tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
can: af_can: do not access proto_tab directly use rcu_access_pointer instead
"proto_tab" is a RCU protected array, when directly accessing the array,
sparse throws these warnings:
CHECK /srv/work/frogger/socketcan/linux/net/can/af_can.c
net/can/af_can.c:115:14: error: incompatible types in comparison expression (different address spaces)
net/can/af_can.c:795:17: error: incompatible types in comparison expression (different address spaces)
net/can/af_can.c:816:9: error: incompatible types in comparison expression (different address spaces)
This patch fixes the problem by using rcu_access_pointer() and
annotating "proto_tab" array as __rcu.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
+3
-3
+3
-3
net/can/af_can.c
+3
-3
net/can/af_can.c
···
78
78
static struct kmem_cache *rcv_cache __read_mostly;
79
79
80
80
/* table of registered CAN protocols */
81
-
static const struct can_proto *proto_tab[CAN_NPROTO] __read_mostly;
81
+
static const struct can_proto __rcu *proto_tab[CAN_NPROTO] __read_mostly;
82
82
static DEFINE_MUTEX(proto_tab_lock);
83
83
84
84
static atomic_t skbcounter = ATOMIC_INIT(0);
···
788
788
789
789
mutex_lock(&proto_tab_lock);
790
790
791
-
if (proto_tab[proto]) {
791
+
if (rcu_access_pointer(proto_tab[proto])) {
792
792
pr_err("can: protocol %d already registered\n", proto);
793
793
err = -EBUSY;
794
794
} else
···
812
812
int proto = cp->protocol;
813
813
814
814
mutex_lock(&proto_tab_lock);
815
-
BUG_ON(proto_tab[proto] != cp);
815
+
BUG_ON(rcu_access_pointer(proto_tab[proto]) != cp);
816
816
RCU_INIT_POINTER(proto_tab[proto], NULL);
817
817
mutex_unlock(&proto_tab_lock);
818
818