1 files changed, 17 insertions, 10 deletions

diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
index 94816aeb95a0..1c02deab068f 100644
--- a/drivers/infiniband/core/uverbs_cmd.c
+++ b/drivers/infiniband/core/uverbs_cmd.c
@@ -62,9 +62,11 @@ static struct uverbs_lock_class rule_lock_class = { .name = "RULE-uobj" };
  * The ib_uobject locking scheme is as follows:
  *
  * - ib_uverbs_idr_lock protects the uverbs idrs themselves, so it
- *   needs to be held during all idr operations.  When an object is
+ *   needs to be held during all idr write operations.  When an object is
  *   looked up, a reference must be taken on the object's kref before
- *   dropping this lock.
+ *   dropping this lock.  For read operations, the rcu_read_lock()
+ *   and rcu_write_lock() but similarly the kref reference is grabbed
+ *   before the rcu_read_unlock().
  *
  * - Each object also has an rwsem.  This rwsem must be held for
  *   reading while an operation that uses the object is performed.
@@ -96,7 +98,7 @@ static void init_uobj(struct ib_uobject *uobj, u64 user_handle,
 
 static void release_uobj(struct kref *kref)
 {
-        kfree(container_of(kref, struct ib_uobject, ref));
+        kfree_rcu(container_of(kref, struct ib_uobject, ref), rcu);
 }
 
 static void put_uobj(struct ib_uobject *uobj)
@@ -145,7 +147,7 @@ static struct ib_uobject *__idr_get_uobj(struct idr *idr, int id,
 {
         struct ib_uobject *uobj;
 
-        spin_lock(&ib_uverbs_idr_lock);
+        rcu_read_lock();
         uobj = idr_find(idr, id);
         if (uobj) {
                 if (uobj->context == context)
@@ -153,7 +155,7 @@ static struct ib_uobject *__idr_get_uobj(struct idr *idr, int id,
                 else
                         uobj = NULL;
         }
-        spin_unlock(&ib_uverbs_idr_lock);
+        rcu_read_unlock();
 
         return uobj;
 }
@@ -2446,6 +2448,7 @@ ssize_t ib_uverbs_post_send(struct ib_uverbs_file *file,
         int                             i, sg_ind;
         int                             is_ud;
         ssize_t                         ret = -EINVAL;
+        size_t                          next_size;
 
         if (copy_from_user(&cmd, buf, sizeof cmd))
                 return -EFAULT;
@@ -2490,7 +2493,8 @@ ssize_t ib_uverbs_post_send(struct ib_uverbs_file *file,
                                 goto out_put;
                         }
 
-                        ud = alloc_wr(sizeof(*ud), user_wr->num_sge);
+                        next_size = sizeof(*ud);
+                        ud = alloc_wr(next_size, user_wr->num_sge);
                         if (!ud) {
                                 ret = -ENOMEM;
                                 goto out_put;
@@ -2511,7 +2515,8 @@ ssize_t ib_uverbs_post_send(struct ib_uverbs_file *file,
                            user_wr->opcode == IB_WR_RDMA_READ) {
                         struct ib_rdma_wr *rdma;
 
-                        rdma = alloc_wr(sizeof(*rdma), user_wr->num_sge);
+                        next_size = sizeof(*rdma);
+                        rdma = alloc_wr(next_size, user_wr->num_sge);
                         if (!rdma) {
                                 ret = -ENOMEM;
                                 goto out_put;
@@ -2525,7 +2530,8 @@ ssize_t ib_uverbs_post_send(struct ib_uverbs_file *file,
                            user_wr->opcode == IB_WR_ATOMIC_FETCH_AND_ADD) {
                         struct ib_atomic_wr *atomic;
 
-                        atomic = alloc_wr(sizeof(*atomic), user_wr->num_sge);
+                        next_size = sizeof(*atomic);
+                        atomic = alloc_wr(next_size, user_wr->num_sge);
                         if (!atomic) {
                                 ret = -ENOMEM;
                                 goto out_put;
@@ -2540,7 +2546,8 @@ ssize_t ib_uverbs_post_send(struct ib_uverbs_file *file,
                 } else if (user_wr->opcode == IB_WR_SEND ||
                            user_wr->opcode == IB_WR_SEND_WITH_IMM ||
                            user_wr->opcode == IB_WR_SEND_WITH_INV) {
-                        next = alloc_wr(sizeof(*next), user_wr->num_sge);
+                        next_size = sizeof(*next);
+                        next = alloc_wr(next_size, user_wr->num_sge);
                         if (!next) {
                                 ret = -ENOMEM;
                                 goto out_put;
@@ -2572,7 +2579,7 @@ ssize_t ib_uverbs_post_send(struct ib_uverbs_file *file,
 
                 if (next->num_sge) {
                         next->sg_list = (void *) next +
-                                ALIGN(sizeof *next, sizeof (struct ib_sge));
+                                ALIGN(next_size, sizeof(struct ib_sge));
                         if (copy_from_user(next->sg_list,
                                            buf + sizeof cmd +
                                            cmd.wr_count * cmd.wqe_size +