[PATCH bpf-next 0/8] samples: bpf: improve/fix cross-compilation

[PATCH bpf-next 0/8] samples: bpf: improve/fix cross-compilation

[Ivan Khoronzhuk]

This series contains mainly fixes/improvements for cross-compilation
(also verified on native platform build), tested on arm, but intended
for any arch.

Initial RFC link:
https://lkml.org/lkml/2019/8/29/1665

Besides the pathces given here, the RFC also contains couple patches
related to llvm clang
  arm: include: asm: swab: mask rev16 instruction for clang
  arm: include: asm: unified: mask .syntax unified for clang

The change touches not only cross-compilation and can have impact on
other archs and build environments, so might be good idea to verify
it in order to add appropriate changes, some warn options could be
tuned also.

Ivan Khoronzhuk (8):
  samples: bpf: Makefile: use --target from cross-compile
  samples: bpf: Makefile: remove target for native build
  libbpf: Makefile: add C/CXX/LDFLAGS to libbpf.so and test_libpf
    targets
  samples: bpf: use own EXTRA_CFLAGS for clang commands
  samples: bpf: Makefile: use vars from KBUILD_CFLAGS to handle linux
    headers
  samples: bpf: makefile: fix HDR_PROBE "echo"
  samples: bpf: add makefile.prog for separate CC build
  samples: bpf: Makefile: base progs build on Makefile.progs

 samples/bpf/Makefile      | 177 ++++++++++++++++++++++----------------
 samples/bpf/Makefile.prog |  77 +++++++++++++++++
 samples/bpf/README.rst    |   7 ++
 tools/lib/bpf/Makefile    |  11 ++-
 4 files changed, 197 insertions(+), 75 deletions(-)
 create mode 100644 samples/bpf/Makefile.prog

-- 
2.17.1

[PATCH bpf-next 1/8] samples: bpf: Makefile: use --target from cross-compile

[Ivan Khoronzhuk]

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 <ivan.khoronzhuk@linaro.org>
---
 samples/bpf/Makefile | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index 1d9be26b4edd..61b7394b811e 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -196,6 +196,8 @@ 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:%-=%))
+else
 CLANG_ARCH_ARGS = -target $(ARCH)
 endif
 
-- 
2.17.1

[PATCH bpf-next 2/8] samples: bpf: Makefile: remove target for native build

[Ivan Khoronzhuk]

No need to set --target for native build, at least for arm, the
default target will be used anyway. In case of arm, for at least
clang 5 - 10 it causes error like:

clang: warning: unknown platform, assuming -mfloat-abi=soft
LLVM ERROR: Unsupported calling convention
make[2]: *** [/home/root/snapshot/samples/bpf/Makefile:299:
/home/root/snapshot/samples/bpf/sockex1_kern.o] Error 1

Only set to real triple helps: --target=arm-linux-gnueabihf
or just drop the target key to use default one. Decision to just
drop it and thus default target will be used (wich is native),
looks better.

Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
---
 samples/bpf/Makefile | 2 --
 1 file changed, 2 deletions(-)

diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index 61b7394b811e..a2953357927e 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -197,8 +197,6 @@ BTF_PAHOLE ?= pahole
 ifdef CROSS_COMPILE
 HOSTCC = $(CROSS_COMPILE)gcc
 CLANG_ARCH_ARGS = --target=$(notdir $(CROSS_COMPILE:%-=%))
-else
-CLANG_ARCH_ARGS = -target $(ARCH)
 endif
 
 # Don't evaluate probes and warnings if we need to run make recursively
-- 
2.17.1

[PATCH bpf-next 3/8] libbpf: Makefile: add C/CXX/LDFLAGS to libbpf.so and test_libpf targets

[Ivan Khoronzhuk]

In case of LDFLAGS and EXTRA_CC flags there is no way to pass them
correctly to build command, for instance when --sysroot is used or
external libraries are used, like -lelf. In follow up patches this is
used for samples/bpf cross-compiling getting elf lib from sysroot.

Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
---
 tools/lib/bpf/Makefile | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
index c6f94cffe06e..bccfa556ef4e 100644
--- a/tools/lib/bpf/Makefile
+++ b/tools/lib/bpf/Makefile
@@ -94,6 +94,10 @@ else
   CFLAGS := -g -Wall
 endif
 
+ifdef EXTRA_CXXFLAGS
+  CXXFLAGS := $(EXTRA_CXXFLAGS)
+endif
+
 ifeq ($(feature-libelf-mmap), 1)
   override CFLAGS += -DHAVE_LIBELF_MMAP_SUPPORT
 endif
@@ -176,8 +180,9 @@ $(BPF_IN): force elfdep bpfdep
 $(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)
 
@@ -185,7 +190,7 @@ $(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 $@
+	$(QUIET_LINK)$(CXX) $(CXXFLAGS) $(LDFLAGS) $(INCLUDES) $^ -lelf -o $@
 
 $(OUTPUT)libbpf.pc:
 	$(QUIET_GEN)sed -e "s|@PREFIX@|$(prefix)|" \
-- 
2.17.1

[PATCH bpf-next 4/8] samples: bpf: use own EXTRA_CFLAGS for clang commands

[Ivan Khoronzhuk]

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 <ivan.khoronzhuk@linaro.org>
---
 samples/bpf/Makefile | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index a2953357927e..cdd742c05200 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -219,10 +219,10 @@ BTF_LLVM_PROBE := $(shell echo "int main() { return 0; }" | \
 			  /bin/rm -f ./llvm_btf_verify.o)
 
 ifneq ($(BTF_LLVM_PROBE),)
-	EXTRA_CFLAGS += -g
+	CLANG_EXTRA_CFLAGS += -g
 else
 ifneq ($(and $(BTF_LLC_PROBE),$(BTF_PAHOLE_PROBE),$(BTF_OBJCOPY_PROBE)),)
-	EXTRA_CFLAGS += -g
+	CLANG_EXTRA_CFLAGS += -g
 	LLC_FLAGS += -mattr=dwarfris
 	DWARF2BTF = y
 endif
@@ -281,8 +281,8 @@ $(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/ \
+	$(Q)$(CLANG) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(CLANG_EXTRA_CFLAGS) \
+		-I$(obj) -I$(srctree)/tools/testing/selftests/bpf/ \
 		-D__KERNEL__ -D__BPF_TRACING__ -Wno-unused-value -Wno-pointer-sign \
 		-D__TARGET_ARCH_$(SRCARCH) -Wno-compare-distinct-pointer-types \
 		-Wno-gnu-variable-sized-type-not-at-end \
-- 
2.17.1

[PATCH bpf-next 5/8] samples: bpf: Makefile: use vars from KBUILD_CFLAGS to handle linux headers

[Ivan Khoronzhuk]

The kernel headers are reused from samples bpf, and autoconf.h is not
enough to reflect complete configuration for clang. One of such
configurations is __LINUX_ARM_ARCH__ min version used as instruction
set selector. In another case an error like "SMP is not
supported" for arm and others errors are issued and final object is
not correct.
---
 samples/bpf/Makefile | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index cdd742c05200..9232efa2b1b3 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -186,6 +186,13 @@ HOSTLDLIBS_map_perf_test	+= -lrt
 HOSTLDLIBS_test_overhead	+= -lrt
 HOSTLDLIBS_xdpsock		+= -pthread
 
+# Strip all expet -D options needed to handle linux headers
+# for arm it's __LINUX_ARM_ARCH__ and potentially others fork vars
+D_OPTIONS = $(shell echo "$(KBUILD_CFLAGS) " | sed 's/[[:blank:]]/\n/g' | \
+	sed '/^-D/!d' | tr '\n' ' ')
+
+CLANG_EXTRA_CFLAGS += $(D_OPTIONS)
+
 # 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
-- 
2.17.1

[PATCH bpf-next 6/8] samples: bpf: makefile: fix HDR_PROBE "echo"

[Ivan Khoronzhuk]

echo should be replaced on echo -e to handle \n correctly, but instead,
replace it on printf as some systems can't handle echo -e.

