From: Hou Tao <houtao1@xxxxxxxxxx>
Add BPF_DYNPTR in btf_field_type to support bpf_dynptr in map key. The
parsing of bpf_dynptr in btf will be done in the following patch, and
the patch only adds two helpers: btf_new_bpf_dynptr_record() creates an
btf record which only includes a bpf_dynptr and btf_type_is_dynptr()
checks whether the btf_type is a bpf_dynptr or not.
Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx>
---
include/linux/bpf.h | 1 +
include/linux/btf.h | 2 ++
kernel/bpf/btf.c | 44 ++++++++++++++++++++++++++++++++++++++------
3 files changed, 41 insertions(+), 6 deletions(-)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 2083905a4e9fa..0b65c98d8b7d5 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -206,6 +206,7 @@ enum btf_field_type {
BPF_WORKQUEUE = (1 << 10),
BPF_UPTR = (1 << 11),
BPF_RES_SPIN_LOCK = (1 << 12),
+ BPF_DYNPTR = (1 << 13),
};
typedef void (*btf_dtor_kfunc_t)(void *);
diff --git a/include/linux/btf.h b/include/linux/btf.h
index ebc0c0c9b9446..2ab48b377d312 100644
--- a/include/linux/btf.h
+++ b/include/linux/btf.h
@@ -226,8 +226,10 @@ bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s,
u32 expected_offset, u32 expected_size);
struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type *t,
u32 field_mask, u32 value_size);
+struct btf_record *btf_new_bpf_dynptr_record(void);
int btf_check_and_fixup_fields(const struct btf *btf, struct btf_record *rec);
bool btf_type_is_void(const struct btf_type *t);
+bool btf_type_is_dynptr(const struct btf *btf, const struct btf_type *t);
s32 btf_find_by_name_kind(const struct btf *btf, const char *name, u8 kind);
s32 bpf_find_btf_id(const char *name, u32 kind, struct btf **btf_p);
const struct btf_type *btf_type_skip_modifiers(const struct btf *btf,
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 16ba36f34dfab..1054a1e27e9d3 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -3939,6 +3939,17 @@ static int btf_field_cmp(const void *_a, const void *_b, const void *priv)
return 0;
}
+static void btf_init_record(struct btf_record *record)
+{
+ record->cnt = 0;
+ record->field_mask = 0;
+ record->spin_lock_off = -EINVAL;
+ record->res_spin_lock_off = -EINVAL;
+ record->timer_off = -EINVAL;
+ record->wq_off = -EINVAL;
+ record->refcount_off = -EINVAL;
+}
+
struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type *t,
u32 field_mask, u32 value_size)
{
@@ -3957,15 +3968,11 @@ struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type
/* This needs to be kzalloc to zero out padding and unused fields, see
* comment in btf_record_equal.
*/
- rec = kzalloc(offsetof(struct btf_record, fields[cnt]), GFP_KERNEL | __GFP_NOWARN);
+ rec = kzalloc(struct_size(rec, fields, cnt), GFP_KERNEL | __GFP_NOWARN);
if (!rec)
return ERR_PTR(-ENOMEM);
- rec->spin_lock_off = -EINVAL;
- rec->res_spin_lock_off = -EINVAL;
- rec->timer_off = -EINVAL;
- rec->wq_off = -EINVAL;
- rec->refcount_off = -EINVAL;
+ btf_init_record(rec);
for (i = 0; i < cnt; i++) {
field_type_size = btf_field_type_size(info_arr[i].type);
if (info_arr[i].off + field_type_size > value_size) {
@@ -4067,6 +4074,25 @@ struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type
return ERR_PTR(ret);
}
+struct btf_record *btf_new_bpf_dynptr_record(void)
+{
+ struct btf_record *record;
+
+ record = kzalloc(struct_size(record, fields, 1), GFP_KERNEL | __GFP_NOWARN);
+ if (!record)
+ return ERR_PTR(-ENOMEM);
+
+ btf_init_record(record);
+
+ record->cnt = 1;
+ record->field_mask = BPF_DYNPTR;
+ record->fields[0].offset = 0;
+ record->fields[0].size = sizeof(struct bpf_dynptr);
+ record->fields[0].type = BPF_DYNPTR;
+
+ return record;
+}
+
int btf_check_and_fixup_fields(const struct btf *btf, struct btf_record *rec)
{
int i;
@@ -7562,6 +7588,12 @@ static bool btf_is_dynptr_ptr(const struct btf *btf, const struct btf_type *t)
return false;
}
+bool btf_type_is_dynptr(const struct btf *btf, const struct btf_type *t)
+{
+ return __btf_type_is_struct(t) && t->size == sizeof(struct bpf_dynptr) &&
+ !strcmp(__btf_name_by_offset(btf, t->name_off), "bpf_dynptr");
+}
+
struct bpf_cand_cache {
const char *name;
u32 name_len;
--
2.29.2
