linux/fs/select.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * This file contains the procedures for the handling of select and poll
   4 *
   5 * Created for Linux based loosely upon Mathius Lattner's minix
   6 * patches by Peter MacDonald. Heavily edited by Linus.
   7 *
   8 *  4 February 1994
   9 *     COFF/ELF binary emulation. If the process has the STICKY_TIMEOUTS
  10 *     flag set in its personality we do *not* modify the given timeout
  11 *     parameter to reflect time remaining.
  12 *
  13 *  24 January 2000
  14 *     Changed sys_poll()/do_poll() to use PAGE_SIZE chunk-based allocation 
  15 *     of fds to overcome nfds < 16390 descriptors limit (Tigran Aivazian).
  16 */
  17
  18#include <linux/kernel.h>
  19#include <linux/sched/signal.h>
  20#include <linux/sched/rt.h>
  21#include <linux/syscalls.h>
  22#include <linux/export.h>
  23#include <linux/slab.h>
  24#include <linux/poll.h>
  25#include <linux/personality.h> /* for STICKY_TIMEOUTS */
  26#include <linux/file.h>
  27#include <linux/fdtable.h>
  28#include <linux/fs.h>
  29#include <linux/rcupdate.h>
  30#include <linux/hrtimer.h>
  31#include <linux/freezer.h>
  32#include <net/busy_poll.h>
  33#include <linux/vmalloc.h>
  34
  35#include <linux/uaccess.h>
  36
  37
  38/*
  39 * Estimate expected accuracy in ns from a timeval.
  40 *
  41 * After quite a bit of churning around, we've settled on
  42 * a simple thing of taking 0.1% of the timeout as the
  43 * slack, with a cap of 100 msec.
  44 * "nice" tasks get a 0.5% slack instead.
  45 *
  46 * Consider this comment an open invitation to come up with even
  47 * better solutions..
  48 */
  49
  50#define MAX_SLACK       (100 * NSEC_PER_MSEC)
  51
  52static long __estimate_accuracy(struct timespec64 *tv)
  53{
  54        long slack;
  55        int divfactor = 1000;
  56
  57        if (tv->tv_sec < 0)
  58                return 0;
  59
  60        if (task_nice(current) > 0)
  61                divfactor = divfactor / 5;
  62
  63        if (tv->tv_sec > MAX_SLACK / (NSEC_PER_SEC/divfactor))
  64                return MAX_SLACK;
  65
  66        slack = tv->tv_nsec / divfactor;
  67        slack += tv->tv_sec * (NSEC_PER_SEC/divfactor);
  68
  69        if (slack > MAX_SLACK)
  70                return MAX_SLACK;
  71
  72        return slack;
  73}
  74
  75u64 select_estimate_accuracy(struct timespec64 *tv)
  76{
  77        u64 ret;
  78        struct timespec64 now;
  79
  80        /*
  81         * Realtime tasks get a slack of 0 for obvious reasons.
  82         */
  83
  84        if (rt_task(current))
  85                return 0;
  86
  87        ktime_get_ts64(&now);
  88        now = timespec64_sub(*tv, now);
  89        ret = __estimate_accuracy(&now);
  90        if (ret < current->timer_slack_ns)
  91                return current->timer_slack_ns;
  92        return ret;
  93}
  94
  95
  96
  97struct poll_table_page {
  98        struct poll_table_page * next;
  99        struct poll_table_entry * entry;
 100        struct poll_table_entry entries[];
 101};
 102
 103#define POLL_TABLE_FULL(table) \
 104        ((unsigned long)((table)->entry+1) > PAGE_SIZE + (unsigned long)(table))
 105
 106/*
 107 * Ok, Peter made a complicated, but straightforward multiple_wait() function.
 108 * I have rewritten this, taking some shortcuts: This code may not be easy to
 109 * follow, but it should be free of race-conditions, and it's practical. If you
 110 * understand what I'm doing here, then you understand how the linux
 111 * sleep/wakeup mechanism works.
 112 *
 113 * Two very simple procedures, poll_wait() and poll_freewait() make all the
 114 * work.  poll_wait() is an inline-function defined in <linux/poll.h>,
 115 * as all select/poll functions have to call it to add an entry to the
 116 * poll table.
