linux/ipc
Chris Metcalf 48b25c43e6 [PATCH v3] ipc: provide generic compat versions of IPC syscalls
When using the "compat" APIs, architectures will generally want to
be able to make direct syscalls to msgsnd(), shmctl(), etc., and
in the kernel we would want them to be handled directly by
compat_sys_xxx() functions, as is true for other compat syscalls.

However, for historical reasons, several of the existing compat IPC
syscalls do not do this.  semctl() expects a pointer to the fourth
argument, instead of the fourth argument itself.  msgsnd(), msgrcv()
and shmat() expect arguments in different order.

This change adds an ARCH_WANT_OLD_COMPAT_IPC config option that can be
set to preserve this behavior for ports that use it (x86, sparc, powerpc,
s390, and mips).  No actual semantics are changed for those architectures,
and there is only a minimal amount of code refactoring in ipc/compat.c.

Newer architectures like tile (and perhaps future architectures such
as arm64 and unicore64) should not select this option, and thus can
avoid having any IPC-specific code at all in their architecture-specific
compat layer.  In the same vein, if this option is not selected, IPC_64
mode is assumed, since that's what the <asm-generic> headers expect.

The workaround code in "tile" for msgsnd() and msgrcv() is removed
with this change; it also fixes the bug that shmat() and semctl() were
not being properly handled.

Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
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
compat.c [PATCH v3] ipc: provide generic compat versions of IPC syscalls 2012-03-15 13:13:38 -04:00
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
Makefile Add generic sys_ipc wrapper 2010-03-12 15:52:32 -08:00
mq_sysctl.c sysctl ipc: Remove dead binary sysctl support code. 2009-11-12 02:04:54 -08:00
mqueue.c ipc/mqueue: simplify reading msgqueue limit 2012-01-23 08:38:47 -08:00
msg.c Fix common misspellings 2011-03-31 11:26:23 -03:00
msgutil.c ... and the same kind of leak for mqueue 2011-12-09 00:40:21 -05:00
namespace.c ns proc: Add support for the ipc namespace 2011-05-10 14:35:47 -07:00
sem.c ipc/sem.c: remove private structures from public header file 2011-11-02 16:07:01 -07:00
shm.c SHM_UNLOCK: fix Unevictable pages stranded after swap 2012-01-23 08:38:48 -08:00
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