diff --git a/lib/libc/sys/select.c b/lib/libc/sys/select.c
index 38a3b53cb..52fd2e378 100644
--- a/lib/libc/sys/select.c
+++ b/lib/libc/sys/select.c
@@ -7,9 +7,9 @@
 #include <errno.h>
 #include <signal.h>
 
-int pselect(int nfds, fd_set *readfds, fd_set *writefds,
-            fd_set *exceptfds, const struct timespec *timeout,
-            const sigset_t *sigmask) {
+int pselect(int nfds, fd_set *restrict readfds, fd_set *restrict writefds,
+            fd_set *restrict exceptfds, const struct timespec *restrict timeout,
+            const sigset_t *restrict sigmask) {
     int kq;
     int ret;
     struct kevent *events;
@@ -21,10 +21,15 @@ int pselect(int nfds, fd_set *readfds, fd_set *writefds,
         return -1;
     }
 
-    kq = kqueue1(O_CLOEXEC);
-    if (kq < 0)
+    if (sigmask && sigprocmask(SIG_SETMASK, sigmask, &sigs))
         return -1;
 
+    kq = kqueue1(O_CLOEXEC);
+    if (kq < 0) {
+        ret = -1;
+        goto restore_sigs;
+    }
+
     events = malloc(2 * nfds * sizeof(struct kevent));
     if (!events) {
         errno = ENOMEM;
@@ -44,9 +49,6 @@ int pselect(int nfds, fd_set *readfds, fd_set *writefds,
     if (writefds != NULL)
         FD_ZERO(writefds);
 
-    if (sigmask && sigprocmask(SIG_SETMASK, sigmask, &sigs))
-        return -1;
-
     ret = kevent(kq, events, nevents, events, nevents, timeout);
     if (ret == -1)
         goto end;
@@ -65,10 +67,11 @@ int pselect(int nfds, fd_set *readfds, fd_set *writefds,
 
 end:
     free(events);
-    if (sigmask && sigprocmask(SIG_SETMASK, &sigs, NULL))
-        ret = -1;
 close_kq:
     close(kq);
+restore_sigs:
+    if (sigmask && sigprocmask(SIG_SETMASK, &sigs, NULL))
+        ret = -1;
     return ret;
 }
 
diff --git a/sys/kern/vm_map.c b/sys/kern/vm_map.c
index 957a517e7..76f4d3d9b 100644
--- a/sys/kern/vm_map.c
+++ b/sys/kern/vm_map.c
@@ -539,6 +539,11 @@ static int cow_page_fault(vm_map_t *map, vm_map_entry_t *ent, size_t off,
   if (old == NULL)
     return 0;
 
+  /* This check is safe. We are the only owner of this anon and the ref count
+   * will not change because we are under vm_map:mtx. */
+  if (old->ref_cnt == 1)
+    return 0;
+
   /* Current mapping will be replaced with new one so remove it from pmap. */
   vaddr_t fault_page = off * PAGESIZE + ent->start;
   pmap_remove(map->pmap, fault_page, fault_page + PAGESIZE);