cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

Makefile (16559B)


      1# SPDX-License-Identifier: GPL-2.0
      2
      3BPF_SAMPLES_PATH ?= $(abspath $(srctree)/$(src))
      4TOOLS_PATH := $(BPF_SAMPLES_PATH)/../../tools
      5
      6pound := \#
      7
      8# List of programs to build
      9tprogs-y := test_lru_dist
     10tprogs-y += sock_example
     11tprogs-y += fds_example
     12tprogs-y += sockex1
     13tprogs-y += sockex2
     14tprogs-y += sockex3
     15tprogs-y += tracex1
     16tprogs-y += tracex2
     17tprogs-y += tracex3
     18tprogs-y += tracex4
     19tprogs-y += tracex5
     20tprogs-y += tracex6
     21tprogs-y += tracex7
     22tprogs-y += test_probe_write_user
     23tprogs-y += trace_output
     24tprogs-y += lathist
     25tprogs-y += offwaketime
     26tprogs-y += spintest
     27tprogs-y += map_perf_test
     28tprogs-y += test_overhead
     29tprogs-y += test_cgrp2_array_pin
     30tprogs-y += test_cgrp2_attach
     31tprogs-y += test_cgrp2_sock
     32tprogs-y += test_cgrp2_sock2
     33tprogs-y += xdp1
     34tprogs-y += xdp2
     35tprogs-y += xdp_router_ipv4
     36tprogs-y += test_current_task_under_cgroup
     37tprogs-y += trace_event
     38tprogs-y += sampleip
     39tprogs-y += tc_l2_redirect
     40tprogs-y += lwt_len_hist
     41tprogs-y += xdp_tx_iptunnel
     42tprogs-y += test_map_in_map
     43tprogs-y += per_socket_stats_example
     44tprogs-y += xdp_rxq_info
     45tprogs-y += syscall_tp
     46tprogs-y += cpustat
     47tprogs-y += xdp_adjust_tail
     48tprogs-y += xdpsock
     49tprogs-y += xdpsock_ctrl_proc
     50tprogs-y += xsk_fwd
     51tprogs-y += xdp_fwd
     52tprogs-y += task_fd_query
     53tprogs-y += xdp_sample_pkts
     54tprogs-y += ibumad
     55tprogs-y += hbm
     56
     57tprogs-y += xdp_redirect_cpu
     58tprogs-y += xdp_redirect_map_multi
     59tprogs-y += xdp_redirect_map
     60tprogs-y += xdp_redirect
     61tprogs-y += xdp_monitor
     62
     63# Libbpf dependencies
     64LIBBPF_SRC = $(TOOLS_PATH)/lib/bpf
     65LIBBPF_OUTPUT = $(abspath $(BPF_SAMPLES_PATH))/libbpf
     66LIBBPF_DESTDIR = $(LIBBPF_OUTPUT)
     67LIBBPF_INCLUDE = $(LIBBPF_DESTDIR)/include
     68LIBBPF = $(LIBBPF_OUTPUT)/libbpf.a
     69
     70CGROUP_HELPERS := ../../tools/testing/selftests/bpf/cgroup_helpers.o
     71TRACE_HELPERS := ../../tools/testing/selftests/bpf/trace_helpers.o
     72XDP_SAMPLE := xdp_sample_user.o
     73
     74fds_example-objs := fds_example.o
     75sockex1-objs := sockex1_user.o
     76sockex2-objs := sockex2_user.o
     77sockex3-objs := sockex3_user.o
     78tracex1-objs := tracex1_user.o $(TRACE_HELPERS)
     79tracex2-objs := tracex2_user.o
     80tracex3-objs := tracex3_user.o
     81tracex4-objs := tracex4_user.o
     82tracex5-objs := tracex5_user.o $(TRACE_HELPERS)
     83tracex6-objs := tracex6_user.o
