lazarus/components/fpdebug/fpimgreaderelf.pas

597 lines
18 KiB
ObjectPascal

{
This unit contains the types needed for reading Elf images.
This file was ported from DUBY. See svn log for details
---------------------------------------------------------------------------
***************************************************************************
* *
* This source is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
* This code 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 *
* General Public License for more details. *
* *
* A copy of the GNU General Public License is available on the World *
* Wide Web at <http://www.gnu.org/copyleft/gpl.html>. You can also *
* obtain it by writing to the Free Software Foundation, *
* Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1335, USA. *
* *
***************************************************************************
}
unit FpImgReaderElf;
{$mode objfpc}{$H+}
{$IFDEF INLINE_OFF}{$INLINE OFF}{$ENDIF}
interface
uses
Classes, SysUtils,
LazUTF8, {$ifdef FORCE_LAZLOGGER_DUMMY} LazLoggerDummy {$else} LazLoggerBase {$endif},
DbgIntfBaseTypes,
// FpDebug
FpImgReaderBase, fpDbgSymTable, FpImgReaderElfTypes, FpDbgCommon, FpDbgLoader;
type
TElfSection = packed record
name : AnsiString;
FileOfs : QWord;
Address : QWord;
Size : QWord;
SectionType : QWord;
Flags : QWord;
end;
PElfSection = ^TElfSection;
{ TElfFile }
TElfFile = class(TObject)
private
FTargetInfo: TTargetDescriptor;
function FElfToMachineType(machinetype: word): TMachineType;
protected
function Load32BitFile(ALoader: TDbgFileLoader): Boolean;
function Load64BitFile(ALoader: TDbgFileLoader): Boolean;
procedure AddSection(const name: AnsiString; FileOffset, Address, Size, SectionType, Flags: Qword);
public
sections : array of TElfSection;
seccount : Integer;
function LoadFromFile(ALoader: TDbgFileLoader): Boolean;
function FindSection(const Name: String): Integer;
end;
{ TElfDbgSource }
TElfDbgSource = class(TDbgImageReader) // executable parser
private
FSections: TStringListUTF8Fast;
FFileLoader : TDbgFileLoader;
fOwnSource : Boolean;
fElfFile : TElfFile;
FImgLoaderDbgFile: TDbgImageLoader;
protected
function GetSection(const AName: String): PDbgImageSection; override;
function GetSection(const ID: integer): PDbgImageSection; override;
procedure LoadSections;
procedure ClearSections;
procedure ClearSectionsButInterP;
public
class function isValid(ASource: TDbgFileLoader): Boolean; override;
class function UserName: AnsiString; override;
constructor Create(ASource: TDbgFileLoader; ADebugMap: TObject; ALoadedTargetImageAddr: TDbgPtr; OwnSource: Boolean); override;
constructor CreateForDbgFile(ASource: TDbgFileLoader; ADebugMap: TObject; ALoadedTargetImageAddr: TDbgPtr; OwnSource: Boolean);
destructor Destroy; override;
procedure ParseSymbolTable(AFpSymbolInfo: TfpSymbolList); override;
procedure AddSubFilesToLoaderList(ALoaderList: TObject; PrimaryLoader: TObject); override;
//function GetSectionInfo(const SectionName: AnsiString; var Size: int64): Boolean; override;
//function GetSectionData(const SectionName: AnsiString; Offset, Size: Int64; var Buf: array of byte): Int64; override;
end;
implementation
var
DBG_WARNINGS: PLazLoggerLogGroup;
type
TElf32symbol=record
st_name : longword;
st_value : longword;
st_size : longword;
st_info : byte; { bit 0-3: type, 4-7: bind }
st_other : byte;
st_shndx : word;
end;
PElf32symbolArray = ^TElf32symbolArray;
TElf32symbolArray = array[0..maxSmallint] of TElf32symbol;
TElf64symbol=record
st_name : longword;
st_info : byte; { bit 0-3: type, 4-7: bind }
st_other : byte;
st_shndx : word;
st_value : qword;
st_size : qword;
end;
PElf64symbolArray = ^TElf64symbolArray;
TElf64symbolArray = array[0..maxSmallint] of TElf64symbol;
const
// Symbol-map section name
_symbol = '.symtab';
_symbolstrings = '.strtab';
_symboldyn = '.dynsym';
_symboldynstrings = '.dynstr';
{ TElfFile }
function TElfFile.FElfToMachineType(machinetype: word): TMachineType;
begin
case machinetype of
EM_386: result := mt386;
EM_68K: result := mt68K;
EM_PPC: result := mtPPC;
EM_PPC64: result := mtPPC64;
EM_ARM: result := mtARM;
EM_OLD_ALPHA: result := mtOLD_ALPHA;
EM_IA_64: result := mtIA_64;
EM_X86_64: result := mtX86_64;
EM_AVR: result := mtAVR8;
EM_XTENSA: result := mtXTENSA;
EM_RISCV: result := mtRISCV;
EM_ALPHA: result := mtALPHA;
else
result := mtNone;
end;
// If OS is not encoded in header, take some guess based on machine type
if FTargetInfo.OS = osNone then
begin
if result in [mtAVR8, mtXTENSA, mtRISCV] then
FTargetInfo.OS := osEmbedded
else
// Default to the same as host...
