aio: fix the compat vectored operations

The aio compat code was not converting the struct iovecs from 32bit to
64bit pointers, causing either EINVAL to be returned from io_getevents, or
EFAULT as the result of the I/O.  This patch passes a compat flag to
io_submit to signal that pointer conversion is necessary for a given iocb
array.

A variant of this was tested by Michael Tokarev.  I have also updated the
libaio test harness to exercise this code path with good success.
Further, I grabbed a copy of ltp and ran the
testcases/kernel/syscall/readv and writev tests there (compiled with -m32
on my 64bit system).  All seems happy, but extra eyes on this would be
welcome.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix CONFIG_COMPAT=n build]
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Reported-by: Michael Tokarev <mjt@tls.msk.ru>
Cc: Zach Brown <zach.brown@oracle.com>
Cc: <stable@kernel.org>		[2.6.35.1]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/fs/compat.c b/fs/compat.c
index 7b4aabb..f0b391c 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -673,7 +673,7 @@ compat_sys_io_submit(aio_context_t ctx_id, int nr, u32 __user *iocb)
 	iocb64 = compat_alloc_user_space(nr * sizeof(*iocb64));
 	ret = copy_iocb(nr, iocb, iocb64);
 	if (!ret)
-		ret = sys_io_submit(ctx_id, nr, iocb64);
+		ret = do_io_submit(ctx_id, nr, iocb64, 1);
 	return ret;
 }