[PATCH 1/2] tools/bpf/bpftool: Reset vmlinux BTF after map dump

[Yichong Chen]

map dump frees the global btf_vmlinux object.

In batch mode, a later map dump can reuse the stale pointer.

Reset the global pointer after freeing it.

Signed-off-by: Yichong Chen <chenyichong@xxxxxxxxxxxxx>
---
 tools/bpf/bpftool/map.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c
index 7ebf7dbcfba4..8aab9ce743cb 100644
--- a/tools/bpf/bpftool/map.c
+++ b/tools/bpf/bpftool/map.c
@@ -790,6 +790,12 @@ static int maps_have_btf(int *fds, int nb_fds)
 
 static struct btf *btf_vmlinux;
 
+static void free_btf_vmlinux(void)
+{
+	btf__free(btf_vmlinux);
+	btf_vmlinux = NULL;
+}
+
 static int get_map_kv_btf(const struct bpf_map_info *info, struct btf **btf)
 {
 	int err = 0;
@@ -958,7 +964,7 @@ static int do_dump(int argc, char **argv)
 		close(fds[i]);
 exit_free:
 	free(fds);
-	btf__free(btf_vmlinux);
+	free_btf_vmlinux();
 	return err;
 }
 
-- 
2.51.0