[PATCH v2] Add recipe for linux kselftest

[Vijai Kumar K <Vijaikumar_Kanagarajan@mentor.com>]

Kselftest is a set of unit and regression tests under the
tools/testing/selftests/ directory of the Linux kernel. These are used
for testing individual code paths in the kernel.

Kselftest is not debianized and is not available as part of the official
Debian repository.

This patch provides a recipe to build kselftest from the linux source of
your choice.

Sometimes developers/testers tend to use the latest version of selftests
from Linux upstream stable releases for testing and hence the need for a
separate recipe instead of being part of the linux recipe of ISAR.

Some kselftest test cases build are known to break in certain linux
versions, this has to be addressed upstream. Right now kselftest build
succeeds even if atleast one of the testcase case build succeeds.

You can change that by setting KSELFTEST_FORCE_TARGETS=1.

TARGETS, TARGETS_SKIP, FORCE_TARGETS can be set using the appropriate
KSELFTEST_* recipe variable.

Signed-off-by: Vijai Kumar K <Vijaikumar_Kanagarajan@mentor.com>
---
Changes since v1:
 - Addressed review comments in v1
   - Used debianize APIs for control, compat and changelog.
   - Moved Depends & S definitions to include file.
   - Added cross compilation bits in rules.
   - Change clang, llvm to clang:native & llvm:native

 .../kselftest/kselftest_5.6.13.bb             | 11 ++++
 .../kselftest/files/debian/rules              | 41 +++++++++++++
 meta/recipes-kernel/kselftest/kselftest.inc   | 61 +++++++++++++++++++
 3 files changed, 113 insertions(+)
 create mode 100644 meta-isar/recipes-kernel/kselftest/kselftest_5.6.13.bb
 create mode 100755 meta/recipes-kernel/kselftest/files/debian/rules
 create mode 100644 meta/recipes-kernel/kselftest/kselftest.inc

diff --git a/meta-isar/recipes-kernel/kselftest/kselftest_5.6.13.bb b/meta-isar/recipes-kernel/kselftest/kselftest_5.6.13.bb
new file mode 100644
index 0000000..0c9818a
--- /dev/null
+++ b/meta-isar/recipes-kernel/kselftest/kselftest_5.6.13.bb
@@ -0,0 +1,11 @@
+# Kselftest package
+#
+# This software is a part of ISAR.
+# Copyright (c) Mentor Graphics, a Siemens business, 2020
+#
+# SPDX-License-Identifier: MIT
+
+require recipes-kernel/kselftest/kselftest.inc
+
+SRC_URI += "https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-${PV}.tar.xz"
+SRC_URI[sha256sum] = "f125d79c8f6974213638787adcad6b575bbd35a05851802fd83f622ec18ff987"
diff --git a/meta/recipes-kernel/kselftest/files/debian/rules b/meta/recipes-kernel/kselftest/files/debian/rules
new file mode 100755
index 0000000..776d341
--- /dev/null
+++ b/meta/recipes-kernel/kselftest/files/debian/rules
@@ -0,0 +1,41 @@
+#!/usr/bin/make -f
+
+# Debian rules for Kselftest build
+#
+# This software is a part of ISAR.
+# Copyright (c) Mentor, A Siemens Business
+#
+# SPDX-License-Identifier: MIT
+
+deb_top_dir:=$(CURDIR)/debian
+kselftest_install_dir :=$(deb_top_dir)/kselftest/usr/libexec/kselftest
+export CROSS_COMPILE=$(DEB_HOST_GNU_TYPE)-
+
+ifeq ($(DEB_HOST_GNU_CPU), arm)
+export ARCH=arm
+endif
+ifeq ($(DEB_HOST_GNU_CPU), aarch64)
+export ARCH=arm64
+endif
+ifeq ($(DEB_HOST_GNU_CPU), riscv64)
+export ARCH=riscv
+endif
+ifneq (,$(findstring 86,$(DEB_HOST_GNU_CPU)))
+export ARCH=x86
+endif
+
+PARALLEL_BUILD=-j $(shell echo $$(($$(nproc) * 2)))
+
+override_dh_auto_build:
+	$(MAKE) defconfig
+	$(MAKE) $(PARALLEL_BUILD) -C tools/testing/selftests/ ${KSELFTEST_ARGS}
+
+override_dh_auto_install:
+	mkdir -p ${kselftest_install_dir}
+	cd tools/testing/selftests/ && KSFT_INSTALL_PATH=${kselftest_install_dir} $(MAKE) $(PARALLEL_BUILD) install ${KSELFTEST_ARGS}
+
+override_dh_auto_clean:
+	rm -rf ${deb_top_dir}/kselftest/
+
+%:
+	CFLAGS= LDFLAGS= dh $@ --parallel
diff --git a/meta/recipes-kernel/kselftest/kselftest.inc b/meta/recipes-kernel/kselftest/kselftest.inc
new file mode 100644
index 0000000..46ca282
--- /dev/null
+++ b/meta/recipes-kernel/kselftest/kselftest.inc
@@ -0,0 +1,61 @@
+# Kselftest package for Linux
+#
+# This software is a part of ISAR.
+# Copyright (c) Mentor Graphics, a Siemens Business, 2020
+#
+# SPDX-License-Identifier: MIT
+
+FILESEXTRAPATHS_prepend := "${THISDIR}/files:"
+
+# Some test-cases like memfd compilation failed in cross-compilation.
+# Force native compilation for now to have consistent output across
+# ISAR native/cross compilation setups.
+ISAR_CROSS_COMPILE = "0"
+
+DESCRIPTION ?= "Kernel selftests from Linux kernel ${PV}"
+
+DEBIAN_BUILD_DEPENDS ?= " \
+    rsync, \
+    flex,  \
+    bison, \
+    fuse, \
+    libelf-dev:native, \
+    libcap-ng-dev:native, \
+    libpopt-dev:native, \
+    libcap-dev:native, \
+    libmount-dev:native, \
+    libnuma-dev:native, \
+    libfuse-dev:native, \
+    libmnl-dev:native, \
+    pkg-config, \
+    clang:native, \
+    llvm:native, \
+"
+
+SRC_URI += "file://debian"
+S = "${WORKDIR}/linux-${PV}"
+
+KSELFTEST_TARGETS ?= ""
+KSELFTEST_SKIP_TARGETS ?= ""
+KSELFTEST_FORCE_TARGETS ?= "0"
+
+inherit dpkg
+
+do_prepare_build() {
+    cp -rf ${WORKDIR}/debian ${S}/debian
+    deb_create_compat
+    deb_create_control
+    deb_add_changelog
+}
+
+dpkg_runbuild_prepend() {
+    if [ -n "${KSELFTEST_TARGETS}" ];then
+        export KSELFTEST_ARGS="TARGETS=\"${KSELFTEST_TARGETS}\""
+    fi
+    if [ ${KSELFTEST_FORCE_TARGETS} -eq 1 ];then
+        export KSELFTEST_ARGS="${KSELFTEST_ARGS} FORCE_TARGETS=1"
+    fi
+    if [ -n "${KSELFTEST_SKIP_TARGETS}" ];then
+        export KSELFTEST_ARGS="${KSELFTEST_ARGS} SKIP_TARGETS=\"${KSELFTEST_SKIP_TARGETS}\""
+    fi
+}
-- 
2.17.1