summaryrefslogtreecommitdiff
path: root/net/tipc/subscr.c
AgeCommit message (Collapse)Author
2016-04-28tipc: remove an unnecessary NULL checkDan Carpenter
This is never called with a NULL "buf" and anyway, we dereference 's' on the lines before so it would Oops before we reach the check. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-14tipc: fix a race condition leading to subscriber refcnt bugParthasarathy Bhuvaragan
Until now, the requests sent to topology server are queued to a workqueue by the generic server framework. These messages are processed by worker threads and trigger the registered callbacks. To reduce latency on uniprocessor systems, explicit rescheduling is performed using cond_resched() after MAX_RECV_MSG_COUNT(25) messages. This implementation on SMP systems leads to an subscriber refcnt error as described below: When a worker thread yields by calling cond_resched() in a SMP system, a new worker is created on another CPU to process the pending workitem. Sometimes the sleeping thread wakes up before the new thread finishes execution. This breaks the assumption on ordering and being single threaded. The fault is more frequent when MAX_RECV_MSG_COUNT is lowered. If the first thread was processing subscription create and the second thread processing close(), the close request will free the subscriber and the create request oops as follows: [31.224137] WARNING: CPU: 2 PID: 266 at include/linux/kref.h:46 tipc_subscrb_rcv_cb+0x317/0x380 [tipc] [31.228143] CPU: 2 PID: 266 Comm: kworker/u8:1 Not tainted 4.5.0+ #97 [31.228377] Workqueue: tipc_rcv tipc_recv_work [tipc] [...] [31.228377] Call Trace: [31.228377] [<ffffffff812fbb6b>] dump_stack+0x4d/0x72 [31.228377] [<ffffffff8105a311>] __warn+0xd1/0xf0 [31.228377] [<ffffffff8105a3fd>] warn_slowpath_null+0x1d/0x20 [31.228377] [<ffffffffa0098067>] tipc_subscrb_rcv_cb+0x317/0x380 [tipc] [31.228377] [<ffffffffa00a4984>] tipc_receive_from_sock+0xd4/0x130 [tipc] [31.228377] [<ffffffffa00a439b>] tipc_recv_work+0x2b/0x50 [tipc] [31.228377] [<ffffffff81071925>] process_one_work+0x145/0x3d0 [31.246554] ---[ end trace c3882c9baa05a4fd ]--- [31.248327] BUG: spinlock bad magic on CPU#2, kworker/u8:1/266 [31.249119] BUG: unable to handle kernel NULL pointer dereference at 0000000000000428 [31.249323] IP: [<ffffffff81099d0c>] spin_dump+0x5c/0xe0 [31.249323] PGD 0 [31.249323] Oops: 0000 [#1] SMP In this commit, we - rename tipc_conn_shutdown() to tipc_conn_release(). - move connection release callback execution from tipc_close_conn() to a new function tipc_sock_release(), which is executed before we free the connection. Thus we release the subscriber during connection release procedure rather than connection shutdown procedure. Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Several cases of overlapping changes, as well as one instance (vxlan) of a bug fix in 'net' overlapping with code movement in 'net-next'. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-06tipc: fix nullptr crash during subscription cancelParthasarathy Bhuvaragan
commit 4d5cfcba2f6e ('tipc: fix connection abort during subscription cancel'), removes the check for a valid subscription before calling tipc_nametbl_subscribe(). This will lead to a nullptr exception when we process a subscription cancel request. For a cancel request, a null subscription is passed to tipc_nametbl_subscribe() resulting in exception. In this commit, we call tipc_nametbl_subscribe() only for a valid subscription. Fixes: 4d5cfcba2f6e ('tipc: fix connection abort during subscription cancel') Reported-by: Anders Widell <anders.widell@ericsson.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06tipc: donot create timers if subscription timeout = TIPC_WAIT_FOREVERParthasarathy Bhuvaragan
Until now, we create timers even for the subscription requests with timeout = TIPC_WAIT_FOREVER. This can be improved by avoiding timer creation when the timeout is set to TIPC_WAIT_FOREVER. In this commit, we introduce a check to creates timers only when timeout != TIPC_WAIT_FOREVER. Acked-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06tipc: protect tipc_subscrb_get() with subscriber spin lockParthasarathy Bhuvaragan
