s390/qeth: fix underestimated count of buffer elements

Browse source

[ Upstream commit 89271c65ed ]

For a memory range/skb where the last byte falls onto a page boundary
(ie. 'end' is of the form xxx...xxx001), the PFN_UP() part of the
calculation currently doesn't round up to the next PFN due to an
off-by-one error.
Thus qeth believes that the skb occupies one page less than it
actually does, and may select a IO buffer that doesn't have enough spare
buffer elements to fit all of the skb's data.
HW detects this as a malformed buffer descriptor, and raises an
exception which then triggers device recovery.

Fixes: 2863c61334 ("qeth: refactor calculation of SBALE count")
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

...

This commit is contained in:

Ursula Braun 2018-02-09 11:03:49 +01:00 • committed by Greg Kroah-Hartman

parent 99a781947c

commit fcdfb9d80d

1 changed files with 1 additions and 1 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

2

drivers/s390/net/qeth_core.h

View file