[PATCH 0/3] ipc: Further updates to sysv/mqueue limits

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* [PATCH 0/3] ipc: Further updates to sysv/mqueue limits
@ 2014-08-12  7:29 Manfred Spraul
  2014-08-12  7:29 ` [PATCH 1/3] ipc/msg: increase MSGMNI, remove scaling Manfred Spraul
  0 siblings, 1 reply; 14+ messages in thread
From: Manfred Spraul @ 2014-08-12  7:29 UTC (permalink / raw)
  To: Andrew Morton
  Cc: LKML, Davidlohr Bueso, Michael Kerrisk, Rafael Aquini,
	Rik van Riel, 1vier1, Manfred Spraul

Hi Andrew,

I got some positive and no negative feedback on my patches, thus:
Could you add the patches to -mm and push them towards Linus?

0001-ipc-msg-increase-MSGMNI-remove-scaling.patch
	- increase MSGMNI to 32000
	- as a bonus, this removes around 300 lines

0002-ipc-sem.c-increase-SEMMSL-SEMMNI-SEMOPM.patch
	- increase all limits
	- update the documentation, it was stale

   Note: Redhat/Oracle recommend values that exceed what I would recommend
   as safe upper limits.

https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/5/html/Tuning_and_Optimizing_Red_Hat_Enterprise_Linux_for_Oracle_9i_and_10g_Databases/sect-Oracle_9i_and_10g_Tuning_Guide-Setting_Semaphores-An_Example_of_Semaphore_Settings.html 

   Unfortunately I didn't get any replies, thus I don't know how to proceed.

   One option would be to switch from kmalloc to ipc_alloc, then the risk of
   failing due to memory fragmentation would be resolved.

0003-ipc-namespace-copy-settings-from-parent-namespace.patch
	Change the namespace code so that a new namespace inherits the values
	from it's parent instead of the boot time defaults.

	Serge Hallyn and Michael Kerrisk also consider the new approach as better.
	One thing that is a bit surprising is that clone(CLONE_NEWIPC)k

I've tested the changes both with unshare -i and with my own test apps.
Unfortunately I didn't manage to get lxc to run on my busybox test setup :-(

--
	Manfred

^ permalink raw reply	[flat|nested] 14+ messages in thread

* [PATCH 1/3] ipc/msg: increase MSGMNI, remove scaling
  2014-08-12  7:29 [PATCH 0/3] ipc: Further updates to sysv/mqueue limits Manfred Spraul
@ 2014-08-12  7:29 ` Manfred Spraul
  2014-08-12  7:29   ` [PATCH 2/3] ipc/sem.c: increase SEMMSL, SEMMNI, SEMOPM Manfred Spraul
  2014-08-15 13:41   ` [PATCH 1/3] ipc/msg: increase MSGMNI, remove scaling Rafael Aquini
  0 siblings, 2 replies; 14+ messages in thread
From: Manfred Spraul @ 2014-08-12  7:29 UTC (permalink / raw)
  To: Andrew Morton
  Cc: LKML, Davidlohr Bueso, Michael Kerrisk, Rafael Aquini,
	Rik van Riel, 1vier1, Manfred Spraul

SysV can be abused to allocate locked kernel memory.
For most systems, a small limit doesn't make sense, see the discussion with
regards to SHMMAX.

Therefore: increase MSGMNI to the maximum supported.

And: If we ignore the risk of locking too much memory, then an automatic
scaling of MSGMNI doesn't make sense. Therefore the logic can be removed.

Notes:
1) If an administrator must limit the memory allocations, then he can set
MSGMNI as necessary.

Or he can disable sysv entirely (as e.g. done by Android).

2) MSGMAX and MSGMNB are intentionally not increased, as these values are used
to control latency vs. throughput:
If MSGMNB is large, then msgsnd() just returns and more messages can be queued
before a task switch to a task that calls msgrcv() is forced.

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
---
 include/linux/ipc_namespace.h | 20 ----------
 include/uapi/linux/msg.h      | 28 +++++++++----
 ipc/Makefile                  |  2 +-
 ipc/ipc_sysctl.c              | 86 +---------------------------------------
 ipc/ipcns_notifier.c          | 92 -------------------------------------------
 ipc/msg.c                     | 36 +----------------
 ipc/namespace.c               | 22 -----------
 ipc/util.c                    | 40 -------------------
 8 files changed, 23 insertions(+), 303 deletions(-)
 delete mode 100644 ipc/ipcns_notifier.c

diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h
index 35e7eca..e365d5e 100644
--- a/include/linux/ipc_namespace.h
+++ b/include/linux/ipc_namespace.h
@@ -7,15 +7,6 @@
 #include <linux/notifier.h>
 #include <linux/nsproxy.h>
 
-/*
- * ipc namespace events
- */
-#define IPCNS_MEMCHANGED   0x00000001   /* Notify lowmem size changed */
-#define IPCNS_CREATED  0x00000002   /* Notify new ipc namespace created */
-#define IPCNS_REMOVED  0x00000003   /* Notify ipc namespace removed */
-
-#define IPCNS_CALLBACK_PRI 0
-
 struct user_namespace;
 
 struct ipc_ids {
@@ -38,7 +29,6 @@ struct ipc_namespace {
 	unsigned int	msg_ctlmni;
 	atomic_t	msg_bytes;
 	atomic_t	msg_hdrs;
-	int		auto_msgmni;
 
 	size_t		shm_ctlmax;
 	size_t		shm_ctlall;
@@ -77,18 +67,8 @@ extern atomic_t nr_ipc_ns;
 extern spinlock_t mq_lock;
 
 #ifdef CONFIG_SYSVIPC
-extern int register_ipcns_notifier(struct ipc_namespace *);
-extern int cond_register_ipcns_notifier(struct ipc_namespace *);
-extern void unregister_ipcns_notifier(struct ipc_namespace *);
-extern int ipcns_notify(unsigned long);
 extern void shm_destroy_orphaned(struct ipc_namespace *ns);
 #else /* CONFIG_SYSVIPC */
-static inline int register_ipcns_notifier(struct ipc_namespace *ns)
-{ return 0; }
-static inline int cond_register_ipcns_notifier(struct ipc_namespace *ns)
-{ return 0; }
-static inline void unregister_ipcns_notifier(struct ipc_namespace *ns) { }
-static inline int ipcns_notify(unsigned long l) { return 0; }
 static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
 #endif /* CONFIG_SYSVIPC */
 
diff --git a/include/uapi/linux/msg.h b/include/uapi/linux/msg.h
index a703755..2733ec8 100644
--- a/include/uapi/linux/msg.h
+++ b/include/uapi/linux/msg.h
@@ -51,16 +51,28 @@ struct msginfo {
 };
 
 /*
- * Scaling factor to compute msgmni:
- * the memory dedicated to msg queues (msgmni * msgmnb) should occupy
- * at most 1/MSG_MEM_SCALE of the lowmem (see the formula in ipc/msg.c):
- * up to 8MB       : msgmni = 16 (MSGMNI)
- * 4 GB            : msgmni = 8K
- * more than 16 GB : msgmni = 32K (IPCMNI)
+ * MSGMNI, MSGMAX and MSGMNB are default values which can be
+ * modified by sysctl.
+ *
+ * MSGMNI is the upper limit for the number of messages queues per
+ * namespace.
+ * It has been chosen to be as large possible without facilitating
+ * scenarios where userspace causes overflows when adjusting the limits via
+ * operations of the form retrieve current limit; add X; update limit".
+ *
+ * MSGMNB is the default size of a new message queue. Non-root tasks can
+ * decrease the size with msgctl(IPC_SET), root tasks
+ * (actually: CAP_SYS_RESOURCE) can both increase and decrease the queue
+ * size. The optimal value is application dependant.
+ * 16384 is used because it was always used (since 0.99.10)
+ *
+ * MAXMAX is the maximum size of an individual message, it's a global
+ * (per-namespace) limit that applies for all message queues.
+ * It's set to 1/2 of MSGMNB, to ensure that at least two messages fit into
+ * the queue. This is also an arbitrary choice (since 2.6.0).
  */
-#define MSG_MEM_SCALE 32
 
-#define MSGMNI    16   /* <= IPCMNI */     /* max # of msg queue identifiers */
+#define MSGMNI 32000   /* <= IPCMNI */     /* max # of msg queue identifiers */
 #define MSGMAX  8192   /* <= INT_MAX */   /* max size of message (bytes) */
 #define MSGMNB 16384   /* <= INT_MAX */   /* default max size of a message queue */
 
diff --git a/ipc/Makefile b/ipc/Makefile
index 9075e17..86c7300 100644
--- a/ipc/Makefile
+++ b/ipc/Makefile
@@ -3,7 +3,7 @@
 #
 
 obj-$(CONFIG_SYSVIPC_COMPAT) += compat.o
-obj-$(CONFIG_SYSVIPC) += util.o msgutil.o msg.o sem.o shm.o ipcns_notifier.o syscall.o
+obj-$(CONFIG_SYSVIPC) += util.o msgutil.o msg.o sem.o shm.o syscall.o
 obj-$(CONFIG_SYSVIPC_SYSCTL) += ipc_sysctl.o
 obj_mq-$(CONFIG_COMPAT) += compat_mq.o
 obj-$(CONFIG_POSIX_MQUEUE) += mqueue.o msgutil.o $(obj_mq-y)
diff --git a/ipc/ipc_sysctl.c b/ipc/ipc_sysctl.c
index c3f0326..a00f9df 100644
--- a/ipc/ipc_sysctl.c
+++ b/ipc/ipc_sysctl.c
@@ -62,29 +62,6 @@ static int proc_ipc_dointvec_minmax_orphans(struct ctl_table *table, int write,
 	return err;
 }
 
-static int proc_ipc_callback_dointvec_minmax(struct ctl_table *table, int write,
-	void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	struct ctl_table ipc_table;
-	size_t lenp_bef = *lenp;
-	int rc;
-
-	memcpy(&ipc_table, table, sizeof(ipc_table));
-	ipc_table.data = get_ipc(table);
-
-	rc = proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos);
-
-	if (write && !rc && lenp_bef == *lenp)
-		/*
-		 * Tunable has successfully been changed by hand. Disable its
-		 * automatic adjustment. This simply requires unregistering
-		 * the notifiers that trigger recalculation.
-		 */
-		unregister_ipcns_notifier(current->nsproxy->ipc_ns);
-
-	return rc;
-}
-
 static int proc_ipc_doulongvec_minmax(struct ctl_table *table, int write,
 	void __user *buffer, size_t *lenp, loff_t *ppos)
 {
@@ -96,64 +73,12 @@ static int proc_ipc_doulongvec_minmax(struct ctl_table *table, int write,
 					lenp, ppos);
 }
 
-/*
- * Routine that is called when the file "auto_msgmni" has successfully been
- * written.
- * Two values are allowed:
- * 0: unregister msgmni's callback routine from the ipc namespace notifier
- *    chain. This means that msgmni won't be recomputed anymore upon memory
- *    add/remove or ipc namespace creation/removal.
- * 1: register back the callback routine.
- */
-static void ipc_auto_callback(int val)
-{
-	if (!val)
-		unregister_ipcns_notifier(current->nsproxy->ipc_ns);
-	else {
-		/*
-		 * Re-enable automatic recomputing only if not already
-		 * enabled.
-		 */
-		recompute_msgmni(current->nsproxy->ipc_ns);
-		cond_register_ipcns_notifier(current->nsproxy->ipc_ns);
-	}
-}
-
-static int proc_ipcauto_dointvec_minmax(struct ctl_table *table, int write,
-	void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	struct ctl_table ipc_table;
-	size_t lenp_bef = *lenp;
-	int oldval;
-	int rc;
-
-	memcpy(&ipc_table, table, sizeof(ipc_table));
-	ipc_table.data = get_ipc(table);
-	oldval = *((int *)(ipc_table.data));
-
-	rc = proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos);
-
-	if (write && !rc && lenp_bef == *lenp) {
-		int newval = *((int *)(ipc_table.data));
-		/*
-		 * The file "auto_msgmni" has correctly been set.
-		 * React by (un)registering the corresponding tunable, if the
-		 * value has changed.
-		 */
-		if (newval != oldval)
-			ipc_auto_callback(newval);
-	}
-
-	return rc;
-}
 
 #else
 #define proc_ipc_doulongvec_minmax NULL
 #define proc_ipc_dointvec	   NULL
 #define proc_ipc_dointvec_minmax   NULL
 #define proc_ipc_dointvec_minmax_orphans   NULL
-#define proc_ipc_callback_dointvec_minmax  NULL
-#define proc_ipcauto_dointvec_minmax NULL
 #endif
 
 static int zero;
@@ -205,7 +130,7 @@ static struct ctl_table ipc_kern_table[] = {
 		.data		= &init_ipc_ns.msg_ctlmni,
 		.maxlen		= sizeof(init_ipc_ns.msg_ctlmni),
 		.mode		= 0644,
-		.proc_handler	= proc_ipc_callback_dointvec_minmax,
+		.proc_handler	= proc_ipc_dointvec_minmax,
 		.extra1		= &zero,
 		.extra2		= &int_max,
 	},
@@ -225,15 +150,6 @@ static struct ctl_table ipc_kern_table[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_ipc_dointvec,
 	},
-	{
-		.procname	= "auto_msgmni",
-		.data		= &init_ipc_ns.auto_msgmni,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= proc_ipcauto_dointvec_minmax,
-		.extra1		= &zero,
-		.extra2		= &one,
-	},
 #ifdef CONFIG_CHECKPOINT_RESTORE
 	{
 		.procname	= "sem_next_id",
diff --git a/ipc/ipcns_notifier.c b/ipc/ipcns_notifier.c
deleted file mode 100644
index b9b31a4..0000000
--- a/ipc/ipcns_notifier.c
+++ /dev/null
@@ -1,92 +0,0 @@
-/*
- * linux/ipc/ipcns_notifier.c
- * Copyright (C) 2007 BULL SA. Nadia Derbey
- *
- * Notification mechanism for ipc namespaces:
- * The callback routine registered in the memory chain invokes the ipcns
- * notifier chain with the IPCNS_MEMCHANGED event.
- * Each callback routine registered in the ipcns namespace recomputes msgmni
- * for the owning namespace.
- */
-
-#include <linux/msg.h>
-#include <linux/rcupdate.h>
-#include <linux/notifier.h>
-#include <linux/nsproxy.h>
-#include <linux/ipc_namespace.h>
-
-#include "util.h"
-
-
-
-static BLOCKING_NOTIFIER_HEAD(ipcns_chain);
-
-
-static int ipcns_callback(struct notifier_block *self,
-				unsigned long action, void *arg)
-{
-	struct ipc_namespace *ns;
-
-	switch (action) {
-	case IPCNS_MEMCHANGED:   /* amount of lowmem has changed */
-	case IPCNS_CREATED:
-	case IPCNS_REMOVED:
-		/*
-		 * It's time to recompute msgmni
-		 */
-		ns = container_of(self, struct ipc_namespace, ipcns_nb);
-		/*
-		 * No need to get a reference on the ns: the 1st job of
-		 * free_ipc_ns() is to unregister the callback routine.
-		 * blocking_notifier_chain_unregister takes the wr lock to do
-		 * it.
-		 * When this callback routine is called the rd lock is held by
-		 * blocking_notifier_call_chain.
-		 * So the ipc ns cannot be freed while we are here.
-		 */
-		recompute_msgmni(ns);
-		break;
-	default:
-		break;
-	}
-
-	return NOTIFY_OK;
-}
-
-int register_ipcns_notifier(struct ipc_namespace *ns)
-{
-	int rc;
-
-	memset(&ns->ipcns_nb, 0, sizeof(ns->ipcns_nb));
-	ns->ipcns_nb.notifier_call = ipcns_callback;
-	ns->ipcns_nb.priority = IPCNS_CALLBACK_PRI;
-	rc = blocking_notifier_chain_register(&ipcns_chain, &ns->ipcns_nb);
-	if (!rc)
-		ns->auto_msgmni = 1;
-	return rc;
-}
-
-int cond_register_ipcns_notifier(struct ipc_namespace *ns)
-{
-	int rc;
-
-	memset(&ns->ipcns_nb, 0, sizeof(ns->ipcns_nb));
-	ns->ipcns_nb.notifier_call = ipcns_callback;
-	ns->ipcns_nb.priority = IPCNS_CALLBACK_PRI;
-	rc = blocking_notifier_chain_cond_register(&ipcns_chain,
-							&ns->ipcns_nb);
-	if (!rc)
-		ns->auto_msgmni = 1;
-	return rc;
-}
-
-void unregister_ipcns_notifier(struct ipc_namespace *ns)
-{
-	blocking_notifier_chain_unregister(&ipcns_chain, &ns->ipcns_nb);
-	ns->auto_msgmni = 0;
-}
-
-int ipcns_notify(unsigned long val)
-{
-	return blocking_notifier_call_chain(&ipcns_chain, val, NULL);
-}
diff --git a/ipc/msg.c b/ipc/msg.c
index c5d8e37..a7261d5 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -989,43 +989,12 @@ SYSCALL_DEFINE5(msgrcv, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
 	return do_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg, do_msg_fill);
 }
 
-/*
- * Scale msgmni with the available lowmem size: the memory dedicated to msg
- * queues should occupy at most 1/MSG_MEM_SCALE of lowmem.
- * Also take into account the number of nsproxies created so far.
- * This should be done staying within the (MSGMNI , IPCMNI/nr_ipc_ns) range.
- */
-void recompute_msgmni(struct ipc_namespace *ns)
-{
-	struct sysinfo i;
-	unsigned long allowed;
-	int nb_ns;
-
-	si_meminfo(&i);
-	allowed = (((i.totalram - i.totalhigh) / MSG_MEM_SCALE) * i.mem_unit)
-		/ MSGMNB;
-	nb_ns = atomic_read(&nr_ipc_ns);
-	allowed /= nb_ns;
-
-	if (allowed < MSGMNI) {
-		ns->msg_ctlmni = MSGMNI;
-		return;
-	}
-
-	if (allowed > IPCMNI / nb_ns) {
-		ns->msg_ctlmni = IPCMNI / nb_ns;
-		return;
-	}
-
-	ns->msg_ctlmni = allowed;
-}
 
 void msg_init_ns(struct ipc_namespace *ns)
 {
 	ns->msg_ctlmax = MSGMAX;
 	ns->msg_ctlmnb = MSGMNB;
-
-	recompute_msgmni(ns);
+	ns->msg_ctlmni = MSGMNI;
 
 	atomic_set(&ns->msg_bytes, 0);
 	atomic_set(&ns->msg_hdrs, 0);
@@ -1069,9 +1038,6 @@ void __init msg_init(void)
 {
 	msg_init_ns(&init_ipc_ns);
 
-	printk(KERN_INFO "msgmni has been set to %d\n",
-		init_ipc_ns.msg_ctlmni);
-
 	ipc_init_proc_interface("sysvipc/msg",
 				"       key      msqid perms      cbytes       qnum lspid lrpid   uid   gid  cuid  cgid      stime      rtime      ctime\n",
 				IPC_MSG_IDS, sysvipc_msg_proc_show);
diff --git a/ipc/namespace.c b/ipc/namespace.c
index b54468e..1a3ffd4 100644
--- a/ipc/namespace.c
+++ b/ipc/namespace.c
@@ -45,14 +45,6 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
 	msg_init_ns(ns);
 	shm_init_ns(ns);
 
