[PATCH 1/1] ipc namespace: initialize init_ipc_ns.count to 1

From: Serge E. Hallyn
Date: Wed Mar 04 2009 - 10:53:21 EST


Hi Andrew,

when I sent an earlier version of the posix mqueue namespaces patchset
you called me on setting init_ipc_ns.count to 2. The following patch
changes that to 1. This is safe because the 1-count is for swapper, who
cannot unshare the namespace. Having init do unshare(CLONE_NEWIPC) only
drops the count to 1. No pre-init resources other than tasks pin (and
therefore can decrease the refcount on) an ipc_ns.

Signed-off-by: Serge E. Hallyn <serue@xxxxxxxxxx>
---
ipc/msgutil.c | 3 +--
1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/ipc/msgutil.c b/ipc/msgutil.c
index e5d6da1..f095ee2 100644
--- a/ipc/msgutil.c
+++ b/ipc/msgutil.c
@@ -26,8 +26,7 @@ DEFINE_SPINLOCK(mq_lock);
* and not CONFIG_IPC_NS.
*/
struct ipc_namespace init_ipc_ns = {
- /* It's not for this patch to change, but should this be 1? */
- .count = ATOMIC_INIT(2),
+ .count = ATOMIC_INIT(1),
#ifdef CONFIG_POSIX_MQUEUE
.mq_queues_max = DFLT_QUEUESMAX,
.mq_msg_max = DFLT_MSGMAX,
--
1.5.4.3

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