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Is simple assembly code causing a segment error?

.section .data

.section .text
.globl _start
_start:
 movl $1, %eax  # this is the linux kernel command
    # number (system call) for exiting
    # a program

movl $4, %ebx   # this is the status number we will
    # return to the operating system.
    # Change this around and it will
    # return different things to
    # echo $?

int $0x80   # this wakes up the kernel to run
    # the exit command

But if I remove the last line of code int 0x80

, then it throws a segment error .

I do not know why? Can someone tell me.

Thank you for your time.

Thanks everyone. Now I am getting the answer.

Without a line of code int $0x80

, the system does not know if this application ended or when this application ended. ... It will crash.

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If you delete int 0x80

, you will have a segmentation fault because it will start executing any random bytes in RAM right after your program. You really can't predict what will happen and something might happen, but a segfault will likely happen because the random data will most likely act as memory access outside of your process memory.



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