diff options
| author | Hou Tao <houtao1@huawei.com> | 2025-01-08 04:07:21 +0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2025-01-09 05:06:36 +0300 |
| commit | 090d7f2e640b265335ac0a5a8e09a99f7f28f567 (patch) | |
| tree | f62ffd39e42e0fdb9a6026667751d81f33aac2e8 /kernel/bpf | |
| parent | dfccfc47bde53f5df5bf42486d12a8a2ecdcea60 (diff) | |
| download | linux-090d7f2e640b265335ac0a5a8e09a99f7f28f567.tar.xz | |
bpf: Disable migration in bpf_selem_free_rcu
bpf_selem_free_rcu() calls bpf_obj_free_fields() to free the special
fields in map value (e.g., kptr). Since kptrs may be allocated from bpf
memory allocator, migrate_{disable|enable} pairs are necessary for the
freeing of these kptrs.
To simplify reasoning about when migrate_disable() is needed for the
freeing of these dynamically-allocated kptrs, let the caller to
guarantee migration is disabled before invoking bpf_obj_free_fields().
Therefore, the patch adds migrate_{disable|enable} pair in
bpf_selem_free_rcu(). The migrate_{disable|enable} pairs in the
underlying implementation of bpf_obj_free_fields() will be removed by
the following patch.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20250108010728.207536-10-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel/bpf')
| -rw-r--r-- | kernel/bpf/bpf_local_storage.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/bpf/bpf_local_storage.c b/kernel/bpf/bpf_local_storage.c index e94820f6b0cd..615a3034baeb 100644 --- a/kernel/bpf/bpf_local_storage.c +++ b/kernel/bpf/bpf_local_storage.c @@ -217,7 +217,10 @@ static void bpf_selem_free_rcu(struct rcu_head *rcu) selem = container_of(rcu, struct bpf_local_storage_elem, rcu); /* The bpf_local_storage_map_free will wait for rcu_barrier */ smap = rcu_dereference_check(SDATA(selem)->smap, 1); + + migrate_disable(); bpf_obj_free_fields(smap->map.record, SDATA(selem)->data); + migrate_enable(); bpf_mem_cache_raw_free(selem); } |