bpf: Emit bpf_timer in vmlinux BTF

Currently 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 the code above may not zero the whole structure due to anonymour members and that code will be replaced by memset in the subsequent patch and bpf_timer definition will disappear from vmlinuxBTF. Let us emit the type explicitly so bpf program can continue to use it from vmlinux.h.

Yonghong Song committed 4 years ago

Commit 3bd916e1 parent acc3c471 file · +2 −0Browse files

Unified · Split

kernel/bpf/helpers.c+2−0

@@ -2,6 +2,7 @@ · 1 unmodified line
2	2	/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
3	3	*/
4	4	#include <linux/bpf.h>
	5	+#include <linux/btf.h>
5	6	#include <linux/bpf-cgroup.h>
6	7	#include <linux/rcupdate.h>
7	8	#include <linux/random.h>
@@ -1075,6 +1076,7 @@ static enum hrtimer_restart bpf_timer_cb(struct hrtimer *hrtimer) · 1067 unmodified lines
1075	1076	void *key;
1076	1077	u32 idx;
1077	1078
	1079	+ BTF_TYPE_EMIT(struct bpf_timer);
1078	1080	callback_fn = rcu_dereference_check(t->callback_fn, rcu_read_lock_bh_held());
1079	1081	if (!callback_fn)
1080	1082	goto out;