From: Hou Tao <houtao1@xxxxxxxxxx>
Disabling migration before calling ops->map_free() to simplify the
freeing of map values or special fields allocated from bpf memory
allocator.
After disabling migration in bpf_map_free(), there is no need for
additional migration_{disable|enable} pairs in the ->map_free()
callbacks. Remove these redundant invocations.
Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx>
---
kernel/bpf/arraymap.c | 2 --
kernel/bpf/bpf_local_storage.c | 2 --
kernel/bpf/hashtab.c | 2 --
kernel/bpf/range_tree.c | 2 --
kernel/bpf/syscall.c | 8 +++++++-
5 files changed, 7 insertions(+), 9 deletions(-)
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
index 451737493b17..eb28c0f219ee 100644
--- a/kernel/bpf/arraymap.c
+++ b/kernel/bpf/arraymap.c
@@ -455,7 +455,6 @@ static void array_map_free(struct bpf_map *map)
struct bpf_array *array = container_of(map, struct bpf_array, map);
int i;
- migrate_disable();
if (!IS_ERR_OR_NULL(map->record)) {
if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
for (i = 0; i < array->map.max_entries; i++) {
@@ -472,7 +471,6 @@ static void array_map_free(struct bpf_map *map)
bpf_obj_free_fields(map->record, array_map_elem_ptr(array, i));
}
}
- migrate_enable();
if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
bpf_array_free_percpu(array);
diff --git a/kernel/bpf/bpf_local_storage.c b/kernel/bpf/bpf_local_storage.c
index b649cf736438..12cf6382175e 100644
--- a/kernel/bpf/bpf_local_storage.c
+++ b/kernel/bpf/bpf_local_storage.c
@@ -905,13 +905,11 @@ void bpf_local_storage_map_free(struct bpf_map *map,
while ((selem = hlist_entry_safe(
rcu_dereference_raw(hlist_first_rcu(&b->list)),
struct bpf_local_storage_elem, map_node))) {
- migrate_disable();
if (busy_counter)
this_cpu_inc(*busy_counter);
bpf_selem_unlink(selem, true);
if (busy_counter)
this_cpu_dec(*busy_counter);
- migrate_enable();
cond_resched_rcu();
}
rcu_read_unlock();
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index 8bf1ad326e02..6051f8a39fec 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -1570,14 +1570,12 @@ static void htab_map_free(struct bpf_map *map)
* underneath and is responsible for waiting for callbacks to finish
* during bpf_mem_alloc_destroy().
*/
- migrate_disable();
if (!htab_is_prealloc(htab)) {
delete_all_elements(htab);
} else {
htab_free_prealloced_fields(htab);
prealloc_destroy(htab);
}
- migrate_enable();
bpf_map_free_elem_count(map);
free_percpu(htab->extra_elems);
diff --git a/kernel/bpf/range_tree.c b/kernel/bpf/range_tree.c
index 5bdf9aadca3a..37b80a23ae1a 100644
--- a/kernel/bpf/range_tree.c
+++ b/kernel/bpf/range_tree.c
@@ -259,9 +259,7 @@ void range_tree_destroy(struct range_tree *rt)
while ((rn = range_it_iter_first(rt, 0, -1U))) {
range_it_remove(rn, rt);
- migrate_disable();
bpf_mem_free(&bpf_global_ma, rn);
- migrate_enable();
}
}
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 0503ce1916b6..e7a41abe4809 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -835,8 +835,14 @@ static void bpf_map_free(struct bpf_map *map)
struct btf_record *rec = map->record;
struct btf *btf = map->btf;
- /* implementation dependent freeing */
+ /* implementation dependent freeing. Disabling migration to simplify
+ * the free of values or special fields allocated from bpf memory
+ * allocator.
+ */
+ migrate_disable();
map->ops->map_free(map);
+ migrate_enable();
+
/* Delay freeing of btf_record for maps, as map_free
* callback usually needs access to them. It is better to do it here
* than require each callback to do the free itself manually.
--
2.29.2
