Commit 12f4bd86 authored by Paolo Abeni's avatar Paolo Abeni Committed by Jakub Kicinski
Browse files

net: add annotation for sock_{lock,unlock}_fast 



The static checker is fooled by the non-static locking scheme
implemented by the mentioned helpers.
Let's make its life easier adding some unconditional annotation
so that the helpers are now interpreted as a plain spinlock from
sparse.

v1 -> v2:
 - add __releases() annotation to unlock_sock_fast()

Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/6ed7ae627d8271fb7f20e0a9c6750fbba1ac2635.1605634911.git.pabeni@redhat.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent c3bc2adb

include/net/sock.h

+7 −3
Original line number Diff line number Diff line
@@ -1595,7 +1595,8 @@ void release_sock(struct sock *sk); 
				SINGLE_DEPTH_NESTING)

#define bh_unlock_sock(__sk)	spin_unlock(&((__sk)->sk_lock.slock))



bool lock_sock_fast(struct sock *sk);

bool lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock);



/**

 * unlock_sock_fast - complement of lock_sock_fast

 * @sk: socket
@@ -1605,12 +1606,15 @@ bool lock_sock_fast(struct sock *sk); 
 * If slow mode is on, we call regular release_sock()

 */

static inline void unlock_sock_fast(struct sock *sk, bool slow)

	__releases(&sk->sk_lock.slock)

{

	if (slow)

	if (slow) {

		release_sock(sk);

	else

		__release(&sk->sk_lock.slock);

	} else {

		spin_unlock_bh(&sk->sk_lock.slock);

	}

}



/* Used by processes to "lock" a socket state, so that

 * interrupts and bottom half handlers won't change it

net/core/sock.c

+2 −1
Original line number Diff line number Diff line
@@ -3078,7 +3078,7 @@ EXPORT_SYMBOL(release_sock); 
 *

 *   sk_lock.slock unlocked, owned = 1, BH enabled

 */

bool lock_sock_fast(struct sock *sk)

bool lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock)

{

	might_sleep();

	spin_lock_bh(&sk->sk_lock.slock);
@@ -3096,6 +3096,7 @@ bool lock_sock_fast(struct sock *sk) 
	 * The sk_lock has mutex_lock() semantics here:

	 */

	mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);

	__acquire(&sk->sk_lock.slock);

	local_bh_enable();

	return true;

}

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