Re: [PATCH] xen: update PV-device interface headers

[Stefano Stabellini]

On Tue, 4 Dec 2023, Juergen Gross wrote:
> Update the Xen PV-device interface headers in order to avoid undefined
> behavior with flexible arrays being defined with one array element.
> 
> Reported-by: Pry Mar 
> Signed-off-by: Juergen Gross 

Acked-by: Stefano Stabellini 

> ---
>  include/xen/interface/io/displif.h | 2 +-
>  include/xen/interface/io/ring.h| 2 +-
>  include/xen/interface/io/sndif.h   | 2 +-
>  3 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/include/xen/interface/io/displif.h 
> b/include/xen/interface/io/displif.h
> index 18417b017869..60e42d3b760e 100644
> --- a/include/xen/interface/io/displif.h
> +++ b/include/xen/interface/io/displif.h
> @@ -537,7 +537,7 @@ struct xendispl_dbuf_create_req {
>  
>  struct xendispl_page_directory {
>   grant_ref_t gref_dir_next_page;
> - grant_ref_t gref[1]; /* Variable length */
> + grant_ref_t gref[];
>  };
>  
>  /*
> diff --git a/include/xen/interface/io/ring.h b/include/xen/interface/io/ring.h
> index ba4c4274b714..4fef1efcdcab 100644
> --- a/include/xen/interface/io/ring.h
> +++ b/include/xen/interface/io/ring.h
> @@ -95,7 +95,7 @@ struct __name##_sring { 
> \
>  RING_IDX req_prod, req_event;   \
>  RING_IDX rsp_prod, rsp_event;   \
>  uint8_t __pad[48];  \
> -union __name##_sring_entry ring[1]; /* variable-length */   \
> +union __name##_sring_entry ring[];  \
>  };  \
>  \
>  /* "Front" end's private variables */   \
> diff --git a/include/xen/interface/io/sndif.h 
> b/include/xen/interface/io/sndif.h
> index 445657cdb1de..b818517588b5 100644
> --- a/include/xen/interface/io/sndif.h
> +++ b/include/xen/interface/io/sndif.h
> @@ -659,7 +659,7 @@ struct xensnd_open_req {
>  
>  struct xensnd_page_directory {
>   grant_ref_t gref_dir_next_page;
> - grant_ref_t gref[1]; /* Variable length */
> + grant_ref_t gref[];
>  };
>  
>  /*
> -- 
> 2.35.3
> 

[PATCH] xen: update PV-device interface headers

[Juergen Gross]

Update the Xen PV-device interface headers in order to avoid undefined
behavior with flexible arrays being defined with one array element.

Reported-by: Pry Mar 
Signed-off-by: Juergen Gross 
---
 include/xen/interface/io/displif.h | 2 +-
 include/xen/interface/io/ring.h| 2 +-
 include/xen/interface/io/sndif.h   | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/xen/interface/io/displif.h 
b/include/xen/interface/io/displif.h
index 18417b017869..60e42d3b760e 100644
--- a/include/xen/interface/io/displif.h
+++ b/include/xen/interface/io/displif.h
@@ -537,7 +537,7 @@ struct xendispl_dbuf_create_req {
 
 struct xendispl_page_directory {
grant_ref_t gref_dir_next_page;
-   grant_ref_t gref[1]; /* Variable length */
+   grant_ref_t gref[];
 };
 
 /*
diff --git a/include/xen/interface/io/ring.h b/include/xen/interface/io/ring.h
index ba4c4274b714..4fef1efcdcab 100644
--- a/include/xen/interface/io/ring.h
+++ b/include/xen/interface/io/ring.h
@@ -95,7 +95,7 @@ struct __name##_sring {   
  \
 RING_IDX req_prod, req_event;   \
 RING_IDX rsp_prod, rsp_event;   \
 uint8_t __pad[48];  \
-union __name##_sring_entry ring[1]; /* variable-length */   \
+union __name##_sring_entry ring[];  \
 };  \
 \
 /* "Front" end's private variables */   \
diff --git a/include/xen/interface/io/sndif.h b/include/xen/interface/io/sndif.h
index 445657cdb1de..b818517588b5 100644
--- a/include/xen/interface/io/sndif.h
+++ b/include/xen/interface/io/sndif.h
@@ -659,7 +659,7 @@ struct xensnd_open_req {
 
 struct xensnd_page_directory {
grant_ref_t gref_dir_next_page;
-   grant_ref_t gref[1]; /* Variable length */
+   grant_ref_t gref[];
 };
 
 /*
-- 
2.35.3