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

From: Mikulas Patocka
Date: Tue Mar 17 2009 - 08:08:22 EST




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@xxxxxxxxxx>

> ---
> 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");
>
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