[PATCH v2 1/3] perf dso: Move dso__read_build_id() from perf inject to dso.c

[Matthew Wood <thepacketgeek@gmail.com>]

dso__read_build_id() reads a DSO's build-id from inside its mount
namespace when it isn't known yet. The libdw unwinder is going to need
it, so move it out of builtin-inject.c and make it available to the rest
of perf.

No functional change.

Signed-off-by: Matthew Wood <thepacketgeek@gmail.com>
---
 tools/perf/builtin-inject.c | 25 -------------------------
 tools/perf/util/dso.c       | 29 +++++++++++++++++++++++++++++
 tools/perf/util/dso.h       |  1 +
 3 files changed, 30 insertions(+), 25 deletions(-)

diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c
index 70bbfad5653e..7e4b45a5062c 100644
--- a/tools/perf/builtin-inject.c
+++ b/tools/perf/builtin-inject.c
@@ -892,31 +892,6 @@ static int perf_event__repipe_tracing_data(const struct perf_tool *tool,
 }
 #endif
 
-static int dso__read_build_id(struct dso *dso)
-{
-	struct nscookie nsc;
-	struct build_id bid = { .size = 0, };
-
-	if (dso__has_build_id(dso))
-		return 0;
-
-	mutex_lock(dso__lock(dso));
-	nsinfo__mountns_enter(dso__nsinfo(dso), &nsc);
-	if (filename__read_build_id(dso__long_name(dso), &bid) > 0)
-		dso__set_build_id(dso, &bid);
-	else if (dso__nsinfo(dso)) {
-		char *new_name = dso__filename_with_chroot(dso, dso__long_name(dso));
-
-		if (new_name && filename__read_build_id(new_name, &bid) > 0)
-			dso__set_build_id(dso, &bid);
-		free(new_name);
-	}
-	nsinfo__mountns_exit(&nsc);
-	mutex_unlock(dso__lock(dso));
-
-	return dso__has_build_id(dso) ? 0 : -1;
-}
-
 static struct strlist *perf_inject__parse_known_build_ids(
 	const char *known_build_ids_string)
 {
diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index 42bfe30a3b51..e03e2cb9212b 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -569,6 +569,35 @@ char *dso__filename_with_chroot(const struct dso *dso, const char *filename)
 	return filename_with_chroot(nsinfo__pid(dso__nsinfo_const(dso)), filename);
 }
 
+/*
+ * Read the build-id from the DSO's file, inside its mount namespace, if it
+ * isn't known yet.
+ */
+int dso__read_build_id(struct dso *dso)
+{
+	struct nscookie nsc;
+	struct build_id bid = { .size = 0, };
+
+	if (dso__has_build_id(dso))
+		return 0;
+
+	mutex_lock(dso__lock(dso));
+	nsinfo__mountns_enter(dso__nsinfo(dso), &nsc);
+	if (filename__read_build_id(dso__long_name(dso), &bid) > 0)
+		dso__set_build_id(dso, &bid);
+	else if (dso__nsinfo(dso)) {
+		char *new_name = dso__filename_with_chroot(dso, dso__long_name(dso));
+
+		if (new_name && filename__read_build_id(new_name, &bid) > 0)
+			dso__set_build_id(dso, &bid);
+		free(new_name);
+	}
+	nsinfo__mountns_exit(&nsc);
+	mutex_unlock(dso__lock(dso));
+
+	return dso__has_build_id(dso) ? 0 : -1;
+}
+
 static char *dso__get_filename(struct dso *dso, const char *root_dir,
 			       bool *decomp)
 {
diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
index 55c4aaa53c38..ece54b9b8552 100644
--- a/tools/perf/util/dso.h
+++ b/tools/perf/util/dso.h
@@ -805,6 +805,7 @@ static inline bool dso__has_symbols(const struct dso *dso)
 }
 
 char *dso__filename_with_chroot(const struct dso *dso, const char *filename);
+int dso__read_build_id(struct dso *dso);
 
 bool dso__sorted_by_name(const struct dso *dso);
 void dso__set_sorted_by_name(struct dso *dso);
-- 
2.53.0-Meta