 117 */
 118static void __pollwait(struct file *filp, wait_queue_head_t *wait_address,
 119                       poll_table *p);
 120
 121void poll_initwait(struct poll_wqueues *pwq)
 122{
 123        init_poll_funcptr(&pwq->pt, __pollwait);
 124        pwq->polling_task = current;
 125        pwq->triggered = 0;
 126        pwq->error = 0;
 127        pwq->table = NULL;
 128        pwq->inline_index = 0;
 129}
 130EXPORT_SYMBOL(poll_initwait);
 131
 132static void free_poll_entry(struct poll_table_entry *entry)
 133{
 134        remove_wait_queue(entry->wait_address, &entry->wait);
 135        fput(entry->filp);
 136}
 137
 138void poll_freewait(struct poll_wqueues *pwq)
 139{
 140        struct poll_table_page * p = pwq->table;
 141        int i;
 142        for (i = 0; i < pwq->inline_index; i++)
 143                free_poll_entry(pwq->inline_entries + i);
 144        while (p) {
 145                struct poll_table_entry * entry;
 146                struct poll_table_page *old;
 147
 148                entry = p->entry;
 149                do {
 150                        entry--;
 151                        free_poll_entry(entry);
 152                } while (entry > p->entries);
 153                old = p;
 154                p = p->next;
 155                free_page((unsigned long) old);
 156        }
 157}
 158EXPORT_SYMBOL(poll_freewait);
 159
 160static struct poll_table_entry *poll_get_entry(struct poll_wqueues *p)
 161{
 162        struct poll_table_page *table = p->table;
 163
 164        if (p->inline_index < N_INLINE_POLL_ENTRIES)
 165                return p->inline_entries + p->inline_index++;
 166
 167        if (!table || POLL_TABLE_FULL(table)) {
 168                struct poll_table_page *new_table;
 169
 170                new_table = (struct poll_table_page *) __get_free_page(GFP_KERNEL);
 171                if (!new_table) {
 172                        p->error = -ENOMEM;
 173                        return NULL;
 174                }
 175                new_table->entry = new_table->entries;
 176                new_table->next = table;
 177                p->table = new_table;
 178                table = new_table;
 179        }
 180
 181        return table->entry++;
 182}
 183
 184static int __pollwake(wait_queue_entry_t *wait, unsigned mode, int sync, void *key)
 185{
 186        struct poll_wqueues *pwq = wait->private;
 187        DECLARE_WAITQUEUE(dummy_wait, pwq->polling_task);
 188
 189        /*
 190         * Although this function is called under waitqueue lock, LOCK
 191         * doesn't imply write barrier and the users expect write
 192         * barrier semantics on wakeup functions.  The following
 193         * smp_wmb() is equivalent to smp_wmb() in try_to_wake_up()
 194         * and is paired with smp_store_mb() in poll_schedule_timeout.
 195         */
 196        smp_wmb();
 197        pwq->triggered = 1;
 198
 199        /*
 200         * Perform the default wake up operation using a dummy
 201         * waitqueue.
 202         *
 203         * TODO: This is hacky but there currently is no interface to
 204         * pass in @sync.  @sync is scheduled to be removed and once
 205         * that happens, wake_up_process() can be used directly.
 206         */
 207        return default_wake_function(&dummy_wait, mode, sync, key);
 208}
 209
 210static int pollwake(wait_queue_entry_t *wait, unsigned mode, int sync, void *key)
 211{
 212        struct poll_table_entry *entry;
 213
 214        entry = container_of(wait, struct poll_table_entry, wait);
 215        if (key && !(key_to_poll(key) & entry->key))
 216                return 0;
 217        return __pollwake(wait, mode, sync, key);
 218}
 219
 220/* Add a new entry */
 221static void __pollwait(struct file *filp, wait_queue_head_t *wait_address,
 222                                poll_table *p)
 223{
 224        struct poll_wqueues *pwq = container_of(p, struct poll_wqueues, pt);
 225        struct poll_table_entry *entry = poll_get_entry(pwq);
 226        if (!entry)
 227                return;
 228        entry->filp = get_file(filp);
 229        entry->wait_address = wait_address;
 230        entry->key = p->_key;
 231        init_waitqueue_func_entry(&entry->wait, pollwake);
 232        entry->wait.private = pwq;
 233        add_wait_queue(wait_address, &entry->wait);
 234}
 235
 236static int poll_schedule_timeout(struct poll_wqueues *pwq, int state,
 237                          ktime_t *expires, unsigned long slack)
 238{
 239        int rc = -EINTR;
 240
 241        set_current_state(state);
 242        if (!pwq->triggered)
 243                rc = schedule_hrtimeout_range(expires, slack, HRTIMER_MODE_ABS);
 244        __set_current_state(TASK_RUNNING);
 245
 246        /*
 247         * Prepare for the next iteration.
