On 9/20/23 8:59 AM, thinker.li@xxxxxxxxx wrote:
From: Kui-Feng Lee <thinker.li@xxxxxxxxx>
Use struct_ops registered and stored in module btf instead of static ones.
Both bpf_dummy_ops and bpf_tcp_ca switches to calling the registration
function instead of listed in bpf_struct_ops_types.h.
Signed-off-by: Kui-Feng Lee <thinker.li@xxxxxxxxx>
---
kernel/bpf/bpf_struct_ops.c | 114 ++++++++++++++++++------------
kernel/bpf/bpf_struct_ops_types.h | 12 ----
net/bpf/bpf_dummy_struct_ops.c | 12 +++-
net/ipv4/bpf_tcp_ca.c | 20 +++++-
4 files changed, 94 insertions(+), 64 deletions(-)
delete mode 100644 kernel/bpf/bpf_struct_ops_types.h
diff --git a/kernel/bpf/bpf_struct_ops.c b/kernel/bpf/bpf_struct_ops.c
index fb684d2ee99d..8b5c859377e9 100644
--- a/kernel/bpf/bpf_struct_ops.c
+++ b/kernel/bpf/bpf_struct_ops.c
@@ -59,35 +59,6 @@ static DEFINE_MUTEX(update_mutex);
#define VALUE_PREFIX "bpf_struct_ops_"
#define VALUE_PREFIX_LEN (sizeof(VALUE_PREFIX) - 1)
-/* bpf_struct_ops_##_name (e.g. bpf_struct_ops_tcp_congestion_ops) is
- * the map's value exposed to the userspace and its btf-type-id is
- * stored at the map->btf_vmlinux_value_type_id.
- *
- */
-#define BPF_STRUCT_OPS_TYPE(_name) \
-extern struct bpf_struct_ops bpf_##_name; \
- \
-struct bpf_struct_ops_##_name { \
- BPF_STRUCT_OPS_COMMON_VALUE; \
- struct _name data ____cacheline_aligned_in_smp; \
-};
-#include "bpf_struct_ops_types.h"
-#undef BPF_STRUCT_OPS_TYPE
-
-enum {
-#define BPF_STRUCT_OPS_TYPE(_name) BPF_STRUCT_OPS_TYPE_##_name,
-#include "bpf_struct_ops_types.h"
-#undef BPF_STRUCT_OPS_TYPE
- __NR_BPF_STRUCT_OPS_TYPE,
-};
-
-static struct bpf_struct_ops * const bpf_struct_ops[] = {
-#define BPF_STRUCT_OPS_TYPE(_name) \
- [BPF_STRUCT_OPS_TYPE_##_name] = &bpf_##_name,
-#include "bpf_struct_ops_types.h"
-#undef BPF_STRUCT_OPS_TYPE
-};
-
const struct bpf_verifier_ops bpf_struct_ops_verifier_ops = {
};
@@ -264,14 +235,11 @@ static void bpf_struct_ops_init_one(struct bpf_struct_ops *st_ops,
void bpf_struct_ops_init(struct btf *btf, struct bpf_verifier_log *log)
{
- struct bpf_struct_ops *st_ops;
+#if defined(CONFIG_BPF_JIT) && defined(CONFIG_NET)
+ extern struct bpf_struct_ops_mod bpf_testmod_struct_ops;
+ int ret;
+#endif
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);
-#include "bpf_struct_ops_types.h"
-#undef BPF_STRUCT_OPS_TYPE
module_id = btf_find_by_name_kind(btf, "module", BTF_KIND_STRUCT);
if (module_id < 0) {
@@ -280,43 +248,95 @@ void bpf_struct_ops_init(struct btf *btf, struct bpf_verifier_log *log)
}
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];
- bpf_struct_ops_init_one(st_ops, btf, log);
+#if defined(CONFIG_BPF_JIT) && defined(CONFIG_NET)
+ ret = register_bpf_struct_ops(&bpf_testmod_struct_ops);
What is stopping the 'register_bpf_struct_ops(&bpf_testmod_struct_ops)' to be
done in bpf_dummy_struct_ops.c instead of here?
