On Mon, 18 Mar 2019, Oscar Salvador wrote:
> Swap mapping->host is NULL, so let us protect __dump_page() for such cases.
Thanks :)
>
> Fixes: 1c6fb1d89e73c ("mm: print more information about mapping in __dump_page")
> Signed-off-by: Oscar Salvador <osalvador@xxxxxxx>
> Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Acked-by: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
> ---
> mm/debug.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/debug.c b/mm/debug.c
> index c0b31b6c3877..7759f12a8fbb 100644
> --- a/mm/debug.c
> +++ b/mm/debug.c
> @@ -79,7 +79,7 @@ void __dump_page(struct page *page, const char *reason)
> pr_warn("ksm ");
> else if (mapping) {
> pr_warn("%ps ", mapping->a_ops);
> - if (mapping->host->i_dentry.first) {
> + if (mapping->host && mapping->host->i_dentry.first) {
> struct dentry *dentry;
> dentry = container_of(mapping->host->i_dentry.first, struct dentry, d_u.d_alias);
> pr_warn("name:\"%pd\" ", dentry);
> --
> 2.13.7
