UPSTREAM: binder: Use memset_page() in binder_alloc_clear_buf()

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().

Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Link: https://lore.kernel.org/r/20220425175754.8180-2-fmdefrancesco@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Bug: 368205746
Bug: 365876437
Bug: 367895677
(cherry picked from commit 26eff2d6)
Change-Id: I7bc041db662ee1e8758c173861b2229d6ad8eb1e
Signed-off-by: yenchia.chen <yenchia.chen@mediatek.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
(cherry picked from commit b15de99b)