1 files changed, 37 insertions, 5 deletions

diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h
index 8a297a5e794c..5499c92a9153 100644
--- a/include/linux/ipc_namespace.h
+++ b/include/linux/ipc_namespace.h
@@ -62,6 +62,8 @@ struct ipc_namespace {
         unsigned int    mq_queues_max;   /* initialized to DFLT_QUEUESMAX */
         unsigned int    mq_msg_max;      /* initialized to DFLT_MSGMAX */
         unsigned int    mq_msgsize_max;  /* initialized to DFLT_MSGSIZEMAX */
+        unsigned int    mq_msg_default;
+        unsigned int    mq_msgsize_default;
 
         /* user_ns which owns the ipc ns */
         struct user_namespace *user_ns;
@@ -90,11 +92,41 @@ static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
 
 #ifdef CONFIG_POSIX_MQUEUE
 extern int mq_init_ns(struct ipc_namespace *ns);
-/* default values */
-#define DFLT_QUEUESMAX 256     /* max number of message queues */
-#define DFLT_MSGMAX    10      /* max number of messages in each queue */
-#define HARD_MSGMAX    (32768*sizeof(void *)/4)
-#define DFLT_MSGSIZEMAX 8192   /* max message size */
+/*
+ * POSIX Message Queue default values:
+ *
+ * MIN_*: Lowest value an admin can set the maximum unprivileged limit to
+ * DFLT_*MAX: Default values for the maximum unprivileged limits
+ * DFLT_{MSG,MSGSIZE}: Default values used when the user doesn't supply
+ *   an attribute to the open call and the queue must be created
+ * HARD_*: Highest value the maximums can be set to.  These are enforced
+ *   on CAP_SYS_RESOURCE apps as well making them inviolate (so make them
+ *   suitably high)
+ *
+ * POSIX Requirements:
+ *   Per app minimum openable message queues - 8.  This does not map well
+ *     to the fact that we limit the number of queues on a per namespace
+ *     basis instead of a per app basis.  So, make the default high enough
+ *     that no given app should have a hard time opening 8 queues.
+ *   Minimum maximum for HARD_MSGMAX - 32767.  I bumped this to 65536.
+ *   Minimum maximum for HARD_MSGSIZEMAX - POSIX is silent on this.  However,
+ *     we have run into a situation where running applications in the wild
+ *     require this to be at least 5MB, and preferably 10MB, so I set the
+ *     value to 16MB in hopes that this user is the worst of the bunch and
+ *     the new maximum will handle anyone else.  I may have to revisit this
+ *     in the future.
+ */
+#define MIN_QUEUESMAX                   1
+#define DFLT_QUEUESMAX                256
+#define HARD_QUEUESMAX               1024
+#define MIN_MSGMAX                      1
+#define DFLT_MSG                       10U
+#define DFLT_MSGMAX                    10
+#define HARD_MSGMAX                 65536
+#define MIN_MSGSIZEMAX                128
+#define DFLT_MSGSIZE                 8192U
+#define DFLT_MSGSIZEMAX              8192
+#define HARD_MSGSIZEMAX     (16*1024*1024)
 #else
 static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
 #endif