Re: [PATCH v2] x86/hyperv: Remove BUG_ON() for kmap_local_page()

[Wei Liu]

On Thu, Oct 20, 2022 at 04:38:20PM +0800, Zhao Liu wrote:
> From: Zhao Liu <zhao1.liu@xxxxxxxxx>
> 
> The commit 154fb14df7a3c ("x86/hyperv: Replace kmap() with
> kmap_local_page()") keeps the BUG_ON() to check if kmap_local_page()
> fails.
> 
> But in fact, kmap_local_page() always returns a valid kernel address
> and won't return NULL here. It will BUG on its own if it fails. [1]
> 
> So directly use memcpy_to_page() which creates local mapping to copy.
> 
> [1]: https://lore.kernel.org/lkml/YztFEyUA48et0yTt@iweiny-mobl/
> 
> Suggested-by: Fabio M. De Francesco <fmdefrancesco@xxxxxxxxx>
> Suggested-by: Ira Weiny <ira.weiny@xxxxxxxxx>
> Reviewed-by: Ira Weiny <ira.weiny@xxxxxxxxx>
> Signed-off-by: Zhao Liu <zhao1.liu@xxxxxxxxx>

Applied to hyperv-fixes. Thanks.