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Commit bf692e7e authored by Jia He's avatar Jia He Committed by Greg Kroah-Hartman
Browse files

qed: fix possible unpaired spin_{un}lock_bh in _qed_mcp_cmd_and_union() 



[ Upstream commit 6206b7981a36476f4695d661ae139f7db36a802d ]

Liajian reported a bug_on hit on a ThunderX2 arm64 server with FastLinQ
QL41000 ethernet controller:
 BUG: scheduling while atomic: kworker/0:4/531/0x00000200
  [qed_probe:488()]hw prepare failed
  kernel BUG at mm/vmalloc.c:2355!
  Internal error: Oops - BUG: 0 [#1] SMP
  CPU: 0 PID: 531 Comm: kworker/0:4 Tainted: G W 5.4.0-77-generic #86-Ubuntu
  pstate: 00400009 (nzcv daif +PAN -UAO)
 Call trace:
  vunmap+0x4c/0x50
  iounmap+0x48/0x58
  qed_free_pci+0x60/0x80 [qed]
  qed_probe+0x35c/0x688 [qed]
  __qede_probe+0x88/0x5c8 [qede]
  qede_probe+0x60/0xe0 [qede]
  local_pci_probe+0x48/0xa0
  work_for_cpu_fn+0x24/0x38
  process_one_work+0x1d0/0x468
  worker_thread+0x238/0x4e0
  kthread+0xf0/0x118
  ret_from_fork+0x10/0x18

In this case, qed_hw_prepare() returns error due to hw/fw error, but in
theory work queue should be in process context instead of interrupt.

The root cause might be the unpaired spin_{un}lock_bh() in
_qed_mcp_cmd_and_union(), which causes botton half is disabled incorrectly.

Reported-by: default avatarLijian Zhang <Lijian.Zhang@arm.com>
Signed-off-by: default avatarJia He <justin.he@arm.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 6bc48348

drivers/net/ethernet/qlogic/qed/qed_mcp.c

+17 −6
Original line number Diff line number Diff line
@@ -498,14 +498,18 @@ _qed_mcp_cmd_and_union(struct qed_hwfn *p_hwfn, 


		spin_lock_bh(&p_hwfn->mcp_info->cmd_lock);



		if (!qed_mcp_has_pending_cmd(p_hwfn))

		if (!qed_mcp_has_pending_cmd(p_hwfn)) {

			spin_unlock_bh(&p_hwfn->mcp_info->cmd_lock);

			break;

		}



		rc = qed_mcp_update_pending_cmd(p_hwfn, p_ptt);

		if (!rc)

		if (!rc) {

			spin_unlock_bh(&p_hwfn->mcp_info->cmd_lock);

			break;

		else if (rc != -EAGAIN)

		} else if (rc != -EAGAIN) {

			goto err;

		}



		spin_unlock_bh(&p_hwfn->mcp_info->cmd_lock);
@@ -522,6 +526,8 @@ _qed_mcp_cmd_and_union(struct qed_hwfn *p_hwfn, 
		return -EAGAIN;

	}



	spin_lock_bh(&p_hwfn->mcp_info->cmd_lock);



	/* Send the mailbox command */

	qed_mcp_reread_offsets(p_hwfn, p_ptt);

	seq_num = ++p_hwfn->mcp_info->drv_mb_seq;
@@ -548,14 +554,18 @@ _qed_mcp_cmd_and_union(struct qed_hwfn *p_hwfn, 


		spin_lock_bh(&p_hwfn->mcp_info->cmd_lock);



		if (p_cmd_elem->b_is_completed)

		if (p_cmd_elem->b_is_completed) {

			spin_unlock_bh(&p_hwfn->mcp_info->cmd_lock);

			break;

		}



		rc = qed_mcp_update_pending_cmd(p_hwfn, p_ptt);

		if (!rc)

		if (!rc) {

			spin_unlock_bh(&p_hwfn->mcp_info->cmd_lock);

			break;

		else if (rc != -EAGAIN)

		} else if (rc != -EAGAIN) {

			goto err;

		}



		spin_unlock_bh(&p_hwfn->mcp_info->cmd_lock);

	} while (++cnt < max_retries);
@@ -576,6 +586,7 @@ _qed_mcp_cmd_and_union(struct qed_hwfn *p_hwfn, 
		return -EAGAIN;

	}



	spin_lock_bh(&p_hwfn->mcp_info->cmd_lock);

	qed_mcp_cmd_del_elem(p_hwfn, p_cmd_elem);

	spin_unlock_bh(&p_hwfn->mcp_info->cmd_lock);