Re: [PATCH v4 0/4] af_packet correctness, performance, cksum

[Stephen Hemminger <stephen@networkplumber.org>]

On Mon,  2 Feb 2026 00:14:52 -0800
scott.k.mitch1@gmail.com wrote:

> From: Scott <scott.k.mitch1@gmail.com>
> 
> This series fixes critical thread safety bugs in the af_packet PMD
> and adds performance optimizations.
> 
> Patch 1 fixes two major correctness issues:
> - Thread safety: tp_status was accessed without memory barriers,
>   violating the kernel's PACKET_MMAP protocol. On aarch64 and other
>   weakly-ordered architectures, this causes packet corruption due to
>   missing memory ordering. The fix matches the kernel's memory model:
>   volatile unaligned reads/writes with explicit rte_smp_rmb/wmb
>   barriers and __may_alias__ protection.
> 
> - Frame calculations: Fixed incorrect frame overhead and address
>   calculations that caused memory corruption when frames don't evenly
>   divide blocks.

Fix patch 4 and resubmit.