FTargetInfo.OS := {$if defined(Linux)}osLinux
{$elseif defined(Darwin)}osDarwin
{$else}osWindows{$endif};
end;
end;
function TElfFile.Load32BitFile(ALoader: TDbgFileLoader): Boolean;
var
hdr : Elf32_Ehdr;
sect : array of Elf32_shdr;
i, j : integer;
nm : string;
sz : LongWord;
strs : array of byte;
begin
Result := ALoader.Read(0, sizeof(hdr), @hdr) = sizeof(hdr);
if not Result then Exit;
FTargetInfo.machineType := FElfToMachineType(hdr.e_machine);
SetLength(sect, hdr.e_shnum);
//ALoader.Position := hdr.e_shoff;
sz := hdr.e_shetsize * hdr.e_shnum;
if sz > LongWord(length(sect)*sizeof(Elf32_shdr)) then begin
debugln(DBG_WARNINGS, ['TElfFile.Load32BitFile Size of SectHdrs is ', sz, ' expected ', LongWord(length(sect)*sizeof(Elf32_shdr))]);
sz := LongWord(length(sect)*sizeof(Elf32_shdr));
end;
//ALoader.Read(sect[0], sz);
ALoader.Read(hdr.e_shoff, sz, @sect[0]);
i := sect[hdr.e_shstrndx].sh_offset;
j := sect[hdr.e_shstrndx].sh_size;
SetLength(strs, j);
//ALoader.Position:=i;
//ALoader.Read(strs[0], j);
ALoader.Read(i, j, @strs[0]);
for i := 0 to hdr.e_shnum - 1 do
with sect[i] do begin
nm := PChar( @strs[sh_name] );
AddSection(nm, sh_offset, sh_addr, sh_size, sh_type, sh_flags);
end;
end;
function TElfFile.Load64BitFile(ALoader: TDbgFileLoader): Boolean;
var
hdr : Elf64_Ehdr;
sect : array of Elf64_shdr;
i, j : integer;
nm : string;
sz : LongWord;
strs : array of byte;
begin
Result := ALoader.Read(0, sizeof(hdr), @hdr) = sizeof(hdr);
if not Result then Exit;
FTargetInfo.machineType := FElfToMachineType(hdr.e_machine);
SetLength(sect, hdr.e_shnum);
//ALoader.Position := hdr.e_shoff;
sz := hdr.e_shentsize * hdr.e_shnum;
if sz > LongWord(length(sect)*sizeof(Elf64_shdr)) then begin
debugln(DBG_WARNINGS, ['TElfFile.Load64BitFile Size of SectHdrs is ', sz, ' expected ', LongWord(length(sect)*sizeof(Elf64_shdr))]);
sz := LongWord(length(sect)*sizeof(Elf64_shdr));
end;
//ALoader.Read(sect[0], sz);
ALoader.Read(hdr.e_shoff, sz, @sect[0]);
i := sect[hdr.e_shstrndx].sh_offset;
j := sect[hdr.e_shstrndx].sh_size;
SetLength(strs, j);
//ALoader.Position:=i;
//ALoader.Read(strs[0], j);
ALoader.Read(i, j, @strs[0]);
for i := 0 to hdr.e_shnum - 1 do
with sect[i] do begin
nm := PChar( @strs[sh_name] );
AddSection(nm, sh_offset, sh_address, sh_size, sh_type, sh_flags);
end;
end;
procedure TElfFile.AddSection(const name: AnsiString; FileOffset, Address,
Size, SectionType, Flags: Qword);
begin
if seccount=Length(sections) then begin
if seccount = 0 then SetLength(sections, 4)
else SetLength(sections, seccount*2);
end;
sections[seccount].Address:= Address;
sections[seccount].name:=name;
sections[seccount].FileOfs:=FileOffset;
sections[seccount].Size:=Size;
sections[seccount].SectionType:=SectionType;
sections[seccount].Flags:=Flags;
inc(seccount);
end;
