[PATCH 1/1] kernel/pid.c: Masking the flag out to get the actual value.

["Raphael S. Carvalho" <raphael.scarv@gmail.com>]

This patch shouldn't be applied if those branches must only be taken when
the pid_allocation(PIDNS_HASH_ADDING) flag was turned off.
Otherwise, we must turn the PIDNS_HASH_ADDING flag (1U << 31) off
before getting into the switch-cases.

Signed-off-by: Raphael S. Carvalho <raphael.scarv@gmail.com>
---
 kernel/pid.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/kernel/pid.c b/kernel/pid.c
index 0db3e79..6bda527 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -263,7 +263,10 @@ void free_pid(struct pid *pid)
 		struct upid *upid = pid->numbers + i;
 		struct pid_namespace *ns = upid->ns;
 		hlist_del_rcu(&upid->pid_chain);
-		switch(--ns->nr_hashed) {
+
+		/* We must turn the PIDNS_HASH_ADDING flag off to
+		   get the actual value of nr_hashed */
+		switch ((--ns->nr_hashed) & ~(PIDNS_HASH_ADDING)) {
 		case 1:
 			/* When all that is left in the pid namespace
 			 * is the reaper wake up the reaper.  The reaper
-- 
1.7.2.5