Re: [PATCH] xenbus: check xen_domain in xenbus_probe_initcall

[Oleksandr Tyshchenko <Oleksandr_Tyshchenko@xxxxxxxx>]

On 22.07.23 02:13, Stefano Stabellini wrote:

Hello Stefano


> The same way we already do in xenbus_init.
> Fixes the following warning:
> 
> [  352.175563] Trying to free already-free IRQ 0
> [  352.177355] WARNING: CPU: 1 PID: 88 at kernel/irq/manage.c:1893 
> free_irq+0xbf/0x350
> [...]
> [  352.213951] Call Trace:
> [  352.214390]  <TASK>
> [  352.214717]  ? __warn+0x81/0x170
> [  352.215436]  ? free_irq+0xbf/0x350
> [  352.215906]  ? report_bug+0x10b/0x200
> [  352.216408]  ? prb_read_valid+0x17/0x20
> [  352.216926]  ? handle_bug+0x44/0x80
> [  352.217409]  ? exc_invalid_op+0x13/0x60
> [  352.217932]  ? asm_exc_invalid_op+0x16/0x20
> [  352.218497]  ? free_irq+0xbf/0x350
> [  352.218979]  ? __pfx_xenbus_probe_thread+0x10/0x10
> [  352.219600]  xenbus_probe+0x7a/0x80
> [  352.221030]  xenbus_probe_thread+0x76/0xc0
> 
> Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxx>
> Tested-by: Petr Mladek <pmladek@xxxxxxxx>


Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>

I guess this wants to gain the Fixes tag:

Fixes: 5b3353949e89 ("xen: add support for initializing xenstore later 
as HVM domain")



> 
> diff --git a/drivers/xen/xenbus/xenbus_probe.c 
> b/drivers/xen/xenbus/xenbus_probe.c
> index 58b732dcbfb8..e9bd3ed70108 100644
> --- a/drivers/xen/xenbus/xenbus_probe.c
> +++ b/drivers/xen/xenbus/xenbus_probe.c
> @@ -811,6 +812,9 @@ static int xenbus_probe_thread(void *unused)
>   
>   static int __init xenbus_probe_initcall(void)
>   {
> +     if (!xen_domain())
> +             return -ENODEV;
> +
>       /*
>        * Probe XenBus here in the XS_PV case, and also XS_HVM unless we
>        * need to wait for the platform PCI device to come up or