 248         *
 249         * The following smp_store_mb() serves two purposes.  First, it's
 250         * the counterpart rmb of the wmb in pollwake() such that data
 251         * written before wake up is always visible after wake up.
 252         * Second, the full barrier guarantees that triggered clearing
 253         * doesn't pass event check of the next iteration.  Note that
 254         * this problem doesn't exist for the first iteration as
 255         * add_wait_queue() has full barrier semantics.
 256         */
 257        smp_store_mb(pwq->triggered, 0);
 258
 259        return rc;
 260}
 261
 262/**
 263 * poll_select_set_timeout - helper function to setup the timeout value
 264 * @to:         pointer to timespec64 variable for the final timeout
 265 * @sec:        seconds (from user space)
 266 * @nsec:       nanoseconds (from user space)
 267 *
 268 * Note, we do not use a timespec for the user space value here, That
 269 * way we can use the function for timeval and compat interfaces as well.
 270 *
 271 * Returns -EINVAL if sec/nsec are not normalized. Otherwise 0.
 272 */
 273int poll_select_set_timeout(struct timespec64 *to, time64_t sec, long nsec)
 274{
 275        struct timespec64 ts = {.tv_sec = sec, .tv_nsec = nsec};
 276
 277        if (!timespec64_valid(&ts))
 278                return -EINVAL;
 279
 280        /* Optimize for the zero timeout value here */
 281        if (!sec && !nsec) {
 282                to->tv_sec = to->tv_nsec = 0;
 283        } else {
 284                ktime_get_ts64(to);
 285                *to = timespec64_add_safe(*to, ts);
 286        }
 287        return 0;
 288}
 289
 290enum poll_time_type {
 291        PT_TIMEVAL = 0,
 292        PT_OLD_TIMEVAL = 1,
 293        PT_TIMESPEC = 2,
 294        PT_OLD_TIMESPEC = 3,
 295};
 296
 297static int poll_select_finish(struct timespec64 *end_time,
 298                              void __user *p,
 299                              enum poll_time_type pt_type, int ret)
 300{
 301        struct timespec64 rts;
 302
 303        restore_saved_sigmask_unless(ret == -ERESTARTNOHAND);
 304
 305        if (!p)
 306                return ret;
 307
 308        if (current->personality & STICKY_TIMEOUTS)
 309                goto sticky;
 310
 311        /* No update for zero timeout */
 312        if (!end_time->tv_sec && !end_time->tv_nsec)
 313                return ret;
 314
 315        ktime_get_ts64(&rts);
 316        rts = timespec64_sub(*end_time, rts);
 317        if (rts.tv_sec < 0)
 318                rts.tv_sec = rts.tv_nsec = 0;
 319
 320
 321        switch (pt_type) {
 322        case PT_TIMEVAL:
 323                {
 324                        struct __kernel_old_timeval rtv;
 325
 326                        if (sizeof(rtv) > sizeof(rtv.tv_sec) + sizeof(rtv.tv_usec))
 327                                memset(&rtv, 0, sizeof(rtv));
 328                        rtv.tv_sec = rts.tv_sec;
 329                        rtv.tv_usec = rts.tv_nsec / NSEC_PER_USEC;
 330                        if (!copy_to_user(p, &rtv, sizeof(rtv)))
 331                                return ret;
 332                }
 333                break;
 334        case PT_OLD_TIMEVAL:
 335                {
 336                        struct old_timeval32 rtv;
 337
 338                        rtv.tv_sec = rts.tv_sec;
 339                        rtv.tv_usec = rts.tv_nsec / NSEC_PER_USEC;
 340                        if (!copy_to_user(p, &rtv, sizeof(rtv)))
 341                                return ret;
 342                }
 343                break;
 344        case PT_TIMESPEC:
 345                if (!put_timespec64(&rts, p))
 346                        return ret;
 347                break;
 348        case PT_OLD_TIMESPEC:
 349                if (!put_old_timespec32(&rts, p))
 350                        return ret;
 351                break;
 352        default:
 353                BUG();
 354        }
 355        /*
 356         * If an application puts its timeval in read-only memory, we
 357         * don't want the Linux-specific update to the timeval to
 358         * cause a fault after the select has completed
 359         * successfully. However, because we're not updating the
 360         * timeval, we can't restart the system call.
