commit a90118c445cc7f07781de26a9684d4ec58bfcfd1 upstream.

Recent gcc compilers (gcc 9.1) generate warnings about an out of bounds
memset, if the memset goes accross several fields of a struct. This
generated a couple of warnings on x86_64 builds in sanitize_boot_params().

Fix this by explicitly saving the fields in struct boot_params
that are intended to be preserved, and zeroing all the rest.

[ tglx: Tagged for stable as it breaks the warning free build there as well ]
Suggested-by: NThomas Gleixner <tglx@linutronix.de>
Suggested-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NJohn Hubbard <jhubbard@nvidia.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20190731054627.5627-2-jhubbard@nvidia.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>