diff options
Diffstat (limited to 'include/linux/slab.h')
| -rw-r--r-- | include/linux/slab.h | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/include/linux/slab.h b/include/linux/slab.h index 98e07e9e9e58..d5a8ab98035c 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -137,6 +137,15 @@ enum _slab_flag_bits { * rcu_read_lock before reading the address, then rcu_read_unlock after * taking the spinlock within the structure expected at that address. * + * Note that object identity check has to be done *after* acquiring a + * reference, therefore user has to ensure proper ordering for loads. + * Similarly, when initializing objects allocated with SLAB_TYPESAFE_BY_RCU, + * the newly allocated object has to be fully initialized *before* its + * refcount gets initialized and proper ordering for stores is required. + * refcount_{add|inc}_not_zero_acquire() and refcount_set_release() are + * designed with the proper fences required for reference counting objects + * allocated with SLAB_TYPESAFE_BY_RCU. + * * Note that it is not possible to acquire a lock within a structure * allocated with SLAB_TYPESAFE_BY_RCU without first acquiring a reference * as described above. The reason is that SLAB_TYPESAFE_BY_RCU pages @@ -236,12 +245,6 @@ enum _slab_flag_bits { #endif /* - * freeptr_t represents a SLUB freelist pointer, which might be encoded - * and not dereferenceable if CONFIG_SLAB_FREELIST_HARDENED is enabled. - */ -typedef struct { unsigned long v; } freeptr_t; - -/* * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests. * * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault. |