From: Dave Hansen <dave.hansen@linux.intel.com>
Date: Wed, 29 Jan 2014 22:05:50 +0000 (-0800)
Subject: mm/slub.c: do not VM_BUG_ON_PAGE() for temporary on-stack pages
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=a0132ac0f275434db32111b8cf7372d991899da3;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git

mm/slub.c: do not VM_BUG_ON_PAGE() for temporary on-stack pages

Commit 309381feaee5 ("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: Dave 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/mm/slub.c b/mm/slub.c
index 34bb8c65a2d8..545a170ebf9f 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -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 @@ redo:
 
 	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 @@ load_freelist:
 	 * 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);