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v3.1
 
   1/*
   2 *  linux/fs/proc/base.c
   3 *
   4 *  Copyright (C) 1991, 1992 Linus Torvalds
   5 *
   6 *  proc base directory handling functions
   7 *
   8 *  1999, Al Viro. Rewritten. Now it covers the whole per-process part.
   9 *  Instead of using magical inumbers to determine the kind of object
  10 *  we allocate and fill in-core inodes upon lookup. They don't even
  11 *  go into icache. We cache the reference to task_struct upon lookup too.
  12 *  Eventually it should become a filesystem in its own. We don't use the
  13 *  rest of procfs anymore.
  14 *
  15 *
  16 *  Changelog:
  17 *  17-Jan-2005
  18 *  Allan Bezerra
  19 *  Bruna Moreira <bruna.moreira@indt.org.br>
  20 *  Edjard Mota <edjard.mota@indt.org.br>
  21 *  Ilias Biris <ilias.biris@indt.org.br>
  22 *  Mauricio Lin <mauricio.lin@indt.org.br>
  23 *
  24 *  Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
  25 *
  26 *  A new process specific entry (smaps) included in /proc. It shows the
  27 *  size of rss for each memory area. The maps entry lacks information
  28 *  about physical memory size (rss) for each mapped file, i.e.,
  29 *  rss information for executables and library files.
  30 *  This additional information is useful for any tools that need to know
  31 *  about physical memory consumption for a process specific library.
  32 *
  33 *  Changelog:
  34 *  21-Feb-2005
  35 *  Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
  36 *  Pud inclusion in the page table walking.
  37 *
  38 *  ChangeLog:
  39 *  10-Mar-2005
  40 *  10LE Instituto Nokia de Tecnologia - INdT:
  41 *  A better way to walks through the page table as suggested by Hugh Dickins.
  42 *
  43 *  Simo Piiroinen <simo.piiroinen@nokia.com>:
  44 *  Smaps information related to shared, private, clean and dirty pages.
  45 *
  46 *  Paul Mundt <paul.mundt@nokia.com>:
  47 *  Overall revision about smaps.
  48 */
  49
  50#include <asm/uaccess.h>
  51
  52#include <linux/errno.h>
  53#include <linux/time.h>
  54#include <linux/proc_fs.h>
  55#include <linux/stat.h>
  56#include <linux/task_io_accounting_ops.h>
  57#include <linux/init.h>
  58#include <linux/capability.h>
  59#include <linux/file.h>
  60#include <linux/fdtable.h>
 
  61#include <linux/string.h>
  62#include <linux/seq_file.h>
  63#include <linux/namei.h>
  64#include <linux/mnt_namespace.h>
  65#include <linux/mm.h>
  66#include <linux/swap.h>
  67#include <linux/rcupdate.h>
  68#include <linux/kallsyms.h>
  69#include <linux/stacktrace.h>
  70#include <linux/resource.h>
  71#include <linux/module.h>
  72#include <linux/mount.h>
  73#include <linux/security.h>
  74#include <linux/ptrace.h>
  75#include <linux/tracehook.h>
 
 
  76#include <linux/cgroup.h>
  77#include <linux/cpuset.h>
  78#include <linux/audit.h>
  79#include <linux/poll.h>
  80#include <linux/nsproxy.h>
  81#include <linux/oom.h>
  82#include <linux/elf.h>
  83#include <linux/pid_namespace.h>
 
  84#include <linux/fs_struct.h>
  85#include <linux/slab.h>
  86#ifdef CONFIG_HARDWALL
  87#include <asm/hardwall.h>
  88#endif
 
 
 
 
 
 
  89#include "internal.h"
 
 
 
  90
  91/* NOTE:
  92 *	Implementing inode permission operations in /proc is almost
  93 *	certainly an error.  Permission checks need to happen during
  94 *	each system call not at open time.  The reason is that most of
  95 *	what we wish to check for permissions in /proc varies at runtime.
  96 *
  97 *	The classic example of a problem is opening file descriptors
  98 *	in /proc for a task before it execs a suid executable.
  99 */
 100
 
 
 
 101struct pid_entry {
 102	char *name;
 103	int len;
 104	mode_t mode;
 105	const struct inode_operations *iop;
 106	const struct file_operations *fop;
 107	union proc_op op;
 108};
 109
 110#define NOD(NAME, MODE, IOP, FOP, OP) {			\
 111	.name = (NAME),					\
 112	.len  = sizeof(NAME) - 1,			\
 113	.mode = MODE,					\
 114	.iop  = IOP,					\
 115	.fop  = FOP,					\
 116	.op   = OP,					\
 117}
 118
 119#define DIR(NAME, MODE, iops, fops)	\
 120	NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
 121#define LNK(NAME, get_link)					\
 122	NOD(NAME, (S_IFLNK|S_IRWXUGO),				\
 123		&proc_pid_link_inode_operations, NULL,		\
 124		{ .proc_get_link = get_link } )
 125#define REG(NAME, MODE, fops)				\
 126	NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
 127#define INF(NAME, MODE, read)				\
 128	NOD(NAME, (S_IFREG|(MODE)), 			\
 129		NULL, &proc_info_file_operations,	\
 130		{ .proc_read = read } )
 131#define ONE(NAME, MODE, show)				\
 132	NOD(NAME, (S_IFREG|(MODE)), 			\
 133		NULL, &proc_single_file_operations,	\
 134		{ .proc_show = show } )
 
 
 
 
 135
 136/*
 137 * Count the number of hardlinks for the pid_entry table, excluding the .
 138 * and .. links.
 139 */
 140static unsigned int pid_entry_count_dirs(const struct pid_entry *entries,
 141	unsigned int n)
 142{
 143	unsigned int i;
 144	unsigned int count;
 145
 146	count = 0;
 147	for (i = 0; i < n; ++i) {
 148		if (S_ISDIR(entries[i].mode))
 149			++count;
 150	}
 151
 152	return count;
 153}
 154
 155static int get_task_root(struct task_struct *task, struct path *root)
 156{
 157	int result = -ENOENT;
 158
 159	task_lock(task);
 160	if (task->fs) {
 161		get_fs_root(task->fs, root);
 162		result = 0;
 163	}
 164	task_unlock(task);
 165	return result;
 166}
 167
 168static int proc_cwd_link(struct inode *inode, struct path *path)
 169{
 170	struct task_struct *task = get_proc_task(inode);
 171	int result = -ENOENT;
 172
 173	if (task) {
 174		task_lock(task);
 175		if (task->fs) {
 176			get_fs_pwd(task->fs, path);
 177			result = 0;
 178		}
 179		task_unlock(task);
 180		put_task_struct(task);
 181	}
 182	return result;
 183}
 184
 185static int proc_root_link(struct inode *inode, struct path *path)
 186{
 187	struct task_struct *task = get_proc_task(inode);
 188	int result = -ENOENT;
 189
 190	if (task) {
 191		result = get_task_root(task, path);
 192		put_task_struct(task);
 193	}
 194	return result;
 195}
 196
 197static struct mm_struct *__check_mem_permission(struct task_struct *task)
 
 
 
 
 
 
 198{
 199	struct mm_struct *mm;
 
 200
 201	mm = get_task_mm(task);
 202	if (!mm)
 203		return ERR_PTR(-EINVAL);
 204
 205	/*
 206	 * A task can always look at itself, in case it chooses
 207	 * to use system calls instead of load instructions.
 208	 */
 209	if (task == current)
 210		return mm;
 211
 212	/*
 213	 * If current is actively ptrace'ing, and would also be
 214	 * permitted to freshly attach with ptrace now, permit it.
 215	 */
 216	if (task_is_stopped_or_traced(task)) {
 217		int match;
 218		rcu_read_lock();
 219		match = (ptrace_parent(task) == current);
 220		rcu_read_unlock();
 221		if (match && ptrace_may_access(task, PTRACE_MODE_ATTACH))
 222			return mm;
 
 
 
 
 
 
 
 223	}
 224
 225	/*
 226	 * No one else is allowed.
 227	 */
 228	mmput(mm);
 229	return ERR_PTR(-EPERM);
 230}
 231
 232/*
 233 * If current may access user memory in @task return a reference to the
 234 * corresponding mm, otherwise ERR_PTR.
 235 */
 236static struct mm_struct *check_mem_permission(struct task_struct *task)
 237{
 238	struct mm_struct *mm;
 239	int err;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 240
 241	/*
 242	 * Avoid racing if task exec's as we might get a new mm but validate
 243	 * against old credentials.
 
 244	 */
 245	err = mutex_lock_killable(&task->signal->cred_guard_mutex);
 246	if (err)
 247		return ERR_PTR(err);
 
 
 
 
 
 
 
 
 
 248
 249	mm = __check_mem_permission(task);
 250	mutex_unlock(&task->signal->cred_guard_mutex);
 
 
 
 
 
 
 
 251
 252	return mm;
 253}
 
 
 
 
 
 
 
 254
 255struct mm_struct *mm_for_maps(struct task_struct *task)
 256{
 257	struct mm_struct *mm;
 258	int err;
 259
 260	err =  mutex_lock_killable(&task->signal->cred_guard_mutex);
 261	if (err)
 262		return ERR_PTR(err);
 
 263
 264	mm = get_task_mm(task);
 265	if (mm && mm != current->mm &&
 266			!ptrace_may_access(task, PTRACE_MODE_READ)) {
 267		mmput(mm);
 268		mm = ERR_PTR(-EACCES);
 
 
 
 
 
 
 
 
 269	}
 270	mutex_unlock(&task->signal->cred_guard_mutex);
 271
 272	return mm;
 
 273}
 274
 275static int proc_pid_cmdline(struct task_struct *task, char * buffer)
 
 276{
 277	int res = 0;
 278	unsigned int len;
 279	struct mm_struct *mm = get_task_mm(task);
 
 280	if (!mm)
 281		goto out;
 282	if (!mm->arg_end)
 283		goto out_mm;	/* Shh! No looking before we're done */
 284
 285 	len = mm->arg_end - mm->arg_start;
 286 
 287	if (len > PAGE_SIZE)
 288		len = PAGE_SIZE;
 289 
 290	res = access_process_vm(task, mm->arg_start, buffer, len, 0);
 291
 292	// If the nul at the end of args has been overwritten, then
 293	// assume application is using setproctitle(3).
 294	if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
 295		len = strnlen(buffer, res);
 296		if (len < res) {
 297		    res = len;
 298		} else {
 299			len = mm->env_end - mm->env_start;
 300			if (len > PAGE_SIZE - res)
 301				len = PAGE_SIZE - res;
 302			res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
 303			res = strnlen(buffer, res);
 304		}
 305	}
 306out_mm:
 307	mmput(mm);
 308out:
 309	return res;
 310}
 311
 312static int proc_pid_auxv(struct task_struct *task, char *buffer)
 
 313{
 314	struct mm_struct *mm = mm_for_maps(task);
 315	int res = PTR_ERR(mm);
 316	if (mm && !IS_ERR(mm)) {
 317		unsigned int nwords = 0;
 318		do {
 319			nwords += 2;
 320		} while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
 321		res = nwords * sizeof(mm->saved_auxv[0]);
 322		if (res > PAGE_SIZE)
 323			res = PAGE_SIZE;
 324		memcpy(buffer, mm->saved_auxv, res);
 325		mmput(mm);
 326	}
 327	return res;
 328}
 329
 
 
 
 
 330
 331#ifdef CONFIG_KALLSYMS
 332/*
 333 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
 334 * Returns the resolved symbol.  If that fails, simply return the address.
 335 */
 336static int proc_pid_wchan(struct task_struct *task, char *buffer)
 
 337{
 338	unsigned long wchan;
 339	char symname[KSYM_NAME_LEN];
 340
 
 
 
 341	wchan = get_wchan(task);
 
 
 
 
 342
 343	if (lookup_symbol_name(wchan, symname) < 0)
 344		if (!ptrace_may_access(task, PTRACE_MODE_READ))
 345			return 0;
 346		else
 347			return sprintf(buffer, "%lu", wchan);
 348	else
 349		return sprintf(buffer, "%s", symname);
 350}
 351#endif /* CONFIG_KALLSYMS */
 352
 353static int lock_trace(struct task_struct *task)
 354{
 355	int err = mutex_lock_killable(&task->signal->cred_guard_mutex);
 356	if (err)
 357		return err;
 358	if (!ptrace_may_access(task, PTRACE_MODE_ATTACH)) {
 359		mutex_unlock(&task->signal->cred_guard_mutex);
 360		return -EPERM;
 361	}
 362	return 0;
 363}
 364
 365static void unlock_trace(struct task_struct *task)
 366{
 367	mutex_unlock(&task->signal->cred_guard_mutex);
 368}
 369
 370#ifdef CONFIG_STACKTRACE
 371
 372#define MAX_STACK_TRACE_DEPTH	64
 373
 374static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
 375			  struct pid *pid, struct task_struct *task)
 376{
 377	struct stack_trace trace;
 378	unsigned long *entries;
 379	int err;
 380	int i;
 381
 382	entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 383	if (!entries)
 384		return -ENOMEM;
 385
 386	trace.nr_entries	= 0;
 387	trace.max_entries	= MAX_STACK_TRACE_DEPTH;
 388	trace.entries		= entries;
 389	trace.skip		= 0;
 390
 391	err = lock_trace(task);
 392	if (!err) {
 393		save_stack_trace_tsk(task, &trace);
 
 
 
 394
 395		for (i = 0; i < trace.nr_entries; i++) {
 396			seq_printf(m, "[<%pK>] %pS\n",
 397				   (void *)entries[i], (void *)entries[i]);
 398		}
 
 399		unlock_trace(task);
 400	}
 401	kfree(entries);
 402
 403	return err;
 404}
 405#endif
 406
 407#ifdef CONFIG_SCHEDSTATS
 408/*
 409 * Provides /proc/PID/schedstat
 410 */
 411static int proc_pid_schedstat(struct task_struct *task, char *buffer)
 
 412{
 413	return sprintf(buffer, "%llu %llu %lu\n",
 414			(unsigned long long)task->se.sum_exec_runtime,
 415			(unsigned long long)task->sched_info.run_delay,
 416			task->sched_info.pcount);
 
 
 
 
 
 417}
 418#endif
 419
 420#ifdef CONFIG_LATENCYTOP
 421static int lstats_show_proc(struct seq_file *m, void *v)
 422{
 423	int i;
 424	struct inode *inode = m->private;
 425	struct task_struct *task = get_proc_task(inode);
 426
 427	if (!task)
 428		return -ESRCH;
 429	seq_puts(m, "Latency Top version : v0.1\n");
 430	for (i = 0; i < 32; i++) {
 431		struct latency_record *lr = &task->latency_record[i];
 432		if (lr->backtrace[0]) {
 433			int q;
 434			seq_printf(m, "%i %li %li",
 435				   lr->count, lr->time, lr->max);
 436			for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
 437				unsigned long bt = lr->backtrace[q];
 
 438				if (!bt)
 439					break;
 440				if (bt == ULONG_MAX)
 441					break;
 442				seq_printf(m, " %ps", (void *)bt);
 443			}
 444			seq_putc(m, '\n');
 445		}
 446
 447	}
 448	put_task_struct(task);
 449	return 0;
 450}
 451
 452static int lstats_open(struct inode *inode, struct file *file)
 453{
 454	return single_open(file, lstats_show_proc, inode);
 455}
 456
 457static ssize_t lstats_write(struct file *file, const char __user *buf,
 458			    size_t count, loff_t *offs)
 459{
 460	struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
 461
 462	if (!task)
 463		return -ESRCH;
 464	clear_all_latency_tracing(task);
 465	put_task_struct(task);
 466
 467	return count;
 468}
 469
 470static const struct file_operations proc_lstats_operations = {
 471	.open		= lstats_open,
 472	.read		= seq_read,
 473	.write		= lstats_write,
 474	.llseek		= seq_lseek,
 475	.release	= single_release,
 476};
 477
 478#endif
 479
 480static int proc_oom_score(struct task_struct *task, char *buffer)
 
 481{
 
 482	unsigned long points = 0;
 
 
 
 
 
 
 
 
 
 
 
 
 483
 484	read_lock(&tasklist_lock);
 485	if (pid_alive(task))
 486		points = oom_badness(task, NULL, NULL,
 487					totalram_pages + total_swap_pages);
 488	read_unlock(&tasklist_lock);
 489	return sprintf(buffer, "%lu\n", points);
 490}
 491
 492struct limit_names {
 493	char *name;
 494	char *unit;
 495};
 496
 497static const struct limit_names lnames[RLIM_NLIMITS] = {
 498	[RLIMIT_CPU] = {"Max cpu time", "seconds"},
 499	[RLIMIT_FSIZE] = {"Max file size", "bytes"},
 500	[RLIMIT_DATA] = {"Max data size", "bytes"},
 501	[RLIMIT_STACK] = {"Max stack size", "bytes"},
 502	[RLIMIT_CORE] = {"Max core file size", "bytes"},
 503	[RLIMIT_RSS] = {"Max resident set", "bytes"},
 504	[RLIMIT_NPROC] = {"Max processes", "processes"},
 505	[RLIMIT_NOFILE] = {"Max open files", "files"},
 506	[RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
 507	[RLIMIT_AS] = {"Max address space", "bytes"},
 508	[RLIMIT_LOCKS] = {"Max file locks", "locks"},
 509	[RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
 510	[RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
 511	[RLIMIT_NICE] = {"Max nice priority", NULL},
 512	[RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
 513	[RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
 514};
 515
 516/* Display limits for a process */
 517static int proc_pid_limits(struct task_struct *task, char *buffer)
 
 518{
 519	unsigned int i;
 520	int count = 0;
 521	unsigned long flags;
 522	char *bufptr = buffer;
 523
 524	struct rlimit rlim[RLIM_NLIMITS];
 525
 526	if (!lock_task_sighand(task, &flags))
 527		return 0;
 528	memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
 529	unlock_task_sighand(task, &flags);
 530
 531	/*
 532	 * print the file header
 533	 */
 534	count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n",
 535			"Limit", "Soft Limit", "Hard Limit", "Units");
 
 
 536
 537	for (i = 0; i < RLIM_NLIMITS; i++) {
 538		if (rlim[i].rlim_cur == RLIM_INFINITY)
 539			count += sprintf(&bufptr[count], "%-25s %-20s ",
 540					 lnames[i].name, "unlimited");
 541		else
 542			count += sprintf(&bufptr[count], "%-25s %-20lu ",
 543					 lnames[i].name, rlim[i].rlim_cur);
 544
 545		if (rlim[i].rlim_max == RLIM_INFINITY)
 546			count += sprintf(&bufptr[count], "%-20s ", "unlimited");
 547		else
 548			count += sprintf(&bufptr[count], "%-20lu ",
 549					 rlim[i].rlim_max);
 550
 551		if (lnames[i].unit)
 552			count += sprintf(&bufptr[count], "%-10s\n",
 553					 lnames[i].unit);
 554		else
 555			count += sprintf(&bufptr[count], "\n");
 556	}
 557
 558	return count;
 559}
 560
 561#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
 562static int proc_pid_syscall(struct task_struct *task, char *buffer)
 
 563{
 564	long nr;
 565	unsigned long args[6], sp, pc;
 566	int res = lock_trace(task);
 
 
 567	if (res)
 568		return res;
 569
 570	if (task_current_syscall(task, &nr, args, 6, &sp, &pc))
 571		res = sprintf(buffer, "running\n");
 572	else if (nr < 0)
 573		res = sprintf(buffer, "%ld 0x%lx 0x%lx\n", nr, sp, pc);
 
 574	else
 575		res = sprintf(buffer,
 576		       "%ld 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
 577		       nr,
 578		       args[0], args[1], args[2], args[3], args[4], args[5],
 579		       sp, pc);
 580	unlock_trace(task);
 581	return res;
 
 582}
 583#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
 584
 585/************************************************************************/
 586/*                       Here the fs part begins                        */
 587/************************************************************************/
 588
 589/* permission checks */
 590static int proc_fd_access_allowed(struct inode *inode)
 591{
 592	struct task_struct *task;
 593	int allowed = 0;
 594	/* Allow access to a task's file descriptors if it is us or we
 595	 * may use ptrace attach to the process and find out that
 596	 * information.
 597	 */
 598	task = get_proc_task(inode);
 599	if (task) {
 600		allowed = ptrace_may_access(task, PTRACE_MODE_READ);
 601		put_task_struct(task);
 602	}
 603	return allowed;
 604}
 605
 606int proc_setattr(struct dentry *dentry, struct iattr *attr)
 607{
 608	int error;
 609	struct inode *inode = dentry->d_inode;
 610
 611	if (attr->ia_valid & ATTR_MODE)
 612		return -EPERM;
 613
 614	error = inode_change_ok(inode, attr);
 615	if (error)
 616		return error;
 617
 618	if ((attr->ia_valid & ATTR_SIZE) &&
 619	    attr->ia_size != i_size_read(inode)) {
 620		error = vmtruncate(inode, attr->ia_size);
 621		if (error)
 622			return error;
 623	}
 624
 625	setattr_copy(inode, attr);
 626	mark_inode_dirty(inode);
 627	return 0;
 628}
 629
 630static const struct inode_operations proc_def_inode_operations = {
 631	.setattr	= proc_setattr,
 632};
 633
 634static int mounts_open_common(struct inode *inode, struct file *file,
 635			      const struct seq_operations *op)
 636{
 637	struct task_struct *task = get_proc_task(inode);
 638	struct nsproxy *nsp;
 639	struct mnt_namespace *ns = NULL;
 640	struct path root;
 641	struct proc_mounts *p;
 642	int ret = -EINVAL;
 643
 644	if (task) {
 645		rcu_read_lock();
 646		nsp = task_nsproxy(task);
 647		if (nsp) {
 648			ns = nsp->mnt_ns;
 649			if (ns)
 650				get_mnt_ns(ns);
 651		}
 652		rcu_read_unlock();
 653		if (ns && get_task_root(task, &root) == 0)
 654			ret = 0;
 655		put_task_struct(task);
 656	}
 657
 658	if (!ns)
 659		goto err;
 660	if (ret)
 661		goto err_put_ns;
 662
 663	ret = -ENOMEM;
 664	p = kmalloc(sizeof(struct proc_mounts), GFP_KERNEL);
 665	if (!p)
 666		goto err_put_path;
 667
 668	file->private_data = &p->m;
 669	ret = seq_open(file, op);
 670	if (ret)
 671		goto err_free;
 672
 673	p->m.private = p;
 674	p->ns = ns;
 675	p->root = root;
 676	p->m.poll_event = ns->event;
 677
 678	return 0;
 679
 680 err_free:
 681	kfree(p);
 682 err_put_path:
 683	path_put(&root);
 684 err_put_ns:
 685	put_mnt_ns(ns);
 686 err:
 687	return ret;
 688}
 689
 690static int mounts_release(struct inode *inode, struct file *file)
 691{
 692	struct proc_mounts *p = file->private_data;
 693	path_put(&p->root);
 694	put_mnt_ns(p->ns);
 695	return seq_release(inode, file);
 696}
 697
 698static unsigned mounts_poll(struct file *file, poll_table *wait)
 699{
 700	struct proc_mounts *p = file->private_data;
 701	unsigned res = POLLIN | POLLRDNORM;
 702
 703	poll_wait(file, &p->ns->poll, wait);
 704	if (mnt_had_events(p))
 705		res |= POLLERR | POLLPRI;
 706
 707	return res;
 708}
 709
 710static int mounts_open(struct inode *inode, struct file *file)
 711{
 712	return mounts_open_common(inode, file, &mounts_op);
 713}
 714
 715static const struct file_operations proc_mounts_operations = {
 716	.open		= mounts_open,
 717	.read		= seq_read,
 718	.llseek		= seq_lseek,
 719	.release	= mounts_release,
 720	.poll		= mounts_poll,
 721};
 722
 723static int mountinfo_open(struct inode *inode, struct file *file)
 724{
 725	return mounts_open_common(inode, file, &mountinfo_op);
 726}
 727
 728static const struct file_operations proc_mountinfo_operations = {
 729	.open		= mountinfo_open,
 730	.read		= seq_read,
 731	.llseek		= seq_lseek,
 732	.release	= mounts_release,
 733	.poll		= mounts_poll,
 734};
 735
 736static int mountstats_open(struct inode *inode, struct file *file)
 737{
 738	return mounts_open_common(inode, file, &mountstats_op);
 
 
 739}
 740
 741static const struct file_operations proc_mountstats_operations = {
 742	.open		= mountstats_open,
 743	.read		= seq_read,
 744	.llseek		= seq_lseek,
 745	.release	= mounts_release,
 746};
 747
 748#define PROC_BLOCK_SIZE	(3*1024)		/* 4K page size but our output routines use some slack for overruns */
 749
 750static ssize_t proc_info_read(struct file * file, char __user * buf,
 751			  size_t count, loff_t *ppos)
 752{
 753	struct inode * inode = file->f_path.dentry->d_inode;
 754	unsigned long page;
 755	ssize_t length;
 756	struct task_struct *task = get_proc_task(inode);
 757
 758	length = -ESRCH;
 759	if (!task)
 760		goto out_no_task;
 
 
 761
 762	if (count > PROC_BLOCK_SIZE)
 763		count = PROC_BLOCK_SIZE;
 
 
 
 
 
 
 
 
 764
 765	length = -ENOMEM;
 766	if (!(page = __get_free_page(GFP_TEMPORARY)))
 767		goto out;
 
 768
 769	length = PROC_I(inode)->op.proc_read(task, (char*)page);
 770
 771	if (length >= 0)
 772		length = simple_read_from_buffer(buf, count, ppos, (char *)page, length);
 773	free_page(page);
 774out:
 775	put_task_struct(task);
 776out_no_task:
 777	return length;
 778}
 779
 780static const struct file_operations proc_info_file_operations = {
 781	.read		= proc_info_read,
 782	.llseek		= generic_file_llseek,
 783};
 784
 785static int proc_single_show(struct seq_file *m, void *v)
 786{
 787	struct inode *inode = m->private;
 788	struct pid_namespace *ns;
 789	struct pid *pid;
 790	struct task_struct *task;
 791	int ret;
 792
 793	ns = inode->i_sb->s_fs_info;
 794	pid = proc_pid(inode);
 795	task = get_pid_task(pid, PIDTYPE_PID);
 796	if (!task)
 797		return -ESRCH;
 798
 799	ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
 800
 801	put_task_struct(task);
 802	return ret;
 803}
 804
 805static int proc_single_open(struct inode *inode, struct file *filp)
 806{
 807	return single_open(filp, proc_single_show, inode);
 808}
 809
 810static const struct file_operations proc_single_file_operations = {
 811	.open		= proc_single_open,
 812	.read		= seq_read,
 813	.llseek		= seq_lseek,
 814	.release	= single_release,
 815};
 816
 817static int mem_open(struct inode* inode, struct file* file)
 818{
 819	file->private_data = (void*)((long)current->self_exec_id);
 820	/* OK to pass negative loff_t, we can catch out-of-range */
 821	file->f_mode |= FMODE_UNSIGNED_OFFSET;
 822	return 0;
 823}
 824
 825static ssize_t mem_read(struct file * file, char __user * buf,
 826			size_t count, loff_t *ppos)
 827{
 828	struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
 829	char *page;
 830	unsigned long src = *ppos;
 831	int ret = -ESRCH;
 832	struct mm_struct *mm;
 833
 834	if (!task)
 835		goto out_no_task;
 
 836
 837	ret = -ENOMEM;
 838	page = (char *)__get_free_page(GFP_TEMPORARY);
 839	if (!page)
 840		goto out;
 
 
 
 841
 842	mm = check_mem_permission(task);
 843	ret = PTR_ERR(mm);
 844	if (IS_ERR(mm))
 845		goto out_free;
 846
 847	ret = -EIO;
 848 
 849	if (file->private_data != (void*)((long)current->self_exec_id))
 850		goto out_put;
 851
 852	ret = 0;
 853 
 854	while (count > 0) {
 855		int this_len, retval;
 856
 857		this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
 858		retval = access_remote_vm(mm, src, page, this_len, 0);
 859		if (!retval) {
 860			if (!ret)
 861				ret = -EIO;
 862			break;
 863		}
 864
 865		if (copy_to_user(buf, page, retval)) {
 866			ret = -EFAULT;
 867			break;
 868		}
 869 
 870		ret += retval;
 871		src += retval;
 872		buf += retval;
 873		count -= retval;
 874	}
 875	*ppos = src;
 876
 877out_put:
 878	mmput(mm);
 879out_free:
 880	free_page((unsigned long) page);
 881out:
 882	put_task_struct(task);
 883out_no_task:
 884	return ret;
 885}
 886
 887static ssize_t mem_write(struct file * file, const char __user *buf,
 888			 size_t count, loff_t *ppos)
 889{
 890	int copied;
 
 
 891	char *page;
 892	struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
 893	unsigned long dst = *ppos;
 894	struct mm_struct *mm;
 895
 896	copied = -ESRCH;
 897	if (!task)
 898		goto out_no_task;
 899
 900	copied = -ENOMEM;
 901	page = (char *)__get_free_page(GFP_TEMPORARY);
 902	if (!page)
 903		goto out_task;
 904
 905	mm = check_mem_permission(task);
 906	copied = PTR_ERR(mm);
 907	if (IS_ERR(mm))
 908		goto out_free;
 909
 910	copied = -EIO;
 911	if (file->private_data != (void *)((long)current->self_exec_id))
 912		goto out_mm;
 913
 914	copied = 0;
 915	while (count > 0) {
 916		int this_len, retval;
 917
 918		this_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
 919		if (copy_from_user(page, buf, this_len)) {
 920			copied = -EFAULT;
 921			break;
 922		}
 923		retval = access_remote_vm(mm, dst, page, this_len, 1);
 924		if (!retval) {
 
