On Thu, Apr 11, 2024 at 6:51 AM Yafang Shao <laoar.shao@xxxxxxxxx> wrote:
>
> On Thu, Apr 11, 2024 at 9:11 PM Yafang Shao <laoar.shao@xxxxxxxxx> wrote:
> >
> > Three new kfuncs, namely bpf_iter_bits_{new,next,destroy}, have been
> > added for the new bpf_iter_bits functionality. These kfuncs enable the
> > iteration of the bits from a given address and a given number of bits.
> >
> > - bpf_iter_bits_new
> > Initialize a new bits iterator for a given memory area. Due to the
> > limitation of bpf memalloc, the max number of bits to be iterated
> > over is (4096 * 8).
> > - bpf_iter_bits_next
> > Get the next bit in a bpf_iter_bits
> > - bpf_iter_bits_destroy
> > Destroy a bpf_iter_bits
> >
> > The bits iterator can be used in any context and on any address.
> >
> > Changes:
> > - v5->v6:
> > - Add positive tests (Andrii)
> > - v4->v5:
> > - Simplify test cases (Andrii)
> > - v3->v4:
> > - Fix endianness error on s390x (Andrii)
> > - zero-initialize kit->bits_copy and zero out nr_bits (Andrii)
> > - v2->v3:
> > - Optimization for u64/u32 mask (Andrii)
> > - v1->v2:
> > - Simplify the CPU number verification code to avoid the failure on s390x
> > (Eduard)
> > - bpf: Add bpf_iter_cpumask
> > https://lwn.net/Articles/961104/
> > - bpf: Add new bpf helper bpf_for_each_cpu
> > https://lwn.net/Articles/939939/
> >
> > Yafang Shao (2):
> > bpf: Add bits iterator
> > selftests/bpf: Add selftest for bits iter
> >
> > kernel/bpf/helpers.c | 120 +++++++++++++++++
> > .../selftests/bpf/prog_tests/verifier.c | 2 +
> > .../selftests/bpf/progs/verifier_bits_iter.c | 127 ++++++++++++++++++
> > 3 files changed, 249 insertions(+)
> > create mode 100644 tools/testing/selftests/bpf/progs/verifier_bits_iter.c
> >
> > --
> > 2.39.1
> >
>
> It appears that the test case failed on s390x when the data is
> a u32 value because we need to set the higher 32 bits.
> will analyze it.
>
Hey Yafang, did you get a chance to debug and fix the issue?
>
> --
> Regards
> Yafang
