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Commit a0132ac0 authored by Dave Hansen's avatar Dave Hansen Committed by Linus Torvalds
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mm/slub.c: do not VM_BUG_ON_PAGE() for temporary on-stack pages 



Commit 309381fe ("mm: dump page when hitting a VM_BUG_ON using
VM_BUG_ON_PAGE") added a bunch of VM_BUG_ON_PAGE() calls.

But, most of the ones in the slub code are for _temporary_ 'struct
page's which are declared on the stack and likely have lots of gunk in
them.  Dumping their contents out will just confuse folks looking at
bad_page() output.  Plus, if we try to page_to_pfn() on them or
soemthing, we'll probably oops anyway.

Turn them back in to VM_BUG_ON()s.

Signed-off-by: default avatarDave Hansen <dave.hansen@linux.intel.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent ba3253c7

mm/slub.c

+6 −6
Original line number Diff line number Diff line
@@ -1559,7 +1559,7 @@ static inline void *acquire_slab(struct kmem_cache *s, 
		new.freelist = freelist;

	}



	VM_BUG_ON_PAGE(new.frozen, &new);

	VM_BUG_ON(new.frozen);

	new.frozen = 1;



	if (!__cmpxchg_double_slab(s, page,
@@ -1812,7 +1812,7 @@ static void deactivate_slab(struct kmem_cache *s, struct page *page, 
			set_freepointer(s, freelist, prior);

			new.counters = counters;

			new.inuse--;

			VM_BUG_ON_PAGE(!new.frozen, &new);

			VM_BUG_ON(!new.frozen);



		} while (!__cmpxchg_double_slab(s, page,

			prior, counters,
@@ -1840,7 +1840,7 @@ static void deactivate_slab(struct kmem_cache *s, struct page *page, 


	old.freelist = page->freelist;

	old.counters = page->counters;

	VM_BUG_ON_PAGE(!old.frozen, &old);

	VM_BUG_ON(!old.frozen);



	/* Determine target state of the slab */

	new.counters = old.counters;
@@ -1952,7 +1952,7 @@ static void unfreeze_partials(struct kmem_cache *s, 


			old.freelist = page->freelist;

			old.counters = page->counters;

			VM_BUG_ON_PAGE(!old.frozen, &old);

			VM_BUG_ON(!old.frozen);



			new.counters = old.counters;

			new.freelist = old.freelist;
@@ -2225,7 +2225,7 @@ static inline void *get_freelist(struct kmem_cache *s, struct page *page) 
		counters = page->counters;



		new.counters = counters;

		VM_BUG_ON_PAGE(!new.frozen, &new);

		VM_BUG_ON(!new.frozen);



		new.inuse = page->objects;

		new.frozen = freelist != NULL;
@@ -2319,7 +2319,7 @@ static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node, 
	 * page is pointing to the page from which the objects are obtained.

	 * That page must be frozen for per cpu allocations to work.

	 */

	VM_BUG_ON_PAGE(!c->page->frozen, c->page);

	VM_BUG_ON(!c->page->frozen);

	c->freelist = get_freepointer(s, freelist);

	c->tid = next_tid(c->tid);

	local_irq_restore(flags);