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* ipc: add sysctl to specify desired next object idStanislav Kinsbursky2013-01-041-0/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Add 3 new variables and sysctls to tune them (by one "next_id" variable for messages, semaphores and shared memory respectively). This variable can be used to set desired id for next allocated IPC object. By default it's equal to -1 and old behaviour is preserved. If this variable is non-negative, then desired idr will be extracted from it and used as a start value to search for free IDR slot. Notes: 1) this patch doesn't guarantee that the new object will have desired id. So it's up to user space how to handle new object with wrong id. 2) After a sucessful id allocation attempt, "next_id" will be set back to -1 (if it was non-negative). [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Cc: Serge Hallyn <serge.hallyn@canonical.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc: introduce shm_rmid_forced sysctlVasiliy Kulikov2011-07-261-0/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add support for the shm_rmid_forced sysctl. If set to 1, all shared memory objects in current ipc namespace will be automatically forced to use IPC_RMID. The POSIX way of handling shmem allows one to create shm objects and call shmdt(), leaving shm object associated with no process, thus consuming memory not counted via rlimits. With shm_rmid_forced=1 the shared memory object is counted at least for one process, so OOM killer may effectively kill the fat process holding the shared memory. It obviously breaks POSIX - some programs relying on the feature would stop working. So set shm_rmid_forced=1 only if you're sure nobody uses "orphaned" memory. Use shm_rmid_forced=0 by default for compatability reasons. The feature was previously impemented in -ow as a configure option. [akpm@linux-foundation.org: fix documentation, per Randy] [akpm@linux-foundation.org: fix warning] [akpm@linux-foundation.org: readability/conventionality tweaks] [akpm@linux-foundation.org: fix shm_rmid_forced/shm_forced_rmid confusion, use standard comment layout] Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: "Serge E. Hallyn" <serge.hallyn@canonical.com> Cc: Daniel Lezcano <daniel.lezcano@free.fr> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Solar Designer <solar@openwall.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sysctl ipc: Remove dead binary sysctl support code.Eric W. Biederman2009-11-121-77/+0
| | | | | | | Now that sys_sysctl is a generic wrapper around /proc/sys .ctl_name and .strategy members of sysctl tables are dead code. Remove them. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: remove "struct file *" argument of ->proc_handlerAlexey Dobriyan2009-09-241-8/+8
| | | | | | | | | | | | | | | | | | | | | It's unused. It isn't needed -- read or write flag is already passed and sysctl shouldn't care about the rest. It _was_ used in two places at arch/frv for some reason. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "David S. Miller" <davem@davemloft.net> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* proc_sysctl: use CONFIG_PROC_SYSCTL around ipc and utsname proc_handlersSerge E. Hallyn2009-04-021-1/+1
| | | | | | | | | | | | | As pointed out by Cedric Le Goater (in response to Alexey's original comment wrt mqns), ipc_sysctl.c and utsname_sysctl.c are using CONFIG_PROC_FS, not CONFIG_PROC_SYSCTL, to determine whether to define the proc_handlers. Change that. Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Acked-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc/ipc_sysctl.c: move the definition of ipc_auto_callback()akpm@linux-foundation.org2009-01-061-23/+23
| | | | | | | | | | | | | | | proc_ipcauto_dointvec_minmax() is the only user of ipc_auto_callback(), since the former function is protected by CONFIG_PROC_FS, so should be the latter one. Just move its definition down. Signed-off-by: WANG Cong <wangcong@zeuux.org> Cc: Eric Biederman <ebiederm@xmision.com> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sysctl: simplify ->strategyAlexey Dobriyan2008-10-161-5/+4
| | | | | | | | | | | | | | | | name and nlen parameters passed to ->strategy hook are unused, remove them. In general ->strategy hook should know what it's doing, and don't do something tricky for which, say, pointer to original userspace array may be needed (name). Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: David S. Miller <davem@davemloft.net> [ networking bits ] Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Howells <dhowells@redhat.com> Cc: Matt Mackall <mpm@selenic.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc: do not use a negative value to re-enable msgmni automatic recomputingNadia Derbey2008-07-251-13/+59
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch proposes an alternative to the "magical positive-versus-negative number trick" Andrew complained about last week in http://lkml.org/lkml/2008/6/24/418. This had been introduced with the patches that scale msgmni to the amount of lowmem. With these patches, msgmni has a registered notification routine that recomputes msgmni value upon memory add/remove or ipc namespace creation/ removal. When msgmni is changed from user space (i.e. value written to the proc file), that notification routine is unregistered, and the way to make it registered back is to write a negative value into the proc file. This is the "magical positive-versus-negative number trick". To fix this, a new proc file is introduced: /proc/sys/kernel/auto_msgmni. This file acts as ON/OFF for msgmni automatic recomputing. With this patch, the process is the following: 1) kernel boots in "automatic recomputing mode" /proc/sys/kernel/msgmni contains the value that has been computed (depends on lowmem) /proc/sys/kernel/automatic_msgmni contains "1" 2) echo <val> > /proc/sys/kernel/msgmni . sets msg_ctlmni to <val> . de-activates automatic recomputing (i.e. if, say, some memory is added msgmni won't be recomputed anymore) . /proc/sys/kernel/automatic_msgmni now contains "0" 3) echo "0" > /proc/sys/kernel/automatic_msgmni . de-activates msgmni automatic recomputing this has the same effect as 2) except that msg_ctlmni's value stays blocked at its current value) 3) echo "1" > /proc/sys/kernel/automatic_msgmni . recomputes msgmni's value based on the current available memory size and number of ipc namespaces . re-activates automatic recomputing for msgmni. Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Cc: Solofo Ramangalahy <Solofo.Ramangalahy@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc: re-enable msgmni automatic recomputing msgmni if set to negativeNadia Derbey2008-04-291-10/+35
| | | | | | | | | | | | | | | | | | The enhancement as asked for by Yasunori: if msgmni is set to a negative value, register it back into the ipcns notifier chain. A new interface has been added to the notification mechanism: notifier_chain_cond_register() registers a notifier block only if not already registered. With that new interface we avoid taking care of the states changes in procfs. Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Mingming Cao <cmm@us.ibm.com> Cc: Pierre Peiffer <pierre.peiffer@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc: do not recompute msgmni anymore if explicitly set by userNadia Derbey2008-04-291-2/+41
| | | | | | | | | | | | | | | | Make msgmni not recomputed anymore upon ipc namespace creation / removal or memory add/remove, as soon as it has been set from userland. As soon as msgmni is explicitly set via procfs or sysctl(), the associated callback routine is unregistered from the ipc namespace notifier chain. Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Mingming Cao <cmm@us.ibm.com> Cc: Pierre Peiffer <pierre.peiffer@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* namespaces: move the IPC namespace under IPC_NS optionPavel Emelyanov2008-02-081-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the IPC namespace management code is spread over the ipc/*.c files. I moved this code into ipc/namespace.c file which is compiled out when needed. The linux/ipc_namespace.h file is used to store the prototypes of the functions in namespace.c and the stubs for NAMESPACES=n case. This is done so, because the stub for copy_ipc_namespace requires the knowledge of the CLONE_NEWIPC flag, which is in sched.h. But the linux/ipc.h file itself in included into many many .c files via the sys.h->sem.h sequence so adding the sched.h into it will make all these .c depend on sched.h which is not that good. On the other hand the knowledge about the namespaces stuff is required in 4 .c files only. Besides, this patch compiles out some auxiliary functions from ipc/sem.c, msg.c and shm.c files. It turned out that moving these functions into namespaces.c is not that easy because they use many other calls and macros from the original file. Moving them would make this patch complicated. On the other hand all these functions can be consolidated, so I will send a separate patch doing this a bit later. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Kirill Korotaev <dev@sw.ru> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc namespace: remove config ipc ns fixCedric Le Goater2007-10-171-4/+0
| | | | | | | | | | | | Finish the work : kill all #ifdef CONFIG_IPC_NS. Thanks Robert ! Signed-off-by: Cedric Le Goater <clg@fr.ibm.com> Cc: Eric Biederman <ebiederm@xmision.com> Cc: Robert P. J. Day <rpjday@mindspring.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] sysctl: remove insert_at_head from register_sysctlEric W. Biederman2007-02-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The semantic effect of insert_at_head is that it would allow new registered sysctl entries to override existing sysctl entries of the same name. Which is pain for caching and the proc interface never implemented. I have done an audit and discovered that none of the current users of register_sysctl care as (excpet for directories) they do not register duplicate sysctl entries. So this patch simply removes the support for overriding existing entries in the sys_sysctl interface since no one uses it or cares and it makes future enhancments harder. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Ralf Baechle <ralf@linux-mips.org> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: David Howells <dhowells@redhat.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Andi Kleen <ak@muc.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: Corey Minyard <minyard@acm.org> Cc: Neil Brown <neilb@suse.de> Cc: "John W. Linville" <linville@tuxdriver.com> Cc: James Bottomley <James.Bottomley@steeleye.com> Cc: Jan Kara <jack@ucw.cz> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Mark Fasheh <mark.fasheh@oracle.com> Cc: David Chinner <dgc@sgi.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Patrick McHardy <kaber@trash.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] sysctl: move SYSV IPC sysctls to their own fileEric W. Biederman2007-02-141-0/+183
This is just a simple cleanup to keep kernel/sysctl.c from getting to crowded with special cases, and by keeping all of the ipc logic to together it makes the code a little more readable. [gcoady.lk@gmail.com: build fix] Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Serge E. Hallyn <serue@us.ibm.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Kirill Korotaev <dev@sw.ru> Signed-off-by: Grant Coady <gcoady.lk@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>