 925			if (!copied)
 926				copied = -EIO;
 927			break;
 928		}
 929		copied += retval;
 930		buf += retval;
 931		dst += retval;
 932		count -= retval;			
 
 
 
 
 
 
 933	}
 934	*ppos = dst;
 935
 936out_mm:
 937	mmput(mm);
 938out_free:
 939	free_page((unsigned long) page);
 940out_task:
 941	put_task_struct(task);
 942out_no_task:
 943	return copied;
 944}
 945
 
 
 
 
 
 
 
 
 
 
 
 
 946loff_t mem_lseek(struct file *file, loff_t offset, int orig)
 947{
 948	switch (orig) {
 949	case 0:
 950		file->f_pos = offset;
 951		break;
 952	case 1:
 953		file->f_pos += offset;
 954		break;
 955	default:
 956		return -EINVAL;
 957	}
 958	force_successful_syscall_return();
 959	return file->f_pos;
 960}
 961
 
 
 
 
 
 
 
 
 962static const struct file_operations proc_mem_operations = {
 963	.llseek		= mem_lseek,
 964	.read		= mem_read,
 965	.write		= mem_write,
 966	.open		= mem_open,
 
 967};
 968
 
 
 
 
 
 969static ssize_t environ_read(struct file *file, char __user *buf,
 970			size_t count, loff_t *ppos)
 971{
 972	struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
 973	char *page;
 974	unsigned long src = *ppos;
 975	int ret = -ESRCH;
 976	struct mm_struct *mm;
 
 977
 978	if (!task)
 979		goto out_no_task;
 
 980
 981	ret = -ENOMEM;
 982	page = (char *)__get_free_page(GFP_TEMPORARY);
 983	if (!page)
 984		goto out;
 985
 
 
 
 986
 987	mm = mm_for_maps(task);
 988	ret = PTR_ERR(mm);
 989	if (!mm || IS_ERR(mm))
 990		goto out_free;
 991
 992	ret = 0;
 993	while (count > 0) {
 994		int this_len, retval, max_len;
 995
 996		this_len = mm->env_end - (mm->env_start + src);
 997
 998		if (this_len <= 0)
 999			break;
1000
1001		max_len = (count > PAGE_SIZE) ? PAGE_SIZE : count;
1002		this_len = (this_len > max_len) ? max_len : this_len;
1003
1004		retval = access_process_vm(task, (mm->env_start + src),
1005			page, this_len, 0);
 
 
1006
1007		if (retval <= 0) {
1008			ret = retval;
1009			break;
1010		}
1011
1012		if (copy_to_user(buf, page, retval)) {
1013			ret = -EFAULT;
1014			break;
1015		}
1016
1017		ret += retval;
1018		src += retval;
1019		buf += retval;
1020		count -= retval;
1021	}
1022	*ppos = src;
1023
1024	mmput(mm);
1025out_free:
 
1026	free_page((unsigned long) page);
1027out:
1028	put_task_struct(task);
1029out_no_task:
1030	return ret;
1031}
1032
1033static const struct file_operations proc_environ_operations = {
 
1034	.read		= environ_read,
1035	.llseek		= generic_file_llseek,
 
1036};
1037
1038static ssize_t oom_adjust_read(struct file *file, char __user *buf,
1039				size_t count, loff_t *ppos)
1040{
1041	struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1042	char buffer[PROC_NUMBUF];
 
1043	size_t len;
1044	int oom_adjust = OOM_DISABLE;
1045	unsigned long flags;
1046
1047	if (!task)
1048		return -ESRCH;
 
 
 
 
 
 
 
 
 
1049
1050	if (lock_task_sighand(task, &flags)) {
1051		oom_adjust = task->signal->oom_adj;
1052		unlock_task_sighand(task, &flags);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1053	}
1054
1055	put_task_struct(task);
 
 
 
 
 
 
1056
1057	len = snprintf(buffer, sizeof(buffer), "%i\n", oom_adjust);
 
 
 
 
 
 
 
1058
1059	return simple_read_from_buffer(buf, count, ppos, buffer, len);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1060}
1061
1062static ssize_t oom_adjust_write(struct file *file, const char __user *buf,
1063				size_t count, loff_t *ppos)
 
 
 
 
 
 
 
 
 
 
1064{
1065	struct task_struct *task;
1066	char buffer[PROC_NUMBUF];
1067	int oom_adjust;
1068	unsigned long flags;
1069	int err;
1070
1071	memset(buffer, 0, sizeof(buffer));
1072	if (count > sizeof(buffer) - 1)
1073		count = sizeof(buffer) - 1;
1074	if (copy_from_user(buffer, buf, count)) {
1075		err = -EFAULT;
1076		goto out;
1077	}
1078
1079	err = kstrtoint(strstrip(buffer), 0, &oom_adjust);
1080	if (err)
1081		goto out;
1082	if ((oom_adjust < OOM_ADJUST_MIN || oom_adjust > OOM_ADJUST_MAX) &&
1083	     oom_adjust != OOM_DISABLE) {
1084		err = -EINVAL;
1085		goto out;
1086	}
1087
1088	task = get_proc_task(file->f_path.dentry->d_inode);
1089	if (!task) {
1090		err = -ESRCH;
1091		goto out;
1092	}
1093
1094	task_lock(task);
1095	if (!task->mm) {
1096		err = -EINVAL;
1097		goto err_task_lock;
1098	}
1099
1100	if (!lock_task_sighand(task, &flags)) {
1101		err = -ESRCH;
1102		goto err_task_lock;
1103	}
1104
1105	if (oom_adjust < task->signal->oom_adj && !capable(CAP_SYS_RESOURCE)) {
1106		err = -EACCES;
1107		goto err_sighand;
1108	}
1109
1110	if (oom_adjust != task->signal->oom_adj) {
1111		if (oom_adjust == OOM_DISABLE)
1112			atomic_inc(&task->mm->oom_disable_count);
1113		if (task->signal->oom_adj == OOM_DISABLE)
1114			atomic_dec(&task->mm->oom_disable_count);
1115	}
1116
1117	/*
1118	 * Warn that /proc/pid/oom_adj is deprecated, see
1119	 * Documentation/feature-removal-schedule.txt.
1120	 */
1121	printk_once(KERN_WARNING "%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1122		  current->comm, task_pid_nr(current), task_pid_nr(task),
1123		  task_pid_nr(task));
1124	task->signal->oom_adj = oom_adjust;
1125	/*
1126	 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1127	 * value is always attainable.
1128	 */
1129	if (task->signal->oom_adj == OOM_ADJUST_MAX)
1130		task->signal->oom_score_adj = OOM_SCORE_ADJ_MAX;
1131	else
1132		task->signal->oom_score_adj = (oom_adjust * OOM_SCORE_ADJ_MAX) /
1133								-OOM_DISABLE;
1134err_sighand:
1135	unlock_task_sighand(task, &flags);
1136err_task_lock:
1137	task_unlock(task);
1138	put_task_struct(task);
1139out:
1140	return err < 0 ? err : count;
1141}
1142
1143static const struct file_operations proc_oom_adjust_operations = {
1144	.read		= oom_adjust_read,
1145	.write		= oom_adjust_write,
1146	.llseek		= generic_file_llseek,
1147};
1148
1149static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1150					size_t count, loff_t *ppos)
1151{
1152	struct task_struct *task = get_proc_task(file->f_path.dentry->d_inode);
1153	char buffer[PROC_NUMBUF];
1154	int oom_score_adj = OOM_SCORE_ADJ_MIN;
1155	unsigned long flags;
1156	size_t len;
1157
1158	if (!task)
1159		return -ESRCH;
1160	if (lock_task_sighand(task, &flags)) {
1161		oom_score_adj = task->signal->oom_score_adj;
1162		unlock_task_sighand(task, &flags);
1163	}
1164	put_task_struct(task);
1165	len = snprintf(buffer, sizeof(buffer), "%d\n", oom_score_adj);
1166	return simple_read_from_buffer(buf, count, ppos, buffer, len);
1167}
1168
1169static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1170					size_t count, loff_t *ppos)
1171{
1172	struct task_struct *task;
1173	char buffer[PROC_NUMBUF];
1174	unsigned long flags;
1175	int oom_score_adj;
1176	int err;
1177
1178	memset(buffer, 0, sizeof(buffer));
1179	if (count > sizeof(buffer) - 1)
1180		count = sizeof(buffer) - 1;
1181	if (copy_from_user(buffer, buf, count)) {
1182		err = -EFAULT;
1183		goto out;
1184	}
1185
1186	err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1187	if (err)
1188		goto out;
1189	if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1190			oom_score_adj > OOM_SCORE_ADJ_MAX) {
1191		err = -EINVAL;
1192		goto out;
1193	}
1194
1195	task = get_proc_task(file->f_path.dentry->d_inode);
1196	if (!task) {
1197		err = -ESRCH;
1198		goto out;
1199	}
1200
1201	task_lock(task);
1202	if (!task->mm) {
1203		err = -EINVAL;
1204		goto err_task_lock;
1205	}
1206
1207	if (!lock_task_sighand(task, &flags)) {
1208		err = -ESRCH;
1209		goto err_task_lock;
1210	}
1211
1212	if (oom_score_adj < task->signal->oom_score_adj_min &&
1213			!capable(CAP_SYS_RESOURCE)) {
1214		err = -EACCES;
1215		goto err_sighand;
1216	}
1217
1218	if (oom_score_adj != task->signal->oom_score_adj) {
1219		if (oom_score_adj == OOM_SCORE_ADJ_MIN)
1220			atomic_inc(&task->mm->oom_disable_count);
1221		if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
1222			atomic_dec(&task->mm->oom_disable_count);
1223	}
1224	task->signal->oom_score_adj = oom_score_adj;
1225	if (has_capability_noaudit(current, CAP_SYS_RESOURCE))
1226		task->signal->oom_score_adj_min = oom_score_adj;
1227	/*
1228	 * Scale /proc/pid/oom_adj appropriately ensuring that OOM_DISABLE is
1229	 * always attainable.
1230	 */
1231	if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MIN)
1232		task->signal->oom_adj = OOM_DISABLE;
1233	else
1234		task->signal->oom_adj = (oom_score_adj * OOM_ADJUST_MAX) /
1235							OOM_SCORE_ADJ_MAX;
1236err_sighand:
1237	unlock_task_sighand(task, &flags);
1238err_task_lock:
1239	task_unlock(task);
1240	put_task_struct(task);
1241out:
1242	return err < 0 ? err : count;
1243}
1244
1245static const struct file_operations proc_oom_score_adj_operations = {
1246	.read		= oom_score_adj_read,
1247	.write		= oom_score_adj_write,
1248	.llseek		= default_llseek,
1249};
1250
1251#ifdef CONFIG_AUDITSYSCALL
1252#define TMPBUFLEN 21
1253static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1254				  size_t count, loff_t *ppos)
1255{
1256	struct inode * inode = file->f_path.dentry->d_inode;
1257	struct task_struct *task = get_proc_task(inode);
1258	ssize_t length;
1259	char tmpbuf[TMPBUFLEN];
1260
1261	if (!task)
1262		return -ESRCH;
1263	length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1264				audit_get_loginuid(task));
 
1265	put_task_struct(task);
1266	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1267}
1268
1269static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1270				   size_t count, loff_t *ppos)
1271{
1272	struct inode * inode = file->f_path.dentry->d_inode;
1273	char *page, *tmp;
1274	ssize_t length;
1275	uid_t loginuid;
1276
1277	if (!capable(CAP_AUDIT_CONTROL))
1278		return -EPERM;
1279
1280	rcu_read_lock();
1281	if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1282		rcu_read_unlock();
1283		return -EPERM;
1284	}
1285	rcu_read_unlock();
1286
1287	if (count >= PAGE_SIZE)
1288		count = PAGE_SIZE - 1;
1289
1290	if (*ppos != 0) {
1291		/* No partial writes. */
1292		return -EINVAL;
1293	}
1294	page = (char*)__get_free_page(GFP_TEMPORARY);
1295	if (!page)
1296		return -ENOMEM;
1297	length = -EFAULT;
1298	if (copy_from_user(page, buf, count))
1299		goto out_free_page;
1300
1301	page[count] = '\0';
1302	loginuid = simple_strtoul(page, &tmp, 10);
1303	if (tmp == page) {
1304		length = -EINVAL;
1305		goto out_free_page;
1306
1307	}
1308	length = audit_set_loginuid(current, loginuid);
1309	if (likely(length == 0))
1310		length = count;
1311
1312out_free_page:
1313	free_page((unsigned long) page);
1314	return length;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1315}
1316
1317static const struct file_operations proc_loginuid_operations = {
1318	.read		= proc_loginuid_read,
1319	.write		= proc_loginuid_write,
1320	.llseek		= generic_file_llseek,
1321};
1322
1323static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1324				  size_t count, loff_t *ppos)
1325{
1326	struct inode * inode = file->f_path.dentry->d_inode;
1327	struct task_struct *task = get_proc_task(inode);
1328	ssize_t length;
1329	char tmpbuf[TMPBUFLEN];
1330
1331	if (!task)
1332		return -ESRCH;
1333	length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1334				audit_get_sessionid(task));
1335	put_task_struct(task);
1336	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1337}
1338
1339static const struct file_operations proc_sessionid_operations = {
1340	.read		= proc_sessionid_read,
1341	.llseek		= generic_file_llseek,
1342};
1343#endif
1344
1345#ifdef CONFIG_FAULT_INJECTION
1346static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1347				      size_t count, loff_t *ppos)
1348{
1349	struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
1350	char buffer[PROC_NUMBUF];
1351	size_t len;
1352	int make_it_fail;
1353
1354	if (!task)
1355		return -ESRCH;
1356	make_it_fail = task->make_it_fail;
1357	put_task_struct(task);
1358
1359	len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1360
1361	return simple_read_from_buffer(buf, count, ppos, buffer, len);
1362}
1363
1364static ssize_t proc_fault_inject_write(struct file * file,
1365			const char __user * buf, size_t count, loff_t *ppos)
1366{
1367	struct task_struct *task;
1368	char buffer[PROC_NUMBUF], *end;
1369	int make_it_fail;
 
1370
1371	if (!capable(CAP_SYS_RESOURCE))
1372		return -EPERM;
1373	memset(buffer, 0, sizeof(buffer));
1374	if (count > sizeof(buffer) - 1)
1375		count = sizeof(buffer) - 1;
1376	if (copy_from_user(buffer, buf, count))
1377		return -EFAULT;
1378	make_it_fail = simple_strtol(strstrip(buffer), &end, 0);
1379	if (*end)
 
 
1380		return -EINVAL;
1381	task = get_proc_task(file->f_dentry->d_inode);
 
1382	if (!task)
1383		return -ESRCH;
1384	task->make_it_fail = make_it_fail;
1385	put_task_struct(task);
1386
1387	return count;
1388}
1389
1390static const struct file_operations proc_fault_inject_operations = {
1391	.read		= proc_fault_inject_read,
1392	.write		= proc_fault_inject_write,
1393	.llseek		= generic_file_llseek,
1394};
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1395#endif
1396
1397
1398#ifdef CONFIG_SCHED_DEBUG
1399/*
1400 * Print out various scheduling related per-task fields:
1401 */
1402static int sched_show(struct seq_file *m, void *v)
1403{
1404	struct inode *inode = m->private;
 
1405	struct task_struct *p;
1406
1407	p = get_proc_task(inode);
1408	if (!p)
1409		return -ESRCH;
1410	proc_sched_show_task(p, m);
1411
1412	put_task_struct(p);
1413
1414	return 0;
1415}
1416
1417static ssize_t
1418sched_write(struct file *file, const char __user *buf,
1419	    size_t count, loff_t *offset)
1420{
1421	struct inode *inode = file->f_path.dentry->d_inode;
1422	struct task_struct *p;
1423
1424	p = get_proc_task(inode);
1425	if (!p)
1426		return -ESRCH;
1427	proc_sched_set_task(p);
1428
1429	put_task_struct(p);
1430
1431	return count;
1432}
1433
1434static int sched_open(struct inode *inode, struct file *filp)
1435{
1436	return single_open(filp, sched_show, inode);
1437}
1438
1439static const struct file_operations proc_pid_sched_operations = {
1440	.open		= sched_open,
1441	.read		= seq_read,
1442	.write		= sched_write,
1443	.llseek		= seq_lseek,
1444	.release	= single_release,
1445};
1446
1447#endif
1448
1449#ifdef CONFIG_SCHED_AUTOGROUP
1450/*
1451 * Print out autogroup related information:
1452 */
1453static int sched_autogroup_show(struct seq_file *m, void *v)
1454{
1455	struct inode *inode = m->private;
1456	struct task_struct *p;
1457
1458	p = get_proc_task(inode);
1459	if (!p)
1460		return -ESRCH;
1461	proc_sched_autogroup_show_task(p, m);
1462
1463	put_task_struct(p);
1464
1465	return 0;
1466}
1467
1468static ssize_t
1469sched_autogroup_write(struct file *file, const char __user *buf,
1470	    size_t count, loff_t *offset)
1471{
1472	struct inode *inode = file->f_path.dentry->d_inode;
1473	struct task_struct *p;
1474	char buffer[PROC_NUMBUF];
1475	int nice;
1476	int err;
1477
1478	memset(buffer, 0, sizeof(buffer));
1479	if (count > sizeof(buffer) - 1)
1480		count = sizeof(buffer) - 1;
1481	if (copy_from_user(buffer, buf, count))
1482		return -EFAULT;
1483
1484	err = kstrtoint(strstrip(buffer), 0, &nice);
1485	if (err < 0)
1486		return err;
1487
1488	p = get_proc_task(inode);
1489	if (!p)
1490		return -ESRCH;
1491
1492	err = nice;
1493	err = proc_sched_autogroup_set_nice(p, &err);
1494	if (err)
1495		count = err;
1496
1497	put_task_struct(p);
1498
1499	return count;
1500}
1501
1502static int sched_autogroup_open(struct inode *inode, struct file *filp)
1503{
1504	int ret;
1505
1506	ret = single_open(filp, sched_autogroup_show, NULL);
1507	if (!ret) {
1508		struct seq_file *m = filp->private_data;
1509
1510		m->private = inode;
1511	}
1512	return ret;
1513}
1514
1515static const struct file_operations proc_pid_sched_autogroup_operations = {
1516	.open		= sched_autogroup_open,
1517	.read		= seq_read,
1518	.write		= sched_autogroup_write,
1519	.llseek		= seq_lseek,
1520	.release	= single_release,
1521};
1522
1523#endif /* CONFIG_SCHED_AUTOGROUP */
1524
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1525static ssize_t comm_write(struct file *file, const char __user *buf,
1526				size_t count, loff_t *offset)
1527{
1528	struct inode *inode = file->f_path.dentry->d_inode;
1529	struct task_struct *p;
1530	char buffer[TASK_COMM_LEN];
 
1531
1532	memset(buffer, 0, sizeof(buffer));
1533	if (count > sizeof(buffer) - 1)
1534		count = sizeof(buffer) - 1;
1535	if (copy_from_user(buffer, buf, count))
1536		return -EFAULT;
1537
1538	p = get_proc_task(inode);
1539	if (!p)
1540		return -ESRCH;
1541
1542	if (same_thread_group(current, p))
1543		set_task_comm(p, buffer);
1544	else
1545		count = -EINVAL;
1546
1547	put_task_struct(p);
1548
1549	return count;
1550}
1551
1552static int comm_show(struct seq_file *m, void *v)
1553{
1554	struct inode *inode = m->private;
1555	struct task_struct *p;
1556
1557	p = get_proc_task(inode);
1558	if (!p)
1559		return -ESRCH;
1560
1561	task_lock(p);
1562	seq_printf(m, "%s\n", p->comm);
1563	task_unlock(p);
1564
1565	put_task_struct(p);
1566
1567	return 0;
1568}
1569
1570static int comm_open(struct inode *inode, struct file *filp)
1571{
1572	return single_open(filp, comm_show, inode);
1573}
1574
1575static const struct file_operations proc_pid_set_comm_operations = {
1576	.open		= comm_open,
1577	.read		= seq_read,
1578	.write		= comm_write,
1579	.llseek		= seq_lseek,
1580	.release	= single_release,
1581};
1582
1583static int proc_exe_link(struct inode *inode, struct path *exe_path)
1584{
1585	struct task_struct *task;
1586	struct mm_struct *mm;
1587	struct file *exe_file;
1588
1589	task = get_proc_task(inode);
1590	if (!task)
1591		return -ENOENT;
1592	mm = get_task_mm(task);
1593	put_task_struct(task);
1594	if (!mm)
1595		return -ENOENT;
1596	exe_file = get_mm_exe_file(mm);
1597	mmput(mm);
1598	if (exe_file) {
1599		*exe_path = exe_file->f_path;
1600		path_get(&exe_file->f_path);
1601		fput(exe_file);
1602		return 0;
1603	} else
1604		return -ENOENT;
1605}
1606
1607static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
 
 
1608{
1609	struct inode *inode = dentry->d_inode;
1610	int error = -EACCES;
1611
1612	/* We don't need a base pointer in the /proc filesystem */
1613	path_put(&nd->path);
1614
1615	/* Are we allowed to snoop on the tasks file descriptors? */
1616	if (!proc_fd_access_allowed(inode))
1617		goto out;
1618
1619	error = PROC_I(inode)->op.proc_get_link(inode, &nd->path);
 
 
 
 
1620out:
1621	return ERR_PTR(error);
1622}
1623
1624static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1625{
1626	char *tmp = (char*)__get_free_page(GFP_TEMPORARY);
1627	char *pathname;
1628	int len;
1629
1630	if (!tmp)
1631		return -ENOMEM;
1632
1633	pathname = d_path(path, tmp, PAGE_SIZE);
1634	len = PTR_ERR(pathname);
1635	if (IS_ERR(pathname))
1636		goto out;
1637	len = tmp + PAGE_SIZE - 1 - pathname;
1638
1639	if (len > buflen)
1640		len = buflen;
1641	if (copy_to_user(buffer, pathname, len))
1642		len = -EFAULT;
1643 out:
1644	free_page((unsigned long)tmp);
1645	return len;
1646}
1647
1648static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1649{
1650	int error = -EACCES;
1651	struct inode *inode = dentry->d_inode;
1652	struct path path;
1653
1654	/* Are we allowed to snoop on the tasks file descriptors? */
1655	if (!proc_fd_access_allowed(inode))
1656		goto out;
1657
1658	error = PROC_I(inode)->op.proc_get_link(inode, &path);
1659	if (error)
1660		goto out;
1661
1662	error = do_proc_readlink(&path, buffer, buflen);
1663	path_put(&path);
1664out:
1665	return error;
1666}
1667
1668static const struct inode_operations proc_pid_link_inode_operations = {
1669	.readlink	= proc_pid_readlink,
1670	.follow_link	= proc_pid_follow_link,
1671	.setattr	= proc_setattr,
1672};
1673
1674
1675/* building an inode */
1676
1677static int task_dumpable(struct task_struct *task)
 
1678{
1679	int dumpable = 0;
1680	struct mm_struct *mm;
 
 
 
 
1681
1682	task_lock(task);
1683	mm = task->mm;
1684	if (mm)
1685		dumpable = get_dumpable(mm);
1686	task_unlock(task);
1687	if(dumpable == 1)
1688		return 1;
1689	return 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1690}
1691
1692struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
 
1693{
1694	struct inode * inode;
1695	struct proc_inode *ei;
1696	const struct cred *cred;
1697
1698	/* We need a new inode */
1699
1700	inode = new_inode(sb);
1701	if (!inode)
1702		goto out;
1703
1704	/* Common stuff */
1705	ei = PROC_I(inode);
 
1706	inode->i_ino = get_next_ino();
1707	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1708	inode->i_op = &proc_def_inode_operations;
1709
1710	/*
1711	 * grab the reference to task.
1712	 */
1713	ei->pid = get_task_pid(task, PIDTYPE_PID);
1714	if (!ei->pid)
1715		goto out_unlock;
1716
1717	if (task_dumpable(task)) {
1718		rcu_read_lock();
1719		cred = __task_cred(task);
1720		inode->i_uid = cred->euid;
1721		inode->i_gid = cred->egid;
1722		rcu_read_unlock();
1723	}
 
 
1724	security_task_to_inode(task, inode);
1725
1726out:
1727	return inode;
1728
1729out_unlock:
1730	iput(inode);
1731	return NULL;
1732}
1733
1734int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
 
1735{
1736	struct inode *inode = dentry->d_inode;
 
1737	struct task_struct *task;
1738	const struct cred *cred;
1739
1740	generic_fillattr(inode, stat);
1741
 
 
1742	rcu_read_lock();
1743	stat->uid = 0;
1744	stat->gid = 0;
1745	task = pid_task(proc_pid(inode), PIDTYPE_PID);
1746	if (task) {
1747		if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1748		    task_dumpable(task)) {
1749			cred = __task_cred(task);
1750			stat->uid = cred->euid;
1751			stat->gid = cred->egid;
 
 
1752		}
 
1753	}
1754	rcu_read_unlock();
1755	return 0;
1756}
1757
1758/* dentry stuff */
1759
1760/*
1761 *	Exceptional case: normally we are not allowed to unhash a busy
1762 * directory. In this case, however, we can do it - no aliasing problems
1763 * due to the way we treat inodes.
1764 *
 
 
 
 
 
 
 
1765 * Rewrite the inode's ownerships here because the owning task may have
1766 * performed a setuid(), etc.
1767 *
1768 * Before the /proc/pid/status file was created the only way to read
1769 * the effective uid of a /process was to stat /proc/pid.  Reading
1770 * /proc/pid/status is slow enough that procps and other packages
1771 * kept stating /proc/pid.  To keep the rules in /proc simple I have
1772 * made this apply to all per process world readable and executable
1773 * directories.
1774 */
1775int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
1776{
1777	struct inode *inode;
1778	struct task_struct *task;
1779	const struct cred *cred;
1780
1781	if (nd && nd->flags & LOOKUP_RCU)
1782		return -ECHILD;
1783
1784	inode = dentry->d_inode;
1785	task = get_proc_task(inode);
1786
1787	if (task) {
1788		if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
1789		    task_dumpable(task)) {
1790			rcu_read_lock();
1791			cred = __task_cred(task);
1792			inode->i_uid = cred->euid;
1793			inode->i_gid = cred->egid;
1794			rcu_read_unlock();
1795		} else {
1796			inode->i_uid = 0;
1797			inode->i_gid = 0;
1798		}
1799		inode->i_mode &= ~(S_ISUID | S_ISGID);
1800		security_task_to_inode(task, inode);
1801		put_task_struct(task);
1802		return 1;
1803	}
1804	d_drop(dentry);
1805	return 0;
1806}
1807
1808static int pid_delete_dentry(const struct dentry * dentry)
 
 
 
 
 
1809{
1810	/* Is the task we represent dead?
1811	 * If so, then don't put the dentry on the lru list,
1812	 * kill it immediately.
1813	 */
1814	return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
1815}
1816
1817const struct dentry_operations pid_dentry_operations =
1818{
1819	.d_revalidate	= pid_revalidate,
1820	.d_delete	= pid_delete_dentry,
1821};
1822
1823/* Lookups */
1824
1825/*
1826 * Fill a directory entry.
1827 *
1828 * If possible create the dcache entry and derive our inode number and
1829 * file type from dcache entry.
1830 *
1831 * Since all of the proc inode numbers are dynamically generated, the inode
1832 * numbers do not exist until the inode is cache.  This means creating the
1833 * the dcache entry in readdir is necessary to keep the inode numbers
1834 * reported by readdir in sync with the inode numbers reported
1835 * by stat.
1836 */
1837int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
1838	const char *name, int len,
1839	instantiate_t instantiate, struct task_struct *task, const void *ptr)
1840{
1841	struct dentry *child, *dir = filp->f_path.dentry;
 
1842	struct inode *inode;
1843	struct qstr qname;
1844	ino_t ino = 0;
1845	unsigned type = DT_UNKNOWN;
 
1846
1847	qname.name = name;
1848	qname.len  = len;
1849	qname.hash = full_name_hash(name, len);
1850
1851	child = d_lookup(dir, &qname);
1852	if (!child) {
1853		struct dentry *new;
1854		new = d_alloc(dir, &qname);
1855		if (new) {
1856			child = instantiate(dir->d_inode, new, task, ptr);
1857			if (child)
1858				dput(new);
1859			else
1860				child = new;
1861		}
1862	}
1863	if (!child || IS_ERR(child) || !child->d_inode)
1864		goto end_instantiate;
1865	inode = child->d_inode;
1866	if (inode) {
1867		ino = inode->i_ino;
1868		type = inode->i_mode >> 12;
1869	}
 
 
 
1870	dput(child);
1871end_instantiate:
1872	if (!ino)
1873		ino = find_inode_number(dir, &qname);
1874	if (!ino)
1875		ino = 1;
1876	return filldir(dirent, name, len, filp->f_pos, ino, type);
1877}
1878
1879static unsigned name_to_int(struct dentry *dentry)
 
 
 
 
 
1880{
1881	const char *name = dentry->d_name.name;
1882	int len = dentry->d_name.len;
1883	unsigned n = 0;
1884
1885	if (len > 1 && *name == '0')
1886		goto out;
1887	while (len-- > 0) {
1888		unsigned c = *name++ - '0';
1889		if (c > 9)
1890			goto out;
1891		if (n >= (~0U-9)/10)
1892			goto out;
1893		n *= 10;
1894		n += c;
1895	}
1896	return n;
1897out:
1898	return ~0U;
1899}
1900
1901#define PROC_FDINFO_MAX 64
 
 
1902
1903static int proc_fd_info(struct inode *inode, struct path *path, char *info)
1904{
1905	struct task_struct *task = get_proc_task(inode);
1906	struct files_struct *files = NULL;
1907	struct file *file;
1908	int fd = proc_fd(inode);
 
 
1909
1910	if (task) {
1911		files = get_files_struct(task);
1912		put_task_struct(task);
1913	}
1914	if (files) {
1915		/*
1916		 * We are not taking a ref to the file structure, so we must
1917		 * hold ->file_lock.
1918		 */
1919		spin_lock(&files->file_lock);
1920		file = fcheck_files(files, fd);
1921		if (file) {
1922			unsigned int f_flags;
1923			struct fdtable *fdt;
1924
1925			fdt = files_fdtable(files);
1926			f_flags = file->f_flags & ~O_CLOEXEC;
1927			if (FD_ISSET(fd, fdt->close_on_exec))
1928				f_flags |= O_CLOEXEC;
1929
1930			if (path) {
1931				*path = file->f_path;
1932				path_get(&file->f_path);
1933			}
1934			if (info)
1935				snprintf(info, PROC_FDINFO_MAX,
1936					 "pos:\t%lli\n"
1937					 "flags:\t0%o\n",
1938					 (long long) file->f_pos,
1939					 f_flags);
1940			spin_unlock(&files->file_lock);
1941			put_files_struct(files);
1942			return 0;
1943		}
1944		spin_unlock(&files->file_lock);
1945		put_files_struct(files);
1946	}
1947	return -ENOENT;
1948}
1949
1950static int proc_fd_link(struct inode *inode, struct path *path)
1951{
1952	return proc_fd_info(inode, path, NULL);
 
1953}
1954
1955static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
1956{
1957	struct inode *inode;
 
 
1958	struct task_struct *task;
1959	int fd;
1960	struct files_struct *files;
1961	const struct cred *cred;
1962
1963	if (nd && nd->flags & LOOKUP_RCU)
1964		return -ECHILD;
1965
1966	inode = dentry->d_inode;
1967	task = get_proc_task(inode);
1968	fd = proc_fd(inode);
 
1969
1970	if (task) {
1971		files = get_files_struct(task);
1972		if (files) {
1973			rcu_read_lock();
1974			if (fcheck_files(files, fd)) {
1975				rcu_read_unlock();
1976				put_files_struct(files);
1977				if (task_dumpable(task)) {
1978					rcu_read_lock();
1979					cred = __task_cred(task);
1980					inode->i_uid = cred->euid;
1981					inode->i_gid = cred->egid;
1982					rcu_read_unlock();
1983				} else {
1984					inode->i_uid = 0;
1985					inode->i_gid = 0;
1986				}
1987				inode->i_mode &= ~(S_ISUID | S_ISGID);
1988				security_task_to_inode(task, inode);
1989				put_task_struct(task);
1990				return 1;
1991			}
1992			rcu_read_unlock();
1993			put_files_struct(files);
1994		}
1995		put_task_struct(task);
1996	}
1997	d_drop(dentry);
1998	return 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
1999}
2000
2001static const struct dentry_operations tid_fd_dentry_operations =
2002{
2003	.d_revalidate	= tid_fd_revalidate,
2004	.d_delete	= pid_delete_dentry,
2005};
2006
2007static struct dentry *proc_fd_instantiate(struct inode *dir,
2008	struct dentry *dentry, struct task_struct *task, const void *ptr)
2009{
2010	unsigned fd = *(const unsigned *)ptr;
2011	struct file *file;
2012	struct files_struct *files;
2013 	struct inode *inode;
2014 	struct proc_inode *ei;
2015	struct dentry *error = ERR_PTR(-ENOENT);
2016
2017	inode = proc_pid_make_inode(dir->i_sb, task);
2018	if (!inode)
 
2019		goto out;
2020	ei = PROC_I(inode);
2021	ei->fd = fd;
2022	files = get_files_struct(task);
2023	if (!files)
2024		goto out_iput;
2025	inode->i_mode = S_IFLNK;
2026
2027	/*
2028	 * We are not taking a ref to the file structure, so we must
2029	 * hold ->file_lock.
2030	 */
2031	spin_lock(&files->file_lock);
2032	file = fcheck_files(files, fd);
2033	if (!file)
2034		goto out_unlock;
2035	if (file->f_mode & FMODE_READ)
2036		inode->i_mode |= S_IRUSR | S_IXUSR;
2037	if (file->f_mode & FMODE_WRITE)
2038		inode->i_mode |= S_IWUSR | S_IXUSR;
2039	spin_unlock(&files->file_lock);
2040	put_files_struct(files);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2041
2042	inode->i_op = &proc_pid_link_inode_operations;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2043	inode->i_size = 64;
2044	ei->op.proc_get_link = proc_fd_link;
2045	d_set_d_op(dentry, &tid_fd_dentry_operations);
2046	d_add(dentry, inode);
2047	/* Close the race of the process dying before we return the dentry */
2048	if (tid_fd_revalidate(dentry, NULL))
2049		error = NULL;
2050
2051 out:
2052	return error;
2053out_unlock:
2054	spin_unlock(&files->file_lock);
2055	put_files_struct(files);
2056out_iput:
2057	iput(inode);
2058	goto out;
2059}
2060
2061static struct dentry *proc_lookupfd_common(struct inode *dir,
2062					   struct dentry *dentry,
2063					   instantiate_t instantiate)
2064{
2065	struct task_struct *task = get_proc_task(dir);
2066	unsigned fd = name_to_int(dentry);
2067	struct dentry *result = ERR_PTR(-ENOENT);
 
 
2068
 
 
2069	if (!task)
2070		goto out_no_task;
2071	if (fd == ~0U)
2072		goto out;
2073
2074	result = instantiate(dir, dentry, task, &fd);
2075out:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2076	put_task_struct(task);
2077out_no_task:
2078	return result;
2079}
2080
2081static int proc_readfd_common(struct file * filp, void * dirent,
2082			      filldir_t filldir, instantiate_t instantiate)
 
 
 
 
 
 
2083{
2084	struct dentry *dentry = filp->f_path.dentry;
2085	struct inode *inode = dentry->d_inode;
2086	struct task_struct *p = get_proc_task(inode);
2087	unsigned int fd, ino;
2088	int retval;
2089	struct files_struct * files;
 
2090
2091	retval = -ENOENT;
2092	if (!p)
2093		goto out_no_task;
2094	retval = 0;
2095
2096	fd = filp->f_pos;
2097	switch (fd) {
2098		case 0:
2099			if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
2100				goto out;
2101			filp->f_pos++;
2102		case 1:
2103			ino = parent_ino(dentry);
2104			if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
2105				goto out;
2106			filp->f_pos++;
2107		default:
2108			files = get_files_struct(p);
2109			if (!files)
2110				goto out;
2111			rcu_read_lock();
2112			for (fd = filp->f_pos-2;
2113			     fd < files_fdtable(files)->max_fds;
2114			     fd++, filp->f_pos++) {
2115				char name[PROC_NUMBUF];
2116				int len;
2117
2118				if (!fcheck_files(files, fd))
2119					continue;
2120				rcu_read_unlock();
2121
2122				len = snprintf(name, sizeof(name), "%d", fd);
2123				if (proc_fill_cache(filp, dirent, filldir,
2124						    name, len, instantiate,
2125						    p, &fd) < 0) {
2126					rcu_read_lock();
2127					break;
2128				}
2129				rcu_read_lock();
2130			}
2131			rcu_read_unlock();
2132			put_files_struct(files);
2133	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2134out:
2135	put_task_struct(p);
2136out_no_task:
2137	return retval;
2138}
2139
2140static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry,
2141				    struct nameidata *nd)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2142{
2143	return proc_lookupfd_common(dir, dentry, proc_fd_instantiate);
 
 
 
 
 
 
 
 
 
 
2144}
2145
2146static int proc_readfd(struct file *filp, void *dirent, filldir_t filldir)
2147{
2148	return proc_readfd_common(filp, dirent, filldir, proc_fd_instantiate);
 
2149}
2150
2151static ssize_t proc_fdinfo_read(struct file *file, char __user *buf,
2152				      size_t len, loff_t *ppos)
2153{
2154	char tmp[PROC_FDINFO_MAX];
2155	int err = proc_fd_info(file->f_path.dentry->d_inode, NULL, tmp);
2156	if (!err)
2157		err = simple_read_from_buffer(buf, len, ppos, tmp, strlen(tmp));
2158	return err;
 
 
 
 
 
 
2159}
2160
2161static const struct file_operations proc_fdinfo_file_operations = {
2162	.open           = nonseekable_open,
2163	.read		= proc_fdinfo_read,
2164	.llseek		= no_llseek,
2165};
 
 
 
 
 
2166
2167static const struct file_operations proc_fd_operations = {
2168	.read		= generic_read_dir,
2169	.readdir	= proc_readfd,
2170	.llseek		= default_llseek,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2171};
2172
2173/*
2174 * /proc/pid/fd needs a special permission handler so that a process can still
2175 * access /proc/self/fd after it has executed a setuid().
2176 */
2177static int proc_fd_permission(struct inode *inode, int mask)
2178{
2179	int rv = generic_permission(inode, mask);
2180	if (rv == 0)
2181		return 0;
2182	if (task_pid(current) == proc_pid(inode))
2183		rv = 0;
2184	return rv;
 
 
 
 
2185}
2186
2187/*
2188 * proc directories can do almost nothing..
2189 */
2190static const struct inode_operations proc_fd_inode_operations = {
2191	.lookup		= proc_lookupfd,
2192	.permission	= proc_fd_permission,
2193	.setattr	= proc_setattr,
2194};
 
2195
2196static struct dentry *proc_fdinfo_instantiate(struct inode *dir,
2197	struct dentry *dentry, struct task_struct *task, const void *ptr)
2198{
2199	unsigned fd = *(unsigned *)ptr;
2200 	struct inode *inode;
2201 	struct proc_inode *ei;
2202	struct dentry *error = ERR_PTR(-ENOENT);
2203
2204	inode = proc_pid_make_inode(dir->i_sb, task);
2205	if (!inode)
2206		goto out;
2207	ei = PROC_I(inode);
2208	ei->fd = fd;
2209	inode->i_mode = S_IFREG | S_IRUSR;
2210	inode->i_fop = &proc_fdinfo_file_operations;
2211	d_set_d_op(dentry, &tid_fd_dentry_operations);
2212	d_add(dentry, inode);
2213	/* Close the race of the process dying before we return the dentry */
2214	if (tid_fd_revalidate(dentry, NULL))
2215		error = NULL;
2216
2217 out:
2218	return error;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2219}
2220
2221static struct dentry *proc_lookupfdinfo(struct inode *dir,
2222					struct dentry *dentry,
2223					struct nameidata *nd)
2224{
2225	return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2226}
2227
2228static int proc_readfdinfo(struct file *filp, void *dirent, filldir_t filldir)
2229{
2230	return proc_readfd_common(filp, dirent, filldir,
2231				  proc_fdinfo_instantiate);
2232}
2233
2234static const struct file_operations proc_fdinfo_operations = {
2235	.read		= generic_read_dir,
2236	.readdir	= proc_readfdinfo,
2237	.llseek		= default_llseek,
2238};
2239
2240/*
2241 * proc directories can do almost nothing..
2242 */
2243static const struct inode_operations proc_fdinfo_inode_operations = {
2244	.lookup		= proc_lookupfdinfo,
2245	.setattr	= proc_setattr,
2246};
2247
2248
2249static struct dentry *proc_pident_instantiate(struct inode *dir,
2250	struct dentry *dentry, struct task_struct *task, const void *ptr)
2251{
2252	const struct pid_entry *p = ptr;
2253	struct inode *inode;
2254	struct proc_inode *ei;
2255	struct dentry *error = ERR_PTR(-ENOENT);
2256
2257	inode = proc_pid_make_inode(dir->i_sb, task);
2258	if (!inode)
2259		goto out;
2260
2261	ei = PROC_I(inode);
2262	inode->i_mode = p->mode;
2263	if (S_ISDIR(inode->i_mode))
2264		inode->i_nlink = 2;	/* Use getattr to fix if necessary */
2265	if (p->iop)
2266		inode->i_op = p->iop;
2267	if (p->fop)
2268		inode->i_fop = p->fop;
2269	ei->op = p->op;
 
2270	d_set_d_op(dentry, &pid_dentry_operations);
2271	d_add(dentry, inode);
2272	/* Close the race of the process dying before we return the dentry */
2273	if (pid_revalidate(dentry, NULL))
2274		error = NULL;
2275out:
2276	return error;
2277}
2278
2279static struct dentry *proc_pident_lookup(struct inode *dir, 
2280					 struct dentry *dentry,
2281					 const struct pid_entry *ents,
2282					 unsigned int nents)
2283{
2284	struct dentry *error;
2285	struct task_struct *task = get_proc_task(dir);
2286	const struct pid_entry *p, *last;
2287
2288	error = ERR_PTR(-ENOENT);
2289
2290	if (!task)
2291		goto out_no_task;
2292
2293	/*
2294	 * Yes, it does not scale. And it should not. Don't add
2295	 * new entries into /proc/<tgid>/ without very good reasons.
2296	 */
2297	last = &ents[nents - 1];
2298	for (p = ents; p <= last; p++) {
2299		if (p->len != dentry->d_name.len)
2300			continue;
2301		if (!memcmp(dentry->d_name.name, p->name, p->len))
 
2302			break;
 
2303	}
2304	if (p > last)
2305		goto out;
2306
2307	error = proc_pident_instantiate(dir, dentry, task, p);
2308out:
2309	put_task_struct(task);
2310out_no_task:
2311	return error;
2312}
2313
2314static int proc_pident_fill_cache(struct file *filp, void *dirent,
2315	filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2316{
2317	return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2318				proc_pident_instantiate, task, p);
2319}
2320
2321static int proc_pident_readdir(struct file *filp,
2322		void *dirent, filldir_t filldir,
2323		const struct pid_entry *ents, unsigned int nents)
2324{
2325	int i;
2326	struct dentry *dentry = filp->f_path.dentry;
2327	struct inode *inode = dentry->d_inode;
2328	struct task_struct *task = get_proc_task(inode);
2329	const struct pid_entry *p, *last;
2330	ino_t ino;
2331	int ret;
2332
2333	ret = -ENOENT;
2334	if (!task)
2335		goto out_no_task;
2336
2337	ret = 0;
2338	i = filp->f_pos;
2339	switch (i) {
2340	case 0:
2341		ino = inode->i_ino;
2342		if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
2343			goto out;
2344		i++;
2345		filp->f_pos++;
2346		/* fall through */
2347	case 1:
2348		ino = parent_ino(dentry);
2349		if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
2350			goto out;
2351		i++;
2352		filp->f_pos++;
2353		/* fall through */
2354	default:
2355		i -= 2;
2356		if (i >= nents) {
2357			ret = 1;
2358			goto out;
2359		}
2360		p = ents + i;
2361		last = &ents[nents - 1];
2362		while (p <= last) {
2363			if (proc_pident_fill_cache(filp, dirent, filldir, task, p) < 0)
2364				goto out;
2365			filp->f_pos++;
2366			p++;
2367		}
2368	}
2369
2370	ret = 1;
 
 
 
 
 
2371out:
2372	put_task_struct(task);
2373out_no_task:
2374	return ret;
2375}
2376
2377#ifdef CONFIG_SECURITY
2378static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2379				  size_t count, loff_t *ppos)
2380{
2381	struct inode * inode = file->f_path.dentry->d_inode;
2382	char *p = NULL;
2383	ssize_t length;
2384	struct task_struct *task = get_proc_task(inode);
2385
2386	if (!task)
2387		return -ESRCH;
2388
2389	length = security_getprocattr(task,
2390				      (char*)file->f_path.dentry->d_name.name,
2391				      &p);
2392	put_task_struct(task);
2393	if (length > 0)
2394		length = simple_read_from_buffer(buf, count, ppos, p, length);
2395	kfree(p);
2396	return length;
2397}
2398
2399static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2400				   size_t count, loff_t *ppos)
2401{
2402	struct inode * inode = file->f_path.dentry->d_inode;
2403	char *page;
2404	ssize_t length;
2405	struct task_struct *task = get_proc_task(inode);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2406
2407	length = -ESRCH;
2408	if (!task)
2409		goto out_no_task;
2410	if (count > PAGE_SIZE)
2411		count = PAGE_SIZE;
2412
2413	/* No partial writes. */
2414	length = -EINVAL;
2415	if (*ppos != 0)
2416		goto out;
2417
2418	length = -ENOMEM;
2419	page = (char*)__get_free_page(GFP_TEMPORARY);
2420	if (!page)
2421		goto out;
2422
2423	length = -EFAULT;
2424	if (copy_from_user(page, buf, count))
2425		goto out_free;
2426
2427	/* Guard against adverse ptrace interaction */
2428	length = mutex_lock_interruptible(&task->signal->cred_guard_mutex);
2429	if (length < 0)
2430		goto out_free;
2431
2432	length = security_setprocattr(task,
2433				      (char*)file->f_path.dentry->d_name.name,
2434				      (void*)page, count);
2435	mutex_unlock(&task->signal->cred_guard_mutex);
2436out_free:
2437	free_page((unsigned long) page);
2438out:
2439	put_task_struct(task);
2440out_no_task:
2441	return length;
2442}
2443
2444static const struct file_operations proc_pid_attr_operations = {
2445	.read		= proc_pid_attr_read,
2446	.write		= proc_pid_attr_write,
2447	.llseek		= generic_file_llseek,
2448};
2449
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2450static const struct pid_entry attr_dir_stuff[] = {
2451	REG("current",    S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2452	REG("prev",       S_IRUGO,	   proc_pid_attr_operations),
2453	REG("exec",       S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2454	REG("fscreate",   S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2455	REG("keycreate",  S_IRUGO|S_IWUGO, proc_pid_attr_operations),
2456	REG("sockcreate", S_IRUGO|S_IWUGO, proc_pid_attr_operations),
 
 
 
 
 
 
 
 
2457};
2458
2459static int proc_attr_dir_readdir(struct file * filp,
2460			     void * dirent, filldir_t filldir)
2461{
2462	return proc_pident_readdir(filp,dirent,filldir,
2463				   attr_dir_stuff,ARRAY_SIZE(attr_dir_stuff));
2464}
2465
2466static const struct file_operations proc_attr_dir_operations = {
2467	.read		= generic_read_dir,
2468	.readdir	= proc_attr_dir_readdir,
2469	.llseek		= default_llseek,
2470};
2471
2472static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2473				struct dentry *dentry, struct nameidata *nd)
2474{
2475	return proc_pident_lookup(dir, dentry,
2476				  attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
 
2477}
2478
2479static const struct inode_operations proc_attr_dir_inode_operations = {
2480	.lookup		= proc_attr_dir_lookup,
2481	.getattr	= pid_getattr,
2482	.setattr	= proc_setattr,
2483};
2484
2485#endif
2486
2487#ifdef CONFIG_ELF_CORE
2488static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2489					 size_t count, loff_t *ppos)
2490{
2491	struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
2492	struct mm_struct *mm;
2493	char buffer[PROC_NUMBUF];
2494	size_t len;
2495	int ret;
2496
2497	if (!task)
2498		return -ESRCH;
2499
2500	ret = 0;
2501	mm = get_task_mm(task);
2502	if (mm) {
2503		len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2504			       ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2505				MMF_DUMP_FILTER_SHIFT));
2506		mmput(mm);
2507		ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2508	}
2509
2510	put_task_struct(task);
2511
2512	return ret;
2513}
2514
2515static ssize_t proc_coredump_filter_write(struct file *file,
2516					  const char __user *buf,
2517					  size_t count,
2518					  loff_t *ppos)
2519{
2520	struct task_struct *task;
2521	struct mm_struct *mm;
2522	char buffer[PROC_NUMBUF], *end;
2523	unsigned int val;
2524	int ret;
2525	int i;
2526	unsigned long mask;
2527
2528	ret = -EFAULT;
2529	memset(buffer, 0, sizeof(buffer));
2530	if (count > sizeof(buffer) - 1)
2531		count = sizeof(buffer) - 1;
2532	if (copy_from_user(buffer, buf, count))
2533		goto out_no_task;
2534
2535	ret = -EINVAL;
2536	val = (unsigned int)simple_strtoul(buffer, &end, 0);
2537	if (*end == '\n')
2538		end++;
2539	if (end - buffer == 0)
2540		goto out_no_task;
2541
2542	ret = -ESRCH;
2543	task = get_proc_task(file->f_dentry->d_inode);
2544	if (!task)
2545		goto out_no_task;
2546
2547	ret = end - buffer;
2548	mm = get_task_mm(task);
2549	if (!mm)
2550		goto out_no_mm;
 
2551
2552	for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2553		if (val & mask)
2554			set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2555		else
2556			clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2557	}
2558
2559	mmput(mm);
2560 out_no_mm:
2561	put_task_struct(task);
2562 out_no_task:
2563	return ret;
 
 
2564}
2565
2566static const struct file_operations proc_coredump_filter_operations = {
2567	.read		= proc_coredump_filter_read,
2568	.write		= proc_coredump_filter_write,
2569	.llseek		= generic_file_llseek,
2570};
2571#endif
2572
2573/*
2574 * /proc/self:
2575 */
2576static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
2577			      int buflen)
2578{
2579	struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2580	pid_t tgid = task_tgid_nr_ns(current, ns);
2581	char tmp[PROC_NUMBUF];
2582	if (!tgid)
2583		return -ENOENT;
2584	sprintf(tmp, "%d", tgid);
2585	return vfs_readlink(dentry,buffer,buflen,tmp);
2586}
2587
2588static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
2589{
2590	struct pid_namespace *ns = dentry->d_sb->s_fs_info;
2591	pid_t tgid = task_tgid_nr_ns(current, ns);
2592	char *name = ERR_PTR(-ENOENT);
2593	if (tgid) {
2594		name = __getname();
2595		if (!name)
2596			name = ERR_PTR(-ENOMEM);
2597		else
2598			sprintf(name, "%d", tgid);
2599	}
2600	nd_set_link(nd, name);
2601	return NULL;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2602}
2603
2604static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd,
2605				void *cookie)
2606{
2607	char *s = nd_get_link(nd);
2608	if (!IS_ERR(s))
2609		__putname(s);
2610}
2611
2612static const struct inode_operations proc_self_inode_operations = {
2613	.readlink	= proc_self_readlink,
2614	.follow_link	= proc_self_follow_link,
2615	.put_link	= proc_self_put_link,
2616};
2617
2618/*
2619 * proc base
2620 *
2621 * These are the directory entries in the root directory of /proc
2622 * that properly belong to the /proc filesystem, as they describe
2623 * describe something that is process related.
2624 */
2625static const struct pid_entry proc_base_stuff[] = {
2626	NOD("self", S_IFLNK|S_IRWXUGO,
2627		&proc_self_inode_operations, NULL, {}),
2628};
2629
2630static struct dentry *proc_base_instantiate(struct inode *dir,
2631	struct dentry *dentry, struct task_struct *task, const void *ptr)
 
2632{
2633	const struct pid_entry *p = ptr;
2634	struct inode *inode;
2635	struct proc_inode *ei;
2636	struct dentry *error;
2637
2638	/* Allocate the inode */
2639	error = ERR_PTR(-ENOMEM);
2640	inode = new_inode(dir->i_sb);
2641	if (!inode)
2642		goto out;
 
 
 
 
2643
2644	/* Initialize the inode */
2645	ei = PROC_I(inode);
2646	inode->i_ino = get_next_ino();
2647	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2648
2649	/*
2650	 * grab the reference to the task.
2651	 */
2652	ei->pid = get_task_pid(task, PIDTYPE_PID);
2653	if (!ei->pid)
2654		goto out_iput;
2655
2656	inode->i_mode = p->mode;
2657	if (S_ISDIR(inode->i_mode))
2658		inode->i_nlink = 2;
2659	if (S_ISLNK(inode->i_mode))
2660		inode->i_size = 64;
2661	if (p->iop)
2662		inode->i_op = p->iop;
2663	if (p->fop)
2664		inode->i_fop = p->fop;
2665	ei->op = p->op;
2666	d_add(dentry, inode);
2667	error = NULL;
2668out:
2669	return error;
2670out_iput:
2671	iput(inode);
2672	goto out;
2673}
2674
2675static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
2676{
2677	struct dentry *error;
2678	struct task_struct *task = get_proc_task(dir);
2679	const struct pid_entry *p, *last;
2680
2681	error = ERR_PTR(-ENOENT);
2682
2683	if (!task)
2684		goto out_no_task;
2685
2686	/* Lookup the directory entry */
2687	last = &proc_base_stuff[ARRAY_SIZE(proc_base_stuff) - 1];
2688	for (p = proc_base_stuff; p <= last; p++) {
2689		if (p->len != dentry->d_name.len)
2690			continue;
2691		if (!memcmp(dentry->d_name.name, p->name, p->len))
2692			break;
2693	}
2694	if (p > last)
2695		goto out;
2696
2697	error = proc_base_instantiate(dir, dentry, task, p);
2698
2699out:
2700	put_task_struct(task);
2701out_no_task:
2702	return error;
2703}
2704
2705static int proc_base_fill_cache(struct file *filp, void *dirent,
2706	filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
2707{
2708	return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
2709				proc_base_instantiate, task, p);
2710}
2711
2712#ifdef CONFIG_TASK_IO_ACCOUNTING
2713static int do_io_accounting(struct task_struct *task, char *buffer, int whole)
2714{
2715	struct task_io_accounting acct = task->ioac;
2716	unsigned long flags;
2717	int result;
2718
2719	result = mutex_lock_killable(&task->signal->cred_guard_mutex);
2720	if (result)
2721		return result;
 
 
 
 
2722
2723	if (!ptrace_may_access(task, PTRACE_MODE_READ)) {
2724		result = -EACCES;
2725		goto out_unlock;
2726	}
 
 
 
2727
2728	if (whole && lock_task_sighand(task, &flags)) {
2729		struct task_struct *t = task;
 
 
 
 
 
2730
2731		task_io_accounting_add(&acct, &task->signal->ioac);
2732		while_each_thread(task, t)
2733			task_io_accounting_add(&acct, &t->ioac);
 
 
2734
2735		unlock_task_sighand(task, &flags);
 
 
 
 
 
 
2736	}
2737	result = sprintf(buffer,
2738			"rchar: %llu\n"
2739			"wchar: %llu\n"
2740			"syscr: %llu\n"
2741			"syscw: %llu\n"
2742			"read_bytes: %llu\n"
2743			"write_bytes: %llu\n"
2744			"cancelled_write_bytes: %llu\n",
2745			(unsigned long long)acct.rchar,
2746			(unsigned long long)acct.wchar,
2747			(unsigned long long)acct.syscr,
2748			(unsigned long long)acct.syscw,
2749			(unsigned long long)acct.read_bytes,
2750			(unsigned long long)acct.write_bytes,
2751			(unsigned long long)acct.cancelled_write_bytes);
2752out_unlock:
2753	mutex_unlock(&task->signal->cred_guard_mutex);
2754	return result;
2755}
2756
2757static int proc_tid_io_accounting(struct task_struct *task, char *buffer)
2758{
2759	return do_io_accounting(task, buffer, 0);
 
 
 
 
 
 
 
 
 
 
 
 
2760}
2761
2762static int proc_tgid_io_accounting(struct task_struct *task, char *buffer)
2763{
2764	return do_io_accounting(task, buffer, 1);
 
 
 
 
2765}
2766#endif /* CONFIG_TASK_IO_ACCOUNTING */
 
 
 
 
 
 
 
 
2767
2768static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
2769				struct pid *pid, struct task_struct *task)
2770{
2771	int err = lock_trace(task);
2772	if (!err) {
2773		seq_printf(m, "%08x\n", task->personality);
2774		unlock_trace(task);
2775	}
2776	return err;
2777}
2778
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2779/*
2780 * Thread groups
2781 */
2782static const struct file_operations proc_task_operations;
2783static const struct inode_operations proc_task_inode_operations;
2784
2785static const struct pid_entry tgid_base_stuff[] = {
2786	DIR("task",       S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
2787	DIR("fd",         S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
 
2788	DIR("fdinfo",     S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
2789	DIR("ns",	  S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
2790#ifdef CONFIG_NET
2791	DIR("net",        S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
2792#endif
2793	REG("environ",    S_IRUSR, proc_environ_operations),
2794	INF("auxv",       S_IRUSR, proc_pid_auxv),
2795	ONE("status",     S_IRUGO, proc_pid_status),
2796	ONE("personality", S_IRUGO, proc_pid_personality),
2797	INF("limits",	  S_IRUGO, proc_pid_limits),
2798#ifdef CONFIG_SCHED_DEBUG
2799	REG("sched",      S_IRUGO|S_IWUSR, proc_pid_sched_operations),
2800#endif
2801#ifdef CONFIG_SCHED_AUTOGROUP
2802	REG("autogroup",  S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
2803#endif
 
 
 
