Re: [bug report] nvmem: add support for cell lookups from machine code

[Greg KH <gregkh@linuxfoundation.org>]

On Wed, Oct 10, 2018 at 01:05:53PM +0200, Bartosz Golaszewski wrote:
> śr., 10 paź 2018 o 12:07 Dan Carpenter <dan.carpenter@oracle.com> napisał(a):
> >
> > Hello Bartosz Golaszewski,
> >
> > The patch 506157be06ba: "nvmem: add support for cell lookups from
> > machine code" from Sep 21, 2018, leads to the following static
> > checker warning:
> >
> >         drivers/nvmem/core.c:960 nvmem_cell_get_from_lookup()
> >         error: 'nvmem' dereferencing possible ERR_PTR()
> >
> > drivers/nvmem/core.c
> >    941
> >    942          if (!dev)
> >    943                  return ERR_PTR(-EINVAL);
> >    944
> >    945          dev_id = dev_name(dev);
> >    946
> >    947          mutex_lock(&nvmem_lookup_mutex);
> >    948
> >    949          list_for_each_entry(lookup, &nvmem_lookup_list, node) {
> >    950                  if ((strcmp(lookup->dev_id, dev_id) = 0) &&
> >    951                      (strcmp(lookup->con_id, con_id) = 0)) {
> >    952                          /* This is the right entry. */
> >    953                          nvmem = __nvmem_device_get(NULL, lookup->nvmem_name);
> >                                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > This returns error pointers.
> >
> >    954                          if (!nvmem) {
> >    955                                  /* Provider may not be registered yet. */
> >    956                                  cell = ERR_PTR(-EPROBE_DEFER);
> >    957                                  goto out;
> >    958                          }
> >    959
> >    960                          cell = nvmem_find_cell_by_name(nvmem,
> >    961                                                         lookup->cell_name);
> >    962                          if (!cell) {
> >    963                                  __nvmem_device_put(nvmem);
> >    964                                  goto out;
> >                                         ^^^^^^^^
> > We probably want to set the error code on this path.
> >
> >    965                          }
> >    966                  }
> >    967          }
> >    968
> >    969  out:
> >    970          mutex_unlock(&nvmem_lookup_mutex);
> >    971          return cell;
> >    972  }
> >    973
> >
> > regards,
> > dan carpenter
> 
> Hi Dan,
> 
> there's already a patch waiting on the list:
> https://www.spinics.net/lists/arm-kernel/msg680023.html
> 
> Greg, Srinivas: can you pick up this one and this
> (https://lkml.org/lkml/2018/10/3/310) for 4.20?

Sorry for the delay, will get to that today.

greg k-h