diff options
Diffstat (limited to 'lib/debugobjects.c')
| -rw-r--r-- | lib/debugobjects.c | 75 |
1 files changed, 65 insertions, 10 deletions
diff --git a/lib/debugobjects.c b/lib/debugobjects.c index 12f50de85b62..877f7675ba26 100644 --- a/lib/debugobjects.c +++ b/lib/debugobjects.c @@ -711,6 +711,50 @@ static struct debug_obj *lookup_object_or_alloc(void *addr, struct debug_bucket return NULL; } +static inline bool debug_objects_is_pi_blocked_on(void) +{ +#ifdef CONFIG_RT_MUTEXES + return current->pi_blocked_on != NULL; +#else + return false; +#endif +} + +static inline bool can_fill_pool(void) +{ + /* + * On !RT enabled kernels there are no restrictions and spinlock_t and + * raw_spinlock_t are the same types. + */ + if (!IS_ENABLED(CONFIG_PREEMPT_RT)) + return true; + + /* + * On RT enabled kernels, the task must not be blocked on a lock as + * that could corrupt the PI state when blocking on a lock in the + * allocation path. + */ + if (debug_objects_is_pi_blocked_on()) + return false; + + /* + * On RT enabled kernels the pool refill should happen in preemptible + * context. + */ + if (preemptible()) + return true; + + /* + * Though during system boot before scheduling is set up, preemption is + * disabled and the pool can get exhausted. Before scheduling is active + * a task cannot be blocked on a sleeping lock, but it might hold a lock + * and if interrupted then hard interrupt context might run into a lock + * inversion. So exclude hard interrupt context from allocations before + * scheduling is active. + */ + return system_state < SYSTEM_SCHEDULING && !in_hardirq(); +} + static void debug_objects_fill_pool(void) { if (!static_branch_likely(&obj_cache_enabled)) @@ -725,17 +769,11 @@ static void debug_objects_fill_pool(void) if (likely(!pool_should_refill(&pool_global))) return; - /* - * On RT enabled kernels the pool refill must happen in preemptible - * context -- for !RT kernels we rely on the fact that spinlock_t and - * raw_spinlock_t are basically the same type and this lock-type - * inversion works just fine. - */ - if (!IS_ENABLED(CONFIG_PREEMPT_RT) || preemptible() || system_state < SYSTEM_SCHEDULING) { + if (can_fill_pool()) { /* * Annotate away the spinlock_t inside raw_spinlock_t warning * by temporarily raising the wait-type to LD_WAIT_CONFIG, matching - * the preemptible() condition above. + * the preemptible() condition in can_fill_pool(). */ static DEFINE_WAIT_OVERRIDE_MAP(fill_pool_map, LD_WAIT_CONFIG); lock_map_acquire_try(&fill_pool_map); @@ -856,6 +894,14 @@ int debug_object_activate(void *addr, const struct debug_obj_descr *descr) } raw_spin_unlock_irqrestore(&db->lock, flags); + + /* + * lookup_object_or_alloc() might have raced with a concurrent + * allocation failure which disabled debug objects. + */ + if (!debug_objects_enabled) + return 0; + debug_print_object(&o, "activate"); switch (o.state) { @@ -1024,7 +1070,7 @@ void debug_object_assert_init(void *addr, const struct debug_obj_descr *descr) raw_spin_lock_irqsave(&db->lock, flags); obj = lookup_object_or_alloc(addr, db, descr, false, true); raw_spin_unlock_irqrestore(&db->lock, flags); - if (likely(!IS_ERR_OR_NULL(obj))) + if (!IS_ERR_OR_NULL(obj)) return; /* If NULL the allocation has hit OOM */ @@ -1033,6 +1079,15 @@ void debug_object_assert_init(void *addr, const struct debug_obj_descr *descr) return; } + /* + * lookup_object_or_alloc() might have raced with a concurrent + * allocation failure which disabled debug objects. Don't run the fixup + * as it might turn a valid object useless. See for example + * hrtimer_fixup_assert_init(). + */ + if (!debug_objects_enabled) + return; + /* Object is neither tracked nor static. It's not initialized. */ debug_print_object(&o, "assert_init"); debug_object_fixup(descr->fixup_assert_init, addr, ODEBUG_STATE_NOTAVAILABLE); @@ -1212,7 +1267,7 @@ struct self_test { static __initconst const struct debug_obj_descr descr_type_test; -static bool __init is_static_object(void *addr) +static __noipa bool __init is_static_object(void *addr) { struct self_test *obj = addr; |