diff options
Diffstat (limited to 'lib/idr.c')
| -rw-r--r-- | lib/idr.c | 24 |
1 files changed, 17 insertions, 7 deletions
diff --git a/lib/idr.c b/lib/idr.c index 63dda62131b3..e2b799989ab0 100644 --- a/lib/idr.c +++ b/lib/idr.c @@ -38,6 +38,15 @@ #include <linux/percpu.h> #include <linux/hardirq.h> +#define MAX_IDR_SHIFT (sizeof(int) * 8 - 1) +#define MAX_IDR_BIT (1U << MAX_IDR_SHIFT) + +/* Leave the possibility of an incomplete final layer */ +#define MAX_IDR_LEVEL ((MAX_IDR_SHIFT + IDR_BITS - 1) / IDR_BITS) + +/* Number of id_layer structs to leave in free list */ +#define MAX_IDR_FREE (MAX_IDR_LEVEL * 2) + static struct kmem_cache *idr_layer_cache; static DEFINE_PER_CPU(struct idr_layer *, idr_preload_head); static DEFINE_PER_CPU(int, idr_preload_cnt); @@ -542,8 +551,8 @@ void idr_remove(struct idr *idp, int id) struct idr_layer *p; struct idr_layer *to_free; - /* Mask off upper bits we don't use for the search. */ - id &= MAX_IDR_MASK; + if (WARN_ON_ONCE(id < 0)) + return; sub_remove(idp, (idp->layers - 1) * IDR_BITS, id); if (idp->top && idp->top->count == 1 && (idp->layers > 1) && @@ -650,14 +659,14 @@ void *idr_find(struct idr *idp, int id) int n; struct idr_layer *p; + if (WARN_ON_ONCE(id < 0)) + return NULL; + p = rcu_dereference_raw(idp->top); if (!p) return NULL; n = (p->layer+1) * IDR_BITS; - /* Mask off upper bits we don't use for the search. */ - id &= MAX_IDR_MASK; - if (id > idr_max(p->layer + 1)) return NULL; BUG_ON(n == 0); @@ -799,14 +808,15 @@ void *idr_replace(struct idr *idp, void *ptr, int id) int n; struct idr_layer *p, *old_p; + if (WARN_ON_ONCE(id < 0)) + return ERR_PTR(-EINVAL); + p = idp->top; if (!p) return ERR_PTR(-EINVAL); n = (p->layer+1) * IDR_BITS; - id &= MAX_IDR_MASK; - if (id >= (1 << n)) return ERR_PTR(-EINVAL); |