From d08e8347b707c9bf19d2eed36870fc85f0384c75 Mon Sep 17 00:00:00 2001 From: Peter Jones Date: Mon, 15 Jun 2020 16:24:08 -0400 Subject: [PATCH] efi: Make it possible to disable efivar_ssdt entirely commit 435d1a471598752446a72ad1201b3c980526d869 upstream. In most cases, such as CONFIG_ACPI_CUSTOM_DSDT and CONFIG_ACPI_TABLE_UPGRADE, boot-time modifications to firmware tables are tied to specific Kconfig options. Currently this is not the case for modifying the ACPI SSDT via the efivar_ssdt kernel command line option and associated EFI variable. This patch adds CONFIG_EFI_CUSTOM_SSDT_OVERLAYS, which defaults disabled, in order to allow enabling or disabling that feature during the build. Cc: Signed-off-by: Peter Jones Link: https://lore.kernel.org/r/20200615202408.2242614-1-pjones@redhat.com Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman --- drivers/firmware/efi/Kconfig | 11 +++++++++++ drivers/firmware/efi/efi.c | 2 +- 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig index 86210f75d2333..a4fadd42221d3 100644 --- a/drivers/firmware/efi/Kconfig +++ b/drivers/firmware/efi/Kconfig @@ -164,6 +164,17 @@ config RESET_ATTACK_MITIGATION have been evicted, since otherwise it will trigger even on clean reboots. +config EFI_CUSTOM_SSDT_OVERLAYS + bool "Load custom ACPI SSDT overlay from an EFI variable" + depends on EFI_VARS && ACPI + default ACPI_TABLE_UPGRADE + help + Allow loading of an ACPI SSDT overlay from an EFI variable specified + by a kernel command line option. + + See Documentation/admin-guide/acpi/ssdt-overlays.rst for more + information.endmenu + endmenu config UEFI_CPER diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index b39b7e6d4e4dc..a3dc6cb7326a5 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -221,7 +221,7 @@ static void generic_ops_unregister(void) efivars_unregister(&generic_efivars); } -#if IS_ENABLED(CONFIG_ACPI) +#ifdef CONFIG_EFI_CUSTOM_SSDT_OVERLAYS #define EFIVAR_SSDT_NAME_MAX 16 static char efivar_ssdt[EFIVAR_SSDT_NAME_MAX] __initdata; static int __init efivar_ssdt_setup(char *str)