OpenCloudOS-Kernel/ipc
Doug Ledford 2c12ea498f ipc/mqueue: correct mq_attr_ok test
While working on the other parts of the mqueue stuff, I noticed that the
calculation for overflow in mq_attr_ok didn't actually match reality (this
is especially true since my last patch which changed how we account memory
slightly).

In particular, we used to test for overflow using:
  msgs * msgsize + msgs * sizeof(struct msg_msg *)

That was never really correct because each message we allocate via
load_msg() is actually a struct msg_msg followed by the data for the
message (and if struct msg_msg + data exceeds PAGE_SIZE we end up
allocating struct msg_msgseg structs too, but accounting for them would
get really tedious, so let's ignore those...they're only a pointer in size
anyway).  This patch updates the calculation to be more accurate in
regards to maximum possible memory consumption by the mqueue.

[akpm@linux-foundation.org: add a local to simplify overflow-checking expression]
Signed-off-by: Doug Ledford <dledford@redhat.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Manfred Spraul <manfred@colorfullife.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-31 17:49:31 -07:00
..
Makefile Add generic sys_ipc wrapper 2010-03-12 15:52:32 -08:00
compat.c [PATCH v3] ipc: provide generic compat versions of IPC syscalls 2012-03-15 13:13:38 -04:00
compat_mq.c ipc: initialize structure memory to zero for compat functions 2010-10-27 18:03:13 -07:00
ipc_sysctl.c ipc: introduce shm_rmid_forced sysctl 2011-07-26 16:49:44 -07:00
ipcns_notifier.c ipc: do not use a negative value to re-enable msgmni automatic recomputing 2008-07-25 10:53:42 -07:00
mq_sysctl.c mqueue: separate mqueue default value from maximum value 2012-05-31 17:49:31 -07:00
mqueue.c ipc/mqueue: correct mq_attr_ok test 2012-05-31 17:49:31 -07:00
msg.c Fix common misspellings 2011-03-31 11:26:23 -03:00
msgutil.c security: trim security.h 2012-02-14 10:45:42 +11:00
namespace.c userns: Use cred->user_ns instead of cred->user->user_ns 2012-04-07 16:55:51 -07:00
sem.c ipc/sem.c: remove private structures from public header file 2011-11-02 16:07:01 -07:00
shm.c hugetlbfs: fix alignment of huge page requests 2012-03-21 17:54:59 -07:00
syscall.c ppc64 sys_ipc breakage in 2.6.34-rc2 2010-03-22 09:57:19 -07:00
util.c ipc,rcu: Convert call_rcu(ipc_immediate_free) to kfree_rcu() 2011-07-20 14:10:16 -07:00
util.h userns: user namespaces: convert several capable() calls 2011-03-23 19:47:08 -07:00