[PATCH] 2.4.28 - AIC driver causes kernel corruption (as a module)

[PATCH] 2.4.28 - AIC driver causes kernel corruption (as a module)

[Mark Bellon]

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Didn't see a patch for this and the problem is in the 2.4.28 sources.

The scsi_register_module call from within ah[cd]_linux_init causes the 
detect routine to be called. The detect routine calls  
ah[cd]_linux_pci_init which does a pci_register_driver call. If no 
hardware is found in the detect routine, ah[cd]_linux_init will exit 
without calling pci_unregister_driver leaving the kernel with pointers 
to a driver that never really loaded.

mark


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Index: drivers/scsi/aic7xxx/aic79xx_osm.c
===================================================================
RCS file: /cvsdev/mvl-kernel/linux/drivers/scsi/aic7xxx/aic79xx_osm.c,v
retrieving revision 1.2.4.2.12.4
diff -a -u -r1.2.4.2.12.4 aic79xx_osm.c
--- drivers/scsi/aic7xxx/aic79xx_osm.c	12 Feb 2004 15:33:49 -0000	1.2.4.2.12.4
+++ drivers/scsi/aic7xxx/aic79xx_osm.c	11 Jan 2005 18:46:42 -0000
@@ -5079,6 +5079,8 @@
 	}
 }
 
+static void ahd_linux_exit(void);
+
 static int __init
 ahd_linux_init(void)
 {
@@ -5087,8 +5089,7 @@
 #else
 	scsi_register_module(MODULE_SCSI_HA, &aic79xx_driver_template);
 	if (aic79xx_driver_template.present == 0) {
-		scsi_unregister_module(MODULE_SCSI_HA,
-				       &aic79xx_driver_template);
+		ahd_linux_exit();
 		return (-ENODEV);
 	}
 
Index: drivers/scsi/aic7xxx/aic7xxx_osm.c
===================================================================
RCS file: /cvsdev/mvl-kernel/linux/drivers/scsi/aic7xxx/aic7xxx_osm.c,v
retrieving revision 1.2.4.2.12.3
diff -a -u -r1.2.4.2.12.3 aic7xxx_osm.c
--- drivers/scsi/aic7xxx/aic7xxx_osm.c	12 Feb 2004 15:33:49 -0000	1.2.4.2.12.3
+++ drivers/scsi/aic7xxx/aic7xxx_osm.c	11 Jan 2005 18:46:43 -0000
@@ -5077,6 +5077,8 @@
 	}
 }
 
+static void ahc_linux_exit(void);
+
 static int __init
 ahc_linux_init(void)
 {
@@ -5085,8 +5087,7 @@
 #else
 	scsi_register_module(MODULE_SCSI_HA, &aic7xxx_driver_template);
 	if (aic7xxx_driver_template.present == 0) {
-		scsi_unregister_module(MODULE_SCSI_HA,
-				       &aic7xxx_driver_template);
+		ahc_linux_exit();
 		return (-ENODEV);
 	}
 

Re: [PATCH] 2.4.28 - AIC driver causes kernel corruption (as a module)

[James Bottomley]

On Tue, 2005-01-11 at 12:24 -0700, Mark Bellon wrote:
> -		scsi_unregister_module(MODULE_SCSI_HA,
> -				       &aic79xx_driver_template);
> +		ahd_linux_exit();

Well, this is pretty much identical to the 2.6 fix for the same problem
except that you forgot to remove the __exit designation from ah
[cd]_linux_exit().  This is required to prevent hanging pointer
references.

James

Re: [PATCH] 2.4.28 - AIC driver causes kernel corruption (as a module)

[Mark Bellon]

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James Bottomley wrote:

>On Tue, 2005-01-11 at 12:24 -0700, Mark Bellon wrote:
>  
>
>>-		scsi_unregister_module(MODULE_SCSI_HA,
>>-				       &aic79xx_driver_template);
>>+		ahd_linux_exit();
>>    
>>
>
>Well, this is pretty much identical to the 2.6 fix for the same problem
>except that you forgot to remove the __exit designation from ah
>[cd]_linux_exit().  This is required to prevent hanging pointer
>references.
>
>James
>
>
>  
>
Ah! Very true, very true. Updated patch attached.

mark


[-- Attachment #2: scsi-patch --]
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Index: drivers/scsi/aic7xxx/aic79xx_osm.c
===================================================================
RCS file: /cvsdev/mvl-kernel/linux/drivers/scsi/aic7xxx/aic79xx_osm.c,v
retrieving revision 1.2.4.2.12.4
diff -a -u -r1.2.4.2.12.4 aic79xx_osm.c
--- drivers/scsi/aic7xxx/aic79xx_osm.c	12 Feb 2004 15:33:49 -0000	1.2.4.2.12.4
+++ drivers/scsi/aic7xxx/aic79xx_osm.c	11 Jan 2005 19:53:02 -0000
@@ -5079,6 +5079,8 @@
 	}
 }
 
+static void ahd_linux_exit(void);
+
 static int __init
 ahd_linux_init(void)
 {
@@ -5087,8 +5089,7 @@
 #else
 	scsi_register_module(MODULE_SCSI_HA, &aic79xx_driver_template);
 	if (aic79xx_driver_template.present == 0) {
-		scsi_unregister_module(MODULE_SCSI_HA,
-				       &aic79xx_driver_template);
+		ahd_linux_exit();
 		return (-ENODEV);
 	}
 
@@ -5096,7 +5097,7 @@
 #endif
 }
 
-static void __exit
+static void
 ahd_linux_exit(void)
 {
 	struct ahd_softc *ahd;
Index: drivers/scsi/aic7xxx/aic7xxx_osm.c
===================================================================
RCS file: /cvsdev/mvl-kernel/linux/drivers/scsi/aic7xxx/aic7xxx_osm.c,v
retrieving revision 1.2.4.2.12.3
diff -a -u -r1.2.4.2.12.3 aic7xxx_osm.c
--- drivers/scsi/aic7xxx/aic7xxx_osm.c	12 Feb 2004 15:33:49 -0000	1.2.4.2.12.3
+++ drivers/scsi/aic7xxx/aic7xxx_osm.c	11 Jan 2005 19:53:08 -0000
@@ -5077,6 +5077,8 @@
 	}
 }
 
+static void ahc_linux_exit(void);
+
 static int __init
 ahc_linux_init(void)
 {
@@ -5085,8 +5087,7 @@
 #else
 	scsi_register_module(MODULE_SCSI_HA, &aic7xxx_driver_template);
 	if (aic7xxx_driver_template.present == 0) {
-		scsi_unregister_module(MODULE_SCSI_HA,
-				       &aic7xxx_driver_template);
+		ahc_linux_exit();
 		return (-ENODEV);
 	}
 
@@ -5094,7 +5095,7 @@
 #endif
 }
 
-static void __exit
+static void
 ahc_linux_exit(void)
 {
 	struct ahc_softc *ahc;