Introduce support for the BPF_F_ALL_CPUS flag in percpu_array maps to
allow updating values for all CPUs with a single value for both
update_elem and update_batch APIs.
Introduce support for the BPF_F_CPU flag in percpu_array maps to allow:
* update value for specified CPU for both update_elem and update_batch
APIs.
* lookup value for specified CPU for both lookup_elem and lookup_batch
APIs.
The BPF_F_CPU flag is passed via:
* map_flags of lookup_elem and update_elem APIs along with embedded cpu
info.
* elem_flags of lookup_batch and update_batch APIs along with embedded
cpu info.
Signed-off-by: Leon Hwang <leon.hwang@xxxxxxxxx>
---
include/linux/bpf.h | 10 ++++++++--
kernel/bpf/arraymap.c | 28 ++++++++++++----------------
kernel/bpf/syscall.c | 2 +-
3 files changed, 21 insertions(+), 19 deletions(-)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index a83364949b64c..bc44b72129e59 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -2746,7 +2746,8 @@ int map_set_for_each_callback_args(struct bpf_verifier_env *env,
struct bpf_func_state *callee);
int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value);
-int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value);
+int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value,
+ u64 flags);
int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value,
u64 flags);
int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value,
@@ -3760,7 +3761,12 @@ struct bpf_prog *bpf_prog_find_from_stack(void);
static inline bool bpf_map_supports_cpu_flags(enum bpf_map_type map_type)
{
- return false;
+ switch (map_type) {
+ case BPF_MAP_TYPE_PERCPU_ARRAY:
+ return true;
+ default:
+ return false;
+ }
}
static inline int bpf_map_check_op_flags(struct bpf_map *map, u64 flags, u64 extra_flags_mask)
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
index 3d080916faf97..42a75fbc588a1 100644
--- a/kernel/bpf/arraymap.c
+++ b/kernel/bpf/arraymap.c
@@ -295,17 +295,21 @@ static void *percpu_array_map_lookup_percpu_elem(struct bpf_map *map, void *key,
return per_cpu_ptr(array->pptrs[index & array->index_mask], cpu);
}
-int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value)
+int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value, u64 flags)
{
struct bpf_array *array = container_of(map, struct bpf_array, map);
u32 index = *(u32 *)key;
void __percpu *pptr;
- int cpu, off = 0;
u32 size;
+ int err;
if (unlikely(index >= array->map.max_entries))
return -ENOENT;
+ err = bpf_map_check_cpu_flags(flags, false);
+ if (unlikely(err))
+ return err;
+
/* per_cpu areas are zero-filled and bpf programs can only
* access 'value_size' of them, so copying rounded areas
* will not leak any kernel data
@@ -313,11 +317,7 @@ int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value)
size = array->elem_size;
rcu_read_lock();
pptr = array->pptrs[index & array->index_mask];
- for_each_possible_cpu(cpu) {
- copy_map_value_long(map, value + off, per_cpu_ptr(pptr, cpu));
- check_and_init_map_value(map, value + off);
- off += size;
- }
+ bpf_percpu_copy_to_user(map, pptr, value, size, flags);
rcu_read_unlock();
return 0;
}
@@ -387,12 +387,12 @@ int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value,
struct bpf_array *array = container_of(map, struct bpf_array, map);
u32 index = *(u32 *)key;
void __percpu *pptr;
- int cpu, off = 0;
u32 size;
+ int err;
- if (unlikely(map_flags > BPF_EXIST))
- /* unknown flags */
- return -EINVAL;
+ err = bpf_map_check_cpu_flags(map_flags, true);
+ if (unlikely(err))
+ return err;
if (unlikely(index >= array->map.max_entries))
/* all elements were pre-allocated, cannot insert a new one */
@@ -411,11 +411,7 @@ int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value,
size = array->elem_size;
rcu_read_lock();
pptr = array->pptrs[index & array->index_mask];
- for_each_possible_cpu(cpu) {
- copy_map_value_long(map, per_cpu_ptr(pptr, cpu), value + off);
- bpf_obj_free_fields(array->map.record, per_cpu_ptr(pptr, cpu));
- off += size;
- }
+ bpf_percpu_copy_from_user(map, pptr, value, size, map_flags);
rcu_read_unlock();
return 0;
}
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index dbd21484d7a4d..2ee2cf5a8cedf 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -316,7 +316,7 @@ static int bpf_map_copy_value(struct bpf_map *map, void *key, void *value,
map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
err = bpf_percpu_hash_copy(map, key, value);
} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
- err = bpf_percpu_array_copy(map, key, value);
+ err = bpf_percpu_array_copy(map, key, value, flags);
} else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
err = bpf_percpu_cgroup_storage_copy(map, key, value);
} else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
--
2.50.1
