Re: [PATCH v3 1/2] Add CABA tree to task_struct

From: kernel test robot
Date: Thu Sep 08 2022 - 21:02:53 EST


Hi Pavel,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on shuah-kselftest/next]
[also build test WARNING on kees/for-next/execve tip/sched/core linus/master v6.0-rc4 next-20220908]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url: https://github.com/intel-lab-lkp/linux/commits/Pavel-Tikhomirov/Introduce-CABA-helper-process-tree/20220908-220639
base: https://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest.git next
config: microblaze-randconfig-s053-20220907 (https://download.01.org/0day-ci/archive/20220909/202209090830.H0tKErRt-lkp@xxxxxxxxx/config)
compiler: microblaze-linux-gcc (GCC) 12.1.0
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# apt-get install sparse
# sparse version: v0.6.4-39-gce1a6720-dirty
# https://github.com/intel-lab-lkp/linux/commit/17a897a33137d4f49f99c8be8d619f6f711fccdb
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Pavel-Tikhomirov/Introduce-CABA-helper-process-tree/20220908-220639
git checkout 17a897a33137d4f49f99c8be8d619f6f711fccdb
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=microblaze SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@xxxxxxxxx>

sparse warnings: (new ones prefixed by >>)
kernel/fork.c:1307:22: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct file *[assigned] old_exe_file @@ got struct file [noderef] __rcu * @@
kernel/fork.c:1307:22: sparse: expected struct file *[assigned] old_exe_file
kernel/fork.c:1307:22: sparse: got struct file [noderef] __rcu *
kernel/fork.c:1638:38: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct refcount_struct [usertype] *r @@ got struct refcount_struct [noderef] __rcu * @@
kernel/fork.c:1638:38: sparse: expected struct refcount_struct [usertype] *r
kernel/fork.c:1638:38: sparse: got struct refcount_struct [noderef] __rcu *
kernel/fork.c:1647:31: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@
kernel/fork.c:1647:31: sparse: expected struct spinlock [usertype] *lock
kernel/fork.c:1647:31: sparse: got struct spinlock [noderef] __rcu *
kernel/fork.c:1648:36: sparse: sparse: incorrect type in argument 2 (different address spaces) @@ expected void const * @@ got struct k_sigaction [noderef] __rcu * @@
kernel/fork.c:1648:36: sparse: expected void const *
kernel/fork.c:1648:36: sparse: got struct k_sigaction [noderef] __rcu *
kernel/fork.c:1649:33: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@
kernel/fork.c:1649:33: sparse: expected struct spinlock [usertype] *lock
kernel/fork.c:1649:33: sparse: got struct spinlock [noderef] __rcu *
kernel/fork.c:2077:31: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@
kernel/fork.c:2077:31: sparse: expected struct spinlock [usertype] *lock
kernel/fork.c:2077:31: sparse: got struct spinlock [noderef] __rcu *
kernel/fork.c:2081:33: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@
kernel/fork.c:2081:33: sparse: expected struct spinlock [usertype] *lock
kernel/fork.c:2081:33: sparse: got struct spinlock [noderef] __rcu *
kernel/fork.c:2403:32: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct task_struct [noderef] __rcu *real_parent @@ got struct task_struct *register [addressable] [toplevel] current @@
kernel/fork.c:2403:32: sparse: expected struct task_struct [noderef] __rcu *real_parent
kernel/fork.c:2403:32: sparse: got struct task_struct *register [addressable] [toplevel] current
>> kernel/fork.c:2407:17: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct task_struct [noderef] __rcu *caba @@ got struct task_struct *register [addressable] [toplevel] current @@
kernel/fork.c:2407:17: sparse: expected struct task_struct [noderef] __rcu *caba
kernel/fork.c:2407:17: sparse: got struct task_struct *register [addressable] [toplevel] current
kernel/fork.c:2413:27: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@
kernel/fork.c:2413:27: sparse: expected struct spinlock [usertype] *lock
kernel/fork.c:2413:27: sparse: got struct spinlock [noderef] __rcu *
