[PATCH 5.9 099/757] seqlock: Unbreak lockdep

Greg Kroah-Hartman
2020-10-27T15:31:30Z

From: peterz@infradead.org <peterz@infradead.org>

[ Upstream commit 267580db047ef428a70bef8287ca62c5a450c139 ]

seqcount_LOCKNAME_init() needs to be a macro due to the lockdep
annotation in seqcount_init(). Since a macro cannot define another
macro, we need to effectively revert commit: e4e9ab3f9f91 ("seqlock:
Fold seqcount_LOCKNAME_init() definition").

Fixes: e4e9ab3f9f91 ("seqlock: Fold seqcount_LOCKNAME_init() definition")
Reported-by: Qian Cai <cai@redhat.com>
Debugged-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Qian Cai <cai@redhat.com>
Link: https://lkml.kernel.org/r/20200915143028.GB2674@hirez.programming.kicks-ass.net
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
include/linux/seqlock.h | 23 ++++++++++++++---------
1 file changed, 14 insertions(+), 9 deletions(-)

diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h
index 962d9768945f0..7b99e3dba2065 100644
--- a/include/linux/seqlock.h
+++ b/include/linux/seqlock.h
@@ -154,6 +154,19 @@ static inline void seqcount_lockdep_reader_access(const seqcount_t *s)
* @lock: Pointer to the associated LOCKTYPE
*/

+#define seqcount_LOCKNAME_init(s, _lock, lockname) \
+ do { \
+ seqcount_##lockname##_t *____s = (s); \
+ seqcount_init(&____s->seqcount); \
+ __SEQ_LOCK(____s->lock = (_lock)); \
+ } while (0)
+
+#define seqcount_raw_spinlock_init(s, lock) seqcount_LOCKNAME_init(s, lock, raw_spinlock)
+#define seqcount_spinlock_init(s, lock) seqcount_LOCKNAME_init(s, lock, spinlock)
+#define seqcount_rwlock_init(s, lock) seqcount_LOCKNAME_init(s, lock, rwlock);
+#define seqcount_mutex_init(s, lock) seqcount_LOCKNAME_init(s, lock, mutex);
+#define seqcount_ww_mutex_init(s, lock) seqcount_LOCKNAME_init(s, lock, ww_mutex);
+
/*
* SEQCOUNT_LOCKTYPE() - Instantiate seqcount_LOCKNAME_t and helpers
* @locktype: actual typename
@@ -167,13 +180,6 @@ typedef struct seqcount_##lockname { \
__SEQ_LOCK(locktype *lock); \
} seqcount_##lockname##_t; \
\
-static __always_inline void \
-seqcount_##lockname##_init(seqcount_##lockname##_t *s, locktype *lock) \
-{ \
- seqcount_init(&s->seqcount); \
- __SEQ_LOCK(s->lock = lock); \
-} \
- \
static __always_inline seqcount_t * \
__seqcount_##lockname##_ptr(seqcount_##lockname##_t *s) \
{ \
@@ -228,13 +234,12 @@ SEQCOUNT_LOCKTYPE(struct ww_mutex, ww_mutex, true, &s->lock->base)
__SEQ_LOCK(.lock = (assoc_lock)) \
}

-#define SEQCNT_SPINLOCK_ZERO(name, lock) SEQCOUNT_LOCKTYPE_ZERO(name, lock)
#define SEQCNT_RAW_SPINLOCK_ZERO(name, lock) SEQCOUNT_LOCKTYPE_ZERO(name, lock)
+#define SEQCNT_SPINLOCK_ZERO(name, lock) SEQCOUNT_LOCKTYPE_ZERO(name, lock)
#define SEQCNT_RWLOCK_ZERO(name, lock) SEQCOUNT_LOCKTYPE_ZERO(name, lock)
#define SEQCNT_MUTEX_ZERO(name, lock) SEQCOUNT_LOCKTYPE_ZERO(name, lock)
#define SEQCNT_WW_MUTEX_ZERO(name, lock) SEQCOUNT_LOCKTYPE_ZERO(name, lock)

-
#define __seqprop_case(s, lockname, prop) \
seqcount_##lockname##_t: __seqcount_##lockname##_##prop((void *)(s))

--
2.25.1