linux-toradex.git/ipc, branch v2.6.27.16

shm: fix shmctl(SHM_INFO) lockup with !CONFIG_SHMEM

2009-02-12T17:31:03+00:00

commit a68e61e8ff2d46327a37b69056998b47745db6fa upstream.

shm_get_stat() assumes that the inode is a "struct shmem_inode_info",
which is incorrect for !CONFIG_SHMEM (see fs/ramfs/inode.c:
ramfs_get_inode() vs.  mm/shmem.c: shmem_get_inode()).

This bad assumption can cause shmctl(SHM_INFO) to lockup when
shm_get_stat() tries to spin_lock(&info->lock).  Users of !CONFIG_SHMEM
may encounter this lockup simply by invoking the 'ipcs' command.

Reported by Jiri Olsa back in February 2008:
http://lkml.org/lkml/2008/2/29/74

Signed-off-by: Tony Battersby 
Cc: Jiri Kosina 
Reported-by: Jiri Olsa 
Cc: Hugh Dickins 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

System call wrappers part 26

2009-01-18T18:35:39+00:00

commit c4ea37c26a691ad0b7e86aa5884aab27830e95c9 upstream.

Signed-off-by: Heiko Carstens 
Signed-off-by: Greg Kroah-Hartman

System call wrappers part 25

2009-01-18T18:35:39+00:00

commit d5460c9974a321a194aded4a8c4daaac68ea8171 upstream.

Signed-off-by: Heiko Carstens 
Signed-off-by: Greg Kroah-Hartman

System call wrappers part 24

2009-01-18T18:35:38+00:00

commit e48fbb699f82ef1e80bd7126046394d2dc9ca7e6 upstream.

Signed-off-by: Heiko Carstens 
Signed-off-by: Greg Kroah-Hartman

System call wrapper special cases

2009-01-18T18:35:34+00:00

commit 6673e0c3fbeaed2cd08e2fd4a4aa97382d6fedb0 upstream.

System calls with an unsigned long long argument can't be converted with
the standard wrappers since that would include a cast to long, which in
turn means that we would lose the upper 32 bit on 32 bit architectures.
Also semctl can't use the standard wrapper since it has a 'union'
parameter.

So we handle them as special case and add some extra wrappers instead.

Signed-off-by: Heiko Carstens 
Signed-off-by: Greg Kroah-Hartman

Convert all system calls to return a long

2009-01-18T18:35:30+00:00

commit 2ed7c03ec17779afb4fcfa3b8c61df61bd4879ba upstream.

Convert all system calls to return a long. This should be a NOP since all
converted types should have the same size anyway.
With the exception of sys_exit_group which returned void. But that doesn't
matter since the system call doesn't return.

Signed-off-by: Heiko Carstens 
Signed-off-by: Greg Kroah-Hartman

sysvipc: fix the ipc structures initialization

2008-12-05T18:55:11+00:00

commit e00b4ff7ebf098b11b11be403921c1cf41d9e321 upstream.

A problem was found while reviewing the code after Bugzilla bug
http://bugzilla.kernel.org/show_bug.cgi?id=11796.

In ipc_addid(), the newly allocated ipc structure is inserted into the
ipcs tree (i.e made visible to readers) without locking it.  This is not
correct since its initialization continues after it has been inserted in
the tree.

This patch moves the ipc structure lock initialization + locking before
the actual insertion.

Signed-off-by: Nadia Derbey 
Reported-by: Clement Calmels 
Cc: Manfred Spraul 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

[PATCH] kill nameidata passing to permission(), rename to inode_permission()

2008-07-27T00:53:31+00:00

Incidentally, the name that gives hundreds of false positives on grep
is not a good idea...

Signed-off-by: Al Viro

SL*B: drop kmem cache argument from constructor

2008-07-26T19:00:07+00:00

Kmem cache passed to constructor is only needed for constructors that are
themselves multiplexeres.  Nobody uses this "feature", nor does anybody uses
passed kmem cache in non-trivial way, so pass only pointer to object.

Non-trivial places are:
	arch/powerpc/mm/init_64.c
	arch/powerpc/mm/hugetlbpage.c

This is flag day, yes.

Signed-off-by: Alexey Dobriyan 
Acked-by: Pekka Enberg 
Acked-by: Christoph Lameter 
Cc: Jon Tollefson 
Cc: Nick Piggin 
Cc: Matt Mackall 
[akpm@linux-foundation.org: fix arch/powerpc/mm/hugetlbpage.c]
[akpm@linux-foundation.org: fix mm/slab.c]
[akpm@linux-foundation.org: fix ubifs]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ipc: do not use a negative value to re-enable msgmni automatic recomputing

2008-07-25T17:53:42+00:00

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  > /proc/sys/kernel/msgmni
   . sets msg_ctlmni to 
   . 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 
Cc: Solofo Ramangalahy 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds