[PATCH v2] lib/ethdev: fix segfault in secondary process by validating dev_private pointer

[Khadem Ullah <14pwcse1224@uetpeshawar.edu.pk>]

In secondary processes, directly accessing 'dev->data->dev_private' can
cause a segmentation fault if the primary process has exited or if the
shared memory is no longer accessible.

This patch adds a safety check using rte_mem_virt2phy(), with an
unlikely() branch hint to minimize performance impact in the fast path.
This ensures 'dev_private' is still valid before accessing it.

Fixes: bdad90d12ec8 ("ethdev: change device info get callback to return int")
Cc: stable@dpdk.org

Signed-off-by: Khadem Ullah <14pwcse1224@uetpeshawar.edu.pk>
---
 lib/ethdev/rte_ethdev.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/lib/ethdev/rte_ethdev.c b/lib/ethdev/rte_ethdev.c
index dd7c00bc94..ef5dc55f2e 100644
--- a/lib/ethdev/rte_ethdev.c
+++ b/lib/ethdev/rte_ethdev.c
@@ -4079,6 +4079,13 @@ rte_eth_dev_info_get(uint16_t port_id, struct rte_eth_dev_info *dev_info)
 
 	if (dev->dev_ops->dev_infos_get == NULL)
 		return -ENOTSUP;
+	if (rte_eal_process_type() == RTE_PROC_SECONDARY &&
+		unlikely(rte_mem_virt2phy(dev->data->dev_private) == RTE_BAD_PHYS_ADDR)) {
+			RTE_ETHDEV_LOG_LINE(ERR,
+			"Secondary: dev_private not accessible (primary exited?)");
+			rte_errno = ENODEV;
+			return -rte_errno;
+	}
 	diag = dev->dev_ops->dev_infos_get(dev, dev_info);
 	if (diag != 0) {
 		/* Cleanup already filled in device information */
-- 
2.43.0