[openib-general] [PATCH] refcount race fixes
Sean Hefty
mshefty at ichips.intel.com
Thu May 11 10:02:21 PDT 2006
Roland, this is the patch that I was referring to.
---
Fix race condition during destruction calls to avoid possibility of accessing
object after it has been freed.
Signed-off-by: Sean Hefty <sean.hefty at intel.com>
---
Index: mad_rmpp.c
===================================================================
--- mad_rmpp.c (revision 6884)
+++ mad_rmpp.c (working copy)
@@ -49,7 +49,7 @@ struct mad_rmpp_recv {
struct list_head list;
struct work_struct timeout_work;
struct work_struct cleanup_work;
- wait_queue_head_t wait;
+ struct completion comp;
enum rmpp_state state;
spinlock_t lock;
atomic_t refcount;
@@ -69,10 +69,16 @@ struct mad_rmpp_recv {
u8 method;
};
+static inline void deref_rmpp_recv(struct mad_rmpp_recv *rmpp_recv)
+{
+ if (atomic_dec_and_test(&rmpp_recv->refcount))
+ complete(&rmpp_recv->comp);
+}
+
static void destroy_rmpp_recv(struct mad_rmpp_recv *rmpp_recv)
{
- atomic_dec(&rmpp_recv->refcount);
- wait_event(rmpp_recv->wait, !atomic_read(&rmpp_recv->refcount));
+ deref_rmpp_recv(rmpp_recv);
+ wait_for_completion(&rmpp_recv->comp);
ib_destroy_ah(rmpp_recv->ah);
kfree(rmpp_recv);
}
@@ -253,7 +259,7 @@ create_rmpp_recv(struct ib_mad_agent_pri
goto error;
rmpp_recv->agent = agent;
- init_waitqueue_head(&rmpp_recv->wait);
+ init_completion(&rmpp_recv->comp);
INIT_WORK(&rmpp_recv->timeout_work, recv_timeout_handler, rmpp_recv);
INIT_WORK(&rmpp_recv->cleanup_work, recv_cleanup_handler, rmpp_recv);
spin_lock_init(&rmpp_recv->lock);
@@ -279,12 +285,6 @@ error: kfree(rmpp_recv);
return NULL;
}
-static inline void deref_rmpp_recv(struct mad_rmpp_recv *rmpp_recv)
-{
- if (atomic_dec_and_test(&rmpp_recv->refcount))
- wake_up(&rmpp_recv->wait);
-}
-
static struct mad_rmpp_recv *
find_rmpp_recv(struct ib_mad_agent_private *agent,
struct ib_mad_recv_wc *mad_recv_wc)
Index: cm.c
===================================================================
--- cm.c (revision 6884)
+++ cm.c (working copy)
@@ -34,6 +34,8 @@
*
* $Id$
*/
+
+#include <linux/completion.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/idr.h>
@@ -122,7 +124,7 @@ struct cm_id_private {
struct rb_node service_node;
struct rb_node sidr_id_node;
spinlock_t lock; /* Do not acquire inside cm.lock */
- wait_queue_head_t wait;
+ struct completion comp;
atomic_t refcount;
struct ib_mad_send_buf *msg;
@@ -160,7 +162,7 @@ static void cm_work_handler(void *data);
static inline void cm_deref_id(struct cm_id_private *cm_id_priv)
{
if (atomic_dec_and_test(&cm_id_priv->refcount))
- wake_up(&cm_id_priv->wait);
+ complete(&cm_id_priv->comp);
}
static int cm_alloc_msg(struct cm_id_private *cm_id_priv,
@@ -611,7 +613,7 @@ struct ib_cm_id *ib_create_cm_id(struct
goto error;
spin_lock_init(&cm_id_priv->lock);
- init_waitqueue_head(&cm_id_priv->wait);
+ init_completion(&cm_id_priv->comp);
INIT_LIST_HEAD(&cm_id_priv->work_list);
atomic_set(&cm_id_priv->work_count, -1);
atomic_set(&cm_id_priv->refcount, 1);
@@ -776,8 +778,8 @@ retest:
}
cm_free_id(cm_id->local_id);
- atomic_dec(&cm_id_priv->refcount);
- wait_event(cm_id_priv->wait, !atomic_read(&cm_id_priv->refcount));
+ cm_deref_id(cm_id_priv);
+ wait_for_completion(&cm_id_priv->comp);
while ((work = cm_dequeue_work(cm_id_priv)) != NULL)
cm_free_work(work);
kfree(cm_id_priv->compare_data);
Index: multicast.c
===================================================================
--- multicast.c (revision 6884)
+++ multicast.c (working copy)
@@ -30,6 +30,7 @@
* SOFTWARE.
