2013-02-13 13:02:59

by Johannes Berg

Subject: [PATCH] mac80211: don't call bss_info_changed on p2p-device/monitor

From: Johannes Berg <[email protected]>

Since the idle decision rework, mac80211 started calling
bss_info_changed() for the driver's monitor interface,
which causes a crash for iwlwifi, but drivers generally
don't expect this to happen. Therefore, avoid it.

While at it, also prevent calling it in such cases and
only print a warning. For the P2P Device interface the
idle will no longer be called (no channel context), so
also prevent that and warn on it.

Reported-by: Chaitanya <[email protected]>
Signed-off-by: Johannes Berg <[email protected]>
---
net/mac80211/chan.c | 10 ++++++++--
net/mac80211/driver-ops.h | 17 ++++++++++-------
2 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index 038f249..b2ccb74 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -137,7 +137,10 @@ static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,

ieee80211_recalc_txpower(sdata);
sdata->vif.bss_conf.idle = false;
- ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IDLE);
+
+ if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
+ sdata->vif.type != NL80211_IFTYPE_MONITOR)
+ ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IDLE);

return 0;
}
@@ -186,7 +189,10 @@ static void ieee80211_unassign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
rcu_assign_pointer(sdata->vif.chanctx_conf, NULL);

sdata->vif.bss_conf.idle = true;
- ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IDLE);
+
+ if (sdata->vif.type != NL80211_IFTYPE_P2P_DEVICE &&
+ sdata->vif.type != NL80211_IFTYPE_MONITOR)
+ ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IDLE);

drv_unassign_vif_chanctx(local, sdata, ctx);

diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h
index 2b08b99..ee56d07 100644
--- a/net/mac80211/driver-ops.h
+++ b/net/mac80211/driver-ops.h
@@ -207,13 +207,16 @@ static inline void drv_bss_info_changed(struct ieee80211_local *local,
{
might_sleep();

- WARN_ON_ONCE(changed & (BSS_CHANGED_BEACON |
- BSS_CHANGED_BEACON_ENABLED) &&
- sdata->vif.type != NL80211_IFTYPE_AP &&
- sdata->vif.type != NL80211_IFTYPE_ADHOC &&
- sdata->vif.type != NL80211_IFTYPE_MESH_POINT);
- WARN_ON_ONCE(sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE &&
- changed & ~BSS_CHANGED_IDLE);
+ if (WARN_ON_ONCE(changed & (BSS_CHANGED_BEACON |
+ BSS_CHANGED_BEACON_ENABLED) &&
+ sdata->vif.type != NL80211_IFTYPE_AP &&
+ sdata->vif.type != NL80211_IFTYPE_ADHOC &&
+ sdata->vif.type != NL80211_IFTYPE_MESH_POINT))
+ return;
+
+ if (WARN_ON_ONCE(sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE ||
+ sdata->vif.type == NL80211_IFTYPE_MONITOR))
+ return;

check_sdata_in_driver(sdata);

--
1.8.0

2013-02-14 17:30:20

by Johannes Berg

Subject: Re: [PATCH] mac80211: don't call bss_info_changed on p2p-device/monitor

On Wed, 2013-02-13 at 14:02 +0100, Johannes Berg wrote:
> From: Johannes Berg <[email protected]>
>
> Since the idle decision rework, mac80211 started calling
> bss_info_changed() for the driver's monitor interface,
> which causes a crash for iwlwifi, but drivers generally
> don't expect this to happen. Therefore, avoid it.
>
> While at it, also prevent calling it in such cases and
> only print a warning. For the P2P Device interface the
> idle will no longer be called (no channel context), so
> also prevent that and warn on it.

Applied.

johannes