freebsd-skq/sys/conf/kern.pre.mk
andrew 5e0e456d9f Add support for the Clang Coverage Sanitizer in the kernel (KCOV).
When building with KCOV enabled the compiler will insert function calls
to probes allowing us to trace the execution of the kernel from userspace.
These probes are on function entry (trace-pc) and on comparison operations
(trace-cmp).

Userspace can enable the use of these probes on a single kernel thread with
an ioctl interface. It can allocate space for the probe with KIOSETBUFSIZE,
then mmap the allocated buffer and enable tracing with KIOENABLE, with the
trace mode being passed in as the int argument. When complete KIODISABLE
is used to disable tracing.

The first item in the buffer is the number of trace event that have
happened. Userspace can write 0 to this to reset the tracing, and is
expected to do so on first use.

The format of the buffer depends on the trace mode. When in PC tracing just
the return address of the probe is stored. Under comparison tracing the
comparison type, the two arguments, and the return address are traced. The
former method uses on entry per trace event, while the later uses 4. As
such they are incompatible so only a single mode may be enabled.

KCOV is expected to help fuzzing the kernel, and while in development has
already found a number of issues. It is required for the syzkaller system
call fuzzer [1]. Other kernel fuzzers could also make use of it, either
with the current interface, or by extending it with new modes.

A man page is currently being worked on and is expected to be committed
soon, however having the code in the kernel now is useful for other
developers to use.

[1] https://github.com/google/syzkaller

Submitted by:	Mitchell Horne <mhorne063@gmail.com> (Earlier version)
Reviewed by:	kib
Testing by:	tuexen
Sponsored by:	DARPA, AFRL
Sponsored by:	The FreeBSD Foundation (Mitchell Horne)
Differential Revision:	https://reviews.freebsd.org/D14599
2019-01-12 11:21:28 +00:00

