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:
- 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 | 57 +++++++++
3 files changed, 179 insertions(+)
create mode 100644 tools/testing/selftests/bpf/progs/verifier_bits_iter.c
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2.39.1
