diff options
author | Ursula Braun <ubraun@linux.vnet.ibm.com> | 2018-02-09 11:03:49 +0100 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-03-08 22:41:18 -0800 |
commit | fcdfb9d80dc926f07b42129d08b197fd5d2ec65d (patch) | |
tree | 88dfa4d6294c596fc59b9c060181adf3116bee62 /drivers/s390/net | |
parent | 99a781947c2ab1e7b77bc88017fa58e78ff5c3ba (diff) |
s390/qeth: fix underestimated count of buffer elements
[ Upstream commit 89271c65edd599207dd982007900506283c90ae3 ]
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: 2863c61334aa ("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>
Diffstat (limited to 'drivers/s390/net')
-rw-r--r-- | drivers/s390/net/qeth_core.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/s390/net/qeth_core.h b/drivers/s390/net/qeth_core.h index 92dd4aef21a3..22b07046e44a 100644 --- a/drivers/s390/net/qeth_core.h +++ b/drivers/s390/net/qeth_core.h @@ -834,7 +834,7 @@ struct qeth_trap_id { */ static inline int qeth_get_elements_for_range(addr_t start, addr_t end) { - return PFN_UP(end - 1) - PFN_DOWN(start); + return PFN_UP(end) - PFN_DOWN(start); } static inline int qeth_get_micros(void) |