I am hoping bpf_dummy_struct_ops.c can eventually be moved out to
bpf_testmod_struct_ops.c but it is better to leave it as a followup later.
+ if (ret)
+ pr_warn("Cannot register bpf_testmod_struct_ops\n");
+#endif
+}
+
+int register_bpf_struct_ops(struct bpf_struct_ops_mod *mod)
+{
+ struct bpf_struct_ops *st_ops = mod->st_ops;
+ struct bpf_verifier_log *log;
+ struct btf *btf;
+ int err;
+
+ if (mod->st_ops == NULL ||
+ mod->owner == NULL)
+ return -EINVAL;
+
+ log = kzalloc(sizeof(*log), GFP_KERNEL | __GFP_NOWARN);
+ if (!log) {
+ err = -ENOMEM;
+ goto errout;
+ }
+
+ log->level = BPF_LOG_KERNEL;
+
+ btf = btf_get_module_btf(mod->owner);
+ if (!btf) {
+ err = -EINVAL;
+ goto errout;
}
+
+ bpf_struct_ops_init_one(st_ops, btf, log);
+
+ btf_put(btf);
+
+ st_ops->owner = mod->owner;
+ err = btf_add_struct_ops(st_ops, st_ops->owner);
+
+errout:
+ kfree(log);
+
+ return err;
}
+EXPORT_SYMBOL_GPL(register_bpf_struct_ops);
extern struct btf *btf_vmlinux;
static const struct bpf_struct_ops *
bpf_struct_ops_find_value(u32 value_id, struct btf *btf)
{
+ const struct bpf_struct_ops *st_ops = NULL;
+ const struct bpf_struct_ops **st_ops_list;
unsigned int i;
+ u32 cnt = 0;
if (!value_id || !btf_vmlinux)
return NULL;
- for (i = 0; i < ARRAY_SIZE(bpf_struct_ops); i++) {
- if (bpf_struct_ops[i]->value_id == value_id)
- return bpf_struct_ops[i];
+ st_ops_list = btf_get_struct_ops(btf, &cnt);
+ for (i = 0; i < cnt; i++) {
+ if (st_ops_list[i]->value_id == value_id) {
+ st_ops = st_ops_list[i];
+ break;
+ }
}
- return NULL;
+ return st_ops;
}
const struct bpf_struct_ops *bpf_struct_ops_find(u32 type_id, struct btf *btf)
{
+ const struct bpf_struct_ops *st_ops = NULL;
+ const struct bpf_struct_ops **st_ops_list;
unsigned int i;
+ u32 cnt;
if (!type_id || !btf_vmlinux)
return NULL;
- for (i = 0; i < ARRAY_SIZE(bpf_struct_ops); i++) {
- if (bpf_struct_ops[i]->type_id == type_id)
- return bpf_struct_ops[i];
+ st_ops_list = btf_get_struct_ops(btf, &cnt);
+ for (i = 0; i < cnt; i++) {
+ if (st_ops_list[i]->type_id == type_id) {
+ st_ops = st_ops_list[i];
+ break;
+ }
}
- return NULL;
+ return st_ops;
}
static int bpf_struct_ops_map_get_next_key(struct bpf_map *map, void *key,
diff --git a/kernel/bpf/bpf_struct_ops_types.h b/kernel/bpf/bpf_struct_ops_types.h
deleted file mode 100644
index 5678a9ddf817..000000000000
--- a/kernel/bpf/bpf_struct_ops_types.h
+++ /dev/null
@@ -1,12 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/* internal file - do not include directly */
-
-#ifdef CONFIG_BPF_JIT
-#ifdef CONFIG_NET
-BPF_STRUCT_OPS_TYPE(bpf_dummy_ops)
-#endif
-#ifdef CONFIG_INET
-#include <net/tcp.h>
