slub: fix high order page allocation problem with __GFP_NOFAIL

SLUB already try to allocate high order page with clearing __GFP_NOFAIL.
But, when allocating shadow page for kmemcheck, it missed clearing
the flag. This trigger WARN_ON_ONCE() reported by Christian Casteyde.

https://bugzilla.kernel.org/show_bug.cgi?id=65991
https://lkml.org/lkml/2013/12/3/764

This patch fix this situation by using same allocation flag as original
allocation.

Reported-by: Christian Casteyde <casteyde.christian@free.fr>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

1 files changed, 3 insertions, 2 deletions

diff --git a/mm/slub.c b/mm/slub.c
index 7e3e0458bce4..591bf985aed0 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1350,11 +1350,12 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
         page = alloc_slab_page(alloc_gfp, node, oo);
         if (unlikely(!page)) {
                 oo = s->min;
+                alloc_gfp = flags;
                 /*
                  * Allocation may have failed due to fragmentation.
                  * Try a lower order alloc if possible
                  */
-                page = alloc_slab_page(flags, node, oo);
+                page = alloc_slab_page(alloc_gfp, node, oo);
 
                 if (page)
                         stat(s, ORDER_FALLBACK);
@@ -1364,7 +1365,7 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
                 && !(s->flags & (SLAB_NOTRACK | DEBUG_DEFAULT_FLAGS))) {
                 int pages = 1 << oo_order(oo);
 
-                kmemcheck_alloc_shadow(page, oo_order(oo), flags, node);
+                kmemcheck_alloc_shadow(page, oo_order(oo), alloc_gfp, node);
 
                 /*
                  * Objects from caches that have a constructor don't get