diff options
Diffstat (limited to 'mm/kasan/quarantine.c')
| -rw-r--r-- | mm/kasan/quarantine.c | 58 |
1 files changed, 17 insertions, 41 deletions
diff --git a/mm/kasan/quarantine.c b/mm/kasan/quarantine.c index 75585077eb6d..6958aa713c67 100644 --- a/mm/kasan/quarantine.c +++ b/mm/kasan/quarantine.c @@ -8,6 +8,8 @@ * Based on code by Dmitry Chernenkov. */ +#define pr_fmt(fmt) "kasan: " fmt + #include <linux/gfp.h> #include <linux/hash.h> #include <linux/kernel.h> @@ -99,7 +101,6 @@ static unsigned long quarantine_size; static DEFINE_RAW_SPINLOCK(quarantine_lock); DEFINE_STATIC_SRCU(remove_cache_srcu); -#ifdef CONFIG_PREEMPT_RT struct cpu_shrink_qlist { raw_spinlock_t lock; struct qlist_head qlist; @@ -108,7 +109,6 @@ struct cpu_shrink_qlist { static DEFINE_PER_CPU(struct cpu_shrink_qlist, shrink_qlist) = { .lock = __RAW_SPIN_LOCK_UNLOCKED(shrink_qlist.lock), }; -#endif /* Maximum size of the global queue. */ static unsigned long quarantine_max_size; @@ -143,11 +143,12 @@ static void *qlink_to_object(struct qlist_node *qlink, struct kmem_cache *cache) static void qlink_free(struct qlist_node *qlink, struct kmem_cache *cache) { void *object = qlink_to_object(qlink, cache); - struct kasan_free_meta *meta = kasan_get_free_meta(cache, object); - unsigned long flags; + struct kasan_free_meta *free_meta = kasan_get_free_meta(cache, object); - if (IS_ENABLED(CONFIG_SLAB)) - local_irq_save(flags); + /* + * Note: Keep per-object metadata to allow KASAN print stack traces for + * use-after-free-before-realloc bugs. + */ /* * If init_on_free is enabled and KASAN's free metadata is stored in @@ -157,18 +158,9 @@ static void qlink_free(struct qlist_node *qlink, struct kmem_cache *cache) */ if (slab_want_init_on_free(cache) && cache->kasan_info.free_meta_offset == 0) - memzero_explicit(meta, sizeof(*meta)); - - /* - * As the object now gets freed from the quarantine, assume that its - * free track is no longer valid. - */ - *(u8 *)kasan_mem_to_shadow(object) = KASAN_SLAB_FREE; + memzero_explicit(free_meta, sizeof(*free_meta)); ___cache_free(cache, object, _THIS_IP_); - - if (IS_ENABLED(CONFIG_SLAB)) - local_irq_restore(flags); } static void qlist_free_all(struct qlist_head *q, struct kmem_cache *cache) @@ -319,16 +311,6 @@ static void qlist_move_cache(struct qlist_head *from, } } -#ifndef CONFIG_PREEMPT_RT -static void __per_cpu_remove_cache(struct qlist_head *q, void *arg) -{ - struct kmem_cache *cache = arg; - struct qlist_head to_free = QLIST_INIT; - - qlist_move_cache(q, &to_free, cache); - qlist_free_all(&to_free, cache); -} -#else static void __per_cpu_remove_cache(struct qlist_head *q, void *arg) { struct kmem_cache *cache = arg; @@ -340,7 +322,6 @@ static void __per_cpu_remove_cache(struct qlist_head *q, void *arg) qlist_move_cache(q, &sq->qlist, cache); raw_spin_unlock_irqrestore(&sq->lock, flags); } -#endif static void per_cpu_remove_cache(void *arg) { @@ -362,6 +343,8 @@ void kasan_quarantine_remove_cache(struct kmem_cache *cache) { unsigned long flags, i; struct qlist_head to_free = QLIST_INIT; + int cpu; + struct cpu_shrink_qlist *sq; /* * Must be careful to not miss any objects that are being moved from @@ -372,20 +355,13 @@ void kasan_quarantine_remove_cache(struct kmem_cache *cache) */ on_each_cpu(per_cpu_remove_cache, cache, 1); -#ifdef CONFIG_PREEMPT_RT - { - int cpu; - struct cpu_shrink_qlist *sq; - - for_each_online_cpu(cpu) { - sq = per_cpu_ptr(&shrink_qlist, cpu); - raw_spin_lock_irqsave(&sq->lock, flags); - qlist_move_cache(&sq->qlist, &to_free, cache); - raw_spin_unlock_irqrestore(&sq->lock, flags); - } - qlist_free_all(&to_free, cache); + for_each_online_cpu(cpu) { + sq = per_cpu_ptr(&shrink_qlist, cpu); + raw_spin_lock_irqsave(&sq->lock, flags); + qlist_move_cache(&sq->qlist, &to_free, cache); + raw_spin_unlock_irqrestore(&sq->lock, flags); } -#endif + qlist_free_all(&to_free, cache); raw_spin_lock_irqsave(&quarantine_lock, flags); for (i = 0; i < QUARANTINE_BATCHES; i++) { @@ -432,7 +408,7 @@ static int __init kasan_cpu_quarantine_init(void) ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "mm/kasan:online", kasan_cpu_online, kasan_cpu_offline); if (ret < 0) - pr_err("kasan cpu quarantine register failed [%d]\n", ret); + pr_err("cpu quarantine register failed [%d]\n", ret); return ret; } late_initcall(kasan_cpu_quarantine_init); |