[RFC PATCH 11/13] netdevice.h: Fix parentheses around macro parameter use

[RFC PATCH 11/13] netdevice.h: Fix parentheses around macro parameter use

[Mathieu Desnoyers]

Add missing parentheses around macro parameter use in the following
pattern:

- "x - 1" changed for "(x) - 1",
- "x->member" changed for "(x)->member".

to ensure operator precedence behaves as expected.

Remove useless parentheses around macro parameter use in the following
pattern:

- m((x), y) changed for m(x, y), because comma has the lowest operator
  precedence, which makes the extra comma useless.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: netdev@vger.kernel.org
---
 include/linux/netdevice.h | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 08fbd4622ccf..5a357262a45b 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -283,7 +283,7 @@ struct hh_cache {
 	/* cached hardware header; allow for machine alignment needs.        */
 #define HH_DATA_MOD	16
 #define HH_DATA_OFF(__len) \
-	(HH_DATA_MOD - (((__len - 1) & (HH_DATA_MOD - 1)) + 1))
+	(HH_DATA_MOD - ((((__len) - 1) & (HH_DATA_MOD - 1)) + 1))
 #define HH_DATA_ALIGN(__len) \
 	(((__len)+(HH_DATA_MOD-1))&~(HH_DATA_MOD - 1))
 	unsigned long	hh_data[HH_DATA_ALIGN(LL_MAX_HEADER) / sizeof(long)];
@@ -4459,7 +4459,7 @@ static inline void netif_tx_unlock_bh(struct net_device *dev)
 }
 
 #define HARD_TX_LOCK(dev, txq, cpu) {			\
-	if ((dev->features & NETIF_F_LLTX) == 0) {	\
+	if (((dev)->features & NETIF_F_LLTX) == 0) {	\
 		__netif_tx_lock(txq, cpu);		\
 	} else {					\
 		__netif_tx_acquire(txq);		\
@@ -4467,12 +4467,12 @@ static inline void netif_tx_unlock_bh(struct net_device *dev)
 }
 
 #define HARD_TX_TRYLOCK(dev, txq)			\
-	(((dev->features & NETIF_F_LLTX) == 0) ?	\
+	((((dev)->features & NETIF_F_LLTX) == 0) ?	\
 		__netif_tx_trylock(txq) :		\
 		__netif_tx_acquire(txq))
 
 #define HARD_TX_UNLOCK(dev, txq) {			\
-	if ((dev->features & NETIF_F_LLTX) == 0) {	\
+	if (((dev)->features & NETIF_F_LLTX) == 0) {	\
 		__netif_tx_unlock(txq);			\
 	} else {					\
 		__netif_tx_release(txq);		\
@@ -4534,7 +4534,7 @@ static inline void netif_addr_unlock_bh(struct net_device *dev)
  * rcu_read_lock held.
  */
 #define for_each_dev_addr(dev, ha) \
-		list_for_each_entry_rcu(ha, &dev->dev_addrs.list, list)
+		list_for_each_entry_rcu(ha, &(dev)->dev_addrs.list, list)
 
 /* These functions live elsewhere (drivers/net/net_init.c, but related) */
 
@@ -5237,6 +5237,6 @@ extern struct net_device *blackhole_netdev;
 /* Note: Avoid these macros in fast path, prefer per-cpu or per-queue counters. */
 #define DEV_STATS_INC(DEV, FIELD) atomic_long_inc(&(DEV)->stats.__##FIELD)
 #define DEV_STATS_ADD(DEV, FIELD, VAL) 	\
-		atomic_long_add((VAL), &(DEV)->stats.__##FIELD)
+		atomic_long_add(VAL, &(DEV)->stats.__##FIELD)
 
 #endif	/* _LINUX_NETDEVICE_H */
-- 
2.25.1

Re: [RFC PATCH 11/13] netdevice.h: Fix parentheses around macro parameter use

[Jakub Kicinski]

On Thu,  4 May 2023 16:05:25 -0400 Mathieu Desnoyers wrote:
> Add missing parentheses around macro parameter use in the following
> pattern:
> 
> - "x - 1" changed for "(x) - 1",
> - "x->member" changed for "(x)->member".
> 
> to ensure operator precedence behaves as expected.
> 
> Remove useless parentheses around macro parameter use in the following
> pattern:
> 
> - m((x), y) changed for m(x, y), because comma has the lowest operator
>   precedence, which makes the extra comma useless.

Sure, why not. Can we take it via netdev, tho?
I can't have any dependencies, right?

Re: [RFC PATCH 11/13] netdevice.h: Fix parentheses around macro parameter use

[Mathieu Desnoyers]

On 2023-05-05 14:44, Jakub Kicinski wrote:
> On Thu,  4 May 2023 16:05:25 -0400 Mathieu Desnoyers wrote:
>> Add missing parentheses around macro parameter use in the following
>> pattern:
>>
>> - "x - 1" changed for "(x) - 1",
>> - "x->member" changed for "(x)->member".
>>
>> to ensure operator precedence behaves as expected.
>>
>> Remove useless parentheses around macro parameter use in the following
>> pattern:
>>
>> - m((x), y) changed for m(x, y), because comma has the lowest operator
>>    precedence, which makes the extra comma useless.
> 
> Sure, why not. Can we take it via netdev, tho?
> I can't have any dependencies, right?

I'll note your Acked-by in my patch for the next round. When I post 
without RFC tag it will be ready for merging. There is still some 
high-level feedback I want to gather on the overall series before I 
remove the RFC tag.

There are no dependencies, each patch in this series only target a 
single header, and there are no dependencies across those patches.

Thanks,

Mathieu

-- 
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com