From 993b858e37b3120ee76d9957a901cca22312ffaa Mon Sep 17 00:00:00 2001 From: Jon Paul Maloy Date: Mon, 9 Dec 2013 22:54:46 -0800 Subject: tipc: correct the order of stopping services at rmmod The 'signal handler' service in TIPC is a mechanism that makes it possible to postpone execution of functions, by launcing them into a job queue for execution in a separate tasklet, independent of the launching execution thread. When we do rmmod on the tipc module, this service is stopped after the network service. At the same time, the stopping of the network service may itself launch jobs for execution, with the risk that these functions may be scheduled for execution after the data structures meant to be accessed by the job have already been deleted. We have seen this happen, most often resulting in an oops. This commit ensures that the signal handler is the very first to be stopped when TIPC is shut down, so there are no surprises during the cleanup of the other services. Signed-off-by: Jon Maloy Reviewed-by: Paul Gortmaker Signed-off-by: David S. Miller --- net/tipc/core.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'net/tipc') diff --git a/net/tipc/core.c b/net/tipc/core.c index fd4eeeaa972..c6d3f75a9e1 100644 --- a/net/tipc/core.c +++ b/net/tipc/core.c @@ -113,7 +113,6 @@ err: static void tipc_core_stop(void) { tipc_netlink_stop(); - tipc_handler_stop(); tipc_cfg_stop(); tipc_subscr_stop(); tipc_nametbl_stop(); @@ -146,9 +145,10 @@ static int tipc_core_start(void) res = tipc_subscr_start(); if (!res) res = tipc_cfg_init(); - if (res) + if (res) { + tipc_handler_stop(); tipc_core_stop(); - + } return res; } @@ -178,6 +178,7 @@ static int __init tipc_init(void) static void __exit tipc_exit(void) { + tipc_handler_stop(); tipc_core_stop_net(); tipc_core_stop(); pr_info("Deactivated\n"); -- cgit v1.2.3-70-g09d2 From 00ede977098be3296d42d05a4265ec5ec4a28419 Mon Sep 17 00:00:00 2001 From: Ying Xue Date: Mon, 9 Dec 2013 22:54:47 -0800 Subject: tipc: protect handler_enabled variable with qitem_lock spin lock 'handler_enabled' is a global flag indicating whether the TIPC signal handling service is enabled or not. The lack of lock protection for this flag incurs a risk for contention, so that a tipc_k_signal() call might queue a signal handler to a destroyed signal queue, with unpredictable results. To correct this, we let the already existing 'qitem_lock' protect the flag, as it already does with the queue itself. This way, we ensure that the flag always is consistent across all cores. Signed-off-by: Ying Xue Reviewed-by: Paul Gortmaker Signed-off-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/handler.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'net/tipc') diff --git a/net/tipc/handler.c b/net/tipc/handler.c index b36f0fcd9bd..e4bc8a29674 100644 --- a/net/tipc/handler.c +++ b/net/tipc/handler.c @@ -56,12 +56,13 @@ unsigned int tipc_k_signal(Handler routine, unsigned long argument) { struct queue_item *item; + spin_lock_bh(&qitem_lock); if (!handler_enabled) { pr_err("Signal request ignored by handler\n"); + spin_unlock_bh(&qitem_lock); return -ENOPROTOOPT; } - spin_lock_bh(&qitem_lock); item = kmem_cache_alloc(tipc_queue_item_cache, GFP_ATOMIC); if (!item) { pr_err("Signal queue out of memory\n"); @@ -112,10 +113,14 @@ void tipc_handler_stop(void) struct list_head *l, *n; struct queue_item *item; - if (!handler_enabled) + spin_lock_bh(&qitem_lock); + if (!handler_enabled) { + spin_unlock_bh(&qitem_lock); return; - + } handler_enabled = 0; + spin_unlock_bh(&qitem_lock); + tasklet_kill(&tipc_tasklet); spin_lock_bh(&qitem_lock); -- cgit v1.2.3-70-g09d2 From 84602761ca4495dd409be936dfa93ed20c946684 Mon Sep 17 00:00:00 2001 From: Ying Xue Date: Fri, 27 Dec 2013 10:18:28 +0800 Subject: tipc: fix deadlock during socket release A deadlock might occur if name table is withdrawn in socket release routine, and while packets are still being received from bearer. CPU0 CPU1 T0: recv_msg() release() T1: tipc_recv_msg() tipc_withdraw() T2: [grab node lock] [grab port lock] T3: tipc_link_wakeup_ports() tipc_nametbl_withdraw() T4: [grab port lock]* named_cluster_distribute() T5: wakeupdispatch() tipc_link_send() T6: [grab node lock]* The opposite order of holding port lock and node lock on above two different paths may result in a deadlock. If socket lock instead of port lock is used to protect port instance in tipc_withdraw(), the reverse order of holding port lock and node lock will be eliminated, as a result, the deadlock is killed as well. Reported-by: Lars Everbrand Reviewed-by: Erik Hugne Signed-off-by: Ying Xue Signed-off-by: David S. Miller --- net/tipc/port.c | 45 +++++++++++++++------------------------------ net/tipc/port.h | 6 +++--- net/tipc/socket.c | 46 +++++++++++++++++++++++++++++++--------------- 3 files changed, 49 insertions(+), 48 deletions(-) (limited to 'net/tipc') diff --git a/net/tipc/port.c b/net/tipc/port.c index c081a763230..d43f3182b1d 100644 --- a/net/tipc/port.c +++ b/net/tipc/port.c @@ -251,18 +251,15 @@ struct tipc_port *tipc_createport(struct sock *sk, return p_ptr; } -int tipc_deleteport(u32 ref) +int tipc_deleteport(struct tipc_port *p_ptr) { - struct tipc_port *p_ptr; struct sk_buff *buf = NULL; - tipc_withdraw(ref, 0, NULL); - p_ptr = tipc_port_lock(ref); - if (!p_ptr) - return -EINVAL; + tipc_withdraw(p_ptr, 0, NULL); - tipc_ref_discard(ref); - tipc_port_unlock(p_ptr); + spin_lock_bh(p_ptr->lock); + tipc_ref_discard(p_ptr->ref); + spin_unlock_bh(p_ptr->lock); k_cancel_timer(&p_ptr->timer); if (p_ptr->connected) { @@ -704,47 +701,36 @@ int tipc_set_portimportance(u32 ref, unsigned int imp) } -int tipc_publish(u32 ref, unsigned int scope, struct tipc_name_seq const *seq) +int tipc_publish(struct tipc_port *p_ptr, unsigned int scope, + struct tipc_name_seq const *seq) { - struct tipc_port *p_ptr; struct publication *publ; u32 key; - int res = -EINVAL; - p_ptr = tipc_port_lock(ref); - if (!p_ptr) + if (p_ptr->connected) return -EINVAL; + key = p_ptr->ref + p_ptr->pub_count + 1; + if (key == p_ptr->ref) + return -EADDRINUSE; - if (p_ptr->connected) - goto exit; - key = ref + p_ptr->pub_count + 1; - if (key == ref) { - res = -EADDRINUSE; - goto exit; - } publ = tipc_nametbl_publish(seq->type, seq->lower, seq->upper, scope, p_ptr->ref, key); if (publ) { list_add(&publ->pport_list, &p_ptr->publications); p_ptr->pub_count++; p_ptr->published = 1; - res = 0; + return 0; } -exit: - tipc_port_unlock(p_ptr); - return res; + return -EINVAL; } -int tipc_withdraw(u32 ref, unsigned int scope, struct tipc_name_seq const *seq) +int tipc_withdraw(struct tipc_port *p_ptr, unsigned int scope, + struct tipc_name_seq const *seq) { - struct tipc_port *p_ptr; struct publication *publ; struct publication *tpubl; int res = -EINVAL; - p_ptr = tipc_port_lock(ref); - if (!p_ptr) - return -EINVAL; if (!seq) { list_for_each_entry_safe(publ, tpubl, &p_ptr->publications, pport_list) { @@ -771,7 +757,6 @@ int tipc_withdraw(u32 ref, unsigned int scope, struct tipc_name_seq const *seq) } if (list_empty(&p_ptr->publications)) p_ptr->published = 0; - tipc_port_unlock(p_ptr); return res; } diff --git a/net/tipc/port.h b/net/tipc/port.h index 91225359734..34f12bd4074 100644 --- a/net/tipc/port.h +++ b/net/tipc/port.h @@ -116,7 +116,7 @@ int tipc_reject_msg(struct sk_buff *buf, u32 err); void tipc_acknowledge(u32 port_ref, u32 ack); -int tipc_deleteport(u32 portref); +int tipc_deleteport(struct tipc_port *p_ptr); int tipc_portimportance(u32 portref, unsigned int *importance); int tipc_set_portimportance(u32 portref, unsigned int importance); @@ -127,9 +127,9 @@ int tipc_set_portunreliable(u32 portref, unsigned int isunreliable); int tipc_portunreturnable(u32 portref, unsigned int *isunreturnable); int tipc_set_portunreturnable(u32 portref, unsigned int isunreturnable); -int tipc_publish(u32 portref, unsigned int scope, +int tipc_publish(struct tipc_port *p_ptr, unsigned int scope, struct tipc_name_seq const *name_seq); -int tipc_withdraw(u32 portref, unsigned int scope, +int tipc_withdraw(struct tipc_port *p_ptr, unsigned int scope, struct tipc_name_seq const *name_seq); int tipc_connect(u32 portref, struct tipc_portid const *port); diff --git a/net/tipc/socket.c b/net/tipc/socket.c index 3b61851bb92..e741416d1d2 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -354,7 +354,7 @@ static int release(struct socket *sock) * Delete TIPC port; this ensures no more messages are queued * (also disconnects an active connection & sends a 'FIN-' to peer) */ - res = tipc_deleteport(tport->ref); + res = tipc_deleteport(tport); /* Discard any remaining (connection-based) messages in receive queue */ __skb_queue_purge(&sk->sk_receive_queue); @@ -386,30 +386,46 @@ static int release(struct socket *sock) */ static int bind(struct socket *sock, struct sockaddr *uaddr, int uaddr_len) { + struct sock *sk = sock->sk; struct sockaddr_tipc *addr = (struct sockaddr_tipc *)uaddr; - u32 portref = tipc_sk_port(sock->sk)->ref; + struct tipc_port *tport = tipc_sk_port(sock->sk); + int res = -EINVAL; - if (unlikely(!uaddr_len)) - return tipc_withdraw(portref, 0, NULL); + lock_sock(sk); + if (unlikely(!uaddr_len)) { + res = tipc_withdraw(tport, 0, NULL); + goto exit; + } - if (uaddr_len < sizeof(struct sockaddr_tipc)) - return -EINVAL; - if (addr->family != AF_TIPC) - return -EAFNOSUPPORT; + if (uaddr_len < sizeof(struct sockaddr_tipc)) { + res = -EINVAL; + goto exit; + } + if (addr->family != AF_TIPC) { + res = -EAFNOSUPPORT; + goto exit; + } if (addr->addrtype == TIPC_ADDR_NAME) addr->addr.nameseq.upper = addr->addr.nameseq.lower; - else if (addr->addrtype != TIPC_ADDR_NAMESEQ) - return -EAFNOSUPPORT; + else if (addr->addrtype != TIPC_ADDR_NAMESEQ) { + res = -EAFNOSUPPORT; + goto exit; + } if ((addr->addr.nameseq.type < TIPC_RESERVED_TYPES) && (addr->addr.nameseq.type != TIPC_TOP_SRV) && - (addr->addr.nameseq.type != TIPC_CFG_SRV)) - return -EACCES; + (addr->addr.nameseq.type != TIPC_CFG_SRV)) { + res = -EACCES; + goto exit; + } - return (addr->scope > 0) ? - tipc_publish(portref, addr->scope, &addr->addr.nameseq) : - tipc_withdraw(portref, -addr->scope, &addr->addr.nameseq); + res = (addr->scope > 0) ? + tipc_publish(tport, addr->scope, &addr->addr.nameseq) : + tipc_withdraw(tport, -addr->scope, &addr->addr.nameseq); +exit: + release_sock(sk); + return res; } /** -- cgit v1.2.3-70-g09d2