     84tracex7-objs := tracex7_user.o
     85test_probe_write_user-objs := test_probe_write_user_user.o
     86trace_output-objs := trace_output_user.o
     87lathist-objs := lathist_user.o
     88offwaketime-objs := offwaketime_user.o $(TRACE_HELPERS)
     89spintest-objs := spintest_user.o $(TRACE_HELPERS)
     90map_perf_test-objs := map_perf_test_user.o
     91test_overhead-objs := test_overhead_user.o
     92test_cgrp2_array_pin-objs := test_cgrp2_array_pin.o
     93test_cgrp2_attach-objs := test_cgrp2_attach.o
     94test_cgrp2_sock-objs := test_cgrp2_sock.o
     95test_cgrp2_sock2-objs := test_cgrp2_sock2.o
     96xdp1-objs := xdp1_user.o
     97# reuse xdp1 source intentionally
     98xdp2-objs := xdp1_user.o
     99test_current_task_under_cgroup-objs := $(CGROUP_HELPERS) \
    100				       test_current_task_under_cgroup_user.o
    101trace_event-objs := trace_event_user.o $(TRACE_HELPERS)
    102sampleip-objs := sampleip_user.o $(TRACE_HELPERS)
    103tc_l2_redirect-objs := tc_l2_redirect_user.o
    104lwt_len_hist-objs := lwt_len_hist_user.o
    105xdp_tx_iptunnel-objs := xdp_tx_iptunnel_user.o
    106test_map_in_map-objs := test_map_in_map_user.o
    107per_socket_stats_example-objs := cookie_uid_helper_example.o
    108xdp_rxq_info-objs := xdp_rxq_info_user.o
    109syscall_tp-objs := syscall_tp_user.o
    110cpustat-objs := cpustat_user.o
    111xdp_adjust_tail-objs := xdp_adjust_tail_user.o
    112xdpsock-objs := xdpsock_user.o
    113xdpsock_ctrl_proc-objs := xdpsock_ctrl_proc.o
    114xsk_fwd-objs := xsk_fwd.o
    115xdp_fwd-objs := xdp_fwd_user.o
    116task_fd_query-objs := task_fd_query_user.o $(TRACE_HELPERS)
    117xdp_sample_pkts-objs := xdp_sample_pkts_user.o
    118ibumad-objs := ibumad_user.o
    119hbm-objs := hbm.o $(CGROUP_HELPERS)
    120
    121xdp_redirect_map_multi-objs := xdp_redirect_map_multi_user.o $(XDP_SAMPLE)
    122xdp_redirect_cpu-objs := xdp_redirect_cpu_user.o $(XDP_SAMPLE)
    123xdp_redirect_map-objs := xdp_redirect_map_user.o $(XDP_SAMPLE)
    124xdp_redirect-objs := xdp_redirect_user.o $(XDP_SAMPLE)
    125xdp_monitor-objs := xdp_monitor_user.o $(XDP_SAMPLE)
    126xdp_router_ipv4-objs := xdp_router_ipv4_user.o $(XDP_SAMPLE)
    127
    128# Tell kbuild to always build the programs
    129always-y := $(tprogs-y)
    130always-y += sockex1_kern.o
    131always-y += sockex2_kern.o
    132always-y += sockex3_kern.o
    133always-y += tracex1_kern.o
    134always-y += tracex2_kern.o
    135always-y += tracex3_kern.o
    136always-y += tracex4_kern.o
    137always-y += tracex5_kern.o
    138always-y += tracex6_kern.o
    139always-y += tracex7_kern.o
    140always-y += sock_flags_kern.o
    141always-y += test_probe_write_user_kern.o
    142always-y += trace_output_kern.o
    143always-y += tcbpf1_kern.o
    144always-y += tc_l2_redirect_kern.o
