@@ -3735,6 +3735,12 @@ static int efx_ef10_filter_table_probe(struct efx_nic *efx)
size_t outlen;
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);
if (!table)
return -ENOMEM;
@@ -3846,7 +3852,6 @@ static void efx_ef10_filter_table_restore(struct efx_nic *efx)
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)
{
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;
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)
return;
@@ -274,4 +274,13 @@ static inline void efx_device_detach_sync(struct efx_nic *efx)
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 */
Based on a patch by Andrew Rybchenko <Andrew.Rybchenko@oktetlabs.ru> Signed-off-by: Edward Cree <ecree@solarflare.com> --- drivers/net/ethernet/sfc/ef10.c | 16 +++++++++++++++- drivers/net/ethernet/sfc/efx.h | 9 +++++++++ 2 files changed, 24 insertions(+), 1 deletion(-)