Re: [Linux-stable-mirror] [PATCHv3 2/5] x86/boot/compressed/64: Print error if 5-level paging is not supported

On Mon, Dec 04, 2017 at 03:40:56PM +0300, Kirill A. Shutemov wrote:

We cannot proceed booting if the machine doesn't support the paging mode kernel was compiled for.

Getting error the usual way -- via validate_cpu() -- is not going to work. We need to enable appropriate paging mode before that, otherwise kernel would triple-fault during KASLR setup.

This code will go away once we get support for boot-time switching between paging modes.

Signed-off-by: Kirill A. Shutemov kirill.shutemov@linux.intel.com Cc: stable@vger.kernel.org [4.14+]

---

arch/x86/boot/compressed/misc.c | 16 ++++++++++++++++ arch/x86/boot/compressed/pgtable_64.c | 2 +- 2 files changed, 17 insertions(+), 1 deletion(-)

Reported-and-tested-by: Borislav Petkov bp@suse.de