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

torvalds · torvalds · commit ec1bc8e4cf47 · 2015-04-13T13:34:46.000-07:00
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()-&gt;numa_clear_kernel_node_hotplug()
diff --git 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++) {
