Re: [PATCH net-next v5 8/9] net: marvell: prestera: Add neighbour cache accounting

[Dan Carpenter]

Hi Yevhen,

url:    https://github.com/intel-lab-lkp/linux/commits/Yevhen-Orlov/net-marvell-prestera-add-nexthop-routes-offloading/20220909-065815
base:   https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git 9f8f1933dce555d3c246f447f54fca8de8889da9
config: openrisc-randconfig-m041-20220907
compiler: or1k-linux-gcc (GCC) 12.1.0

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

smatch warnings:
drivers/net/ethernet/marvell/prestera/prestera_router.c:751 __prestera_k_arb_n_lpm_set() error: uninitialized symbol 'fib_node'.

vim +/fib_node +751 drivers/net/ethernet/marvell/prestera/prestera_router.c

5a826d874f2b0e Yevhen Orlov 2022-09-09  715  static void
5a826d874f2b0e Yevhen Orlov 2022-09-09  716  __prestera_k_arb_n_lpm_set(struct prestera_switch *sw,
5a826d874f2b0e Yevhen Orlov 2022-09-09  717  			   struct prestera_kern_neigh_cache *n_cache,
5a826d874f2b0e Yevhen Orlov 2022-09-09  718  			   bool enabled)
5a826d874f2b0e Yevhen Orlov 2022-09-09  719  {
5a826d874f2b0e Yevhen Orlov 2022-09-09  720  	struct prestera_nexthop_group_key nh_grp_key;
5a826d874f2b0e Yevhen Orlov 2022-09-09  721  	struct prestera_kern_fib_cache_key fc_key;
5a826d874f2b0e Yevhen Orlov 2022-09-09  722  	struct prestera_kern_fib_cache *fib_cache;
5a826d874f2b0e Yevhen Orlov 2022-09-09  723  	struct prestera_fib_node *fib_node;
5a826d874f2b0e Yevhen Orlov 2022-09-09  724  	struct prestera_fib_key fib_key;
5a826d874f2b0e Yevhen Orlov 2022-09-09  725  
5a826d874f2b0e Yevhen Orlov 2022-09-09  726  	/* Exception for fc with prefix 32: LPM entry is already used by fib */
5a826d874f2b0e Yevhen Orlov 2022-09-09  727  	memset(&fc_key, 0, sizeof(fc_key));
5a826d874f2b0e Yevhen Orlov 2022-09-09  728  	fc_key.addr = n_cache->key.addr;
5a826d874f2b0e Yevhen Orlov 2022-09-09  729  	fc_key.prefix_len = PRESTERA_IP_ADDR_PLEN(n_cache->key.addr.v);
5a826d874f2b0e Yevhen Orlov 2022-09-09  730  	/* But better to use tb_id of route, which pointed to this neighbour. */
5a826d874f2b0e Yevhen Orlov 2022-09-09  731  	/* We take it from rif, because rif inconsistent.
5a826d874f2b0e Yevhen Orlov 2022-09-09  732  	 * Must be separated in_rif and out_rif.
5a826d874f2b0e Yevhen Orlov 2022-09-09  733  	 * Also note: for each fib pointed to this neigh should be separated
5a826d874f2b0e Yevhen Orlov 2022-09-09  734  	 *            neigh lpm entry (for each ingress vr)
5a826d874f2b0e Yevhen Orlov 2022-09-09  735  	 */
5a826d874f2b0e Yevhen Orlov 2022-09-09  736  	fc_key.kern_tb_id = l3mdev_fib_table(n_cache->key.dev);
5a826d874f2b0e Yevhen Orlov 2022-09-09  737  	fib_cache = prestera_kern_fib_cache_find(sw, &fc_key);
5a826d874f2b0e Yevhen Orlov 2022-09-09  738  	if (!fib_cache || !fib_cache->reachable) {
5a826d874f2b0e Yevhen Orlov 2022-09-09  739  		memset(&fib_key, 0, sizeof(fib_key));
5a826d874f2b0e Yevhen Orlov 2022-09-09  740  		fib_key.addr = n_cache->key.addr;
5a826d874f2b0e Yevhen Orlov 2022-09-09  741  		fib_key.prefix_len = PRESTERA_IP_ADDR_PLEN(n_cache->key.addr.v);
5a826d874f2b0e Yevhen Orlov 2022-09-09  742  		fib_key.tb_id = prestera_fix_tb_id(fc_key.kern_tb_id);
5a826d874f2b0e Yevhen Orlov 2022-09-09  743  		fib_node = prestera_fib_node_find(sw, &fib_key);
5a826d874f2b0e Yevhen Orlov 2022-09-09  744  		if (!enabled && fib_node) {
5a826d874f2b0e Yevhen Orlov 2022-09-09  745  			if (prestera_fib_node_util_is_neighbour(fib_node))
5a826d874f2b0e Yevhen Orlov 2022-09-09  746  				prestera_fib_node_destroy(sw, fib_node);
5a826d874f2b0e Yevhen Orlov 2022-09-09  747  			return;
5a826d874f2b0e Yevhen Orlov 2022-09-09  748  		}
5a826d874f2b0e Yevhen Orlov 2022-09-09  749  	}

fib_node not initialized on else path.

5a826d874f2b0e Yevhen Orlov 2022-09-09  750  
5a826d874f2b0e Yevhen Orlov 2022-09-09 @751  	if (enabled && !fib_node) {
5a826d874f2b0e Yevhen Orlov 2022-09-09  752  		memset(&nh_grp_key, 0, sizeof(nh_grp_key));
5a826d874f2b0e Yevhen Orlov 2022-09-09  753  		prestera_util_nc_key2nh_key(&n_cache->key,
5a826d874f2b0e Yevhen Orlov 2022-09-09  754  					    &nh_grp_key.neigh[0]);
5a826d874f2b0e Yevhen Orlov 2022-09-09  755  		fib_node = prestera_fib_node_create(sw, &fib_key,
5a826d874f2b0e Yevhen Orlov 2022-09-09  756  						    PRESTERA_FIB_TYPE_UC_NH,
5a826d874f2b0e Yevhen Orlov 2022-09-09  757  						    &nh_grp_key);
5a826d874f2b0e Yevhen Orlov 2022-09-09  758  		if (!fib_node)
5a826d874f2b0e Yevhen Orlov 2022-09-09  759  			pr_err("%s failed ip=%pI4n", "prestera_fib_node_create",
5a826d874f2b0e Yevhen Orlov 2022-09-09  760  			       &fib_key.addr.u.ipv4);
5a826d874f2b0e Yevhen Orlov 2022-09-09  761  		return;
5a826d874f2b0e Yevhen Orlov 2022-09-09  762  	}
5a826d874f2b0e Yevhen Orlov 2022-09-09  763  }