atm: add owner of push() callback to atmvcc (ec809bd8) · Commits · 戴 / test

The atm is using atmvcc->push(vcc, NULL) callback to notify protocol that vcc will be closed and protocol must detach from it. This callback is usually used by protocol to decrement module usage count by module_put(), but it leaves small window then module is still used after module_put(). Now the owner of push() callback is kept in atmvcc and module_put(atmvcc->owner) is called after the protocol is detached from vcc. Signed-off-by:

Krzysztof Mazur <krzysiek@podlesie.net> Signed-off-by:

David Woodhouse <David.Woodhouse@intel.com> Acked-by:

Chas Williams <chas@cmf.nrl.navy.mil>

include/linux/atmdev.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -106,6 +106,7 @@ struct atm_vcc {
		void dev_data; / per-device data */
		void proto_data; / per-protocol data */
		struct k_atm_aal_stats stats; / pointer to AAL stats group */
		struct module owner; / owner of ->push function */
		/* SVC part --- may move later ------------------------------------- */
		short itf; /* interface number */
		struct sockaddr_atmsvc local;

net/atm/common.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -156,6 +156,7 @@ int vcc_create(struct net net, struct socket sock, int protocol, int family)
		atomic_set(&sk->sk_rmem_alloc, 0);
		vcc->push = NULL;
		vcc->pop = NULL;
		vcc->owner = NULL;
		vcc->push_oam = NULL;
		vcc->vpi = vcc->vci = 0; /* no VCI/VPI yet */
		vcc->atm_options = vcc->aal_options = 0;
		@@ -175,6 +176,7 @@ static void vcc_destroy_socket(struct sock *sk)
		vcc->dev->ops->close(vcc);
		if (vcc->push)
		vcc->push(vcc, NULL); /* atmarpd has no push */
		module_put(vcc->owner);

		while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
		atm_return(vcc, skb->truesize);

Admin message