bpf: Support kptrs in percpu arraymap

Enable support for kptrs in percpu BPF arraymap by wiring up the freeing
of these kptrs from percpu map elements.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20220904204145.3089-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
index 6245274..832b265 100644 (file)
--- a/kernel/bpf/arraymap.c
+++ b/kernel/bpf/arraymap.c
@@ -279,7 +279,8 @@ int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value)
        rcu_read_lock();
        pptr = array->pptrs[index & array->index_mask];
        for_each_possible_cpu(cpu) {
-               bpf_long_memcpy(value + off, per_cpu_ptr(pptr, cpu), size);
+               copy_map_value_long(map, value + off, per_cpu_ptr(pptr, cpu));
+               check_and_init_map_value(map, value + off);
                off += size;
        }
        rcu_read_unlock();
@@ -338,8 +339,9 @@ static int array_map_update_elem(struct bpf_map *map, void *key, void *value,
                return -EINVAL;
 
        if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
-               memcpy(this_cpu_ptr(array->pptrs[index & array->index_mask]),
-                      value, map->value_size);
+               val = this_cpu_ptr(array->pptrs[index & array->index_mask]);
+               copy_map_value(map, val, value);
+               check_and_free_fields(array, val);
        } else {
                val = array->value +
                        (u64)array->elem_size * (index & array->index_mask);
@@ -383,7 +385,8 @@ int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value,
        rcu_read_lock();
        pptr = array->pptrs[index & array->index_mask];
        for_each_possible_cpu(cpu) {
-               bpf_long_memcpy(per_cpu_ptr(pptr, cpu), value + off, size);
+               copy_map_value_long(map, per_cpu_ptr(pptr, cpu), value + off);
+               check_and_free_fields(array, per_cpu_ptr(pptr, cpu));
                off += size;
        }
        rcu_read_unlock();
@@ -421,8 +424,20 @@ static void array_map_free(struct bpf_map *map)
        int i;
 
        if (map_value_has_kptrs(map)) {
-               for (i = 0; i < array->map.max_entries; i++)
-                       bpf_map_free_kptrs(map, array_map_elem_ptr(array, i));
+               if (array->map.map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
+                       for (i = 0; i < array->map.max_entries; i++) {
+                               void __percpu *pptr = array->pptrs[i & array->index_mask];
+                               int cpu;
+
+                               for_each_possible_cpu(cpu) {
+                                       bpf_map_free_kptrs(map, per_cpu_ptr(pptr, cpu));
+                                       cond_resched();
+                               }
+                       }
+               } else {
+                       for (i = 0; i < array->map.max_entries; i++)
+                               bpf_map_free_kptrs(map, array_map_elem_ptr(array, i));
+               }
                bpf_map_free_kptr_off_tab(map);
        }
 
@@ -608,9 +623,9 @@ static int __bpf_array_map_seq_show(struct seq_file *seq, void *v)
                        pptr = v;
                        size = array->elem_size;
                        for_each_possible_cpu(cpu) {
-                               bpf_long_memcpy(info->percpu_value_buf + off,
-                                               per_cpu_ptr(pptr, cpu),
-                                               size);
+                               copy_map_value_long(map, info->percpu_value_buf + off,
+                                                   per_cpu_ptr(pptr, cpu));
+                               check_and_init_map_value(map, info->percpu_value_buf + off);
                                off += size;
                        }
                        ctx.value = info->percpu_value_buf;

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index d35a6aa..69be1c6 100644 (file)
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1049,7 +1049,8 @@ static int map_check_btf(struct bpf_map *map, const struct btf *btf,
                }
                if (map->map_type != BPF_MAP_TYPE_HASH &&
                    map->map_type != BPF_MAP_TYPE_LRU_HASH &&
-                   map->map_type != BPF_MAP_TYPE_ARRAY) {
+                   map->map_type != BPF_MAP_TYPE_ARRAY &&
+                   map->map_type != BPF_MAP_TYPE_PERCPU_ARRAY) {
                        ret = -EOPNOTSUPP;
                        goto free_map_tab;
                }