301 lines
10 KiB
Makefile

# $FreeBSD$
# Part of a unified Makefile for building kernels. This part contains all
# of the definitions that need to be before %BEFORE_DEPEND.
# Allow user to configure things that only effect src tree builds.
# Note: This is duplicated from src.sys.mk to ensure that we include
# /etc/src.conf when building the kernel. Kernels can be built without
# the rest of /usr/src, but they still always process SRCCONF even though
# the normal mechanisms to prevent that (compiling out of tree) won't
# work. To ensure they do work, we have to duplicate thee few lines here.
SRCCONF?= /etc/src.conf
.if (exists(${SRCCONF}) || ${SRCCONF} != "/etc/src.conf") && !target(_srcconf_included_)
.include "${SRCCONF}"
_srcconf_included_:
.endif
.include <bsd.own.mk>
.include <bsd.compiler.mk>
.include "kern.opts.mk"
# The kernel build always occurs in the object directory which is .CURDIR.
.if ${.MAKE.MODE:Unormal:Mmeta}
.MAKE.MODE+= curdirOk=yes
.endif
# The kernel build always expects .OBJDIR=.CURDIR.
.OBJDIR: ${.CURDIR}
.if defined(NO_OBJWALK) || ${MK_AUTO_OBJ} == "yes"
NO_OBJWALK= t
NO_MODULES_OBJ= t
.endif
.if !defined(NO_OBJWALK)
_obj= obj
.endif
# Can be overridden by makeoptions or /etc/make.conf
KERNEL_KO?= kernel
KERNEL?= kernel
KODIR?= /boot/${KERNEL}
LDSCRIPT_NAME?= ldscript.$M
LDSCRIPT?= $S/conf/${LDSCRIPT_NAME}
M= ${MACHINE}
AWK?= awk
CP?= cp
NM?= nm
OBJCOPY?= objcopy
SIZE?= size
.if defined(DEBUG)
_MINUS_O= -O
CTFFLAGS+= -g
.else
.if ${MACHINE_CPUARCH} == "powerpc"
_MINUS_O= -O # gcc miscompiles some code at -O2
.else
_MINUS_O= -O2
.endif
.endif
.if ${MACHINE_CPUARCH} == "amd64"
.if ${COMPILER_TYPE} == "clang"
COPTFLAGS?=-O2 -pipe
.else
COPTFLAGS?=-O2 -frename-registers -pipe
.endif
.else
COPTFLAGS?=${_MINUS_O} -pipe
.endif
.if !empty(COPTFLAGS:M-O[23s]) && empty(COPTFLAGS:M-fno-strict-aliasing)
COPTFLAGS+= -fno-strict-aliasing
.endif
.if !defined(NO_CPU_COPTFLAGS)
COPTFLAGS+= ${_CPUCFLAGS}
.endif
NOSTDINC= -nostdinc
INCLUDES= ${NOSTDINC} ${INCLMAGIC} -I. -I$S -I$S/contrib/ck/include
CFLAGS= ${COPTFLAGS} ${DEBUG}
CFLAGS+= ${INCLUDES} -D_KERNEL -DHAVE_KERNEL_OPTION_HEADERS -include opt_global.h
CFLAGS_PARAM_INLINE_UNIT_GROWTH?=100
CFLAGS_PARAM_LARGE_FUNCTION_GROWTH?=1000
.if ${MACHINE_CPUARCH} == "mips"
CFLAGS_ARCH_PARAMS?=--param max-inline-insns-single=1000 -DMACHINE_ARCH='"${MACHINE_ARCH}"'
.endif
CFLAGS.gcc+= -fno-common -fms-extensions -finline-limit=${INLINE_LIMIT}
CFLAGS.gcc+= --param inline-unit-growth=${CFLAGS_PARAM_INLINE_UNIT_GROWTH}
CFLAGS.gcc+= --param large-function-growth=${CFLAGS_PARAM_LARGE_FUNCTION_GROWTH}
CFLAGS.gcc+= -fms-extensions
