1 # SPDX-License-Identifier: GPL-2.0
2
3 HID_SAMPLES_PATH ?= $(abspath $(src))
4 TOOLS_PATH := $(HID_SAMPLES_PATH)/../../tools
5
6 pound := \#
7
8 # List of programs to build
9 tprogs-y += hid_mouse
10 tprogs-y += hid_surface_dial
11
12 # Libbpf dependencies
13 LIBBPF_SRC = $(TOOLS_PATH)/lib/bpf
14 LIBBPF_OUTPUT = $(abspath $(HID_SAMPLES_PATH))/libbpf
15 LIBBPF_DESTDIR = $(LIBBPF_OUTPUT)
16 LIBBPF_INCLUDE = $(LIBBPF_DESTDIR)/include
17 LIBBPF = $(LIBBPF_OUTPUT)/libbpf.a
18
19 EXTRA_BPF_HEADERS := hid_bpf_helpers.h
20
21 hid_mouse-objs := hid_mouse.o
22 hid_surface_dial-objs := hid_surface_dial.o
23
24 # Tell kbuild to always build the programs
25 always-y := $(tprogs-y)
26
27 ifeq ($(ARCH), arm)
28 # Strip all except -D__LINUX_ARM_ARCH__ option needed to handle linux
29 # headers when arm instruction set identification is requested.
30 ARM_ARCH_SELECTOR := $(filter -D__LINUX_ARM_ARCH__%, $(KBUILD_CFLAGS))
31 BPF_EXTRA_CFLAGS := $(ARM_ARCH_SELECTOR)
32 TPROGS_CFLAGS += $(ARM_ARCH_SELECTOR)
33 endif
34
35 ifeq ($(ARCH), mips)
36 TPROGS_CFLAGS += -D__SANE_USERSPACE_TYPES__
37 ifdef CONFIG_MACH_LOONGSON64
38 BPF_EXTRA_CFLAGS += -I$(srctree)/arch/mips/include/asm/mach-loongson64
39 BPF_EXTRA_CFLAGS += -I$(srctree)/arch/mips/include/asm/mach-generic
40 endif
41 endif
42
43 TPROGS_CFLAGS += -Wall -O2
44 TPROGS_CFLAGS += -Wmissing-prototypes
45 TPROGS_CFLAGS += -Wstrict-prototypes
46
47 TPROGS_CFLAGS += -I$(objtree)/usr/include
48 TPROGS_CFLAGS += -I$(LIBBPF_INCLUDE)
49 TPROGS_CFLAGS += -I$(srctree)/tools/include
50
51 ifdef SYSROOT
52 TPROGS_CFLAGS += --sysroot=$(SYSROOT)
53 TPROGS_LDFLAGS := -L$(SYSROOT)/usr/lib
54 endif
55
56 TPROGS_LDLIBS += $(LIBBPF) -lelf -lz
57
58 # Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline:
59 # make M=samples/bpf LLC=~/git/llvm-project/llvm/build/bin/llc CLANG=~/git/llvm-project/llvm/build/bin/clang
60 LLC ?= llc
61 CLANG ?= clang
62 OPT ?= opt
63 LLVM_DIS ?= llvm-dis
64 LLVM_OBJCOPY ?= llvm-objcopy
65 LLVM_READELF ?= llvm-readelf
66 BTF_PAHOLE ?= pahole
67
68 # Detect that we're cross compiling and use the cross compiler
69 ifdef CROSS_COMPILE
70 CLANG_ARCH_ARGS = --target=$(notdir $(CROSS_COMPILE:%-=%))
71 endif
72
73 # Don't evaluate probes and warnings if we need to run make recursively
74 ifneq ($(src),)
75 HDR_PROBE := $(shell printf "$(pound)include <linux/types.h>\n struct list_head { int a; }; int main() { return 0; }" | \
76 $(CC) $(TPROGS_CFLAGS) $(TPROGS_LDFLAGS) -x c - \
77 -o /dev/null 2>/dev/null && echo okay)
78
79 ifeq ($(HDR_PROBE),)
80 $(warning WARNING: Detected possible issues with include path.)
81 $(warning WARNING: Please install kernel headers locally (make headers_install).)
