On Thu, 08 Dec, at 12:30:45PM, David Howells wrote:
> Get the firmware's secure-boot status in the kernel boot wrapper and stash
> it somewhere that the main kernel image can find.
>
> The efi_get_secureboot() function is extracted from the arm stub and (a)
> generalised so that it can be called from x86 and (b) made to use
> efi_call_runtime() so that it can be run in mixed-mode.
>
> Suggested-by: Lukas Wunner <[email protected]>
> Signed-off-by: David Howells <[email protected]>
> ---
>
> Documentation/x86/zero-page.txt | 2 +
> arch/x86/boot/compressed/eboot.c | 2 +
> arch/x86/boot/compressed/head_32.S | 1
> arch/x86/boot/compressed/head_64.S | 1
> arch/x86/include/asm/bootparam_utils.h | 5 +-
> arch/x86/include/uapi/asm/bootparam.h | 3 +
> arch/x86/kernel/asm-offsets.c | 1
> drivers/firmware/efi/libstub/Makefile | 2 -
> drivers/firmware/efi/libstub/arm-stub.c | 63
> +++--------------------------
> drivers/firmware/efi/libstub/secureboot.c | 63
> +++++++++++++++++++++++++++++
> include/linux/efi.h | 8 ++++
> 11 files changed, 90 insertions(+), 61 deletions(-)
> create mode 100644 drivers/firmware/efi/libstub/secureboot.c
[...]
> diff --git a/arch/x86/boot/compressed/head_32.S
> b/arch/x86/boot/compressed/head_32.S
> index d85b9625e836..c635f7e32f5c 100644
> --- a/arch/x86/boot/compressed/head_32.S
> +++ b/arch/x86/boot/compressed/head_32.S
> @@ -61,6 +61,7 @@
>
> __HEAD
> ENTRY(startup_32)
> + movb $0, BP_secure_boot(%esi)
> #ifdef CONFIG_EFI_STUB
> jmp preferred_addr
>
> diff --git a/arch/x86/boot/compressed/head_64.S
> b/arch/x86/boot/compressed/head_64.S
> index beab8322f72a..ccd2c7461b7f 100644
> --- a/arch/x86/boot/compressed/head_64.S
> +++ b/arch/x86/boot/compressed/head_64.S
> @@ -244,6 +244,7 @@ ENTRY(startup_64)
> * that maps our entire kernel(text+data+bss+brk), zero page
> * and command line.
> */
> + movb $0, BP_secure_boot(%rsi)
> #ifdef CONFIG_EFI_STUB
> /*
> * The entry point for the PE/COFF executable is efi_pe_entry, so
Is clearing ::secure_boot really necessary? Any code path that goes
via efi_main() will set it correctly and all other code paths should
get it cleared in sanitize_boot_params(), no?
> diff --git a/include/linux/efi.h b/include/linux/efi.h
> index c7904556d7a8..92e23f03045e 100644
> --- a/include/linux/efi.h
> +++ b/include/linux/efi.h
> @@ -1477,6 +1477,14 @@ efi_status_t efi_setup_gop(efi_system_table_t
> *sys_table_arg,
> bool efi_runtime_disabled(void);
> extern void efi_call_virt_check_flags(unsigned long flags, const char *call);
>
> +enum efi_secureboot_mode {
> + efi_secureboot_mode_unset,
> + efi_secureboot_mode_unknown,
> + efi_secureboot_mode_disabled,
> + efi_secureboot_mode_enabled,
> +};
> +enum efi_secureboot_mode efi_get_secureboot(efi_system_table_t *sys_table);
> +
> /*
> * Arch code can implement the following three template macros, avoiding
> * reptition for the void/non-void return cases of {__,}efi_call_virt():
>
What's the distinction between the unset and unknown enums?