Until now, during subscription creation the mod_time() & tipc_subscrb_get() are called after releasing the subscriber spin lock. In a SMP system when performing a subscription creation, if the subscription timeout occurs simultaneously (the timer is scheduled to run on another CPU) then the timer thread might decrement the subscribers refcount before the create thread increments the refcount. This can be simulated by creating subscription with timeout=0 and sometimes the timeout occurs before the create request is complete. This leads to the following message: [30.702949] BUG: spinlock bad magic on CPU#1, kworker/u8:3/87 [30.703834] general protection fault: 0000 [#1] SMP [30.704826] CPU: 1 PID: 87 Comm: kworker/u8:3 Not tainted 4.4.0-rc8+ #18 [30.704826] Workqueue: tipc_rcv tipc_recv_work [tipc] [30.704826] task: ffff88003f878600 ti: ffff88003fae0000 task.ti: ffff88003fae0000 [30.704826] RIP: 0010:[<ffffffff8109196c>] [<ffffffff8109196c>] spin_dump+0x5c/0xe0 [...] [30.704826] Call Trace: [30.704826] [<ffffffff81091a16>] spin_bug+0x26/0x30 [30.704826] [<ffffffff81091b75>] do_raw_spin_lock+0xe5/0x120 [30.704826] [<ffffffff81684439>] _raw_spin_lock_bh+0x19/0x20 [30.704826] [<ffffffffa0096f10>] tipc_subscrb_rcv_cb+0x1d0/0x330 [tipc] [30.704826] [<ffffffffa00a37b1>] tipc_receive_from_sock+0xc1/0x150 [tipc] [30.704826] [<ffffffffa00a31df>] tipc_recv_work+0x3f/0x80 [tipc] [30.704826] [<ffffffff8106a739>] process_one_work+0x149/0x3c0 [30.704826] [<ffffffff8106aa16>] worker_thread+0x66/0x460 [30.704826] [<ffffffff8106a9b0>] ? process_one_work+0x3c0/0x3c0 [30.704826] [<ffffffff8106a9b0>] ? process_one_work+0x3c0/0x3c0 [30.704826] [<ffffffff8107029d>] kthread+0xed/0x110 [30.704826] [<ffffffff810701b0>] ? kthread_create_on_node+0x190/0x190 [30.704826] [<ffffffff81684bdf>] ret_from_fork+0x3f/0x70 In this commit, 1. we remove the check for the return code for mod_timer() 2. we protect tipc_subscrb_get() using the subscriber spin lock. We increment the subscriber's refcount as soon as we add the subscription to subscriber's subscription list. Acked-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06tipc: hold subscriber->lock for tipc_nametbl_subscribe()Parthasarathy Bhuvaragan
Until now, while creating a subscription the subscriber lock protects only the subscribers subscription list and not the nametable. The call to tipc_nametbl_subscribe() is outside the lock. However, at subscription timeout and cancel both the subscribers subscription list and the nametable are protected by the subscriber lock. This asymmetric locking mechanism leads to the following problem: In a SMP system, the timer can be fire on another core before the create request is complete. When the timer thread calls tipc_nametbl_unsubscribe() before create thread calls tipc_nametbl_subscribe(), we get a nullptr exception. This can be simulated by creating subscription with timeout=0 and sometimes the timeout occurs before the create request is complete. The following is the oops: [57.569661] BUG: unable to handle kernel NULL pointer dereference at (null) [57.577498] IP: [<ffffffffa02135aa>] tipc_nametbl_unsubscribe+0x8a/0x120 [tipc] [57.584820] PGD 0 [57.586834] Oops: 0002 [#1] SMP [57.685506] CPU: 14 PID: 10077 Comm: kworker/u40:1 Tainted: P OENX 3.12.48-52.27.1. 9688.1.PTF-default #1 [57.703637] Workqueue: tipc_rcv tipc_recv_work [tipc] [57.708697] task: ffff88064c7f00c0 ti: ffff880629ef4000 task.ti: ffff880629ef4000 [57.716181] RIP: 0010:[<ffffffffa02135aa>] [<ffffffffa02135aa>] tipc_nametbl_unsubscribe+0x8a/ 0x120 [tipc] [...] [57.812327] Call Trace: [57.814806] [<ffffffffa0211c77>] tipc_subscrp_delete+0x37/0x90 [tipc] [57.821357] [<ffffffffa0211e2f>] tipc_subscrp_timeout+0x3f/0x70 [tipc] [57.827982] [<ffffffff810618c1>] call_timer_fn+0x31/0x100 [57.833490] [<ffffffff81062709>] run_timer_softirq+0x1f9/0x2b0 [57.839414] [<ffffffff8105a795>] __do_softirq+0xe5/0x230 [57.844827] [<ffffffff81520d1c>] call_softirq+0x1c/0x30 [57.850150] [<ffffffff81004665>] do_softirq+0x55/0x90 [57.855285] [<ffffffff8105aa35>] irq_exit+0x95/0xa0 [57.860290] [<ffffffff815215b5>] smp_apic_timer_interrupt+0x45/0x60 [57.866644] [<ffffffff8152005d>] apic_timer_interrupt+0x6d/0x80 [57.872686] [<ffffffffa02121c5>] tipc_subscrb_rcv_cb+0x2a5/0x3f0 [tipc] [57.879425] [<ffffffffa021c65f>] tipc_receive_from_sock+0x9f/0x100 [tipc] [57.886324] [<ffffffffa021c826>] tipc_recv_work+0x26/0x60 [tipc] [57.892463] [<ffffffff8106fb22>] process_one_work+0x172/0x420 [57.898309] [<ffffffff8107079a>] worker_thread+0x11a/0x3c0 [57.903871] [<ffffffff81077114>] kthread+0xb4/0xc0 [57.908751] [<ffffffff8151f318>] ret_from_fork+0x58/0x90 In this commit, we do the following at subscription creation: 1. set the subscription's subscriber pointer before performing tipc_nametbl_subscribe(), as this value is required further in the call chain ex: by tipc_subscrp_send_event(). 2. move tipc_nametbl_subscribe() under the scope of subscriber lock Acked-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06tipc: fix connection abort when receiving invalid cancel requestParthasarathy Bhuvaragan
