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Add code to find base address in unix ELF aux vector above enviroment in startup stack

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git-svn-id: trunk@33007 -
This commit is contained in:
pierre 2016-01-26 14:44:31 +00:00
parent c2b0256869
commit 90359bcb3c
1 changed files with 106 additions and 1 deletions
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107
rtl/inc/exeinfo.pp
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@ -16,6 +16,9 @@
This unit should not be compiled in objfpc mode, since this would make it
dependent on objpas unit.
}
{$mode objfpc}
unit exeinfo;
interface
@ -51,7 +54,7 @@ procedure GetModuleByAddr(addr: pointer; var baseaddr: pointer; var filename: st
implementation
uses
strings{$ifdef windows},windows{$endif windows};
sysutils,strings{$ifdef windows},windows{$endif windows};
{$ifdef unix}
@ -116,8 +119,10 @@ uses
{$if defined(freebsd) or defined(netbsd) or defined (openbsd) or defined(linux) or defined(sunos) or defined(android) or defined(dragonfly)}
{$ifdef cpu64}
{$define ELF64}
{$define FIND_BASEADDR_ELF}
{$else}
{$define ELF32}
{$define FIND_BASEADDR_ELF}
{$endif}
{$endif}
@ -793,6 +798,102 @@ type
{$if defined(ELF32) or defined(ELF64) or defined(BEOS)}
{$ifdef FIND_BASEADDR_ELF}
var
envp : ppchar external name 'operatingsystem_parameter_envp';
procedure GetExeInMemoryBaseAddr(addr : pointer; var BaseAddr : pointer;
var filename : openstring);
type
AT_HDR = record
typ : ptruint;
value : ptruint;
end;
P_AT_HDR = ^AT_HDR;
{ Values taken from /usr/include/linux/auxvec.h }
const
AT_HDR_COUNT = 5;{ AT_PHNUM }
AT_HDR_SIZE = 4; { AT_PHENT }
AT_HDR_Addr = 3; { AT_PHDR }
AT_EXE_FN = 31; {AT_EXECFN }
var
pc : ppchar;
pat_hdr : P_AT_HDR;
i, phdr_count : ptrint;
phdr_size : ptruint;
phdr : ^telfproghdr;
found_addr : ptruint;
begin
filename:=ParamStr(0);
Try
pc:=envp;
phdr_count:=-1;
phdr_size:=0;
phdr:=nil;
found_addr:=ptruint(-1);
while (assigned(pc^)) do
inc (pointer(pc), sizeof(ptruint));
inc(pointer(pc), sizeof(ptruint));
pat_hdr:=P_AT_HDR(pc);
while assigned(pat_hdr) do
begin
if (pat_hdr^.typ=0) and (pat_hdr^.value=0) then
break;
if pat_hdr^.typ = AT_HDR_COUNT then
phdr_count:=pat_hdr^.value;
if pat_hdr^.typ = AT_HDR_SIZE then
phdr_size:=pat_hdr^.value;
if pat_hdr^.typ = AT_HDR_Addr then
phdr := pointer(pat_hdr^.value);
if pat_hdr^.typ = AT_EXE_FN then
filename:=strpas(pchar(pat_hdr^.value));
inc (pointer(pat_hdr),sizeof(AT_HDR));
end;
if (phdr_count>0) and (phdr_size = sizeof (telfproghdr))
and assigned(phdr) then
begin
for i:=0 to phdr_count -1 do
begin
if (phdr^.p_type = 1 {PT_LOAD}) and (ptruint(phdr^.p_vaddr) < found_addr) then
found_addr:=phdr^.p_vaddr;
inc(phdr, phdr_size);
end;
{$ifdef DEBUG}
end
else
begin
if (phdr_count=-1) then
writeln(stderr,'AUX entry AT_PHNUM not found');
if (phdr_size=0) then
writeln(stderr,'AUX entry AT_PHENT not found');
if (phdr=nil) then
writeln(stderr,'AUX entry AT_PHDR not found');
{$endif DEBUG}
end;
if found_addr<>ptruint(-1) then
begin
{$ifdef DEBUG}
Writeln(stderr,'Found addr = $',hexstr(found_addr,2 * sizeof(ptruint)));
{$endif}
BaseAddr:=pointer(found_addr);
end
{$ifdef DEBUG}
else
writeln(stderr,'Error parsing stack');
{$endif DEBUG}
except
{$ifdef DEBUG}
writeln(stderr,'Exception parsing stack');
{$endif DEBUG}
end
end;
{$endif FIND_BASEADDR_ELF}
function OpenElf(var e:TExeFile):boolean;
var
elfheader : telfheader;
@ -1240,4 +1341,8 @@ begin
end;
begin
{$ifdef FIND_BASEADDR_ELF}
UnixGetModuleByAddrHook:=@GetExeInMemoryBaseAddr;
{$endif FIND_BASEADDR_ELF}
end.