i386-linux.elf.execve-fold.s

UPX 源代码

/*
;  i386-linux.elf.execve-fold.S -- linkage to C code to process Elf binary
;
;  This file is part of the UPX executable compressor.
;
;  Copyright (C) 2000-2007 John F. Reiser
;  All Rights Reserved.
;
;  UPX and the UCL library are free software; you can redistribute them
;  and/or modify them 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 program 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.
;
;  You should have received a copy of the GNU General Public License
;  along with this program; see the file COPYING.
;  If not, write to the Free Software Foundation, Inc.,
;  59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
;
;  Markus F.X.J. Oberhumer              Laszlo Molnar
;  <[e-mail]>          <[e-mail]>
;
;  John F. Reiser
;  <[e-mail]>
;
*/

#include "arch/i386/macros.S"


// control just falls through, after this part and compiled C code
// are uncompressed.

#define szElf32_Ehdr 0x34
#define szElf32_Phdr 8*4
#define e_entry  (16 + 2*2 + 4)
#define p_vaddr  2*4
#define p_memsz  5*4
#define szl_info 12
#define szp_info 12

fold_begin:  // enter: %ebx= &Elf32_Ehdr of this program

                pop     eax                 // Pop the argument count
                mov     ecx, esp            // argv starts just at the current stack top
                lea     edx, [esp+eax*4+4]  // envp = &argv[argc + 1]
                mov edi, [ebx + e_entry]
                lea esi, [ebx + szElf32_Ehdr + 2*szElf32_Phdr + szl_info]
                sub edi, esi  // length
                lea ebx, [2 + ebp]  // f_unfilter, maybe
                pusha  // (cprLen, cprSrc, f_decpr, xx, f_unf, envp, argv, argc)
.extern upx_main
                call    upx_main            // Call the UPX main function
                hlt                         // Crash if somehow upx_main does return

#define __NR_mmap 90

mmap: .globl mmap
        push ebx
        lea ebx, [2*4 + esp]
        push __NR_mmap
        pop eax
        int 0x80
        pop ebx
        ret

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