 361         */
 362
 363sticky:
 364        if (ret == -ERESTARTNOHAND)
 365                ret = -EINTR;
 366        return ret;
 367}
 368
 369/*
 370 * Scalable version of the fd_set.
 371 */
 372
 373typedef struct {
 374        unsigned long *in, *out, *ex;
 375        unsigned long *res_in, *res_out, *res_ex;
 376} fd_set_bits;
 377
 378/*
 379 * How many longwords for "nr" bits?
 380 */
 381#define FDS_BITPERLONG  (8*sizeof(long))
 382#define FDS_LONGS(nr)   (((nr)+FDS_BITPERLONG-1)/FDS_BITPERLONG)
 383#define FDS_BYTES(nr)   (FDS_LONGS(nr)*sizeof(long))
 384
 385/*
 386 * Use "unsigned long" accesses to let user-mode fd_set's be long-aligned.
 387 */
 388static inline
 389int get_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset)
 390{
 391        nr = FDS_BYTES(nr);
 392        if (ufdset)
 393                return copy_from_user(fdset, ufdset, nr) ? -EFAULT : 0;
 394
 395        memset(fdset, 0, nr);
 396        return 0;
 397}
 398
 399static inline unsigned long __must_check
 400set_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset)
 401{
 402        if (ufdset)
 403                return __copy_to_user(ufdset, fdset, FDS_BYTES(nr));
 404        return 0;
 405}
 406
 407static inline
 408void zero_fd_set(unsigned long nr, unsigned long *fdset)
 409{
 410        memset(fdset, 0, FDS_BYTES(nr));
 411}
 412
 413#define FDS_IN(fds, n)          (fds->in + n)
 414#define FDS_OUT(fds, n)         (fds->out + n)
 415#define FDS_EX(fds, n)          (fds->ex + n)
 416
 417#define BITS(fds, n)    (*FDS_IN(fds, n)|*FDS_OUT(fds, n)|*FDS_EX(fds, n))
 418
 419static int max_select_fd(unsigned long n, fd_set_bits *fds)
 420{
 421        unsigned long *open_fds;
 422        unsigned long set;
 423        int max;
 424        struct fdtable *fdt;
 425
 426        /* handle last in-complete long-word first */
 427        set = ~(~0UL << (n & (BITS_PER_LONG-1)));
 428        n /= BITS_PER_LONG;
 429        fdt = files_fdtable(current->files);
 430        open_fds = fdt->open_fds + n;
 431        max = 0;
 432        if (set) {
 433                set &= BITS(fds, n);
 434                if (set) {
 435                        if (!(set & ~*open_fds))
 436                                goto get_max;
 437                        return -EBADF;
 438                }
 439        }
 440        while (n) {
 441                open_fds--;
 442                n--;
 443                set = BITS(fds, n);
 444                if (!set)
 445                        continue;
 446                if (set & ~*open_fds)
 447                        return -EBADF;
 448                if (max)
 449                        continue;
 450get_max:
 451                do {
 452                        max++;
 453                        set >>= 1;
 454                } while (set);
 455                max += n * BITS_PER_LONG;
 456        }
 457
 458        return max;
 459}
 460
 461#define POLLIN_SET (EPOLLRDNORM | EPOLLRDBAND | EPOLLIN | EPOLLHUP | EPOLLERR)
 462#define POLLOUT_SET (EPOLLWRBAND | EPOLLWRNORM | EPOLLOUT | EPOLLERR)
 463#define POLLEX_SET (EPOLLPRI)
 464
 465static inline void wait_key_set(poll_table *wait, unsigned long in,
 466                                unsigned long out, unsigned long bit,
 467                                __poll_t ll_flag)
 468{
 469        wait->_key = POLLEX_SET | ll_flag;
 470        if (in & bit)
 471                wait->_key |= POLLIN_SET;
 472        if (out & bit)
 473                wait->_key |= POLLOUT_SET;
 474}
 475
 476static int do_select(int n, fd_set_bits *fds, struct timespec64 *end_time)
 477{
 478        ktime_t expire, *to = NULL;
 479        struct poll_wqueues table;
 480        poll_table *wait;
 481        int retval, i, timed_out = 0;
 482        u64 slack = 0;
 483        __poll_t busy_flag = net_busy_loop_on() ? POLL_BUSY_LOOP : 0;
 484        unsigned long busy_start = 0;
 485
 486        rcu_read_lock();
 487        retval = max_select_fd(n, fds);
 488        rcu_read_unlock();
 489
 490        if (retval < 0)
 491                return retval;
 492        n = retval;
 493
 494        poll_initwait(&table);
 495        wait = &table.pt;
 496        if (end_time && !end_time->tv_sec && !end_time->tv_nsec) {
 497                wait->_qproc = NULL;
 498                timed_out = 1;
 499        }
 500
 501        if (end_time && !timed_out)
 502                slack = select_estimate_accuracy(end_time);
 503
 504        retval = 0;
 505        for (;;) {
 506                unsigned long *rinp, *routp, *rexp, *inp, *outp, *exp;
 507                bool can_busy_loop = false;
