diff options
Diffstat (limited to 'kernel/bpf/arena.c')
| -rw-r--r-- | kernel/bpf/arena.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/kernel/bpf/arena.c b/kernel/bpf/arena.c index 343c3456c8..a59ae9c582 100644 --- a/kernel/bpf/arena.c +++ b/kernel/bpf/arena.c @@ -212,6 +212,7 @@ static u64 arena_map_mem_usage(const struct bpf_map *map) struct vma_list { struct vm_area_struct *vma; struct list_head head; + atomic_t mmap_count; }; static int remember_vma(struct bpf_arena *arena, struct vm_area_struct *vma) @@ -221,20 +222,30 @@ static int remember_vma(struct bpf_arena *arena, struct vm_area_struct *vma) vml = kmalloc(sizeof(*vml), GFP_KERNEL); if (!vml) return -ENOMEM; + atomic_set(&vml->mmap_count, 1); vma->vm_private_data = vml; vml->vma = vma; list_add(&vml->head, &arena->vma_list); return 0; } +static void arena_vm_open(struct vm_area_struct *vma) +{ + struct vma_list *vml = vma->vm_private_data; + + atomic_inc(&vml->mmap_count); +} + static void arena_vm_close(struct vm_area_struct *vma) { struct bpf_map *map = vma->vm_file->private_data; struct bpf_arena *arena = container_of(map, struct bpf_arena, map); - struct vma_list *vml; + struct vma_list *vml = vma->vm_private_data; + if (!atomic_dec_and_test(&vml->mmap_count)) + return; guard(mutex)(&arena->lock); - vml = vma->vm_private_data; + /* update link list under lock */ list_del(&vml->head); vma->vm_private_data = NULL; kfree(vml); @@ -287,6 +298,7 @@ out: } static const struct vm_operations_struct arena_vm_ops = { + .open = arena_vm_open, .close = arena_vm_close, .fault = arena_vm_fault, }; |