mm: slub: SLUB_DEBUG=n: use the same alloc/free hooks as for SLUB_DEBUG=y

There are two versions of alloc/free hooks now - one for
CONFIG_SLUB_DEBUG=y and another one for CONFIG_SLUB_DEBUG=n.

I see no reason why calls to other debugging subsystems (LOCKDEP,
DEBUG_ATOMIC_SLEEP, KMEMCHECK and FAILSLAB) are hidden under SLUB_DEBUG.
All this features should work regardless of SLUB_DEBUG config, as all of
them already have own Kconfig options.

This also fixes failslab for CONFIG_SLUB_DEBUG=n configuration.  It
simply has not worked before because should_failslab() call was in a
hook hidden under "#ifdef CONFIG_SLUB_DEBUG #else".

Note: There is one concealed change in allocation path for SLUB_DEBUG=n
and all other debugging features disabled.  The might_sleep_if() call
can generate some code even if DEBUG_ATOMIC_SLEEP=n.  For
PREEMPT_VOLUNTARY=y might_sleep() inserts _cond_resched() call, but I
think it should be ok.

Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.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>
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 2d61503..92d8139 100644 (file)
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -940,60 +940,6 @@ static void trace(struct kmem_cache *s, struct page *page, void *object,
 }
 
 /*
- * Hooks for other subsystems that check memory allocations. In a typical
- * production configuration these hooks all should produce no code at all.
- */
-static inline void kmalloc_large_node_hook(void *ptr, size_t size, gfp_t flags)
-{
-       kmemleak_alloc(ptr, size, 1, flags);
-}
-
-static inline void kfree_hook(const void *x)
-{
-       kmemleak_free(x);
-}
-
-static inline int slab_pre_alloc_hook(struct kmem_cache *s, gfp_t flags)
-{
-       flags &= gfp_allowed_mask;
-       lockdep_trace_alloc(flags);
-       might_sleep_if(flags & __GFP_WAIT);
-
-       return should_failslab(s->object_size, flags, s->flags);
-}
-
-static inline void slab_post_alloc_hook(struct kmem_cache *s,
-                                       gfp_t flags, void *object)
-{
-       flags &= gfp_allowed_mask;
-       kmemcheck_slab_alloc(s, flags, object, slab_ksize(s));
-       kmemleak_alloc_recursive(object, s->object_size, 1, s->flags, flags);
-}
-
-static inline void slab_free_hook(struct kmem_cache *s, void *x)
-{
-       kmemleak_free_recursive(x, s->flags);
-
-       /*
-        * Trouble is that we may no longer disable interrupts in the fast path
-        * So in order to make the debug calls that expect irqs to be
-        * disabled we need to disable interrupts temporarily.
-        */
-#if defined(CONFIG_KMEMCHECK) || defined(CONFIG_LOCKDEP)
-       {
-               unsigned long flags;
-
-               local_irq_save(flags);
-               kmemcheck_slab_free(s, x, s->object_size);
-               debug_check_no_locks_freed(x, s->object_size);
-               local_irq_restore(flags);
-       }
-#endif
-       if (!(s->flags & SLAB_DEBUG_OBJECTS))
-               debug_check_no_obj_freed(x, s->object_size);
-}
-
-/*
  * Tracking of fully allocated slabs for debugging purposes.
  */
 static void add_full(struct kmem_cache *s,
@@ -1277,6 +1223,12 @@ static inline void inc_slabs_node(struct kmem_cache *s, int node,
 static inline void dec_slabs_node(struct kmem_cache *s, int node,
                                                        int objects) {}
 
+#endif /* CONFIG_SLUB_DEBUG */
+
+/*
+ * Hooks for other subsystems that check memory allocations. In a typical
+ * production configuration these hooks all should produce no code at all.
+ */
 static inline void kmalloc_large_node_hook(void *ptr, size_t size, gfp_t flags)
 {
        kmemleak_alloc(ptr, size, 1, flags);
@@ -1288,21 +1240,44 @@ static inline void kfree_hook(const void *x)
 }
 
 static inline int slab_pre_alloc_hook(struct kmem_cache *s, gfp_t flags)
-                                                       { return 0; }
+{
+       flags &= gfp_allowed_mask;
+       lockdep_trace_alloc(flags);
+       might_sleep_if(flags & __GFP_WAIT);
 
-static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags,
-               void *object)
+       return should_failslab(s->object_size, flags, s->flags);
+}
+
+static inline void slab_post_alloc_hook(struct kmem_cache *s,
+                                       gfp_t flags, void *object)
 {
-       kmemleak_alloc_recursive(object, s->object_size, 1, s->flags,
-               flags & gfp_allowed_mask);
+       flags &= gfp_allowed_mask;
+       kmemcheck_slab_alloc(s, flags, object, slab_ksize(s));
+       kmemleak_alloc_recursive(object, s->object_size, 1, s->flags, flags);
 }
 
 static inline void slab_free_hook(struct kmem_cache *s, void *x)
 {
        kmemleak_free_recursive(x, s->flags);
-}
 
-#endif /* CONFIG_SLUB_DEBUG */
+       /*
+        * Trouble is that we may no longer disable interrupts in the fast path
+        * So in order to make the debug calls that expect irqs to be
+        * disabled we need to disable interrupts temporarily.
+        */
+#if defined(CONFIG_KMEMCHECK) || defined(CONFIG_LOCKDEP)
+       {
+               unsigned long flags;
+
+               local_irq_save(flags);
+               kmemcheck_slab_free(s, x, s->object_size);
+               debug_check_no_locks_freed(x, s->object_size);
+               local_irq_restore(flags);
+       }
+#endif
+       if (!(s->flags & SLAB_DEBUG_OBJECTS))
+               debug_check_no_obj_freed(x, s->object_size);
+}
 
 /*
  * Slab allocation and freeing