I am having a linux asm failure in a add-up program,which receive two input and ouput the sum. And running result is segment fault.I am running it on linux 32bit ubuntu.

.section .data
.section .text
.globl _start	
_start:
	pushl %ebp
	movl $0,-4(%ebp)
	movl $0,-8(%ebp)

	movl $3,%eax
	movl $0,%ebx
	movl -4(%ebp),%ecx
	int $0x80
	
	movl $3,%eax
	movl $0,%ebx
	movl -4(%ebp),%ecx
	int $0x80

	movl -4(%ebp),%ecx
	addl -8(%ebp),%ecx
	movl $4,%eax
	movl $1,%ebx
	int $0x80

	movl $1,%eax
	movl $0,%ebx
	int $0x80