5.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Petr Tesarik <petr@xxxxxxxxxxx>
[ 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@xxxxxxxxxxxx/
Signed-off-by: Petr Tesarik <petr@xxxxxxxxxxx>
Reviewed-by: Simon Horman <horms@xxxxxxxxxx>
Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240404075740.30682-1-petr@xxxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
include/linux/u64_stats_sync.h | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
--- 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)
{
