From: Johannes Berg <johannes.berg@xxxxxxxxx> commit 6cb5f3ea4654faf8c28b901266e960b1a4787b26 upstream. When fixing the initialization race, we neglected to account for the fact that debugfs is initialized in wiphy_register(), and some debugfs things went missing (or rather were rerooted to the global debugfs root). Fix this by adding debugfs entries only after wiphy_register(). This requires some changes in the rate control code since it currently adds debugfs at alloc time, which can no longer be done after the reordering. Reported-by: Jouni Malinen <j@xxxxx> Reported-by: kernel test robot <rong.a.chen@xxxxxxxxx> Reported-by: Hauke Mehrtens <hauke@xxxxxxxxxx> Reported-by: Felix Fietkau <nbd@xxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Fixes: 52e04b4ce5d0 ("mac80211: fix race in ieee80211_register_hw()") Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> Acked-by: Sumit Garg <sumit.garg@xxxxxxxxxx> Link: https://lore.kernel.org/r/20200423111344.0e00d3346f12.Iadc76a03a55093d94391fc672e996a458702875d@changeid Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/wireless/intel/iwlegacy/3945-rs.c | 2 +- drivers/net/wireless/intel/iwlegacy/4965-rs.c | 2 +- drivers/net/wireless/intel/iwlwifi/dvm/rs.c | 2 +- drivers/net/wireless/intel/iwlwifi/mvm/rs.c | 2 +- drivers/net/wireless/realtek/rtlwifi/rc.c | 2 +- include/net/mac80211.h | 4 +++- net/mac80211/main.c | 5 +++-- net/mac80211/rate.c | 15 ++++----------- net/mac80211/rate.h | 23 +++++++++++++++++++++++ net/mac80211/rc80211_minstrel_ht.c | 19 +++++++++++++------ 10 files changed, 51 insertions(+), 25 deletions(-) --- a/drivers/net/wireless/intel/iwlegacy/3945-rs.c +++ b/drivers/net/wireless/intel/iwlegacy/3945-rs.c @@ -374,7 +374,7 @@ out: } static void * -il3945_rs_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir) +il3945_rs_alloc(struct ieee80211_hw *hw) { return hw->priv; } --- a/drivers/net/wireless/intel/iwlegacy/4965-rs.c +++ b/drivers/net/wireless/intel/iwlegacy/4965-rs.c @@ -2474,7 +2474,7 @@ il4965_rs_fill_link_cmd(struct il_priv * } static void * -il4965_rs_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir) +il4965_rs_alloc(struct ieee80211_hw *hw) { return hw->priv; } --- a/drivers/net/wireless/intel/iwlwifi/dvm/rs.c +++ b/drivers/net/wireless/intel/iwlwifi/dvm/rs.c @@ -3019,7 +3019,7 @@ static void rs_fill_link_cmd(struct iwl_ cpu_to_le16(priv->lib->bt_params->agg_time_limit); } -static void *rs_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir) +static void *rs_alloc(struct ieee80211_hw *hw) { return hw->priv; } --- a/drivers/net/wireless/intel/iwlwifi/mvm/rs.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/rs.c @@ -3663,7 +3663,7 @@ static void rs_fill_lq_cmd(struct iwl_mv cpu_to_le16(iwl_mvm_coex_agg_time_limit(mvm, sta)); } -static void *rs_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir) +static void *rs_alloc(struct ieee80211_hw *hw) { return hw->priv; } --- a/drivers/net/wireless/realtek/rtlwifi/rc.c +++ b/drivers/net/wireless/realtek/rtlwifi/rc.c @@ -261,7 +261,7 @@ static void rtl_rate_update(void *ppriv, { } -static void *rtl_rate_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir) +static void *rtl_rate_alloc(struct ieee80211_hw *hw) { struct rtl_priv *rtlpriv = rtl_priv(hw); return rtlpriv; --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -5933,7 +5933,9 @@ enum rate_control_capabilities { struct rate_control_ops { unsigned long capa; const char *name; - void *(*alloc)(struct ieee80211_hw *hw, struct dentry *debugfsdir); + void *(*alloc)(struct ieee80211_hw *hw); + void (*add_debugfs)(struct ieee80211_hw *hw, void *priv, + struct dentry *debugfsdir); void (*free)(void *priv); void *(*alloc_sta)(void *priv, struct ieee80211_sta *sta, gfp_t