82 endif
83
84 BTF_LLC_PROBE := $(shell $(LLC) -march=bpf -mattr=help 2>&1 | grep dwarfris)
85 BTF_PAHOLE_PROBE := $(shell $(BTF_PAHOLE) --help 2>&1 | grep BTF)
86 BTF_OBJCOPY_PROBE := $(shell $(LLVM_OBJCOPY) --help 2>&1 | grep -i 'usage.*llvm')
87 BTF_LLVM_PROBE := $(shell echo "int main() { return 0; }" | \
88 $(CLANG) --target=bpf -O2 -g -c -x c - -o ./llvm_btf_verify.o; \
89 $(LLVM_READELF) -S ./llvm_btf_verify.o | grep BTF; \
90 /bin/rm -f ./llvm_btf_verify.o)
91
92 BPF_EXTRA_CFLAGS += -fno-stack-protector
93 ifneq ($(BTF_LLVM_PROBE),)
94 BPF_EXTRA_CFLAGS += -g
95 else
96 ifneq ($(and $(BTF_LLC_PROBE),$(BTF_PAHOLE_PROBE),$(BTF_OBJCOPY_PROBE)),)
97 BPF_EXTRA_CFLAGS += -g
98 LLC_FLAGS += -mattr=dwarfris
99 DWARF2BTF = y
100 endif
101 endif
102 endif
103
104 # Trick to allow make to be run from this directory
105 all:
106 $(MAKE) -C ../../ M=$(CURDIR) HID_SAMPLES_PATH=$(CURDIR)
107
108 clean:
109 $(MAKE) -C ../../ M=$(CURDIR) clean
110 @find $(CURDIR) -type f -name '*~' -delete
111 @$(RM) -r $(CURDIR)/libbpf $(CURDIR)/bpftool
112
113 $(LIBBPF): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(LIBBPF_OUTPUT)
114 # Fix up variables inherited from Kbuild that tools/ build system won't like
115 $(MAKE) -C $(LIBBPF_SRC) RM='rm -rf' EXTRA_CFLAGS="$(TPROGS_CFLAGS)" \
116 LDFLAGS=$(TPROGS_LDFLAGS) srctree=$(HID_SAMPLES_PATH)/../../ \
117 O= OUTPUT=$(LIBBPF_OUTPUT)/ DESTDIR=$(LIBBPF_DESTDIR) prefix= \
118 $@ install_headers
119
120 BPFTOOLDIR := $(TOOLS_PATH)/bpf/bpftool
121 BPFTOOL_OUTPUT := $(abspath $(HID_SAMPLES_PATH))/bpftool
122 BPFTOOL := $(BPFTOOL_OUTPUT)/bootstrap/bpftool
123 $(BPFTOOL): $(wildcard $(BPFTOOLDIR)/*.[ch] $(BPFTOOLDIR)/Makefile) | $(BPFTOOL_OUTPUT)
124 $(MAKE) -C $(BPFTOOLDIR) srctree=$(HID_SAMPLES_PATH)/../../ \
125 OUTPUT=$(BPFTOOL_OUTPUT)/ bootstrap
126
127 $(LIBBPF_OUTPUT) $(BPFTOOL_OUTPUT):
128 $(call msg,MKDIR,$@)
129 $(Q)mkdir -p $@
130
131 FORCE:
132
133
134 # Verify LLVM compiler tools are available and bpf target is supported by llc
135 .PHONY: verify_cmds verify_target_bpf $(CLANG) $(LLC)
136
137 verify_cmds: $(CLANG) $(LLC)
138 @for TOOL in $^ ; do \
139 if ! (which -- "$${TOOL}" > /dev/null 2>&1); then \
140 echo "*** ERROR: Cannot find LLVM tool $${TOOL}" ;\
141 exit 1; \
142 else true; fi; \
143 done
144
145 verify_target_bpf: verify_cmds
146 @if ! (${LLC} -march=bpf -mattr=help > /dev/null 2>&1); then \
147 echo "*** ERROR: LLVM (${LLC}) does not support 'bpf' target" ;\
148 echo " NOTICE: LLVM version >= 3.7.1 required" ;\
149 exit 2; \
150 else true; fi
151
152 $(HID_SAMPLES_PATH)/*.c: verify_target_bpf $(LIBBPF)
153 $(src)/*.c: verify_target_bpf $(LIBBPF)
154
155 libbpf_hdrs: $(LIBBPF)
156
157 .PHONY: libbpf_hdrs
158
159 $(obj)/hid_mouse.o: $(obj)/hid_mouse.skel.h
160 $(obj)/hid_surface_dial.o: $(obj)/hid_surface_dial.skel.h
161
162 -include $(HID_SAMPLES_PATH)/Makefile.target
163
164 VMLINUX_BTF_PATHS ?= $(abspath $(if $(O),$(O)/vmlinux)) \
165 $(abspath $(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux)) \
166 $(abspath ./vmlinux)
167 VMLINUX_BTF ?= $(abspath $(firstword $(wildcard $(VMLINUX_BTF_PATHS))))
168
169 $(obj)/vmlinux.h: $(VMLINUX_BTF) $(BPFTOOL)
170 ifeq ($(VMLINUX_H),)
171 ifeq ($(VMLINUX_BTF),)
172 $(error Cannot find a vmlinux for VMLINUX_BTF at any of "$(VMLINUX_BTF_PATHS)",\
173 build the kernel or set VMLINUX_BTF or VMLINUX_H variable)
174 endif
175 $(Q)$(BPFTOOL) btf dump file $(VMLINUX_BTF) format c > $@
176 else
177 $(Q)cp "$(VMLINUX_H)" $@
178 endif
179
180 clean-files += vmlinux.h
181
182 # Get Clang's default includes on this system, as opposed to those seen by
183 # '--target=bpf'. This fixes "missing" files on some architectures/distros,
184 # such as asm/byteorder.h, asm/socket.h, asm/sockios.h, sys/cdefs.h etc.
