298 lines
11 KiB
Makefile
298 lines
11 KiB
Makefile
# ch5/lkm_template/Makefile
|
|
# ***************************************************************
|
|
# This program is part of the source code released for the book
|
|
# "Linux Kernel Programming" 2E
|
|
# (c) Author: Kaiwan N Billimoria
|
|
# Publisher: Packt
|
|
# GitHub repository:
|
|
# https://github.com/PacktPublishing/Linux-Kernel-Programming_2E
|
|
#
|
|
# From: Ch 5 : Writing Your First Kernel Module LKMs, Part 2
|
|
# ***************************************************************
|
|
# Brief Description:
|
|
# A 'better' Makefile template for Linux LKMs (Loadable Kernel Modules); besides
|
|
# the 'usual' targets (the build, install and clean), we incorporate targets to
|
|
# do useful (and indeed required) stuff like:
|
|
# - adhering to kernel coding style (indent+checkpatch)
|
|
# - several static analysis targets (via sparse, gcc, flawfinder, cppcheck)
|
|
# - two _dummy_ dynamic analysis targets (KASAN, LOCKDEP); just to remind you!
|
|
# - a packaging (.tar.xz) target and
|
|
# - a help target.
|
|
#
|
|
# To get started, just type:
|
|
# make help
|
|
#
|
|
# For details, please refer the book, Ch 5, section
|
|
# 'A "better" Makefile template for your kernel modules'.
|
|
#
|
|
# AUTHOR : Kaiwan N Billimoria
|
|
# DESCRIPTION : A simple kernel module 'better' Makefile template
|
|
# LICENSE : Dual MIT/GPL
|
|
# VERSION : 0.2
|
|
|
|
#------------------------------------------------------------------
|
|
# IMPORTANT : Set FNAME_C to the kernel module name source filename (without .c).
|
|
# This enables you to use this Makefile as a template; just update this variable!
|
|
# As well, the MYDEBUG variable (see it below) can be set to 'y' or 'n' (no being
|
|
# the default)
|
|
FNAME_C := miscdrv_rdwr_rwlock
|
|
ifeq ($(FNAME_C),)
|
|
$(error ERROR: you Must set the FNAME_C variable in the Makefile)
|
|
endif
|
|
#------------------------------------------------------------------
|
|
|
|
#--- To support cross-compiling for kernel modules
|
|
# For architecture (cpu) 'arch', invoke make as:
|
|
# make ARCH=<arch> CROSS_COMPILE=<cross-compiler-prefix>
|
|
# F.e. to cross-compile for the AArch64:
|
|
# make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu-
|
|
#
|
|
# Alternately:
|
|
# export ARCH=<arch>
|
|
# export CROSS_COMPILE=<cross-compiler-prefix>
|
|
# make
|
|
#
|
|
# The KDIR var is set to a sample path below; you're expected to update it on
|
|
# your box to the appropriate path to the kernel source tree for that arch.
|
|
ifeq ($(ARCH),arm)
|
|
# *UPDATE* 'KDIR' below to point to the ARM Linux kernel source tree on your box
|
|
KDIR ?= ~/arm_prj/kernel/linux
|
|
else ifeq ($(ARCH),arm64)
|
|
# *UPDATE* 'KDIR' below to point to the ARM64 (Aarch64) Linux kernel source
|
|
# tree on your box
|
|
KDIR ?= ~/arm64_prj/kernel/linux-5.10.60
|
|
else ifeq ($(ARCH),powerpc)
|
|
# *UPDATE* 'KDIR' below to point to the PPC64 Linux kernel source tree on your box
|
|
KDIR ?= ~/ppc_prj/kernel/linux-5.4
|
|
else
|
|
# 'KDIR' is the Linux 'kernel headers' package on your host system; this is
|
|
# usually an x86_64, but could be anything, really (f.e. building directly
|
|
# on a Raspberry Pi implies that it's the host)
|
|
KDIR ?= /lib/modules/$(shell uname -r)/build
|
|
endif
|
|
#---
|
|
|
|
# Compiler
|
|
CC := $(CROSS_COMPILE)gcc
|
|
#CC := clang
|
|
STRIP := ${CROSS_COMPILE}strip
|
|
|
|
PWD := $(shell pwd)
|
|
obj-m := ${FNAME_C}.o
|
|
|
|
#--- Debug or production mode?
