From 7183d8c9a114d16ca50d1cab4fc1712148ecdded Mon Sep 17 00:00:00 2001
From: Preeti Nagar <pnagar@codeaurora.org>
Date: Thu, 14 May 2020 15:08:38 +0530
Subject: [PATCH] Enable RTIC MPGen using QGKI

Added RTIC environmental variable check. If set, this will trigger
RTIC MPGen during the kernel build. MPGen generates and embeds the
kernel MP.s (measurement parameters) to the vmlinux. It has to be
called during the kernel build, before vmlinux is generated.
RTIC MP.s to be consumed by the RTIC TA.

Change-Id: I035ea2580bef891e0a8c50c3992ecdfd48cc0a62
Signed-off-by: Preeti Nagar <pnagar@codeaurora.org>
---
 arch/arm64/boot/Makefile | 15 ++++++++
 drivers/soc/qcom/Kconfig |  8 ++++
 scripts/link-vmlinux.sh  | 81 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 104 insertions(+)

diff --git a/arch/arm64/boot/Makefile b/arch/arm64/boot/Makefile
index cd3414898d10..c6bd6844b195 100644
--- a/arch/arm64/boot/Makefile
+++ b/arch/arm64/boot/Makefile
@@ -18,6 +18,21 @@ OBJCOPYFLAGS_Image :=-O binary -R .note -R .note.gnu.build-id -R .comment -S
 
 targets := Image Image.bz2 Image.gz Image.lz4 Image.lzma Image.lzo
 
+ifeq ($(CONFIG_QCOM_RTIC),y)
+# Add RTIC DTB to the DTB list if RTIC MPGen is enabled
+# Note, we keep this for compatibility with
+# BUILD_ARM64_APPENDED_DTB_IMAGE targets.
+# The rtic_mp.dts would be generated with the vmlinux if
+# MPGen enabled (RTIC_MPGEN defined).
+ifdef RTIC_MPGEN
+DTB_OBJS += rtic_mp.dtb
+endif
+
+rtic_mp.dtb: vmlinux FORCE
+	$(DTC) -O dtb -o rtic_mp.dtb -b 0 $(DTC_FLAGS) rtic_mp.dts
+
+endif
+
 $(obj)/Image: vmlinux FORCE
 	$(call if_changed,objcopy)
 
diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
index 70544777f8a0..d7c5fd8089f8 100644
--- a/drivers/soc/qcom/Kconfig
+++ b/drivers/soc/qcom/Kconfig
@@ -841,4 +841,12 @@ config QTI_HW_KEY_MANAGER
 	 HWKM hardware to perform key operations from the kernel which will
 	 be used for storage encryption.
 
+config QCOM_RTIC
+	bool "Enable Qualcomm Technologies, Inc. RTIC feature"
+	depends on QGKI
+	default y if QGKI
+	help
+	  This option enables QCOM Real Time Integrity Check feature. This
+	  will trigger RTIC kernel MP.s (measurement parameters) generation
+	  during the kernel build.
 endmenu
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index ec26255a29cb..8f65bfffca0a 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -124,6 +124,11 @@ vmlinux_link()
 				vmlinux.o 			\
 				--no-whole-archive		\
 				${@}"
+
+			if [ -n "${CONFIG_QCOM_RTIC}" ] &&	\
+				[ -n "${RTIC_MP_O}" ]; then
+				objects=${objects}" "${RTIC_MP_O}
+			fi
 		else
 			objects="--whole-archive		\
 				${KBUILD_VMLINUX_OBJS}		\
@@ -229,6 +234,33 @@ kallsyms_step()
 	kallsyms ${kallsyms_vmlinux} ${kallsymso}
 }
 
