linux-toradex.git/ipc/util.c, branch v3.10.2

ipc_schedule_free() can do vfree() directly now

2013-05-02T15:03:33+00:00

Commit 32fcfd40715e ("make vfree() safe to call from interrupt
contexts") made it safe to do vfree directly from the RCU callback,
which allows us to simplify ipc/util.c a lot by getting rid of the
differences between vmalloc/kmalloc memory.

Signed-off-by: Al Viro 
Signed-off-by: Linus Torvalds

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2013-05-02T00:51:54+00:00

Pull VFS updates from Al Viro,

Misc cleanups all over the place, mainly wrt /proc interfaces (switch
create_proc_entry to proc_create(), get rid of the deprecated
create_proc_read_entry() in favor of using proc_create_data() and
seq_file etc).

7kloc removed.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (204 commits)
  don't bother with deferred freeing of fdtables
  proc: Move non-public stuff from linux/proc_fs.h to fs/proc/internal.h
  proc: Make the PROC_I() and PDE() macros internal to procfs
  proc: Supply a function to remove a proc entry by PDE
  take cgroup_open() and cpuset_open() to fs/proc/base.c
  ppc: Clean up scanlog
  ppc: Clean up rtas_flash driver somewhat
  hostap: proc: Use remove_proc_subtree()
  drm: proc: Use remove_proc_subtree()
  drm: proc: Use minor->index to label things, not PDE->name
  drm: Constify drm_proc_list[]
  zoran: Don't print proc_dir_entry data in debug
  reiserfs: Don't access the proc_dir_entry in r_open(), r_start() r_show()
  proc: Supply an accessor for getting the data from a PDE's parent
  airo: Use remove_proc_subtree()
  rtl8192u: Don't need to save device proc dir PDE
  rtl8187se: Use a dir under /proc/net/r8180/
  proc: Add proc_mkdir_data()
  proc: Move some bits from linux/proc_fs.h to linux/{of.h,signal.h,tty.h}
  proc: Move PDE_NET() to fs/proc/proc_net.c
  ...

ipc,sem: fine grained locking for semtimedop

2013-05-01T15:12:58+00:00

Introduce finer grained locking for semtimedop, to handle the common case
of a program wanting to manipulate one semaphore from an array with
multiple semaphores.

If the call is a semop manipulating just one semaphore in an array with
multiple semaphores, only take the lock for that semaphore itself.

If the call needs to manipulate multiple semaphores, or another caller is
in a transaction that manipulates multiple semaphores, the sem_array lock
is taken, as well as all the locks for the individual semaphores.

On a 24 CPU system, performance numbers with the semop-multi
test with N threads and N semaphores, look like this:

	vanilla		Davidlohr's	Davidlohr's +	Davidlohr's +
threads			patches		rwlock patches	v3 patches
10	610652		726325		1783589		2142206
20	341570		365699		1520453		1977878
30	288102		307037		1498167		2037995
40	290714		305955		1612665		2256484
50	288620		312890		1733453		2650292
60	289987		306043		1649360		2388008
70	291298		306347		1723167		2717486
80	290948		305662		1729545		2763582
90	290996		306680		1736021		2757524
100	292243		306700		1773700		3059159

[davidlohr.bueso@hp.com: do not call sem_lock when bogus sma]
[davidlohr.bueso@hp.com: make refcounter atomic]
Signed-off-by: Rik van Riel 
Suggested-by: Linus Torvalds 
Acked-by: Davidlohr Bueso 
Cc: Chegu Vinod 
Cc: Jason Low 
Reviewed-by: Michel Lespinasse 
Cc: Peter Hurley 
Cc: Stanislav Kinsbursky 
Tested-by: Emmanuel Benisty 
Tested-by: Sedat Dilek 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ipc: introduce lockless pre_down ipcctl

2013-05-01T15:12:58+00:00

Various forms of ipc use ipcctl_pre_down() to retrieve an ipc object and
check permissions, mostly for IPC_RMID and IPC_SET commands.

Introduce ipcctl_pre_down_nolock(), a lockless version of this function.
The locking version is retained, yet modified to call the nolock version
without affecting its semantics, thus transparent to all ipc callers.

Signed-off-by: Davidlohr Bueso 
Signed-off-by: Rik van Riel 
Suggested-by: Linus Torvalds 
Cc: Chegu Vinod 
Cc: Emmanuel Benisty 
Cc: Jason Low 
Cc: Michel Lespinasse 
Cc: Peter Hurley 
Cc: Stanislav Kinsbursky 
Tested-by: Sedat Dilek 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ipc: introduce obtaining a lockless ipc object

2013-05-01T15:12:57+00:00

Through ipc_lock() and therefore ipc_lock_check() we currently return the
locked ipc object.  This is not necessary for all situations and can,
therefore, cause unnecessary ipc lock contention.

Introduce analogous ipc_obtain_object() and ipc_obtain_object_check()
functions that only lookup and return the ipc object.

Both these functions must be called within the RCU read critical section.

[akpm@linux-foundation.org: propagate the ipc_obtain_object() errno from ipc_lock()]
Signed-off-by: Davidlohr Bueso 
Signed-off-by: Rik van Riel 
Reviewed-by: Chegu Vinod 
Acked-by: Michel Lespinasse 
Cc: Emmanuel Benisty 
Cc: Jason Low 
Cc: Peter Hurley 
Cc: Stanislav Kinsbursky 
Tested-by: Sedat Dilek 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ipc/util.c: use register_hotmemory_notifier()

2013-04-29T22:54:36+00:00

Squishes a statement-with-no-effect warning, removes some ifdefs and
shrinks .text by one byte!

Note that this code fails to check for blocking_notifier_chain_register()
failures.

Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

procfs: new helper - PDE_DATA(inode)

2013-04-09T18:13:32+00:00

The only part of proc_dir_entry the code outside of fs/proc
really cares about is PDE(inode)->data.  Provide a helper
for that; static inline for now, eventually will be moved
to fs/proc, along with the knowledge of struct proc_dir_entry
layout.

Signed-off-by: Al Viro

ipc: convert to idr_alloc()

2013-02-28T03:10:19+00:00

Convert to the much saner new idr interface.

The new interface doesn't directly translate to the way idr_pre_get()
was used around ipc_addid() as preloading disables preemption.  From
my cursory reading, it seems like we should be able to do all
allocation from ipc_addid(), so I moved it there.  Can you please
check whether this would be okay?  If this is wrong and ipc_addid()
should be allowed to be called from non-sleepable context, I'd suggest
allocating id itself in the outer functions and later install the
pointer using idr_replace().

Signed-off-by: Tejun Heo 
Reported-by: Sedat Dilek 
Tested-by: Sedat Dilek 
Cc: Stanislav Kinsbursky 
Cc: "Eric W. Biederman" 
Cc: James Morris 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ipc: add sysctl to specify desired next object id

2013-01-05T00:11:45+00:00

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 
Cc: Serge Hallyn 
Cc: "Eric W. Biederman" 
Cc: Pavel Emelyanov 
Cc: Al Viro 
Cc: KOSAKI Motohiro 
Cc: Michael Kerrisk 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

userns: Convert ipc to use kuid and kgid where appropriate

2012-09-07T05:17:20+00:00

- 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