-	/*
-	 * msgmni has already been computed for the new ipc ns.
-	 * Thus, do the ipcns creation notification before registering that
-	 * new ipcns in the chain.
-	 */
-	ipcns_notify(IPCNS_CREATED);
-	register_ipcns_notifier(ns);
-
 	ns->user_ns = get_user_ns(user_ns);
 
 	return ns;
@@ -99,25 +91,11 @@ void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids,
 
 static void free_ipc_ns(struct ipc_namespace *ns)
 {
-	/*
-	 * Unregistering the hotplug notifier at the beginning guarantees
-	 * that the ipc namespace won't be freed while we are inside the
-	 * callback routine. Since the blocking_notifier_chain_XXX routines
-	 * hold a rw lock on the notifier list, unregister_ipcns_notifier()
-	 * won't take the rw lock before blocking_notifier_call_chain() has
-	 * released the rd lock.
-	 */
-	unregister_ipcns_notifier(ns);
 	sem_exit_ns(ns);
 	msg_exit_ns(ns);
 	shm_exit_ns(ns);
 	atomic_dec(&nr_ipc_ns);
 
-	/*
-	 * Do the ipcns removal notification after decrementing nr_ipc_ns in
-	 * order to have a correct value when recomputing msgmni.
-	 */
-	ipcns_notify(IPCNS_REMOVED);
 	put_user_ns(ns->user_ns);
 	proc_free_inum(ns->proc_inum);
 	kfree(ns);
diff --git a/ipc/util.c b/ipc/util.c
index 27d74e6..0001560 100644
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -71,44 +71,6 @@ struct ipc_proc_iface {
 	int (*show)(struct seq_file *, void *);
 };
 
-static void ipc_memory_notifier(struct work_struct *work)
-{
-	ipcns_notify(IPCNS_MEMCHANGED);
-}
-
-static int ipc_memory_callback(struct notifier_block *self,
-				unsigned long action, void *arg)
-{
-	static DECLARE_WORK(ipc_memory_wq, ipc_memory_notifier);
-
-	switch (action) {
-	case MEM_ONLINE:    /* memory successfully brought online */
-	case MEM_OFFLINE:   /* or offline: it's time to recompute msgmni */
-		/*
-		 * This is done by invoking the ipcns notifier chain with the
-		 * IPC_MEMCHANGED event.
-		 * In order not to keep the lock on the hotplug memory chain
-		 * for too long, queue a work item that will, when waken up,
-		 * activate the ipcns notification chain.
-		 */
-		schedule_work(&ipc_memory_wq);
-		break;
-	case MEM_GOING_ONLINE:
-	case MEM_GOING_OFFLINE:
-	case MEM_CANCEL_ONLINE:
-	case MEM_CANCEL_OFFLINE:
-	default:
-		break;
-	}
-
-	return NOTIFY_OK;
-}
-
-static struct notifier_block ipc_memory_nb = {
-	.notifier_call = ipc_memory_callback,
-	.priority = IPC_CALLBACK_PRI,
-};
-
 /**
  * ipc_init - initialise ipc subsystem
  *
@@ -124,8 +86,6 @@ static int __init ipc_init(void)
 	sem_init();
 	msg_init();
 	shm_init();
-	register_hotmemory_notifier(&ipc_memory_nb);
-	register_ipcns_notifier(&init_ipc_ns);
 	return 0;
 }
 device_initcall(ipc_init);
-- 
1.9.3


^ permalink raw reply related	[flat|nested] 14+ messages in thread

* [PATCH 2/3] ipc/sem.c: increase SEMMSL, SEMMNI, SEMOPM
  2014-08-12  7:29 ` [PATCH 1/3] ipc/msg: increase MSGMNI, remove scaling Manfred Spraul
@ 2014-08-12  7:29   ` Manfred Spraul
       [not found]     ` <1407828557-31995-3-git-send-email-manfred-nhLOkwUX5cPe2c5cEj3t2g@public.gmane.org>
  2014-08-15 13:42     ` [PATCH 2/3] ipc/sem.c: increase SEMMSL, SEMMNI, SEMOPM Rafael Aquini
  2014-08-15 13:41   ` [PATCH 1/3] ipc/msg: increase MSGMNI, remove scaling Rafael Aquini
  1 sibling, 2 replies; 14+ messages in thread
From: Manfred Spraul @ 2014-08-12  7:29 UTC (permalink / raw)
  To: Andrew Morton
  Cc: LKML, Davidlohr Bueso, Michael Kerrisk, Rafael Aquini,
	Rik van Riel, 1vier1, Manfred Spraul

a)
SysV can be abused to allocate locked kernel memory.  For most systems, a
small limit doesn't make sense, see the discussion with regards to SHMMAX.

Therefore: Increase the sysv sem limits so that all known applications
will work with these defaults.

b)
With regards to the maximum supported:
Some of the specified hard limits are not correct anymore, therefore the
patch updates the documentation.

- SEMMNI must stay below IPCMNI, which is 32768.
  As for SHMMAX: Stay a bit below this limit.

- SEMMSL was limited to 8k, to ensure that the kmalloc for the kernel array
  was limited to 16 kB (order=2)

  This doesn't apply anymore:
   - the allocation size isn't sizeof(short)*nsems anymore.
   - ipc_alloc falls back to vmalloc

- SEMOPM should stay below 1000, to limit the kmalloc in semtimedop() to an
  order=1 allocation.
  Therefore: Leave it at 500 (order=0 allocation).

Note:
If an administrator must limit the memory allocations, then he can set the
values as necessary.

Or he can disable sysv entirely (as e.g. done by Android).

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
---
 include/uapi/linux/sem.h | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/include/uapi/linux/sem.h b/include/uapi/linux/sem.h
index 541fce0..dd73b90 100644
--- a/include/uapi/linux/sem.h
+++ b/include/uapi/linux/sem.h
@@ -63,10 +63,22 @@ struct  seminfo {
 	int semaem;
 };
 
-#define SEMMNI  128             /* <= IPCMNI  max # of semaphore identifiers */
-#define SEMMSL  250             /* <= 8 000 max num of semaphores per id */
+/*
+ * SEMMNI, SEMMSL and SEMMNS are default values which can be
+ * modified by sysctl.
+ * The values has been chosen to be larger than necessary for any
+ * known configuration.
+ *
+ * SEMOPM should not be increased beyond 1000, otherwise there is the
+ * risk that semop()/semtimedop() fails due to kernel memory fragmentation when
+ * allocating the sop array.
+ */
+
+
+#define SEMMNI  32000           /* <= IPCMNI  max # of semaphore identifiers */
+#define SEMMSL  32000           /* <= INT_MAX max num of semaphores per id */
 #define SEMMNS  (SEMMNI*SEMMSL) /* <= INT_MAX max # of semaphores in system */
-#define SEMOPM  32	        /* <= 1 000 max num of ops per semop call */
+#define SEMOPM  500	        /* <= 1 000 max num of ops per semop call */
 #define SEMVMX  32767           /* <= 32767 semaphore maximum value */
 #define SEMAEM  SEMVMX          /* adjust on exit max value */
 
-- 
1.9.3


^ permalink raw reply related	[flat|nested] 14+ messages in thread

[parent not found: <1407828557-31995-3-git-send-email-manfred-nhLOkwUX5cPe2c5cEj3t2g@public.gmane.org>]

* [PATCH 3/3] ipc namespace: copy settings from parent namespace
  2014-08-12  7:29   ` [PATCH 2/3] ipc/sem.c: increase SEMMSL, SEMMNI, SEMOPM Manfred Spraul
@ 2014-08-12  7:29         ` Manfred Spraul
  2014-08-15 13:42     ` [PATCH 2/3] ipc/sem.c: increase SEMMSL, SEMMNI, SEMOPM Rafael Aquini
  1 sibling, 0 replies; 14+ messages in thread
From: Manfred Spraul @ 2014-08-12  7:29 UTC (permalink / raw)
  To: Andrew Morton
  Cc: Rik van Riel, ebiederm-aS9lmoZGLiVWk0Htik3J/w, Manfred Spraul,
	Rafael Aquini, Davidlohr Bueso, LKML, Michael Kerrisk,
	1vier1-S0/GAf8tV78,
	containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA

Right now, each new IPC namespace starts with the kernel default values.
This means that changes that were made to the limits get overwritten.

With this patch, a new namespace inherits the settings from the parent
namespace, which is less surprising.

The patch updates
- SysV msg
- SysV sem
- SysV shm
- POSIX mqueues

Cc: serge-A9i7LUbDfNHQT0dZR+AlfA@public.gmane.org
Cc: ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org
Cc: containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org
Cc: mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org

Signed-off-by: Manfred Spraul <manfred-nhLOkwUX5cPe2c5cEj3t2g@public.gmane.org>
---
 include/linux/ipc_namespace.h |  6 ++++--
 ipc/mqueue.c                  | 23 ++++++++++++++++-------
 ipc/msg.c                     | 16 +++++++++++-----
 ipc/namespace.c               |  8 ++++----
 ipc/sem.c                     | 19 +++++++++++++------
 ipc/shm.c                     | 19 +++++++++++++------
 ipc/util.h                    | 20 ++++++++++++++------
 7 files changed, 75 insertions(+), 36 deletions(-)

diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h
index e365d5e..1cc36a0 100644
--- a/include/linux/ipc_namespace.h
+++ b/include/linux/ipc_namespace.h
@@ -73,7 +73,7 @@ static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
 #endif /* CONFIG_SYSVIPC */
 
 #ifdef CONFIG_POSIX_MQUEUE
-extern int mq_init_ns(struct ipc_namespace *ns);
+extern int mq_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns);
 /*
  * POSIX Message Queue default values:
  *
@@ -108,7 +108,9 @@ extern int mq_init_ns(struct ipc_namespace *ns);
 #define DFLT_MSGSIZEMAX		     8192
 #define HARD_MSGSIZEMAX	    (16*1024*1024)
 #else
-static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
+static inline int mq_init_ns(struct ipc_namespace *ns,
+				struct ipc_namespace *old_ns)
+{ return 0; }
 #endif
 
 #if defined(CONFIG_IPC_NS)
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 4fcf39a..3473072d 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -1397,14 +1397,23 @@ static struct file_system_type mqueue_fs_type = {
 	.fs_flags = FS_USERNS_MOUNT,
 };
 
-int mq_init_ns(struct ipc_namespace *ns)
+int mq_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns)
 {
+	if (old_ns != NULL) {
+		ns->mq_queues_max    = old_ns->mq_queues_max;
+		ns->mq_msg_max       = old_ns->mq_msg_max;
+		ns->mq_msgsize_max   = old_ns->mq_msgsize_max;
+		ns->mq_msg_default   = old_ns->mq_msg_default;
+		ns->mq_msgsize_default  = old_ns->mq_msgsize_default;
+	} else {
+		ns->mq_queues_max    = DFLT_QUEUESMAX;
+		ns->mq_msg_max       = DFLT_MSGMAX;
+		ns->mq_msgsize_max   = DFLT_MSGSIZEMAX;
+		ns->mq_msg_default   = DFLT_MSG;
+		ns->mq_msgsize_default  = DFLT_MSGSIZE;
+	}
+
 	ns->mq_queues_count  = 0;
-	ns->mq_queues_max    = DFLT_QUEUESMAX;
-	ns->mq_msg_max       = DFLT_MSGMAX;
-	ns->mq_msgsize_max   = DFLT_MSGSIZEMAX;
-	ns->mq_msg_default   = DFLT_MSG;
-	ns->mq_msgsize_default  = DFLT_MSGSIZE;
 
 	ns->mq_mnt = kern_mount_data(&mqueue_fs_type, ns);
 	if (IS_ERR(ns->mq_mnt)) {
@@ -1444,7 +1453,7 @@ static int __init init_mqueue_fs(void)
 
 	spin_lock_init(&mq_lock);
 
-	error = mq_init_ns(&init_ipc_ns);
+	error = mq_init_ns(&init_ipc_ns, NULL);
 	if (error)
 		goto out_filesystem;
 
diff --git a/ipc/msg.c b/ipc/msg.c
index a7261d5..3cbd2ad 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -990,11 +990,17 @@ SYSCALL_DEFINE5(msgrcv, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
 }
 
 
-void msg_init_ns(struct ipc_namespace *ns)
+void msg_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns)
 {
-	ns->msg_ctlmax = MSGMAX;
-	ns->msg_ctlmnb = MSGMNB;
-	ns->msg_ctlmni = MSGMNI;
+	if (old_ns != NULL) {
+		ns->msg_ctlmax = old_ns->msg_ctlmax;
+		ns->msg_ctlmnb = old_ns->msg_ctlmnb;
+		ns->msg_ctlmni = old_ns->msg_ctlmni;
+	} else {
+		ns->msg_ctlmax = MSGMAX;
+		ns->msg_ctlmnb = MSGMNB;
+		ns->msg_ctlmni = MSGMNI;
+	}
 
 	atomic_set(&ns->msg_bytes, 0);
 	atomic_set(&ns->msg_hdrs, 0);
@@ -1036,7 +1042,7 @@ static int sysvipc_msg_proc_show(struct seq_file *s, void *it)
 
 void __init msg_init(void)
 {
-	msg_init_ns(&init_ipc_ns);
+	msg_init_ns(&init_ipc_ns, NULL);
 
 	ipc_init_proc_interface("sysvipc/msg",
 				"       key      msqid perms      cbytes       qnum lspid lrpid   uid   gid  cuid  cgid      stime      rtime      ctime\n",
diff --git a/ipc/namespace.c b/ipc/namespace.c
index 1a3ffd4..97e3332 100644
--- a/ipc/namespace.c
+++ b/ipc/namespace.c
@@ -33,7 +33,7 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
 	}
 
 	atomic_set(&ns->count, 1);
-	err = mq_init_ns(ns);
+	err = mq_init_ns(ns, old_ns);
 	if (err) {
 		proc_free_inum(ns->proc_inum);
 		kfree(ns);
@@ -41,9 +41,9 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
 	}
 	atomic_inc(&nr_ipc_ns);
 
-	sem_init_ns(ns);
-	msg_init_ns(ns);
-	shm_init_ns(ns);
+	sem_init_ns(ns, old_ns);
+	msg_init_ns(ns, old_ns);
+	shm_init_ns(ns, old_ns);
 
 	ns->user_ns = get_user_ns(user_ns);
 
diff --git a/ipc/sem.c b/ipc/sem.c
index 454f6c6..f1ded77 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -170,12 +170,19 @@ static int sysvipc_sem_proc_show(struct seq_file *s, void *it);
 #define sc_semopm	sem_ctls[2]
 #define sc_semmni	sem_ctls[3]
 
-void sem_init_ns(struct ipc_namespace *ns)
+void sem_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns)
 {
-	ns->sc_semmsl = SEMMSL;
-	ns->sc_semmns = SEMMNS;
-	ns->sc_semopm = SEMOPM;
-	ns->sc_semmni = SEMMNI;
+	if (old_ns != NULL) {
+		ns->sc_semmsl = old_ns->sc_semmsl;
+		ns->sc_semmns = old_ns->sc_semmns;
+		ns->sc_semopm = old_ns->sc_semopm;
+		ns->sc_semmni = old_ns->sc_semmni;
+	} else {
+		ns->sc_semmsl = SEMMSL;
+		ns->sc_semmns = SEMMNS;
+		ns->sc_semopm = SEMOPM;
+		ns->sc_semmni = SEMMNI;
+	}
 	ns->used_sems = 0;
 	ipc_init_ids(&ns->ids[IPC_SEM_IDS]);
 }
@@ -190,7 +197,7 @@ void sem_exit_ns(struct ipc_namespace *ns)
 
 void __init sem_init(void)
 {
-	sem_init_ns(&init_ipc_ns);
+	sem_init_ns(&init_ipc_ns, NULL);
 	ipc_init_proc_interface("sysvipc/sem",
 				"       key      semid perms      nsems   uid   gid  cuid  cgid      otime      ctime\n",
 				IPC_SEM_IDS, sysvipc_sem_proc_show);
diff --git a/ipc/shm.c b/ipc/shm.c
index 7fc9f9f..7856952 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -72,12 +72,19 @@ static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp);
 static int sysvipc_shm_proc_show(struct seq_file *s, void *it);
 #endif
 
-void shm_init_ns(struct ipc_namespace *ns)
+void shm_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns)
 {
-	ns->shm_ctlmax = SHMMAX;
-	ns->shm_ctlall = SHMALL;
-	ns->shm_ctlmni = SHMMNI;
-	ns->shm_rmid_forced = 0;
+	if (old_ns != NULL) {
+		ns->shm_ctlmax = old_ns->shm_ctlmax;
+		ns->shm_ctlall = old_ns->shm_ctlall;
+		ns->shm_ctlmni = old_ns->shm_ctlmni;
+		ns->shm_rmid_forced = old_ns->shm_rmid_forced;
+	} else {
+		ns->shm_ctlmax = SHMMAX;
+		ns->shm_ctlall = SHMALL;
+		ns->shm_ctlmni = SHMMNI;
+		ns->shm_rmid_forced = 0;
+	}
 	ns->shm_tot = 0;
 	ipc_init_ids(&shm_ids(ns));
 }
@@ -110,7 +117,7 @@ void shm_exit_ns(struct ipc_namespace *ns)
 
 static int __init ipc_ns_init(void)
 {
-	shm_init_ns(&init_ipc_ns);
+	shm_init_ns(&init_ipc_ns, NULL);
 	return 0;
 }
 
diff --git a/ipc/util.h b/ipc/util.h
index 1a5a0fc..1be9830 100644
--- a/ipc/util.h
+++ b/ipc/util.h
@@ -30,17 +30,25 @@ static inline void mq_put_mnt(struct ipc_namespace *ns) { }
 #endif
 
 #ifdef CONFIG_SYSVIPC
-void sem_init_ns(struct ipc_namespace *ns);
-void msg_init_ns(struct ipc_namespace *ns);
-void shm_init_ns(struct ipc_namespace *ns);
+void sem_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns);
+void msg_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns);
+void shm_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns);
 
 void sem_exit_ns(struct ipc_namespace *ns);
 void msg_exit_ns(struct ipc_namespace *ns);
 void shm_exit_ns(struct ipc_namespace *ns);
 #else
-static inline void sem_init_ns(struct ipc_namespace *ns) { }
-static inline void msg_init_ns(struct ipc_namespace *ns) { }
-static inline void shm_init_ns(struct ipc_namespace *ns) { }
+static inline void sem_init_ns(struct ipc_namespace *ns,
+				struct ipc_namespace *old_ns)
+{ }
+
+static inline void msg_init_ns(struct ipc_namespace *ns,
+				struct ipc_namespace *old_ns)
+{ }
+
+static inline void shm_init_ns(struct ipc_namespace *ns,
+				struct ipc_namespace *old_ns)
+{ }
 
 static inline void sem_exit_ns(struct ipc_namespace *ns) { }
 static inline void msg_exit_ns(struct ipc_namespace *ns) { }
-- 
1.9.3

^ permalink raw reply related	[flat|nested] 14+ messages in thread

* [PATCH 3/3] ipc namespace: copy settings from parent namespace
@ 2014-08-12  7:29         ` Manfred Spraul
  0 siblings, 0 replies; 14+ messages in thread
From: Manfred Spraul @ 2014-08-12  7:29 UTC (permalink / raw)
  To: Andrew Morton
  Cc: LKML, Davidlohr Bueso, Michael Kerrisk, Rafael Aquini,
	Rik van Riel, 1vier1, Manfred Spraul, serge, ebiederm, containers

Right now, each new IPC namespace starts with the kernel default values.
This means that changes that were made to the limits get overwritten.

With this patch, a new namespace inherits the settings from the parent
namespace, which is less surprising.

The patch updates
- SysV msg
- SysV sem
- SysV shm
- POSIX mqueues

Cc: serge@hallyn.com
Cc: ebiederm@xmission.com
Cc: containers@lists.linux-foundation.org
Cc: mtk.manpages@gmail.com

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
---
 include/linux/ipc_namespace.h |  6 ++++--
 ipc/mqueue.c                  | 23 ++++++++++++++++-------
 ipc/msg.c                     | 16 +++++++++++-----
 ipc/namespace.c               |  8 ++++----
 ipc/sem.c                     | 19 +++++++++++++------
 ipc/shm.c                     | 19 +++++++++++++------
 ipc/util.h                    | 20 ++++++++++++++------
 7 files changed, 75 insertions(+), 36 deletions(-)

diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h
index e365d5e..1cc36a0 100644
--- a/include/linux/ipc_namespace.h
+++ b/include/linux/ipc_namespace.h
@@ -73,7 +73,7 @@ static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
 #endif /* CONFIG_SYSVIPC */
 
 #ifdef CONFIG_POSIX_MQUEUE
-extern int mq_init_ns(struct ipc_namespace *ns);
+extern int mq_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns);
 /*
  * POSIX Message Queue default values:
  *
@@ -108,7 +108,9 @@ extern int mq_init_ns(struct ipc_namespace *ns);
 #define DFLT_MSGSIZEMAX		     8192
 #define HARD_MSGSIZEMAX	    (16*1024*1024)
 #else
-static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
+static inline int mq_init_ns(struct ipc_namespace *ns,
+				struct ipc_namespace *old_ns)
+{ return 0; }
 #endif
 
 #if defined(CONFIG_IPC_NS)
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 4fcf39a..3473072d 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -1397,14 +1397,23 @@ static struct file_system_type mqueue_fs_type = {
 	.fs_flags = FS_USERNS_MOUNT,
 };
 
-int mq_init_ns(struct ipc_namespace *ns)
+int mq_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns)
 {
+	if (old_ns != NULL) {
+		ns->mq_queues_max    = old_ns->mq_queues_max;
+		ns->mq_msg_max       = old_ns->mq_msg_max;
+		ns->mq_msgsize_max   = old_ns->mq_msgsize_max;
+		ns->mq_msg_default   = old_ns->mq_msg_default;
+		ns->mq_msgsize_default  = old_ns->mq_msgsize_default;
+	} else {
+		ns->mq_queues_max    = DFLT_QUEUESMAX;
+		ns->mq_msg_max       = DFLT_MSGMAX;
+		ns->mq_msgsize_max   = DFLT_MSGSIZEMAX;
+		ns->mq_msg_default   = DFLT_MSG;
+		ns->mq_msgsize_default  = DFLT_MSGSIZE;
+	}
+
 	ns->mq_queues_count  = 0;
-	ns->mq_queues_max    = DFLT_QUEUESMAX;
-	ns->mq_msg_max       = DFLT_MSGMAX;
-	ns->mq_msgsize_max   = DFLT_MSGSIZEMAX;
-	ns->mq_msg_default   = DFLT_MSG;
-	ns->mq_msgsize_default  = DFLT_MSGSIZE;
 
 	ns->mq_mnt = kern_mount_data(&mqueue_fs_type, ns);
 	if (IS_ERR(ns->mq_mnt)) {
@@ -1444,7 +1453,7 @@ static int __init init_mqueue_fs(void)
 
 	spin_lock_init(&mq_lock);
 
-	error = mq_init_ns(&init_ipc_ns);
+	error = mq_init_ns(&init_ipc_ns, NULL);
 	if (error)
 		goto out_filesystem;
 
diff --git a/ipc/msg.c b/ipc/msg.c
index a7261d5..3cbd2ad 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -990,11 +990,17 @@ SYSCALL_DEFINE5(msgrcv, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
 }
 
 
-void msg_init_ns(struct ipc_namespace *ns)
+void msg_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns)
 {
-	ns->msg_ctlmax = MSGMAX;
-	ns->msg_ctlmnb = MSGMNB;
-	ns->msg_ctlmni = MSGMNI;
+	if (old_ns != NULL) {
+		ns->msg_ctlmax = old_ns->msg_ctlmax;
+		ns->msg_ctlmnb = old_ns->msg_ctlmnb;
+		ns->msg_ctlmni = old_ns->msg_ctlmni;
+	} else {
+		ns->msg_ctlmax = MSGMAX;
+		ns->msg_ctlmnb = MSGMNB;
+		ns->msg_ctlmni = MSGMNI;
+	}
 
 	atomic_set(&ns->msg_bytes, 0);
 	atomic_set(&ns->msg_hdrs, 0);
@@ -1036,7 +1042,7 @@ static int sysvipc_msg_proc_show(struct seq_file *s, void *it)
 
 void __init msg_init(void)
 {
-	msg_init_ns(&init_ipc_ns);
+	msg_init_ns(&init_ipc_ns, NULL);
 
 	ipc_init_proc_interface("sysvipc/msg",
 				"       key      msqid perms      cbytes       qnum lspid lrpid   uid   gid  cuid  cgid      stime      rtime      ctime\n",
diff --git a/ipc/namespace.c b/ipc/namespace.c
index 1a3ffd4..97e3332 100644
--- a/ipc/namespace.c
+++ b/ipc/namespace.c
@@ -33,7 +33,7 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
 	}
 
 	atomic_set(&ns->count, 1);
-	err = mq_init_ns(ns);
+	err = mq_init_ns(ns, old_ns);
 	if (err) {
 		proc_free_inum(ns->proc_inum);
 		kfree(ns);
@@ -41,9 +41,9 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
 	}
 	atomic_inc(&nr_ipc_ns);
 
-	sem_init_ns(ns);
-	msg_init_ns(ns);
-	shm_init_ns(ns);
+	sem_init_ns(ns, old_ns);
+	msg_init_ns(ns, old_ns);
+	shm_init_ns(ns, old_ns);
 
 	ns->user_ns = get_user_ns(user_ns);
 
diff --git a/ipc/sem.c b/ipc/sem.c
index 454f6c6..f1ded77 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -170,12 +170,19 @@ static int sysvipc_sem_proc_show(struct seq_file *s, void *it);
 #define sc_semopm	sem_ctls[2]
 #define sc_semmni	sem_ctls[3]
 
-void sem_init_ns(struct ipc_namespace *ns)
+void sem_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns)
 {
-	ns->sc_semmsl = SEMMSL;
-	ns->sc_semmns = SEMMNS;
-	ns->sc_semopm = SEMOPM;
-	ns->sc_semmni = SEMMNI;
+	if (old_ns != NULL) {
+		ns->sc_semmsl = old_ns->sc_semmsl;
+		ns->sc_semmns = old_ns->sc_semmns;
+		ns->sc_semopm = old_ns->sc_semopm;
+		ns->sc_semmni = old_ns->sc_semmni;
+	} else {
+		ns->sc_semmsl = SEMMSL;
+		ns->sc_semmns = SEMMNS;
+		ns->sc_semopm = SEMOPM;
+		ns->sc_semmni = SEMMNI;
+	}
 	ns->used_sems = 0;
 	ipc_init_ids(&ns->ids[IPC_SEM_IDS]);
 }
@@ -190,7 +197,7 @@ void sem_exit_ns(struct ipc_namespace *ns)
 
 void __init sem_init(void)
 {
-	sem_init_ns(&init_ipc_ns);
+	sem_init_ns(&init_ipc_ns, NULL);
 	ipc_init_proc_interface("sysvipc/sem",
 				"       key      semid perms      nsems   uid   gid  cuid  cgid      otime      ctime\n",
 				IPC_SEM_IDS, sysvipc_sem_proc_show);
diff --git a/ipc/shm.c b/ipc/shm.c
index 7fc9f9f..7856952 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -72,12 +72,19 @@ static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp);
 static int sysvipc_shm_proc_show(struct seq_file *s, void *it);
 #endif
 
-void shm_init_ns(struct ipc_namespace *ns)
+void shm_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns)
 {
-	ns->shm_ctlmax = SHMMAX;
-	ns->shm_ctlall = SHMALL;
-	ns->shm_ctlmni = SHMMNI;
-	ns->shm_rmid_forced = 0;
+	if (old_ns != NULL) {
+		ns->shm_ctlmax = old_ns->shm_ctlmax;
+		ns->shm_ctlall = old_ns->shm_ctlall;
+		ns->shm_ctlmni = old_ns->shm_ctlmni;
+		ns->shm_rmid_forced = old_ns->shm_rmid_forced;
+	} else {
+		ns->shm_ctlmax = SHMMAX;
+		ns->shm_ctlall = SHMALL;
+		ns->shm_ctlmni = SHMMNI;
+		ns->shm_rmid_forced = 0;
+	}
 	ns->shm_tot = 0;
 	ipc_init_ids(&shm_ids(ns));
 }
@@ -110,7 +117,7 @@ void shm_exit_ns(struct ipc_namespace *ns)
 
 static int __init ipc_ns_init(void)
 {
-	shm_init_ns(&init_ipc_ns);
+	shm_init_ns(&init_ipc_ns, NULL);
 	return 0;
 }
 
diff --git a/ipc/util.h b/ipc/util.h
index 1a5a0fc..1be9830 100644
--- a/ipc/util.h
+++ b/ipc/util.h
@@ -30,17 +30,25 @@ static inline void mq_put_mnt(struct ipc_namespace *ns) { }
 #endif
 
 #ifdef CONFIG_SYSVIPC
-void sem_init_ns(struct ipc_namespace *ns);
-void msg_init_ns(struct ipc_namespace *ns);
-void shm_init_ns(struct ipc_namespace *ns);
+void sem_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns);
+void msg_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns);
+void shm_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns);
 
 void sem_exit_ns(struct ipc_namespace *ns);
 void msg_exit_ns(struct ipc_namespace *ns);
 void shm_exit_ns(struct ipc_namespace *ns);
 #else
-static inline void sem_init_ns(struct ipc_namespace *ns) { }
-static inline void msg_init_ns(struct ipc_namespace *ns) { }
-static inline void shm_init_ns(struct ipc_namespace *ns) { }
+static inline void sem_init_ns(struct ipc_namespace *ns,
+				struct ipc_namespace *old_ns)
+{ }
+
+static inline void msg_init_ns(struct ipc_namespace *ns,
+				struct ipc_namespace *old_ns)
+{ }
+
+static inline void shm_init_ns(struct ipc_namespace *ns,
+				struct ipc_namespace *old_ns)
+{ }
 
 static inline void sem_exit_ns(struct ipc_namespace *ns) { }
 static inline void msg_exit_ns(struct ipc_namespace *ns) { }
-- 
1.9.3


^ permalink raw reply related	[flat|nested] 14+ messages in thread

[parent not found: <1407828557-31995-4-git-send-email-manfred-nhLOkwUX5cPe2c5cEj3t2g@public.gmane.org>]

* Re: [PATCH 3/3] ipc namespace: copy settings from parent namespace
  2014-08-12  7:29         ` Manfred Spraul
@ 2014-08-12 10:37             ` Eric W. Biederman
  -1 siblings, 0 replies; 14+ messages in thread
From: Eric W. Biederman @ 2014-08-12 10:37 UTC (permalink / raw)
  To: Manfred Spraul
  Cc: Rik van Riel, Rafael Aquini, Davidlohr Bueso, LKML,
	Michael Kerrisk, 1vier1-S0/GAf8tV78, Andrew Morton,
	containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA

Manfred Spraul <manfred-nhLOkwUX5cPe2c5cEj3t2g@public.gmane.org> writes:

Sigh. Patches for new code during the merge window.  It is a really
rotten time to look at new things.

> Right now, each new IPC namespace starts with the kernel default values.
> This means that changes that were made to the limits get overwritten.
>
> With this patch, a new namespace inherits the settings from the parent
> namespace, which is less surprising.

In principle I agree.

In practice I have to ask what have you done to survey applications
that use the ipc namespace to see if they will break with this change in
semantics.

Eric

> The patch updates
> - SysV msg
> - SysV sem
> - SysV shm
> - POSIX mqueues

>
> Cc: serge-A9i7LUbDfNHQT0dZR+AlfA@public.gmane.org
> Cc: ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org
> Cc: containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org
> Cc: mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org
>
> Signed-off-by: Manfred Spraul <manfred-nhLOkwUX5cPe2c5cEj3t2g@public.gmane.org>
> ---
>  include/linux/ipc_namespace.h |  6 ++++--
>  ipc/mqueue.c                  | 23 ++++++++++++++++-------
>  ipc/msg.c                     | 16 +++++++++++-----
>  ipc/namespace.c               |  8 ++++----
>  ipc/sem.c                     | 19 +++++++++++++------
>  ipc/shm.c                     | 19 +++++++++++++------
>  ipc/util.h                    | 20 ++++++++++++++------
>  7 files changed, 75 insertions(+), 36 deletions(-)
>
> diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h
> index e365d5e..1cc36a0 100644
> --- a/include/linux/ipc_namespace.h
> +++ b/include/linux/ipc_namespace.h
> @@ -73,7 +73,7 @@ static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
>  #endif /* CONFIG_SYSVIPC */
>  
>  #ifdef CONFIG_POSIX_MQUEUE
> -extern int mq_init_ns(struct ipc_namespace *ns);
> +extern int mq_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns);
>  /*
>   * POSIX Message Queue default values:
>   *
> @@ -108,7 +108,9 @@ extern int mq_init_ns(struct ipc_namespace *ns);
>  #define DFLT_MSGSIZEMAX		     8192
>  #define HARD_MSGSIZEMAX	    (16*1024*1024)
>  #else
> -static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
> +static inline int mq_init_ns(struct ipc_namespace *ns,
> +				struct ipc_namespace *old_ns)
> +{ return 0; }
>  #endif
>  
>  #if defined(CONFIG_IPC_NS)
> diff --git a/ipc/mqueue.c b/ipc/mqueue.c
> index 4fcf39a..3473072d 100644
> --- a/ipc/mqueue.c
> +++ b/ipc/mqueue.c
> @@ -1397,14 +1397,23 @@ static struct file_system_type mqueue_fs_type = {
>  	.fs_flags = FS_USERNS_MOUNT,
>  };
>  
> -int mq_init_ns(struct ipc_namespace *ns)
> +int mq_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns)
>  {
> +	if (old_ns != NULL) {
> +		ns->mq_queues_max    = old_ns->mq_queues_max;
> +		ns->mq_msg_max       = old_ns->mq_msg_max;
> +		ns->mq_msgsize_max   = old_ns->mq_msgsize_max;
> +		ns->mq_msg_default   = old_ns->mq_msg_default;
> +		ns->mq_msgsize_default  = old_ns->mq_msgsize_default;
> +	} else {
> +		ns->mq_queues_max    = DFLT_QUEUESMAX;
> +		ns->mq_msg_max       = DFLT_MSGMAX;
> +		ns->mq_msgsize_max   = DFLT_MSGSIZEMAX;
> +		ns->mq_msg_default   = DFLT_MSG;
> +		ns->mq_msgsize_default  = DFLT_MSGSIZE;
> +	}
> +
>  	ns->mq_queues_count  = 0;
> -	ns->mq_queues_max    = DFLT_QUEUESMAX;
> -	ns->mq_msg_max       = DFLT_MSGMAX;
> -	ns->mq_msgsize_max   = DFLT_MSGSIZEMAX;
> -	ns->mq_msg_default   = DFLT_MSG;
> -	ns->mq_msgsize_default  = DFLT_MSGSIZE;
>  
>  	ns->mq_mnt = kern_mount_data(&mqueue_fs_type, ns);
>  	if (IS_ERR(ns->mq_mnt)) {
> @@ -1444,7 +1453,7 @@ static int __init init_mqueue_fs(void)
>  
>  	spin_lock_init(&mq_lock);
>  
> -	error = mq_init_ns(&init_ipc_ns);
> +	error = mq_init_ns(&init_ipc_ns, NULL);
>  	if (error)
>  		goto out_filesystem;
>  
> diff --git a/ipc/msg.c b/ipc/msg.c
> index a7261d5..3cbd2ad 100644
> --- a/ipc/msg.c
> +++ b/ipc/msg.c
> @@ -990,11 +990,17 @@ SYSCALL_DEFINE5(msgrcv, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
>  }
>  
>  
> -void msg_init_ns(struct ipc_namespace *ns)
> +void msg_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns)
>  {
> -	ns->msg_ctlmax = MSGMAX;
> -	ns->msg_ctlmnb = MSGMNB;
> -	ns->msg_ctlmni = MSGMNI;
> +	if (old_ns != NULL) {
> +		ns->msg_ctlmax = old_ns->msg_ctlmax;
> +		ns->msg_ctlmnb = old_ns->msg_ctlmnb;
> +		ns->msg_ctlmni = old_ns->msg_ctlmni;
> +	} else {
> +		ns->msg_ctlmax = MSGMAX;
> +		ns->msg_ctlmnb = MSGMNB;
> +		ns->msg_ctlmni = MSGMNI;
> +	}
>  
>  	atomic_set(&ns->msg_bytes, 0);
>  	atomic_set(&ns->msg_hdrs, 0);
> @@ -1036,7 +1042,7 @@ static int sysvipc_msg_proc_show(struct seq_file *s, void *it)
>  
>  void __init msg_init(void)
>  {
> -	msg_init_ns(&init_ipc_ns);
> +	msg_init_ns(&init_ipc_ns, NULL);
>  
>  	ipc_init_proc_interface("sysvipc/msg",
>  				"       key      msqid perms      cbytes       qnum lspid lrpid   uid   gid  cuid  cgid      stime      rtime      ctime\n",
> diff --git a/ipc/namespace.c b/ipc/namespace.c
> index 1a3ffd4..97e3332 100644
> --- a/ipc/namespace.c
> +++ b/ipc/namespace.c
> @@ -33,7 +33,7 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
>  	}
>  
>  	atomic_set(&ns->count, 1);
> -	err = mq_init_ns(ns);
> +	err = mq_init_ns(ns, old_ns);
>  	if (err) {
>  		proc_free_inum(ns->proc_inum);
>  		kfree(ns);
> @@ -41,9 +41,9 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
>  	}
>  	atomic_inc(&nr_ipc_ns);
>  
> -	sem_init_ns(ns);
> -	msg_init_ns(ns);
> -	shm_init_ns(ns);
> +	sem_init_ns(ns, old_ns);
> +	msg_init_ns(ns, old_ns);
> +	shm_init_ns(ns, old_ns);
>  
>  	ns->user_ns = get_user_ns(user_ns);
>  
> diff --git a/ipc/sem.c b/ipc/sem.c
> index 454f6c6..f1ded77 100644
> --- a/ipc/sem.c
> +++ b/ipc/sem.c
> @@ -170,12 +170,19 @@ static int sysvipc_sem_proc_show(struct seq_file *s, void *it);
>  #define sc_semopm	sem_ctls[2]
>  #define sc_semmni	sem_ctls[3]
>  
> -void sem_init_ns(struct ipc_namespace *ns)
> +void sem_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns)
>  {
> -	ns->sc_semmsl = SEMMSL;
> -	ns->sc_semmns = SEMMNS;
> -	ns->sc_semopm = SEMOPM;
> -	ns->sc_semmni = SEMMNI;
> +	if (old_ns != NULL) {
> +		ns->sc_semmsl = old_ns->sc_semmsl;
> +		ns->sc_semmns = old_ns->sc_semmns;
> +		ns->sc_semopm = old_ns->sc_semopm;
> +		ns->sc_semmni = old_ns->sc_semmni;
> +	} else {
> +		ns->sc_semmsl = SEMMSL;
> +		ns->sc_semmns = SEMMNS;
> +		ns->sc_semopm = SEMOPM;
> +		ns->sc_semmni = SEMMNI;
> +	}
>  	ns->used_sems = 0;
>  	ipc_init_ids(&ns->ids[IPC_SEM_IDS]);
>  }
> @@ -190,7 +197,7 @@ void sem_exit_ns(struct ipc_namespace *ns)
>  
>  void __init sem_init(void)
>  {
> -	sem_init_ns(&init_ipc_ns);
> +	sem_init_ns(&init_ipc_ns, NULL);
>  	ipc_init_proc_interface("sysvipc/sem",
>  				"       key      semid perms      nsems   uid   gid  cuid  cgid      otime      ctime\n",
>  				IPC_SEM_IDS, sysvipc_sem_proc_show);
> diff --git a/ipc/shm.c b/ipc/shm.c
> index 7fc9f9f..7856952 100644
> --- a/ipc/shm.c
> +++ b/ipc/shm.c
> @@ -72,12 +72,19 @@ static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp);
>  static int sysvipc_shm_proc_show(struct seq_file *s, void *it);
>  #endif
>  
> -void shm_init_ns(struct ipc_namespace *ns)
> +void shm_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns)
>  {
> -	ns->shm_ctlmax = SHMMAX;
> -	ns->shm_ctlall = SHMALL;
> -	ns->shm_ctlmni = SHMMNI;
> -	ns->shm_rmid_forced = 0;
> +	if (old_ns != NULL) {
> +		ns->shm_ctlmax = old_ns->shm_ctlmax;
> +		ns->shm_ctlall = old_ns->shm_ctlall;
> +		ns->shm_ctlmni = old_ns->shm_ctlmni;
> +		ns->shm_rmid_forced = old_ns->shm_rmid_forced;
> +	} else {
> +		ns->shm_ctlmax = SHMMAX;
> +		ns->shm_ctlall = SHMALL;
> +		ns->shm_ctlmni = SHMMNI;
> +		ns->shm_rmid_forced = 0;
> +	}
>  	ns->shm_tot = 0;
>  	ipc_init_ids(&shm_ids(ns));
>  }
> @@ -110,7 +117,7 @@ void shm_exit_ns(struct ipc_namespace *ns)
>  
>  static int __init ipc_ns_init(void)
>  {
> -	shm_init_ns(&init_ipc_ns);
> +	shm_init_ns(&init_ipc_ns, NULL);
>  	return 0;
>  }
>  
> diff --git a/ipc/util.h b/ipc/util.h
> index 1a5a0fc..1be9830 100644
> --- a/ipc/util.h
> +++ b/ipc/util.h
> @@ -30,17 +30,25 @@ static inline void mq_put_mnt(struct ipc_namespace *ns) { }
>  #endif
>  
>  #ifdef CONFIG_SYSVIPC
> -void sem_init_ns(struct ipc_namespace *ns);
> -void msg_init_ns(struct ipc_namespace *ns);
> -void shm_init_ns(struct ipc_namespace *ns);
> +void sem_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns);
> +void msg_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns);
> +void shm_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns);
>  
>  void sem_exit_ns(struct ipc_namespace *ns);
>  void msg_exit_ns(struct ipc_namespace *ns);
>  void shm_exit_ns(struct ipc_namespace *ns);
>  #else
> -static inline void sem_init_ns(struct ipc_namespace *ns) { }
> -static inline void msg_init_ns(struct ipc_namespace *ns) { }
> -static inline void shm_init_ns(struct ipc_namespace *ns) { }
> +static inline void sem_init_ns(struct ipc_namespace *ns,
> +				struct ipc_namespace *old_ns)
> +{ }
> +
> +static inline void msg_init_ns(struct ipc_namespace *ns,
> +				struct ipc_namespace *old_ns)
> +{ }
> +
> +static inline void shm_init_ns(struct ipc_namespace *ns,
> +				struct ipc_namespace *old_ns)
> +{ }
>  
>  static inline void sem_exit_ns(struct ipc_namespace *ns) { }
>  static inline void msg_exit_ns(struct ipc_namespace *ns) { }

