selftests/bpf: Enable some of the blocked cpuv4 instruction tests for bpf-gcc

A bunch of tests are gated behind clang only __clang_major__ and thus
fail to build under BPF_GCC. What's worse is, before the prev patch they
were also declared as passing/OK.

This need not be because (a) bpf-gcc does support the feature in codegen
and (b) also advertises correctly with feature support preprocessor macros:

  __BPF_FEATURE_BSWAP, __BPF_FEATURE_GOTOL, __BPF_FEATURE_LDSX,
  __BPF_FEATURE_MOVSX, __BPF_FEATURE_SDIV_SMOD, __BPF_FEATURE_ST

So loosen up the gates to also add specific feature check.
clang >=18 has to stay, despite it being true for so long: clang only
defines __BPF_FEATURE_MOVSX and friends at -mcpu=v4, but assembles the
inline asm at -mcpu=v3 too, and dropping it would remove these tests from
the default test_progs flavour where they run today.

Since bpf-gcc doesn't support addr_space_cast, wrap the corresponding
tests under __BPF_FEATURE_ADDR_SPACE_CAST to skip under it.
And also move the map under that guard so that a bpf-gcc object does not
declare an arena map that no program in it references.

Recovered under BPF_GCC (programs per object, was 1 dummy each):

  verifier_sdiv    80
  verifier_movsx   17
  verifier_ldsx    14   (20 under clang; 5 arena tests,
                       kfunc_root and the arena map stay clang-only)
  verifier_bswap   13

CAN_USE_GOTOL and CAN_USE_BPF_ST only gate parts of a file, so those were
not dummies to begin with:

  compute_live_registers        17 -> 19  (21 under clang)
  verifier_gotol                 1 -> 2
  verifier_iterating_callbacks  34 -> 35

The clang builds are unchanged: verifier_ldsx still emits 20 programs under
the cpuv4 flavour.

One thing left alone: verifier_load_acquire.c and verifier_store_release.c
stay clang-only, and their gates are correct as gas doesn't implement
those (experimental -mxbpf not implemented at all). FWIW LLVM groups
those under -mcpu=v4 and defines __BPF_FEATURE_LOAD_ACQ_STORE_REL there.

Signed-off-by: Vineet Gupta <vineet.gupta@linux.dev>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20260824210142.3933580-4-vineet.gupta@linux.dev

0 files changed, 0 insertions, 0 deletions