2804	REG("comm",      S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
2805#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
2806	INF("syscall",    S_IRUGO, proc_pid_syscall),
2807#endif
2808	INF("cmdline",    S_IRUGO, proc_pid_cmdline),
2809	ONE("stat",       S_IRUGO, proc_tgid_stat),
2810	ONE("statm",      S_IRUGO, proc_pid_statm),
2811	REG("maps",       S_IRUGO, proc_maps_operations),
2812#ifdef CONFIG_NUMA
2813	REG("numa_maps",  S_IRUGO, proc_numa_maps_operations),
2814#endif
2815	REG("mem",        S_IRUSR|S_IWUSR, proc_mem_operations),
2816	LNK("cwd",        proc_cwd_link),
2817	LNK("root",       proc_root_link),
2818	LNK("exe",        proc_exe_link),
2819	REG("mounts",     S_IRUGO, proc_mounts_operations),
2820	REG("mountinfo",  S_IRUGO, proc_mountinfo_operations),
2821	REG("mountstats", S_IRUSR, proc_mountstats_operations),
2822#ifdef CONFIG_PROC_PAGE_MONITOR
2823	REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
2824	REG("smaps",      S_IRUGO, proc_smaps_operations),
2825	REG("pagemap",    S_IRUGO, proc_pagemap_operations),
 
2826#endif
2827#ifdef CONFIG_SECURITY
2828	DIR("attr",       S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
2829#endif
2830#ifdef CONFIG_KALLSYMS
2831	INF("wchan",      S_IRUGO, proc_pid_wchan),
2832#endif
2833#ifdef CONFIG_STACKTRACE
2834	ONE("stack",      S_IRUGO, proc_pid_stack),
2835#endif
2836#ifdef CONFIG_SCHEDSTATS
2837	INF("schedstat",  S_IRUGO, proc_pid_schedstat),
2838#endif
2839#ifdef CONFIG_LATENCYTOP
2840	REG("latency",  S_IRUGO, proc_lstats_operations),
2841#endif
2842#ifdef CONFIG_PROC_PID_CPUSET
2843	REG("cpuset",     S_IRUGO, proc_cpuset_operations),
2844#endif
2845#ifdef CONFIG_CGROUPS
2846	REG("cgroup",  S_IRUGO, proc_cgroup_operations),
 
 
 
2847#endif
2848	INF("oom_score",  S_IRUGO, proc_oom_score),
2849	REG("oom_adj",    S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
2850	REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
2851#ifdef CONFIG_AUDITSYSCALL
2852	REG("loginuid",   S_IWUSR|S_IRUGO, proc_loginuid_operations),
2853	REG("sessionid",  S_IRUGO, proc_sessionid_operations),
2854#endif
2855#ifdef CONFIG_FAULT_INJECTION
2856	REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
 
2857#endif
2858#ifdef CONFIG_ELF_CORE
2859	REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
2860#endif
2861#ifdef CONFIG_TASK_IO_ACCOUNTING
2862	INF("io",	S_IRUSR, proc_tgid_io_accounting),
 
 
 
 
 
 
 
 
 
2863#endif
2864#ifdef CONFIG_HARDWALL
2865	INF("hardwall",   S_IRUGO, proc_pid_hardwall),
 
 
 
 
 
 
 
2866#endif
2867};
2868
2869static int proc_tgid_base_readdir(struct file * filp,
2870			     void * dirent, filldir_t filldir)
2871{
2872	return proc_pident_readdir(filp,dirent,filldir,
2873				   tgid_base_stuff,ARRAY_SIZE(tgid_base_stuff));
2874}
2875
2876static const struct file_operations proc_tgid_base_operations = {
2877	.read		= generic_read_dir,
2878	.readdir	= proc_tgid_base_readdir,
2879	.llseek		= default_llseek,
2880};
2881
2882static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
 
 
 
 
 
 
 
 
 
2883	return proc_pident_lookup(dir, dentry,
2884				  tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
 
2885}
2886
2887static const struct inode_operations proc_tgid_base_inode_operations = {
2888	.lookup		= proc_tgid_base_lookup,
2889	.getattr	= pid_getattr,
2890	.setattr	= proc_setattr,
 
2891};
2892
2893static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
2894{
2895	struct dentry *dentry, *leader, *dir;
2896	char buf[PROC_NUMBUF];
2897	struct qstr name;
2898
2899	name.name = buf;
2900	name.len = snprintf(buf, sizeof(buf), "%d", pid);
2901	dentry = d_hash_and_lookup(mnt->mnt_root, &name);
2902	if (dentry) {
2903		shrink_dcache_parent(dentry);
2904		d_drop(dentry);
2905		dput(dentry);
2906	}
2907
2908	name.name = buf;
2909	name.len = snprintf(buf, sizeof(buf), "%d", tgid);
2910	leader = d_hash_and_lookup(mnt->mnt_root, &name);
2911	if (!leader)
2912		goto out;
2913
2914	name.name = "task";
2915	name.len = strlen(name.name);
2916	dir = d_hash_and_lookup(leader, &name);
2917	if (!dir)
2918		goto out_put_leader;
2919
2920	name.name = buf;
2921	name.len = snprintf(buf, sizeof(buf), "%d", pid);
2922	dentry = d_hash_and_lookup(dir, &name);
2923	if (dentry) {
2924		shrink_dcache_parent(dentry);
2925		d_drop(dentry);
2926		dput(dentry);
2927	}
2928
2929	dput(dir);
2930out_put_leader:
2931	dput(leader);
2932out:
2933	return;
2934}
2935
2936/**
2937 * proc_flush_task -  Remove dcache entries for @task from the /proc dcache.
2938 * @task: task that should be flushed.
2939 *
2940 * When flushing dentries from proc, one needs to flush them from global
2941 * proc (proc_mnt) and from all the namespaces' procs this task was seen
2942 * in. This call is supposed to do all of this job.
2943 *
2944 * Looks in the dcache for
2945 * /proc/@pid
2946 * /proc/@tgid/task/@pid
2947 * if either directory is present flushes it and all of it'ts children
2948 * from the dcache.
2949 *
2950 * It is safe and reasonable to cache /proc entries for a task until
2951 * that task exits.  After that they just clog up the dcache with
2952 * useless entries, possibly causing useful dcache entries to be
2953 * flushed instead.  This routine is proved to flush those useless
2954 * dcache entries at process exit time.
2955 *
2956 * NOTE: This routine is just an optimization so it does not guarantee
2957 *       that no dcache entries will exist at process exit time it
2958 *       just makes it very unlikely that any will persist.
2959 */
2960
2961void proc_flush_task(struct task_struct *task)
2962{
2963	int i;
2964	struct pid *pid, *tgid;
2965	struct upid *upid;
2966
2967	pid = task_pid(task);
2968	tgid = task_tgid(task);
2969
2970	for (i = 0; i <= pid->level; i++) {
2971		upid = &pid->numbers[i];
2972		proc_flush_task_mnt(upid->ns->proc_mnt, upid->nr,
2973					tgid->numbers[i].nr);
2974	}
2975
2976	upid = &pid->numbers[pid->level];
2977	if (upid->nr == 1)
2978		pid_ns_release_proc(upid->ns);
2979}
2980
2981static struct dentry *proc_pid_instantiate(struct inode *dir,
2982					   struct dentry * dentry,
2983					   struct task_struct *task, const void *ptr)
2984{
2985	struct dentry *error = ERR_PTR(-ENOENT);
2986	struct inode *inode;
2987
2988	inode = proc_pid_make_inode(dir->i_sb, task);
2989	if (!inode)
2990		goto out;
2991
2992	inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
2993	inode->i_op = &proc_tgid_base_inode_operations;
2994	inode->i_fop = &proc_tgid_base_operations;
2995	inode->i_flags|=S_IMMUTABLE;
2996
2997	inode->i_nlink = 2 + pid_entry_count_dirs(tgid_base_stuff,
2998		ARRAY_SIZE(tgid_base_stuff));
2999
3000	d_set_d_op(dentry, &pid_dentry_operations);
3001
3002	d_add(dentry, inode);
3003	/* Close the race of the process dying before we return the dentry */
3004	if (pid_revalidate(dentry, NULL))
3005		error = NULL;
3006out:
3007	return error;
3008}
3009
3010struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3011{
3012	struct dentry *result;
3013	struct task_struct *task;
3014	unsigned tgid;
 
3015	struct pid_namespace *ns;
 
3016
3017	result = proc_base_lookup(dir, dentry);
3018	if (!IS_ERR(result) || PTR_ERR(result) != -ENOENT)
3019		goto out;
3020
3021	tgid = name_to_int(dentry);
3022	if (tgid == ~0U)
3023		goto out;
3024
3025	ns = dentry->d_sb->s_fs_info;
 
3026	rcu_read_lock();
3027	task = find_task_by_pid_ns(tgid, ns);
3028	if (task)
3029		get_task_struct(task);
3030	rcu_read_unlock();
3031	if (!task)
3032		goto out;
3033
3034	result = proc_pid_instantiate(dir, dentry, task, NULL);
 
 
 
 
 
 
 
3035	put_task_struct(task);
3036out:
3037	return result;
3038}
3039
3040/*
3041 * Find the first task with tgid >= tgid
3042 *
3043 */
3044struct tgid_iter {
3045	unsigned int tgid;
3046	struct task_struct *task;
3047};
3048static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3049{
3050	struct pid *pid;
3051
3052	if (iter.task)
3053		put_task_struct(iter.task);
3054	rcu_read_lock();
3055retry:
3056	iter.task = NULL;
3057	pid = find_ge_pid(iter.tgid, ns);
3058	if (pid) {
3059		iter.tgid = pid_nr_ns(pid, ns);
3060		iter.task = pid_task(pid, PIDTYPE_PID);
3061		/* What we to know is if the pid we have find is the
3062		 * pid of a thread_group_leader.  Testing for task
3063		 * being a thread_group_leader is the obvious thing
3064		 * todo but there is a window when it fails, due to
3065		 * the pid transfer logic in de_thread.
3066		 *
3067		 * So we perform the straight forward test of seeing
3068		 * if the pid we have found is the pid of a thread
3069		 * group leader, and don't worry if the task we have
3070		 * found doesn't happen to be a thread group leader.
3071		 * As we don't care in the case of readdir.
3072		 */
3073		if (!iter.task || !has_group_leader_pid(iter.task)) {
3074			iter.tgid += 1;
3075			goto retry;
3076		}
3077		get_task_struct(iter.task);
3078	}
3079	rcu_read_unlock();
3080	return iter;
3081}
3082
3083#define TGID_OFFSET (FIRST_PROCESS_ENTRY + ARRAY_SIZE(proc_base_stuff))
3084
3085static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3086	struct tgid_iter iter)
3087{
3088	char name[PROC_NUMBUF];
3089	int len = snprintf(name, sizeof(name), "%d", iter.tgid);
3090	return proc_fill_cache(filp, dirent, filldir, name, len,
3091				proc_pid_instantiate, iter.task, NULL);
3092}
3093
3094/* for the /proc/ directory itself, after non-process stuff has been done */
3095int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
3096{
3097	unsigned int nr;
3098	struct task_struct *reaper;
3099	struct tgid_iter iter;
3100	struct pid_namespace *ns;
 
 
3101
3102	if (filp->f_pos >= PID_MAX_LIMIT + TGID_OFFSET)
3103		goto out_no_task;
3104	nr = filp->f_pos - FIRST_PROCESS_ENTRY;
3105
3106	reaper = get_proc_task(filp->f_path.dentry->d_inode);
3107	if (!reaper)
3108		goto out_no_task;
3109
3110	for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
3111		const struct pid_entry *p = &proc_base_stuff[nr];
3112		if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
3113			goto out;
 
3114	}
3115
3116	ns = filp->f_dentry->d_sb->s_fs_info;
 
 
 
 
 
3117	iter.task = NULL;
3118	iter.tgid = filp->f_pos - TGID_OFFSET;
3119	for (iter = next_tgid(ns, iter);
3120	     iter.task;
3121	     iter.tgid += 1, iter = next_tgid(ns, iter)) {
3122		filp->f_pos = iter.tgid + TGID_OFFSET;
3123		if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) {
 
 
 
 
 
 
 
 
 
3124			put_task_struct(iter.task);
3125			goto out;
3126		}
3127	}
3128	filp->f_pos = PID_MAX_LIMIT + TGID_OFFSET;
3129out:
3130	put_task_struct(reaper);
3131out_no_task:
3132	return 0;
3133}
3134
3135/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3136 * Tasks
3137 */
3138static const struct pid_entry tid_base_stuff[] = {
3139	DIR("fd",        S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3140	DIR("fdinfo",    S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3141	DIR("ns",	 S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
 
 
 
3142	REG("environ",   S_IRUSR, proc_environ_operations),
3143	INF("auxv",      S_IRUSR, proc_pid_auxv),
3144	ONE("status",    S_IRUGO, proc_pid_status),
3145	ONE("personality", S_IRUGO, proc_pid_personality),
3146	INF("limits",	 S_IRUGO, proc_pid_limits),
3147#ifdef CONFIG_SCHED_DEBUG
3148	REG("sched",     S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3149#endif
3150	REG("comm",      S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
 
 
3151#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3152	INF("syscall",   S_IRUGO, proc_pid_syscall),
3153#endif
3154	INF("cmdline",   S_IRUGO, proc_pid_cmdline),
3155	ONE("stat",      S_IRUGO, proc_tid_stat),
3156	ONE("statm",     S_IRUGO, proc_pid_statm),
3157	REG("maps",      S_IRUGO, proc_maps_operations),
 
 
 
3158#ifdef CONFIG_NUMA
3159	REG("numa_maps", S_IRUGO, proc_numa_maps_operations),
3160#endif
3161	REG("mem",       S_IRUSR|S_IWUSR, proc_mem_operations),
3162	LNK("cwd",       proc_cwd_link),
3163	LNK("root",      proc_root_link),
3164	LNK("exe",       proc_exe_link),
3165	REG("mounts",    S_IRUGO, proc_mounts_operations),
3166	REG("mountinfo",  S_IRUGO, proc_mountinfo_operations),
3167#ifdef CONFIG_PROC_PAGE_MONITOR
3168	REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3169	REG("smaps",     S_IRUGO, proc_smaps_operations),
3170	REG("pagemap",    S_IRUGO, proc_pagemap_operations),
 
3171#endif
3172#ifdef CONFIG_SECURITY
3173	DIR("attr",      S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3174#endif
3175#ifdef CONFIG_KALLSYMS
3176	INF("wchan",     S_IRUGO, proc_pid_wchan),
3177#endif
3178#ifdef CONFIG_STACKTRACE
3179	ONE("stack",      S_IRUGO, proc_pid_stack),
3180#endif
3181#ifdef CONFIG_SCHEDSTATS
3182	INF("schedstat", S_IRUGO, proc_pid_schedstat),
3183#endif
3184#ifdef CONFIG_LATENCYTOP
3185	REG("latency",  S_IRUGO, proc_lstats_operations),
3186#endif
3187#ifdef CONFIG_PROC_PID_CPUSET
3188	REG("cpuset",    S_IRUGO, proc_cpuset_operations),
3189#endif
3190#ifdef CONFIG_CGROUPS
3191	REG("cgroup",  S_IRUGO, proc_cgroup_operations),
 
 
 
3192#endif
3193	INF("oom_score", S_IRUGO, proc_oom_score),
3194	REG("oom_adj",   S_IRUGO|S_IWUSR, proc_oom_adjust_operations),
3195	REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3196#ifdef CONFIG_AUDITSYSCALL
3197	REG("loginuid",  S_IWUSR|S_IRUGO, proc_loginuid_operations),
3198	REG("sessionid",  S_IRUGO, proc_sessionid_operations),
3199#endif
3200#ifdef CONFIG_FAULT_INJECTION
3201	REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
 
3202#endif
3203#ifdef CONFIG_TASK_IO_ACCOUNTING
3204	INF("io",	S_IRUSR, proc_tid_io_accounting),
 
 
 
 
 
 
 
 
 
3205#endif
3206#ifdef CONFIG_HARDWALL
3207	INF("hardwall",   S_IRUGO, proc_pid_hardwall),
3208#endif
3209};
3210
3211static int proc_tid_base_readdir(struct file * filp,
3212			     void * dirent, filldir_t filldir)
3213{
3214	return proc_pident_readdir(filp,dirent,filldir,
3215				   tid_base_stuff,ARRAY_SIZE(tid_base_stuff));
3216}
3217
3218static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){
 
3219	return proc_pident_lookup(dir, dentry,
3220				  tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
 
3221}
3222
3223static const struct file_operations proc_tid_base_operations = {
3224	.read		= generic_read_dir,
3225	.readdir	= proc_tid_base_readdir,
3226	.llseek		= default_llseek,
3227};
3228
3229static const struct inode_operations proc_tid_base_inode_operations = {
3230	.lookup		= proc_tid_base_lookup,
3231	.getattr	= pid_getattr,
3232	.setattr	= proc_setattr,
3233};
3234
3235static struct dentry *proc_task_instantiate(struct inode *dir,
3236	struct dentry *dentry, struct task_struct *task, const void *ptr)
3237{
3238	struct dentry *error = ERR_PTR(-ENOENT);
3239	struct inode *inode;
3240	inode = proc_pid_make_inode(dir->i_sb, task);
3241
3242	if (!inode)
3243		goto out;
3244	inode->i_mode = S_IFDIR|S_IRUGO|S_IXUGO;
3245	inode->i_op = &proc_tid_base_inode_operations;
3246	inode->i_fop = &proc_tid_base_operations;
3247	inode->i_flags|=S_IMMUTABLE;
3248
3249	inode->i_nlink = 2 + pid_entry_count_dirs(tid_base_stuff,
3250		ARRAY_SIZE(tid_base_stuff));
3251
3252	d_set_d_op(dentry, &pid_dentry_operations);
3253
3254	d_add(dentry, inode);
3255	/* Close the race of the process dying before we return the dentry */
3256	if (pid_revalidate(dentry, NULL))
3257		error = NULL;
3258out:
3259	return error;
3260}
3261
3262static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
3263{
3264	struct dentry *result = ERR_PTR(-ENOENT);
3265	struct task_struct *task;
3266	struct task_struct *leader = get_proc_task(dir);
3267	unsigned tid;
 
3268	struct pid_namespace *ns;
 
3269
3270	if (!leader)
3271		goto out_no_task;
3272
3273	tid = name_to_int(dentry);
3274	if (tid == ~0U)
3275		goto out;
3276
3277	ns = dentry->d_sb->s_fs_info;
 
3278	rcu_read_lock();
3279	task = find_task_by_pid_ns(tid, ns);
3280	if (task)
3281		get_task_struct(task);
3282	rcu_read_unlock();
3283	if (!task)
3284		goto out;
3285	if (!same_thread_group(leader, task))
3286		goto out_drop_task;
3287
3288	result = proc_task_instantiate(dir, dentry, task, NULL);
3289out_drop_task:
3290	put_task_struct(task);
3291out:
3292	put_task_struct(leader);
3293out_no_task:
3294	return result;
3295}
3296
3297/*
3298 * Find the first tid of a thread group to return to user space.
3299 *
3300 * Usually this is just the thread group leader, but if the users
3301 * buffer was too small or there was a seek into the middle of the
3302 * directory we have more work todo.
3303 *
3304 * In the case of a short read we start with find_task_by_pid.
3305 *
3306 * In the case of a seek we start with the leader and walk nr
3307 * threads past it.
3308 */
3309static struct task_struct *first_tid(struct task_struct *leader,
3310		int tid, int nr, struct pid_namespace *ns)
3311{
3312	struct task_struct *pos;
 
 
 
 
3313
3314	rcu_read_lock();
3315	/* Attempt to start with the pid of a thread */
3316	if (tid && (nr > 0)) {
 
 
 
 
3317		pos = find_task_by_pid_ns(tid, ns);
3318		if (pos && (pos->group_leader == leader))
3319			goto found;
3320	}
3321
3322	/* If nr exceeds the number of threads there is nothing todo */
3323	pos = NULL;
3324	if (nr && nr >= get_nr_threads(leader))
3325		goto out;
3326
3327	/* If we haven't found our starting place yet start
3328	 * with the leader and walk nr threads forward.
3329	 */
3330	for (pos = leader; nr > 0; --nr) {
3331		pos = next_thread(pos);
3332		if (pos == leader) {
3333			pos = NULL;
3334			goto out;
3335		}
3336	}
 
3337found:
3338	get_task_struct(pos);
3339out:
3340	rcu_read_unlock();
3341	return pos;
3342}
3343
3344/*
3345 * Find the next thread in the thread list.
3346 * Return NULL if there is an error or no next thread.
3347 *
3348 * The reference to the input task_struct is released.
3349 */
3350static struct task_struct *next_tid(struct task_struct *start)
3351{
3352	struct task_struct *pos = NULL;
3353	rcu_read_lock();
3354	if (pid_alive(start)) {
3355		pos = next_thread(start);
3356		if (thread_group_leader(pos))
3357			pos = NULL;
3358		else
3359			get_task_struct(pos);
3360	}
3361	rcu_read_unlock();
3362	put_task_struct(start);
3363	return pos;
3364}
3365
3366static int proc_task_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
3367	struct task_struct *task, int tid)
3368{
3369	char name[PROC_NUMBUF];
3370	int len = snprintf(name, sizeof(name), "%d", tid);
3371	return proc_fill_cache(filp, dirent, filldir, name, len,
3372				proc_task_instantiate, task, NULL);
3373}
3374
3375/* for the /proc/TGID/task/ directories */
3376static int proc_task_readdir(struct file * filp, void * dirent, filldir_t filldir)
3377{
3378	struct dentry *dentry = filp->f_path.dentry;
3379	struct inode *inode = dentry->d_inode;
3380	struct task_struct *leader = NULL;
3381	struct task_struct *task;
3382	int retval = -ENOENT;
3383	ino_t ino;
3384	int tid;
3385	struct pid_namespace *ns;
 
3386
3387	task = get_proc_task(inode);
3388	if (!task)
3389		goto out_no_task;
3390	rcu_read_lock();
3391	if (pid_alive(task)) {
3392		leader = task->group_leader;
3393		get_task_struct(leader);
3394	}
3395	rcu_read_unlock();
3396	put_task_struct(task);
3397	if (!leader)
3398		goto out_no_task;
3399	retval = 0;
3400
3401	switch ((unsigned long)filp->f_pos) {
3402	case 0:
3403		ino = inode->i_ino;
3404		if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) < 0)
3405			goto out;
3406		filp->f_pos++;
3407		/* fall through */
3408	case 1:
3409		ino = parent_ino(dentry);
3410		if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) < 0)
3411			goto out;
3412		filp->f_pos++;
3413		/* fall through */
3414	}
3415
3416	/* f_version caches the tgid value that the last readdir call couldn't
3417	 * return. lseek aka telldir automagically resets f_version to 0.
3418	 */
3419	ns = filp->f_dentry->d_sb->s_fs_info;
3420	tid = (int)filp->f_version;
3421	filp->f_version = 0;
3422	for (task = first_tid(leader, tid, filp->f_pos - 2, ns);
3423	     task;
3424	     task = next_tid(task), filp->f_pos++) {
 
 
3425		tid = task_pid_nr_ns(task, ns);
3426		if (proc_task_fill_cache(filp, dirent, filldir, task, tid) < 0) {
 
 
3427			/* returning this tgid failed, save it as the first
3428			 * pid for the next readir call */
3429			filp->f_version = (u64)tid;
3430			put_task_struct(task);
3431			break;
3432		}
3433	}
3434out:
3435	put_task_struct(leader);
3436out_no_task:
3437	return retval;
3438}
3439
3440static int proc_task_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
 
3441{
3442	struct inode *inode = dentry->d_inode;
3443	struct task_struct *p = get_proc_task(inode);
3444	generic_fillattr(inode, stat);
3445
3446	if (p) {
3447		stat->nlink += get_nr_threads(p);
3448		put_task_struct(p);
3449	}
3450
3451	return 0;
3452}
3453
3454static const struct inode_operations proc_task_inode_operations = {
3455	.lookup		= proc_task_lookup,
3456	.getattr	= proc_task_getattr,
3457	.setattr	= proc_setattr,
 
3458};
3459
3460static const struct file_operations proc_task_operations = {
3461	.read		= generic_read_dir,
3462	.readdir	= proc_task_readdir,
3463	.llseek		= default_llseek,
3464};
v5.9
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 *  linux/fs/proc/base.c
   4 *
   5 *  Copyright (C) 1991, 1992 Linus Torvalds
   6 *
   7 *  proc base directory handling functions
   8 *
   9 *  1999, Al Viro. Rewritten. Now it covers the whole per-process part.
  10 *  Instead of using magical inumbers to determine the kind of object
  11 *  we allocate and fill in-core inodes upon lookup. They don't even
  12 *  go into icache. We cache the reference to task_struct upon lookup too.
  13 *  Eventually it should become a filesystem in its own. We don't use the
  14 *  rest of procfs anymore.
  15 *
  16 *
  17 *  Changelog:
  18 *  17-Jan-2005
  19 *  Allan Bezerra
  20 *  Bruna Moreira <bruna.moreira@indt.org.br>
  21 *  Edjard Mota <edjard.mota@indt.org.br>
  22 *  Ilias Biris <ilias.biris@indt.org.br>
  23 *  Mauricio Lin <mauricio.lin@indt.org.br>
  24 *
  25 *  Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
  26 *
  27 *  A new process specific entry (smaps) included in /proc. It shows the
  28 *  size of rss for each memory area. The maps entry lacks information
  29 *  about physical memory size (rss) for each mapped file, i.e.,
  30 *  rss information for executables and library files.
  31 *  This additional information is useful for any tools that need to know
  32 *  about physical memory consumption for a process specific library.
  33 *
  34 *  Changelog:
  35 *  21-Feb-2005
  36 *  Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
  37 *  Pud inclusion in the page table walking.
  38 *
  39 *  ChangeLog:
  40 *  10-Mar-2005
  41 *  10LE Instituto Nokia de Tecnologia - INdT:
  42 *  A better way to walks through the page table as suggested by Hugh Dickins.
  43 *
  44 *  Simo Piiroinen <simo.piiroinen@nokia.com>:
  45 *  Smaps information related to shared, private, clean and dirty pages.
  46 *
  47 *  Paul Mundt <paul.mundt@nokia.com>:
  48 *  Overall revision about smaps.
  49 */
  50
  51#include <linux/uaccess.h>
  52
  53#include <linux/errno.h>
  54#include <linux/time.h>
  55#include <linux/proc_fs.h>
  56#include <linux/stat.h>
  57#include <linux/task_io_accounting_ops.h>
  58#include <linux/init.h>
  59#include <linux/capability.h>
  60#include <linux/file.h>
  61#include <linux/fdtable.h>
  62#include <linux/generic-radix-tree.h>
  63#include <linux/string.h>
  64#include <linux/seq_file.h>
  65#include <linux/namei.h>
  66#include <linux/mnt_namespace.h>
  67#include <linux/mm.h>
  68#include <linux/swap.h>
  69#include <linux/rcupdate.h>
  70#include <linux/kallsyms.h>
  71#include <linux/stacktrace.h>
  72#include <linux/resource.h>
  73#include <linux/module.h>
  74#include <linux/mount.h>
  75#include <linux/security.h>
  76#include <linux/ptrace.h>
  77#include <linux/tracehook.h>
  78#include <linux/printk.h>
  79#include <linux/cache.h>
  80#include <linux/cgroup.h>
  81#include <linux/cpuset.h>
  82#include <linux/audit.h>
  83#include <linux/poll.h>
  84#include <linux/nsproxy.h>
  85#include <linux/oom.h>
  86#include <linux/elf.h>
  87#include <linux/pid_namespace.h>
  88#include <linux/user_namespace.h>
  89#include <linux/fs_struct.h>
  90#include <linux/slab.h>
  91#include <linux/sched/autogroup.h>
  92#include <linux/sched/mm.h>
  93#include <linux/sched/coredump.h>
  94#include <linux/sched/debug.h>
  95#include <linux/sched/stat.h>
  96#include <linux/posix-timers.h>
  97#include <linux/time_namespace.h>
  98#include <linux/resctrl.h>
  99#include <trace/events/oom.h>
 100#include "internal.h"
 101#include "fd.h"
 102
 103#include "../../lib/kstrtox.h"
 104
 105/* NOTE:
 106 *	Implementing inode permission operations in /proc is almost
 107 *	certainly an error.  Permission checks need to happen during
 108 *	each system call not at open time.  The reason is that most of
 109 *	what we wish to check for permissions in /proc varies at runtime.
 110 *
 111 *	The classic example of a problem is opening file descriptors
 112 *	in /proc for a task before it execs a suid executable.
 113 */
 114
 115static u8 nlink_tid __ro_after_init;
 116static u8 nlink_tgid __ro_after_init;
 117
 118struct pid_entry {
 119	const char *name;
 120	unsigned int len;
 121	umode_t mode;
 122	const struct inode_operations *iop;
 123	const struct file_operations *fop;
 124	union proc_op op;
 125};
 126
 127#define NOD(NAME, MODE, IOP, FOP, OP) {			\
 128	.name = (NAME),					\
 129	.len  = sizeof(NAME) - 1,			\
 130	.mode = MODE,					\
 131	.iop  = IOP,					\
 132	.fop  = FOP,					\
 133	.op   = OP,					\
 134}
 135
 136#define DIR(NAME, MODE, iops, fops)	\
 137	NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
 138#define LNK(NAME, get_link)					\
 139	NOD(NAME, (S_IFLNK|S_IRWXUGO),				\
 140		&proc_pid_link_inode_operations, NULL,		\
 141		{ .proc_get_link = get_link } )
 142#define REG(NAME, MODE, fops)				\
 143	NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
 
 
 
 
 144#define ONE(NAME, MODE, show)				\
 145	NOD(NAME, (S_IFREG|(MODE)),			\
 146		NULL, &proc_single_file_operations,	\
 147		{ .proc_show = show } )
 148#define ATTR(LSM, NAME, MODE)				\
 149	NOD(NAME, (S_IFREG|(MODE)),			\
 150		NULL, &proc_pid_attr_operations,	\
 151		{ .lsm = LSM })
 152
 153/*
 154 * Count the number of hardlinks for the pid_entry table, excluding the .
 155 * and .. links.
 156 */
 157static unsigned int __init pid_entry_nlink(const struct pid_entry *entries,
 158	unsigned int n)
 159{
 160	unsigned int i;
 161	unsigned int count;
 162
 163	count = 2;
 164	for (i = 0; i < n; ++i) {
 165		if (S_ISDIR(entries[i].mode))
 166			++count;
 167	}
 168
 169	return count;
 170}
 171
 172static int get_task_root(struct task_struct *task, struct path *root)
 173{
 174	int result = -ENOENT;
 175
 176	task_lock(task);
 177	if (task->fs) {
 178		get_fs_root(task->fs, root);
 179		result = 0;
 180	}
 181	task_unlock(task);
 182	return result;
 183}
 184
 185static int proc_cwd_link(struct dentry *dentry, struct path *path)
 186{
 187	struct task_struct *task = get_proc_task(d_inode(dentry));
 188	int result = -ENOENT;
 189
 190	if (task) {
 191		task_lock(task);
 192		if (task->fs) {
 193			get_fs_pwd(task->fs, path);
 194			result = 0;
 195		}
 196		task_unlock(task);
 197		put_task_struct(task);
 198	}
 199	return result;
 200}
 201
 202static int proc_root_link(struct dentry *dentry, struct path *path)
 203{
 204	struct task_struct *task = get_proc_task(d_inode(dentry));
 205	int result = -ENOENT;
 206
 207	if (task) {
 208		result = get_task_root(task, path);
 209		put_task_struct(task);
 210	}
 211	return result;
 212}
 213
 214/*
 215 * If the user used setproctitle(), we just get the string from
 216 * user space at arg_start, and limit it to a maximum of one page.
 217 */
 218static ssize_t get_mm_proctitle(struct mm_struct *mm, char __user *buf,
 219				size_t count, unsigned long pos,
 220				unsigned long arg_start)
 221{
 222	char *page;
 223	int ret, got;
 224
 225	if (pos >= PAGE_SIZE)
 226		return 0;
 
 227
 228	page = (char *)__get_free_page(GFP_KERNEL);
 229	if (!page)
 230		return -ENOMEM;
 
 
 
 231
 232	ret = 0;
 233	got = access_remote_vm(mm, arg_start, page, PAGE_SIZE, FOLL_ANON);
 234	if (got > 0) {
 235		int len = strnlen(page, got);
 236
 237		/* Include the NUL character if it was found */
 238		if (len < got)
 239			len++;
 240
 241		if (len > pos) {
 242			len -= pos;
 243			if (len > count)
 244				len = count;
 245			len -= copy_to_user(buf, page+pos, len);
 246			if (!len)
 247				len = -EFAULT;
 248			ret = len;
 249		}
 250	}
 251	free_page((unsigned long)page);
 252	return ret;
 
 
 
 
 253}
 254
 255static ssize_t get_mm_cmdline(struct mm_struct *mm, char __user *buf,
 256			      size_t count, loff_t *ppos)
 
 
 
 257{
 258	unsigned long arg_start, arg_end, env_start, env_end;
 259	unsigned long pos, len;
 260	char *page, c;
 261
 262	/* Check if process spawned far enough to have cmdline. */
 263	if (!mm->env_end)
 264		return 0;
 265
 266	spin_lock(&mm->arg_lock);
 267	arg_start = mm->arg_start;
 268	arg_end = mm->arg_end;
 269	env_start = mm->env_start;
 270	env_end = mm->env_end;
 271	spin_unlock(&mm->arg_lock);
 272
 273	if (arg_start >= arg_end)
 274		return 0;
 275
 276	/*
 277	 * We allow setproctitle() to overwrite the argument
 278	 * strings, and overflow past the original end. But
 279	 * only when it overflows into the environment area.
 280	 */
 281	if (env_start != arg_end || env_end < env_start)
 282		env_start = env_end = arg_end;
 283	len = env_end - arg_start;
 284
 285	/* We're not going to care if "*ppos" has high bits set */
 286	pos = *ppos;
 287	if (pos >= len)
 288		return 0;
 289	if (count > len - pos)
 290		count = len - pos;
 291	if (!count)
 292		return 0;
 293
 294	/*
 295	 * Magical special case: if the argv[] end byte is not
 296	 * zero, the user has overwritten it with setproctitle(3).
 297	 *
 298	 * Possible future enhancement: do this only once when
 299	 * pos is 0, and set a flag in the 'struct file'.
 300	 */
 301	if (access_remote_vm(mm, arg_end-1, &c, 1, FOLL_ANON) == 1 && c)
 302		return get_mm_proctitle(mm, buf, count, pos, arg_start);
 303
 304	/*
 305	 * For the non-setproctitle() case we limit things strictly
 306	 * to the [arg_start, arg_end[ range.
 307	 */
 308	pos += arg_start;
 309	if (pos < arg_start || pos >= arg_end)
 310		return 0;
 311	if (count > arg_end - pos)
 312		count = arg_end - pos;
 313
 314	page = (char *)__get_free_page(GFP_KERNEL);
 315	if (!page)
 316		return -ENOMEM;
 
 317
 318	len = 0;
 319	while (count) {
 320		int got;
 321		size_t size = min_t(size_t, PAGE_SIZE, count);
 322
 323		got = access_remote_vm(mm, pos, page, size, FOLL_ANON);
 324		if (got <= 0)
 325			break;
 326		got -= copy_to_user(buf, page, got);
 327		if (unlikely(!got)) {
 328			if (!len)
 329				len = -EFAULT;
 330			break;
 331		}
 332		pos += got;
 333		buf += got;
 334		len += got;
 335		count -= got;
 336	}
 
 337
 338	free_page((unsigned long)page);
 339	return len;
 340}
 341
 342static ssize_t get_task_cmdline(struct task_struct *tsk, char __user *buf,
 343				size_t count, loff_t *pos)
 344{
 345	struct mm_struct *mm;
 346	ssize_t ret;
 347
 348	mm = get_task_mm(tsk);
 349	if (!mm)
 350		return 0;
 
 
 351
 352	ret = get_mm_cmdline(mm, buf, count, pos);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 353	mmput(mm);
 354	return ret;
 
 355}
 356
 357static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
 358				     size_t count, loff_t *pos)
 359{
 360	struct task_struct *tsk;
 361	ssize_t ret;
 362
 363	BUG_ON(*pos < 0);
 364
 365	tsk = get_proc_task(file_inode(file));
 366	if (!tsk)
 367		return -ESRCH;
 368	ret = get_task_cmdline(tsk, buf, count, pos);
 369	put_task_struct(tsk);
 370	if (ret > 0)
 371		*pos += ret;
 372	return ret;
 
 373}
 374
 375static const struct file_operations proc_pid_cmdline_ops = {
 376	.read	= proc_pid_cmdline_read,
 377	.llseek	= generic_file_llseek,
 378};
 379
 380#ifdef CONFIG_KALLSYMS
 381/*
 382 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
 383 * Returns the resolved symbol.  If that fails, simply return the address.
 384 */
 385static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
 386			  struct pid *pid, struct task_struct *task)
 387{
 388	unsigned long wchan;
 389	char symname[KSYM_NAME_LEN];
 390
 391	if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
 392		goto print0;
 393
 394	wchan = get_wchan(task);
 395	if (wchan && !lookup_symbol_name(wchan, symname)) {
 396		seq_puts(m, symname);
 397		return 0;
 398	}
 399
 400print0:
 401	seq_putc(m, '0');
 402	return 0;
 
 
 
 
 403}
 404#endif /* CONFIG_KALLSYMS */
 405
 406static int lock_trace(struct task_struct *task)
 407{
 408	int err = mutex_lock_killable(&task->signal->exec_update_mutex);
 409	if (err)
 410		return err;
 411	if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
 412		mutex_unlock(&task->signal->exec_update_mutex);
 413		return -EPERM;
 414	}
 415	return 0;
 416}
 417
 418static void unlock_trace(struct task_struct *task)
 419{
 420	mutex_unlock(&task->signal->exec_update_mutex);
 421}
 422
 423#ifdef CONFIG_STACKTRACE
 424
 425#define MAX_STACK_TRACE_DEPTH	64
 426
 427static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
 428			  struct pid *pid, struct task_struct *task)
 429{
 
 430	unsigned long *entries;
 431	int err;
 
 432
 433	/*
 434	 * The ability to racily run the kernel stack unwinder on a running task
 435	 * and then observe the unwinder output is scary; while it is useful for
 436	 * debugging kernel issues, it can also allow an attacker to leak kernel
 437	 * stack contents.
 438	 * Doing this in a manner that is at least safe from races would require
 439	 * some work to ensure that the remote task can not be scheduled; and
 440	 * even then, this would still expose the unwinder as local attack
 441	 * surface.
 442	 * Therefore, this interface is restricted to root.
 443	 */
 444	if (!file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN))
 445		return -EACCES;
 446
 447	entries = kmalloc_array(MAX_STACK_TRACE_DEPTH, sizeof(*entries),
 448				GFP_KERNEL);
 449	if (!entries)
 450		return -ENOMEM;
 451
 
 
 
 
 
 452	err = lock_trace(task);
 453	if (!err) {
 454		unsigned int i, nr_entries;
 455
 456		nr_entries = stack_trace_save_tsk(task, entries,
 457						  MAX_STACK_TRACE_DEPTH, 0);
 458
 459		for (i = 0; i < nr_entries; i++) {
 460			seq_printf(m, "[<0>] %pB\n", (void *)entries[i]);
 
 461		}
 462
 463		unlock_trace(task);
 464	}
 465	kfree(entries);
 466
 467	return err;
 468}
 469#endif
 470
 471#ifdef CONFIG_SCHED_INFO
 472/*
 473 * Provides /proc/PID/schedstat
 474 */
 475static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
 476			      struct pid *pid, struct task_struct *task)
 477{
 478	if (unlikely(!sched_info_on()))
 479		seq_puts(m, "0 0 0\n");
 480	else
 481		seq_printf(m, "%llu %llu %lu\n",
 482		   (unsigned long long)task->se.sum_exec_runtime,
 483		   (unsigned long long)task->sched_info.run_delay,
 484		   task->sched_info.pcount);
 485
 486	return 0;
 487}
 488#endif
 489
 490#ifdef CONFIG_LATENCYTOP
 491static int lstats_show_proc(struct seq_file *m, void *v)
 492{
 493	int i;
 494	struct inode *inode = m->private;
 495	struct task_struct *task = get_proc_task(inode);
 496
 497	if (!task)
 498		return -ESRCH;
 499	seq_puts(m, "Latency Top version : v0.1\n");
 500	for (i = 0; i < LT_SAVECOUNT; i++) {
 501		struct latency_record *lr = &task->latency_record[i];
 502		if (lr->backtrace[0]) {
 503			int q;
 504			seq_printf(m, "%i %li %li",
 505				   lr->count, lr->time, lr->max);
 506			for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
 507				unsigned long bt = lr->backtrace[q];
 508
 509				if (!bt)
 510					break;
 
 
 511				seq_printf(m, " %ps", (void *)bt);
 512			}
 513			seq_putc(m, '\n');
 514		}
 515
 516	}
 517	put_task_struct(task);
 518	return 0;
 519}
 520
 521static int lstats_open(struct inode *inode, struct file *file)
 522{
 523	return single_open(file, lstats_show_proc, inode);
 524}
 525
 526static ssize_t lstats_write(struct file *file, const char __user *buf,
 527			    size_t count, loff_t *offs)
 528{
 529	struct task_struct *task = get_proc_task(file_inode(file));
 530
 531	if (!task)
 532		return -ESRCH;
 533	clear_tsk_latency_tracing(task);
 534	put_task_struct(task);
 535
 536	return count;
 537}
 538
 539static const struct file_operations proc_lstats_operations = {
 540	.open		= lstats_open,
 541	.read		= seq_read,
 542	.write		= lstats_write,
 543	.llseek		= seq_lseek,
 544	.release	= single_release,
 545};
 546
 547#endif
 548
 549static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
 550			  struct pid *pid, struct task_struct *task)
 551{
 552	unsigned long totalpages = totalram_pages() + total_swap_pages;
 553	unsigned long points = 0;
 554	long badness;
 555
 556	badness = oom_badness(task, totalpages);
 557	/*
 558	 * Special case OOM_SCORE_ADJ_MIN for all others scale the
 559	 * badness value into [0, 2000] range which we have been
 560	 * exporting for a long time so userspace might depend on it.
 561	 */
 562	if (badness != LONG_MIN)
 563		points = (1000 + badness * 1000 / (long)totalpages) * 2 / 3;
 564
 565	seq_printf(m, "%lu\n", points);
 566
 567	return 0;
 
 
 
 
 
 568}
 569
 570struct limit_names {
 571	const char *name;
 572	const char *unit;
 573};
 574
 575static const struct limit_names lnames[RLIM_NLIMITS] = {
 576	[RLIMIT_CPU] = {"Max cpu time", "seconds"},
 577	[RLIMIT_FSIZE] = {"Max file size", "bytes"},
 578	[RLIMIT_DATA] = {"Max data size", "bytes"},
 579	[RLIMIT_STACK] = {"Max stack size", "bytes"},
 580	[RLIMIT_CORE] = {"Max core file size", "bytes"},
 581	[RLIMIT_RSS] = {"Max resident set", "bytes"},
 582	[RLIMIT_NPROC] = {"Max processes", "processes"},
 583	[RLIMIT_NOFILE] = {"Max open files", "files"},
 584	[RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
 585	[RLIMIT_AS] = {"Max address space", "bytes"},
 586	[RLIMIT_LOCKS] = {"Max file locks", "locks"},
 587	[RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
 588	[RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
 589	[RLIMIT_NICE] = {"Max nice priority", NULL},
 590	[RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
 591	[RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
 592};
 593
 594/* Display limits for a process */
 595static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
 596			   struct pid *pid, struct task_struct *task)
 597{
 598	unsigned int i;
 
 599	unsigned long flags;
 
 600
 601	struct rlimit rlim[RLIM_NLIMITS];
 602
 603	if (!lock_task_sighand(task, &flags))
 604		return 0;
 605	memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
 606	unlock_task_sighand(task, &flags);
 607
 608	/*
 609	 * print the file header
 610	 */
 611	seq_puts(m, "Limit                     "
 612		"Soft Limit           "
 613		"Hard Limit           "
 614		"Units     \n");
 615
 616	for (i = 0; i < RLIM_NLIMITS; i++) {
 617		if (rlim[i].rlim_cur == RLIM_INFINITY)
 618			seq_printf(m, "%-25s %-20s ",
 619				   lnames[i].name, "unlimited");
 620		else
 621			seq_printf(m, "%-25s %-20lu ",
 622				   lnames[i].name, rlim[i].rlim_cur);
 623
 624		if (rlim[i].rlim_max == RLIM_INFINITY)
 625			seq_printf(m, "%-20s ", "unlimited");
 626		else
 627			seq_printf(m, "%-20lu ", rlim[i].rlim_max);
 
 628
 629		if (lnames[i].unit)
 630			seq_printf(m, "%-10s\n", lnames[i].unit);
 
 631		else
 632			seq_putc(m, '\n');
 633	}
 634
 635	return 0;
 636}
 637
 638#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
 639static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
 640			    struct pid *pid, struct task_struct *task)
 641{
 642	struct syscall_info info;
 643	u64 *args = &info.data.args[0];
 644	int res;
 645
 646	res = lock_trace(task);
 647	if (res)
 648		return res;
 649
 650	if (task_current_syscall(task, &info))
 651		seq_puts(m, "running\n");
 652	else if (info.data.nr < 0)
 653		seq_printf(m, "%d 0x%llx 0x%llx\n",
 654			   info.data.nr, info.sp, info.data.instruction_pointer);
 655	else
 656		seq_printf(m,
 657		       "%d 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx\n",
 658		       info.data.nr,
 659		       args[0], args[1], args[2], args[3], args[4], args[5],
 660		       info.sp, info.data.instruction_pointer);
 661	unlock_trace(task);
 662
 663	return 0;
 664}
 665#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */
 666
 667/************************************************************************/
 668/*                       Here the fs part begins                        */
 669/************************************************************************/
 670
 671/* permission checks */
 672static int proc_fd_access_allowed(struct inode *inode)
 673{
 674	struct task_struct *task;
 675	int allowed = 0;
 676	/* Allow access to a task's file descriptors if it is us or we
 677	 * may use ptrace attach to the process and find out that
 678	 * information.
 679	 */
 680	task = get_proc_task(inode);
 681	if (task) {
 682		allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
 683		put_task_struct(task);
 684	}
 685	return allowed;
 686}
 687
 688int proc_setattr(struct dentry *dentry, struct iattr *attr)
 689{
 690	int error;
 691	struct inode *inode = d_inode(dentry);
 692
 693	if (attr->ia_valid & ATTR_MODE)
 694		return -EPERM;
 695
 696	error = setattr_prepare(dentry, attr);
 697	if (error)
 698		return error;
 699
 
 
 
 
 
 
 
 700	setattr_copy(inode, attr);
 701	mark_inode_dirty(inode);
 702	return 0;
 703}
 704
 705/*
 706 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
 707 * or euid/egid (for hide_pid_min=2)?
 708 */
 709static bool has_pid_permissions(struct proc_fs_info *fs_info,
 710				 struct task_struct *task,
 711				 enum proc_hidepid hide_pid_min)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 712{
 713	/*
 714	 * If 'hidpid' mount option is set force a ptrace check,
 715	 * we indicate that we are using a filesystem syscall
 716	 * by passing PTRACE_MODE_READ_FSCREDS
 717	 */
 718	if (fs_info->hide_pid == HIDEPID_NOT_PTRACEABLE)
 719		return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
 
 
 
 720
 721	if (fs_info->hide_pid < hide_pid_min)
 722		return true;
 723	if (in_group_p(fs_info->pid_gid))
 724		return true;
 725	return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
 726}
 727
 
 
 
 
 
 
 728
 729static int proc_pid_permission(struct inode *inode, int mask)
 
 
 
 730{
 731	struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
 732	struct task_struct *task;
 733	bool has_perms;
 
 734
 735	task = get_proc_task(inode);
 736	if (!task)
 737		return -ESRCH;
 738	has_perms = has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS);
 739	put_task_struct(task);
 740
 741	if (!has_perms) {
 742		if (fs_info->hide_pid == HIDEPID_INVISIBLE) {
 743			/*
 744			 * Let's make getdents(), stat(), and open()
 745			 * consistent with each other.  If a process
 746			 * may not stat() a file, it shouldn't be seen
 747			 * in procfs at all.
 748			 */
 749			return -ENOENT;
 750		}
 751
 752		return -EPERM;
 753	}
 754	return generic_permission(inode, mask);
 755}
 756
 
 757
 
 
 
 
 
 
 
 
 758
 759static const struct inode_operations proc_def_inode_operations = {
 760	.setattr	= proc_setattr,
 
 761};
 762
 763static int proc_single_show(struct seq_file *m, void *v)
 764{
 765	struct inode *inode = m->private;
 766	struct pid_namespace *ns = proc_pid_ns(inode->i_sb);
 767	struct pid *pid = proc_pid(inode);
 768	struct task_struct *task;
 769	int ret;
 770
 
 
 771	task = get_pid_task(pid, PIDTYPE_PID);
 772	if (!task)
 773		return -ESRCH;
 774
 775	ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);
 776
 777	put_task_struct(task);
 778	return ret;
 779}
 780
 781static int proc_single_open(struct inode *inode, struct file *filp)
 782{
 783	return single_open(filp, proc_single_show, inode);
 784}
 785
 786static const struct file_operations proc_single_file_operations = {
 787	.open		= proc_single_open,
 788	.read		= seq_read,
 789	.llseek		= seq_lseek,
 790	.release	= single_release,
 791};
 792
 
 
 
 
 
 
 
 793
 794struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
 
 795{
 796	struct task_struct *task = get_proc_task(inode);
 797	struct mm_struct *mm = ERR_PTR(-ESRCH);
 
 
 
 798
 799	if (task) {
 800		mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
 801		put_task_struct(task);
 802
 803		if (!IS_ERR_OR_NULL(mm)) {
 804			/* ensure this mm_struct can't be freed */
 805			mmgrab(mm);
 806			/* but do not pin its memory */
 807			mmput(mm);
 808		}
 809	}
 810
 811	return mm;
 812}
 
 
 813
 814static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
 815{
 816	struct mm_struct *mm = proc_mem_open(inode, mode);
 
 817
 818	if (IS_ERR(mm))
 819		return PTR_ERR(mm);
 
 
 820
 821	file->private_data = mm;
 822	return 0;
 823}
 
 
 
 
 824
 825static int mem_open(struct inode *inode, struct file *file)
 826{
 827	int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);
 828
 829	/* OK to pass negative loff_t, we can catch out-of-range */
 830	file->f_mode |= FMODE_UNSIGNED_OFFSET;
 
 
 
 
 
 831
 
 
 
 
 
 
 
 832	return ret;
 833}
 834
 835static ssize_t mem_rw(struct file *file, char __user *buf,
 836			size_t count, loff_t *ppos, int write)
 837{
 838	struct mm_struct *mm = file->private_data;
 839	unsigned long addr = *ppos;
 840	ssize_t copied;
 841	char *page;
 842	unsigned int flags;
 
 
 843
 844	if (!mm)
 845		return 0;
 
 846
 847	page = (char *)__get_free_page(GFP_KERNEL);
 
 848	if (!page)
 849		return -ENOMEM;
 850
 851	copied = 0;
 852	if (!mmget_not_zero(mm))
 853		goto free;
 
 854
 855	flags = FOLL_FORCE | (write ? FOLL_WRITE : 0);
 
 
 856
 
 857	while (count > 0) {
 858		int this_len = min_t(int, count, PAGE_SIZE);
 859
 860		if (write && copy_from_user(page, buf, this_len)) {
 
 861			copied = -EFAULT;
 862			break;
 863		}
 864
 865		this_len = access_remote_vm(mm, addr, page, this_len, flags);
 866		if (!this_len) {
 867			if (!copied)
 868				copied = -EIO;
 869			break;
 870		}
 871
 872		if (!write && copy_to_user(buf, page, this_len)) {
 873			copied = -EFAULT;
 874			break;
 875		}
 876
 877		buf += this_len;
 878		addr += this_len;
 879		copied += this_len;
 880		count -= this_len;
 881	}
 882	*ppos = addr;
 883
 
 884	mmput(mm);
 885free:
 886	free_page((unsigned long) page);
 
 
 
 887	return copied;
 888}
 889
 890static ssize_t mem_read(struct file *file, char __user *buf,
 891			size_t count, loff_t *ppos)
 892{
 893	return mem_rw(file, buf, count, ppos, 0);
 894}
 895
 896static ssize_t mem_write(struct file *file, const char __user *buf,
 897			 size_t count, loff_t *ppos)
 898{
 899	return mem_rw(file, (char __user*)buf, count, ppos, 1);
 900}
 901
 902loff_t mem_lseek(struct file *file, loff_t offset, int orig)
 903{
 904	switch (orig) {
 905	case 0:
 906		file->f_pos = offset;
 907		break;
 908	case 1:
 909		file->f_pos += offset;
 910		break;
 911	default:
 912		return -EINVAL;
 913	}
 914	force_successful_syscall_return();
 915	return file->f_pos;
 916}
 917
 918static int mem_release(struct inode *inode, struct file *file)
 919{
 920	struct mm_struct *mm = file->private_data;
 921	if (mm)
 922		mmdrop(mm);
 923	return 0;
 924}
 925
 926static const struct file_operations proc_mem_operations = {
 927	.llseek		= mem_lseek,
 928	.read		= mem_read,
 929	.write		= mem_write,
 930	.open		= mem_open,
 931	.release	= mem_release,
 932};
 933
 934static int environ_open(struct inode *inode, struct file *file)
 935{
 936	return __mem_open(inode, file, PTRACE_MODE_READ);
 937}
 938
 939static ssize_t environ_read(struct file *file, char __user *buf,
 940			size_t count, loff_t *ppos)
 941{
 
 942	char *page;
 943	unsigned long src = *ppos;
 944	int ret = 0;
 945	struct mm_struct *mm = file->private_data;
 946	unsigned long env_start, env_end;
 947
 948	/* Ensure the process spawned far enough to have an environment. */
 949	if (!mm || !mm->env_end)
 950		return 0;
 951
 952	page = (char *)__get_free_page(GFP_KERNEL);
 
 953	if (!page)
 954		return -ENOMEM;
 955
 956	ret = 0;
 957	if (!mmget_not_zero(mm))
 958		goto free;
 959
 960	spin_lock(&mm->arg_lock);
 961	env_start = mm->env_start;
 962	env_end = mm->env_end;
 963	spin_unlock(&mm->arg_lock);
 964
 
 965	while (count > 0) {
 966		size_t this_len, max_len;
 967		int retval;
 
 968
 969		if (src >= (env_end - env_start))
 970			break;
 971
 972		this_len = env_end - (env_start + src);
 
 973
 974		max_len = min_t(size_t, PAGE_SIZE, count);
 975		this_len = min(max_len, this_len);
 976
 977		retval = access_remote_vm(mm, (env_start + src), page, this_len, FOLL_ANON);
 978
 979		if (retval <= 0) {
 980			ret = retval;
 981			break;
 982		}
 983
 984		if (copy_to_user(buf, page, retval)) {
 985			ret = -EFAULT;
 986			break;
 987		}
 988
 989		ret += retval;
 990		src += retval;
 991		buf += retval;
 992		count -= retval;
 993	}
 994	*ppos = src;
 
 995	mmput(mm);
 996
 997free:
 998	free_page((unsigned long) page);
 
 
 
 999	return ret;
1000}
1001
1002static const struct file_operations proc_environ_operations = {
1003	.open		= environ_open,
1004	.read		= environ_read,
1005	.llseek		= generic_file_llseek,
1006	.release	= mem_release,
1007};
1008
1009static int auxv_open(struct inode *inode, struct file *file)
 
1010{
1011	return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
1012}
1013
1014static ssize_t auxv_read(struct file *file, char __user *buf,
1015			size_t count, loff_t *ppos)
1016{
1017	struct mm_struct *mm = file->private_data;
1018	unsigned int nwords = 0;
1019
1020	if (!mm)
1021		return 0;
1022	do {
1023		nwords += 2;
1024	} while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
1025	return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv,
1026				       nwords * sizeof(mm->saved_auxv[0]));
1027}
1028
1029static const struct file_operations proc_auxv_operations = {
1030	.open		= auxv_open,
1031	.read		= auxv_read,
1032	.llseek		= generic_file_llseek,
1033	.release	= mem_release,
1034};
1035
1036static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
1037			    loff_t *ppos)
1038{
1039	struct task_struct *task = get_proc_task(file_inode(file));
1040	char buffer[PROC_NUMBUF];
1041	int oom_adj = OOM_ADJUST_MIN;
1042	size_t len;
 
 
1043
1044	if (!task)
1045		return -ESRCH;
1046	if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
1047		oom_adj = OOM_ADJUST_MAX;
1048	else
1049		oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
1050			  OOM_SCORE_ADJ_MAX;
1051	put_task_struct(task);
1052	len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
1053	return simple_read_from_buffer(buf, count, ppos, buffer, len);
1054}
1055
1056static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
1057{
1058	static DEFINE_MUTEX(oom_adj_mutex);
1059	struct mm_struct *mm = NULL;
1060	struct task_struct *task;
1061	int err = 0;
1062
1063	task = get_proc_task(file_inode(file));
1064	if (!task)
1065		return -ESRCH;
1066
1067	mutex_lock(&oom_adj_mutex);
1068	if (legacy) {
1069		if (oom_adj < task->signal->oom_score_adj &&
1070				!capable(CAP_SYS_RESOURCE)) {
1071			err = -EACCES;
1072			goto err_unlock;
1073		}
1074		/*
1075		 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
1076		 * /proc/pid/oom_score_adj instead.
1077		 */
1078		pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
1079			  current->comm, task_pid_nr(current), task_pid_nr(task),
1080			  task_pid_nr(task));
1081	} else {
1082		if ((short)oom_adj < task->signal->oom_score_adj_min &&
1083				!capable(CAP_SYS_RESOURCE)) {
1084			err = -EACCES;
1085			goto err_unlock;
1086		}
1087	}
1088
1089	/*
1090	 * Make sure we will check other processes sharing the mm if this is
1091	 * not vfrok which wants its own oom_score_adj.
1092	 * pin the mm so it doesn't go away and get reused after task_unlock
1093	 */
1094	if (!task->vfork_done) {
1095		struct task_struct *p = find_lock_task_mm(task);
1096
1097		if (p) {
1098			if (atomic_read(&p->mm->mm_users) > 1) {
1099				mm = p->mm;
1100				mmgrab(mm);
1101			}
1102			task_unlock(p);
1103		}
1104	}
1105
1106	task->signal->oom_score_adj = oom_adj;
1107	if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1108		task->signal->oom_score_adj_min = (short)oom_adj;
1109	trace_oom_score_adj_update(task);
1110
1111	if (mm) {
1112		struct task_struct *p;
1113
1114		rcu_read_lock();
1115		for_each_process(p) {
1116			if (same_thread_group(task, p))
1117				continue;
1118
1119			/* do not touch kernel threads or the global init */
1120			if (p->flags & PF_KTHREAD || is_global_init(p))
1121				continue;
1122
1123			task_lock(p);
1124			if (!p->vfork_done && process_shares_mm(p, mm)) {
1125				p->signal->oom_score_adj = oom_adj;
1126				if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
1127					p->signal->oom_score_adj_min = (short)oom_adj;
1128			}
1129			task_unlock(p);
1130		}
1131		rcu_read_unlock();
1132		mmdrop(mm);
1133	}
1134err_unlock:
1135	mutex_unlock(&oom_adj_mutex);
1136	put_task_struct(task);
1137	return err;
1138}
1139
1140/*
1141 * /proc/pid/oom_adj exists solely for backwards compatibility with previous
1142 * kernels.  The effective policy is defined by oom_score_adj, which has a
1143 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly.
1144 * Values written to oom_adj are simply mapped linearly to oom_score_adj.
1145 * Processes that become oom disabled via oom_adj will still be oom disabled
1146 * with this implementation.
1147 *
1148 * oom_adj cannot be removed since existing userspace binaries use it.
1149 */
1150static ssize_t oom_adj_write(struct file *file, const char __user *buf,
1151			     size_t count, loff_t *ppos)
1152{
 