Until now, the subscribers endianness for a subscription create/cancel request is determined as: swap = !(s->filter & (TIPC_SUB_PORTS | TIPC_SUB_SERVICE)) The checks are performed only for port/service subscriptions. The swap calculation is incorrect if the filter in the subscription cancellation request is set to TIPC_SUB_CANCEL (it's a malformed cancel request, as the corresponding subscription create filter is missing). Thus, the check if the request is for cancellation fails and the request is treated as a subscription create request. The subscription creation fails as the request is illegal, which terminates this connection. In this commit we determine the endianness by including TIPC_SUB_CANCEL, which will set swap correctly and the request is processed as a cancellation request. Acked-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06tipc: fix connection abort during subscription cancellationParthasarathy Bhuvaragan
In 'commit 7fe8097cef5f ("tipc: fix nullpointer bug when subscribing to events")', we terminate the connection if the subscription creation fails. In the same commit, the subscription creation result was based on the value of subscription pointer (set in the function) instead of the return code. Unfortunately, the same function also handles subscription cancellation request. For a subscription cancellation request, the subscription pointer cannot be set. Thus the connection is terminated during cancellation request. In this commit, we move the subcription cancel check outside of tipc_subscrp_create(). Hence, - tipc_subscrp_create() will create a subscripton - tipc_subscrb_rcv_cb() will subscribe or cancel a subscription. Fixes: 'commit 7fe8097cef5f ("tipc: fix nullpointer bug when subscribing to events")' Acked-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06tipc: introduce tipc_subscrb_subscribe() routineParthasarathy Bhuvaragan
In this commit, we split tipc_subscrp_create() into two: 1. tipc_subscrp_create() creates a subscription 2. A new function tipc_subscrp_subscribe() adds the subscription to the subscriber subscription list, activates the subscription timer and subscribes to the nametable updates. In future commits, the purpose of tipc_subscrb_rcv_cb() will be to either subscribe or cancel a subscription. There is no functional change in this commit. Acked-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06tipc: remove struct tipc_name_seq from struct tipc_subscriptionParthasarathy Bhuvaragan
Until now, struct tipc_subscriber has duplicate fields for type, upper and lower (as member of struct tipc_name_seq) at: 1. as member seq in struct tipc_subscription 2. as member seq in struct tipc_subscr, which is contained in struct tipc_event The former structure contains the type, upper and lower values in network byte order and the later contains the intact copy of the request. The struct tipc_subscription contains a field swap to determine if request needs network byte order conversion. Thus by using swap, we can convert the request when required instead of duplicating it. In this commit, 1. we remove the references to these elements as members of struct tipc_subscription and replace them with elements from struct tipc_subscr. 2. provide new functions to convert the user request into network byte order. Acked-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06tipc: remove filter and timeout elements from struct tipc_subscriptionParthasarathy Bhuvaragan
Until now, struct tipc_subscription has duplicate timeout and filter attributes present: 1. directly as members of struct tipc_subscription 2. in struct tipc_subscr, which is contained in struct tipc_event In this commit, we remove the references to these elements as members of struct tipc_subscription and replace them with elements from struct tipc_subscr. Acked-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06tipc: remove incorrect check for subscription timeout valueParthasarathy Bhuvaragan
Until now, during subscription creation we set sub->timeout by converting the timeout request value in milliseconds to jiffies. This is followed by setting the timeout value in the timer if sub->timeout != TIPC_WAIT_FOREVER. For a subscription create request with a timeout value of TIPC_WAIT_FOREVER, msecs_to_jiffies(TIPC_WAIT_FOREVER) returns MAX_JIFFY_OFFSET (0xfffffffe). This is not equal to TIPC_WAIT_FOREVER (0xffffffff). In this commit, we remove this check. Acked-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-29tipc: fix connection abort during subscription cancelParthasarathy Bhuvaragan
