[bpf-next,1/2] libbpf: Add missing per-arch include path

From: Björn Töpel <bjorn@rivosinc.com>

libbpf does not include the per-arch tools include path, e.g.
tools/arch/riscv/include. Some architectures depend those files to
build properly.

Include tools/arch/$(SUBARCH)/include in the libbpf build.

Fixes: 6d74d178fe6e ("tools: Add riscv barrier implementation")
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
---
 tools/lib/bpf/Makefile | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)


base-commit: db5ca265e3334b48c4e3fa07eef79e8bc578c430

On Fri, Sep 27, 2024 at 6:14 AM Björn Töpel <bjorn@kernel.org> wrote:
>
> From: Björn Töpel <bjorn@rivosinc.com>
>
> libbpf does not include the per-arch tools include path, e.g.
> tools/arch/riscv/include. Some architectures depend those files to
> build properly.
>
> Include tools/arch/$(SUBARCH)/include in the libbpf build.
>
> Fixes: 6d74d178fe6e ("tools: Add riscv barrier implementation")
> Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
> ---
>  tools/lib/bpf/Makefile | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
> index 1b22f0f37288..857a5f7b413d 100644
> --- a/tools/lib/bpf/Makefile
> +++ b/tools/lib/bpf/Makefile
> @@ -61,7 +61,8 @@ ifndef VERBOSE
>  endif
>
>  INCLUDES = -I$(or $(OUTPUT),.) \
> -          -I$(srctree)/tools/include -I$(srctree)/tools/include/uapi
> +          -I$(srctree)/tools/include -I$(srctree)/tools/include/uapi \
> +          -I$(srctree)/tools/arch/$(SRCARCH)/include
>
>  export prefix libdir src obj
>

Do you know what exactly is used from tools/arch/$(SRCARCH)/include
for (I assume) RISC-V? I'm asking because we'd need to make sure that
Github version of libbpf Makefile and include directory has all the
necessary pieces as well (so I'd appreciate if you could take a look
at that as well, if you haven't already).

>
> base-commit: db5ca265e3334b48c4e3fa07eef79e8bc578c430
> --
> 2.43.0
>

Andrii,

On Fri, 27 Sept 2024 at 22:51, Andrii Nakryiko
<andrii.nakryiko@gmail.com> wrote:
>
> On Fri, Sep 27, 2024 at 6:14 AM Björn Töpel <bjorn@kernel.org> wrote:
> >
> > From: Björn Töpel <bjorn@rivosinc.com>
> >
> > libbpf does not include the per-arch tools include path, e.g.
> > tools/arch/riscv/include. Some architectures depend those files to
> > build properly.
> >
> > Include tools/arch/$(SUBARCH)/include in the libbpf build.
> >
> > Fixes: 6d74d178fe6e ("tools: Add riscv barrier implementation")
> > Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
> > ---
> >  tools/lib/bpf/Makefile | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
> > index 1b22f0f37288..857a5f7b413d 100644
> > --- a/tools/lib/bpf/Makefile
> > +++ b/tools/lib/bpf/Makefile
> > @@ -61,7 +61,8 @@ ifndef VERBOSE
> >  endif
> >
> >  INCLUDES = -I$(or $(OUTPUT),.) \
> > -          -I$(srctree)/tools/include -I$(srctree)/tools/include/uapi
> > +          -I$(srctree)/tools/include -I$(srctree)/tools/include/uapi \
> > +          -I$(srctree)/tools/arch/$(SRCARCH)/include
> >
> >  export prefix libdir src obj
> >
>
> Do you know what exactly is used from tools/arch/$(SRCARCH)/include
> for (I assume) RISC-V? I'm asking because we'd need to make sure that
> Github version of libbpf Makefile and include directory has all the
> necessary pieces as well (so I'd appreciate if you could take a look
> at that as well, if you haven't already).

Ah, apologies for not stating that explicitly. It's
tools/arch/riscv/include/asm/{barrier.h,fence.h}

Cheers,
Björn

On Fri, 27 Sept 2024 at 22:52, Andrii Nakryiko
<andrii.nakryiko@gmail.com> wrote:
>
> On Fri, Sep 27, 2024 at 6:14 AM Björn Töpel <bjorn@kernel.org> wrote:
> >
> > From: Björn Töpel <bjorn@rivosinc.com>
> >
> > The prog_tests programs do not include the per-arch tools include
> > path, e.g. tools/arch/riscv/include. Some architectures depend those
> > files to build properly.
> >
> > Include tools/arch/$(SUBARCH)/include in the selftests bpf build.
> >
> > Fixes: 6d74d178fe6e ("tools: Add riscv barrier implementation")
> > Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
> > ---
> >  tools/testing/selftests/bpf/Makefile | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
> > index 365740f24d2e..d6a53afa449f 100644
> > --- a/tools/testing/selftests/bpf/Makefile
> > +++ b/tools/testing/selftests/bpf/Makefile
> > @@ -10,6 +10,7 @@ TOOLSDIR := $(abspath ../../..)
> >  LIBDIR := $(TOOLSDIR)/lib
> >  BPFDIR := $(LIBDIR)/bpf
> >  TOOLSINCDIR := $(TOOLSDIR)/include
> > +TOOLSARCHINCDIR := $(TOOLSDIR)/arch/$(SRCARCH)/include
> >  BPFTOOLDIR := $(TOOLSDIR)/bpf/bpftool
> >  APIDIR := $(TOOLSINCDIR)/uapi
> >  ifneq ($(O),)
> > @@ -44,7 +45,7 @@ CFLAGS += -g $(OPT_FLAGS) -rdynamic                                   \
> >           -Wall -Werror -fno-omit-frame-pointer                         \
> >           $(GENFLAGS) $(SAN_CFLAGS) $(LIBELF_CFLAGS)                    \
> >           -I$(CURDIR) -I$(INCLUDE_DIR) -I$(GENDIR) -I$(LIBDIR)          \
> > -         -I$(TOOLSINCDIR) -I$(APIDIR) -I$(OUTPUT)
> > +         -I$(TOOLSINCDIR) -I$(TOOLSARCHINCDIR) -I$(APIDIR) -I$(OUTPUT)
>
> Eduard was going to switch selftests to use kernel UAPI headers, I
> wonder if we should do just that and then set up arch-specific
> includes from kernel (not from tools/) as well?

In the end it's up to you guys! This is broken on Linus' master for
RISC-V now, so from my (RISC-V) perspective having a workaround sooner
than later would be nice!

@Eduard Do you have any patches around? If so, I can take them for a spin on RV.


Björn