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mptsas: Fix oops for insmod during kexec

PATCH In review Judith Lebzelter 3 participants 5 messages Mar 9, 2007 – Mar 12, 2007

Subsystems (2)
SCSI LSI Logic MPT fusion drivers (FC/SAS/SPI)
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Judith Lebzelter

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#0 lore raw

PATCH 1/1 mptsas: Fix oops for insmod during kexec

Hello,

This patch is to fix an oops on insmod for mptsas during kexec. This applies to 2.6.21-rc3.

Signed-off-by Judith Lebzelter <[email protected]

---

drivers/message/fusion/mptsas.c +5 -2
Index: linux-2.6.21-rc3/drivers/message/fusion/mptsas.c
===================================================================
@@ -815,7 +815,7 @@ mptsas_taskmgmt_complete(MPT_ADAPTER *io
 static int
 mptsas_ioc_reset(MPT_ADAPTER *ioc, int reset_phase)
 {
-	MPT_SCSI_HOST	*hd = (MPT_SCSI_HOST *)ioc->sh->hostdata;
+	MPT_SCSI_HOST	*hd;
 	struct mptsas_target_reset_event *target_reset_list, *n;
 	int rc;
 

@@ -827,7 +827,10 @@ mptsas_ioc_reset(MPT_ADAPTER *ioc, int r
 	if (reset_phase != MPT_IOC_POST_RESET)
 		goto out;
 
-	if (!hd || !hd->ioc)
+	if (!ioc->sh || !ioc->sh->hostdata)
+		goto out;
+	hd = (MPT_SCSI_HOST *)ioc->sh->hostdata;
+	if (!hd->ioc)
 		goto out;
 
 	if (list_empty(&hd->target_reset_list))
#1 lore raw
Quoted 24 lines · Judith Lebzelter

Hello,

This patch is to fix an oops on insmod for mptsas during kexec. This applies to 2.6.21-rc3.

Signed-off-by Judith Lebzelter <[email protected]

---

Index: linux-2.6.21-rc3/drivers/message/fusion/mptsas.c
===================================================================

drivers/message/fusion/mptsas.c +1 -1
@@ -815,7 +815,7 @@ mptsas_taskmgmt_complete(MPT_ADAPTER *io
 static int
 mptsas_ioc_reset(MPT_ADAPTER *ioc, int reset_phase)
 {
-	MPT_SCSI_HOST	*hd = (MPT_SCSI_HOST *)ioc->sh->hostdata;
+	MPT_SCSI_HOST	*hd;
 	struct mptsas_target_reset_event *target_reset_list, *n;
 	int rc;

drivers/message/fusion/mptsas.c mptsas_ioc_reset(MPT_ADAPTER *ioc, int r · line 833

Quoted 8 lines
drivers/message/fusion/mptsas.c +4 -1
@@ -827,7 +827,10 @@ mptsas_ioc_reset(MPT_ADAPTER *ioc, int r
 	if (reset_phase != MPT_IOC_POST_RESET)
 		goto out;
 
-	if (!hd || !hd->ioc)
+	if (!ioc->sh || !ioc->sh->hostdata)
+		goto out;
+	hd = (MPT_SCSI_HOST *)ioc->sh->hostdata;
+	if (!hd->ioc)

This needs a much better explanation. Please show the codepath leading to this.

#2 lore raw
Quoted 4 lines · Christoph Hellwig

This needs a much better explanation. Please show the codepath leading to this.

I was working with Judith on this patch earlier this week, so this is approved by LSI,,, ACK.

This fix's an oops during driver load time. mptsas_probe calls
mpt_attach(over in mptbase.c). Inside that call, we read some manufacturing config pages to setup some defaults. While reading the config pages, the firmware doesn't complete the reply in time, and we have a timeout. The timeout results in hardreset handler being called. The hardreset handler calls all the fusion upper layer driver reset callback handlers. The mptsas_ioc_reset function is the callback
handler in mptsas.c. So where I'm getting to, is mptsas_ioc_reset is
getting called before scsi_host_alloc is called, and the pointer ioc->sh is NULL.,,, as well as the hostdata.

#3 lore raw
Quoted 11 lines · Eric
Quoted 4 lines · Christoph Hellwig

This needs a much better explanation. Please show the codepath leading to this.

I was working with Judith on this patch earlier this week, so this is approved by LSI,,, ACK.

Quoted 10 lines

This fix's an oops during driver load time. mptsas_probe calls
mpt_attach(over in mptbase.c). Inside that call, we read some manufacturing config pages to setup some defaults. While reading the config pages, the firmware doesn't complete the reply in time, and we have a timeout. The timeout results in hardreset handler being called. The hardreset handler calls all the fusion upper layer driver reset callback handlers. The mptsas_ioc_reset function is the callback
handler in mptsas.c. So where I'm getting to, is mptsas_ioc_reset is
getting called before scsi_host_alloc is called, and the pointer ioc->sh is NULL.,,, as well as the hostdata.

Ok. Please put a reformulated version of the above statement as a comment above the checks, so that people don't rip it out again.

author
#4 lore raw

PATCH 1/1 mptsas: Fix oops during driver load time(rev 2)

This fixes an oops during driver load time.

mptsas_probe calls mpt_attach(over in mptbase.c). Inside that call, we read some manufacturing config pages to setup some defaults. While reading the config pages, the firmware doesn't complete the reply in time, and we have a timeout. The timeout results in hardreset handler being called. The hardreset handler calls all the fusion upper layer driver reset callback handlers. The mptsas_ioc_reset function is the callback handler
in mptsas.c. In summary, mptsas_ioc_reset is getting called
before scsi_host_alloc is called, and the pointer ioc->sh is NULL, as well as the hostdata.

Signed-off-by Judith Lebzelter <[email protected]

---
Sorry I was not more descriptive. Here is the patch with Eric's description as requested.

drivers/message/fusion/mptsas.c +5 -2
Index: linux-2.6.21-rc3/drivers/message/fusion/mptsas.c
===================================================================
@@ -815,7 +815,7 @@ mptsas_taskmgmt_complete(MPT_ADAPTER *io
 static int
 mptsas_ioc_reset(MPT_ADAPTER *ioc, int reset_phase)
 {
-	MPT_SCSI_HOST	*hd = (MPT_SCSI_HOST *)ioc->sh->hostdata;
+	MPT_SCSI_HOST	*hd;
 	struct mptsas_target_reset_event *target_reset_list, *n;
 	int rc;
 

@@ -827,7 +827,10 @@ mptsas_ioc_reset(MPT_ADAPTER *ioc, int r
 	if (reset_phase != MPT_IOC_POST_RESET)
 		goto out;
 
-	if (!hd || !hd->ioc)
+	if (!ioc->sh || !ioc->sh->hostdata)
+		goto out;
+	hd = (MPT_SCSI_HOST *)ioc->sh->hostdata;
+	if (!hd->ioc)
 		goto out;
 
 	if (list_empty(&hd->target_reset_list))