procedure */
#define N_STSYM 0x26 /* initialized static symbol */
#define N_LCSYM 0x28 /* unitialized static symbol */
#define N_ROSYM 0x2c /* read-only static symbol */
#define N_OPT   0x3c /* compiler options */
#define N_ENDM  0x62 /* end module */
#define N_SO    0x64 /* source directory and file */
#define N_ENTRY 0xa4 /* fortran alternate subroutine entry point */
#define N_BCOMM 0xe2 /* start fortran named common block */
#define N_ECOMM 0xe4 /* start fortran named common block */

// Language code -- the desc field in a N_SO entry is a language code
#define N_SO_AS      1 /* assembler source */
#define N_SO_C       2 /* K & R C source */
#define N_SO_ANSI_C  3 /* ANSI C source */
#define N_SO_CC      4 /* C++ source */
#define N_SO_FORTRAN 5 /* fortran source */
#define N_SO_PASCAL  6 /* Pascal source */
#define N_SO_F90     7 /* Fortran90 source */

//line information data
#define N_SLINE  0x44 /* line number in text segment */
#define N_SOL    0x84 /* name of the include file*/

// Symbol descriptors
// The format of a name is "<name>:<symbol descriptor><rest of name>
// The following are the descriptors of interest
#define SD_GLOBAL_FUN 'F' /* global function or procedure */
#define SD_PROTOTYPE  'P'  /* function prototypes */
#define SD_GLOBAL_VAR 'G' /* global variable */

// end of stab declarations

class pdElfShdr;

class Symtab;
class Region;
class Object;
class emitElf;
class emitElf64;

class Object : public AObject {
  friend class emitElf;
  friend class emitElf64;
 public:
  Object() {}
  Object(MappedFile *, bool, void (*)(const char *) = log_msg, bool alloc_syms = true);
  Object(MappedFile *, dyn_hash_map<std::string, LineInformation> &, std::vector<Region *> &, void (*)(const char *) = log_msg);
  Object(MappedFile *, std::string &member_name, Offset offset, 
          void (*)(const char *) = log_msg, void *base = NULL, bool alloc_syms = true);
  Object(const Object &);
  virtual ~Object();
  //const Object& operator=(const Object &);

  bool emitDriver(Symtab *obj, std::string fName, std::vector<Symbol *>&allSymbols, unsigned flag);  
  
  const char *elf_vaddr_to_ptr(Offset vaddr) const;
  bool hasStabInfo() const { return ! ( !stab_off_ || !stab_size_ || !stabstr_off_ ); }
  bool hasDwarfInfo() const { return dwarvenDebugInfo; }
  stab_entry * get_stab_info() const;
  const char * getFileName() const { return mf->filename().c_str(); }
  void getModuleLanguageInfo(dyn_hash_map<std::string, supportedLanguages> *mod_langs);
  void parseFileLineInfo(Symtab *obj, dyn_hash_map<std::string, LineInformation> &li);
  void parseTypeInfo(Symtab *obj);

  bool needs_function_binding() const { return (plt_addr_ > 0); } 
  bool get_func_binding_table(std::vector<relocationEntry> &fbt) const;
  bool get_func_binding_table_ptr(const std::vector<relocationEntry> *&fbt) const;
  void getDependencies(std::vector<std::string> &deps);
  std::vector<std::string> &libsRMd();

  bool addRelocationEntry(relocationEntry &re);

  //getLoadAddress may return 0 on shared objects
  Offset getLoadAddress() const { return loadAddress_; }

  Offset getEntryAddress() const { return entryAddress_; }
  // To be changed later - Giri
  Offset getBaseAddress() const { return 0; }
  static bool truncateLineFilenames;

  void insertPrereqLibrary(std::string libname);
  bool removePrereqLibrary(std::string libname);
  void insertDynamicEntry(long name, long value);
 
  virtual char *mem_image() const 
  {
     assert(mf);
     return (char *)mf->base_addr();
  }

  SYMTAB_EXPORT ObjectType objType() const;
  const char *interpreter_name() const;


