[PATCH bpf-next 0/2] bpf: range_within() must check cnum ranges instead of min/max pairs

[Eduard Zingerman <eddyz87@gmail.com>]

This is a follow-up for series [1].
is_state_visited() should check cnum's subset relations using
cnum-based operations, not min/max projections. See patch #1 for
detailed explanation and patch #2 for an example of buggy program
accepted by verifier w/o this fix.

Updated veristat performance numbers compared to master before [1]
merge follow. Measurements done for the same set of selftests/
sched_ext/meta/cilium programs as in [1].

Net increase:   98K insn 88 programs
Net decrease: -282K insn 52 programs

Raw stats filtered as -f insns_pct>1 -f !insns<10000:

========= selftests: master vs experiment =========

File  Program  Insns (A)  Insns (B)  Insns (DIFF)
----  -------  ---------  ---------  ------------

Total progs: 4665
total_insns diff min:   -0.44%
total_insns diff max:   52.94%
total_insns abs max old: 837,487
total_insns abs max new: 837,487
  -5 .. 0    %: 8
   0 .. 5    %: 4652
   5 .. 15   %: 1
  40 .. 50   %: 3
  50 .. 55   %: 1

========= scx: master vs experiment =========

File               Program          Insns (A)  Insns (B)  Insns     (DIFF)
-----------------  ---------------  ---------  ---------  ----------------
scx_layered.bpf.o  layered_enqueue      13718      14402     +684 (+4.99%)
scx_rusty.bpf.o    rusty_enqueue        39842      22053  -17789 (-44.65%)
scx_rusty.bpf.o    rusty_stopping       37738      19949  -17789 (-47.14%)
scx_wd40.bpf.o     wd40_stopping        37729      19880  -17849 (-47.31%)

Total progs: 376
total_insns diff min:  -47.31%
total_insns diff max:   19.61%
total_insns abs max old: 233,669
total_insns abs max new: 233,696
 -50 .. -40  %: 3
  -5 .. 0    %: 3
   0 .. 5    %: 367
   5 .. 15   %: 2
  15 .. 20   %: 1

========= meta: master vs experiment =========

File                                    Program              Insns (A)  Insns (B)  Insns     (DIFF)
--------------------------------------  -------------------  ---------  ---------  ----------------
<sandbox>                               test_file_open           88771     104160  +15389 (+17.34%)
<profiler>                              on_perf_event            48056      54544   +6488 (+13.50%)
<profiler>                              on_tracepoint_event      48059      54547   +6488 (+13.50%)
<profiler>                              on_perf_event            48056      54544   +6488 (+13.50%)
<profiler>                              on_tracepoint_event      48059      54547   +6488 (+13.50%)
<profiler>                              on_alloc                 50445      56933   +6488 (+12.86%)
<profiler>                              on_free                  50251      56739   +6488 (+12.91%)
<profiler>                              on_perf_event            48056      54544   +6488 (+13.50%)
<profiler>                              on_tracepoint_event      48059      54547   +6488 (+13.50%)
<profiler>                              future_iter_resume       50114      56602   +6488 (+12.95%)
<profiler>                              on_py_event              50042      56530   +6488 (+12.97%)
scx_layered_bpf_skel_genskel-bpf.bpf.o  layered_enqueue          13287      13963     +676 (+5.09%)
scx_layered_bpf_skel_genskel-bpf.bpf.o  layered_enqueue          13269      13945     +676 (+5.09%)
scx_layered_bpf_skel_genskel-bpf.bpf.o  layered_enqueue          13269      13945     +676 (+5.09%)
<firewall>                              ..._egress              222327     164648  -57679 (-25.94%)
<firewall>                              ..._tc_eg               222839     164772  -58067 (-26.06%)
<firewall>                              ..._egress              222327     164648  -57679 (-25.94%)
<firewall>                              ..._tc_eg               222839     164772  -58067 (-26.06%)

Total progs: 1540
total_insns diff min:  -26.06%
total_insns diff max:   37.25%
total_insns abs max old: 666,036
total_insns abs max new: 666,036
 -30 .. -20  %: 4
  -5 .. 0    %: 10
   0 .. 5    %: 1494
   5 .. 10   %: 10
  10 .. 15   %: 13
  15 .. 25   %: 5
  35 .. 40   %: 4

========= cilium: master vs experiment =========

File             Program                            Insns (A)  Insns (B)  Insns    (DIFF)
---------------  ---------------------------------  ---------  ---------  ---------------
bpf_host.o       tail_handle_ipv4_cont_from_host        20962      26024  +5062 (+24.15%)
bpf_host.o       tail_handle_ipv6_cont_from_host        17036      18672   +1636 (+9.60%)
bpf_host.o       tail_nodeport_nat_ingress_ipv4         20080      19858    -222 (-1.11%)
bpf_lxc.o        tail_nodeport_nat_ingress_ipv4         10697      10510    -187 (-1.75%)
bpf_overlay.o    tail_handle_inter_cluster_revsnat      11099      10857    -242 (-2.18%)
bpf_overlay.o    tail_nodeport_nat_ingress_ipv4         11951      11768    -183 (-1.53%)
bpf_wireguard.o  tail_nodeport_nat_ingress_ipv4         11993      11811    -182 (-1.52%)

Total progs: 134
total_insns diff min:   -3.32%
total_insns diff max:   24.15%
total_insns abs max old: 152,012
total_insns abs max new: 152,012
  -5 .. 0    %: 12
   0 .. 5    %: 120
   5 .. 15   %: 1
  20 .. 25   %: 1

[1] https://lore.kernel.org/bpf/fd376f47b9512daf669a87b23573f614ec146385.camel@gmail.com/T/

---
Eduard Zingerman (2):
      bpf: range_within() must check cnum ranges instead of min/max pairs
      selftests/bpf: a test for proper cnums compare in is_state_visited()

 include/linux/cnum.h                               |  2 ++
 kernel/bpf/cnum_defs.h                             | 14 +++++++++++
 kernel/bpf/states.c                                | 11 +++------
 .../testing/selftests/bpf/progs/verifier_bounds.c  | 27 ++++++++++++++++++++++
 4 files changed, 46 insertions(+), 8 deletions(-)
---
base-commit: 6c60b2dd5a7889a583389e95e79689191206f86f
change-id: 20260425-cnum-range-within-4a755ba81e93