|
|
# Set the MYDEBUG variable accordingly to y/n resp. We keep it off (n) by default.
|
|
# (Actually, debug info is always going to be generated when you build the
|
|
# module on a debug kernel, where CONFIG_DEBUG_INFO is defined, making this
|
|
# setting of the ccflags-y (or the older EXTRA_CFLAGS) variable mostly redundant
|
|
# (besides the still useful -DDEBUG).
|
|
# This simply helps us influence the build on a production kernel, forcing
|
|
# generation of debug symbols, if so required. Also, realize that the DEBUG
|
|
# macro is turned on by many CONFIG_*DEBUG* options; hence, we use a different
|
|
# macro var name, MYDEBUG).
|
|
MYDEBUG := y
|
|
DBG_STRIP := y
|
|
ifeq (${MYDEBUG}, y)
|
|
# https://www.kernel.org/doc/html/latest/kbuild/makefiles.html#compilation-flags
|
|
# EXTRA_CFLAGS deprecated; use ccflags-y
|
|
ccflags-y += -DDEBUG -g -ggdb -gdwarf-4 -Wall -fno-omit-frame-pointer -fvar-tracking-assignments
|
|
DBG_STRIP := n
|
|
else
|
|
ccflags-y += -UDEBUG
|
|
endif
|
|
# We always keep the dynamic debug facility enabled; this allows us to turn
|
|
# dynamically turn on/off debug printk's later... To disable it simply comment
|
|
# out the following line
|
|
ccflags-y += -DDYNAMIC_DEBUG_MODULE
|
|
KMODDIR ?= /lib/modules/$(shell uname -r)
|
|
|
|
# Gain access to kernel configs
|
|
-include $(KDIR)/.config
|
|
|
|
# Strip the module? Note:
|
|
# a) Only strip debug symbols else it won't load correctly
|
|
# b) WARNING! Don't strip modules when using CONFIG_MODULE_SIG* crytographic security
|
|
ifdef CONFIG_MODULE_SIG
|
|
DBG_STRIP := n
|
|
endif
|
|
ifdef CONFIG_MODULE_SIG_ALL
|
|
DBG_STRIP := n
|
|
endif
|
|
ifdef CONFIG_MODULE_SIG_FORCE
|
|
DBG_STRIP := n
|
|
endif
|
|
|
|
|
|
all:
|
|
@echo
|
|
@echo '--- Building : KDIR=${KDIR} ARCH=${ARCH} CROSS_COMPILE=${CROSS_COMPILE} ccflags-y="${ccflags-y}" MYDEBUG=${MYDEBUG} DBG_STRIP=${DBG_STRIP} ---'
|
|
@${CC} --version|head -n1
|
|
@echo
|
|
make -C $(KDIR) M=$(PWD) modules
|
|
if [ "${DBG_STRIP}" = "y" ]; then \
|
|
${STRIP} --strip-debug ${FNAME_C}.ko ; \
|
|
fi
|
|
install:
|
|
@echo
|
|
@echo "--- installing ---"
|
|
@echo " [First, invoking the 'make' ]"
|
|
make
|
|
@echo
|
|
@echo " [Now for the 'sudo make install' ]"
|
|
sudo make -C $(KDIR) M=$(PWD) modules_install
|
|
sudo depmod
|
|
@echo " [If !debug and !(module signing), stripping debug info from ${KMODDIR}/extra/${FNAME_C}.ko]"
|
|
if [ "${DBG_STRIP}" = "y" ]; then \
|
|
sudo ${STRIP} --strip-debug ${KMODDIR}/extra/${FNAME_C}.ko ; \
|
|
fi
|
|
nsdeps:
|
|
@echo "--- nsdeps (namespace dependencies resolution; for possibly importing ns's) ---"
|
|
make -C $(KDIR) M=$(PWD) nsdeps
|
|
clean:
|
|
@echo
|
|
@echo "--- cleaning ---"
|
|
@echo
|
|
make -C $(KDIR) M=$(PWD) clean
|
|
# from 'indent'; comment out if you want the backup kept
|
|
rm -f *~
|
|
|
|
# Any usermode programs to build? Insert the build target(s) below
|
|
|
|
|
|
#--------------- More (useful) targets! -------------------------------
|
|
INDENT := indent
|
|
|
|
# code-style : "wrapper" target over the following kernel code style targets
|
|
code-style:
