[rppt:ramdax 1/1] drivers/nvdimm/ramdax.c:89:6: warning: variable 'err' is used uninitialized whenever 'if' condition is true

[kernel test robot <lkp@intel.com>]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/rppt/linux.git ramdax
head:   0b81d6e851e5acf76aba4697db1281798bedbec8
commit: 0b81d6e851e5acf76aba4697db1281798bedbec8 [1/1] nvdimm: allow exposing RAM carveouts as NVDIMM devices
config: x86_64-buildonly-randconfig-003-20250515 (https://download.01.org/0day-ci/archive/20250515/202505150504.66GhNnqk-lkp@intel.com/config)
compiler: clang version 20.1.2 (https://github.com/llvm/llvm-project 58df0ef89dd64126512e4ee27b4ac3fd8ddf6247)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250515/202505150504.66GhNnqk-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202505150504.66GhNnqk-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/nvdimm/ramdax.c:89:6: warning: variable 'err' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
      89 |         if (!dimm->label_area)
         |             ^~~~~~~~~~~~~~~~~
   drivers/nvdimm/ramdax.c:117:9: note: uninitialized use occurs here
     117 |         return err;
         |                ^~~
   drivers/nvdimm/ramdax.c:89:2: note: remove the 'if' if its condition is always false
      89 |         if (!dimm->label_area)
         |         ^~~~~~~~~~~~~~~~~~~~~~
      90 |                 goto err_free_dimm;
         |                 ~~~~~~~~~~~~~~~~~~
   drivers/nvdimm/ramdax.c:81:9: note: initialize the variable 'err' to silence this warning
      81 |         int err;
         |                ^
         |                 = 0
   1 warning generated.


vim +89 drivers/nvdimm/ramdax.c

    73	
    74	static int ramdax_register_dimm(struct resource *res, void *data)
    75	{
    76		resource_size_t start = res->start;
    77		resource_size_t size = resource_size(res);
    78		unsigned long flags = 0, cmd_mask = 0;
    79		struct nvdimm_bus *nvdimm_bus = data;
    80		struct ramdax_dimm *dimm;
    81		int err;
    82	
    83		dimm = kzalloc(sizeof(*dimm), GFP_KERNEL);
    84		if (!dimm)
    85			return -ENOMEM;
    86	
    87		dimm->label_area = memremap(start + size - LABEL_AREA_SIZE,
    88					    LABEL_AREA_SIZE, MEMREMAP_WB);
  > 89		if (!dimm->label_area)
    90			goto err_free_dimm;
    91	
    92		set_bit(NDD_LABELING, &flags);
    93		set_bit(NDD_REGISTER_SYNC, &flags);
    94		set_bit(ND_CMD_GET_CONFIG_SIZE, &cmd_mask);
    95		set_bit(ND_CMD_GET_CONFIG_DATA, &cmd_mask);
    96		set_bit(ND_CMD_SET_CONFIG_DATA, &cmd_mask);
    97		dimm->nvdimm = nvdimm_create(nvdimm_bus, dimm,
    98					     /* dimm_attribute_groups */ NULL,
    99					     flags, cmd_mask, 0, NULL);
   100		if (!dimm->nvdimm) {
   101			err = -ENOMEM;
   102			goto err_unmap_label;
   103		}
   104	
   105		err = ramdax_register_region(res, dimm->nvdimm, nvdimm_bus);
   106		if (err)
   107			goto err_remove_nvdimm;
   108	
   109		return 0;
   110	
   111	err_remove_nvdimm:
   112		nvdimm_delete(dimm->nvdimm);
   113	err_unmap_label:
   114		memunmap(dimm->label_area);
   115	err_free_dimm:
   116		kfree(dimm);
   117		return err;
   118	}
   119	

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