1153	char buffer[PROC_NUMBUF];
1154	int oom_adj;
 
1155	int err;
1156
1157	memset(buffer, 0, sizeof(buffer));
1158	if (count > sizeof(buffer) - 1)
1159		count = sizeof(buffer) - 1;
1160	if (copy_from_user(buffer, buf, count)) {
1161		err = -EFAULT;
1162		goto out;
1163	}
1164
1165	err = kstrtoint(strstrip(buffer), 0, &oom_adj);
1166	if (err)
1167		goto out;
1168	if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
1169	     oom_adj != OOM_DISABLE) {
1170		err = -EINVAL;
1171		goto out;
1172	}
1173
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1174	/*
1175	 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
1176	 * value is always attainable.
1177	 */
1178	if (oom_adj == OOM_ADJUST_MAX)
1179		oom_adj = OOM_SCORE_ADJ_MAX;
1180	else
1181		oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;
1182
1183	err = __set_oom_adj(file, oom_adj, true);
 
 
 
 
1184out:
1185	return err < 0 ? err : count;
1186}
1187
1188static const struct file_operations proc_oom_adj_operations = {
1189	.read		= oom_adj_read,
1190	.write		= oom_adj_write,
1191	.llseek		= generic_file_llseek,
1192};
1193
1194static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
1195					size_t count, loff_t *ppos)
1196{
1197	struct task_struct *task = get_proc_task(file_inode(file));
1198	char buffer[PROC_NUMBUF];
1199	short oom_score_adj = OOM_SCORE_ADJ_MIN;
 
1200	size_t len;
1201
1202	if (!task)
1203		return -ESRCH;
1204	oom_score_adj = task->signal->oom_score_adj;
 
 
 
1205	put_task_struct(task);
1206	len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
1207	return simple_read_from_buffer(buf, count, ppos, buffer, len);
1208}
1209
1210static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
1211					size_t count, loff_t *ppos)
1212{
 
1213	char buffer[PROC_NUMBUF];
 
1214	int oom_score_adj;
1215	int err;
1216
1217	memset(buffer, 0, sizeof(buffer));
1218	if (count > sizeof(buffer) - 1)
1219		count = sizeof(buffer) - 1;
1220	if (copy_from_user(buffer, buf, count)) {
1221		err = -EFAULT;
1222		goto out;
1223	}
1224
1225	err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
1226	if (err)
1227		goto out;
1228	if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
1229			oom_score_adj > OOM_SCORE_ADJ_MAX) {
1230		err = -EINVAL;
1231		goto out;
1232	}
1233
1234	err = __set_oom_adj(file, oom_score_adj, false);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1235out:
1236	return err < 0 ? err : count;
1237}
1238
1239static const struct file_operations proc_oom_score_adj_operations = {
1240	.read		= oom_score_adj_read,
1241	.write		= oom_score_adj_write,
1242	.llseek		= default_llseek,
1243};
1244
1245#ifdef CONFIG_AUDIT
1246#define TMPBUFLEN 11
1247static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
1248				  size_t count, loff_t *ppos)
1249{
1250	struct inode * inode = file_inode(file);
1251	struct task_struct *task = get_proc_task(inode);
1252	ssize_t length;
1253	char tmpbuf[TMPBUFLEN];
1254
1255	if (!task)
1256		return -ESRCH;
1257	length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1258			   from_kuid(file->f_cred->user_ns,
1259				     audit_get_loginuid(task)));
1260	put_task_struct(task);
1261	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1262}
1263
1264static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
1265				   size_t count, loff_t *ppos)
1266{
1267	struct inode * inode = file_inode(file);
 
 
1268	uid_t loginuid;
1269	kuid_t kloginuid;
1270	int rv;
 
1271
1272	rcu_read_lock();
1273	if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
1274		rcu_read_unlock();
1275		return -EPERM;
1276	}
1277	rcu_read_unlock();
1278
 
 
 
1279	if (*ppos != 0) {
1280		/* No partial writes. */
1281		return -EINVAL;
1282	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1283
1284	rv = kstrtou32_from_user(buf, count, 10, &loginuid);
1285	if (rv < 0)
1286		return rv;
1287
1288	/* is userspace tring to explicitly UNSET the loginuid? */
1289	if (loginuid == AUDIT_UID_UNSET) {
1290		kloginuid = INVALID_UID;
1291	} else {
1292		kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
1293		if (!uid_valid(kloginuid))
1294			return -EINVAL;
1295	}
1296
1297	rv = audit_set_loginuid(kloginuid);
1298	if (rv < 0)
1299		return rv;
1300	return count;
1301}
1302
1303static const struct file_operations proc_loginuid_operations = {
1304	.read		= proc_loginuid_read,
1305	.write		= proc_loginuid_write,
1306	.llseek		= generic_file_llseek,
1307};
1308
1309static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
1310				  size_t count, loff_t *ppos)
1311{
1312	struct inode * inode = file_inode(file);
1313	struct task_struct *task = get_proc_task(inode);
1314	ssize_t length;
1315	char tmpbuf[TMPBUFLEN];
1316
1317	if (!task)
1318		return -ESRCH;
1319	length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1320				audit_get_sessionid(task));
1321	put_task_struct(task);
1322	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1323}
1324
1325static const struct file_operations proc_sessionid_operations = {
1326	.read		= proc_sessionid_read,
1327	.llseek		= generic_file_llseek,
1328};
1329#endif
1330
1331#ifdef CONFIG_FAULT_INJECTION
1332static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
1333				      size_t count, loff_t *ppos)
1334{
1335	struct task_struct *task = get_proc_task(file_inode(file));
1336	char buffer[PROC_NUMBUF];
1337	size_t len;
1338	int make_it_fail;
1339
1340	if (!task)
1341		return -ESRCH;
1342	make_it_fail = task->make_it_fail;
1343	put_task_struct(task);
1344
1345	len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
1346
1347	return simple_read_from_buffer(buf, count, ppos, buffer, len);
1348}
1349
1350static ssize_t proc_fault_inject_write(struct file * file,
1351			const char __user * buf, size_t count, loff_t *ppos)
1352{
1353	struct task_struct *task;
1354	char buffer[PROC_NUMBUF];
1355	int make_it_fail;
1356	int rv;
1357
1358	if (!capable(CAP_SYS_RESOURCE))
1359		return -EPERM;
1360	memset(buffer, 0, sizeof(buffer));
1361	if (count > sizeof(buffer) - 1)
1362		count = sizeof(buffer) - 1;
1363	if (copy_from_user(buffer, buf, count))
1364		return -EFAULT;
1365	rv = kstrtoint(strstrip(buffer), 0, &make_it_fail);
1366	if (rv < 0)
1367		return rv;
1368	if (make_it_fail < 0 || make_it_fail > 1)
1369		return -EINVAL;
1370
1371	task = get_proc_task(file_inode(file));
1372	if (!task)
1373		return -ESRCH;
1374	task->make_it_fail = make_it_fail;
1375	put_task_struct(task);
1376
1377	return count;
1378}
1379
1380static const struct file_operations proc_fault_inject_operations = {
1381	.read		= proc_fault_inject_read,
1382	.write		= proc_fault_inject_write,
1383	.llseek		= generic_file_llseek,
1384};
1385
1386static ssize_t proc_fail_nth_write(struct file *file, const char __user *buf,
1387				   size_t count, loff_t *ppos)
1388{
1389	struct task_struct *task;
1390	int err;
1391	unsigned int n;
1392
1393	err = kstrtouint_from_user(buf, count, 0, &n);
1394	if (err)
1395		return err;
1396
1397	task = get_proc_task(file_inode(file));
1398	if (!task)
1399		return -ESRCH;
1400	task->fail_nth = n;
1401	put_task_struct(task);
1402
1403	return count;
1404}
1405
1406static ssize_t proc_fail_nth_read(struct file *file, char __user *buf,
1407				  size_t count, loff_t *ppos)
1408{
1409	struct task_struct *task;
1410	char numbuf[PROC_NUMBUF];
1411	ssize_t len;
1412
1413	task = get_proc_task(file_inode(file));
1414	if (!task)
1415		return -ESRCH;
1416	len = snprintf(numbuf, sizeof(numbuf), "%u\n", task->fail_nth);
1417	put_task_struct(task);
1418	return simple_read_from_buffer(buf, count, ppos, numbuf, len);
1419}
1420
1421static const struct file_operations proc_fail_nth_operations = {
1422	.read		= proc_fail_nth_read,
1423	.write		= proc_fail_nth_write,
1424};
1425#endif
1426
1427
1428#ifdef CONFIG_SCHED_DEBUG
1429/*
1430 * Print out various scheduling related per-task fields:
1431 */
1432static int sched_show(struct seq_file *m, void *v)
1433{
1434	struct inode *inode = m->private;
1435	struct pid_namespace *ns = proc_pid_ns(inode->i_sb);
1436	struct task_struct *p;
1437
1438	p = get_proc_task(inode);
1439	if (!p)
1440		return -ESRCH;
1441	proc_sched_show_task(p, ns, m);
1442
1443	put_task_struct(p);
1444
1445	return 0;
1446}
1447
1448static ssize_t
1449sched_write(struct file *file, const char __user *buf,
1450	    size_t count, loff_t *offset)
1451{
1452	struct inode *inode = file_inode(file);
1453	struct task_struct *p;
1454
1455	p = get_proc_task(inode);
1456	if (!p)
1457		return -ESRCH;
1458	proc_sched_set_task(p);
1459
1460	put_task_struct(p);
1461
1462	return count;
1463}
1464
1465static int sched_open(struct inode *inode, struct file *filp)
1466{
1467	return single_open(filp, sched_show, inode);
1468}
1469
1470static const struct file_operations proc_pid_sched_operations = {
1471	.open		= sched_open,
1472	.read		= seq_read,
1473	.write		= sched_write,
1474	.llseek		= seq_lseek,
1475	.release	= single_release,
1476};
1477
1478#endif
1479
1480#ifdef CONFIG_SCHED_AUTOGROUP
1481/*
1482 * Print out autogroup related information:
1483 */
1484static int sched_autogroup_show(struct seq_file *m, void *v)
1485{
1486	struct inode *inode = m->private;
1487	struct task_struct *p;
1488
1489	p = get_proc_task(inode);
1490	if (!p)
1491		return -ESRCH;
1492	proc_sched_autogroup_show_task(p, m);
1493
1494	put_task_struct(p);
1495
1496	return 0;
1497}
1498
1499static ssize_t
1500sched_autogroup_write(struct file *file, const char __user *buf,
1501	    size_t count, loff_t *offset)
1502{
1503	struct inode *inode = file_inode(file);
1504	struct task_struct *p;
1505	char buffer[PROC_NUMBUF];
1506	int nice;
1507	int err;
1508
1509	memset(buffer, 0, sizeof(buffer));
1510	if (count > sizeof(buffer) - 1)
1511		count = sizeof(buffer) - 1;
1512	if (copy_from_user(buffer, buf, count))
1513		return -EFAULT;
1514
1515	err = kstrtoint(strstrip(buffer), 0, &nice);
1516	if (err < 0)
1517		return err;
1518
1519	p = get_proc_task(inode);
1520	if (!p)
1521		return -ESRCH;
1522
1523	err = proc_sched_autogroup_set_nice(p, nice);
 
1524	if (err)
1525		count = err;
1526
1527	put_task_struct(p);
1528
1529	return count;
1530}
1531
1532static int sched_autogroup_open(struct inode *inode, struct file *filp)
1533{
1534	int ret;
1535
1536	ret = single_open(filp, sched_autogroup_show, NULL);
1537	if (!ret) {
1538		struct seq_file *m = filp->private_data;
1539
1540		m->private = inode;
1541	}
1542	return ret;
1543}
1544
1545static const struct file_operations proc_pid_sched_autogroup_operations = {
1546	.open		= sched_autogroup_open,
1547	.read		= seq_read,
1548	.write		= sched_autogroup_write,
1549	.llseek		= seq_lseek,
1550	.release	= single_release,
1551};
1552
1553#endif /* CONFIG_SCHED_AUTOGROUP */
1554
1555#ifdef CONFIG_TIME_NS
1556static int timens_offsets_show(struct seq_file *m, void *v)
1557{
1558	struct task_struct *p;
1559
1560	p = get_proc_task(file_inode(m->file));
1561	if (!p)
1562		return -ESRCH;
1563	proc_timens_show_offsets(p, m);
1564
1565	put_task_struct(p);
1566
1567	return 0;
1568}
1569
1570static ssize_t timens_offsets_write(struct file *file, const char __user *buf,
1571				    size_t count, loff_t *ppos)
1572{
1573	struct inode *inode = file_inode(file);
1574	struct proc_timens_offset offsets[2];
1575	char *kbuf = NULL, *pos, *next_line;
1576	struct task_struct *p;
1577	int ret, noffsets;
1578
1579	/* Only allow < page size writes at the beginning of the file */
1580	if ((*ppos != 0) || (count >= PAGE_SIZE))
1581		return -EINVAL;
1582
1583	/* Slurp in the user data */
1584	kbuf = memdup_user_nul(buf, count);
1585	if (IS_ERR(kbuf))
1586		return PTR_ERR(kbuf);
1587
1588	/* Parse the user data */
1589	ret = -EINVAL;
1590	noffsets = 0;
1591	for (pos = kbuf; pos; pos = next_line) {
1592		struct proc_timens_offset *off = &offsets[noffsets];
1593		char clock[10];
1594		int err;
1595
1596		/* Find the end of line and ensure we don't look past it */
1597		next_line = strchr(pos, '\n');
1598		if (next_line) {
1599			*next_line = '\0';
1600			next_line++;
1601			if (*next_line == '\0')
1602				next_line = NULL;
1603		}
1604
1605		err = sscanf(pos, "%9s %lld %lu", clock,
1606				&off->val.tv_sec, &off->val.tv_nsec);
1607		if (err != 3 || off->val.tv_nsec >= NSEC_PER_SEC)
1608			goto out;
1609
1610		clock[sizeof(clock) - 1] = 0;
1611		if (strcmp(clock, "monotonic") == 0 ||
1612		    strcmp(clock, __stringify(CLOCK_MONOTONIC)) == 0)
1613			off->clockid = CLOCK_MONOTONIC;
1614		else if (strcmp(clock, "boottime") == 0 ||
1615			 strcmp(clock, __stringify(CLOCK_BOOTTIME)) == 0)
1616			off->clockid = CLOCK_BOOTTIME;
1617		else
1618			goto out;
1619
1620		noffsets++;
1621		if (noffsets == ARRAY_SIZE(offsets)) {
1622			if (next_line)
1623				count = next_line - kbuf;
1624			break;
1625		}
1626	}
1627
1628	ret = -ESRCH;
1629	p = get_proc_task(inode);
1630	if (!p)
1631		goto out;
1632	ret = proc_timens_set_offset(file, p, offsets, noffsets);
1633	put_task_struct(p);
1634	if (ret)
1635		goto out;
1636
1637	ret = count;
1638out:
1639	kfree(kbuf);
1640	return ret;
1641}
1642
1643static int timens_offsets_open(struct inode *inode, struct file *filp)
1644{
1645	return single_open(filp, timens_offsets_show, inode);
1646}
1647
1648static const struct file_operations proc_timens_offsets_operations = {
1649	.open		= timens_offsets_open,
1650	.read		= seq_read,
1651	.write		= timens_offsets_write,
1652	.llseek		= seq_lseek,
1653	.release	= single_release,
1654};
1655#endif /* CONFIG_TIME_NS */
1656
1657static ssize_t comm_write(struct file *file, const char __user *buf,
1658				size_t count, loff_t *offset)
1659{
1660	struct inode *inode = file_inode(file);
1661	struct task_struct *p;
1662	char buffer[TASK_COMM_LEN];
1663	const size_t maxlen = sizeof(buffer) - 1;
1664
1665	memset(buffer, 0, sizeof(buffer));
1666	if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
 
 
1667		return -EFAULT;
1668
1669	p = get_proc_task(inode);
1670	if (!p)
1671		return -ESRCH;
1672
1673	if (same_thread_group(current, p))
1674		set_task_comm(p, buffer);
1675	else
1676		count = -EINVAL;
1677
1678	put_task_struct(p);
1679
1680	return count;
1681}
1682
1683static int comm_show(struct seq_file *m, void *v)
1684{
1685	struct inode *inode = m->private;
1686	struct task_struct *p;
1687
1688	p = get_proc_task(inode);
1689	if (!p)
1690		return -ESRCH;
1691
1692	proc_task_name(m, p, false);
1693	seq_putc(m, '\n');
 
1694
1695	put_task_struct(p);
1696
1697	return 0;
1698}
1699
1700static int comm_open(struct inode *inode, struct file *filp)
1701{
1702	return single_open(filp, comm_show, inode);
1703}
1704
1705static const struct file_operations proc_pid_set_comm_operations = {
1706	.open		= comm_open,
1707	.read		= seq_read,
1708	.write		= comm_write,
1709	.llseek		= seq_lseek,
1710	.release	= single_release,
1711};
1712
1713static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
1714{
1715	struct task_struct *task;
 
1716	struct file *exe_file;
1717
1718	task = get_proc_task(d_inode(dentry));
1719	if (!task)
1720		return -ENOENT;
1721	exe_file = get_task_exe_file(task);
1722	put_task_struct(task);
 
 
 
 
1723	if (exe_file) {
1724		*exe_path = exe_file->f_path;
1725		path_get(&exe_file->f_path);
1726		fput(exe_file);
1727		return 0;
1728	} else
1729		return -ENOENT;
1730}
1731
1732static const char *proc_pid_get_link(struct dentry *dentry,
1733				     struct inode *inode,
1734				     struct delayed_call *done)
1735{
1736	struct path path;
1737	int error = -EACCES;
1738
1739	if (!dentry)
1740		return ERR_PTR(-ECHILD);
1741
1742	/* Are we allowed to snoop on the tasks file descriptors? */
1743	if (!proc_fd_access_allowed(inode))
1744		goto out;
1745
1746	error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1747	if (error)
1748		goto out;
1749
1750	error = nd_jump_link(&path);
1751out:
1752	return ERR_PTR(error);
1753}
1754
1755static int do_proc_readlink(struct path *path, char __user *buffer, int buflen)
1756{
1757	char *tmp = (char *)__get_free_page(GFP_KERNEL);
1758	char *pathname;
1759	int len;
1760
1761	if (!tmp)
1762		return -ENOMEM;
1763
1764	pathname = d_path(path, tmp, PAGE_SIZE);
1765	len = PTR_ERR(pathname);
1766	if (IS_ERR(pathname))
1767		goto out;
1768	len = tmp + PAGE_SIZE - 1 - pathname;
1769
1770	if (len > buflen)
1771		len = buflen;
1772	if (copy_to_user(buffer, pathname, len))
1773		len = -EFAULT;
1774 out:
1775	free_page((unsigned long)tmp);
1776	return len;
1777}
1778
1779static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
1780{
1781	int error = -EACCES;
1782	struct inode *inode = d_inode(dentry);
1783	struct path path;
1784
1785	/* Are we allowed to snoop on the tasks file descriptors? */
1786	if (!proc_fd_access_allowed(inode))
1787		goto out;
1788
1789	error = PROC_I(inode)->op.proc_get_link(dentry, &path);
1790	if (error)
1791		goto out;
1792
1793	error = do_proc_readlink(&path, buffer, buflen);
1794	path_put(&path);
1795out:
1796	return error;
1797}
1798
1799const struct inode_operations proc_pid_link_inode_operations = {
1800	.readlink	= proc_pid_readlink,
1801	.get_link	= proc_pid_get_link,
1802	.setattr	= proc_setattr,
1803};
1804
1805
1806/* building an inode */
1807
1808void task_dump_owner(struct task_struct *task, umode_t mode,
1809		     kuid_t *ruid, kgid_t *rgid)
1810{
1811	/* Depending on the state of dumpable compute who should own a
1812	 * proc file for a task.
1813	 */
1814	const struct cred *cred;
1815	kuid_t uid;
1816	kgid_t gid;
1817
1818	if (unlikely(task->flags & PF_KTHREAD)) {
1819		*ruid = GLOBAL_ROOT_UID;
1820		*rgid = GLOBAL_ROOT_GID;
1821		return;
1822	}
1823
1824	/* Default to the tasks effective ownership */
1825	rcu_read_lock();
1826	cred = __task_cred(task);
1827	uid = cred->euid;
1828	gid = cred->egid;
1829	rcu_read_unlock();
1830
1831	/*
1832	 * Before the /proc/pid/status file was created the only way to read
1833	 * the effective uid of a /process was to stat /proc/pid.  Reading
1834	 * /proc/pid/status is slow enough that procps and other packages
1835	 * kept stating /proc/pid.  To keep the rules in /proc simple I have
1836	 * made this apply to all per process world readable and executable
1837	 * directories.
1838	 */
1839	if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) {
1840		struct mm_struct *mm;
1841		task_lock(task);
1842		mm = task->mm;
1843		/* Make non-dumpable tasks owned by some root */
1844		if (mm) {
1845			if (get_dumpable(mm) != SUID_DUMP_USER) {
1846				struct user_namespace *user_ns = mm->user_ns;
1847
1848				uid = make_kuid(user_ns, 0);
1849				if (!uid_valid(uid))
1850					uid = GLOBAL_ROOT_UID;
1851
1852				gid = make_kgid(user_ns, 0);
1853				if (!gid_valid(gid))
1854					gid = GLOBAL_ROOT_GID;
1855			}
1856		} else {
1857			uid = GLOBAL_ROOT_UID;
1858			gid = GLOBAL_ROOT_GID;
1859		}
1860		task_unlock(task);
1861	}
1862	*ruid = uid;
1863	*rgid = gid;
1864}
1865
1866void proc_pid_evict_inode(struct proc_inode *ei)
1867{
1868	struct pid *pid = ei->pid;
1869
1870	if (S_ISDIR(ei->vfs_inode.i_mode)) {
1871		spin_lock(&pid->lock);
1872		hlist_del_init_rcu(&ei->sibling_inodes);
1873		spin_unlock(&pid->lock);
1874	}
1875
1876	put_pid(pid);
1877}
1878
1879struct inode *proc_pid_make_inode(struct super_block * sb,
1880				  struct task_struct *task, umode_t mode)
1881{
1882	struct inode * inode;
1883	struct proc_inode *ei;
1884	struct pid *pid;
1885
1886	/* We need a new inode */
1887
1888	inode = new_inode(sb);
1889	if (!inode)
1890		goto out;
1891
1892	/* Common stuff */
1893	ei = PROC_I(inode);
1894	inode->i_mode = mode;
1895	inode->i_ino = get_next_ino();
1896	inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
1897	inode->i_op = &proc_def_inode_operations;
1898
1899	/*
1900	 * grab the reference to task.
1901	 */
1902	pid = get_task_pid(task, PIDTYPE_PID);
1903	if (!pid)
1904		goto out_unlock;
1905
1906	/* Let the pid remember us for quick removal */
1907	ei->pid = pid;
1908	if (S_ISDIR(mode)) {
1909		spin_lock(&pid->lock);
1910		hlist_add_head_rcu(&ei->sibling_inodes, &pid->inodes);
1911		spin_unlock(&pid->lock);
1912	}
1913
1914	task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
1915	security_task_to_inode(task, inode);
1916
1917out:
1918	return inode;
1919
1920out_unlock:
1921	iput(inode);
1922	return NULL;
1923}
1924
1925int pid_getattr(const struct path *path, struct kstat *stat,
1926		u32 request_mask, unsigned int query_flags)
1927{
1928	struct inode *inode = d_inode(path->dentry);
1929	struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
1930	struct task_struct *task;
 
1931
1932	generic_fillattr(inode, stat);
1933
1934	stat->uid = GLOBAL_ROOT_UID;
1935	stat->gid = GLOBAL_ROOT_GID;
1936	rcu_read_lock();
 
 
1937	task = pid_task(proc_pid(inode), PIDTYPE_PID);
1938	if (task) {
1939		if (!has_pid_permissions(fs_info, task, HIDEPID_INVISIBLE)) {
1940			rcu_read_unlock();
1941			/*
1942			 * This doesn't prevent learning whether PID exists,
1943			 * it only makes getattr() consistent with readdir().
1944			 */
1945			return -ENOENT;
1946		}
1947		task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid);
1948	}
1949	rcu_read_unlock();
1950	return 0;
1951}
1952
1953/* dentry stuff */
1954
1955/*
1956 * Set <pid>/... inode ownership (can change due to setuid(), etc.)
1957 */
1958void pid_update_inode(struct task_struct *task, struct inode *inode)
1959{
1960	task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid);
1961
1962	inode->i_mode &= ~(S_ISUID | S_ISGID);
1963	security_task_to_inode(task, inode);
1964}
1965
1966/*
1967 * Rewrite the inode's ownerships here because the owning task may have
1968 * performed a setuid(), etc.
1969 *
 
 
 
 
 
 
1970 */
1971static int pid_revalidate(struct dentry *dentry, unsigned int flags)
1972{
1973	struct inode *inode;
1974	struct task_struct *task;
 
1975
1976	if (flags & LOOKUP_RCU)
1977		return -ECHILD;
1978
1979	inode = d_inode(dentry);
1980	task = get_proc_task(inode);
1981
1982	if (task) {
1983		pid_update_inode(task, inode);
 
 
 
 
 
 
 
 
 
 
 
 
1984		put_task_struct(task);
1985		return 1;
1986	}
 
1987	return 0;
1988}
1989
1990static inline bool proc_inode_is_dead(struct inode *inode)
1991{
1992	return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
1993}
1994
1995int pid_delete_dentry(const struct dentry *dentry)
1996{
1997	/* Is the task we represent dead?
1998	 * If so, then don't put the dentry on the lru list,
1999	 * kill it immediately.
2000	 */
2001	return proc_inode_is_dead(d_inode(dentry));
2002}
2003
2004const struct dentry_operations pid_dentry_operations =
2005{
2006	.d_revalidate	= pid_revalidate,
2007	.d_delete	= pid_delete_dentry,
2008};
2009
2010/* Lookups */
2011
2012/*
2013 * Fill a directory entry.
2014 *
2015 * If possible create the dcache entry and derive our inode number and
2016 * file type from dcache entry.
2017 *
2018 * Since all of the proc inode numbers are dynamically generated, the inode
2019 * numbers do not exist until the inode is cache.  This means creating the
2020 * the dcache entry in readdir is necessary to keep the inode numbers
2021 * reported by readdir in sync with the inode numbers reported
2022 * by stat.
2023 */
2024bool proc_fill_cache(struct file *file, struct dir_context *ctx,
2025	const char *name, unsigned int len,
2026	instantiate_t instantiate, struct task_struct *task, const void *ptr)
2027{
2028	struct dentry *child, *dir = file->f_path.dentry;
2029	struct qstr qname = QSTR_INIT(name, len);
2030	struct inode *inode;
 
 
2031	unsigned type = DT_UNKNOWN;
2032	ino_t ino = 1;
2033
2034	child = d_hash_and_lookup(dir, &qname);
 
 
 
 
2035	if (!child) {
2036		DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
2037		child = d_alloc_parallel(dir, &qname, &wq);
2038		if (IS_ERR(child))
2039			goto end_instantiate;
2040		if (d_in_lookup(child)) {
2041			struct dentry *res;
2042			res = instantiate(child, task, ptr);
2043			d_lookup_done(child);
2044			if (unlikely(res)) {
2045				dput(child);
2046				child = res;
2047				if (IS_ERR(child))
2048					goto end_instantiate;
2049			}
2050		}
 
2051	}
2052	inode = d_inode(child);
2053	ino = inode->i_ino;
2054	type = inode->i_mode >> 12;
2055	dput(child);
2056end_instantiate:
2057	return dir_emit(ctx, name, len, ino, type);
 
 
 
 
2058}
2059
2060/*
2061 * dname_to_vma_addr - maps a dentry name into two unsigned longs
2062 * which represent vma start and end addresses.
2063 */
2064static int dname_to_vma_addr(struct dentry *dentry,
2065			     unsigned long *start, unsigned long *end)
2066{
2067	const char *str = dentry->d_name.name;
2068	unsigned long long sval, eval;
2069	unsigned int len;
2070
2071	if (str[0] == '0' && str[1] != '-')
2072		return -EINVAL;
2073	len = _parse_integer(str, 16, &sval);
2074	if (len & KSTRTOX_OVERFLOW)
2075		return -EINVAL;
2076	if (sval != (unsigned long)sval)
2077		return -EINVAL;
2078	str += len;
 
 
 
 
 
 
 
