1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (c) 2020 Facebook */
4 #include <linux/init.h>
5 #include <linux/namei.h>
6 #include <linux/pid_namespace.h>
8 #include <linux/fdtable.h>
9 #include <linux/filter.h>
10 #include <linux/btf_ids.h>
12 struct bpf_iter_seq_task_common {
13 struct pid_namespace *ns;
16 struct bpf_iter_seq_task_info {
17 /* The first field must be struct bpf_iter_seq_task_common.
18 * this is assumed by {init, fini}_seq_pidns() callback functions.
20 struct bpf_iter_seq_task_common common;
24 static struct task_struct *task_seq_get_next(struct pid_namespace *ns,
27 struct task_struct *task = NULL;
32 pid = idr_get_next(&ns->idr, tid);
34 task = get_pid_task(pid, PIDTYPE_PID);
45 static void *task_seq_start(struct seq_file *seq, loff_t *pos)
47 struct bpf_iter_seq_task_info *info = seq->private;
48 struct task_struct *task;
50 task = task_seq_get_next(info->common.ns, &info->tid);
59 static void *task_seq_next(struct seq_file *seq, void *v, loff_t *pos)
61 struct bpf_iter_seq_task_info *info = seq->private;
62 struct task_struct *task;
66 put_task_struct((struct task_struct *)v);
67 task = task_seq_get_next(info->common.ns, &info->tid);
74 struct bpf_iter__task {
75 __bpf_md_ptr(struct bpf_iter_meta *, meta);
76 __bpf_md_ptr(struct task_struct *, task);
79 DEFINE_BPF_ITER_FUNC(task, struct bpf_iter_meta *meta, struct task_struct *task)
81 static int __task_seq_show(struct seq_file *seq, struct task_struct *task,
84 struct bpf_iter_meta meta;
85 struct bpf_iter__task ctx;
86 struct bpf_prog *prog;
89 prog = bpf_iter_get_info(&meta, in_stop);
96 return bpf_iter_run_prog(prog, &ctx);
99 static int task_seq_show(struct seq_file *seq, void *v)
101 return __task_seq_show(seq, v, false);
104 static void task_seq_stop(struct seq_file *seq, void *v)
107 (void)__task_seq_show(seq, v, true);
109 put_task_struct((struct task_struct *)v);
112 static const struct seq_operations task_seq_ops = {
113 .start = task_seq_start,
114 .next = task_seq_next,
115 .stop = task_seq_stop,
116 .show = task_seq_show,
119 struct bpf_iter_seq_task_file_info {
120 /* The first field must be struct bpf_iter_seq_task_common.
121 * this is assumed by {init, fini}_seq_pidns() callback functions.
123 struct bpf_iter_seq_task_common common;
124 struct task_struct *task;
125 struct files_struct *files;
131 task_file_seq_get_next(struct bpf_iter_seq_task_file_info *info,
132 struct task_struct **task, struct files_struct **fstruct)
134 struct pid_namespace *ns = info->common.ns;
135 u32 curr_tid = info->tid, max_fds;
136 struct files_struct *curr_files;
137 struct task_struct *curr_task;
138 int curr_fd = info->fd;
140 /* If this function returns a non-NULL file object,
141 * it held a reference to the task/files_struct/file.
142 * Otherwise, it does not hold any reference.