Signed-off-by: Ivan Khoronzhuk <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 9232efa2b1b3..043f9cc14cdd 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -208,7 +208,7 @@ endif
 
 # Don't evaluate probes and warnings if we need to run make recursively
 ifneq ($(src),)
-HDR_PROBE := $(shell echo "\#include <linux/types.h>\n struct list_head { int a; }; int main() { return 0; }" | \
+HDR_PROBE := $(shell printf "\#include <linux/types.h>\n struct list_head { int a; }; int main() { return 0; }" | \
 	$(HOSTCC) $(KBUILD_HOSTCFLAGS) -x c - -o /dev/null 2>/dev/null && \
 	echo okay)
 
-- 
2.17.1

[PATCH bpf-next 7/8] samples: bpf: add makefile.prog for separate CC build

[Ivan Khoronzhuk]

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.prog for simplicity, having definition and routines similar
to ones, used in script/Makefile.host. That allows later add
cross-compilation to samples/bpf with minimum changes.

Makefile.prog contains only stuff needed for samples/bpf, potentially
can be reused and extended for other prog sets later and now needed
only for unblocking tricky samples/bpf cross compilation.

Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
---
 samples/bpf/Makefile.prog | 77 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 77 insertions(+)
 create mode 100644 samples/bpf/Makefile.prog

diff --git a/samples/bpf/Makefile.prog b/samples/bpf/Makefile.prog
new file mode 100644
index 000000000000..1d138bc21dd4
--- /dev/null
+++ b/samples/bpf/Makefile.prog
@@ -0,0 +1,77 @@
+# SPDX-License-Identifier: GPL-2.0
+# ==========================================================================
+# Building binaries on the host system
+# Binaries are not used during the compilation of the kernel, and intendent to
+# be build for target board, target board can be host ofc. Added to build
+# binaries to run not on host system.
+#
+# Only C is supported, but can be extended for C++.
+#
+# Sample syntax (see Documentation/kbuild/makefiles.rst for reference)
+# progs-y := xdpsock_example
+# Will compile xdpsock_example.c and create an executable named xdpsock_example
+#
+# progs-y    := xdpsock
+# xdpsock-objs := xdpsock_user.o xdpsock_user2.o
+# Will compile xdpsock.c and xdpsock.c, and then link the executable
+# xdpsock, based on xdpsock_user.o and xdpsock_user2.o
+#
+# Inherited from scripts/Makefile.host
+#
+__progs := $(sort $(progs-y))
+
+# C code
+# Executables compiled from a single .c file
+prog-csingle	:= $(foreach m,$(__progs), \
+			$(if $($(m)-objs)$($(m)-cxxobjs),,$(m)))
+
+# C executables linked based on several .o files
+prog-cmulti	:= $(foreach m,$(__progs),\
+		   $(if $($(m)-cxxobjs),,$(if $($(m)-objs),$(m))))
+
+# Object (.o) files compiled from .c files
+prog-cobjs	:= $(sort $(foreach m,$(__progs),$($(m)-objs)))
+
+prog-csingle	:= $(addprefix $(obj)/,$(prog-csingle))
+prog-cmulti	:= $(addprefix $(obj)/,$(prog-cmulti))
+prog-cobjs	:= $(addprefix $(obj)/,$(prog-cobjs))
+
+#####
+# Handle options to gcc. Support building with separate output directory
+
+_progc_flags   = $(PROGS_CFLAGS) \
+                 $(PROGCFLAGS_$(basetarget).o)
+
+# $(objtree)/$(obj) for including generated headers from checkin source files
+ifeq ($(KBUILD_EXTMOD),)
+ifdef building_out_of_srctree
+_progc_flags   += -I $(objtree)/$(obj)
+endif
+endif
+
+progc_flags    = -Wp,-MD,$(depfile) $(_progc_flags)
+
+# Create executable from a single .c file
+# prog-csingle -> Executable
+quiet_cmd_prog-csingle 	= CC  $@
+      cmd_prog-csingle	= $(CC) $(progc_flags) $(PROGS_LDFLAGS) -o $@ $< \
+		$(PROGS_LDLIBS) $(PROGLDLIBS_$(@F))
+$(prog-csingle): $(obj)/%: $(src)/%.c FORCE
+	$(call if_changed_dep,prog-csingle)
+
+# Link an executable based on list of .o files, all plain c
+# prog-cmulti -> executable
+quiet_cmd_prog-cmulti	= LD  $@
+      cmd_prog-cmulti	= $(CC) $(progc_flags) $(PROGS_LDFLAGS) -o $@ \
+			  $(addprefix $(obj)/,$($(@F)-objs)) \
+			  $(PROGS_LDLIBS) $(PROGLDLIBS_$(@F))
+$(prog-cmulti): $(prog-cobjs) FORCE
+	$(call if_changed,prog-cmulti)
+$(call multi_depend, $(prog-cmulti), , -objs)
+
+# Create .o file from a single .c file
+# prog-cobjs -> .o
+quiet_cmd_prog-cobjs	= CC  $@
+      cmd_prog-cobjs	= $(CC) $(progc_flags) -c -o $@ $<
+$(prog-cobjs): $(obj)/%.o: $(src)/%.c FORCE
+	$(call if_changed_dep,prog-cobjs)
-- 
2.17.1

