[kbuild-all] [linux-stable-rc:linux-5.4.y 4356/5111] include/linux/rcupdate.h:651:9: sparse: sparse: too many warnings

tree: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-5.4.y head: ed1728340b22cd2d0143fcc832c76ac40f409888 commit: 5f2d04139aa5ed04eab54b84e8a25bab87a2449c [4356/5111] signal: Extend exec_id to 64bits config: s390-randconfig-s002-20200517 (attached as .config) reproduce: # apt-get install sparse # sparse version: v0.6.1-193-gb8fad4bc-dirty git checkout 5f2d04139aa5ed04eab54b84e8a25bab87a2449c # save the attached .config to linux build tree make C=1 ARCH=s390 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' If you fix the issue, kindly add following tag as appropriate Reported-by: kbuild test robot <lkp(a)intel.com&gt; sparse warnings: (new ones prefixed by >>) kernel/signal.c:2030:24: sparse: expected struct task_struct *parent kernel/signal.c:2030:24: sparse: got struct task_struct [noderef] <asn:4> *real_parent kernel/signal.c:2511:52: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct task_struct *tsk @@ got struct task_structstruct task_struct *tsk @@ kernel/signal.c:2511:52: sparse: expected struct task_struct *tsk kernel/signal.c:2511:52: sparse: got struct task_struct [noderef] <asn:4> *parent kernel/signal.c:2513:49: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected void const volatile *p @@ got struct cred const [noderef] <asn:4>void const volatile *p @@ kernel/signal.c:2513:49: sparse: expected void const volatile *p kernel/signal.c:2513:49: sparse: got struct cred const [noderef] <asn:4> *[noderef] <asn:4> * kernel/signal.c:2513:49: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected void const volatile *p @@ got struct cred const [noderef] <asn:4>void const volatile *p @@ kernel/signal.c:2513:49: sparse: expected void const volatile *p kernel/signal.c:2513:49: sparse: got struct cred const [noderef] <asn:4> *[noderef] <asn:4> * kernel/signal.c:3015:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3015:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3015:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3015:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3046:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3046:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3046:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3046:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3087:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3087:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3103:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3103:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3495:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3495:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3495:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3495:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3495:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3495:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3528:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3528:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3528:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3528:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3528:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3528:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3561:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3561:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3561:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3561:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3561:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3561:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3592:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3592:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3592:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3592:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3592:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3592:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3681:46: sparse: sparse: incorrect type in argument 2 (different address spaces) @@ expected struct siginfo const [noderef] [usertype] <asn:1> *from @@ got deref] [usertype] <asn:1> *from @@ kernel/signal.c:3681:46: sparse: expected struct siginfo const [noderef] [usertype] <asn:1> *from kernel/signal.c:3681:46: sparse: got struct siginfo [usertype] *info kernel/signal.c:3713:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3713:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3863:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3863:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3874:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3874:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3903:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3903:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3914:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:3914:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4042:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4042:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4042:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4042:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4110:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4110:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4110:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4110:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4146:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4146:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4162:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4162:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4185:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4185:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4185:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4185:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4233:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4233:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4233:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4233:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4258:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4258:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4258:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4258:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4305:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4305:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4305:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4305:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4341:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4341:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4341:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4341:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4409:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4409:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4456:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4456:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4470:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:4470:1: sparse: sparse: Using plain integer as NULL pointer kernel/signal.c:1294:9: sparse: sparse: context imbalance in 'do_send_sig_info' - different lock contexts for basic block include/linux/rcupdate.h:649:9: sparse: sparse: context imbalance in '__lock_task_sighand' - different lock contexts for basic block vim +651 include/linux/rcupdate.h ^1da177e4c3f41 Linus Torvalds 2005-04-16 603 ^1da177e4c3f41 Linus Torvalds 2005-04-16 604 /* ^1da177e4c3f41 Linus Torvalds 2005-04-16 605 * So where is rcu_write_lock()? It does not exist, as there is no ^1da177e4c3f41 Linus Torvalds 2005-04-16 606 * way for writers to lock out RCU readers. This is a feature, not ^1da177e4c3f41 Linus Torvalds 2005-04-16 607 * a bug -- this property is what provides RCU's performance benefits. ^1da177e4c3f41 Linus Torvalds 2005-04-16 608 * Of course, writers must coordinate with each other. The normal ^1da177e4c3f41 Linus Torvalds 2005-04-16 609 * spinlock primitives work well for this, but any other technique may be ^1da177e4c3f41 Linus Torvalds 2005-04-16 610 * used as well. RCU does not care how the writers keep out of each ^1da177e4c3f41 Linus Torvalds 2005-04-16 611 * others' way, as long as they do so. ^1da177e4c3f41 Linus Torvalds 2005-04-16 612 */ 3d76c082907e8f Paul E. McKenney 2009-09-28 613 3d76c082907e8f Paul E. McKenney 2009-09-28 614 /** ca5ecddfa8fcbd Paul E. McKenney 2010-04-28 615 * rcu_read_unlock() - marks the end of an RCU read-side critical section. 3d76c082907e8f Paul E. McKenney 2009-09-28 616 * f27bc4873fa8b7 Paul E. McKenney 2014-05-04 617 * In most situations, rcu_read_unlock() is immune from deadlock. f27bc4873fa8b7 Paul E. McKenney 2014-05-04 618 * However, in kernels built with CONFIG_RCU_BOOST, rcu_read_unlock() f27bc4873fa8b7 Paul E. McKenney 2014-05-04 619 * is responsible for deboosting, which it does via rt_mutex_unlock(). f27bc4873fa8b7 Paul E. McKenney 2014-05-04 620 * Unfortunately, this function acquires the scheduler's runqueue and f27bc4873fa8b7 Paul E. McKenney 2014-05-04 621 * priority-inheritance spinlocks. This means that deadlock could result f27bc4873fa8b7 Paul E. McKenney 2014-05-04 622 * if the caller of rcu_read_unlock() already holds one of these locks or ec84b27f9b3b56 Anna-Maria Gleixner 2018-05-25 623 * any lock that is ever acquired while holding them. f27bc4873fa8b7 Paul E. McKenney 2014-05-04 624 * f27bc4873fa8b7 Paul E. McKenney 2014-05-04 625 * That said, RCU readers are never priority boosted unless they were f27bc4873fa8b7 Paul E. McKenney 2014-05-04 626 * preempted. Therefore, one way to avoid deadlock is to make sure f27bc4873fa8b7 Paul E. McKenney 2014-05-04 627 * that preemption never happens within any RCU read-side critical f27bc4873fa8b7 Paul E. McKenney 2014-05-04 628 * section whose outermost rcu_read_unlock() is called with one of f27bc4873fa8b7 Paul E. McKenney 2014-05-04 629 * rt_mutex_unlock()'s locks held. Such preemption can be avoided in f27bc4873fa8b7 Paul E. McKenney 2014-05-04 630 * a number of ways, for example, by invoking preempt_disable() before f27bc4873fa8b7 Paul E. McKenney 2014-05-04 631 * critical section's outermost rcu_read_lock(). f27bc4873fa8b7 Paul E. McKenney 2014-05-04 632 * f27bc4873fa8b7 Paul E. McKenney 2014-05-04 633 * Given that the set of locks acquired by rt_mutex_unlock() might change f27bc4873fa8b7 Paul E. McKenney 2014-05-04 634 * at any time, a somewhat more future-proofed approach is to make sure f27bc4873fa8b7 Paul E. McKenney 2014-05-04 635 * that that preemption never happens within any RCU read-side critical f27bc4873fa8b7 Paul E. McKenney 2014-05-04 636 * section whose outermost rcu_read_unlock() is called with irqs disabled. f27bc4873fa8b7 Paul E. McKenney 2014-05-04 637 * This approach relies on the fact that rt_mutex_unlock() currently only f27bc4873fa8b7 Paul E. McKenney 2014-05-04 638 * acquires irq-disabled locks. f27bc4873fa8b7 Paul E. McKenney 2014-05-04 639 * f27bc4873fa8b7 Paul E. McKenney 2014-05-04 640 * The second of these two approaches is best in most situations, f27bc4873fa8b7 Paul E. McKenney 2014-05-04 641 * however, the first approach can also be useful, at least to those f27bc4873fa8b7 Paul E. McKenney 2014-05-04 642 * developers willing to keep abreast of the set of locks acquired by f27bc4873fa8b7 Paul E. McKenney 2014-05-04 643 * rt_mutex_unlock(). f27bc4873fa8b7 Paul E. McKenney 2014-05-04 644 * 3d76c082907e8f Paul E. McKenney 2009-09-28 645 * See rcu_read_lock() for more information. 3d76c082907e8f Paul E. McKenney 2009-09-28 646 */ bc33f24bdca8b6 Paul E. McKenney 2009-08-22 647 static inline void rcu_read_unlock(void) bc33f24bdca8b6 Paul E. McKenney 2009-08-22 648 { f78f5b90c4ffa5 Paul E. McKenney 2015-06-18 649 RCU_LOCKDEP_WARN(!rcu_is_watching(), bde23c6892878e Heiko Carstens 2012-02-01 650 "rcu_read_unlock() used illegally while idle"); bc33f24bdca8b6 Paul E. McKenney 2009-08-22 @651 __release(RCU); bc33f24bdca8b6 Paul E. McKenney 2009-08-22 652 __rcu_read_unlock(); d24209bb689e2c Paul E. McKenney 2015-01-21 653 rcu_lock_release(&rcu_lock_map); /* Keep acq info for rls diags. */ bc33f24bdca8b6 Paul E. McKenney 2009-08-22 654 } ^1da177e4c3f41 Linus Torvalds 2005-04-16 655 :::::: The code at line 651 was first introduced by commit :::::: bc33f24bdca8b6e97376e3a182ab69e6cdefa989 rcu: Consolidate sparse and lockdep declarations in include/linux/rcupdate.h :::::: TO: Paul E. McKenney <paulmck(a)linux.vnet.ibm.com&gt; :::::: CC: Ingo Molnar <mingo(a)elte.hu&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org