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH 3/3] ipc namespace: copy settings from parent namespace
@ 2014-08-12 10:37             ` Eric W. Biederman
  0 siblings, 0 replies; 14+ messages in thread
From: Eric W. Biederman @ 2014-08-12 10:37 UTC (permalink / raw)
  To: Manfred Spraul
  Cc: Andrew Morton, LKML, Davidlohr Bueso, Michael Kerrisk,
	Rafael Aquini, Rik van Riel, 1vier1, serge, containers

Manfred Spraul <manfred@colorfullife.com> writes:

Sigh. Patches for new code during the merge window.  It is a really
rotten time to look at new things.

> Right now, each new IPC namespace starts with the kernel default values.
> This means that changes that were made to the limits get overwritten.
>
> With this patch, a new namespace inherits the settings from the parent
> namespace, which is less surprising.

In principle I agree.

In practice I have to ask what have you done to survey applications
that use the ipc namespace to see if they will break with this change in
semantics.

Eric

> The patch updates
> - SysV msg
> - SysV sem
> - SysV shm
> - POSIX mqueues

>
> Cc: serge@hallyn.com
> Cc: ebiederm@xmission.com
> Cc: containers@lists.linux-foundation.org
> Cc: mtk.manpages@gmail.com
>
> Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
> ---
>  include/linux/ipc_namespace.h |  6 ++++--
>  ipc/mqueue.c                  | 23 ++++++++++++++++-------
>  ipc/msg.c                     | 16 +++++++++++-----
>  ipc/namespace.c               |  8 ++++----
>  ipc/sem.c                     | 19 +++++++++++++------
>  ipc/shm.c                     | 19 +++++++++++++------
>  ipc/util.h                    | 20 ++++++++++++++------
>  7 files changed, 75 insertions(+), 36 deletions(-)
>
> diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h
> index e365d5e..1cc36a0 100644
> --- a/include/linux/ipc_namespace.h
> +++ b/include/linux/ipc_namespace.h
> @@ -73,7 +73,7 @@ static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
>  #endif /* CONFIG_SYSVIPC */
>  
>  #ifdef CONFIG_POSIX_MQUEUE
> -extern int mq_init_ns(struct ipc_namespace *ns);
> +extern int mq_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns);
>  /*
>   * POSIX Message Queue default values:
>   *
> @@ -108,7 +108,9 @@ extern int mq_init_ns(struct ipc_namespace *ns);
>  #define DFLT_MSGSIZEMAX		     8192
>  #define HARD_MSGSIZEMAX	    (16*1024*1024)
>  #else
> -static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
> +static inline int mq_init_ns(struct ipc_namespace *ns,
> +				struct ipc_namespace *old_ns)
> +{ return 0; }
>  #endif
>  
>  #if defined(CONFIG_IPC_NS)
> diff --git a/ipc/mqueue.c b/ipc/mqueue.c
> index 4fcf39a..3473072d 100644
> --- a/ipc/mqueue.c
> +++ b/ipc/mqueue.c
> @@ -1397,14 +1397,23 @@ static struct file_system_type mqueue_fs_type = {
>  	.fs_flags = FS_USERNS_MOUNT,
>  };
>  
> -int mq_init_ns(struct ipc_namespace *ns)
> +int mq_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns)
>  {
> +	if (old_ns != NULL) {
> +		ns->mq_queues_max    = old_ns->mq_queues_max;
> +		ns->mq_msg_max       = old_ns->mq_msg_max;
> +		ns->mq_msgsize_max   = old_ns->mq_msgsize_max;
> +		ns->mq_msg_default   = old_ns->mq_msg_default;
> +		ns->mq_msgsize_default  = old_ns->mq_msgsize_default;
> +	} else {
> +		ns->mq_queues_max    = DFLT_QUEUESMAX;
> +		ns->mq_msg_max       = DFLT_MSGMAX;
> +		ns->mq_msgsize_max   = DFLT_MSGSIZEMAX;
> +		ns->mq_msg_default   = DFLT_MSG;
> +		ns->mq_msgsize_default  = DFLT_MSGSIZE;
> +	}
> +
>  	ns->mq_queues_count  = 0;
> -	ns->mq_queues_max    = DFLT_QUEUESMAX;
> -	ns->mq_msg_max       = DFLT_MSGMAX;
> -	ns->mq_msgsize_max   = DFLT_MSGSIZEMAX;
> -	ns->mq_msg_default   = DFLT_MSG;
> -	ns->mq_msgsize_default  = DFLT_MSGSIZE;
>  
>  	ns->mq_mnt = kern_mount_data(&mqueue_fs_type, ns);
>  	if (IS_ERR(ns->mq_mnt)) {
> @@ -1444,7 +1453,7 @@ static int __init init_mqueue_fs(void)
>  
>  	spin_lock_init(&mq_lock);
>  
> -	error = mq_init_ns(&init_ipc_ns);
> +	error = mq_init_ns(&init_ipc_ns, NULL);
>  	if (error)
>  		goto out_filesystem;
>  
> diff --git a/ipc/msg.c b/ipc/msg.c
> index a7261d5..3cbd2ad 100644
> --- a/ipc/msg.c
> +++ b/ipc/msg.c
> @@ -990,11 +990,17 @@ SYSCALL_DEFINE5(msgrcv, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
>  }
>  
>  
> -void msg_init_ns(struct ipc_namespace *ns)
> +void msg_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns)
>  {
> -	ns->msg_ctlmax = MSGMAX;
> -	ns->msg_ctlmnb = MSGMNB;
> -	ns->msg_ctlmni = MSGMNI;
> +	if (old_ns != NULL) {
> +		ns->msg_ctlmax = old_ns->msg_ctlmax;
> +		ns->msg_ctlmnb = old_ns->msg_ctlmnb;
> +		ns->msg_ctlmni = old_ns->msg_ctlmni;
> +	} else {
> +		ns->msg_ctlmax = MSGMAX;
> +		ns->msg_ctlmnb = MSGMNB;
> +		ns->msg_ctlmni = MSGMNI;
> +	}
>  
>  	atomic_set(&ns->msg_bytes, 0);
>  	atomic_set(&ns->msg_hdrs, 0);
> @@ -1036,7 +1042,7 @@ static int sysvipc_msg_proc_show(struct seq_file *s, void *it)
>  
>  void __init msg_init(void)
>  {
> -	msg_init_ns(&init_ipc_ns);
> +	msg_init_ns(&init_ipc_ns, NULL);
>  
>  	ipc_init_proc_interface("sysvipc/msg",
>  				"       key      msqid perms      cbytes       qnum lspid lrpid   uid   gid  cuid  cgid      stime      rtime      ctime\n",
> diff --git a/ipc/namespace.c b/ipc/namespace.c
> index 1a3ffd4..97e3332 100644
> --- a/ipc/namespace.c
> +++ b/ipc/namespace.c
> @@ -33,7 +33,7 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
>  	}
>  
>  	atomic_set(&ns->count, 1);
> -	err = mq_init_ns(ns);
> +	err = mq_init_ns(ns, old_ns);
>  	if (err) {
>  		proc_free_inum(ns->proc_inum);
>  		kfree(ns);
> @@ -41,9 +41,9 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
>  	}
>  	atomic_inc(&nr_ipc_ns);
>  
> -	sem_init_ns(ns);
> -	msg_init_ns(ns);
> -	shm_init_ns(ns);
> +	sem_init_ns(ns, old_ns);
> +	msg_init_ns(ns, old_ns);
> +	shm_init_ns(ns, old_ns);
>  
>  	ns->user_ns = get_user_ns(user_ns);
>  
> diff --git a/ipc/sem.c b/ipc/sem.c
> index 454f6c6..f1ded77 100644
> --- a/ipc/sem.c
> +++ b/ipc/sem.c
> @@ -170,12 +170,19 @@ static int sysvipc_sem_proc_show(struct seq_file *s, void *it);
>  #define sc_semopm	sem_ctls[2]
>  #define sc_semmni	sem_ctls[3]
>  
> -void sem_init_ns(struct ipc_namespace *ns)
> +void sem_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns)
>  {
> -	ns->sc_semmsl = SEMMSL;
> -	ns->sc_semmns = SEMMNS;
> -	ns->sc_semopm = SEMOPM;
> -	ns->sc_semmni = SEMMNI;
> +	if (old_ns != NULL) {
> +		ns->sc_semmsl = old_ns->sc_semmsl;
> +		ns->sc_semmns = old_ns->sc_semmns;
> +		ns->sc_semopm = old_ns->sc_semopm;
> +		ns->sc_semmni = old_ns->sc_semmni;
> +	} else {
> +		ns->sc_semmsl = SEMMSL;
> +		ns->sc_semmns = SEMMNS;
> +		ns->sc_semopm = SEMOPM;
> +		ns->sc_semmni = SEMMNI;
> +	}
>  	ns->used_sems = 0;
>  	ipc_init_ids(&ns->ids[IPC_SEM_IDS]);
>  }
> @@ -190,7 +197,7 @@ void sem_exit_ns(struct ipc_namespace *ns)
>  
>  void __init sem_init(void)
>  {
> -	sem_init_ns(&init_ipc_ns);
> +	sem_init_ns(&init_ipc_ns, NULL);
>  	ipc_init_proc_interface("sysvipc/sem",
>  				"       key      semid perms      nsems   uid   gid  cuid  cgid      otime      ctime\n",
>  				IPC_SEM_IDS, sysvipc_sem_proc_show);
> diff --git a/ipc/shm.c b/ipc/shm.c
> index 7fc9f9f..7856952 100644
> --- a/ipc/shm.c
> +++ b/ipc/shm.c
> @@ -72,12 +72,19 @@ static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp);
>  static int sysvipc_shm_proc_show(struct seq_file *s, void *it);
>  #endif
>  
> -void shm_init_ns(struct ipc_namespace *ns)
> +void shm_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns)
>  {
> -	ns->shm_ctlmax = SHMMAX;
> -	ns->shm_ctlall = SHMALL;
> -	ns->shm_ctlmni = SHMMNI;
> -	ns->shm_rmid_forced = 0;
> +	if (old_ns != NULL) {
> +		ns->shm_ctlmax = old_ns->shm_ctlmax;
> +		ns->shm_ctlall = old_ns->shm_ctlall;
> +		ns->shm_ctlmni = old_ns->shm_ctlmni;
> +		ns->shm_rmid_forced = old_ns->shm_rmid_forced;
> +	} else {
> +		ns->shm_ctlmax = SHMMAX;
> +		ns->shm_ctlall = SHMALL;
> +		ns->shm_ctlmni = SHMMNI;
> +		ns->shm_rmid_forced = 0;
> +	}
>  	ns->shm_tot = 0;
>  	ipc_init_ids(&shm_ids(ns));
>  }
> @@ -110,7 +117,7 @@ void shm_exit_ns(struct ipc_namespace *ns)
>  
>  static int __init ipc_ns_init(void)
>  {
> -	shm_init_ns(&init_ipc_ns);
> +	shm_init_ns(&init_ipc_ns, NULL);
>  	return 0;
>  }
>  
> diff --git a/ipc/util.h b/ipc/util.h
> index 1a5a0fc..1be9830 100644
> --- a/ipc/util.h
> +++ b/ipc/util.h
> @@ -30,17 +30,25 @@ static inline void mq_put_mnt(struct ipc_namespace *ns) { }
>  #endif
>  
>  #ifdef CONFIG_SYSVIPC
> -void sem_init_ns(struct ipc_namespace *ns);
> -void msg_init_ns(struct ipc_namespace *ns);
> -void shm_init_ns(struct ipc_namespace *ns);
> +void sem_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns);
> +void msg_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns);
> +void shm_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns);
>  
>  void sem_exit_ns(struct ipc_namespace *ns);
>  void msg_exit_ns(struct ipc_namespace *ns);
>  void shm_exit_ns(struct ipc_namespace *ns);
>  #else
> -static inline void sem_init_ns(struct ipc_namespace *ns) { }
> -static inline void msg_init_ns(struct ipc_namespace *ns) { }
> -static inline void shm_init_ns(struct ipc_namespace *ns) { }
> +static inline void sem_init_ns(struct ipc_namespace *ns,
> +				struct ipc_namespace *old_ns)
> +{ }
> +
> +static inline void msg_init_ns(struct ipc_namespace *ns,
> +				struct ipc_namespace *old_ns)
> +{ }
> +
> +static inline void shm_init_ns(struct ipc_namespace *ns,
> +				struct ipc_namespace *old_ns)
> +{ }
>  
>  static inline void sem_exit_ns(struct ipc_namespace *ns) { }
>  static inline void msg_exit_ns(struct ipc_namespace *ns) { }

^ permalink raw reply	[flat|nested] 14+ messages in thread

[parent not found: <877g2ec7tg.fsf-JOvCrm2gF+uungPnsOpG7nhyD016LWXt@public.gmane.org>]

* Re: [PATCH 3/3] ipc namespace: copy settings from parent namespace
  2014-08-12 10:37             ` Eric W. Biederman
@ 2014-08-12 20:39                 ` Manfred Spraul
  -1 siblings, 0 replies; 14+ messages in thread
From: Manfred Spraul @ 2014-08-12 20:39 UTC (permalink / raw)
  To: Eric W. Biederman
  Cc: Rik van Riel, Rafael Aquini, Davidlohr Bueso, LKML,
	Michael Kerrisk, 1vier1-S0/GAf8tV78, Andrew Morton,
	containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA

Hi Eric,

On 08/12/2014 12:37 PM, Eric W. Biederman wrote:
> Manfred Spraul <manfred-nhLOkwUX5cPe2c5cEj3t2g@public.gmane.org> writes:
>
> Sigh. Patches for new code during the merge window.  It is a really
> rotten time to look at new things.
>
>> Right now, each new IPC namespace starts with the kernel default values.
>> This means that changes that were made to the limits get overwritten.
>>
>> With this patch, a new namespace inherits the settings from the parent
>> namespace, which is less surprising.
> In principle I agree.
>
> In practice I have to ask what have you done to survey applications
> that use the ipc namespace to see if they will break with this change in
> semantics.
I know this is the wrong answer, but:
What I find are problems caused by the current behavior.

