From aa2e93b8e58e18442edfb2427446732415bc215e Mon Sep 17 00:00:00 2001 From: Brian Vazquez Date: Wed, 15 Jan 2020 10:43:02 -0800 Subject: [PATCH] bpf: Add generic support for update and delete batch ops This commit adds generic support for update and delete batch ops that can be used for almost all the bpf maps. These commands share the same UAPI attr that lookup and lookup_and_delete batch ops use and the syscall commands are: BPF_MAP_UPDATE_BATCH BPF_MAP_DELETE_BATCH The main difference between update/delete and lookup batch ops is that for update/delete keys/values must be specified for userspace and because of that, neither in_batch nor out_batch are used. Suggested-by: Stanislav Fomichev Signed-off-by: Brian Vazquez Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200115184308.162644-4-brianvv@google.com --- include/linux/bpf.h | 10 ++++ include/uapi/linux/bpf.h | 2 + kernel/bpf/syscall.c | 115 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 127 insertions(+) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 807744ecaa5a1a..05466ad6cf1c5b 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -46,6 +46,10 @@ struct bpf_map_ops { void *(*map_lookup_elem_sys_only)(struct bpf_map *map, void *key); int (*map_lookup_batch)(struct bpf_map *map, const union bpf_attr *attr, union bpf_attr __user *uattr); + int (*map_update_batch)(struct bpf_map *map, const union bpf_attr *attr, + union bpf_attr __user *uattr); + int (*map_delete_batch)(struct bpf_map *map, const union bpf_attr *attr, + union bpf_attr __user *uattr); /* funcs callable from userspace and from eBPF programs */ void *(*map_lookup_elem)(struct bpf_map *map, void *key); @@ -987,6 +991,12 @@ void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr); int generic_map_lookup_batch(struct bpf_map *map, const union bpf_attr *attr, union bpf_attr __user *uattr); +int generic_map_update_batch(struct bpf_map *map, + const union bpf_attr *attr, + union bpf_attr __user *uattr); +int generic_map_delete_batch(struct bpf_map *map, + const union bpf_attr *attr, + union bpf_attr __user *uattr); extern int sysctl_unprivileged_bpf_disabled; diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 0721b2c6bb8c55..d5320b0be459af 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -108,6 +108,8 @@ enum bpf_cmd { BPF_MAP_FREEZE, BPF_BTF_GET_NEXT_ID, BPF_MAP_LOOKUP_BATCH, + BPF_MAP_UPDATE_BATCH, + BPF_MAP_DELETE_BATCH, }; enum bpf_map_type { diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index d604ddbb1afbe1..ce8244d1ba99c0 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1218,6 +1218,111 @@ static int map_get_next_key(union bpf_attr *attr) return err; } +int generic_map_delete_batch(struct bpf_map *map, + const union bpf_attr *attr, + union bpf_attr __user *uattr) +{ + void __user *keys = u64_to_user_ptr(attr->batch.keys); + u32 cp, max_count; + int err = 0; + void *key; + + if (attr->batch.elem_flags & ~BPF_F_LOCK) + return -EINVAL; + + if ((attr->batch.elem_flags & BPF_F_LOCK) && + !map_value_has_spin_lock(map)) { + return -EINVAL; + } + + max_count = attr->batch.count; + if (!max_count) + return 0; + + for (cp = 0; cp < max_count; cp++) { + key = __bpf_copy_key(keys + cp * map->key_size, map->key_size); + if (IS_ERR(key)) { + err = PTR_ERR(key); + break; + } + + if (bpf_map_is_dev_bound(map)) { + err = bpf_map_offload_delete_elem(map, key); + break; + } + + preempt_disable(); + __this_cpu_inc(bpf_prog_active); + rcu_read_lock(); + err = map->ops->map_delete_elem(map, key); + rcu_read_unlock(); + __this_cpu_dec(bpf_prog_active); + preempt_enable(); + maybe_wait_bpf_programs(map); + if (err) + break; + } + if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp))) + err = -EFAULT; + return err; +} + +int generic_map_update_batch(struct bpf_map *map, + const union bpf_attr *attr, + union bpf_attr __user *uattr) +{ + void __user *values = u64_to_user_ptr(attr->batch.values); + void __user *keys = u64_to_user_ptr(attr->batch.keys); + u32 value_size, cp, max_count; + int ufd = attr->map_fd; + void *key, *value; + struct fd f; + int err = 0; + + f = fdget(ufd); + if (attr->batch.elem_flags & ~BPF_F_LOCK) + return -EINVAL; + + if ((attr->batch.elem_flags & BPF_F_LOCK) && + !map_value_has_spin_lock(map)) { + return -EINVAL; + } + + value_size = bpf_map_value_size(map); + + max_count = attr->batch.count; + if (!max_count) + return 0; + + value = kmalloc(value_size, GFP_USER | __GFP_NOWARN); + if (!value) + return -ENOMEM; + + for (cp = 0; cp < max_count; cp++) { + key = __bpf_copy_key(keys + cp * map->key_size, map->key_size); + if (IS_ERR(key)) { + err = PTR_ERR(key); + break; + } + err = -EFAULT; + if (copy_from_user(value, values + cp * value_size, value_size)) + break; + + err = bpf_map_update_value(map, f, key, value, + attr->batch.elem_flags); + + if (err) + break; + } + + if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp))) + err = -EFAULT; + + kfree(value); + kfree(key); + return err; +} + #define MAP_LOOKUP_RETRIES 3 int generic_map_lookup_batch(struct bpf_map *map, @@ -3219,6 +3324,10 @@ static int bpf_map_do_batch(const union bpf_attr *attr, if (cmd == BPF_MAP_LOOKUP_BATCH) BPF_DO_BATCH(map->ops->map_lookup_batch); + else if (cmd == BPF_MAP_UPDATE_BATCH) + BPF_DO_BATCH(map->ops->map_update_batch); + else + BPF_DO_BATCH(map->ops->map_delete_batch); err_put: fdput(f); @@ -3325,6 +3434,12 @@ SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, siz case BPF_MAP_LOOKUP_BATCH: err = bpf_map_do_batch(&attr, uattr, BPF_MAP_LOOKUP_BATCH); break; + case BPF_MAP_UPDATE_BATCH: + err = bpf_map_do_batch(&attr, uattr, BPF_MAP_UPDATE_BATCH); + break; + case BPF_MAP_DELETE_BATCH: + err = bpf_map_do_batch(&attr, uattr, BPF_MAP_DELETE_BATCH); + break; default: err = -EINVAL; break;