Re: [PATCH] crash with /proc/iomem on sparc64

[Mikulas Patocka <mpatocka@redhat.com>]

On Tue, 17 Mar 2009, Mikulas Patocka wrote:

> 
> 
> On Tue, 17 Mar 2009, Mikulas Patocka wrote:
> 
> > Hi
> > 
> > When you compile kernel on Sparc64 with heap memory checking and type
> > "cat /proc/iomem", you get a crash, because pointers in struct resource 
> > are uninitialized.
> > 
> > Most code fills struct resource with zeros, so I assume that it is 
> > responsibility of the caller of request_resource to initialized it, not 
> > the responsibility of request_resource functuion.
> > 
> > After 2.6.29 is out, there could be a check for uninitialized fields added 
> > to request_resource to avoid crashes like this.
> > 
> > Mikulas
> 
> I forgot to add:
> 
> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

... and

Cc: stable@kernel.org

because it applies to old kernels as well, even 2.6.26 crashes.

Mikulas

> > ---
> >  arch/sparc/kernel/pci_common.c |    2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > Index: linux-2.6.29-rc8-devel/arch/sparc/kernel/pci_common.c
> > ===================================================================
> > --- linux-2.6.29-rc8-devel.orig/arch/sparc/kernel/pci_common.c	2009-03-17 12:49:51.000000000 +0100
> > +++ linux-2.6.29-rc8-devel/arch/sparc/kernel/pci_common.c	2009-03-17 12:50:16.000000000 +0100
> > @@ -368,7 +368,7 @@ static void pci_register_iommu_region(st
> >  	const u32 *vdma = of_get_property(pbm->op->node, "virtual-dma", NULL);
> >  
> >  	if (vdma) {
> > -		struct resource *rp = kmalloc(sizeof(*rp), GFP_KERNEL);
> > +		struct resource *rp = kzalloc(sizeof(*rp), GFP_KERNEL);
> >  
> >  		if (!rp) {
> >  			prom_printf("Cannot allocate IOMMU resource.\n");
> > 
>