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-rw-r--r--include/linux/ipc_namespace.h47
-rw-r--r--ipc/mqueue.c11
2 files changed, 44 insertions, 14 deletions
diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h
index bde094e..6e1dd08 100644
--- a/include/linux/ipc_namespace.h
+++ b/include/linux/ipc_namespace.h
@@ -90,18 +90,41 @@ 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 MIN_QUEUESMAX 1
-#define DFLT_QUEUESMAX 256 /* max number of message queues */
-#define HARD_QUEUESMAX 1024
-#define MIN_MSGMAX 1
-#define DFLT_MSG 10U
-#define DFLT_MSGMAX 10 /* max number of messages in each queue */
-#define HARD_MSGMAX (32768*sizeof(void *)/4)
-#define MIN_MSGSIZEMAX 128
-#define DFLT_MSGSIZE 8192U
-#define DFLT_MSGSIZEMAX 8192 /* max message size */
-#define HARD_MSGSIZEMAX (8192*128)
+/*
+ * 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 64U
+#define DFLT_MSGMAX 1024
+#define HARD_MSGMAX 65536
+#define MIN_MSGSIZEMAX 128
+#define DFLT_MSGSIZE 8192U
+#define DFLT_MSGSIZEMAX (1024*1024)
+#define HARD_MSGSIZEMAX (16*1024*1024)
#else
static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
#endif
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 6e10a55..f8eba5e 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -24,6 +24,7 @@
#include <linux/mqueue.h>
#include <linux/msg.h>
#include <linux/skbuff.h>
+#include <linux/vmalloc.h>
#include <linux/netlink.h>
#include <linux/syscalls.h>
#include <linux/audit.h>
@@ -152,7 +153,10 @@ static struct inode *mqueue_get_inode(struct super_block *sb,
info->attr.mq_msgsize = attr->mq_msgsize;
}
mq_msg_tblsz = info->attr.mq_maxmsg * sizeof(struct msg_msg *);
- info->messages = kmalloc(mq_msg_tblsz, GFP_KERNEL);
+ if (mq_msg_tblsz > KMALLOC_MAX_SIZE)
+ info->messages = vmalloc(mq_msg_tblsz);
+ else
+ info->messages = kmalloc(mq_msg_tblsz, GFP_KERNEL);
if (!info->messages)
goto out_inode;
@@ -262,7 +266,10 @@ static void mqueue_evict_inode(struct inode *inode)
spin_lock(&info->lock);
for (i = 0; i < info->attr.mq_curmsgs; i++)
free_msg(info->messages[i]);
- kfree(info->messages);
+ if (info->attr.mq_maxmsg * sizeof(struct msg_msg *) > KMALLOC_MAX_SIZE)
+ vfree(info->messages);
+ else
+ kfree(info->messages);
spin_unlock(&info->lock);
/* Total amount of bytes accounted for the mqueue */
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