CODEWITHSUNDEEP
assemblynasm
Wealot
Wealot

Reputation: 209

Segmentation fault simple nasm program

I just started learning linux 64bit assembly and was trying to really understand the differences between lea and mov. But when creating a test file I get a segmentation fault of which I just do not understand why. The fault arises with the mov r10,[rax] in the sample code. But when I change the place of mov r10,[rax] with lea r11,[rax] I get the fault when the lea is executed.

My program:

global _start
section .text

_start:
mov rax,16
lea r11,[rax]
mov r10,[rax]
mov r9,rax

mov rax,60
xor edi,edi
syscall

Upvotes: 0

Views: 61

Answers (1)

Uwe Plonus
Uwe Plonus

Reputation: 9954

What do you expect at the memory location 16(0x10)?

Your code is

mov rax,16
mov r10,[rax]

which means that you try to load the 64bit value from memory address RAX into R10. The address 16 is normally not mapped into your program space.

Upvotes: 2

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