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rhashtable: Restore RCU marking on rhash_lock_head

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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>
This commit is contained in:
Herbert Xu 2020-07-24 20:14:34 +10:00 committed by David S. Miller
parent 1748f6a2cb
commit ce9b362bf6
2 changed files with 40 additions and 51 deletions
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56
include/linux/rhashtable.h
View File

@ -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 rhashtable *ht,
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_nested_insert(struct rhashtable *ht,
#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 **rht_bucket_insert(
*/
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 bucket_table *tbl,
}
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(struct bucket_table *tbl,
}
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_ptr(
* 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 *__rhashtable_lookup(
.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_fast(
.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_fast_one(
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_fast(
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;

35
lib/rhashtable.c
View File

@ -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,
@ -222,7 +222,7 @@ static struct bucket_table *rhashtable_last_table(struct rhashtable *ht,
}
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);
@ -275,7 +275,7 @@ static int rhashtable_rehash_chain(struct rhashtable *ht,
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)
@ -485,7 +485,7 @@ static int rhashtable_insert_rehash(struct rhashtable *ht,
}
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)
{
@ -535,12 +535,10 @@ static void *rhashtable_lookup_one(struct rhashtable *ht,
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;
@ -591,7 +589,7 @@ static void *rhashtable_try_insert(struct rhashtable *ht, const void *key,
{
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;
@ -1173,8 +1171,8 @@ void rhashtable_destroy(struct rhashtable *ht)
}
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);
@ -1202,10 +1200,10 @@ struct rhash_lock_head **__rht_bucket_nested(const struct bucket_table *tbl,
}
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);
@ -1213,9 +1211,8 @@ struct rhash_lock_head **rht_bucket_nested(const struct bucket_table *tbl,
}
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);