[PATCH bpf-next 8/8] samples: bpf: Makefile: base progs build on Makefile.progs

[Ivan Khoronzhuk]

The main reason for that - HOSTCC and CC have different aims.
It was tested for arm cross compilation, based on linaro toolchain,
but should work for others.

In order to split cross compilation with host build, base bpf samples
on Makefile.progs. It's also convenient when NFC is used:

export ARCH=arm
export CROSS_COMPILE=arm-linux-gnueabihf-
make samples/bpf/ SYSROOT="path/to/sysroot"

Sysroot contains correct headers installed ofc.

Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
---
 samples/bpf/Makefile   | 164 ++++++++++++++++++++++++-----------------
 samples/bpf/README.rst |   7 ++
 2 files changed, 102 insertions(+), 69 deletions(-)

diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index 043f9cc14cdd..ed7131851172 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
+progs-y := test_lru_dist
+progs-y += sock_example
+progs-y += fds_example
+progs-y += sockex1
+progs-y += sockex2
+progs-y += sockex3
+progs-y += tracex1
+progs-y += tracex2
+progs-y += tracex3
+progs-y += tracex4
+progs-y += tracex5
+progs-y += tracex6
+progs-y += tracex7
+progs-y += test_probe_write_user
+progs-y += trace_output
+progs-y += lathist
+progs-y += offwaketime
+progs-y += spintest
+progs-y += map_perf_test
+progs-y += test_overhead
+progs-y += test_cgrp2_array_pin
+progs-y += test_cgrp2_attach
+progs-y += test_cgrp2_sock
+progs-y += test_cgrp2_sock2
+progs-y += xdp1
+progs-y += xdp2
+progs-y += xdp_router_ipv4
+progs-y += test_current_task_under_cgroup
+progs-y += trace_event
+progs-y += sampleip
+progs-y += tc_l2_redirect
+progs-y += lwt_len_hist
+progs-y += xdp_tx_iptunnel
+progs-y += test_map_in_map
+progs-y += xdp_redirect_map
+progs-y += xdp_redirect_cpu
+progs-y += xdp_monitor
+progs-y += xdp_rxq_info
+progs-y += syscall_tp
+progs-y += cpustat
+progs-y += xdp_adjust_tail
+progs-y += xdpsock
+progs-y += xdp_fwd
+progs-y += task_fd_query
+progs-y += xdp_sample_pkts
+progs-y += ibumad
+progs-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 := $(progs-y)
 always += sockex1_kern.o
 always += sockex2_kern.o
 always += sockex3_kern.o
@@ -171,26 +169,51 @@ 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 += -I$(objtree)/usr/include -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
-
 # Strip all expet -D options needed to handle linux headers
 # for arm it's __LINUX_ARM_ARCH__ and potentially others fork vars
 D_OPTIONS = $(shell echo "$(KBUILD_CFLAGS) " | sed 's/[[:blank:]]/\n/g' | \
 	sed '/^-D/!d' | tr '\n' ' ')
 