See e.g.:
https://bugzilla.redhat.com/show_bug.cgi?id=1004724

Some background:
The e.g. sysvshm limits were not updated for many years and many
applications only ran properly if sysvshm limits are increased.
(now the defaults are large, but only since ~3.15)

Increasing is simple: sysctl kernel.shmmax=<>, but somehow this
must happen inside the container.

Right now, the most common approach seems to be the solution from the 
bugzilla above:
Just marc /proc as read-write and do it manually.

With the patch, the kernel would propagate the value from parent to child.

--
     Manfred

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH 3/3] ipc namespace: copy settings from parent namespace
@ 2014-08-12 20:39                 ` Manfred Spraul
  0 siblings, 0 replies; 14+ messages in thread
From: Manfred Spraul @ 2014-08-12 20:39 UTC (permalink / raw)
  To: Eric W. Biederman
  Cc: Andrew Morton, LKML, Davidlohr Bueso, Michael Kerrisk,
	Rafael Aquini, Rik van Riel, 1vier1, serge, containers

Hi Eric,

On 08/12/2014 12:37 PM, Eric W. Biederman wrote:
> Manfred Spraul <manfred@colorfullife.com> writes:
>
> Sigh. Patches for new code during the merge window.  It is a really
> rotten time to look at new things.
>
>> Right now, each new IPC namespace starts with the kernel default values.
>> This means that changes that were made to the limits get overwritten.
>>
>> With this patch, a new namespace inherits the settings from the parent
>> namespace, which is less surprising.
> In principle I agree.
>
> In practice I have to ask what have you done to survey applications
> that use the ipc namespace to see if they will break with this change in
> semantics.
I know this is the wrong answer, but:
What I find are problems caused by the current behavior.

See e.g.:
https://bugzilla.redhat.com/show_bug.cgi?id=1004724

Some background:
The e.g. sysvshm limits were not updated for many years and many
applications only ran properly if sysvshm limits are increased.
(now the defaults are large, but only since ~3.15)

Increasing is simple: sysctl kernel.shmmax=<>, but somehow this
must happen inside the container.

Right now, the most common approach seems to be the solution from the 
bugzilla above:
Just marc /proc as read-write and do it manually.

With the patch, the kernel would propagate the value from parent to child.

--
     Manfred

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH 3/3] ipc namespace: copy settings from parent namespace
  2014-08-12  7:29         ` Manfred Spraul
@ 2014-08-15 13:42             ` Rafael Aquini
  -1 siblings, 0 replies; 14+ messages in thread
From: Rafael Aquini @ 2014-08-15 13:42 UTC (permalink / raw)
  To: Manfred Spraul
  Cc: Rik van Riel, ebiederm-aS9lmoZGLiVWk0Htik3J/w, Davidlohr Bueso,
	LKML, Michael Kerrisk, 1vier1-S0/GAf8tV78, Andrew Morton,
	containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA

On Tue, Aug 12, 2014 at 09:29:17AM +0200, Manfred Spraul wrote:
> Right now, each new IPC namespace starts with the kernel default values.
> This means that changes that were made to the limits get overwritten.
> 
> With this patch, a new namespace inherits the settings from the parent
> namespace, which is less surprising.
> 
> The patch updates
> - SysV msg
> - SysV sem
> - SysV shm
> - POSIX mqueues
> 
> Cc: serge-A9i7LUbDfNHQT0dZR+AlfA@public.gmane.org
> Cc: ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org
> Cc: containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org
> Cc: mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org
> 
> Signed-off-by: Manfred Spraul <manfred-nhLOkwUX5cPe2c5cEj3t2g@public.gmane.org>
> ---

Acked-by: Rafael Aquini <aquini-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>


>  include/linux/ipc_namespace.h |  6 ++++--
>  ipc/mqueue.c                  | 23 ++++++++++++++++-------
>  ipc/msg.c                     | 16 +++++++++++-----
>  ipc/namespace.c               |  8 ++++----
>  ipc/sem.c                     | 19 +++++++++++++------
>  ipc/shm.c                     | 19 +++++++++++++------
>  ipc/util.h                    | 20 ++++++++++++++------
>  7 files changed, 75 insertions(+), 36 deletions(-)
> 
> diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h
> index e365d5e..1cc36a0 100644
> --- a/include/linux/ipc_namespace.h
> +++ b/include/linux/ipc_namespace.h
> @@ -73,7 +73,7 @@ static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
>  #endif /* CONFIG_SYSVIPC */
>  
>  #ifdef CONFIG_POSIX_MQUEUE
> -extern int mq_init_ns(struct ipc_namespace *ns);
> +extern int mq_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns);
>  /*
>   * POSIX Message Queue default values:
>   *
> @@ -108,7 +108,9 @@ extern int mq_init_ns(struct ipc_namespace *ns);
>  #define DFLT_MSGSIZEMAX		     8192
>  #define HARD_MSGSIZEMAX	    (16*1024*1024)
>  #else
> -static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
> +static inline int mq_init_ns(struct ipc_namespace *ns,
> +				struct ipc_namespace *old_ns)
> +{ return 0; }
>  #endif
>  
>  #if defined(CONFIG_IPC_NS)
> diff --git a/ipc/mqueue.c b/ipc/mqueue.c
> index 4fcf39a..3473072d 100644
> --- a/ipc/mqueue.c
> +++ b/ipc/mqueue.c
> @@ -1397,14 +1397,23 @@ static struct file_system_type mqueue_fs_type = {
>  	.fs_flags = FS_USERNS_MOUNT,
>  };
>  
> -int mq_init_ns(struct ipc_namespace *ns)
> +int mq_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns)
>  {
> +	if (old_ns != NULL) {
> +		ns->mq_queues_max    = old_ns->mq_queues_max;
> +		ns->mq_msg_max       = old_ns->mq_msg_max;
> +		ns->mq_msgsize_max   = old_ns->mq_msgsize_max;
> +		ns->mq_msg_default   = old_ns->mq_msg_default;
> +		ns->mq_msgsize_default  = old_ns->mq_msgsize_default;
> +	} else {
> +		ns->mq_queues_max    = DFLT_QUEUESMAX;
> +		ns->mq_msg_max       = DFLT_MSGMAX;
> +		ns->mq_msgsize_max   = DFLT_MSGSIZEMAX;
> +		ns->mq_msg_default   = DFLT_MSG;
> +		ns->mq_msgsize_default  = DFLT_MSGSIZE;
> +	}
> +
>  	ns->mq_queues_count  = 0;
> -	ns->mq_queues_max    = DFLT_QUEUESMAX;
> -	ns->mq_msg_max       = DFLT_MSGMAX;
> -	ns->mq_msgsize_max   = DFLT_MSGSIZEMAX;
> -	ns->mq_msg_default   = DFLT_MSG;
> -	ns->mq_msgsize_default  = DFLT_MSGSIZE;
>  
>  	ns->mq_mnt = kern_mount_data(&mqueue_fs_type, ns);
>  	if (IS_ERR(ns->mq_mnt)) {
> @@ -1444,7 +1453,7 @@ static int __init init_mqueue_fs(void)
>  
>  	spin_lock_init(&mq_lock);
>  
> -	error = mq_init_ns(&init_ipc_ns);
> +	error = mq_init_ns(&init_ipc_ns, NULL);
>  	if (error)
>  		goto out_filesystem;
>  
> diff --git a/ipc/msg.c b/ipc/msg.c
> index a7261d5..3cbd2ad 100644
> --- a/ipc/msg.c
> +++ b/ipc/msg.c
> @@ -990,11 +990,17 @@ SYSCALL_DEFINE5(msgrcv, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
>  }
>  
>  
> -void msg_init_ns(struct ipc_namespace *ns)
> +void msg_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns)
>  {
> -	ns->msg_ctlmax = MSGMAX;
> -	ns->msg_ctlmnb = MSGMNB;
> -	ns->msg_ctlmni = MSGMNI;
> +	if (old_ns != NULL) {
> +		ns->msg_ctlmax = old_ns->msg_ctlmax;
> +		ns->msg_ctlmnb = old_ns->msg_ctlmnb;
> +		ns->msg_ctlmni = old_ns->msg_ctlmni;
> +	} else {
> +		ns->msg_ctlmax = MSGMAX;
> +		ns->msg_ctlmnb = MSGMNB;
> +		ns->msg_ctlmni = MSGMNI;
> +	}
>  
>  	atomic_set(&ns->msg_bytes, 0);
>  	atomic_set(&ns->msg_hdrs, 0);
> @@ -1036,7 +1042,7 @@ static int sysvipc_msg_proc_show(struct seq_file *s, void *it)
>  
>  void __init msg_init(void)
>  {
> -	msg_init_ns(&init_ipc_ns);
> +	msg_init_ns(&init_ipc_ns, NULL);
>  
>  	ipc_init_proc_interface("sysvipc/msg",
>  				"       key      msqid perms      cbytes       qnum lspid lrpid   uid   gid  cuid  cgid      stime      rtime      ctime\n",
> diff --git a/ipc/namespace.c b/ipc/namespace.c
> index 1a3ffd4..97e3332 100644
> --- a/ipc/namespace.c
> +++ b/ipc/namespace.c
> @@ -33,7 +33,7 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
>  	}
>  
>  	atomic_set(&ns->count, 1);
> -	err = mq_init_ns(ns);
> +	err = mq_init_ns(ns, old_ns);
>  	if (err) {
>  		proc_free_inum(ns->proc_inum);
>  		kfree(ns);
> @@ -41,9 +41,9 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
>  	}
>  	atomic_inc(&nr_ipc_ns);
>  
> -	sem_init_ns(ns);
> -	msg_init_ns(ns);
> -	shm_init_ns(ns);
> +	sem_init_ns(ns, old_ns);
> +	msg_init_ns(ns, old_ns);
> +	shm_init_ns(ns, old_ns);
>  
>  	ns->user_ns = get_user_ns(user_ns);
>  
> diff --git a/ipc/sem.c b/ipc/sem.c
> index 454f6c6..f1ded77 100644
> --- a/ipc/sem.c
> +++ b/ipc/sem.c
> @@ -170,12 +170,19 @@ static int sysvipc_sem_proc_show(struct seq_file *s, void *it);
>  #define sc_semopm	sem_ctls[2]
>  #define sc_semmni	sem_ctls[3]
>  
> -void sem_init_ns(struct ipc_namespace *ns)
> +void sem_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns)
>  {
> -	ns->sc_semmsl = SEMMSL;
> -	ns->sc_semmns = SEMMNS;
> -	ns->sc_semopm = SEMOPM;
> -	ns->sc_semmni = SEMMNI;
> +	if (old_ns != NULL) {
> +		ns->sc_semmsl = old_ns->sc_semmsl;
> +		ns->sc_semmns = old_ns->sc_semmns;
> +		ns->sc_semopm = old_ns->sc_semopm;
> +		ns->sc_semmni = old_ns->sc_semmni;
> +	} else {
> +		ns->sc_semmsl = SEMMSL;
> +		ns->sc_semmns = SEMMNS;
> +		ns->sc_semopm = SEMOPM;
> +		ns->sc_semmni = SEMMNI;
> +	}
>  	ns->used_sems = 0;
>  	ipc_init_ids(&ns->ids[IPC_SEM_IDS]);
>  }
> @@ -190,7 +197,7 @@ void sem_exit_ns(struct ipc_namespace *ns)
>  
>  void __init sem_init(void)
>  {
> -	sem_init_ns(&init_ipc_ns);
> +	sem_init_ns(&init_ipc_ns, NULL);
>  	ipc_init_proc_interface("sysvipc/sem",
>  				"       key      semid perms      nsems   uid   gid  cuid  cgid      otime      ctime\n",
>  				IPC_SEM_IDS, sysvipc_sem_proc_show);
> diff --git a/ipc/shm.c b/ipc/shm.c
> index 7fc9f9f..7856952 100644
> --- a/ipc/shm.c
> +++ b/ipc/shm.c
> @@ -72,12 +72,19 @@ static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp);
>  static int sysvipc_shm_proc_show(struct seq_file *s, void *it);
>  #endif
>  
> -void shm_init_ns(struct ipc_namespace *ns)
> +void shm_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns)
>  {
> -	ns->shm_ctlmax = SHMMAX;
> -	ns->shm_ctlall = SHMALL;
> -	ns->shm_ctlmni = SHMMNI;
> -	ns->shm_rmid_forced = 0;
> +	if (old_ns != NULL) {
> +		ns->shm_ctlmax = old_ns->shm_ctlmax;
> +		ns->shm_ctlall = old_ns->shm_ctlall;
> +		ns->shm_ctlmni = old_ns->shm_ctlmni;
> +		ns->shm_rmid_forced = old_ns->shm_rmid_forced;
> +	} else {
> +		ns->shm_ctlmax = SHMMAX;
> +		ns->shm_ctlall = SHMALL;
> +		ns->shm_ctlmni = SHMMNI;
> +		ns->shm_rmid_forced = 0;
> +	}
>  	ns->shm_tot = 0;
>  	ipc_init_ids(&shm_ids(ns));
>  }
> @@ -110,7 +117,7 @@ void shm_exit_ns(struct ipc_namespace *ns)
>  
>  static int __init ipc_ns_init(void)
>  {
> -	shm_init_ns(&init_ipc_ns);
> +	shm_init_ns(&init_ipc_ns, NULL);
>  	return 0;
>  }
>  
> diff --git a/ipc/util.h b/ipc/util.h
> index 1a5a0fc..1be9830 100644
> --- a/ipc/util.h
> +++ b/ipc/util.h
> @@ -30,17 +30,25 @@ static inline void mq_put_mnt(struct ipc_namespace *ns) { }
>  #endif
>  
>  #ifdef CONFIG_SYSVIPC
> -void sem_init_ns(struct ipc_namespace *ns);
> -void msg_init_ns(struct ipc_namespace *ns);
> -void shm_init_ns(struct ipc_namespace *ns);
> +void sem_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns);
> +void msg_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns);
> +void shm_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns);
>  
>  void sem_exit_ns(struct ipc_namespace *ns);
>  void msg_exit_ns(struct ipc_namespace *ns);
>  void shm_exit_ns(struct ipc_namespace *ns);
>  #else
> -static inline void sem_init_ns(struct ipc_namespace *ns) { }
> -static inline void msg_init_ns(struct ipc_namespace *ns) { }
> -static inline void shm_init_ns(struct ipc_namespace *ns) { }
> +static inline void sem_init_ns(struct ipc_namespace *ns,
> +				struct ipc_namespace *old_ns)
> +{ }
> +
> +static inline void msg_init_ns(struct ipc_namespace *ns,
> +				struct ipc_namespace *old_ns)
> +{ }
> +
> +static inline void shm_init_ns(struct ipc_namespace *ns,
> +				struct ipc_namespace *old_ns)
> +{ }
>  
>  static inline void sem_exit_ns(struct ipc_namespace *ns) { }
>  static inline void msg_exit_ns(struct ipc_namespace *ns) { }
> -- 
> 1.9.3
> 

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH 3/3] ipc namespace: copy settings from parent namespace
@ 2014-08-15 13:42             ` Rafael Aquini
  0 siblings, 0 replies; 14+ messages in thread
From: Rafael Aquini @ 2014-08-15 13:42 UTC (permalink / raw)
  To: Manfred Spraul
  Cc: Andrew Morton, LKML, Davidlohr Bueso, Michael Kerrisk,
	Rik van Riel, 1vier1, serge, ebiederm, containers

On Tue, Aug 12, 2014 at 09:29:17AM +0200, Manfred Spraul wrote:
> Right now, each new IPC namespace starts with the kernel default values.
> This means that changes that were made to the limits get overwritten.
> 
> With this patch, a new namespace inherits the settings from the parent
> namespace, which is less surprising.
> 
> The patch updates
> - SysV msg
> - SysV sem
> - SysV shm
> - POSIX mqueues
> 
> Cc: serge@hallyn.com
> Cc: ebiederm@xmission.com
> Cc: containers@lists.linux-foundation.org
> Cc: mtk.manpages@gmail.com
> 
> Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
> ---

