Re: [PATCH v4 1/5] fs,io_uring: add infrastructure for uring-cmd

[Christoph Hellwig <hch@lst.de>]

On Thu, May 05, 2022 at 11:36:12AM +0530, Kanchan Joshi wrote:
> +	void (*uring_cmd)(struct io_uring_cmd *ioucmd, unsigned int issue_flags);

This adds an overly long line now.

>  } __randomize_layout;
> +struct io_uring_cmd {
> +	struct file	*file;
> +	const u8	*cmd;
> +	/* callback to defer completions to task context */
> +	void (*task_work_cb)(struct io_uring_cmd *cmd);
> +	u32		cmd_op;
> +	u8		pdu[32]; /* available inline for free use */

And with both unused and flags gone, pdu is unaligned again and will
crash the kernel on 64-bit architectures that do not support unaligned
loads and stores, so we'll need a "u32 __pad" here now.