From cdd5b2d1fc86f8dda383d4f0b4ac9b533539e76a Mon Sep 17 00:00:00 2001 From: Ivan Khoronzhuk Date: Fri, 11 Oct 2019 03:27:54 +0300 Subject: [PATCH 01/15] samples/bpf: Fix HDR_PROBE "echo" echo should be replaced with echo -e to handle '\n' correctly, but instead, replace it with printf as some systems can't handle echo -e. Signed-off-by: Ivan Khoronzhuk Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20191011002808.28206-2-ivan.khoronzhuk@linaro.org --- samples/bpf/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index a11d7270583d..4f61725b1d86 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -201,7 +201,7 @@ endif # Don't evaluate probes and warnings if we need to run make recursively ifneq ($(src),) -HDR_PROBE := $(shell echo "\#include \n struct list_head { int a; }; int main() { return 0; }" | \ +HDR_PROBE := $(shell printf "\#include \n struct list_head { int a; }; int main() { return 0; }" | \ $(HOSTCC) $(KBUILD_HOSTCFLAGS) -x c - -o /dev/null 2>/dev/null && \ echo okay) From 39e0c3649f2ef5fc1beac4f6cc5f5f9ddb1885a9 Mon Sep 17 00:00:00 2001 From: Ivan Khoronzhuk Date: Fri, 11 Oct 2019 03:27:55 +0300 Subject: [PATCH 02/15] samples/bpf: Fix cookie_uid_helper_example obj build Don't list userspace "cookie_uid_helper_example" object in list for bpf objects. 'always' target is used for listing bpf programs, but 'cookie_uid_helper_example.o' is a user space ELF file, and covered by rule `per_socket_stats_example`, so shouldn't be in 'always'. Let us remove `always += cookie_uid_helper_example.o`, which avoids breaking cross compilation due to mismatched includes. Signed-off-by: Ivan Khoronzhuk Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20191011002808.28206-3-ivan.khoronzhuk@linaro.org --- samples/bpf/Makefile | 1 - 1 file changed, 1 deletion(-) diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 4f61725b1d86..045fa43842e6 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -145,7 +145,6 @@ always += sampleip_kern.o always += lwt_len_hist_kern.o always += xdp_tx_iptunnel_kern.o always += test_map_in_map_kern.o -always += cookie_uid_helper_example.o always += tcp_synrto_kern.o always += tcp_rwnd_kern.o always += tcp_bufs_kern.o From 518c13401e16eae1d83d6e459daf6e776a97eba9 Mon Sep 17 00:00:00 2001 From: Ivan Khoronzhuk Date: Fri, 11 Oct 2019 03:27:56 +0300 Subject: [PATCH 03/15] samples/bpf: Use --target from cross-compile For cross compiling the target triple can be inherited from cross-compile prefix as it's done in CLANG_FLAGS from kernel makefile. So copy-paste this decision from kernel Makefile. Signed-off-by: Ivan Khoronzhuk Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20191011002808.28206-4-ivan.khoronzhuk@linaro.org --- samples/bpf/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 045fa43842e6..9c8c9872004d 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -195,7 +195,7 @@ BTF_PAHOLE ?= pahole # Detect that we're cross compiling and use the cross compiler ifdef CROSS_COMPILE HOSTCC = $(CROSS_COMPILE)gcc -CLANG_ARCH_ARGS = -target $(ARCH) +CLANG_ARCH_ARGS = --target=$(notdir $(CROSS_COMPILE:%-=%)) endif # Don't evaluate probes and warnings if we need to run make recursively From 2a560df7c147abcced2ff8c3b5572e0b1b36ac3f Mon Sep 17 00:00:00 2001 From: Ivan Khoronzhuk Date: Fri, 11 Oct 2019 03:27:57 +0300 Subject: [PATCH 04/15] samples/bpf: Use own EXTRA_CFLAGS for clang commands It can overlap with CFLAGS used for libraries built with gcc if not now then in next patches. Correct it here for simplicity. Signed-off-by: Ivan Khoronzhuk Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20191011002808.28206-5-ivan.khoronzhuk@linaro.org --- samples/bpf/Makefile | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 9c8c9872004d..cf882e43648a 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -218,10 +218,10 @@ BTF_LLVM_PROBE := $(shell echo "int main() { return 0; }" | \ /bin/rm -f ./llvm_btf_verify.o) ifneq ($(BTF_LLVM_PROBE),) - EXTRA_CFLAGS += -g + BPF_EXTRA_CFLAGS += -g else ifneq ($(and $(BTF_LLC_PROBE),$(BTF_PAHOLE_PROBE),$(BTF_OBJCOPY_PROBE)),) - EXTRA_CFLAGS += -g + BPF_EXTRA_CFLAGS += -g LLC_FLAGS += -mattr=dwarfris DWARF2BTF = y endif @@ -280,8 +280,9 @@ $(obj)/hbm_edt_kern.o: $(src)/hbm.h $(src)/hbm_kern.h # useless for BPF samples. $(obj)/%.o: $(src)/%.c @echo " CLANG-bpf " $@ - $(Q)$(CLANG) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(EXTRA_CFLAGS) -I$(obj) \ - -I$(srctree)/tools/testing/selftests/bpf/ -I$(srctree)/tools/lib/bpf/ \ + $(Q)$(CLANG) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(BPF_EXTRA_CFLAGS) \ + -I$(obj) -I$(srctree)/tools/testing/selftests/bpf/ \ + -I$(srctree)/tools/lib/bpf/ \ -D__KERNEL__ -D__BPF_TRACING__ -Wno-unused-value -Wno-pointer-sign \ -D__TARGET_ARCH_$(SRCARCH) -Wno-compare-distinct-pointer-types \ -Wno-gnu-variable-sized-type-not-at-end \ From 0e865aedad571b93b2d8bb780f17befd5ee4b308 Mon Sep 17 00:00:00 2001 From: Ivan Khoronzhuk Date: Fri, 11 Oct 2019 03:27:58 +0300 Subject: [PATCH 05/15] samples/bpf: Use __LINUX_ARM_ARCH__ selector for arm For arm, -D__LINUX_ARM_ARCH__=X is min version used as instruction set selector and is absolutely required while parsing some parts of headers. It's present in KBUILD_CFLAGS but not in autoconf.h, so let's retrieve it from and add to programs cflags. In another case errors like "SMP is not supported" for armv7 and bunch of other errors are issued resulting to incorrect final object. Signed-off-by: Ivan Khoronzhuk Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20191011002808.28206-6-ivan.khoronzhuk@linaro.org --- samples/bpf/Makefile | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index cf882e43648a..9b33e7395eac 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -185,6 +185,14 @@ HOSTLDLIBS_map_perf_test += -lrt HOSTLDLIBS_test_overhead += -lrt HOSTLDLIBS_xdpsock += -pthread +ifeq ($(ARCH), arm) +# Strip all except -D__LINUX_ARM_ARCH__ option needed to handle linux +# headers when arm instruction set identification is requested. +ARM_ARCH_SELECTOR := $(filter -D__LINUX_ARM_ARCH__%, $(KBUILD_CFLAGS)) +BPF_EXTRA_CFLAGS := $(ARM_ARCH_SELECTOR) +KBUILD_HOSTCFLAGS += $(ARM_ARCH_SELECTOR) +endif + # Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline: # make samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang LLC ?= llc From 54b7fbd4484bdf8a13045abdf57a66185390f07f Mon Sep 17 00:00:00 2001 From: Ivan Khoronzhuk Date: Fri, 11 Oct 2019 03:27:59 +0300 Subject: [PATCH 06/15] samples/bpf: Drop unnecessarily inclusion for bpf_load Drop inclusion for bpf_load -I$(objtree)/usr/include as it is included for all objects anyway, with above line: KBUILD_HOSTCFLAGS += -I$(objtree)/usr/include Signed-off-by: Ivan Khoronzhuk Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20191011002808.28206-7-ivan.khoronzhuk@linaro.org --- samples/bpf/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 9b33e7395eac..bb2d976e824e 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -176,7 +176,7 @@ KBUILD_HOSTCFLAGS += -I$(srctree)/tools/testing/selftests/bpf/ KBUILD_HOSTCFLAGS += -I$(srctree)/tools/lib/ -I$(srctree)/tools/include KBUILD_HOSTCFLAGS += -I$(srctree)/tools/perf -HOSTCFLAGS_bpf_load.o += -I$(objtree)/usr/include -Wno-unused-variable +HOSTCFLAGS_bpf_load.o += -Wno-unused-variable KBUILD_HOSTLDLIBS += $(LIBBPF) -lelf HOSTLDLIBS_tracex4 += -lrt From 752677e89fca11fd6e239df2fb9877b9e6b83ab2 Mon Sep 17 00:00:00 2001 From: Ivan Khoronzhuk Date: Fri, 11 Oct 2019 03:28:00 +0300 Subject: [PATCH 07/15] samples/bpf: Add makefile.target for separate CC target build The Makefile.target is added only and will be used in sample/bpf/Makefile