title: Enable/Disable Kernel Configuration options in Yocto
body: <p>I have a configuration option called <code>CONFIG_X86_SMAP</code> that I would like to disable in my kernel image. The problem is that I can't identify where this option is being set. I can confirm that it isn't set in my <code>defconfig</code> file and also it's not set by any configuration fragment "<code>.cfg</code>".</p>
  
  <p>Even when I try to disable it using a <code>.cfg</code> as follows: </p>
  
  <pre><code># CONFIG_FOO is not set
  </code></pre>
  
  <p>I still find it enabled in my final generated .config file. I cant get to understand how this option is being enabled.</p>
  
  <p>Note: There is no dependency on this configuration option from any other driver/feature.</p>