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Commit dd98708c authored by Edward Cree's avatar Edward Cree Committed by David S. Miller
Browse files

sfc: Assert filter_sem write locked when required 



Based on a patch by Andrew Rybchenko <Andrew.Rybchenko@oktetlabs.ru>

Signed-off-by: default avatarEdward Cree <ecree@solarflare.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ebfcd0fd

drivers/net/ethernet/sfc/ef10.c

+15 −1
Original line number Original line Diff line number Diff line
@@ -3735,6 +3735,12 @@ static int efx_ef10_filter_table_probe(struct efx_nic *efx) 
	size_t outlen;

	size_t outlen;

	int rc;

	int rc;





	if (!efx_rwsem_assert_write_locked(&efx->filter_sem))

		return -EINVAL;



	if (efx->filter_state) /* already probed */

		return 0;



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

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

	if (!table)

	if (!table)

		return -ENOMEM;

		return -ENOMEM;
@@ -3846,7 +3852,6 @@ static void efx_ef10_filter_table_restore(struct efx_nic *efx) 
		nic_data->must_restore_filters = false;

		nic_data->must_restore_filters = false;

}

}





/* Caller must hold efx->filter_sem for write */

static void efx_ef10_filter_table_remove(struct efx_nic *efx)

static void efx_ef10_filter_table_remove(struct efx_nic *efx)

{

{

	struct efx_ef10_filter_table *table = efx->filter_state;

	struct efx_ef10_filter_table *table = efx->filter_state;
@@ -3856,6 +3861,15 @@ static void efx_ef10_filter_table_remove(struct efx_nic *efx) 
	int rc;

	int rc;





	efx->filter_state = NULL;

	efx->filter_state = NULL;

	/* If we were called without locking, then it's not safe to free

	 * the table as others might be using it.  So we just WARN, leak

	 * the memory, and potentially get an inconsistent filter table

	 * state.

	 * This should never actually happen.

	 */

	if (!efx_rwsem_assert_write_locked(&efx->filter_sem))

		return;



	if (!table)

	if (!table)

		return;

		return;

drivers/net/ethernet/sfc/efx.h

+9 −0
Original line number Original line Diff line number Diff line
@@ -274,4 +274,13 @@ static inline void efx_device_detach_sync(struct efx_nic *efx) 
	netif_tx_unlock_bh(dev);

	netif_tx_unlock_bh(dev);

}

}





static inline bool efx_rwsem_assert_write_locked(struct rw_semaphore *sem)

{

	if (WARN_ON(down_read_trylock(sem))) {

		up_read(sem);

		return false;

	}

	return true;

}



#endif /* EFX_EFX_H */
 
#endif /* EFX_EFX_H */