Re: libxl: cannot start guest

[Christoph Egger <Christoph.Egger@amd.com>]

On 05/23/12 12:11, Ian Campbell wrote:

> On Tue, 2012-05-22 at 16:32 +0100, Christoph Egger wrote:
>> On 05/22/12 17:21, Ian Campbell wrote:
>>
>>> On Tue, 2012-05-22 at 16:16 +0100, Christoph Egger wrote:
>>>> On 05/22/12 16:20, Ian Campbell wrote:
>>>>> All the >= checks on *xcg_handle seem wrong to me. Really they should be
>>>>> checking != NULL, since otherwise they don't actually discriminate the
>>>>> two cases! Does making that change help?
>>>>
>>>> Yes, that helps! I can start guests again.
>>>
>>> Excellent, I assume you are going to submit the patch (i.e. I don't need
>>> to..)
>>
>> Yes, patch attached.
> 
> I fixed up the commit message as follows. I'll apply if IanJ agrees or
> acks it.

Thank you. Ian J. what do you say?

Christoph


> 8<-----------------------------
> 
> From 6b43ca97f5f8c4fa9bf24101253af21bc66ddf96 Mon Sep 17 00:00:00 2001
> From: Christoph Egger <Christoph.Egger@amd.com>
> Date: Tue, 22 May 2012 17:32:21 +0200
> Subject: [PATCH] xenstore: fix crash on platforms with no gntdev driver implementation.
> 
> Fix pointer checks introduced in changeset 24757:aae516b78fce.
> 
> Signed-off-by: Christoph Egger <Christoph.Egger@amd.com>
> Acked-by: Ian Campbell <ian.campbell@citrix.com>
> ---
>  tools/xenstore/xenstored_domain.c |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/xenstore/xenstored_domain.c b/tools/xenstore/xenstored_domain.c
> index f8c822f..bf83d58 100644
> --- a/tools/xenstore/xenstored_domain.c
> +++ b/tools/xenstore/xenstored_domain.c
> @@ -167,7 +167,7 @@ static int readchn(struct connection *conn, void *data, unsigned int len)
>  
>  static void *map_interface(domid_t domid, unsigned long mfn)
>  {
> -	if (*xcg_handle >= 0) {
> +	if (*xcg_handle != NULL) {
>  		/* this is the preferred method */
>  		return xc_gnttab_map_grant_ref(*xcg_handle, domid,
>  			GNTTAB_RESERVED_XENSTORE, PROT_READ|PROT_WRITE);
> @@ -179,7 +179,7 @@ static void *map_interface(domid_t domid, unsigned long mfn)
>  
>  static void unmap_interface(void *interface)
>  {
> -	if (*xcg_handle >= 0)
> +	if (*xcg_handle != NULL)
>  		xc_gnttab_munmap(*xcg_handle, interface, 1);
>  	else
>  		munmap(interface, getpagesize());



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