function TElfFile.LoadFromFile(ALoader: TDbgFileLoader): Boolean;
var
ident : array [0..EINDENT-1] of byte;
begin
try
Result := ALoader.Read(0, sizeof(ident), @ident[0]) = sizeof(ident);
if not Result then Exit;
Result := (ident[EI_MAG0] = $7f) and
(ident[EI_MAG1] = byte('E')) and
(ident[EI_MAG2] = byte('L')) and
(ident[EI_MAG3] = byte('F'));
if not Result then Exit;
Result := False;
case ident[EI_DATA] of
ELFDATA2LSB: FTargetInfo.ByteOrder := boLSB;
ELFDATA2MSB: FTargetInfo.ByteOrder := boMSB;
else
FTargetInfo.byteOrder := boNone;
end;
case ident[EI_OSABI] of
ELFOSABI_LINUX: FTargetInfo.OS := osLinux;
ELFOSABI_STANDALONE: FTargetInfo.OS := osEmbedded;
else
FTargetInfo.OS := osNone; // Will take a guess after machine type is available
end;
if ident[EI_CLASS] = ELFCLASS32 then begin
FTargetInfo.bitness := b32;
Result := Load32BitFile(ALoader);
exit;
end;
if ident[EI_CLASS] = ELFCLASS64 then begin
FTargetInfo.bitness := b64;
Result := Load64BitFile(ALoader);
exit;
end;
except
Result := false;
end;
end;
function TElfFile.FindSection(const Name: String): Integer;
var
i : Integer;
begin
Result := -1;
for i := 0 to seccount - 1 do
if sections[i].name = Name then begin
Result := i;
Exit;
end;
end;
{ TElfDbgSource }
function TElfDbgSource.GetSection(const AName: String): PDbgImageSection;
var
i: Integer;
ex: PDbgImageSectionEx;
begin
Result := nil;
i := FSections.IndexOf(AName);
if i < 0 then
exit;
ex := PDbgImageSectionEx(FSections.Objects[i]);
Result := @ex^.Sect;
if ex^.Loaded then
exit;
ex^.Loaded := True;
FFileLoader.LoadMemory(ex^.Offs, Result^.Size, Result^.RawData);
end;
function TElfDbgSource.GetSection(const ID: integer): PDbgImageSection;
var
ex: PDbgImageSectionEx;
begin
if (ID >= 0) and (ID < FSections.Count) then
begin
ex := PDbgImageSectionEx(FSections.Objects[ID]);
Result := @ex^.Sect;
Result^.Name := FSections[ID];
if not ex^.Loaded then
begin
FFileLoader.LoadMemory(ex^.Offs, Result^.Size, Result^.RawData);
ex^.Loaded := True;
end;
end
else
Result := nil;
end;
procedure TElfDbgSource.LoadSections;
var
p: PDbgImageSectionEx;
idx: integer;
i: Integer;
fs: TElfSection;
begin
for i := 0 to fElfFile.seccount - 1 do begin
fs := fElfFile.sections[i];
idx := FSections.AddObject(fs.name, nil);
New(p);
P^.Offs := fs.FileOfs;
p^.Sect.Size := fs.Size;
p^.Sect.VirtualAddress := fs.Address; //0; // Todo? fs.Address - ImageBase
p^.Sect.IsLoadable := ((fs.SectionType and SHT_PROGBITS) > 0) and ((fs.Flags and SHF_ALLOC) > 0) and
((fs.SectionType and SHT_NOBITS) = 0);
p^.Loaded := False;
FSections.Objects[idx] := TObject(p);
end;
end;
procedure TElfDbgSource.ClearSections;
var
i: Integer;
begin
for i := 0 to FSections.Count-1 do
Freemem(FSections.Objects[i]);
FSections.Clear;
end;
procedure TElfDbgSource.ClearSectionsButInterP;