    145always-y += lathist_kern.o
    146always-y += offwaketime_kern.o
    147always-y += spintest_kern.o
    148always-y += map_perf_test_kern.o
    149always-y += test_overhead_tp_kern.o
    150always-y += test_overhead_raw_tp_kern.o
    151always-y += test_overhead_kprobe_kern.o
    152always-y += parse_varlen.o parse_simple.o parse_ldabs.o
    153always-y += test_cgrp2_tc_kern.o
    154always-y += xdp1_kern.o
    155always-y += xdp2_kern.o
    156always-y += test_current_task_under_cgroup_kern.o
    157always-y += trace_event_kern.o
    158always-y += sampleip_kern.o
    159always-y += lwt_len_hist_kern.o
    160always-y += xdp_tx_iptunnel_kern.o
    161always-y += test_map_in_map_kern.o
    162always-y += tcp_synrto_kern.o
    163always-y += tcp_rwnd_kern.o
    164always-y += tcp_bufs_kern.o
    165always-y += tcp_cong_kern.o
    166always-y += tcp_iw_kern.o
    167always-y += tcp_clamp_kern.o
    168always-y += tcp_basertt_kern.o
    169always-y += tcp_tos_reflect_kern.o
    170always-y += tcp_dumpstats_kern.o
    171always-y += xdp_rxq_info_kern.o
    172always-y += xdp2skb_meta_kern.o
    173always-y += syscall_tp_kern.o
    174always-y += cpustat_kern.o
    175always-y += xdp_adjust_tail_kern.o
    176always-y += xdp_fwd_kern.o
    177always-y += task_fd_query_kern.o
    178always-y += xdp_sample_pkts_kern.o
    179always-y += ibumad_kern.o
    180always-y += hbm_out_kern.o
    181always-y += hbm_edt_kern.o
    182always-y += xdpsock_kern.o
    183
    184ifeq ($(ARCH), arm)
    185# Strip all except -D__LINUX_ARM_ARCH__ option needed to handle linux
    186# headers when arm instruction set identification is requested.
    187ARM_ARCH_SELECTOR := $(filter -D__LINUX_ARM_ARCH__%, $(KBUILD_CFLAGS))
    188BPF_EXTRA_CFLAGS := $(ARM_ARCH_SELECTOR)
    189TPROGS_CFLAGS += $(ARM_ARCH_SELECTOR)
    190endif
    191
    192ifeq ($(ARCH), mips)
    193TPROGS_CFLAGS += -D__SANE_USERSPACE_TYPES__
    194ifdef CONFIG_MACH_LOONGSON64
    195BPF_EXTRA_CFLAGS += -I$(srctree)/arch/mips/include/asm/mach-loongson64
    196BPF_EXTRA_CFLAGS += -I$(srctree)/arch/mips/include/asm/mach-generic
    197endif
    198endif
    199
    200TPROGS_CFLAGS += -Wall -O2
    201TPROGS_CFLAGS += -Wmissing-prototypes
    202TPROGS_CFLAGS += -Wstrict-prototypes
    203
    204TPROGS_CFLAGS += -I$(objtree)/usr/include
    205TPROGS_CFLAGS += -I$(srctree)/tools/testing/selftests/bpf/
    206TPROGS_CFLAGS += -I$(LIBBPF_INCLUDE)
    207TPROGS_CFLAGS += -I$(srctree)/tools/include
    208TPROGS_CFLAGS += -I$(srctree)/tools/perf
    209TPROGS_CFLAGS += -DHAVE_ATTR_TEST=0
    210
    211ifdef SYSROOT
    212TPROGS_CFLAGS += --sysroot=$(SYSROOT)
    213TPROGS_LDFLAGS := -L$(SYSROOT)/usr/lib
    214endif
    215
    216TPROGS_LDLIBS			+= $(LIBBPF) -lelf -lz
    217TPROGLDLIBS_xdp_monitor		+= -lm
