From: Herbert Xu herbert@gondor.apana.org.au
[ Upstream commit ce9b362bf6db51a083c4221ef0f93c16cfb1facf ]
This patch restores the RCU marking on bucket_table->buckets as it really does need RCU protection. Its removal had led to a fatal bug.
Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- include/linux/rhashtable.h | 56 +++++++++++++++++++-------------------------- lib/rhashtable.c | 35 ++++++++++++---------------- 2 files changed, 40 insertions(+), 51 deletions(-)
--- a/include/linux/rhashtable.h +++ b/include/linux/rhashtable.h @@ -84,7 +84,7 @@ struct bucket_table {
struct lockdep_map dep_map;
- struct rhash_lock_head *buckets[] ____cacheline_aligned_in_smp; + struct rhash_lock_head __rcu *buckets[] ____cacheline_aligned_in_smp; };
/* @@ -261,13 +261,12 @@ void rhashtable_free_and_destroy(struct void *arg); void rhashtable_destroy(struct rhashtable *ht);
-struct rhash_lock_head **rht_bucket_nested(const struct bucket_table *tbl, - unsigned int hash); -struct rhash_lock_head **__rht_bucket_nested(const struct bucket_table *tbl, - unsigned int hash); -struct rhash_lock_head **rht_bucket_nested_insert(struct rhashtable *ht, - struct bucket_table *tbl, - unsigned int hash); +struct rhash_lock_head __rcu **rht_bucket_nested( + const struct bucket_table *tbl, unsigned int hash); +struct rhash_lock_head __rcu **__rht_bucket_nested( + const struct bucket_table *tbl, unsigned int hash); +struct rhash_lock_head __rcu **rht_bucket_nested_insert( + struct rhashtable *ht, struct bucket_table *tbl, unsigned int hash);
#define rht_dereference(p, ht) \ rcu_dereference_protected(p, lockdep_rht_mutex_is_held(ht)) @@ -284,21 +283,21 @@ struct rhash_lock_head **rht_bucket_nest #define rht_entry(tpos, pos, member) \ ({ tpos = container_of(pos, typeof(*tpos), member); 1; })
-static inline struct rhash_lock_head *const *rht_bucket( +static inline struct rhash_lock_head __rcu *const *rht_bucket( const struct bucket_table *tbl, unsigned int hash) { return unlikely(tbl->nest) ? rht_bucket_nested(tbl, hash) : &tbl->buckets[hash]; }
-static inline struct rhash_lock_head **rht_bucket_var( +static inline struct rhash_lock_head __rcu **rht_bucket_var( struct bucket_table *tbl, unsigned int hash) { return unlikely(tbl->nest) ? __rht_bucket_nested(tbl, hash) : &tbl->buckets[hash]; }
-static inline struct rhash_lock_head **rht_bucket_insert( +static inline struct rhash_lock_head __rcu **rht_bucket_insert( struct rhashtable *ht, struct bucket_table *tbl, unsigned int hash) { return unlikely(tbl->nest) ? rht_bucket_nested_insert(ht, tbl, hash) : @@ -325,7 +324,7 @@ static inline struct rhash_lock_head **r */
static inline void rht_lock(struct bucket_table *tbl, - struct rhash_lock_head **bkt) + struct rhash_lock_head __rcu **bkt) { local_bh_disable(); bit_spin_lock(0, (unsigned long *)bkt); @@ -333,7 +332,7 @@ static inline void rht_lock(struct bucke }
static inline void rht_lock_nested(struct bucket_table *tbl, - struct rhash_lock_head **bucket, + struct rhash_lock_head __rcu **bucket, unsigned int subclass) { local_bh_disable(); @@ -342,7 +341,7 @@ static inline void rht_lock_nested(struc }
static inline void rht_unlock(struct bucket_table *tbl, - struct rhash_lock_head **bkt) + struct rhash_lock_head __rcu **bkt) { lock_map_release(&tbl->dep_map); bit_spin_unlock(0, (unsigned long *)bkt); @@ -365,48 +364,41 @@ static inline struct rhash_head *__rht_p * access is guaranteed, such as when destroying the table. */ static inline struct rhash_head *rht_ptr_rcu( - struct rhash_lock_head *const *p) + struct rhash_lock_head __rcu *const *bkt) { - struct rhash_lock_head __rcu *const *bkt = (void *)p; return __rht_ptr(rcu_dereference(*bkt), bkt); }
static inline struct rhash_head *rht_ptr( - struct rhash_lock_head *const *p, + struct rhash_lock_head __rcu *const *bkt, struct bucket_table *tbl, unsigned int hash) { - struct rhash_lock_head __rcu *const *bkt = (void *)p; return __rht_ptr(rht_dereference_bucket(*bkt, tbl, hash), bkt); }
static inline struct rhash_head *rht_ptr_exclusive( - struct rhash_lock_head *const *p) + struct rhash_lock_head __rcu *const *bkt) { - struct rhash_lock_head __rcu *const *bkt = (void *)p; return __rht_ptr(rcu_dereference_protected(*bkt, 1), bkt); }
-static inline void rht_assign_locked(struct rhash_lock_head **bkt, +static inline void rht_assign_locked(struct rhash_lock_head __rcu **bkt, struct rhash_head *obj) { - struct rhash_head __rcu **p = (struct rhash_head __rcu **)bkt; - if (rht_is_a_nulls(obj)) obj = NULL; - rcu_assign_pointer(*p, (void *)((unsigned long)obj | BIT(0))); + rcu_assign_pointer(*bkt, (void *)((unsigned long)obj | BIT(0))); }
