From: Gavin Hu <gavin.hu@arm.com>
To: dev@dpdk.org
Cc: nd@arm.com, david.marchand@redhat.com, thomas@monjalon.net,
ktraynor@redhat.com, jerinj@marvell.com,
honnappa.nagarahalli@arm.com, ruifeng.wang@arm.com,
phil.yang@arm.com, joyce.kong@arm.com, stable@dpdk.org
Subject: [dpdk-dev] [PATCH v2] mbuf: replace zero-length marker with unnamed union
Date: Sat, 7 Mar 2020 15:56:29 +0000 [thread overview]
Message-ID: <20200307155629.45021-1-gavin.hu@arm.com> (raw)
In-Reply-To: <20200303162728.93744-1-gavin.hu@arm.com>
Declaring zero-length arrays in other contexts, including as interior
members of structure objects or as non-member objects, is discouraged.
Accessing elements of zero-length arrays declared in such contexts is
undefined and may be diagnosed.[1]
Fix by using unnamed union and struct.
https://bugs.dpdk.org/show_bug.cgi?id=396
Bugzilla ID: 396
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
Fixes: 3e6181b07038 ("mbuf: use structure marker from EAL")
Cc: stable@dpdk.org
Signed-off-by: Gavin Hu <gavin.hu@arm.com>
---
v2:
* change 'uint64_t rearm_data' to 'uint_64_t rearm_data[1]' to fix
the SFC PMD compiling error on x86. <Kevin Traynor>
---
lib/librte_mbuf/rte_mbuf_core.h | 54 +++++++++++++++++++--------------
1 file changed, 32 insertions(+), 22 deletions(-)
diff --git a/lib/librte_mbuf/rte_mbuf_core.h b/lib/librte_mbuf/rte_mbuf_core.h
index b9a59c879..34cb152e2 100644
--- a/lib/librte_mbuf/rte_mbuf_core.h
+++ b/lib/librte_mbuf/rte_mbuf_core.h
@@ -480,31 +480,41 @@ struct rte_mbuf {
rte_iova_t buf_physaddr; /**< deprecated */
} __rte_aligned(sizeof(rte_iova_t));
- /* next 8 bytes are initialised on RX descriptor rearm */
- RTE_MARKER64 rearm_data;
- uint16_t data_off;
-
- /**
- * Reference counter. Its size should at least equal to the size
- * of port field (16 bits), to support zero-copy broadcast.
- * It should only be accessed using the following functions:
- * rte_mbuf_refcnt_update(), rte_mbuf_refcnt_read(), and
- * rte_mbuf_refcnt_set(). The functionality of these functions (atomic,
- * or non-atomic) is controlled by the CONFIG_RTE_MBUF_REFCNT_ATOMIC
- * config option.
- */
RTE_STD_C11
union {
- rte_atomic16_t refcnt_atomic; /**< Atomically accessed refcnt */
- /** Non-atomically accessed refcnt */
- uint16_t refcnt;
- };
- uint16_t nb_segs; /**< Number of segments. */
+ /* next 8 bytes are initialised on RX descriptor rearm */
+ uint64_t rearm_data[1];
+ RTE_STD_C11
+ struct {
+ uint16_t data_off;
+
+ /**
+ * Reference counter. Its size should at least equal to
+ * the size of port field (16 bits), to support
+ * zero-copy broadcast. It should only be accessed
+ * using the following functions:
+ * rte_mbuf_refcnt_update(), rte_mbuf_refcnt_read(),
+ * and rte_mbuf_refcnt_set(). The functionality of
+ * these functions (atomic, or non-atomic) is
+ * controlled by the CONFIG_RTE_MBUF_REFCNT_ATOMIC
+ * config option.
+ */
+ RTE_STD_C11
+ union {
+ /**< Atomically accessed refcnt */
+ rte_atomic16_t refcnt_atomic;
+ /** Non-atomically accessed refcnt */
+ uint16_t refcnt;
+ };
+ uint16_t nb_segs; /**< Number of segments. */
- /** Input port (16 bits to support more than 256 virtual ports).
- * The event eth Tx adapter uses this field to specify the output port.
- */
- uint16_t port;
+ /** Input port (16 bits to support more than 256
+ * virtual ports). The event eth Tx adapter uses this
+ * field to specify the output port.
+ */
+ uint16_t port;
+ };
+ };
uint64_t ol_flags; /**< Offload features. */
--
2.25.0
next prev parent reply other threads:[~2020-03-07 15:57 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-03 16:27 [dpdk-dev] [PATCH v1] " Gavin Hu
2020-03-04 12:32 ` Kevin Traynor
2020-03-07 14:52 ` Gavin Hu
2020-03-07 15:56 ` Gavin Hu [this message]
2020-03-09 8:55 ` [dpdk-dev] [PATCH v2] " Ferruh Yigit
2020-03-09 9:45 ` Gavin Hu
2020-03-09 11:29 ` Ferruh Yigit
2020-03-09 13:30 ` Morten Brørup
2020-03-09 14:16 ` Richardson, Bruce
2020-03-09 14:50 ` [dpdk-dev] [PATCH v2] mbuf: replace zero-length markerwith " Morten Brørup
2020-03-11 7:50 ` [dpdk-dev] [PATCH v2] mbuf: replace zero-length marker with " Gavin Hu
2020-03-11 9:04 ` Morten Brørup
2020-03-11 12:07 ` Bruce Richardson
2020-03-13 7:36 ` Gavin Hu
2020-03-13 9:22 ` Gavin Hu
2020-04-07 17:13 ` Kevin Traynor
2020-04-08 15:04 ` Gavin Hu
2020-04-08 15:22 ` [dpdk-dev] [dpdk-stable] " David Marchand
2020-04-09 9:48 ` Gavin Hu
2020-04-09 10:49 ` Thomas Monjalon
2020-04-09 16:09 ` Ray Kinsella
2020-04-11 2:50 ` Gavin Hu
2020-05-14 13:24 ` Kevin Traynor
2020-03-09 15:47 ` [dpdk-dev] " Stephen Hemminger
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