Hi Mimi, According to "Documentation/RCU/rcu_dereference": "->rcu_protected_pointer might be declared as follows: struct foo __rcu *rcu_protected_pointer; " it seems only "ima_rules" should add "__rcu" annotation, because it a "rcu_protected_pointer". "sparse" only check this pointer. Adding ""__rcu" annotation to "ima_rules_tmp", it could not help to avoid the warnings. 在 2021年09月17日 22:27, Mimi Zohar 写道: > On Thu, 2021-09-16 at 20:05 +0800, liqiong wrote: >> Hi Mini, >> >> I got this sparse warnings, should i fix it ? >> >> It seems the follow patch can fix, but i don't think should do >> this check (ima_rules_tmp == NULL). >> >> >> -static struct list_head *ima_rules = &ima_default_rules; >> +static struct list_head __rcu *ima_rules = (struct list_head __rcu *)(&ima_default_rules); >> >> ima_rules_tmp = rcu_dereference(ima_rules); >> +if (ima_rules_tmp == NULL) >> + return ; > Agreed, the "__rcu" annotation is missing. Probably both ima_rules > and ima_rules_tmp should be annotated with "__rcu". Agreed, > ima_rules_tmp will either point to the default or custom policy rules. > No need for the check. > > Please post a new version of the patch, with "Reported-by: kernel test > robot <lkp@xxxxxxxxx> (Fix sparse: incompatible types in comparison > expression)". > > thanks, > > Mimi >
