On 9/12/23 11:14 PM, thinker.li@xxxxxxxxx wrote:
From: Kui-Feng Lee <thinker.li@xxxxxxxxx> Move most of code to bpf_struct_ops_init_one() that can be use to initialize new struct_ops types registered dynamically.
While in RFC, still better to have SOB so that it won't be overlooked in the future.
--- kernel/bpf/bpf_struct_ops.c | 157 +++++++++++++++++++----------------- 1 file changed, 83 insertions(+), 74 deletions(-) diff --git a/kernel/bpf/bpf_struct_ops.c b/kernel/bpf/bpf_struct_ops.c index fdc3e8705a3c..1662875e0ebe 100644 --- a/kernel/bpf/bpf_struct_ops.c +++ b/kernel/bpf/bpf_struct_ops.c @@ -110,102 +110,111 @@ const struct bpf_prog_ops bpf_struct_ops_prog_ops = {static const struct btf_type *module_type; -void bpf_struct_ops_init(struct btf *btf, struct bpf_verifier_log *log)+static void bpf_struct_ops_init_one(struct bpf_struct_ops *st_ops, + struct btf *btf, + struct bpf_verifier_log *log) { - s32 type_id, value_id, module_id; const struct btf_member *member; - struct bpf_struct_ops *st_ops; const struct btf_type *t; + s32 type_id, value_id; char value_name[128]; const char *mname; - u32 i, j; + int i;- /* Ensure BTF type is emitted for "struct bpf_struct_ops_##_name" */-#define BPF_STRUCT_OPS_TYPE(_name) BTF_TYPE_EMIT(struct bpf_struct_ops_##_name); -#include "bpf_struct_ops_types.h" -#undef BPF_STRUCT_OPS_TYPE + if (strlen(st_ops->name) + VALUE_PREFIX_LEN >= + sizeof(value_name)) { + pr_warn("struct_ops name %s is too long\n", + st_ops->name); + return; + } + sprintf(value_name, "%s%s", VALUE_PREFIX, st_ops->name);- module_id = btf_find_by_name_kind(btf, "module", BTF_KIND_STRUCT);- if (module_id < 0) { - pr_warn("Cannot find struct module in btf_vmlinux\n"); + value_id = btf_find_by_name_kind(btf, value_name, + BTF_KIND_STRUCT);
It needs to do some sanity checks on the value_type since this won't be statically enforced by bpf_struct_ops.c.
[ ... ]
+void bpf_struct_ops_init(struct btf *btf, struct bpf_verifier_log *log) +{ + struct bpf_struct_ops *st_ops; + s32 module_id; + u32 i;- if (__btf_member_bitfield_size(t, member)) {- pr_warn("bit field member %s in struct %s is not supported\n", - mname, st_ops->name); - break; - } + /* Ensure BTF type is emitted for "struct bpf_struct_ops_##_name" */ +#define BPF_STRUCT_OPS_TYPE(_name) BTF_TYPE_EMIT(struct bpf_struct_ops_##_name); +#include "bpf_struct_ops_types.h" +#undef BPF_STRUCT_OPS_TYPE
Can this static way of defining struct_ops be removed? bpf_tcp_ca should be able to use the register_bpf_struct_ops() introduced in patch 2.
For the future subsystem supporting struct_ops, the subsystem could be compiled as a kernel module or as a built-in. register_bpf_struct_ops() should work for both.
