jory/upx
1
0
Fork 0
Code Issues Pull Requests 1 Actions Packages Projects Releases Wiki Activity

CLD and documentation

Browse Source 
amd_d_nrv2e.S l_lx_elf64amd.S fold_elf64amd.S

committer: jreiser <jreiser> 1131854052 +0000
This commit is contained in:
John Reiser 2005-11-13 03:54:12 +00:00
parent ce33ffb62a
commit db5a099097
3 changed files with 24 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
src/stub/amd_d_nrv2e.S
View File

@ -171,6 +171,7 @@ bot_n2b: # In: 0==len
jmp top_n2b
setup_rdx:
cld
pop %rdx; addq $ getbit - ra_setup_rdx,%rdx # %rdx= &getbit
cmpl $ M_NRV2E_LE32,meth; je bot_n2e
cmpl $ M_NRV2B_LE32,meth; je bot_n2b

1
src/stub/fold_elf64amd.S
View File

@ -54,6 +54,7 @@ __NR_brk= 12
__NR_exit= 60
/* In:
cld
%rbp= &decompress
%rsp= &{LENX,ADRX,LENU,ADRU,JMPU,argc,argv...,0,env...,0,auxv...,0...,strings}
*/

29
src/stub/l_lx_elf64amd.S
View File

@ -55,9 +55,6 @@ PAGE_SIZE= -PAGE_MASK
/*__LEXEC000__*/
_start: .globl _start
/* The following 'call' must be at _start; fold_begin knows this,
and so does PackLinuxElf64amd::pack3() .
*/
call main # push &decompress
#include "amd_d_nrv2e.S"
@ -75,15 +72,27 @@ _start: .globl _start
unfold:
pop %rbx # &b_info
.byte 7+0xB8; .ascii "ADRM" # movl $'ADRM',%edi
/* Get some pages. If small, then get 1 page located just after the end
of the first PT_LOAD of the compressed program. This will still be below
all of the uncompressed program. If large (>=3MB compressed), then get enough
to duplicate the entire compressed PT_LOAD, plus 1 page, located just after
the brk() of the _un_compressed program. The address and length are pre-
calculated by PackLinuxElf64amd::pack3(), and patched in at compress time.
*/
.byte 7+0xB8; .ascii "ADRM" # movl $'ADRM',%edi XXX: 4GB
push $ PROT_READ | PROT_WRITE | PROT_EXEC; pop %arg3
.byte 6+0xB8; .ascii "LENM" # movl $'LENM',%esi
.byte 6+0xB8; .ascii "LENM" # movl $'LENM',%esi XXX: 4GB
push $ MAP_PRIVATE | MAP_FIXED | MAP_ANONYMOUS; pop %sys4
subl %arg5l,%arg5l #; subl %arg6l,%arg6l # MAP_ANON ==> ignore offset
push $ SYS_mmap; pop %rax
syscall # %rax= result; trashes %rcx,%r11 only
cmpl %eax,%edi; je 0f; hlt; 0: # XXX: 4GB
/* Load the addresses and lengths that ::pack3() patched in.
XXX: 2GB Note that PUSH $imm32 sign-extends to 64 bits.
XXX: 4GB Note that MOVL $imm32,reg zero-extends to 64-bits.
If desired, then use an temporary register to extend the 2GB PUSH to 4GB.
*/
.byte 0x68; .ascii "JMPU" # push $'JMPU' # for unmap in fold
.byte 0x68; .ascii "ADRU" # push $'ADRU' # for unmap in fold
.byte 6+0xB8; .ascii "ADRC" # movl $'ADRC',%esi
@ -92,14 +101,19 @@ unfold:
.byte 0x68; .ascii "ADRX" # push $'ADRX' # for upx_main
.byte 0x68; .ascii "LENX" # push $'LENX' # for upx_main
movl %edi,%edx
subl %esi,%edx # relocation amount
/* Move and relocate if compressed overlaps uncompressed.
Move by 0 when total compressed executable is < 3MB.
*/
movl %edi,%edx # ADRM
subl %esi,%edx # (ADRM - ADRC) == relocation amount
addl %edx,%ebp # update &decompress
addl %edx,%ebx # update &b_info
cld
rep; movsq
xchgl %eax,%edi
/* Decompress the folded part of this stub, then execute it. */
movl %ebx,%esi # %arg2l= &b_info (relocated)
push %rax # ret_addr after decompression
xchgl %eax,%arg3l # %arg3= dst for unfolding XXX: 4GB
@ -108,6 +122,7 @@ unfold:
lodsl; movzbl %al,%arg5l # b_method
xchg %arg1l,%arg2l # XXX: 4GB
jmp *%rbp # goto decompress; return to unfolded loader
main:
# int3 # uncomment for debugging
pop %rbp # &decompress