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 not worked before because should_failslab() call was in 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. might_sleep_if() call can generate some code
even if DEBUG_ATOMIC_SLEEP=n. For PREEMPT_VOLUNTARY=y migth_sleep() inserts
_cond_resched() call, but I think it should be ok.
Signed-off-by: Andrey Ryabinin <a.ryabinin@xxxxxxxxxxx>
---
mm/slub.c | 97 ++++++++++++++++++++++++---------------------------------------
1 file changed, 36 insertions(+), 61 deletions(-)
diff --git a/mm/slub.c b/mm/slub.c
index b2b0473..8f477c3 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -945,60 +945,6 @@ 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,
@@ -1282,6 +1228,12 @@ 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);
@@ -1293,22 +1245,45 @@ 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);
+
+ 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)
+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);
+
+ /*
+ * 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);
}
-#endif /* CONFIG_SLUB_DEBUG */
-
/*
* Slab allocation and freeing
*/
--
1.8.5.5
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