*/
+#include <linux/completion.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/interrupt.h>
@@ -69,7 +70,7 @@ struct mcast_port {
spinlock_t lock;
struct rb_root table;
atomic_t refcount;
- wait_queue_head_t wait;
+ struct completion comp;
u8 port_num;
};
@@ -110,7 +111,7 @@ struct mcast_member {
struct list_head list;
enum mcast_state state;
atomic_t refcount;
- wait_queue_head_t wait;
+ struct completion comp;
};
static void join_handler(int status, struct ib_sa_mcmember_rec *rec,
@@ -168,7 +169,7 @@ static struct mcast_group *mcast_insert(
static void deref_port(struct mcast_port *port)
{
if (atomic_dec_and_test(&port->refcount))
- wake_up(&port->wait);
+ complete(&port->comp);
}
static void release_group(struct mcast_group *group)
@@ -189,7 +190,7 @@ static void release_group(struct mcast_g
static void deref_member(struct mcast_member *member)
{
if (atomic_dec_and_test(&member->refcount))
- wake_up(&member->wait);
+ complete(&member->comp);
}
static void queue_join(struct mcast_member *member)
@@ -512,7 +513,7 @@ struct ib_multicast *ib_join_multicast(s
member->multicast.comp_mask = comp_mask;
member->multicast.callback = callback;
member->multicast.context = context;
- init_waitqueue_head(&member->wait);
+ init_completion(&member->comp);
atomic_set(&member->refcount, 1);
member->state = MCAST_JOINING;
@@ -569,8 +570,8 @@ void ib_free_multicast(struct ib_multica
release_group(group);
}
- atomic_dec(&member->refcount);
- wait_event(member->wait, !atomic_read(&member->refcount));
+ deref_member(member);
+ wait_for_completion(&member->comp);
kfree(member);
}
EXPORT_SYMBOL(ib_free_multicast);
@@ -602,7 +603,7 @@ static void mcast_add_one(struct ib_devi
port->port_num = dev->start_port + i;
spin_lock_init(&port->lock);
port->table = RB_ROOT;
- init_waitqueue_head(&port->wait);
+ init_completion(&port->comp);
atomic_set(&port->refcount, 1);
}
@@ -644,8 +645,8 @@ static void mcast_remove_one(struct ib_d
for (i = 0; i < dev->end_port - dev->start_port; i++) {
port = &dev->port[i];
leave_groups(port);
- atomic_dec(&port->refcount);
- wait_event(port->wait, !atomic_read(&port->refcount));
+ deref_port(port);
+ wait_for_completion(&port->comp);
}
kfree(dev);
Index: cma.c
===================================================================
--- cma.c (revision 6948)
+++ cma.c (working copy)
@@ -29,6 +29,7 @@
*
*/
+#include <linux/completion.h>
#include <linux/in.h>
#include <linux/in6.h>
#include <linux/mutex.h>
@@ -70,7 +71,7 @@ struct cma_device {
struct list_head list;
struct ib_device *device;
__be64 node_guid;
- wait_queue_head_t wait;
+ struct completion comp;
atomic_t refcount;
struct list_head id_list;
};
@@ -111,7 +112,7 @@ struct rdma_id_private {
enum cma_state state;
spinlock_t lock;
- wait_queue_head_t wait;
+ struct completion comp;
atomic_t refcount;
wait_queue_head_t wait_remove;
atomic_t dev_remove;
@@ -244,11 +245,16 @@ static void cma_attach_to_dev(struct rdm
list_add_tail(&id_priv->list, &cma_dev->id_list);
}
+static inline void cma_deref_dev(struct cma_device *cma_dev)
+{
+ if (atomic_dec_and_test(&cma_dev->refcount))
+ complete(&cma_dev->comp);
+}
+
static void cma_detach_from_dev(struct rdma_id_private *id_priv)
{
list_del(&id_priv->list);
