From 1f17430bf0e9a8234da22e7f28714b16cc81d9d7 Mon Sep 17 00:00:00 2001
From: Swetha Chikkaboraiah <schikk@codeaurora.org>
Date: Wed, 29 Jul 2020 22:47:07 +0530
Subject: [PATCH] AndroidKernel: Disable debugfs for user builds

Debugfs is not needed on user builds, so disabling
same at compile time for ARM 64.

Change-Id: If6708c9de060584ebcba4cac9bad8e85d6a5ab7f
Signed-off-by: Swetha Chikkaboraiah <schikk@codeaurora.org>
---
 AndroidKernel.mk | 20 +++++++++++++++++---
 disable_dbgfs.sh | 29 +++++++++++++++++++++++++++++
 2 files changed, 46 insertions(+), 3 deletions(-)
 create mode 100755 disable_dbgfs.sh

diff --git a/AndroidKernel.mk b/AndroidKernel.mk
index f7e26617f635..73a2232be4a2 100644
--- a/AndroidKernel.mk
+++ b/AndroidKernel.mk
@@ -10,6 +10,8 @@ ifneq ($(TARGET_KERNEL_APPEND_DTB), true)
 $(info Using DTB Image)
 INSTALLED_DTBIMAGE_TARGET := $(PRODUCT_OUT)/dtb.img
 endif
+MAKE_ARGS := $(strip $(TARGET_KERNEL_MAKE_ARGS))
+KERNEL_DISABLE_DEBUGFS := $(TARGET_KERNEL_DISABLE_DEBUGFS)
 
 TARGET_KERNEL_MAKE_ENV := $(strip $(TARGET_KERNEL_MAKE_ENV))
 ifeq ($(TARGET_KERNEL_MAKE_ENV),)
@@ -138,6 +140,7 @@ $(info Using appended DTB)
 TARGET_PREBUILT_INT_KERNEL := $(TARGET_PREBUILT_INT_KERNEL)-dtb
 endif
 
+KERNEL_DEBUGFS := $(KERNEL_OUT)/tmp
 KERNEL_HEADERS_INSTALL := $(KERNEL_OUT)/usr
 KERNEL_MODULES_INSTALL ?= system
 KERNEL_MODULES_OUT ?= $(PRODUCT_OUT)/$(KERNEL_MODULES_INSTALL)/lib/modules
@@ -162,6 +165,9 @@ mpath=`dirname $$mdpath`; rm -rf $$mpath;\
 fi
 endef
 
+$(KERNEL_OUT): $(KERNEL_DEBUGFS)
+	mkdir -p $(KERNEL_OUT)
+
 ifneq ($(KERNEL_LEGACY_DIR),true)
 $(KERNEL_USR): $(KERNEL_HEADERS_INSTALL)
 	rm -rf $(KERNEL_SYMLINK)
@@ -170,9 +176,6 @@ $(KERNEL_USR): $(KERNEL_HEADERS_INSTALL)
 $(TARGET_PREBUILT_INT_KERNEL): $(KERNEL_USR)
 endif
 
-$(KERNEL_OUT):
-	mkdir -p $(KERNEL_OUT)
-
 $(KERNEL_CONFIG): $(KERNEL_OUT)
 	$(MAKE) -C $(TARGET_KERNEL_SOURCE) O=$(BUILD_ROOT_LOC)$(KERNEL_OUT) $(KERNEL_MAKE_ENV) ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) $(real_cc) $(KERNEL_DEFCONFIG)
 	$(hide) if [ ! -z "$(KERNEL_CONFIG_OVERRIDE)" ]; then \
@@ -206,6 +209,17 @@ $(TARGET_PREBUILT_INT_KERNEL): $(KERNEL_OUT) $(KERNEL_HEADERS_INSTALL)
 	$(clean-module-folder)
 endif
 
+$(KERNEL_DEBUGFS):
+	KERNEL_DIR=$(TARGET_KERNEL_SOURCE) \
+	DEFCONFIG=$(KERNEL_DEFCONFIG) \
+	OUT_DIR=$(KERNEL_OUT) \
+	ARCH=$(KERNEL_ARCH) \
+	CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) \
+	DISABLE_DEBUGFS=$(KERNEL_DISABLE_DEBUGFS) \
+	$(TARGET_KERNEL_SOURCE)/disable_dbgfs.sh \
+	$(real_cc) \
+	$(TARGET_KERNEL_MAKE_ARGS)
+
 $(KERNEL_HEADERS_INSTALL): $(KERNEL_OUT)
 	$(hide) if [ ! -z "$(KERNEL_HEADER_DEFCONFIG)" ]; then \
 			rm -f $(BUILD_ROOT_LOC)$(KERNEL_CONFIG) && \
diff --git a/disable_dbgfs.sh b/disable_dbgfs.sh
new file mode 100755
index 000000000000..fe23680972a5
--- /dev/null
+++ b/disable_dbgfs.sh
@@ -0,0 +1,29 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# disable debugfs for user builds
+export MAKE_ARGS=$@
+
+if [ ${DISABLE_DEBUGFS} == "true" ]; then
+	echo "build variant ${TARGET_BUILD_VARIANT}"
+	if [ ${TARGET_BUILD_VARIANT} == "user" ] && \
+		[ ${ARCH} == "arm64" ]; then
+		echo "combining fragments for user build"
+		(cd $KERNEL_DIR && \
+		ARCH=${ARCH} CROSS_COMPILE=${CROSS_COMPILE}\
+		./scripts/kconfig/merge_config.sh \
+		./arch/${ARCH}/configs/$DEFCONFIG \
+		./arch/${ARCH}/configs/vendor/debugfs.config
+		make ${MAKE_ARGS} ARCH=${ARCH} \
+		CROSS_COMPILE=${CROSS_COMPILE} savedefconfig
+		mv defconfig ./arch/${ARCH}/configs/$DEFCONFIG
+		rm .config)
+	else
+		if [[ ${DEFCONFIG} == *"perf_defconfig" ]] && \
+			[ ${ARCH} == "arm64" ]; then
+			echo "resetting perf defconfig"
+			(cd ${KERNEL_DIR} && \
+			git checkout arch/$ARCH/configs/$DEFCONFIG)
+		fi
+	fi
+fi