bpf: Add bpf_map iterator (6086d29d) · Commits · 戴 / test

include/linux/bpf.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -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;

kernel/bpf/Makefile

+1 −1

Original line number	Diff line number	Diff line
		@@ -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

kernel/bpf/map_iter.c

0 → 100644

+97 −0

Original line number	Diff line number	Diff line
		// 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(&reg_info);
		}

		late_initcall(bpf_map_iter_init);

kernel/bpf/syscall.c

+19 −0

Original line number	Diff line number	Diff line
		@@ -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)

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