Re: [PATCH 2/3] mbuf: add a non fatal sanity check helper

[Andrew Rybchenko <arybchenko@solarflare.com>]

On 09/10/2018 08:45 AM, David Marchand wrote:
> Let's add a little helper that does the same as rte_mbuf_sanity_check but
> without the panic.
>
> Signed-off-by: David Marchand <david.marchand@6wind.com>
> ---

<...>

> diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
> index a50b05c64..e12a4c765 100644
> --- a/lib/librte_mbuf/rte_mbuf.h
> +++ b/lib/librte_mbuf/rte_mbuf.h
> @@ -977,6 +977,29 @@ rte_mbuf_ext_refcnt_update(struct rte_mbuf_ext_shared_info *shinfo,
>   void
>   rte_mbuf_sanity_check(const struct rte_mbuf *m, int is_header);
>   
> +/**
> + * Sanity checks on a mbuf.
> + *
> + * Almost like rte_mbuf_sanity_check(), but this function gives the reason
> + * if corruption is detected rather than panic.
> + *
> + * @param m
> + *   The mbuf to be checked.
> + * @param is_header
> + *   True if the mbuf is a packet header, false if it is a sub-segment
> + *   of a packet (in this case, some fields like nb_segs are not checked)
> + * @param reason
> + *   A reference to a string pointer where to store the reason why a mbuf is
> + *   considered invalid.
> + * @return
> + *   - 0 if no issue has been found, reason is left untouched.
> + *   - -1 if a problem is detected, reason then points to a string describing
> + *     the reason why the mbuf is deemed invalid.
> + */
> +__rte_experimental
> +int rte_mbuf_check(const struct rte_mbuf *m, int is_header,
> +		   const char **reason);
> +

May be it would be better to return reason as return value and if it is 
NULL everything is OK?

<...>