Acked-by: Rafael Aquini <aquini@redhat.com>


>  include/linux/ipc_namespace.h |  6 ++++--
>  ipc/mqueue.c                  | 23 ++++++++++++++++-------
>  ipc/msg.c                     | 16 +++++++++++-----
>  ipc/namespace.c               |  8 ++++----
>  ipc/sem.c                     | 19 +++++++++++++------
>  ipc/shm.c                     | 19 +++++++++++++------
>  ipc/util.h                    | 20 ++++++++++++++------
>  7 files changed, 75 insertions(+), 36 deletions(-)
> 
> diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h
> index e365d5e..1cc36a0 100644
> --- a/include/linux/ipc_namespace.h
> +++ b/include/linux/ipc_namespace.h
> @@ -73,7 +73,7 @@ static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
>  #endif /* CONFIG_SYSVIPC */
>  
>  #ifdef CONFIG_POSIX_MQUEUE
> -extern int mq_init_ns(struct ipc_namespace *ns);
> +extern int mq_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns);
>  /*
>   * POSIX Message Queue default values:
>   *
> @@ -108,7 +108,9 @@ extern int mq_init_ns(struct ipc_namespace *ns);
>  #define DFLT_MSGSIZEMAX		     8192
>  #define HARD_MSGSIZEMAX	    (16*1024*1024)
>  #else
> -static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
> +static inline int mq_init_ns(struct ipc_namespace *ns,
> +				struct ipc_namespace *old_ns)
> +{ return 0; }
>  #endif
>  
>  #if defined(CONFIG_IPC_NS)
> diff --git a/ipc/mqueue.c b/ipc/mqueue.c
> index 4fcf39a..3473072d 100644
> --- a/ipc/mqueue.c
> +++ b/ipc/mqueue.c
> @@ -1397,14 +1397,23 @@ static struct file_system_type mqueue_fs_type = {
>  	.fs_flags = FS_USERNS_MOUNT,
>  };
>  
> -int mq_init_ns(struct ipc_namespace *ns)
> +int mq_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns)
>  {
> +	if (old_ns != NULL) {
> +		ns->mq_queues_max    = old_ns->mq_queues_max;
> +		ns->mq_msg_max       = old_ns->mq_msg_max;
> +		ns->mq_msgsize_max   = old_ns->mq_msgsize_max;
> +		ns->mq_msg_default   = old_ns->mq_msg_default;
> +		ns->mq_msgsize_default  = old_ns->mq_msgsize_default;
> +	} else {
> +		ns->mq_queues_max    = DFLT_QUEUESMAX;
> +		ns->mq_msg_max       = DFLT_MSGMAX;
> +		ns->mq_msgsize_max   = DFLT_MSGSIZEMAX;
> +		ns->mq_msg_default   = DFLT_MSG;
> +		ns->mq_msgsize_default  = DFLT_MSGSIZE;
> +	}
> +
>  	ns->mq_queues_count  = 0;
> -	ns->mq_queues_max    = DFLT_QUEUESMAX;
> -	ns->mq_msg_max       = DFLT_MSGMAX;
> -	ns->mq_msgsize_max   = DFLT_MSGSIZEMAX;
> -	ns->mq_msg_default   = DFLT_MSG;
> -	ns->mq_msgsize_default  = DFLT_MSGSIZE;
>  
>  	ns->mq_mnt = kern_mount_data(&mqueue_fs_type, ns);
>  	if (IS_ERR(ns->mq_mnt)) {
> @@ -1444,7 +1453,7 @@ static int __init init_mqueue_fs(void)
>  
>  	spin_lock_init(&mq_lock);
>  
> -	error = mq_init_ns(&init_ipc_ns);
> +	error = mq_init_ns(&init_ipc_ns, NULL);
>  	if (error)
>  		goto out_filesystem;
>  
> diff --git a/ipc/msg.c b/ipc/msg.c
> index a7261d5..3cbd2ad 100644
> --- a/ipc/msg.c
> +++ b/ipc/msg.c
> @@ -990,11 +990,17 @@ SYSCALL_DEFINE5(msgrcv, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
>  }
>  
>  
> -void msg_init_ns(struct ipc_namespace *ns)
> +void msg_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns)
>  {
> -	ns->msg_ctlmax = MSGMAX;
> -	ns->msg_ctlmnb = MSGMNB;
> -	ns->msg_ctlmni = MSGMNI;
> +	if (old_ns != NULL) {
> +		ns->msg_ctlmax = old_ns->msg_ctlmax;
> +		ns->msg_ctlmnb = old_ns->msg_ctlmnb;
> +		ns->msg_ctlmni = old_ns->msg_ctlmni;
> +	} else {
> +		ns->msg_ctlmax = MSGMAX;
> +		ns->msg_ctlmnb = MSGMNB;
> +		ns->msg_ctlmni = MSGMNI;
> +	}
>  
>  	atomic_set(&ns->msg_bytes, 0);
>  	atomic_set(&ns->msg_hdrs, 0);
> @@ -1036,7 +1042,7 @@ static int sysvipc_msg_proc_show(struct seq_file *s, void *it)
>  
>  void __init msg_init(void)
>  {
> -	msg_init_ns(&init_ipc_ns);
> +	msg_init_ns(&init_ipc_ns, NULL);
>  
>  	ipc_init_proc_interface("sysvipc/msg",
>  				"       key      msqid perms      cbytes       qnum lspid lrpid   uid   gid  cuid  cgid      stime      rtime      ctime\n",
> diff --git a/ipc/namespace.c b/ipc/namespace.c
> index 1a3ffd4..97e3332 100644
> --- a/ipc/namespace.c
> +++ b/ipc/namespace.c
> @@ -33,7 +33,7 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
>  	}
>  
>  	atomic_set(&ns->count, 1);
> -	err = mq_init_ns(ns);
> +	err = mq_init_ns(ns, old_ns);
>  	if (err) {
>  		proc_free_inum(ns->proc_inum);
>  		kfree(ns);
> @@ -41,9 +41,9 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
>  	}
>  	atomic_inc(&nr_ipc_ns);
>  
> -	sem_init_ns(ns);
> -	msg_init_ns(ns);
> -	shm_init_ns(ns);
> +	sem_init_ns(ns, old_ns);
> +	msg_init_ns(ns, old_ns);
> +	shm_init_ns(ns, old_ns);
>  
>  	ns->user_ns = get_user_ns(user_ns);
>  
> diff --git a/ipc/sem.c b/ipc/sem.c
> index 454f6c6..f1ded77 100644
> --- a/ipc/sem.c
> +++ b/ipc/sem.c
> @@ -170,12 +170,19 @@ static int sysvipc_sem_proc_show(struct seq_file *s, void *it);
>  #define sc_semopm	sem_ctls[2]
>  #define sc_semmni	sem_ctls[3]
>  
> -void sem_init_ns(struct ipc_namespace *ns)
> +void sem_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns)
>  {
> -	ns->sc_semmsl = SEMMSL;
> -	ns->sc_semmns = SEMMNS;
> -	ns->sc_semopm = SEMOPM;
> -	ns->sc_semmni = SEMMNI;
> +	if (old_ns != NULL) {
> +		ns->sc_semmsl = old_ns->sc_semmsl;
> +		ns->sc_semmns = old_ns->sc_semmns;
> +		ns->sc_semopm = old_ns->sc_semopm;
> +		ns->sc_semmni = old_ns->sc_semmni;
> +	} else {
> +		ns->sc_semmsl = SEMMSL;
> +		ns->sc_semmns = SEMMNS;
> +		ns->sc_semopm = SEMOPM;
> +		ns->sc_semmni = SEMMNI;
> +	}
>  	ns->used_sems = 0;
>  	ipc_init_ids(&ns->ids[IPC_SEM_IDS]);
>  }
> @@ -190,7 +197,7 @@ void sem_exit_ns(struct ipc_namespace *ns)
>  
>  void __init sem_init(void)
>  {
> -	sem_init_ns(&init_ipc_ns);
> +	sem_init_ns(&init_ipc_ns, NULL);
>  	ipc_init_proc_interface("sysvipc/sem",
>  				"       key      semid perms      nsems   uid   gid  cuid  cgid      otime      ctime\n",
>  				IPC_SEM_IDS, sysvipc_sem_proc_show);
> diff --git a/ipc/shm.c b/ipc/shm.c
> index 7fc9f9f..7856952 100644
> --- a/ipc/shm.c
> +++ b/ipc/shm.c
> @@ -72,12 +72,19 @@ static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp);
>  static int sysvipc_shm_proc_show(struct seq_file *s, void *it);
>  #endif
>  
> -void shm_init_ns(struct ipc_namespace *ns)
> +void shm_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns)
>  {
> -	ns->shm_ctlmax = SHMMAX;
> -	ns->shm_ctlall = SHMALL;
> -	ns->shm_ctlmni = SHMMNI;
> -	ns->shm_rmid_forced = 0;
> +	if (old_ns != NULL) {
> +		ns->shm_ctlmax = old_ns->shm_ctlmax;
> +		ns->shm_ctlall = old_ns->shm_ctlall;
> +		ns->shm_ctlmni = old_ns->shm_ctlmni;
> +		ns->shm_rmid_forced = old_ns->shm_rmid_forced;
> +	} else {
> +		ns->shm_ctlmax = SHMMAX;
> +		ns->shm_ctlall = SHMALL;
> +		ns->shm_ctlmni = SHMMNI;
> +		ns->shm_rmid_forced = 0;
> +	}
>  	ns->shm_tot = 0;
>  	ipc_init_ids(&shm_ids(ns));
>  }
> @@ -110,7 +117,7 @@ void shm_exit_ns(struct ipc_namespace *ns)
>  
>  static int __init ipc_ns_init(void)
>  {
> -	shm_init_ns(&init_ipc_ns);
> +	shm_init_ns(&init_ipc_ns, NULL);
>  	return 0;
>  }
>  
> diff --git a/ipc/util.h b/ipc/util.h
> index 1a5a0fc..1be9830 100644
> --- a/ipc/util.h
> +++ b/ipc/util.h
> @@ -30,17 +30,25 @@ static inline void mq_put_mnt(struct ipc_namespace *ns) { }
>  #endif
>  
>  #ifdef CONFIG_SYSVIPC
> -void sem_init_ns(struct ipc_namespace *ns);
> -void msg_init_ns(struct ipc_namespace *ns);
> -void shm_init_ns(struct ipc_namespace *ns);
> +void sem_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns);
> +void msg_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns);
> +void shm_init_ns(struct ipc_namespace *ns, struct ipc_namespace *old_ns);
>  
>  void sem_exit_ns(struct ipc_namespace *ns);
>  void msg_exit_ns(struct ipc_namespace *ns);
>  void shm_exit_ns(struct ipc_namespace *ns);
>  #else
> -static inline void sem_init_ns(struct ipc_namespace *ns) { }
> -static inline void msg_init_ns(struct ipc_namespace *ns) { }
> -static inline void shm_init_ns(struct ipc_namespace *ns) { }
> +static inline void sem_init_ns(struct ipc_namespace *ns,
> +				struct ipc_namespace *old_ns)
> +{ }
> +
> +static inline void msg_init_ns(struct ipc_namespace *ns,
> +				struct ipc_namespace *old_ns)
> +{ }
> +
> +static inline void shm_init_ns(struct ipc_namespace *ns,
> +				struct ipc_namespace *old_ns)
> +{ }
>  
>  static inline void sem_exit_ns(struct ipc_namespace *ns) { }
>  static inline void msg_exit_ns(struct ipc_namespace *ns) { }
> -- 
> 1.9.3
> 

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH 2/3] ipc/sem.c: increase SEMMSL, SEMMNI, SEMOPM
  2014-08-12  7:29   ` [PATCH 2/3] ipc/sem.c: increase SEMMSL, SEMMNI, SEMOPM Manfred Spraul
       [not found]     ` <1407828557-31995-3-git-send-email-manfred-nhLOkwUX5cPe2c5cEj3t2g@public.gmane.org>
@ 2014-08-15 13:42     ` Rafael Aquini
  1 sibling, 0 replies; 14+ messages in thread
From: Rafael Aquini @ 2014-08-15 13:42 UTC (permalink / raw)
  To: Manfred Spraul
  Cc: Andrew Morton, LKML, Davidlohr Bueso, Michael Kerrisk,
	Rik van Riel, 1vier1

On Tue, Aug 12, 2014 at 09:29:16AM +0200, Manfred Spraul wrote:
> a)
> SysV can be abused to allocate locked kernel memory.  For most systems, a
> small limit doesn't make sense, see the discussion with regards to SHMMAX.
> 
> Therefore: Increase the sysv sem limits so that all known applications
> will work with these defaults.
> 
> b)
> With regards to the maximum supported:
> Some of the specified hard limits are not correct anymore, therefore the
> patch updates the documentation.
> 
> - SEMMNI must stay below IPCMNI, which is 32768.
>   As for SHMMAX: Stay a bit below this limit.
> 
> - SEMMSL was limited to 8k, to ensure that the kmalloc for the kernel array
>   was limited to 16 kB (order=2)
> 
>   This doesn't apply anymore:
>    - the allocation size isn't sizeof(short)*nsems anymore.
>    - ipc_alloc falls back to vmalloc
> 
> - SEMOPM should stay below 1000, to limit the kmalloc in semtimedop() to an
>   order=1 allocation.
>   Therefore: Leave it at 500 (order=0 allocation).
> 
> Note:
> If an administrator must limit the memory allocations, then he can set the
> values as necessary.
> 
> Or he can disable sysv entirely (as e.g. done by Android).
> 
> Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
> ---

Acked-by: Rafael Aquini <aquini@redhat.com>


>  include/uapi/linux/sem.h | 18 +++++++++++++++---
>  1 file changed, 15 insertions(+), 3 deletions(-)
> 
> diff --git a/include/uapi/linux/sem.h b/include/uapi/linux/sem.h
> index 541fce0..dd73b90 100644
> --- a/include/uapi/linux/sem.h
> +++ b/include/uapi/linux/sem.h
> @@ -63,10 +63,22 @@ struct  seminfo {
>  	int semaem;
>  };
>  
> -#define SEMMNI  128             /* <= IPCMNI  max # of semaphore identifiers */
> -#define SEMMSL  250             /* <= 8 000 max num of semaphores per id */
> +/*
> + * SEMMNI, SEMMSL and SEMMNS are default values which can be
> + * modified by sysctl.
> + * The values has been chosen to be larger than necessary for any
> + * known configuration.
> + *
> + * SEMOPM should not be increased beyond 1000, otherwise there is the
> + * risk that semop()/semtimedop() fails due to kernel memory fragmentation when
> + * allocating the sop array.
> + */
> +
> +
> +#define SEMMNI  32000           /* <= IPCMNI  max # of semaphore identifiers */
> +#define SEMMSL  32000           /* <= INT_MAX max num of semaphores per id */
>  #define SEMMNS  (SEMMNI*SEMMSL) /* <= INT_MAX max # of semaphores in system */
> -#define SEMOPM  32	        /* <= 1 000 max num of ops per semop call */
> +#define SEMOPM  500	        /* <= 1 000 max num of ops per semop call */
>  #define SEMVMX  32767           /* <= 32767 semaphore maximum value */
>  #define SEMAEM  SEMVMX          /* adjust on exit max value */
>  
> -- 
> 1.9.3
> 

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [PATCH 1/3] ipc/msg: increase MSGMNI, remove scaling
  2014-08-12  7:29 ` [PATCH 1/3] ipc/msg: increase MSGMNI, remove scaling Manfred Spraul
  2014-08-12  7:29   ` [PATCH 2/3] ipc/sem.c: increase SEMMSL, SEMMNI, SEMOPM Manfred Spraul
@ 2014-08-15 13:41   ` Rafael Aquini
  1 sibling, 0 replies; 14+ messages in thread
From: Rafael Aquini @ 2014-08-15 13:41 UTC (permalink / raw)
  To: Manfred Spraul
  Cc: Andrew Morton, LKML, Davidlohr Bueso, Michael Kerrisk,
	Rik van Riel, 1vier1

On Tue, Aug 12, 2014 at 09:29:15AM +0200, Manfred Spraul wrote:
> SysV can be abused to allocate locked kernel memory.
> For most systems, a small limit doesn't make sense, see the discussion with
> regards to SHMMAX.
> 
> Therefore: increase MSGMNI to the maximum supported.
> 
> And: If we ignore the risk of locking too much memory, then an automatic
> scaling of MSGMNI doesn't make sense. Therefore the logic can be removed.
> 
> Notes:
> 1) If an administrator must limit the memory allocations, then he can set
> MSGMNI as necessary.
> 
> Or he can disable sysv entirely (as e.g. done by Android).
> 
> 2) MSGMAX and MSGMNB are intentionally not increased, as these values are used
> to control latency vs. throughput:
> If MSGMNB is large, then msgsnd() just returns and more messages can be queued
> before a task switch to a task that calls msgrcv() is forced.
> 
> Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
> ---

