[PATCH bpf-next v11 06/13] bpf: lookup struct_ops types from a given module BTF.

thinker.li
2023-11-06T20:13:11Z

From: Kui-Feng Lee <thinker.li@gmail.com>

This is a preparation for searching for struct_ops types from a specified
module. BTF is always btf_vmlinux now. This patch passes a pointer of BTF
to bpf_struct_ops_find_value() and bpf_struct_ops_find(). Once the new
registration API of struct_ops types is used, other BTFs besides
btf_vmlinux can also be passed to them.

Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
---
include/linux/bpf.h | 4 ++--
kernel/bpf/bpf_struct_ops.c | 11 ++++++-----
kernel/bpf/verifier.c | 2 +-
3 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index b55e27162df0..f0ed874d5ac3 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1641,7 +1641,7 @@ struct bpf_struct_ops_desc {

#if defined(CONFIG_BPF_JIT) && defined(CONFIG_BPF_SYSCALL)
#define BPF_MODULE_OWNER ((void *)((0xeB9FUL << 2) + POISON_POINTER_DELTA))
-const struct bpf_struct_ops_desc *bpf_struct_ops_find(u32 type_id);
+const struct bpf_struct_ops_desc *bpf_struct_ops_find(struct btf *btf, u32 type_id);
void bpf_struct_ops_init(struct btf *btf, struct bpf_verifier_log *log);
bool bpf_struct_ops_get(const void *kdata);
void bpf_struct_ops_put(const void *kdata);
@@ -1684,7 +1684,7 @@ int bpf_struct_ops_test_run(struct bpf_prog *prog, const union bpf_attr *kattr,
union bpf_attr __user *uattr);
#endif
#else
-static inline const struct bpf_struct_ops_desc *bpf_struct_ops_find(u32 type_id)
+static inline const struct bpf_struct_ops_desc *bpf_struct_ops_find(struct btf *btf, u32 type_id)
{
return NULL;
}
diff --git a/kernel/bpf/bpf_struct_ops.c b/kernel/bpf/bpf_struct_ops.c
index a0291877a792..4ba6181ed1c4 100644
--- a/kernel/bpf/bpf_struct_ops.c
+++ b/kernel/bpf/bpf_struct_ops.c
@@ -221,11 +221,11 @@ void bpf_struct_ops_init(struct btf *btf, struct bpf_verifier_log *log)
extern struct btf *btf_vmlinux;

static const struct bpf_struct_ops_desc *
-bpf_struct_ops_find_value(u32 value_id)
+bpf_struct_ops_find_value(struct btf *btf, u32 value_id)
{
unsigned int i;

- if (!value_id || !btf_vmlinux)
+ if (!value_id || !btf)
return NULL;

for (i = 0; i < ARRAY_SIZE(bpf_struct_ops); i++) {
@@ -236,11 +236,12 @@ bpf_struct_ops_find_value(u32 value_id)
return NULL;
}

-const struct bpf_struct_ops_desc *bpf_struct_ops_find(u32 type_id)
+const struct bpf_struct_ops_desc *
+bpf_struct_ops_find(struct btf *btf, u32 type_id)
{
unsigned int i;

- if (!type_id || !btf_vmlinux)
+ if (!type_id || !btf)
return NULL;

for (i = 0; i < ARRAY_SIZE(bpf_struct_ops); i++) {
@@ -676,7 +677,7 @@ static struct bpf_map *bpf_struct_ops_map_alloc(union bpf_attr *attr)
struct bpf_map *map;
int ret;

- st_ops_desc = bpf_struct_ops_find_value(attr->btf_vmlinux_value_type_id);
+ st_ops_desc = bpf_struct_ops_find_value(btf_vmlinux, attr->btf_vmlinux_value_type_id);
if (!st_ops_desc)
return ERR_PTR(-ENOTSUPP);

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 290e3a7ee72f..bdd166cab977 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -20094,7 +20094,7 @@ static int check_struct_ops_btf_id(struct bpf_verifier_env *env)
}

btf_id = prog->aux->attach_btf_id;
- st_ops_desc = bpf_struct_ops_find(btf_id);
+ st_ops_desc = bpf_struct_ops_find(btf_vmlinux, btf_id);
if (!st_ops_desc) {
verbose(env, "attach_btf_id %u is not a supported struct\n",
btf_id);
--
2.34.1