+ifdef SYSROOT
+ccflags-y += --sysroot=${SYSROOT}
+ccflags-y += -I${SYSROOT}/usr/include
+CLANG_EXTRA_CFLAGS := $(ccflags-y)
+PROGS_LDFLAGS := -L${SYSROOT}/usr/lib
+endif
+
+ccflags-y += -I$(srctree)/tools/lib/bpf/
+ccflags-y += -I$(srctree)/tools/testing/selftests/bpf/
+ccflags-y += -I$(srctree)/tools/lib/
+ccflags-y += -I$(srctree)/tools/perf
+
+ccflags-y += $(D_OPTIONS)
+ccflags-y += -Wall
+ccflags-y += -Wmissing-prototypes
+ccflags-y += -Wstrict-prototypes
+ccflags-y += -fomit-frame-pointer
+
+PROGS_CFLAGS := $(ccflags-y)
+
+ccflags-y += -I$(objtree)/usr/include
+ccflags-y += -I$(srctree)/tools/include
+
+PROGCFLAGS_bpf_load.o += -I$(objtree)/usr/include -I$(srctree)/tools/include \
+			 -Wno-unused-variable
+PROGCFLAGS_sampleip_user.o += -I$(srctree)/tools/include
+PROGCFLAGS_task_fd_query_user.o += -I$(srctree)/tools/include
+PROGCFLAGS_trace_event_user.o += -I$(srctree)/tools/include
+PROGCFLAGS_trace_output_user.o += -I$(srctree)/tools/include
+PROGCFLAGS_tracex6_user.o += -I$(srctree)/tools/include
+PROGCFLAGS_xdp_sample_pkts_user.o += -I$(srctree)/tools/include
+PROGCFLAGS_xdpsock_user.o += -I$(srctree)/tools/include
+
+PROGS_LDLIBS			:= $(LIBBPF) -lelf
+PROGLDLIBS_tracex4		+= -lrt
+PROGLDLIBS_trace_output		+= -lrt
+PROGLDLIBS_map_perf_test	+= -lrt
+PROGLDLIBS_test_overhead	+= -lrt
+PROGLDLIBS_xdpsock		+= -pthread
+
 CLANG_EXTRA_CFLAGS += $(D_OPTIONS)
 
 # Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline:
@@ -202,15 +225,14 @@ 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 <linux/types.h>\n struct list_head { int a; }; int main() { return 0; }" | \
-	$(HOSTCC) $(KBUILD_HOSTCFLAGS) -x c - -o /dev/null 2>/dev/null && \
-	echo okay)
+	$(CC) $(PROGS_CFLAGS) $(PROGS_LDFLAGS) -x c - -o /dev/null \
+	2>/dev/null && echo okay)
 
 ifeq ($(HDR_PROBE),)
 $(warning WARNING: Detected possible issues with include path.)
@@ -246,7 +268,9 @@ 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 $@) RM='rm -rf' EXTRA_CFLAGS="$(ccflags-y)" \
+		EXTRA_CXXFLAGS="$(ccflags-y)" LDFLAGS=$(PROGS_LDFLAGS) \
+		srctree=$(BPF_SAMPLES_PATH)/../../ O=
 
