linux-toradex.git/ipc/msg.c, branch tegra-10.9.4

ipc ns: fix memory leak (idr)

2010-01-28T23:02:25+00:00

commit 7d6feeb287c61aafa88f06345387b1188edf4b86 upstream.

We have apparently had a memory leak since
7ca7e564e049d8b350ec9d958ff25eaa24226352 "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 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Acked-by: Nick Piggin 
Signed-off-by: Greg Kroah-Hartman

[CVE-2009-0029] System call wrappers part 24

2009-01-14T13:15:28+00:00

Signed-off-by: Heiko Carstens

ipc: only output msgmni value at boot time

2008-06-06T18:29:12+00:00

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 
Cc: Pierre Peiffer 
Cc: Manfred Spraul 
Acked-by: Tony Luck 
Cc: "Serge E. Hallyn" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ipc: add definitions of USHORT_MAX and others

2008-04-29T15:06:14+00:00

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 
Reviewed-by: Christoph Lameter 
Cc: Nadia Derbey 
Cc: "Pierre Peiffer" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

IPC: consolidate all xxxctl_down() functions

2008-04-29T15:06:14+00:00

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 
Acked-by: Serge Hallyn 
Cc: Nadia Derbey 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

IPC: introduce ipc_update_perm()

2008-04-29T15:06:13+00:00

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 
Acked-by: Serge Hallyn 
Cc: Nadia Derbey 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

IPC: get rid of the use *_setbuf structure.

2008-04-29T15:06:13+00:00

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 
Acked-by: Serge Hallyn 
Cc: Nadia Derbey 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

IPC/message queues: introduce msgctl_down

2008-04-29T15:06:13+00:00

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 
Acked-by: Serge Hallyn 
Cc: Nadia Derbey 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ipc: recompute msgmni on memory add / remove

2008-04-29T15:06:12+00:00

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 
Cc: Yasunori Goto 
Cc: Matt Helsley 
Cc: Mingming Cao 
Cc: Pierre Peiffer 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ipc: scale msgmni to the number of ipc namespaces

2008-04-29T15:06:12+00:00

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 
Cc: Yasunori Goto 
Cc: Matt Helsley 
Cc: Mingming Cao 
Cc: Pierre Peiffer 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds