Protect the move operation of buflib against IRQs.

This makes accessing the buffers with core_get_data() from
interrupt context safe, other buflib functions aren't really safe (yet).

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@30736 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 10 insertions, 0 deletions

diff --git a/firmware/buflib.c b/firmware/buflib.c
index 3b4f522dcf..d82acd77d3 100644
--- a/firmware/buflib.c
+++ b/firmware/buflib.c
@@ -206,16 +206,26 @@ move_block(struct buflib_context* ctx, union buflib_data* block, int shift)
             handle, shift, shift*sizeof(union buflib_data));
     new_block = block + shift;
     new_start = tmp->alloc + shift*sizeof(union buflib_data);
+
+    /* disable IRQs to make accessing the buffer from interrupt context safe. */
+    /* protect the move callback, as a cached global pointer might be updated
+     * in it. and protect "tmp->alloc = new_start" for buflib_get_data() */
+    disable_irq();
     /* call the callback before moving */
     if (ops)
     {
         if (ops->move_callback(handle, tmp->alloc, new_start)
                 == BUFLIB_CB_CANNOT_MOVE)
+        {
+            enable_irq();
             return false;
+        }
     }
+
     tmp->alloc = new_start; /* update handle table */
     memmove(new_block, block, block->val * sizeof(union buflib_data));
 
+    enable_irq();
     return true;
 }