    218TPROGLDLIBS_xdp_redirect	+= -lm
    219TPROGLDLIBS_xdp_redirect_cpu	+= -lm
    220TPROGLDLIBS_xdp_redirect_map	+= -lm
    221TPROGLDLIBS_xdp_redirect_map_multi += -lm
    222TPROGLDLIBS_xdp_router_ipv4	+= -lm -pthread
    223TPROGLDLIBS_tracex4		+= -lrt
    224TPROGLDLIBS_trace_output	+= -lrt
    225TPROGLDLIBS_map_perf_test	+= -lrt
    226TPROGLDLIBS_test_overhead	+= -lrt
    227TPROGLDLIBS_xdpsock		+= -pthread -lcap
    228TPROGLDLIBS_xsk_fwd		+= -pthread
    229
    230# Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline:
    231# make M=samples/bpf LLC=~/git/llvm-project/llvm/build/bin/llc CLANG=~/git/llvm-project/llvm/build/bin/clang
    232LLC ?= llc
    233CLANG ?= clang
    234OPT ?= opt
    235LLVM_DIS ?= llvm-dis
    236LLVM_OBJCOPY ?= llvm-objcopy
    237LLVM_READELF ?= llvm-readelf
    238BTF_PAHOLE ?= pahole
    239
    240# Detect that we're cross compiling and use the cross compiler
    241ifdef CROSS_COMPILE
    242CLANG_ARCH_ARGS = --target=$(notdir $(CROSS_COMPILE:%-=%))
    243endif
    244
    245# Don't evaluate probes and warnings if we need to run make recursively
    246ifneq ($(src),)
    247HDR_PROBE := $(shell printf "$(pound)include <linux/types.h>\n struct list_head { int a; }; int main() { return 0; }" | \
    248	$(CC) $(TPROGS_CFLAGS) $(TPROGS_LDFLAGS) -x c - \
    249	-o /dev/null 2>/dev/null && echo okay)
    250
    251ifeq ($(HDR_PROBE),)
    252$(warning WARNING: Detected possible issues with include path.)
    253$(warning WARNING: Please install kernel headers locally (make headers_install).)
    254endif
    255
    256BTF_LLC_PROBE := $(shell $(LLC) -march=bpf -mattr=help 2>&1 | grep dwarfris)
    257BTF_PAHOLE_PROBE := $(shell $(BTF_PAHOLE) --help 2>&1 | grep BTF)
    258BTF_OBJCOPY_PROBE := $(shell $(LLVM_OBJCOPY) --help 2>&1 | grep -i 'usage.*llvm')
    259BTF_LLVM_PROBE := $(shell echo "int main() { return 0; }" | \
    260			  $(CLANG) -target bpf -O2 -g -c -x c - -o ./llvm_btf_verify.o; \
    261			  $(LLVM_READELF) -S ./llvm_btf_verify.o | grep BTF; \
    262			  /bin/rm -f ./llvm_btf_verify.o)
    263
    264BPF_EXTRA_CFLAGS += -fno-stack-protector
    265ifneq ($(BTF_LLVM_PROBE),)
    266	BPF_EXTRA_CFLAGS += -g
    267else
    268ifneq ($(and $(BTF_LLC_PROBE),$(BTF_PAHOLE_PROBE),$(BTF_OBJCOPY_PROBE)),)
    269	BPF_EXTRA_CFLAGS += -g
    270	LLC_FLAGS += -mattr=dwarfris
    271	DWARF2BTF = y
    272endif
    273endif
    274endif
    275
    276# Trick to allow make to be run from this directory
    277all:
    278	$(MAKE) -C ../../ M=$(CURDIR) BPF_SAMPLES_PATH=$(CURDIR)
    279
    280clean:
    281	$(MAKE) -C ../../ M=$(CURDIR) clean
    282	@find $(CURDIR) -type f -name '*~' -delete
    283	@$(RM) -r $(CURDIR)/libbpf $(CURDIR)/bpftool
    284
    285$(LIBBPF): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(LIBBPF_OUTPUT)
