selftests/bpf: Follow-up to JIT instruction tests

Close gaps in the JIT instruction tests found by earlier Sashiko review,
by comparing the programs with what reaches the JIT, and by a sweep
through RFC9669 to construct tests for corner cases. Non-exhaustive list:

- The staggered jumps loaded their operands once, so the verifier decided
  the later guards of ja and gotol and the later jumps of jeq_k and
  jlt32_k, and a landing short of the target passed with r0 at zero.
  Reload the operands per region and let r0 carry the region number
  from the jump to its target.
- The matching 32-bit cmpxchg compared an r0 the mismatching one had zero
  extended. Reload r0 with the full value first and check that the source
  register keeps its upper half, as test_bpf did.
- The 32-bit atomics wrote and read back only their word, so a JIT touching
  all 64 bits passed when the other half was zero. Fill and read back the
  whole slot.
- The sub-word loads of the zero offset, offsets and probe_mem tests landed
  in a register holding nothing in particular. Set it to all ones first.
- Let probe_mem load every size, sign extending too, and run ld_imm64 into
  every register, not only r1.
- Drop the load-acquire probe: a JIT without the instruction fails like for
  any other one instead of skipping.

  # LDLIBS=-static PKG_CONFIG='pkg-config --static' ./vmtest.sh -- ./test_progs -t jit_insns
  [...]
  #191/1   jit_insns/arena access with zero offset:OK
  #191/2   jit_insns/cast to a user address:OK
  #191/3   jit_insns/alu_imm:OK
  #191/4   jit_insns/alu_reg:OK
  #191/5   jit_insns/alu_imm_regs:OK
  #191/6   jit_insns/div_const:OK
  #191/7   jit_insns/alu_reg_pairs:OK
  #191/8   jit_insns/alu_edges:OK
  #191/9   jit_insns/shifts:OK
  #191/10  jit_insns/shift_counts:OK
  #191/11  jit_insns/atomics:OK
  #191/12  jit_insns/atomic_reg_pairs:OK
  #191/13  jit_insns/xadd_chain:OK
  #191/14  jit_insns/ld_imm64:OK
  #191/15  jit_insns/jmp_imm:OK
  #191/16  jit_insns/jmp_reg:OK
  #191/17  jit_insns/jmp_reg_pairs:OK
  #191/18  jit_insns/jmp_edges:OK
  #191/19  jit_insns/staggered_jumps:OK
  #191/20  jit_insns/max_jmp:OK
  #191/21  jit_insns/convergence:OK
  #191/22  jit_insns/calls:OK
  #191/23  jit_insns/helper_calls:OK
  #191/24  jit_insns/ldst_zero_off:OK
  #191/25  jit_insns/ldst_offsets:OK
  #191/26  jit_insns/acq_rel:OK
  #191/27  jit_insns/movsx:OK
  #191/28  jit_insns/jset_imm:OK
  #191/29  jit_insns/cmp_imm:OK
  #191/30  jit_insns/alu_consts:OK
  #191/31  jit_insns/bswap:OK
  #191/32  jit_insns/probe_mem:OK
  #191     jit_insns:OK
  #192/1   jit_insns_blinded/alu_imm:OK
  #192/2   jit_insns_blinded/alu_imm_regs:OK
  #192/3   jit_insns_blinded/alu_edges:OK
  #192/4   jit_insns_blinded/div_const:OK
  #192/5   jit_insns_blinded/shifts:OK
  #192/6   jit_insns_blinded/xadd_chain:OK
  #192/7   jit_insns_blinded/ld_imm64:OK
  #192/8   jit_insns_blinded/jmp_imm:OK
  #192/9   jit_insns_blinded/jmp_edges:OK
  #192/10  jit_insns_blinded/ldst_zero_off:OK
  #192/11  jit_insns_blinded/ldst_offsets:OK
  #192/12  jit_insns_blinded/jset_imm:OK
  #192/13  jit_insns_blinded/cmp_imm:OK
  #192/14  jit_insns_blinded/alu_consts:OK
  #192     jit_insns_blinded:OK
  Summary: 2/46 PASSED, 0 SKIPPED, 0/0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://patch.msgid.link/20261016101822.632891-3-daniel@iogearbox.net

0 files changed, 0 insertions, 0 deletions