later in order to switch cross-compiling to CC from HOSTCC environment. The HOSTCC is supposed to build binaries and tools running on the host afterwards, in order to simplify build or so, like "fixdep" or else. In case of cross compiling "fixdep" is executed on host when the rest samples should run on target arch. In order to build binaries for target arch with CC and tools running on host with HOSTCC, lets add Makefile.target for simplicity, having definition and routines similar to ones, used in script/Makefile.host. This allows later add cross-compilation to samples/bpf with minimum changes. The tprog stands for target programs built with CC. Makefile.target contains only stuff needed for samples/bpf, potentially can be reused later and now needed only for unblocking tricky samples/bpf cross compilation. Signed-off-by: Ivan Khoronzhuk Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20191011002808.28206-8-ivan.khoronzhuk@linaro.org --- samples/bpf/Makefile.target | 75 +++++++++++++++++++++++++++++++++++++ 1 file changed, 75 insertions(+) create mode 100644 samples/bpf/Makefile.target diff --git a/samples/bpf/Makefile.target b/samples/bpf/Makefile.target new file mode 100644 index 000000000000..7621f55e2947 --- /dev/null +++ b/samples/bpf/Makefile.target @@ -0,0 +1,75 @@ +# SPDX-License-Identifier: GPL-2.0 +# ========================================================================== +# Building binaries on the host system +# Binaries are not used during the compilation of the kernel, and intended +# to be build for target board, target board can be host of course. Added to +# build binaries to run not on host system. +# +# Sample syntax +# tprogs-y := xsk_example +# Will compile xsk_example.c and create an executable named xsk_example +# +# tprogs-y := xdpsock +# xdpsock-objs := xdpsock_1.o xdpsock_2.o +# Will compile xdpsock_1.c and xdpsock_2.c, and then link the executable +# xdpsock, based on xdpsock_1.o and xdpsock_2.o +# +# Derived from scripts/Makefile.host +# +__tprogs := $(sort $(tprogs-y)) + +# C code +# Executables compiled from a single .c file +tprog-csingle := $(foreach m,$(__tprogs), \ + $(if $($(m)-objs),,$(m))) + +# C executables linked based on several .o files +tprog-cmulti := $(foreach m,$(__tprogs),\ + $(if $($(m)-objs),$(m))) + +# Object (.o) files compiled from .c files +tprog-cobjs := $(sort $(foreach m,$(__tprogs),$($(m)-objs))) + +tprog-csingle := $(addprefix $(obj)/,$(tprog-csingle)) +tprog-cmulti := $(addprefix $(obj)/,$(tprog-cmulti)) +tprog-cobjs := $(addprefix $(obj)/,$(tprog-cobjs)) + +##### +# Handle options to gcc. Support building with separate output directory + +_tprogc_flags = $(TPROGS_CFLAGS) \ + $(TPROGCFLAGS_$(basetarget).o) + +# $(objtree)/$(obj) for including generated headers from checkin source files +ifeq ($(KBUILD_EXTMOD),) +ifdef building_out_of_srctree +_tprogc_flags += -I $(objtree)/$(obj) +endif +endif + +tprogc_flags = -Wp,-MD,$(depfile) $(_tprogc_flags) + +# Create executable from a single .c file +# tprog-csingle -> Executable +quiet_cmd_tprog-csingle = CC $@ + cmd_tprog-csingle = $(CC) $(tprogc_flags) $(TPROGS_LDFLAGS) -o $@ $< \ + $(TPROGS_LDLIBS) $(TPROGLDLIBS_$(@F)) +$(tprog-csingle): $(obj)/%: $(src)/%.c FORCE + $(call if_changed_dep,tprog-csingle) + +# Link an executable based on list of .o files, all plain c +# tprog-cmulti -> executable +quiet_cmd_tprog-cmulti = LD $@ + cmd_tprog-cmulti = $(CC) $(tprogc_flags) $(TPROGS_LDFLAGS) -o $@ \ + $(addprefix $(obj)/,$($(@F)-objs)) \ + $(TPROGS_LDLIBS) $(TPROGLDLIBS_$(@F)) +$(tprog-cmulti): $(tprog-cobjs) FORCE + $(call if_changed,tprog-cmulti) +$(call multi_depend, $(tprog-cmulti), , -objs) + +# Create .o file from a single .c file +# tprog-cobjs -> .o +quiet_cmd_tprog-cobjs = CC $@ + cmd_tprog-cobjs = $(CC) $(tprogc_flags) -c -o $@ $< +$(tprog-cobjs): $(obj)/%.o: $(src)/%.c FORCE + $(call if_changed_dep,tprog-cobjs) From 1d97c6c2511f10e19f683a4431e8ee887c1daab6 Mon Sep 17 00:00:00 2001 From: Ivan Khoronzhuk Date: Fri, 11 Oct 2019 03:28:01 +0300 Subject: [PATCH 08/15] samples/bpf: Base target programs rules on Makefile.target The main reason for that - HOSTCC and CC have different aims. HOSTCC is used to build programs running on host, that can cross-comple target programs with CC. It was tested for arm and arm64 cross compilation, based on linaro toolchain, but should work for others. So, in order to split cross compilation (CC) with host build (HOSTCC), lets base samples on Makefile.target. It allows to cross-compile samples/bpf programs with CC while auxialry tools running on host built with HOSTCC. Signed-off-by: Ivan Khoronzhuk Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20191011002808.28206-9-ivan.khoronzhuk@linaro.org --- samples/bpf/Makefile | 135 ++++++++++++++++++++++--------------------- 1 file changed, 69 insertions(+), 66 deletions(-) diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index bb2d976e824e..91bfb421c278 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -4,55 +4,53 @@ BPF_SAMPLES_PATH ?= $(abspath $(srctree)/$(src)) TOOLS_PATH := $(BPF_SAMPLES_PATH)/../../tools # List of programs to build -hostprogs-y := test_lru_dist -hostprogs-y += sock_example -hostprogs-y += fds_example -hostprogs-y += sockex1 -hostprogs-y += sockex2 -hostprogs-y += sockex3 -hostprogs-y += tracex1 -hostprogs-y += tracex2 -hostprogs-y += tracex3 -hostprogs-y += tracex4 -hostprogs-y += tracex5 -hostprogs-y += tracex6 -hostprogs-y += tracex7 -hostprogs-y += test_probe_write_user -hostprogs-y += trace_output -hostprogs-y += lathist -hostprogs-y += offwaketime -hostprogs-y += spintest -hostprogs-y += map_perf_test -hostprogs-y += test_overhead -hostprogs-y += test_cgrp2_array_pin -hostprogs-y += test_cgrp2_attach -hostprogs-y += test_cgrp2_sock -hostprogs-y += test_cgrp2_sock2 -hostprogs-y += xdp1 -hostprogs-y += xdp2 -hostprogs-y += xdp_router_ipv4 -hostprogs-y += test_current_task_under_cgroup -hostprogs-y += trace_event -hostprogs-y += sampleip -hostprogs-y += tc_l2_redirect -hostprogs-y += lwt_len_hist -hostprogs-y += xdp_tx_iptunnel -hostprogs-y += test_map_in_map -hostprogs-y += per_socket_stats_example -hostprogs-y += xdp_redirect -hostprogs-y += xdp_redirect_map -hostprogs-y += xdp_redirect_cpu -hostprogs-y += xdp_monitor -hostprogs-y += xdp_rxq_info -hostprogs-y += syscall_tp -hostprogs-y += cpustat -hostprogs-y += xdp_adjust_tail -hostprogs-y += xdpsock -hostprogs-y += xdp_fwd -hostprogs-y += task_fd_query -hostprogs-y += xdp_sample_pkts -hostprogs-y += ibumad -hostprogs-y += hbm +tprogs-y := test_lru_dist +tprogs-y += sock_example +tprogs-y += fds_example +tprogs-y += sockex1 +tprogs-y += sockex2 +tprogs-y += sockex3 +tprogs-y += tracex1 +tprogs-y += tracex2 +tprogs-y += tracex3 +tprogs-y += tracex4 +tprogs-y += tracex5 +tprogs-y += tracex6 +tprogs-y += tracex7 +tprogs-y += test_probe_write_user +tprogs-y += trace_output +tprogs-y += lathist +tprogs-y += offwaketime +tprogs-y += spintest +tprogs-y += map_perf_test +tprogs-y += test_overhead +tprogs-y += test_cgrp2_array_pin +tprogs-y += test_cgrp2_attach +tprogs-y += test_cgrp2_sock +tprogs-y += test_cgrp2_sock2 +tprogs-y += xdp1 +tprogs-y += xdp2 +tprogs-y += xdp_router_ipv4 +tprogs-y += test_current_task_under_cgroup +tprogs-y += trace_event +tprogs-y += sampleip +tprogs-y += tc_l2_redirect +tprogs-y += lwt_len_hist +tprogs-y += xdp_tx_iptunnel +tprogs-y += test_map_in_map +tprogs-y += xdp_redirect_map +tprogs-y += xdp_redirect_cpu +tprogs-y += xdp_monitor +tprogs-y += xdp_rxq_info +tprogs-y += syscall_tp +tprogs-y += cpustat +tprogs-y += xdp_adjust_tail +tprogs-y += xdpsock +tprogs-y += xdp_fwd +tprogs-y += task_fd_query +tprogs-y += xdp_sample_pkts +tprogs-y += ibumad +tprogs-y += hbm # Libbpf dependencies LIBBPF = $(TOOLS_PATH)/lib/bpf/libbpf.a @@ -111,7 +109,7 @@ ibumad-objs := bpf_load.o ibumad_user.o $(TRACE_HELPERS) hbm-objs := bpf_load.o hbm.o $(CGROUP_HELPERS) # Tell kbuild to always build the programs -always := $(hostprogs-y) +always := $(tprogs-y) always += sockex1_kern.o always += sockex2_kern.o always += sockex3_kern.o @@ -170,29 +168,32 @@ always += ibumad_kern.o always += hbm_out_kern.o always += hbm_edt_kern.o -KBUILD_HOSTCFLAGS += -I$(objtree)/usr/include -KBUILD_HOSTCFLAGS += -I$(srctree)/tools/lib/bpf/ -KBUILD_HOSTCFLAGS += -I$(srctree)/tools/testing/selftests/bpf/ -KBUILD_HOSTCFLAGS += -I$(srctree)/tools/lib/ -I$(srctree)/tools/include -KBUILD_HOSTCFLAGS += -I$(srctree)/tools/perf - -HOSTCFLAGS_bpf_load.o += -Wno-unused-variable - -KBUILD_HOSTLDLIBS += $(LIBBPF) -lelf -HOSTLDLIBS_tracex4 += -lrt -HOSTLDLIBS_trace_output += -lrt -HOSTLDLIBS_map_perf_test += -lrt -HOSTLDLIBS_test_overhead += -lrt -HOSTLDLIBS_xdpsock += -pthread - ifeq ($(ARCH), arm) # Strip all except -D__LINUX_ARM_ARCH__ option needed to handle linux # headers when arm instruction set identification is requested. ARM_ARCH_SELECTOR := $(filter -D__LINUX_ARM_ARCH__%, $(KBUILD_CFLAGS)) BPF_EXTRA_CFLAGS := $(ARM_ARCH_SELECTOR) -KBUILD_HOSTCFLAGS += $(ARM_ARCH_SELECTOR) +TPROGS_CFLAGS += $(ARM_ARCH_SELECTOR) endif +TPROGS_LDLIBS := $(KBUILD_HOSTLDLIBS) +TPROGS_CFLAGS += $(KBUILD_HOSTCFLAGS) $(HOST_EXTRACFLAGS) +TPROGS_CFLAGS += -I$(objtree)/usr/include +TPROGS_CFLAGS += -I$(srctree)/tools/lib/bpf/ +TPROGS_CFLAGS += -I$(srctree)/tools/testing/selftests/bpf/ +TPROGS_CFLAGS += -I$(srctree)/tools/lib/ +TPROGS_CFLAGS += -I$(srctree)/tools/include +TPROGS_CFLAGS += -I$(srctree)/tools/perf + +TPROGCFLAGS_bpf_load.o += -Wno-unused-variable + +TPROGS_LDLIBS += $(LIBBPF) -lelf +TPROGLDLIBS_tracex4 += -lrt +TPROGLDLIBS_trace_output += -lrt +TPROGLDLIBS_map_perf_test += -lrt +TPROGLDLIBS_test_overhead += -lrt +TPROGLDLIBS_xdpsock += -pthread + # Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline: # make samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang LLC ?= llc @@ -283,6 +284,8 @@ $(obj)/hbm_out_kern.o: $(src)/hbm.h $(src)/hbm_kern.h $(obj)/hbm.o: $(src)/hbm.h $(obj)/hbm_edt_kern.o: $(src)/hbm.h $(src)/hbm_kern.h +-include $(BPF_SAMPLES_PATH)/Makefile.target + # asm/sysreg.h - inline assembly used by it is incompatible with llvm. # But, there is no easy way to fix it, so just exclude it since it is # useless for BPF samples. From 10cb3d8706dbaa0521e761b96b3be5b7a497ae3f Mon Sep 17 00:00:00 2001 From: Ivan Khoronzhuk Date: Fri, 11 Oct 2019 03:28:02 +0300 Subject: [PATCH 09/15] samples/bpf: Use own flags but not HOSTCFLAGS While compiling natively, the host's cflags and ldflags are equal to ones used from HOSTCFLAGS and HOSTLDFLAGS. When cross compiling it should have own, used for target arch. While verification, for arm, arm64 and x86_64 the following flags were used always: -Wall -O2 -fomit-frame-pointer -Wmissing-prototypes -Wstrict-prototypes So, add them as they were verified and used before adding Makefile.target and lets omit "-fomit-frame-pointer" as were proposed while review, as no sense in such optimization for samples. Signed-off-by: Ivan Khoronzhuk Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20191011002808.28206-10-ivan.khoronzhuk@linaro.org --- samples/bpf/Makefile | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 91bfb421c278..57a15ff938a6 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -176,8 +176,10 @@ BPF_EXTRA_CFLAGS := $(ARM_ARCH_SELECTOR) TPROGS_CFLAGS += $(ARM_ARCH_SELECTOR) endif -TPROGS_LDLIBS := $(KBUILD_HOSTLDLIBS) -TPROGS_CFLAGS += $(KBUILD_HOSTCFLAGS) $(HOST_EXTRACFLAGS) +TPROGS_CFLAGS += -Wall -O2 +TPROGS_CFLAGS += -Wmissing-prototypes +TPROGS_CFLAGS += -Wstrict-prototypes + TPROGS_CFLAGS += -I$(objtree)/usr/include TPROGS_CFLAGS += -I$(srctree)/tools/lib/bpf/ TPROGS_CFLAGS += -I$(srctree)/tools/testing/selftests/bpf/ From a833effa15903d07946645fc5e76b3b18a591409 Mon Sep 17 00:00:00 2001 From: Ivan Khoronzhuk Date: Fri, 11 Oct 2019 03:28:03 +0300 Subject: [PATCH 10/15] samples/bpf: Use target CC environment for HDR_PROBE No need in hacking HOSTCC to be cross-compiler any more, so drop this trick and use target CC for HDR_PROBE. Signed-off-by: Ivan Khoronzhuk Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20191011002808.28206-11-ivan.khoronzhuk@linaro.org --- samples/bpf/Makefile | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 57a15ff938a6..a6c33496e8ca 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -205,15 +205,14 @@ BTF_PAHOLE ?= pahole # Detect that we're cross compiling and use the cross compiler ifdef CROSS_COMPILE -HOSTCC = $(CROSS_COMPILE)gcc CLANG_ARCH_ARGS = --target=$(notdir $(CROSS_COMPILE:%-=%)) endif # Don't evaluate probes and warnings if we need to run make recursively ifneq ($(src),) HDR_PROBE := $(shell printf "\#include \n struct list_head { int a; }; int main() { return 0; }" | \ - $(HOSTCC) $(KBUILD_HOSTCFLAGS) -x c - -o /dev/null 2>/dev/null && \ - echo okay) + $(CC) $(TPROGS_CFLAGS) $(TPROGS_LDFLAGS) -x c - \ + -o /dev/null 2>/dev/null && echo okay) ifeq ($(HDR_PROBE),) $(warning WARNING: Detected possible issues with include path.) From 5c26f9a783581058c5de93627ae64139c4b32ceb Mon Sep 17 00:00:00 2001 From: Ivan Khoronzhuk Date: Fri, 11 Oct 2019 03:28:04 +0300 Subject: [PATCH 11/15] libbpf: Don't use cxx to test_libpf target No need to use C++ for test_libbpf target when libbpf is on C and it can be tested with C, after this change the CXXFLAGS in makefiles can be avoided, at least in bpf samples, when sysroot is used, passing same C/LDFLAGS as for lib. Add "return 0" in test_libbpf to avoid warn, but also remove spaces at start of the lines to keep same style and avoid warns while apply. Signed-off-by: Ivan Khoronzhuk Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20191011002808.28206-12-ivan.khoronzhuk@linaro.org --- tools/lib/bpf/Makefile | 18 +++++------------- .../lib/bpf/{test_libbpf.cpp => test_libbpf.c} | 14 ++++++++------ 2 files changed, 13 insertions(+), 19 deletions(-) rename tools/lib/bpf/{test_libbpf.cpp => test_libbpf.c} (61%) diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile index 1270955e4845..46280b5ad48d 100644 --- a/tools/lib/bpf/Makefile +++ b/tools/lib/bpf/Makefile @@ -52,7 +52,7 @@ ifndef VERBOSE endif FEATURE_USER = .libbpf -FEATURE_TESTS = libelf libelf-mmap bpf reallocarray cxx +FEATURE_TESTS = libelf libelf-mmap bpf reallocarray FEATURE_DISPLAY = libelf bpf INCLUDES = -I. -I$(srctree)/tools/include -I$(srctree)/tools/arch/$(ARCH)/include/uapi -I$(srctree)/tools/include/uapi @@ -142,15 +142,7 @@ GLOBAL_SYM_COUNT = $(shell readelf -s --wide $(BPF_IN) | \ VERSIONED_SYM_COUNT = $(shell readelf -s --wide $(OUTPUT)libbpf.so | \ grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 | sort -u | wc -l) -CMD_TARGETS = $(LIB_TARGET) $(PC_FILE) - -CXX_TEST_TARGET = $(OUTPUT)test_libbpf - -ifeq ($(feature-cxx), 1) - CMD_TARGETS += $(CXX_TEST_TARGET) -endif - -TARGETS = $(CMD_TARGETS) +CMD_TARGETS = $(LIB_TARGET) $(PC_FILE) $(OUTPUT)test_libbpf all: fixdep $(Q)$(MAKE) all_cmd @@ -190,8 +182,8 @@ $(OUTPUT)libbpf.so.$(LIBBPF_VERSION): $(BPF_IN) $(OUTPUT)libbpf.a: $(BPF_IN) $(QUIET_LINK)$(RM) $@; $(AR) rcs $@ $^ -$(OUTPUT)test_libbpf: test_libbpf.cpp $(OUTPUT)libbpf.a - $(QUIET_LINK)$(CXX) $(INCLUDES) $^ -lelf -o $@ +$(OUTPUT)test_libbpf: test_libbpf.c $(OUTPUT)libbpf.a + $(QUIET_LINK)$(CC) $(INCLUDES) $^ -lelf -o $@ $(OUTPUT)libbpf.pc: $(QUIET_GEN)sed -e "s|@PREFIX@|$(prefix)|" \ @@ -266,7 +258,7 @@ config-clean: $(Q)$(MAKE) -C $(srctree)/tools/build/feature/ clean >/dev/null clean: - $(call QUIET_CLEAN, libbpf) $(RM) $(TARGETS) $(CXX_TEST_TARGET) \ + $(call QUIET_CLEAN, libbpf) $(RM) $(CMD_TARGETS) \ *.o *~ *.a *.so *.so.