| SUB instruction | (gdb) disass Dump of assembler code for function *__GI___poll: 0x00007fc50ab670b0 : sub $0x28,%rsp 0x00007fc50ab670b4 : mov 0x29c52e(%rip),%eax # 0x7fc50ae035e8 0x00007fc50ab670ba : test %eax,%eax 0x00007fc50ab670bc : jne 0x7fc50ab670d5 0x00007fc50ab670be : movslq %edx,%rdx 0x00007fc50ab670c1 : mov $0x7,%eax 0x00007fc50ab670c6 : syscall => 0x00007fc50ab670c8 : cmp $0xfffffffffffff000,%rax 0x00007fc50ab670ce : ja 0x7fc50ab67121 0x00007fc50ab670d0 : add $0x28,%rsp …
Author Archives: jeffrin
addition. using PHP
addition #!/usr/bin/php # Author : Jeffrin # jeffrin@rocketmail.com # License GNU GPL V3 # usage : php addition.php <?php $f=’1′; $s=’1′; echo $f + $s ; echo “\n”; ?> A Screenshot $./addition.php # Author : Jeffrin # jeffrin@rocketmail.com # License GNU GPL V3 # usage : php addition.php 2 $
What is a SYSENTER instruction ?
ABOUT sysenter instruction The SYSENTER instruction is part of the “Fast System Call” facility introduced on the Pentium(R) II processor. The SYSENTER instruction is optimized to provide the maximum performance for transitions to protection ring 0 (CPL 0). The SYSENTER instruction sets the following registers according to values specified by the operating system in certain …
SYSENTER instruction.. Pentium II..
| sysenter instruction | (gdb) disass Dump of assembler code for function __kernel_vsyscall: 0xb780b414 : push %ecx 0xb780b415 : push %edx 0xb780b416 : push %ebp 0xb780b417 : mov %esp,%ebp 0xb780b419 : sysenter 0xb780b41b : nop 0xb780b41c : nop 0xb780b41d : nop 0xb780b41e : nop 0xb780b41f : nop 0xb780b420 : nop 0xb780b421 : nop 0xb780b422 : …
NOUVEAU modeset . HOWTO
Problem I attempted to go along with a new resolution with boot time messages, but there was a conflict, the boot time messages differed from console resolution when a [nouveau] driver took control. Debian Based Solution 1. Find out the module which which takes over. [ dmesg | grep fb ] 2. Look for the …
NOP machine instruction
| Cracking | (gdb) disass Dump of assembler code for function main: 0x0000000000400494 : push %rbp 0x0000000000400495 : mov %rsp,%rbp 0x0000000000400498 : nop => 0x0000000000400499 : jmp 0x400498 End of assembler dump. (gdb) #include<stdio.h> main () { while (1) asm(“nop”); } NOPs are often involved when cracking software that checks for serial numbers, specific hardware …
NOP machine instruction
| NOP instruction | source : | Windows Debugger | In computer science NOP or NOOP (short for No Operation or No Operation Performed) is an assembly language instruction, sequence of programming language statements, or computer protocol command that effectively does nothing at all. source : http://en.wikipedia.org/wiki/NOP
What is a PUSH instruction ?
ABOUT PUSH INSTRUCTION RELATED In 8086, the main stack register is called stack pointer – SP. The stack segment register (SS) is usually used to store information about the memory segment that stores the call stack of currently executed program. SP points to current stack top. By default, the stack grows downward in memory, so …
push instruction.. push %rbx
| push instruction | (gdb) disass Dump of assembler code for function _IO_default_uflow: 0x00007f7c1e9964d0 : mov 0xd8(%rdi),%rax => 0x00007f7c1e9964d7 : push %rbx 0x00007f7c1e9964d8 : mov %rdi,%rbx 0x00007f7c1e9964db : callq *0x20(%rax) 0x00007f7c1e9964de : cmp $0xffffffffffffffff,%eax 0x00007f7c1e9964e1 : je 0x7f7c1e9964f2 0x00007f7c1e9964e3 : mov 0x8(%rbx),%rdx 0x00007f7c1e9964e7 : movzbl (%rdx),%eax 0x00007f7c1e9964ea : add $0x1,%rdx 0x00007f7c1e9964ee : mov %rdx,0x8(%rbx) 0x00007f7c1e9964f2 …
pop instruction and stack…
| POP Instruction | source : Windows Debugger. MOV AX,1234H MOV BX,5678H PUSH AX PUSH BX POP AX POP BX The values: AX=5678h BX=1234h First the value 1234h was pushed after that the value 5678h was pushed to the stack. Acording to LIFO 5678h comes of first, so AX will pop that value and BX …