Creating a new sytem call: solution

Forum: The Linux Kernel Hackers' Guide
Re: Problem creating a new system call
Date: Sun, 12 Oct 1997 06:32:03 GMT
From: C.H.Gopinath <gopich@cse.iitb.ernet.in>

The problem is using printk, it won't print on the stdout, it will be stored in the buffers. If you want the data to be displayed on the stdout use sys_write(1,ptr,len); where ptr is the string to be displayed and len is its length. Using this you can check your sys call is created or not. But regarding assigning a value to a global variable or local variable i don't know. I am also struggling for the past one week. I tried to assign and print a string in the system call. It is compiling without any problem butwhen i try to execute that, at the assignment it is giving General Protection:000 and then dumping all the register values with Segmentation Fault. Can cny body explain why it is happeing like this. By the by is there any kernel debugging tool for 4.2 kernel, if so can anybody please give pointers for that. Thanx in advance, -- C.H.Gopinath gopich@cse.iitb.ernet.in

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