In 'commit 7fe8097cef5f ("tipc: fix nullpointer bug when subscribing to events")', we terminate the connection if the subscription creation fails. In the same commit, the subscription creation result was based on the value of the subscription pointer (set in the function) instead of the return code. Unfortunately, the same function tipc_subscrp_create() handles subscription cancel request. For a subscription cancellation request, the subscription pointer cannot be set. Thus if a subscriber has several subscriptions and cancels any of them, the connection is terminated. In this commit, we terminate the connection based on the return value of tipc_subscrp_create(). Fixes: commit 7fe8097cef5f ("tipc: fix nullpointer bug when subscribing to events") Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-04tipc: adjust locking policy of subscriptionYing Xue
Currently subscriber's lock protects not only subscriber's subscription list but also all subscriptions linked into the list. However, as all members of subscription are never changed after they are initialized, it's unnecessary for subscription to be protected under subscriber's lock. If the lock is used to only protect subscriber's subscription list, the adjustment not only makes the locking policy simpler, but also helps to avoid a deadlock which may happen once creating a subscription is failed. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-04tipc: involve reference counter for subscriberYing Xue
At present subscriber's lock is used to protect the subscription list of subscriber as well as subscriptions linked into the list. While one or all subscriptions are deleted through iterating the list, the subscriber's lock must be held. Meanwhile, as deletion of subscription may happen in subscription timer's handler, the lock must be grabbed in the function as well. When subscription's timer is terminated with del_timer_sync() during above iteration, subscriber's lock has to be temporarily released, otherwise, deadlock may occur. However, the temporary release may cause the double free of a subscription as the subscription is not disconnected from the subscription list. Now if a reference counter is introduced to subscriber, subscription's timer can be asynchronously stopped with del_timer(). As a result, the issue is not only able to be fixed, but also relevant code is pretty readable and understandable. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-04tipc: introduce tipc_subscrb_create routineYing Xue
Introducing a new function makes the purpose of tipc_subscrb_connect_cb callback routine more clear. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-04tipc: rename functions defined in subscr.cYing Xue
When a topology server accepts a connection request from its client, it allocates a connection instance and a tipc_subscriber structure object. The former is used to communicate with client, and the latter is often treated as a subscriber which manages all subscription events requested from a same client. When a topology server receives a request of subscribing name services from a client through the connection, it creates a tipc_subscription structure instance which is seen as a subscription recording what name services are subscribed. In order to manage all subscriptions from a same client, topology server links them into the subscrp_list of the subscriber. So subscriber and subscription completely represents different meanings respectively, but function names associated with them make us so confused that we are unable to easily tell which function is against subscriber and which is to subscription. So we want to eliminate the confusion by renaming them. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-27tipc: fix nullpointer bug when subscribing to eventsErik Hugne
If a subscription request is sent to a topology server connection, and any error occurs (malformed request, oom or limit reached) while processing this request, TIPC should terminate the subscriber connection. While doing so, it tries to access fields in an already freed (or never allocated) subscription element leading to a nullpointer exception. We fix this by removing the subscr_terminate function and terminate the connection immediately upon any subscription failure. Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-12tipc: make subscriber server support net namespaceYing Xue
TIPC establishes one subscriber server which allows users to subscribe their interesting name service status. After tipc supports namespace, one dedicated tipc stack instance is created for each namespace, and each instance can be deemed as one independent TIPC node. As a result, subscriber server must be built for each namespace. Signed-off-by: Ying Xue <ying.xue@windriver.com> Tested-by: Tero Aho <Tero.Aho@coriant.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-12tipc: name tipc name table support net namespaceYing Xue
