Commit Graph

62 Commits

Author SHA1 Message Date
Peter Hurley
d076ac9112 ipc: simplify msg list search
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Acked-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-05-01 08:12:57 -07:00
Peter Hurley
8ac6ed5857 ipc: implement MSG_COPY as a new receive mode
Teach the helper routines about MSG_COPY so that msgtyp is preserved as
the message number to copy.

The security functions affected by this change were audited and no
additional changes are necessary.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Acked-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-05-01 08:12:57 -07:00
Peter Hurley
852028af86 ipc: remove msg handling from queue scan
In preparation for refactoring the queue scan into a separate
function, relocate msg copying.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Acked-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-05-01 08:12:57 -07:00
Stanislav Kinsbursky
2dc958fa2f ipc: set msg back to -EAGAIN if copy wasn't performed
Make sure that msg pointer is set back to error value in case of
MSG_COPY flag is set and desired message to copy wasn't found.  This
garantees that msg is either a error pointer or a copy address.

Otherwise the last message in queue will be freed without unlinking from
the queue (which leads to memory corruption) and the dummy allocated
copy won't be released.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-02 10:09:01 -07:00
Peter Hurley
88b9e456b1 ipc: don't allocate a copy larger than max
When MSG_COPY is set, a duplicate message must be allocated for the copy
before locking the queue.  However, the copy could not be larger than was
sent which is limited to msg_ctlmax.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Acked-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-03-08 15:05:33 -08:00
Stanislav Kinsbursky
3fcfe78658 ipc: add more comments to message copying related code
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-04 16:11:46 -08:00
Stanislav Kinsbursky
51eeacaa07 ipc: simplify message copying
Remove the redundant and confusing fill_copy().  Also add copy_msg()
check for error.  In this case exit from the function have to be done
instead of break, because further code interprets any error as EAGAIN.

Also define copy_msg() for the case when CONFIG_CHECKPOINT_RESTORE is
disabled.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-04 16:11:46 -08:00
Stanislav Kinsbursky
b30efe2775 ipc: convert prepare_copy() from macro to function
This code works if CONFIG_CHECKPOINT_RESTORE is disabled.

[akpm@linux-foundation.org: remove __maybe_unused]
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-04 16:11:46 -08:00
Stanislav Kinsbursky
85398aa8de ipc: simplify free_copy() call
Passing and checking of msgflg to free_copy() is redundant.  This patch
sets copy to NULL on declaration instead and checks for non-NULL in
free_copy().

Note: in case of copy allocation failure, error is returned immediately.
So no need to check for IS_ERR() in free_copy().

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-04 16:11:45 -08:00
Stanislav Kinsbursky
4a674f34ba ipc: introduce message queue copy feature
This patch is required for checkpoint/restore in userspace.

c/r requires some way to get all pending IPC messages without deleting
them from the queue (checkpoint can fail and in this case tasks will be
resumed, so queue have to be valid).

To achive this, new operation flag MSG_COPY for sys_msgrcv() system call
was introduced.  If this flag was specified, then mtype is interpreted as
number of the message to copy.

If MSG_COPY is set, then kernel will allocate dummy message with passed
size, and then use new copy_msg() helper function to copy desired message
(instead of unlinking it from the queue).

Notes:

1) Return -ENOSYS if MSG_COPY is specified, but
   CONFIG_CHECKPOINT_RESTORE is not set.

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>
2013-01-04 16:11:45 -08:00
Stanislav Kinsbursky
f9dd87f473 ipc: message queue receive cleanup
Move all message related manipulation into one function msg_fill().
Actually, two functions because of the compat one.

[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>
2013-01-04 16:11:45 -08:00
Stanislav Kinsbursky
9afdacda02 ipc: remove forced assignment of selected message
This is a cleanup patch. The assignment is redundant.

