390/qeth: Fix locking warning during qeth device setup

Do not wait for channel command buffers in IPA commands.
The potential wait could be done while holding a spin lock and causes
in recent kernels such a bug if kernel lock debugging is enabled:

kernel: BUG: sleeping function called from invalid context at drivers/s390/net/qeth_core_main.c:
794
kernel: in_atomic(): 1, irqs_disabled(): 0, pid: 2031, name: NetworkManager
kernel: 2 locks held by NetworkManager/2031:
kernel:  #0:  (rtnl_mutex){+.+.+.}, at: [<00000000006e0d7a>] rtnetlink_rcv+0x32/0x50
kernel:  #1:  (_xmit_ETHER){+.....}, at: [<00000000006cfe90>] dev_set_rx_mode+0x30/0x50
kernel: CPU: 0 PID: 2031 Comm: NetworkManager Not tainted 3.18.0-rc5-next-20141124 #1
kernel:        00000000275fb1f0 00000000275fb280 0000000000000002 0000000000000000
               00000000275fb320 00000000275fb298 00000000275fb298 00000000007e326a
               0000000000000000 000000000099ce2c 00000000009b4988 000000000000000b
               00000000275fb2e0 00000000275fb280 0000000000000000 0000000000000000
               0000000000000000 00000000001129c8 00000000275fb280 00000000275fb2e0
kernel: Call Trace:
kernel: ([<00000000001128b0>] show_trace+0xf8/0x158)
kernel:  [<000000000011297a>] show_stack+0x6a/0xe8
kernel:  [<00000000007e995a>] dump_stack+0x82/0xb0
kernel:  [<000000000017d668>] ___might_sleep+0x170/0x228
kernel:  [<000003ff80026f0e>] qeth_wait_for_buffer+0x36/0xd0 [qeth]
kernel:  [<000003ff80026fe2>] qeth_get_ipacmd_buffer+0x3a/0xc0 [qeth]
kernel:  [<000003ff80105078>] qeth_l3_send_setdelmc+0x58/0xf8 [qeth_l3]
kernel:  [<000003ff8010b1fe>] qeth_l3_set_ip_addr_list+0x2c6/0x848 [qeth_l3]
kernel:  [<000003ff8010bbb4>] qeth_l3_set_multicast_list+0x434/0xc48 [qeth_l3]
kernel:  [<00000000006cfe9a>] dev_set_rx_mode+0x3a/0x50
kernel:  [<00000000006cff90>] __dev_open+0xe0/0x140
kernel:  [<00000000006d02a0>] __dev_change_flags+0xa0/0x178
kernel:  [<00000000006d03a8>] dev_change_flags+0x30/0x70
kernel:  [<00000000006e14ee>] do_setlink+0x346/0x9a0
...

The device driver has plenty of command buffers available
per channel for channel command communication.
In the extremely rare case when there is no command buffer
available, return a NULL pointer and issue a warning
in the kernel log. The caller handles the case when
a NULL pointer is encountered and returns an error.

In the case the wait for command buffer is possible
(because no lock is held as in the OSN case), still wait
until a channel command buffer is available.

Signed-off-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Reviewed-by: Eugene Crosser <Eugene.Crosser@ru.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 67 insertions, 14 deletions

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index e2fbfff53b50..642c77c76b84 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -1784,6 +1784,8 @@ static int qeth_idx_activate_get_answer(struct qeth_channel *channel,
 	QETH_DBF_TEXT(SETUP, 2, "idxanswr");
 	card = CARD_FROM_CDEV(channel->ccwdev);
 	iob = qeth_get_buffer(channel);
+	if (!iob)
+		return -ENOMEM;
 	iob->callback = idx_reply_cb;
 	memcpy(&channel->ccw, READ_CCW, sizeof(struct ccw1));
 	channel->ccw.count = QETH_BUFSIZE;
@@ -1834,6 +1836,8 @@ static int qeth_idx_activate_channel(struct qeth_channel *channel,
 	QETH_DBF_TEXT(SETUP, 2, "idxactch");
 
