Hi Herbert, I love your patch! Perhaps something to improve: [auto build test WARNING on linus/master] [also build test WARNING on v5.8-rc6 next-20200723] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Herbert-Xu/rhashtable-Fix-unprotected-RCU-dereference-in-__rht_ptr/20200724-092031 base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git d15be546031cf65a0fc34879beca02fd90fe7ac7 config: i386-randconfig-s002-20200724 (attached as .config) compiler: gcc-9 (Debian 9.3.0-14) 9.3.0 reproduce: # apt-get install sparse # sparse version: v0.6.2-93-g4c6cbe55-dirty # save the attached .config to linux build tree make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=i386 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot sparse warnings: (new ones prefixed by >>) net/sched/cls_flower.c:211:19: sparse: got restricted __be16 [usertype] dst net/sched/cls_flower.c:211:19: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:211:19: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:214:21: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:214:21: sparse: sparse: incorrect type in argument 1 (different base types) @@ expected unsigned short [usertype] val @@ got restricted __be16 [usertype] dst @@ net/sched/cls_flower.c:214:21: sparse: expected unsigned short [usertype] val net/sched/cls_flower.c:214:21: sparse: got restricted __be16 [usertype] dst net/sched/cls_flower.c:214:21: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:214:21: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:214:21: sparse: sparse: restricted __be16 degrades to integer net/sched/cls_flower.c:214:51: sparse: sparse: restricted __be16 degrades to integer net/sched/cls_flower.c:215:21: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:215:21: sparse: sparse: incorrect type in argument 1 (different base types) @@ expected unsigned short [usertype] val @@ got restricted __be16 [usertype] dst @@ net/sched/cls_flower.c:215:21: sparse: expected unsigned short [usertype] val net/sched/cls_flower.c:215:21: sparse: got restricted __be16 [usertype] dst net/sched/cls_flower.c:215:21: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:215:21: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:215:21: sparse: sparse: restricted __be16 degrades to integer net/sched/cls_flower.c:215:51: sparse: sparse: restricted __be16 degrades to integer net/sched/cls_flower.c:231:20: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:231:20: sparse: sparse: incorrect type in argument 1 (different base types) @@ expected unsigned short [usertype] val @@ got restricted __be16 [usertype] src @@ net/sched/cls_flower.c:231:20: sparse: expected unsigned short [usertype] val net/sched/cls_flower.c:231:20: sparse: got restricted __be16 [usertype] src net/sched/cls_flower.c:231:20: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:231:20: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:232:20: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:232:20: sparse: sparse: incorrect type in argument 1 (different base types) @@ expected unsigned short [usertype] val @@ got restricted __be16 [usertype] src @@ net/sched/cls_flower.c:232:20: sparse: expected unsigned short [usertype] val net/sched/cls_flower.c:232:20: sparse: got restricted __be16 [usertype] src net/sched/cls_flower.c:232:20: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:232:20: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:233:19: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:233:19: sparse: sparse: incorrect type in argument 1 (different base types) @@ expected unsigned short [usertype] val @@ got restricted __be16 [usertype] src @@ net/sched/cls_flower.c:233:19: sparse: expected unsigned short [usertype] val net/sched/cls_flower.c:233:19: sparse: got restricted __be16 [usertype] src net/sched/cls_flower.c:233:19: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:233:19: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:234:19: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:234:19: sparse: sparse: incorrect type in argument 1 (different base types) @@ expected unsigned short [usertype] val @@ got restricted __be16 [usertype] src @@ net/sched/cls_flower.c:234:19: sparse: expected unsigned short [usertype] val net/sched/cls_flower.c:234:19: sparse: got restricted __be16 [usertype] src net/sched/cls_flower.c:234:19: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:234:19: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:237:21: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:237:21: sparse: sparse: incorrect type in argument 1 (different base types) @@ expected unsigned short [usertype] val @@ got restricted __be16 [usertype] src @@ net/sched/cls_flower.c:237:21: sparse: expected unsigned short [usertype] val net/sched/cls_flower.c:237:21: sparse: got restricted __be16 [usertype] src net/sched/cls_flower.c:237:21: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:237:21: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:237:21: sparse: sparse: restricted __be16 degrades to integer net/sched/cls_flower.c:237:51: sparse: sparse: restricted __be16 degrades to integer net/sched/cls_flower.c:238:21: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:238:21: sparse: sparse: incorrect type in argument 1 (different base types) @@ expected unsigned short [usertype] val @@ got restricted __be16 [usertype] src @@ net/sched/cls_flower.c:238:21: sparse: expected unsigned short [usertype] val net/sched/cls_flower.c:238:21: sparse: got restricted __be16 [usertype] src net/sched/cls_flower.c:238:21: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:238:21: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:238:21: sparse: sparse: restricted __be16 degrades to integer net/sched/cls_flower.c:238:51: sparse: sparse: restricted __be16 degrades to integer net/sched/cls_flower.c:769:13: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:769:13: sparse: sparse: incorrect type in argument 1 (different base types) @@ expected unsigned short [usertype] val @@ got restricted __be16 [usertype] dst @@ net/sched/cls_flower.c:769:13: sparse: expected unsigned short [usertype] val net/sched/cls_flower.c:769:13: sparse: got restricted __be16 [usertype] dst net/sched/cls_flower.c:769:13: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:769:13: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:770:13: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:770:13: sparse: sparse: incorrect type in argument 1 (different base types) @@ expected unsigned short [usertype] val @@ got restricted __be16 [usertype] dst @@ net/sched/cls_flower.c:770:13: sparse: expected unsigned short [usertype] val net/sched/cls_flower.c:770:13: sparse: got restricted __be16 [usertype] dst net/sched/cls_flower.c:770:13: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:770:13: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:769:13: sparse: sparse: restricted __be16 degrades to integer net/sched/cls_flower.c:770:13: sparse: sparse: restricted __be16 degrades to integer net/sched/cls_flower.c:777:13: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:777:13: sparse: sparse: incorrect type in argument 1 (different base types) @@ expected unsigned short [usertype] val @@ got restricted __be16 [usertype] src @@ net/sched/cls_flower.c:777:13: sparse: expected unsigned short [usertype] val