From: Jouni Malinen <j@w1.fi>
Date: Mon, 11 Feb 2019 14:29:04 +0000 (+0200)
Subject: cfg80211: Use const more consistently in for_each_element macros
X-Git-Url: https://jxself.org/git/?a=commitdiff_plain;h=63bccab8740ad8c254ec9a44fde250895a399b1c;p=carl9170fw.git

cfg80211: Use const more consistently in for_each_element macros

Enforce the first argument to be a correct type of a pointer to struct
element and avoid unnecessary typecasts from const to non-const pointers
(the change in validate_ie_attr() is needed to make this part work). In
addition, avoid signed/unsigned comparison within for_each_element() and
mark struct element packed just in case.

Signed-off-by: Jouni Malinen <j@w1.fi>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
---

diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index 4e47319..c2cc9a9 100644
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -3214,16 +3214,16 @@ struct element {
 	u8 id;
 	u8 datalen;
 	u8 data[];
-};
+} __packed;
 
 /* element iteration helpers */
-#define for_each_element(element, _data, _datalen)			\
-	for (element = (void *)(_data);					\
-	     (u8 *)(_data) + (_datalen) - (u8 *)element >=		\
-		sizeof(*element) &&					\
-	     (u8 *)(_data) + (_datalen) - (u8 *)element >=		\
-		sizeof(*element) + element->datalen;			\
-	     element = (void *)(element->data + element->datalen))
+#define for_each_element(_elem, _data, _datalen)			\
+	for (_elem = (const struct element *)(_data);			\
+	     (const u8 *)(_data) + (_datalen) - (const u8 *)_elem >=	\
+		(int)sizeof(*_elem) &&					\
+	     (const u8 *)(_data) + (_datalen) - (const u8 *)_elem >=	\
+		(int)sizeof(*_elem) + _elem->datalen;			\
+	     _elem = (const struct element *)(_elem->data + _elem->datalen))
 
 #define for_each_element_id(element, _id, data, datalen)		\
 	for_each_element(element, data, datalen)			\
@@ -3260,7 +3260,7 @@ struct element {
 static inline bool for_each_element_completed(const struct element *element,
 					      const void *data, size_t datalen)
 {
-	return (u8 *)element == (u8 *)data + datalen;
+	return (const u8 *)element == (const u8 *)data + datalen;
 }
 
 #endif /* __LINUX_IEEE80211_H */