memory-hotplug: don't BUG() in register_memory_resource()

Out of memory condition is not a bug and while we can't add new memory
in such case crashing the system seems wrong.  Propagating the return
value from register_memory_resource() requires interface change.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Sheng Yong <shengyong1@huawei.com>
Cc: Zhu Guihua <zhugh.fnst@cn.fujitsu.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index a042a9d537bb31984d6b2a8d3cc8ae1e54361e4f..92f95952692b0f9aa20bec8afa3cd1725e573452 100644 (file)
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -131,7 +131,8 @@ static struct resource *register_memory_resource(u64 start, u64 size)
 {
        struct resource *res;
        res = kzalloc(sizeof(struct resource), GFP_KERNEL);
-       BUG_ON(!res);
+       if (!res)
+               return ERR_PTR(-ENOMEM);
 
        res->name = "System RAM";
        res->start = start;
@@ -140,7 +141,7 @@ static struct resource *register_memory_resource(u64 start, u64 size)
        if (request_resource(&iomem_resource, res) < 0) {
                pr_debug("System RAM resource %pR cannot be added\n", res);
                kfree(res);
-               res = NULL;
+               return ERR_PTR(-EEXIST);
        }
        return res;
 }
@@ -1312,8 +1313,8 @@ int __ref add_memory(int nid, u64 start, u64 size)
        int ret;
 
        res = register_memory_resource(start, size);
-       if (!res)
-               return -EEXIST;
+       if (IS_ERR(res))
+               return PTR_ERR(res);
 
        ret = add_memory_resource(nid, res);
        if (ret < 0)