netdev - [PATCH net-next 0/2] page_pool: Convert stats to u64_stats

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250221115221.291006-1-bigeasy@linutronix.de>
Date: Fri, 21 Feb 2025 12:52:19 +0100
From: Sebastian Andrzej Siewior <bigeasy@...utronix.de>
To: linux-rdma@...r.kernel.org,
	netdev@...r.kernel.org
Cc: "David S. Miller" <davem@...emloft.net>,
	Andrew Lunn <andrew+netdev@...n.ch>,
	Eric Dumazet <edumazet@...gle.com>,
	Ilias Apalodimas <ilias.apalodimas@...aro.org>,
	Jakub Kicinski <kuba@...nel.org>,
	Jesper Dangaard Brouer <hawk@...nel.org>,
	Leon Romanovsky <leon@...nel.org>,
	Paolo Abeni <pabeni@...hat.com>,
	Saeed Mahameed <saeedm@...dia.com>,
	Simon Horman <horms@...nel.org>,
	Tariq Toukan <tariqt@...dia.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Yunsheng Lin <linyunsheng@...wei.com>,
	Sebastian Andrzej Siewior <bigeasy@...utronix.de>
Subject: [PATCH net-next 0/2] page_pool: Convert stats to u64_stats_t.

This is a follow-up on
	https://lore.kernel.org/all/20250213093925.x_ggH1aj@linutronix.de/

to convert the page_pool statistics to u64_stats_t to avoid u64 related
problems on 32bit architectures.
While looking over it, the comment for recycle_stat_inc() says that it
is safe to use in preemptible context. The 32bit update is split into
two 32bit writes and if we get preempted in the middle and another one
makes an update then the value gets inconsistent and the previous update
can overwrite the following. (Rare but still).
I don't know if it is ensured that only *one* update can happen because
the stats are per-CPU and per NAPI device. But there will be now a
warning on 32bit if this is really attempted in preemptible context.

Sebastian Andrzej Siewior (2):
  page_pool: Convert page_pool_recycle_stats to u64_stats_t.
  page_pool: Convert page_pool_alloc_stats to u64_stats_t.

 Documentation/networking/page_pool.rst        |  4 +-
 .../ethernet/mellanox/mlx5/core/en_stats.c    | 24 ++---
 include/linux/u64_stats_sync.h                |  5 +
 include/net/page_pool/types.h                 | 27 +++---
 net/core/page_pool.c                          | 95 +++++++++++++------
 net/core/page_pool_user.c                     | 22 ++---
 6 files changed, 113 insertions(+), 64 deletions(-)

-- 
2.47.2