- if (atomic_dec_and_test(&id_priv->cma_dev->refcount))
- wake_up(&id_priv->cma_dev->wait);
+ cma_deref_dev(id_priv->cma_dev);
id_priv->cma_dev = NULL;
}
@@ -288,7 +294,7 @@ static int cma_acquire_dev(struct rdma_i
static void cma_deref_id(struct rdma_id_private *id_priv)
{
if (atomic_dec_and_test(&id_priv->refcount))
- wake_up(&id_priv->wait);
+ complete(&id_priv->comp);
}
static void cma_release_remove(struct rdma_id_private *id_priv)
@@ -311,7 +317,7 @@ struct rdma_cm_id* rdma_create_id(rdma_c
id_priv->id.event_handler = event_handler;
id_priv->id.ps = ps;
spin_lock_init(&id_priv->lock);
- init_waitqueue_head(&id_priv->wait);
+ init_completion(&id_priv->comp);
atomic_set(&id_priv->refcount, 1);
init_waitqueue_head(&id_priv->wait_remove);
atomic_set(&id_priv->dev_remove, 0);
@@ -618,8 +624,8 @@ static void cma_destroy_listen(struct rd
}
list_del(&id_priv->listen_list);
- atomic_dec(&id_priv->refcount);
- wait_event(id_priv->wait, !atomic_read(&id_priv->refcount));
+ cma_deref_id(id_priv);
+ wait_for_completion(&id_priv->comp);
kfree(id_priv);
}
@@ -699,8 +705,8 @@ void rdma_destroy_id(struct rdma_cm_id *
}
cma_release_port(id_priv);
- atomic_dec(&id_priv->refcount);
- wait_event(id_priv->wait, !atomic_read(&id_priv->refcount));
+ cma_deref_id(id_priv);
+ wait_for_completion(&id_priv->comp);
kfree(id_priv->id.route.path_rec);
kfree(id_priv);
@@ -1778,7 +1784,7 @@ static void cma_add_one(struct ib_device
if (!cma_dev->node_guid)
goto err;
- init_waitqueue_head(&cma_dev->wait);
+ init_completion(&cma_dev->comp);
atomic_set(&cma_dev->refcount, 1);
INIT_LIST_HEAD(&cma_dev->id_list);
ib_set_client_data(device, &cma_client, cma_dev);
@@ -1845,8 +1851,8 @@ static void cma_process_remove(struct cm
}
mutex_unlock(&lock);
- atomic_dec(&cma_dev->refcount);
- wait_event(cma_dev->wait, !atomic_read(&cma_dev->refcount));
+ cma_deref_dev(cma_dev);
+ wait_for_completion(&cma_dev->comp);
}
static void cma_remove_one(struct ib_device *device)
Index: mad.c
===================================================================
--- mad.c (revision 6886)
+++ mad.c (working copy)
@@ -353,7 +353,7 @@ struct ib_mad_agent *ib_register_mad_age
INIT_WORK(&mad_agent_priv->local_work, local_completions,
mad_agent_priv);
atomic_set(&mad_agent_priv->refcount, 1);
- init_waitqueue_head(&mad_agent_priv->wait);
+ init_completion(&mad_agent_priv->comp);
return &mad_agent_priv->agent;
@@ -468,7 +468,7 @@ struct ib_mad_agent *ib_register_mad_sno
mad_snoop_priv->agent.qp = port_priv->qp_info[qpn].qp;
mad_snoop_priv->agent.port_num = port_num;
mad_snoop_priv->mad_snoop_flags = mad_snoop_flags;
- init_waitqueue_head(&mad_snoop_priv->wait);
+ init_completion(&mad_snoop_priv->comp);
mad_snoop_priv->snoop_index = register_snoop_agent(
&port_priv->qp_info[qpn],
mad_snoop_priv);
@@ -487,6 +487,18 @@ error1:
}
EXPORT_SYMBOL(ib_register_mad_snoop);
+static inline void deref_mad_agent(struct ib_mad_agent_private *mad_agent_priv)
+{
+ if (atomic_dec_and_test(&mad_agent_priv->refcount))
+ complete(&mad_agent_priv->comp);
+}
+
+static inline void deref_snoop_agent(struct ib_mad_snoop_private *mad_snoop_priv)
+{
+ if (atomic_dec_and_test(&mad_snoop_priv->refcount))
+ complete(&mad_snoop_priv->comp);
