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bpf: refactory struct_ops type initialization to a function.

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Move the majority of the code to bpf_struct_ops_init_one(), which can then
be utilized for the initialization of newly registered dynamically
allocated struct_ops types in the following patches.

Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Link: https://lore.kernel.org/r/20240119225005.668602-2-thinker.li@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
This commit is contained in:
Kui-Feng Lee 2024-01-19 14:49:52 -08:00 committed by Martin KaFai Lau
parent b7d1af3791
commit 3b1f89e747
3 changed files with 92 additions and 77 deletions
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1
include/linux/btf.h
View file

@ -137,6 +137,7 @@ struct btf_struct_metas {
extern const struct file_operations btf_fops;
const char *btf_get_name(const struct btf *btf);
void btf_get(struct btf *btf);
void btf_put(struct btf *btf);
int btf_new_fd(const union bpf_attr *attr, bpfptr_t uattr, u32 uattr_sz);

163
kernel/bpf/bpf_struct_ops.c
View file

@ -110,15 +110,95 @@ 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;
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);
value_id = btf_find_by_name_kind(btf, value_name,
BTF_KIND_STRUCT);
if (value_id < 0) {
pr_warn("Cannot find struct %s in %s\n",
value_name, btf_get_name(btf));
return;
}
type_id = btf_find_by_name_kind(btf, st_ops->name,
BTF_KIND_STRUCT);
if (type_id < 0) {
pr_warn("Cannot find struct %s in %s\n",
st_ops->name, btf_get_name(btf));
return;
}
t = btf_type_by_id(btf, type_id);
if (btf_type_vlen(t) > BPF_STRUCT_OPS_MAX_NR_MEMBERS) {
pr_warn("Cannot support #%u members in struct %s\n",
btf_type_vlen(t), st_ops->name);
return;
}
for_each_member(i, t, member) {
const struct btf_type *func_proto;
mname = btf_name_by_offset(btf, member->name_off);
if (!*mname) {
pr_warn("anon member in struct %s is not supported\n",
st_ops->name);
break;
}
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;
}
func_proto = btf_type_resolve_func_ptr(btf,
member->type,
NULL);
if (func_proto &&
btf_distill_func_proto(log, btf,
func_proto, mname,
&st_ops->func_models[i])) {
pr_warn("Error in parsing func ptr %s in struct %s\n",
mname, st_ops->name);
break;
}
}
if (i == btf_type_vlen(t)) {
if (st_ops->init(btf)) {
pr_warn("Error in init bpf_struct_ops %s\n",
st_ops->name);
} else {
st_ops->type_id = type_id;
st_ops->type = t;
st_ops->value_id = value_id;
st_ops->value_type = btf_type_by_id(btf,
value_id);
}
}
}
void bpf_struct_ops_init(struct btf *btf, struct bpf_verifier_log *log)
{
struct bpf_struct_ops *st_ops;
s32 module_id;
u32 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);
@ -127,85 +207,14 @@ void bpf_struct_ops_init(struct btf *btf, struct bpf_verifier_log *log)
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");
pr_warn("Cannot find struct module in %s\n", btf_get_name(btf));
return;
}
module_type = btf_type_by_id(btf, module_id);
for (i = 0; i < ARRAY_SIZE(bpf_struct_ops); i++) {
st_ops = bpf_struct_ops[i];
if (strlen(st_ops->name) + VALUE_PREFIX_LEN >=
sizeof(value_name)) {
pr_warn("struct_ops name %s is too long\n",
st_ops->name);
continue;
}
sprintf(value_name, "%s%s", VALUE_PREFIX, st_ops->name);
value_id = btf_find_by_name_kind(btf, value_name,
BTF_KIND_STRUCT);
if (value_id < 0) {
pr_warn("Cannot find struct %s in btf_vmlinux\n",
value_name);
continue;
}
type_id = btf_find_by_name_kind(btf, st_ops->name,
BTF_KIND_STRUCT);
if (type_id < 0) {
pr_warn("Cannot find struct %s in btf_vmlinux\n",
st_ops->name);
continue;
}
t = btf_type_by_id(btf, type_id);
if (btf_type_vlen(t) > BPF_STRUCT_OPS_MAX_NR_MEMBERS) {
pr_warn("Cannot support #%u members in struct %s\n",
btf_type_vlen(t), st_ops->name);
continue;
}
for_each_member(j, t, member) {
const struct btf_type *func_proto;
mname = btf_name_by_offset(btf, member->name_off);
if (!*mname) {
pr_warn("anon member in struct %s is not supported\n",
st_ops->name);
break;
}
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;
}
func_proto = btf_type_resolve_func_ptr(btf,
member->type,
NULL);
if (func_proto &&
btf_distill_func_proto(log, btf,
func_proto, mname,
&st_ops->func_models[j])) {
pr_warn("Error in parsing func ptr %s in struct %s\n",
mname, st_ops->name);
break;
}
}
if (j == btf_type_vlen(t)) {
if (st_ops->init(btf)) {
pr_warn("Error in init bpf_struct_ops %s\n",
st_ops->name);
} else {
st_ops->type_id = type_id;
st_ops->type = t;
st_ops->value_id = value_id;
st_ops->value_type = btf_type_by_id(btf,
value_id);
}
}
bpf_struct_ops_init_one(st_ops, btf, log);
}
}

5
kernel/bpf/btf.c
View file

@ -1707,6 +1707,11 @@ static void btf_free_rcu(struct rcu_head *rcu)
btf_free(btf);
}
const char *btf_get_name(const struct btf *btf)
{
return btf->name;
}
void btf_get(struct btf *btf)
{
refcount_inc(&btf->refcnt);