$(LIBBPF_MAJOR_VERSION) .*.d .*.cmd \ *.pc LIBBPF-CFLAGS bpf_helper_defs.h $(call QUIET_CLEAN, core-gen) $(RM) $(OUTPUT)FEATURE-DUMP.libbpf diff --git a/tools/lib/bpf/test_libbpf.cpp b/tools/lib/bpf/test_libbpf.c similarity index 61% rename from tools/lib/bpf/test_libbpf.cpp rename to tools/lib/bpf/test_libbpf.c index fc134873bb6d..f0eb2727b766 100644 --- a/tools/lib/bpf/test_libbpf.cpp +++ b/tools/lib/bpf/test_libbpf.c @@ -7,12 +7,14 @@ int main(int argc, char *argv[]) { - /* libbpf.h */ - libbpf_set_print(NULL); + /* libbpf.h */ + libbpf_set_print(NULL); - /* bpf.h */ - bpf_prog_get_fd_by_id(0); + /* bpf.h */ + bpf_prog_get_fd_by_id(0); - /* btf.h */ - btf__new(NULL, 0); + /* btf.h */ + btf__new(NULL, 0); + + return 0; } From 793a349cd8192ad67c784d231011591a57eac001 Mon Sep 17 00:00:00 2001 From: Ivan Khoronzhuk Date: Fri, 11 Oct 2019 03:28:05 +0300 Subject: [PATCH 12/15] libbpf: Add C/LDFLAGS to libbpf.so and test_libpf targets In case of C/LDFLAGS there is no way to pass them correctly to build command, for instance when --sysroot is used or external libraries are used, like -lelf, wich can be absent in toolchain. This can be used for samples/bpf cross-compiling allowing to get elf lib from sysroot. Signed-off-by: Ivan Khoronzhuk Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20191011002808.28206-13-ivan.khoronzhuk@linaro.org --- tools/lib/bpf/Makefile | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile index 46280b5ad48d..75b538577c17 100644 --- a/tools/lib/bpf/Makefile +++ b/tools/lib/bpf/Makefile @@ -174,8 +174,9 @@ bpf_helper_defs.h: $(srctree)/include/uapi/linux/bpf.h $(OUTPUT)libbpf.so: $(OUTPUT)libbpf.so.$(LIBBPF_VERSION) $(OUTPUT)libbpf.so.$(LIBBPF_VERSION): $(BPF_IN) - $(QUIET_LINK)$(CC) --shared -Wl,-soname,libbpf.so.$(LIBBPF_MAJOR_VERSION) \ - -Wl,--version-script=$(VERSION_SCRIPT) $^ -lelf -o $@ + $(QUIET_LINK)$(CC) $(LDFLAGS) \ + --shared -Wl,-soname,libbpf.so.$(LIBBPF_MAJOR_VERSION) \ + -Wl,--version-script=$(VERSION_SCRIPT) $^ -lelf -o $@ @ln -sf $(@F) $(OUTPUT)libbpf.so @ln -sf $(@F) $(OUTPUT)libbpf.so.$(LIBBPF_MAJOR_VERSION) @@ -183,7 +184,7 @@ $(OUTPUT)libbpf.a: $(BPF_IN) $(QUIET_LINK)$(RM) $@; $(AR) rcs $@ $^ $(OUTPUT)test_libbpf: test_libbpf.c $(OUTPUT)libbpf.a - $(QUIET_LINK)$(CC) $(INCLUDES) $^ -lelf -o $@ + $(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $(INCLUDES) $^ -lelf -o $@ $(OUTPUT)libbpf.pc: $(QUIET_GEN)sed -e "s|@PREFIX@|$(prefix)|" \ From d8ceae91e9f031232d225a7159cca36e9eefdf85 Mon Sep 17 00:00:00 2001 From: Ivan Khoronzhuk Date: Fri, 11 Oct 2019 03:28:06 +0300 Subject: [PATCH 13/15] samples/bpf: Provide C/LDFLAGS to libbpf In order to build lib using C/LD flags of target arch, provide them to libbpf make. Signed-off-by: Ivan Khoronzhuk Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20191011002808.28206-14-ivan.khoronzhuk@linaro.org --- samples/bpf/Makefile | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index a6c33496e8ca..6b161326ac67 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -248,7 +248,8 @@ clean: $(LIBBPF): FORCE # Fix up variables inherited from Kbuild that tools/ build system won't like - $(MAKE) -C $(dir $@) RM='rm -rf' LDFLAGS= srctree=$(BPF_SAMPLES_PATH)/../../ O= + $(MAKE) -C $(dir $@) RM='rm -rf' EXTRA_CFLAGS="$(TPROGS_CFLAGS)" \ + LDFLAGS=$(TPROGS_LDFLAGS) srctree=$(BPF_SAMPLES_PATH)/../../ O= $(obj)/syscall_nrs.h: $(obj)/syscall_nrs.s FORCE $(call filechk,offsets,__SYSCALL_NRS_H__) From b2327c107d6255e4ea591042120514bedcdc616a Mon Sep 17 00:00:00 2001 From: Ivan Khoronzhuk