2079
2080	if (*str != '-')
2081		return -EINVAL;
2082	str++;
2083
2084	if (str[0] == '0' && str[1])
2085		return -EINVAL;
2086	len = _parse_integer(str, 16, &eval);
2087	if (len & KSTRTOX_OVERFLOW)
2088		return -EINVAL;
2089	if (eval != (unsigned long)eval)
2090		return -EINVAL;
2091	str += len;
2092
2093	if (*str != '\0')
2094		return -EINVAL;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2095
2096	*start = sval;
2097	*end = eval;
2098
2099	return 0;
2100}
2101
2102static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
2103{
2104	unsigned long vm_start, vm_end;
2105	bool exact_vma_exists = false;
2106	struct mm_struct *mm = NULL;
2107	struct task_struct *task;
2108	struct inode *inode;
2109	int status = 0;
 
2110
2111	if (flags & LOOKUP_RCU)
2112		return -ECHILD;
2113
2114	inode = d_inode(dentry);
2115	task = get_proc_task(inode);
2116	if (!task)
2117		goto out_notask;
2118
2119	mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
2120	if (IS_ERR_OR_NULL(mm))
2121		goto out;
2122
2123	if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
2124		status = mmap_read_lock_killable(mm);
2125		if (!status) {
2126			exact_vma_exists = !!find_exact_vma(mm, vm_start,
2127							    vm_end);
2128			mmap_read_unlock(mm);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2129		}
 
2130	}
2131
2132	mmput(mm);
2133
2134	if (exact_vma_exists) {
2135		task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
2136
2137		security_task_to_inode(task, inode);
2138		status = 1;
2139	}
2140
2141out:
2142	put_task_struct(task);
2143
2144out_notask:
2145	return status;
2146}
2147
2148static const struct dentry_operations tid_map_files_dentry_operations = {
2149	.d_revalidate	= map_files_d_revalidate,
 
2150	.d_delete	= pid_delete_dentry,
2151};
2152
2153static int map_files_get_link(struct dentry *dentry, struct path *path)
 
2154{
2155	unsigned long vm_start, vm_end;
2156	struct vm_area_struct *vma;
2157	struct task_struct *task;
2158	struct mm_struct *mm;
2159	int rc;
 
2160
2161	rc = -ENOENT;
2162	task = get_proc_task(d_inode(dentry));
2163	if (!task)
2164		goto out;
 
 
 
 
 
 
2165
2166	mm = get_task_mm(task);
2167	put_task_struct(task);
2168	if (!mm)
2169		goto out;
2170
2171	rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
2172	if (rc)
2173		goto out_mmput;
2174
2175	rc = mmap_read_lock_killable(mm);
2176	if (rc)
2177		goto out_mmput;
2178
2179	rc = -ENOENT;
2180	vma = find_exact_vma(mm, vm_start, vm_end);
2181	if (vma && vma->vm_file) {
2182		*path = vma->vm_file->f_path;
2183		path_get(path);
2184		rc = 0;
2185	}
2186	mmap_read_unlock(mm);
2187
2188out_mmput:
2189	mmput(mm);
2190out:
2191	return rc;
2192}
2193
2194struct map_files_info {
2195	unsigned long	start;
2196	unsigned long	end;
2197	fmode_t		mode;
2198};
2199
2200/*
2201 * Only allow CAP_SYS_ADMIN and CAP_CHECKPOINT_RESTORE to follow the links, due
2202 * to concerns about how the symlinks may be used to bypass permissions on
2203 * ancestor directories in the path to the file in question.
2204 */
2205static const char *
2206proc_map_files_get_link(struct dentry *dentry,
2207			struct inode *inode,
2208		        struct delayed_call *done)
2209{
2210	if (!checkpoint_restore_ns_capable(&init_user_ns))
2211		return ERR_PTR(-EPERM);
2212
2213	return proc_pid_get_link(dentry, inode, done);
2214}
2215
2216/*
2217 * Identical to proc_pid_link_inode_operations except for get_link()
2218 */
2219static const struct inode_operations proc_map_files_link_inode_operations = {
2220	.readlink	= proc_pid_readlink,
2221	.get_link	= proc_map_files_get_link,
2222	.setattr	= proc_setattr,
2223};
2224
2225static struct dentry *
2226proc_map_files_instantiate(struct dentry *dentry,
2227			   struct task_struct *task, const void *ptr)
2228{
2229	fmode_t mode = (fmode_t)(unsigned long)ptr;
2230	struct proc_inode *ei;
2231	struct inode *inode;
2232
2233	inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK |
2234				    ((mode & FMODE_READ ) ? S_IRUSR : 0) |
2235				    ((mode & FMODE_WRITE) ? S_IWUSR : 0));
2236	if (!inode)
2237		return ERR_PTR(-ENOENT);
2238
2239	ei = PROC_I(inode);
2240	ei->op.proc_get_link = map_files_get_link;
2241
2242	inode->i_op = &proc_map_files_link_inode_operations;
2243	inode->i_size = 64;
 
 
 
 
 
 
2244
2245	d_set_d_op(dentry, &tid_map_files_dentry_operations);
2246	return d_splice_alias(inode, dentry);
 
 
 
 
 
 
2247}
2248
2249static struct dentry *proc_map_files_lookup(struct inode *dir,
2250		struct dentry *dentry, unsigned int flags)
 
2251{
2252	unsigned long vm_start, vm_end;
2253	struct vm_area_struct *vma;
2254	struct task_struct *task;
2255	struct dentry *result;
2256	struct mm_struct *mm;
2257
2258	result = ERR_PTR(-ENOENT);
2259	task = get_proc_task(dir);
2260	if (!task)
 
 
2261		goto out;
2262
2263	result = ERR_PTR(-EACCES);
2264	if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2265		goto out_put_task;
2266
2267	result = ERR_PTR(-ENOENT);
2268	if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
2269		goto out_put_task;
2270
2271	mm = get_task_mm(task);
2272	if (!mm)
2273		goto out_put_task;
2274
2275	result = ERR_PTR(-EINTR);
2276	if (mmap_read_lock_killable(mm))
2277		goto out_put_mm;
2278
2279	result = ERR_PTR(-ENOENT);
2280	vma = find_exact_vma(mm, vm_start, vm_end);
2281	if (!vma)
2282		goto out_no_vma;
2283
2284	if (vma->vm_file)
2285		result = proc_map_files_instantiate(dentry, task,
2286				(void *)(unsigned long)vma->vm_file->f_mode);
2287
2288out_no_vma:
2289	mmap_read_unlock(mm);
2290out_put_mm:
2291	mmput(mm);
2292out_put_task:
2293	put_task_struct(task);
2294out:
2295	return result;
2296}
2297
2298static const struct inode_operations proc_map_files_inode_operations = {
2299	.lookup		= proc_map_files_lookup,
2300	.permission	= proc_fd_permission,
2301	.setattr	= proc_setattr,
2302};
2303
2304static int
2305proc_map_files_readdir(struct file *file, struct dir_context *ctx)
2306{
2307	struct vm_area_struct *vma;
2308	struct task_struct *task;
2309	struct mm_struct *mm;
2310	unsigned long nr_files, pos, i;
2311	GENRADIX(struct map_files_info) fa;
2312	struct map_files_info *p;
2313	int ret;
2314
2315	genradix_init(&fa);
 
 
 
2316
2317	ret = -ENOENT;
2318	task = get_proc_task(file_inode(file));
2319	if (!task)
2320		goto out;
2321
2322	ret = -EACCES;
2323	if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
2324		goto out_put_task;
2325
2326	ret = 0;
2327	if (!dir_emit_dots(file, ctx))
2328		goto out_put_task;
2329
2330	mm = get_task_mm(task);
2331	if (!mm)
2332		goto out_put_task;
2333
2334	ret = mmap_read_lock_killable(mm);
2335	if (ret) {
2336		mmput(mm);
2337		goto out_put_task;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2338	}
2339
2340	nr_files = 0;
2341
2342	/*
2343	 * We need two passes here:
2344	 *
2345	 *  1) Collect vmas of mapped files with mmap_lock taken
2346	 *  2) Release mmap_lock and instantiate entries
2347	 *
2348	 * otherwise we get lockdep complained, since filldir()
2349	 * routine might require mmap_lock taken in might_fault().
2350	 */
2351
2352	for (vma = mm->mmap, pos = 2; vma; vma = vma->vm_next) {
2353		if (!vma->vm_file)
2354			continue;
2355		if (++pos <= ctx->pos)
2356			continue;
2357
2358		p = genradix_ptr_alloc(&fa, nr_files++, GFP_KERNEL);
2359		if (!p) {
2360			ret = -ENOMEM;
2361			mmap_read_unlock(mm);
2362			mmput(mm);
2363			goto out_put_task;
2364		}
2365
2366		p->start = vma->vm_start;
2367		p->end = vma->vm_end;
2368		p->mode = vma->vm_file->f_mode;
2369	}
2370	mmap_read_unlock(mm);
2371	mmput(mm);
2372
2373	for (i = 0; i < nr_files; i++) {
2374		char buf[4 * sizeof(long) + 2];	/* max: %lx-%lx\0 */
2375		unsigned int len;
2376
2377		p = genradix_ptr(&fa, i);
2378		len = snprintf(buf, sizeof(buf), "%lx-%lx", p->start, p->end);
2379		if (!proc_fill_cache(file, ctx,
2380				      buf, len,
2381				      proc_map_files_instantiate,
2382				      task,
2383				      (void *)(unsigned long)p->mode))
2384			break;
2385		ctx->pos++;
2386	}
2387
2388out_put_task:
2389	put_task_struct(task);
2390out:
2391	genradix_free(&fa);
2392	return ret;
 
2393}
2394
2395static const struct file_operations proc_map_files_operations = {
2396	.read		= generic_read_dir,
2397	.iterate_shared	= proc_map_files_readdir,
2398	.llseek		= generic_file_llseek,
2399};
2400
2401#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
2402struct timers_private {
2403	struct pid *pid;
2404	struct task_struct *task;
2405	struct sighand_struct *sighand;
2406	struct pid_namespace *ns;
2407	unsigned long flags;
2408};
2409
2410static void *timers_start(struct seq_file *m, loff_t *pos)
2411{
2412	struct timers_private *tp = m->private;
2413
2414	tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
2415	if (!tp->task)
2416		return ERR_PTR(-ESRCH);
2417
2418	tp->sighand = lock_task_sighand(tp->task, &tp->flags);
2419	if (!tp->sighand)
2420		return ERR_PTR(-ESRCH);
2421
2422	return seq_list_start(&tp->task->signal->posix_timers, *pos);
2423}
2424
2425static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
2426{
2427	struct timers_private *tp = m->private;
2428	return seq_list_next(v, &tp->task->signal->posix_timers, pos);
2429}
2430
2431static void timers_stop(struct seq_file *m, void *v)
 
2432{
2433	struct timers_private *tp = m->private;
2434
2435	if (tp->sighand) {
2436		unlock_task_sighand(tp->task, &tp->flags);
2437		tp->sighand = NULL;
2438	}
2439
2440	if (tp->task) {
2441		put_task_struct(tp->task);
2442		tp->task = NULL;
2443	}
2444}
2445
2446static int show_timer(struct seq_file *m, void *v)
2447{
2448	struct k_itimer *timer;
2449	struct timers_private *tp = m->private;
2450	int notify;
2451	static const char * const nstr[] = {
2452		[SIGEV_SIGNAL] = "signal",
2453		[SIGEV_NONE] = "none",
2454		[SIGEV_THREAD] = "thread",
2455	};
2456
2457	timer = list_entry((struct list_head *)v, struct k_itimer, list);
2458	notify = timer->it_sigev_notify;
2459
2460	seq_printf(m, "ID: %d\n", timer->it_id);
2461	seq_printf(m, "signal: %d/%px\n",
2462		   timer->sigq->info.si_signo,
2463		   timer->sigq->info.si_value.sival_ptr);
2464	seq_printf(m, "notify: %s/%s.%d\n",
2465		   nstr[notify & ~SIGEV_THREAD_ID],
2466		   (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
2467		   pid_nr_ns(timer->it_pid, tp->ns));
2468	seq_printf(m, "ClockID: %d\n", timer->it_clock);
2469
2470	return 0;
2471}
2472
2473static const struct seq_operations proc_timers_seq_ops = {
2474	.start	= timers_start,
2475	.next	= timers_next,
2476	.stop	= timers_stop,
2477	.show	= show_timer,
2478};
2479
2480static int proc_timers_open(struct inode *inode, struct file *file)
 
 
 
 
2481{
2482	struct timers_private *tp;
2483
2484	tp = __seq_open_private(file, &proc_timers_seq_ops,
2485			sizeof(struct timers_private));
2486	if (!tp)
2487		return -ENOMEM;
2488
2489	tp->pid = proc_pid(inode);
2490	tp->ns = proc_pid_ns(inode->i_sb);
2491	return 0;
2492}
2493
2494static const struct file_operations proc_timers_operations = {
2495	.open		= proc_timers_open,
2496	.read		= seq_read,
2497	.llseek		= seq_lseek,
2498	.release	= seq_release_private,
 
 
2499};
2500#endif
2501
2502static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
2503					size_t count, loff_t *offset)
2504{
2505	struct inode *inode = file_inode(file);
2506	struct task_struct *p;
2507	u64 slack_ns;
2508	int err;
2509
2510	err = kstrtoull_from_user(buf, count, 10, &slack_ns);
2511	if (err < 0)
2512		return err;
 
 
 
 
 
 
 
 
 
2513
2514	p = get_proc_task(inode);
2515	if (!p)
2516		return -ESRCH;
2517
2518	if (p != current) {
2519		rcu_read_lock();
2520		if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2521			rcu_read_unlock();
2522			count = -EPERM;
2523			goto out;
2524		}
2525		rcu_read_unlock();
2526
2527		err = security_task_setscheduler(p);
2528		if (err) {
2529			count = err;
2530			goto out;
2531		}
2532	}
2533
2534	task_lock(p);
2535	if (slack_ns == 0)
2536		p->timer_slack_ns = p->default_timer_slack_ns;
2537	else
2538		p->timer_slack_ns = slack_ns;
2539	task_unlock(p);
2540
2541out:
2542	put_task_struct(p);
2543
2544	return count;
2545}
2546
2547static int timerslack_ns_show(struct seq_file *m, void *v)
 
 
2548{
2549	struct inode *inode = m->private;
2550	struct task_struct *p;
2551	int err = 0;
2552
2553	p = get_proc_task(inode);
2554	if (!p)
2555		return -ESRCH;
2556
2557	if (p != current) {
2558		rcu_read_lock();
2559		if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
2560			rcu_read_unlock();
2561			err = -EPERM;
2562			goto out;
2563		}
2564		rcu_read_unlock();
2565
2566		err = security_task_getscheduler(p);
2567		if (err)
2568			goto out;
2569	}
2570
2571	task_lock(p);
2572	seq_printf(m, "%llu\n", p->timer_slack_ns);
2573	task_unlock(p);
2574
2575out:
2576	put_task_struct(p);
2577
2578	return err;
2579}
2580
2581static int timerslack_ns_open(struct inode *inode, struct file *filp)
2582{
2583	return single_open(filp, timerslack_ns_show, inode);
 
2584}
2585
2586static const struct file_operations proc_pid_set_timerslack_ns_operations = {
2587	.open		= timerslack_ns_open,
2588	.read		= seq_read,
2589	.write		= timerslack_ns_write,
2590	.llseek		= seq_lseek,
2591	.release	= single_release,
 
 
 
 
 
 
2592};
2593
2594static struct dentry *proc_pident_instantiate(struct dentry *dentry,
2595	struct task_struct *task, const void *ptr)
 
2596{
2597	const struct pid_entry *p = ptr;
2598	struct inode *inode;
2599	struct proc_inode *ei;
 
2600
2601	inode = proc_pid_make_inode(dentry->d_sb, task, p->mode);
2602	if (!inode)
2603		return ERR_PTR(-ENOENT);
2604
2605	ei = PROC_I(inode);
 
2606	if (S_ISDIR(inode->i_mode))
2607		set_nlink(inode, 2);	/* Use getattr to fix if necessary */
2608	if (p->iop)
2609		inode->i_op = p->iop;
2610	if (p->fop)
2611		inode->i_fop = p->fop;
2612	ei->op = p->op;
2613	pid_update_inode(task, inode);
2614	d_set_d_op(dentry, &pid_dentry_operations);
2615	return d_splice_alias(inode, dentry);
 
 
 
 
 
2616}
2617
2618static struct dentry *proc_pident_lookup(struct inode *dir, 
2619					 struct dentry *dentry,
2620					 const struct pid_entry *p,
2621					 const struct pid_entry *end)
2622{
 
2623	struct task_struct *task = get_proc_task(dir);
2624	struct dentry *res = ERR_PTR(-ENOENT);
 
 
2625
2626	if (!task)
2627		goto out_no_task;
2628
2629	/*
2630	 * Yes, it does not scale. And it should not. Don't add
2631	 * new entries into /proc/<tgid>/ without very good reasons.
2632	 */
2633	for (; p < end; p++) {
 
2634		if (p->len != dentry->d_name.len)
2635			continue;
2636		if (!memcmp(dentry->d_name.name, p->name, p->len)) {
2637			res = proc_pident_instantiate(dentry, task, p);
2638			break;
2639		}
2640	}
 
 
 
 
 
2641	put_task_struct(task);
2642out_no_task:
2643	return res;
 
 
 
 
 
 
 
2644}
2645
2646static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
 
2647		const struct pid_entry *ents, unsigned int nents)
2648{
2649	struct task_struct *task = get_proc_task(file_inode(file));
2650	const struct pid_entry *p;
 
 
 
 
 
2651
 
2652	if (!task)
2653		return -ENOENT;
2654
2655	if (!dir_emit_dots(file, ctx))
2656		goto out;
2657
2658	if (ctx->pos >= nents + 2)
2659		goto out;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2660
2661	for (p = ents + (ctx->pos - 2); p < ents + nents; p++) {
2662		if (!proc_fill_cache(file, ctx, p->name, p->len,
2663				proc_pident_instantiate, task, p))
2664			break;
2665		ctx->pos++;
2666	}
2667out:
2668	put_task_struct(task);
2669	return 0;
 
2670}
2671
2672#ifdef CONFIG_SECURITY
2673static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
2674				  size_t count, loff_t *ppos)
2675{
2676	struct inode * inode = file_inode(file);
2677	char *p = NULL;
2678	ssize_t length;
2679	struct task_struct *task = get_proc_task(inode);
2680
2681	if (!task)
2682		return -ESRCH;
2683
2684	length = security_getprocattr(task, PROC_I(inode)->op.lsm,
2685				      (char*)file->f_path.dentry->d_name.name,
2686				      &p);
2687	put_task_struct(task);
2688	if (length > 0)
2689		length = simple_read_from_buffer(buf, count, ppos, p, length);
2690	kfree(p);
2691	return length;
2692}
2693
2694static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
2695				   size_t count, loff_t *ppos)
2696{
2697	struct inode * inode = file_inode(file);
2698	struct task_struct *task;
2699	void *page;
2700	int rv;
2701
2702	rcu_read_lock();
2703	task = pid_task(proc_pid(inode), PIDTYPE_PID);
2704	if (!task) {
2705		rcu_read_unlock();
2706		return -ESRCH;
2707	}
2708	/* A task may only write its own attributes. */
2709	if (current != task) {
2710		rcu_read_unlock();
2711		return -EACCES;
2712	}
2713	/* Prevent changes to overridden credentials. */
2714	if (current_cred() != current_real_cred()) {
2715		rcu_read_unlock();
2716		return -EBUSY;
2717	}
2718	rcu_read_unlock();
2719
 
 
 
2720	if (count > PAGE_SIZE)
2721		count = PAGE_SIZE;
2722
2723	/* No partial writes. */
 
2724	if (*ppos != 0)
2725		return -EINVAL;
2726
2727	page = memdup_user(buf, count);
2728	if (IS_ERR(page)) {
2729		rv = PTR_ERR(page);
2730		goto out;
2731	}
 
 
 
2732
2733	/* Guard against adverse ptrace interaction */
2734	rv = mutex_lock_interruptible(&current->signal->cred_guard_mutex);
2735	if (rv < 0)
2736		goto out_free;
2737
2738	rv = security_setprocattr(PROC_I(inode)->op.lsm,
2739				  file->f_path.dentry->d_name.name, page,
2740				  count);
2741	mutex_unlock(&current->signal->cred_guard_mutex);
2742out_free:
2743	kfree(page);
2744out:
2745	return rv;
 
 
2746}
2747
2748static const struct file_operations proc_pid_attr_operations = {
2749	.read		= proc_pid_attr_read,
2750	.write		= proc_pid_attr_write,
2751	.llseek		= generic_file_llseek,
2752};
2753
2754#define LSM_DIR_OPS(LSM) \
2755static int proc_##LSM##_attr_dir_iterate(struct file *filp, \
2756			     struct dir_context *ctx) \
2757{ \
2758	return proc_pident_readdir(filp, ctx, \
2759				   LSM##_attr_dir_stuff, \
2760				   ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2761} \
2762\
2763static const struct file_operations proc_##LSM##_attr_dir_ops = { \
2764	.read		= generic_read_dir, \
2765	.iterate	= proc_##LSM##_attr_dir_iterate, \
2766	.llseek		= default_llseek, \
2767}; \
2768\
2769static struct dentry *proc_##LSM##_attr_dir_lookup(struct inode *dir, \
2770				struct dentry *dentry, unsigned int flags) \
2771{ \
2772	return proc_pident_lookup(dir, dentry, \
2773				  LSM##_attr_dir_stuff, \
2774				  LSM##_attr_dir_stuff + ARRAY_SIZE(LSM##_attr_dir_stuff)); \
2775} \
2776\
2777static const struct inode_operations proc_##LSM##_attr_dir_inode_ops = { \
2778	.lookup		= proc_##LSM##_attr_dir_lookup, \
2779	.getattr	= pid_getattr, \
2780	.setattr	= proc_setattr, \
2781}
2782
2783#ifdef CONFIG_SECURITY_SMACK
2784static const struct pid_entry smack_attr_dir_stuff[] = {
2785	ATTR("smack", "current",	0666),
2786};
2787LSM_DIR_OPS(smack);
2788#endif
2789
2790#ifdef CONFIG_SECURITY_APPARMOR
2791static const struct pid_entry apparmor_attr_dir_stuff[] = {
2792	ATTR("apparmor", "current",	0666),
2793	ATTR("apparmor", "prev",	0444),
2794	ATTR("apparmor", "exec",	0666),
2795};
2796LSM_DIR_OPS(apparmor);
2797#endif
2798
2799static const struct pid_entry attr_dir_stuff[] = {
2800	ATTR(NULL, "current",		0666),
2801	ATTR(NULL, "prev",		0444),
2802	ATTR(NULL, "exec",		0666),
2803	ATTR(NULL, "fscreate",		0666),
2804	ATTR(NULL, "keycreate",		0666),
2805	ATTR(NULL, "sockcreate",	0666),
2806#ifdef CONFIG_SECURITY_SMACK
2807	DIR("smack",			0555,
2808	    proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops),
2809#endif
2810#ifdef CONFIG_SECURITY_APPARMOR
2811	DIR("apparmor",			0555,
2812	    proc_apparmor_attr_dir_inode_ops, proc_apparmor_attr_dir_ops),
2813#endif
2814};
2815
2816static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
 
2817{
2818	return proc_pident_readdir(file, ctx, 
2819				   attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
2820}
2821
2822static const struct file_operations proc_attr_dir_operations = {
2823	.read		= generic_read_dir,
2824	.iterate_shared	= proc_attr_dir_readdir,
2825	.llseek		= generic_file_llseek,
2826};
2827
2828static struct dentry *proc_attr_dir_lookup(struct inode *dir,
2829				struct dentry *dentry, unsigned int flags)
2830{
2831	return proc_pident_lookup(dir, dentry,
2832				  attr_dir_stuff,
2833				  attr_dir_stuff + ARRAY_SIZE(attr_dir_stuff));
2834}
2835
2836static const struct inode_operations proc_attr_dir_inode_operations = {
2837	.lookup		= proc_attr_dir_lookup,
2838	.getattr	= pid_getattr,
2839	.setattr	= proc_setattr,
2840};
2841
2842#endif
2843
2844#ifdef CONFIG_ELF_CORE
2845static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
2846					 size_t count, loff_t *ppos)
2847{
2848	struct task_struct *task = get_proc_task(file_inode(file));
2849	struct mm_struct *mm;
2850	char buffer[PROC_NUMBUF];
2851	size_t len;
2852	int ret;
2853
2854	if (!task)
2855		return -ESRCH;
2856
2857	ret = 0;
2858	mm = get_task_mm(task);
2859	if (mm) {
2860		len = snprintf(buffer, sizeof(buffer), "%08lx\n",
2861			       ((mm->flags & MMF_DUMP_FILTER_MASK) >>
2862				MMF_DUMP_FILTER_SHIFT));
2863		mmput(mm);
2864		ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
2865	}
2866
2867	put_task_struct(task);
2868
2869	return ret;
2870}
2871
2872static ssize_t proc_coredump_filter_write(struct file *file,
2873					  const char __user *buf,
2874					  size_t count,
2875					  loff_t *ppos)
2876{
2877	struct task_struct *task;
2878	struct mm_struct *mm;
 
2879	unsigned int val;
2880	int ret;
2881	int i;
2882	unsigned long mask;
2883
2884	ret = kstrtouint_from_user(buf, count, 0, &val);
2885	if (ret < 0)
2886		return ret;
 
 
 
 
 
 
 
 
 
 
2887
2888	ret = -ESRCH;
2889	task = get_proc_task(file_inode(file));
2890	if (!task)
2891		goto out_no_task;
2892
 
2893	mm = get_task_mm(task);
2894	if (!mm)
2895		goto out_no_mm;
2896	ret = 0;
2897
2898	for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
2899		if (val & mask)
2900			set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2901		else
2902			clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
2903	}
2904
2905	mmput(mm);
2906 out_no_mm:
2907	put_task_struct(task);
2908 out_no_task:
2909	if (ret < 0)
2910		return ret;
2911	return count;
2912}
2913
2914static const struct file_operations proc_coredump_filter_operations = {
2915	.read		= proc_coredump_filter_read,
2916	.write		= proc_coredump_filter_write,
2917	.llseek		= generic_file_llseek,
2918};
2919#endif
2920
2921#ifdef CONFIG_TASK_IO_ACCOUNTING
2922static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
 
 
 
2923{
2924	struct task_io_accounting acct = task->ioac;
2925	unsigned long flags;
2926	int result;
 
 
 
 
 
2927
2928	result = mutex_lock_killable(&task->signal->exec_update_mutex);
2929	if (result)
2930		return result;
2931
2932	if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
2933		result = -EACCES;
2934		goto out_unlock;
 
 
 
 
2935	}
2936
2937	if (whole && lock_task_sighand(task, &flags)) {
2938		struct task_struct *t = task;
2939
2940		task_io_accounting_add(&acct, &task->signal->ioac);
2941		while_each_thread(task, t)
2942			task_io_accounting_add(&acct, &t->ioac);
2943
2944		unlock_task_sighand(task, &flags);
2945	}
2946	seq_printf(m,
2947		   "rchar: %llu\n"
2948		   "wchar: %llu\n"
2949		   "syscr: %llu\n"
2950		   "syscw: %llu\n"
2951		   "read_bytes: %llu\n"
2952		   "write_bytes: %llu\n"
2953		   "cancelled_write_bytes: %llu\n",
2954		   (unsigned long long)acct.rchar,
2955		   (unsigned long long)acct.wchar,
2956		   (unsigned long long)acct.syscr,
2957		   (unsigned long long)acct.syscw,
2958		   (unsigned long long)acct.read_bytes,
2959		   (unsigned long long)acct.write_bytes,
2960		   (unsigned long long)acct.cancelled_write_bytes);
2961	result = 0;
2962
2963out_unlock:
2964	mutex_unlock(&task->signal->exec_update_mutex);
2965	return result;
2966}
2967
2968static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2969				  struct pid *pid, struct task_struct *task)
2970{
2971	return do_io_accounting(task, m, 0);
 
 
2972}
2973
2974static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
2975				   struct pid *pid, struct task_struct *task)
2976{
2977	return do_io_accounting(task, m, 1);
2978}
2979#endif /* CONFIG_TASK_IO_ACCOUNTING */
 
 
 
 
 
 
 
 
 
 
 
2980
2981#ifdef CONFIG_USER_NS
2982static int proc_id_map_open(struct inode *inode, struct file *file,
2983	const struct seq_operations *seq_ops)
2984{
2985	struct user_namespace *ns = NULL;
2986	struct task_struct *task;
2987	struct seq_file *seq;
2988	int ret = -EINVAL;
2989
2990	task = get_proc_task(inode);
2991	if (task) {
2992		rcu_read_lock();
2993		ns = get_user_ns(task_cred_xxx(task, user_ns));
2994		rcu_read_unlock();
2995		put_task_struct(task);
2996	}
2997	if (!ns)
2998		goto err;
2999
3000	ret = seq_open(file, seq_ops);
3001	if (ret)
3002		goto err_put_ns;
 
3003
3004	seq = file->private_data;
3005	seq->private = ns;
 
 
 
 
3006
3007	return 0;
3008err_put_ns:
3009	put_user_ns(ns);
3010err:
3011	return ret;
 
 
 
 
 
 
 
 
 
 
 
 
3012}
3013
3014static int proc_id_map_release(struct inode *inode, struct file *file)
3015{
3016	struct seq_file *seq = file->private_data;
3017	struct user_namespace *ns = seq->private;
3018	put_user_ns(ns);
3019	return seq_release(inode, file);
3020}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3021
3022static int proc_uid_map_open(struct inode *inode, struct file *file)
3023{
3024	return proc_id_map_open(inode, file, &proc_uid_seq_operations);
 
