Commit d39d7149 authored by Cong Wang's avatar Cong Wang Committed by David S. Miller
Browse files

idr: introduce idr_for_each_entry_continue_ul() 



Similarly, other callers of idr_get_next_ul() suffer the same
overflow bug as they don't handle it properly either.

Introduce idr_for_each_entry_continue_ul() to help these callers
iterate from a given ID.

cls_flower needs more care here because it still has overflow when
does arg->cookie++, we have to fold its nested loops into one
and remove the arg->cookie++.

Fixes: 01683a14 ("net: sched: refactor flower walk to iterate over idr")
Fixes: 12d6066c ("net/mlx5: Add flow counters idr")
Reported-by: default avatarLi Shuang <shuali@redhat.com>
Cc: Davide Caratti <dcaratti@redhat.com>
Cc: Vlad Buslov <vladbu@mellanox.com>
Cc: Chris Mi <chrism@mellanox.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
Tested-by: default avatarDavide Caratti <dcaratti@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e33d2b74

drivers/net/ethernet/mellanox/mlx5/core/fs_counters.c

+6 −4
Original line number Diff line number Diff line
@@ -102,13 +102,15 @@ static struct list_head *mlx5_fc_counters_lookup_next(struct mlx5_core_dev *dev, 
	struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;

	unsigned long next_id = (unsigned long)id + 1;

	struct mlx5_fc *counter;

	unsigned long tmp;



	rcu_read_lock();

	/* skip counters that are in idr, but not yet in counters list */

	while ((counter = idr_get_next_ul(&fc_stats->counters_idr,

					  &next_id)) != NULL &&

	       list_empty(&counter->list))

		next_id++;

	idr_for_each_entry_continue_ul(&fc_stats->counters_idr,

				       counter, tmp, next_id) {

		if (!list_empty(&counter->list))

			break;

	}

	rcu_read_unlock();



	return counter ? &counter->list : &fc_stats->counters;

include/linux/idr.h

+14 −0
Original line number Diff line number Diff line
@@ -216,6 +216,20 @@ static inline void idr_preload_end(void) 
	     entry;							\

	     ++id, (entry) = idr_get_next((idr), &(id)))



/**

 * idr_for_each_entry_continue_ul() - Continue iteration over an IDR's elements of a given type

 * @idr: IDR handle.

 * @entry: The type * to use as a cursor.

 * @tmp: A temporary placeholder for ID.

 * @id: Entry ID.

 *

 * Continue to iterate over entries, continuing after the current position.

 */

#define idr_for_each_entry_continue_ul(idr, entry, tmp, id)		\

	for (tmp = id;							\

	     tmp <= id && ((entry) = idr_get_next_ul(idr, &(id))) != NULL; \

	     tmp = id, ++id)



/*

 * IDA - ID Allocator, use when translation from id to pointer isn't necessary.

 */

net/sched/cls_flower.c

+7 −20
Original line number Diff line number Diff line
@@ -524,24 +524,6 @@ static struct cls_fl_filter *__fl_get(struct cls_fl_head *head, u32 handle) 
	return f;

}



static struct cls_fl_filter *fl_get_next_filter(struct tcf_proto *tp,

						unsigned long *handle)

{

	struct cls_fl_head *head = fl_head_dereference(tp);

	struct cls_fl_filter *f;



	rcu_read_lock();

	while ((f = idr_get_next_ul(&head->handle_idr, handle))) {

		/* don't return filters that are being deleted */

		if (refcount_inc_not_zero(&f->refcnt))

			break;

		++(*handle);

	}

	rcu_read_unlock();



	return f;

}



static int __fl_delete(struct tcf_proto *tp, struct cls_fl_filter *f,

		       bool *last, bool rtnl_held,

		       struct netlink_ext_ack *extack)
@@ -1691,20 +1673,25 @@ static int fl_delete(struct tcf_proto *tp, void *arg, bool *last, 
static void fl_walk(struct tcf_proto *tp, struct tcf_walker *arg,

		    bool rtnl_held)

{

	struct cls_fl_head *head = fl_head_dereference(tp);

	unsigned long id = arg->cookie, tmp;

	struct cls_fl_filter *f;



	arg->count = arg->skip;



	while ((f = fl_get_next_filter(tp, &arg->cookie)) != NULL) {

	idr_for_each_entry_continue_ul(&head->handle_idr, f, tmp, id) {

		/* don't return filters that are being deleted */

		if (!refcount_inc_not_zero(&f->refcnt))

			continue;

		if (arg->fn(tp, f, arg) < 0) {

			__fl_put(f);

			arg->stop = 1;

			break;

		}

		__fl_put(f);

		arg->cookie++;

		arg->count++;

	}

	arg->cookie = id;

}



static struct cls_fl_filter *

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