[PATCH v6 8/8] perf buildid-cache: recognize vdso when adding files

From: Changbin Du
Date: Wed Jul 24 2024 - 22:18:42 EST


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@xxxxxxxxxx>
---
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