Commit 14fc6bd6 authored by Yonghong Song's avatar Yonghong Song Committed by Alexei Starovoitov
Browse files

bpf: Refactor bpf_iter_reg to have separate seq_info member 



There is no functionality change for this patch.
Struct bpf_iter_reg is used to register a bpf_iter target,
which includes information for both prog_load, link_create
and seq_file creation.

This patch puts fields related seq_file creation into
a different structure. This will be useful for map
elements iterator where one iterator covers different
map types and different map types may have different
seq_ops, init/fini private_data function and
private_data size.

Signed-off-by: default avatarYonghong Song <yhs@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200723184109.590030-1-yhs@fb.com
parent a228a64f

include/linux/bpf.h

+10 −7
Original line number Diff line number Diff line
@@ -37,6 +37,15 @@ struct seq_operations; 
extern struct idr btf_idr;

extern spinlock_t btf_idr_lock;



typedef int (*bpf_iter_init_seq_priv_t)(void *private_data);

typedef void (*bpf_iter_fini_seq_priv_t)(void *private_data);

struct bpf_iter_seq_info {

	const struct seq_operations *seq_ops;

	bpf_iter_init_seq_priv_t init_seq_private;

	bpf_iter_fini_seq_priv_t fini_seq_private;

	u32 seq_priv_size;

};



/* map is generic key/value storage optionally accesible by eBPF programs */

struct bpf_map_ops {

	/* funcs callable from userspace (via syscall) */
@@ -1189,18 +1198,12 @@ int bpf_obj_get_user(const char __user *pathname, int flags); 
	extern int bpf_iter_ ## target(args);			\

	int __init bpf_iter_ ## target(args) { return 0; }



typedef int (*bpf_iter_init_seq_priv_t)(void *private_data);

typedef void (*bpf_iter_fini_seq_priv_t)(void *private_data);



#define BPF_ITER_CTX_ARG_MAX 2

struct bpf_iter_reg {

	const char *target;

	const struct seq_operations *seq_ops;

	bpf_iter_init_seq_priv_t init_seq_private;

	bpf_iter_fini_seq_priv_t fini_seq_private;

	u32 seq_priv_size;

	u32 ctx_arg_info_size;

	struct bpf_ctx_arg_aux ctx_arg_info[BPF_ITER_CTX_ARG_MAX];

	const struct bpf_iter_seq_info *seq_info;

};



struct bpf_iter_meta {

kernel/bpf/bpf_iter.c

+6 −6
Original line number Diff line number Diff line
@@ -218,8 +218,8 @@ static int iter_release(struct inode *inode, struct file *file) 
	iter_priv = container_of(seq->private, struct bpf_iter_priv_data,

				 target_private);



	if (iter_priv->tinfo->reg_info->fini_seq_private)

		iter_priv->tinfo->reg_info->fini_seq_private(seq->private);

	if (iter_priv->tinfo->reg_info->seq_info->fini_seq_private)

		iter_priv->tinfo->reg_info->seq_info->fini_seq_private(seq->private);



	bpf_prog_put(iter_priv->prog);

	seq->private = iter_priv;
@@ -433,16 +433,16 @@ static int prepare_seq_file(struct file *file, struct bpf_iter_link *link) 


	tinfo = link->tinfo;

	total_priv_dsize = offsetof(struct bpf_iter_priv_data, target_private) +

			   tinfo->reg_info->seq_priv_size;

	priv_data = __seq_open_private(file, tinfo->reg_info->seq_ops,

			   tinfo->reg_info->seq_info->seq_priv_size;

	priv_data = __seq_open_private(file, tinfo->reg_info->seq_info->seq_ops,

				       total_priv_dsize);

	if (!priv_data) {

		err = -ENOMEM;

		goto release_prog;

	}



	if (tinfo->reg_info->init_seq_private) {

		err = tinfo->reg_info->init_seq_private(priv_data->target_private);

	if (tinfo->reg_info->seq_info->init_seq_private) {

		err = tinfo->reg_info->seq_info->init_seq_private(priv_data->target_private);

		if (err)

			goto release_seq_file;