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>
2013-01-04 16:11:45 -08:00
Eric W. Biederman
1efdb69b0b userns: Convert ipc to use kuid and kgid where appropriate
- Store the ipc owner and creator with a kuid
- Store the ipc group and the crators group with a kgid.
- Add error handling to ipc_update_perms, allowing it to
  fail if the uids and gids can not be converted to kuids
  or kgids.
- Modify the proc files to display the ipc creator and
  owner in the user namespace of the opener of the proc file.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-09-06 22:17:20 -07:00
Lucas De Marchi
25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Serge E. Hallyn
b0e77598f8 userns: user namespaces: convert several capable() calls
CAP_IPC_OWNER and CAP_IPC_LOCK can be checked against current_user_ns(),
because the resource comes from current's own ipc namespace.

setuid/setgid are to uids in own namespace, so again checks can be against
current_user_ns().

Changelog:
	Jan 11: Use task_ns_capable() in place of sched_capable().
	Jan 11: Use nsown_capable() as suggested by Bastian Blank.
	Jan 11: Clarify (hopefully) some logic in futex and sched.c
	Feb 15: use ns_capable for ipc, not nsown_capable
	Feb 23: let copy_ipcs handle setting ipc_ns->user_ns
	Feb 23: pass ns down rather than taking it from current

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Daniel Lezcano <daniel.lezcano@free.fr>
Acked-by: David Howells <dhowells@redhat.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23 19:47:08 -07:00
Alexey Dobriyan
4be929be34 kernel-wide: replace USHORT_MAX, SHORT_MAX and SHORT_MIN with USHRT_MAX, SHRT_MAX and SHRT_MIN
- C99 knows about USHRT_MAX/SHRT_MAX/SHRT_MIN, not
  USHORT_MAX/SHORT_MAX/SHORT_MIN.

- Make SHRT_MIN of type s16, not int, for consistency.

[akpm@linux-foundation.org: fix drivers/dma/timb_dma.c]
[akpm@linux-foundation.org: fix security/keys/keyring.c]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:07:02 -07:00
Tejun Heo
5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Serge E. Hallyn
7d6feeb287 ipc ns: fix memory leak (idr)
We have apparently had a memory leak since
7ca7e564e0 "ipc: store ipcs into IDRs" in
2007.  The idr of which 3 exist for each ipc namespace is never freed.

This patch simply frees them when the ipcns is freed.  I don't believe any
idr_remove() are done from rcu (and could therefore be delayed until after
this idr_destroy()), so the patch should be safe.  Some quick testing
showed no harm, and the memory leak fixed.

Caught by kmemleak.

Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16 07:20:09 -08:00
Felipe Contreras
f1970c48ef ipc: fix unused variable warning
Commit a0d092f introduced the following warning:
ipc/msg.c: In function ?msgctl_down?:
ipc/msg.c:415: warning: ?msqid64? may be used uninitialized in this function

The gcc warning in this case is actually bogus, as msqid64 is touched only
iff cmd == IPC_SET, and in such case, copy_msqid_from_user() initializes
it properly.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-12-04 15:39:49 +01:00
Heiko Carstens
e48fbb699f [CVE-2009-0029] System call wrappers part 24
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:28 +01:00
Nadia Derbey
dfcceb26f8 ipc: only output msgmni value at boot time
When posting:
[PATCH 1/8] Scaling msgmni to the amount of lowmem
(see http://lkml.org/lkml/2008/2/11/171), I have added a KERN_INFO message
that is output each time msgmni is recomputed.

In http://lkml.org/lkml/2008/4/29/575 Tony Luck complained that this
message references an ipc namespace address that is useless.

I first thought of using an audit_log instead of a printk, as suggested by
Serge Hallyn.  But unfortunately, we do not have any other information
than the namespace address to provide here too.  So I chose to move the
message and output it only at boot time, removing the reference to the
namespace.

Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>
Cc: Pierre Peiffer <peifferp@gmail.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Cc: "Serge E. Hallyn" <serue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-06 11:29:12 -07:00
Zhang, Yanmin
44f564a4bf ipc: add definitions of USHORT_MAX and others
Add definitions of USHORT_MAX and others into kernel.  ipc uses it and slub
implementation might also use it.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com>
Reviewed-by: Christoph Lameter <clameter@sgi.com>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Cc: "Pierre Peiffer" <peifferp@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:14 -07:00
Pierre Peiffer
a5f75e7f25 IPC: consolidate all xxxctl_down() functions
semctl_down(), msgctl_down() and shmctl_down() are used to handle the same set
of commands for each kind of IPC.  They all start to do the same job (they
retrieve the ipc and do some permission checks) before handling the commands
on their own.

