Support direct fixed-size (and for now, read-only) memory access when
kfunc's return type is a pointer to non-struct type. Calculate type size
and let BPF program access that many bytes directly. This is crucial for
numbers iterator.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230302235015.2044271-13-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
return -EFAULT;
}
} else if (!__btf_type_is_struct(ptr_type)) {
+ if (!meta.r0_size) {
+ __u32 sz;
+
+ if (!IS_ERR(btf_resolve_size(desc_btf, ptr_type, &sz))) {
+ meta.r0_size = sz;
+ meta.r0_rdonly = true;
+ }
+ }
if (!meta.r0_size) {
ptr_type_name = btf_name_by_offset(desc_btf,
ptr_type->name_off);