diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/exit.c | 9 | ||||
| -rw-r--r-- | kernel/futex.c | 28 | ||||
| -rw-r--r-- | kernel/hung_task.c | 14 | ||||
| -rw-r--r-- | kernel/ptrace.c | 13 | ||||
| -rw-r--r-- | kernel/signal.c | 2 | ||||
| -rw-r--r-- | kernel/time/clockevents.c | 1 |
6 files changed, 50 insertions, 17 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index 8eab62fac37a..90757807b27b 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -1540,8 +1540,15 @@ static int wait_consider_task(struct wait_opts *wo, int ptrace, } /* dead body doesn't have much to contribute */ - if (p->exit_state == EXIT_DEAD) + if (unlikely(p->exit_state == EXIT_DEAD)) { + /* + * But do not ignore this task until the tracer does + * wait_task_zombie()->do_notify_parent(). + */ + if (likely(!ptrace) && unlikely(ptrace_reparented(p))) + wo->notask_error = 0; return 0; + } /* slay zombie? */ if (p->exit_state == EXIT_ZOMBIE) { diff --git a/kernel/futex.c b/kernel/futex.c index b104a3184132..2d311cdad5a6 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -314,17 +314,29 @@ again: #endif lock_page(page_head); + + /* + * If page_head->mapping is NULL, then it cannot be a PageAnon + * page; but it might be the ZERO_PAGE or in the gate area or + * in a special mapping (all cases which we are happy to fail); + * or it may have been a good file page when get_user_pages_fast + * found it, but truncated or holepunched or subjected to + * invalidate_complete_page2 before we got the page lock (also + * cases which we are happy to fail). And we hold a reference, + * so refcount care in invalidate_complete_page's remove_mapping + * prevents drop_caches from setting mapping to NULL beneath us. + * + * The case we do have to guard against is when memory pressure made + * shmem_writepage move it from filecache to swapcache beneath us: + * an unlikely race, but we do need to retry for page_head->mapping. + */ if (!page_head->mapping) { + int shmem_swizzled = PageSwapCache(page_head); unlock_page(page_head); put_page(page_head); - /* - * ZERO_PAGE pages don't have a mapping. Avoid a busy loop - * trying to find one. RW mapping would have COW'd (and thus - * have a mapping) so this page is RO and won't ever change. - */ - if ((page_head == ZERO_PAGE(address))) - return -EFAULT; - goto again; + if (shmem_swizzled) + goto again; + return -EFAULT; } /* diff --git a/kernel/hung_task.c b/kernel/hung_task.c index 8b1748d0172c..2e48ec0c2e91 100644 --- a/kernel/hung_task.c +++ b/kernel/hung_task.c @@ -74,11 +74,17 @@ static void check_hung_task(struct task_struct *t, unsigned long timeout) /* * Ensure the task is not frozen. - * Also, when a freshly created task is scheduled once, changes - * its state to TASK_UNINTERRUPTIBLE without having ever been - * switched out once, it musn't be checked. + * Also, skip vfork and any other user process that freezer should skip. */ - if (unlikely(t->flags & PF_FROZEN || !switch_count)) + if (unlikely(t->flags & (PF_FROZEN | PF_FREEZER_SKIP))) + return; + + /* + * When a freshly created task is scheduled once, changes its state to + * TASK_UNINTERRUPTIBLE without having ever been switched out once, it + * musn't be checked. + */ + if (unlikely(!switch_count)) return; if (switch_count != t->last_switch_count) { diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 24d04477b257..78ab24a7b0e4 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -96,9 +96,20 @@ void __ptrace_unlink(struct task_struct *child) */ if (!(child->flags & PF_EXITING) && (child->signal->flags & SIGNAL_STOP_STOPPED || - child->signal->group_stop_count)) + child->signal->group_stop_count)) { child->jobctl |= JOBCTL_STOP_PENDING; + /* + * This is only possible if this thread was cloned by the + * traced task running in the stopped group, set the signal + * for the future reports. + * FIXME: we should change ptrace_init_task() to handle this + * case. + */ + if (!(child->jobctl & JOBCTL_STOP_SIGMASK)) + child->jobctl |= SIGSTOP; + } + /* * If transition to TASK_STOPPED is pending or in TASK_TRACED, kick * @child in the butt. Note that @resume should be used iff @child diff --git a/kernel/signal.c b/kernel/signal.c index d9cc78c9a53b..194c3667faae 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2064,8 +2064,6 @@ static bool do_signal_stop(int signr) */ if (!(sig->flags & SIGNAL_STOP_STOPPED)) sig->group_exit_code = signr; - else - WARN_ON_ONCE(!current->ptrace); sig->group_stop_count = 0; diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c index c4eb71c8b2ea..1ecd6ba36d6c 100644 --- a/kernel/time/clockevents.c +++ b/kernel/time/clockevents.c @@ -387,7 +387,6 @@ void clockevents_exchange_device(struct clock_event_device *old, * released list and do a notify add later. */ if (old) { - old->event_handler = clockevents_handle_noop; clockevents_set_mode(old, CLOCK_EVT_MODE_UNUSED); list_del(&old->list); list_add(&old->list, &clockevents_released); |