Re: [PATCH] PCI, x86: clear initial value for root info resources

From: Bjorn Helgaas
Date: Tue Sep 18 2012 - 18:47:14 EST


On Fri, Sep 14, 2012 at 6:48 PM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
> Found one system one root bus hot remove get panic.
> Panic happens when try to release hostbridge resource.
>
> It turns out that resource get reject during put into resource tree
> because of conflicts.
> Also that resource parent pointer have random value.
>
> That invalid value cause it pass through check __release_pci_root_info
> and panic in release_resource.
>
> Try to use kzalloc instead.

Don't we need the same fix for ia64 in pci_acpi_scan_root()? Here's
what it does:

if (windows) {
controller->window =
kmalloc_node(sizeof(*controller->window) * windows,
GFP_KERNEL, controller->node);


> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
> Cc: x86@xxxxxxxxxx
>
> ---
> arch/x86/pci/acpi.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> Index: linux-2.6/arch/x86/pci/acpi.c
> ===================================================================
> --- linux-2.6.orig/arch/x86/pci/acpi.c
> +++ linux-2.6/arch/x86/pci/acpi.c
> @@ -305,7 +305,6 @@ setup_resource(struct acpi_resource *acp
> res->flags = flags;
> res->start = start;
> res->end = end;
> - res->child = NULL;
>
> if (!pci_use_crs) {
> dev_printk(KERN_DEBUG, &info->bridge->dev,
> @@ -434,7 +433,7 @@ probe_pci_root_info(struct pci_root_info
>
> size = sizeof(*info->res) * info->res_num;
> info->res_num = 0;
> - info->res = kmalloc(size, GFP_KERNEL);
> + info->res = kzalloc(size, GFP_KERNEL);
> if (!info->res)
> return;
>
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