selftests/bpf: Fix a test_verifier failure

The following test_verifier subtest failed due to
new encoding for BSWAP.

$ ./test_verifier
...
#99/u invalid 64-bit BPF_END FAIL
Unexpected success to load!
verification time 215 usec
stack depth 0
processed 3 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0
#99/p invalid 64-bit BPF_END FAIL
Unexpected success to load!
verification time 198 usec
stack depth 0
processed 3 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0

Tighten the test so it still reports a failure.

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230728011244.3717464-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests: bpf: add tests for shifts by zero

There are currently no tests for ALU64 shift operations when the shift
amount is 0. This adds 6 new tests to make sure they are equivalent
to a no-op. The x32 JIT had such bugs that could have been caught by
these tests.

Cc: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Luke Nelson <luke.r.nels@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

selftests: bpf: move sub-register zero extension checks into subreg.c

It is better to centralize all sub-register zero extension checks into an
independent file.

This patch takes the first step to move existing sub-register zero
extension checks into subreg.c.

Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

selftests: bpf: add zero extend checks for ALU32 and/or/xor

Add three tests to test_verifier/basic_instr that make sure that the
high 32-bits of the destination register is cleared after an ALU32
and/or/xor.

Signed-off-by: Björn Töpel <bjorn.topel@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

selftests: bpf: break up the rest of test_verifier

Break up the rest of test_verifier tests into separate
files.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests: bpf: break up test_verifier

Break up the first 10 kLoC of test verifier test cases
out into smaller files. Looks like git line counting
gets a little flismy above 16 bit integers, so we need
two commits to break up test_verifier.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>