TIPC name table is used to store the mapping relationship between TIPC service name and socket port ID. When tipc supports namespace, it allows users to publish service names only owned by a certain namespace. Therefore, every namespace must have its private name table to prevent service names published to one namespace from being contaminated by other service names in another namespace. Therefore, The name table global variable (ie, nametbl) and its lock must be moved to tipc_net structure, and a parameter of namespace must be added for necessary functions so that they can obtain name table variable defined in tipc_net structure. Signed-off-by: Ying Xue <ying.xue@windriver.com> Tested-by: Tero Aho <Tero.Aho@coriant.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-12tipc: remove unnecessary wrapper functions of kernel timer APIsYing Xue
Not only some wrapper function like k_term_timer() is empty, but also some others including k_start_timer() and k_cancel_timer() don't return back any value to its caller, what's more, there is no any component in the kernel world to do such thing. Therefore, these timer interfaces defined in tipc module should be purged. Signed-off-by: Ying Xue <ying.xue@windriver.com> Tested-by: Tero Aho <Tero.Aho@coriant.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-08tipc: remove unnecessary INIT_LIST_HEADYing Xue
When a list_head variable is seen as a new entry to be added to a list head, it's unnecessary to be initialized with INIT_LIST_HEAD(). Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Tested-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-23tipc: remove include file port.hJon Paul Maloy
We move the inline functions in the file port.h to socket.c, and modify their names accordingly. We move struct tipc_port and some macros to socket.h. Finally, we remove the file port.h. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-24tipc: fix spinlock recursion bug for failed subscriptionsErik Hugne
If a topology event subscription fails for any reason, such as out of memory, max number reached or because we received an invalid request the correct behavior is to terminate the subscribers connection to the topology server. This is currently broken and produces the following oops: [27.953662] tipc: Subscription rejected, illegal request [27.955329] BUG: spinlock recursion on CPU#1, kworker/u4:0/6 [27.957066] lock: 0xffff88003c67f408, .magic: dead4ead, .owner: kworker/u4:0/6, .owner_cpu: 1 [27.958054] CPU: 1 PID: 6 Comm: kworker/u4:0 Not tainted 3.14.0-rc6+ #5 [27.960230] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [27.960874] Workqueue: tipc_rcv tipc_recv_work [tipc] [27.961430] ffff88003c67f408 ffff88003de27c18 ffffffff815c0207 ffff88003de1c050 [27.962292] ffff88003de27c38 ffffffff815beec5 ffff88003c67f408 ffffffff817f0a8a [27.963152] ffff88003de27c58 ffffffff815beeeb ffff88003c67f408 ffffffffa0013520 [27.964023] Call Trace: [27.964292] [<ffffffff815c0207>] dump_stack+0x45/0x56 [27.964874] [<ffffffff815beec5>] spin_dump+0x8c/0x91 [27.965420] [<ffffffff815beeeb>] spin_bug+0x21/0x26 [27.965995] [<ffffffff81083df6>] do_raw_spin_lock+0x116/0x140 [27.966631] [<ffffffff815c6215>] _raw_spin_lock_bh+0x15/0x20 [27.967256] [<ffffffffa0008540>] subscr_conn_shutdown_event+0x20/0xa0 [tipc] [27.968051] [<ffffffffa000fde4>] tipc_close_conn+0xa4/0xb0 [tipc] [27.968722] [<ffffffffa00101ba>] tipc_conn_terminate+0x1a/0x30 [tipc] [27.969436] [<ffffffffa00089a2>] subscr_conn_msg_event+0x1f2/0x2f0 [tipc] [27.970209] [<ffffffffa0010000>] tipc_receive_from_sock+0x90/0xf0 [tipc] [27.970972] [<ffffffffa000fa79>] tipc_recv_work+0x29/0x50 [tipc] [27.971633] [<ffffffff8105dbf5>] process_one_work+0x165/0x3e0 [27.972267] [<ffffffff8105e869>] worker_thread+0x119/0x3a0 [27.972896] [<ffffffff8105e750>] ? manage_workers.isra.25+0x2a0/0x2a0 [27.973622] [<ffffffff810648af>] kthread+0xdf/0x100 [27.974168] [<ffffffff810647d0>] ? kthread_create_on_node+0x1a0/0x1a0 [27.974893] [<ffffffff815ce13c>] ret_from_fork+0x7c/0xb0 [27.975466] [<ffffffff810647d0>] ? kthread_create_on_node+0x1a0/0x1a0 The recursion occurs when subscr_terminate tries to grab the subscriber lock, which is already taken by subscr_conn_msg_event. We fix this by checking if the request to establish a new subscription was successful, and if not we initiate termination of the subscriber after we have released the subscriber lock. Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-06tipc: drop subscriber connection id invalidationErik Hugne
