[PATCH 1/2] vmxnet3: Fix inconsistent DMA accesses in vmxnet3_probe_device()

From: Brian Johannesmeyer
Date: Wed Nov 13 2024 - 15:01:08 EST


After mapping `adapter` to streaming DMA, but before accessing it,
synchronize it to the CPU. Then, before returning, synchronize it back to
the device. This mitigates any inconsistent accesses to it from
vmxnet3_probe_device().

Co-developed-by: Raphael Isemann <teemperor@xxxxxxxxx>
Signed-off-by: Raphael Isemann <teemperor@xxxxxxxxx>
Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@xxxxxxxxx>
---
drivers/net/vmxnet3/vmxnet3_drv.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/net/vmxnet3/vmxnet3_drv.c b/drivers/net/vmxnet3/vmxnet3_drv.c
index 7fa74b8b2100..cc76134c7db4 100644
--- a/drivers/net/vmxnet3/vmxnet3_drv.c
+++ b/drivers/net/vmxnet3/vmxnet3_drv.c
@@ -3623,6 +3623,8 @@ vmxnet3_probe_device(struct pci_dev *pdev,
int num_rx_queues;
int queues;
unsigned long flags;
+ struct device *dev;
+ dma_addr_t adapter_pa;

if (!pci_msi_enabled())
enable_mq = 0;
@@ -3662,14 +3664,19 @@ vmxnet3_probe_device(struct pci_dev *pdev,
}

spin_lock_init(&adapter->cmd_lock);
- adapter->adapter_pa = dma_map_single(&adapter->pdev->dev, adapter,
+ dev = &adapter->pdev->dev;
+ adapter_pa = dma_map_single(dev, adapter,
sizeof(struct vmxnet3_adapter),
DMA_TO_DEVICE);
- if (dma_mapping_error(&adapter->pdev->dev, adapter->adapter_pa)) {
+ if (dma_mapping_error(dev, adapter_pa)) {
dev_err(&pdev->dev, "Failed to map dma\n");
err = -EFAULT;
goto err_set_mask;
}
+ dma_sync_single_for_cpu(dev, adapter_pa,
+ sizeof(struct vmxnet3_adapter), DMA_TO_DEVICE);
+ adapter->adapter_pa = adapter_pa;
+
adapter->shared = dma_alloc_coherent(
&adapter->pdev->dev,
sizeof(struct Vmxnet3_DriverShared),
@@ -3928,6 +3935,8 @@ vmxnet3_probe_device(struct pci_dev *pdev,
}

vmxnet3_check_link(adapter, false);
+ dma_sync_single_for_device(dev, adapter_pa,
+ sizeof(struct vmxnet3_adapter), DMA_TO_DEVICE);
return 0;

err_register:
--
2.34.1