Acked-by: Rafael Aquini <aquini@redhat.com>


>  include/linux/ipc_namespace.h | 20 ----------
>  include/uapi/linux/msg.h      | 28 +++++++++----
>  ipc/Makefile                  |  2 +-
>  ipc/ipc_sysctl.c              | 86 +---------------------------------------
>  ipc/ipcns_notifier.c          | 92 -------------------------------------------
>  ipc/msg.c                     | 36 +----------------
>  ipc/namespace.c               | 22 -----------
>  ipc/util.c                    | 40 -------------------
>  8 files changed, 23 insertions(+), 303 deletions(-)
>  delete mode 100644 ipc/ipcns_notifier.c
> 
> diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h
> index 35e7eca..e365d5e 100644
> --- a/include/linux/ipc_namespace.h
> +++ b/include/linux/ipc_namespace.h
> @@ -7,15 +7,6 @@
>  #include <linux/notifier.h>
>  #include <linux/nsproxy.h>
>  
> -/*
> - * ipc namespace events
> - */
> -#define IPCNS_MEMCHANGED   0x00000001   /* Notify lowmem size changed */
> -#define IPCNS_CREATED  0x00000002   /* Notify new ipc namespace created */
> -#define IPCNS_REMOVED  0x00000003   /* Notify ipc namespace removed */
> -
> -#define IPCNS_CALLBACK_PRI 0
> -
>  struct user_namespace;
>  
>  struct ipc_ids {
> @@ -38,7 +29,6 @@ struct ipc_namespace {
>  	unsigned int	msg_ctlmni;
>  	atomic_t	msg_bytes;
>  	atomic_t	msg_hdrs;
> -	int		auto_msgmni;
>  
>  	size_t		shm_ctlmax;
>  	size_t		shm_ctlall;
> @@ -77,18 +67,8 @@ extern atomic_t nr_ipc_ns;
>  extern spinlock_t mq_lock;
>  
>  #ifdef CONFIG_SYSVIPC
> -extern int register_ipcns_notifier(struct ipc_namespace *);
> -extern int cond_register_ipcns_notifier(struct ipc_namespace *);
> -extern void unregister_ipcns_notifier(struct ipc_namespace *);
> -extern int ipcns_notify(unsigned long);
>  extern void shm_destroy_orphaned(struct ipc_namespace *ns);
>  #else /* CONFIG_SYSVIPC */
> -static inline int register_ipcns_notifier(struct ipc_namespace *ns)
> -{ return 0; }
> -static inline int cond_register_ipcns_notifier(struct ipc_namespace *ns)
> -{ return 0; }
> -static inline void unregister_ipcns_notifier(struct ipc_namespace *ns) { }
> -static inline int ipcns_notify(unsigned long l) { return 0; }
>  static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
>  #endif /* CONFIG_SYSVIPC */
>  
> diff --git a/include/uapi/linux/msg.h b/include/uapi/linux/msg.h
> index a703755..2733ec8 100644
> --- a/include/uapi/linux/msg.h
> +++ b/include/uapi/linux/msg.h
> @@ -51,16 +51,28 @@ struct msginfo {
>  };
>  
>  /*
> - * Scaling factor to compute msgmni:
> - * the memory dedicated to msg queues (msgmni * msgmnb) should occupy
> - * at most 1/MSG_MEM_SCALE of the lowmem (see the formula in ipc/msg.c):
> - * up to 8MB       : msgmni = 16 (MSGMNI)
> - * 4 GB            : msgmni = 8K
> - * more than 16 GB : msgmni = 32K (IPCMNI)
> + * MSGMNI, MSGMAX and MSGMNB are default values which can be
> + * modified by sysctl.
> + *
> + * MSGMNI is the upper limit for the number of messages queues per
> + * namespace.
> + * It has been chosen to be as large possible without facilitating
> + * scenarios where userspace causes overflows when adjusting the limits via
> + * operations of the form retrieve current limit; add X; update limit".
> + *
> + * MSGMNB is the default size of a new message queue. Non-root tasks can
> + * decrease the size with msgctl(IPC_SET), root tasks
> + * (actually: CAP_SYS_RESOURCE) can both increase and decrease the queue
> + * size. The optimal value is application dependant.
> + * 16384 is used because it was always used (since 0.99.10)
> + *
> + * MAXMAX is the maximum size of an individual message, it's a global
> + * (per-namespace) limit that applies for all message queues.
> + * It's set to 1/2 of MSGMNB, to ensure that at least two messages fit into
> + * the queue. This is also an arbitrary choice (since 2.6.0).
>   */
> -#define MSG_MEM_SCALE 32
>  
> -#define MSGMNI    16   /* <= IPCMNI */     /* max # of msg queue identifiers */
> +#define MSGMNI 32000   /* <= IPCMNI */     /* max # of msg queue identifiers */
>  #define MSGMAX  8192   /* <= INT_MAX */   /* max size of message (bytes) */
>  #define MSGMNB 16384   /* <= INT_MAX */   /* default max size of a message queue */
>  
> diff --git a/ipc/Makefile b/ipc/Makefile
> index 9075e17..86c7300 100644
> --- a/ipc/Makefile
> +++ b/ipc/Makefile
> @@ -3,7 +3,7 @@
>  #
>  
>  obj-$(CONFIG_SYSVIPC_COMPAT) += compat.o
> -obj-$(CONFIG_SYSVIPC) += util.o msgutil.o msg.o sem.o shm.o ipcns_notifier.o syscall.o
> +obj-$(CONFIG_SYSVIPC) += util.o msgutil.o msg.o sem.o shm.o syscall.o
>  obj-$(CONFIG_SYSVIPC_SYSCTL) += ipc_sysctl.o
>  obj_mq-$(CONFIG_COMPAT) += compat_mq.o
>  obj-$(CONFIG_POSIX_MQUEUE) += mqueue.o msgutil.o $(obj_mq-y)
> diff --git a/ipc/ipc_sysctl.c b/ipc/ipc_sysctl.c
> index c3f0326..a00f9df 100644
> --- a/ipc/ipc_sysctl.c
> +++ b/ipc/ipc_sysctl.c
> @@ -62,29 +62,6 @@ static int proc_ipc_dointvec_minmax_orphans(struct ctl_table *table, int write,
>  	return err;
>  }
>  
> -static int proc_ipc_callback_dointvec_minmax(struct ctl_table *table, int write,
> -	void __user *buffer, size_t *lenp, loff_t *ppos)
> -{
> -	struct ctl_table ipc_table;
> -	size_t lenp_bef = *lenp;
> -	int rc;
> -
> -	memcpy(&ipc_table, table, sizeof(ipc_table));
> -	ipc_table.data = get_ipc(table);
> -
> -	rc = proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos);
> -
> -	if (write && !rc && lenp_bef == *lenp)
> -		/*
> -		 * Tunable has successfully been changed by hand. Disable its
> -		 * automatic adjustment. This simply requires unregistering
> -		 * the notifiers that trigger recalculation.
> -		 */
> -		unregister_ipcns_notifier(current->nsproxy->ipc_ns);
> -
> -	return rc;
> -}
> -
>  static int proc_ipc_doulongvec_minmax(struct ctl_table *table, int write,
>  	void __user *buffer, size_t *lenp, loff_t *ppos)
>  {
> @@ -96,64 +73,12 @@ static int proc_ipc_doulongvec_minmax(struct ctl_table *table, int write,
>  					lenp, ppos);
>  }
>  
> -/*
> - * Routine that is called when the file "auto_msgmni" has successfully been
> - * written.
> - * Two values are allowed:
> - * 0: unregister msgmni's callback routine from the ipc namespace notifier
> - *    chain. This means that msgmni won't be recomputed anymore upon memory
> - *    add/remove or ipc namespace creation/removal.
> - * 1: register back the callback routine.
> - */
> -static void ipc_auto_callback(int val)
> -{
> -	if (!val)
> -		unregister_ipcns_notifier(current->nsproxy->ipc_ns);
> -	else {
> -		/*
> -		 * Re-enable automatic recomputing only if not already
> -		 * enabled.
> -		 */
> -		recompute_msgmni(current->nsproxy->ipc_ns);
> -		cond_register_ipcns_notifier(current->nsproxy->ipc_ns);
> -	}
> -}
> -
> -static int proc_ipcauto_dointvec_minmax(struct ctl_table *table, int write,
> -	void __user *buffer, size_t *lenp, loff_t *ppos)
> -{
> -	struct ctl_table ipc_table;
> -	size_t lenp_bef = *lenp;
> -	int oldval;
> -	int rc;
> -
> -	memcpy(&ipc_table, table, sizeof(ipc_table));
> -	ipc_table.data = get_ipc(table);
> -	oldval = *((int *)(ipc_table.data));
> -
> -	rc = proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos);
> -
> -	if (write && !rc && lenp_bef == *lenp) {
> -		int newval = *((int *)(ipc_table.data));
> -		/*
> -		 * The file "auto_msgmni" has correctly been set.
> -		 * React by (un)registering the corresponding tunable, if the
> -		 * value has changed.
> -		 */
> -		if (newval != oldval)
> -			ipc_auto_callback(newval);
> -	}
> -
> -	return rc;
> -}
>  
>  #else
>  #define proc_ipc_doulongvec_minmax NULL
>  #define proc_ipc_dointvec	   NULL
>  #define proc_ipc_dointvec_minmax   NULL
>  #define proc_ipc_dointvec_minmax_orphans   NULL
> -#define proc_ipc_callback_dointvec_minmax  NULL
> -#define proc_ipcauto_dointvec_minmax NULL
>  #endif
>  
>  static int zero;
> @@ -205,7 +130,7 @@ static struct ctl_table ipc_kern_table[] = {
>  		.data		= &init_ipc_ns.msg_ctlmni,
>  		.maxlen		= sizeof(init_ipc_ns.msg_ctlmni),
>  		.mode		= 0644,
> -		.proc_handler	= proc_ipc_callback_dointvec_minmax,
> +		.proc_handler	= proc_ipc_dointvec_minmax,
>  		.extra1		= &zero,
>  		.extra2		= &int_max,
>  	},
> @@ -225,15 +150,6 @@ static struct ctl_table ipc_kern_table[] = {
>  		.mode		= 0644,
>  		.proc_handler	= proc_ipc_dointvec,
>  	},
> -	{
> -		.procname	= "auto_msgmni",
> -		.data		= &init_ipc_ns.auto_msgmni,
> -		.maxlen		= sizeof(int),
> -		.mode		= 0644,
> -		.proc_handler	= proc_ipcauto_dointvec_minmax,
> -		.extra1		= &zero,
> -		.extra2		= &one,
> -	},
>  #ifdef CONFIG_CHECKPOINT_RESTORE
>  	{
>  		.procname	= "sem_next_id",
> diff --git a/ipc/ipcns_notifier.c b/ipc/ipcns_notifier.c
> deleted file mode 100644
> index b9b31a4..0000000
> --- a/ipc/ipcns_notifier.c
> +++ /dev/null
> @@ -1,92 +0,0 @@
> -/*
> - * linux/ipc/ipcns_notifier.c
> - * Copyright (C) 2007 BULL SA. Nadia Derbey
> - *
> - * Notification mechanism for ipc namespaces:
> - * The callback routine registered in the memory chain invokes the ipcns
> - * notifier chain with the IPCNS_MEMCHANGED event.
> - * Each callback routine registered in the ipcns namespace recomputes msgmni
> - * for the owning namespace.
> - */
> -
> -#include <linux/msg.h>
> -#include <linux/rcupdate.h>
> -#include <linux/notifier.h>
> -#include <linux/nsproxy.h>
> -#include <linux/ipc_namespace.h>
> -
> -#include "util.h"
> -
> -
> -
> -static BLOCKING_NOTIFIER_HEAD(ipcns_chain);
> -
> -
> -static int ipcns_callback(struct notifier_block *self,
> -				unsigned long action, void *arg)
> -{
> -	struct ipc_namespace *ns;
> -
> -	switch (action) {
> -	case IPCNS_MEMCHANGED:   /* amount of lowmem has changed */
> -	case IPCNS_CREATED:
> -	case IPCNS_REMOVED:
> -		/*
> -		 * It's time to recompute msgmni
> -		 */
> -		ns = container_of(self, struct ipc_namespace, ipcns_nb);
> -		/*
> -		 * No need to get a reference on the ns: the 1st job of
> -		 * free_ipc_ns() is to unregister the callback routine.
> -		 * blocking_notifier_chain_unregister takes the wr lock to do
> -		 * it.
> -		 * When this callback routine is called the rd lock is held by
> -		 * blocking_notifier_call_chain.
> -		 * So the ipc ns cannot be freed while we are here.
> -		 */
> -		recompute_msgmni(ns);
> -		break;
> -	default:
> -		break;
> -	}
> -
> -	return NOTIFY_OK;
> -}
> -
> -int register_ipcns_notifier(struct ipc_namespace *ns)
> -{
> -	int rc;
> -
> -	memset(&ns->ipcns_nb, 0, sizeof(ns->ipcns_nb));
> -	ns->ipcns_nb.notifier_call = ipcns_callback;
> -	ns->ipcns_nb.priority = IPCNS_CALLBACK_PRI;
> -	rc = blocking_notifier_chain_register(&ipcns_chain, &ns->ipcns_nb);
> -	if (!rc)
> -		ns->auto_msgmni = 1;
> -	return rc;
> -}
> -
> -int cond_register_ipcns_notifier(struct ipc_namespace *ns)
> -{
> -	int rc;
> -
> -	memset(&ns->ipcns_nb, 0, sizeof(ns->ipcns_nb));
> -	ns->ipcns_nb.notifier_call = ipcns_callback;
> -	ns->ipcns_nb.priority = IPCNS_CALLBACK_PRI;
> -	rc = blocking_notifier_chain_cond_register(&ipcns_chain,
> -							&ns->ipcns_nb);
> -	if (!rc)
> -		ns->auto_msgmni = 1;
> -	return rc;
> -}
> -
> -void unregister_ipcns_notifier(struct ipc_namespace *ns)
> -{
> -	blocking_notifier_chain_unregister(&ipcns_chain, &ns->ipcns_nb);
> -	ns->auto_msgmni = 0;
> -}
> -
> -int ipcns_notify(unsigned long val)
> -{
> -	return blocking_notifier_call_chain(&ipcns_chain, val, NULL);
> -}
> diff --git a/ipc/msg.c b/ipc/msg.c
> index c5d8e37..a7261d5 100644
> --- a/ipc/msg.c
> +++ b/ipc/msg.c
> @@ -989,43 +989,12 @@ SYSCALL_DEFINE5(msgrcv, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
>  	return do_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg, do_msg_fill);
>  }
>  
> -/*
> - * Scale msgmni with the available lowmem size: the memory dedicated to msg
> - * queues should occupy at most 1/MSG_MEM_SCALE of lowmem.
> - * Also take into account the number of nsproxies created so far.
> - * This should be done staying within the (MSGMNI , IPCMNI/nr_ipc_ns) range.
> - */
> -void recompute_msgmni(struct ipc_namespace *ns)
> -{
> -	struct sysinfo i;
> -	unsigned long allowed;
> -	int nb_ns;
> -
> -	si_meminfo(&i);
> -	allowed = (((i.totalram - i.totalhigh) / MSG_MEM_SCALE) * i.mem_unit)
> -		/ MSGMNB;
> -	nb_ns = atomic_read(&nr_ipc_ns);
> -	allowed /= nb_ns;
> -
> -	if (allowed < MSGMNI) {
> -		ns->msg_ctlmni = MSGMNI;
> -		return;
> -	}
> -
> -	if (allowed > IPCMNI / nb_ns) {
> -		ns->msg_ctlmni = IPCMNI / nb_ns;
> -		return;
> -	}
> -
> -	ns->msg_ctlmni = allowed;
> -}
>  
>  void msg_init_ns(struct ipc_namespace *ns)
>  {
>  	ns->msg_ctlmax = MSGMAX;
>  	ns->msg_ctlmnb = MSGMNB;
> -
> -	recompute_msgmni(ns);
> +	ns->msg_ctlmni = MSGMNI;
>  
>  	atomic_set(&ns->msg_bytes, 0);
>  	atomic_set(&ns->msg_hdrs, 0);
> @@ -1069,9 +1038,6 @@ void __init msg_init(void)
>  {
>  	msg_init_ns(&init_ipc_ns);
>  
> -	printk(KERN_INFO "msgmni has been set to %d\n",
> -		init_ipc_ns.msg_ctlmni);
> -
>  	ipc_init_proc_interface("sysvipc/msg",
>  				"       key      msqid perms      cbytes       qnum lspid lrpid   uid   gid  cuid  cgid      stime      rtime      ctime\n",
>  				IPC_MSG_IDS, sysvipc_msg_proc_show);
> diff --git a/ipc/namespace.c b/ipc/namespace.c
> index b54468e..1a3ffd4 100644
> --- a/ipc/namespace.c
> +++ b/ipc/namespace.c
> @@ -45,14 +45,6 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
>  	msg_init_ns(ns);
>  	shm_init_ns(ns);
>  
> -	/*
> -	 * msgmni has already been computed for the new ipc ns.
> -	 * Thus, do the ipcns creation notification before registering that
> -	 * new ipcns in the chain.
> -	 */
> -	ipcns_notify(IPCNS_CREATED);
> -	register_ipcns_notifier(ns);
> -
>  	ns->user_ns = get_user_ns(user_ns);
>  
>  	return ns;
> @@ -99,25 +91,11 @@ void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids,
>  
>  static void free_ipc_ns(struct ipc_namespace *ns)
>  {
> -	/*
> -	 * Unregistering the hotplug notifier at the beginning guarantees
> -	 * that the ipc namespace won't be freed while we are inside the
> -	 * callback routine. Since the blocking_notifier_chain_XXX routines
> -	 * hold a rw lock on the notifier list, unregister_ipcns_notifier()
> -	 * won't take the rw lock before blocking_notifier_call_chain() has
> -	 * released the rd lock.
> -	 */
> -	unregister_ipcns_notifier(ns);
>  	sem_exit_ns(ns);
>  	msg_exit_ns(ns);
>  	shm_exit_ns(ns);
>  	atomic_dec(&nr_ipc_ns);
>  
> -	/*
> -	 * Do the ipcns removal notification after decrementing nr_ipc_ns in
> -	 * order to have a correct value when recomputing msgmni.
> -	 */
> -	ipcns_notify(IPCNS_REMOVED);
>  	put_user_ns(ns->user_ns);
>  	proc_free_inum(ns->proc_inum);
>  	kfree(ns);
> diff --git a/ipc/util.c b/ipc/util.c
> index 27d74e6..0001560 100644
> --- a/ipc/util.c
> +++ b/ipc/util.c
> @@ -71,44 +71,6 @@ struct ipc_proc_iface {
>  	int (*show)(struct seq_file *, void *);
>  };
>  
> -static void ipc_memory_notifier(struct work_struct *work)
> -{
> -	ipcns_notify(IPCNS_MEMCHANGED);
> -}
> -
> -static int ipc_memory_callback(struct notifier_block *self,
> -				unsigned long action, void *arg)
> -{
> -	static DECLARE_WORK(ipc_memory_wq, ipc_memory_notifier);
> -
> -	switch (action) {
> -	case MEM_ONLINE:    /* memory successfully brought online */
> -	case MEM_OFFLINE:   /* or offline: it's time to recompute msgmni */
> -		/*
> -		 * This is done by invoking the ipcns notifier chain with the
> -		 * IPC_MEMCHANGED event.
> -		 * In order not to keep the lock on the hotplug memory chain
> -		 * for too long, queue a work item that will, when waken up,
> -		 * activate the ipcns notification chain.
> -		 */
> -		schedule_work(&ipc_memory_wq);
> -		break;
> -	case MEM_GOING_ONLINE:
> -	case MEM_GOING_OFFLINE:
> -	case MEM_CANCEL_ONLINE:
> -	case MEM_CANCEL_OFFLINE:
> -	default:
> -		break;
> -	}
> -
> -	return NOTIFY_OK;
> -}
> -
> -static struct notifier_block ipc_memory_nb = {
> -	.notifier_call = ipc_memory_callback,
> -	.priority = IPC_CALLBACK_PRI,
> -};
> -
>  /**
>   * ipc_init - initialise ipc subsystem
>   *
> @@ -124,8 +86,6 @@ static int __init ipc_init(void)
>  	sem_init();
>  	msg_init();
>  	shm_init();
> -	register_hotmemory_notifier(&ipc_memory_nb);
> -	register_ipcns_notifier(&init_ipc_ns);
>  	return 0;
>  }
>  device_initcall(ipc_init);
> -- 
> 1.9.3
> 

^ permalink raw reply	[flat|nested] 14+ messages in thread

* [PATCH 0/3] ipc: Further updates to sysv/mqueue limits
@ 2014-05-29 18:46 Manfred Spraul
  2014-05-29 18:46 ` [PATCH 1/3] ipc/msg: increase MSGMNI, remove scaling Manfred Spraul
  0 siblings, 1 reply; 14+ messages in thread
From: Manfred Spraul @ 2014-05-29 18:46 UTC (permalink / raw)
  To: Davidlohr Bueso, Michael Kerrisk, Rafael Aquini, Rik van Riel
  Cc: LKML, 1vier1, Manfred Spraul

Hi all,

a) If we increase SHMMAX/SHMALL, then it makes sense to
   increase MSGMNI, too.
   And: This allows to remove the automatic scaling (~300 lines)

b) We can also increase SEMMSL, SEMMNI and SEMOPM

c) I think it would make more sense if a namespace starts with the
   limits from it's parent:
   If an admin set the limits, then he probably wants that these limits also
   apply for a new child namespace.

All patches are RFC - they compile, but that's it.

TODO:
- check if the sysv sem limits are sane.
  Especially the SEMOPM - if real users exist that pass > 1k ops, then
  switch from kmalloc to vmalloc.

  @the Redhat developers: Do you have any idea where this "often
  recommended" comes from?
  https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/5/html/Tuning_and_Optimizing_Red_Hat_Enterprise_Linux_for_Oracle_9i_and_10g_Databases/sect-Oracle_9i_and_10g_Tuning_Guide-Setting_Semaphores-The_SEMOPM_Parameter.html

- copy Davidlohrs explanation for the sysv shm limits to sysv msg and
  sysv sem.

- check if we should also increase the limits for posix mqueue

- decide if it would make sense to increase IPCMNI:

  Right now, it is 32768. This means that after 65536 pairs of
  semget()/semctl(IPC_RMID), semget() will return the same identifier
  again - and a semop(old_id) won't return -EINVAL, instead it will
  access the "new" array, which is probably now what the caller
  intended to do.

  The split is arbitrary - we could also split it 1048576/2048 or any
  other split we want.

- test everything.

--
	Manfred

^ permalink raw reply	[flat|nested] 14+ messages in thread

* [PATCH 1/3] ipc/msg: increase MSGMNI, remove scaling
  2014-05-29 18:46 [PATCH 0/3] ipc: Further updates to sysv/mqueue limits Manfred Spraul
@ 2014-05-29 18:46 ` Manfred Spraul
  0 siblings, 0 replies; 14+ messages in thread
From: Manfred Spraul @ 2014-05-29 18:46 UTC (permalink / raw)
  To: Davidlohr Bueso, Michael Kerrisk, Rafael Aquini, Rik van Riel
  Cc: LKML, 1vier1, Manfred Spraul

SysV can be abused to allocated locked kernel memory.
For most systems, a small limit doesn't make sense,
see the discussion with regards to SHMMAX.

Therefore: increase MSGMNI to the maximum supported.

And: if we ignore the risk of locking too much memory, then
an automatic scaling of MSGMNI doesn't make sense.

Therefore: remove the whole logic.

Note:
If an administrator must limit the memory allocations, then
he can set MSGMNI as necessary.

