Re: [PATCH 02/33] efi/libstub: Make initrd file loader configurable

Ard Biesheuvel
2020-04-24T13:15:59Z

On Fri, 24 Apr 2020 at 15:06, Ard Biesheuvel <ardb@kernel.org> wrote:
>
> Loading an initrd passed via the kernel command line is deprecated: it
> is limited to files that reside in the same volume as the one the kernel
> itself was loaded from, and we have more flexible ways to achieve the
> same. So make it configurable so new architectures can decide not to
> enable it.
>
> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
> ---
> drivers/firmware/efi/Kconfig | 11 ++++++++
> drivers/firmware/efi/libstub/efistub.h | 38 ++++++++++++++++++++------
> drivers/firmware/efi/libstub/file.c | 32 +++++-----------------
> 3 files changed, 47 insertions(+), 34 deletions(-)
>
> diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig
> index 2a2b2b96a1dc..4e788dd55b03 100644
> --- a/drivers/firmware/efi/Kconfig
> +++ b/drivers/firmware/efi/Kconfig
> @@ -124,6 +124,17 @@ config EFI_ARMSTUB_DTB_LOADER
> functionality for bootloaders that do not have such support
> this option is necessary.
>
> +config EFI_GENERIC_STUB_INITRD_CMDLINE_LOADER
> + bool "Enable the command line initrd loader"
> + depends on EFI_GENERIC_STUB

Right after hitting send, I realised this should be

depends on EFI_GENERIC_STUB || X86

Care to fix that up before applying, please?

> + default y
> + help
> + Select this config option to add support for the initrd= command
> + line parameter, allowing an initrd that resides on the same volume
> + as the kernel image to be loaded into memory.
> +
> + This method is deprecated.
> +
> config EFI_BOOTLOADER_CONTROL
> tristate "EFI Bootloader Control"
> depends on EFI_VARS
> diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
> index 67d26949fd26..7517683b31e9 100644
> --- a/drivers/firmware/efi/libstub/efistub.h
> +++ b/drivers/firmware/efi/libstub/efistub.h
> @@ -651,15 +651,35 @@ efi_status_t efi_parse_options(char const *cmdline);
> efi_status_t efi_setup_gop(struct screen_info *si, efi_guid_t *proto,
> unsigned long size);
>
> -efi_status_t efi_load_dtb(efi_loaded_image_t *image,
> - unsigned long *load_addr,
> - unsigned long *load_size);
> -
> -efi_status_t efi_load_initrd(efi_loaded_image_t *image,
> - unsigned long *load_addr,
> - unsigned long *load_size,
> - unsigned long soft_limit,
> - unsigned long hard_limit);
> +efi_status_t handle_cmdline_files(efi_loaded_image_t *image,
> + const efi_char16_t *optstr,
> + int optstr_size,
> + unsigned long soft_limit,
> + unsigned long hard_limit,
> + unsigned long *load_addr,
> + unsigned long *load_size);
> +
> +
> +static inline efi_status_t efi_load_dtb(efi_loaded_image_t *image,
> + unsigned long *load_addr,
> + unsigned long *load_size)
> +{
> + return handle_cmdline_files(image, L"dtb=", sizeof(L"dtb=") - 2,
> + ULONG_MAX, ULONG_MAX, load_addr, load_size);
> +}
> +
> +static inline efi_status_t efi_load_initrd(efi_loaded_image_t *image,
> + unsigned long *load_addr,
> + unsigned long *load_size,
> + unsigned long soft_limit,
> + unsigned long hard_limit)
> +{
> + if (!IS_ENABLED(CONFIG_EFI_GENERIC_STUB_INITRD_CMDLINE_LOADER))
> + return EFI_SUCCESS;
> +
> + return handle_cmdline_files(image, L"initrd=", sizeof(L"initrd=") - 2,
> + soft_limit, hard_limit, load_addr, load_size);
> +}
>
> efi_status_t efi_load_initrd_dev_path(unsigned long *load_addr,
> unsigned long *load_size,
> diff --git a/drivers/firmware/efi/libstub/file.c b/drivers/firmware/efi/libstub/file.c
> index ea66b1f16a79..27e014ea4459 100644
> --- a/drivers/firmware/efi/libstub/file.c
> +++ b/drivers/firmware/efi/libstub/file.c
> @@ -121,13 +121,13 @@ static int find_file_option(const efi_char16_t *cmdline, int cmdline_len,
> * We only support loading a file from the same filesystem as
> * the kernel image.
> */
> -static efi_status_t handle_cmdline_files(efi_loaded_image_t *image,
> - const efi_char16_t *optstr,
> - int optstr_size,
> - unsigned long soft_limit,
> - unsigned long hard_limit,
> - unsigned long *load_addr,
> - unsigned long *load_size)
> +efi_status_t handle_cmdline_files(efi_loaded_image_t *image,
> + const efi_char16_t *optstr,
> + int optstr_size,
> + unsigned long soft_limit,
> + unsigned long hard_limit,
> + unsigned long *load_addr,
> + unsigned long *load_size)
> {
> const efi_char16_t *cmdline = image->load_options;
> int cmdline_len = image->load_options_size / 2;
> @@ -239,21 +239,3 @@ static efi_status_t handle_cmdline_files(efi_loaded_image_t *image,
> efi_free(alloc_size, alloc_addr);
> return status;
> }
> -
> -efi_status_t efi_load_dtb(efi_loaded_image_t *image,
> - unsigned long *load_addr,
> - unsigned long *load_size)
> -{
> - return handle_cmdline_files(image, L"dtb=", sizeof(L"dtb=") - 2,
> - ULONG_MAX, ULONG_MAX, load_addr, load_size);
> -}
> -
> -efi_status_t efi_load_initrd(efi_loaded_image_t *image,
> - unsigned long *load_addr,
> - unsigned long *load_size,
> - unsigned long soft_limit,
> - unsigned long hard_limit)
> -{
> - return handle_cmdline_files(image, L"initrd=", sizeof(L"initrd=") - 2,
> - soft_limit, hard_limit, load_addr, load_size);
> -}
> --
> 2.17.1
>