From: Sergei Zviagintsev Date: Tue, 9 Jun 2015 23:59:59 +0300 Subject: [PATCH] kdbus: fix operator precedence issues in item macros `_i' argument in KDBUS_ITEM_NEXT and KDBUS_ITEMS_END macros is not enclosed into parentheses when the cast operator is applied, which leads to improper type conversion if `_i' is supplied as a complex expression, e.g. KDBUS_ITEM_NEXT(condition ? a : b) KDBUS_ITEMS_SIZE macro has similar issue, missing parentheses around `_h' when using indirection operator. Use parentheses properly to guarantee right precedence. Signed-off-by: Sergei Zviagintsev Reviewed-by: David Herrmann Signed-off-by: Greg Kroah-Hartman --- ipc/kdbus/item.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/ipc/kdbus/item.h b/ipc/kdbus/item.h index eeefd8beac3b..32909e2e7954 100644 --- a/ipc/kdbus/item.h +++ b/ipc/kdbus/item.h @@ -21,8 +21,8 @@ #include "util.h" /* generic access and iterators over a stream of items */ -#define KDBUS_ITEM_NEXT(_i) (typeof(_i))(((u8 *)_i) + KDBUS_ALIGN8((_i)->size)) -#define KDBUS_ITEMS_SIZE(_h, _is) ((_h)->size - offsetof(typeof(*_h), _is)) +#define KDBUS_ITEM_NEXT(_i) (typeof(_i))((u8 *)(_i) + KDBUS_ALIGN8((_i)->size)) +#define KDBUS_ITEMS_SIZE(_h, _is) ((_h)->size - offsetof(typeof(*(_h)), _is)) #define KDBUS_ITEM_HEADER_SIZE offsetof(struct kdbus_item, data) #define KDBUS_ITEM_SIZE(_s) KDBUS_ALIGN8(KDBUS_ITEM_HEADER_SIZE + (_s)) #define KDBUS_ITEM_PAYLOAD_SIZE(_i) ((_i)->size - KDBUS_ITEM_HEADER_SIZE) @@ -40,7 +40,7 @@ (u8 *)(_i) >= (u8 *)(_is)) #define KDBUS_ITEMS_END(_i, _is, _s) \ - ((u8 *)_i == ((u8 *)(_is) + KDBUS_ALIGN8(_s))) + ((u8 *)(_i) == ((u8 *)(_is) + KDBUS_ALIGN8(_s))) /** * struct kdbus_item_header - Describes the fix part of an item