When a topology server subscriber is disconnected, the associated connection id is set to zero. A check vs zero is then done in the subscription timeout function to see if the subscriber have been shut down. This is unnecessary, because all subscription timers will be cancelled when a subscriber terminates. Setting the connection id to zero is actually harmful because id zero is the identity of the topology server listening socket, and can cause a race that leads to this socket being closed instead. Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-06tipc: allow connection shutdown callback to be invoked in advanceYing Xue
Currently connection shutdown callback function is called when connection instance is released in tipc_conn_kref_release(), and receiving packets and sending packets are running in different threads. Even if connection is closed by the thread of receiving packets, its shutdown callback may not be called immediately as the connection reference count is non-zero at that moment. So, although the connection is shut down by the thread of receiving packets, the thread of sending packets doesn't know it. Before its shutdown callback is invoked to tell the sending thread its connection has been closed, the sending thread may deliver messages by tipc_conn_sendmsg(), this is why the following error information appears: "Sending subscription event failed, no memory" To eliminate it, allow connection shutdown callback function to be called before connection id is removed in tipc_close_conn(), which makes the sending thread know the truth in time that its socket is closed so that it doesn't send message to it. We also remove the "Sending XXX failed..." error reporting for topology and config services. Signed-off-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-14tipc: spelling fixesstephen hemminger
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-17tipc: cosmetic realignment of function argumentsPaul Gortmaker
No runtime code changes here. Just a realign of the function arguments to start where the 1st one was, and fit as many args as can be put in an 80 char line. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-17tipc: convert topology server to use new server facilityYing Xue
As the new TIPC server infrastructure has been introduced, we can now convert the TIPC topology server to it. We get two benefits from doing this: 1) It simplifies the topology server locking policy. In the original locking policy, we placed one spin lock pointer in the tipc_subscriber structure to reuse the lock of the subscriber's server port, controlling access to members of tipc_subscriber instance. That is, we only used one lock to ensure both tipc_port and tipc_subscriber members were safely accessed. Now we introduce another spin lock for tipc_subscriber structure only protecting themselves, to get a finer granularity locking policy. Moreover, the change will allow us to make the topology server code more readable and maintainable. 2) It fixes a bug where sent subscription events may be lost when the topology port is congested. Using the new service, the topology server now queues sent events into an outgoing buffer, and then wakes up a sender process which has been blocked in workqueue context. The process will keep picking events from the buffer and send them to their respective subscribers, using the kernel socket interface, until the buffer is empty. Even if the socket is congested during transmission there is no risk that events may be dropped, since the sender process may block when needed. Some minor reordering of initialization is done, since we now have a scenario where the topology server must be started after socket initialization has taken place, as the former depends on the latter. And overall, we see a simplification of the TIPC subscriber code in making this changeover. Signed-off-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-07tipc: standardize across connect/disconnect function namingPaul Gortmaker
