cfg80211: constify wowlan/coalesce mask/pattern pointers

This requires changing the nl80211 parsing code a bit to use
intermediate pointers for the allocation, but clarifies the
API towards the drivers.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index ca19b15..49adf58 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -8554,6 +8554,8 @@
 
 		nla_for_each_nested(pat, tb[NL80211_WOWLAN_TRIG_PKT_PATTERN],
 				    rem) {
+			u8 *mask_pat;
+
 			nla_parse(pat_tb, MAX_NL80211_PKTPAT, nla_data(pat),
 				  nla_len(pat), NULL);
 			err = -EINVAL;
@@ -8577,19 +8579,18 @@
 				goto error;
 			new_triggers.patterns[i].pkt_offset = pkt_offset;
 
-			new_triggers.patterns[i].mask =
-				kmalloc(mask_len + pat_len, GFP_KERNEL);
-			if (!new_triggers.patterns[i].mask) {
+			mask_pat = kmalloc(mask_len + pat_len, GFP_KERNEL);
+			if (!mask_pat) {
 				err = -ENOMEM;
 				goto error;
 			}
-			new_triggers.patterns[i].pattern =
-				new_triggers.patterns[i].mask + mask_len;
-			memcpy(new_triggers.patterns[i].mask,
-			       nla_data(pat_tb[NL80211_PKTPAT_MASK]),
+			new_triggers.patterns[i].mask = mask_pat;
+			memcpy(mask_pat, nla_data(pat_tb[NL80211_PKTPAT_MASK]),
 			       mask_len);
+			mask_pat += mask_len;
+			new_triggers.patterns[i].pattern = mask_pat;
 			new_triggers.patterns[i].pattern_len = pat_len;
-			memcpy(new_triggers.patterns[i].pattern,
+			memcpy(mask_pat,
 			       nla_data(pat_tb[NL80211_PKTPAT_PATTERN]),
 			       pat_len);
 			i++;
@@ -8781,6 +8782,8 @@
 
 	nla_for_each_nested(pat, tb[NL80211_ATTR_COALESCE_RULE_PKT_PATTERN],
 			    rem) {
+		u8 *mask_pat;
+
 		nla_parse(pat_tb, MAX_NL80211_PKTPAT, nla_data(pat),
 			  nla_len(pat), NULL);
 		if (!pat_tb[NL80211_PKTPAT_MASK] ||
@@ -8802,17 +8805,19 @@
 			return -EINVAL;
 		new_rule->patterns[i].pkt_offset = pkt_offset;
 
-		new_rule->patterns[i].mask =
-			kmalloc(mask_len + pat_len, GFP_KERNEL);
-		if (!new_rule->patterns[i].mask)
+		mask_pat = kmalloc(mask_len + pat_len, GFP_KERNEL);
+		if (!mask_pat)
 			return -ENOMEM;
-		new_rule->patterns[i].pattern =
-			new_rule->patterns[i].mask + mask_len;
-		memcpy(new_rule->patterns[i].mask,
-		       nla_data(pat_tb[NL80211_PKTPAT_MASK]), mask_len);
+
+		new_rule->patterns[i].mask = mask_pat;
+		memcpy(mask_pat, nla_data(pat_tb[NL80211_PKTPAT_MASK]),
+		       mask_len);
+
+		mask_pat += mask_len;
+		new_rule->patterns[i].pattern = mask_pat;
 		new_rule->patterns[i].pattern_len = pat_len;
-		memcpy(new_rule->patterns[i].pattern,
-		       nla_data(pat_tb[NL80211_PKTPAT_PATTERN]), pat_len);
+		memcpy(mask_pat, nla_data(pat_tb[NL80211_PKTPAT_PATTERN]),
+		       pat_len);
 		i++;
 	}