Commit 6df653c7 authored Jun 18, 2012 by Luciano Coelho Committed by Johannes Berg Jun 20, 2012

mac80211: initialize sta pointer to avoid false-positive warning



Some compilers (eg. gcc 4.4.1 for ARM) report a false positive warning
in mlme.c:

net/mac80211/mlme.c: In function 'ieee80211_prep_connection':
net/mac80211/mlme.c:3035: warning: 'sta' may be used uninitialized in this function

This is a false positive because the place where 'sta' is used is
inside an if with the same condition of where it is set:

[...]
        if (!have_sta) {
                sta = sta_info_alloc(sdata, cbss->bssid, GFP_KERNEL);
                if (!sta)
                        return -ENOMEM;
        }
[...]
        if (!have_sta) {
[...]
                sta->sta.supp_rates[cbss->channel->band] = rates;
[...]

For some reason the compiler doesn't understand this and warns.

While this is not a problem in the code itself, we can avoid polluting
the build logs with false positives by setting sta to NULL on
declaration and checking for sta instead of !have_sta in the second if.

Reported-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

parent 559cef99

net/mac80211/mlme.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -3012,7 +3012,7 @@ static int ieee80211_prep_connection(struct ieee80211_sub_if_data *sdata,
		struct ieee80211_local *local = sdata->local;
		struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
		struct ieee80211_bss bss = (void )cbss->priv;
		struct sta_info *sta;
		struct sta_info *sta = NULL;
		bool have_sta = false;
		int err;
		int ht_cfreq;
		@@ -3102,7 +3102,7 @@ static int ieee80211_prep_connection(struct ieee80211_sub_if_data *sdata,
		local->oper_channel = cbss->channel;
		ieee80211_hw_config(local, 0);

		if (!have_sta) {
		if (sta) {
		u32 rates = 0, basic_rates = 0;
		bool have_higher_than_11mbit;
		int min_rate = INT_MAX, min_rate_index = -1;

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