ath10k: use msdu headroom to store txfrag

[cascardo/linux.git] / ipc / shm.c

diff --git a/ipc/shm.c b/ipc/shm.c
index e7d5107..c6b4ad5 100644 (file)
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -757,31 +757,42 @@ static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd,
                        return -EFAULT;
        }
 
+       down_write(&shm_ids(ns).rw_mutex);
+       rcu_read_lock();
+
        ipcp = ipcctl_pre_down(ns, &shm_ids(ns), shmid, cmd,
                               &shmid64.shm_perm, 0);
-       if (IS_ERR(ipcp))
-               return PTR_ERR(ipcp);
+       if (IS_ERR(ipcp)) {
+               err = PTR_ERR(ipcp);
+               /* the ipc lock is not held upon failure */
+               goto out_unlock1;
+       }
 
        shp = container_of(ipcp, struct shmid_kernel, shm_perm);
 
        err = security_shm_shmctl(shp, cmd);
        if (err)
-               goto out_unlock;
+               goto out_unlock0;
+
        switch (cmd) {
        case IPC_RMID:
+               /* do_shm_rmid unlocks the ipc object and rcu */
                do_shm_rmid(ns, ipcp);
                goto out_up;
        case IPC_SET:
                err = ipc_update_perm(&shmid64.shm_perm, ipcp);
                if (err)
-                       goto out_unlock;
+                       goto out_unlock0;
                shp->shm_ctim = get_seconds();
                break;
        default:
                err = -EINVAL;
        }
-out_unlock:
-       shm_unlock(shp);
+
+out_unlock0:
+       ipc_unlock_object(&shp->shm_perm);
+out_unlock1:
+       rcu_read_unlock();
 out_up:
        up_write(&shm_ids(ns).rw_mutex);
        return err;