The check of the return code is already done a few lines above.
Although it doesn't cause any functional issues, remove the superfluous
checks
Addresses-Coverity-ID: 492766 Control flow issues (DEADCODE)
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Previous patches enabled SetVariableRT using a RAM backend.
Although EBBR [0] defines a variable format we can teach userspace tools
and write the altered variables, it's better if we skip the ABI
requirements completely.
So let's add a new variable, in its own namespace called "VarToFile"
which contains a binary dump of the updated RT, BS and, NV variables
and will be updated when GetVariable is called.
Some adjustments are needed to do that.
Currently we discard BS-only variables in EBS(). We need to preserve
those on the RAM backend that exposes the variables. Since BS-only
variables can't appear at runtime we need to move the memory masking
checks from efi_var_collect() to efi_get_next_variable_name_mem()/
efi_get_variable_mem() and do the filtering at runtime.
We also need an efi_var_collect() variant available at runtime, in order
to construct the "VarToFile" buffer on the fly.
All users and applications (for linux) have to do when updating a variable
is dd that variable in the file described by "RTStorageVolatile".
Linux efivarfs uses a first 4 bytes of the output to represent attributes
in little-endian format. So, storing variables works like this:
$~ efibootmgr -n 0001
$~ dd if=/sys/firmware/efi/efivars/VarToFile-b2ac5fc9-92b7-4acd-aeac-11e818c3130c of=/boot/efi/ubootefi.var skip=4 bs=1
[0] https://arm-software.github.io/ebbr/index.html#document-chapter5-variable-storage
Suggested-by: Ard Biesheuvel <ardb@kernel.org> # dumping all variables to a variable
Co-developed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com> # contributed on efi_var_collect_mem()
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
We largely do not need <common.h> in these files, so drop it. The only
exception here is that efi_freestanding.c needs <linux/types.h> and had
been getting that via <common.h>.
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Rini <trini@konsulko.com>
The efi_var_mem_free() function calculates the available size for a new
EFI variable by subtracting the occupied buffer size and the overhead
for a new variable from the maximum buffer size set in Kconfig. This
is then returned as QueryVariableInfo()'s RemainingVariableStorageSize
output.
This can underflow as the calculation is done in and processed as
unsigned integer types. Check for underflow before doing the subtraction
and return zero if there's no space.
Fixes: f1f990a8c9 ("efi_loader: memory buffer for variables")
Signed-off-by: Alper Nebi Yasak <alpernebiyasak@gmail.com>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
The VariableNameSize parameter is in bytes but u16_strnlen() counts u16.
Fix the parameter check for null termination.
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
UEFI variable names are typically constants and hence should be defined as
const. Unfortunately some of our API functions do not define the parameters
for UEFI variable names as const. This requires unnecessary conversions.
Adjust parameters of several internal functions to tre UEFI variable names
as const.
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
If GetNextVariableName() is called with a non-existing combination of
VariableName and VendorGuid, return EFI_INVALID_PARAMETER.
If GetNextVariableName() is called with a string that is not zero
terminated, return EFI_INVALID_PARAMETER.
Reformat a line over 80 characters.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
efi_var_mem_notify_exit_boot_services() is invoked when ExitBootServices()
is called by the UEFI payload.
efi_var_mem_notify_exit_boot_services() should not be defined as
__efi_runtime as it is invoking EFI_ENTRY() and EFI_EXIT() which themselves
are not __efi_runtime.
Fixes: f1f990a8c9 ("efi_loader: memory buffer for variables")
Fixes: e01aed47d6 ("efi_loader: Enable run-time variable support for tee based variables")
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
We recently added functions for storing/restoring variables
from a file to a memory backed buffer marked as __efi_runtime_data
commit f1f990a8c9 ("efi_loader: memory buffer for variables")
commit 5f7dcf079d ("efi_loader: UEFI variable persistence")
Using the same idea we now can support GetVariable() and GetNextVariable()
on the OP-TEE based variables as well.
So let's re-arrange the code a bit and move the commmon code for
accessing variables out of efi_variable.c. Create common functions for
reading variables from memory that both implementations can use on
run-time. Then just use those functions in the run-time variants of the
OP-TEE based EFI variable implementation and initialize the memory
buffer on ExitBootServices()
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
efi_var_mem_del() is in __efi_runtime because it would be needed for a
runtime implementation of SetVariable(). memmove() is not in __efi_runtime.
So we should not use it in efi_var_mem_del().
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Variable efi_current_var is a pointer to a physical memory address that
becomes invalid after SetVirtualAddressMap(). Instead of converting it via
ConvertPointer() simply set it to NULL.
Fixes: b02a707152 ("efi_loader: enable UEFI variables at runtime")
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Saving UEFI variable as encoded U-Boot environment variables does not allow
support at runtime.
Provide functions to manage a memory buffer with UEFI variables.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
