[PATCH] pid: change task_struct::pid to read-only

[Peter Zijlstra]

On Mon, Dec 16, 2013 at 04:03:38PM -0500, Richard Guy Briggs wrote:
> task->pid is only ever assigned once (well ok, twice).  For system health and
> secure logging confidence, make it const to make it much more intentional when
> it is being changed.
> ---
> 
> Peter, as you had suggested, does this approach work for you in terms of making
> task_struct::pid a lot more difficult to accidentally change to try to preserve
> its integrity?

Yeah, looks good to me.

> Is the use of memcpy() significantly different from *p = *q ?

You'd have to look at the asm, but I suspect gcc knows to do full struct
copies using mempcy.