Re: [PATCH net-next 0/4] u64_stats: Introduce u64_stats_copy()
From: Ido Schimmel <idosch@nvidia.com>
Date: 2026-01-21 11:16:58
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From: Ido Schimmel <idosch@nvidia.com>
Date: 2026-01-21 11:16:58
Also in:
bridge, lkml
On Tue, Jan 20, 2026 at 05:21:28PM +0800, David Yang wrote:
On 64bit arches, struct u64_stats_sync is empty and provides no help against load/store tearing. memcpy() should not be considered atomic against u64 values. Use u64_stats_copy() instead.
The existing memcpy() does seem problematic (even if in practice it's not) and the proposed solution in patch #1 seems OK to me given that all the callers only pass structures containing 64 bit counters. Couldn't find any more instances of this pattern. Reviewed-by: Ido Schimmel <idosch@nvidia.com>