efi/x86: Ensure that EFI_RUNTIME_MAP is enabled for kexec

CONFIG_EFI_RUNTIME_MAP needs to be enabled in order for kexec to be able
to provide the required information about the EFI runtime mappings to
the incoming kernel, regardless of whether kexec_load() or
kexec_file_load() is being used. Without this information, kexec boot in
EFI mode is not possible.

The CONFIG_EFI_RUNTIME_MAP option is currently directly configurable if
CONFIG_EXPERT is enabled, so that it can be turned on for debugging
purposes even if KEXEC is not enabled. However, the upshot of this is
that it can also be disabled even when it shouldn't.

So tweak the Kconfig declarations to avoid this situation.

Reported-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
This commit is contained in:
Ard Biesheuvel 2023-08-02 17:17:04 +02:00
parent 762f169f5d
commit aba7e066c7

View file

@ -1945,6 +1945,7 @@ config EFI
select UCS2_STRING
select EFI_RUNTIME_WRAPPERS
select ARCH_USE_MEMREMAP_PROT
select EFI_RUNTIME_MAP if KEXEC_CORE
help
This enables the kernel to use EFI runtime services that are
available (such as the EFI variable services).
@ -2020,7 +2021,6 @@ config EFI_MAX_FAKE_MEM
config EFI_RUNTIME_MAP
bool "Export EFI runtime maps to sysfs" if EXPERT
depends on EFI
default KEXEC_CORE
help
Export EFI runtime memory regions to /sys/firmware/efi/runtime-map.
That memory map is required by the 2nd kernel to set up EFI virtual