    286# Fix up variables inherited from Kbuild that tools/ build system won't like
    287	$(MAKE) -C $(LIBBPF_SRC) RM='rm -rf' EXTRA_CFLAGS="$(TPROGS_CFLAGS)" \
    288		LDFLAGS=$(TPROGS_LDFLAGS) srctree=$(BPF_SAMPLES_PATH)/../../ \
    289		O= OUTPUT=$(LIBBPF_OUTPUT)/ DESTDIR=$(LIBBPF_DESTDIR) prefix= \
    290		$@ install_headers
    291
    292BPFTOOLDIR := $(TOOLS_PATH)/bpf/bpftool
    293BPFTOOL_OUTPUT := $(abspath $(BPF_SAMPLES_PATH))/bpftool
    294BPFTOOL := $(BPFTOOL_OUTPUT)/bpftool
    295$(BPFTOOL): $(LIBBPF) $(wildcard $(BPFTOOLDIR)/*.[ch] $(BPFTOOLDIR)/Makefile) | $(BPFTOOL_OUTPUT)
    296	    $(MAKE) -C $(BPFTOOLDIR) srctree=$(BPF_SAMPLES_PATH)/../../ \
    297		OUTPUT=$(BPFTOOL_OUTPUT)/ \
    298		LIBBPF_OUTPUT=$(LIBBPF_OUTPUT)/ \
    299		LIBBPF_DESTDIR=$(LIBBPF_DESTDIR)/
    300
    301$(LIBBPF_OUTPUT) $(BPFTOOL_OUTPUT):
    302	$(call msg,MKDIR,$@)
    303	$(Q)mkdir -p $@
    304
    305$(obj)/syscall_nrs.h:	$(obj)/syscall_nrs.s FORCE
    306	$(call filechk,offsets,__SYSCALL_NRS_H__)
    307
    308targets += syscall_nrs.s
    309clean-files += syscall_nrs.h
    310
    311FORCE:
    312
    313
    314# Verify LLVM compiler tools are available and bpf target is supported by llc
    315.PHONY: verify_cmds verify_target_bpf $(CLANG) $(LLC)
    316
    317verify_cmds: $(CLANG) $(LLC)
    318	@for TOOL in $^ ; do \
    319		if ! (which -- "$${TOOL}" > /dev/null 2>&1); then \
    320			echo "*** ERROR: Cannot find LLVM tool $${TOOL}" ;\
    321			exit 1; \
    322		else true; fi; \
    323	done
    324
    325verify_target_bpf: verify_cmds
    326	@if ! (${LLC} -march=bpf -mattr=help > /dev/null 2>&1); then \
    327		echo "*** ERROR: LLVM (${LLC}) does not support 'bpf' target" ;\
    328		echo "   NOTICE: LLVM version >= 3.7.1 required" ;\
    329		exit 2; \
    330	else true; fi
    331
    332$(BPF_SAMPLES_PATH)/*.c: verify_target_bpf $(LIBBPF)
    333$(src)/*.c: verify_target_bpf $(LIBBPF)
    334
    335libbpf_hdrs: $(LIBBPF)
    336$(obj)/$(TRACE_HELPERS) $(obj)/$(CGROUP_HELPERS) $(obj)/$(XDP_SAMPLE): | libbpf_hdrs
    337
    338.PHONY: libbpf_hdrs
    339
    340$(obj)/xdp_redirect_cpu_user.o: $(obj)/xdp_redirect_cpu.skel.h
    341$(obj)/xdp_redirect_map_multi_user.o: $(obj)/xdp_redirect_map_multi.skel.h
    342$(obj)/xdp_redirect_map_user.o: $(obj)/xdp_redirect_map.skel.h
    343$(obj)/xdp_redirect_user.o: $(obj)/xdp_redirect.skel.h
    344$(obj)/xdp_monitor_user.o: $(obj)/xdp_monitor.skel.h
    345$(obj)/xdp_router_ipv4_user.o: $(obj)/xdp_router_ipv4.skel.h
    346
    347$(obj)/tracex5_kern.o: $(obj)/syscall_nrs.h
    348$(obj)/hbm_out_kern.o: $(src)/hbm.h $(src)/hbm_kern.h
    349$(obj)/hbm.o: $(src)/hbm.h
    350$(obj)/hbm_edt_kern.o: $(src)/hbm.h $(src)/hbm_kern.h
    351
    352# Override includes for xdp_sample_user.o because $(srctree)/usr/include in
