[PATCH] net: qed: fixes crash while running driver in kdump kernel

[PATCH] net: qed: fixes crash while running driver in kdump kernel

[Alok Prasad]

This fixes a crash introduced by recent is_kdump_kernel() check.
The source of the crash is that kdump kernel can be loaded on a
system with already created VFs. But for such VFs, it will follow
a logic path of PF and eventually crash.

Thus, we are partially reverting back previous changes and instead
use is_kdump_kernel is a single init point of PF init, where we
disable SRIOV explicitly.

Fixes: 37d4f8a6b41f ("net: qed: Disable SRIOV functionality inside kdump kernel")
Cc: Bhupesh Sharma <bhsharma@redhat.com>
Signed-off-by: Igor Russkikh <irusskikh@marvell.com>
Signed-off-by: Alok Prasad <palok@marvell.com>
---
 drivers/net/ethernet/qlogic/qed/qed_sriov.c  |  4 ++++
 drivers/net/ethernet/qlogic/qed/qed_sriov.h  | 10 +++-------
 drivers/net/ethernet/qlogic/qede/qede_main.c |  2 +-
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/qlogic/qed/qed_sriov.c b/drivers/net/ethernet/qlogic/qed/qed_sriov.c
index 66876af814c4..20679fd4204b 100644
--- a/drivers/net/ethernet/qlogic/qed/qed_sriov.c
+++ b/drivers/net/ethernet/qlogic/qed/qed_sriov.c
@@ -33,6 +33,7 @@
 #include <linux/etherdevice.h>
 #include <linux/crc32.h>
 #include <linux/vmalloc.h>
+#include <linux/crash_dump.h>
 #include <linux/qed/qed_iov_if.h>
 #include "qed_cxt.h"
 #include "qed_hsi.h"
@@ -607,6 +608,9 @@ int qed_iov_hw_info(struct qed_hwfn *p_hwfn)
 	int pos;
 	int rc;
 
+	if (is_kdump_kernel())
+		return 0;
+
 	if (IS_VF(p_hwfn->cdev))
 		return 0;
 
diff --git a/drivers/net/ethernet/qlogic/qed/qed_sriov.h b/drivers/net/ethernet/qlogic/qed/qed_sriov.h
index aabeaf03135e..368e88565783 100644
--- a/drivers/net/ethernet/qlogic/qed/qed_sriov.h
+++ b/drivers/net/ethernet/qlogic/qed/qed_sriov.h
@@ -32,7 +32,6 @@
 
 #ifndef _QED_SRIOV_H
 #define _QED_SRIOV_H
-#include <linux/crash_dump.h>
 #include <linux/types.h>
 #include "qed_vf.h"
 
@@ -41,12 +40,9 @@
 #define QED_VF_ARRAY_LENGTH (3)
 
 #ifdef CONFIG_QED_SRIOV
-#define IS_VF(cdev)             (is_kdump_kernel() ? \
-				 (0) : ((cdev)->b_is_vf))
-#define IS_PF(cdev)             (is_kdump_kernel() ? \
-				 (1) : !((cdev)->b_is_vf))
-#define IS_PF_SRIOV(p_hwfn)     (is_kdump_kernel() ? \
-				 (0) : !!((p_hwfn)->cdev->p_iov_info))
+#define IS_VF(cdev)             ((cdev)->b_is_vf)
+#define IS_PF(cdev)             (!((cdev)->b_is_vf))
+#define IS_PF_SRIOV(p_hwfn)     (!!((p_hwfn)->cdev->p_iov_info))
 #else
 #define IS_VF(cdev)             (0)
 #define IS_PF(cdev)             (1)
diff --git a/drivers/net/ethernet/qlogic/qede/qede_main.c b/drivers/net/ethernet/qlogic/qede/qede_main.c
index b2d154258b07..756c05eb96f3 100644
--- a/drivers/net/ethernet/qlogic/qede/qede_main.c
+++ b/drivers/net/ethernet/qlogic/qede/qede_main.c
@@ -1265,7 +1265,7 @@ static int qede_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	case QEDE_PRIVATE_VF:
 		if (debug & QED_LOG_VERBOSE_MASK)
 			dev_err(&pdev->dev, "Probing a VF\n");
-		is_vf = is_kdump_kernel() ? false : true;
+		is_vf = true;
 		break;
 	default:
 		if (debug & QED_LOG_VERBOSE_MASK)
-- 
2.17.1

Re: [PATCH] net: qed: fixes crash while running driver in kdump kernel

[David Miller]

From: Alok Prasad <palok@marvell.com>
Date: Fri, 5 Jun 2020 16:30:34 +0000

> This fixes a crash introduced by recent is_kdump_kernel() check.
> The source of the crash is that kdump kernel can be loaded on a
> system with already created VFs. But for such VFs, it will follow
> a logic path of PF and eventually crash.
> 
> Thus, we are partially reverting back previous changes and instead
> use is_kdump_kernel is a single init point of PF init, where we
> disable SRIOV explicitly.
> 
> Fixes: 37d4f8a6b41f ("net: qed: Disable SRIOV functionality inside kdump kernel")
> Cc: Bhupesh Sharma <bhsharma@redhat.com>
> Signed-off-by: Igor Russkikh <irusskikh@marvell.com>
> Signed-off-by: Alok Prasad <palok@marvell.com>

Applied.