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* [PATCH] io/ring.h: drop unused and broken *_RING_ATTACH() macros
@ 2013-06-11  8:47 Jan Beulich
  2013-06-11 10:09 ` Keir Fraser
  0 siblings, 1 reply; 2+ messages in thread
From: Jan Beulich @ 2013-06-11  8:47 UTC (permalink / raw)
  To: xen-devel

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Initializing r*_prod_pvt and r*_cons from independent shared ring
fields is broken, as other macros in this header rely on them being
coupled. Furthermore using the backend variant would also imply a
security vulnerability.

Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/include/public/io/ring.h
+++ b/xen/include/public/io/ring.h
@@ -174,21 +174,6 @@ typedef struct __name##_back_ring __name
     (_r)->sring = (_s);                                                 \
 } while (0)
 
-/* Initialize to existing shared indexes -- for recovery */
-#define FRONT_RING_ATTACH(_r, _s, __size) do {                          \
-    (_r)->sring = (_s);                                                 \
-    (_r)->req_prod_pvt = (_s)->req_prod;                                \
-    (_r)->rsp_cons = (_s)->rsp_prod;                                    \
-    (_r)->nr_ents = __RING_SIZE(_s, __size);                            \
-} while (0)
-
-#define BACK_RING_ATTACH(_r, _s, __size) do {                           \
-    (_r)->sring = (_s);                                                 \
-    (_r)->rsp_prod_pvt = (_s)->rsp_prod;                                \
-    (_r)->req_cons = (_s)->req_prod;                                    \
-    (_r)->nr_ents = __RING_SIZE(_s, __size);                            \
-} while (0)
-
 /* How big is this ring? */
 #define RING_SIZE(_r)                                                   \
     ((_r)->nr_ents)




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io/ring.h: drop unused and broken *_RING_ATTACH() macros

Initializing r*_prod_pvt and r*_cons from independent shared ring
fields is broken, as other macros in this header rely on them being
coupled. Furthermore using the backend variant would also imply a
security vulnerability.

Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/include/public/io/ring.h
+++ b/xen/include/public/io/ring.h
@@ -174,21 +174,6 @@ typedef struct __name##_back_ring __name
     (_r)->sring = (_s);                                                 \
 } while (0)
 
-/* Initialize to existing shared indexes -- for recovery */
-#define FRONT_RING_ATTACH(_r, _s, __size) do {                          \
-    (_r)->sring = (_s);                                                 \
-    (_r)->req_prod_pvt = (_s)->req_prod;                                \
-    (_r)->rsp_cons = (_s)->rsp_prod;                                    \
-    (_r)->nr_ents = __RING_SIZE(_s, __size);                            \
-} while (0)
-
-#define BACK_RING_ATTACH(_r, _s, __size) do {                           \
-    (_r)->sring = (_s);                                                 \
-    (_r)->rsp_prod_pvt = (_s)->rsp_prod;                                \
-    (_r)->req_cons = (_s)->req_prod;                                    \
-    (_r)->nr_ents = __RING_SIZE(_s, __size);                            \
-} while (0)
-
 /* How big is this ring? */
 #define RING_SIZE(_r)                                                   \
     ((_r)->nr_ents)

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^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: [PATCH] io/ring.h: drop unused and broken *_RING_ATTACH() macros
  2013-06-11  8:47 [PATCH] io/ring.h: drop unused and broken *_RING_ATTACH() macros Jan Beulich
@ 2013-06-11 10:09 ` Keir Fraser
  0 siblings, 0 replies; 2+ messages in thread
From: Keir Fraser @ 2013-06-11 10:09 UTC (permalink / raw)
  To: Jan Beulich, xen-devel

On 11/06/2013 09:47, "Jan Beulich" <JBeulich@suse.com> wrote:

> Initializing r*_prod_pvt and r*_cons from independent shared ring
> fields is broken, as other macros in this header rely on them being
> coupled. Furthermore using the backend variant would also imply a
> security vulnerability.
> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

Acked-by: Keir Fraser <keir@xen.org>

> --- a/xen/include/public/io/ring.h
> +++ b/xen/include/public/io/ring.h
> @@ -174,21 +174,6 @@ typedef struct __name##_back_ring __name
>      (_r)->sring = (_s);                                                 \
>  } while (0)
>  
> -/* Initialize to existing shared indexes -- for recovery */
> -#define FRONT_RING_ATTACH(_r, _s, __size) do {                          \
> -    (_r)->sring = (_s);                                                 \
> -    (_r)->req_prod_pvt = (_s)->req_prod;                                \
> -    (_r)->rsp_cons = (_s)->rsp_prod;                                    \
> -    (_r)->nr_ents = __RING_SIZE(_s, __size);                            \
> -} while (0)
> -
> -#define BACK_RING_ATTACH(_r, _s, __size) do {                           \
> -    (_r)->sring = (_s);                                                 \
> -    (_r)->rsp_prod_pvt = (_s)->rsp_prod;                                \
> -    (_r)->req_cons = (_s)->req_prod;                                    \
> -    (_r)->nr_ents = __RING_SIZE(_s, __size);                            \
> -} while (0)
> -
>  /* How big is this ring? */
>  #define RING_SIZE(_r)                                                   \
>      ((_r)->nr_ents)
> 
> 
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel

^ permalink raw reply	[flat|nested] 2+ messages in thread

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