#!/usr/bin/stap

global traceme;

probe syscall.open {
    if(pid() != target() || filename != "not_exists") 
        next;   

    traceme = target();

    printf("=> syscall.open [%s]\n", execname());
}

probe syscall.open.return {
    if(pid() == target()) {
        traceme = 0;
    }   
}

probe kernel.function("*@fs/*").call ?,
      kernel.function("*@fs/*").return ? {
    if(!traceme || traceme != pid()) 
        next;

    if(!is_return()) {
        printf("%s -> %s\n", indent( 1), probefunc());
    }
    else {
        ret = 0;
        if(@defined($return))
                ret = $return;

        printf("%s <- %s [%d]\n", indent(-1), probefunc(), ret);
    }
}