This patch proposes to consolidate this by moving these same pieces of code
into one common function called ipcctl_pre_down().

It simplifies a little these xxxctl_down() functions and increases a little
the maintainability.

Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:14 -07:00
Pierre Peiffer
8f4a3809c1 IPC: introduce ipc_update_perm()
The IPC_SET command performs the same permission setting for all IPCs.  This
patch introduces a common ipc_update_perm() function to update these
permissions and makes use of it for all IPCs.

Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:13 -07:00
Pierre Peiffer
016d7132f2 IPC: get rid of the use *_setbuf structure.
All IPCs make use of an intermetiate *_setbuf structure to handle the IPC_SET
command.  This is not really needed and, moreover, it complicates a little bit
the code.

This patch gets rid of the use of it and uses directly the semid64_ds/
msgid64_ds/shmid64_ds structure.

In addition of removing one struture declaration, it also simplifies and
improves a little bit the common 64-bits path.

Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:13 -07:00
Pierre Peiffer
a0d092fc2d IPC/message queues: introduce msgctl_down
Currently, sys_msgctl is not easy to read.

This patch tries to improve that by introducing the msgctl_down function to
handle all commands requiring the rwmutex to be taken in write mode (ie
IPC_SET and IPC_RMID for now).  It is the equivalent function of semctl_down
for message queues.

This greatly changes the readability of sys_msgctl and also harmonizes the way
these commands are handled among all IPCs.

Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:13 -07:00
Nadia Derbey
b6b337ad1c ipc: recompute msgmni on memory add / remove
Introduce the registration of a callback routine that recomputes msg_ctlmni
upon memory add / remove.

A single notifier block is registered in the hotplug memory chain for all the
ipc namespaces.

Since the ipc namespaces are not linked together, they have their own
notification chain: one notifier_block is defined per ipc namespace.

Each time an ipc namespace is created (removed) it registers (unregisters) its
notifier block in (from) the ipcns chain.  The callback routine registered in
the memory chain invokes the ipcns notifier chain with the IPCNS_LOWMEM event.
 Each callback routine registered in the ipcns namespace, in turn, recomputes
msgmni for the owning namespace.

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>
2008-04-29 08:06:12 -07:00
Nadia Derbey
4d89dc6ab2 ipc: scale msgmni to the number of ipc namespaces
Since all the namespaces see the same amount of memory (the total one) this
patch introduces a new variable that counts the ipc namespaces and divides
msg_ctlmni by this counter.

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>
2008-04-29 08:06:12 -07:00
Nadia Derbey
f7bf3df8be ipc: scale msgmni to the amount of lowmem
On large systems we'd like to allow a larger number of message queues.  In
some cases up to 32K.  However simply setting MSGMNI to a larger value may
cause problems for smaller systems.

The first patch of this series introduces a default maximum number of message
queue ids that scales with the amount of lowmem.

Since msgmni is per namespace and there is no amount of memory dedicated to
each namespace so far, the second patch of this series scales msgmni to the
number of ipc namespaces too.

Since msgmni depends on the amount of memory, it becomes necessary to
recompute it upon memory add/remove.  In the 4th patch, memory hotplug
management is added: a notifier block is registered into the memory hotplug
notifier chain for the ipc subsystem.  Since the ipc namespaces are not linked
together, they have their own notification chain: one notifier_block is
defined per ipc namespace.  Each time an ipc namespace is created (removed) it
registers (unregisters) its notifier block in (from) the ipcns chain.  The
callback routine registered in the memory chain invokes the ipcns notifier
chain with the IPCNS_MEMCHANGE event.  Each callback routine registered in the
ipcns namespace, in turn, recomputes msgmni for the owning namespace.

The 5th patch makes it possible to keep the memory hotplug notifier chain's
lock for a lesser amount of time: instead of directly notifying the ipcns
notifier chain upon memory add/remove, a work item is added to the global
workqueue.  When activated, this work item is the one who notifies the ipcns
notifier chain.

