Re: [PATCH v2] perf buildid-cache: recognize vdso when adding files

[Arnaldo Carvalho de Melo]

On Thu, Sep 12, 2024 at 08:03:03PM +0800, Changbin Du wrote:
> Identify vdso by file name matching. The vdso objects have name
> as vdso[32,64].so[.dbg].
> 
> $ perf buildid-cache -a /work/linux/arch/x86/entry/vdso/vdso64.so.dbg
> 
> Without this change, added vdso using above command actually will never
> be used.
> 
> Reviewed-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> Tested-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> Signed-off-by: Changbin Du <changbin.du@xxxxxxxxxx>


Thanks, applied to perf-tools-next,

- Arnaldo
 
> ---
> This patch is separated from the series "perf: Support searching local
> debugging vdso or specify vdso path in cmdline".
> 
> v2: also update build_id_cache__update_file().
> ---
>  tools/perf/builtin-buildid-cache.c | 34 ++++++++++++++++++++++++++++--
>  1 file changed, 32 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/perf/builtin-buildid-cache.c b/tools/perf/builtin-buildid-cache.c
> index b0511d16aeb6..69f43460d007 100644
> --- a/tools/perf/builtin-buildid-cache.c
> +++ b/tools/perf/builtin-buildid-cache.c
> @@ -172,6 +172,36 @@ static int build_id_cache__add_kcore(const char *filename, bool force)
>  	return 0;
>  }
>  
> +static bool filename_is_vdso(const char *filename)
> +{
> +	bool is_vdso = false;
> +	char *fname, *bname;
> +	static const char * const vdso_names[] = {
> +		"vdso.so", "vdso32.so", "vdso64.so", "vdsox32.so"
> +	};
> +
> +	fname = strdup(filename);
> +	if (!fname) {
> +		pr_err("no memory\n");
> +		return false;
> +	}
> +
> +	bname = basename(fname);
> +	if (!bname)
> +		goto out;
> +
> +	for (unsigned int i = 0; i < ARRAY_SIZE(vdso_names); i++) {
> +		if (strstarts(bname, vdso_names[i])) {
> +			is_vdso = true;
> +			break;
> +		}
> +	}
> +
> +out:
> +	free(fname);
> +	return is_vdso;
> +}
> +
>  static int build_id_cache__add_file(const char *filename, struct nsinfo *nsi)
>  {
>  	char sbuild_id[SBUILD_ID_SIZE];
> @@ -189,7 +219,7 @@ static int build_id_cache__add_file(const char *filename, struct nsinfo *nsi)
>  
>  	build_id__sprintf(&bid, sbuild_id);
>  	err = build_id_cache__add_s(sbuild_id, filename, nsi,
> -				    false, false);
> +				    false, filename_is_vdso(filename));
>  	pr_debug("Adding %s %s: %s\n", sbuild_id, filename,
>  		 err ? "FAIL" : "Ok");
>  	return err;
> @@ -323,7 +353,7 @@ static int build_id_cache__update_file(const char *filename, struct nsinfo *nsi)
>  
>  	if (!err)
>  		err = build_id_cache__add_s(sbuild_id, filename, nsi, false,
> -					    false);
> +					    filename_is_vdso(filename));
>  
>  	pr_debug("Updating %s %s: %s\n", sbuild_id, filename,
>  		 err ? "FAIL" : "Ok");
> -- 
> 2.34.1