cciss: bug fix to prevent cciss from loading in kdump crash kernel

PATCH In review Mike Miller 2 participants 3 messages Apr 23, 2013 – May 3, 2013

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Mike Miller

author

2013-04-23 17:25 UTC #0 lore raw

PATCH 1/1 cciss: bug fix to prevent cciss from loading in kdump crash kernel

PATCH 1/1

By default the cciss driver supports all "older" HP Smart Array controllers and hpsa supports all controllers starting with the G6 family. There are module parameters that allow a user to override those defaults and use hpsa for any HP Smart Array controller.
If the user does override the default behavior and uses hpsa for older controllers it is possible that cciss may try to load in a kdump crash kernel. This may happen if cciss is loaded first from the kdump initrd image. If cciss does load rather than hpsa and reset_devices is true we immediately call cciss_hard_reset_controller. This will result in a kernel panic and the core file cannot be created.
This patch prevents cciss from trying to load in this scenario.

Tested with 3.9.0-rc7.

From: Mike <[email protected]>

Signed-off-by Mike Miller <[email protected]>

---
 drivers/block/cciss.c |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)

drivers/block/cciss.c +10 -0

index 1c1b8e5..06c8dba 100644
@@ -4960,6 +4960,16 @@ static int cciss_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	ctlr_info_t *h;
 	unsigned long flags;
 
+	/*
+	 * By default the cciss driver is used for all older HP Smart Array
+	 * controllers. There are module paramaters that allow a user to
+	 * override this behavior and instead use the hpsa SCSI driver. If
+	 * this is the case cciss may be loaded first from the kdump initrd
+	 * image and cause a kernel panic. So if reset_devices is true and
+	 * cciss_allow_hpsa is set just bail.
+	 */
+	if ((reset_devices) && (cciss_allow_hpsa == 1))
+		return -ENODEV;
 	rc = cciss_init_reset_devices(pdev);
 	if (rc) {
 		if (rc != -ENOTSUPP)

James Bottomley

maintainer

2013-05-03 18:02 UTC #1 lore raw

Quoted 34 lines · Mike Miller

PATCH 1/1
By default the cciss driver supports all "older" HP Smart Array controllers and hpsa supports all controllers starting with the G6 family. There are module parameters that allow a user to override those defaults and use hpsa for any HP Smart Array controller.
If the user does override the default behavior and uses hpsa for older controllers it is possible that cciss may try to load in a kdump crash kernel. This may happen if cciss is loaded first from the kdump initrd image. If cciss does load rather than hpsa and reset_devices is true we immediately call cciss_hard_reset_controller. This will result in a kernel panic and the core file cannot be created.
This patch prevents cciss from trying to load in this scenario.
Tested with 3.9.0-rc7.
From: Mike <[email protected]>
Signed-off-by Mike Miller <[email protected]>
---
 drivers/block/cciss.c |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)
drivers/block/cciss.c +3 -0
index 1c1b8e5..06c8dba 100644
@@ -4960,6 +4960,16 @@ static int cciss_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	ctlr_info_t *h;
 	unsigned long flags;
 
+	/*
+	 * By default the cciss driver is used for all older HP Smart Array
+	 * controllers. There are module paramaters that allow a user to

drivers/block/cciss.c static int cciss_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) · line 4975

Quoted 10 lines

drivers/block/cciss.c +7 -0

+	 * override this behavior and instead use the hpsa SCSI driver. If
+	 * this is the case cciss may be loaded first from the kdump initrd
+	 * image and cause a kernel panic. So if reset_devices is true and
+	 * cciss_allow_hpsa is set just bail.
+	 */
+	if ((reset_devices) && (cciss_allow_hpsa == 1))
+		return -ENODEV;
 	rc = cciss_init_reset_devices(pdev);
 	if (rc) {
 		if (rc != -ENOTSUPP)

Sigh, right change log, incomplete bug fix.

Can we all agree that this is the right one?

James

---

Quoted 1 line

From 746ba9f715b9037264ae0b8175c6286f5f8f62d4 Mon Sep 17 00:00:00 2001

From: Mike Miller <[email protected]>
Date: Thu, 18 Apr 2013 13:49:37 -0500
Subject: [PATCH] [SCSI] cciss: bug fix to prevent cciss from loading in kdump
crash kernel

Signed-off-by Mike Miller <[email protected]>

Cc <[email protected]>

Signed-off-by James Bottomley <[email protected]>

drivers/block/cciss.c +16 -0

index 1c1b8e5..daaab88 100644
@@ -75,6 +75,12 @@ module_param(cciss_simple_mode, int, S_IRUGO|S_IWUSR);
 MODULE_PARM_DESC(cciss_simple_mode,
 	"Use 'simple mode' rather than 'performant mode'");
 
+static int cciss_allow_hpsa;
+module_param(cciss_allow_hpsa, int, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(cciss_allow_hpsa,
+	"Prevent cciss driver from accessing hardware known to be "
+	" supported by the hpsa driver");
+
 static DEFINE_MUTEX(cciss_mutex);
 static struct proc_dir_entry *proc_cciss;

@@ -4960,6 +4966,16 @@ static int cciss_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	ctlr_info_t *h;
 	unsigned long flags;
 