    353# TPROGS_CFLAGS causes conflicts
    354XDP_SAMPLE_CFLAGS += -Wall -O2 \
    355		     -I$(src)/../../tools/include \
    356		     -I$(src)/../../tools/include/uapi \
    357		     -I$(LIBBPF_INCLUDE) \
    358		     -I$(src)/../../tools/testing/selftests/bpf
    359
    360$(obj)/$(XDP_SAMPLE): TPROGS_CFLAGS = $(XDP_SAMPLE_CFLAGS)
    361$(obj)/$(XDP_SAMPLE): $(src)/xdp_sample_user.h $(src)/xdp_sample_shared.h
    362
    363-include $(BPF_SAMPLES_PATH)/Makefile.target
    364
    365VMLINUX_BTF_PATHS ?= $(abspath $(if $(O),$(O)/vmlinux))				\
    366		     $(abspath $(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux))	\
    367		     $(abspath ./vmlinux)
    368VMLINUX_BTF ?= $(abspath $(firstword $(wildcard $(VMLINUX_BTF_PATHS))))
    369
    370$(obj)/vmlinux.h: $(VMLINUX_BTF) $(BPFTOOL)
    371ifeq ($(VMLINUX_H),)
    372ifeq ($(VMLINUX_BTF),)
    373	$(error Cannot find a vmlinux for VMLINUX_BTF at any of "$(VMLINUX_BTF_PATHS)",\
    374		build the kernel or set VMLINUX_BTF or VMLINUX_H variable)
    375endif
    376	$(Q)$(BPFTOOL) btf dump file $(VMLINUX_BTF) format c > $@
    377else
    378	$(Q)cp "$(VMLINUX_H)" $@
    379endif
    380
    381clean-files += vmlinux.h
    382
    383# Get Clang's default includes on this system, as opposed to those seen by
    384# '-target bpf'. This fixes "missing" files on some architectures/distros,
    385# such as asm/byteorder.h, asm/socket.h, asm/sockios.h, sys/cdefs.h etc.
    386#
    387# Use '-idirafter': Don't interfere with include mechanics except where the
    388# build would have failed anyways.
    389define get_sys_includes
    390$(shell $(1) -v -E - </dev/null 2>&1 \
    391        | sed -n '/<...> search starts here:/,/End of search list./{ s| \(/.*\)|-idirafter \1|p }') \
    392$(shell $(1) -dM -E - </dev/null | grep '#define __riscv_xlen ' | sed 's/#define /-D/' | sed 's/ /=/')
    393endef
    394
    395CLANG_SYS_INCLUDES = $(call get_sys_includes,$(CLANG))
    396
    397$(obj)/xdp_redirect_cpu.bpf.o: $(obj)/xdp_sample.bpf.o
    398$(obj)/xdp_redirect_map_multi.bpf.o: $(obj)/xdp_sample.bpf.o
    399$(obj)/xdp_redirect_map.bpf.o: $(obj)/xdp_sample.bpf.o
    400$(obj)/xdp_redirect.bpf.o: $(obj)/xdp_sample.bpf.o
    401$(obj)/xdp_monitor.bpf.o: $(obj)/xdp_sample.bpf.o
    402$(obj)/xdp_router_ipv4.bpf.o: $(obj)/xdp_sample.bpf.o
    403
    404$(obj)/%.bpf.o: $(src)/%.bpf.c $(obj)/vmlinux.h $(src)/xdp_sample.bpf.h $(src)/xdp_sample_shared.h
    405	@echo "  CLANG-BPF " $@
    406	$(Q)$(CLANG) -g -O2 -target bpf -D__TARGET_ARCH_$(SRCARCH) \
    407		-Wno-compare-distinct-pointer-types -I$(srctree)/include \
    408		-I$(srctree)/samples/bpf -I$(srctree)/tools/include \
    409		-I$(LIBBPF_INCLUDE) $(CLANG_SYS_INCLUDES) \
    410		-c $(filter %.bpf.c,$^) -o $@
    411
    412LINKED_SKELS := xdp_redirect_cpu.skel.h xdp_redirect_map_multi.skel.h \
