[kbuild-all] Re: [selinuxproject-selinux:stable-5.15 1/1] include/linux/rcupdate.h:395:2: warning: passing argument 1 of 'security_locked_down' discards 'const' qualifier from pointer target type

tree: https://github.com/SELinuxProject/selinux-kernel stable-5.15 head: c491f0a471580712a4254adece400c3ebb3d8e44 commit: c491f0a471580712a4254adece400c3ebb3d8e44 [1/1] lockdown,selinux: fix wrong subject in some SELinux lockdown checks config: um-x86_64_defconfig (attached as .config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce (this is a W=1 build): # https://github.com/SELinuxProject/selinux-kernel/commit/c491f0a471580712a... git remote add selinuxproject-selinux https://github.com/SELinuxProject/selinux-kernel git fetch --no-tags selinuxproject-selinux stable-5.15 git checkout c491f0a471580712a4254adece400c3ebb3d8e44 # save the attached .config to linux build tree make W=1 ARCH=um SUBARCH=x86_64 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 >>): In file included from include/linux/rbtree.h:24, from include/linux/mm_types.h:10, from include/linux/mmzone.h:21, from include/linux/gfp.h:6, from include/linux/mm.h:10, from drivers/char/mem.c:12: drivers/char/mem.c: In function 'open_port': >> include/linux/rcupdate.h:395:2: warning: passing argument 1 of 'security_locked_down' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers] 395 | ({ \ | ~^~~ 396 | RCU_LOCKDEP_WARN(!(c), "suspicious rcu_dereference_protected() usage"); \ | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 397 | rcu_check_sparse(p, space); \ | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 398 | ((typeof(*p) __force __kernel *)(p)); \ | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 399 | }) | ~~ include/linux/rcupdate.h:587:2: note: in expansion of macro '__rcu_dereference_protected' 587 | __rcu_dereference_protected((p), (c), __rcu) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/cred.h:299:2: note: in expansion of macro 'rcu_dereference_protected' 299 | rcu_dereference_protected(current->cred, 1) | ^~~~~~~~~~~~~~~~~~~~~~~~~ drivers/char/mem.c:620:28: note: in expansion of macro 'current_cred' 620 | rc = security_locked_down(current_cred(), LOCKDOWN_DEV_MEM); | ^~~~~~~~~~~~ In file included from include/linux/fs_context.h:14, from include/linux/fs_parser.h:11, from include/linux/shmem_fs.h:11, from drivers/char/mem.c:25: include/linux/security.h:1347:53: note: expected 'struct cred *' but argument is of type 'const struct cred *' 1347 | static inline int security_locked_down(struct cred *cred, enum lockdown_reason what) | ~~~~~~~~~~~~~^~~~

vim +395 include/linux/rcupdate.h 76c8eaafe4f061 Paul E. McKenney 2021-04-21 379 ca5ecddfa8fcbd Paul E. McKenney 2010-04-28 380 #define __rcu_access_pointer(p, space) \ ca5ecddfa8fcbd Paul E. McKenney 2010-04-28 381 ({ \ 7d0ae8086b8283 Paul E. McKenney 2015-03-03 382 typeof(*p) *_________p1 = (typeof(*p) *__force)READ_ONCE(p); \ 423a86a610cad1 Joel Fernandes (Google 2018-12-12 383) rcu_check_sparse(p, space); \ ca5ecddfa8fcbd Paul E. McKenney 2010-04-28 384 ((typeof(*p) __force __kernel *)(_________p1)); \ ca5ecddfa8fcbd Paul E. McKenney 2010-04-28 385 }) ca5ecddfa8fcbd Paul E. McKenney 2010-04-28 386 #define __rcu_dereference_check(p, c, space) \ ca5ecddfa8fcbd Paul E. McKenney 2010-04-28 387 ({ \ ac59853c06993a Pranith Kumar 2014-11-13 388 /* Dependency order vs. p above. */ \ 506458efaf153c Will Deacon 2017-10-24 389 typeof(*p) *________p1 = (typeof(*p) *__force)READ_ONCE(p); \ f78f5b90c4ffa5 Paul E. McKenney 2015-06-18 390 RCU_LOCKDEP_WARN(!(c), "suspicious rcu_dereference_check() usage"); \ 423a86a610cad1 Joel Fernandes (Google 2018-12-12 391) rcu_check_sparse(p, space); \ ac59853c06993a Pranith Kumar 2014-11-13 392 ((typeof(*p) __force __kernel *)(________p1)); \ ca5ecddfa8fcbd Paul E. McKenney 2010-04-28 393 }) ca5ecddfa8fcbd Paul E. McKenney 2010-04-28 394 #define __rcu_dereference_protected(p, c, space) \ ca5ecddfa8fcbd Paul E. McKenney 2010-04-28 @395 ({ \ f78f5b90c4ffa5 Paul E. McKenney 2015-06-18 396 RCU_LOCKDEP_WARN(!(c), "suspicious rcu_dereference_protected() usage"); \ 423a86a610cad1 Joel Fernandes (Google 2018-12-12 397) rcu_check_sparse(p, space); \ ca5ecddfa8fcbd Paul E. McKenney 2010-04-28 398 ((typeof(*p) __force __kernel *)(p)); \ ca5ecddfa8fcbd Paul E. McKenney 2010-04-28 399 }) 995f1405610bd8 Paul E. McKenney 2016-07-01 400 #define rcu_dereference_raw(p) \ 995f1405610bd8 Paul E. McKenney 2016-07-01 401 ({ \ 995f1405610bd8 Paul E. McKenney 2016-07-01 402 /* Dependency order vs. p above. */ \ 506458efaf153c Will Deacon 2017-10-24 403 typeof(p) ________p1 = READ_ONCE(p); \ 995f1405610bd8 Paul E. McKenney 2016-07-01 404 ((typeof(*p) __force __kernel *)(________p1)); \ 995f1405610bd8 Paul E. McKenney 2016-07-01 405 }) ca5ecddfa8fcbd Paul E. McKenney 2010-04-28 406 :::::: The code at line 395 was first introduced by commit :::::: ca5ecddfa8fcbd948c95530e7e817cee9fb43a3d rcu: define __rcu address space modifier for sparse :::::: TO: Paul E. McKenney <paulmck(a)linux.vnet.ibm.com&gt; :::::: CC: Paul E. McKenney <paulmck(a)linux.vnet.ibm.com&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org