bybrooklyn/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-05-14 21:53:21 -04:00
Code Issues Packages Projects Releases Wiki Activity

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
Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/s390/net/qeth_core.h
View File

@@ -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)