[PATCH net] mvpp2: use correct size for memset

[PATCH net] mvpp2: use correct size for memset

[Arnd Bergmann]

gcc-7 detects a short memset in mvpp2, introduced in the original
merge of the driver:

drivers/net/ethernet/marvell/mvpp2.c: In function 'mvpp2_cls_init':
drivers/net/ethernet/marvell/mvpp2.c:3296:2: error: 'memset' used with length equal to number of elements without multiplication by element size [-Werror=memset-elt-size]

The result seems to be that we write uninitialized data into the
flow table registers, although we did not get any warning about
that uninitialized data usage.

Using sizeof() lets us initialize then entire array instead.

Fixes: 3f518509dedc ("ethernet: Add new driver for Marvell Armada 375 network unit")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/net/ethernet/marvell/mvpp2.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/marvell/mvpp2.c b/drivers/net/ethernet/marvell/mvpp2.c
index ee857868bea5..dabc5418efcc 100644
--- a/drivers/net/ethernet/marvell/mvpp2.c
+++ b/drivers/net/ethernet/marvell/mvpp2.c
@@ -3293,7 +3293,7 @@ static void mvpp2_cls_init(struct mvpp2 *priv)
 	mvpp2_write(priv, MVPP2_CLS_MODE_REG, MVPP2_CLS_MODE_ACTIVE_MASK);
 
 	/* Clear classifier flow table */
-	memset(&fe.data, 0, MVPP2_CLS_FLOWS_TBL_DATA_WORDS);
+	memset(&fe.data, 0, sizeof(fe.data));
 	for (index = 0; index < MVPP2_CLS_FLOWS_TBL_SIZE; index++) {
 		fe.index = index;
 		mvpp2_cls_flow_write(priv, &fe);
-- 
2.9.0

Re: [PATCH net] mvpp2: use correct size for memset

[David Miller]

From: Arnd Bergmann <arnd@arndb.de>
Date: Thu, 24 Nov 2016 17:28:12 +0100

> gcc-7 detects a short memset in mvpp2, introduced in the original
> merge of the driver:
> 
> drivers/net/ethernet/marvell/mvpp2.c: In function 'mvpp2_cls_init':
> drivers/net/ethernet/marvell/mvpp2.c:3296:2: error: 'memset' used with length equal to number of elements without multiplication by element size [-Werror=memset-elt-size]
> 
> The result seems to be that we write uninitialized data into the
> flow table registers, although we did not get any warning about
> that uninitialized data usage.
> 
> Using sizeof() lets us initialize then entire array instead.
> 
> Fixes: 3f518509dedc ("ethernet: Add new driver for Marvell Armada 375 network unit")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Applied, thanks.