 508
 509                inp = fds->in; outp = fds->out; exp = fds->ex;
 510                rinp = fds->res_in; routp = fds->res_out; rexp = fds->res_ex;
 511
 512                for (i = 0; i < n; ++rinp, ++routp, ++rexp) {
 513                        unsigned long in, out, ex, all_bits, bit = 1, j;
 514                        unsigned long res_in = 0, res_out = 0, res_ex = 0;
 515                        __poll_t mask;
 516
 517                        in = *inp++; out = *outp++; ex = *exp++;
 518                        all_bits = in | out | ex;
 519                        if (all_bits == 0) {
 520                                i += BITS_PER_LONG;
 521                                continue;
 522                        }
 523
 524                        for (j = 0; j < BITS_PER_LONG; ++j, ++i, bit <<= 1) {
 525                                struct fd f;
 526                                if (i >= n)
 527                                        break;
 528                                if (!(bit & all_bits))
 529                                        continue;
 530                                f = fdget(i);
 531                                if (f.file) {
 532                                        wait_key_set(wait, in, out, bit,
 533                                                     busy_flag);
 534                                        mask = vfs_poll(f.file, wait);
 535
 536                                        fdput(f);
 537                                        if ((mask & POLLIN_SET) && (in & bit)) {
 538                                                res_in |= bit;
 539                                                retval++;
 540                                                wait->_qproc = NULL;
 541                                        }
 542                                        if ((mask & POLLOUT_SET) && (out & bit)) {
 543                                                res_out |= bit;
 544                                                retval++;
 545                                                wait->_qproc = NULL;
 546                                        }
 547                                        if ((mask & POLLEX_SET) && (ex & bit)) {
 548                                                res_ex |= bit;
 549                                                retval++;
 550                                                wait->_qproc = NULL;
 551                                        }
 552                                        /* got something, stop busy polling */
 553                                        if (retval) {
 554                                                can_busy_loop = false;
 555                                                busy_flag = 0;
 556
 557                                        /*
 558                                         * only remember a returned
 559                                         * POLL_BUSY_LOOP if we asked for it
 560                                         */
 561                                        } else if (busy_flag & mask)
 562                                                can_busy_loop = true;
 563
 564                                }
 565                        }
 566                        if (res_in)
 567                                *rinp = res_in;
 568                        if (res_out)
 569                                *routp = res_out;
 570                        if (res_ex)
 571                                *rexp = res_ex;
 572                        cond_resched();
 573                }
 574                wait->_qproc = NULL;
 575                if (retval || timed_out || signal_pending(current))
 576                        break;
 577                if (table.error) {
 578                        retval = table.error;
 579                        break;
 580                }
 581
 582                /* only if found POLL_BUSY_LOOP sockets && not out of time */
 583                if (can_busy_loop && !need_resched()) {
 584                        if (!busy_start) {
 585                                busy_start = busy_loop_current_time();
 586                                continue;
 587                        }
 588                        if (!busy_loop_timeout(busy_start))
 589                                continue;
 590                }
 591                busy_flag = 0;
 592
 593                /*
 594                 * If this is the first loop and we have a timeout
 595                 * given, then we convert to ktime_t and set the to
 596                 * pointer to the expiry value.
