| Message ID | 20250204164240.370153-1-Alexander@wetzel-home.de |
|---|---|
| State | New |
| Headers | show |
| Series | wifi: mac80211: remove debugfs dir for virtual monitor | expand |
On 2/4/2025 8:42 AM, Alexander Wetzel wrote: > Don't call ieee80211_debugfs_recreate_netdev() for virtual monitor > interface when deleting it. > > The virtual monitor interface shouldn't have debugfs entries and trying > to update them will *create* them on deletion. > > And when the virtual monitor interface is created/destroyed multiple > times we'll get warnings about debugfs name conflicts. > > Signed-off-by: Alexander Wetzel <Alexander@wetzel-home.de> > --- > That was a bit more tricky than expected: > > local->monitor_sdata is normally already deleted when we call > drv_remove_interface. And we can't simply skip the call for all monitor > interfaces... > > And one additional remark: > My iwlmvm card is not taking it well when I bring down the monitor interface > while TXing on it. The firmware crashes for my "Alder Lake-S PCH CNVi WiFi" > card. > > But that also happens with unpatched kernels and so I don't care > much about that. I can make a bug report, if that's news and want you to > look into that. > > Alexander > --- > net/mac80211/driver-ops.c | 10 ++++++++-- > net/mac80211/iface.c | 11 ++++++----- > 2 files changed, 14 insertions(+), 7 deletions(-) > > diff --git a/net/mac80211/driver-ops.c b/net/mac80211/driver-ops.c > index 299d38e9e863..2fc60e1e77a5 100644 > --- a/net/mac80211/driver-ops.c > +++ b/net/mac80211/driver-ops.c > @@ -116,8 +116,14 @@ void drv_remove_interface(struct ieee80211_local *local, > > sdata->flags &= ~IEEE80211_SDATA_IN_DRIVER; > > - /* Remove driver debugfs entries */ > - ieee80211_debugfs_recreate_netdev(sdata, sdata->vif.valid_links); > + /* > + * Remove driver debugfs entries. > + * The virtual monitor interface doesn't get a debugfs > + * entry, so it's exempt here. > + */ > + if (sdata != local->monitor_sdata) > + ieee80211_debugfs_recreate_netdev(sdata, > + sdata->vif.valid_links); With make W=1 C=1 I'm seeing the following which I think is a result of this patch: net/mac80211/driver-ops.c:124:19: error: incompatible types in comparison expression (different address spaces): net/mac80211/driver-ops.c:124:19: struct ieee80211_sub_if_data * net/mac80211/driver-ops.c:124:19: struct ieee80211_sub_if_data [noderef] __rcu *
>> Alexander >> --- >> net/mac80211/driver-ops.c | 10 ++++++++-- >> net/mac80211/iface.c | 11 ++++++----- >> 2 files changed, 14 insertions(+), 7 deletions(-) >> >> diff --git a/net/mac80211/driver-ops.c b/net/mac80211/driver-ops.c >> index 299d38e9e863..2fc60e1e77a5 100644 >> --- a/net/mac80211/driver-ops.c >> +++ b/net/mac80211/driver-ops.c >> @@ -116,8 +116,14 @@ void drv_remove_interface(struct ieee80211_local *local, >> >> sdata->flags &= ~IEEE80211_SDATA_IN_DRIVER; >> >> - /* Remove driver debugfs entries */ >> - ieee80211_debugfs_recreate_netdev(sdata, sdata->vif.valid_links); >> + /* >> + * Remove driver debugfs entries. >> + * The virtual monitor interface doesn't get a debugfs >> + * entry, so it's exempt here. >> + */ >> + if (sdata != local->monitor_sdata) >> + ieee80211_debugfs_recreate_netdev(sdata, >> + sdata->vif.valid_links); > > With make W=1 C=1 I'm seeing the following which I think is a result of this > patch: > > net/mac80211/driver-ops.c:124:19: error: incompatible types in comparison expression (different address spaces): > net/mac80211/driver-ops.c:124:19: struct ieee80211_sub_if_data * > net/mac80211/driver-ops.c:124:19: struct ieee80211_sub_if_data [noderef] __rcu * > > That should be fixed with https://lore.kernel.org/linux-wireless/20250213214330.6113-1-Alexander@wetzel-home.de/ It has been accepted in the last days, but looks like it was too late for wt-2025-02-25. Alexander
diff --git a/net/mac80211/driver-ops.c b/net/mac80211/driver-ops.c index 299d38e9e863..2fc60e1e77a5 100644 --- a/net/mac80211/driver-ops.c +++ b/net/mac80211/driver-ops.c @@ -116,8 +116,14 @@ void drv_remove_interface(struct ieee80211_local *local, sdata->flags &= ~IEEE80211_SDATA_IN_DRIVER; - /* Remove driver debugfs entries */ - ieee80211_debugfs_recreate_netdev(sdata, sdata->vif.valid_links); + /* + * Remove driver debugfs entries. + * The virtual monitor interface doesn't get a debugfs + * entry, so it's exempt here. + */ + if (sdata != local->monitor_sdata) + ieee80211_debugfs_recreate_netdev(sdata, + sdata->vif.valid_links); trace_drv_remove_interface(local, sdata); local->ops->remove_interface(&local->hw, &sdata->vif); diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c index 7d3ebfcb8c2b..e627e2df3038 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -1203,16 +1203,17 @@ void ieee80211_del_virtual_monitor(struct ieee80211_local *local) return; } - RCU_INIT_POINTER(local->monitor_sdata, NULL); - mutex_unlock(&local->iflist_mtx); - - synchronize_net(); - + clear_bit(SDATA_STATE_RUNNING, &sdata->state); ieee80211_link_release_channel(&sdata->deflink); if (ieee80211_hw_check(&local->hw, WANT_MONITOR_VIF)) drv_remove_interface(local, sdata); + RCU_INIT_POINTER(local->monitor_sdata, NULL); + mutex_unlock(&local->iflist_mtx); + + synchronize_net(); + kfree(sdata); }
Don't call ieee80211_debugfs_recreate_netdev() for virtual monitor interface when deleting it. The virtual monitor interface shouldn't have debugfs entries and trying to update them will *create* them on deletion. And when the virtual monitor interface is created/destroyed multiple times we'll get warnings about debugfs name conflicts. Signed-off-by: Alexander Wetzel <Alexander@wetzel-home.de> --- That was a bit more tricky than expected: local->monitor_sdata is normally already deleted when we call drv_remove_interface. And we can't simply skip the call for all monitor interfaces... And one additional remark: My iwlmvm card is not taking it well when I bring down the monitor interface while TXing on it. The firmware crashes for my "Alder Lake-S PCH CNVi WiFi" card. But that also happens with unpatched kernels and so I don't care much about that. I can make a bug report, if that's news and want you to look into that. Alexander --- net/mac80211/driver-ops.c | 10 ++++++++-- net/mac80211/iface.c | 11 ++++++----- 2 files changed, 14 insertions(+), 7 deletions(-)