On 5/6/2024 5:54 PM, Martin KaFai Lau wrote: > On 5/6/24 1:50 PM, Abhishek Chauhan (ABC) wrote: >> >> >> On 5/6/2024 12:04 PM, Willem de Bruijn wrote: >>> Abhishek Chauhan wrote: >>>> With changes in the design to forward CLOCK_TAI in the skbuff >>>> framework, existing selftest framework needs modification >>>> to handle forwarding of UDP packets with CLOCK_TAI as clockid. >>>> >>>> Link: https://lore.kernel.org/netdev/bc037db4-58bb-4861-ac31-a361a93841d3@xxxxxxxxx/ >>>> Signed-off-by: Abhishek Chauhan <quic_abchauha@xxxxxxxxxxx> >>>> --- >>>> tools/include/uapi/linux/bpf.h | 15 ++++--- >>>> .../selftests/bpf/prog_tests/ctx_rewrite.c | 10 +++-- >>>> .../selftests/bpf/prog_tests/tc_redirect.c | 3 -- >>>> .../selftests/bpf/progs/test_tc_dtime.c | 39 +++++++++---------- >>>> 4 files changed, 34 insertions(+), 33 deletions(-) >>>> >>>> diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h >>>> index 90706a47f6ff..25ea393cf084 100644 >>>> --- a/tools/include/uapi/linux/bpf.h >>>> +++ b/tools/include/uapi/linux/bpf.h >>>> @@ -6207,12 +6207,17 @@ union { \ >>>> __u64 :64; \ >>>> } __attribute__((aligned(8))) >>>> +/* The enum used in skb->tstamp_type. It specifies the clock type >>>> + * of the time stored in the skb->tstamp. >>>> + */ >>>> enum { >>>> - BPF_SKB_TSTAMP_UNSPEC, >>>> - BPF_SKB_TSTAMP_DELIVERY_MONO, /* tstamp has mono delivery time */ >>>> - /* For any BPF_SKB_TSTAMP_* that the bpf prog cannot handle, >>>> - * the bpf prog should handle it like BPF_SKB_TSTAMP_UNSPEC >>>> - * and try to deduce it by ingress, egress or skb->sk->sk_clockid. >>>> + BPF_SKB_TSTAMP_UNSPEC = 0, /* DEPRECATED */ >>>> + BPF_SKB_TSTAMP_DELIVERY_MONO = 1, /* DEPRECATED */ >>>> + BPF_SKB_CLOCK_REALTIME = 0, >>>> + BPF_SKB_CLOCK_MONOTONIC = 1, >>>> + BPF_SKB_CLOCK_TAI = 2, >>>> + /* For any future BPF_SKB_CLOCK_* that the bpf prog cannot handle, >>>> + * the bpf prog can try to deduce it by ingress/egress/skb->sk->sk_clockid. >>>> */ >>>> }; >>>> diff --git a/tools/testing/selftests/bpf/prog_tests/ctx_rewrite.c b/tools/testing/selftests/bpf/prog_tests/ctx_rewrite.c >>>> index 3b7c57fe55a5..71940f4ef0fb 100644 >>>> --- a/tools/testing/selftests/bpf/prog_tests/ctx_rewrite.c >>>> +++ b/tools/testing/selftests/bpf/prog_tests/ctx_rewrite.c >>>> @@ -69,15 +69,17 @@ static struct test_case test_cases[] = { >>>> { >>>> N(SCHED_CLS, struct __sk_buff, tstamp), >>>> .read = "r11 = *(u8 *)($ctx + sk_buff::__mono_tc_offset);" >>>> - "w11 &= 3;" >>>> - "if w11 != 0x3 goto pc+2;" >>>> + "if w11 == 0x4 goto pc+1;" >>>> + "goto pc+4;" >>>> + "if w11 == 0x3 goto pc+1;" >>>> + "goto pc+2;" >>> >>> Not an expert on this code, and I see that the existing code already >>> has this below, but: isn't it odd and unnecessary to jump to an >>> unconditional jump statement? >>> >> I am closely looking into your comment and i will evalute it(Martin can correct me >> if the jumps are correct or not as i am new to BPF as well) but i found out that >> JSET = "&" and not "==". So the above two ins has to change from - > > Yes, this should be bitwise "&" instead of "==". > > The bpf CI did report this: https://github.com/kernel-patches/bpf/actions/runs/8947652196/job/24579927178 > > Please monitor the bpf CI test result. > > Do you have issue running the test locally? > Yes, To be honest. I am facing compilation issues when i follow the documentation to Make BPF on latest kernel. This is slowing down my development with this patch. Very similar to the problem described here :- https://github.com/jsitnicki/ebpf-summit-2020/issues/1 local/mnt/workspace/kernel_master/linux-next/tools/testing/selftests/bpf/tools/build/bpftool/bootstrap/libbpf/include/bpf/bpf_core_read.h:379:26: note: expanded from macro '___arrow2' #define ___arrow2(a, b) a->b ~^ skeleton/pid_iter.bpf.c:19:9: note: forward declaration of 'struct bpf_link' struct bpf_link link; ^ skeleton/pid_iter.bpf.c:105:7: error: incomplete definition of type 'struct bpf_link' if (BPF_CORE_READ(link, type) == bpf_core_enum_value(enum bpf_link_type___local, ^~~~~~~~~~~~~~~~~~~~~~~~~ >> >> "if w11 == 0x4 goto pc+1;" ==>(needs to be corrected to) "if w11 & 0x4 goto pc+1;" >> "if w11 == 0x3 goto pc+1;" ==> (needs to be correct to) "if w11 & 0x3 goto pc+1;" >> >> >>>> "$dst = 0;" >>>> "goto pc+1;" >>>> "$dst = *(u64 *)($ctx + sk_buff::tstamp);", >>>> .write = "r11 = *(u8 *)($ctx + sk_buff::__mono_tc_offset);" >>>> - "if w11 & 0x2 goto pc+1;" >>>> + "if w11 & 0x4 goto pc+1;" >>>> "goto pc+2;" >>>> - "w11 &= -2;" >>>> + "w11 &= -3;" >> Martin, >> Also i am not sure why the the dissembly complains because the value of SKB_TSTAMP_TYPE_MASK = 3 and we are >> negating it ~3 = -3. >> >> Can't match disassembly(left) with pattern(right): >> r11 = *(u8 *)(r1 +129) ; r11 = *(u8 *)($ctx + sk_buff::__mono_tc_offset) >> if w11 & 0x4 goto pc+1 ; if w11 & 0x4 goto pc+1 >> goto pc+2 ; goto pc+2 >> w11 &= -4 ; w11 &= -3 >> >>>> "*(u8 *)($ctx + sk_buff::__mono_tc_offset) = r11;" >>>> "*(u64 *)($ctx + sk_buff::tstamp) = $src;", >>>> }, >
