re: Thermal: int340x_thermal: expose acpi thermal relationship tables

[Dan Carpenter <dan.carpenter@oracle.com>]

Hello Jacob Pan,

The patch 52b1c69d7e3c: "Thermal: int340x_thermal: expose acpi
thermal relationship tables" from Sep 3, 2014, leads to the following
static checker warning:

	drivers/thermal/int340x_thermal/acpi_thermal_rel.c:327 acpi_thermal_rel_ioctl()
	warn: passing casted pointer '&count' to 'acpi_parse_trt()' 64 vs 32.

drivers/thermal/int340x_thermal/acpi_thermal_rel.c
   315  static long acpi_thermal_rel_ioctl(struct file *f, unsigned int cmd,
   316                                     unsigned long __arg)
   317  {
   318          int ret = 0;
   319          unsigned long length = 0;
   320          unsigned long count = 0;
   321          char __user *arg = (void __user *)__arg;
   322          struct trt *trts;
   323          struct art *arts;
   324  
   325          switch (cmd) {
   326          case ACPI_THERMAL_GET_TRT_COUNT:
   327                  ret = acpi_parse_trt(acpi_thermal_rel_handle, (int *)&count,
                                                                       ^^^^^^^^^^^^
The reason for the static checker warning is that this will not work on
big endian 64 bit systems.  It's most likely not a concern but it's
still pretty ugly.

You could just make "count" an int and remove the casting.  The copy to
user will still work if it's an int because the user pointer has been
casted to unsigned long __user pointer.

   328                                  &trts, false);
   329                  kfree(trts);
   330                  if (!ret)
   331                          return put_user(count, (unsigned long __user *)__arg);
   332                  return ret;
   333          case ACPI_THERMAL_GET_TRT_LEN:

regards,
dan carpenter