Re: [PATCH] drm/i915: clarify reasoning for the access_ok call

On Mon, Mar 11, 2013 at 1:51 PM, Chris Wilson chris@chris-wilson.co.uk wrote:

On Mon, Mar 11, 2013 at 12:26:30PM -0700, Kees Cook wrote:

...

This clarifies the comment above the access_ok check so a missing VERIFY_READ doesn't alarm anyone.

Do we really need to copy the interface documentation?

/**

• access_ok: - Checks if a user space pointer is valid
• @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that

•    %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
  

•    to write to a block, it is always safe to read from it.
  

• @addr: User space pointer to start of block to check
• @size: Size of block to check

*/ -Chris

Probably not. It just seemed like the existing comment was insufficient after the removal of the redundant VERIFY_READ check that happened recently.

-Kees