On Mon, Apr 10, 2017 at 05:35:02PM -0700, Dan Williams wrote:
> Before we rework the "pmem api" to stop abusing __copy_user_nocache()
> for memcpy_to_pmem() we need to fix cases where we may strand dirty data
> in the cpu cache. The problem occurs when copy_from_iter_pmem() is used
> for arbitrary data transfers from userspace. There is no guarantee that
> these transfers, performed by dax_iomap_actor(), will have aligned
> destinations or aligned transfer lengths. Backstop the usage
> __copy_user_nocache() with explicit cache management in these unaligned
> cases.
>
> Yes, copy_from_iter_pmem() is now too big for an inline, but addressing
> that is saved for a later patch that moves the entirety of the "pmem
> api" into the pmem driver directly.
>
> Fixes: 5de490daec8b ("pmem: add copy_from_iter_pmem() and clear_pmem()")
> Cc: <[email protected]>
> Cc: <[email protected]>
> Cc: Jan Kara <[email protected]>
> Cc: Jeff Moyer <[email protected]>
> Cc: Ingo Molnar <[email protected]>
> Cc: Christoph Hellwig <[email protected]>
> Cc: "H. Peter Anvin" <[email protected]>
> Cc: Al Viro <[email protected]>
> Cc: Thomas Gleixner <[email protected]>
> Cc: Matthew Wilcox <[email protected]>
> Cc: Ross Zwisler <[email protected]>
> Signed-off-by: Toshi Kani <[email protected]>
> Signed-off-by: Dan Williams <[email protected]>
This looks good to me, thanks for fixing this.
Reviewed-by: Ross Zwisler <[email protected]>