gfp); --- a/net/mac80211/main.c +++ b/net/mac80211/main.c @@ -1155,8 +1155,6 @@ int ieee80211_register_hw(struct ieee802 local->tx_headroom = max_t(unsigned int , local->hw.extra_tx_headroom, IEEE80211_TX_STATUS_HEADROOM); - debugfs_hw_add(local); - /* * if the driver doesn't specify a max listen interval we * use 5 which should be a safe default @@ -1248,6 +1246,9 @@ int ieee80211_register_hw(struct ieee802 if (result < 0) goto fail_wiphy_register; + debugfs_hw_add(local); + rate_control_add_debugfs(local); + rtnl_lock(); /* add one default STA interface if supported */ --- a/net/mac80211/rate.c +++ b/net/mac80211/rate.c @@ -214,17 +214,16 @@ static ssize_t rcname_read(struct file * ref->ops->name, len); } -static const struct file_operations rcname_ops = { +const struct file_operations rcname_ops = { .read = rcname_read, .open = simple_open, .llseek = default_llseek, }; #endif -static struct rate_control_ref *rate_control_alloc(const char *name, - struct ieee80211_local *local) +static struct rate_control_ref * +rate_control_alloc(const char *name, struct ieee80211_local *local) { - struct dentry *debugfsdir = NULL; struct rate_control_ref *ref; ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL); @@ -234,13 +233,7 @@ static struct rate_control_ref *rate_con if (!ref->ops) goto free; -#ifdef CONFIG_MAC80211_DEBUGFS - debugfsdir = debugfs_create_dir("rc", local->hw.wiphy->debugfsdir); - local->debugfs.rcdir = debugfsdir; - debugfs_create_file("name", 0400, debugfsdir, ref, &rcname_ops); -#endif - - ref->priv = ref->ops->alloc(&local->hw, debugfsdir); + ref->priv = ref->ops->alloc(&local->hw); if (!ref->priv) goto free; return ref; --- a/net/mac80211/rate.h +++ b/net/mac80211/rate.h @@ -60,6 +60,29 @@ static inline void rate_control_add_sta_ #endif } +extern const struct file_operations rcname_ops; + +static inline void rate_control_add_debugfs(struct ieee80211_local *local) +{ +#ifdef CONFIG_MAC80211_DEBUGFS + struct dentry *debugfsdir; + + if (!local->rate_ctrl) + return; + + if (!local->rate_ctrl->ops->add_debugfs) + return; + + debugfsdir = debugfs_create_dir("rc", local->hw.wiphy->debugfsdir); + local->debugfs.rcdir = debugfsdir; + debugfs_create_file("name", 0400, debugfsdir, + local->rate_ctrl, &rcname_ops); + + local->rate_ctrl->ops->add_debugfs(&local->hw, local->rate_ctrl->priv, + debugfsdir); +#endif +} + void ieee80211_check_rate_mask(struct ieee80211_sub_if_data *sdata); /* Get a reference to the rate control algorithm. If `name' is NULL, get the --- a/net/mac80211/rc80211_minstrel_ht.c +++ b/net/mac80211/rc80211_minstrel_ht.c @@ -1631,7 +1631,7 @@ minstrel_ht_init_cck_rates(struct minstr } static void * -minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir) +minstrel_ht_alloc(struct ieee80211_hw *hw) { struct minstrel_priv *mp; @@ -1668,18 +1668,24 @@ minstrel_ht_alloc(struct ieee80211_hw *h mp->hw = hw; mp->update_interval = 100; + minstrel_ht_init_cck_rates(mp); + + return mp; +} + #ifdef CONFIG_MAC80211_DEBUGFS +static void minstrel_ht_add_debugfs(struct ieee80211_hw *hw, void *priv, + struct dentry *debugfsdir) +{ + struct minstrel_priv *mp = priv; + mp->fixed_rate_idx = (u32) -1; debugfs_create_u32("fixed_rate_idx", S_IRUGO | S_IWUGO, debugfsdir, &mp->fixed_rate_idx); debugfs_create_u32("sample_switch", S_IRUGO | S_IWUSR, debugfsdir, &mp->sample_switch); -#endif - - minstrel_ht_init_cck_rates(mp); - - return mp; } +#endif static void minstrel_ht_free(void *priv) @@ -1718,6 +1724,7 @@ static const struct rate_control_ops mac .alloc = minstrel_ht_alloc, .free = minstrel_ht_free, #ifdef CONFIG_MAC80211_DEBUGFS + .add_debugfs = minstrel_ht_add_debugfs, .add_sta_debugfs = minstrel_ht_add_sta_debugfs, #endif .get_expected_throughput = minstrel_ht_get_expected_throughput,