Commit a926a903 authored by Bob Pearson's avatar Bob Pearson Committed by Jason Gunthorpe
Browse files

RDMA/rxe: Do not call dev_mc_add/del() under a spinlock 

These routines were not intended to be called under a spinlock and will
throw debugging warnings:

   raw_local_irq_restore() called with IRQs enabled
   WARNING: CPU: 13 PID: 3107 at kernel/locking/irqflag-debug.c:10 warn_bogus_irq_restore+0x2f/0x50
   CPU: 13 PID: 3107 Comm: python3 Tainted: G            E     5.18.0-rc1+ #7
   Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
   RIP: 0010:warn_bogus_irq_restore+0x2f/0x50
   Call Trace:
    <TASK>
    _raw_spin_unlock_irqrestore+0x75/0x80
    rxe_attach_mcast+0x304/0x480 [rdma_rxe]
    ib_attach_mcast+0x88/0xa0 [ib_core]
    ib_uverbs_attach_mcast+0x186/0x1e0 [ib_uverbs]
    ib_uverbs_handler_UVERBS_METHOD_INVOKE_WRITE+0xcd/0x140 [ib_uverbs]
    ib_uverbs_cmd_verbs+0xdb0/0xea0 [ib_uverbs]
    ib_uverbs_ioctl+0xd2/0x160 [ib_uverbs]
    do_syscall_64+0x5c/0x80
    entry_SYSCALL_64_after_hwframe+0x44/0xae

Move them out of the spinlock, it is OK if there is some races setting up
the MC reception at the ethernet layer with rbtree lookups.

Fixes: 6090a0c4 ("RDMA/rxe: Cleanup rxe_mcast.c")
Link: https://lore.kernel.org/r/20220504202817.98247-1-rpearsonhpe@gmail.com


Signed-off-by: default avatarBob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
parent ef91271c

drivers/infiniband/sw/rxe/rxe_mcast.c

+23 −28
Original line number Diff line number Diff line
@@ -38,13 +38,13 @@ static int rxe_mcast_add(struct rxe_dev *rxe, union ib_gid *mgid) 
}



/**

 * rxe_mcast_delete - delete multicast address from rxe device

 * rxe_mcast_del - delete multicast address from rxe device

 * @rxe: rxe device object

 * @mgid: multicast address as a gid

 *

 * Returns 0 on success else an error

 */

static int rxe_mcast_delete(struct rxe_dev *rxe, union ib_gid *mgid)

static int rxe_mcast_del(struct rxe_dev *rxe, union ib_gid *mgid)

{

	unsigned char ll_addr[ETH_ALEN];
@@ -159,17 +159,10 @@ struct rxe_mcg *rxe_lookup_mcg(struct rxe_dev *rxe, union ib_gid *mgid) 
 * @mcg: new mcg object

 *

 * Context: caller should hold rxe->mcg lock

 * Returns: 0 on success else an error

 */

static int __rxe_init_mcg(struct rxe_dev *rxe, union ib_gid *mgid,

static void __rxe_init_mcg(struct rxe_dev *rxe, union ib_gid *mgid,

			   struct rxe_mcg *mcg)

{

	int err;



	err = rxe_mcast_add(rxe, mgid);

	if (unlikely(err))

		return err;



	kref_init(&mcg->ref_cnt);

	memcpy(&mcg->mgid, mgid, sizeof(mcg->mgid));

	INIT_LIST_HEAD(&mcg->qp_list);
@@ -184,8 +177,6 @@ static int __rxe_init_mcg(struct rxe_dev *rxe, union ib_gid *mgid, 
	 */

	kref_get(&mcg->ref_cnt);

	__rxe_insert_mcg(mcg);



	return 0;

}



/**
@@ -209,6 +200,12 @@ static struct rxe_mcg *rxe_get_mcg(struct rxe_dev *rxe, union ib_gid *mgid) 
	if (mcg)

		return mcg;



	/* check to see if we have reached limit */

	if (atomic_inc_return(&rxe->mcg_num) > rxe->attr.max_mcast_grp) {

		err = -ENOMEM;

		goto err_dec;

	}



	/* speculative alloc of new mcg */

	mcg = kzalloc(sizeof(*mcg), GFP_KERNEL);

	if (!mcg)
@@ -218,27 +215,23 @@ static struct rxe_mcg *rxe_get_mcg(struct rxe_dev *rxe, union ib_gid *mgid) 
	/* re-check to see if someone else just added it */

	tmp = __rxe_lookup_mcg(rxe, mgid);

	if (tmp) {

		spin_unlock_irqrestore(&rxe->mcg_lock, flags);

		atomic_dec(&rxe->mcg_num);

		kfree(mcg);

		mcg = tmp;

		goto out;

	}



	if (atomic_inc_return(&rxe->mcg_num) > rxe->attr.max_mcast_grp) {

		err = -ENOMEM;

		goto err_dec;

		return tmp;

	}



	err = __rxe_init_mcg(rxe, mgid, mcg);

	if (err)

		goto err_dec;

out:

	__rxe_init_mcg(rxe, mgid, mcg);

	spin_unlock_irqrestore(&rxe->mcg_lock, flags);



	/* add mcast address outside of lock */

	err = rxe_mcast_add(rxe, mgid);

	if (!err)

		return mcg;



	kfree(mcg);

err_dec:

	atomic_dec(&rxe->mcg_num);

	spin_unlock_irqrestore(&rxe->mcg_lock, flags);

	kfree(mcg);

	return ERR_PTR(err);

}
@@ -268,7 +261,6 @@ static void __rxe_destroy_mcg(struct rxe_mcg *mcg) 
	__rxe_remove_mcg(mcg);

	kref_put(&mcg->ref_cnt, rxe_cleanup_mcg);



	rxe_mcast_delete(mcg->rxe, &mcg->mgid);

	atomic_dec(&rxe->mcg_num);

}
@@ -282,6 +274,9 @@ static void rxe_destroy_mcg(struct rxe_mcg *mcg) 
{

	unsigned long flags;



	/* delete mcast address outside of lock */

	rxe_mcast_del(mcg->rxe, &mcg->mgid);



	spin_lock_irqsave(&mcg->rxe->mcg_lock, flags);

	__rxe_destroy_mcg(mcg);

	spin_unlock_irqrestore(&mcg->rxe->mcg_lock, flags);