From 7b0501dd6b1862a83c5c1c65beadce99014b97a4 Mon Sep 17 00:00:00 2001
From: Jesper Dangaard Brouer <brouer@redhat.com>
Date: Tue, 15 Mar 2016 14:53:53 -0700
Subject: [PATCH] slab: avoid running debug SLAB code with IRQs disabled for
 alloc_bulk

Move the call to cache_alloc_debugcheck_after() outside the IRQ disabled
section in kmem_cache_alloc_bulk().

When CONFIG_DEBUG_SLAB is disabled the compiler should remove this code.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 mm/slab.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/mm/slab.c b/mm/slab.c
index 0c2e2ca..207fa92 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -3391,6 +3391,16 @@ void kmem_cache_free_bulk(struct kmem_cache *s, size_t size, void **p)
 }
 EXPORT_SYMBOL(kmem_cache_free_bulk);
 
+static __always_inline void
+cache_alloc_debugcheck_after_bulk(struct kmem_cache *s, gfp_t flags,
+				  size_t size, void **p, unsigned long caller)
+{
+	size_t i;
+
+	for (i = 0; i < size; i++)
+		p[i] = cache_alloc_debugcheck_after(s, flags, p[i], caller);
+}
+
 int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
 			  void **p)
 {
@@ -3406,15 +3416,14 @@ int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
 	for (i = 0; i < size; i++) {
 		void *objp = __do_cache_alloc(s, flags);
 
-		/* this call could be done outside IRQ disabled section */
-		objp = cache_alloc_debugcheck_after(s, flags, objp, _RET_IP_);
-
 		if (unlikely(!objp))
 			goto error;
 		p[i] = objp;
 	}
 	local_irq_enable();
 
+	cache_alloc_debugcheck_after_bulk(s, flags, size, p, _RET_IP_);
+
 	/* Clear memory outside IRQ disabled section */
 	if (unlikely(flags & __GFP_ZERO))
 		for (i = 0; i < size; i++)
@@ -3425,6 +3434,7 @@ int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
 	return size;
 error:
 	local_irq_enable();
+	cache_alloc_debugcheck_after_bulk(s, flags, i, p, _RET_IP_);
 	slab_post_alloc_hook(s, flags, i, p);
 	__kmem_cache_free_bulk(s, i, p);
 	return 0;
-- 
2.7.4