selftests/kexec: remove broken EFI_VARS secure boot fallback check

Commit b433a52aa28733e0 ("selftests/kexec: update get_secureboot_mode")
refactored the code that discovers the EFI secure boot mode so it only
depends on either the efivars pseudo filesystem or the efivars sysfs
interface, but never both.

However, the latter version was not implemented correctly, given the
fact that the local 'efi_vars' variable never assumes a value. This
means the fallback has been dead code ever since it was introduced.

So let's drop the fallback altogether. The sysfs interface has been
deprecated for ~10 years now, and is only enabled on x86 to begin with,
so it is time to get rid of it entirely.

Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

selftests/kexec: Enable secureboot tests for PowerPC

Existing test cases determine secureboot state using efi variable, which
is available only on x86 architecture. Add support for determining
secureboot state using device tree property on PowerNV architecture.

Signed-off-by: Nageswara R Sastry <rnsastry@linux.ibm.com>
Reviewed-by: Nayna Jain <nayna@linux.ibm.com>
Tested-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

selftests/kexec: update searching for the Kconfig

First check /lib/modules/`uname -r`/config, before using the IKCONFIG.
In addition, the configs.ko might be compressed. Fix the configs.ko
name.

Reviewed-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

selftests/kexec: update get_secureboot_mode

The get_secureboot_mode() function unnecessarily requires both
CONFIG_EFIVAR_FS and CONFIG_EFI_VARS to be enabled to determine if the
system is booted in secure boot mode. On some systems the old EFI
variable support is not enabled or, possibly, even implemented.

This patch first checks the efivars filesystem for the SecureBoot and
SetupMode flags, but falls back to using the old EFI variable support.

The "secure_boot_file" and "setup_mode_file" couldn't be quoted due to
globbing. This patch also removes the globbing.

Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/kexec: kexec_file_load syscall test

The kernel can be configured to verify PE signed kernel images, IMA
kernel image signatures, both types of signatures, or none. This test
verifies only properly signed kernel images are loaded into memory,
based on the kernel configuration and runtime policies.

Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/kexec: define "require_root_privileges"

Many tests require root privileges. Define a common function.

Suggested-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/kexec: define common logging functions

Define log_info, log_pass, log_fail, and log_skip functions.

Suggested-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/kexec: define a set of common functions

Define, update and move get_secureboot_mode() to a common file for use
by other tests.

Updated to check both the efivar SecureBoot-$(UUID) and
SetupMode-$(UUID), based on Dave Young's review.

Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>