diff options
Diffstat (limited to 'kernel/exit.c')
| -rw-r--r-- | kernel/exit.c | 58 |
1 files changed, 34 insertions, 24 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index 389a88cb3081..727150f28103 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -66,7 +66,6 @@ #include <linux/uaccess.h> #include <asm/unistd.h> -#include <asm/pgtable.h> #include <asm/mmu_context.h> static void __unhash_process(struct task_struct *p, bool group_dead) @@ -219,6 +218,7 @@ repeat: write_unlock_irq(&tasklist_lock); proc_flush_pid(thread_pid); + put_pid(thread_pid); release_thread(p); put_task_struct_rcu_user(p); @@ -227,8 +227,9 @@ repeat: goto repeat; } -void rcuwait_wake_up(struct rcuwait *w) +int rcuwait_wake_up(struct rcuwait *w) { + int ret = 0; struct task_struct *task; rcu_read_lock(); @@ -236,7 +237,7 @@ void rcuwait_wake_up(struct rcuwait *w) /* * Order condition vs @task, such that everything prior to the load * of @task is visible. This is the condition as to why the user called - * rcuwait_trywake() in the first place. Pairs with set_current_state() + * rcuwait_wake() in the first place. Pairs with set_current_state() * barrier (A) in rcuwait_wait_event(). * * WAIT WAKE @@ -248,8 +249,10 @@ void rcuwait_wake_up(struct rcuwait *w) task = rcu_dereference(w->task); if (task) - wake_up_process(task); + ret = wake_up_process(task); rcu_read_unlock(); + + return ret; } EXPORT_SYMBOL_GPL(rcuwait_wake_up); @@ -437,17 +440,17 @@ static void exit_mm(void) sync_mm_rss(mm); /* * Serialize with any possible pending coredump. - * We must hold mmap_sem around checking core_state + * We must hold mmap_lock around checking core_state * and clearing tsk->mm. The core-inducing thread * will increment ->nr_threads for each thread in the * group with ->mm != NULL. */ - down_read(&mm->mmap_sem); + mmap_read_lock(mm); core_state = mm->core_state; if (core_state) { struct core_thread self; - up_read(&mm->mmap_sem); + mmap_read_unlock(mm); self.task = current; self.next = xchg(&core_state->dumper.next, &self); @@ -465,14 +468,14 @@ static void exit_mm(void) freezable_schedule(); } __set_current_state(TASK_RUNNING); - down_read(&mm->mmap_sem); + mmap_read_lock(mm); } mmgrab(mm); BUG_ON(mm != current->active_mm); /* more a memory barrier than a real lock */ task_lock(current); current->mm = NULL; - up_read(&mm->mmap_sem); + mmap_read_unlock(mm); enter_lazy_tlb(mm, current); task_unlock(current); mm_update_next_owner(mm); @@ -707,8 +710,12 @@ void __noreturn do_exit(long code) struct task_struct *tsk = current; int group_dead; - profile_task_exit(tsk); - kcov_task_exit(tsk); + /* + * We can get here from a kernel oops, sometimes with preemption off. + * Start by checking for critical errors. + * Then fix up important state like USER_DS and preemption. + * Then do everything else. + */ WARN_ON(blk_needs_flush_plug(tsk)); @@ -726,6 +733,16 @@ void __noreturn do_exit(long code) */ set_fs(USER_DS); + if (unlikely(in_atomic())) { + pr_info("note: %s[%d] exited with preempt_count %d\n", + current->comm, task_pid_nr(current), + preempt_count()); + preempt_count_set(PREEMPT_ENABLED); + } + + profile_task_exit(tsk); + kcov_task_exit(tsk); + ptrace_event(PTRACE_EVENT_EXIT, code); validate_creds_for_do_exit(tsk); @@ -743,13 +760,6 @@ void __noreturn do_exit(long code) exit_signals(tsk); /* sets PF_EXITING */ - if (unlikely(in_atomic())) { - pr_info("note: %s[%d] exited with preempt_count %d\n", - current->comm, task_pid_nr(current), - preempt_count()); - preempt_count_set(PREEMPT_ENABLED); - } - /* sync mm's RSS info before statistics gathering */ if (tsk->mm) sync_mm_rss(tsk->mm); @@ -1557,7 +1567,7 @@ SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *, if (!infop) return err; - if (!user_access_begin(infop, sizeof(*infop))) + if (!user_write_access_begin(infop, sizeof(*infop))) return -EFAULT; unsafe_put_user(signo, &infop->si_signo, Efault); @@ -1566,10 +1576,10 @@ SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *, unsafe_put_user(info.pid, &infop->si_pid, Efault); unsafe_put_user(info.uid, &infop->si_uid, Efault); unsafe_put_user(info.status, &infop->si_status, Efault); - user_access_end(); + user_write_access_end(); return err; Efault: - user_access_end(); + user_write_access_end(); return -EFAULT; } @@ -1684,7 +1694,7 @@ COMPAT_SYSCALL_DEFINE5(waitid, if (!infop) return err; - if (!user_access_begin(infop, sizeof(*infop))) + if (!user_write_access_begin(infop, sizeof(*infop))) return -EFAULT; unsafe_put_user(signo, &infop->si_signo, Efault); @@ -1693,10 +1703,10 @@ COMPAT_SYSCALL_DEFINE5(waitid, unsafe_put_user(info.pid, &infop->si_pid, Efault); unsafe_put_user(info.uid, &infop->si_uid, Efault); unsafe_put_user(info.status, &infop->si_status, Efault); - user_access_end(); + user_write_access_end(); return err; Efault: - user_access_end(); + user_write_access_end(); return -EFAULT; } #endif |