Merge tag 'for-5.4/io_uring-2019-09-24' of git://git.kernel.dk/linux-block

Pull more io_uring updates from Jens Axboe:
 "A collection of later fixes and additions, that weren't quite ready
  for pushing out with the initial pull request.

  This contains:

   - Fix potential use-after-free of shadow requests (Jackie)

   - Fix potential OOM crash in request allocation (Jackie)

   - kmalloc+memcpy -> kmemdup cleanup (Jackie)

   - Fix poll crash regression (me)

   - Fix SQ thread not being nice and giving up CPU for !PREEMPT (me)

   - Add support for timeouts, making it easier to do epoll_wait()
     conversions, for instance (me)

   - Ensure io_uring works without f_ops->read_iter() and
     f_ops->write_iter() (me)"

* tag 'for-5.4/io_uring-2019-09-24' of git://git.kernel.dk/linux-block:
  io_uring: correctly handle non ->{read,write}_iter() file_operations
  io_uring: IORING_OP_TIMEOUT support
  io_uring: use cond_resched() in sqthread
  io_uring: fix potential crash issue due to io_get_req failure
  io_uring: ensure poll commands clear ->sqe
  io_uring: fix use-after-free of shadow_req
  io_uring: use kmemdup instead of kmalloc and memcpy

include/uapi/linux/io_uring.h

@@ -28,6 +28,7 @@ struct io_uring_sqe {
 		__u16		poll_events;
 		__u32		sync_range_flags;
 		__u32		msg_flags;
+		__u32		timeout_flags;
 	};
 	__u64	user_data;	/* data to be passed back at completion time */
 	union {
@@ -61,6 +62,7 @@ struct io_uring_sqe {
 #define IORING_OP_SYNC_FILE_RANGE	8
 #define IORING_OP_SENDMSG	9
 #define IORING_OP_RECVMSG	10
+#define IORING_OP_TIMEOUT	11
 
 /*
  * sqe->fsync_flags