+# Generates ${2} .o file with RTIC MP's from the ${1} object file (vmlinux)
+# ${3} the file name where the sizes of the RTIC MP structure are stored
+# just in case, save copy of the RTIC mp to ${4}
+# Note: RTIC_MPGEN has to be set if MPGen is available
+rtic_mp()
+{
+	if [ -n "${CONFIG_QCOM_RTIC}" ]; then
+	# assume that RTIC_MP_O generation may fail
+	RTIC_MP_O=
+
+	local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL}               \
+		${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}"
+
+	${RTIC_MPGEN} --objcopy="${OBJCOPY}" --objdump="${OBJDUMP}" \
+	--binpath='' --vmlinux=${1} --config=${KCONFIG_CONFIG} && \
+	cat rtic_mp.c | ${CC} ${aflags} -c -o ${2} -x c - && \
+	cp rtic_mp.c ${4} && \
+	${NM} --print-size --size-sort ${2} > ${3} && \
+	RTIC_MP_O=${2} || echo “RTIC MP generation has failed”
+	# NM - save generated variable sizes for verification
+	# RTIC_MP_O is our retval - great success if set to generated .o file
+	# Echo statement above prints the error message in case any of the
+	# above RTIC MP generation commands fail and it ensures rtic mp failure
+	# does not cause kernel compilation to fail.
+	fi
+}
+
 # Create map file with all symbols from ${1}
 # See mksymap for additional details
 mksysmap()
@@ -252,6 +284,10 @@ cleanup()
 	rm -f System.map
 	rm -f vmlinux
 	rm -f vmlinux.o
+if [ -n "${CONFIG_QCOM_RTIC}" ]; then
+	rm -f .tmp_rtic_mp_sz*
+	rm -f rtic_mp.*
+fi
 }
 
 on_exit()
@@ -323,6 +359,16 @@ if [ -n "${CONFIG_DEBUG_INFO_BTF}" ]; then
 	fi
 fi
 
+if [ -n "${CONFIG_QCOM_RTIC}" ]; then
+	# Generate RTIC MP placeholder compile unit of the correct size
+	# and add it to the list of link objects
+	# this needs to be done before generating kallsyms
+	if [ ! -z ${RTIC_MPGEN+x} ]; then
+		rtic_mp vmlinux.o rtic_mp.o .tmp_rtic_mp_sz1 .tmp_rtic_mp1.c
+		KBUILD_VMLINUX_LIBS=$KBUILD_VMLINUX_LIBS" "$RTIC_MP_O
+	fi
+fi
+
 kallsymso=""
 kallsymso_prev=""
 kallsyms_vmlinux=""
@@ -363,6 +409,24 @@ if [ -n "${CONFIG_KALLSYMS}" ]; then
 	fi
 fi
 
+if [ -n "${CONFIG_QCOM_RTIC}" ]; then
+	# Update RTIC MP object by replacing the place holder
+	# with actual MP data of the same size
+	# Also double check that object size did not change
+	# Note: Check initilally if RTIC_MP_O is not empty or uninitialized,
+	# as incase RTIC_MPGEN is set and failure occurs in RTIC_MP_O
+	# generation, below check for comparing object sizes fails
+	# due to an empty RTIC_MP_O object.
+	if [ ! -z ${RTIC_MP_O} ]; then
+		rtic_mp "${kallsyms_vmlinux}" rtic_mp.o .tmp_rtic_mp_sz2 \
+			.tmp_rtic_mp2.c
+		if ! cmp -s .tmp_rtic_mp_sz1 .tmp_rtic_mp_sz2; then
+			echo >&2 'ERROR: RTIC MP object files size mismatch'
+			exit 1
+		fi
+	fi
+fi
+
 vmlinux_link vmlinux "${kallsymso}" ${btf_vmlinux_bin_o}
 
 if [ -n "${CONFIG_BUILDTIME_EXTABLE_SORT}" ]; then
@@ -383,3 +447,20 @@ if [ -n "${CONFIG_KALLSYMS}" ]; then
 		exit 1
 	fi
 fi
+
+if [ -n "${CONFIG_QCOM_RTIC}" ]; then
+	# Starting Android Q, the DTB's are part of dtb.img and not part
+	# of the kernel image. RTIC DTS relies on the kernel environment
+	# and could not build outside of the kernel. Generate RTIC DTS after
+	# successful kernel build if MPGen is enabled. The DTB will be
+	# generated with dtb.img in kernel_definitions.mk.
+	if [ ! -z ${RTIC_MPGEN+x} ]; then
+		${RTIC_MPGEN} --objcopy="${OBJCOPY}" --objdump="${OBJDUMP}" \
+		--binpath="" --vmlinux="vmlinux" --config=${KCONFIG_CONFIG} \
+		--cc="${CC} ${KBUILD_AFLAGS}" --dts=rtic_mp.dts \
+		|| echo “RTIC MP DTS generation has failed”
+		# Echo statement above prints the error message in case above
+		# RTIC MP DTS generation command fails and it ensures rtic mp
+		# failure does not cause kernel compilation to fail.
+	fi
+fi