cfg80211: fix rfkill locking problem (2f0accc1) · Commits · 戴 / test

rfkill currently requires a global lock within the rfkill_register() function, and holds that lock over calls to the set_block() methods. This means that we cannot hold a lock around rfkill_register() that we also require in set_block(), directly or indirectly. Fix cfg80211 to register rfkill outside the block locked by its global lock. Much of what cfg80211 does in the locked block doesn't need to be locked anyway. Reported-by:

Vasanthakumar Thiagarajan <vasanth@atheros.com> Signed-off-by:

Johannes Berg <johannes@sipsolutions.net> Signed-off-by:

John W. Linville <linville@tuxdriver.com>

net/wireless/core.c

+9 −10

Original line number	Diff line number	Diff line
		@@ -395,21 +395,23 @@ int wiphy_register(struct wiphy *wiphy)
		/* check and set up bitrates */
		ieee80211_set_bitrate_flags(wiphy);

		mutex_lock(&cfg80211_mutex);

		/* set up regulatory info */
		wiphy_update_regulatory(wiphy, NL80211_REGDOM_SET_BY_CORE);

		res = device_add(&drv->wiphy.dev);
		if (res)
		goto out_unlock;
		return res;

		res = rfkill_register(drv->rfkill);
		if (res)
		goto out_rm_dev;

		mutex_lock(&cfg80211_mutex);

		/* set up regulatory info */
		wiphy_update_regulatory(wiphy, NL80211_REGDOM_SET_BY_CORE);

		list_add(&drv->list, &cfg80211_drv_list);

		mutex_unlock(&cfg80211_mutex);

		/* add to debugfs */
		drv->wiphy.debugfsdir =
		debugfs_create_dir(wiphy_name(&drv->wiphy),
		@@ -430,13 +432,10 @@ int wiphy_register(struct wiphy *wiphy)

		cfg80211_debugfs_drv_add(drv);

		res = 0;
		goto out_unlock;
		return 0;

		out_rm_dev:
		device_del(&drv->wiphy.dev);
		out_unlock:
		mutex_unlock(&cfg80211_mutex);
		return res;
		}
		EXPORT_SYMBOL(wiphy_register);

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