Date: Fri, 11 Oct 2019 03:28:07 +0300 Subject: [PATCH 14/15] samples/bpf: Add sysroot support Basically it only enables that was added by previous couple fixes. Sysroot contains correct libs installed and its headers. Useful when working with NFC or virtual machine. Usage example: clean (on demand) make ARCH=arm -C samples/bpf clean make ARCH=arm -C tools clean make ARCH=arm clean configure and install headers: make ARCH=arm defconfig make ARCH=arm headers_install build samples/bpf: make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- samples/bpf/ \ SYSROOT="path/to/sysroot" Signed-off-by: Ivan Khoronzhuk Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20191011002808.28206-15-ivan.khoronzhuk@linaro.org --- samples/bpf/Makefile | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 6b161326ac67..4df11ddb9c75 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -187,6 +187,11 @@ TPROGS_CFLAGS += -I$(srctree)/tools/lib/ TPROGS_CFLAGS += -I$(srctree)/tools/include TPROGS_CFLAGS += -I$(srctree)/tools/perf +ifdef SYSROOT +TPROGS_CFLAGS += --sysroot=$(SYSROOT) +TPROGS_LDFLAGS := -L$(SYSROOT)/usr/lib +endif + TPROGCFLAGS_bpf_load.o += -Wno-unused-variable TPROGS_LDLIBS += $(LIBBPF) -lelf From 1600c9c26f6bbdd29fb1b44f13fb751846d2ebe8 Mon Sep 17 00:00:00 2001 From: Ivan Khoronzhuk Date: Fri, 11 Oct 2019 03:28:08 +0300 Subject: [PATCH 15/15] samples/bpf: Add preparation steps and sysroot info to readme Add couple preparation steps: clean and configuration. Also add newly added sysroot support info to cross-compile section. Signed-off-by: Ivan Khoronzhuk Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20191011002808.28206-16-ivan.khoronzhuk@linaro.org --- samples/bpf/README.rst | 41 ++++++++++++++++++++++++++++++++++++----- 1 file changed, 36 insertions(+), 5 deletions(-) diff --git a/samples/bpf/README.rst b/samples/bpf/README.rst index 5f27e4faca50..cc1f00a1ee06 100644 --- a/samples/bpf/README.rst +++ b/samples/bpf/README.rst @@ -14,6 +14,20 @@ Compiling requires having installed: Note that LLVM's tool 'llc' must support target 'bpf', list version and supported targets with command: ``llc --version`` +Clean and configuration +----------------------- + +It can be needed to clean tools, samples or kernel before trying new arch or +after some changes (on demand):: + + make -C tools clean + make -C samples/bpf clean + make clean + +Configure kernel, defconfig for instance:: + + make defconfig + Kernel headers -------------- @@ -68,9 +82,26 @@ It is also possible to point make to the newly compiled 'llc' or Cross compiling samples ----------------------- In order to cross-compile, say for arm64 targets, export CROSS_COMPILE and ARCH -environment variables before calling make. This will direct make to build -samples for the cross target. +environment variables before calling make. But do this before clean, +cofiguration and header install steps described above. This will direct make to +build samples for the cross target:: -export ARCH=arm64 -export CROSS_COMPILE="aarch64-linux-gnu-" -make samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang + export ARCH=arm64 + export CROSS_COMPILE="aarch64-linux-gnu-" + +Headers can be also installed on RFS of target board if need to keep them in +sync (not necessarily and it creates a local "usr/include" directory also):: + + make INSTALL_HDR_PATH=~/some_sysroot/usr headers_install + +Pointing LLC and CLANG is not necessarily if it's installed on HOST and have +in its targets appropriate arm64 arch (usually it has several arches). +Build samples:: + + make samples/bpf/ + +Or build samples with SYSROOT if some header or library is absent in toolchain, +say libelf, providing address to file system containing headers and libs, +can be RFS of target board:: + + make samples/bpf/ SYSROOT=~/some_sysroot