Re: [PATCH] synclink fix ldisc buffer argument

[Chen Gang <gang.chen@asianux.com>]

Hello Paul Fulghum:

it seems you are very busy,
  and can not get your reply for "checking length in function rx_get_buf".

so I suggest:
  design:
    to give it additional length checking in function rx_get_buf.
    if realy > max_frame_size, will return false (also need call free_rbufs).
  unit test plan:
    write a simple driver to integrate relative functions (already modified as design).
    pass compiling, and can succeed loading.
    and then
      call the relative function (rx_get_buf) with intended values
      check the work flow of our modification whether as expected.

at last, I still suggestion Paul Fulghum to provide the patch when he has free time.
  for synclink, he is more expert than me.
  for synclink, he can give better test.

  if still get no reply within an additonal week:
    I should provide the patch, it is my duty.
    I will be according to the patch which Paul Fulghum has already provided.
    and then add the "checking length in function rx_get_buf".


  Regards

gchen.

于 2012年12月05日 09:57, Chen Gang 写道:
> by the way:
>   does it also need check the length in function rx_get_buf ? 
>   (it seems not, but I am not quite sure, can you give a confirm ?)
> 
> 4779 /*
> 4780  * pass receive buffer (RAW synchronous mode) to tty layer
> 4781  * return true if buffer available, otherwise false
> 4782  */
> 4783 static bool rx_get_buf(struct slgt_info *info)
> 4784 {
> 4785         unsigned int i = info->rbuf_current;
> 4786         unsigned int count;
> 4787 
> 4788         if (!desc_complete(info->rbufs[i]))
> 4789                 return false;
> 4790         count = desc_count(info->rbufs[i]);
> 4791         switch(info->params.mode) {
> 4792         case MGSL_MODE_MONOSYNC:
> 4793         case MGSL_MODE_BISYNC:
> 4794         case MGSL_MODE_XSYNC:
> 4795                 /* ignore residue in byte synchronous modes */
> 4796                 if (desc_residue(info->rbufs[i]))
> 4797                         count--;
> 4798                 break;
> 4799         }
> 4800         DBGDATA(info, info->rbufs[i].buf, count, "rx");
> 4801         DBGINFO(("rx_get_buf size=%d\n", count));
> 4802         if (count)
> 4803                 ldisc_receive_buf(info->port.tty, info->rbufs[i].buf,
> 4804                                   info->flag_buf, count);
> 4805         free_rbufs(info, i, i);
> 4806         return true;
> 4807 }


-- 
Chen Gang

Asianux Corporation