Re: [PATCH dwarves 5/5] btf_encoder: skip BTF encoding of static functions with inconsistent prototypes

[Jiri Olsa <olsajiri@gmail.com>]

On Tue, Jan 24, 2023 at 01:45:31PM +0000, Alan Maguire wrote:

SNIP

>  	} else {
>  		struct btf_encoder_state *state = zalloc(sizeof(*state));
>  
> @@ -898,10 +954,12 @@ static void btf_encoder__add_saved_func(const void *nodep, const VISIT which,
>  	/* we can safely free encoder state since we visit each node once */
>  	free(fn->priv);
>  	fn->priv = NULL;
> -	if (fn->proto.optimized_parms) {
> +	if (fn->proto.optimized_parms || fn->proto.inconsistent_proto) {
>  		if (encoder->verbose)
> -			printf("skipping addition of '%s' due to optimized-out parameters\n",
> -			       function__name(fn));
> +			printf("skipping addition of '%s' due to %s\n",
> +			       function__name(fn),
> +			       fn->proto.optimized_parms ? "optimized-out parameters" :
> +							   "multiple inconsistent function prototypes");
>  	} else {
>  		btf_encoder__add_func(encoder, fn);
>  	}
> @@ -1775,6 +1833,8 @@ int btf_encoder__encode_cu(struct btf_encoder *encoder, struct cu *cu, struct co
>  		 */
>  		if (fn->declaration)
>  			continue;
> +		if (!fn->external)
> +			save = true;

how about conflicts between static and global functions,
I can see still few cases like:

  void __init msg_init(void)
  static void msg_init(struct spi_message *m, struct spi_transfer *x,
                       u8 *addr, size_t count, char *tx, char *rx)

  static inline void free_pgtable_page(u64 *pt)
  void free_pgtable_page(void *vaddr)

  STATIC inline long INIT parse_header(u8 *input, long *skip, long in_len)
  static struct tb_cfg_result parse_header(const struct ctl_pkg *pkg, u32 len,
                                         enum tb_cfg_pkg_type type, u64 route)
  static void __init parse_header(char *s)


could we enable the check/save globaly?

jirka

>  		if (!ftype__has_arg_names(&fn->proto))
>  			continue;
>  		if (encoder->functions.cnt) {
> @@ -1790,7 +1850,8 @@ int btf_encoder__encode_cu(struct btf_encoder *encoder, struct cu *cu, struct co
>  			if (func) {
>  				if (func->generated)
>  					continue;
> -				func->generated = true;
> +				if (!save)
> +					func->generated = true;
>  			} else if (encoder->functions.suffix_cnt) {
>  				/* falling back to name.isra.0 match if no exact
>  				 * match is found; only bother if we found any
> diff --git a/dwarves.h b/dwarves.h
> index 1ad1b3b..9b80262 100644
> --- a/dwarves.h
> +++ b/dwarves.h
> @@ -830,6 +830,7 @@ struct ftype {
>  	uint16_t	 nr_parms;
>  	uint8_t		 unspec_parms:1; /* just one bit is needed */
>  	uint8_t		 optimized_parms:1;
> +	uint8_t		 inconsistent_proto:1;
>  };
>  
>  static inline struct ftype *tag__ftype(const struct tag *tag)
> -- 
> 1.8.3.1
>