diff options
| author | Pei Xiao <xiaopei01@kylinos.cn> | 2024-12-30 15:16:55 +0800 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2024-12-30 20:12:21 -0800 |
| commit | dfa94ce54f4139c893b9c4ec17df6f7c6a7515d3 (patch) | |
| tree | 3fb221e3bfd77169e5af86a4af19775ad2c4deaa | |
| parent | 654a3381e3b4df5ab1b87e21b5d9ffd979362cd1 (diff) | |
bpf: Use refcount_t instead of atomic_t for mmap_count
Use an API that resembles more the actual use of mmap_count.
Found by cocci:
kernel/bpf/arena.c:245:6-25: WARNING: atomic_dec_and_test variation before object free at line 249.
Fixes: b90d77e5fd78 ("bpf: Fix remap of arena.")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202412292037.LXlYSHKl-lkp@intel.com/
Signed-off-by: Pei Xiao <xiaopei01@kylinos.cn>
Link: https://lore.kernel.org/r/6ecce439a6bc81adb85d5080908ea8959b792a50.1735542814.git.xiaopei01@kylinos.cn
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| -rw-r--r-- | kernel/bpf/arena.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/kernel/bpf/arena.c b/kernel/bpf/arena.c index f5f6b00a982e..41a76ca56040 100644 --- a/kernel/bpf/arena.c +++ b/kernel/bpf/arena.c @@ -218,7 +218,7 @@ 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; + refcount_t mmap_count; }; static int remember_vma(struct bpf_arena *arena, struct vm_area_struct *vma) @@ -228,7 +228,7 @@ 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); + refcount_set(&vml->mmap_count, 1); vma->vm_private_data = vml; vml->vma = vma; list_add(&vml->head, &arena->vma_list); @@ -239,7 +239,7 @@ static void arena_vm_open(struct vm_area_struct *vma) { struct vma_list *vml = vma->vm_private_data; - atomic_inc(&vml->mmap_count); + refcount_inc(&vml->mmap_count); } static void arena_vm_close(struct vm_area_struct *vma) @@ -248,7 +248,7 @@ static void arena_vm_close(struct vm_area_struct *vma) struct bpf_arena *arena = container_of(map, struct bpf_arena, map); struct vma_list *vml = vma->vm_private_data; - if (!atomic_dec_and_test(&vml->mmap_count)) + if (!refcount_dec_and_test(&vml->mmap_count)) return; guard(mutex)(&arena->lock); /* update link list under lock */ |