var
i: Integer;
begin
i := 0;
while i < FSections.Count do begin
if FSections[i] <> '.interp' then begin
Freemem(FSections.Objects[i]);
FSections.Delete(i);
end
else
inc(i);
end;
end;
class function TElfDbgSource.isValid(ASource: TDbgFileLoader): Boolean;
var
buf : array [0..3+sizeof(Elf32_EHdr)] of byte;
begin
try
Result := Assigned(ASource) and
(ASource.Read(0, sizeof(Elf32_EHdr), @buf[0]) = sizeof(Elf32_EHdr));
if not Result then Exit;
Result := (buf[EI_MAG0] = $7f) and (buf[EI_MAG1] = byte('E')) and
(buf[EI_MAG2] = byte('L')) and (buf[EI_MAG3] = byte('F'));
except
Result := false;
end;
end;
class function TElfDbgSource.UserName: AnsiString;
begin
Result := 'ELF executable';
end;
constructor TElfDbgSource.Create(ASource: TDbgFileLoader; ADebugMap: TObject; ALoadedTargetImageAddr: TDbgPtr; OwnSource: Boolean);
var
DbgFileName, SourceFileName: String;
crc: Cardinal;
NewFileLoader: TDbgFileLoader;
ImgReadeDbgFile: TElfDbgSource;
begin
inherited Create(ASource, ADebugMap, ALoadedTargetImageAddr, OwnSource);
FSections := TStringListUTF8Fast.Create;
FSections.Sorted := True;
//FSections.Duplicates := dupError;
FSections.CaseSensitive := False;
// Elf-binaries do not have an internal offset encoded into the binary (ImageBase)
// so their reloction-offset is just equal to the location at which the binary
// has been loaded into memory. (The LoadedTargetImageAddr)
SetRelocationOffset(ALoadedTargetImageAddr);
FFileLoader := ASource;
fOwnSource := OwnSource;
fElfFile := TElfFile.Create;
fElfFile.LoadFromFile(FFileLoader);
LoadSections;
// check external debug file
if ReadGnuDebugLinkSection(DbgFileName, crc) then
begin
SourceFileName := ASource.FileName;
if SourceFileName<>'' then
SourceFileName := ExtractFilePath(SourceFileName);
NewFileLoader := LoadGnuDebugLink(SourceFileName, DbgFileName, crc);
if NewFileLoader <> nil then begin
ImgReadeDbgFile := TElfDbgSource.CreateForDbgFile(NewFileLoader, ADebugMap, ALoadedTargetImageAddr, True);
FImgLoaderDbgFile := TDbgImageLoader.Create(ImgReadeDbgFile);
ClearSectionsButInterP;
end;
end;
FTargetInfo := fElfFile.FTargetInfo;
end;
constructor TElfDbgSource.CreateForDbgFile(ASource: TDbgFileLoader; ADebugMap: TObject;
ALoadedTargetImageAddr: TDbgPtr; OwnSource: Boolean);
begin
inherited Create(ASource, ADebugMap, ALoadedTargetImageAddr, OwnSource);
FSections := TStringListUTF8Fast.Create;
FSections.Sorted := True;
//FSections.Duplicates := dupError;
FSections.CaseSensitive := False;
// Elf-binaries do not have an internal offset encoded into the binary (ImageBase)
// so their reloction-offset is just equal to the location at which the binary
// has been loaded into memory. (The LoadedTargetImageAddr)
SetRelocationOffset(ALoadedTargetImageAddr);
FFileLoader := ASource;
fOwnSource := OwnSource;
