[OE-core] [PATCH 5/9] kernel: specify dependencies for compilation for config tasks

[Bruce Ashfield]

With recent kernels (i.e. 4.17+) the configuration phase of the kernel
will check for capabilities/options of the compiler for CVE and other
mitigation support.

For a general kernel, we want to ensure that CC is fully defined when
the config targets are invoked (so the proper compiler will be checked).

For linux-yocto, we also need to specify the compiler/tools dependencies
for the configme task since it executes before configure and hence the
main kernel build DEPENDS will not always be in the sysroot before it
executes. Without those dependencies the kernel will be incorrectly
configured (i.e. bison is missing) or the configuration will fail the
mitigation tests.

[YOCTO #12757]

Signed-off-by: Bruce Ashfield <bruce.ashfield at windriver.com>
---
 meta/classes/kernel-yocto.bbclass | 5 ++++-
 meta/classes/kernel.bbclass       | 2 +-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/meta/classes/kernel-yocto.bbclass b/meta/classes/kernel-yocto.bbclass
index 4ac3a39e4750..82d80741a951 100644
--- a/meta/classes/kernel-yocto.bbclass
+++ b/meta/classes/kernel-yocto.bbclass
@@ -275,6 +275,9 @@ addtask kernel_metadata after do_validate_branches do_unpack before do_patch
 do_kernel_metadata[depends] = "kern-tools-native:do_populate_sysroot"
 do_validate_branches[depends] = "kern-tools-native:do_populate_sysroot"
 
+do_kernel_configme[depends] += "virtual/${TARGET_PREFIX}binutils:do_populate_sysroot"
+do_kernel_configme[depends] += "virtual/${TARGET_PREFIX}gcc:do_populate_sysroot"
+do_kernel_configme[depends] += "bc-native:do_populate_sysroot bison-native:do_populate_sysroot"
 do_kernel_configme[dirs] += "${S} ${B}"
 do_kernel_configme() {
 	set +e
@@ -304,7 +307,7 @@ do_kernel_configme() {
 		bbfatal_log "Could not find configuration queue (${meta_dir}/config.queue)"
 	fi
 
-	CFLAGS="${CFLAGS} ${TOOLCHAIN_OPTIONS}"	ARCH=${ARCH} merge_config.sh -O ${B} ${config_flags} ${configs} > ${meta_dir}/cfg/merge_config_build.log 2>&1
+	CFLAGS="${CFLAGS} ${TOOLCHAIN_OPTIONS}"	HOSTCC="${BUILD_CC} ${BUILD_CFLAGS} ${BUILD_LDFLAGS}" HOSTCPP="${BUILD_CPP}" CC="${KERNEL_CC}" ARCH=${ARCH} merge_config.sh -O ${B} ${config_flags} ${configs} > ${meta_dir}/cfg/merge_config_build.log 2>&1
 	if [ $? -ne 0 ]; then
 		bbfatal_log "Could not configure ${KMACHINE}-${LINUX_KERNEL_TYPE}"
 	fi
diff --git a/meta/classes/kernel.bbclass b/meta/classes/kernel.bbclass
index 68d218584a7e..972ac52814ef 100644
--- a/meta/classes/kernel.bbclass
+++ b/meta/classes/kernel.bbclass
@@ -494,7 +494,7 @@ sysroot_stage_all () {
 	:
 }
 
-KERNEL_CONFIG_COMMAND ?= "oe_runmake_call -C ${S} O=${B} oldnoconfig"
+KERNEL_CONFIG_COMMAND ?= "oe_runmake_call -C ${S} CC="${KERNEL_CC}" O=${B} oldnoconfig"
 
 python check_oldest_kernel() {
     oldest_kernel = d.getVar('OLDEST_KERNEL')
-- 
2.5.0