Commit baa35b3c authored by Kumar Kartikeya Dwivedi's avatar Kumar Kartikeya Dwivedi Committed by Alexei Starovoitov
Browse files

bpf: Retire rcu_trace_implies_rcu_gp() from local storage 



This assumption will always hold going forward, hence just remove the
various checks and assume it is true with a comment for the uninformed
reader.

Reviewed-by: default avatarPaul E. McKenney <paulmck@kernel.org>
Reviewed-by: default avatarAmery Hung <ameryhung@gmail.com>
Signed-off-by: default avatarKumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260227224806.646888-5-memxor@gmail.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent f41deee0

kernel/bpf/bpf_local_storage.c

+19 −18
Original line number Diff line number Diff line
@@ -107,14 +107,12 @@ static void __bpf_local_storage_free_trace_rcu(struct rcu_head *rcu) 
{

	struct bpf_local_storage *local_storage;



	/* If RCU Tasks Trace grace period implies RCU grace period, do

	 * kfree(), else do kfree_rcu().

	/*

	 * RCU Tasks Trace grace period implies RCU grace period, do

	 * kfree() directly.

	 */

	local_storage = container_of(rcu, struct bpf_local_storage, rcu);

	if (rcu_trace_implies_rcu_gp())

	kfree(local_storage);

	else

		kfree_rcu(local_storage, rcu);

}



/* Handle use_kmalloc_nolock == false */
@@ -138,10 +136,11 @@ static void bpf_local_storage_free_rcu(struct rcu_head *rcu) 


static void bpf_local_storage_free_trace_rcu(struct rcu_head *rcu)

{

	if (rcu_trace_implies_rcu_gp())

	/*

	 * RCU Tasks Trace grace period implies RCU grace period, do

	 * kfree() directly.

	 */

	bpf_local_storage_free_rcu(rcu);

	else

		call_rcu(rcu, bpf_local_storage_free_rcu);

}



static void bpf_local_storage_free(struct bpf_local_storage *local_storage,
@@ -182,10 +181,11 @@ static void __bpf_selem_free_rcu(struct rcu_head *rcu) 
/* rcu tasks trace callback for use_kmalloc_nolock == false */

static void __bpf_selem_free_trace_rcu(struct rcu_head *rcu)

{

	if (rcu_trace_implies_rcu_gp())

	/*

	 * RCU Tasks Trace grace period implies RCU grace period, do

	 * kfree() directly.

	 */

	__bpf_selem_free_rcu(rcu);

	else

		call_rcu(rcu, __bpf_selem_free_rcu);

}



/* Handle use_kmalloc_nolock == false */
@@ -214,10 +214,11 @@ static void bpf_selem_free_rcu(struct rcu_head *rcu) 


static void bpf_selem_free_trace_rcu(struct rcu_head *rcu)

{

	if (rcu_trace_implies_rcu_gp())

	/*

	 * RCU Tasks Trace grace period implies RCU grace period, do

	 * kfree() directly.

	 */

	bpf_selem_free_rcu(rcu);

	else

		call_rcu(rcu, bpf_selem_free_rcu);

}



void bpf_selem_free(struct bpf_local_storage_elem *selem,