kernel/fork.c:2460:54: sparse: sparse: incorrect type in argument 2 (different address spaces) @@ expected struct list_head *head @@ got struct list_head [noderef] __rcu * @@
kernel/fork.c:2460:54: sparse: expected struct list_head *head
kernel/fork.c:2460:54: sparse: got struct list_head [noderef] __rcu *
kernel/fork.c:2461:51: sparse: sparse: incorrect type in argument 2 (different address spaces) @@ expected struct list_head *head @@ got struct list_head [noderef] __rcu * @@
kernel/fork.c:2461:51: sparse: expected struct list_head *head
kernel/fork.c:2461:51: sparse: got struct list_head [noderef] __rcu *
kernel/fork.c:2482:29: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@
kernel/fork.c:2482:29: sparse: expected struct spinlock [usertype] *lock
kernel/fork.c:2482:29: sparse: got struct spinlock [noderef] __rcu *
kernel/fork.c:2503:29: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@
kernel/fork.c:2503:29: sparse: expected struct spinlock [usertype] *lock
kernel/fork.c:2503:29: sparse: got struct spinlock [noderef] __rcu *
kernel/fork.c:2530:28: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct sighand_struct *sighand @@ got struct sighand_struct [noderef] __rcu *sighand @@
kernel/fork.c:2530:28: sparse: expected struct sighand_struct *sighand
kernel/fork.c:2530:28: sparse: got struct sighand_struct [noderef] __rcu *sighand
kernel/fork.c:2559:31: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@
kernel/fork.c:2559:31: sparse: expected struct spinlock [usertype] *lock
kernel/fork.c:2559:31: sparse: got struct spinlock [noderef] __rcu *
kernel/fork.c:2561:33: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct spinlock [usertype] *lock @@ got struct spinlock [noderef] __rcu * @@
kernel/fork.c:2561:33: sparse: expected struct spinlock [usertype] *lock
kernel/fork.c:2561:33: sparse: got struct spinlock [noderef] __rcu *
kernel/fork.c:2997:24: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct task_struct *[assigned] parent @@ got struct task_struct [noderef] __rcu *real_parent @@
kernel/fork.c:2997:24: sparse: expected struct task_struct *[assigned] parent
kernel/fork.c:2997:24: sparse: got struct task_struct [noderef] __rcu *real_parent
kernel/fork.c:3078:43: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct refcount_struct const [usertype] *r @@ got struct refcount_struct [noderef] __rcu * @@
kernel/fork.c:3078:43: sparse: expected struct refcount_struct const [usertype] *r
kernel/fork.c:3078:43: sparse: got struct refcount_struct [noderef] __rcu *
kernel/fork.c:1742:9: sparse: sparse: dereference of noderef expression
kernel/fork.c:2122:22: sparse: sparse: dereference of noderef expression
kernel/fork.c: note: in included file (through include/uapi/asm-generic/bpf_perf_event.h, arch/microblaze/include/generated/uapi/asm/bpf_perf_event.h, ...):
include/linux/ptrace.h:210:45: sparse: sparse: incorrect type in argument 2 (different address spaces) @@ expected struct task_struct *new_parent @@ got struct task_struct [noderef] __rcu *parent @@
include/linux/ptrace.h:210:45: sparse: expected struct task_struct *new_parent
include/linux/ptrace.h:210:45: sparse: got struct task_struct [noderef] __rcu *parent
include/linux/ptrace.h:210:62: sparse: sparse: incorrect type in argument 3 (different address spaces) @@ expected struct cred const *ptracer_cred @@ got struct cred const [noderef] __rcu *ptracer_cred @@
include/linux/ptrace.h:210:62: sparse: expected struct cred const *ptracer_cred
include/linux/ptrace.h:210:62: sparse: got struct cred const [noderef] __rcu *ptracer_cred
kernel/fork.c:2458:59: sparse: sparse: dereference of noderef expression
kernel/fork.c:2459:59: sparse: sparse: dereference of noderef expression

vim +2407 kernel/fork.c

2355
2356 /*
2357 * Ensure that the cgroup subsystem policies allow the new process to be
2358 * forked. It should be noted that the new process's css_set can be changed
2359 * between here and cgroup_post_fork() if an organisation operation is in
2360 * progress.
