linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* drivers/scsi/sata_vsc.c: inconsistent NULL checking
@ 2006-03-09 11:02 Adrian Bunk
  2006-03-09 19:44 ` Dan Williams
  0 siblings, 1 reply; 4+ messages in thread
From: Adrian Bunk @ 2006-03-09 11:02 UTC (permalink / raw)
  To: Dan Williams; +Cc: Jeff Garzik, linux-ide, linux-kernel

The Coverity checker found this inconsistent NULL checking recently 
introduced by the following commit:

  2ae5b30ff08cee422c7f6388a759f7
  Author: Dan Williams <dan.j.williams@intel.com>
  [PATCH] Necessary evil to get sata_vsc to initialize with Intel iq3124h hba


In function vsc_sata_interrupt():

	err_status = ap ? vsc_sata_scr_read(ap, SCR_ERROR) : 0;
	vsc_sata_scr_write(ap, SCR_ERROR, err_status);


vsc_sata_scr_write() always dereferences ap
(since SCR_ERROR < SCR_CONTROL).

Checking for NULL in one line and unconditionally dereferencing the 
variable in the next line can't be right.

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed


^ permalink raw reply	[flat|nested] 4+ messages in thread
* Re: drivers/scsi/sata_vsc.c: inconsistent NULL checking
  2006-03-09 11:02 drivers/scsi/sata_vsc.c: inconsistent NULL checking Adrian Bunk
@ 2006-03-09 19:44 ` Dan Williams
  2006-03-09 20:41   ` Dan Williams
  0 siblings, 1 reply; 4+ messages in thread
From: Dan Williams @ 2006-03-09 19:44 UTC (permalink / raw)
  To: Adrian Bunk
  Cc: Dan Williams, Jeff Garzik, linux-ide, linux-kernel, Jeremy Higdon

[-- Attachment #1: Type: text/plain, Size: 831 bytes --]

On 3/9/06, Adrian Bunk <bunk@stusta.de> wrote:
> The Coverity checker found this inconsistent NULL checking recently
> introduced by the following commit:
>
>   2ae5b30ff08cee422c7f6388a759f7
>   Author: Dan Williams <dan.j.williams@intel.com>
>   [PATCH] Necessary evil to get sata_vsc to initialize with Intel iq3124h hba
>
>
> In function vsc_sata_interrupt():
>
>         err_status = ap ? vsc_sata_scr_read(ap, SCR_ERROR) : 0;
>         vsc_sata_scr_write(ap, SCR_ERROR, err_status);
>
>
> vsc_sata_scr_write() always dereferences ap
> (since SCR_ERROR < SCR_CONTROL).
>
> Checking for NULL in one line and unconditionally dereferencing the
> variable in the next line can't be right.
>

The attached patch cleans up the code, and adds GD31244 to the driver
description in drivers/scsi/Kconfig.

Dan

[-- Attachment #2: sata_vsc_clean_up.patch --]
[-- Type: text/x-patch, Size: 3476 bytes --]

diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index 3c606cf..d01edc3 100644
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -587,10 +587,10 @@ config SCSI_SATA_VIA
 	  If unsure, say N.
 
 config SCSI_SATA_VITESSE
-	tristate "VITESSE VSC-7174 SATA support"
+	tristate "VITESSE VSC-7174 / INTEL 31244 SATA support"
 	depends on SCSI_SATA && PCI
 	help
-	  This option enables support for Vitesse VSC7174 Serial ATA.
+	  This option enables support for Vitesse VSC7174 and Intel 31244 Serial ATA.
 
 	  If unsure, say N.
 
diff --git a/drivers/scsi/sata_vsc.c b/drivers/scsi/sata_vsc.c
index e484e8d..5b65fc7 100644
--- a/drivers/scsi/sata_vsc.c
+++ b/drivers/scsi/sata_vsc.c
@@ -82,17 +82,20 @@
 #define VSC_SATA_PORT_OFFSET		0x200
 
 /* Error interrupt status bit offsets */
-#define VSC_SATA_INT_ERROR_E_OFFSET	2
-#define VSC_SATA_INT_ERROR_P_OFFSET	4
-#define VSC_SATA_INT_ERROR_T_OFFSET	5
-#define VSC_SATA_INT_ERROR_M_OFFSET	1
+#define VSC_SATA_INT_ERROR_CRC		(1 << 6)
+#define VSC_SATA_INT_ERROR_T		(1 << 5)
+#define VSC_SATA_INT_ERROR_P		(1 << 4)
+#define VSC_SATA_INT_ERROR_R		(1 << 3)
+#define VSC_SATA_INT_ERROR_E		(1 << 2)
+#define VSC_SATA_INT_ERROR_M		(1 << 1)
+#define VSC_SATA_INT_PHY_CHANGE	(1 << 0)
+#define VSC_SATA_INT_ERROR (VSC_SATA_INT_ERROR_CRC  + VSC_SATA_INT_ERROR_T + \
+			     VSC_SATA_INT_ERROR_P    + VSC_SATA_INT_ERROR_R + \
+			     VSC_SATA_INT_ERROR_E    + VSC_SATA_INT_ERROR_M + \
+			     VSC_SATA_INT_PHY_CHANGE)
+
 #define is_vsc_sata_int_err(port_idx, int_status) \
-	 (int_status & ((1 << (VSC_SATA_INT_ERROR_E_OFFSET + (8 * port_idx))) | \
-		        (1 << (VSC_SATA_INT_ERROR_P_OFFSET + (8 * port_idx))) | \
-		        (1 << (VSC_SATA_INT_ERROR_T_OFFSET + (8 * port_idx))) | \
-		        (1 << (VSC_SATA_INT_ERROR_M_OFFSET + (8 * port_idx)))   \
-		       )\
- 	 )
+	 (int_status & (VSC_SATA_INT_ERROR << (8 * port_idx)))
 
 
 static u32 vsc_sata_scr_read (struct ata_port *ap, unsigned int sc_reg)
@@ -215,14 +218,6 @@ static irqreturn_t vsc_sata_interrupt (i
 
 			ap = host_set->ports[i];
 
-			if (is_vsc_sata_int_err(i, int_status)) {
-				u32 err_status;
-				printk(KERN_DEBUG "%s: ignoring interrupt(s)\n", __FUNCTION__);
-				err_status = ap ? vsc_sata_scr_read(ap, SCR_ERROR) : 0;
-				vsc_sata_scr_write(ap, SCR_ERROR, err_status);
-				handled++;
-			}
-
 			if (ap && !(ap->flags &
 				    (ATA_FLAG_PORT_DISABLED|ATA_FLAG_NOINTR))) {
 				struct ata_queued_cmd *qc;
@@ -230,12 +225,26 @@ static irqreturn_t vsc_sata_interrupt (i
 				qc = ata_qc_from_tag(ap, ap->active_tag);
 				if (qc && (!(qc->tf.ctl & ATA_NIEN))) {
 					handled += ata_host_intr(ap, qc);
-				} else {
-					printk(KERN_DEBUG "%s: ignoring interrupt(s)\n", __FUNCTION__);
+				} else if (is_vsc_sata_int_err(i, int_status)) {
+					/*
+					 * On some chips (i.e. Intel 31244), an error 
+					 * interrupt will sneak in at initialization
+					 * time (phy state changes).  Clearing the SCR
+					 * error register is not required, but it prevents
+					 * the phy state change interrupts from recurring 
+					 * later.
+					 */
+					u32 err_status;
+					err_status = vsc_sata_scr_read(ap, SCR_ERROR);
+					printk(KERN_DEBUG "%s: clearing interrupt, "
+					       "status %x; sata err status %x\n",
+					       __FUNCTION__,
+					       int_status, err_status);
+					vsc_sata_scr_write(ap, SCR_ERROR, err_status);
+					/* Clear interrupt status */
 					ata_chk_status(ap);
 					handled++;
 				}
-
 			}
 		}
 	}


^ permalink raw reply related	[flat|nested] 4+ messages in thread
* Re: drivers/scsi/sata_vsc.c: inconsistent NULL checking
  2006-03-09 19:44 ` Dan Williams
@ 2006-03-09 20:41   ` Dan Williams
  2006-03-22  3:08     ` Jeff Garzik
  0 siblings, 1 reply; 4+ messages in thread
From: Dan Williams @ 2006-03-09 20:41 UTC (permalink / raw)
  To: Adrian Bunk; +Cc: Dan Williams, Jeff Garzik, linux-ide, linux-kernel

[-- Attachment #1: Type: text/plain, Size: 198 bytes --]

>
> The attached patch cleans up the code, and adds GD31244 to the driver
> description in drivers/scsi/Kconfig.
>

Joe Perches suggested some coding style changes.  Here is version 2.

Dan

[-- Attachment #2: sata_vsc_clean_up-v2.patch --]
[-- Type: text/x-patch, Size: 3443 bytes --]

diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index 3c606cf..d01edc3 100644
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -587,10 +587,10 @@ config SCSI_SATA_VIA
 	  If unsure, say N.
 
 config SCSI_SATA_VITESSE
-	tristate "VITESSE VSC-7174 SATA support"
+	tristate "VITESSE VSC-7174 / INTEL 31244 SATA support"
 	depends on SCSI_SATA && PCI
 	help
-	  This option enables support for Vitesse VSC7174 Serial ATA.
+	  This option enables support for Vitesse VSC7174 and Intel 31244 Serial ATA.
 
