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Index > Linux > segmentation fault on calling atoi

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gAr



Joined: 18 Apr 2010
Posts: 5
gAr
Hi,

I tried to convert the characters read from terminal to integer using atoi, but atoi is triggering a segmentation fault. What may be the cause? Is there any easier way to read from the terminal?

Code:
format ELF 

public  _start
extrn atoi
extrn exit

section '.data'
n dd 1
len=$-n


section '.text' executable



_start:
mov eax,3
mov ebx,0
mov ecx,n
mov edx,len
int 0x80      ;read system call

push 0
push [n]
call atoi
add esp,8

mov [n],eax

push 0
call exit    


./fasm atoi.asm atoi.o
ld -dynamic-linker /lib/ld-linux.so.2 -o atoi -lc atoi.o
Post 23 Jun 2010, 13:28
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revolution
When all else fails, read the source


Joined: 24 Aug 2004
Posts: 17270
Location: In your JS exploiting you and your system
revolution
Try with:
Code:
;...
push 0
push n ;You want the address of n, not the contents.
call atoi
;...    
Post 23 Jun 2010, 14:07
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gAr



Joined: 18 Apr 2010
Posts: 5
gAr
Oh, thanks Smile

Didn't check that!!
Post 23 Jun 2010, 14:20
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