diff options
| -rw-r--r-- | fs/coredump.c | 6 | ||||
| -rw-r--r-- | kernel/exit.c | 76 | ||||
| -rw-r--r-- | mm/oom_kill.c | 6 |
3 files changed, 47 insertions, 41 deletions
diff --git a/fs/coredump.c b/fs/coredump.c index 3224dee44d30..5e0e08a7fb9b 100644 --- a/fs/coredump.c +++ b/fs/coredump.c @@ -404,8 +404,8 @@ static int zap_threads(struct task_struct *tsk, struct mm_struct *mm, * * do_exit: * The caller holds mm->mmap_lock. This means that the task which - * uses this mm can't pass exit_mm(), so it can't exit or clear - * its ->mm. + * uses this mm can't pass coredump_exit_mm(), so it can't exit or + * clear its ->mm. * * de_thread: * It does list_replace_rcu(&leader->tasks, ¤t->tasks), @@ -500,7 +500,7 @@ static void coredump_finish(struct mm_struct *mm, bool core_dumped) next = curr->next; task = curr->task; /* - * see exit_mm(), curr->task must not see + * see coredump_exit_mm(), curr->task must not see * ->task == NULL before we read ->next. */ smp_mb(); diff --git a/kernel/exit.c b/kernel/exit.c index 91a43e57a32e..cb1619d8fd64 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -339,6 +339,46 @@ kill_orphaned_pgrp(struct task_struct *tsk, struct task_struct *parent) } } +static void coredump_exit_mm(struct mm_struct *mm) +{ + struct core_state *core_state; + + /* + * Serialize with any possible pending coredump. + * 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. + */ + core_state = mm->core_state; + if (core_state) { + struct core_thread self; + + mmap_read_unlock(mm); + + self.task = current; + if (self.task->flags & PF_SIGNALED) + self.next = xchg(&core_state->dumper.next, &self); + else + self.task = NULL; + /* + * Implies mb(), the result of xchg() must be visible + * to core_state->dumper. + */ + if (atomic_dec_and_test(&core_state->nr_threads)) + complete(&core_state->startup); + + for (;;) { + set_current_state(TASK_UNINTERRUPTIBLE); + if (!self.task) /* see coredump_finish() */ + break; + freezable_schedule(); + } + __set_current_state(TASK_RUNNING); + mmap_read_lock(mm); + } +} + #ifdef CONFIG_MEMCG /* * A task is exiting. If it owned this mm, find a new owner for the mm. @@ -434,47 +474,13 @@ assign_new_owner: static void exit_mm(void) { struct mm_struct *mm = current->mm; - struct core_state *core_state; exit_mm_release(current, mm); if (!mm) return; sync_mm_rss(mm); - /* - * Serialize with any possible pending coredump. - * 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. - */ mmap_read_lock(mm); - core_state = mm->core_state; - if (core_state) { - struct core_thread self; - - mmap_read_unlock(mm); - - self.task = current; - if (self.task->flags & PF_SIGNALED) - self.next = xchg(&core_state->dumper.next, &self); - else - self.task = NULL; - /* - * Implies mb(), the result of xchg() must be visible - * to core_state->dumper. - */ - if (atomic_dec_and_test(&core_state->nr_threads)) - complete(&core_state->startup); - - for (;;) { - set_current_state(TASK_UNINTERRUPTIBLE); - if (!self.task) /* see coredump_finish() */ - break; - freezable_schedule(); - } - __set_current_state(TASK_RUNNING); - mmap_read_lock(mm); - } + coredump_exit_mm(mm); mmgrab(mm); BUG_ON(mm != current->active_mm); /* more a memory barrier than a real lock */ diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 831340e7ad8b..295c8bdfd6c8 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -787,9 +787,9 @@ static inline bool __task_will_free_mem(struct task_struct *task) struct signal_struct *sig = task->signal; /* - * A coredumping process may sleep for an extended period in exit_mm(), - * so the oom killer cannot assume that the process will promptly exit - * and release memory. + * A coredumping process may sleep for an extended period in + * coredump_exit_mm(), so the oom killer cannot assume that + * the process will promptly exit and release memory. */ if (sig->flags & SIGNAL_GROUP_COREDUMP) return false; |