1 files changed, 10 insertions, 24 deletions

diff --git a/arch/um/kernel/irq.c b/arch/um/kernel/irq.c
index 589c69a75043..ce7f233fc490 100644
--- a/arch/um/kernel/irq.c
+++ b/arch/um/kernel/irq.c
@@ -142,19 +142,6 @@ int activate_fd(int irq, int fd, int type, void *dev_id)
                                      .events            = events,
                                      .current_events    = 0 } );
 
-        /* Critical section - locked by a spinlock because this stuff can
-         * be changed from interrupt handlers.  The stuff above is done
-         * outside the lock because it allocates memory.
-         */
-
-        /* Actually, it only looks like it can be called from interrupt
-         * context.  The culprit is reactivate_fd, which calls
-         * maybe_sigio_broken, which calls write_sigio_workaround,
-         * which calls activate_fd.  However, write_sigio_workaround should
-         * only be called once, at boot time.  That would make it clear that
-         * this is called only from process context, and can be locked with
-         * a semaphore.
-         */
         spin_lock_irqsave(&irq_lock, flags);
         for (irq_fd = active_fds; irq_fd != NULL; irq_fd = irq_fd->next) {
                 if ((irq_fd->fd == fd) && (irq_fd->type == type)) {
@@ -165,7 +152,6 @@ int activate_fd(int irq, int fd, int type, void *dev_id)
                 }
         }
 
-        /*-------------*/
         if (type == IRQ_WRITE)
                 fd = -1;
 
@@ -198,7 +184,6 @@ int activate_fd(int irq, int fd, int type, void *dev_id)
 
                 spin_lock_irqsave(&irq_lock, flags);
         }
-        /*-------------*/
 
         *last_irq_ptr = new_fd;
         last_irq_ptr = &new_fd->next;
@@ -210,14 +195,14 @@ int activate_fd(int irq, int fd, int type, void *dev_id)
          */
         maybe_sigio_broken(fd, (type == IRQ_READ));
 
-        return(0);
+        return 0;
 
  out_unlock:
         spin_unlock_irqrestore(&irq_lock, flags);
  out_kfree:
         kfree(new_fd);
  out:
-        return(err);
+        return err;
 }
 
 static void free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg)
@@ -302,10 +287,7 @@ void reactivate_fd(int fd, int irqnum)
         os_set_pollfd(i, irq->fd);
         spin_unlock_irqrestore(&irq_lock, flags);
 
-        /* This calls activate_fd, so it has to be outside the critical
-         * section.
-         */
-        maybe_sigio_broken(fd, (irq->type == IRQ_READ));
+        add_sigio_fd(fd);
 }
 
 void deactivate_fd(int fd, int irqnum)
@@ -316,11 +298,15 @@ void deactivate_fd(int fd, int irqnum)
 
         spin_lock_irqsave(&irq_lock, flags);
         irq = find_irq_by_fd(fd, irqnum, &i);
-        if (irq == NULL)
-                goto out;
+        if(irq == NULL){
+                spin_unlock_irqrestore(&irq_lock, flags);
+                return;
+        }
+
         os_set_pollfd(i, -1);
- out:
         spin_unlock_irqrestore(&irq_lock, flags);
+
+        ignore_sigio_fd(fd);
 }
 
 int deactivate_all_fds(void)