memory hotplug: Refuse to add unaligned memory regions

The sysfs memory probe interface allows unaligned regions
to be added:

# echo 0xffffff > /sys/devices/system/memory/probe

# cat /proc/iomem
00ffffff-01fffffe : System RAM
01ffffff-02fffffe : System RAM
02ffffff-03fffffe : System RAM
03ffffff-04fffffe : System RAM
04ffffff-05fffffe : System RAM

Return -EINVAL instead of creating these bad regions.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 2840ed4668c1..2a0b5f1020ed 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -380,9 +380,13 @@ memory_probe_store(struct class *class, struct class_attribute *attr,
         u64 phys_addr;
         int nid;
         int i, ret;
+        unsigned long pages_per_block = PAGES_PER_SECTION * sections_per_block;
 
         phys_addr = simple_strtoull(buf, NULL, 0);
 
+        if (phys_addr & ((pages_per_block << PAGE_SHIFT) - 1))
+                return -EINVAL;
+
         for (i = 0; i < sections_per_block; i++) {
                 nid = memory_add_physaddr_to_nid(phys_addr);
                 ret = add_memory(nid, phys_addr,