Re: [PATCH bpf-next v3 6/9] selftests/bpf: Add JIT-sequence tests for __arena kfunc arguments

On Mon, 2026-08-03 at 14:51 +0200, Kumar Kartikeya Dwivedi wrote:

...

> diff --git a/tools/testing/selftests/bpf/prog_tests/arena_kfunc_jit.c b/tools/testing/selftests/bpf/prog_tests/arena_kfunc_jit.c
> new file mode 100644
> index 000000000000..2359cde24c45
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/prog_tests/arena_kfunc_jit.c
> @@ -0,0 +1,13 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/* Copyright (c) 2026 Meta Platforms, Inc. and affiliates. */
> +#include <test_progs.h>
> +#include "arena_kfunc_jit.skel.h"
> +
> +/*
> + * Runs with full capabilities: resolving module kfunc ksyms requires
> + * CAP_SYS_ADMIN, which rules out the capability-restricted runner.
> + */
> +void test_arena_kfunc_jit(void)
> +{
> +	RUN_TESTS(arena_kfunc_jit);
> +}

Nit: please avoid adding this file, and instead put this
     function under prog_tests/verifier.c.
     There are multiple tests there that invoke RUN_TESTS
     instead of RUN for same exact reason.
     Same applies to the previous patch.

> diff --git a/tools/testing/selftests/bpf/progs/arena_kfunc_jit.c b/tools/testing/selftests/bpf/progs/arena_kfunc_jit.c

...

> +SEC("syscall")
> +__arch_x86_64
> +__jited("...")
> +__jited("	movl	%edi, %edi")
> +__jited("	testl	%edi, %edi")
> +__jited("	je	{{.*}}")
> +__jited("	addq	%r12, %rdi")
> +__success

Note that __jited output generates labels like this:

  50:     89 ff                                   movl    %edi, %edi
  52:     85 ff                                   testl   %edi, %edi
  54:     74 03                                   je      L0
  56:     4c 01 e7                                addq    %r12, %rdi
  59:     e8 42 5f 40 00                      L0: callq   0x405fa0

I think it would make sense to match L0 in this test.

> +int arena_arg_jit_nullable(void *ctx)
> +{
> +	stash = (u64)bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0);
> +	bpf_kfunc_arena_cap_nullable_test((u64 *)stash);
> +	return 0;
> +}

...