1 files changed, 69 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/security_bpf_map.c b/tools/testing/selftests/bpf/progs/security_bpf_map.c
new file mode 100644
index 000000000000..7216b3450e96
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/security_bpf_map.c
@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include "vmlinux.h"
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_helpers.h>
+
+char _license[] SEC("license") = "GPL";
+
+#define EPERM 1 /* Operation not permitted */
+
+/* From include/linux/mm.h. */
+#define FMODE_WRITE	0x2
+
+struct map;
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, __u32);
+	__type(value, __u32);
+	__uint(max_entries, 1);
+} prot_status_map SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, __u32);
+	__type(value, __u32);
+	__uint(max_entries, 3);
+} prot_map SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, __u32);
+	__type(value, __u32);
+	__uint(max_entries, 3);
+} not_prot_map SEC(".maps");
+
+SEC("fmod_ret/security_bpf_map")
+int BPF_PROG(fmod_bpf_map, struct bpf_map *map, int fmode)
+{
+	__u32 key = 0;
+	__u32 *status_ptr = bpf_map_lookup_elem(&prot_status_map, &key);
+
+	if (!status_ptr || !*status_ptr)
+		return 0;
+
+	if (map == &prot_map) {
+		/* Allow read-only access */
+		if (fmode & FMODE_WRITE)
+			return -EPERM;
+	}
+
+	return 0;
+}
+
+/*
+ * This program keeps references to maps. This is needed to prevent
+ * optimizing them out.
+ */
+SEC("fentry/bpf_fentry_test1")
+int BPF_PROG(fentry_dummy1, int a)
+{
+	__u32 key = 0;
+	__u32 val1 = a;
+	__u32 val2 = a + 1;
+
+	bpf_map_update_elem(&prot_map, &key, &val1, BPF_ANY);
+	bpf_map_update_elem(&not_prot_map, &key, &val2, BPF_ANY);
+	return 0;
+}