 597                 */
 598                if (end_time && !to) {
 599                        expire = timespec64_to_ktime(*end_time);
 600                        to = &expire;
 601                }
 602
 603                if (!poll_schedule_timeout(&table, TASK_INTERRUPTIBLE,
 604                                           to, slack))
 605                        timed_out = 1;
 606        }
 607
 608        poll_freewait(&table);
 609
 610        return retval;
 611}
 612
 613/*
 614 * We can actually return ERESTARTSYS instead of EINTR, but I'd
 615 * like to be certain this leads to no problems. So I return
 616 * EINTR just for safety.
 617 *
 618 * Update: ERESTARTSYS breaks at least the xview clock binary, so
 619 * I'm trying ERESTARTNOHAND which restart only when you want to.
 620 */
 621int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp,
 622                           fd_set __user *exp, struct timespec64 *end_time)
 623{
 624        fd_set_bits fds;
 625        void *bits;
 626        int ret, max_fds;
 627        size_t size, alloc_size;
 628        struct fdtable *fdt;
 629        /* Allocate small arguments on the stack to save memory and be faster */
 630        long stack_fds[SELECT_STACK_ALLOC/sizeof(long)];
 631
 632        ret = -EINVAL;
 633        if (n < 0)
 634                goto out_nofds;
 635
 636        /* max_fds can increase, so grab it once to avoid race */
 637        rcu_read_lock();
 638        fdt = files_fdtable(current->files);
 639        max_fds = fdt->max_fds;
 640        rcu_read_unlock();
 641        if (n > max_fds)
 642                n = max_fds;
 643
 644        /*
 645         * We need 6 bitmaps (in/out/ex for both incoming and outgoing),
 646         * since we used fdset we need to allocate memory in units of
 647         * long-words. 
 648         */
 649        size = FDS_BYTES(n);
 650        bits = stack_fds;
 651        if (size > sizeof(stack_fds) / 6) {
 652                /* Not enough space in on-stack array; must use kmalloc */
 653                ret = -ENOMEM;
 654                if (size > (SIZE_MAX / 6))
 655                        goto out_nofds;
 656
 657                alloc_size = 6 * size;
 658                bits = kvmalloc(alloc_size, GFP_KERNEL);
 659                if (!bits)
 660                        goto out_nofds;
 661        }
 662        fds.in      = bits;
 663        fds.out     = bits +   size;
 664        fds.ex      = bits + 2*size;
 665        fds.res_in  = bits + 3*size;
 666        fds.res_out = bits + 4*size;
 667        fds.res_ex  = bits + 5*size;
 668
 669        if ((ret = get_fd_set(n, inp, fds.in)) ||
 670            (ret = get_fd_set(n, outp, fds.out)) ||
 671            (ret = get_fd_set(n, exp, fds.ex)))
 672                goto out;
 673        zero_fd_set(n, fds.res_in);
 674        zero_fd_set(n, fds.res_out);
 675        zero_fd_set(n, fds.res_ex);
 676
 677        ret = do_select(n, &fds, end_time);
 678
 679        if (ret < 0)
 680                goto out;
 681        if (!ret) {
 682                ret = -ERESTARTNOHAND;
 683                if (signal_pending(current))
 684                        goto out;
 685                ret = 0;
 686        }
 687
 688        if (set_fd_set(n, inp, fds.res_in) ||
 689            set_fd_set(n, outp, fds.res_out) ||
 690            set_fd_set(n, exp, fds.res_ex))
 691                ret = -EFAULT;
 692
 693out:
 694        if (bits != stack_fds)
 695                kvfree(bits);
 696out_nofds:
 697        return ret;
 698}
 699
 700static int kern_select(int n, fd_set __user *inp, fd_set __user *outp,
 701                       fd_set __user *exp, struct __kernel_old_timeval __user *tvp)
 702{
 703        struct timespec64 end_time, *to = NULL;
 704        struct __kernel_old_timeval tv;
 705        int ret;
 706
 707        if (tvp) {
 708                if (copy_from_user(&tv, tvp, sizeof(tv)))
 709                        return -EFAULT;
 710
 711                to = &end_time;
