Hi Alexei, I love your patch! Perhaps something to improve: [auto build test WARNING on bpf/master] url: https://github.com/0day-ci/linux/commits/Alexei-Starovoitov/ftrace-Fix-mo... base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git master config: i386-randconfig-s002-20210316 (attached as .config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce: # apt-get install sparse # sparse version: v0.6.3-277-gc089cd2d-dirty # https://github.com/0day-ci/linux/commit/517b5af19a5e543f639389ecd65badacf... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Alexei-Starovoitov/ftrace-Fix-modify_ftrace_direct/20210317-031309 git checkout 517b5af19a5e543f639389ecd65badacf7523a69 # 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 <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): kernel/trace/ftrace.c:302:5: warning: no previous prototype for '__register_ftrace_function' [-Wmissing-prototypes] 302 | int __register_ftrace_function(struct ftrace_ops *ops) | ^~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/trace/ftrace.c:345:5: warning: no previous prototype for '__unregister_ftrace_function' [-Wmissing-prototypes] 345 | int __unregister_ftrace_function(struct ftrace_ops *ops) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/trace/ftrace.c:584:5: warning: no previous prototype for 'ftrace_profile_pages_init' [-Wmissing-prototypes] 584 | int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) | ^~~~~~~~~~~~~~~~~~~~~~~~~ kernel/trace/ftrace.c:3876:15: warning: no previous prototype for 'arch_ftrace_match_adjust' [-Wmissing-prototypes] 3876 | char * __weak arch_ftrace_match_adjust(char *str, const char *search) | ^~~~~~~~~~~~~~~~~~~~~~~~ 5048 | struct ftrace_direct_func *ftrace_alloc_direct_func(unsigned long addr) | ^~~~~~~~~~~~~~~~~~~~~~~~ sparse warnings: (new ones prefixed by >>) kernel/trace/ftrace.c:118:59: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected struct ftrace_ops [noderef] __rcu *[addressable] [toplevel] ftrace_ops_list @@ got struct ftrace_ops * @@ kernel/trace/ftrace.c:118:59: sparse: expected struct ftrace_ops [noderef] __rcu *[addressable] [toplevel] ftrace_ops_list kernel/trace/ftrace.c:118:59: sparse: got struct ftrace_ops * kernel/trace/ftrace.c:202:49: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct ftrace_ops *ops @@ got struct ftrace_ops [noderef] __rcu *[addressable] [toplevel] ftrace_ops_list @@ kernel/trace/ftrace.c:202:49: sparse: expected struct ftrace_ops *ops kernel/trace/ftrace.c:202:49: sparse: got struct ftrace_ops [noderef] __rcu *[addressable] [toplevel] ftrace_ops_list kernel/trace/ftrace.c:285:23: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct ftrace_ops [noderef] __rcu * @@ got struct ftrace_ops * @@ kernel/trace/ftrace.c:285:23: sparse: expected struct ftrace_ops [noderef] __rcu * kernel/trace/ftrace.c:285:23: sparse: got struct ftrace_ops * kernel/trace/ftrace.c:289:16: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct ftrace_ops **p @@ got struct ftrace_ops [noderef] __rcu **list @@ kernel/trace/ftrace.c:289:16: sparse: expected struct ftrace_ops **p kernel/trace/ftrace.c:289:16: sparse: got struct ftrace_ops [noderef] __rcu **list kernel/trace/ftrace.c:289:50: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct ftrace_ops **p @@ got struct ftrace_ops [noderef] __rcu ** @@ kernel/trace/ftrace.c:289:50: sparse: expected struct ftrace_ops **p kernel/trace/ftrace.c:289:50: sparse: got struct ftrace_ops [noderef] __rcu ** kernel/trace/ftrace.c:296:12: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct ftrace_ops * @@ got struct ftrace_ops [noderef] __rcu *next @@ kernel/trace/ftrace.c:296:12: sparse: expected struct ftrace_ops * kernel/trace/ftrace.c:296:12: sparse: got struct ftrace_ops [noderef] __rcu *next kernel/trace/ftrace.c:584:5: sparse: sparse: symbol 'ftrace_profile_pages_init' was not declared. Should it be static? kernel/trace/ftrace.c:1040:43: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected struct ftrace_hash [noderef] __rcu *notrace_hash @@ got struct ftrace_hash * @@ kernel/trace/ftrace.c:1040:43: sparse: expected struct ftrace_hash [noderef] __rcu *notrace_hash kernel/trace/ftrace.c:1040:43: sparse: got struct ftrace_hash * kernel/trace/ftrace.c:1041:43: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected struct ftrace_hash [noderef] __rcu *filter_hash @@ got struct ftrace_hash * @@ kernel/trace/ftrace.c:1041:43: sparse: expected struct ftrace_hash [noderef] __rcu *filter_hash kernel/trace/ftrace.c:1041:43: sparse: got struct ftrace_hash * kernel/trace/ftrace.c:1259:40: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct ftrace_hash *hash @@ got struct ftrace_hash [noderef] __rcu *filter_hash @@ kernel/trace/ftrace.c:1259:40: sparse: expected struct ftrace_hash *hash kernel/trace/ftrace.c:1259:40: sparse: