From 4dd19196c5539c377beaa9850fac30c18318c7a1 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Fri, 9 Dec 2016 09:36:29 -0200 Subject: [media] dvb: avoid warning in dvb_net With gcc-5 or higher on x86, we can get a bogus warning in the dvb-net code: drivers/media/dvb-core/dvb_net.c: In function 'dvb_net_ule': arch/x86/include/asm/string_32.h:78:22: error: '*((void *)&dest_addr+4)' may be used uninitialized in this function [-Werror=maybe-uninitialized] The problem here is that gcc doesn't track all of the conditions to prove it can't end up copying uninitialized data. This changes the logic around so we zero out the destination address earlier when we determine that it is not set here. This allows the compiler to figure it out. Signed-off-by: Arnd Bergmann Signed-off-by: Mauro Carvalho Chehab --- drivers/media/dvb-core/dvb_net.c | 15 +++++---------- 1 file changed, 5 insertions(+), 10 deletions(-) (limited to 'drivers') diff --git a/drivers/media/dvb-core/dvb_net.c b/drivers/media/dvb-core/dvb_net.c index bd833b0824c6..eb60cb1442f2 100644 --- a/drivers/media/dvb-core/dvb_net.c +++ b/drivers/media/dvb-core/dvb_net.c @@ -719,6 +719,9 @@ static void dvb_net_ule_check_crc(struct dvb_net_ule_handle *h, skb_copy_from_linear_data(h->priv->ule_skb, dest_addr, ETH_ALEN); skb_pull(h->priv->ule_skb, ETH_ALEN); + } else { + /* dest_addr buffer is only valid if h->priv->ule_dbit == 0 */ + eth_zero_addr(dest_addr); } /* Handle ULE Extension Headers. */ @@ -750,16 +753,8 @@ static void dvb_net_ule_check_crc(struct dvb_net_ule_handle *h, if (!h->priv->ule_bridged) { skb_push(h->priv->ule_skb, ETH_HLEN); h->ethh = (struct ethhdr *)h->priv->ule_skb->data; - if (!h->priv->ule_dbit) { - /* - * dest_addr buffer is only valid if - * h->priv->ule_dbit == 0 - */ - memcpy(h->ethh->h_dest, dest_addr, ETH_ALEN); - eth_zero_addr(h->ethh->h_source); - } else /* zeroize source and dest */ - memset(h->ethh, 0, ETH_ALEN * 2); - + memcpy(h->ethh->h_dest, dest_addr, ETH_ALEN); + eth_zero_addr(h->ethh->h_source); h->ethh->h_proto = htons(h->priv->ule_sndu_type); } /* else: skb is in correct state; nothing to do. */ -- cgit v1.2.3