| Message ID | 20190910103830.20794-6-ivan.khoronzhuk@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | [bpf-next,01/11] samples: bpf: makefile: fix HDR_PROBE "echo" | expand |
On 9/10/19 11:38 AM, Ivan Khoronzhuk wrote: > The kernel headers are reused from samples bpf, and autoconf.h is not > enough to reflect complete arch configuration for clang. But CLANG-bpf > cmds are sensitive for assembler part taken from linux headers and -D > vars, usually used in CFLAGS, should be carefully added for each arch. > For that, for CLANG-bpf, lets filter them only for arm arch as it > definitely requires __LINUX_ARM_ARCH__ to be set, but ignore for > others till it's really needed. For arm, -D__LINUX_ARM_ARCH__ is min > version used as instruction set selector. In another case errors > like "SMP is not supported" for arm and bunch of other errors are > issued resulting to incorrect final object. > > Later D_OPTIONS can be used for gcc part. > --- > samples/bpf/Makefile | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile > index 8ecc5d0c2d5b..6492b7e65c08 100644 > --- a/samples/bpf/Makefile > +++ b/samples/bpf/Makefile > @@ -185,6 +185,15 @@ 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' ' ') > + > +ifeq ($(ARCH), arm) > +CLANG_EXTRA_CFLAGS := $(D_OPTIONS) > +endif Do you need this for native compilation? so arm64 compilation does not need this? If only -D__LINUX_ARM_ARCH__ is needed, maybe just with CLANG_EXTRA_CFLAGS := -D__LINUX_ARM_ARCH__ Otherwise, people will wonder whether this is needed for other architectures. Or just do CLANG_EXTRA_CFLAGS := $(D_OPTIONS) for all cross compilation? > + > # 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 >
On Fri, Sep 13, 2019 at 09:12:01PM +0000, Yonghong Song wrote: > > >On 9/10/19 11:38 AM, Ivan Khoronzhuk wrote: >> The kernel headers are reused from samples bpf, and autoconf.h is not >> enough to reflect complete arch configuration for clang. But CLANG-bpf >> cmds are sensitive for assembler part taken from linux headers and -D >> vars, usually used in CFLAGS, should be carefully added for each arch. >> For that, for CLANG-bpf, lets filter them only for arm arch as it >> definitely requires __LINUX_ARM_ARCH__ to be set, but ignore for >> others till it's really needed. For arm, -D__LINUX_ARM_ARCH__ is min >> version used as instruction set selector. In another case errors >> like "SMP is not supported" for arm and bunch of other errors are >> issued resulting to incorrect final object. >> >> Later D_OPTIONS can be used for gcc part. >> --- >> samples/bpf/Makefile | 9 +++++++++ >> 1 file changed, 9 insertions(+) >> >> diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile >> index 8ecc5d0c2d5b..6492b7e65c08 100644 >> --- a/samples/bpf/Makefile >> +++ b/samples/bpf/Makefile >> @@ -185,6 +185,15 @@ 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' ' ') >> + >> +ifeq ($(ARCH), arm) >> +CLANG_EXTRA_CFLAGS := $(D_OPTIONS) >> +endif > >Do you need this for native compilation? Yes, native "arm" also requires it. > >so arm64 compilation does not need this? yes, now only arm >If only -D__LINUX_ARM_ARCH__ is needed, maybe just >with > CLANG_EXTRA_CFLAGS := -D__LINUX_ARM_ARCH__ Value also needed: -D__LINUX_ARM_ARCH_=7 or -D__LINUX_ARM_ARCH_=6 So, need retrieve it. >Otherwise, people will wonder whether this is needed for >other architectures. Or just do > CLANG_EXTRA_CFLAGS := $(D_OPTIONS) >for all cross compilation? arm, cross and native requires it. Will do this: # Strip all expet -D options needed to handle linux headers # for arm it's __LINUX_ARM_ARCH__ and potentially others fork vars ifeq ($(ARCH), arm) D_OPTIONS = $(shell echo "$(KBUILD_CFLAGS) " | sed 's/[[:blank:]]/\n/g' | \ sed '/^-D/!d' | tr '\n' ' ') endif 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 >> -- Regards, Ivan Khoronzhuk
diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 8ecc5d0c2d5b..6492b7e65c08 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -185,6 +185,15 @@ 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' ' ') + +ifeq ($(ARCH), arm) +CLANG_EXTRA_CFLAGS := $(D_OPTIONS) +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