On Wed, Aug 07, 2019 at 05:07:07PM -0700, Matthew Garrett wrote: > From: Josh Boyer <jwboyer@xxxxxxxxxx> > > This option allows userspace to pass the RSDP address to the kernel, which > makes it possible for a user to modify the workings of hardware. Reject > the option when the kernel is locked down. This requires some reworking > of the existing RSDP command line logic, since the early boot code also > makes use of a command-line passed RSDP when locating the SRAT table > before the lockdown code has been initialised. This is achieved by > separating the command line RSDP path in the early boot code from the > generic RSDP path, and then copying the command line RSDP into boot > params in the kernel proper if lockdown is not enabled. If lockdown is > enabled and an RSDP is provided on the command line, this will only be > used when parsing SRAT (which shouldn't permit kernel code execution) > and will be ignored in the rest of the kernel. > > (Modified by Matthew Garrett in order to handle the early boot RSDP > environment) > > Signed-off-by: Josh Boyer <jwboyer@xxxxxxxxxx> > Signed-off-by: David Howells <dhowells@xxxxxxxxxx> > Signed-off-by: Matthew Garrett <mjg59@xxxxxxxxxx> > Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx> > cc: Dave Young <dyoung@xxxxxxxxxx> > cc: linux-acpi@xxxxxxxxxxxxxxx > --- > arch/x86/boot/compressed/acpi.c | 19 +++++++++++++------ > arch/x86/include/asm/acpi.h | 9 +++++++++ > arch/x86/include/asm/x86_init.h | 2 ++ > arch/x86/kernel/acpi/boot.c | 5 +++++ > arch/x86/kernel/x86_init.c | 1 + > drivers/acpi/osl.c | 14 +++++++++++++- > include/linux/acpi.h | 6 ++++++ > 7 files changed, 49 insertions(+), 7 deletions(-) Also, why isn't an x86 person CCed here? This clearly needs an x86 maintainer's ACK before it goes in? Thx. -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.