[PATCH 3.4 33/43] x86, x32: Use compat shims for io_{setup,submit}

Greg Kroah-Hartman
2014-06-28T19:19:35Z

From: Mike Frysinger <vapier@gentoo.org>

commit 7fd44dacdd803c0bbf38bf478d51d280902bb0f1 upstream.

The io_setup takes a pointer to a context id of type aio_context_t.
This in turn is typed to a __kernel_ulong_t. We could tweak the
exported headers to define this as a 64bit quantity for specific
ABIs, but since we already have a 32bit compat shim for the x86 ABI,
let's just re-use that logic. The libaio package is also written to
expect this as a pointer type, so a compat shim would simplify that.

The io_submit func operates on an array of pointers to iocb structs.
Padding out the array to be 64bit aligned is a huge pain, so convert
it over to the existing compat shim too.

We don't convert io_getevents to the compat func as its only purpose
is to handle the timespec struct, and the x32 ABI uses 64bit times.

With this change, the libaio package can now pass its testsuite when
built for the x32 ABI.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Link: http://lkml.kernel.org/r/1399250595-5005-1-git-send-email-vapier@gentoo.org
Cc: H.J. Lu <hjl.tools@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/x86/syscalls/syscall_64.tbl | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

--- a/arch/x86/syscalls/syscall_64.tbl
+++ b/arch/x86/syscalls/syscall_64.tbl
@@ -212,10 +212,10 @@
203 common sched_setaffinity sys_sched_setaffinity
204 common sched_getaffinity sys_sched_getaffinity
205 64 set_thread_area
-206 common io_setup sys_io_setup
+206 64 io_setup sys_io_setup
207 common io_destroy sys_io_destroy
208 common io_getevents sys_io_getevents
-209 common io_submit sys_io_submit
+209 64 io_submit sys_io_submit
210 common io_cancel sys_io_cancel
211 64 get_thread_area
212 common lookup_dcookie sys_lookup_dcookie
@@ -353,3 +353,5 @@
540 x32 process_vm_writev compat_sys_process_vm_writev
541 x32 setsockopt compat_sys_setsockopt
542 x32 getsockopt compat_sys_getsockopt
+543 x32 io_setup compat_sys_io_setup
+544 x32 io_submit compat_sys_io_submit