Re: 2.5.72-bk3 oops when loading aha152X(isapnp)

Martin Diehl (lists@mdiehl.de)
Sat, 21 Jun 2003 16:29:06 +0200 (CEST)


On Sat, 21 Jun 2003 schmurtz@netcourrier.com wrote:

> aha152x0: trying software interrupt, <1>Unable to handle kernel NULL pointer dec
...
> EIP is at swintr+0x4a/0x70 [aha152x]

Seems there are two problems:
* interrupt handler expects to find the host in aha152x_host[] array which
is currently set too late after probing irq's
* despite testing for NULL swintr derefences a shpnt==NULL anyway, looks
like a victim of HOSTNO obfuscation ;-)

The patch below fixes the issue for me - succesfully tested to compile,
load and even use my attached scanner.

Martin
----------------------

--- linux-2.5.72-bk3/drivers/scsi/aha152x.c Sat Jun 21 16:14:40 2003
+++ v2.5.72bk3-md/drivers/scsi/aha152x.c Sat Jun 21 16:07:05 2003
@@ -941,7 +941,8 @@ static irqreturn_t swintr(int irqno, voi
struct Scsi_Host *shpnt = lookup_irq(irqno);

if (!shpnt) {
- printk(KERN_ERR "aha152x%d: catched software interrupt %d for unknown controller.\n", HOSTNO, irqno);
+ /* no point using HOSTNO here! */
+ printk(KERN_ERR "aha152x: catched software interrupt %d for unknown controller.\n", irqno);
return IRQ_NONE;
}

@@ -1049,6 +1050,10 @@ struct Scsi_Host *aha152x_probe_one(stru

printk(KERN_INFO "aha152x%d: trying software interrupt, ",
shost->host_no);
+
+ /* need to have host registered before triggering any interrupt */
+ aha152x_host[registered_count] = shost;
+ mb();
SETPORT(DMACNTRL0, SWINT|INTEN);
mdelay(1000);
free_irq(shost->irq, shost);
@@ -1064,7 +1069,7 @@ struct Scsi_Host *aha152x_probe_one(stru

printk(KERN_ERR "aha152x%d: IRQ %d possibly wrong. "
"Please verify.\n", shost->host_no, shost->irq);
- goto out_release_region;
+ goto out_unregister_host;
}
printk("ok.\n");

@@ -1077,12 +1082,12 @@ struct Scsi_Host *aha152x_probe_one(stru
"aha152x", shost) < 0) {
printk(KERN_ERR "aha152x%d: failed to reassign interrupt.\n",
shost->host_no);
- goto out_release_region;
+ goto out_unregister_host;
}
-
- aha152x_host[registered_count] = shost;
return shost; /* the pcmcia stub needs the return value; */

+out_unregister_host:
+ aha152x_host[registered_count] = NULL;
out_release_region:
release_region(shost->io_port, IO_RANGE);
out_unregister:

-
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