1 files changed, 20 insertions, 18 deletions

diff --git a/arch/um/os-Linux/sigio.c b/arch/um/os-Linux/sigio.c
index 925a65240cfe..b2e1fd8e3571 100644
--- a/arch/um/os-Linux/sigio.c
+++ b/arch/um/os-Linux/sigio.c
@@ -97,20 +97,22 @@ static int write_sigio_thread(void *unused)
 
 static int need_poll(struct pollfds *polls, int n)
 {
-        if(n <= polls->size){
-                polls->used = n;
+        struct pollfd *new;
+
+        if(n <= polls->size)
                 return 0;
-        }
-        kfree(polls->poll);
-        polls->poll = um_kmalloc_atomic(n * sizeof(struct pollfd));
-        if(polls->poll == NULL){
+
+        new = um_kmalloc_atomic(n * sizeof(struct pollfd));
+        if(new == NULL){
                 printk("need_poll : failed to allocate new pollfds\n");
-                polls->size = 0;
-                polls->used = 0;
                 return -ENOMEM;
         }
+
+        memcpy(new, polls->poll, polls->used * sizeof(struct pollfd));
+        kfree(polls->poll);
+
+        polls->poll = new;
         polls->size = n;
-        polls->used = n;
         return 0;
 }
 
@@ -171,15 +173,15 @@ int add_sigio_fd(int fd)
                         goto out;
         }
 
-        n = current_poll.used + 1;
-        err = need_poll(&next_poll, n);
+        n = current_poll.used;
+        err = need_poll(&next_poll, n + 1);
         if(err)
                 goto out;
 
-        for(i = 0; i < current_poll.used; i++)
-                next_poll.poll[i] = current_poll.poll[i];
-
-        next_poll.poll[n - 1] = *p;
+        memcpy(next_poll.poll, current_poll.poll,
+               current_poll.used * sizeof(struct pollfd));
+        next_poll.poll[n] = *p;
+        next_poll.used = n + 1;
         update_thread();
  out:
         sigio_unlock();
@@ -214,6 +216,7 @@ int ignore_sigio_fd(int fd)
                 if(p->fd != fd)
                         next_poll.poll[n++] = *p;
         }
+        next_poll.used = current_poll.used - 1;
 
         update_thread();
  out:
@@ -331,10 +334,9 @@ void maybe_sigio_broken(int fd, int read)
 
         sigio_lock();
         err = need_poll(&all_sigio_fds, all_sigio_fds.used + 1);
-        if(err){
-                printk("maybe_sigio_broken - failed to add pollfd\n");
+        if(err)
                 goto out;
-        }
+
         all_sigio_fds.poll[all_sigio_fds.used++] =
                 ((struct pollfd) { .fd          = fd,
                                    .events      = read ? POLLIN : POLLOUT,