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>
11 struct bpf_iter_seq_task_common {
12 struct pid_namespace *ns;
15 struct bpf_iter_seq_task_info {
16 /* The first field must be struct bpf_iter_seq_task_common.
17 * this is assumed by {init, fini}_seq_pidns() callback functions.
19 struct bpf_iter_seq_task_common common;
23 static struct task_struct *task_seq_get_next(struct pid_namespace *ns,
26 struct task_struct *task = NULL;
31 pid = idr_get_next(&ns->idr, tid);
33 task = get_pid_task(pid, PIDTYPE_PID);
44 static void *task_seq_start(struct seq_file *seq, loff_t *pos)
46 struct bpf_iter_seq_task_info *info = seq->private;
47 struct task_struct *task;
49 task = task_seq_get_next(info->common.ns, &info->tid);
57 static void *task_seq_next(struct seq_file *seq, void *v, loff_t *pos)
59 struct bpf_iter_seq_task_info *info = seq->private;
60 struct task_struct *task;
64 put_task_struct((struct task_struct *)v);
65 task = task_seq_get_next(info->common.ns, &info->tid);
72 struct bpf_iter__task {
73 __bpf_md_ptr(struct bpf_iter_meta *, meta);
74 __bpf_md_ptr(struct task_struct *, task);
77 DEFINE_BPF_ITER_FUNC(task, struct bpf_iter_meta *meta, struct task_struct *task)
79 static int __task_seq_show(struct seq_file *seq, struct task_struct *task,
82 struct bpf_iter_meta meta;
83 struct bpf_iter__task ctx;
84 struct bpf_prog *prog;
87 prog = bpf_iter_get_info(&meta, in_stop);
94 return bpf_iter_run_prog(prog, &ctx);
97 static int task_seq_show(struct seq_file *seq, void *v)
99 return __task_seq_show(seq, v, false);
102 static void task_seq_stop(struct seq_file *seq, void *v)
105 (void)__task_seq_show(seq, v, true);
107 put_task_struct((struct task_struct *)v);
110 static const struct seq_operations task_seq_ops = {
111 .start = task_seq_start,
112 .next = task_seq_next,
113 .stop = task_seq_stop,
114 .show = task_seq_show,
117 struct bpf_iter_seq_task_file_info {
118 /* The first field must be struct bpf_iter_seq_task_common.
119 * this is assumed by {init, fini}_seq_pidns() callback functions.
121 struct bpf_iter_seq_task_common common;
122 struct task_struct *task;
123 struct files_struct *files;
129 task_file_seq_get_next(struct bpf_iter_seq_task_file_info *info,
130 struct task_struct **task, struct files_struct **fstruct)
132 struct pid_namespace *ns = info->common.ns;
133 u32 curr_tid = info->tid, max_fds;
134 struct files_struct *curr_files;
135 struct task_struct *curr_task;
136 int curr_fd = info->fd;
138 /* If this function returns a non-NULL file object,
139 * it held a reference to the task/files_struct/file.
140 * Otherwise, it does not hold any reference.
145 curr_files = *fstruct;
148 curr_task = task_seq_get_next(ns, &curr_tid);
152 curr_files = get_files_struct(curr_task);
154 put_task_struct(curr_task);
155 curr_tid = ++(info->tid);
160 /* set *fstruct, *task and info->tid */
161 *fstruct = curr_files;
163 if (curr_tid == info->tid) {
166 info->tid = curr_tid;
172 max_fds = files_fdtable(curr_files)->max_fds;
173 for (; curr_fd < max_fds; curr_fd++) {
176 f = fcheck_files(curr_files, curr_fd);
187 /* the current task is done, go to the next task */
189 put_files_struct(curr_files);
190 put_task_struct(curr_task);
194 curr_tid = ++(info->tid);
198 static void *task_file_seq_start(struct seq_file *seq, loff_t *pos)
200 struct bpf_iter_seq_task_file_info *info = seq->private;
201 struct files_struct *files = NULL;
202 struct task_struct *task = NULL;
205 file = task_file_seq_get_next(info, &task, &files);
219 static void *task_file_seq_next(struct seq_file *seq, void *v, loff_t *pos)
221 struct bpf_iter_seq_task_file_info *info = seq->private;
222 struct files_struct *files = info->files;
223 struct task_struct *task = info->task;
228 fput((struct file *)v);
229 file = task_file_seq_get_next(info, &task, &files);
242 struct bpf_iter__task_file {
243 __bpf_md_ptr(struct bpf_iter_meta *, meta);
244 __bpf_md_ptr(struct task_struct *, task);
246 __bpf_md_ptr(struct file *, file);
249 DEFINE_BPF_ITER_FUNC(task_file, struct bpf_iter_meta *meta,
250 struct task_struct *task, u32 fd,
253 static int __task_file_seq_show(struct seq_file *seq, struct file *file,
256 struct bpf_iter_seq_task_file_info *info = seq->private;
257 struct bpf_iter__task_file ctx;
258 struct bpf_iter_meta meta;
259 struct bpf_prog *prog;
262 prog = bpf_iter_get_info(&meta, in_stop);
267 ctx.task = info->task;
270 return bpf_iter_run_prog(prog, &ctx);
273 static int task_file_seq_show(struct seq_file *seq, void *v)
275 return __task_file_seq_show(seq, v, false);
278 static void task_file_seq_stop(struct seq_file *seq, void *v)
280 struct bpf_iter_seq_task_file_info *info = seq->private;
283 (void)__task_file_seq_show(seq, v, true);
285 fput((struct file *)v);
286 put_files_struct(info->files);
287 put_task_struct(info->task);
293 static int init_seq_pidns(void *priv_data)
295 struct bpf_iter_seq_task_common *common = priv_data;
297 common->ns = get_pid_ns(task_active_pid_ns(current));
301 static void fini_seq_pidns(void *priv_data)
303 struct bpf_iter_seq_task_common *common = priv_data;
305 put_pid_ns(common->ns);
308 static const struct seq_operations task_file_seq_ops = {
309 .start = task_file_seq_start,
310 .next = task_file_seq_next,
311 .stop = task_file_seq_stop,
312 .show = task_file_seq_show,
315 static const struct bpf_iter_reg task_reg_info = {
317 .seq_ops = &task_seq_ops,
318 .init_seq_private = init_seq_pidns,
319 .fini_seq_private = fini_seq_pidns,
320 .seq_priv_size = sizeof(struct bpf_iter_seq_task_info),
321 .ctx_arg_info_size = 1,
323 { offsetof(struct bpf_iter__task, task),
324 PTR_TO_BTF_ID_OR_NULL },
328 static const struct bpf_iter_reg task_file_reg_info = {
329 .target = "task_file",
330 .seq_ops = &task_file_seq_ops,
331 .init_seq_private = init_seq_pidns,
332 .fini_seq_private = fini_seq_pidns,
333 .seq_priv_size = sizeof(struct bpf_iter_seq_task_file_info),
334 .ctx_arg_info_size = 2,
336 { offsetof(struct bpf_iter__task_file, task),
337 PTR_TO_BTF_ID_OR_NULL },
338 { offsetof(struct bpf_iter__task_file, file),
339 PTR_TO_BTF_ID_OR_NULL },
343 static int __init task_iter_init(void)
347 ret = bpf_iter_reg_target(&task_reg_info);
351 return bpf_iter_reg_target(&task_file_reg_info);
353 late_initcall(task_iter_init);