Currently we have tipc_disconnect and tipc_disconnect_port. It is not clear from the names alone, what they do or how they differ. It turns out that tipc_disconnect just deals with the port locking and then calls tipc_disconnect_port which does all the work. If we rename as follows: tipc_disconnect_port --> __tipc_disconnect then we will be following typical linux convention, where: __tipc_disconnect: "raw" function that does all the work. tipc_disconnect: wrapper that deals with locking and then calls the real core __tipc_disconnect function With this, the difference is immediately evident, and locking violations are more apt to be spotted by chance while working on, or even just while reading the code. On the connect side of things, we currently only have the single "tipc_connect2port" function. It does both the locking at enter/exit, and the core of the work. Pending changes will make it desireable to have the connect be a two part locking wrapper + worker function, just like the disconnect is already. Here, we make the connect look just like the updated disconnect case, for the above reason, and for consistency. In the process, we also get rid of the "2port" suffix that was on the original name, since it adds no descriptive value. On close examination, one might notice that the above connect changes implicitly move the call to tipc_link_get_max_pkt() to be within the scope of tipc_port_lock() protected region; when it was not previously. We don't see any issues with this, and it is in keeping with __tipc_connect doing the work and tipc_connect just handling the locking. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-08-20tipc: eliminate configuration for maximum number of name subscriptionsYing Xue
Gets rid of the need for users to specify the maximum number of name subscriptions supported by TIPC. TIPC now automatically provides support for the maximum number of name subscriptions to 65535. Signed-off-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-13tipc: use standard printk shortcut macros (pr_err etc.)Erik Hugne
All messages should go directly to the kernel log. The TIPC specific error, warning, info and debug trace macro's are removed and all references replaced with pr_err, pr_warn, pr_info and pr_debug. Commonly used sub-strings are explicitly declared as a const char to reduce .text size. Note that this means the debug messages (changed to pr_debug), are now enabled through dynamic debugging, instead of a TIPC specific Kconfig option (TIPC_DEBUG). The latter will be phased out completely Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> [PG: use pr_fmt as suggested by Joe Perches <joe@perches.com>] Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-04-30tipc: compress out gratuitous extra carriage returnsPaul Gortmaker
Some of the comment blocks are floating in limbo between two functions, or between blocks of code. Delete the extra line feeds between any comment and its associated following block of code, to be consistent with the majority of the rest of the kernel. Also delete trailing newlines at EOF and fix a couple trivial typos in existing comments. This is a 100% cosmetic change with no runtime impact. We get rid of over 500 lines of non-code, and being blank line deletes, they won't even show up as noise in git blame. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-04-26tipc: remove redundant memset and stale comment from subscr.cAllan Stephens
Eliminate code to zero-out the main topology service structure, which is already zeroed-out. Get rid of a comment documenting a field of the main topology service structure that no longer exists. Both are cosmetic changes with no impact on runtime behaviour. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-24tipc: Simplify enforcement of reserved name type prohibitionAllan Stephens
Streamlines the logic that prevents an application from binding a reserved TIPC name type to a port by moving the check to the code that handles a socket bind() operation. This allows internal TIPC subsystems to bind a reserved name without having to set an atomic flag to gain permission to use such a name. (This simplification is now possible due to the elimination of support for TIPC's native API.) Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-12-29tipc: rename struct subscriber to struct tipc_subscriberPaul Gortmaker
Make this rename so that it is consistent with the majority of the other tipc structs and to assist in removing any ambiguity with other similar names in other subsystems. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-12-29tipc: rename struct subscription to struct tipc_subscriptionPaul Gortmaker
Make this rename so that it is consistent with the majority of the other tipc structs and to assist in removing any ambiguity with other similar names in other subsystems. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-09-17tipc: Remove callback field from subscription structureYing Xue
Eliminate the "event_cb" member from TIPC's "subscription" structure since the function pointer it holds always points to subscr_send_event(). Signed-off-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-05-10tipc: Avoid recomputation of outgoing message lengthAllan Stephens
