| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.13 058/151] net: mvvp2: fix short frame size on s390 | Date | Mon, 16 Aug 2021 15:01:28 +0200 |
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From: John Hubbard <jhubbard@nvidia.com>
[ Upstream commit 704e624f7b3e8a4fc1ce43fb564746d1d07b20c0 ]
On s390, the following build warning occurs:
drivers/net/ethernet/marvell/mvpp2/mvpp2.h:844:2: warning: overflow in conversion from 'long unsigned int' to 'int' changes value from '18446744073709551584' to '-32' [-Woverflow] 844 | ((total_size) - MVPP2_SKB_HEADROOM - MVPP2_SKB_SHINFO_SIZE)
This happens because MVPP2_SKB_SHINFO_SIZE, which is 320 bytes (which is already 64-byte aligned) on some architectures, actually gets ALIGN'd up to 512 bytes in the s390 case.
So then, when this is invoked:
MVPP2_RX_MAX_PKT_SIZE(MVPP2_BM_SHORT_FRAME_SIZE)
...that turns into:
704 - 224 - 512 == -32
...which is not a good frame size to end up with! The warning above is a bit lucky: it notices a signed/unsigned bad behavior here, which leads to the real problem of a frame that is too short for its contents.
Increase MVPP2_BM_SHORT_FRAME_SIZE by 32 (from 704 to 736), which is just exactly big enough. (The other values can't readily be changed without causing a lot of other problems.)
Fixes: 07dd0a7aae7f ("mvpp2: add basic XDP support") Cc: Sven Auhagen <sven.auhagen@voleatech.de> Cc: Matteo Croce <mcroce@microsoft.com> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/net/ethernet/marvell/mvpp2/mvpp2.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2.h b/drivers/net/ethernet/marvell/mvpp2/mvpp2.h index 4a61c90003b5..722209a14f53 100644 --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2.h +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2.h @@ -938,7 +938,7 @@ enum mvpp22_ptp_packet_format { #define MVPP2_BM_COOKIE_POOL_OFFS 8 #define MVPP2_BM_COOKIE_CPU_OFFS 24 -#define MVPP2_BM_SHORT_FRAME_SIZE 704 /* frame size 128 */ +#define MVPP2_BM_SHORT_FRAME_SIZE 736 /* frame size 128 */ #define MVPP2_BM_LONG_FRAME_SIZE 2240 /* frame size 1664 */ #define MVPP2_BM_JUMBO_FRAME_SIZE 10432 /* frame size 9856 */ /* BM short pool packet size -- 2.30.2
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