Since msgmni depends on the number of ipc namespaces, it becomes necessary to
recompute it upon ipc namespace creation / removal.  The 6th patch uses the
ipc namespace notifier chain for that purpose: that chain is notified each
time an ipc namespace is created or removed.  This makes it possible to
recompute msgmni for all the namespaces each time one of them is created or
removed.

When msgmni is explicitely set from userspace, we should avoid recomputing it
upon memory add/remove or ipcns creation/removal.  This is what the 7th patch
does: it simply unregisters the ipcns callback routine as soon as msgmni has
been changed from procfs or sysctl().

Even if msgmni is set by hand, it should be possible to make it back
automatically recomputed upon memory add/remove or ipcns creation/removal.
This what is achieved in patch 8: if set to a negative value, msgmni is added
back to the ipcns notifier chain, making it automatically recomputed again.

This patch:

Compute msg_ctlmni to make it scale with the amount of lowmem.  msg_ctlmni is
now set to make the message queues occupy 1/32 of the available lowmem.

Some cleaning has also been done for the MSGPOOL constant: the msgctl man page
says it's not used, but it also defines it as a size in bytes (the code
expresses it in Kbytes).

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>
2008-04-29 08:06:12 -07:00
Pierre Peiffer
48dea404ed IPC: use ipc_buildid() directly from ipc_addid()
By continuing to consolidate a little the IPC code, each id can be built
directly in ipc_addid() instead of having it built from each callers of
ipc_addid()

And I also remove shm_addid() in order to have, as much as possible, the
same code for shm/sem/msg.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:12 -07:00
Pierre Peiffer
01b8b07a5d IPC: consolidate sem_exit_ns(), msg_exit_ns() and shm_exit_ns()
sem_exit_ns(), msg_exit_ns() and shm_exit_ns() are all called when an
ipc_namespace is released to free all ipcs of each type.  But in fact, they
do the same thing: they loop around all ipcs to free them individually by
calling a specific routine.

This patch proposes to consolidate this by introducing a common function,
free_ipcs(), that do the job.  The specific routine to call on each
individual ipcs is passed as parameter.  For this, these ipc-specific
'free' routines are reworked to take a generic 'struct ipc_perm' as
parameter.

Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:26 -08:00
Pierre Peiffer
ed2ddbf88c IPC: make struct ipc_ids static in ipc_namespace
Each ipc_namespace contains a table of 3 pointers to struct ipc_ids (3 for
msg, sem and shm, structure used to store all ipcs) These 'struct ipc_ids'
are dynamically allocated for each icp_namespace as the ipc_namespace
itself (for the init namespace, they are initialized with pointers to
static variables instead)

It is so for historical reason: in fact, before the use of idr to store the
ipcs, the ipcs were stored in tables of variable length, depending of the
maximum number of ipc allowed.  Now, these 'struct ipc_ids' have a fixed
size.  As they are allocated in any cases for each new ipc_namespace, there
is no gain of memory in having them allocated separately of the struct
ipc_namespace.

This patch proposes to make this table static in the struct ipc_namespace.
Thus, we can allocate all in once and get rid of all the code needed to
allocate and free these ipc_ids separately.

Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net>
Acked-by: Cedric Le Goater <clg@fr.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:26 -08:00
Pavel Emelyanov
ae5e1b22f1 namespaces: move the IPC namespace under IPC_NS option
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>
2008-02-08 09:22:23 -08:00
Pierre Peiffer
b1ed88b47f IPC: fix error check in all new xxx_lock() and xxx_exit_ns() functions
In the new implementation of the [sem|shm|msg]_lock[_check]() routines, we
use the return value of ipc_lock() in container_of() without any check.
But ipc_lock may return a errcode.  The use of this errcode in
container_of() may alter this errcode, and we don't want this.

And in xxx_exit_ns, the pointer return by idr_find is of type 'struct
kern_ipc_per'...

Today, the code will work as is because the member used in these
container_of() is the first member of its container (offset == 0), the
errcode isn't changed then.  But in the general case, we can't count on
this assumption and this may lead later to a real bug if we don't correct
this.

