Perl: what does checkstack.pl in linux source do?

Question

I am doing a project in linux kernel and I wanted to know what does this checkstack.pl do? I have never studied perl so cant understand the program. It will be great if I co

Answer 1

As already explained above that Perl script is used to find out the stack usage of kernel code, I think that Perl is used due to the fact that parsing the output of objdump -d won't be so easy if done through C code.

You can find the stack usage at the runtime by taking the address of the first argument and the address of last local variable, then subtract them, something like:

int stack_usage_func(char i)
{
    int j,k,l;

    char buf[256];
    char m;
    unsigned long stack_use = &i - &m;
    //do all processing
    return stack_use
}

The return of the function should give you the runtime stack usage, I have not compiled the code, so please ignore if it gives compilation errors, but the logic should work.