Loadfile2 code is installing two protocols on it's own handle
and uses efi_delete_handle() to clean it up on failure(s). However
commit 05c4c9e21a ("efi_loader: define internal implementations of
install/uninstallmultiple") prepares the ground for us to clean up
efi_delete_handle() used in favor of Install/UninstallMultipleProtocol.
While at it clean up the non needed void casts to (void *) on the
protolcol installation.
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
A following patch is cleaning up the core EFI code trying to remove
sequences of efi_create_handle, efi_add_protocol.
Although this works fine there's a problem with the latter since it is
usually combined with efi_delete_handle() which blindly removes all
protocols on a handle and deletes the handle. We should try to adhere to
the EFI spec which only deletes a handle if the last instance of a protocol
has been removed. Another problem is that efi_delete_handle() never checks
for opened protocols, but the EFI spec defines that the caller is
responsible for ensuring that there are no references to a protocol
interface that is going to be removed.
So let's fix this by replacing all callsites of
efi_create_handle(), efi_add_protocol() , efi_delete_handle() with
Install/UninstallMultipleProtocol.
In order to do that redefine functions that can be used by the U-Boot
proper internally and add '_ext' variants that will be used from the
EFI API
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Create the GUID as a global variable.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Up to now we install EFI_LOAD_FILE2_PROTOCOL to load an initrd
unconditionally. Although we correctly return various EFI exit codes
depending on the file status (i.e EFI_NO_MEDIA, EFI_NOT_FOUND etc), the
kernel loader, only falls back to the cmdline interpreted initrd if the
protocol is not installed.
This creates a problem for EFI installers, since they won't be able to
load their own initrd and continue the installation. It also makes the
feature hard to use, since we can either have a single initrd or we have
to recompile u-boot if the filename changes.
So let's introduce a different logic that will decouple the initrd
path from the config option we currently have.
When defining a UEFI BootXXXX we can use the filepathlist and store
a file path pointing to our initrd. Specifically the EFI spec describes:
"The first element of the array is a device path that describes the device
and location of the Image for this load option. Other device paths may
optionally exist in the FilePathList, but their usage is OSV specific"
When the EFI application is launched through the bootmgr, we'll try to
interpret the extra device path. If that points to a file that exists on
our disk, we'll now install the load_file2 and the efi-stub will be able
to use it.
This opens up another path using U-Boot and defines a new boot flow.
A user will be able to control the kernel/initrd pairs without explicit
cmdline args or GRUB.
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
dm.h and env.h serve no purpose here. Remove them and sort the
remaining in alphabetical order.
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
The EFI_LOAD_FILE_PROTOCOL_GUID and EFI_LOAD_FILE2_PROTOCOL_GUID are needed
to complement the implementation of the LoadFile() boot service.
Remove a duplicate declaration of a variable for the
EFI_LOAD_FILE2_PROTOCOL_GUID.
Move the remaining declaration to efi_boottime.c.
Add a variable for the EFI_LOAD_FILE_PROTOCOL_GUID.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
strsep() changes the address that its first argument points to.
We cannot use the changed address as argument of free().
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
U-Boot offers a EFI_LOAD_FILE2_PROTOCOL which the Linux EFI stub can use to
load an initial RAM disk. Update the function comments of the
implementation.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Following kernel's proposal for an arch-agnostic initrd loading
mechanism [1] let's implement the U-boot counterpart.
This new approach has a number of advantages compared to what we did up
to now. The file is loaded into memory only when requested limiting the
area of TOCTOU attacks. Users will be allowed to place the initramfs
file on any u-boot accessible partition instead of just the ESP one.
Finally this is an attempt of a generic interface across architectures
in the linux kernel so it makes sense to support that.
The file location is intentionally only supported as a config option
argument(CONFIG_EFI_INITRD_FILESPEC), in an effort to enhance security.
Although U-boot is not responsible for verifying the integrity of the
initramfs, we can enhance the offered security by only accepting a
built-in option, which will be naturally verified by UEFI Secure Boot.
This can easily change in the future if needed and configure that via ENV
or UEFI variable.
[1] https://lore.kernel.org/linux-efi/20200207202637.GA3464906@rani.riverdale.lan/T/#m4a25eb33112fab7a22faa0fd65d4d663209af32f
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
