| Message ID | 1352240222-363-3-git-send-email-krzysiek@podlesie.net |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
On Tue, 6 Nov 2012 23:16:57 +0100 Krzysztof Mazur <krzysiek@podlesie.net> wrote: > 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> Acked-by: Chas Williams <chas@cmf.nrl.navy.mil> -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/linux/atmdev.h b/include/linux/atmdev.h index 06fd4bb..31c16c6 100644 --- a/include/linux/atmdev.h +++ b/include/linux/atmdev.h @@ -315,6 +315,7 @@ 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; diff --git a/net/atm/common.c b/net/atm/common.c index a0e4411..ea952b2 100644 --- a/net/atm/common.c +++ b/net/atm/common.c @@ -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; @@ -173,6 +174,7 @@ static void vcc_destroy_socket(struct sock *sk) if (vcc->dev) { if (vcc->push) vcc->push(vcc, NULL); /* atmarpd has no push */ + module_put(vcc->owner); if (vcc->dev->ops->close) vcc->dev->ops->close(vcc);
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> --- include/linux/atmdev.h | 1 + net/atm/common.c | 2 ++ 2 files changed, 3 insertions(+)