Re: [dpdk-dev] [PATCH v4 11/23] rte_mbuf.h: explicit cast restricting ptrdiff to uint16

[Bruce Richardson]

On Mon, May 14, 2018 at 01:10:22PM +0800, Andy Green wrote:
> /projects/lagopus/src/dpdk/build/include/rte_common.h:141:34:
> warning: conversion from 'long unsigned int' to 'uint16_t'
> {aka 'short unsigned int'} may change value [-Wconversion]
>  #define RTE_PTR_DIFF(ptr1, ptr2) ((uintptr_t)(ptr1) -
> (uintptr_t)(ptr2))
>                                   ^
> /projects/lagopus/src/dpdk/build/include/rte_mbuf.h:1360:13:
> note: in expansion of macro 'RTE_PTR_DIFF'
>   *buf_len = RTE_PTR_DIFF(shinfo, buf_addr);
> 
> Signed-off-by: Andy Green <a...@warmcat.com>
> ---
>  lib/librte_mbuf/rte_mbuf.h |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
> index a27dbb878..0580ec8a0 100644
> --- a/lib/librte_mbuf/rte_mbuf.h
> +++ b/lib/librte_mbuf/rte_mbuf.h
> @@ -1358,7 +1358,7 @@ rte_pktmbuf_ext_shinfo_init_helper(void *buf_addr, 
> uint16_t *buf_len,
>       shinfo->fcb_opaque = fcb_opaque;
>       rte_mbuf_ext_refcnt_set(shinfo, 1);
>  
> -     *buf_len = RTE_PTR_DIFF(shinfo, buf_addr);
> +     *buf_len = (uint16_t)RTE_PTR_DIFF(shinfo, buf_addr);
>       return shinfo;
>  }
Acked-by: Bruce Richardson <bruce.richard...@intel.com>