2361 */
2362 retval = cgroup_can_fork(p, args);
2363 if (retval)
2364 goto bad_fork_put_pidfd;
2365
2366 /*
2367 * Now that the cgroups are pinned, re-clone the parent cgroup and put
2368 * the new task on the correct runqueue. All this *before* the task
2369 * becomes visible.
2370 *
2371 * This isn't part of ->can_fork() because while the re-cloning is
2372 * cgroup specific, it unconditionally needs to place the task on a
2373 * runqueue.
2374 */
2375 sched_cgroup_fork(p, args);
2376
2377 /*
2378 * From this point on we must avoid any synchronous user-space
2379 * communication until we take the tasklist-lock. In particular, we do
2380 * not want user-space to be able to predict the process start-time by
2381 * stalling fork(2) after we recorded the start_time but before it is
2382 * visible to the system.
2383 */
2384
2385 p->start_time = ktime_get_ns();
2386 p->start_boottime = ktime_get_boottime_ns();
2387
2388 /*
2389 * Make it visible to the rest of the system, but dont wake it up yet.
2390 * Need tasklist lock for parent etc handling!
2391 */
2392 write_lock_irq(&tasklist_lock);
2393
2394 /* CLONE_PARENT re-uses the old parent */
2395 if (clone_flags & (CLONE_PARENT|CLONE_THREAD)) {
2396 p->real_parent = current->real_parent;
2397 p->parent_exec_id = current->parent_exec_id;
2398 if (clone_flags & CLONE_THREAD)
2399 p->exit_signal = -1;
2400 else
2401 p->exit_signal = current->group_leader->exit_signal;
2402 } else {
2403 p->real_parent = current;
2404 p->parent_exec_id = current->self_exec_id;
2405 p->exit_signal = args->exit_signal;
2406 }
> 2407 p->caba = current;
2408
2409 klp_copy_process(p);
2410
2411 sched_core_fork(p);
2412
2413 spin_lock(&current->sighand->siglock);
2414
2415 /*
2416 * Copy seccomp details explicitly here, in case they were changed
2417 * before holding sighand lock.
2418 */
2419 copy_seccomp(p);
2420
2421 rv_task_fork(p);
2422
2423 rseq_fork(p, clone_flags);
2424
2425 /* Don't start children in a dying pid namespace */
2426 if (unlikely(!(ns_of_pid(pid)->pid_allocated & PIDNS_ADDING))) {
2427 retval = -ENOMEM;
2428 goto bad_fork_cancel_cgroup;
2429 }
2430
2431 /* Let kill terminate clone/fork in the middle */
2432 if (fatal_signal_pending(current)) {
2433 retval = -EINTR;
2434 goto bad_fork_cancel_cgroup;
2435 }
2436
2437 init_task_pid_links(p);
2438 if (likely(p->pid)) {
2439 ptrace_init_task(p, (clone_flags & CLONE_PTRACE) || trace);
2440
2441 init_task_pid(p, PIDTYPE_PID, pid);
2442 if (thread_group_leader(p)) {
2443 init_task_pid(p, PIDTYPE_TGID, pid);
2444 init_task_pid(p, PIDTYPE_PGID, task_pgrp(current));
2445 init_task_pid(p, PIDTYPE_SID, task_session(current));
2446
2447 if (is_child_reaper(pid)) {
2448 ns_of_pid(pid)->child_reaper = p;
2449 p->signal->flags |= SIGNAL_UNKILLABLE;
2450 }
2451 p->signal->shared_pending.signal = delayed.signal;
2452 p->signal->tty = tty_kref_get(current->signal->tty);
2453 /*
2454 * Inherit has_child_subreaper flag under the same
2455 * tasklist_lock with adding child to the process tree
2456 * for propagate_has_child_subreaper optimization.
