Merge branch 'tools-bpf-bpftool-fix-vmlinux-btf-state-cleanup'

Yichong Chen says:

====================
tools/bpf/bpftool: Fix vmlinux BTF state cleanup

This series fixes stale vmlinux BTF state in bpftool batch mode.

Patch 1 resets the map command cached vmlinux BTF pointer when the
command releases it, and avoids freeing the cached object from the
map lookup path.

Patch 2 resets the struct_ops command cached vmlinux BTF pointer and
dependent cached map info state after each struct_ops command.

Changes in v4:
- Add Emil's Reviewed-by tag to patch 1.
- Inline the struct_ops cleanup instead of adding a helper.

Changes in v3:
- Add Fixes tags to both patches.

Changes in v2:
- Fold the map lookup path fix into patch 1.
- Update patch 1 subject and commit message to cover map commands
  rather than only map dump.
====================

Link: https://patch.msgid.link/12A35C14DA710D2E+20260624025055.1574875-1-chenyichong@uniontech.com
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>

2 files changed, 13 insertions, 3 deletions

diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c
index 71a45d96617e..6b9649294ca1 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 @@ exit_close:
 		close(fds[i]);
 exit_free:
 	free(fds);
-	btf__free(btf_vmlinux);
+	free_btf_vmlinux();
 	return err;
 }
 
@@ -1049,7 +1055,7 @@ static void print_key_value(struct bpf_map_info *info, void *key,
 		btf_wtr = get_btf_writer();
 		if (!btf_wtr) {
 			p_info("failed to create json writer for btf. falling back to plain output");
-			btf__free(btf);
+			free_map_kv_btf(btf);
 			btf = NULL;
 			print_entry_plain(info, key, value);
 		} else {
@@ -1065,7 +1071,7 @@ static void print_key_value(struct bpf_map_info *info, void *key,
 	} else {
 		print_entry_plain(info, key, value);
 	}
-	btf__free(btf);
+	free_map_kv_btf(btf);
 }
 
 static int do_lookup(int argc, char **argv)
diff --git a/tools/bpf/bpftool/struct_ops.c b/tools/bpf/bpftool/struct_ops.c
index aa43dead249c..835e5e561f7f 100644
--- a/tools/bpf/bpftool/struct_ops.c
+++ b/tools/bpf/bpftool/struct_ops.c
@@ -643,6 +643,10 @@ int do_struct_ops(int argc, char **argv)
 	err = cmd_select(cmds, argc, argv, do_help);
 
 	btf__free(btf_vmlinux);
+	btf_vmlinux = NULL;
+	map_info_type = NULL;
+	map_info_alloc_len = 0;
+	map_info_type_id = 0;
 
 	return err;
 }