[PATCH AUTOSEL 5.4 2/6] bnx2x: fix page fault following EEH recovery

Sasha Levin
2023-08-29T13:35:22Z

From: David Christensen <drc@linux.vnet.ibm.com>

[ Upstream commit 7ebe4eda4265642859507d1b3ca330d8c196cfe5 ]

In the last step of the EEH recovery process, the EEH driver calls into
bnx2x_io_resume() to re-initialize the NIC hardware via the function
bnx2x_nic_load(). If an error occurs during bnx2x_nic_load(), OS and
hardware resources are released and an error code is returned to the
caller. When called from bnx2x_io_resume(), the return code is ignored
and the network interface is brought up unconditionally. Later attempts
to send a packet via this interface result in a page fault due to a null
pointer reference.

This patch checks the return code of bnx2x_nic_load(), prints an error
message if necessary, and does not enable the interface.

Signed-off-by: David Christensen <drc@linux.vnet.ibm.com>
Reviewed-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
index b5f58c62e7d20..211fbc8f75712 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
@@ -14426,11 +14426,16 @@ static void bnx2x_io_resume(struct pci_dev *pdev)
bp->fw_seq = SHMEM_RD(bp, func_mb[BP_FW_MB_IDX(bp)].drv_mb_header) &
DRV_MSG_SEQ_NUMBER_MASK;

- if (netif_running(dev))
- bnx2x_nic_load(bp, LOAD_NORMAL);
+ if (netif_running(dev)) {
+ if (bnx2x_nic_load(bp, LOAD_NORMAL)) {
+ netdev_err(bp->dev, "Error during driver initialization, try unloading/reloading the driver\n");
+ goto done;
+ }
+ }

netif_device_attach(dev);

+done:
rtnl_unlock();
}

--
2.40.1