 712                if (poll_select_set_timeout(to,
 713                                tv.tv_sec + (tv.tv_usec / USEC_PER_SEC),
 714                                (tv.tv_usec % USEC_PER_SEC) * NSEC_PER_USEC))
 715                        return -EINVAL;
 716        }
 717
 718        ret = core_sys_select(n, inp, outp, exp, to);
 719        return poll_select_finish(&end_time, tvp, PT_TIMEVAL, ret);
 720}
 721
 722SYSCALL_DEFINE5(select, int, n, fd_set __user *, inp, fd_set __user *, outp,
 723                fd_set __user *, exp, struct __kernel_old_timeval __user *, tvp)
 724{
 725        return kern_select(n, inp, outp, exp, tvp);
 726}
 727
 728static long do_pselect(int n, fd_set __user *inp, fd_set __user *outp,
 729                       fd_set __user *exp, void __user *tsp,
 730                       const sigset_t __user *sigmask, size_t sigsetsize,
 731                       enum poll_time_type type)
 732{
 733        struct timespec64 ts, end_time, *to = NULL;
 734        int ret;
 735
 736        if (tsp) {
 737                switch (type) {
 738                case PT_TIMESPEC:
 739                        if (get_timespec64(&ts, tsp))
 740                                return -EFAULT;
 741                        break;
 742                case PT_OLD_TIMESPEC:
 743                        if (get_old_timespec32(&ts, tsp))
 744                                return -EFAULT;
 745                        break;
 746                default:
 747                        BUG();
 748                }
 749
 750                to = &end_time;
 751                if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec))
 752                        return -EINVAL;
 753        }
 754
 755        ret = set_user_sigmask(sigmask, sigsetsize);
 756        if (ret)
 757                return ret;
 758
 759        ret = core_sys_select(n, inp, outp, exp, to);
 760        return poll_select_finish(&end_time, tsp, type, ret);
 761}
 762
 763/*
 764 * Most architectures can't handle 7-argument syscalls. So we provide a
 765 * 6-argument version where the sixth argument is a pointer to a structure
 766 * which has a pointer to the sigset_t itself followed by a size_t containing
 767 * the sigset size.
 768 */
 769struct sigset_argpack {
 770        sigset_t __user *p;
 771        size_t size;
 772};
 773
 774static inline int get_sigset_argpack(struct sigset_argpack *to,
 775                                     struct sigset_argpack __user *from)
 776{
 777        // the path is hot enough for overhead of copy_from_user() to matter
 778        if (from) {
 779                if (!user_read_access_begin(from, sizeof(*from)))
 780                        return -EFAULT;
 781                unsafe_get_user(to->p, &from->p, Efault);
 782                unsafe_get_user(to->size, &from->size, Efault);
 783                user_read_access_end();
 784        }
 785        return 0;
 786Efault:
 787        user_access_end();
 788        return -EFAULT;
 789}
 790
 791SYSCALL_DEFINE6(pselect6, int, n, fd_set __user *, inp, fd_set __user *, outp,
 792                fd_set __user *, exp, struct __kernel_timespec __user *, tsp,
 793                void __user *, sig)
 794{
 795        struct sigset_argpack x = {NULL, 0};
 796
 797        if (get_sigset_argpack(&x, sig))
 798                return -EFAULT;
 799
 800        return do_pselect(n, inp, outp, exp, tsp, x.p, x.size, PT_TIMESPEC);
 801}
 802
 803#if defined(CONFIG_COMPAT_32BIT_TIME) && !defined(CONFIG_64BIT)
 804
 805SYSCALL_DEFINE6(pselect6_time32, int, n, fd_set __user *, inp, fd_set __user *, outp,
 806                fd_set __user *, exp, struct old_timespec32 __user *, tsp,
 807                void __user *, sig)
 808{
 809        struct sigset_argpack x = {NULL, 0};
 810
 811        if (get_sigset_argpack(&x, sig))
 812                return -EFAULT;
 813
 814        return do_pselect(n, inp, outp, exp, tsp, x.p, x.size, PT_OLD_TIMESPEC);
 815}
 816
 817#endif
 818
 819#ifdef __ARCH_WANT_SYS_OLD_SELECT
