when using gtags-cscope to lookup xxx reference in vim, It has not displaying the function call xxx

when I use cscope to lookup the reference of "kernel_read", in kernel
code, vim quickfix window is like:
==============================
 1 arch/mips/kernel/elf.c|121| <<arch_elf_pt_proc>> ret = kernel_read(elf, &abiflags, sizeof(abiflags), &pos);                                                                                                                                                        2 arch/um/drivers/mconsole_kern.c|152| <<mconsole_proc>> len = kernel_read(file, buf, PAGE_SIZE - 1, &pos);
  3 arch/x86/ia32/ia32_aout.c|414| <<load_aout_library>> error = kernel_read(file, &ex, sizeof(ex), &pos);
  4 drivers/mtd/nand/raw/nandsim.c|1364| <<read_file>> tx = kernel_read(file, buf, count, &pos);
  5 drivers/usb/gadget/function/f_mass_storage.c|694| <<do_read>> nread = kernel_read(curlun->filp, bh->buf, amount,
  6 drivers/usb/gadget/function/f_mass_storage.c|1028| <<do_verify>> nread = kernel_read(curlun->filp, bh->buf, amount,
  7 fs/binfmt_aout.c|350| <<load_aout_library>> error = kernel_read(file, &ex, sizeof(ex), &pos);
  8 fs/binfmt_elf.c|446| <<load_elf_phdrs>> retval = kernel_read(elf_file, elf_phdata, size, &pos);
  9 fs/binfmt_elf.c|768| <<load_elf_binary>> retval = kernel_read(bprm->file, elf_interpreter,
 10 fs/binfmt_elf.c|794| <<load_elf_binary>> retval = kernel_read(interpreter, &loc->interp_elf_ex,
 ================================

 but use gtags-cscope, vim quickfix window is like:
 ================================
1 drivers/crypto/ccp/sev-dev.c|295| <<kernel_read>> nread = kernel_read(fp, sev_init_ex_buffer, NV_LENGTH, NULL);
2 drivers/mtd/nand/raw/nandsim.c|1352| <<kernel_read>> tx = kernel_read(file, buf, count, &pos);
3 drivers/usb/gadget/function/f_mass_storage.c|684| <<kernel_read>> nread = kernel_read(curlun->filp, bh->buf, amount,
4 drivers/usb/gadget/function/f_mass_storage.c|1021| <<kernel_read>> nread = kernel_read(curlun->filp, bh->buf, amount,
5 fs/binfmt_elf.c|469| <<kernel_read>> rv = kernel_read(file, buf, len, &pos);
6 fs/binfmt_elf.c|786| <<kernel_read>> n = kernel_read(f, &note, phdr->p_filesz, &pos);
 ================================


the function in "<<*>>" is different, I can't get the functon who call the "kernel_read"