Re: [PATCH v2] xenguest: Alter xsa-25 decompression limit prototypes

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

On 28/01/13 11:50, Ian Campbell wrote:
> On Mon, 2013-01-28 at 11:44 +0000, Andrew Cooper wrote:
>> To allow xenguest consumers to make use of the extra protection added as a
>> result of xsa-25.
>>
>> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
>>
>> ---
>> Changes since v1:
>>  * Remove prototypes from xc_dom.h to remove duplication
>>
>> diff -r 5af4f2ab06f3 -r 75aafcd809a7 tools/libxc/xc_dom.h
>> --- a/tools/libxc/xc_dom.h
>> +++ b/tools/libxc/xc_dom.h
>> @@ -209,10 +209,7 @@ int xc_dom_mem_init(struct xc_dom_image 
>>  #endif
>>  
>>  int xc_dom_kernel_check_size(struct xc_dom_image *dom, size_t sz);
>> -int xc_dom_kernel_max_size(struct xc_dom_image *dom, size_t sz);
>> -
>>  int xc_dom_ramdisk_check_size(struct xc_dom_image *dom, size_t sz);
>> -int xc_dom_ramdisk_max_size(struct xc_dom_image *dom, size_t sz);
>>  
>>  size_t xc_dom_check_gzip(xc_interface *xch,
>>                       void *blob, size_t ziplen);
>> diff -r 5af4f2ab06f3 -r 75aafcd809a7 tools/libxc/xenguest.h
>> --- a/tools/libxc/xenguest.h
>> +++ b/tools/libxc/xenguest.h
>> @@ -177,6 +177,10 @@ int xc_dom_linux_build(xc_interface *xch
>>  		       unsigned int console_evtchn,
>>  		       unsigned long *console_mfn);
>>  
>> +#define XENCTRL_HAS_DECOMPRESS_LIMITS
>> +int xc_dom_kernel_max_size(struct xc_dom_image *dom, size_t sz);
>> +int xc_dom_ramdisk_max_size(struct xc_dom_image *dom, size_t sz);
> Looking at this a bit closer, do you know where a utility which only
> includes xenguest.h is getting the necessary struct xc_dom_image *
> handle from? None of the functions in xenguest.h seem to return it and
> the only functions I can find which do are in xc_dom.h...
>
> This seems to be true for the two existing functions in xenguest.h which
> take such a handle as well.
>
> The only in tree caller seems to be the Python bindings, and they just
> include xc_dom.h. Is there some reason why the ocaml tools can't just do
> this?
>
> Ian.
>

The immediate preceeding function, xc_dom_linux_build returns a struct
xc_dom_image * as its second parameter, to allow the user of xenguest to
manage the structure (in so far as it can be managed without the full
declaration).

~Andrew