On 2/15/21 5:12 PM, Ilya Leoshkevich wrote:
The logic follows that of BTF_KIND_INT most of the time. Sanitization replaces BTF_KIND_FLOATs with equally-sized BTF_KIND_INTs on older kernels. Signed-off-by: Ilya Leoshkevich <iii@xxxxxxxxxxxxx> --- tools/lib/bpf/btf.c | 44 +++++++++++++++++++++++++++++++++ tools/lib/bpf/btf.h | 8 ++++++ tools/lib/bpf/btf_dump.c | 4 +++ tools/lib/bpf/libbpf.c | 29 +++++++++++++++++++++- tools/lib/bpf/libbpf.map | 5 ++++ tools/lib/bpf/libbpf_internal.h | 2 ++ 6 files changed, 91 insertions(+), 1 deletion(-) diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index d9c10830d749..07a30e98c3de 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -291,6 +291,7 @@ static int btf_type_size(const struct btf_type *t) case BTF_KIND_PTR: case BTF_KIND_TYPEDEF: case BTF_KIND_FUNC: + case BTF_KIND_FLOAT: return base_size; case BTF_KIND_INT: return base_size + sizeof(__u32); @@ -338,6 +339,7 @@ static int btf_bswap_type_rest(struct btf_type *t) case BTF_KIND_PTR: case BTF_KIND_TYPEDEF: case BTF_KIND_FUNC: + case BTF_KIND_FLOAT: return 0; case BTF_KIND_INT: *(__u32 *)(t + 1) = bswap_32(*(__u32 *)(t + 1)); @@ -578,6 +580,7 @@ __s64 btf__resolve_size(const struct btf *btf, __u32 type_id) case BTF_KIND_UNION: case BTF_KIND_ENUM: case BTF_KIND_DATASEC: + case BTF_KIND_FLOAT: size = t->size; goto done; case BTF_KIND_PTR: @@ -621,6 +624,7 @@ int btf__align_of(const struct btf *btf, __u32 id) switch (kind) { case BTF_KIND_INT: case BTF_KIND_ENUM: + case BTF_KIND_FLOAT: return min(btf_ptr_sz(btf), (size_t)t->size); case BTF_KIND_PTR: return btf_ptr_sz(btf); @@ -2373,6 +2377,42 @@ int btf__add_datasec(struct btf *btf, const char *name, __u32 byte_sz) return btf_commit_type(btf, sz); }+/*+ * Append new BTF_KIND_FLOAT type with: + * - *name* - non-empty, non-NULL type name; + * - *sz* - size of the type, in bytes; + * Returns: + * - >0, type ID of newly added BTF type; + * - <0, on error. + */ +int btf__add_float(struct btf *btf, const char *name, size_t byte_sz) +{ + struct btf_type *t; + int sz, name_off; + + /* non-empty name */ + if (!name || !name[0]) + return -EINVAL;
Do we want to ensure byte_sz to be 2/4/8/16? Currently, the int type supports 1/2/4/8/16. In LLVM, the following are supported float types: case BuiltinType::Half: case BuiltinType::Float: case BuiltinType::LongDouble: case BuiltinType::Float16: case BuiltinType::BFloat16: case BuiltinType::Float128: case BuiltinType::Double:
+ + if (btf_ensure_modifiable(btf)) + return -ENOMEM; + + sz = sizeof(struct btf_type); + t = btf_add_type_mem(btf, sz); + if (!t) + return -ENOMEM; + + name_off = btf__add_str(btf, name); + if (name_off < 0) + return name_off; + + t->name_off = name_off; + t->info = btf_type_info(BTF_KIND_FLOAT, 0, 0); + t->size = byte_sz; + + return btf_commit_type(btf, sz); +} +
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