commit 5606f577a707aa4ccc391714dca815933aeba508
Author: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date:   Wed Jul 18 07:56:38 2018 +0200

    Linux 4.17.8

commit 27d8b7daf73827e8263ab0b740da6ebdda9f9d56
Author: Pavel Tatashin <pasha.tatashin@oracle.com>
Date:   Mon Jul 16 11:16:30 2018 -0400

    mm: don't do zero_resv_unavail if memmap is not allocated
    
    commit d1b47a7c9efcf3c3384b70f6e3c8f1423b44d8c7 upstream.
    
    Moving zero_resv_unavail before memmap_init_zone(), caused a regression on
    x86-32.
    
    The cause is that we access struct pages before they are allocated when
    CONFIG_FLAT_NODE_MEM_MAP is used.
    
    free_area_init_nodes()
      zero_resv_unavail()
        mm_zero_struct_page(pfn_to_page(pfn)); <- struct page is not alloced
      free_area_init_node()
        if CONFIG_FLAT_NODE_MEM_MAP
          alloc_node_mem_map()
            memblock_virt_alloc_node_nopanic() <- struct page alloced here
    
    On the other hand memblock_virt_alloc_node_nopanic() zeroes all the memory
    that it returns, so we do not need to do zero_resv_unavail() here.
    
    Fixes: e181ae0c5db9 ("mm: zero unavailable pages before memmap init")
    Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
    Tested-by: Matt Hart <matt@mattface.org>
    Acked-by: Michal Hocko <mhocko@suse.com>
    Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>