On Mon, Apr 22, 2024 at 7:46 AM Xin Liu <liuxin350@xxxxxxxxxx> wrote: > > In btf__add_int, the size of the new btf_kind_int type is limited. > When the size is greater than 16, btf__add_int fails to be added > and -EINVAL is returned. This is usually effective. > > However, when the built-in type __builtin_aarch64_simd_xi in the > NEON instruction is used in the code in the arm64 system, the value > of DW_AT_byte_size is 64. This causes btf__add_int to fail to > properly add btf information to it. > > like this: > ... > <1><cf>: Abbrev Number: 2 (DW_TAG_base_type) > <d0> DW_AT_byte_size : 64 // over max size 16 > <d1> DW_AT_encoding : 5 (signed) > <d2> DW_AT_name : (indirect string, offset: 0x53): __builtin_aarch64_simd_xi > <1><d6>: Abbrev Number: 0 > ... > > An easier way to solve this problem is to treat it as a base type > and set byte_size to 64. This patch is modified along these lines. > > Fixes: 4a3b33f8579a ("libbpf: Add BTF writing APIs") > Signed-off-by: Xin Liu <liuxin350@xxxxxxxxxx> > --- > tools/lib/bpf/btf.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c > index 2d0840ef599a..0af121293b65 100644 > --- a/tools/lib/bpf/btf.c > +++ b/tools/lib/bpf/btf.c > @@ -1934,7 +1934,7 @@ int btf__add_int(struct btf *btf, const char *name, size_t byte_sz, int encoding > if (!name || !name[0]) > return libbpf_err(-EINVAL); > /* byte_sz must be power of 2 */ > - if (!byte_sz || (byte_sz & (byte_sz - 1)) || byte_sz > 16) > + if (!byte_sz || (byte_sz & (byte_sz - 1)) || byte_sz > 64) maybe we should just remove byte_sz upper limit? We can probably imagine 256-byte integers at some point, so why bother artificially restricting it? pw-bot: cr > return libbpf_err(-EINVAL); > if (encoding & ~(BTF_INT_SIGNED | BTF_INT_CHAR | BTF_INT_BOOL)) > return libbpf_err(-EINVAL); > -- > 2.33.0 >