  // On most platforms, the TOC offset doesn't exist and is thus null. 
  // On PPC64, it varies _by function_ and is used to point into the GOT,
  // a big data table. We can look it up by parsing the OPD, a function
  // descriptor table. 
  Offset getTOCoffset(Offset off) const;

  // This is an override for the whole thing; we could do per-function but 
  // we're missing a _lot_ of hardware for that. 
  void setTOCoffset(Offset off);

  const std::ostream &dump_state_info(std::ostream &s);
  bool isEEL() { return EEL; }

    //to determine if a mutation falls in the text section of
    // a shared library
    bool isinText(Offset addr, Offset baseaddr) const { 
        //printf(" baseaddr %x TESTING %x %x \n", baseaddr, text_addr_ + baseaddr  , text_addr_ + baseaddr + text_size_ );
        if(addr > text_addr_ + baseaddr     &&
           addr < text_addr_ + baseaddr + text_size_ ) {
            return true;
        }
        return false;
    } 
    // to determine where in the .plt this function is listed 
    // returns an offset from the base address of the object
    // so the entry can easily be located in memory
    Offset getPltSlot(std::string funcName) const ;
    Offset textAddress(){ return text_addr_;}
    bool isText( Offset addr ) const
    {
        if( addr >= text_addr_ && addr <= text_addr_ + text_size_ )
        return true;
        return false;
    }

   Dyninst::Architecture getArch();

    bool is_offset_in_plt(Offset offset) const;
    Elf_X_Shdr *getRegionHdrByAddr(Offset addr);
    int getRegionHdrIndexByAddr(Offset addr);
    Elf_X_Shdr *getRegionHdrByIndex(unsigned index);
    bool isRegionPresent(Offset segmentStart, Offset segmentSize, unsigned newPerms);

    bool getRegValueAtFrame(Address pc, 
                            Dyninst::MachRegister reg, 
                            Dyninst::MachRegisterVal &reg_result,
                            MemRegReader *reader);
    bool hasFrameDebugInfo();
    
    bool convertDebugOffset(Offset off, Offset &new_off);

    std::vector< std::vector<Offset> > getMoveSecAddrRange() const {return moveSecAddrRange;};
    dyn_hash_map<int, Region*> getTagRegionMapping() const { return secTagRegionMapping;}

    bool hasReldyn() const {return hasReldyn_;}
    bool hasReladyn() const {return hasReladyn_;}
    bool hasRelplt() const {return hasRelplt_;}
    bool hasRelaplt() const {return hasRelaplt_;}
    bool isBlueGeneP() const {return isBlueGeneP_;}
    bool isBlueGeneQ() const {return isBlueGeneQ_;}
    bool hasNoteSection() const {return hasNoteSection_;}
    Region::RegionType getRelType() const { return relType_; }

    Offset getTextAddr() const {return text_addr_;}
    Offset getSymtabAddr() const {return symtab_addr_;}
    Offset getStrtabAddr() const {return strtab_addr_;}
    Offset getDynamicAddr() const {return dynamic_addr_;}
    Offset getDynsymSize() const {return dynsym_size_;}
    Offset getElfHashAddr() const {return elf_hash_addr_;}
    Offset getGnuHashAddr() const {return gnu_hash_addr_;}
    Offset getRelPLTAddr() const { return rel_plt_addr_; }
    Offset getRelPLTSize() const { return rel_plt_size_; }
    Offset getRelDynAddr() const { return rel_addr_; }
    Offset getRelDynSize() const { return rel_size_; }

    std::vector<relocationEntry> &getPLTRelocs() { return fbt_; }
    std::vector<relocationEntry> &getDynRelocs() { return relocation_table_; }

    Offset getInitAddr() const {return init_addr_; }
    Offset getFiniAddr() const { return fini_addr_; }

    virtual void setTruncateLinePaths(bool value);
    virtual bool getTruncateLinePaths();
    
    Elf_X * getElfHandle() { return elfHdr; }

    unsigned gotSize() const { return got_size_; }
    Offset gotAddr() const { return got_addr_; }

    SYMTAB_EXPORT virtual void getSegmentsSymReader(std::vector<SymSegment> &segs); 

  private:
  static void log_elferror (void (*)(const char *), const char *);
    