 	iob = qeth_get_buffer(channel);
+	if (!iob)
+		return -ENOMEM;
 	iob->callback = idx_reply_cb;
 	memcpy(&channel->ccw, WRITE_CCW, sizeof(struct ccw1));
 	channel->ccw.count = IDX_ACTIVATE_SIZE;
@@ -2940,9 +2944,16 @@ struct qeth_cmd_buffer *qeth_get_ipacmd_buffer(struct qeth_card *card,
 	struct qeth_cmd_buffer *iob;
 	struct qeth_ipa_cmd *cmd;
 
-	iob = qeth_wait_for_buffer(&card->write);
-	cmd = (struct qeth_ipa_cmd *)(iob->data+IPA_PDU_HEADER_SIZE);
-	qeth_fill_ipacmd_header(card, cmd, ipacmd, prot);
+	iob = qeth_get_buffer(&card->write);
+	if (iob) {
+		cmd = (struct qeth_ipa_cmd *)(iob->data+IPA_PDU_HEADER_SIZE);
+		qeth_fill_ipacmd_header(card, cmd, ipacmd, prot);
+	} else {
+		dev_warn(&card->gdev->dev,
+			 "The qeth driver ran out of channel command buffers\n");
+		QETH_DBF_MESSAGE(1, "%s The qeth driver ran out of channel command buffers",
+				 dev_name(&card->gdev->dev));
+	}
 
 	return iob;
 }
@@ -3000,6 +3011,8 @@ int qeth_send_startlan(struct qeth_card *card)
 	QETH_DBF_TEXT(SETUP, 2, "strtlan");
 
 	iob = qeth_get_ipacmd_buffer(card, IPA_CMD_STARTLAN, 0);
+	if (!iob)
+		return -ENOMEM;
 	rc = qeth_send_ipa_cmd(card, iob, NULL, NULL);
 	return rc;
 }
@@ -3045,11 +3058,13 @@ static struct qeth_cmd_buffer *qeth_get_adapter_cmd(struct qeth_card *card,
 
 	iob = qeth_get_ipacmd_buffer(card, IPA_CMD_SETADAPTERPARMS,
 				     QETH_PROT_IPV4);
-	cmd = (struct qeth_ipa_cmd *)(iob->data+IPA_PDU_HEADER_SIZE);
-	cmd->data.setadapterparms.hdr.cmdlength = cmdlen;
-	cmd->data.setadapterparms.hdr.command_code = command;
-	cmd->data.setadapterparms.hdr.used_total = 1;
-	cmd->data.setadapterparms.hdr.seq_no = 1;
+	if (iob) {
+		cmd = (struct qeth_ipa_cmd *)(iob->data+IPA_PDU_HEADER_SIZE);
+		cmd->data.setadapterparms.hdr.cmdlength = cmdlen;
+		cmd->data.setadapterparms.hdr.command_code = command;
+		cmd->data.setadapterparms.hdr.used_total = 1;
+		cmd->data.setadapterparms.hdr.seq_no = 1;
+	}
 
 	return iob;
 }
@@ -3062,6 +3077,8 @@ int qeth_query_setadapterparms(struct qeth_card *card)
 	QETH_CARD_TEXT(card, 3, "queryadp");
 	iob = qeth_get_adapter_cmd(card, IPA_SETADP_QUERY_COMMANDS_SUPPORTED,
 				   sizeof(struct qeth_ipacmd_setadpparms));
+	if (!iob)
+		return -ENOMEM;
 	rc = qeth_send_ipa_cmd(card, iob, qeth_query_setadapterparms_cb, NULL);
 	return rc;
 }
@@ -3112,6 +3129,8 @@ int qeth_query_ipassists(struct qeth_card *card, enum qeth_prot_versions prot)
 
