The use of kmap() is being deprecated in favor of kmap_local_page()
where it is feasible. With kmap_local_page(), the mapping is per
thread, CPU local and not globally visible.
binder_alloc_clear_buf() is a function where the use of kmap_local_page()
in place of kmap() is correctly suited because the mapping is local to the
thread.
Therefore, use kmap_local_page() / kunmap_local() but, instead of open
coding these two functions and adding a memset() of the virtual address
of the mapping, prefer memset_page().
Signed-off-by: Fabio M. De Francesco <[email protected]>
---
drivers/android/binder_alloc.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c
index 2ac1008a5f39..0b3f2f569053 100644
--- a/drivers/android/binder_alloc.c
+++ b/drivers/android/binder_alloc.c
@@ -1175,14 +1175,11 @@ static void binder_alloc_clear_buf(struct binder_alloc *alloc,
unsigned long size;
struct page *page;
pgoff_t pgoff;
- void *kptr;
page = binder_alloc_get_page(alloc, buffer,
buffer_offset, &pgoff);
size = min_t(size_t, bytes, PAGE_SIZE - pgoff);
- kptr = kmap(page) + pgoff;
- memset(kptr, 0, size);
- kunmap(page);
+ memset_page(page, pgoff, 0, size);
bytes -= size;
buffer_offset += size;
}
--
2.34.1
On Sat, Apr 23, 2022 at 3:24 AM Fabio M. De Francesco
<[email protected]> wrote:
>
> The use of kmap() is being deprecated in favor of kmap_local_page()
> where it is feasible. With kmap_local_page(), the mapping is per
> thread, CPU local and not globally visible.
>
> binder_alloc_clear_buf() is a function where the use of kmap_local_page()
> in place of kmap() is correctly suited because the mapping is local to the
> thread.
>
> Therefore, use kmap_local_page() / kunmap_local() but, instead of open
> coding these two functions and adding a memset() of the virtual address
> of the mapping, prefer memset_page().
>
> Signed-off-by: Fabio M. De Francesco <[email protected]>
Acked-by: Todd Kjos <[email protected]>
> ---
> drivers/android/binder_alloc.c | 5 +----
> 1 file changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c
> index 2ac1008a5f39..0b3f2f569053 100644
> --- a/drivers/android/binder_alloc.c
> +++ b/drivers/android/binder_alloc.c
> @@ -1175,14 +1175,11 @@ static void binder_alloc_clear_buf(struct binder_alloc *alloc,
> unsigned long size;
> struct page *page;
> pgoff_t pgoff;
> - void *kptr;
>
> page = binder_alloc_get_page(alloc, buffer,
> buffer_offset, &pgoff);
> size = min_t(size_t, bytes, PAGE_SIZE - pgoff);
> - kptr = kmap(page) + pgoff;
> - memset(kptr, 0, size);
> - kunmap(page);
> + memset_page(page, pgoff, 0, size);
> bytes -= size;
> buffer_offset += size;
> }
> --
> 2.34.1
>