  Elf_X *elfHdr;
 
  std::vector< std::vector<Offset> > moveSecAddrRange;
  dyn_hash_map<Offset, int> secAddrTagMapping;
  dyn_hash_map<int, unsigned long> secTagSizeMapping;
  dyn_hash_map<int, Region*> secTagRegionMapping;

  bool hasReldyn_;
  bool hasReladyn_;
  bool hasRelplt_;
  bool hasRelaplt_;
  Region::RegionType relType_;

  bool isBlueGeneP_;
  bool isBlueGeneQ_;
  bool hasNoteSection_;

  Offset   elf_hash_addr_;   //.hash section 
  Offset   gnu_hash_addr_;   //.gnu.hash section 

  Offset   dynamic_offset_;
  size_t   dynamic_size_;
  size_t   dynsym_size_;
  Offset   init_addr_;
  Offset   fini_addr_;
  Offset   text_addr_;   //.text section 
  Offset   text_size_;   //.text section size
  Offset   symtab_addr_;
  Offset   strtab_addr_;
  Offset   dynamic_addr_;    //.dynamic section
  Offset   dynsym_addr_;        // .dynsym section
  Offset   dynstr_addr_;        // .dynstr section
  Offset   got_addr_;           // global offset table
  unsigned got_size_;           // global offset table
  Offset   plt_addr_;           // procedure linkage table
  unsigned plt_size_;           // procedure linkage table
  unsigned plt_entry_size_;     // procedure linkage table
  Offset   rel_plt_addr_;       // .rel[a].plt section
  unsigned rel_plt_size_;       // .rel[a].plt section
  unsigned rel_plt_entry_size_; // .rel[a].plt section
  Offset    rel_addr_;
  unsigned  rel_size_;       // DT_REL/DT_RELA in dynamic section
  unsigned  rel_entry_size_; // DT_REL/DT_RELA in dynamic section
  Offset   opd_addr_;
  unsigned opd_size_;

  Offset   stab_off_;           // .stab section
  unsigned stab_size_;          // .stab section
  Offset   stabstr_off_;        // .stabstr section

  Offset   stab_indx_off_;   // .stab.index section
  unsigned  stab_indx_size_;     // .stab.index section
  Offset   stabstr_indx_off_;    // .stabstr.index section

  bool      dwarvenDebugInfo;    // is DWARF debug info present?
  Offset   loadAddress_;      // The object may specify a load address
                               //   Set to 0 if it may load anywhere
  Offset entryAddress_;
  char *interpreter_name_;
  bool  isStripped;

  std::map<Offset, Offset> TOC_table_;

  public:
  Dyninst::Dwarf::DwarfHandle::ptr dwarf;
  private:

  bool      EEL;                 // true if EEL rewritten
  bool      did_open;       // true if the file has been mmapped
  ObjectType obj_type_;

  // for sparc-solaris this is a table of PLT entry addr, function_name
  // for x86-solaris this is a table of GOT entry addr, function_name
  // on sparc-solaris the runtime linker modifies the PLT entry when it
  // binds a function, on X86 the PLT entry is not modified, but it uses
  // an indirect jump to a GOT entry that is modified when the function 
  // is bound....is this correct???? or should it be <PLTentry_addr, name> 
  // for both?
  std::vector<relocationEntry> relocation_table_;
  std::vector<relocationEntry> fbt_;

  // all section headers, sorted by address
  // we use these to do a better job of finding the end of symbols
  std::vector<Elf_X_Shdr*> allRegionHdrs;
  std::vector<Elf_X_Shdr*> allRegionHdrsByShndx;

  // Symbol version mappings. used to store symbol version names.
  dyn_hash_map<unsigned, std::vector<std::string> >versionMapping;
  dyn_hash_map<unsigned, std::string> versionFileNameMapping;

  std::vector<std::string> deps_;
  std::vector<std::string> rmd_deps;

  bool loaded_elf( Offset &, Offset &,
            Elf_X_Shdr* &,
            Elf_X_Shdr* &, Elf_X_Shdr* &, 
            Elf_X_Shdr* &, Elf_X_Shdr* &, 
            Elf_X_Shdr* &, Elf_X_Shdr* &, 
            Elf_X_Shdr*& rel_plt_scnp, Elf_X_Shdr*& plt_scnp, 
            Elf_X_Shdr*& got_scnp, Elf_X_Shdr*& dynsym_scnp,
            Elf_X_Shdr*& dynstr_scnp, Elf_X_Shdr*& dynamic_scnp, Elf_X_Shdr*& eh_frame,
            Elf_X_Shdr*& gcc_except, Elf_X_Shdr *& interp_scnp,
           Elf_X_Shdr *&opd_scnp,
          bool a_out=false);
  
