From: Josh Boyer Date: Wed, 8 Nov 2017 15:11:34 +0000 Subject: [16/29] acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down Origin: https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/commit?id=67890a0361626ec3e035264656896c77670c414b 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. Signed-off-by: Josh Boyer Signed-off-by: David Howells Reviewed-by: "Lee, Chun-Yi" cc: Dave Young cc: linux-acpi@vger.kernel.org --- drivers/acpi/osl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Index: linux/drivers/acpi/osl.c =================================================================== --- linux.orig/drivers/acpi/osl.c +++ linux/drivers/acpi/osl.c @@ -194,7 +194,7 @@ acpi_physical_address __init acpi_os_get acpi_physical_address pa; #ifdef CONFIG_KEXEC - if (acpi_rsdp) + if (acpi_rsdp && !kernel_is_locked_down("ACPI RSDP specification")) return acpi_rsdp; #endif pa = acpi_arch_get_root_pointer();