diff options
Diffstat (limited to 'kernel/exit.c')
-rw-r--r-- | kernel/exit.c | 146 |
1 files changed, 82 insertions, 64 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index 60d6fdcc926..5859f598c95 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -976,8 +976,6 @@ NORET_TYPE void do_exit(long code) disassociate_ctty(1); module_put(task_thread_info(tsk)->exec_domain->module); - if (tsk->binfmt) - module_put(tsk->binfmt->module); proc_exit_connector(tsk); @@ -1097,28 +1095,28 @@ struct wait_opts { int __user *wo_stat; struct rusage __user *wo_rusage; + wait_queue_t child_wait; int notask_error; }; -static struct pid *task_pid_type(struct task_struct *task, enum pid_type type) +static inline +struct pid *task_pid_type(struct task_struct *task, enum pid_type type) { - struct pid *pid = NULL; - if (type == PIDTYPE_PID) - pid = task->pids[type].pid; - else if (type < PIDTYPE_MAX) - pid = task->group_leader->pids[type].pid; - return pid; + if (type != PIDTYPE_PID) + task = task->group_leader; + return task->pids[type].pid; } -static int eligible_child(struct wait_opts *wo, struct task_struct *p) +static int eligible_pid(struct wait_opts *wo, struct task_struct *p) { - int err; - - if (wo->wo_type < PIDTYPE_MAX) { - if (task_pid_type(p, wo->wo_type) != wo->wo_pid) - return 0; - } + return wo->wo_type == PIDTYPE_MAX || + task_pid_type(p, wo->wo_type) == wo->wo_pid; +} +static int eligible_child(struct wait_opts *wo, struct task_struct *p) +{ + if (!eligible_pid(wo, p)) + return 0; /* Wait for all children (clone and not) if __WALL is set; * otherwise, wait for clone children *only* if __WCLONE is * set; otherwise, wait for non-clone children *only*. (Note: @@ -1128,10 +1126,6 @@ static int eligible_child(struct wait_opts *wo, struct task_struct *p) && !(wo->wo_flags & __WALL)) return 0; - err = security_task_wait(p); - if (err) - return err; - return 1; } @@ -1144,18 +1138,20 @@ static int wait_noreap_copyout(struct wait_opts *wo, struct task_struct *p, put_task_struct(p); infop = wo->wo_info; - if (!retval) - retval = put_user(SIGCHLD, &infop->si_signo); - if (!retval) - retval = put_user(0, &infop->si_errno); - if (!retval) - retval = put_user((short)why, &infop->si_code); - if (!retval) - retval = put_user(pid, &infop->si_pid); - if (!retval) - retval = put_user(uid, &infop->si_uid); - if (!retval) - retval = put_user(status, &infop->si_status); + if (infop) { + if (!retval) + retval = put_user(SIGCHLD, &infop->si_signo); + if (!retval) + retval = put_user(0, &infop->si_errno); + if (!retval) + retval = put_user((short)why, &infop->si_code); + if (!retval) + retval = put_user(pid, &infop->si_pid); + if (!retval) + retval = put_user(uid, &infop->si_uid); + if (!retval) + retval = put_user(status, &infop->si_status); + } if (!retval) retval = pid; return retval; @@ -1485,13 +1481,14 @@ static int wait_task_continued(struct wait_opts *wo, struct task_struct *p) * then ->notask_error is 0 if @p is an eligible child, * or another error from security_task_wait(), or still -ECHILD. */ -static int wait_consider_task(struct wait_opts *wo, struct task_struct *parent, - int ptrace, struct task_struct *p) +static int wait_consider_task(struct wait_opts *wo, int ptrace, + struct task_struct *p) { int ret = eligible_child(wo, p); if (!ret) return ret; + ret = security_task_wait(p); if (unlikely(ret < 0)) { /* * If we have not yet seen any eligible child, @@ -1553,7 +1550,7 @@ static int do_wait_thread(struct wait_opts *wo, struct task_struct *tsk) * Do not consider detached threads. */ if (!task_detached(p)) { - int ret = wait_consider_task(wo, tsk, 0, p); + int ret = wait_consider_task(wo, 0, p); if (ret) return ret; } @@ -1567,7 +1564,7 @@ static int ptrace_do_wait(struct wait_opts *wo, struct task_struct *tsk) struct task_struct *p; list_for_each_entry(p, &tsk->ptraced, ptrace_entry) { - int ret = wait_consider_task(wo, tsk, 1, p); + int ret = wait_consider_task(wo, 1, p); if (ret) return ret; } @@ -1575,15 +1572,38 @@ static int ptrace_do_wait(struct wait_opts *wo, struct task_struct *tsk) return 0; } +static int child_wait_callback(wait_queue_t *wait, unsigned mode, + int sync, void *key) +{ + struct wait_opts *wo = container_of(wait, struct wait_opts, + child_wait); + struct task_struct *p = key; + + if (!eligible_pid(wo, p)) + return 0; + + if ((wo->wo_flags & __WNOTHREAD) && wait->private != p->parent) + return 0; + + return default_wake_function(wait, mode, sync, key); +} + +void __wake_up_parent(struct task_struct *p, struct task_struct *parent) +{ + __wake_up_sync_key(&parent->signal->wait_chldexit, + TASK_INTERRUPTIBLE, 1, p); +} + static long do_wait(struct wait_opts *wo) { - DECLARE_WAITQUEUE(wait, current); struct task_struct *tsk; int retval; trace_sched_process_wait(wo->wo_pid); - add_wait_queue(¤t->signal->wait_chldexit,&wait); + init_waitqueue_func_entry(&wo->child_wait, child_wait_callback); + wo->child_wait.private = current; + add_wait_queue(¤t->signal->wait_chldexit, &wo->child_wait); repeat: /* * If there is nothing that can match our critiera just get out. @@ -1624,32 +1644,7 @@ notask: } end: __set_current_state(TASK_RUNNING); - remove_wait_queue(¤t->signal->wait_chldexit,&wait); - if (wo->wo_info) { - struct siginfo __user *infop = wo->wo_info; - - if (retval > 0) - retval = 0; - else { - /* - * For a WNOHANG return, clear out all the fields - * we would set so the user can easily tell the - * difference. - */ - if (!retval) - retval = put_user(0, &infop->si_signo); - if (!retval) - retval = put_user(0, &infop->si_errno); - if (!retval) - retval = put_user(0, &infop->si_code); - if (!retval) - retval = put_user(0, &infop->si_pid); - if (!retval) - retval = put_user(0, &infop->si_uid); - if (!retval) - retval = put_user(0, &infop->si_status); - } - } + remove_wait_queue(¤t->signal->wait_chldexit, &wo->child_wait); return retval; } @@ -1694,6 +1689,29 @@ SYSCALL_DEFINE5(waitid, int, which, pid_t, upid, struct siginfo __user *, wo.wo_stat = NULL; wo.wo_rusage = ru; ret = do_wait(&wo); + + if (ret > 0) { + ret = 0; + } else if (infop) { + /* + * For a WNOHANG return, clear out all the fields + * we would set so the user can easily tell the + * difference. + */ + if (!ret) + ret = put_user(0, &infop->si_signo); + if (!ret) + ret = put_user(0, &infop->si_errno); + if (!ret) + ret = put_user(0, &infop->si_code); + if (!ret) + ret = put_user(0, &infop->si_pid); + if (!ret) + ret = put_user(0, &infop->si_uid); + if (!ret) + ret = put_user(0, &infop->si_status); + } + put_pid(pid); /* avoid REGPARM breakage on x86: */ |