Here below I have a peace of code for two programs that cannot be debugged. Written in assembly language. Main point is that I need to debug it using DDD debugger. However, it displays "Segmentation Fault" in each case. I also tried to debug it in a simple way and with online debugger, but returns error meassage. Can someone help me with that?
Code A)
#Program asmddd.s for debugging with ddd
.global _start
.text
_start: movq $0x01289AB76EF34567, %rax
movb $-1, %al
movw $-1, %ax
movl $-1, %eax
movq $-1, %rax
movq $0x01289AB76EF34567, %rbx
movb $0xBB, %dl
movb %dl, %bl
movsbq %dl, %rbx
movzbq %dl, %rbx
movq $65535, %rbx
addq %rbx, %rax
subq %rax, %rbx
negq %rbx
subq %rbx, %rax
movq $60000, %rsi
movq $65535, %rdx
movq %rsi, %rax
imulq %rdx
cqto
idivq %rsi
testq %rsi,%rdi
jnz down1
up1: cmpq %rsi,%rdi
setl %al
movzbq %al, %rax
jmp down2
down1: pushq %rax
pushq %rbx
popq %rax
popq %rbx
movq %rdi, %rax
subq %rsi, %rax
movq %rsi, %rdx
subq %rdi, %rdx
cmpq %rsi, %rdi
cmovle %rdx, %rax
cmp %rdx, %rax
jz up1
down2: xorq %rax, %rbx
xorq %rbx, %rax
xorq %rax, %rbx
andq %rsi, %rax
orq %rsi, %rax
xorq %rax, %rax
notq %rax
negq %rax
incq %rax
decq %rax
addq $99,%rax
leaq (%rax, %rax, 8), %rax
leaq (%rax, %rax,4), %rax
salq $3, %rax
negq %rax
sarq %rax
ret
Code B)
.global _start
.data
n: .quad 0x0000000000000008
nfact: .quad 0x0000000000000000
.text
_start:
movq n, %rbx
movq %rbx,%rax
call ffact
movq $nfact, %rdi
movq %rax, (%rdi)
movq $60, %rax # system call 60 for exit
xorq %rdi, %rdi # return code 0 syscall
syscall
ffact: cmpq $1, %rbx
je L1
decq %rbx
pushq %rbx
call ffact
popq %rbx
mulq %rbx
L1: ret
