Re: [PATCH bpf-next v7 3/6] bpf: Show more useful info in stack depth stats

[Eduard Zingerman <eddyz87@gmail.com>]

On Sat, 2026-08-08 at 08:25 +0200, Kumar Kartikeya Dwivedi wrote:
> Stack depth statistics list captured depths in subprogram-number order,
> while per-verification instruction counts are reported separately. Since
> libbpf determines subprogram numbers, it is hard to associate either
> statistic with its subprogram name or see where verifier work is spent.
> 
> Now that self and inclusive instruction counts are available for every
> subprogram, keep the combined maximum stack depth on its own line and print
> one uniform record for each subprogram. Represent the main program as
> subprog 0, then classify each record as main, global, or static before
> reporting insns_self, insns_total, and stack depth.
> 
> The aggregate processed count is the sum of all self counts, while each
> total shows verifier work rooted at that subprogram.
> 
> When no subprogram name is available, print <unknown>. Keep the existing
> aggregate "processed ... insns" record unchanged for compatibility.
> 
> Suggested-by: Andrii Nakryiko <andrii@kernel.org>
> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
> ---

Acked-by: Eduard Zingerman <eddyz87@gmail.com>

...

> diff --git a/tools/testing/selftests/bpf/progs/verifier_basic_stack.c b/tools/testing/selftests/bpf/progs/verifier_basic_stack.c
> index d3df7a9f1d8c..3a9ee8b55fbd 100644
> --- a/tools/testing/selftests/bpf/progs/verifier_basic_stack.c
> +++ b/tools/testing/selftests/bpf/progs/verifier_basic_stack.c
> @@ -27,7 +27,9 @@ __naked void stack_out_of_bounds(void)
>  
>  SEC("socket")
>  __description("uninitialized stack1")
> -__success __log_level(4) __msg("stack depth 8")
> +__success __log_level(4)
> +__msg("subprog 0 (uninitialized_stack1) main insns_self {{[0-9]+}} "
> +      "insns_total {{[0-9]+}} stack 8")

Nit: let's avoid splitting these literals, also the following would do:

     __msg("subprog 0 (uninitialized_stack1) main {{.*}} stack 8").

...