From 7b7331511e66cfe671e88daa7133f6597a86aced Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Mon, 29 Jul 2019 19:13:54 -0500 Subject: s390/net: Mark expected switch fall-throughs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Mark switch cases where we are expecting to fall through. This patch fixes the following warnings (Building: s390): drivers/s390/net/ctcm_fsms.c: In function ‘ctcmpc_chx_attnbusy’: drivers/s390/net/ctcm_fsms.c:1703:6: warning: this statement may fall through [-Wimplicit-fallthrough=] if (grp->changed_side == 1) { ^ drivers/s390/net/ctcm_fsms.c:1707:2: note: here case MPCG_STATE_XID0IOWAIX: ^~~~ drivers/s390/net/ctcm_mpc.c: In function ‘ctc_mpc_alloc_channel’: drivers/s390/net/ctcm_mpc.c:358:6: warning: this statement may fall through [-Wimplicit-fallthrough=] if (callback) ^ drivers/s390/net/ctcm_mpc.c:360:2: note: here case MPCG_STATE_XID0IOWAIT: ^~~~ drivers/s390/net/ctcm_mpc.c: In function ‘mpc_action_timeout’: drivers/s390/net/ctcm_mpc.c:1469:6: warning: this statement may fall through [-Wimplicit-fallthrough=] if ((fsm_getstate(rch->fsm) == CH_XID0_PENDING) && ^ drivers/s390/net/ctcm_mpc.c:1472:2: note: here default: ^~~~~~~ drivers/s390/net/ctcm_mpc.c: In function ‘mpc_send_qllc_discontact’: drivers/s390/net/ctcm_mpc.c:2087:6: warning: this statement may fall through [-Wimplicit-fallthrough=] if (grp->estconnfunc) { ^ drivers/s390/net/ctcm_mpc.c:2092:2: note: here case MPCG_STATE_FLOWC: ^~~~ drivers/s390/net/qeth_l2_main.c: In function ‘qeth_l2_process_inbound_buffer’: drivers/s390/net/qeth_l2_main.c:328:7: warning: this statement may fall through [-Wimplicit-fallthrough=] if (IS_OSN(card)) { ^ drivers/s390/net/qeth_l2_main.c:337:3: note: here default: ^~~~~~~ Reviewed-by: Kees Cook Signed-off-by: Gustavo A. R. Silva --- drivers/s390/net/ctcm_fsms.c | 1 + drivers/s390/net/ctcm_mpc.c | 3 +++ drivers/s390/net/qeth_l2_main.c | 2 +- 3 files changed, 5 insertions(+), 1 deletion(-) (limited to 'drivers/s390/net') diff --git a/drivers/s390/net/ctcm_fsms.c b/drivers/s390/net/ctcm_fsms.c index 1b4ee570b712..4a8a5373cb35 100644 --- a/drivers/s390/net/ctcm_fsms.c +++ b/drivers/s390/net/ctcm_fsms.c @@ -1704,6 +1704,7 @@ static void ctcmpc_chx_attnbusy(fsm_instance *fsm, int event, void *arg) grp->changed_side = 2; break; } + /* Else, fall through */ case MPCG_STATE_XID0IOWAIX: case MPCG_STATE_XID7INITW: case MPCG_STATE_XID7INITX: diff --git a/drivers/s390/net/ctcm_mpc.c b/drivers/s390/net/ctcm_mpc.c index e02f295d38a9..1534420a0243 100644 --- a/drivers/s390/net/ctcm_mpc.c +++ b/drivers/s390/net/ctcm_mpc.c @@ -357,6 +357,7 @@ int ctc_mpc_alloc_channel(int port_num, void (*callback)(int, int)) /*fsm_newstate(grp->fsm, MPCG_STATE_XID2INITW);*/ if (callback) grp->send_qllc_disc = 1; + /* Else, fall through */ case MPCG_STATE_XID0IOWAIT: fsm_deltimer(&grp->timer); grp->outstanding_xid2 = 0; @@ -1469,6 +1470,7 @@ static void mpc_action_timeout(fsm_instance *fi, int event, void *arg) if ((fsm_getstate(rch->fsm) == CH_XID0_PENDING) && (fsm_getstate(wch->fsm) == CH_XID0_PENDING)) break; + /* Else, fall through */ default: fsm_event(grp->fsm, MPCG_EVENT_INOP, dev); } @@ -2089,6 +2091,7 @@ static int mpc_send_qllc_discontact(struct net_device *dev) grp->estconnfunc = NULL; break; } + /* Else, fall through */ case MPCG_STATE_FLOWC: case MPCG_STATE_READY: grp->send_qllc_disc = 2; diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c index fd64bc3f4062..cbead3d1b2fd 100644 --- a/drivers/s390/net/qeth_l2_main.c +++ b/drivers/s390/net/qeth_l2_main.c @@ -333,7 +333,7 @@ static int qeth_l2_process_inbound_buffer(struct qeth_card *card, card->osn_info.data_cb(skb); break; } - /* else unknown */ + /* Else, fall through */ default: dev_kfree_skb_any(skb); QETH_CARD_TEXT(card, 3, "inbunkno"); -- cgit v1.2.3 From 072f79400032f74917726cf76f4248367ea2b5b8 Mon Sep 17 00:00:00 2001 From: Julian Wiedmann Date: Mon, 12 Aug 2019 16:44:35 +0200 Subject: s390/qeth: serialize cmd reply with concurrent timeout Callbacks for a cmd reply run outside the protection of card->lock, to allow for additional cmds to be issued & enqueued in parallel. When qeth_send_control_data() bails out for a cmd without having received a reply (eg. due to timeout), its callback may concurrently be processing a reply that just arrived. In this case, the callback potentially accesses a stale reply->reply_param area that eg. was on-stack and has already been released. To avoid this race, add some locking so that qeth_send_control_data() can (1) wait for a concurrently running callback, and (2) zap any pending callback that still wants to run. Signed-off-by: Julian Wiedmann Signed-off-by: Jakub Kicinski --- drivers/s390/net/qeth_core.h | 1 + drivers/s390/net/qeth_core_main.c | 20 ++++++++++++++++++++ 2 files changed, 21 insertions(+) (limited to 'drivers/s390/net') diff --git a/drivers/s390/net/qeth_core.h b/drivers/s390/net/qeth_core.h index c7ee07ce3615..28db887d38ed 100644 --- a/drivers/s390/net/qeth_core.h +++ b/drivers/s390/net/qeth_core.h @@ -629,6 +629,7 @@ struct qeth_seqno { struct qeth_reply { struct list_head list; struct completion received; + spinlock_t lock; int (*callback)(struct qeth_card *, struct qeth_reply *, unsigned long); u32 seqno; diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c index 4d0caeebc802..9c3310c4d61d 100644 --- a/drivers/s390/net/qeth_core_main.c +++ b/drivers/s390/net/qeth_core_main.c @@ -544,6 +544,7 @@ static struct qeth_reply *qeth_alloc_reply(struct qeth_card *card) if (reply) { refcount_set(&reply->refcnt, 1); init_completion(&reply->received); + spin_lock_init(&reply->lock); } return reply; } @@ -799,6 +800,13 @@ static void qeth_issue_next_read_cb(struct qeth_card *card, if (!reply->callback) { rc = 0; + goto no_callback; + } + + spin_lock_irqsave(&reply->lock, flags); + if (reply->rc) { + /* Bail out when the requestor has already left: */ + rc = reply->rc; } else { if (cmd) { reply->offset = (u16)((char *)cmd - (char *)iob->data); @@ -807,7 +815,9 @@ static void qeth_issue_next_read_cb(struct qeth_card *card, rc = reply->callback(card, reply, (unsigned long)iob); } } + spin_unlock_irqrestore(&reply->lock, flags); +no_callback: if (rc <= 0) qeth_notify_reply(reply, rc); qeth_put_reply(reply); @@ -1749,6 +1759,16 @@ static int qeth_send_control_data(struct qeth_card *card, rc = (timeout == -ERESTARTSYS) ? -EINTR : -ETIME; qeth_dequeue_reply(card, reply); + + if (reply_cb) { + /* Wait until the callback for a late reply has completed: */ + spin_lock_irq(&reply->lock); + if (rc) + /* Zap any callback that's still pending: */ + reply->rc = rc; + spin_unlock_irq(&reply->lock); + } + if (!rc) rc = reply->rc; qeth_put_reply(reply); -- cgit v1.2.3