[tip:timers/core 2/58] kernel/time/posix-cpu-timers.c:1307:9: sparse: sparse: incorrect type in argument 1 (different address spaces)
kernel test robot <[email protected]>
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tree: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git timers/core head: 4fa377c19e111c539a530a8200996b911ceff9ff commit: a73d7f98e41a96d6e1bcb0e731ab185d9d67878e [2/58] posix-cpu-timers: Don't abuse lock_task_sighand() in handle_posix_cpu_timers() config: microblaze-randconfig-r122-20260812 (https://download.01.org/0day-ci/archive/20260813/[email protected]/config) compiler: microblaze-linux-gcc (GCC) 11.5.0 sparse: v0.6.5-rc1 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260813/[email protected]/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <[email protected]> | Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/ sparse warnings: (new ones prefixed by >>) >> kernel/time/posix-cpu-timers.c:1307:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/time/posix-cpu-timers.c:1307:9: sparse: expected struct spinlock [usertype] *lock kernel/time/posix-cpu-timers.c:1307:9: sparse: got struct spinlock [noderef] __rcu * kernel/time/posix-cpu-timers.c:1367:36: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ kernel/time/posix-cpu-timers.c:1367:36: sparse: expected struct spinlock [usertype] *lock kernel/time/posix-cpu-timers.c:1367:36: sparse: got struct spinlock [noderef] __rcu * kernel/time/posix-cpu-timers.c: note: in included file: include/linux/sched/signal.h:749:37: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ include/linux/sched/signal.h:749:37: sparse: expected struct spinlock [usertype] *lock include/linux/sched/signal.h:749:37: sparse: got struct spinlock [noderef] __rcu * include/linux/sched/signal.h:749:37: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ include/linux/sched/signal.h:749:37: sparse: expected struct spinlock [usertype] *lock include/linux/sched/signal.h:749:37: sparse: got struct spinlock [noderef] __rcu * include/linux/sched/signal.h:749:37: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ include/linux/sched/signal.h:749:37: sparse: expected struct spinlock [usertype] *lock include/linux/sched/signal.h:749:37: sparse: got struct spinlock [noderef] __rcu * include/linux/sched/signal.h:749:37: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ include/linux/sched/signal.h:749:37: sparse: expected struct spinlock [usertype] *lock include/linux/sched/signal.h:749:37: sparse: got struct spinlock [noderef] __rcu * include/linux/sched/signal.h:749:37: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@ include/linux/sched/signal.h:749:37: sparse: expected struct spinlock [usertype] *lock include/linux/sched/signal.h:749:37: sparse: got struct spinlock [noderef] __rcu * vim +1307 kernel/time/posix-cpu-timers.c 1296 1297 static void handle_posix_cpu_timers(struct task_struct *tsk) 1298 { 1299 struct k_itimer *timer, *next; 1300 unsigned long flags, start; 1301 LIST_HEAD(firing); 1302 1303 /* 1304 * tsk is current and ->sighand is stable, see the 1305 * tsk->exit_state check in run_posix_cpu_timers() 1306 */ > 1307 spin_lock_irqsave(&tsk->sighand->siglock, flags); 1308 1309 do { 1310 /* 1311 * On RT locking sighand lock does not disable interrupts, 1312 * so this needs to be careful vs. ticks. Store the current 1313 * jiffies value. 1314 */ 1315 start = READ_ONCE(jiffies); 1316 barrier(); 1317 1318 /* 1319 * Here we take off tsk->signal->cpu_timers[N] and 1320 * tsk->cpu_timers[N] all the timers that are firing, and 1321 * put them on the firing list. 1322 */ 1323 check_thread_timers(tsk, &firing); 1324 1325 check_process_timers(tsk, &firing); 1326 1327 /* 1328 * The above timer checks have updated the expiry cache and 1329 * because nothing can have queued or modified timers after 1330 * sighand lock was taken above it is guaranteed to be 1331 * consistent. So the next timer interrupt fastpath check 1332 * will find valid data. 1333 * 1334 * If timer expiry runs in the timer interrupt context then 1335 * the loop is not relevant as timers will be directly 1336 * expired in interrupt context. The stub function below 1337 * returns always true which allows the compiler to 1338 * optimize the loop out. 1339 * 1340 * If timer expiry is deferred to task work context then 1341 * the following rules apply: 1342 * 1343 * - On !RT kernels no tick can have happened on this CPU 1344 * after sighand lock was acquired because interrupts are 1345 * disabled. So reenabling task work before dropping 1346 * sighand lock and reenabling interrupts is race free. 1347 * 1348 * - On RT kernels ticks might have happened but the tick 1349 * work ignored posix CPU timer handling because the 1350 * CPUTIMERS_WORK_SCHEDULED bit is set. Reenabling work 1351 * must be done very carefully including a check whether 1352 * ticks have happened since the start of the timer 1353 * expiry checks. posix_cpu_timers_enable_work() takes 1354 * care of that and eventually lets the expiry checks 1355 * run again. 1356 */ 1357 } while (!posix_cpu_timers_enable_work(tsk, start)); 1358 1359 /* 1360 * We must release sighand lock before taking any timer's lock. 1361 * There is a potential race with timer deletion here, as the 1362 * siglock now protects our private firing list. We have set 1363 * the firing flag in each timer, so that a deletion attempt 1364 * that gets the timer lock before we do will give it up and 1365 * spin until we've taken care of that timer below. 1366 */ 1367 spin_unlock_irqrestore(&tsk->sighand->siglock, flags); 1368 1369 /* 1370 * Now that all the timers on our list have the firing flag, 1371 * no one will touch their list entries but us. We'll take 1372 * each timer's lock before clearing its firing flag, so no 1373 * timer call will interfere. 1374 */ 1375 list_for_each_entry_safe(timer, next, &firing, it.cpu.elist) { 1376 bool cpu_firing; 1377 1378 /* 1379 * spin_lock() is sufficient here even independent of the 1380 * expiry context. If expiry happens in hard interrupt 1381 * context it's obvious. For task work context it's safe 1382 * because all other operations on timer::it_lock happen in 1383 * task context (syscall or exit). 1384 */ 1385 spin_lock(&timer->it_lock); 1386 list_del_init(&timer->it.cpu.elist); 1387 cpu_firing = timer->it.cpu.firing; 1388 timer->it.cpu.firing = false; 1389 /* 1390 * If the firing flag is cleared then this raced with a 1391 * timer rearm/delete operation. So don't generate an 1392 * event. 1393 */ 1394 if (likely(cpu_firing)) 1395 cpu_timer_fire(timer); 1396 /* See posix_cpu_timer_wait_running() */ 1397 rcu_assign_pointer(timer->it.cpu.handling, NULL); 1398 spin_unlock(&timer->it_lock); 1399 } 1400 } 1401 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki