On 25.02.2025 10:21:11, Eduard Zingerman wrote: > On Tue, 2025-02-25 at 16:55 +0100, Marc Kleine-Budde wrote: > > On 23.01.2023 12:35:41, Chris Ward wrote: > > > The 5.15.0 kernel (built by 'git checkout v5.15' from the kernel.org > > > torvalds tree) fails in the same way that the 6.2.0-rc5+ kernel fails. > > > So it seems that something Canonical did for the Ubuntu 20.04 kernel > > > causes eBPF to work correctly. > > > > > > On Mon, 23 Jan 2023 at 11:06, Chris Ward <tjcw01@xxxxxxxxx> wrote: > > > > > > > > I am trying to use the 'bleeding edge' kernel to determine whether a > > > > problem I see has already been fixed, but with this kernel the eBPF > > > > verifier will not load the dispatcher program that is contained within > > > > libxdp. I am testing kernel commit hash 2475bf0 which fails, and the > > > > kernel in Ubuntu 22.04 (5.15.0-58-generic) works properly. I am > > > > running the test case from > > > > https://github.com/tjcw/bpf-examples/tree/tjcw-explore-sameeth ; to > > > > build it go to the AF_XDP-filter directory and type 'make', and to run > > > > it go to the AF_XDP-filter/runscripts/iperf3-namespace directory and > > > > type 'sudo FILTER=af_xdp_kern PORT=50000 ./run.sh' . > > > > The lines from the run output indicating the failure are > > > > libbpf: prog 'xdp_dispatcher': BPF program load failed: Invalid argument > > > > libbpf: prog 'xdp_dispatcher': -- BEGIN PROG LOAD LOG -- > > > > Func#11 is safe for any args that match its prototype > > > > btf_vmlinux is malformed > > > > reg type unsupported for arg#0 function xdp_dispatcher#29 > > > > 0: R1=ctx(off=0,imm=0) R10=fp0 > > > > ; int xdp_dispatcher(struct xdp_md *ctx) > > > > 0: (bf) r6 = r1 ; R1=ctx(off=0,imm=0) > > > > R6_w=ctx(off=0,imm=0) > > > > 1: (b7) r0 = 2 ; R0_w=2 > > > > ; __u8 num_progs_enabled = conf.num_progs_enabled; > > > > 2: (18) r8 = 0xffffb2f6c06d8000 ; R8_w=map_value(off=0,ks=4,vs=84,imm=0) > > > > 4: (71) r7 = *(u8 *)(r8 +0) ; R7=1 > > > > R8=map_value(off=0,ks=4,vs=84,imm=0) > > > > ; if (num_progs_enabled < 1) > > > > 5: (15) if r7 == 0x0 goto pc+141 ; R7=1 > > > > ; ret = prog0(ctx); > > > > 6: (bf) r1 = r6 ; R1_w=ctx(off=0,imm=0) > > > > R6=ctx(off=0,imm=0) > > > > 7: (85) call pc+140 > > > > btf_vmlinux is malformed > > > > R1 type=ctx expected=fp > > > > Caller passes invalid args into func#1 > > > > processed 84 insns (limit 1000000) max_states_per_insn 0 total_states > > > > 9 peak_states 9 mark_read 1 > > > > -- END PROG LOAD LOG -- > > > > libbpf: prog 'xdp_dispatcher': failed to load: -22 > > > > libbpf: failed to load object 'xdp-dispatcher.o' > > > > libxdp: Failed to load dispatcher: Invalid argument > > > > libxdp: Falling back to loading single prog without dispatcher > > > > > > > > Can this regression be fixed before kernel 6.2 ships ? > > > > I'm seeing the same failure on 32 bit ARM on v6.13. > > > > Have you found a solution? > When I try the link from the discussion: > https://github.com/tjcw/bpf-examples/tree/tjcw-explore-sameeth > I get a 404 error from github. I'm have the same error as Chris Ward wrote in their original mail. But I'm using the xdp-tutorial's [1] basic01-xdp-pass/xdp_pass_user example. [1] https://github.com/xdp-project/xdp-tutorial.git This is my error message. | sudo ./xdp_pass_user -d lan0 | libbpf: elf: skipping unrecognized data section(7) xdp_metadata | libbpf: elf: skipping unrecognized data section(7) xdp_metadata | libbpf: prog 'xdp_dispatcher': BPF program load failed: Invalid argument | libbpf: prog 'xdp_dispatcher': -- BEGIN PROG LOAD LOG -- | btf_vmlinux is malformed ^^^^^^^^^^^^^^^^^^^^^^^^ Now I understand, what this error message wants to tell me. I should recompile my kernel with CONFIG_DEBUG_INFO_BTF=y. | 0: R1=ctx() R10=fp0 | ; int xdp_dispatcher(struct xdp_md *ctx) @ xdp-dispatcher.c:118 | 0: (bf) r6 = r1 ; R1=ctx() R6_w=ctx() | ; __u8 num_progs_enabled = conf.num_progs_enabled; @ xdp-dispatcher.c:120 | 1: (18) r8 = 0xc3b45cc8 ; R8_w=map_value(map=xdp_disp.rodata,ks=4,vs=124) | 3: (71) r7 = *(u8 *)(r8 +2) ; R7_w=1 R8_w=map_value(map=xdp_disp.rodata,ks=4,vs=124) | 4: (b7) r0 = 2 ; R0_w=2 | ; if (num_progs_enabled < 1) @ xdp-dispatcher.c:123 | 5: (15) if r7 == 0x0 goto pc+136 ; R7_w=1 | ; ret = prog0(ctx); @ xdp-dispatcher.c:125 | 6: (bf) r1 = r6 ; R1_w=ctx() R6_w=ctx() | 7: (85) call pc+135 | btf_vmlinux is malformed | R1 type=ctx expected=fp | Caller passes invalid args into func#1 ('prog0') | processed 7 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0 | -- END PROG LOAD LOG -- | libbpf: prog 'xdp_dispatcher': failed to load: -22 | libbpf: failed to load object 'xdp-dispatcher.o' | libxdp: Failed to load dispatcher: Invalid argument | libxdp: Falling back to loading single prog without dispatcher | libbpf: elf: skipping unrecognized data section(7) xdp_metadata | Success: Loading XDP prog name:xdp_prog_simple(id:118) on device:lan0(ifindex:4) With the CONFIG_DEBUG_INFO_BTF=y kernel the verifier seems to be more happy. Now it fails with "-22": | sudo ./xdp_pass_user -d lan0 | libbpf: elf: skipping unrecognized data section(7) xdp_metadata | libbpf: elf: skipping unrecognized data section(7) xdp_metadata | libbpf: elf: skipping unrecognized data section(7) xdp_metadata | libbpf: elf: skipping unrecognized data section(7) xdp_metadata | libbpf: prog 'xdp_pass': BPF program load failed: Invalid argument | libbpf: prog 'xdp_pass': -- BEGIN PROG LOAD LOG -- | Extension programs should be JITed | processed 0 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0 | -- END PROG LOAD LOG -- | libbpf: prog 'xdp_pass': failed to load: -22 | libbpf: failed to load object 'xdp-dispatcher.o' | libxdp: Compatibility check for dispatcher program failed: Invalid argument | libxdp: Falling back to loading single prog without dispatcher | libbpf: elf: skipping unrecognized data section(7) xdp_metadata | Success: Loading XDP prog name:xdp_prog_simple(id:20) on device:lan0(ifindex:4) After unloading and enabling the JIT... | ➜ (pts/0) frogger@riot:xdp-tutorial/basic01-xdp-pass (main✗) echo 1 |sudo tee /proc/sys/net/core/bpf_jit_enable ... the dispatcher fails to load with "524". Yes, the number is positive. | ➜ (pts/0) frogger@riot:xdp-tutorial/basic01-xdp-pass (main✗) sudo ./xdp_pass_user -d lan0 --unload-all | Success: Unloading XDP prog name: xdp_prog_simple | ➜ (pts/0) frogger@riot:xdp-tutorial/basic01-xdp-pass (main✗) sudo ./xdp_pass_user -d lan0 | libbpf: elf: skipping unrecognized data section(7) xdp_metadata | libbpf: elf: skipping unrecognized data section(7) xdp_metadata | libbpf: elf: skipping unrecognized data section(7) xdp_metadata | libbpf: elf: skipping unrecognized data section(7) xdp_metadata | libxdp: Compatibility check for dispatcher program failed: Unknown error 524 | libxdp: Falling back to loading single prog without dispatcher | libbpf: elf: skipping unrecognized data section(7) xdp_metadata | Success: Loading XDP prog name:xdp_prog_simple(id:48) on device:lan0(ifindex:4) strace indicates this syscalls fails: | bpf(BPF_RAW_TRACEPOINT_OPEN, {raw_tracepoint={name=NULL, prog_fd=17}}, 16) = -1 ENOTSUPP (Unknown error 524) I'm on a armv7l, i.e. a 32 bit ARM system. Maybe I'm missing some kernel option or BPF_RAW_TRACEPOINT_OPEN is not supported on armv7l. Will look deeper into the kernel config options tomorrow. regards, Marc -- Pengutronix e.K. | Marc Kleine-Budde | Embedded Linux | https://www.pengutronix.de | Vertretung Nürnberg | Phone: +49-5121-206917-129 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-9 |
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