On 2019-05-10 22:04, Ben Greear wrote:
On 05/10/2019 12:01 AM, Yibo Zhao wrote:
In multiple SSID cases, it takes time to prepare every AP interface
to be ready in initializing phase. If a sta already knows everything
it
needs to join one of the APs and sends authentication to the AP which
is not fully prepared at this point of time, AP's channel context
could be NULL. As a result, warning message occurs.
Even worse, if the AP is under attack via tools such as MDK3 and
massive
authentication requests are received in a very short time, console
will
be hung due to kernel warning messages.
Since it is a WARN_ON_ONCE, how it the console hang due to warnings?
You should
get no more than once per boot?
Hi Ben,
I was planning to use WARN_ON_ONCE() in the first place to replace
WARN_ON() then after some discussion, we think removing it could be
better. So the patch was based on my first version. Sorry for the
confusing. Will raise another one.
I have no problem with removing it though. Seems a harmless splat and
I removed
it from my tree some time back as well.
Thanks,
Ben
If this case can be hit during normal functionality, there should be
no
WARN_ON(). Those should be reserved to cases that are not supposed to
be
hit at all or some other more specific cases like indicating obsolete
interface.
Signed-off-by: Zhi Chen <zhichen@xxxxxxxxxxxxxx>
Signed-off-by: Yibo Zhao <yiboz@xxxxxxxxxxxxxx>
---
net/mac80211/ieee80211_i.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 2ae0364..f39c289 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1435,7 +1435,7 @@ struct ieee80211_local {
rcu_read_lock();
chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
- if (WARN_ON_ONCE(!chanctx_conf)) {
+ if (!chanctx_conf) {
rcu_read_unlock();
return NULL;
}
--
Yibo
