Introduce BPF_F_ALL_CPUS flag support for percpu_cgroup_storage maps to allow updating values for all CPUs with a single value for update_elem API.
Introduce BPF_F_CPU flag support for percpu_cgroup_storage maps to allow:
* update value for specified CPU for update_elem API. * lookup value for specified CPU for lookup_elem API.
The BPF_F_CPU flag is passed via map_flags along with embedded cpu info.
Signed-off-by: Leon Hwang leon.hwang@linux.dev --- include/linux/bpf-cgroup.h | 4 ++-- include/linux/bpf.h | 1 + kernel/bpf/local_storage.c | 23 ++++++++++++++++++----- kernel/bpf/syscall.c | 2 +- 4 files changed, 22 insertions(+), 8 deletions(-)
diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h index aedf573bdb42..013f4db9903f 100644 --- a/include/linux/bpf-cgroup.h +++ b/include/linux/bpf-cgroup.h @@ -172,7 +172,7 @@ void bpf_cgroup_storage_link(struct bpf_cgroup_storage *storage, void bpf_cgroup_storage_unlink(struct bpf_cgroup_storage *storage); int bpf_cgroup_storage_assign(struct bpf_prog_aux *aux, struct bpf_map *map);
-int bpf_percpu_cgroup_storage_copy(struct bpf_map *map, void *key, void *value); +int bpf_percpu_cgroup_storage_copy(struct bpf_map *map, void *key, void *value, u64 flags); int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, void *value, u64 flags);
@@ -467,7 +467,7 @@ static inline struct bpf_cgroup_storage *bpf_cgroup_storage_alloc( static inline void bpf_cgroup_storage_free( struct bpf_cgroup_storage *storage) {} static inline int bpf_percpu_cgroup_storage_copy(struct bpf_map *map, void *key, - void *value) { + void *value, u64 flags) { return 0; } static inline int bpf_percpu_cgroup_storage_update(struct bpf_map *map, diff --git a/include/linux/bpf.h b/include/linux/bpf.h index f79d2ae27335..9e756db5e132 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -3835,6 +3835,7 @@ static inline bool bpf_map_supports_cpu_flags(enum bpf_map_type map_type) case BPF_MAP_TYPE_PERCPU_ARRAY: case BPF_MAP_TYPE_PERCPU_HASH: case BPF_MAP_TYPE_LRU_PERCPU_HASH: + case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE: return true; default: return false; diff --git a/kernel/bpf/local_storage.c b/kernel/bpf/local_storage.c index 2ab4b60ffe61..1ccbf28b2ad9 100644 --- a/kernel/bpf/local_storage.c +++ b/kernel/bpf/local_storage.c @@ -180,7 +180,7 @@ static long cgroup_storage_update_elem(struct bpf_map *map, void *key, }
int bpf_percpu_cgroup_storage_copy(struct bpf_map *_map, void *key, - void *value) + void *value, u64 map_flags) { struct bpf_cgroup_storage_map *map = map_to_storage(_map); struct bpf_cgroup_storage *storage; @@ -198,11 +198,17 @@ int bpf_percpu_cgroup_storage_copy(struct bpf_map *_map, void *key, * access 'value_size' of them, so copying rounded areas * will not leak any kernel data */ + if (map_flags & BPF_F_CPU) { + cpu = map_flags >> 32; + copy_map_value(_map, value, per_cpu_ptr(storage->percpu_buf, cpu)); + goto unlock; + } size = round_up(_map->value_size, 8); for_each_possible_cpu(cpu) { copy_map_value_long(_map, value + off, per_cpu_ptr(storage->percpu_buf, cpu)); off += size; } +unlock: rcu_read_unlock(); return 0; } @@ -212,10 +218,11 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *_map, void *key, { struct bpf_cgroup_storage_map *map = map_to_storage(_map); struct bpf_cgroup_storage *storage; - int cpu, off = 0; + void *val; u32 size; + int cpu;
- if (map_flags != BPF_ANY && map_flags != BPF_EXIST) + if ((u32)map_flags & ~(BPF_ANY | BPF_EXIST | BPF_F_CPU | BPF_F_ALL_CPUS)) return -EINVAL;
rcu_read_lock(); @@ -231,11 +238,17 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *_map, void *key, * returned or zeros which were zero-filled by percpu_alloc, * so no kernel data leaks possible */ + if (map_flags & BPF_F_CPU) { + cpu = map_flags >> 32; + copy_map_value(_map, per_cpu_ptr(storage->percpu_buf, cpu), value); + goto unlock; + } size = round_up(_map->value_size, 8); for_each_possible_cpu(cpu) { - copy_map_value_long(_map, per_cpu_ptr(storage->percpu_buf, cpu), value + off); - off += size; + val = (map_flags & BPF_F_ALL_CPUS) ? value : value + size * cpu; + copy_map_value(_map, per_cpu_ptr(storage->percpu_buf, cpu), val); } +unlock: rcu_read_unlock(); return 0; } diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 94ac63b1115f..d8c2336124b6 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -320,7 +320,7 @@ static int bpf_map_copy_value(struct bpf_map *map, void *key, void *value, } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { 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); + err = bpf_percpu_cgroup_storage_copy(map, key, value, flags); } else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) { err = bpf_stackmap_extract(map, key, value, false); } else if (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map)) {