|
|
make indent
|
|
make checkpatch
|
|
|
|
# indent- "beautifies" C code - to conform to the the Linux kernel
|
|
# coding style guidelines.
|
|
# Note! original source file(s) is overwritten, so we back it up.
|
|
indent:
|
|
ifeq (,$(shell which indent))
|
|
$(error ERROR: install indent first)
|
|
endif
|
|
@echo
|
|
@echo "--- applying kernel code style indentation with indent ---"
|
|
@echo
|
|
mkdir bkp 2> /dev/null; cp -f *.[chsS] bkp/
|
|
${INDENT} -linux --line-length95 *.[chsS]
|
|
# add source files as required
|
|
|
|
# Detailed check on the source code styling / etc
|
|
checkpatch:
|
|
make clean
|
|
@echo
|
|
@echo "--- kernel code style check with checkpatch.pl ---"
|
|
@echo
|
|
$(KDIR)/scripts/checkpatch.pl --no-tree -f --max-line-length=95 *.[ch]
|
|
# add source files as required
|
|
|
|
#--- Static Analysis
|
|
# sa : "wrapper" target over the following kernel static analyzer targets
|
|
sa:
|
|
make sa_sparse
|
|
make sa_gcc
|
|
make sa_flawfinder
|
|
make sa_cppcheck
|
|
|
|
# static analysis with sparse
|
|
sa_sparse:
|
|
ifeq (,$(shell which sparse))
|
|
$(error ERROR: install sparse first)
|
|
endif
|
|
make clean
|
|
@echo
|
|
@echo "--- static analysis with sparse ---"
|
|
@echo
|
|
# If you feel it's too much, use C=1 instead
|
|
# NOTE: deliberately IGNORING warnings from kernel headers!
|
|
make -Wsparse-all C=2 CHECK="/usr/bin/sparse --os=linux --arch=$(ARCH)" -C $(KDIR) M=$(PWD) modules 2>&1 |egrep -v "^\./include/.*\.h|^\./arch/.*\.h"
|
|
|
|
# static analysis with gcc
|
|
sa_gcc:
|
|
make clean
|
|
@echo
|
|
@echo "--- static analysis with gcc ---"
|
|
@echo
|
|
make W=1 -C $(KDIR) M=$(PWD) modules
|
|
|
|
# static analysis with flawfinder
|
|
sa_flawfinder:
|
|
ifeq (,$(shell which flawfinder))
|
|
$(error ERROR: install flawfinder first)
|
|
endif
|
|
make clean
|
|
@echo
|
|
@echo "--- static analysis with flawfinder ---"
|
|
@echo
|
|
flawfinder *.[ch]
|
|
|
|
# static analysis with cppcheck
|
|
sa_cppcheck:
|
|
ifeq (,$(shell which cppcheck))
|
|
$(error ERROR: install cppcheck first)
|
|
endif
|
|
make clean
|
|
@echo
|
|
@echo "--- static analysis with cppcheck ---"
|
|
@echo
|
|
cppcheck -v --force --enable=all -i .tmp_versions/ -i *.mod.c -i bkp/ --suppress=missingIncludeSystem .
