// 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 const struct bpf_iter_reg bpf_map_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),	.ctx_arg_info_size	= 1,	.ctx_arg_info		= {		{ offsetof(struct bpf_iter__bpf_map, map),		  PTR_TO_BTF_ID_OR_NULL },	},}; static int __init bpf_map_iter_init(void){	return bpf_iter_reg_target(&bpf_map_reg_info);} late_initcall(bpf_map_iter_init);