 	  If unsure, say N.
 
diff --git a/drivers/scsi/sata_vsc.c b/drivers/scsi/sata_vsc.c
index e484e8d..b4e0a46 100644
--- a/drivers/scsi/sata_vsc.c
+++ b/drivers/scsi/sata_vsc.c
@@ -82,17 +82,20 @@
 #define VSC_SATA_PORT_OFFSET		0x200
 
 /* Error interrupt status bit offsets */
-#define VSC_SATA_INT_ERROR_E_OFFSET	2
-#define VSC_SATA_INT_ERROR_P_OFFSET	4
-#define VSC_SATA_INT_ERROR_T_OFFSET	5
-#define VSC_SATA_INT_ERROR_M_OFFSET	1
+#define VSC_SATA_INT_ERROR_CRC		0x40
+#define VSC_SATA_INT_ERROR_T		0x20
+#define VSC_SATA_INT_ERROR_P		0x10
+#define VSC_SATA_INT_ERROR_R		0x8
+#define VSC_SATA_INT_ERROR_E		0x4
+#define VSC_SATA_INT_ERROR_M		0x2
+#define VSC_SATA_INT_PHY_CHANGE	0x1
+#define VSC_SATA_INT_ERROR (VSC_SATA_INT_ERROR_CRC  | VSC_SATA_INT_ERROR_T | \
+			     VSC_SATA_INT_ERROR_P    | VSC_SATA_INT_ERROR_R | \
+			     VSC_SATA_INT_ERROR_E    | VSC_SATA_INT_ERROR_M | \
+			     VSC_SATA_INT_PHY_CHANGE)
+
 #define is_vsc_sata_int_err(port_idx, int_status) \
-	 (int_status & ((1 << (VSC_SATA_INT_ERROR_E_OFFSET + (8 * port_idx))) | \
-		        (1 << (VSC_SATA_INT_ERROR_P_OFFSET + (8 * port_idx))) | \
-		        (1 << (VSC_SATA_INT_ERROR_T_OFFSET + (8 * port_idx))) | \
-		        (1 << (VSC_SATA_INT_ERROR_M_OFFSET + (8 * port_idx)))   \
-		       )\
- 	 )
+	 (int_status & (VSC_SATA_INT_ERROR << (8 * port_idx)))
 
 
 static u32 vsc_sata_scr_read (struct ata_port *ap, unsigned int sc_reg)
@@ -215,14 +218,6 @@ static irqreturn_t vsc_sata_interrupt (i
 
 			ap = host_set->ports[i];
 
-			if (is_vsc_sata_int_err(i, int_status)) {
-				u32 err_status;
-				printk(KERN_DEBUG "%s: ignoring interrupt(s)\n", __FUNCTION__);
-				err_status = ap ? vsc_sata_scr_read(ap, SCR_ERROR) : 0;
-				vsc_sata_scr_write(ap, SCR_ERROR, err_status);
-				handled++;
-			}
-
 			if (ap && !(ap->flags &
 				    (ATA_FLAG_PORT_DISABLED|ATA_FLAG_NOINTR))) {
 				struct ata_queued_cmd *qc;
@@ -230,12 +225,26 @@ static irqreturn_t vsc_sata_interrupt (i
 				qc = ata_qc_from_tag(ap, ap->active_tag);
 				if (qc && (!(qc->tf.ctl & ATA_NIEN))) {
 					handled += ata_host_intr(ap, qc);
-				} else {
-					printk(KERN_DEBUG "%s: ignoring interrupt(s)\n", __FUNCTION__);
+				} else if (is_vsc_sata_int_err(i, int_status)) {
+					/*
+					 * On some chips (i.e. Intel 31244), an error 
+					 * interrupt will sneak in at initialization
+					 * time (phy state changes).  Clearing the SCR
+					 * error register is not required, but it prevents
+					 * the phy state change interrupts from recurring 
+					 * later.
+					 */
+					u32 err_status;
+					err_status = vsc_sata_scr_read(ap, SCR_ERROR);
+					printk(KERN_DEBUG "%s: clearing interrupt, "
+					       "status %x; sata err status %x\n",
+					       __FUNCTION__,
+					       int_status, err_status);
+					vsc_sata_scr_write(ap, SCR_ERROR, err_status);
+					/* Clear interrupt status */
 					ata_chk_status(ap);
 					handled++;
 				}
-
 			}
 		}
 	}

^ permalink raw reply related	[flat|nested] 4+ messages in thread
* Re: drivers/scsi/sata_vsc.c: inconsistent NULL checking
  2006-03-09 20:41   ` Dan Williams
@ 2006-03-22  3:08     ` Jeff Garzik
  0 siblings, 0 replies; 4+ messages in thread
From: Jeff Garzik @ 2006-03-22  3:08 UTC (permalink / raw)
  To: Dan Williams; +Cc: Adrian Bunk, Dan Williams, linux-ide, linux-kernel

Dan Williams wrote:
>>The attached patch cleans up the code, and adds GD31244 to the driver
>>description in drivers/scsi/Kconfig.

> Joe Perches suggested some coding style changes.  Here is version 2.

Applied.  When resending patches, please continue to follow the standard 
patch submission format, particularly #2, #5 and #6:
	http://linux.yyz.us/patch-format.html

Regards,

	Jeff



^ permalink raw reply	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2006-03-22  3:08 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2006-03-09 11:02 drivers/scsi/sata_vsc.c: inconsistent NULL checking Adrian Bunk
2006-03-09 19:44 ` Dan Williams
2006-03-09 20:41   ` Dan Williams
2006-03-22  3:08     ` Jeff Garzik

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).