4.18-stable review patch. If anyone has any objections, please let me know.
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From: Petr Machata petrm@mellanox.com
[ Upstream commit 08193d1a893c802c4b807e4d522865061f4e9f4f ]
The function dcb_app_lookup walks the list of specified DCB APP entries, looking for one that matches a given criteria: ifindex, selector, protocol ID and optionally also priority. The "don't care" value for priority is set to 0, because that priority has not been allowed under CEE regime, which predates the IEEE standardization.
Under IEEE, 0 is a valid priority number. But because dcb_app_lookup considers zero a wild card, attempts to add an APP entry with priority 0 fail when other entries exist for a given ifindex / selector / PID triplet.
Fix by changing the wild-card value to -1.
Signed-off-by: Petr Machata petrm@mellanox.com Signed-off-by: Ido Schimmel idosch@mellanox.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/dcb/dcbnl.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
--- a/net/dcb/dcbnl.c +++ b/net/dcb/dcbnl.c @@ -1786,7 +1786,7 @@ static struct dcb_app_type *dcb_app_look if (itr->app.selector == app->selector && itr->app.protocol == app->protocol && itr->ifindex == ifindex && - (!prio || itr->app.priority == prio)) + ((prio == -1) || itr->app.priority == prio)) return itr; }
@@ -1821,7 +1821,8 @@ u8 dcb_getapp(struct net_device *dev, st u8 prio = 0;
spin_lock_bh(&dcb_lock); - if ((itr = dcb_app_lookup(app, dev->ifindex, 0))) + itr = dcb_app_lookup(app, dev->ifindex, -1); + if (itr) prio = itr->app.priority; spin_unlock_bh(&dcb_lock);
@@ -1849,7 +1850,8 @@ int dcb_setapp(struct net_device *dev, s
spin_lock_bh(&dcb_lock); /* Search for existing match and replace */ - if ((itr = dcb_app_lookup(new, dev->ifindex, 0))) { + itr = dcb_app_lookup(new, dev->ifindex, -1); + if (itr) { if (new->priority) itr->app.priority = new->priority; else { @@ -1882,7 +1884,8 @@ u8 dcb_ieee_getapp_mask(struct net_devic u8 prio = 0;
spin_lock_bh(&dcb_lock); - if ((itr = dcb_app_lookup(app, dev->ifindex, 0))) + itr = dcb_app_lookup(app, dev->ifindex, -1); + if (itr) prio |= 1 << itr->app.priority; spin_unlock_bh(&dcb_lock);