On 1/1/07, Jan Kiszka <[EMAIL PROTECTED]> wrote:
Hacking a bit on rt2x00 to make it work in master and ad-hoc mode, lockdep
popped up on some hostapd ioctls, pointing out remaining inconsistencies
related to sta_lock:

1. sta_lock holders must always be protected against softirq
2. bss_tim_set/clear must not be called with sta_lock held, rather an
   unprotected variant
3. ieee80211_ioctl_remove_sta is not already holding the lock when calling
   sta_info_free

As I was not sure if sta_info_remove_aid_ptr needs lock protection or
not, I played safe and moved it always under the lock. Please correct me
if this is overkill.

Signed-off-by: Jan Kiszka <[EMAIL PROTECTED]>

[Sorry, patch is against rt2x00 CVS. I'm lacking time and bandwidth to pull
the d80211 git repos and rebase.]

To make it easier for everybody, here is the same patch
only this time applied to the dscape git tree. ;)

Signed-off-by: Jan Kiszka <[EMAIL PROTECTED]>
Signed-off-by: Ivo van Doorn <[EMAIL PROTECTED]>

---

diff --git a/net/d80211/ieee80211_i.h b/net/d80211/ieee80211_i.h
index ef303da..b132ae0 100644
--- a/net/d80211/ieee80211_i.h
+++ b/net/d80211/ieee80211_i.h
@@ -558,20 +558,32 @@ struct sta_attribute {
        ssize_t (*store)(struct sta_info *, const char *buf, size_t count);
};

+static inline void __bss_tim_set(struct ieee80211_local *local,
+                                struct ieee80211_if_ap *bss, int aid)
+{
+       bss->tim[(aid)/8] |= 1<<((aid) % 8);
+}
+
static inline void bss_tim_set(struct ieee80211_local *local,
                               struct ieee80211_if_ap *bss, int aid)
{
-       spin_lock(&local->sta_lock);
-       bss->tim[(aid)/8] |= 1<<((aid) % 8);
-       spin_unlock(&local->sta_lock);
+       spin_lock_bh(&local->sta_lock);
+       __bss_tim_set(local, bss, aid);
+       spin_unlock_bh(&local->sta_lock);
+}
+
+static inline void __bss_tim_clear(struct ieee80211_local *local,
+                                  struct ieee80211_if_ap *bss, int aid)
+{
+       bss->tim[(aid)/8] &= !(1<<((aid) % 8));
}

static inline void bss_tim_clear(struct ieee80211_local *local,
                                 struct ieee80211_if_ap *bss, int aid)
{
-       spin_lock(&local->sta_lock);
-       bss->tim[(aid)/8] &= !(1<<((aid) % 8));
-       spin_unlock(&local->sta_lock);
+       spin_lock_bh(&local->sta_lock);
+       __bss_tim_clear(local, bss, aid);
+       spin_unlock_bh(&local->sta_lock);
}

/* ieee80211.c */
diff --git a/net/d80211/ieee80211_ioctl.c b/net/d80211/ieee80211_ioctl.c
index c74b431..1363a01 100644
--- a/net/d80211/ieee80211_ioctl.c
+++ b/net/d80211/ieee80211_ioctl.c
@@ -285,7 +285,9 @@ static int ieee80211_ioctl_add_sta(struct net_device *dev,
        if (sta->dev != dev) {
                /* Binding STA to a new interface, so remove all references to
                 * the old BSS. */
+               spin_lock_bh(&local->sta_lock);
                sta_info_remove_aid_ptr(sta);
+               spin_unlock_bh(&local->sta_lock);
        }

        /* TODO
@@ -359,7 +361,7 @@ static int ieee80211_ioctl_remove_sta(struct
net_device *dev,
        sta = sta_info_get(local, param->sta_addr);
        if (sta) {
                sta_info_put(sta);
-               sta_info_free(sta, 1);
+               sta_info_free(sta, 0);
        }

        return sta ? 0 : -ENOENT;
diff --git a/net/d80211/sta_info.c b/net/d80211/sta_info.c
index 0c42ae8..e120a4f 100644
--- a/net/d80211/sta_info.c
+++ b/net/d80211/sta_info.c
@@ -439,7 +439,7 @@ void sta_info_remove_aid_ptr(struct sta_info *sta)
                sdata->local->ops->set_tim(local_to_hw(sdata->local),
                                          sta->aid, 0);
        if (sdata->bss)
-               bss_tim_clear(sdata->local, sdata->bss, sta->aid);
+               __bss_tim_clear(sdata->local, sdata->bss, sta->aid);
}
-
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