mqueues: selwakeup() needs the MP lock to be held

Briefly-discussed-with: sjg@

diff --git a/sys/kern/sys_mqueue.c b/sys/kern/sys_mqueue.c
index 2b1fc17..0901a7c 100644 (file)
--- a/sys/kern/sys_mqueue.c
+++ b/sys/kern/sys_mqueue.c
@@ -52,6 +52,7 @@
 #include <sys/priv.h>
 #include <sys/kernel.h>
 #include <sys/malloc.h>
+#include <sys/mplock2.h>
 #include <sys/mqueue.h>
 #include <sys/objcache.h>
 #include <sys/poll.h>
@@ -669,7 +670,9 @@ mq_receive1(struct lwp *l, mqd_t mqdes, void *msg_ptr, size_t msg_len,
        wakeup_one(&mq->mq_recv_cv);
 
        /* Ready for sending now */
+       get_mplock();
        selwakeup(&mq->mq_wsel);
+       rel_mplock();
 error:
        lockmgr(&mq->mq_mtx, LK_RELEASE);
        fdrop(fp);
@@ -858,7 +861,9 @@ mq_send1(struct lwp *l, mqd_t mqdes, const char *msg_ptr, size_t msg_len,
        wakeup_one(&mq->mq_send_cv);
 
        /* Ready for receiving now */
+       get_mplock();
        selwakeup(&mq->mq_rsel);
+       rel_mplock();
 error:
        lockmgr(&mq->mq_mtx, LK_RELEASE);
        fdrop(fp);
@@ -1081,8 +1086,10 @@ sys_mq_unlink(struct mq_unlink_args *uap)
        wakeup(&mq->mq_send_cv);
        wakeup(&mq->mq_recv_cv);
 
+       get_mplock();
        selwakeup(&mq->mq_rsel);
        selwakeup(&mq->mq_wsel);
+       rel_mplock();
 
        refcnt = mq->mq_refcnt;
        if (refcnt == 0)