Again, the proposed solution is simple and correct.  But, as pointed by
Nadia, with this solution, the same check will be done several times (in
all sub-callers...), what is not very funny/optimal...

Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-06 10:41:01 -08:00
Pierre Peiffer
283bb7fada IPC: fix error case when idr-cache is empty in ipcget()
With the use of idr to store the ipc, the case where the idr cache is
empty, when idr_get_new is called (this may happen even if we call
idr_pre_get() before), is not well handled: it lets
semget()/shmget()/msgget() return ENOSPC when this cache is empty, what 1.
does not reflect the facts and 2.  does not conform to the man(s).

This patch fixes this by retrying the whole process of allocation in this case.

Signed-off-by: Pierre Peiffer <pierre.peiffer@bull.net>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 11:53:49 -07:00
Kirill Korotaev
3ac88a41ff virtualization of sysv msg queues is incomplete
Virtualization of sysv msg queues is incomplete: msg_hdrs and msg_bytes
variables visible from userspace are global.  Let's make them
per-namespace.

Signed-off-by: Alexey Kuznetsov <alexey@openvz.org>
Signed-off-by: Kirill Korotaev <dev@openvz.org>
Cc: Pierre Peiffer <pierre.peiffer@bull.net>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Cc: Serge Hallyn <serue@us.ibm.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 11:53:48 -07:00
Nadia Derbey
1b531f2136 ipc: remove unneeded parameters
Remvoe the unneeded parameters from ipc_checkid() and ipc_buildid()
interfaces.

Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 11:53:48 -07:00
Nadia Derbey
3e148c7993 fix idr_find() locking
This is a patch that fixes the way idr_find() used to be called in ipc_lock():
in all the paths that don't imply an update of the ipcs idr, it was called
without the idr tree being locked.

The changes are:
  . in ipc_ids, the mutex has been changed into a reader/writer semaphore.
  . ipc_lock() now takes the mutex as a reader during the idr_find().
  . a new routine ipc_lock_down() has been defined: it doesn't take the
    mutex, assuming that it is being held by the caller. This is the routine
    that is now called in all the update paths.

Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>
Acked-by: Jarek Poplawski <jarkao2@o2.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 11:53:48 -07:00
Nadia Derbey
f4566f0485 ipc: fix wrong comments
This patch fixes the wrong / obsolete comments in the ipc code.  Also adds
a missing lock around ipc_get_maxid() in shm_get_stat().

Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 11:53:47 -07:00
Nadia Derbey
03f02c7657 Storing ipcs into IDRs
This patch converts casts of struct kern_ipc_perm to
   . struct msg_queue
   . struct sem_array
   . struct shmid_kernel
into the equivalent container_of() macro. It improves code maintenance
because the code need not change if kern_ipc_perm is no longer at the
beginning of the containing struct.

Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 11:53:46 -07:00
Nadia Derbey
023a53557e ipc: integrate ipc_checkid() into ipc_lock()
This patch introduces a new ipc_lock_check() routine interface:
   . each time ipc_checkid() is called, this is done after calling ipc_lock().
     ipc_checkid() is now called from inside ipc_lock_check().

[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: fix RCU locking]
Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 11:53:44 -07:00
Nadia Derbey
7748dbfaa0 ipc: unify the syscalls code
This patch introduces a change into the sys_msgget(), sys_semget() and
sys_shmget() routines: they now share a common code, which is better for
maintainability.

Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 11:53:44 -07:00
Nadia Derbey
7ca7e564e0 ipc: store ipcs into IDRs
This patch introduces ipcs storage into IDRs. The main changes are:
  . This ipc_ids structure is changed: the entries array is changed into a
    root idr structure.
  . The grow_ary() routine is removed: it is not needed anymore when adding
    an ipc structure, since we are now using the IDR facility.
  . The ipc_rmid() routine interface is changed:
       . there is no need for this routine to return the pointer passed in as
         argument: it is now declared as a void
       . since the id is now part of the kern_ipc_perm structure, no need to
         have it as an argument to the routine

Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 11:53:44 -07:00
Pavel Emelyanov
b488893a39 pid namespaces: changes to show virtual ids to user
This is the largest patch in the set. Make all (I hope) the places where
the pid is shown to or get from user operate on the virtual pids.

