linux/net/nfc/af_nfc.c
Ziyang Xuan 0911ab3189 nfc: fix error handling of nfc_proto_register()
When nfc proto id is using, nfc_proto_register() return -EBUSY error
code, but forgot to unregister proto. Fix it by adding proto_unregister()
in the error handling case.

Fixes: c7fe3b52c1 ("NFC: add NFC socket family")
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20211013034932.2833737-1-william.xuanziyang@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-10-13 17:32:38 -07:00

89 lines
1.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2011 Instituto Nokia de Tecnologia
*
* Authors:
* Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
* Lauro Ramos Venancio <lauro.venancio@openbossa.org>
*/
#include <linux/nfc.h>
#include <linux/module.h>
#include "nfc.h"
static DEFINE_RWLOCK(proto_tab_lock);
static const struct nfc_protocol *proto_tab[NFC_SOCKPROTO_MAX];
static int nfc_sock_create(struct net *net, struct socket *sock, int proto,
int kern)
{
int rc = -EPROTONOSUPPORT;
if (net != &init_net)
return -EAFNOSUPPORT;
if (proto < 0 || proto >= NFC_SOCKPROTO_MAX)
return -EINVAL;
read_lock(&proto_tab_lock);
if (proto_tab[proto] && try_module_get(proto_tab[proto]->owner)) {
rc = proto_tab[proto]->create(net, sock, proto_tab[proto], kern);
module_put(proto_tab[proto]->owner);
}
read_unlock(&proto_tab_lock);
return rc;
}
static const struct net_proto_family nfc_sock_family_ops = {
.owner = THIS_MODULE,
.family = PF_NFC,
.create = nfc_sock_create,
};
int nfc_proto_register(const struct nfc_protocol *nfc_proto)
{
int rc;
if (nfc_proto->id < 0 || nfc_proto->id >= NFC_SOCKPROTO_MAX)
return -EINVAL;
rc = proto_register(nfc_proto->proto, 0);
if (rc)
return rc;
write_lock(&proto_tab_lock);
if (proto_tab[nfc_proto->id])
rc = -EBUSY;
else
proto_tab[nfc_proto->id] = nfc_proto;
write_unlock(&proto_tab_lock);
if (rc)
proto_unregister(nfc_proto->proto);
return rc;
}
EXPORT_SYMBOL(nfc_proto_register);
void nfc_proto_unregister(const struct nfc_protocol *nfc_proto)
{
write_lock(&proto_tab_lock);
proto_tab[nfc_proto->id] = NULL;
write_unlock(&proto_tab_lock);
proto_unregister(nfc_proto->proto);
}
EXPORT_SYMBOL(nfc_proto_unregister);
int __init af_nfc_init(void)
{
return sock_register(&nfc_sock_family_ops);
}
void __exit af_nfc_exit(void)
{
sock_unregister(PF_NFC);
}