3025}
3026
3027static int proc_gid_map_open(struct inode *inode, struct file *file)
 
3028{
3029	return proc_id_map_open(inode, file, &proc_gid_seq_operations);
 
3030}
3031
3032static int proc_projid_map_open(struct inode *inode, struct file *file)
 
3033{
3034	return proc_id_map_open(inode, file, &proc_projid_seq_operations);
3035}
 
3036
3037static const struct file_operations proc_uid_map_operations = {
3038	.open		= proc_uid_map_open,
3039	.write		= proc_uid_map_write,
3040	.read		= seq_read,
3041	.llseek		= seq_lseek,
3042	.release	= proc_id_map_release,
3043};
3044
3045static const struct file_operations proc_gid_map_operations = {
3046	.open		= proc_gid_map_open,
3047	.write		= proc_gid_map_write,
3048	.read		= seq_read,
3049	.llseek		= seq_lseek,
3050	.release	= proc_id_map_release,
3051};
3052
3053static const struct file_operations proc_projid_map_operations = {
3054	.open		= proc_projid_map_open,
3055	.write		= proc_projid_map_write,
3056	.read		= seq_read,
3057	.llseek		= seq_lseek,
3058	.release	= proc_id_map_release,
3059};
3060
3061static int proc_setgroups_open(struct inode *inode, struct file *file)
3062{
3063	struct user_namespace *ns = NULL;
3064	struct task_struct *task;
3065	int ret;
3066
3067	ret = -ESRCH;
3068	task = get_proc_task(inode);
3069	if (task) {
3070		rcu_read_lock();
3071		ns = get_user_ns(task_cred_xxx(task, user_ns));
3072		rcu_read_unlock();
3073		put_task_struct(task);
3074	}
3075	if (!ns)
3076		goto err;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3077
3078	if (file->f_mode & FMODE_WRITE) {
3079		ret = -EACCES;
3080		if (!ns_capable(ns, CAP_SYS_ADMIN))
3081			goto err_put_ns;
3082	}
3083
3084	ret = single_open(file, &proc_setgroups_show, ns);
3085	if (ret)
3086		goto err_put_ns;
3087
3088	return 0;
3089err_put_ns:
3090	put_user_ns(ns);
3091err:
3092	return ret;
3093}
3094
3095static int proc_setgroups_release(struct inode *inode, struct file *file)
3096{
3097	struct seq_file *seq = file->private_data;
3098	struct user_namespace *ns = seq->private;
3099	int ret = single_release(inode, file);
3100	put_user_ns(ns);
3101	return ret;
3102}
3103
3104static const struct file_operations proc_setgroups_operations = {
3105	.open		= proc_setgroups_open,
3106	.write		= proc_setgroups_write,
3107	.read		= seq_read,
3108	.llseek		= seq_lseek,
3109	.release	= proc_setgroups_release,
3110};
3111#endif /* CONFIG_USER_NS */
3112
3113static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
3114				struct pid *pid, struct task_struct *task)
3115{
3116	int err = lock_trace(task);
3117	if (!err) {
3118		seq_printf(m, "%08x\n", task->personality);
3119		unlock_trace(task);
3120	}
3121	return err;
3122}
3123
3124#ifdef CONFIG_LIVEPATCH
3125static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns,
3126				struct pid *pid, struct task_struct *task)
3127{
3128	seq_printf(m, "%d\n", task->patch_state);
3129	return 0;
3130}
3131#endif /* CONFIG_LIVEPATCH */
3132
3133#ifdef CONFIG_STACKLEAK_METRICS
3134static int proc_stack_depth(struct seq_file *m, struct pid_namespace *ns,
3135				struct pid *pid, struct task_struct *task)
3136{
3137	unsigned long prev_depth = THREAD_SIZE -
3138				(task->prev_lowest_stack & (THREAD_SIZE - 1));
3139	unsigned long depth = THREAD_SIZE -
3140				(task->lowest_stack & (THREAD_SIZE - 1));
3141
3142	seq_printf(m, "previous stack depth: %lu\nstack depth: %lu\n",
3143							prev_depth, depth);
3144	return 0;
3145}
3146#endif /* CONFIG_STACKLEAK_METRICS */
3147
3148/*
3149 * Thread groups
3150 */
3151static const struct file_operations proc_task_operations;
3152static const struct inode_operations proc_task_inode_operations;
3153
3154static const struct pid_entry tgid_base_stuff[] = {
3155	DIR("task",       S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
3156	DIR("fd",         S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3157	DIR("map_files",  S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
3158	DIR("fdinfo",     S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3159	DIR("ns",	  S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3160#ifdef CONFIG_NET
3161	DIR("net",        S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3162#endif
3163	REG("environ",    S_IRUSR, proc_environ_operations),
3164	REG("auxv",       S_IRUSR, proc_auxv_operations),
3165	ONE("status",     S_IRUGO, proc_pid_status),
3166	ONE("personality", S_IRUSR, proc_pid_personality),
3167	ONE("limits",	  S_IRUGO, proc_pid_limits),
3168#ifdef CONFIG_SCHED_DEBUG
3169	REG("sched",      S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3170#endif
3171#ifdef CONFIG_SCHED_AUTOGROUP
3172	REG("autogroup",  S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
3173#endif
3174#ifdef CONFIG_TIME_NS
3175	REG("timens_offsets",  S_IRUGO|S_IWUSR, proc_timens_offsets_operations),
3176#endif
3177	REG("comm",      S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
3178#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3179	ONE("syscall",    S_IRUSR, proc_pid_syscall),
3180#endif
3181	REG("cmdline",    S_IRUGO, proc_pid_cmdline_ops),
3182	ONE("stat",       S_IRUGO, proc_tgid_stat),
3183	ONE("statm",      S_IRUGO, proc_pid_statm),
3184	REG("maps",       S_IRUGO, proc_pid_maps_operations),
3185#ifdef CONFIG_NUMA
3186	REG("numa_maps",  S_IRUGO, proc_pid_numa_maps_operations),
3187#endif
3188	REG("mem",        S_IRUSR|S_IWUSR, proc_mem_operations),
3189	LNK("cwd",        proc_cwd_link),
3190	LNK("root",       proc_root_link),
3191	LNK("exe",        proc_exe_link),
3192	REG("mounts",     S_IRUGO, proc_mounts_operations),
3193	REG("mountinfo",  S_IRUGO, proc_mountinfo_operations),
3194	REG("mountstats", S_IRUSR, proc_mountstats_operations),
3195#ifdef CONFIG_PROC_PAGE_MONITOR
3196	REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3197	REG("smaps",      S_IRUGO, proc_pid_smaps_operations),
3198	REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3199	REG("pagemap",    S_IRUSR, proc_pagemap_operations),
3200#endif
3201#ifdef CONFIG_SECURITY
3202	DIR("attr",       S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3203#endif
3204#ifdef CONFIG_KALLSYMS
3205	ONE("wchan",      S_IRUGO, proc_pid_wchan),
3206#endif
3207#ifdef CONFIG_STACKTRACE
3208	ONE("stack",      S_IRUSR, proc_pid_stack),
3209#endif
3210#ifdef CONFIG_SCHED_INFO
3211	ONE("schedstat",  S_IRUGO, proc_pid_schedstat),
3212#endif
3213#ifdef CONFIG_LATENCYTOP
3214	REG("latency",  S_IRUGO, proc_lstats_operations),
3215#endif
3216#ifdef CONFIG_PROC_PID_CPUSET
3217	ONE("cpuset",     S_IRUGO, proc_cpuset_show),
3218#endif
3219#ifdef CONFIG_CGROUPS
3220	ONE("cgroup",  S_IRUGO, proc_cgroup_show),
3221#endif
3222#ifdef CONFIG_PROC_CPU_RESCTRL
3223	ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show),
3224#endif
3225	ONE("oom_score",  S_IRUGO, proc_oom_score),
3226	REG("oom_adj",    S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3227	REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3228#ifdef CONFIG_AUDIT
3229	REG("loginuid",   S_IWUSR|S_IRUGO, proc_loginuid_operations),
3230	REG("sessionid",  S_IRUGO, proc_sessionid_operations),
3231#endif
3232#ifdef CONFIG_FAULT_INJECTION
3233	REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3234	REG("fail-nth", 0644, proc_fail_nth_operations),
3235#endif
3236#ifdef CONFIG_ELF_CORE
3237	REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
3238#endif
3239#ifdef CONFIG_TASK_IO_ACCOUNTING
3240	ONE("io",	S_IRUSR, proc_tgid_io_accounting),
3241#endif
3242#ifdef CONFIG_USER_NS
3243	REG("uid_map",    S_IRUGO|S_IWUSR, proc_uid_map_operations),
3244	REG("gid_map",    S_IRUGO|S_IWUSR, proc_gid_map_operations),
3245	REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3246	REG("setgroups",  S_IRUGO|S_IWUSR, proc_setgroups_operations),
3247#endif
3248#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
3249	REG("timers",	  S_IRUGO, proc_timers_operations),
3250#endif
3251	REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
3252#ifdef CONFIG_LIVEPATCH
3253	ONE("patch_state",  S_IRUSR, proc_pid_patch_state),
3254#endif
3255#ifdef CONFIG_STACKLEAK_METRICS
3256	ONE("stack_depth", S_IRUGO, proc_stack_depth),
3257#endif
3258#ifdef CONFIG_PROC_PID_ARCH_STATUS
3259	ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3260#endif
3261};
3262
3263static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
 
3264{
3265	return proc_pident_readdir(file, ctx,
3266				   tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3267}
3268
3269static const struct file_operations proc_tgid_base_operations = {
3270	.read		= generic_read_dir,
3271	.iterate_shared	= proc_tgid_base_readdir,
3272	.llseek		= generic_file_llseek,
3273};
3274
3275struct pid *tgid_pidfd_to_pid(const struct file *file)
3276{
3277	if (file->f_op != &proc_tgid_base_operations)
3278		return ERR_PTR(-EBADF);
3279
3280	return proc_pid(file_inode(file));
3281}
3282
3283static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3284{
3285	return proc_pident_lookup(dir, dentry,
3286				  tgid_base_stuff,
3287				  tgid_base_stuff + ARRAY_SIZE(tgid_base_stuff));
3288}
3289
3290static const struct inode_operations proc_tgid_base_inode_operations = {
3291	.lookup		= proc_tgid_base_lookup,
3292	.getattr	= pid_getattr,
3293	.setattr	= proc_setattr,
3294	.permission	= proc_pid_permission,
3295};
3296
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3297/**
3298 * proc_flush_pid -  Remove dcache entries for @pid from the /proc dcache.
3299 * @pid: pid that should be flushed.
3300 *
3301 * This function walks a list of inodes (that belong to any proc
3302 * filesystem) that are attached to the pid and flushes them from
3303 * the dentry cache.
 
 
 
 
 
 
3304 *
3305 * It is safe and reasonable to cache /proc entries for a task until
3306 * that task exits.  After that they just clog up the dcache with
3307 * useless entries, possibly causing useful dcache entries to be
3308 * flushed instead.  This routine is provided to flush those useless
3309 * dcache entries when a process is reaped.
3310 *
3311 * NOTE: This routine is just an optimization so it does not guarantee
3312 *       that no dcache entries will exist after a process is reaped
3313 *       it just makes it very unlikely that any will persist.
3314 */
3315
3316void proc_flush_pid(struct pid *pid)
3317{
3318	proc_invalidate_siblings_dcache(&pid->inodes, &pid->lock);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3319}
3320
3321static struct dentry *proc_pid_instantiate(struct dentry * dentry,
3322				   struct task_struct *task, const void *ptr)
 
3323{
 
3324	struct inode *inode;
3325
3326	inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
3327	if (!inode)
3328		return ERR_PTR(-ENOENT);
3329
 
3330	inode->i_op = &proc_tgid_base_inode_operations;
3331	inode->i_fop = &proc_tgid_base_operations;
3332	inode->i_flags|=S_IMMUTABLE;
3333
3334	set_nlink(inode, nlink_tgid);
3335	pid_update_inode(task, inode);
3336
3337	d_set_d_op(dentry, &pid_dentry_operations);
3338	return d_splice_alias(inode, dentry);
 
 
 
 
 
 
3339}
3340
3341struct dentry *proc_pid_lookup(struct dentry *dentry, unsigned int flags)
3342{
 
3343	struct task_struct *task;
3344	unsigned tgid;
3345	struct proc_fs_info *fs_info;
3346	struct pid_namespace *ns;
3347	struct dentry *result = ERR_PTR(-ENOENT);
3348
3349	tgid = name_to_int(&dentry->d_name);
 
 
 
 
3350	if (tgid == ~0U)
3351		goto out;
3352
3353	fs_info = proc_sb_info(dentry->d_sb);
3354	ns = fs_info->pid_ns;
3355	rcu_read_lock();
3356	task = find_task_by_pid_ns(tgid, ns);
3357	if (task)
3358		get_task_struct(task);
3359	rcu_read_unlock();
3360	if (!task)
3361		goto out;
3362
3363	/* Limit procfs to only ptraceable tasks */
3364	if (fs_info->hide_pid == HIDEPID_NOT_PTRACEABLE) {
3365		if (!has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS))
3366			goto out_put_task;
3367	}
3368
3369	result = proc_pid_instantiate(dentry, task, NULL);
3370out_put_task:
3371	put_task_struct(task);
3372out:
3373	return result;
3374}
3375
3376/*
3377 * Find the first task with tgid >= tgid
3378 *
3379 */
3380struct tgid_iter {
3381	unsigned int tgid;
3382	struct task_struct *task;
3383};
3384static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
3385{
3386	struct pid *pid;
3387
3388	if (iter.task)
3389		put_task_struct(iter.task);
3390	rcu_read_lock();
3391retry:
3392	iter.task = NULL;
3393	pid = find_ge_pid(iter.tgid, ns);
3394	if (pid) {
3395		iter.tgid = pid_nr_ns(pid, ns);
3396		iter.task = pid_task(pid, PIDTYPE_TGID);
3397		if (!iter.task) {
 
 
 
 
 
 
 
 
 
 
 
 
3398			iter.tgid += 1;
3399			goto retry;
3400		}
3401		get_task_struct(iter.task);
3402	}
3403	rcu_read_unlock();
3404	return iter;
3405}
3406
3407#define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)
 
 
 
 
 
 
 
 
 
3408
3409/* for the /proc/ directory itself, after non-process stuff has been done */
3410int proc_pid_readdir(struct file *file, struct dir_context *ctx)
3411{
 
 
3412	struct tgid_iter iter;
3413	struct proc_fs_info *fs_info = proc_sb_info(file_inode(file)->i_sb);
3414	struct pid_namespace *ns = proc_pid_ns(file_inode(file)->i_sb);
3415	loff_t pos = ctx->pos;
3416
3417	if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
3418		return 0;
 
 
 
 
 
3419
3420	if (pos == TGID_OFFSET - 2) {
3421		struct inode *inode = d_inode(fs_info->proc_self);
3422		if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
3423			return 0;
3424		ctx->pos = pos = pos + 1;
3425	}
3426	if (pos == TGID_OFFSET - 1) {
3427		struct inode *inode = d_inode(fs_info->proc_thread_self);
3428		if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
3429			return 0;
3430		ctx->pos = pos = pos + 1;
3431	}
3432	iter.tgid = pos - TGID_OFFSET;
3433	iter.task = NULL;
 
3434	for (iter = next_tgid(ns, iter);
3435	     iter.task;
3436	     iter.tgid += 1, iter = next_tgid(ns, iter)) {
3437		char name[10 + 1];
3438		unsigned int len;
3439
3440		cond_resched();
3441		if (!has_pid_permissions(fs_info, iter.task, HIDEPID_INVISIBLE))
3442			continue;
3443
3444		len = snprintf(name, sizeof(name), "%u", iter.tgid);
3445		ctx->pos = iter.tgid + TGID_OFFSET;
3446		if (!proc_fill_cache(file, ctx, name, len,
3447				     proc_pid_instantiate, iter.task, NULL)) {
3448			put_task_struct(iter.task);
3449			return 0;
3450		}
3451	}
3452	ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
 
 
 
3453	return 0;
3454}
3455
3456/*
3457 * proc_tid_comm_permission is a special permission function exclusively
3458 * used for the node /proc/<pid>/task/<tid>/comm.
3459 * It bypasses generic permission checks in the case where a task of the same
3460 * task group attempts to access the node.
3461 * The rationale behind this is that glibc and bionic access this node for
3462 * cross thread naming (pthread_set/getname_np(!self)). However, if
3463 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0,
3464 * which locks out the cross thread naming implementation.
3465 * This function makes sure that the node is always accessible for members of
3466 * same thread group.
3467 */
3468static int proc_tid_comm_permission(struct inode *inode, int mask)
3469{
3470	bool is_same_tgroup;
3471	struct task_struct *task;
3472
3473	task = get_proc_task(inode);
3474	if (!task)
3475		return -ESRCH;
3476	is_same_tgroup = same_thread_group(current, task);
3477	put_task_struct(task);
3478
3479	if (likely(is_same_tgroup && !(mask & MAY_EXEC))) {
3480		/* This file (/proc/<pid>/task/<tid>/comm) can always be
3481		 * read or written by the members of the corresponding
3482		 * thread group.
3483		 */
3484		return 0;
3485	}
3486
3487	return generic_permission(inode, mask);
3488}
3489
3490static const struct inode_operations proc_tid_comm_inode_operations = {
3491		.permission = proc_tid_comm_permission,
3492};
3493
3494/*
3495 * Tasks
3496 */
3497static const struct pid_entry tid_base_stuff[] = {
3498	DIR("fd",        S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
3499	DIR("fdinfo",    S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
3500	DIR("ns",	 S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
3501#ifdef CONFIG_NET
3502	DIR("net",        S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
3503#endif
3504	REG("environ",   S_IRUSR, proc_environ_operations),
3505	REG("auxv",      S_IRUSR, proc_auxv_operations),
3506	ONE("status",    S_IRUGO, proc_pid_status),
3507	ONE("personality", S_IRUSR, proc_pid_personality),
3508	ONE("limits",	 S_IRUGO, proc_pid_limits),
3509#ifdef CONFIG_SCHED_DEBUG
3510	REG("sched",     S_IRUGO|S_IWUSR, proc_pid_sched_operations),
3511#endif
3512	NOD("comm",      S_IFREG|S_IRUGO|S_IWUSR,
3513			 &proc_tid_comm_inode_operations,
3514			 &proc_pid_set_comm_operations, {}),
3515#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
3516	ONE("syscall",   S_IRUSR, proc_pid_syscall),
3517#endif
3518	REG("cmdline",   S_IRUGO, proc_pid_cmdline_ops),
3519	ONE("stat",      S_IRUGO, proc_tid_stat),
3520	ONE("statm",     S_IRUGO, proc_pid_statm),
3521	REG("maps",      S_IRUGO, proc_pid_maps_operations),
3522#ifdef CONFIG_PROC_CHILDREN
3523	REG("children",  S_IRUGO, proc_tid_children_operations),
3524#endif
3525#ifdef CONFIG_NUMA
3526	REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
3527#endif
3528	REG("mem",       S_IRUSR|S_IWUSR, proc_mem_operations),
3529	LNK("cwd",       proc_cwd_link),
3530	LNK("root",      proc_root_link),
3531	LNK("exe",       proc_exe_link),
3532	REG("mounts",    S_IRUGO, proc_mounts_operations),
3533	REG("mountinfo",  S_IRUGO, proc_mountinfo_operations),
3534#ifdef CONFIG_PROC_PAGE_MONITOR
3535	REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
3536	REG("smaps",     S_IRUGO, proc_pid_smaps_operations),
3537	REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
3538	REG("pagemap",    S_IRUSR, proc_pagemap_operations),
3539#endif
3540#ifdef CONFIG_SECURITY
3541	DIR("attr",      S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
3542#endif
3543#ifdef CONFIG_KALLSYMS
3544	ONE("wchan",     S_IRUGO, proc_pid_wchan),
3545#endif
3546#ifdef CONFIG_STACKTRACE
3547	ONE("stack",      S_IRUSR, proc_pid_stack),
3548#endif
3549#ifdef CONFIG_SCHED_INFO
3550	ONE("schedstat", S_IRUGO, proc_pid_schedstat),
3551#endif
3552#ifdef CONFIG_LATENCYTOP
3553	REG("latency",  S_IRUGO, proc_lstats_operations),
3554#endif
3555#ifdef CONFIG_PROC_PID_CPUSET
3556	ONE("cpuset",    S_IRUGO, proc_cpuset_show),
3557#endif
3558#ifdef CONFIG_CGROUPS
3559	ONE("cgroup",  S_IRUGO, proc_cgroup_show),
3560#endif
3561#ifdef CONFIG_PROC_CPU_RESCTRL
3562	ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show),
3563#endif
3564	ONE("oom_score", S_IRUGO, proc_oom_score),
3565	REG("oom_adj",   S_IRUGO|S_IWUSR, proc_oom_adj_operations),
3566	REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
3567#ifdef CONFIG_AUDIT
3568	REG("loginuid",  S_IWUSR|S_IRUGO, proc_loginuid_operations),
3569	REG("sessionid",  S_IRUGO, proc_sessionid_operations),
3570#endif
3571#ifdef CONFIG_FAULT_INJECTION
3572	REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
3573	REG("fail-nth", 0644, proc_fail_nth_operations),
3574#endif
3575#ifdef CONFIG_TASK_IO_ACCOUNTING
3576	ONE("io",	S_IRUSR, proc_tid_io_accounting),
3577#endif
3578#ifdef CONFIG_USER_NS
3579	REG("uid_map",    S_IRUGO|S_IWUSR, proc_uid_map_operations),
3580	REG("gid_map",    S_IRUGO|S_IWUSR, proc_gid_map_operations),
3581	REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
3582	REG("setgroups",  S_IRUGO|S_IWUSR, proc_setgroups_operations),
3583#endif
3584#ifdef CONFIG_LIVEPATCH
3585	ONE("patch_state",  S_IRUSR, proc_pid_patch_state),
3586#endif
3587#ifdef CONFIG_PROC_PID_ARCH_STATUS
3588	ONE("arch_status", S_IRUGO, proc_pid_arch_status),
3589#endif
3590};
3591
3592static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
 
3593{
3594	return proc_pident_readdir(file, ctx,
3595				   tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3596}
3597
3598static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
3599{
3600	return proc_pident_lookup(dir, dentry,
3601				  tid_base_stuff,
3602				  tid_base_stuff + ARRAY_SIZE(tid_base_stuff));
3603}
3604
3605static const struct file_operations proc_tid_base_operations = {
3606	.read		= generic_read_dir,
3607	.iterate_shared	= proc_tid_base_readdir,
3608	.llseek		= generic_file_llseek,
3609};
3610
3611static const struct inode_operations proc_tid_base_inode_operations = {
3612	.lookup		= proc_tid_base_lookup,
3613	.getattr	= pid_getattr,
3614	.setattr	= proc_setattr,
3615};
3616
3617static struct dentry *proc_task_instantiate(struct dentry *dentry,
3618	struct task_struct *task, const void *ptr)
3619{
 
3620	struct inode *inode;
3621	inode = proc_pid_make_inode(dentry->d_sb, task, S_IFDIR | S_IRUGO | S_IXUGO);
 
3622	if (!inode)
3623		return ERR_PTR(-ENOENT);
3624
3625	inode->i_op = &proc_tid_base_inode_operations;
3626	inode->i_fop = &proc_tid_base_operations;
3627	inode->i_flags |= S_IMMUTABLE;
3628
3629	set_nlink(inode, nlink_tid);
3630	pid_update_inode(task, inode);
3631
3632	d_set_d_op(dentry, &pid_dentry_operations);
3633	return d_splice_alias(inode, dentry);
 
 
 
 
 
 
3634}
3635
3636static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
3637{
 
3638	struct task_struct *task;
3639	struct task_struct *leader = get_proc_task(dir);
3640	unsigned tid;
3641	struct proc_fs_info *fs_info;
3642	struct pid_namespace *ns;
3643	struct dentry *result = ERR_PTR(-ENOENT);
3644
3645	if (!leader)
3646		goto out_no_task;
3647
3648	tid = name_to_int(&dentry->d_name);
3649	if (tid == ~0U)
3650		goto out;
3651
3652	fs_info = proc_sb_info(dentry->d_sb);
3653	ns = fs_info->pid_ns;
3654	rcu_read_lock();
3655	task = find_task_by_pid_ns(tid, ns);
3656	if (task)
3657		get_task_struct(task);
3658	rcu_read_unlock();
3659	if (!task)
3660		goto out;
3661	if (!same_thread_group(leader, task))
3662		goto out_drop_task;
3663
3664	result = proc_task_instantiate(dentry, task, NULL);
3665out_drop_task:
3666	put_task_struct(task);
3667out:
3668	put_task_struct(leader);
3669out_no_task:
3670	return result;
3671}
3672
3673/*
3674 * Find the first tid of a thread group to return to user space.
3675 *
3676 * Usually this is just the thread group leader, but if the users
3677 * buffer was too small or there was a seek into the middle of the
3678 * directory we have more work todo.
3679 *
3680 * In the case of a short read we start with find_task_by_pid.
3681 *
3682 * In the case of a seek we start with the leader and walk nr
3683 * threads past it.
3684 */
3685static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
3686					struct pid_namespace *ns)
3687{
3688	struct task_struct *pos, *task;
3689	unsigned long nr = f_pos;
3690
3691	if (nr != f_pos)	/* 32bit overflow? */
3692		return NULL;
3693
3694	rcu_read_lock();
3695	task = pid_task(pid, PIDTYPE_PID);
3696	if (!task)
3697		goto fail;
3698
3699	/* Attempt to start with the tid of a thread */
3700	if (tid && nr) {
3701		pos = find_task_by_pid_ns(tid, ns);
3702		if (pos && same_thread_group(pos, task))
3703			goto found;
3704	}
3705
3706	/* If nr exceeds the number of threads there is nothing todo */
3707	if (nr >= get_nr_threads(task))
3708		goto fail;
 
3709
3710	/* If we haven't found our starting place yet start
3711	 * with the leader and walk nr threads forward.
3712	 */
3713	pos = task = task->group_leader;
3714	do {
3715		if (!nr--)
3716			goto found;
3717	} while_each_thread(task, pos);
3718fail:
3719	pos = NULL;
3720	goto out;
3721found:
3722	get_task_struct(pos);
3723out:
3724	rcu_read_unlock();
3725	return pos;
3726}
3727
3728/*
3729 * Find the next thread in the thread list.
3730 * Return NULL if there is an error or no next thread.
3731 *
3732 * The reference to the input task_struct is released.
3733 */
3734static struct task_struct *next_tid(struct task_struct *start)
3735{
3736	struct task_struct *pos = NULL;
3737	rcu_read_lock();
3738	if (pid_alive(start)) {
3739		pos = next_thread(start);
3740		if (thread_group_leader(pos))
3741			pos = NULL;
3742		else
3743			get_task_struct(pos);
3744	}
3745	rcu_read_unlock();
3746	put_task_struct(start);
3747	return pos;
3748}
3749
 
 
 
 
 
 
 
 
 
3750/* for the /proc/TGID/task/ directories */
3751static int proc_task_readdir(struct file *file, struct dir_context *ctx)
3752{
3753	struct inode *inode = file_inode(file);
 
 
3754	struct task_struct *task;
 
 
 
3755	struct pid_namespace *ns;
3756	int tid;
3757
3758	if (proc_inode_is_dead(inode))
3759		return -ENOENT;
 
 
 
 
 
 
 
 
 
 
 
3760
3761	if (!dir_emit_dots(file, ctx))
3762		return 0;
 
 
 
 
 
 
 
 
 
 
 
 
3763
3764	/* f_version caches the tgid value that the last readdir call couldn't
3765	 * return. lseek aka telldir automagically resets f_version to 0.
3766	 */
3767	ns = proc_pid_ns(inode->i_sb);
3768	tid = (int)file->f_version;
3769	file->f_version = 0;
3770	for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
3771	     task;
3772	     task = next_tid(task), ctx->pos++) {
3773		char name[10 + 1];
3774		unsigned int len;
3775		tid = task_pid_nr_ns(task, ns);
3776		len = snprintf(name, sizeof(name), "%u", tid);
3777		if (!proc_fill_cache(file, ctx, name, len,
3778				proc_task_instantiate, task, NULL)) {
3779			/* returning this tgid failed, save it as the first
3780			 * pid for the next readir call */
3781			file->f_version = (u64)tid;
3782			put_task_struct(task);
3783			break;
3784		}
3785	}
3786
3787	return 0;
 
 
3788}
3789
3790static int proc_task_getattr(const struct path *path, struct kstat *stat,
3791			     u32 request_mask, unsigned int query_flags)
3792{
3793	struct inode *inode = d_inode(path->dentry);
3794	struct task_struct *p = get_proc_task(inode);
3795	generic_fillattr(inode, stat);
3796
3797	if (p) {
3798		stat->nlink += get_nr_threads(p);
3799		put_task_struct(p);
3800	}
3801
3802	return 0;
3803}
3804
3805static const struct inode_operations proc_task_inode_operations = {
3806	.lookup		= proc_task_lookup,
3807	.getattr	= proc_task_getattr,
3808	.setattr	= proc_setattr,
3809	.permission	= proc_pid_permission,
3810};
3811
3812static const struct file_operations proc_task_operations = {
3813	.read		= generic_read_dir,
3814	.iterate_shared	= proc_task_readdir,
3815	.llseek		= generic_file_llseek,
3816};
3817
3818void __init set_proc_pid_nlink(void)
3819{
3820	nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
3821	nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
3822}