 $(obj)/syscall_nrs.h:	$(obj)/syscall_nrs.s FORCE
 	$(call filechk,offsets,__SYSCALL_NRS_H__)
@@ -283,6 +307,8 @@ $(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.prog
+
 # 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.
diff --git a/samples/bpf/README.rst b/samples/bpf/README.rst
index 5f27e4faca50..6b5e4eace977 100644
--- a/samples/bpf/README.rst
+++ b/samples/bpf/README.rst
@@ -74,3 +74,10 @@ 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
+
+If need to use environment of target board, the SYSROOT also can be set,
+pointing on FS of target board:
+
+make samples/bpf/ LLC=~/git/llvm/build/bin/llc \
+     CLANG=~/git/llvm/build/bin/clang \
+     SYSROOT=~/some_sdk/linux-devkit/sysroots/aarch64-linux-gnu
-- 
2.17.1

Re: [PATCH bpf-next 2/8] samples: bpf: Makefile: remove target for native build

[Alexei Starovoitov]

On Thu, Sep 05, 2019 at 12:22:06AM +0300, Ivan Khoronzhuk wrote:
> No need to set --target for native build, at least for arm, the
> default target will be used anyway. In case of arm, for at least
> clang 5 - 10 it causes error like:
> 
> clang: warning: unknown platform, assuming -mfloat-abi=soft
> LLVM ERROR: Unsupported calling convention
> make[2]: *** [/home/root/snapshot/samples/bpf/Makefile:299:
> /home/root/snapshot/samples/bpf/sockex1_kern.o] Error 1
> 
> Only set to real triple helps: --target=arm-linux-gnueabihf
> or just drop the target key to use default one. Decision to just
> drop it and thus default target will be used (wich is native),
> looks better.
> 
> Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
> ---
>  samples/bpf/Makefile | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
> index 61b7394b811e..a2953357927e 100644
> --- a/samples/bpf/Makefile
> +++ b/samples/bpf/Makefile
> @@ -197,8 +197,6 @@ BTF_PAHOLE ?= pahole
>  ifdef CROSS_COMPILE
>  HOSTCC = $(CROSS_COMPILE)gcc
>  CLANG_ARCH_ARGS = --target=$(notdir $(CROSS_COMPILE:%-=%))
> -else
> -CLANG_ARCH_ARGS = -target $(ARCH)
>  endif

I don't follow here.
Didn't you introduce this bug in patch 1 and now fixing it in patch 2?

Re: [PATCH bpf-next 8/8] samples: bpf: Makefile: base progs build on Makefile.progs

[Alexei Starovoitov]

On Thu, Sep 05, 2019 at 12:22:12AM +0300, Ivan Khoronzhuk wrote:
> +
> +If need to use environment of target board, the SYSROOT also can be set,
> +pointing on FS of target board:
> +
> +make samples/bpf/ LLC=~/git/llvm/build/bin/llc \
> +     CLANG=~/git/llvm/build/bin/clang \
> +     SYSROOT=~/some_sdk/linux-devkit/sysroots/aarch64-linux-gnu

Patches 7 and 8 look quite heavy. I don't have a way to test them
which makes me a bit uneasy to accept them as-is.
Would be great if somebody could give Tested-by.

Re: [PATCH bpf-next 2/8] samples: bpf: Makefile: remove target for native build

[Ivan Khoronzhuk]

