Add enum64 parsing support and two new enum64 public APIs:
btf__add_enum64
btf__add_enum64_value
Also add support of signedness for BTF_KIND_ENUM. The
BTF_KIND_ENUM API signatures are not changed. The signedness
will be changed from unsigned to signed if btf__add_enum_value()
finds any negative values.
Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
Signed-off-by: Yonghong Song <yhs@xxxxxx>
---
tools/lib/bpf/btf.c | 103 +++++++++++++++++++++++++++++++++++++++
tools/lib/bpf/btf.h | 12 +++++
tools/lib/bpf/libbpf.map | 2 +
3 files changed, 117 insertions(+)
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 1972d0c65e0c..8676efb2baba 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -305,6 +305,8 @@ static int btf_type_size(const struct btf_type *t)
return base_size + sizeof(__u32);
case BTF_KIND_ENUM:
return base_size + vlen * sizeof(struct btf_enum);
+ case BTF_KIND_ENUM64:
+ return base_size + vlen * sizeof(struct btf_enum64);
case BTF_KIND_ARRAY:
return base_size + sizeof(struct btf_array);
case BTF_KIND_STRUCT:
@@ -334,6 +336,7 @@ static void btf_bswap_type_base(struct btf_type *t)
static int btf_bswap_type_rest(struct btf_type *t)
{
struct btf_var_secinfo *v;
+ struct btf_enum64 *e64;
struct btf_member *m;
struct btf_array *a;
struct btf_param *p;
@@ -361,6 +364,13 @@ static int btf_bswap_type_rest(struct btf_type *t)
e->val = bswap_32(e->val);
}
return 0;
+ case BTF_KIND_ENUM64:
+ for (i = 0, e64 = btf_enum64(t); i < vlen; i++, e64++) {
+ e64->name_off = bswap_32(e64->name_off);
+ e64->val_lo32 = bswap_32(e64->val_lo32);
+ e64->val_hi32 = bswap_32(e64->val_hi32);
+ }
+ return 0;
case BTF_KIND_ARRAY:
a = btf_array(t);
a->type = bswap_32(a->type);
@@ -611,6 +621,7 @@ __s64 btf__resolve_size(const struct btf *btf, __u32 type_id)
case BTF_KIND_STRUCT:
case BTF_KIND_UNION:
case BTF_KIND_ENUM:
+ case BTF_KIND_ENUM64:
case BTF_KIND_DATASEC:
case BTF_KIND_FLOAT:
size = t->size;
@@ -658,6 +669,7 @@ int btf__align_of(const struct btf *btf, __u32 id)
switch (kind) {
case BTF_KIND_INT:
case BTF_KIND_ENUM:
+ case BTF_KIND_ENUM64:
case BTF_KIND_FLOAT:
return min(btf_ptr_sz(btf), (size_t)t->size);
case BTF_KIND_PTR:
@@ -2176,6 +2188,10 @@ static int btf_add_enum_common(struct btf *btf, const char *name, __u32 byte_sz,
*/
int btf__add_enum(struct btf *btf, const char *name, __u32 byte_sz)
{
+ /*
+ * set the signedness to be unsigned, it will change to signed
+ * if any later enumerator is negative.
+ */
return btf_add_enum_common(btf, name, byte_sz, false, BTF_KIND_ENUM);
}
@@ -2226,6 +2242,82 @@ int btf__add_enum_value(struct btf *btf, const char *name, __s64 value)
t = btf_last_type(btf);
btf_type_inc_vlen(t);
+ /* if negative value, set signedness to signed */
+ if (value < 0)
+ t->info = btf_type_info(btf_kind(t), btf_vlen(t), true);
+
+ btf->hdr->type_len += sz;
+ btf->hdr->str_off += sz;
+ return 0;
+}
+
+/*
+ * Append new BTF_KIND_ENUM64 type with:
+ * - *name* - name of the enum, can be NULL or empty for anonymous enums;
+ * - *byte_sz* - size of the enum, in bytes.
+ * - *is_signed* - whether the enum values are signed or not;
+ *
+ * Enum initially has no enum values in it (and corresponds to enum forward
+ * declaration). Enumerator values can be added by btf__add_enum64_value()
+ * immediately after btf__add_enum64() succeeds.
+ *
+ * Returns:
+ * - >0, type ID of newly added BTF type;
+ * - <0, on error.
