diff options
Diffstat (limited to 'kernel/bpf/memalloc.c')
| -rw-r--r-- | kernel/bpf/memalloc.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/kernel/bpf/memalloc.c b/kernel/bpf/memalloc.c index c5d822d7cfaa..961df89d45f1 100644 --- a/kernel/bpf/memalloc.c +++ b/kernel/bpf/memalloc.c @@ -778,11 +778,16 @@ static void notrace unit_free(struct bpf_mem_cache *c, void *ptr) llist_add(llnode, &c->free_llist_extra); } local_dec(&c->active); - local_irq_restore(flags); if (cnt > c->high_watermark) /* free few objects from current cpu into global kmalloc pool */ irq_work_raise(c); + /* Enable IRQ after irq_work_raise() completes, otherwise when current + * task is preempted by task which does unit_alloc(), unit_alloc() may + * return NULL unexpectedly because irq work is already pending but can + * not been triggered and free_llist can not be refilled timely. + */ + local_irq_restore(flags); } static void notrace unit_free_rcu(struct bpf_mem_cache *c, void *ptr) @@ -800,10 +805,10 @@ static void notrace unit_free_rcu(struct bpf_mem_cache *c, void *ptr) llist_add(llnode, &c->free_llist_extra_rcu); } local_dec(&c->active); - local_irq_restore(flags); if (!atomic_read(&c->call_rcu_in_progress)) irq_work_raise(c); + local_irq_restore(flags); } /* Called from BPF program or from sys_bpf syscall. |