struct msg_sender {
struct list_head list;
struct task_struct *tsk;
+ size_t msgsz;
};
#define SEARCH_ANY 1
return msq->q_perm.id;
}
-static inline void ss_add(struct msg_queue *msq, struct msg_sender *mss)
+static inline bool msg_fits_inqueue(struct msg_queue *msq, size_t msgsz)
+{
+ return msgsz + msq->q_cbytes <= msq->q_qbytes &&
+ 1 + msq->q_qnum <= msq->q_qbytes;
+}
+
+static inline void ss_add(struct msg_queue *msq,
+ struct msg_sender *mss, size_t msgsz)
{
mss->tsk = current;
+ mss->msgsz = msgsz;
__set_current_state(TASK_INTERRUPTIBLE);
list_add_tail(&mss->list, &msq->q_senders);
}
static inline void ss_del(struct msg_sender *mss)
{
- if (mss->list.next != NULL)
+ if (mss->list.next)
list_del(&mss->list);
}
-static void ss_wakeup(struct list_head *h, int kill)
+static void ss_wakeup(struct msg_queue *msq,
+ struct wake_q_head *wake_q, bool kill)
{
struct msg_sender *mss, *t;
+ struct task_struct *stop_tsk = NULL;
+ struct list_head *h = &msq->q_senders;
list_for_each_entry_safe(mss, t, h, list) {
if (kill)
mss->list.next = NULL;
- wake_up_process(mss->tsk);
+
+ /*
+ * Stop at the first task we don't wakeup,
+ * we've already iterated the original
+ * sender queue.
+ */
+ else if (stop_tsk == mss->tsk)
+ break;
+ /*
+ * We are not in an EIDRM scenario here, therefore
+ * verify that we really need to wakeup the task.
+ * To maintain current semantics and wakeup order,
+ * move the sender to the tail on behalf of the
+ * blocked task.
+ */
+ else if (!msg_fits_inqueue(msq, mss->msgsz)) {
+ if (!stop_tsk)
+ stop_tsk = mss->tsk;
+
+ list_move_tail(&mss->list, &msq->q_senders);
+ continue;
+ }
+
+ wake_q_add(wake_q, mss->tsk);
}
}
WAKE_Q(wake_q);
expunge_all(msq, -EIDRM, &wake_q);
- ss_wakeup(&msq->q_senders, 1);
+ ss_wakeup(msq, &wake_q, true);
msg_rmid(ns, msq);
ipc_unlock_object(&msq->q_perm);
wake_up_q(&wake_q);
struct kern_ipc_perm *ipcp;
struct msqid64_ds uninitialized_var(msqid64);
struct msg_queue *msq;
- WAKE_Q(wake_q);
int err;
if (cmd == IPC_SET) {
freeque(ns, ipcp);
goto out_up;
case IPC_SET:
+ {
+ WAKE_Q(wake_q);
+
if (msqid64.msg_qbytes > ns->msg_ctlmnb &&
!capable(CAP_SYS_RESOURCE)) {
err = -EPERM;
msq->q_qbytes = msqid64.msg_qbytes;
msq->q_ctime = get_seconds();
- /* sleeping receivers might be excluded by
+ /*
+ * Sleeping receivers might be excluded by
* stricter permissions.
*/
expunge_all(msq, -EAGAIN, &wake_q);
- /* sleeping senders might be able to send
+ /*
+ * Sleeping senders might be able to send
* due to a larger queue size.
*/
- ss_wakeup(&msq->q_senders, 0);
- break;
+ ss_wakeup(msq, &wake_q, false);
+ ipc_unlock_object(&msq->q_perm);
+ wake_up_q(&wake_q);
+
+ goto out_unlock1;
+ }
default:
err = -EINVAL;
goto out_unlock1;
out_unlock0:
ipc_unlock_object(&msq->q_perm);
- wake_up_q(&wake_q);
out_unlock1:
rcu_read_unlock();
out_up:
if (err)
goto out_unlock0;
- if (msgsz + msq->q_cbytes <= msq->q_qbytes &&
- 1 + msq->q_qnum <= msq->q_qbytes) {
+ if (msg_fits_inqueue(msq, msgsz))
break;
- }
/* queue full, wait: */
if (msgflg & IPC_NOWAIT) {
}
/* enqueue the sender and prepare to block */
- ss_add(msq, &s);
+ ss_add(msq, &s, msgsz);
if (!ipc_rcu_getref(msq)) {
err = -EIDRM;
}
}
+
msq->q_lspid = task_tgid_vnr(current);
msq->q_stime = get_seconds();
struct msg_queue *msq;
struct ipc_namespace *ns;
struct msg_msg *msg, *copy = NULL;
+ WAKE_Q(wake_q);
ns = current->nsproxy->ipc_ns;
msq->q_cbytes -= msg->m_ts;
atomic_sub(msg->m_ts, &ns->msg_bytes);
atomic_dec(&ns->msg_hdrs);
- ss_wakeup(&msq->q_senders, 0);
+ ss_wakeup(msq, &wake_q, false);
goto out_unlock0;
}
out_unlock0:
ipc_unlock_object(&msq->q_perm);
+ wake_up_q(&wake_q);
out_unlock1:
rcu_read_unlock();
if (IS_ERR(msg)) {