.if defined(CFLAGS_ARCH_PARAMS)
CFLAGS.gcc+=${CFLAGS_ARCH_PARAMS}
.endif
WERROR?= -Werror
# XXX LOCORE means "don't declare C stuff" not "for locore.s".
ASM_CFLAGS= -x assembler-with-cpp -DLOCORE ${CFLAGS} ${ASM_CFLAGS.${.IMPSRC:T}}
.if defined(PROFLEVEL) && ${PROFLEVEL} >= 1
CFLAGS+= -DGPROF
CFLAGS.gcc+= -falign-functions=16
.if ${PROFLEVEL} >= 2
CFLAGS+= -DGPROF4 -DGUPROF
PROF= -pg
.if ${COMPILER_TYPE} == "gcc"
PROF+= -mprofiler-epilogue
.endif
.else
PROF= -pg
.endif
.endif
DEFINED_PROF= ${PROF}
KUBSAN_ENABLED!= grep KUBSAN opt_global.h || true ; echo
.if !empty(KUBSAN_ENABLED)
SAN_CFLAGS+= -fsanitize=undefined
.endif
KCOV_ENABLED!= grep KCOV opt_kcov.h || true ; echo
.if !empty(KCOV_ENABLED)
SAN_CFLAGS+= -fsanitize-coverage=trace-pc,trace-cmp
.endif
CFLAGS+= ${SAN_CFLAGS}
# Put configuration-specific C flags last (except for ${PROF}) so that they
# can override the others.
CFLAGS+= ${CONF_CFLAGS}
.if defined(LINKER_FEATURES) && ${LINKER_FEATURES:Mbuild-id}
LDFLAGS+= -Wl,--build-id=sha1
.endif
.if (${MACHINE_CPUARCH} == "aarch64" || ${MACHINE_CPUARCH} == "amd64" || \
${MACHINE_CPUARCH} == "i386") && \
defined(LINKER_FEATURES) && ${LINKER_FEATURES:Mifunc} == ""
.error amd64/arm64/i386 kernel requires linker ifunc support
.endif
.if ${MACHINE_CPUARCH} == "amd64"
LDFLAGS+= -Wl,-z max-page-size=2097152
.if ${LINKER_TYPE} != "lld"
LDFLAGS+= -Wl,-z common-page-size=4096
.else
LDFLAGS+= -Wl,-z -Wl,ifunc-noplt
.endif
.endif
NORMAL_C= ${CC} -c ${CFLAGS} ${WERROR} ${PROF} ${.IMPSRC}
NORMAL_S= ${CC:N${CCACHE_BIN}} -c ${ASM_CFLAGS} ${WERROR} ${.IMPSRC}
PROFILE_C= ${CC} -c ${CFLAGS} ${WERROR} ${.IMPSRC}
NORMAL_C_NOWERROR= ${CC} -c ${CFLAGS} ${PROF} ${.IMPSRC}
NORMAL_M= ${AWK} -f $S/tools/makeobjops.awk ${.IMPSRC} -c ; \
${CC} -c ${CFLAGS} ${WERROR} ${PROF} ${.PREFIX}.c
NORMAL_FW= uudecode -o ${.TARGET} ${.ALLSRC}
NORMAL_FWO= ${LD} -b binary --no-warn-mismatch -d -warn-common -r \
-m ${LD_EMULATION} -o ${.TARGET} ${.ALLSRC:M*.fw}
# for ZSTD in the kernel (include zstd/lib/freebsd before other CFLAGS)
ZSTD_C= ${CC} -c -DZSTD_HEAPMODE=1 -I$S/contrib/zstd/lib/freebsd ${CFLAGS} -I$S/contrib/zstd/lib -I$S/contrib/zstd/lib/common ${WERROR} -Wno-inline -Wno-missing-prototypes ${PROF} -U__BMI__ ${.IMPSRC}
# Common for dtrace / zfs
CDDL_CFLAGS= -DFREEBSD_NAMECACHE -nostdinc -I$S/cddl/compat/opensolaris -I$S/cddl/contrib/opensolaris/uts/common -I$S -I$S/cddl/contrib/opensolaris/common ${CFLAGS} -Wno-unknown-pragmas -Wno-missing-prototypes -Wno-undef -Wno-strict-prototypes -Wno-cast-qual -Wno-parentheses -Wno-redundant-decls -Wno-missing-braces -Wno-uninitialized -Wno-unused -Wno-inline -Wno-switch -Wno-pointer-arith -Wno-unknown-pragmas
