Changeset 39217 in vbox

Timestamp:

Nov 7, 2011 3:25:14 PM (13 years ago)

Author:

vboxsync

Message:

Additions/solaris/SharedFolders: fix recursive mutex panic due to sffs_write causing pagefaults for mmap'd buffers.

File:

• trunk/src/VBox/Additions/solaris/SharedFolders/vboxfs_vnode.c (modified) (4 diffs)

trunk/src/VBox/Additions/solaris/SharedFolders/vboxfs_vnode.c

@@ -1602 +1602 @@
 {
         int error = 0;
+        int is_recursive = 0;
         page_t **pageliststart = pagelist;
         sfnode_t *node = VN2SFN(dvp);
@@ -1623 +1624 @@
                 *protp = PROT_ALL;
 
-        mutex_enter(&sffs_lock);
+        /*
+         * The buffer passed to sffs_write may be mmap'd so we may get a
+         * pagefault there, in which case we'll end up here with this thread
+         * already owning the mutex. Mutexes aren't recursive.
+         */
+        if (mutex_owner(&sffs_lock) == curthread)
+                is_recursive = 1;
+        else
+                mutex_enter(&sffs_lock);
 
         /* Don't map pages past end of the file. */
@@ -1645 +1654 @@
 
                         *pagelist = NULL;
-                        mutex_exit(&sffs_lock);
+                        if (!is_recursive)
+                                mutex_exit(&sffs_lock);
                         return (error);
                 }
@@ -1677 +1687 @@
 
         *pagelist = NULL;
-        mutex_exit(&sffs_lock);
+        if (!is_recursive)
+                mutex_exit(&sffs_lock);
         return (error);
 }