Re: [PATCH 1/3 RESEND] sched: Remove __rcu annotation from cred pointer

From: Amol Grover
Date: Sun May 24 2020 - 04:12:07 EST

On Thu, Apr 02, 2020 at 11:26:38AM +0530, Amol Grover wrote:
> task_struct::cred (subjective credentials) is *always* used
> task-synchronously, hence, does not require RCU semantics.
> task_struct::real_cred (objective credentials) can be used in
> RCU context and its __rcu annotation is retained.
> However, task_struct::cred and task_struct::real_cred *may*
> point to the same object, hence, the object pointed to by
> task_struct::cred *may* have RCU delayed freeing.
> Suggested-by: Jann Horn <jannh@xxxxxxxxxx>
> Co-developed-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
> Signed-off-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
> Signed-off-by: Amol Grover <frextrite@xxxxxxxxx>

Hello everyone,

Could you please go through patches 1/3 and 2/3 and if deemed OK, give
your acks. I sent the original patch in beginning of February (~4 months
back) and resent the patches again in beginning of April due to lack of
traffic. Paul Moore was kind enough to ack twice - the 3/3 and its
resend patch. However these 2 patches still remain. I'd really
appreciate if someone reviewed them.