Re: [RFC PATCH 1/2] perf dso: Use libbfd to read build_id and .gnu_debuglink section

[Jiri Olsa <jolsa@redhat.com>]

On Mon, Jun 01, 2020 at 01:19:14PM +0200, Rémi Bernon wrote:

SNIP

>  int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
> @@ -611,6 +638,37 @@ int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
>  int filename__read_debuglink(const char *filename, char *debuglink,
>  			     size_t size)
>  {
> +#ifdef HAVE_LIBBFD_SUPPORT
> +	int err = -1;
> +	asection *section;
> +	bfd *abfd;
> +
> +	abfd = bfd_openr(filename, NULL);
> +	if (!abfd)
> +		return -1;
> +
> +	if (!bfd_check_format(abfd, bfd_object)) {
> +		pr_debug2("%s: cannot read %s bfd file.\n", __func__, filename);
> +		goto out_close;
> +	}
> +
> +	section = bfd_get_section_by_name(abfd, ".gnu_debuglink");
> +	if (!section)
> +		goto out_close;
> +
> +	if (section->size > size)
> +		goto out_close;
> +
> +	if (!bfd_get_section_contents(abfd, section, debuglink, 0,
> +				      section->size))
> +		goto out_close;
> +
> +	err = 0;
> +
> +out_close:
> +	bfd_close(abfd);
> +	return err;
> +#else

please define 2 filename__read_debuglink functions
for each ifdef leg

thanks,
jirka

>  	int fd, err = -1;
>  	Elf *elf;
>  	GElf_Ehdr ehdr;
> @@ -658,6 +716,7 @@ int filename__read_debuglink(const char *filename, char *debuglink,
>  	close(fd);
>  out:
>  	return err;
> +#endif
>  }
>  
>  static int dso__swap_init(struct dso *dso, unsigned char eidata)
> -- 
> 2.26.1
>