From ff93bca769925a2d8fd7f910cdf543d992e17f07 Mon Sep 17 00:00:00 2001
From: Cong Wang <xiyou.wangcong@gmail.com>
Date: Tue, 14 Aug 2018 15:21:31 -0700
Subject: [PATCH] ila: make lockdep happy again
Previously, alloc_ila_locks() and bucket_table_alloc() call
spin_lock_init() separately, therefore they have two different
lock names and lock class keys. However, after commit b893281715ab
("ila: Call library function alloc_bucket_locks") they both call
helper alloc_bucket_spinlocks() which now only has one lock
name and lock class key. This causes a few bogus lockdep warnings
as reported by syzbot.
Fix this by making alloc_bucket_locks() a macro and pass declaration
name as lock name and a static lock class key inside the macro.
Fixes: b893281715ab ("ila: Call library function alloc_bucket_locks")
Reported-by: <syzbot+b66a5a554991a8ed027c@syzkaller.appspotmail.com>
Cc: Tom Herbert <tom@quantonium.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
include/linux/spinlock.h | 17 ++++++++++++++---
lib/bucket_locks.c | 11 +++++++----
2 files changed, 21 insertions(+), 7 deletions(-)
diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h
index 3190997df9cac..e089157dcf97c 100644
--- a/include/linux/spinlock.h
+++ b/include/linux/spinlock.h
@@ -451,9 +451,20 @@ extern int _atomic_dec_and_lock_irqsave(atomic_t *atomic, spinlock_t *lock,
#define atomic_dec_and_lock_irqsave(atomic, lock, flags) \
__cond_lock(lock, _atomic_dec_and_lock_irqsave(atomic, lock, &(flags)))
-int alloc_bucket_spinlocks(spinlock_t **locks, unsigned int *lock_mask,
- size_t max_size, unsigned int cpu_mult,
- gfp_t gfp);
+int __alloc_bucket_spinlocks(spinlock_t **locks, unsigned int *lock_mask,
+ size_t max_size, unsigned int cpu_mult,
+ gfp_t gfp, const char *name,
+ struct lock_class_key *key);
+
+#define alloc_bucket_spinlocks(locks, lock_mask, max_size, cpu_mult, gfp) \
+ ({ \
+ static struct lock_class_key key; \
+ int ret; \
+ \
+ ret = __alloc_bucket_spinlocks(locks, lock_mask, max_size, \
+ cpu_mult, gfp, #locks, &key); \
+ ret; \
+ })
void free_bucket_spinlocks(spinlock_t *locks);
diff --git a/lib/bucket_locks.c b/lib/bucket_locks.c
index ade3ce6c4af6a..64b92e1dbace5 100644
--- a/lib/bucket_locks.c
+++ b/lib/bucket_locks.c
@@ -11,8 +11,9 @@
* to a power of 2 to be suitable as a hash table.
*/
-int alloc_bucket_spinlocks(spinlock_t **locks, unsigned int *locks_mask,
- size_t max_size, unsigned int cpu_mult, gfp_t gfp)
+int __alloc_bucket_spinlocks(spinlock_t **locks, unsigned int *locks_mask,
+ size_t max_size, unsigned int cpu_mult, gfp_t gfp,
+ const char *name, struct lock_class_key *key)
{
spinlock_t *tlocks = NULL;
unsigned int i, size;
@@ -33,8 +34,10 @@ int alloc_bucket_spinlocks(spinlock_t **locks, unsigned int *locks_mask,
tlocks = kvmalloc_array(size, sizeof(spinlock_t), gfp);
if (!tlocks)
return -ENOMEM;
- for (i = 0; i < size; i++)
+ for (i = 0; i < size; i++) {
spin_lock_init(&tlocks[i]);
+ lockdep_init_map(&tlocks[i].dep_map, name, key, 0);
+ }
}
*locks = tlocks;
@@ -42,7 +45,7 @@ int alloc_bucket_spinlocks(spinlock_t **locks, unsigned int *locks_mask,
return 0;
}
-EXPORT_SYMBOL(alloc_bucket_spinlocks);
+EXPORT_SYMBOL(__alloc_bucket_spinlocks);
void free_bucket_spinlocks(spinlock_t *locks)
{
--
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