diff options
| -rw-r--r-- | include/linux/bpf.h | 1 | ||||
| -rw-r--r-- | kernel/bpf/Makefile | 2 | ||||
| -rw-r--r-- | kernel/bpf/map_iter.c | 97 | ||||
| -rw-r--r-- | kernel/bpf/syscall.c | 19 |
4 files changed, 118 insertions, 1 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index ffe0b9b669bf..363ab0751967 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1082,6 +1082,7 @@ int generic_map_update_batch(struct bpf_map *map, int generic_map_delete_batch(struct bpf_map *map, const union bpf_attr *attr, union bpf_attr __user *uattr); +struct bpf_map *bpf_map_get_curr_or_next(u32 *id); extern int sysctl_unprivileged_bpf_disabled; diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile index 6a8b0febd3f6..b2b5eefc5254 100644 --- a/kernel/bpf/Makefile +++ b/kernel/bpf/Makefile @@ -2,7 +2,7 @@ obj-y := core.o CFLAGS_core.o += $(call cc-disable-warning, override-init) -obj-$(CONFIG_BPF_SYSCALL) += syscall.o verifier.o inode.o helpers.o tnum.o bpf_iter.o +obj-$(CONFIG_BPF_SYSCALL) += syscall.o verifier.o inode.o helpers.o tnum.o bpf_iter.o map_iter.o obj-$(CONFIG_BPF_SYSCALL) += hashtab.o arraymap.o percpu_freelist.o bpf_lru_list.o lpm_trie.o map_in_map.o obj-$(CONFIG_BPF_SYSCALL) += local_storage.o queue_stack_maps.o obj-$(CONFIG_BPF_SYSCALL) += disasm.o diff --git a/kernel/bpf/map_iter.c b/kernel/bpf/map_iter.c new file mode 100644 index 000000000000..8162e0c00b9f --- /dev/null +++ b/kernel/bpf/map_iter.c @@ -0,0 +1,97 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2020 Facebook */ +#include <linux/bpf.h> +#include <linux/fs.h> +#include <linux/filter.h> +#include <linux/kernel.h> + +struct bpf_iter_seq_map_info { + u32 mid; +}; + +static void *bpf_map_seq_start(struct seq_file *seq, loff_t *pos) +{ + struct bpf_iter_seq_map_info *info = seq->private; + struct bpf_map *map; + + map = bpf_map_get_curr_or_next(&info->mid); + if (!map) + return NULL; + + ++*pos; + return map; +} + +static void *bpf_map_seq_next(struct seq_file *seq, void *v, loff_t *pos) +{ + struct bpf_iter_seq_map_info *info = seq->private; + struct bpf_map *map; + + ++*pos; + ++info->mid; + bpf_map_put((struct bpf_map *)v); + map = bpf_map_get_curr_or_next(&info->mid); + if (!map) + return NULL; + + return map; +} + +struct bpf_iter__bpf_map { + __bpf_md_ptr(struct bpf_iter_meta *, meta); + __bpf_md_ptr(struct bpf_map *, map); +}; + +DEFINE_BPF_ITER_FUNC(bpf_map, struct bpf_iter_meta *meta, struct bpf_map *map) + +static int __bpf_map_seq_show(struct seq_file *seq, void *v, bool in_stop) +{ + struct bpf_iter__bpf_map ctx; + struct bpf_iter_meta meta; + struct bpf_prog *prog; + int ret = 0; + + ctx.meta = &meta; + ctx.map = v; + meta.seq = seq; + prog = bpf_iter_get_info(&meta, in_stop); + if (prog) + ret = bpf_iter_run_prog(prog, &ctx); + + return ret; +} + +static int bpf_map_seq_show(struct seq_file *seq, void *v) +{ + return __bpf_map_seq_show(seq, v, false); +} + +static void bpf_map_seq_stop(struct seq_file *seq, void *v) +{ + if (!v) + (void)__bpf_map_seq_show(seq, v, true); + else + bpf_map_put((struct bpf_map *)v); +} + +static const struct seq_operations bpf_map_seq_ops = { + .start = bpf_map_seq_start, + .next = bpf_map_seq_next, + .stop = bpf_map_seq_stop, + .show = bpf_map_seq_show, +}; + +static int __init bpf_map_iter_init(void) +{ + struct bpf_iter_reg reg_info = { + .target = "bpf_map", + .seq_ops = &bpf_map_seq_ops, + .init_seq_private = NULL, + .fini_seq_private = NULL, + .seq_priv_size = sizeof(struct bpf_iter_seq_map_info), + }; + + return bpf_iter_reg_target(®_info); +} + +late_initcall(bpf_map_iter_init); diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index a293e88ee01a..de2a75500233 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2934,6 +2934,25 @@ static int bpf_obj_get_next_id(const union bpf_attr *attr, return err; } +struct bpf_map *bpf_map_get_curr_or_next(u32 *id) +{ + struct bpf_map *map; + + spin_lock_bh(&map_idr_lock); +again: + map = idr_get_next(&map_idr, id); + if (map) { + map = __bpf_map_inc_not_zero(map, false); + if (IS_ERR(map)) { + (*id)++; + goto again; + } + } + spin_unlock_bh(&map_idr_lock); + + return map; +} + #define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id struct bpf_prog *bpf_prog_by_id(u32 id) |