On Fri, Sep 06, 2019 at 04:31:39PM -0700, Alexei Starovoitov wrote:
>On Thu, Sep 05, 2019 at 12:22:06AM +0300, Ivan Khoronzhuk wrote:
>> No need to set --target for native build, at least for arm, the
>> default target will be used anyway. In case of arm, for at least
>> clang 5 - 10 it causes error like:
>>
>> clang: warning: unknown platform, assuming -mfloat-abi=soft
>> LLVM ERROR: Unsupported calling convention
>> make[2]: *** [/home/root/snapshot/samples/bpf/Makefile:299:
>> /home/root/snapshot/samples/bpf/sockex1_kern.o] Error 1
>>
>> Only set to real triple helps: --target=arm-linux-gnueabihf
>> or just drop the target key to use default one. Decision to just
>> drop it and thus default target will be used (wich is native),
>> looks better.
>>
>> Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
>> ---
>>  samples/bpf/Makefile | 2 --
>>  1 file changed, 2 deletions(-)
>>
>> diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
>> index 61b7394b811e..a2953357927e 100644
>> --- a/samples/bpf/Makefile
>> +++ b/samples/bpf/Makefile
>> @@ -197,8 +197,6 @@ BTF_PAHOLE ?= pahole
>>  ifdef CROSS_COMPILE
>>  HOSTCC = $(CROSS_COMPILE)gcc
>>  CLANG_ARCH_ARGS = --target=$(notdir $(CROSS_COMPILE:%-=%))
>> -else
>> -CLANG_ARCH_ARGS = -target $(ARCH)
>>  endif
>
>I don't follow here.
>Didn't you introduce this bug in patch 1 and now fixing it in patch 2?
>

It looks like but that's not true.
Previous patch adds target only for cross compiling,
before the patch the target was used for both, cross compiling and w/o cc.

This patch removes target only for native build (it's not cross compiling).

By fact, it's two separate significant changes.

-- 
Regards,
Ivan Khoronzhuk

Re: [PATCH bpf-next 2/8] samples: bpf: Makefile: remove target for native build

[Alexei Starovoitov]

On Fri, Sep 6, 2019 at 4:52 PM Ivan Khoronzhuk
<ivan.khoronzhuk@linaro.org> wrote:
>
> On Fri, Sep 06, 2019 at 04:31:39PM -0700, Alexei Starovoitov wrote:
> >On Thu, Sep 05, 2019 at 12:22:06AM +0300, Ivan Khoronzhuk wrote:
> >> No need to set --target for native build, at least for arm, the
> >> default target will be used anyway. In case of arm, for at least
> >> clang 5 - 10 it causes error like:
> >>
> >> clang: warning: unknown platform, assuming -mfloat-abi=soft
> >> LLVM ERROR: Unsupported calling convention
> >> make[2]: *** [/home/root/snapshot/samples/bpf/Makefile:299:
> >> /home/root/snapshot/samples/bpf/sockex1_kern.o] Error 1
> >>
> >> Only set to real triple helps: --target=arm-linux-gnueabihf
> >> or just drop the target key to use default one. Decision to just
> >> drop it and thus default target will be used (wich is native),
> >> looks better.
> >>
> >> Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
> >> ---
> >>  samples/bpf/Makefile | 2 --
> >>  1 file changed, 2 deletions(-)
> >>
> >> diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
> >> index 61b7394b811e..a2953357927e 100644
> >> --- a/samples/bpf/Makefile
> >> +++ b/samples/bpf/Makefile
> >> @@ -197,8 +197,6 @@ BTF_PAHOLE ?= pahole
> >>  ifdef CROSS_COMPILE
> >>  HOSTCC = $(CROSS_COMPILE)gcc
> >>  CLANG_ARCH_ARGS = --target=$(notdir $(CROSS_COMPILE:%-=%))
> >> -else
> >> -CLANG_ARCH_ARGS = -target $(ARCH)
> >>  endif
> >
> >I don't follow here.
> >Didn't you introduce this bug in patch 1 and now fixing it in patch 2?
> >
>
> It looks like but that's not true.
> Previous patch adds target only for cross compiling,
> before the patch the target was used for both, cross compiling and w/o cc.
>
> This patch removes target only for native build (it's not cross compiling).
>
> By fact, it's two separate significant changes.

How so?
before first patch CLANG_ARCH_ARGS is only used under CROSS_COMPILE.
After the first patch CLANG_ARCH_ARGS is now suddenly defined w/o CROSS_COMPILE
and second patch brings it to the state before first patch.

