tools: bpftool: refactor btf_dumper_int_bits()

The core dump funcitonality in btf_dumper_int_bits() is
refactored into a separate function btf_dumper_bitfield()
which will be used by the next patch.

Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

diff --git a/tools/bpf/bpftool/btf_dumper.c b/tools/bpf/bpftool/btf_dumper.c
index 5cdb2ef..06e3d2b 100644 (file)
--- a/tools/bpf/bpftool/btf_dumper.c
+++ b/tools/bpf/bpftool/btf_dumper.c
@@ -73,20 +73,17 @@ static int btf_dumper_array(const struct btf_dumper *d, __u32 type_id,
        return ret;
 }
 
-static void btf_dumper_int_bits(__u32 int_type, __u8 bit_offset,
+static void btf_dumper_bitfield(__u32 nr_bits, __u8 bit_offset,
                                const void *data, json_writer_t *jw,
                                bool is_plain_text)
 {
        int left_shift_bits, right_shift_bits;
-       int nr_bits = BTF_INT_BITS(int_type);
-       int total_bits_offset;
        int bytes_to_copy;
        int bits_to_copy;
        __u64 print_num;
 
-       total_bits_offset = bit_offset + BTF_INT_OFFSET(int_type);
-       data += BITS_ROUNDDOWN_BYTES(total_bits_offset);
-       bit_offset = BITS_PER_BYTE_MASKED(total_bits_offset);
+       data += BITS_ROUNDDOWN_BYTES(bit_offset);
+       bit_offset = BITS_PER_BYTE_MASKED(bit_offset);
        bits_to_copy = bit_offset + nr_bits;
        bytes_to_copy = BITS_ROUNDUP_BYTES(bits_to_copy);
 
@@ -109,6 +106,22 @@ static void btf_dumper_int_bits(__u32 int_type, __u8 bit_offset,
                jsonw_printf(jw, "%llu", print_num);
 }
 
+
+static void btf_dumper_int_bits(__u32 int_type, __u8 bit_offset,
+                               const void *data, json_writer_t *jw,
+                               bool is_plain_text)
+{
+       int nr_bits = BTF_INT_BITS(int_type);
+       int total_bits_offset;
+
+       /* bits_offset is at most 7.
+        * BTF_INT_OFFSET() cannot exceed 64 bits.
+        */
+       total_bits_offset = bit_offset + BTF_INT_OFFSET(int_type);
+       btf_dumper_bitfield(nr_bits, total_bits_offset, data, jw,
+                           is_plain_text);
+}
+
 static int btf_dumper_int(const struct btf_type *t, __u8 bit_offset,
                          const void *data, json_writer_t *jw,
                          bool is_plain_text)