From 784ba0a03ddd16a54b9d23757d587b67b832e2b7 Mon Sep 17 00:00:00 2001 From: Chengwen Feng Date: Thu, 11 Apr 2024 12:04:08 +0000 Subject: [PATCH] ethdev: fix strict aliasing lead to link cannot be up Fix a problem introduced by a compiler upgrade (from gcc10 to gcc12.3), which will lead the hns3 NIC can't link up. The root cause is strict aliasing violation in rte_eth_linkstatus_set() with hns3 driver, see [1] for more details. This commit use union to avoid such aliasing violation. [1] Strict aliasing problem with rte_eth_linkstatus_set() https://marc.info/?l=dpdk-dev&m=171274148514777&w=3 Cc: stable@dpdk.org Signed-off-by: Chengwen Feng Signed-off-by: Dengdui Huang --- lib/ethdev/ethdev_driver.h | 23 +++++++---------------- lib/ethdev/rte_ethdev.h | 16 ++++++++++------ 2 files changed, 17 insertions(+), 22 deletions(-) diff --git a/lib/ethdev/ethdev_driver.h b/lib/ethdev/ethdev_driver.h index b482cd1..12a7bfc 100644 --- a/lib/ethdev/ethdev_driver.h +++ b/lib/ethdev/ethdev_driver.h @@ -1655,18 +1655,13 @@ static inline int rte_eth_linkstatus_set(struct rte_eth_dev *dev, const struct rte_eth_link *new_link) { - RTE_ATOMIC(uint64_t) *dev_link = (uint64_t __rte_atomic *)&(dev->data->dev_link); - union { - uint64_t val64; - struct rte_eth_link link; - } orig; - - RTE_BUILD_BUG_ON(sizeof(*new_link) != sizeof(uint64_t)); + struct rte_eth_link old_link; - orig.val64 = rte_atomic_exchange_explicit(dev_link, *(const uint64_t *)new_link, - rte_memory_order_seq_cst); + old_link.val64 = rte_atomic_exchange_explicit(&dev->data->dev_link.val64, + new_link->val64, + rte_memory_order_seq_cst); - return (orig.link.link_status == new_link->link_status) ? -1 : 0; + return (old_link.link_status == new_link->link_status) ? -1 : 0; } /** @@ -1682,12 +1677,8 @@ static inline void rte_eth_linkstatus_get(const struct rte_eth_dev *dev, struct rte_eth_link *link) { - RTE_ATOMIC(uint64_t) *src = (uint64_t __rte_atomic *)&(dev->data->dev_link); - uint64_t *dst = (uint64_t *)link; - - RTE_BUILD_BUG_ON(sizeof(*link) != sizeof(uint64_t)); - - *dst = rte_atomic_load_explicit(src, rte_memory_order_seq_cst); + link->val64 = rte_atomic_load_explicit(&dev->data->dev_link.val64, + rte_memory_order_seq_cst); } /** diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h index 57a9a55..b4b0357 100644 --- a/lib/ethdev/rte_ethdev.h +++ b/lib/ethdev/rte_ethdev.h @@ -331,13 +331,17 @@ struct rte_eth_stats { /** * A structure used to retrieve link-level information of an Ethernet port. */ -__extension__ struct rte_eth_link { - uint32_t link_speed; /**< RTE_ETH_SPEED_NUM_ */ - uint16_t link_duplex : 1; /**< RTE_ETH_LINK_[HALF/FULL]_DUPLEX */ - uint16_t link_autoneg : 1; /**< RTE_ETH_LINK_[AUTONEG/FIXED] */ - uint16_t link_status : 1; /**< RTE_ETH_LINK_[DOWN/UP] */ -} __rte_aligned(8); /**< aligned for atomic64 read/write */ + union { + RTE_ATOMIC(uint64_t) val64; /**< used for atomic64 read/write */ + struct { + uint32_t link_speed; /**< RTE_ETH_SPEED_NUM_ */ + uint16_t link_duplex : 1; /**< RTE_ETH_LINK_[HALF/FULL]_DUPLEX */ + uint16_t link_autoneg : 1; /**< RTE_ETH_LINK_[AUTONEG/FIXED] */ + uint16_t link_status : 1; /**< RTE_ETH_LINK_[DOWN/UP] */ + }; + }; +}; /**@{@name Link negotiation * Constants used in link management. -- 2.33.0