Or he can disable sysv entirely (as e.g. done with Android).
---
 include/linux/ipc_namespace.h | 20 ----------
 include/uapi/linux/msg.h      | 12 +-----
 ipc/Makefile                  |  2 +-
 ipc/ipc_sysctl.c              | 87 +---------------------------------------
 ipc/ipcns_notifier.c          | 92 -------------------------------------------
 ipc/msg.c                     | 36 +----------------
 ipc/namespace.c               | 22 -----------
 ipc/util.c                    | 40 -------------------
 8 files changed, 4 insertions(+), 307 deletions(-)
 delete mode 100644 ipc/ipcns_notifier.c

diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h
index 35e7eca..e365d5e 100644
--- a/include/linux/ipc_namespace.h
+++ b/include/linux/ipc_namespace.h
@@ -7,15 +7,6 @@
 #include <linux/notifier.h>
 #include <linux/nsproxy.h>
 
-/*
- * ipc namespace events
- */
-#define IPCNS_MEMCHANGED   0x00000001   /* Notify lowmem size changed */
-#define IPCNS_CREATED  0x00000002   /* Notify new ipc namespace created */
-#define IPCNS_REMOVED  0x00000003   /* Notify ipc namespace removed */
-
-#define IPCNS_CALLBACK_PRI 0
-
 struct user_namespace;
 
 struct ipc_ids {
@@ -38,7 +29,6 @@ struct ipc_namespace {
 	unsigned int	msg_ctlmni;
 	atomic_t	msg_bytes;
 	atomic_t	msg_hdrs;
-	int		auto_msgmni;
 
 	size_t		shm_ctlmax;
 	size_t		shm_ctlall;
@@ -77,18 +67,8 @@ extern atomic_t nr_ipc_ns;
 extern spinlock_t mq_lock;
 
 #ifdef CONFIG_SYSVIPC
-extern int register_ipcns_notifier(struct ipc_namespace *);
-extern int cond_register_ipcns_notifier(struct ipc_namespace *);
-extern void unregister_ipcns_notifier(struct ipc_namespace *);
-extern int ipcns_notify(unsigned long);
 extern void shm_destroy_orphaned(struct ipc_namespace *ns);
 #else /* CONFIG_SYSVIPC */
-static inline int register_ipcns_notifier(struct ipc_namespace *ns)
-{ return 0; }
-static inline int cond_register_ipcns_notifier(struct ipc_namespace *ns)
-{ return 0; }
-static inline void unregister_ipcns_notifier(struct ipc_namespace *ns) { }
-static inline int ipcns_notify(unsigned long l) { return 0; }
 static inline void shm_destroy_orphaned(struct ipc_namespace *ns) {}
 #endif /* CONFIG_SYSVIPC */
 
diff --git a/include/uapi/linux/msg.h b/include/uapi/linux/msg.h
index a703755..ae9ddd2 100644
--- a/include/uapi/linux/msg.h
+++ b/include/uapi/linux/msg.h
@@ -50,17 +50,7 @@ struct msginfo {
 	unsigned short  msgseg; 
 };
 
-/*
- * Scaling factor to compute msgmni:
- * the memory dedicated to msg queues (msgmni * msgmnb) should occupy
- * at most 1/MSG_MEM_SCALE of the lowmem (see the formula in ipc/msg.c):
- * up to 8MB       : msgmni = 16 (MSGMNI)
- * 4 GB            : msgmni = 8K
- * more than 16 GB : msgmni = 32K (IPCMNI)
- */
-#define MSG_MEM_SCALE 32
-
-#define MSGMNI    16   /* <= IPCMNI */     /* max # of msg queue identifiers */
+#define MSGMNI 32000   /* <= IPCMNI */     /* max # of msg queue identifiers */
 #define MSGMAX  8192   /* <= INT_MAX */   /* max size of message (bytes) */
 #define MSGMNB 16384   /* <= INT_MAX */   /* default max size of a message queue */
 
diff --git a/ipc/Makefile b/ipc/Makefile
index 9075e17..86c7300 100644
--- a/ipc/Makefile
+++ b/ipc/Makefile
@@ -3,7 +3,7 @@
 #
 
 obj-$(CONFIG_SYSVIPC_COMPAT) += compat.o
-obj-$(CONFIG_SYSVIPC) += util.o msgutil.o msg.o sem.o shm.o ipcns_notifier.o syscall.o
+obj-$(CONFIG_SYSVIPC) += util.o msgutil.o msg.o sem.o shm.o syscall.o
 obj-$(CONFIG_SYSVIPC_SYSCTL) += ipc_sysctl.o
 obj_mq-$(CONFIG_COMPAT) += compat_mq.o
 obj-$(CONFIG_POSIX_MQUEUE) += mqueue.o msgutil.o $(obj_mq-y)
diff --git a/ipc/ipc_sysctl.c b/ipc/ipc_sysctl.c
index 998d31b..cc34646 100644
--- a/ipc/ipc_sysctl.c
+++ b/ipc/ipc_sysctl.c
@@ -62,29 +62,6 @@ static int proc_ipc_dointvec_minmax_orphans(ctl_table *table, int write,
 	return err;
 }
 
-static int proc_ipc_callback_dointvec_minmax(ctl_table *table, int write,
-	void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	struct ctl_table ipc_table;
-	size_t lenp_bef = *lenp;
-	int rc;
-
-	memcpy(&ipc_table, table, sizeof(ipc_table));
-	ipc_table.data = get_ipc(table);
-
-	rc = proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos);
-
-	if (write && !rc && lenp_bef == *lenp)
-		/*
-		 * Tunable has successfully been changed by hand. Disable its
-		 * automatic adjustment. This simply requires unregistering
-		 * the notifiers that trigger recalculation.
-		 */
-		unregister_ipcns_notifier(current->nsproxy->ipc_ns);
-
-	return rc;
-}
-
 static int proc_ipc_doulongvec_minmax(ctl_table *table, int write,
 	void __user *buffer, size_t *lenp, loff_t *ppos)
 {
@@ -96,64 +73,11 @@ static int proc_ipc_doulongvec_minmax(ctl_table *table, int write,
 					lenp, ppos);
 }
 
-/*
- * Routine that is called when the file "auto_msgmni" has successfully been
- * written.
- * Two values are allowed:
- * 0: unregister msgmni's callback routine from the ipc namespace notifier
- *    chain. This means that msgmni won't be recomputed anymore upon memory
- *    add/remove or ipc namespace creation/removal.
- * 1: register back the callback routine.
- */
-static void ipc_auto_callback(int val)
-{
-	if (!val)
-		unregister_ipcns_notifier(current->nsproxy->ipc_ns);
-	else {
-		/*
-		 * Re-enable automatic recomputing only if not already
-		 * enabled.
-		 */
-		recompute_msgmni(current->nsproxy->ipc_ns);
-		cond_register_ipcns_notifier(current->nsproxy->ipc_ns);
-	}
-}
-
-static int proc_ipcauto_dointvec_minmax(ctl_table *table, int write,
-	void __user *buffer, size_t *lenp, loff_t *ppos)
-{
-	struct ctl_table ipc_table;
-	size_t lenp_bef = *lenp;
-	int oldval;
-	int rc;
-
-	memcpy(&ipc_table, table, sizeof(ipc_table));
-	ipc_table.data = get_ipc(table);
-	oldval = *((int *)(ipc_table.data));
-
-	rc = proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos);
-
-	if (write && !rc && lenp_bef == *lenp) {
-		int newval = *((int *)(ipc_table.data));
-		/*
-		 * The file "auto_msgmni" has correctly been set.
-		 * React by (un)registering the corresponding tunable, if the
-		 * value has changed.
-		 */
-		if (newval != oldval)
-			ipc_auto_callback(newval);
-	}
-
-	return rc;
-}
-
 #else
 #define proc_ipc_doulongvec_minmax NULL
 #define proc_ipc_dointvec	   NULL
 #define proc_ipc_dointvec_minmax   NULL
 #define proc_ipc_dointvec_minmax_orphans   NULL
-#define proc_ipc_callback_dointvec_minmax  NULL
-#define proc_ipcauto_dointvec_minmax NULL
 #endif
 
 static int zero;
@@ -205,7 +129,7 @@ static struct ctl_table ipc_kern_table[] = {
 		.data		= &init_ipc_ns.msg_ctlmni,
 		.maxlen		= sizeof(init_ipc_ns.msg_ctlmni),
 		.mode		= 0644,
-		.proc_handler	= proc_ipc_callback_dointvec_minmax,
+		.proc_handler	= proc_ipc_dointvec_minmax,
 		.extra1		= &zero,
 		.extra2		= &int_max,
 	},
@@ -225,15 +149,6 @@ static struct ctl_table ipc_kern_table[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_ipc_dointvec,
 	},
-	{
-		.procname	= "auto_msgmni",
-		.data		= &init_ipc_ns.auto_msgmni,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= proc_ipcauto_dointvec_minmax,
-		.extra1		= &zero,
-		.extra2		= &one,
-	},
 #ifdef CONFIG_CHECKPOINT_RESTORE
 	{
 		.procname	= "sem_next_id",
diff --git a/ipc/ipcns_notifier.c b/ipc/ipcns_notifier.c
deleted file mode 100644
index b9b31a4..0000000
--- a/ipc/ipcns_notifier.c
+++ /dev/null
@@ -1,92 +0,0 @@
-/*
- * linux/ipc/ipcns_notifier.c
- * Copyright (C) 2007 BULL SA. Nadia Derbey
- *
- * Notification mechanism for ipc namespaces:
- * The callback routine registered in the memory chain invokes the ipcns
- * notifier chain with the IPCNS_MEMCHANGED event.
- * Each callback routine registered in the ipcns namespace recomputes msgmni
- * for the owning namespace.
- */
-
-#include <linux/msg.h>
-#include <linux/rcupdate.h>
-#include <linux/notifier.h>
-#include <linux/nsproxy.h>
-#include <linux/ipc_namespace.h>
-
-#include "util.h"
-
-
-
-static BLOCKING_NOTIFIER_HEAD(ipcns_chain);
-
-
-static int ipcns_callback(struct notifier_block *self,
-				unsigned long action, void *arg)
-{
-	struct ipc_namespace *ns;
-
-	switch (action) {
-	case IPCNS_MEMCHANGED:   /* amount of lowmem has changed */
-	case IPCNS_CREATED:
-	case IPCNS_REMOVED:
-		/*
-		 * It's time to recompute msgmni
-		 */
-		ns = container_of(self, struct ipc_namespace, ipcns_nb);
-		/*
-		 * No need to get a reference on the ns: the 1st job of
-		 * free_ipc_ns() is to unregister the callback routine.
-		 * blocking_notifier_chain_unregister takes the wr lock to do
-		 * it.
-		 * When this callback routine is called the rd lock is held by
-		 * blocking_notifier_call_chain.
-		 * So the ipc ns cannot be freed while we are here.
-		 */
-		recompute_msgmni(ns);
-		break;
-	default:
-		break;
-	}
-
-	return NOTIFY_OK;
-}
-
-int register_ipcns_notifier(struct ipc_namespace *ns)
-{
-	int rc;
-
-	memset(&ns->ipcns_nb, 0, sizeof(ns->ipcns_nb));
-	ns->ipcns_nb.notifier_call = ipcns_callback;
-	ns->ipcns_nb.priority = IPCNS_CALLBACK_PRI;
-	rc = blocking_notifier_chain_register(&ipcns_chain, &ns->ipcns_nb);
-	if (!rc)
-		ns->auto_msgmni = 1;
-	return rc;
-}
-
-int cond_register_ipcns_notifier(struct ipc_namespace *ns)
-{
-	int rc;
-
-	memset(&ns->ipcns_nb, 0, sizeof(ns->ipcns_nb));
-	ns->ipcns_nb.notifier_call = ipcns_callback;
-	ns->ipcns_nb.priority = IPCNS_CALLBACK_PRI;
-	rc = blocking_notifier_chain_cond_register(&ipcns_chain,
-							&ns->ipcns_nb);
-	if (!rc)
-		ns->auto_msgmni = 1;
-	return rc;
-}
-
-void unregister_ipcns_notifier(struct ipc_namespace *ns)
-{
-	blocking_notifier_chain_unregister(&ipcns_chain, &ns->ipcns_nb);
-	ns->auto_msgmni = 0;
-}
-
-int ipcns_notify(unsigned long val)
-{
-	return blocking_notifier_call_chain(&ipcns_chain, val, NULL);
-}
diff --git a/ipc/msg.c b/ipc/msg.c
index 6498531..ea7e0d1 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -76,43 +76,12 @@ static int newque(struct ipc_namespace *, struct ipc_params *);
 static int sysvipc_msg_proc_show(struct seq_file *s, void *it);
 #endif
 
-/*
- * Scale msgmni with the available lowmem size: the memory dedicated to msg
- * queues should occupy at most 1/MSG_MEM_SCALE of lowmem.
- * Also take into account the number of nsproxies created so far.
- * This should be done staying within the (MSGMNI , IPCMNI/nr_ipc_ns) range.
- */
-void recompute_msgmni(struct ipc_namespace *ns)
-{
-	struct sysinfo i;
-	unsigned long allowed;
-	int nb_ns;
-
-	si_meminfo(&i);
-	allowed = (((i.totalram - i.totalhigh) / MSG_MEM_SCALE) * i.mem_unit)
-		/ MSGMNB;
-	nb_ns = atomic_read(&nr_ipc_ns);
-	allowed /= nb_ns;
-
-	if (allowed < MSGMNI) {
-		ns->msg_ctlmni = MSGMNI;
-		return;
-	}
-
-	if (allowed > IPCMNI / nb_ns) {
-		ns->msg_ctlmni = IPCMNI / nb_ns;
-		return;
-	}
-
-	ns->msg_ctlmni = allowed;
-}
 
 void msg_init_ns(struct ipc_namespace *ns)
 {
 	ns->msg_ctlmax = MSGMAX;
 	ns->msg_ctlmnb = MSGMNB;
-
-	recompute_msgmni(ns);
+	ns->msg_ctlmni = MSGMNI;
 
 	atomic_set(&ns->msg_bytes, 0);
 	atomic_set(&ns->msg_hdrs, 0);
@@ -131,9 +100,6 @@ void __init msg_init(void)
 {
 	msg_init_ns(&init_ipc_ns);
 
-	printk(KERN_INFO "msgmni has been set to %d\n",
-		init_ipc_ns.msg_ctlmni);
-
 	ipc_init_proc_interface("sysvipc/msg",
 				"       key      msqid perms      cbytes       qnum lspid lrpid   uid   gid  cuid  cgid      stime      rtime      ctime\n",
 				IPC_MSG_IDS, sysvipc_msg_proc_show);
diff --git a/ipc/namespace.c b/ipc/namespace.c
index 59451c1..6c01c2a 100644
--- a/ipc/namespace.c
+++ b/ipc/namespace.c
@@ -45,14 +45,6 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
 	msg_init_ns(ns);
 	shm_init_ns(ns);
 
-	/*
-	 * msgmni has already been computed for the new ipc ns.
-	 * Thus, do the ipcns creation notification before registering that
-	 * new ipcns in the chain.
-	 */
-	ipcns_notify(IPCNS_CREATED);
-	register_ipcns_notifier(ns);
-
 	ns->user_ns = get_user_ns(user_ns);
 
 	return ns;
@@ -99,25 +91,11 @@ void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids,
 
 static void free_ipc_ns(struct ipc_namespace *ns)
 {
-	/*
-	 * Unregistering the hotplug notifier at the beginning guarantees
-	 * that the ipc namespace won't be freed while we are inside the
-	 * callback routine. Since the blocking_notifier_chain_XXX routines
-	 * hold a rw lock on the notifier list, unregister_ipcns_notifier()
-	 * won't take the rw lock before blocking_notifier_call_chain() has
-	 * released the rd lock.
-	 */
-	unregister_ipcns_notifier(ns);
 	sem_exit_ns(ns);
 	msg_exit_ns(ns);
 	shm_exit_ns(ns);
 	atomic_dec(&nr_ipc_ns);
 
-	/*
-	 * Do the ipcns removal notification after decrementing nr_ipc_ns in
-	 * order to have a correct value when recomputing msgmni.
-	 */
-	ipcns_notify(IPCNS_REMOVED);
 	put_user_ns(ns->user_ns);
 	proc_free_inum(ns->proc_inum);
 	kfree(ns);
diff --git a/ipc/util.c b/ipc/util.c
index 2eb0d1e..768e1fc75 100644
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -71,44 +71,6 @@ struct ipc_proc_iface {
 	int (*show)(struct seq_file *, void *);
 };
 
-static void ipc_memory_notifier(struct work_struct *work)
-{
-	ipcns_notify(IPCNS_MEMCHANGED);
-}
-
-static int ipc_memory_callback(struct notifier_block *self,
-				unsigned long action, void *arg)
-{
-	static DECLARE_WORK(ipc_memory_wq, ipc_memory_notifier);
-
-	switch (action) {
-	case MEM_ONLINE:    /* memory successfully brought online */
-	case MEM_OFFLINE:   /* or offline: it's time to recompute msgmni */
-		/*
-		 * This is done by invoking the ipcns notifier chain with the
-		 * IPC_MEMCHANGED event.
-		 * In order not to keep the lock on the hotplug memory chain
-		 * for too long, queue a work item that will, when waken up,
-		 * activate the ipcns notification chain.
-		 */
-		schedule_work(&ipc_memory_wq);
-		break;
-	case MEM_GOING_ONLINE:
-	case MEM_GOING_OFFLINE:
-	case MEM_CANCEL_ONLINE:
-	case MEM_CANCEL_OFFLINE:
-	default:
-		break;
-	}
-
-	return NOTIFY_OK;
-}
-
-static struct notifier_block ipc_memory_nb = {
-	.notifier_call = ipc_memory_callback,
-	.priority = IPC_CALLBACK_PRI,
-};
-
 /**
  * ipc_init - initialise ipc subsystem
  *
@@ -124,8 +86,6 @@ static int __init ipc_init(void)
 	sem_init();
 	msg_init();
 	shm_init();
-	register_hotmemory_notifier(&ipc_memory_nb);
-	register_ipcns_notifier(&init_ipc_ns);
 	return 0;
 }
 device_initcall(ipc_init);
-- 
1.9.3


^ permalink raw reply related	[flat|nested] 14+ messages in thread

end of thread, other threads:[~2014-08-15 13:43 UTC | newest]

Thread overview: 14+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2014-08-12  7:29 [PATCH 0/3] ipc: Further updates to sysv/mqueue limits Manfred Spraul
2014-08-12  7:29 ` [PATCH 1/3] ipc/msg: increase MSGMNI, remove scaling Manfred Spraul
2014-08-12  7:29   ` [PATCH 2/3] ipc/sem.c: increase SEMMSL, SEMMNI, SEMOPM Manfred Spraul
     [not found]     ` <1407828557-31995-3-git-send-email-manfred-nhLOkwUX5cPe2c5cEj3t2g@public.gmane.org>
2014-08-12  7:29       ` [PATCH 3/3] ipc namespace: copy settings from parent namespace Manfred Spraul
2014-08-12  7:29         ` Manfred Spraul
     [not found]         ` <1407828557-31995-4-git-send-email-manfred-nhLOkwUX5cPe2c5cEj3t2g@public.gmane.org>
2014-08-12 10:37           ` Eric W. Biederman
2014-08-12 10:37             ` Eric W. Biederman
     [not found]             ` <877g2ec7tg.fsf-JOvCrm2gF+uungPnsOpG7nhyD016LWXt@public.gmane.org>
2014-08-12 20:39               ` Manfred Spraul
2014-08-12 20:39                 ` Manfred Spraul
2014-08-15 13:42           ` Rafael Aquini
2014-08-15 13:42             ` Rafael Aquini
2014-08-15 13:42     ` [PATCH 2/3] ipc/sem.c: increase SEMMSL, SEMMNI, SEMOPM Rafael Aquini
2014-08-15 13:41   ` [PATCH 1/3] ipc/msg: increase MSGMNI, remove scaling Rafael Aquini
  -- strict thread matches above, loose matches on Subject: below --
2014-05-29 18:46 [PATCH 0/3] ipc: Further updates to sysv/mqueue limits Manfred Spraul
2014-05-29 18:46 ` [PATCH 1/3] ipc/msg: increase MSGMNI, remove scaling Manfred Spraul

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