Fix bpf_strnstr() wrong 'len' parameter, bpf_strnstr("open", "open", 4) should return 0 instead of -ENOENT.

Rong Tao (2): bpf/helpers: bpf_strnstr: Exact match length selftests/bpf: Add tests for bpf_strnstr

kernel/bpf/helpers.c | 4 +++- tools/testing/selftests/bpf/progs/string_kfuncs_success.c | 4 +++- 2 files changed, 6 insertions(+), 2 deletions(-)

--- v3: Fix selftests/bpf error in v2, sorry about that; v2: Follow Andrii Nakryiko's advise, fix the 'wrong fix'; https://lore.kernel.org/lkml/tencent_DF4DA83EEBFB9246E5E3357BB40911CCA005@qq... v1: https://lore.kernel.org/lkml/tencent_65E5988AD52BEC280D22964189505CD6ED06@qq...