问题描述
我是nasm的新手,我真的很想学习如何通过用户输入来存储数字.使用scanf时,我无法摆脱出现分段错误的问题.我已经在网上搜索了,但是还没有找到解决此问题的任何方法.我尝试了代码,但它对我不起作用.
I am new to nasm and I really want to learn how to store a number with user input. I can't get rid of getting segmentation fault when using scanf. I have searched the web, but havent found any solution to this problem.I tried this code but it doesn't work for me.
有人可以向我解释我在做什么错吗?
Can someone explain me what am I doing wrong?
global main
extern printf, scanf
section .data
msg: db "Enter a number: ",10,0
format:db "%d",0
section .bss
number resb 4
section .text
main:
mov rdi, msg
mov al, 0
call printf
push number
push format
call scanf
ret
提前谢谢!
推荐答案
x86-64调用惯例通常不会推论据.此外,您还必须告诉一个具有可变数量的参数的函数,以及您提供了多少个浮点参数.
The x86-64 calling convention doesn't push the arguments generally. Additionally you have to tell a function with variable count of arguments, how many floating point arguments you provide.
这有效:
global main
extern printf, scanf
section .data
msg: db "Enter a number: ",10,0
format:db "%d",0
section .bss
number resb 4
section .text
main:
sub rsp, 8 ; align the stack to a 16B boundary before function calls
mov rdi, msg
mov al, 0
call printf
mov rsi, number
mov rdi, format
mov al, 0
call scanf
add rsp, 8 ; restore the stack
ret
顺便说一句:如果要使用浮点数,则必须在调用该函数之前将堆栈对齐到16个字节的边界.
BTW: If you want to work with floating point numbers, you have to align the stack to a 16 byte boundary before calling the function.
这篇关于NASM x86_64 scanf分段故障的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!