185 #
186 # Use '-idirafter': Don't interfere with include mechanics except where the
187 # build would have failed anyways.
188 define get_sys_includes
189 $(shell $(1) -v -E - </dev/null 2>&1 \
190 | sed -n '/<...> search starts here:/,/End of search list./{ s| \(/.*\)|-idirafter \1|p }') \
191 $(shell $(1) -dM -E - </dev/null | grep '#define __riscv_xlen ' | sed 's/#define /-D/' | sed 's/ /=/')
192 endef
193
194 CLANG_SYS_INCLUDES = $(call get_sys_includes,$(CLANG))
195
196 EXTRA_BPF_HEADERS_SRC := $(addprefix $(src)/,$(EXTRA_BPF_HEADERS))
197
198 $(obj)/%.bpf.o: $(src)/%.bpf.c $(EXTRA_BPF_HEADERS_SRC) $(obj)/vmlinux.h
199 @echo " CLANG-BPF " $@
200 $(Q)$(CLANG) -g -O2 --target=bpf -D__TARGET_ARCH_$(SRCARCH) \
201 -Wno-compare-distinct-pointer-types -I$(srctree)/include \
202 -I$(srctree)/samples/bpf -I$(srctree)/tools/include \
203 -I$(LIBBPF_INCLUDE) $(CLANG_SYS_INCLUDES) \
204 -c $(filter %.bpf.c,$^) -o $@
205
206 LINKED_SKELS := hid_mouse.skel.h hid_surface_dial.skel.h
207 clean-files += $(LINKED_SKELS)
208
209 hid_mouse.skel.h-deps := hid_mouse.bpf.o
210 hid_surface_dial.skel.h-deps := hid_surface_dial.bpf.o
211
212 LINKED_BPF_SRCS := $(patsubst %.bpf.o,%.bpf.c,$(foreach skel,$(LINKED_SKELS),$($(skel)-deps)))
213
214 BPF_SRCS_LINKED := $(notdir $(wildcard $(src)/*.bpf.c))
215 BPF_OBJS_LINKED := $(patsubst %.bpf.c,$(obj)/%.bpf.o, $(BPF_SRCS_LINKED))
216 BPF_SKELS_LINKED := $(addprefix $(obj)/,$(LINKED_SKELS))
217
218 $(BPF_SKELS_LINKED): $(BPF_OBJS_LINKED) $(BPFTOOL)
219 @echo " BPF GEN-OBJ " $(@:.skel.h=)
220 $(Q)$(BPFTOOL) gen object $(@:.skel.h=.lbpf.o) $(addprefix $(obj)/,$($(@F)-deps))
221 @echo " BPF GEN-SKEL" $(@:.skel.h=)
222 $(Q)$(BPFTOOL) gen skeleton $(@:.skel.h=.lbpf.o) name $(notdir $(@:.skel.h=)) > $@
223
224 # asm/sysreg.h - inline assembly used by it is incompatible with llvm.
225 # But, there is no easy way to fix it, so just exclude it since it is
226 # useless for BPF samples.
227 # below we use long chain of commands, clang | opt | llvm-dis | llc,
228 # to generate final object file. 'clang' compiles the source into IR
229 # with native target, e.g., x64, arm64, etc. 'opt' does bpf CORE IR builtin
230 # processing (llvm12) and IR optimizations. 'llvm-dis' converts
231 # 'opt' output to IR, and finally 'llc' generates bpf byte code.
232 $(obj)/%.o: $(src)/%.c
233 @echo " CLANG-bpf " $@
234 $(Q)$(CLANG) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(BPF_EXTRA_CFLAGS) \
235 -I$(obj) -I$(srctree)/tools/testing/selftests/bpf/ \
236 -I$(LIBBPF_INCLUDE) \
237 -D__KERNEL__ -D__BPF_TRACING__ -Wno-unused-value -Wno-pointer-sign \
238 -D__TARGET_ARCH_$(SRCARCH) -Wno-compare-distinct-pointer-types \
239 -Wno-gnu-variable-sized-type-not-at-end \
240 -Wno-address-of-packed-member -Wno-tautological-compare \
241 -Wno-unknown-warning-option $(CLANG_ARCH_ARGS) \
242 -fno-asynchronous-unwind-tables \
243 -I$(srctree)/samples/hid/ \
244 -O2 -emit-llvm -Xclang -disable-llvm-passes -c $< -o - | \
245 $(OPT) -O2 -mtriple=bpf-pc-linux | $(LLVM_DIS) | \
246 $(LLC) -march=bpf $(LLC_FLAGS) -filetype=obj -o $@
247 ifeq ($(DWARF2BTF),y)
248 $(BTF_PAHOLE) -J $@
249 endif
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