|
|
|
|
# Packaging: just generates a tar.xz of the source as of now
|
|
tarxz-pkg:
|
|
rm -f ../${FNAME_C}.tar.xz 2>/dev/null
|
|
make clean
|
|
@echo
|
|
@echo "--- packaging ---"
|
|
@echo
|
|
tar caf ../${FNAME_C}.tar.xz *
|
|
ls -l ../${FNAME_C}.tar.xz
|
|
@echo '=== package created: ../$(FNAME_C).tar.xz ==='
|
|
@echo ' TIP: When extracting, to extract into a directory with the same name as the tar file, do this:'
|
|
@echo ' tar -xvf ${FNAME_C}.tar.xz --one-top-level'
|
|
|
|
help:
|
|
@echo '=== Makefile Help : additional targets available ==='
|
|
@echo
|
|
@echo 'TIP: Type make <tab><tab> to show all valid targets'
|
|
@echo 'FYI: KDIR=${KDIR} ARCH=${ARCH} CROSS_COMPILE=${CROSS_COMPILE} ccflags-y="${ccflags-y}" MYDEBUG=${MYDEBUG} DBG_STRIP=${DBG_STRIP}'
|
|
|
|
@echo
|
|
@echo '--- 'usual' kernel LKM targets ---'
|
|
@echo 'typing "make" or "all" target : builds the kernel module object (the .ko)'
|
|
@echo 'install : installs the kernel module(s) to INSTALL_MOD_PATH (default here: /lib/modules/$(shell uname -r)/).'
|
|
@echo ' : Takes care of performing debug-only symbols stripping iff MYDEBUG=n and not using module signature'
|
|
@echo 'nsdeps : namespace dependencies resolution; for possibly importing namespaces'
|
|
@echo 'clean : cleanup - remove all kernel objects, temp files/dirs, etc'
|
|
|
|
@echo
|
|
@echo '--- kernel code style targets ---'
|
|
@echo 'code-style : "wrapper" target over the following kernel code style targets'
|
|
@echo ' indent : run the $(INDENT) utility on source file(s) to indent them as per the kernel code style'
|
|
@echo ' checkpatch : run the kernel code style checker tool on source file(s)'
|
|
|
|
@echo
|
|
@echo '--- kernel static analyzer targets ---'
|
|
@echo 'sa : "wrapper" target over the following kernel static analyzer targets'
|
|
@echo ' sa_sparse : run the static analysis sparse tool on the source file(s)'
|
|
@echo ' sa_gcc : run gcc with option -W1 ("Generally useful warnings") on the source file(s)'
|
|
@echo ' sa_flawfinder : run the static analysis flawfinder tool on the source file(s)'
|
|
@echo ' sa_cppcheck : run the static analysis cppcheck tool on the source file(s)'
|
|
@echo 'TIP: use Coccinelle as well: https://www.kernel.org/doc/html/v6.1/dev-tools/coccinelle.html'
|
|
|
|
@echo
|
|
@echo '--- kernel dynamic analysis targets ---'
|
|
@echo 'da_kasan : DUMMY target: this is to remind you to run your code with the dynamic analysis KASAN tool enabled; requires configuring the kernel with CONFIG_KASAN On, rebuild and boot it'
|
|
@echo 'da_lockdep : DUMMY target: this is to remind you to run your code with the dynamic analysis LOCKDEP tool (for deep locking issues analysis) enabled; requires configuring the kernel with CONFIG_PROVE_LOCKING On, rebuild and boot it'
|
|
@echo 'TIP: Best to build a debug kernel with several kernel debug config options turned On, boot via it and run all your test cases'
|
|
|
|
@echo
|
|
@echo '--- misc targets ---'
|
|
@echo 'tarxz-pkg : tar and compress the LKM source files as a tar.xz into the dir above; allows one to transfer and build the module on another system'
|
|
@echo ' TIP: When extracting, to extract into a directory with the same name as the tar file, do this:'
|
|
@echo ' tar -xvf ${FNAME_C}.tar.xz --one-top-level'
|
|
@echo 'help : this help target'
|