http://list.linux-vserver.org/archive?mss:4196

[linux-2.6.git] / delta-vx_rss_avail.patch

diff --git a/delta-vx_rss_avail.patch b/delta-vx_rss_avail.patch
new file mode 100644 (file)
index 0000000..bb658a5
--- /dev/null
+++ b/delta-vx_rss_avail.patch
@@ -0,0 +1,24 @@
+
+    the check_stack_guard_page() has, under certain circumstances, side-effects which can not easily be undone in case the vx_rss_avail() fails
+
+diff --git a/mm/memory.c b/mm/memory.c
+index c53939d..158c500 100644
+--- a/mm/memory.c
++++ b/mm/memory.c
+@@ -2439,13 +2439,14 @@ static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
+ 
+       pte_unmap(page_table);
+ 
++      if (!vx_rss_avail(mm, 1))
++              goto oom;
++
+       /* Check if we need to add a guard page to the stack */
+       if (check_stack_guard_page(vma, address) < 0)
+               return VM_FAULT_SIGBUS;
+ 
+       /* Allocate our own private page. */
+-      if (!vx_rss_avail(mm, 1))
+-              goto oom;
+       if (unlikely(anon_vma_prepare(vma)))
+               goto oom;
+       page = alloc_zeroed_user_highpage_movable(vma, address);