    413		xdp_redirect_map.skel.h xdp_redirect.skel.h xdp_monitor.skel.h \
    414		xdp_router_ipv4.skel.h
    415clean-files += $(LINKED_SKELS)
    416
    417xdp_redirect_cpu.skel.h-deps := xdp_redirect_cpu.bpf.o xdp_sample.bpf.o
    418xdp_redirect_map_multi.skel.h-deps := xdp_redirect_map_multi.bpf.o xdp_sample.bpf.o
    419xdp_redirect_map.skel.h-deps := xdp_redirect_map.bpf.o xdp_sample.bpf.o
    420xdp_redirect.skel.h-deps := xdp_redirect.bpf.o xdp_sample.bpf.o
    421xdp_monitor.skel.h-deps := xdp_monitor.bpf.o xdp_sample.bpf.o
    422xdp_router_ipv4.skel.h-deps := xdp_router_ipv4.bpf.o xdp_sample.bpf.o
    423
    424LINKED_BPF_SRCS := $(patsubst %.bpf.o,%.bpf.c,$(foreach skel,$(LINKED_SKELS),$($(skel)-deps)))
    425
    426BPF_SRCS_LINKED := $(notdir $(wildcard $(src)/*.bpf.c))
    427BPF_OBJS_LINKED := $(patsubst %.bpf.c,$(obj)/%.bpf.o, $(BPF_SRCS_LINKED))
    428BPF_SKELS_LINKED := $(addprefix $(obj)/,$(LINKED_SKELS))
    429
    430$(BPF_SKELS_LINKED): $(BPF_OBJS_LINKED) $(BPFTOOL)
    431	@echo "  BPF GEN-OBJ " $(@:.skel.h=)
    432	$(Q)$(BPFTOOL) gen object $(@:.skel.h=.lbpf.o) $(addprefix $(obj)/,$($(@F)-deps))
    433	@echo "  BPF GEN-SKEL" $(@:.skel.h=)
    434	$(Q)$(BPFTOOL) gen skeleton $(@:.skel.h=.lbpf.o) name $(notdir $(@:.skel.h=)) > $@
    435
    436# asm/sysreg.h - inline assembly used by it is incompatible with llvm.
    437# But, there is no easy way to fix it, so just exclude it since it is
    438# useless for BPF samples.
    439# below we use long chain of commands, clang | opt | llvm-dis | llc,
    440# to generate final object file. 'clang' compiles the source into IR
    441# with native target, e.g., x64, arm64, etc. 'opt' does bpf CORE IR builtin
    442# processing (llvm12) and IR optimizations. 'llvm-dis' converts
    443# 'opt' output to IR, and finally 'llc' generates bpf byte code.
    444$(obj)/%.o: $(src)/%.c
    445	@echo "  CLANG-bpf " $@
    446	$(Q)$(CLANG) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(BPF_EXTRA_CFLAGS) \
    447		-I$(obj) -I$(srctree)/tools/testing/selftests/bpf/ \
    448		-I$(LIBBPF_INCLUDE) \
    449		-D__KERNEL__ -D__BPF_TRACING__ -Wno-unused-value -Wno-pointer-sign \
    450		-D__TARGET_ARCH_$(SRCARCH) -Wno-compare-distinct-pointer-types \
    451		-Wno-gnu-variable-sized-type-not-at-end \
    452		-Wno-address-of-packed-member -Wno-tautological-compare \
    453		-Wno-unknown-warning-option $(CLANG_ARCH_ARGS) \
    454		-fno-asynchronous-unwind-tables \
    455		-I$(srctree)/samples/bpf/ -include asm_goto_workaround.h \
    456		-O2 -emit-llvm -Xclang -disable-llvm-passes -c $< -o - | \
    457		$(OPT) -O2 -mtriple=bpf-pc-linux | $(LLVM_DIS) | \
    458		$(LLC) -march=bpf $(LLC_FLAGS) -filetype=obj -o $@
    459ifeq ($(DWARF2BTF),y)
    460	$(BTF_PAHOLE) -J $@
    461endif