net/sched/cls_flower.c:777:13: sparse: got restricted __be16 [usertype] src net/sched/cls_flower.c:777:13: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:777:13: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:778:13: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:778:13: sparse: sparse: incorrect type in argument 1 (different base types) @@ expected unsigned short [usertype] val @@ got restricted __be16 [usertype] src @@ net/sched/cls_flower.c:778:13: sparse: expected unsigned short [usertype] val net/sched/cls_flower.c:778:13: sparse: got restricted __be16 [usertype] src net/sched/cls_flower.c:778:13: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:778:13: sparse: sparse: cast from restricted __be16 net/sched/cls_flower.c:777:13: sparse: sparse: restricted __be16 degrades to integer net/sched/cls_flower.c:778:13: sparse: sparse: restricted __be16 degrades to integer net/sched/cls_flower.c:1030:15: sparse: sparse: cast to restricted __be32 net/sched/cls_flower.c:1030:15: sparse: sparse: cast to restricted __be32 net/sched/cls_flower.c:1030:15: sparse: sparse: cast to restricted __be32 net/sched/cls_flower.c:1030:15: sparse: sparse: cast to restricted __be32 net/sched/cls_flower.c:1030:15: sparse: sparse: cast to restricted __be32 net/sched/cls_flower.c:1030:15: sparse: sparse: cast to restricted __be32 net/sched/cls_flower.c:1031:16: sparse: sparse: cast to restricted __be32 net/sched/cls_flower.c:1031:16: sparse: sparse: cast to restricted __be32 net/sched/cls_flower.c:1031:16: sparse: sparse: cast to restricted __be32 net/sched/cls_flower.c:1031:16: sparse: sparse: cast to restricted __be32 net/sched/cls_flower.c:1031:16: sparse: sparse: cast to restricted __be32 net/sched/cls_flower.c:1031:16: sparse: sparse: cast to restricted __be32 net/sched/cls_flower.c: note: in included file: >> include/linux/rhashtable.h:1156:13: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct rhash_lock_head **bkt @@ got struct rhash_lock_head [noderef] __rcu ** @@ >> include/linux/rhashtable.h:1156:13: sparse: expected struct rhash_lock_head **bkt >> include/linux/rhashtable.h:1156:13: sparse: got struct rhash_lock_head [noderef] __rcu ** >> include/linux/rhashtable.h:1161:23: sparse: sparse: incorrect type in argument 2 (different address spaces) @@ expected struct rhash_lock_head [noderef] __rcu **bkt @@ got struct rhash_lock_head **bkt @@ >> include/linux/rhashtable.h:1161:23: sparse: expected struct rhash_lock_head [noderef] __rcu **bkt >> include/linux/rhashtable.h:1161:23: sparse: got struct rhash_lock_head **bkt >> include/linux/rhashtable.h:1163:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct rhash_lock_head [noderef] __rcu *const *bkt @@ got struct rhash_lock_head **bkt @@ >> include/linux/rhashtable.h:1163:9: sparse: expected struct rhash_lock_head [noderef] __rcu *const *bkt include/linux/rhashtable.h:1163:9: sparse: got struct rhash_lock_head **bkt include/linux/rhashtable.h:1172:41: sparse: sparse: incorrect type in argument 2 (different address spaces) @@ expected struct rhash_lock_head [noderef] __rcu **bkt @@ got struct rhash_lock_head **bkt @@ include/linux/rhashtable.h:1172:41: sparse: expected struct rhash_lock_head [noderef] __rcu **bkt include/linux/rhashtable.h:1172:41: sparse: got struct rhash_lock_head **bkt include/linux/rhashtable.h:1174:48: sparse: sparse: incorrect type in argument 2 (different address spaces) @@ expected struct rhash_lock_head [noderef] __rcu **bkt @@ got struct rhash_lock_head **bkt @@ include/linux/rhashtable.h:1174:48: sparse: expected struct rhash_lock_head [noderef] __rcu **bkt include/linux/rhashtable.h:1174:48: sparse: got struct rhash_lock_head **bkt