From: Russell King <rmk+lkml@arm.linux.org.uk>
To: Sharyathi Nagesh <sharyath@in.ibm.com>
Cc: linux-kernel@vger.kernel.org,
Arjan van de Ven <arjan@infradead.org>,
Sachin Sant <sachinp@in.ibm.com>
Subject: Re: Bug while executing : cat /proc/iomem on 2.6.17-rc1/rc2
Date: Thu, 11 May 2006 08:32:05 +0100 [thread overview]
Message-ID: <20060511073205.GA28693@flint.arm.linux.org.uk> (raw)
In-Reply-To: <1147332468.17798.13.camel@localhost.localdomain>
On Thu, May 11, 2006 at 12:57:48PM +0530, Sharyathi Nagesh wrote:
> I was able to replicate the Bug, even when all the drivers are built into the kernel.
> It looks like while traversing through p->parent field of resource structure is leading to NULL pointer.
> Would it be appropriate to make the following code change.
> But I found cat /proc/iomem hangs after line kernel data..
>
> --- kernel/resource.c.old 2006-05-11 05:29:33.000000000 -0700
> +++ kernel/resource.c 2006-05-11 05:29:58.000000000 -0700
> @@ -81,7 +81,7 @@ static int r_show(struct seq_file *m, vo
> int depth;
>
> for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent){
> - if (p->parent == root)
> + if (p->parent == root || p->parent == NULL)
> break;
> }
> seq_printf(m, "%*s%0*lx-%0*lx : %s\n",
Only the root should have a NULL parent, so this is just covering up some
other problem - you have a resource which somehow has illegally ended up
with a NULL parent pointer while it's been registered.
Maybe try adding:
if (p->parent == NULL) {
printk("resource with null parent: %lx-%lx: %s\n",
p->start, p->end, p->name);
break;
}
just before the test in that loop, and then finding out why that resource
is becoming invalid.
--
Russell King
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
maintainer of: 2.6 Serial core
next prev parent reply other threads:[~2006-05-11 7:32 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-04-25 10:43 Bug while executing : cat /proc/iomem on 2.6.17-rc1/rc2 Sachin Sant
2006-04-25 10:48 ` Arjan van de Ven
2006-05-11 7:27 ` Sharyathi Nagesh
2006-05-11 7:32 ` Russell King [this message]
2006-05-11 8:38 ` Sachin Sant
2006-05-13 10:30 ` Maneesh Soni
2006-05-13 14:56 ` Linus Torvalds
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