binder: read pre-translated fds from sender buffer

binder: read pre-translated fds from sender buffer

This patch is to prepare for an up coming patch where we read
pre-translated fds from the sender buffer and translate them before
copying them to the target.  It does not change run time.

The patch adds two new parameters to binder_translate_fd_array() to
hold the sender buffer and sender buffer parent.  These parameters let
us call copy_from_user() directly from the sender instead of using
binder_alloc_copy_from_buffer() to copy from the target.  Also the patch
adds some new alignment checks.  Previously the alignment checks would
have been done in a different place, but this lets us print more
useful error messages.

Reviewed-by: Martijn Coenen <maco@android.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Todd Kjos <tkjos@google.com>
Link: https://lore.kernel.org/r/20211130185152.437403-4-tkjos@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>