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, 5 insertions, 0 deletions

diff --git a/include/linux/aio.h b/include/linux/aio.h
index 811dbb369379..7a8db4155281 100644
--- a/include/linux/aio.h
+++ b/include/linux/aio.h
@@ -212,6 +212,8 @@ extern void kick_iocb(struct kiocb *iocb);
 extern int aio_complete(struct kiocb *iocb, long res, long res2);
 struct mm_struct;
 extern void exit_aio(struct mm_struct *mm);
+extern long do_io_submit(aio_context_t ctx_id, long nr,
+                         struct iocb __user *__user *iocbpp, bool compat);
 #else
 static inline ssize_t wait_on_sync_kiocb(struct kiocb *iocb) { return 0; }
 static inline int aio_put_req(struct kiocb *iocb) { return 0; }
@@ -219,6 +221,9 @@ static inline void kick_iocb(struct kiocb *iocb) { }
 static inline int aio_complete(struct kiocb *iocb, long res, long res2) { return 0; }
 struct mm_struct;
 static inline void exit_aio(struct mm_struct *mm) { }
+static inline long do_io_submit(aio_context_t ctx_id, long nr,
+                                struct iocb __user * __user *iocbpp,
+                                bool compat) { return 0; }
 #endif /* CONFIG_AIO */
 
 static inline struct kiocb *list_kiocb(struct list_head *h)