| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 053/101] gianfar: Do not reuse pages from emergency reserve | Date | Mon, 3 Jul 2017 15:34:53 +0200 |
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4.4-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet <edumazet@google.com>
[ 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 | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/net/ethernet/freescale/gianfar.c +++ b/drivers/net/ethernet/freescale/gianfar.c @@ -2939,7 +2939,7 @@ static bool gfar_add_rx_frag(struct gfar size, GFAR_RXB_TRUESIZE); /* try reuse page */ - if (unlikely(page_count(page) != 1)) + if (unlikely(page_count(page) != 1 || page_is_pfmemalloc(page))) return false; /* change offset to the other half */
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