Re: [PATCH 2/3] selftests/lib.mk: Introduce check to validate required configs

[Petr Mladek <pmladek@suse.com>]

On Thu 2024-12-05 17:17:56, Siddharth Menon wrote:
> Currently, kselftests does not have a generalised mechanism to skip compilation
> and run tests when required kernel configuration flags are missing.
> 
> This patch introduces a check to validate the presence of required config flags
> specified in the selftest makefile. In case scripts/config is not found,
> this check is skipped.
> 
> Use TEST_CONFIG_DEPS to check for specific config options before compiling,
> example usage:
> ```
> TEST_CONFIG_DEPS := CONFIG_LIVEPATCH CONFIG_DYNAMIC_DEBUG

What is the reason to add another set of dependencies, please?

Both CONFIG_LIVEPATCH CONFIG_DYNAMIC_DEBUG are already mentioned in
tools/testing/selftests/livepatch/config

IMHO, the new check should read the dependencies
from the existing tools/testing/selftests/<test>/config file.

> --- a/tools/testing/selftests/lib.mk
> +++ b/tools/testing/selftests/lib.mk
> @@ -97,7 +97,21 @@ TEST_GEN_PROGS := $(patsubst %,$(OUTPUT)/%,$(TEST_GEN_PROGS))
>  TEST_GEN_PROGS_EXTENDED := $(patsubst %,$(OUTPUT)/%,$(TEST_GEN_PROGS_EXTENDED))
>  TEST_GEN_FILES := $(patsubst %,$(OUTPUT)/%,$(TEST_GEN_FILES))
>  
> -all: $(TEST_GEN_PROGS) $(TEST_GEN_PROGS_EXTENDED) $(TEST_GEN_FILES) \
> +KDIR ?= /lib/modules/$(shell uname -r)/build
> +
> +define CHECK_CONFIG_DEPS
> +    $(if $(wildcard $(KDIR)/scripts/config),
> +        $(eval MISSING_FLAGS := $(filter-out 1,$(foreach cfg,$(TEST_CONFIG_DEPS),\
> +            $(shell cd $(KDIR) && scripts/config --state $(cfg) | grep -q '^\(y\|m\)$$' && echo 1 || echo $(cfg))))),
> +        $(info Skipping CHECK_GEN_REQ: $(KDIR)/scripts/config not found)
> +    )
> +    $(if $(MISSING_FLAGS),$(error Missing required config flags: $(MISSING_FLAGS)))
> +endef

It somehow does not work here. I get:

tools/testing/selftests/livepatch # make run_tests 
grep: .config: No such file or directory
grep: .config: No such file or directory
grep: .config: No such file or directory
grep: .config: No such file or directory
../lib.mk:112: *** Missing required config flags: CONFIG_LIVEPATCH CONFIG_DYNAMIC_DEBUG.  Stop.


I run the livepatch tests the following way.

1. On my workstation, I build the kernel RPMs using

     make rpm-pkg

2. In qemu test system, I mount the build directory from the
   workstation and install both kernel and kernel-devel packages:

    rpm -ivh rpmbuild/RPMS/x86_64/kernel-6.12.0_default+-35.x86_64.rpm
    rpm -ivh rpmbuild/RPMS/x86_64/kernel-devel-6.12.0_default+-35.x86_64.rpm

   and reboot

3. In rebooted qemu test system, I mount once again the build
   directory from the workstation and run the tests:

     cd tools/testing/selftests/livepatch
     make run_tests


The "grep" errors come from the "scripts/config" command. For example:

   tools/testing/selftests/livepatch # /lib/modules/6.12.0-default+/build/scripts/config -s CONFIG_LIVEPATCH
   grep: .config: No such file or directory
   grep: .config: No such file or directory
   undef

It helps to define patch to the config file installed by the devel
package:

   tools/testing/selftests/livepatch # /lib/modules/6.12.0-default+/build/scripts/config --file /lib/modules/6.12.0-default+/config -s CONFIG_LIVEPATCH
   y


But I am not sure if this works when people run the "make" in the
original build directory on the workstation.

Best Regards,
Petr