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Diffstat (limited to 'net/can/bcm.c')
-rw-r--r--net/can/bcm.c79
1 files changed, 54 insertions, 25 deletions
diff --git a/net/can/bcm.c b/net/can/bcm.c
index 0bca1b9b3f70..6bc1cc4c94c5 100644
--- a/net/can/bcm.c
+++ b/net/can/bcm.c
@@ -58,6 +58,7 @@
#include <linux/can/skb.h>
#include <linux/can/bcm.h>
#include <linux/slab.h>
+#include <linux/spinlock.h>
#include <net/sock.h>
#include <net/net_namespace.h>
@@ -122,6 +123,7 @@ struct bcm_op {
struct canfd_frame last_sframe;
struct sock *sk;
struct net_device *rx_reg_dev;
+ spinlock_t bcm_tx_lock; /* protect currframe/count in runtime updates */
};
struct bcm_sock {
@@ -217,7 +219,9 @@ static int bcm_proc_show(struct seq_file *m, void *v)
seq_printf(m, " / bound %s", bcm_proc_getifname(net, ifname, bo->ifindex));
seq_printf(m, " <<<\n");
- list_for_each_entry(op, &bo->rx_ops, list) {
+ rcu_read_lock();
+
+ list_for_each_entry_rcu(op, &bo->rx_ops, list) {
unsigned long reduction;
@@ -273,6 +277,9 @@ static int bcm_proc_show(struct seq_file *m, void *v)
seq_printf(m, "# sent %ld\n", op->frames_abs);
}
seq_putc(m, '\n');
+
+ rcu_read_unlock();
+
return 0;
}
#endif /* CONFIG_PROC_FS */
@@ -285,13 +292,18 @@ static void bcm_can_tx(struct bcm_op *op)
{
struct sk_buff *skb;
struct net_device *dev;
- struct canfd_frame *cf = op->frames + op->cfsiz * op->currframe;
+ struct canfd_frame *cf;
int err;
/* no target device? => exit */
if (!op->ifindex)
return;
+ /* read currframe under lock protection */
+ spin_lock_bh(&op->bcm_tx_lock);
+ cf = op->frames + op->cfsiz * op->currframe;
+ spin_unlock_bh(&op->bcm_tx_lock);
+
dev = dev_get_by_index(sock_net(op->sk), op->ifindex);
if (!dev) {
/* RFC: should this bcm_op remove itself here? */
@@ -312,6 +324,10 @@ static void bcm_can_tx(struct bcm_op *op)
skb->dev = dev;
can_skb_set_owner(skb, op->sk);
err = can_send(skb, 1);
+
+ /* update currframe and count under lock protection */
+ spin_lock_bh(&op->bcm_tx_lock);
+
if (!err)
op->frames_abs++;
@@ -320,6 +336,11 @@ static void bcm_can_tx(struct bcm_op *op)
/* reached last frame? */
if (op->currframe >= op->nframes)
op->currframe = 0;
+
+ if (op->count > 0)
+ op->count--;
+
+ spin_unlock_bh(&op->bcm_tx_lock);
out:
dev_put(dev);
}
@@ -430,7 +451,7 @@ static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
struct bcm_msg_head msg_head;
if (op->kt_ival1 && (op->count > 0)) {
- op->count--;
+ bcm_can_tx(op);
if (!op->count && (op->flags & TX_COUNTEVT)) {
/* create notification to user */
@@ -445,7 +466,6 @@ static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer)
bcm_send_to_user(op, &msg_head, NULL, 0);
}
- bcm_can_tx(op);
} else if (op->kt_ival2) {
bcm_can_tx(op);
@@ -843,7 +863,7 @@ static int bcm_delete_rx_op(struct list_head *ops, struct bcm_msg_head *mh,
REGMASK(op->can_id),
bcm_rx_handler, op);
- list_del(&op->list);
+ list_del_rcu(&op->list);
bcm_remove_op(op);
return 1; /* done */
}
@@ -863,7 +883,7 @@ static int bcm_delete_tx_op(struct list_head *ops, struct bcm_msg_head *mh,
list_for_each_entry_safe(op, n, ops, list) {
if ((op->can_id == mh->can_id) && (op->ifindex == ifindex) &&
(op->flags & CAN_FD_FRAME) == (mh->flags & CAN_FD_FRAME)) {
- list_del(&op->list);
+ list_del_rcu(&op->list);
bcm_remove_op(op);
return 1; /* done */
}
@@ -956,6 +976,27 @@ static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
}
op->flags = msg_head->flags;
+ /* only lock for unlikely count/nframes/currframe changes */
+ if (op->nframes != msg_head->nframes ||
+ op->flags & TX_RESET_MULTI_IDX ||
+ op->flags & SETTIMER) {
+
+ spin_lock_bh(&op->bcm_tx_lock);
+
+ if (op->nframes != msg_head->nframes ||
+ op->flags & TX_RESET_MULTI_IDX) {
+ /* potentially update changed nframes */
+ op->nframes = msg_head->nframes;
+ /* restart multiple frame transmission */
+ op->currframe = 0;
+ }
+
+ if (op->flags & SETTIMER)
+ op->count = msg_head->count;
+
+ spin_unlock_bh(&op->bcm_tx_lock);
+ }
+
} else {
/* insert new BCM operation for the given can_id */
@@ -963,9 +1004,14 @@ static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
if (!op)
return -ENOMEM;
+ spin_lock_init(&op->bcm_tx_lock);
op->can_id = msg_head->can_id;
op->cfsiz = CFSIZ(msg_head->flags);
op->flags = msg_head->flags;
+ op->nframes = msg_head->nframes;
+
+ if (op->flags & SETTIMER)
+ op->count = msg_head->count;
/* create array for CAN frames and copy the data */
if (msg_head->nframes > 1) {
@@ -1023,22 +1069,8 @@ static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
} /* if ((op = bcm_find_op(&bo->tx_ops, msg_head->can_id, ifindex))) */
- if (op->nframes != msg_head->nframes) {
- op->nframes = msg_head->nframes;
- /* start multiple frame transmission with index 0 */
- op->currframe = 0;
- }
-
- /* check flags */
-
- if (op->flags & TX_RESET_MULTI_IDX) {
- /* start multiple frame transmission with index 0 */
- op->currframe = 0;
- }
-
if (op->flags & SETTIMER) {
/* set timer values */
- op->count = msg_head->count;
op->ival1 = msg_head->ival1;
op->ival2 = msg_head->ival2;
op->kt_ival1 = bcm_timeval_to_ktime(msg_head->ival1);
@@ -1055,11 +1087,8 @@ static int bcm_tx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
op->flags |= TX_ANNOUNCE;
}
- if (op->flags & TX_ANNOUNCE) {
+ if (op->flags & TX_ANNOUNCE)
bcm_can_tx(op);
- if (op->count)
- op->count--;
- }
if (op->flags & STARTTIMER)
bcm_tx_start_timer(op);
@@ -1272,7 +1301,7 @@ static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
bcm_rx_handler, op, "bcm", sk);
if (err) {
/* this bcm rx op is broken -> remove it */
- list_del(&op->list);
+ list_del_rcu(&op->list);
bcm_remove_op(op);
return err;
}