+}
+
static void unregister_mad_agent(struct ib_mad_agent_private *mad_agent_priv)
{
struct ib_mad_port_private *port_priv;
@@ -510,9 +522,8 @@ static void unregister_mad_agent(struct
flush_workqueue(port_priv->wq);
ib_cancel_rmpp_recvs(mad_agent_priv);
- atomic_dec(&mad_agent_priv->refcount);
- wait_event(mad_agent_priv->wait,
- !atomic_read(&mad_agent_priv->refcount));
+ deref_mad_agent(mad_agent_priv);
+ wait_for_completion(&mad_agent_priv->comp);
kfree(mad_agent_priv->reg_req);
ib_dereg_mr(mad_agent_priv->agent.mr);
@@ -530,9 +541,8 @@ static void unregister_mad_snoop(struct
atomic_dec(&qp_info->snoop_count);
spin_unlock_irqrestore(&qp_info->snoop_lock, flags);
- atomic_dec(&mad_snoop_priv->refcount);
- wait_event(mad_snoop_priv->wait,
- !atomic_read(&mad_snoop_priv->refcount));
+ deref_snoop_agent(mad_snoop_priv);
+ wait_for_completion(&mad_snoop_priv->comp);
kfree(mad_snoop_priv);
}
@@ -601,8 +611,7 @@ static void snoop_send(struct ib_mad_qp_
spin_unlock_irqrestore(&qp_info->snoop_lock, flags);
mad_snoop_priv->agent.snoop_handler(&mad_snoop_priv->agent,
send_buf, mad_send_wc);
- if (atomic_dec_and_test(&mad_snoop_priv->refcount))
- wake_up(&mad_snoop_priv->wait);
+ deref_snoop_agent(mad_snoop_priv);
spin_lock_irqsave(&qp_info->snoop_lock, flags);
}
spin_unlock_irqrestore(&qp_info->snoop_lock, flags);
@@ -627,8 +636,7 @@ static void snoop_recv(struct ib_mad_qp_
spin_unlock_irqrestore(&qp_info->snoop_lock, flags);
mad_snoop_priv->agent.recv_handler(&mad_snoop_priv->agent,
mad_recv_wc);
- if (atomic_dec_and_test(&mad_snoop_priv->refcount))
- wake_up(&mad_snoop_priv->wait);
+ deref_snoop_agent(mad_snoop_priv);
spin_lock_irqsave(&qp_info->snoop_lock, flags);
}
spin_unlock_irqrestore(&qp_info->snoop_lock, flags);
@@ -969,8 +977,7 @@ void ib_free_send_mad(struct ib_mad_send
free_send_rmpp_list(mad_send_wr);
kfree(send_buf->mad);
- if (atomic_dec_and_test(&mad_agent_priv->refcount))
- wake_up(&mad_agent_priv->wait);
+ deref_mad_agent(mad_agent_priv);
}
EXPORT_SYMBOL(ib_free_send_mad);
@@ -1789,8 +1796,7 @@ static void ib_mad_complete_recv(struct
mad_recv_wc = ib_process_rmpp_recv_wc(mad_agent_priv,
mad_recv_wc);
if (!mad_recv_wc) {
- if (atomic_dec_and_test(&mad_agent_priv->refcount))
- wake_up(&mad_agent_priv->wait);
+ deref_mad_agent(mad_agent_priv);
return;
}
}
@@ -1802,8 +1808,7 @@ static void ib_mad_complete_recv(struct
if (!mad_send_wr) {
spin_unlock_irqrestore(&mad_agent_priv->lock, flags);
ib_free_recv_mad(mad_recv_wc);
- if (atomic_dec_and_test(&mad_agent_priv->refcount))
- wake_up(&mad_agent_priv->wait);
+ deref_mad_agent(mad_agent_priv);
return;
}
ib_mark_mad_done(mad_send_wr);
@@ -1822,8 +1827,7 @@ static void ib_mad_complete_recv(struct
} else {
mad_agent_priv->agent.recv_handler(&mad_agent_priv->agent,
mad_recv_wc);
- if (atomic_dec_and_test(&mad_agent_priv->refcount))
- wake_up(&mad_agent_priv->wait);
+ deref_mad_agent(mad_agent_priv);
}
}
@@ -2053,8 +2057,7 @@ void ib_mad_complete_send_wr(struct ib_m
mad_send_wc);
/* Release reference on agent taken when sending */
- if (atomic_dec_and_test(&mad_agent_priv->refcount))
- wake_up(&mad_agent_priv->wait);
+ deref_mad_agent(mad_agent_priv);
return;
done:
spin_unlock_irqrestore(&mad_agent_priv->lock, flags);
