3 files changed, 13 insertions, 0 deletions

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 50895c2f937d..e67513e2cbbb 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -14,6 +14,7 @@
 #include <linux/acpi.h>
 #include <linux/firmware-map.h>
 #include <linux/sort.h>
+#include <linux/memory_hotplug.h>
 
 #include <asm/e820/api.h>
 #include <asm/setup.h>
@@ -881,6 +882,10 @@ static int __init parse_memopt(char *p)
 
         e820__range_remove(mem_size, ULLONG_MAX - mem_size, E820_TYPE_RAM, 1);
 
+#ifdef CONFIG_MEMORY_HOTPLUG
+        max_mem_size = mem_size;
+#endif
+
         return 0;
 }
 early_param("mem", parse_memopt);
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index 368267c1b71b..cfd12078172a 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -100,6 +100,8 @@ extern void __online_page_free(struct page *page);
 
 extern int try_online_node(int nid);
 
+extern u64 max_mem_size;
+
 extern bool memhp_auto_online;
 /* If movable_node boot option specified */
 extern bool movable_node_enabled;
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 124e794867c5..519f9db063ff 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -96,10 +96,16 @@ void mem_hotplug_done(void)
         cpus_read_unlock();
 }
 
+u64 max_mem_size = U64_MAX;
+
 /* add this memory to iomem resource */
 static struct resource *register_memory_resource(u64 start, u64 size)
 {
         struct resource *res, *conflict;
+
+        if (start + size > max_mem_size)
+                return ERR_PTR(-E2BIG);
+
         res = kzalloc(sizeof(struct resource), GFP_KERNEL);
         if (!res)
                 return ERR_PTR(-ENOMEM);