Commit cfe14564 authored by Yonghong Song's avatar Yonghong Song Committed by Alexei Starovoitov
Browse files

bpf: Add support for kfunc set with common btf_ids 



Later on, we will introduce kfuncs bpf_cast_to_kern_ctx() and
bpf_rdonly_cast() which apply to all program types. Currently kfunc set
only supports individual prog types. This patch added support for kfunc
applying to all program types.

Signed-off-by: default avatarYonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20221120195426.3113828-1-yhs@fb.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent e181d3f1

kernel/bpf/btf.c

+8 −0
Original line number Diff line number Diff line
@@ -199,6 +199,7 @@ DEFINE_IDR(btf_idr); 
DEFINE_SPINLOCK(btf_idr_lock);



enum btf_kfunc_hook {

	BTF_KFUNC_HOOK_COMMON,

	BTF_KFUNC_HOOK_XDP,

	BTF_KFUNC_HOOK_TC,

	BTF_KFUNC_HOOK_STRUCT_OPS,
@@ -7531,6 +7532,8 @@ static u32 *__btf_kfunc_id_set_contains(const struct btf *btf, 
static int bpf_prog_type_to_kfunc_hook(enum bpf_prog_type prog_type)

{

	switch (prog_type) {

	case BPF_PROG_TYPE_UNSPEC:

		return BTF_KFUNC_HOOK_COMMON;

	case BPF_PROG_TYPE_XDP:

		return BTF_KFUNC_HOOK_XDP;

	case BPF_PROG_TYPE_SCHED_CLS:
@@ -7559,6 +7562,11 @@ u32 *btf_kfunc_id_set_contains(const struct btf *btf, 
			       u32 kfunc_btf_id)

{

	enum btf_kfunc_hook hook;

	u32 *kfunc_flags;



	kfunc_flags = __btf_kfunc_id_set_contains(btf, BTF_KFUNC_HOOK_COMMON, kfunc_btf_id);

	if (kfunc_flags)

		return kfunc_flags;



	hook = bpf_prog_type_to_kfunc_hook(prog_type);

	return __btf_kfunc_id_set_contains(btf, hook, kfunc_btf_id);

kernel/bpf/helpers.c

+11 −1
Original line number Diff line number Diff line
@@ -1901,10 +1901,19 @@ static const struct btf_kfunc_id_set generic_kfunc_set = { 
	.set   = &generic_btf_ids,

};





BTF_ID_LIST(generic_dtor_ids)

BTF_ID(struct, task_struct)

BTF_ID(func, bpf_task_release)



BTF_SET8_START(common_btf_ids)

BTF_SET8_END(common_btf_ids)



static const struct btf_kfunc_id_set common_kfunc_set = {

	.owner = THIS_MODULE,

	.set   = &common_btf_ids,

};



static int __init kfunc_init(void)

{

	int ret;
@@ -1918,9 +1927,10 @@ static int __init kfunc_init(void) 
	ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, &generic_kfunc_set);

	ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS, &generic_kfunc_set);

	ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_STRUCT_OPS, &generic_kfunc_set);

	return ret ?: register_btf_id_dtor_kfuncs(generic_dtors,

	ret = ret ?: register_btf_id_dtor_kfuncs(generic_dtors,

						  ARRAY_SIZE(generic_dtors),

						  THIS_MODULE);

	return ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_UNSPEC, &common_kfunc_set);

}



late_initcall(kfunc_init);