The idea is:
 - all in-kernel data structures must store either struct pid itself
   or the pid's global nr, obtained with pid_nr() call;
 - when seeking the task from kernel code with the stored id one
   should use find_task_by_pid() call that works with global pids;
 - when showing pid's numerical value to the user the virtual one
   should be used, but however when one shows task's pid outside this
   task's namespace the global one is to be used;
 - when getting the pid from userspace one need to consider this as
   the virtual one and use appropriate task/pid-searching functions.

[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: nuther build fix]
[akpm@linux-foundation.org: yet nuther build fix]
[akpm@linux-foundation.org: remove unneeded casts]
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Paul Menage <menage@google.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>
2007-10-19 11:53:40 -07:00
Jeff Garzik
8e1c091ccc arch/i386/* fs/* ipc/*: mark variables with uninitialized_var()
Mark variables with uninitialized_var() if such a warning appears,
and analysis proves that the var is initialized properly on all paths
it is used.

Signed-off-by: Jeff Garzik <jeff@garzik.org>
2007-07-17 16:23:19 -04:00
Cedric Le Goater
7d69a1f4a7 remove CONFIG_UTS_NS and CONFIG_IPC_NS
CONFIG_UTS_NS and CONFIG_IPC_NS have very little value as they only
deactivate the unshare of the uts and ipc namespaces and do not improve
performance.

Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Acked-by: "Serge E. Hallyn" <serue@us.ibm.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Pavel Emelianov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 09:05:47 -07:00
suzuki
651971cb72 [PATCH] Fix the size limit of compat space msgsize
Currently we allocate 64k space on the user stack and use it the msgbuf for
sys_{msgrcv,msgsnd} for compat and the results are later copied in user [
by copy_in_user].  This patch introduces helper routines for
sys_{msgrcv,msgsnd} as below:

do_msgsnd() : Accepts the mtype and user space ptr to the buffer along with
the msqid and msgflg.

do_msgrcv() : Accepts a kernel space ptr to mtype and a userspace ptr to
the buffer.  The mtype has to be copied back the user space msgbuf by the
caller.

These changes avoid the need to allocate the msgsize on the userspace (
thus removing the size limt ) and the overhead of an extra copy_in_user().

Signed-off-by: Suzuki K P <suzuki@in.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:38 -08:00
Linus Torvalds
80491eb90c Revert unintentional "volatile" changes in ipc/msg.c
Commit 5a06a363ef ("[PATCH] ipc/msg.c:
clean up coding style") breaks fakeroot on Alpha (variously hangs or
oopses), according to a report by Falk Hueffner.

The fact that the code seems to rely on compiler access ordering through
the use of "volatile" is a pretty certain sign that the code has locking
problems, and we should fix those properly and then remove the whole
"volatile" entirely.

But in the meantime, the movement of "volatile" was unintentional, and
should be reverted.

Cc: Falk Hueffner <falk@debian.org>
Cc: Andrew Morton <akpm@osdl.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-11-04 09:55:00 -08:00
Pavel Emelianov
c7e12b8389 [PATCH] Fix ipc entries removal
Fix two issuses related to ipc_ids->entries freeing.

1. When freeing ipc namespace we need to free entries allocated
   with ipc_init_ids().

2. When removing old entries in grow_ary() ipc_rcu_putref()
   may be called on entries set to &ids->nullentry earlier in
   ipc_init_ids().
   This is almost impossible without namespaces, but with
   them this situation becomes possible.

Found during OpenVZ testing after obvious leaks in beancounters.

Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Cc: Kirill Korotaev <dev@openvz.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-11-03 12:27:56 -08:00
Kirill Korotaev
1e78693738 [PATCH] IPC namespace - msg
IPC namespace support for IPC msg code.

Signed-off-by: Pavel Emelianiov <xemul@openvz.org>
Signed-off-by: Kirill Korotaev <dev@openvz.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 07:57:22 -07:00