[PATCH v2 02/18] PCI: endpoint: Introduce pci_epc_map_align()

[Dan Carpenter]

Hi Damien,

kernel test robot noticed the following build warnings:

https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Damien-Le-Moal/PCI-endpoint-Introduce-pci_epc_function_is_valid/20240330-122311
base:   https://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git next
patch link:    https://lore.kernel.org/r/20240330041928.1555578-3-dlemoal%40kernel.org
patch subject: [PATCH v2 02/18] PCI: endpoint: Introduce pci_epc_map_align()
config: parisc-randconfig-r071-20240405 (https://download.01.org/0day-ci/archive/20240405/202404051508.hvNRDVZq-lkp@intel.com/config)
compiler: hppa-linux-gcc (GCC) 13.2.0

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 at intel.com>
| Reported-by: Dan Carpenter <dan.carpenter at linaro.org>
| Closes: https://lore.kernel.org/r/202404051508.hvNRDVZq-lkp@intel.com/

smatch warnings:
drivers/pci/endpoint/pci-epc-core.c:493 pci_epc_map_align() error: we previously assumed 'features' could be null (see line 487)

vim +/features +493 drivers/pci/endpoint/pci-epc-core.c

9d2f10d2ace040 Damien Le Moal         2024-03-30  458  int pci_epc_map_align(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
9d2f10d2ace040 Damien Le Moal         2024-03-30  459  		      u64 pci_addr, size_t size, struct pci_epc_map *map)
9d2f10d2ace040 Damien Le Moal         2024-03-30  460  {
9d2f10d2ace040 Damien Le Moal         2024-03-30  461  	const struct pci_epc_features *features;
9d2f10d2ace040 Damien Le Moal         2024-03-30  462  	size_t mask;
9d2f10d2ace040 Damien Le Moal         2024-03-30  463  	int ret;
9d2f10d2ace040 Damien Le Moal         2024-03-30  464  
9d2f10d2ace040 Damien Le Moal         2024-03-30  465  	if (!pci_epc_function_is_valid(epc, func_no, vfunc_no))
9d2f10d2ace040 Damien Le Moal         2024-03-30  466  		return -EINVAL;
9d2f10d2ace040 Damien Le Moal         2024-03-30  467  
9d2f10d2ace040 Damien Le Moal         2024-03-30  468  	if (!size || !map)
9d2f10d2ace040 Damien Le Moal         2024-03-30  469  		return -EINVAL;
9d2f10d2ace040 Damien Le Moal         2024-03-30  470  
9d2f10d2ace040 Damien Le Moal         2024-03-30  471  	memset(map, 0, sizeof(*map));
9d2f10d2ace040 Damien Le Moal         2024-03-30  472  	map->pci_addr = pci_addr;
9d2f10d2ace040 Damien Le Moal         2024-03-30  473  	map->pci_size = size;
9d2f10d2ace040 Damien Le Moal         2024-03-30  474  
9d2f10d2ace040 Damien Le Moal         2024-03-30  475  	if (epc->ops->map_align) {
9d2f10d2ace040 Damien Le Moal         2024-03-30  476  		mutex_lock(&epc->lock);
9d2f10d2ace040 Damien Le Moal         2024-03-30  477  		ret = epc->ops->map_align(epc, func_no, vfunc_no, map);
9d2f10d2ace040 Damien Le Moal         2024-03-30  478  		mutex_unlock(&epc->lock);
9d2f10d2ace040 Damien Le Moal         2024-03-30  479  		return ret;
9d2f10d2ace040 Damien Le Moal         2024-03-30  480  	}
9d2f10d2ace040 Damien Le Moal         2024-03-30  481  
9d2f10d2ace040 Damien Le Moal         2024-03-30  482  	/*
9d2f10d2ace040 Damien Le Moal         2024-03-30  483  	 * Assume a fixed alignment constraint as specified by the controller
9d2f10d2ace040 Damien Le Moal         2024-03-30  484  	 * features.
9d2f10d2ace040 Damien Le Moal         2024-03-30  485  	 */
9d2f10d2ace040 Damien Le Moal         2024-03-30  486  	features = pci_epc_get_features(epc, func_no, vfunc_no);
9d2f10d2ace040 Damien Le Moal         2024-03-30 @487  	if (!features || !features->align) {
                                                            ^^^^^^^^^
Check for NULL

9d2f10d2ace040 Damien Le Moal         2024-03-30  488  		map->map_pci_addr = pci_addr;
9d2f10d2ace040 Damien Le Moal         2024-03-30  489  		map->map_size = size;
9d2f10d2ace040 Damien Le Moal         2024-03-30  490  		map->map_ofst = 0;

Missing return 0?

9d2f10d2ace040 Damien Le Moal         2024-03-30  491  	}
9d2f10d2ace040 Damien Le Moal         2024-03-30  492  
9d2f10d2ace040 Damien Le Moal         2024-03-30 @493  	mask = features->align - 1;
                                                               ^^^^^^^^^^

9d2f10d2ace040 Damien Le Moal         2024-03-30  494  	map->map_pci_addr = map->pci_addr & ~mask;
9d2f10d2ace040 Damien Le Moal         2024-03-30  495  	map->map_ofst = map->pci_addr & mask;
9d2f10d2ace040 Damien Le Moal         2024-03-30  496  	map->map_size = ALIGN(map->map_ofst + map->pci_size, features->align);
9d2f10d2ace040 Damien Le Moal         2024-03-30  497  
9d2f10d2ace040 Damien Le Moal         2024-03-30  498  	return 0;
9d2f10d2ace040 Damien Le Moal         2024-03-30  499  }

-- 
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