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

ipc/msg.c: use list_for_each_entry_[safe] for list traversing

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

The ipc/msg.c code does its list operations by hand and it open-codes the
accesses, instead of using for_each_entry_[safe].

Signed-off-by: Nikola Pajkovsky 
Cc: Stanislav Kinsbursky 
Cc: "Eric W. Biederman" 
Cc: Peter Hurley 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

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: refactor msg list search into separate function

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

[fengguang.wu@intel.com: find_msg can be static]
Signed-off-by: Peter Hurley 
Cc: Fengguang Wu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ipc: simplify msg list search

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

Signed-off-by: Peter Hurley 
Acked-by: Stanislav Kinsbursky 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ipc: implement MSG_COPY as a new receive mode

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

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 
Acked-by: Stanislav Kinsbursky 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ipc: remove msg handling from queue scan

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

In preparation for refactoring the queue scan into a separate
function, relocate msg copying.

Signed-off-by: Peter Hurley 
Acked-by: Stanislav Kinsbursky 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ipc: set msg back to -EAGAIN if copy wasn't performed

2013-04-02T17:09:01+00:00

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 
Signed-off-by: Linus Torvalds

ipc: don't allocate a copy larger than max

2013-03-08T23:05:33+00:00

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 
Acked-by: Stanislav Kinsbursky 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ipc: add more comments to message copying related code

2013-01-05T00:11:46+00:00

Signed-off-by: Stanislav Kinsbursky 
Cc: "Eric W. Biederman" 
Cc: James Morris 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

ipc: simplify message copying

2013-01-05T00:11:46+00:00

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 
Cc: "Eric W. Biederman" 
Cc: James Morris 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds