We change regulatory code to be protected by its own regulatory
spinlock and alleviate cfg80211_mutex to only be used to protect
cfg80211_rdev_list, the registered device list.
By doing this we will be able to work on regulatory core components
without having to have hog up the cfg80211_mutex. An example here is
we no longer need to use the cfg80211_mutex during the country IE
regulatory hint; by doing so we end up curing this new lockdep warning:
=======================================================
[ INFO: possible circular locking dependency detected ]
2.6.31-rc4-wl #12
-------------------------------------------------------
phy1/1709 is trying to acquire lock:
(cfg80211_mutex){+.+.+.}, at: [<ffffffffa00af852>] regulatory_hint_11d+0x32/0x3f0 [cfg80211]
but task is already holding lock:
(&ifmgd->mtx){+.+.+.}, at: [<ffffffffa0144228>] ieee80211_sta_work+0x108/0x10f0 [mac80211]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #3 (&ifmgd->mtx){+.+.+.}:
[<ffffffff810857b6>] __lock_acquire+0xd76/0x12b0
[<ffffffff81085dd3>] lock_acquire+0xe3/0x120
[<ffffffff814eeae4>] mutex_lock_nested+0x44/0x350
[<ffffffffa0141bb8>] ieee80211_mgd_auth+0x108/0x1f0 [mac80211]
[<ffffffffa0148563>] ieee80211_auth+0x13/0x20 [mac80211]
[<ffffffffa00bc3a1>] __cfg80211_mlme_auth+0x1b1/0x2a0 [cfg80211]
[<ffffffffa00bc516>] cfg80211_mlme_auth+0x86/0xc0 [cfg80211]
[<ffffffffa00b368d>] nl80211_authenticate+0x21d/0x230 [cfg80211]
[<ffffffff81416ba6>] genl_rcv_msg+0x1b6/0x1f0
[<ffffffff81415c39>] netlink_rcv_skb+0x89/0xb0
[<ffffffff814169d9>] genl_rcv+0x29/0x40
[<ffffffff8141591d>] netlink_unicast+0x29d/0x2b0
[<ffffffff81416514>] netlink_sendmsg+0x214/0x300
[<ffffffff813e4407>] sock_sendmsg+0x107/0x130
[<ffffffff813e45b9>] sys_sendmsg+0x189/0x320
[<ffffffff81011f82>] system_call_fastpath+0x16/0x1b
[<ffffffffffffffff>] 0xffffffffffffffff
-> #2 (&wdev->mtx){+.+.+.}:
[<ffffffff810857b6>] __lock_acquire+0xd76/0x12b0
[<ffffffff81085dd3>] lock_acquire+0xe3/0x120
[<ffffffff814eeae4>] mutex_lock_nested+0x44/0x350
[<ffffffffa00ab304>] cfg80211_netdev_notifier_call+0x1a4/0x390 [cfg80211]
[<ffffffff814f3dff>] notifier_call_chain+0x3f/0x80
[<ffffffff81075a91>] raw_notifier_call_chain+0x11/0x20
[<ffffffff813f665a>] dev_open+0x10a/0x120
[<ffffffff813f59bd>] dev_change_flags+0x9d/0x1e0
[<ffffffff8144eb6e>] devinet_ioctl+0x6fe/0x760
[<ffffffff81450204>] inet_ioctl+0x94/0xc0
[<ffffffff813e25fa>] sock_ioctl+0x6a/0x290
[<ffffffff8111e911>] vfs_ioctl+0x31/0xa0
[<ffffffff8111ea9a>] do_vfs_ioctl+0x8a/0x5c0
[<ffffffff8111f069>] sys_ioctl+0x99/0xa0
[<ffffffff81011f82>] system_call_fastpath+0x16/0x1b
[<ffffffffffffffff>] 0xffffffffffffffff
-> #1 (&rdev->mtx){+.+.+.}:
[<ffffffff810857b6>] __lock_acquire+0xd76/0x12b0
[<ffffffff81085dd3>] lock_acquire+0xe3/0x120
[<ffffffff814eeae4>] mutex_lock_nested+0x44/0x350
[<ffffffffa00ac4d0>] cfg80211_get_dev_from_ifindex+0x60/0x90 [cfg80211]
[<ffffffffa00b21ff>] get_rdev_dev_by_info_ifindex+0x6f/0xa0 [cfg80211]
[<ffffffffa00b51eb>] nl80211_set_interface+0x3b/0x260 [cfg80211]
[<ffffffff81416ba6>] genl_rcv_msg+0x1b6/0x1f0
[<ffffffff81415c39>] netlink_rcv_skb+0x89/0xb0
[<ffffffff814169d9>] genl_rcv+0x29/0x40
[<ffffffff8141591d>] netlink_unicast+0x29d/0x2b0
[<ffffffff81416514>] netlink_sendmsg+0x214/0x300
[<ffffffff813e4407>] sock_sendmsg+0x107/0x130
[<ffffffff813e45b9>] sys_sendmsg+0x189/0x320
[<ffffffff81011f82>] system_call_fastpath+0x16/0x1b
[<ffffffffffffffff>] 0xffffffffffffffff
other info that might help us debug this:
3 locks held by phy1/1709:
#0: ((wiphy_name(local->hw.wiphy))){+.+.+.}, at: [<ffffffff8106b45d>] worker_thread+0x19d/0x340
#1: (&ifmgd->work){+.+.+.}, at: [<ffffffff8106b45d>] worker_thread+0x19d/0x340
#2: (&ifmgd->mtx){+.+.+.}, at: [<ffffffffa0144228>] ieee80211_sta_work+0x108/0x10f0 [mac80211]
Reported-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Signed-off-by: Luis R. Rodriguez <lrodriguez@xxxxxxxxxxx>
---
net/wireless/core.c | 4 +---
net/wireless/reg.c | 26 +++++++++++++++++++++-----
2 files changed, 22 insertions(+), 8 deletions(-)
diff --git a/net/wireless/core.c b/net/wireless/core.c
index 755cdf1..d8dbd7f 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -34,9 +34,7 @@ MODULE_DESCRIPTION("wireless configuration support");
LIST_HEAD(cfg80211_rdev_list);
/*
- * This is used to protect the cfg80211_rdev_list, cfg80211_regdomain,
- * country_ie_regdomain, the reg_beacon_list and the the last regulatory
- * request receipt (last_request).
+ * This is used to protect the cfg80211_rdev_list
*/
DEFINE_MUTEX(cfg80211_mutex);
diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index 2d1d183..41c16fc 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -62,6 +62,15 @@ const struct ieee80211_regdomain *cfg80211_regdomain;
*/
static const struct ieee80211_regdomain *country_ie_regdomain;
+/*
+ * Protects static reg.c components:
+ * - cfg80211_world_regdom
+ * - cfg80211_regdom
+ * - country_ie_regdomain
+ * - last_request
+ */
+static spinlock_t reg_lock;
+
/* Used to queue up regulatory hints */
static LIST_HEAD(reg_requests_list);
static spinlock_t reg_requests_lock;
@@ -1570,6 +1579,7 @@ static void reg_process_hint(struct regulatory_request *reg_request)
BUG_ON(!reg_request->alpha2);
mutex_lock(&cfg80211_mutex);
+ spin_lock(®_lock);
if (wiphy_idx_valid(reg_request->wiphy_idx))
wiphy = wiphy_idx_to_wiphy(reg_request->wiphy_idx);
@@ -1585,6 +1595,7 @@ static void reg_process_hint(struct regulatory_request *reg_request)
if (r == -EALREADY && wiphy && wiphy->strict_regulatory)
wiphy_update_regulatory(wiphy, reg_request->initiator);
out:
+ spin_unlock(®_lock);
mutex_unlock(&cfg80211_mutex);
}
@@ -1734,13 +1745,12 @@ int regulatory_hint(struct wiphy *wiphy, const char *alpha2)
}
EXPORT_SYMBOL(regulatory_hint);
+/* Caller must hold reg_lock */
static bool reg_same_country_ie_hint(struct wiphy *wiphy,
u32 country_ie_checksum)
{
struct wiphy *request_wiphy;
- assert_cfg80211_lock();
-
if (unlikely(last_request->initiator !=
NL80211_REGDOM_SET_BY_COUNTRY_IE))
return false;
@@ -1772,7 +1782,7 @@ void regulatory_hint_11d(struct wiphy *wiphy,
enum environment_cap env = ENVIRON_ANY;
struct regulatory_request *request;
- mutex_lock(&cfg80211_mutex);
+ spin_lock(®_lock);
if (unlikely(!last_request))
goto out;
@@ -1883,7 +1893,7 @@ void regulatory_hint_11d(struct wiphy *wiphy,
request->country_ie_checksum = checksum;
request->country_ie_env = env;
- mutex_unlock(&cfg80211_mutex);
+ spin_unlock(®_lock);
queue_regulatory_request(request);
@@ -1892,7 +1902,7 @@ void regulatory_hint_11d(struct wiphy *wiphy,
free_rd_out:
kfree(rd);
out:
- mutex_unlock(&cfg80211_mutex);
+ spin_unlock(®_lock);
}
EXPORT_SYMBOL(regulatory_hint_11d);
@@ -2225,10 +2235,13 @@ int set_regdom(const struct ieee80211_regdomain *rd)
assert_cfg80211_lock();
+ spin_lock(®_lock);
+
/* Note that this doesn't update the wiphys, this is done below */
r = __set_regdom(rd);
if (r) {
kfree(rd);
+ spin_unlock(®_lock);
return r;
}
@@ -2243,6 +2256,8 @@ int set_regdom(const struct ieee80211_regdomain *rd)
nl80211_send_reg_change_event(last_request);
+ spin_unlock(®_lock);
+
return r;
}
@@ -2275,6 +2290,7 @@ int regulatory_init(void)
spin_lock_init(®_requests_lock);
spin_lock_init(®_pending_beacons_lock);
+ spin_lock_init(®_lock);
#ifdef CONFIG_WIRELESS_OLD_REGULATORY
cfg80211_regdomain = static_regdom(ieee80211_regdom);
--
1.6.0.4
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