+ */
+int btf__add_enum64(struct btf *btf, const char *name, __u32 byte_sz,
+ bool is_signed)
+{
+ return btf_add_enum_common(btf, name, byte_sz, is_signed,
+ BTF_KIND_ENUM64);
+}
+
+/*
+ * Append new enum value for the current ENUM64 type with:
+ * - *name* - name of the enumerator value, can't be NULL or empty;
+ * - *value* - integer value corresponding to enum value *name*;
+ * Returns:
+ * - 0, on success;
+ * - <0, on error.
+ */
+int btf__add_enum64_value(struct btf *btf, const char *name, __u64 value)
+{
+ struct btf_enum64 *v;
+ struct btf_type *t;
+ int sz, name_off;
+
+ /* last type should be BTF_KIND_ENUM64 */
+ if (btf->nr_types == 0)
+ return libbpf_err(-EINVAL);
+ t = btf_last_type(btf);
+ if (!btf_is_enum64(t))
+ return libbpf_err(-EINVAL);
+
+ /* non-empty name */
+ if (!name || !name[0])
+ return libbpf_err(-EINVAL);
+
+ /* decompose and invalidate raw data */
+ if (btf_ensure_modifiable(btf))
+ return libbpf_err(-ENOMEM);
+
+ sz = sizeof(struct btf_enum64);
+ v = btf_add_type_mem(btf, sz);
+ if (!v)
+ return libbpf_err(-ENOMEM);
+
+ name_off = btf__add_str(btf, name);
+ if (name_off < 0)
+ return name_off;
+
+ v->name_off = name_off;
+ v->val_lo32 = (__u32)value;
+ v->val_hi32 = value >> 32;
+
+ /* update parent type's vlen */
+ t = btf_last_type(btf);
+ btf_type_inc_vlen(t);
+
btf->hdr->type_len += sz;
btf->hdr->str_off += sz;
return 0;
@@ -4737,6 +4829,7 @@ int btf_type_visit_type_ids(struct btf_type *t, type_id_visit_fn visit, void *ct
case BTF_KIND_INT:
case BTF_KIND_FLOAT:
case BTF_KIND_ENUM:
+ case BTF_KIND_ENUM64:
return 0;
case BTF_KIND_FWD:
@@ -4831,6 +4924,16 @@ int btf_type_visit_str_offs(struct btf_type *t, str_off_visit_fn visit, void *ct
}
break;
}
+ case BTF_KIND_ENUM64: {
+ struct btf_enum64 *m = btf_enum64(t);
+
+ for (i = 0, n = btf_vlen(t); i < n; i++, m++) {
+ err = visit(&m->name_off, ctx);
+ if (err)
+ return err;
+ }
+ break;
+ }
case BTF_KIND_FUNC_PROTO: {
struct btf_param *m = btf_params(t);
diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index 951ac7475794..a41463bf9060 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -215,6 +215,8 @@ LIBBPF_API int btf__add_field(struct btf *btf, const char *name, int field_type_
/* enum construction APIs */
LIBBPF_API int btf__add_enum(struct btf *btf, const char *name, __u32 bytes_sz);
LIBBPF_API int btf__add_enum_value(struct btf *btf, const char *name, __s64 value);
+LIBBPF_API int btf__add_enum64(struct btf *btf, const char *name, __u32 bytes_sz, bool is_signed);
+LIBBPF_API int btf__add_enum64_value(struct btf *btf, const char *name, __u64 value);
enum btf_fwd_kind {
BTF_FWD_STRUCT = 0,
@@ -454,6 +456,11 @@ static inline bool btf_is_enum(const struct btf_type *t)
return btf_kind(t) == BTF_KIND_ENUM;
}
+static inline bool btf_is_enum64(const struct btf_type *t)
+{
+ return btf_kind(t) == BTF_KIND_ENUM64;
+}
+
static inline bool btf_is_fwd(const struct btf_type *t)
{
return btf_kind(t) == BTF_KIND_FWD;
@@ -549,6 +556,11 @@ static inline struct btf_enum *btf_enum(const struct btf_type *t)
return (struct btf_enum *)(t + 1);
}
+static inline struct btf_enum64 *btf_enum64(const struct btf_type *t)
+{
+ return (struct btf_enum64 *)(t + 1);
+}
+
static inline struct btf_member *btf_members(const struct btf_type *t)
{
return (struct btf_member *)(t + 1);
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index 38e284ff057d..116a2a8ee7c2 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -462,6 +462,8 @@ LIBBPF_0.8.0 {
LIBBPF_1.0.0 {
global:
+ btf__add_enum64;
+ btf__add_enum64_value;
libbpf_bpf_attach_type_str;
libbpf_bpf_link_type_str;
libbpf_bpf_map_type_str;
--
2.30.2