147 curr_files = *fstruct;
150 curr_task = task_seq_get_next(ns, &curr_tid);
154 curr_files = get_files_struct(curr_task);
156 put_task_struct(curr_task);
157 curr_tid = ++(info->tid);
162 /* set *fstruct, *task and info->tid */
163 *fstruct = curr_files;
165 if (curr_tid == info->tid) {
168 info->tid = curr_tid;
174 max_fds = files_fdtable(curr_files)->max_fds;
175 for (; curr_fd < max_fds; curr_fd++) {
178 f = fcheck_files(curr_files, curr_fd);
189 /* the current task is done, go to the next task */
191 put_files_struct(curr_files);
192 put_task_struct(curr_task);
196 curr_tid = ++(info->tid);
200 static void *task_file_seq_start(struct seq_file *seq, loff_t *pos)
202 struct bpf_iter_seq_task_file_info *info = seq->private;
203 struct files_struct *files = NULL;
204 struct task_struct *task = NULL;
207 file = task_file_seq_get_next(info, &task, &files);
222 static void *task_file_seq_next(struct seq_file *seq, void *v, loff_t *pos)
224 struct bpf_iter_seq_task_file_info *info = seq->private;
225 struct files_struct *files = info->files;
226 struct task_struct *task = info->task;
231 fput((struct file *)v);
232 file = task_file_seq_get_next(info, &task, &files);
245 struct bpf_iter__task_file {
246 __bpf_md_ptr(struct bpf_iter_meta *, meta);
247 __bpf_md_ptr(struct task_struct *, task);
249 __bpf_md_ptr(struct file *, file);
252 DEFINE_BPF_ITER_FUNC(task_file, struct bpf_iter_meta *meta,
253 struct task_struct *task, u32 fd,
256 static int __task_file_seq_show(struct seq_file *seq, struct file *file,
259 struct bpf_iter_seq_task_file_info *info = seq->private;
260 struct bpf_iter__task_file ctx;
261 struct bpf_iter_meta meta;
262 struct bpf_prog *prog;
265 prog = bpf_iter_get_info(&meta, in_stop);
270 ctx.task = info->task;
273 return bpf_iter_run_prog(prog, &ctx);
276 static int task_file_seq_show(struct seq_file *seq, void *v)
278 return __task_file_seq_show(seq, v, false);
281 static void task_file_seq_stop(struct seq_file *seq, void *v)
283 struct bpf_iter_seq_task_file_info *info = seq->private;
286 (void)__task_file_seq_show(seq, v, true);
288 fput((struct file *)v);
289 put_files_struct(info->files);
290 put_task_struct(info->task);
296 static int init_seq_pidns(void *priv_data, struct bpf_iter_aux_info *aux)
298 struct bpf_iter_seq_task_common *common = priv_data;
300 common->ns = get_pid_ns(task_active_pid_ns(current));
304 static void fini_seq_pidns(void *priv_data)
306 struct bpf_iter_seq_task_common *common = priv_data;
308 put_pid_ns(common->ns);
311 static const struct seq_operations task_file_seq_ops = {
312 .start = task_file_seq_start,
313 .next = task_file_seq_next,
314 .stop = task_file_seq_stop,
315 .show = task_file_seq_show,
318 BTF_ID_LIST(btf_task_file_ids)
319 BTF_ID(struct, task_struct)
322 static const struct bpf_iter_seq_info task_seq_info = {
323 .seq_ops = &task_seq_ops,
324 .init_seq_private = init_seq_pidns,
325 .fini_seq_private = fini_seq_pidns,
326 .seq_priv_size = sizeof(struct bpf_iter_seq_task_info),
329 static struct bpf_iter_reg task_reg_info = {
331 .ctx_arg_info_size = 1,
333 { offsetof(struct bpf_iter__task, task),
334 PTR_TO_BTF_ID_OR_NULL },
336 .seq_info = &task_seq_info,
339 static const struct bpf_iter_seq_info task_file_seq_info = {
340 .seq_ops = &task_file_seq_ops,
341 .init_seq_private = init_seq_pidns,
342 .fini_seq_private = fini_seq_pidns,
343 .seq_priv_size = sizeof(struct bpf_iter_seq_task_file_info),
346 static struct bpf_iter_reg task_file_reg_info = {
347 .target = "task_file",
348 .ctx_arg_info_size = 2,
350 { offsetof(struct bpf_iter__task_file, task),
351 PTR_TO_BTF_ID_OR_NULL },
352 { offsetof(struct bpf_iter__task_file, file),
353 PTR_TO_BTF_ID_OR_NULL },
355 .seq_info = &task_file_seq_info,
358 static int __init task_iter_init(void)
362 task_reg_info.ctx_arg_info[0].btf_id = btf_task_file_ids[0];
363 ret = bpf_iter_reg_target(&task_reg_info);
367 task_file_reg_info.ctx_arg_info[0].btf_id = btf_task_file_ids[0];
368 task_file_reg_info.ctx_arg_info[1].btf_id = btf_task_file_ids[1];
369 return bpf_iter_reg_target(&task_file_reg_info);
371 late_initcall(task_iter_init);