Re: [PATCH] x86/reboot: Avoid EFI reboot when not running on EFI

From: Thomas Gleixner
Date: Thu Aug 29 2019 - 08:18:34 EST


On Thu, 29 Aug 2019, Rob Bradford wrote:

CC+ Ard

> Replace the check using efi_runtime_disabled() which only checks if EFI
> runtime was disabled on the kernel command line with a call to
> efi_enabled(EFI_RUNTIME_SERVICES) to check if EFI runtime services are
> available.
>
> In the situation where the kernel was booted without an EFI environment
> then only efi_enabled(EFI_RUNTIME_SERVICES) correctly represents that no
> EFI is available. Setting "noefi" or "efi=noruntime" on the commandline
> continue to have the same effect as efi_enabled(EFI_RUNTIME_SERVICES)
> will return false.
>
>
> Signed-off-by: Rob Bradford <robert.bradford@xxxxxxxxx>
> ---
> arch/x86/kernel/reboot.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
> index 09d6bded3c1e..0b0a7fccdb00 100644
> --- a/arch/x86/kernel/reboot.c
> +++ b/arch/x86/kernel/reboot.c
> @@ -500,7 +500,7 @@ static int __init reboot_init(void)
> */
> rv = dmi_check_system(reboot_dmi_table);
>
> - if (!rv && efi_reboot_required() && !efi_runtime_disabled())
> + if (!rv && efi_reboot_required() && efi_enabled(EFI_RUNTIME_SERVICES))

Why is efi_reboot_required() set at all in that situation?

Thanks,

tglx