[PATCH 2/4] sysvipc: duplicate lock comments wrt ipc_addid()

[Davidlohr Bueso <dave@stgolabs.net>]

The comment in msgqueues when using ipc_addid() is quite
useful imo. Duplicate it for shm and semaphores.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
---
 ipc/sem.c | 1 +
 ipc/shm.c | 1 +
 2 files changed, 2 insertions(+)

diff --git a/ipc/sem.c b/ipc/sem.c
index 013c7981f3c7..29c6ab6badc2 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -514,6 +514,7 @@ static int newary(struct ipc_namespace *ns, struct ipc_params *params)
 	sma->sem_nsems = nsems;
 	sma->sem_ctime = get_seconds();
 
+	/* ipc_addid() locks sma upon success. */
 	retval = ipc_addid(&sem_ids(ns), &sma->sem_perm, ns->sc_semmni);
 	if (retval < 0) {
 		call_rcu(&sma->sem_perm.rcu, sem_rcu_free);
diff --git a/ipc/shm.c b/ipc/shm.c
index 8fc97beb5234..ea64ed8782b3 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -600,6 +600,7 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
 	shp->shm_file = file;
 	shp->shm_creator = current;
 
+	/* ipc_addid() locks shp upon success. */
 	error = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni);
 	if (error < 0)
 		goto no_id;
-- 
2.12.0