Re: [PATCH] hvmloader: Use xen/errno.h rather than the host systems errno.h

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 19/02/16 11:00, Ian Campbell wrote:
> On Fri, 2016-02-19 at 10:50 +0000, Andrew Cooper wrote:
>> On 19/02/16 10:40, Wei Liu wrote:
>>> On Thu, Feb 18, 2016 at 10:10:09PM +0000, Andrew Cooper wrote:
>>>> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
>>>> ---
>>>> CC: Jan Beulich <JBeulich@suse.com>
>>>> CC: Ian Campbell <Ian.Campbell@citrix.com>
>>>> CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
>>>> CC: Wei Liu <wei.liu2@citrix.com>
>>>> CC: Doug Goldstein <cardoe@cardoe.com>
>>>> ---
>>>>  tools/firmware/hvmloader/xenbus.c | 2 +-
>>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/tools/firmware/hvmloader/xenbus.c
>>>> b/tools/firmware/hvmloader/xenbus.c
>>>> index d0ed993..947d865 100644
>>>> --- a/tools/firmware/hvmloader/xenbus.c
>>>> +++ b/tools/firmware/hvmloader/xenbus.c
>>>> @@ -27,7 +27,7 @@
>>>>  
>>>>  #include "util.h"
>>>>  #include "hypercall.h"
>>>> -#include <errno.h>
>>>> +#include <xen/errno.h>
>>> This doesn't seem to compile for me. Xen's error numbers live in a
>>> different name space.
>> It compiled fine for me.  HVMLoader should use __XEN_TOOLS__.
> It shouldn't and doesn't, see 3237645813d7 which stopped setting
> __XEN_TOOLS__ globally for all of tools/* and consequently removed the
> -U__XEN_TOOLS__ from hvmloader.
>
> In any case I don't think __XEN_TOOLS__ has any impact on xen/errno.h
> (which is, perhaps confusingly, xen/include/public/errno.h and not
> xen/include/xen/errno.h)
>
> For normal userspace uses of __XEN_TOOLS__ you wouldn't want unprefixed Xen
> errno values added to your namespace anyway -- since you need to deal with
> OS errno names/values.

HVMloader is an unhosted 32bit environment, which is why it should not
be using the hosts errno.h in the first place.

~Andrew