Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fix from Ingo Molnar:
 "Leftover from 4.0

  Fix a local stack variable corruption with certain kdump usage
  patterns (Dave Young)"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm/numa: Fix kernel stack corruption in numa_init()->numa_clear_kernel_node_hotplug()

1 files changed, 9 insertions, 2 deletions

diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
index cd4785bbacb9..4053bb58bf92 100644
--- a/arch/x86/mm/numa.c
+++ b/arch/x86/mm/numa.c
@@ -482,9 +482,16 @@ static void __init numa_clear_kernel_node_hotplug(void)
                                   &memblock.reserved, mb->nid);
         }
 
-        /* Mark all kernel nodes. */
+        /*
+         * Mark all kernel nodes.
+         *
+         * When booting with mem=nn[kMG] or in a kdump kernel, numa_meminfo
+         * may not include all the memblock.reserved memory ranges because
+         * trim_snb_memory() reserves specific pages for Sandy Bridge graphics.
+         */
         for_each_memblock(reserved, r)
-                node_set(r->nid, numa_kernel_nodes);
+                if (r->nid != MAX_NUMNODES)
+                        node_set(r->nid, numa_kernel_nodes);
 
         /* Clear MEMBLOCK_HOTPLUG flag for memory in kernel nodes. */
         for (i = 0; i < numa_meminfo.nr_blks; i++) {