From 2f75517633608228fd3c49f6b8c5dbc8f8490e2e Mon Sep 17 00:00:00 2001 From: Petr Tesarik Date: Thu, 4 Apr 2024 09:57:40 +0200 Subject: [PATCH] u64_stats: fix u64_stats_init() for lockdep when used repeatedly in one file [ Upstream commit 38a15d0a50e0a43778561a5861403851f0b0194c ] Fix bogus lockdep warnings if multiple u64_stats_sync variables are initialized in the same file. With CONFIG_LOCKDEP, seqcount_init() is a macro which declares: static struct lock_class_key __key; Since u64_stats_init() is a function (albeit an inline one), all calls within the same file end up using the same instance, effectively treating them all as a single lock-class. Fixes: 9464ca650008 ("net: make u64_stats_init() a function") Closes: https://lore.kernel.org/netdev/ea1567d9-ce66-45e6-8168-ac40a47d1821@roeck-us.net/ Signed-off-by: Petr Tesarik Reviewed-by: Simon Horman Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/20240404075740.30682-1-petr@tesarici.cz Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- include/linux/u64_stats_sync.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/include/linux/u64_stats_sync.h b/include/linux/u64_stats_sync.h index 11096b561dab..ca40163933e3 100644 --- a/include/linux/u64_stats_sync.h +++ b/include/linux/u64_stats_sync.h @@ -70,7 +70,11 @@ struct u64_stats_sync { #if BITS_PER_LONG == 32 && defined(CONFIG_SMP) -#define u64_stats_init(syncp) seqcount_init(&(syncp)->seq) +#define u64_stats_init(syncp) \ + do { \ + struct u64_stats_sync *__s = (syncp); \ + seqcount_init(&__s->seq); \ + } while (0) #else static inline void u64_stats_init(struct u64_stats_sync *syncp) {