6 files changed, 20 insertions, 22 deletions

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 8d1f644a7fdc..991d38daa87d 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -979,8 +979,6 @@ int i2c_add_numbered_adapter(struct i2c_adapter *adap)
 
 	if (adap->nr == -1) /* -1 means dynamically assign bus id */
 		return i2c_add_adapter(adap);
-	if (adap->nr & ~MAX_IDR_MASK)
-		return -EINVAL;
 
 	mutex_lock(&core_lock);
 	id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1,
diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c
index 98281fe5ea4b..784b97cb05b0 100644
--- a/drivers/infiniband/core/cm.c
+++ b/drivers/infiniband/core/cm.c
@@ -390,7 +390,7 @@ static int cm_alloc_id(struct cm_id_private *cm_id_priv)
 
 	id = idr_alloc(&cm.local_id_table, cm_id_priv, next_id, 0, GFP_NOWAIT);
 	if (id >= 0)
-		next_id = ((unsigned) id + 1) & MAX_IDR_MASK;
+		next_id = max(id + 1, 0);
 
 	spin_unlock_irqrestore(&cm.lock, flags);
 	idr_preload_end();
diff --git a/drivers/infiniband/hw/mlx4/cm.c b/drivers/infiniband/hw/mlx4/cm.c
index 80e59ed864b3..e0d79b2395e4 100644
--- a/drivers/infiniband/hw/mlx4/cm.c
+++ b/drivers/infiniband/hw/mlx4/cm.c
@@ -225,7 +225,7 @@ id_map_alloc(struct ib_device *ibdev, int slave_id, u32 sl_cm_id)
 
 	ret = idr_alloc(&sriov->pv_id_table, ent, next_id, 0, GFP_NOWAIT);
 	if (ret >= 0) {
-		next_id = ((unsigned)ret + 1) & MAX_IDR_MASK;
+		next_id = max(ret + 1, 0);
 		ent->pv_cm_id = (u32)ret;
 		sl_id_map_add(ibdev, ent);
 		list_add_tail(&ent->list, &sriov->cm_list);
diff --git a/fs/super.c b/fs/super.c
index 12f123712161..df6c2f4c6b59 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -842,7 +842,7 @@ int get_anon_bdev(dev_t *p)
 	else if (error)
 		return -EAGAIN;
 
-	if ((dev & MAX_IDR_MASK) == (1 << MINORBITS)) {
+	if (dev == (1 << MINORBITS)) {
 		spin_lock(&unnamed_dev_lock);
 		ida_remove(&unnamed_dev_ida, dev);
 		if (unnamed_dev_start > dev)
diff --git a/include/linux/idr.h b/include/linux/idr.h
index 6dcf133f208a..99b0ce533f0e 100644
--- a/include/linux/idr.h
+++ b/include/linux/idr.h
@@ -38,16 +38,6 @@
 #define IDR_SIZE (1 << IDR_BITS)
 #define IDR_MASK ((1 << IDR_BITS)-1)
 
-#define MAX_IDR_SHIFT (sizeof(int)*8 - 1)
-#define MAX_IDR_BIT (1U << MAX_IDR_SHIFT)
-#define MAX_IDR_MASK (MAX_IDR_BIT - 1)
-
-/* 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)
-
 struct idr_layer {
 	unsigned long		bitmap;	/* A zero bit means "space here" */
 	struct idr_layer __rcu	*ary[1<<IDR_BITS];
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);