static inline void rht_assign_unlock(struct bucket_table *tbl, - struct rhash_lock_head **bkt, + struct rhash_lock_head __rcu **bkt, struct rhash_head *obj) { - struct rhash_head __rcu **p = (struct rhash_head __rcu **)bkt; - if (rht_is_a_nulls(obj)) obj = NULL; lock_map_release(&tbl->dep_map); - rcu_assign_pointer(*p, obj); + rcu_assign_pointer(*bkt, (void *)obj); preempt_enable(); __release(bitlock); local_bh_enable(); @@ -594,7 +586,7 @@ static inline struct rhash_head *__rhash .ht = ht, .key = key, }; - struct rhash_lock_head *const *bkt; + struct rhash_lock_head __rcu *const *bkt; struct bucket_table *tbl; struct rhash_head *he; unsigned int hash; @@ -710,7 +702,7 @@ static inline void *__rhashtable_insert_ .ht = ht, .key = key, }; - struct rhash_lock_head **bkt; + struct rhash_lock_head __rcu **bkt; struct rhash_head __rcu **pprev; struct bucket_table *tbl; struct rhash_head *head; @@ -996,7 +988,7 @@ static inline int __rhashtable_remove_fa struct rhash_head *obj, const struct rhashtable_params params, bool rhlist) { - struct rhash_lock_head **bkt; + struct rhash_lock_head __rcu **bkt; struct rhash_head __rcu **pprev; struct rhash_head *he; unsigned int hash; @@ -1148,7 +1140,7 @@ static inline int __rhashtable_replace_f struct rhash_head *obj_old, struct rhash_head *obj_new, const struct rhashtable_params params) { - struct rhash_lock_head **bkt; + struct rhash_lock_head __rcu **bkt; struct rhash_head __rcu **pprev; struct rhash_head *he; unsigned int hash; --- a/lib/rhashtable.c +++ b/lib/rhashtable.c @@ -31,7 +31,7 @@
union nested_table { union nested_table __rcu *table; - struct rhash_lock_head *bucket; + struct rhash_lock_head __rcu *bucket; };
static u32 head_hashfn(struct rhashtable *ht, @@ -213,7 +213,7 @@ static struct bucket_table *rhashtable_l }
static int rhashtable_rehash_one(struct rhashtable *ht, - struct rhash_lock_head **bkt, + struct rhash_lock_head __rcu **bkt, unsigned int old_hash) { struct bucket_table *old_tbl = rht_dereference(ht->tbl, ht); @@ -266,7 +266,7 @@ static int rhashtable_rehash_chain(struc unsigned int old_hash) { struct bucket_table *old_tbl = rht_dereference(ht->tbl, ht); - struct rhash_lock_head **bkt = rht_bucket_var(old_tbl, old_hash); + struct rhash_lock_head __rcu **bkt = rht_bucket_var(old_tbl, old_hash); int err;
if (!bkt) @@ -476,7 +476,7 @@ fail: }
static void *rhashtable_lookup_one(struct rhashtable *ht, - struct rhash_lock_head **bkt, + struct rhash_lock_head __rcu **bkt, struct bucket_table *tbl, unsigned int hash, const void *key, struct rhash_head *obj) { @@ -526,12 +526,10 @@ static void *rhashtable_lookup_one(struc return ERR_PTR(-ENOENT); }
-static struct bucket_table *rhashtable_insert_one(struct rhashtable *ht, - struct rhash_lock_head **bkt, - struct bucket_table *tbl, - unsigned int hash, - struct rhash_head *obj, - void *data) +static struct bucket_table *rhashtable_insert_one( + struct rhashtable *ht, struct rhash_lock_head __rcu **bkt, + struct bucket_table *tbl, unsigned int hash, struct rhash_head *obj, + void *data) { struct bucket_table *new_tbl; struct rhash_head *head; @@ -582,7 +580,7 @@ static void *rhashtable_try_insert(struc { struct bucket_table *new_tbl; struct bucket_table *tbl; - struct rhash_lock_head **bkt; + struct rhash_lock_head __rcu **bkt; unsigned int hash; void *data;
@@ -1164,8 +1162,8 @@ void rhashtable_destroy(struct rhashtabl } EXPORT_SYMBOL_GPL(rhashtable_destroy);
-struct rhash_lock_head **__rht_bucket_nested(const struct bucket_table *tbl, - unsigned int hash) +struct rhash_lock_head __rcu **__rht_bucket_nested( + const struct bucket_table *tbl, unsigned int hash) { const unsigned int shift = PAGE_SHIFT - ilog2(sizeof(void *)); unsigned int index = hash & ((1 << tbl->nest) - 1); @@ -1193,10 +1191,10 @@ struct rhash_lock_head **__rht_bucket_ne } EXPORT_SYMBOL_GPL(__rht_bucket_nested);
-struct rhash_lock_head **rht_bucket_nested(const struct bucket_table *tbl, - unsigned int hash) +struct rhash_lock_head __rcu **rht_bucket_nested( + const struct bucket_table *tbl, unsigned int hash) { - static struct rhash_lock_head *rhnull; + static struct rhash_lock_head __rcu *rhnull;
if (!rhnull) INIT_RHT_NULLS_HEAD(rhnull); @@ -1204,9 +1202,8 @@ struct rhash_lock_head **rht_bucket_nest } EXPORT_SYMBOL_GPL(rht_bucket_nested);
-struct rhash_lock_head **rht_bucket_nested_insert(struct rhashtable *ht, - struct bucket_table *tbl, - unsigned int hash) +struct rhash_lock_head __rcu **rht_bucket_nested_insert( + struct rhashtable *ht, struct bucket_table *tbl, unsigned int hash) { const unsigned int shift = PAGE_SHIFT - ilog2(sizeof(void *)); unsigned int index = hash & ((1 << tbl->nest) - 1);