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, adding vdso using above command actually will never
be used.

Signed-off-by: Changbin Du <changbin.du@huawei.com>
---
 tools/perf/builtin-buildid-cache.c | 26 +++++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/tools/perf/builtin-buildid-cache.c b/tools/perf/builtin-buildid-cache.c
index b0511d16aeb6..8edea9044a65 100644
--- a/tools/perf/builtin-buildid-cache.c
+++ b/tools/perf/builtin-buildid-cache.c
@@ -172,6 +172,30 @@ static int build_id_cache__add_kcore(const char *filename, bool force)
 	return 0;
 }
 
+static bool filename_is_vdso(const char *filename)
+{
+	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 mememory\n");
+		return false;
+	}
+
+	bname = basename(fname);
+	if (!bname)
+		return false;
+
+	for (unsigned int i = 0; i < ARRAY_SIZE(vdso_names); i++) {
+		if (!strncmp(bname, vdso_names[i], strlen(vdso_names[i])))
+			return true;
+	}
+	return false;
+}
+
 static int build_id_cache__add_file(const char *filename, struct nsinfo *nsi)
 {
 	char sbuild_id[SBUILD_ID_SIZE];
@@ -189,7 +213,7 @@ 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;
-- 
2.34.1