CDDL_CFLAGS+= -include $S/cddl/compat/opensolaris/sys/debug_compat.h
CDDL_C= ${CC} -c ${CDDL_CFLAGS} ${WERROR} ${PROF} ${.IMPSRC}
# Special flags for managing the compat compiles for ZFS
ZFS_CFLAGS= -DBUILDING_ZFS -I$S/cddl/contrib/opensolaris/uts/common/fs/zfs
ZFS_CFLAGS+= -I$S/cddl/contrib/opensolaris/uts/common/fs/zfs/lua
ZFS_CFLAGS+= -I$S/cddl/contrib/opensolaris/uts/common/zmod
ZFS_CFLAGS+= -I$S/cddl/contrib/opensolaris/common/zfs
ZFS_CFLAGS+= ${CDDL_CFLAGS}
ZFS_ASM_CFLAGS= -x assembler-with-cpp -DLOCORE ${ZFS_CFLAGS}
ZFS_C= ${CC} -c ${ZFS_CFLAGS} ${WERROR} ${PROF} ${.IMPSRC}
ZFS_S= ${CC} -c ${ZFS_ASM_CFLAGS} ${WERROR} ${.IMPSRC}
# Special flags for managing the compat compiles for DTrace
DTRACE_CFLAGS= -DBUILDING_DTRACE ${CDDL_CFLAGS} -I$S/cddl/dev/dtrace -I$S/cddl/dev/dtrace/${MACHINE_CPUARCH}
.if ${MACHINE_CPUARCH} == "amd64" || ${MACHINE_CPUARCH} == "i386"
DTRACE_CFLAGS+= -I$S/cddl/contrib/opensolaris/uts/intel -I$S/cddl/dev/dtrace/x86
.endif
DTRACE_CFLAGS+= -I$S/cddl/contrib/opensolaris/common/util -I$S -DDIS_MEM -DSMP
DTRACE_ASM_CFLAGS= -x assembler-with-cpp -DLOCORE ${DTRACE_CFLAGS}
DTRACE_C= ${CC} -c ${DTRACE_CFLAGS} ${WERROR} ${PROF} ${.IMPSRC}
DTRACE_S= ${CC} -c ${DTRACE_ASM_CFLAGS} ${WERROR} ${.IMPSRC}
# Special flags for managing the compat compiles for DTrace/FBT
FBT_CFLAGS= -DBUILDING_DTRACE -nostdinc -I$S/cddl/dev/fbt/${MACHINE_CPUARCH} -I$S/cddl/dev/fbt -I$S/cddl/compat/opensolaris -I$S/cddl/contrib/opensolaris/uts/common -I$S ${CDDL_CFLAGS}
.if ${MACHINE_CPUARCH} == "amd64" || ${MACHINE_CPUARCH} == "i386"
FBT_CFLAGS+= -I$S/cddl/dev/fbt/x86
.endif
FBT_C= ${CC} -c ${FBT_CFLAGS} ${WERROR} ${PROF} ${.IMPSRC}
.if ${MK_CTF} != "no"
NORMAL_CTFCONVERT= ${CTFCONVERT} ${CTFFLAGS} ${.TARGET}
.elif ${MAKE_VERSION} >= 5201111300
NORMAL_CTFCONVERT=
.else
NORMAL_CTFCONVERT= @:
.endif
# Linux Kernel Programming Interface C-flags
LINUXKPI_INCLUDES= -I$S/compat/linuxkpi/common/include
LINUXKPI_C= ${NORMAL_C} ${LINUXKPI_INCLUDES}
# Infiniband C flags. Correct include paths and omit errors that linux
# does not honor.
OFEDINCLUDES= -I$S/ofed/include -I$S/ofed/include/uapi ${LINUXKPI_INCLUDES}
OFEDNOERR= -Wno-cast-qual -Wno-pointer-arith
OFEDCFLAGS= ${CFLAGS:N-I*} -DCONFIG_INFINIBAND_USER_MEM \
${OFEDINCLUDES} ${CFLAGS:M-I*} ${OFEDNOERR}
OFED_C_NOIMP= ${CC} -c -o ${.TARGET} ${OFEDCFLAGS} ${WERROR} ${PROF}
OFED_C= ${OFED_C_NOIMP} ${.IMPSRC}
GEN_CFILES= $S/$M/$M/genassym.c ${MFILES:T:S/.m$/.c/}
SYSTEM_CFILES= config.c env.c hints.c vnode_if.c
SYSTEM_DEP= Makefile ${SYSTEM_OBJS}
SYSTEM_OBJS= locore.o ${MDOBJS} ${OBJS}
SYSTEM_OBJS+= ${SYSTEM_CFILES:.c=.o}
SYSTEM_OBJS+= hack.pico
