ARM: 9290/1: uaccess: Fix KASAN false-positives

__copy_to_user_memcpy() and __clear_user_memset() had been calling
memcpy() and memset() respectively, leading to false-positive KASAN
reports when starting userspace:

[ 10.707901] Run /init as init process
[ 10.731892] process '/bin/busybox' started with executable stack
[ 10.745234] ==================================================================
[ 10.745796] BUG: KASAN: user-memory-access in __clear_user_memset+0x258/0x3ac
[ 10.747260] Write of size 2687 at addr 000de581 by task init/1

Use __memcpy() and __memset() instead to allow userspace access, which
is of course the intent of these functions.

Signed-off-by: Andrew Jeffery <[e-mail]>
Signed-off-by: Zev Weiss <[e-mail]>
Reviewed-by: Arnd Bergmann <[e-mail]>
Signed-off-by: Russell King (Oracle) <[e-mail]>

arch/arm/lib/uaccess_with_memcpy.c

···
 			tocopy = n;
 
 		ua_flags = uaccess_save_and_enable();
-		memcpy((void *)to, from, tocopy);
+		__memcpy((void *)to, from, tocopy);
 		uaccess_restore(ua_flags);
 		to += tocopy;
 		from += tocopy;
···
 			tocopy = n;
 
 		ua_flags = uaccess_save_and_enable();
-		memset((void *)addr, 0, tocopy);
+		__memset((void *)addr, 0, tocopy);
 		uaccess_restore(ua_flags);
 		addr += tocopy;
 		n -= tocopy;