 	QETH_DBF_TEXT_(SETUP, 2, "qipassi%i", prot);
 	iob = qeth_get_ipacmd_buffer(card, IPA_CMD_QIPASSIST, prot);
+	if (!iob)
+		return -ENOMEM;
 	rc = qeth_send_ipa_cmd(card, iob, qeth_query_ipassists_cb, NULL);
 	return rc;
 }
@@ -3151,6 +3170,8 @@ int qeth_query_switch_attributes(struct qeth_card *card,
 		return -ENOMEDIUM;
 	iob = qeth_get_adapter_cmd(card, IPA_SETADP_QUERY_SWITCH_ATTRIBUTES,
 				sizeof(struct qeth_ipacmd_setadpparms_hdr));
+	if (!iob)
+		return -ENOMEM;
 	return qeth_send_ipa_cmd(card, iob,
 				qeth_query_switch_attributes_cb, sw_info);
 }
@@ -3178,6 +3199,8 @@ static int qeth_query_setdiagass(struct qeth_card *card)
 
 	QETH_DBF_TEXT(SETUP, 2, "qdiagass");
 	iob = qeth_get_ipacmd_buffer(card, IPA_CMD_SET_DIAG_ASS, 0);
+	if (!iob)
+		return -ENOMEM;
 	cmd = (struct qeth_ipa_cmd *)(iob->data+IPA_PDU_HEADER_SIZE);
 	cmd->data.diagass.subcmd_len = 16;
 	cmd->data.diagass.subcmd = QETH_DIAGS_CMD_QUERY;
@@ -3229,6 +3252,8 @@ int qeth_hw_trap(struct qeth_card *card, enum qeth_diags_trap_action action)
 
 	QETH_DBF_TEXT(SETUP, 2, "diagtrap");
 	iob = qeth_get_ipacmd_buffer(card, IPA_CMD_SET_DIAG_ASS, 0);
+	if (!iob)
+		return -ENOMEM;
 	cmd = (struct qeth_ipa_cmd *)(iob->data+IPA_PDU_HEADER_SIZE);
 	cmd->data.diagass.subcmd_len = 80;
 	cmd->data.diagass.subcmd = QETH_DIAGS_CMD_TRAP;
@@ -4194,6 +4219,8 @@ void qeth_setadp_promisc_mode(struct qeth_card *card)
 
 	iob = qeth_get_adapter_cmd(card, IPA_SETADP_SET_PROMISC_MODE,
 			sizeof(struct qeth_ipacmd_setadpparms));
+	if (!iob)
+		return;
 	cmd = (struct qeth_ipa_cmd *)(iob->data + IPA_PDU_HEADER_SIZE);
 	cmd->data.setadapterparms.data.mode = mode;
 	qeth_send_ipa_cmd(card, iob, qeth_setadp_promisc_mode_cb, NULL);
@@ -4264,6 +4291,8 @@ int qeth_setadpparms_change_macaddr(struct qeth_card *card)
 
 	iob = qeth_get_adapter_cmd(card, IPA_SETADP_ALTER_MAC_ADDRESS,
 				   sizeof(struct qeth_ipacmd_setadpparms));
+	if (!iob)
+		return -ENOMEM;
 	cmd = (struct qeth_ipa_cmd *)(iob->data+IPA_PDU_HEADER_SIZE);
 	cmd->data.setadapterparms.data.change_addr.cmd = CHANGE_ADDR_READ_MAC;
 	cmd->data.setadapterparms.data.change_addr.addr_size = OSA_ADDR_LEN;
@@ -4377,6 +4406,8 @@ static int qeth_setadpparms_set_access_ctrl(struct qeth_card *card,
 	iob = qeth_get_adapter_cmd(card, IPA_SETADP_SET_ACCESS_CONTROL,
 				   sizeof(struct qeth_ipacmd_setadpparms_hdr) +
 				   sizeof(struct qeth_set_access_ctrl));
+	if (!iob)
+		return -ENOMEM;
 	cmd = (struct qeth_ipa_cmd *)(iob->data+IPA_PDU_HEADER_SIZE);
 	access_ctrl_req = &cmd->data.setadapterparms.data.set_access_ctrl;
 	access_ctrl_req->subcmd_code = isolation;
@@ -4620,6 +4651,10 @@ int qeth_snmp_command(struct qeth_card *card, char __user *udata)
 
