From: Arnd Bergmann Date: Fri, 9 Dec 2016 11:36:29 +0000 (-0200) Subject: [media] dvb: avoid warning in dvb_net X-Git-Tag: v4.11-rc2~21^2~239 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=4dd19196c5539c377beaa9850fac30c18318c7a1;p=platform%2Fkernel%2Flinux-exynos.git [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 --- diff --git a/drivers/media/dvb-core/dvb_net.c b/drivers/media/dvb-core/dvb_net.c index bd833b0..eb60cb1 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. */