Linux

Question 1

Linux process

Answer 1

Defined via struct task_struct

These structs are held in a circular doubly linked list

Question 2

What are the two interfaces by which a process can execute in kernel space

Answer 2

System call

Exception handlers

Question 3

process creation

Answer 3

Two phased …fork followed by exec

Copy on write mechanism…on fork only parents page tables are duplicated and create a process descriptir

Question 4

Difference between process and thread

Answer 4

Linux doesn’t have differentiation like windows and solaris
Threads are process that shared resources

How to create thread
Clone(vm|fs|files|sighand,0)

How to create a process
Clone(sighand,0)

Question 5

System calls

Answer 5

Identified by a number
Users invoke using software interrupt or expection. On x86 it is interrupt no 128
System call number is given in eax register
To pass parameters registers ebx ecx edx esi edi are used
Return value in eax register