Re: [PATCH dwarves v9 2/3] pahole: Add --btf_feature=decl_tag_kfuncs feature

[Arnaldo Carvalho de Melo <acme@kernel.org>]

On Mon, Apr 29, 2024 at 04:45:59PM -0600, Daniel Xu wrote:
> Add a feature flag to guard tagging of kfuncs. The next commit will
> implement the actual tagging.
> 
> Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
> Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>

Also 'decl_tag_kfuncs' is not enabled when using --btf_features=default,
right? as:

        BTF_DEFAULT_FEATURE(decl_tag_kfuncs, btf_decl_tag_kfuncs, false),

And that false is .default_enabled=false.

So I added:

diff --git a/man-pages/pahole.1 b/man-pages/pahole.1
index be04f1c617291e21..f0605935a9f1b4dc 100644
--- a/man-pages/pahole.1
+++ b/man-pages/pahole.1
@@ -308,7 +308,6 @@ Encode BTF using the specified feature list, or specify 'default' for all standa
 	                   in some CUs and not others, or when the same
 	                   function name has inconsistent BTF descriptions
 	                   in different CUs.
-	decl_tag_kfuncs    Inject a BTF_KIND_DECL_TAG for each discovered kfunc.
 .fi
 
 Supported non-standard features (not enabled for 'default')
@@ -317,6 +316,7 @@ Supported non-standard features (not enabled for 'default')
 	reproducible_build Ensure generated BTF is consistent every time;
 	                   without this parallel BTF encoding can result in
 	                   inconsistent BTF ids.
+	decl_tag_kfuncs    Inject a BTF_KIND_DECL_TAG for each discovered kfunc.
 .fi
 
 So for example, specifying \-\-btf_encode=var,enum64 will result in a BTF encoding that (as well as encoding basic BTF information) will contain variables and enum64 values.


----

Please ack. Alan, please check if your Reviewed-by stands with the above
change.

Thanks,

- Arnaldo

> ---
>  btf_encoder.c      | 2 ++
>  dwarves.h          | 1 +
>  man-pages/pahole.1 | 1 +
>  pahole.c           | 1 +
>  4 files changed, 5 insertions(+)
> 
> diff --git a/btf_encoder.c b/btf_encoder.c
> index 5ffaf5d..f0ef20a 100644
> --- a/btf_encoder.c
> +++ b/btf_encoder.c
> @@ -76,6 +76,7 @@ struct btf_encoder {
>  			  verbose,
>  			  force,
>  			  gen_floats,
> +			  tag_kfuncs,
>  			  is_rel;
>  	uint32_t	  array_index_id;
>  	struct {
> @@ -1661,6 +1662,7 @@ struct btf_encoder *btf_encoder__new(struct cu *cu, const char *detached_filenam
>  		encoder->force		 = conf_load->btf_encode_force;
>  		encoder->gen_floats	 = conf_load->btf_gen_floats;
>  		encoder->skip_encoding_vars = conf_load->skip_encoding_btf_vars;
> +		encoder->tag_kfuncs	 = conf_load->btf_decl_tag_kfuncs;
>  		encoder->verbose	 = verbose;
>  		encoder->has_index_type  = false;
>  		encoder->need_index_type = false;
> diff --git a/dwarves.h b/dwarves.h
> index dd35a4e..7d566b6 100644
> --- a/dwarves.h
> +++ b/dwarves.h
> @@ -94,6 +94,7 @@ struct conf_load {
>  	bool			btf_gen_floats;
>  	bool			btf_encode_force;
>  	bool			reproducible_build;
> +	bool			btf_decl_tag_kfuncs;
>  	uint8_t			hashtable_bits;
>  	uint8_t			max_hashtable_bits;
>  	uint16_t		kabi_prefix_len;
> diff --git a/man-pages/pahole.1 b/man-pages/pahole.1
> index e3c58e0..4769b58 100644
> --- a/man-pages/pahole.1
> +++ b/man-pages/pahole.1
> @@ -308,6 +308,7 @@ Encode BTF using the specified feature list, or specify 'default' for all standa
>  	                   in some CUs and not others, or when the same
>  	                   function name has inconsistent BTF descriptions
>  	                   in different CUs.
> +	decl_tag_kfuncs    Inject a BTF_KIND_DECL_TAG for each discovered kfunc.
>  .fi
>  
>  Supported non-standard features (not enabled for 'default')
> diff --git a/pahole.c b/pahole.c
> index 750b847..954498d 100644
> --- a/pahole.c
> +++ b/pahole.c
> @@ -1289,6 +1289,7 @@ struct btf_feature {
>  	BTF_DEFAULT_FEATURE(enum64, skip_encoding_btf_enum64, true),
>  	BTF_DEFAULT_FEATURE(optimized_func, btf_gen_optimized, false),
>  	BTF_DEFAULT_FEATURE(consistent_func, skip_encoding_btf_inconsistent_proto, false),
> +	BTF_DEFAULT_FEATURE(decl_tag_kfuncs, btf_decl_tag_kfuncs, false),
>  	BTF_NON_DEFAULT_FEATURE(reproducible_build, reproducible_build, false),
>  };
>  
> -- 
> 2.44.0