Enable context analysis for rhashtable, which was used as an initial test as it contains a combination of RCU, mutex, and bit_spinlock usage.
Users of rhashtable now also benefit from annotations on the API, which will now warn if the RCU read lock is not held where required. Signed-off-by: Marco Elver <[email protected]> Cc: Thomas Graf <[email protected]> Cc: Herbert Xu <[email protected]> Cc: [email protected] --- v5: * Fix annotations for recently modified/added functions. v4: * Rename capability -> context analysis. v2: * Remove disable/enable_context_analysis() around headers. --- include/linux/rhashtable.h | 16 +++++++++++++--- lib/Makefile | 2 ++ lib/rhashtable.c | 5 +++-- 3 files changed, 18 insertions(+), 5 deletions(-) diff --git a/include/linux/rhashtable.h b/include/linux/rhashtable.h index 08e664b21f5a..133ccb39137a 100644 --- a/include/linux/rhashtable.h +++ b/include/linux/rhashtable.h @@ -245,16 +245,17 @@ void *rhashtable_insert_slow(struct rhashtable *ht, const void *key, void rhashtable_walk_enter(struct rhashtable *ht, struct rhashtable_iter *iter); void rhashtable_walk_exit(struct rhashtable_iter *iter); -int rhashtable_walk_start_check(struct rhashtable_iter *iter) __acquires(RCU); +int rhashtable_walk_start_check(struct rhashtable_iter *iter) __acquires_shared(RCU); static inline void rhashtable_walk_start(struct rhashtable_iter *iter) + __acquires_shared(RCU) { (void)rhashtable_walk_start_check(iter); } void *rhashtable_walk_next(struct rhashtable_iter *iter); void *rhashtable_walk_peek(struct rhashtable_iter *iter); -void rhashtable_walk_stop(struct rhashtable_iter *iter) __releases(RCU); +void rhashtable_walk_stop(struct rhashtable_iter *iter) __releases_shared(RCU); void rhashtable_free_and_destroy(struct rhashtable *ht, void (*free_fn)(void *ptr, void *arg), @@ -325,6 +326,7 @@ static inline struct rhash_lock_head __rcu **rht_bucket_insert( static inline unsigned long rht_lock(struct bucket_table *tbl, struct rhash_lock_head __rcu **bkt) + __acquires(__bitlock(0, bkt)) { unsigned long flags; @@ -337,6 +339,7 @@ static inline unsigned long rht_lock(struct bucket_table *tbl, static inline unsigned long rht_lock_nested(struct bucket_table *tbl, struct rhash_lock_head __rcu **bucket, unsigned int subclass) + __acquires(__bitlock(0, bucket)) { unsigned long flags; @@ -349,6 +352,7 @@ static inline unsigned long rht_lock_nested(struct bucket_table *tbl, static inline void rht_unlock(struct bucket_table *tbl, struct rhash_lock_head __rcu **bkt, unsigned long flags) + __releases(__bitlock(0, bkt)) { lock_map_release(&tbl->dep_map); bit_spin_unlock(0, (unsigned long *)bkt); @@ -424,13 +428,14 @@ static inline void rht_assign_unlock(struct bucket_table *tbl, struct rhash_lock_head __rcu **bkt, struct rhash_head *obj, unsigned long flags) + __releases(__bitlock(0, bkt)) { if (rht_is_a_nulls(obj)) obj = NULL; lock_map_release(&tbl->dep_map); rcu_assign_pointer(*bkt, (void *)obj); preempt_enable(); - __release(bitlock); + __release(__bitlock(0, bkt)); local_irq_restore(flags); } @@ -612,6 +617,7 @@ static __always_inline struct rhash_head *__rhashtable_lookup( struct rhashtable *ht, const void *key, const struct rhashtable_params params, const enum rht_lookup_freq freq) + __must_hold_shared(RCU) { struct rhashtable_compare_arg arg = { .ht = ht, @@ -666,6 +672,7 @@ static __always_inline struct rhash_head *__rhashtable_lookup( static __always_inline void *rhashtable_lookup( struct rhashtable *ht, const void *key, const struct rhashtable_params params) + __must_hold_shared(RCU) { struct rhash_head *he = __rhashtable_lookup(ht, key, params, RHT_LOOKUP_NORMAL); @@ -676,6 +683,7 @@ static __always_inline void *rhashtable_lookup( static __always_inline void *rhashtable_lookup_likely( struct rhashtable *ht, const void *key, const struct rhashtable_params params) + __must_hold_shared(RCU) { struct rhash_head *he = __rhashtable_lookup(ht, key, params, RHT_LOOKUP_LIKELY); @@ -727,6 +735,7 @@ static __always_inline void *rhashtable_lookup_fast( static __always_inline struct rhlist_head *rhltable_lookup( struct rhltable *hlt, const void *key, const struct rhashtable_params params) + __must_hold_shared(RCU) { struct rhash_head *he = __rhashtable_lookup(&hlt->ht, key, params, RHT_LOOKUP_NORMAL); @@ -737,6 +746,7 @@ static __always_inline struct rhlist_head *rhltable_lookup( static __always_inline struct rhlist_head *rhltable_lookup_likely( struct rhltable *hlt, const void *key, const struct rhashtable_params params) + __must_hold_shared(RCU) { struct rhash_head *he = __rhashtable_lookup(&hlt->ht, key, params, RHT_LOOKUP_LIKELY); diff --git a/lib/Makefile b/lib/Makefile index e755eee4e76f..22d8742bba57 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -50,6 +50,8 @@ lib-$(CONFIG_MIN_HEAP) += min_heap.o lib-y += kobject.o klist.o obj-y += lockref.o +CONTEXT_ANALYSIS_rhashtable.o := y + obj-y += bcd.o sort.o parser.o debug_locks.o random32.o \ bust_spinlocks.o kasprintf.o bitmap.o scatterlist.o \ list_sort.o uuid.o iov_iter.o clz_ctz.o \ diff --git a/lib/rhashtable.c b/lib/rhashtable.c index fde0f0e556f8..6074ed5f66f3 100644 --- a/lib/rhashtable.c +++ b/lib/rhashtable.c @@ -358,6 +358,7 @@ static int rhashtable_rehash_table(struct rhashtable *ht) static int rhashtable_rehash_alloc(struct rhashtable *ht, struct bucket_table *old_tbl, unsigned int size) + __must_hold(&ht->mutex) { struct bucket_table *new_tbl; int err; @@ -392,6 +393,7 @@ static int rhashtable_rehash_alloc(struct rhashtable *ht, * bucket locks or concurrent RCU protected lookups and traversals. */ static int rhashtable_shrink(struct rhashtable *ht) + __must_hold(&ht->mutex) { struct bucket_table *old_tbl = rht_dereference(ht->tbl, ht); unsigned int nelems = atomic_read(&ht->nelems); @@ -724,7 +726,7 @@ EXPORT_SYMBOL_GPL(rhashtable_walk_exit); * resize events and always continue. */ int rhashtable_walk_start_check(struct rhashtable_iter *iter) - __acquires(RCU) + __acquires_shared(RCU) { struct rhashtable *ht = iter->ht; bool rhlist = ht->rhlist; @@ -940,7 +942,6 @@ EXPORT_SYMBOL_GPL(rhashtable_walk_peek); * hash table. */ void rhashtable_walk_stop(struct rhashtable_iter *iter) - __releases(RCU) { struct rhashtable *ht; struct bucket_table *tbl = iter->walker.tbl; -- 2.52.0.322.g1dd061c0dc-goog