Re: [PATCH bpf-next 2/8] samples: bpf: Makefile: remove target for native build

[Ivan Khoronzhuk]

On Fri, Sep 06, 2019 at 05:04:08PM -0700, Alexei Starovoitov wrote:
>On Fri, Sep 6, 2019 at 4:52 PM Ivan Khoronzhuk
><ivan.khoronzhuk@linaro.org> wrote:
>>
>> On Fri, Sep 06, 2019 at 04:31:39PM -0700, Alexei Starovoitov wrote:
>> >On Thu, Sep 05, 2019 at 12:22:06AM +0300, Ivan Khoronzhuk wrote:
>> >> No need to set --target for native build, at least for arm, the
>> >> default target will be used anyway. In case of arm, for at least
>> >> clang 5 - 10 it causes error like:
>> >>
>> >> clang: warning: unknown platform, assuming -mfloat-abi=soft
>> >> LLVM ERROR: Unsupported calling convention
>> >> make[2]: *** [/home/root/snapshot/samples/bpf/Makefile:299:
>> >> /home/root/snapshot/samples/bpf/sockex1_kern.o] Error 1
>> >>
>> >> Only set to real triple helps: --target=arm-linux-gnueabihf
>> >> or just drop the target key to use default one. Decision to just
>> >> drop it and thus default target will be used (wich is native),
>> >> looks better.
>> >>
>> >> Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
>> >> ---
>> >>  samples/bpf/Makefile | 2 --
>> >>  1 file changed, 2 deletions(-)
>> >>
>> >> diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
>> >> index 61b7394b811e..a2953357927e 100644
>> >> --- a/samples/bpf/Makefile
>> >> +++ b/samples/bpf/Makefile
>> >> @@ -197,8 +197,6 @@ BTF_PAHOLE ?= pahole
>> >>  ifdef CROSS_COMPILE
>> >>  HOSTCC = $(CROSS_COMPILE)gcc
>> >>  CLANG_ARCH_ARGS = --target=$(notdir $(CROSS_COMPILE:%-=%))
>> >> -else
>> >> -CLANG_ARCH_ARGS = -target $(ARCH)
>> >>  endif
>> >
>> >I don't follow here.
>> >Didn't you introduce this bug in patch 1 and now fixing it in patch 2?
>> >
>>
>> It looks like but that's not true.
>> Previous patch adds target only for cross compiling,
>> before the patch the target was used for both, cross compiling and w/o cc.
>>
>> This patch removes target only for native build (it's not cross compiling).
>>
>> By fact, it's two separate significant changes.
>
>How so?
>before first patch CLANG_ARCH_ARGS is only used under CROSS_COMPILE.
>After the first patch CLANG_ARCH_ARGS is now suddenly defined w/o CROSS_COMPILE
>and second patch brings it to the state before first patch.

Oh sorry ), messed with my local exp with target bpf, after rebase, even forgot
that's mine. Will drop it, with removing "else" for previous patch.

-- 
Regards,
Ivan Khoronzhuk

Re: [PATCH bpf-next 8/8] samples: bpf: Makefile: base progs build on Makefile.progs

[Ivan Khoronzhuk]

On Fri, Sep 06, 2019 at 04:34:31PM -0700, Alexei Starovoitov wrote:
>On Thu, Sep 05, 2019 at 12:22:12AM +0300, Ivan Khoronzhuk wrote:
>> +
>> +If need to use environment of target board, the SYSROOT also can be set,
>> +pointing on FS of target board:
>> +
>> +make samples/bpf/ LLC=~/git/llvm/build/bin/llc \
>> +     CLANG=~/git/llvm/build/bin/clang \
>> +     SYSROOT=~/some_sdk/linux-devkit/sysroots/aarch64-linux-gnu
>
>Patches 7 and 8 look quite heavy. I don't have a way to test them
>which makes me a bit uneasy to accept them as-is.
>Would be great if somebody could give Tested-by.
>
I can try to split patch 8 in v2, but not significantly.

-- 
Regards,
Ivan Khoronzhuk