diff options
| author | Ursula Braun <ubraun@linux.vnet.ibm.com> | 2018-02-09 11:03:49 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-03-11 16:21:33 +0100 |
| commit | 8d072588de679ef1593f67d8d4de7184111efa4f (patch) | |
| tree | 94b56b0f752e2e5b0049dcfaa1ef61ad7aa77ac3 /drivers/s390/net | |
| parent | a818270c30685bc22033b1af2f7d72f72b052602 (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 9b5fc502f6a1..2fe218101c46 100644 --- a/drivers/s390/net/qeth_core.h +++ b/drivers/s390/net/qeth_core.h @@ -849,7 +849,7 @@ 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) |