Index: mad_priv.h
===================================================================
--- mad_priv.h (revision 6884)
+++ mad_priv.h (working copy)
@@ -37,6 +37,7 @@
#ifndef __IB_MAD_PRIV_H__
#define __IB_MAD_PRIV_H__
+#include <linux/completion.h>
#include <linux/pci.h>
#include <linux/kthread.h>
#include <linux/workqueue.h>
@@ -108,7 +109,7 @@ struct ib_mad_agent_private {
struct list_head rmpp_list;
atomic_t refcount;
- wait_queue_head_t wait;
+ struct completion comp;
};
struct ib_mad_snoop_private {
@@ -117,7 +118,7 @@ struct ib_mad_snoop_private {
int snoop_index;
int mad_snoop_flags;
atomic_t refcount;
- wait_queue_head_t wait;
+ struct completion comp;
};
struct ib_mad_send_wr_private {
Index: ucm.c
===================================================================
--- ucm.c (revision 6884)
+++ ucm.c (working copy)
@@ -32,6 +32,8 @@
*
* $Id$
*/
+
+#include <linux/completion.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/module.h>
@@ -73,7 +75,7 @@ struct ib_ucm_file {
struct ib_ucm_context {
int id;
- wait_queue_head_t wait;
+ struct completion comp;
atomic_t ref;
int events_reported;
@@ -139,7 +141,7 @@ static struct ib_ucm_context *ib_ucm_ctx
static void ib_ucm_ctx_put(struct ib_ucm_context *ctx)
{
if (atomic_dec_and_test(&ctx->ref))
- wake_up(&ctx->wait);
+ complete(&ctx->comp);
}
static inline int ib_ucm_new_cm_id(int event)
@@ -179,7 +181,7 @@ static struct ib_ucm_context *ib_ucm_ctx
return NULL;
atomic_set(&ctx->ref, 1);
- init_waitqueue_head(&ctx->wait);
+ init_completion(&ctx->comp);
ctx->file = file;
INIT_LIST_HEAD(&ctx->events);
@@ -559,8 +561,8 @@ static ssize_t ib_ucm_destroy_id(struct
if (IS_ERR(ctx))
return PTR_ERR(ctx);
- atomic_dec(&ctx->ref);
- wait_event(ctx->wait, !atomic_read(&ctx->ref));
+ ib_ucm_ctx_put(ctx);
+ wait_for_completion(&ctx->comp);
/* No new events will be generated after destroying the cm_id. */
ib_destroy_cm_id(ctx->cm_id);
Index: ucma.c
===================================================================
--- ucma.c (revision 6949)
+++ ucma.c (working copy)
@@ -30,6 +30,7 @@
* SOFTWARE.
*/
+#include <linux/completion.h>
#include <linux/mutex.h>
#include <linux/poll.h>
#include <linux/idr.h>
@@ -61,7 +62,7 @@ struct ucma_file {
struct ucma_context {
int id;
- wait_queue_head_t wait;
+ struct completion comp;
atomic_t ref;
int events_reported;
int backlog;
@@ -105,7 +106,7 @@ static struct ucma_context* ucma_get_ctx
static void ucma_put_ctx(struct ucma_context *ctx)
{
if (atomic_dec_and_test(&ctx->ref))
- wake_up(&ctx->wait);
+ complete(&ctx->comp);
}
static void ucma_cleanup_events(struct ucma_context *ctx)
@@ -140,7 +141,7 @@ static struct ucma_context* ucma_alloc_c
return NULL;
atomic_set(&ctx->ref, 1);
- init_waitqueue_head(&ctx->wait);
+ init_completion(&ctx->comp);
ctx->file = file;
INIT_LIST_HEAD(&ctx->events);
@@ -341,8 +342,8 @@ static ssize_t ucma_destroy_id(struct uc
if (IS_ERR(ctx))
return PTR_ERR(ctx);
- atomic_dec(&ctx->ref);
- wait_event(ctx->wait, !atomic_read(&ctx->ref));
+ ucma_put_ctx(ctx);
+ wait_for_completion(&ctx->comp);
/* No new events will be generated after destroying the id. */
rdma_destroy_id(ctx->cm_id);
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