Commit 38a15d0a authored by Petr Tesarik's avatar Petr Tesarik Committed by Jakub Kicinski
Browse files

u64_stats: fix u64_stats_init() for lockdep when used repeatedly in one file 

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: 9464ca65 ("net: make u64_stats_init() a function")
Closes: https://lore.kernel.org/netdev/ea1567d9-ce66-45e6-8168-ac40a47d1821@roeck-us.net/


Signed-off-by: default avatarPetr Tesarik <petr@tesarici.cz>
Reviewed-by: default avatarSimon Horman <horms@kernel.org>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240404075740.30682-1-petr@tesarici.cz


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 4539f91f

include/linux/u64_stats_sync.h

+5 −4
Original line number Diff line number Diff line
@@ -135,10 +135,11 @@ static inline void u64_stats_inc(u64_stats_t *p) 
	p->v++;

}



static inline void u64_stats_init(struct u64_stats_sync *syncp)

{

	seqcount_init(&syncp->seq);

}

#define u64_stats_init(syncp)				\

	do {						\

		struct u64_stats_sync *__s = (syncp);	\

		seqcount_init(&__s->seq);		\

	} while (0)



static inline void __u64_stats_update_begin(struct u64_stats_sync *syncp)

{