-BPF_STRUCT_OPS_TYPE(tcp_congestion_ops)
-#endif
-#endif
diff --git a/net/bpf/bpf_dummy_struct_ops.c b/net/bpf/bpf_dummy_struct_ops.c
index 5918d1b32e19..9cb982c67c4c 100644
--- a/net/bpf/bpf_dummy_struct_ops.c
+++ b/net/bpf/bpf_dummy_struct_ops.c
@@ -7,7 +7,7 @@
#include <linux/bpf.h>
#include <linux/btf.h>
-extern struct bpf_struct_ops bpf_bpf_dummy_ops;
+static struct bpf_struct_ops bpf_bpf_dummy_ops;
/* A common type for test_N with return value in bpf_dummy_ops */
typedef int (*dummy_ops_test_ret_fn)(struct bpf_dummy_ops_state *state, ...);
@@ -218,9 +218,12 @@ static int bpf_dummy_reg(void *kdata)
static void bpf_dummy_unreg(void *kdata)
{
+ BTF_STRUCT_OPS_TYPE_EMIT(bpf_dummy_ops);
}
-struct bpf_struct_ops bpf_bpf_dummy_ops = {
+DEFINE_STRUCT_OPS_VALUE_TYPE(bpf_dummy_ops);
+
+static struct bpf_struct_ops bpf_bpf_dummy_ops = {
.verifier_ops = &bpf_dummy_verifier_ops,
.init = bpf_dummy_init,
.check_member = bpf_dummy_ops_check_member,
@@ -229,3 +232,8 @@ struct bpf_struct_ops bpf_bpf_dummy_ops = {
.unreg = bpf_dummy_unreg,
.name = "bpf_dummy_ops",
};
+
+struct bpf_struct_ops_mod bpf_testmod_struct_ops = {
+ .st_ops = &bpf_bpf_dummy_ops,
+ .owner = THIS_MODULE,
+};
diff --git a/net/ipv4/bpf_tcp_ca.c b/net/ipv4/bpf_tcp_ca.c
index 39dcccf0f174..9947323f3e22 100644
--- a/net/ipv4/bpf_tcp_ca.c
+++ b/net/ipv4/bpf_tcp_ca.c
@@ -12,7 +12,7 @@
#include <net/bpf_sk_storage.h>
/* "extern" is to avoid sparse warning. It is only used in bpf_struct_ops.c. */
-extern struct bpf_struct_ops bpf_tcp_congestion_ops;
+static struct bpf_struct_ops bpf_tcp_congestion_ops;
static u32 unsupported_ops[] = {
offsetof(struct tcp_congestion_ops, get_info),
@@ -271,7 +271,9 @@ static int bpf_tcp_ca_validate(void *kdata)
return tcp_validate_congestion_control(kdata);
}
-struct bpf_struct_ops bpf_tcp_congestion_ops = {
+DEFINE_STRUCT_OPS_VALUE_TYPE(tcp_congestion_ops);
+
+static struct bpf_struct_ops bpf_tcp_congestion_ops = {
.verifier_ops = &bpf_tcp_ca_verifier_ops,
.reg = bpf_tcp_ca_reg,
.unreg = bpf_tcp_ca_unreg,
@@ -283,8 +285,20 @@ struct bpf_struct_ops bpf_tcp_congestion_ops = {
.name = "tcp_congestion_ops",
};
+static struct bpf_struct_ops_mod bpf_tcp_ca_ops_mod = {
+ .st_ops = &bpf_tcp_congestion_ops,
+ .owner = THIS_MODULE,
+};
+
static int __init bpf_tcp_ca_kfunc_init(void)
{
- return register_btf_kfunc_id_set(BPF_PROG_TYPE_STRUCT_OPS, &bpf_tcp_ca_kfunc_set);
+ int ret;
+
+ BTF_STRUCT_OPS_TYPE_EMIT(tcp_congestion_ops);
+
+ ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_STRUCT_OPS, &bpf_tcp_ca_kfunc_set);
+ ret = ret ?: register_bpf_struct_ops(&bpf_tcp_ca_ops_mod);
+
+ return ret;
}
late_initcall(bpf_tcp_ca_kfunc_init);
