Re: [PATCH] xen: check return value of xenbus_printf

From	David Vrabel <david.vrabel@citrix.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH] xen: check return value of xenbus_printf
Date	2015-10-15 18:50 +0200
Message-ID	<qjTT4-3IL-15@gated-at.bofh.it> (permalink)
References	<qjTzI-3md-9@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On 15/10/15 17:25, Insu Yun wrote:
> Internally, xenbus_printf uses memory allocation, so it can be failed in
> memory pressure.Therefore, xenbus_printf's return should be checked 
> and properly handled.
[...]
> --- a/drivers/input/misc/xen-kbdfront.c
> +++ b/drivers/input/misc/xen-kbdfront.c
> @@ -129,8 +129,11 @@ static int xenkbd_probe(struct xenbus_device *dev,
>  
>  	if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-abs-pointer", "%d", &abs) < 0)
>  		abs = 0;
> -	if (abs)
> -		xenbus_printf(XBT_NIL, dev->nodename, "request-abs-pointer", "1");
> +	if (abs) {
> +		ret = xenbus_printf(XBT_NIL, dev->nodename, "request-abs-pointer", "1");
> +		if (ret)
> +			pr_warning("xenkbd: can't request abs-pointer");

I think you want abs = 0 here or input device will be configured as
absolute but the backend will supply relative coordinates.

David
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Thread

[PATCH] xen: check return value of xenbus_printf Insu Yun <wuninsu@gmail.com> - 2015-10-15 18:30 +0200
  Re: [PATCH] xen: check return value of xenbus_printf David Vrabel <david.vrabel@citrix.com> - 2015-10-15 18:50 +0200
    Re: [PATCH] xen: check return value of xenbus_printf Julien Grall <julien.grall@citrix.com> - 2015-10-15 20:30 +0200

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