2457 */
2458 p->signal->has_child_subreaper = p->real_parent->signal->has_child_subreaper ||
2459 p->real_parent->signal->is_child_subreaper;
2460 list_add_tail(&p->sibling, &p->real_parent->children);
2461 list_add_tail(&p->cabd, &p->caba->cabds);
2462 list_add_tail_rcu(&p->tasks, &init_task.tasks);
2463 attach_pid(p, PIDTYPE_TGID);
2464 attach_pid(p, PIDTYPE_PGID);
2465 attach_pid(p, PIDTYPE_SID);
2466 __this_cpu_inc(process_counts);
2467 } else {
2468 current->signal->nr_threads++;
2469 atomic_inc(&current->signal->live);
2470 refcount_inc(&current->signal->sigcnt);
2471 task_join_group_stop(p);
2472 list_add_tail_rcu(&p->thread_group,
2473 &p->group_leader->thread_group);
2474 list_add_tail_rcu(&p->thread_node,
2475 &p->signal->thread_head);
2476 }
2477 attach_pid(p, PIDTYPE_PID);
2478 nr_threads++;
2479 }
2480 total_forks++;
2481 hlist_del_init(&delayed.node);
2482 spin_unlock(&current->sighand->siglock);
2483 syscall_tracepoint_update(p);
2484 write_unlock_irq(&tasklist_lock);
2485
2486 if (pidfile)
2487 fd_install(pidfd, pidfile);
2488
2489 proc_fork_connector(p);
2490 sched_post_fork(p);
2491 cgroup_post_fork(p, args);
2492 perf_event_fork(p);
2493
2494 trace_task_newtask(p, clone_flags);
2495 uprobe_copy_process(p, clone_flags);
2496
2497 copy_oom_score_adj(clone_flags, p);
2498
2499 return p;
2500
2501 bad_fork_cancel_cgroup:
2502 sched_core_free(p);
2503 spin_unlock(&current->sighand->siglock);
2504 write_unlock_irq(&tasklist_lock);
2505 cgroup_cancel_fork(p, args);
2506 bad_fork_put_pidfd:
2507 if (clone_flags & CLONE_PIDFD) {
2508 fput(pidfile);
2509 put_unused_fd(pidfd);
2510 }
2511 bad_fork_free_pid:
2512 if (pid != &init_struct_pid)
2513 free_pid(pid);
2514 bad_fork_cleanup_thread:
2515 exit_thread(p);
2516 bad_fork_cleanup_io:
2517 if (p->io_context)
2518 exit_io_context(p);
2519 bad_fork_cleanup_namespaces:
2520 exit_task_namespaces(p);
2521 bad_fork_cleanup_mm:
2522 if (p->mm) {
2523 mm_clear_owner(p->mm, p);
2524 mmput(p->mm);
2525 }
2526 bad_fork_cleanup_signal:
2527 if (!(clone_flags & CLONE_THREAD))
2528 free_signal_struct(p->signal);
2529 bad_fork_cleanup_sighand:
2530 __cleanup_sighand(p->sighand);
2531 bad_fork_cleanup_fs:
2532 exit_fs(p); /* blocking */
2533 bad_fork_cleanup_files:
2534 exit_files(p); /* blocking */
2535 bad_fork_cleanup_semundo:
2536 exit_sem(p);
2537 bad_fork_cleanup_security:
2538 security_task_free(p);
2539 bad_fork_cleanup_audit:
2540 audit_free(p);
2541 bad_fork_cleanup_perf:
2542 perf_event_free_task(p);
2543 bad_fork_cleanup_policy:
2544 lockdep_free_task(p);
2545 #ifdef CONFIG_NUMA
2546 mpol_put(p->mempolicy);
2547 #endif
2548 bad_fork_cleanup_delayacct:
2549 delayacct_tsk_free(p);
2550 bad_fork_cleanup_count:
2551 dec_rlimit_ucounts(task_ucounts(p), UCOUNT_RLIMIT_NPROC, 1);
2552 exit_creds(p);
2553 bad_fork_free:
2554 WRITE_ONCE(p->__state, TASK_DEAD);
2555 exit_task_stack_account(p);
2556 put_task_stack(p);
2557 delayed_free_task(p);
2558 fork_out:
2559 spin_lock_irq(&current->sighand->siglock);
2560 hlist_del_init(&delayed.node);
2561 spin_unlock_irq(&current->sighand->siglock);
2562 return ERR_PTR(retval);
2563 }
2564

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