Rework TIPC's message sending routines to take advantage of the total amount of data value passed to it by the kernel socket infrastructure. This change eliminates the need for TIPC to compute the size of outgoing messages itself, as well as the check for an oversize message in tipc_msg_build(). In addition, this change warrants an explanation: - res = send_packet(NULL, sock, &my_msg, 0); + res = send_packet(NULL, sock, &my_msg, bytes_to_send); Previously, the final argument to send_packet() was ignored (since the amount of data being sent was recalculated by a lower-level routine) and we could just pass in a dummy value (0). Now that the recalculation is being eliminated, the argument value being passed to send_packet() is significant and we have to supply the actual amount of data we want to send. Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-02-23tipc: Minor optimization to topology service connection establishmentAllan Stephens
Eliminates a local iovec structure containing no data, which was previously used during the establishment of a topology service connection, since the same effect can be achieved by passing in a NULL pointer and an iovec length of zero. Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-02-23tipc: Eliminate unnecessary locking when starting topology serviceAllan Stephens
Modifies the initialization code for TIPC's topology service to avoid taking the spinlock protecting the subscriber list, since there is no need to do this. Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-02-23tipc: Combine port structure with tipc_port structureAllan Stephens
Merge two distinct structures containing information about a TIPC port into a single structure. The structures were previously kept separate so that public information about a port could be made available to applications using TIPC's native API, while the remaining information was kept private for use by TIPC itself. However, now that the native API has been removed there is no longer any need for this somewhat confusing arrangement. Since one of the structures was already embedded within the other, the change largely involves replacing instances of "publ.foo" with "foo". The changes do not otherwise alter the operation of TIPC ports. Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-01-01tipc: remove zeroing assignments to static global variablesAllan Stephens
Cleans up TIPC's source code to eliminate the needless initialization of static variables to zero. These changes are purely cosmetic and do not alter the operation of TIPC in any way. Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-01tipc: cleanup various cosmetic whitespace issuesAllan Stephens
Cleans up TIPC's source code to eliminate deviations from generally accepted coding conventions relating to leading/trailing white space and white space around commas, braces, cases, and sizeof. These changes are purely cosmetic and do not alter the operation of TIPC in any way. Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-01tipc: remove calls to dbg() and msg_dbg()Allan Stephens
Eliminates obsolete calls to two of TIPC's main debugging macros, as well as a pair of associated debugging routines that are no longer required. Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-01tipc: Remove user registry subsystemAllan Stephens
Eliminates routines, data structures, and files that make up TIPC's user registry. The user registry is no longer needed since the native API routines that utilized it no longer exist and there are no longer any internal TIPC services that use it. Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-01tipc: Eliminate use of user registry by topology serviceAllan Stephens
Simplifies TIPC's network topology service so that it no longer registers its ports with the user registry, since the service doesn't take advantage of any of the registry's capabilities. Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-02tipc: Eliminate useless initialization when creating subscriberAllan Stephens
Removes initialization of a local variable that is always assigned a different value before it is referenced. Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-02tipc: Remove support for TIPC mode change callbackAllan Stephens
Eliminates support for the callback routine invoked when TIPC changes its mode of operation from inactive to standalone or from standalone to networked. This callback was part of TIPC's obsolete native API and is not used by TIPC internally. Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>