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From: Stephen Hemminger <stephen@networkplumber.org>
To: Robin Jarry <rjarry@redhat.com>
Cc: dev@dpdk.org
Subject: Re: [PATCH dpdk v2] mbuf: fix strict aliasing error in allocator
Date: Wed, 25 Sep 2024 08:47:41 -0700	[thread overview]
Message-ID: <20240925084741.60852bd6@fedora> (raw)
In-Reply-To: <20240925154053.80861-2-rjarry@redhat.com>

On Wed, 25 Sep 2024 11:40:54 -0400
Robin Jarry <rjarry@redhat.com> wrote:

> From: Robin Jarry <rjarry@redhat.com>
> To: dev@dpdk.org
> Subject: [PATCH dpdk v2] mbuf: fix strict aliasing error in allocator
> Date: Wed, 25 Sep 2024 11:40:54 -0400
> 
> When building an application with -fstrict-aliasing -Wstrict-aliasing=2,
> we get errors triggered by rte_mbuf_raw_alloc() which is called inline
> from rte_pktmbuf_alloc().
> 
>  ../dpdk/lib/mbuf/rte_mbuf.h: In function ‘rte_mbuf_raw_alloc’:
>  ../dpdk/lib/mbuf/rte_mbuf.h:600:42: error: dereferencing type-punned
>  pointer might break strict-aliasing rules [-Werror=strict-aliasing]
>    600 |         if (rte_mempool_get(mp, (void **)&m) < 0)
>        |                                          ^~
> 
> Avoid incorrect casting by using an inline union variable.
> 
> Signed-off-by: Robin Jarry <rjarry@redhat.com>

Thanks, union is safer than cast.

Reviewed-by: Stephen Hemminger <stephen@networkplumber.org>

  reply	other threads:[~2024-09-25 15:47 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-09-25 14:00 [PATCH dpdk] " Robin Jarry
2024-09-25 15:21 ` Morten Brørup
2024-09-25 15:23   ` Stephen Hemminger
2024-09-25 15:24     ` Robin Jarry
2024-09-25 15:40 ` [PATCH dpdk v2] " Robin Jarry
2024-09-25 15:47   ` Stephen Hemminger [this message]
2024-10-17 19:44     ` Thomas Monjalon
2024-10-17 14:17   ` Ali Alnubani
2024-09-26 16:38 ` [PATCH dpdk] " Patrick Robb

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