  Symbol *handle_opd_symbol(Region *opd, Symbol *sym);
  void handle_opd_relocations();
  void parse_opd(Elf_X_Shdr *);
  void parseStabFileLineInfo(Symtab *, dyn_hash_map<std::string, LineInformation> &li);
  void parseDwarfFileLineInfo(dyn_hash_map<std::string, LineInformation> &li);

  void parseDwarfTypes(Symtab *obj);
  void parseStabTypes(Symtab *obj);

  void load_object(bool);
  void load_shared_object(bool);

  // initialize relocation_table_ from .rel[a].plt section entries 
  bool get_relocation_entries(Elf_X_Shdr *&rel_plt_scnp,
                  Elf_X_Shdr *&dynsym_scnp, 
                  Elf_X_Shdr *&dynstr_scnp);

  bool get_relocationDyn_entries( unsigned rel_index,
                     Elf_X_Shdr *&dynsym_scnp,
                     Elf_X_Shdr *&dynstr_scnp );

  // Parses sections with relocations and links these relocations to
  // existing symbols
  bool parse_all_relocations(Elf_X &, Elf_X_Shdr *, Elf_X_Shdr *,
          Elf_X_Shdr *, Elf_X_Shdr *);
  
  void parseDynamic(Elf_X_Shdr *& dyn_scnp, Elf_X_Shdr *&dynsym_scnp, 
                    Elf_X_Shdr *&dynstr_scnp);
  
  bool parse_symbols(Elf_X_Data &symdata, Elf_X_Data &strdata,
                     Elf_X_Shdr* bssscnp,
                     Elf_X_Shdr* symscnp,
                     bool shared_library,
                     std::string module);
  
  void parse_dynamicSymbols( Elf_X_Shdr *& dyn_scnp, Elf_X_Data &symdata,
                             Elf_X_Data &strdata, bool shared_library,
                             std::string module);

  void find_code_and_data(Elf_X &elf,
       Offset txtaddr, Offset dataddr);
  //void insert_symbols_static(std::vector<Symbol *> &allsymbols);
  bool fix_global_symbol_modules_static_stab(Elf_X_Shdr *stabscnp,
                         Elf_X_Shdr *stabstrscnp);
  bool fix_global_symbol_modules_static_dwarf();

  void get_valid_memory_areas(Elf_X &elf);

  bool find_catch_blocks(Elf_X_Shdr *eh_frame, Elf_X_Shdr *except_scn,
                         Address textaddr, Address dataaddr,
                         std::vector<ExceptionBlock> &catch_addrs);

#if defined(USES_DWARF_DEBUG)
  std::string find_symbol(std::string name); 
  bool fixSymbolsInModule(Dwarf_Debug dbg, std::string & moduleName, Dwarf_Die dieEntry);
  unsigned fixSymbolsInModuleByRange(IntervalTree<Dwarf_Addr, std::string> &module_ranges);
#endif

 public:
  struct DbgAddrConversion_t {
     DbgAddrConversion_t() : dbg_offset(0x0), dbg_size(0x0), orig_offset(0x0) {}
     std::string name;
     Offset dbg_offset;
     unsigned dbg_size;
     Offset orig_offset;
  };
 private:
  bool DbgSectionMapSorted;
  std::vector<DbgAddrConversion_t> DebugSectionMap;

 public:  
  std::set<std::string> prereq_libs;
  std::vector<std::pair<long, long> > new_dynamic_entries;
};

//const char *pdelf_get_shnames(Elf *elfp, bool is64);

}//namespace SymtabAPI
}//namespace Dyninst

#endif /* !defined(_Object_elf_h_) */