+	/*
+	 * By default the cciss driver is used for all older HP Smart Array
+	 * controllers. There are module paramaters that allow a user to
+	 * override this behavior and instead use the hpsa SCSI driver. If
+	 * this is the case cciss may be loaded first from the kdump initrd
+	 * image and cause a kernel panic. So if reset_devices is true and
+	 * cciss_allow_hpsa is set just bail.
+	 */
+	if ((reset_devices) && (cciss_allow_hpsa == 1))
+		return -ENODEV;
 	rc = cciss_init_reset_devices(pdev);
 	if (rc) {
 		if (rc != -ENOTSUPP)

Mike Miller (OS Dev)

author

2013-05-03 18:17 UTC #2 lore raw

Quoted 48 lines · James Bottomley

Quoted 34 lines · Mike Miller
PATCH 1/1
By default the cciss driver supports all "older" HP Smart Array controllers and hpsa supports all controllers starting with the G6 family. There are module parameters that allow a user to override those defaults and use hpsa for any HP Smart Array controller.
If the user does override the default behavior and uses hpsa for older controllers it is possible that cciss may try to load in a kdump crash kernel. This may happen if cciss is loaded first from the kdump initrd image. If cciss does load rather than hpsa and reset_devices is true we immediately call cciss_hard_reset_controller. This will result in a kernel panic and the core file cannot be created.
This patch prevents cciss from trying to load in this scenario.
Tested with 3.9.0-rc7.
From: Mike <[email protected]>
Signed-off-by Mike Miller <[email protected]>
---
 drivers/block/cciss.c |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)
drivers/block/cciss.c +3 -0
index 1c1b8e5..06c8dba 100644
@@ -4960,6 +4960,16 @@ static int cciss_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	ctlr_info_t *h;
 	unsigned long flags;
 
+	/*
+	 * By default the cciss driver is used for all older HP Smart Array
+	 * controllers. There are module paramaters that allow a user to
drivers/block/cciss.c static int cciss_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) · line 4975
Quoted 10 lines
drivers/block/cciss.c +7 -0
+	 * override this behavior and instead use the hpsa SCSI driver. If
+	 * this is the case cciss may be loaded first from the kdump initrd
+	 * image and cause a kernel panic. So if reset_devices is true and
+	 * cciss_allow_hpsa is set just bail.
+	 */
+	if ((reset_devices) && (cciss_allow_hpsa == 1))
+		return -ENODEV;
 	rc = cciss_init_reset_devices(pdev);
 	if (rc) {
 		if (rc != -ENOTSUPP)
Sigh, right change log, incomplete bug fix.

Quoted 3 lines

Can we all agree that this is the right one?
James

I submitted 2 patches. Below the 2 are combined and make the fix complete.

-- mikem

Quoted 60 lines

---
Quoted 1 line
From 746ba9f715b9037264ae0b8175c6286f5f8f62d4 Mon Sep 17 00:00:00 2001
From: Mike Miller <[email protected]>
Date: Thu, 18 Apr 2013 13:49:37 -0500
Subject: [PATCH] [SCSI] cciss: bug fix to prevent cciss from loading in kdump
crash kernel
By default the cciss driver supports all "older" HP Smart Array controllers and hpsa supports all controllers starting with the G6 family. There are module parameters that allow a user to override those defaults and use hpsa for any HP Smart Array controller.
If the user does override the default behavior and uses hpsa for older controllers it is possible that cciss may try to load in a kdump crash kernel. This may happen if cciss is loaded first from the kdump initrd image. If cciss does load rather than hpsa and reset_devices is true we immediately call cciss_hard_reset_controller. This will result in a kernel panic and the core file cannot be created.
This patch prevents cciss from trying to load in this scenario.
Signed-off-by Mike Miller <[email protected]>
Cc <[email protected]>
Signed-off-by James Bottomley <[email protected]>
drivers/block/cciss.c +16 -0
index 1c1b8e5..daaab88 100644
@@ -75,6 +75,12 @@ module_param(cciss_simple_mode, int, S_IRUGO|S_IWUSR);
 MODULE_PARM_DESC(cciss_simple_mode,
 	"Use 'simple mode' rather than 'performant mode'");
 
+static int cciss_allow_hpsa;
+module_param(cciss_allow_hpsa, int, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(cciss_allow_hpsa,
+	"Prevent cciss driver from accessing hardware known to be "
+	" supported by the hpsa driver");
+
 static DEFINE_MUTEX(cciss_mutex);
 static struct proc_dir_entry *proc_cciss;
 
@@ -4960,6 +4966,16 @@ static int cciss_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	ctlr_info_t *h;
 	unsigned long flags;
 
+	/*
+	 * By default the cciss driver is used for all older HP Smart Array
+	 * controllers. There are module paramaters that allow a user to
+	 * override this behavior and instead use the hpsa SCSI driver. If
+	 * this is the case cciss may be loaded first from the kdump initrd
+	 * image and cause a kernel panic. So if reset_devices is true and
+	 * cciss_allow_hpsa is set just bail.
+	 */
+	if ((reset_devices) && (cciss_allow_hpsa == 1))
+		return -ENODEV;
 	rc = cciss_init_reset_devices(pdev);
 	if (rc) {
 		if (rc != -ENOTSUPP)