fElfFile := TElfFile.Create;
fElfFile.LoadFromFile(FFileLoader);
LoadSections;
FTargetInfo := fElfFile.FTargetInfo;
end;
destructor TElfDbgSource.Destroy;
begin
if fOwnSource then FFileLoader.Free;
fElfFile.Free;
ClearSections;
FreeAndNil(FSections);
inherited Destroy;
end;
procedure TElfDbgSource.ParseSymbolTable(AFpSymbolInfo: TfpSymbolList);
var
p: PDbgImageSection;
ps: PDbgImageSection;
SymbolArr32: PElf32symbolArray;
SymbolArr64: PElf64symbolArray;
SymbolStr: pointer;
i: integer;
SymbolCount: integer;
SymbolName: AnsiString;
SectIdx: Word;
Sect: PElfSection;
begin
AfpSymbolInfo.SetAddressBounds(1, High(AFpSymbolInfo.HighAddr)); // always search / TODO: iterate all sections for bounds
p := Section[_symbol];
ps := Section[_symbolstrings];
if (p = nil) or (ps = nil) then begin
p := Section[_symboldyn];
ps := Section[_symboldynstrings];
end;
if assigned(p) and assigned(ps) then
begin
SymbolStr:=PDbgImageSectionEx(ps)^.Sect.RawData;
if FTargetInfo.Bitness = b64 then
begin
SymbolArr64:=PDbgImageSectionEx(p)^.Sect.RawData;
SymbolCount := PDbgImageSectionEx(p)^.Sect.Size div sizeof(TElf64symbol);
for i := 0 to SymbolCount-1 do
begin
begin
{$push}
{$R-}
if SymbolArr64^[i].st_name<>0 then
begin
SectIdx := SymbolArr64^[i].st_shndx;
if (SectIdx < 0) or (SectIdx >= fElfFile.seccount) then
continue;
Sect := @fElfFile.sections[SectIdx];
if (Sect^.Flags and SHF_ALLOC) = 0 then
continue; // not loaded, symbol not in memory
SymbolName:=pchar(SymbolStr+SymbolArr64^[i].st_name);
{$Q-}
AfpSymbolInfo.Add(SymbolName, TDbgPtr(SymbolArr64^[i].st_value+RelocationOffset),
Sect^.Address + Sect^.Size + RelocationOffset);
end;
{$pop}
end
end;
end
else
begin
SymbolArr32:=PDbgImageSectionEx(p)^.Sect.RawData;
SymbolCount := PDbgImageSectionEx(p)^.Sect.Size div sizeof(TElf32symbol);
for i := 0 to SymbolCount-1 do
begin
begin
{$push}
{$R-}
if SymbolArr32^[i].st_name<>0 then
begin
SectIdx := SymbolArr32^[i].st_shndx;
if (SectIdx < 0) or (SectIdx >= fElfFile.seccount) then
continue;
Sect := @fElfFile.sections[SectIdx];
if (Sect^.Flags and SHF_ALLOC) = 0 then
continue; // not loaded, symbol not in memory
SymbolName:=pchar(SymbolStr+SymbolArr32^[i].st_name);
{$Q-}{$R-}
AfpSymbolInfo.Add(SymbolName, DWord(SymbolArr32^[i].st_value+RelocationOffset),
DWORD(Sect^.Address + Sect^.Size+RelocationOffset));
end;
{$pop}
end
end;
end;
end;
end;
procedure TElfDbgSource.AddSubFilesToLoaderList(ALoaderList: TObject; PrimaryLoader: TObject);
begin
inherited AddSubFilesToLoaderList(ALoaderList, PrimaryLoader);
if FImgLoaderDbgFile <> nil then
TDbgImageLoaderList(ALoaderList).Add(FImgLoaderDbgFile);
end;
initialization
DBG_WARNINGS := DebugLogger.FindOrRegisterLogGroup('DBG_WARNINGS' {$IFDEF DBG_WARNINGS} , True {$ENDIF} );
RegisterImageReaderClass( TElfDbgSource );
end.