On Tue, Jul 13, 2021 at 07:52:30AM +0200, Christoph Hellwig wrote:
> memcpy_to_page and memzero_page can write to arbitrary pages, which could
> be in the page cache or in high memory, so call flush_kernel_dcache_pages
> to flush the dcache.
>
> Fixes: bb90d4bc7b6a ("mm/highmem: Lift memcpy_[to|from]_page to core")
> Fixes: 28961998f858 ("iov_iter: lift memzero_page() to highmem.h")
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Ira Weiny <ira.weiny@xxxxxxxxx>
> ---
> include/linux/highmem.h | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/include/linux/highmem.h b/include/linux/highmem.h
> index 8c6e8e996c87..8e7e50a53a12 100644
> --- a/include/linux/highmem.h
> +++ b/include/linux/highmem.h
> @@ -318,6 +318,7 @@ static inline void memcpy_to_page(struct page *page, size_t offset,
>
> VM_BUG_ON(offset + len > PAGE_SIZE);
> memcpy(to + offset, from, len);
> + flush_dcache_page(page);
> kunmap_local(to);
> }
>
> @@ -325,6 +326,7 @@ static inline void memzero_page(struct page *page, size_t offset, size_t len)
> {
> char *addr = kmap_atomic(page);
> memset(addr + offset, 0, len);
> + flush_dcache_page(page);
> kunmap_atomic(addr);
> }
>
> --
> 2.30.2
>
