This is a note to let you know that I've just added the patch titled
s390/qeth: size calculation outbound buffers
to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: s390-qeth-size-calculation-outbound-buffers.patch and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From foo@baz Thu Dec 21 09:02:40 CET 2017
From: Julian Wiedmann jwi@linux.vnet.ibm.com Date: Thu, 23 Mar 2017 14:55:08 +0100 Subject: s390/qeth: size calculation outbound buffers
From: Julian Wiedmann jwi@linux.vnet.ibm.com
[ Upstream commit 7d969d2e8890f546c8cec634b3aa5f57d4eef883 ]
Depending on the device type, hard_start_xmit() builds different output buffer formats. For instance with HiperSockets, on both L2 and L3 we strip the ETH header from the skb - L3 doesn't need it, and L2 carries it in the buffer's header element. For this, we pass data_offset = ETH_HLEN all the way down to __qeth_fill_buffer(), where skb->data is then adjusted accordingly. But the initial size calculation still considers the *full* skb length (including the ETH header). So qeth_get_elements_no() can erroneously reject a skb as too big, even though it would actually fit into an output buffer once the ETH header has been trimmed off later.
Fix this by passing an additional offset to qeth_get_elements_no(), that indicates where in the skb the on-wire data actually begins. Since the current code uses data_offset=-1 for some special handling on OSA, we need to clamp data_offset to 0...
On HiperSockets this helps when sending ~MTU-size skbs with weird page alignment. No change for OSA or AF_IUCV.
Signed-off-by: Julian Wiedmann jwi@linux.vnet.ibm.com Signed-off-by: Ursula Braun ubraun@linux.vnet.ibm.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/s390/net/qeth_core.h | 3 ++- drivers/s390/net/qeth_core_main.c | 5 +++-- drivers/s390/net/qeth_l2_main.c | 5 +++-- drivers/s390/net/qeth_l3_main.c | 5 +++-- 4 files changed, 11 insertions(+), 7 deletions(-)
--- a/drivers/s390/net/qeth_core.h +++ b/drivers/s390/net/qeth_core.h @@ -969,7 +969,8 @@ int qeth_bridgeport_query_ports(struct q int qeth_bridgeport_setrole(struct qeth_card *card, enum qeth_sbp_roles role); int qeth_bridgeport_an_set(struct qeth_card *card, int enable); int qeth_get_priority_queue(struct qeth_card *, struct sk_buff *, int, int); -int qeth_get_elements_no(struct qeth_card *, struct sk_buff *, int); +int qeth_get_elements_no(struct qeth_card *card, struct sk_buff *skb, + int extra_elems, int data_offset); int qeth_get_elements_for_frags(struct sk_buff *); int qeth_do_send_packet_fast(struct qeth_card *, struct qeth_qdio_out_q *, struct sk_buff *, struct qeth_hdr *, int, int, int); --- a/drivers/s390/net/qeth_core_main.c +++ b/drivers/s390/net/qeth_core_main.c @@ -3842,6 +3842,7 @@ EXPORT_SYMBOL_GPL(qeth_get_elements_for_ * @card: qeth card structure, to check max. elems. * @skb: SKB address * @extra_elems: extra elems needed, to check against max. + * @data_offset: range starts at skb->data + data_offset * * Returns the number of pages, and thus QDIO buffer elements, needed to cover * skb data, including linear part and fragments. Checks if the result plus @@ -3849,10 +3850,10 @@ EXPORT_SYMBOL_GPL(qeth_get_elements_for_ * Note: extra_elems is not included in the returned result. */ int qeth_get_elements_no(struct qeth_card *card, - struct sk_buff *skb, int extra_elems) + struct sk_buff *skb, int extra_elems, int data_offset) { int elements = qeth_get_elements_for_range( - (addr_t)skb->data, + (addr_t)skb->data + data_offset, (addr_t)skb->data + skb_headlen(skb)) + qeth_get_elements_for_frags(skb);
--- a/drivers/s390/net/qeth_l2_main.c +++ b/drivers/s390/net/qeth_l2_main.c @@ -865,7 +865,7 @@ static int qeth_l2_hard_start_xmit(struc * chaining we can not send long frag lists */ if ((card->info.type != QETH_CARD_TYPE_IQD) && - !qeth_get_elements_no(card, new_skb, 0)) { + !qeth_get_elements_no(card, new_skb, 0, 0)) { int lin_rc = skb_linearize(new_skb);
if (card->options.performance_stats) { @@ -910,7 +910,8 @@ static int qeth_l2_hard_start_xmit(struc } }
- elements = qeth_get_elements_no(card, new_skb, elements_needed); + elements = qeth_get_elements_no(card, new_skb, elements_needed, + (data_offset > 0) ? data_offset : 0); if (!elements) { if (data_offset >= 0) kmem_cache_free(qeth_core_header_cache, hdr); --- a/drivers/s390/net/qeth_l3_main.c +++ b/drivers/s390/net/qeth_l3_main.c @@ -2870,7 +2870,7 @@ static int qeth_l3_hard_start_xmit(struc */ if ((card->info.type != QETH_CARD_TYPE_IQD) && ((use_tso && !qeth_l3_get_elements_no_tso(card, new_skb, 1)) || - (!use_tso && !qeth_get_elements_no(card, new_skb, 0)))) { + (!use_tso && !qeth_get_elements_no(card, new_skb, 0, 0)))) { int lin_rc = skb_linearize(new_skb);
if (card->options.performance_stats) { @@ -2912,7 +2912,8 @@ static int qeth_l3_hard_start_xmit(struc
elements = use_tso ? qeth_l3_get_elements_no_tso(card, new_skb, hdr_elements) : - qeth_get_elements_no(card, new_skb, hdr_elements); + qeth_get_elements_no(card, new_skb, hdr_elements, + (data_offset > 0) ? data_offset : 0); if (!elements) { if (data_offset >= 0) kmem_cache_free(qeth_core_header_cache, hdr);
Patches currently in stable-queue which might be from jwi@linux.vnet.ibm.com are
queue-4.9/s390-qeth-size-calculation-outbound-buffers.patch queue-4.9/s390-qeth-no-eth-header-for-outbound-af_iucv.patch