[PATCH 4.4 29/36] s390/qeth: fix SETIP command handling

Greg Kroah-Hartman
2018-03-10T00:18:45Z

From: Julian Wiedmann <jwi@linux.vnet.ibm.com>

[ Upstream commit 1c5b2216fbb973a9410e0b06389740b5c1289171 ]

send_control_data() applies some special handling to SETIP v4 IPA
commands. But current code parses *all* command types for the SETIP
command code. Limit the command code check to IPA commands.

Fixes: 5b54e16f1a54 ("qeth: do not spin for SETIP ip assist command")
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>
---
drivers/s390/net/qeth_core.h | 5 +++++
drivers/s390/net/qeth_core_main.c | 14 ++++++++------
2 files changed, 13 insertions(+), 6 deletions(-)

--- a/drivers/s390/net/qeth_core.h
+++ b/drivers/s390/net/qeth_core.h
@@ -591,6 +591,11 @@ struct qeth_cmd_buffer {
void (*callback) (struct qeth_channel *, struct qeth_cmd_buffer *);
};

+static inline struct qeth_ipa_cmd *__ipa_cmd(struct qeth_cmd_buffer *iob)
+{
+ return (struct qeth_ipa_cmd *)(iob->data + IPA_PDU_HEADER_SIZE);
+}
+
/**
* definition of a qeth channel, used for read and write
*/
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -2054,7 +2054,7 @@ int qeth_send_control_data(struct qeth_c
unsigned long flags;
struct qeth_reply *reply = NULL;
unsigned long timeout, event_timeout;
- struct qeth_ipa_cmd *cmd;
+ struct qeth_ipa_cmd *cmd = NULL;

QETH_CARD_TEXT(card, 2, "sendctl");

@@ -2081,10 +2081,13 @@ int qeth_send_control_data(struct qeth_c
while (atomic_cmpxchg(&card->write.irq_pending, 0, 1)) ;
qeth_prepare_control_data(card, len, iob);

- if (IS_IPA(iob->data))
+ if (IS_IPA(iob->data)) {
+ cmd = __ipa_cmd(iob);
event_timeout = QETH_IPA_TIMEOUT;
- else
+ } else {
event_timeout = QETH_TIMEOUT;
+ }
+
timeout = jiffies + event_timeout;

QETH_CARD_TEXT(card, 6, "noirqpnd");
@@ -2109,9 +2112,8 @@ int qeth_send_control_data(struct qeth_c

/* we have only one long running ipassist, since we can ensure
process context of this command we can sleep */
- cmd = (struct qeth_ipa_cmd *)(iob->data+IPA_PDU_HEADER_SIZE);
- if ((cmd->hdr.command == IPA_CMD_SETIP) &&
- (cmd->hdr.prot_version == QETH_PROT_IPV4)) {
+ if (cmd && cmd->hdr.command == IPA_CMD_SETIP &&
+ cmd->hdr.prot_version == QETH_PROT_IPV4) {
if (!wait_event_timeout(reply->wait_q,
atomic_read(&reply->received), event_timeout))
goto time_err;