MD_ROOT_SIZE_CONFIGURED!= grep MD_ROOT_SIZE opt_md.h || true ; echo
.if ${MFS_IMAGE:Uno} != "no"
.if empty(MD_ROOT_SIZE_CONFIGURED)
SYSTEM_OBJS+= embedfs_${MFS_IMAGE:T:R}.o
.endif
.endif
SYSTEM_LD= @${LD} -m ${LD_EMULATION} -Bdynamic -T ${LDSCRIPT} ${_LDFLAGS} \
--no-warn-mismatch --warn-common --export-dynamic \
--dynamic-linker /red/herring \
-o ${.TARGET} -X ${SYSTEM_OBJS} vers.o
SYSTEM_LD_TAIL= @${OBJCOPY} --strip-symbol gcc2_compiled. ${.TARGET} ; \
${SIZE} ${.TARGET} ; chmod 755 ${.TARGET}
SYSTEM_DEP+= ${LDSCRIPT}
# Calculate path for .m files early, if needed.
.if !defined(NO_MODULES) && !defined(__MPATH) && !make(install) && \
(empty(.MAKEFLAGS:M-V) || defined(NO_SKIP_MPATH))
__MPATH!=find ${S:tA}/ -name \*_if.m
.endif
# MKMODULESENV is set here so that port makefiles can augment
# them.
MKMODULESENV+= MAKEOBJDIRPREFIX=${.OBJDIR}/modules KMODDIR=${KODIR}
MKMODULESENV+= MACHINE_CPUARCH=${MACHINE_CPUARCH}
MKMODULESENV+= MACHINE=${MACHINE} MACHINE_ARCH=${MACHINE_ARCH}
MKMODULESENV+= MODULES_EXTRA="${MODULES_EXTRA}" WITHOUT_MODULES="${WITHOUT_MODULES}"
MKMODULESENV+= ARCH_FLAGS="${ARCH_FLAGS}"
.if (${KERN_IDENT} == LINT)
MKMODULESENV+= ALL_MODULES=LINT
.endif
.if defined(MODULES_OVERRIDE)
MKMODULESENV+= MODULES_OVERRIDE="${MODULES_OVERRIDE}"
.endif
.if defined(DEBUG)
MKMODULESENV+= DEBUG_FLAGS="${DEBUG}"
.endif
.if !defined(NO_MODULES)
MKMODULESENV+= __MPATH="${__MPATH}"
.endif
# Architecture and output format arguments for objcopy to convert image to
# object file
.if ${MFS_IMAGE:Uno} != "no"
.if empty(MD_ROOT_SIZE_CONFIGURED)
.if !defined(EMBEDFS_FORMAT.${MACHINE_ARCH})
EMBEDFS_FORMAT.${MACHINE_ARCH}!= awk -F'"' '/OUTPUT_FORMAT/ {print $$2}' ${LDSCRIPT}
.if empty(EMBEDFS_FORMAT.${MACHINE_ARCH})
.undef EMBEDFS_FORMAT.${MACHINE_ARCH}
.endif
.endif
.if !defined(EMBEDFS_ARCH.${MACHINE_ARCH})
EMBEDFS_ARCH.${MACHINE_ARCH}!= sed -n '/OUTPUT_ARCH/s/.*(\(.*\)).*/\1/p' ${LDSCRIPT}
.if empty(EMBEDFS_ARCH.${MACHINE_ARCH})
.undef EMBEDFS_ARCH.${MACHINE_ARCH}
.endif
.endif
EMBEDFS_FORMAT.arm?= elf32-littlearm
EMBEDFS_FORMAT.armv6?= elf32-littlearm
EMBEDFS_FORMAT.armv7?= elf32-littlearm
EMBEDFS_FORMAT.aarch64?= elf64-littleaarch64
EMBEDFS_FORMAT.mips?= elf32-tradbigmips
EMBEDFS_FORMAT.mipsel?= elf32-tradlittlemips
EMBEDFS_FORMAT.mips64?= elf64-tradbigmips
EMBEDFS_FORMAT.mips64el?= elf64-tradlittlemips
EMBEDFS_FORMAT.riscv?= elf64-littleriscv
.endif
.endif
# Detect kernel config options that force stack frames to be turned on.
DDB_ENABLED!= grep DDB opt_ddb.h || true ; echo
DTR_ENABLED!= grep KDTRACE_FRAME opt_kdtrace.h || true ; echo
HWPMC_ENABLED!= grep HWPMC opt_hwpmc_hooks.h || true ; echo