On Tue, 27 Jun 2017 22:32:26 -0400 "MD I. Islam" <tamim@xxxxxxxxxxx> wrote:
> Hi Song
>
> On Tue, Jun 27, 2017 at 10:05 PM, Y Song <ys114321@xxxxxxxxx> wrote:
> > xdp meta data is different:
> >
> > struct xdp_md {
> > __u32 data;
> > __u32 data_end;
> > };
> >
> > All other fields available for skb metadata won't be available in XDP.
> > That is way
> > you get verification failure.
> >
>
>
> Thanks for the quick reply! Now I'm trying xdp1_kern.c which uses
> xdp_md. Now I'm getting the error:
>
> Note: 8 bytes struct bpf_elf_map fixup performed due to size mismatch!
> RTNETLINK answers: Operation not supported
>
> Could you please advise me what is wrong here?
The xdp1_kern.c bpf program expect to be loaded with the tool
xdp1_user.c (compiled to executable xdp1) which uses the bpf-elf loader
located in the kernel/samples/bpf/ directory.
You are trying to load this xdp1_kern.c program with the TC utility,
which have it's own bpf-elf loader. These two loaders are not expected
to be compatible... specifically struct bpf_elf_map are different.
p.s. I'm maintaining some bpf samples here:
https://github.com/netoptimizer/prototype-kernel/tree/master/kernel/samples/bpf
--Jesper
> > On Tue, Jun 27, 2017 at 7:00 PM, MD I. Islam <tamim@xxxxxxxxxxx> wrote:
> >> Hi
> >>
> >> I'm using http://lingrok.org/xref/linux-net-next/samples/bpf/parse_simple.c.
> >>
> >> I can load the program as tc_cls using following commands:
> >>
> >> sudo tc qdisc add dev eno1 clsact
> >> sudo tc filter add dev eno1 ingress bpf da obj parse_simple.o sec simple
> >>
> >> But I get error when I load the same program in XDP:
> >>
> >> sudo ip link set dev eno1 xdp obj parse_simple.o section simple
> >>
> >> Prog section 'simple' rejected: Permission denied (13)!
> >> - Type: 6
> >> - Instructions: 23 (0 over limit)
> >> - License: GPL
> >>
> >> Verifier analysis:
> >>
> >> 0: (b7) r0 = 0
> >> 1: (61) r2 = *(u32 *)(r1 +80)
> >> invalid bpf_context access off=80 size=4
> >>
> >> Error fetching program/map!
> >>
> >> I made sure that the parse_simple.o have necessary permission. Could
> >> you please advise what is wrong here? I'm using Kernel 4.11+. Does XDP
> >> need any specific kernel configuration enabled? clang and LLVM
> >> versions are as following:
> >>
> >> clang --version
> >> clang version 3.8.0-2ubuntu4 (tags/RELEASE_380/final)
> >> Target: x86_64-pc-linux-gnu
> >>
> >> llc --version
> >> LLVM (http://llvm.org/):
> >> LLVM version 3.8.0
> >>
> >> Optimized build.
> >> Built Jul 9 2016 (11:22:59).
> >> Default target: x86_64-pc-linux-gnu
> >> Host CPU: haswell
> >>
> >> Registered Targets:
> >> aarch64 - AArch64 (little endian)
> >> aarch64_be - AArch64 (big endian)
> >> amdgcn - AMD GCN GPUs
> >> arm - ARM
> >> arm64 - ARM64 (little endian)
> >> armeb - ARM (big endian)
> >> bpf - BPF (host endian)
> >> bpfeb - BPF (big endian)
> >> bpfel - BPF (little endian)
> >> cpp - C++ backend
> >> hexagon - Hexagon
> >> mips - Mips
> >> mips64 - Mips64 [experimental]
> >> mips64el - Mips64el [experimental]
> >> mipsel - Mipsel
> >> msp430 - MSP430 [experimental]
> >> nvptx - NVIDIA PTX 32-bit
> >> nvptx64 - NVIDIA PTX 64-bit
> >> ppc32 - PowerPC 32
> >> ppc64 - PowerPC 64
> >> ppc64le - PowerPC 64 LE
> >> r600 - AMD GPUs HD2XXX-HD6XXX
> >> sparc - Sparc
> >> sparcel - Sparc LE
> >> sparcv9 - Sparc V9
> >> systemz - SystemZ
> >> thumb - Thumb
> >> thumbeb - Thumb (big endian)
> >> x86 - 32-bit X86: Pentium-Pro and above
> >> x86-64 - 64-bit X86: EM64T and AMD64
> >> xcore - XCore
> >>
> >> Many thanks
> >> Tamim
>
> Thanks
> Tamim
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
LinkedIn: http://www.linkedin.com/in/brouer
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