gianfar: Do not reuse pages from emergency reserve
authorEric Dumazet <edumazet@google.com>
Thu, 19 Jan 2017 03:44:42 +0000 (19:44 -0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 5 Jul 2017 12:40:22 +0000 (14:40 +0200)
commit83571e9ef7c91ef6e249aae374de068b30963551
tree67228161bc9d8a7aaab4016b240ef63d309d7cd5
parentc48a862c47d481838b26f5d6cd5c29e2064339da
gianfar: Do not reuse pages from emergency reserve

[ Upstream commit 69fed99baac186013840ced3524562841296034f ]

A driver using dev_alloc_page() must not reuse a page that had to
use emergency memory reserve.

Otherwise all packets using this page will be immediately dropped,
unless for very specific sockets having SOCK_MEMALLOC bit set.

This issue might be hard to debug, because only a fraction of the RX
ring buffer would suffer from drops.

Fixes: 75354148ce69 ("gianfar: Add paged allocation and Rx S/G")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Claudiu Manoil <claudiu.manoil@freescale.com>
Acked-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/net/ethernet/freescale/gianfar.c