got struct ftrace_hash [noderef] __rcu *filter_hash kernel/trace/ftrace.c:1260:40: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct ftrace_hash *hash @@ got struct ftrace_hash [noderef] __rcu *notrace_hash @@ kernel/trace/ftrace.c:1260:40: sparse: expected struct ftrace_hash *hash kernel/trace/ftrace.c:1260:40: sparse: got struct ftrace_hash [noderef] __rcu *notrace_hash kernel/trace/ftrace.c:1957:54: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected struct ftrace_hash *old_hash @@ got struct ftrace_hash [noderef] __rcu *filter_hash @@ kernel/trace/ftrace.c:1957:54: sparse: expected struct ftrace_hash *old_hash kernel/trace/ftrace.c:1957:54: sparse: got struct ftrace_hash [noderef] __rcu *filter_hash kernel/trace/ftrace.c:1441:9: sparse: sparse: incompatible types in comparison expression (different address spaces): kernel/trace/ftrace.c:1441:9: sparse: struct ftrace_hash [noderef] __rcu * kernel/trace/ftrace.c:1441:9: sparse: struct ftrace_hash * kernel/trace/ftrace.c:1457:39: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct ftrace_hash *hash @@ got struct ftrace_hash [noderef] __rcu *filter_hash @@ kernel/trace/ftrace.c:1458:40: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct ftrace_hash *hash @@ got struct ftrace_hash [noderef] __rcu *filter_hash @@ kernel/trace/ftrace.c:1459:40: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct ftrace_hash *hash @@ got struct ftrace_hash [noderef] __rcu *notrace_hash @@ kernel/trace/ftrace.c:1460:42: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct ftrace_hash *hash @@ got struct ftrace_hash [noderef] __rcu *notrace_hash @@ kernel/trace/ftrace.c:1614:18: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct ftrace_ops *ops @@ got struct ftrace_ops [noderef] __rcu *[addressable] [toplevel] ftrace_ops_list @@ kernel/trace/ftrace.c:1615:43: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct ftrace_ops *ops @@ got struct ftrace_ops [noderef] __rcu *next @@ kernel/trace/ftrace.c:1663:22: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct ftrace_hash *hash @@ got struct ftrace_hash [noderef] __rcu *filter_hash @@ kernel/trace/ftrace.c:1664:28: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct ftrace_hash *other_hash @@ got struct ftrace_hash [noderef] __rcu *notrace_hash @@ kernel/trace/ftrace.c:1669:22: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct ftrace_hash *hash @@ got struct ftrace_hash [noderef] __rcu *notrace_hash @@ kernel/trace/ftrace.c:1670:28: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct ftrace_hash *other_hash @@ got struct ftrace_hash [noderef] __rcu *filter_hash @@ kernel/trace/ftrace.c:1935:50: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected struct ftrace_hash *hash @@ got struct ftrace_hash [noderef] __rcu *filter_hash @@ kernel/trace/ftrace.c:1946:50: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected struct ftrace_hash *hash @@ got struct ftrace_hash [noderef] __rcu *filter_hash @@ kernel/trace/ftrace.c:3295:14: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct ftrace_hash *hash @@ got struct ftrace_hash [noderef] __rcu *filter_hash @@ kernel/trace/ftrace.c:3312:22: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct ftrace_hash *hash @@ got struct ftrace_hash [noderef] __rcu *filter_hash @@ kernel/trace/ftrace.c:3787:22: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct ftrace_hash *hash @@ got struct ftrace_hash [noderef] __rcu *notrace_hash @@ kernel/trace/ftrace.c:3790:22: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct ftrace_hash *hash @@ got struct ftrace_hash [noderef] __rcu *filter_hash @@ kernel/trace/ftrace.c:4191:27: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct ftrace_hash **orig_hash @@ got struct ftrace_hash [noderef] __rcu ** @@ kernel/trace/ftrace.c:4193:27: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct ftrace_hash **orig_hash @@ got struct ftrace_hash [noderef] __rcu ** @@ kernel/trace/ftrace.c:4565:19: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct ftrace_hash **orig_hash @@ got struct ftrace_hash [noderef] __rcu ** @@ kernel/trace/ftrace.c:4707:19: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct ftrace_hash **orig_hash @@ got struct ftrace_hash [noderef] __rcu ** @@ kernel/trace/ftrace.c:4713:34: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct ftrace_hash [noderef] __rcu *filter_hash @@ got struct ftrace_hash *[assigned] old_hash @@ kernel/trace/ftrace.c:4965:27: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct ftrace_hash **orig_hash @@ got struct ftrace_hash [noderef] __rcu ** @@ kernel/trace/ftrace.c:4967:27: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct ftrace_hash **orig_hash @@ got struct ftrace_hash [noderef] __rcu ** @@ kernel/trace/ftrace.c:5576:35: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct ftrace_hash [noderef] __rcu *extern [addressable] [toplevel] ftrace_graph_hash @@ got struct ftrace_hash *[assigned] hash @@ kernel/trace/ftrace.c:5578:43: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct ftrace_hash [noderef] __rcu *extern [addressable] [toplevel] ftrace_graph_notrace_hash @@ got struct ftrace_hash *[assigned] hash @@ kernel/trace/ftrace.c:5636:35: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct ftrace_hash **orig_hash @@ got struct ftrace_hash [noderef] __rcu ** @@ kernel/trace/ftrace.c:5640:35: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct ftrace_hash **orig_hash @@ got struct ftrace_hash [noderef] __rcu ** @@ kernel/trace/ftrace.c:5694:47: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected struct ftrace_hash [noderef] __rcu *[addressable] [toplevel] ftrace_graph_hash @@ got struct ftrace_hash * @@ kernel/trace/ftrace.c:5695:55: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected struct ftrace_hash [noderef] __rcu *[addressable] [toplevel] ftrace_graph_notrace_hash @@ got struct ftrace_hash * @@ kernel/trace/ftrace.c:6311:18: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct ftrace_ops *ops @@ got struct ftrace_ops [noderef] __rcu *[addressable] [toplevel] ftrace_ops_list @@ kernel/trace/ftrace.c:6311:66: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct ftrace_ops *ops @@ got struct ftrace_ops [noderef] __rcu *next @@ kernel/trace/ftrace.c:6363:59: sparse: sparse: incorrect type in argument 2 (different address spaces) @@ expected struct ftrace_hash *hash @@ got struct ftrace_hash [noderef] __rcu *filter_hash @@ kernel/trace/ftrace.c:6364:59: sparse: sparse: incorrect type in argument 2 (different address spaces) @@ expected struct ftrace_hash *hash @@ got struct ftrace_hash [noderef] __rcu *notrace_hash @@ kernel/trace/ftrace.c:6734:62: sparse: sparse: incorrect type in argument 2 (different address spaces) @@ expected struct ftrace_hash *hash @@ got struct ftrace_hash [noderef] __rcu *filter_hash @@ kernel/trace/ftrace.c:6735:62: sparse: sparse: incorrect type in argument 2 (different address spaces) @@ expected struct ftrace_hash *hash @@ got struct ftrace_hash [noderef] __rcu *notrace_hash @@ kernel/trace/ftrace.c:6781:36: sparse: sparse: incompatible types in comparison expression (different address spaces): kernel/trace/ftrace.c:6781:36: sparse: struct ftrace_ops [noderef] __rcu * kernel/trace/ftrace.c:6781:36: sparse: struct ftrace_ops * kernel/trace/ftrace.c:200:20: sparse: sparse: dereference of noderef expression kernel/trace/ftrace.c:200:20: sparse: sparse: dereference of noderef expression kernel/trace/ftrace.c:200:20: sparse: sparse: dereference of noderef expression kernel/trace/ftrace.c:3084:46: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct ftrace_hash *hash @@ got struct ftrace_hash [noderef] __rcu *filter_hash @@ kernel/trace/ftrace.c:3084:46: sparse: expected struct ftrace_hash *hash kernel/trace/ftrace.c:3084:46: sparse: got struct ftrace_hash [noderef] __rcu *filter_hash kernel/trace/ftrace.c:3085:47: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct ftrace_hash *hash @@ got struct ftrace_hash [noderef] __rcu *filter_hash @@ kernel/trace/ftrace.c:3085:47: sparse: expected struct ftrace_hash *hash kernel/trace/ftrace.c:3085:47: sparse: got struct ftrace_hash [noderef] __rcu *filter_hash kernel/trace/ftrace.c:3089:44: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct ftrace_hash *hash @@ got struct ftrace_hash [noderef] __rcu *notrace_hash @@ kernel/trace/ftrace.c:3089:44: sparse: expected struct ftrace_hash *hash kernel/trace/ftrace.c:3089:44: sparse: got struct ftrace_hash [noderef] __rcu *notrace_hash kernel/trace/ftrace.c:3061:48: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct ftrace_hash *hash @@ got struct ftrace_hash [noderef] __rcu *filter_hash @@ kernel/trace/ftrace.c:3061:48: sparse: expected struct ftrace_hash *hash kernel/trace/ftrace.c:3061:48: sparse: got struct ftrace_hash [noderef] __rcu *filter_hash kernel/trace/ftrace.c:3062:49: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct ftrace_hash *hash @@ got struct ftrace_hash [noderef] __rcu *notrace_hash @@ kernel/trace/ftrace.c:3062:49: sparse: expected struct ftrace_hash *hash kernel/trace/ftrace.c:3062:49: sparse: got struct ftrace_hash [noderef] __rcu *notrace_hash Please review and possibly fold the followup patch. vim +/ftrace_alloc_direct_func +5048 kernel/trace/ftrace.c 5047 5049 { 5050 struct ftrace_direct_func *direct; 5051 5052 direct = kmalloc(sizeof(*direct), GFP_KERNEL); 5053 if (!direct) 5054 return NULL; 5055 direct->addr = addr; 5056 direct->count = 0; 5057 list_add_rcu(&direct->next, &ftrace_direct_funcs); 5058 ftrace_direct_func_count++; 5059 return direct; 5060 } 5061 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org