	}

kernel/bpf/map_iter.c

+6 −2
Original line number Diff line number Diff line
@@ -81,17 +81,21 @@ static const struct seq_operations bpf_map_seq_ops = { 
BTF_ID_LIST(btf_bpf_map_id)

BTF_ID(struct, bpf_map)



static struct bpf_iter_reg bpf_map_reg_info = {

	.target			= "bpf_map",

static const struct bpf_iter_seq_info bpf_map_seq_info = {

	.seq_ops		= &bpf_map_seq_ops,

	.init_seq_private	= NULL,

	.fini_seq_private	= NULL,

	.seq_priv_size		= sizeof(struct bpf_iter_seq_map_info),

};



static struct bpf_iter_reg bpf_map_reg_info = {

	.target			= "bpf_map",

	.ctx_arg_info_size	= 1,

	.ctx_arg_info		= {

		{ offsetof(struct bpf_iter__bpf_map, map),

		  PTR_TO_BTF_ID_OR_NULL },

	},

	.seq_info		= &bpf_map_seq_info,

};



static int __init bpf_map_iter_init(void)

kernel/bpf/prog_iter.c

+6 −2
Original line number Diff line number Diff line
@@ -81,17 +81,21 @@ static const struct seq_operations bpf_prog_seq_ops = { 
BTF_ID_LIST(btf_bpf_prog_id)

BTF_ID(struct, bpf_prog)



static struct bpf_iter_reg bpf_prog_reg_info = {

	.target			= "bpf_prog",

static const struct bpf_iter_seq_info bpf_prog_seq_info = {

	.seq_ops		= &bpf_prog_seq_ops,

	.init_seq_private	= NULL,

	.fini_seq_private	= NULL,

	.seq_priv_size		= sizeof(struct bpf_iter_seq_prog_info),

};



static struct bpf_iter_reg bpf_prog_reg_info = {

	.target			= "bpf_prog",

	.ctx_arg_info_size	= 1,

	.ctx_arg_info		= {

		{ offsetof(struct bpf_iter__bpf_prog, prog),

		  PTR_TO_BTF_ID_OR_NULL },

	},

	.seq_info		= &bpf_prog_seq_info,

};



static int __init bpf_prog_iter_init(void)

kernel/bpf/task_iter.c

+12 −4
Original line number Diff line number Diff line
@@ -319,25 +319,32 @@ BTF_ID_LIST(btf_task_file_ids) 
BTF_ID(struct, task_struct)

BTF_ID(struct, file)



static struct bpf_iter_reg task_reg_info = {

	.target			= "task",

static const struct bpf_iter_seq_info task_seq_info = {

	.seq_ops		= &task_seq_ops,

	.init_seq_private	= init_seq_pidns,

	.fini_seq_private	= fini_seq_pidns,

	.seq_priv_size		= sizeof(struct bpf_iter_seq_task_info),

};



static struct bpf_iter_reg task_reg_info = {

	.target			= "task",

	.ctx_arg_info_size	= 1,

	.ctx_arg_info		= {

		{ offsetof(struct bpf_iter__task, task),

		  PTR_TO_BTF_ID_OR_NULL },

	},

	.seq_info		= &task_seq_info,

};



static struct bpf_iter_reg task_file_reg_info = {

	.target			= "task_file",

static const struct bpf_iter_seq_info task_file_seq_info = {

	.seq_ops		= &task_file_seq_ops,

	.init_seq_private	= init_seq_pidns,

	.fini_seq_private	= fini_seq_pidns,

	.seq_priv_size		= sizeof(struct bpf_iter_seq_task_file_info),

};



static struct bpf_iter_reg task_file_reg_info = {

	.target			= "task_file",

	.ctx_arg_info_size	= 2,

	.ctx_arg_info		= {

		{ offsetof(struct bpf_iter__task_file, task),
@@ -345,6 +352,7 @@ static struct bpf_iter_reg task_file_reg_info = { 
		{ offsetof(struct bpf_iter__task_file, file),

		  PTR_TO_BTF_ID_OR_NULL },

	},

	.seq_info		= &task_file_seq_info,

};



static int __init task_iter_init(void)