[PATCH bpf 2/2] bpf: emit bpf_timer in vmlinux BTF

[Yonghong Song <yhs@xxxxxx>]

Previously, the following code in check_and_init_map_value()
  *(struct bpf_timer *)(dst + map->timer_off) =
      (struct bpf_timer){};
can help generate bpf_timer definition in vmlinuxBTF.
But previous patch replaced the above code with memset
so bpf_timer definition disappears from vmlinuxBTF.
Let us emit the type explicitly so bpf program can continue
to use it from vmlinux.h.

Signed-off-by: Yonghong Song <yhs@xxxxxx>
---
 kernel/bpf/helpers.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index 4e5969fde0b3..d7fc3c270a4c 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -17,6 +17,7 @@
 #include <linux/proc_ns.h>
 #include <linux/security.h>
 #include <linux/btf_ids.h>
+#include <linux/btf.h>
 
 #include "../../lib/kstrtox.h"
 
@@ -1109,6 +1110,7 @@ static enum hrtimer_restart bpf_timer_cb(struct hrtimer *hrtimer)
 	void *key;
 	u32 idx;
 
+	BTF_TYPE_EMIT(struct bpf_timer);
 	callback_fn = rcu_dereference_check(t->callback_fn, rcu_read_lock_bh_held());
 	if (!callback_fn)
 		goto out;
-- 
2.30.2