include/linux/rhashtable.h:1180:25: sparse: sparse: incorrect type in argument 2 (different address spaces) @@ expected struct rhash_lock_head [noderef] __rcu **bkt @@ got struct rhash_lock_head **bkt @@ include/linux/rhashtable.h:1180:25: sparse: expected struct rhash_lock_head [noderef] __rcu **bkt include/linux/rhashtable.h:1180:25: sparse: got struct rhash_lock_head **bkt vim +1156 include/linux/rhashtable.h 02fd97c3d4a8a14 Herbert Xu 2015-03-20 1136 3502cad73c4bbf8 Tom Herbert 2015-12-15 1137 /* Internal function, please use rhashtable_replace_fast() instead */ 3502cad73c4bbf8 Tom Herbert 2015-12-15 1138 static inline int __rhashtable_replace_fast( 3502cad73c4bbf8 Tom Herbert 2015-12-15 1139 struct rhashtable *ht, struct bucket_table *tbl, 3502cad73c4bbf8 Tom Herbert 2015-12-15 1140 struct rhash_head *obj_old, struct rhash_head *obj_new, 3502cad73c4bbf8 Tom Herbert 2015-12-15 1141 const struct rhashtable_params params) 3502cad73c4bbf8 Tom Herbert 2015-12-15 1142 { ba6306e3f648a85 Herbert Xu 2019-05-16 1143 struct rhash_lock_head **bkt; 3502cad73c4bbf8 Tom Herbert 2015-12-15 1144 struct rhash_head __rcu **pprev; 3502cad73c4bbf8 Tom Herbert 2015-12-15 1145 struct rhash_head *he; 3502cad73c4bbf8 Tom Herbert 2015-12-15 1146 unsigned int hash; 3502cad73c4bbf8 Tom Herbert 2015-12-15 1147 int err = -ENOENT; 3502cad73c4bbf8 Tom Herbert 2015-12-15 1148 3502cad73c4bbf8 Tom Herbert 2015-12-15 1149 /* Minimally, the old and new objects must have same hash 3502cad73c4bbf8 Tom Herbert 2015-12-15 1150 * (which should mean identifiers are the same). 3502cad73c4bbf8 Tom Herbert 2015-12-15 1151 */ 3502cad73c4bbf8 Tom Herbert 2015-12-15 1152 hash = rht_head_hashfn(ht, tbl, obj_old, params); 3502cad73c4bbf8 Tom Herbert 2015-12-15 1153 if (hash != rht_head_hashfn(ht, tbl, obj_new, params)) 3502cad73c4bbf8 Tom Herbert 2015-12-15 1154 return -EINVAL; 3502cad73c4bbf8 Tom Herbert 2015-12-15 1155 8f0db018006a421 NeilBrown 2019-04-02 @1156 bkt = rht_bucket_var(tbl, hash); 8f0db018006a421 NeilBrown 2019-04-02 1157 if (!bkt) 8f0db018006a421 NeilBrown 2019-04-02 1158 return -ENOENT; 3502cad73c4bbf8 Tom Herbert 2015-12-15 1159 8f0db018006a421 NeilBrown 2019-04-02 1160 pprev = NULL; 149212f07856b25 NeilBrown 2019-04-02 @1161 rht_lock(tbl, bkt); 3502cad73c4bbf8 Tom Herbert 2015-12-15 1162 adc6a3ab192eb40 NeilBrown 2019-04-12 @1163 rht_for_each_from(he, rht_ptr(bkt, tbl, hash), tbl, hash) { 3502cad73c4bbf8 Tom Herbert 2015-12-15 1164 if (he != obj_old) { 3502cad73c4bbf8 Tom Herbert 2015-12-15 1165 pprev = &he->next; 3502cad73c4bbf8 Tom Herbert 2015-12-15 1166 continue; 3502cad73c4bbf8 Tom Herbert 2015-12-15 1167 } 3502cad73c4bbf8 Tom Herbert 2015-12-15 1168 3502cad73c4bbf8 Tom Herbert 2015-12-15 1169 rcu_assign_pointer(obj_new->next, obj_old->next); 8f0db018006a421 NeilBrown 2019-04-02 1170 if (pprev) { 3502cad73c4bbf8 Tom Herbert 2015-12-15 1171 rcu_assign_pointer(*pprev, obj_new); 149212f07856b25 NeilBrown 2019-04-02 1172 rht_unlock(tbl, bkt); 8f0db018006a421 NeilBrown 2019-04-02 1173 } else { 149212f07856b25 NeilBrown 2019-04-02 1174 rht_assign_unlock(tbl, bkt, obj_new); 8f0db018006a421 NeilBrown 2019-04-02 1175 } 3502cad73c4bbf8 Tom Herbert 2015-12-15 1176 err = 0; 8f0db018006a421 NeilBrown 2019-04-02 1177 goto unlocked; 3502cad73c4bbf8 Tom Herbert 2015-12-15 1178 } 3502cad73c4bbf8 Tom Herbert 2015-12-15 1179 149212f07856b25 NeilBrown 2019-04-02 1180 rht_unlock(tbl, bkt); 8f0db018006a421 NeilBrown 2019-04-02 1181 8f0db018006a421 NeilBrown 2019-04-02 1182 unlocked: 3502cad73c4bbf8 Tom Herbert 2015-12-15 1183 return err; 3502cad73c4bbf8 Tom Herbert 2015-12-15 1184 } 3502cad73c4bbf8 Tom Herbert 2015-12-15 1185 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org