 	iob = qeth_get_adapter_cmd(card, IPA_SETADP_SET_SNMP_CONTROL,
 				   QETH_SNMP_SETADP_CMDLENGTH + req_len);
+	if (!iob) {
+		rc = -ENOMEM;
+		goto out;
+	}
 	cmd = (struct qeth_ipa_cmd *)(iob->data+IPA_PDU_HEADER_SIZE);
 	memcpy(&cmd->data.setadapterparms.data.snmp, &ureq->cmd, req_len);
 	rc = qeth_send_ipa_snmp_cmd(card, iob, QETH_SETADP_BASE_LEN + req_len,
@@ -4631,7 +4666,7 @@ int qeth_snmp_command(struct qeth_card *card, char __user *udata)
 		if (copy_to_user(udata, qinfo.udata, qinfo.udata_len))
 			rc = -EFAULT;
 	}
-
+out:
 	kfree(ureq);
 	kfree(qinfo.udata);
 	return rc;
@@ -4702,6 +4737,10 @@ int qeth_query_oat_command(struct qeth_card *card, char __user *udata)
 	iob = qeth_get_adapter_cmd(card, IPA_SETADP_QUERY_OAT,
 				   sizeof(struct qeth_ipacmd_setadpparms_hdr) +
 				   sizeof(struct qeth_query_oat));
+	if (!iob) {
+		rc = -ENOMEM;
+		goto out_free;
+	}
 	cmd = (struct qeth_ipa_cmd *)(iob->data+IPA_PDU_HEADER_SIZE);
 	oat_req = &cmd->data.setadapterparms.data.query_oat;
 	oat_req->subcmd_code = oat_data.command;
@@ -4767,6 +4806,8 @@ static int qeth_query_card_info(struct qeth_card *card,
 		return -EOPNOTSUPP;
 	iob = qeth_get_adapter_cmd(card, IPA_SETADP_QUERY_CARD_INFO,
 		sizeof(struct qeth_ipacmd_setadpparms_hdr));
+	if (!iob)
+		return -ENOMEM;
 	return qeth_send_ipa_cmd(card, iob, qeth_query_card_info_cb,
 					(void *)carrier_info);
 }
@@ -5092,11 +5133,23 @@ retriable:
 	card->options.adp.supported_funcs = 0;
 	card->options.sbp.supported_funcs = 0;
 	card->info.diagass_support = 0;
-	qeth_query_ipassists(card, QETH_PROT_IPV4);
-	if (qeth_is_supported(card, IPA_SETADAPTERPARMS))
-		qeth_query_setadapterparms(card);
-	if (qeth_adp_supported(card, IPA_SETADP_SET_DIAG_ASSIST))
-		qeth_query_setdiagass(card);
+	rc = qeth_query_ipassists(card, QETH_PROT_IPV4);
+	if (rc == -ENOMEM)
+		goto out;
+	if (qeth_is_supported(card, IPA_SETADAPTERPARMS)) {
+		rc = qeth_query_setadapterparms(card);
+		if (rc < 0) {
+			QETH_DBF_TEXT_(SETUP, 2, "6err%d", rc);
+			goto out;
+		}
+	}
+	if (qeth_adp_supported(card, IPA_SETADP_SET_DIAG_ASSIST)) {
+		rc = qeth_query_setdiagass(card);
+		if (rc < 0) {
+			QETH_DBF_TEXT_(SETUP, 2, "7err%d", rc);
+			goto out;
+		}
+	}
 	return 0;
 out:
 	dev_warn(&card->gdev->dev, "The qeth device driver failed to recover "