 820struct sel_arg_struct {
 821        unsigned long n;
 822        fd_set __user *inp, *outp, *exp;
 823        struct __kernel_old_timeval __user *tvp;
 824};
 825
 826SYSCALL_DEFINE1(old_select, struct sel_arg_struct __user *, arg)
 827{
 828        struct sel_arg_struct a;
 829
 830        if (copy_from_user(&a, arg, sizeof(a)))
 831                return -EFAULT;
 832        return kern_select(a.n, a.inp, a.outp, a.exp, a.tvp);
 833}
 834#endif
 835
 836struct poll_list {
 837        struct poll_list *next;
 838        int len;
 839        struct pollfd entries[];
 840};
 841
 842#define POLLFD_PER_PAGE  ((PAGE_SIZE-sizeof(struct poll_list)) / sizeof(struct pollfd))
 843
 844/*
 845 * Fish for pollable events on the pollfd->fd file descriptor. We're only
 846 * interested in events matching the pollfd->events mask, and the result
 847 * matching that mask is both recorded in pollfd->revents and returned. The
 848 * pwait poll_table will be used by the fd-provided poll handler for waiting,
 849 * if pwait->_qproc is non-NULL.
 850 */
 851static inline __poll_t do_pollfd(struct pollfd *pollfd, poll_table *pwait,
 852                                     bool *can_busy_poll,
 853                                     __poll_t busy_flag)
 854{
 855        int fd = pollfd->fd;
 856        __poll_t mask = 0, filter;
 857        struct fd f;
 858
 859        if (fd < 0)
 860                goto out;
 861        mask = EPOLLNVAL;
 862        f = fdget(fd);
 863        if (!f.file)
 864                goto out;
 865
 866        /* userland u16 ->events contains POLL... bitmap */
 867        filter = demangle_poll(pollfd->events) | EPOLLERR | EPOLLHUP;
 868        pwait->_key = filter | busy_flag;
 869        mask = vfs_poll(f.file, pwait);
 870        if (mask & busy_flag)
 871                *can_busy_poll = true;
 872        mask &= filter;         /* Mask out unneeded events. */
 873        fdput(f);
 874
 875out:
 876        /* ... and so does ->revents */
 877        pollfd->revents = mangle_poll(mask);
 878        return mask;
 879}
 880
 881static int do_poll(struct poll_list *list, struct poll_wqueues *wait,
 882                   struct timespec64 *end_time)
 883{
 884        poll_table* pt = &wait->pt;
 885        ktime_t expire, *to = NULL;
 886        int timed_out = 0, count = 0;
 887        u64 slack = 0;
 888        __poll_t busy_flag = net_busy_loop_on() ? POLL_BUSY_LOOP : 0;
 889        unsigned long busy_start = 0;
 890
 891        /* Optimise the no-wait case */
 892        if (end_time && !end_time->tv_sec && !end_time->tv_nsec) {
 893                pt->_qproc = NULL;
 894                timed_out = 1;
 895        }
 896
 897        if (end_time && !timed_out)
 898                slack = select_estimate_accuracy(end_time);
 899
 900        for (;;) {
 901                struct poll_list *walk;
 902                bool can_busy_loop = false;
 903
 904                for (walk = list; walk != NULL; walk = walk->next) {
 905                        struct pollfd * pfd, * pfd_end;
 906
 907                        pfd = walk->entries;
 908                        pfd_end = pfd + walk->len;
 909                        for (; pfd != pfd_end; pfd++) {
 910                                /*
 911                                 * Fish for events. If we found one, record it
 912                                 * and kill poll_table->_qproc, so we don't
 913                                 * needlessly register any other waiters after
 914                                 * this. They'll get immediately deregistered
 915                                 * when we break out and return.
 916                                 */
 917                                if (do_pollfd(pfd, pt, &can_busy_loop,
 918                                              busy_flag)) {
 919                                        count++;
 920                                        pt->_qproc = NULL;
 921                                        /* found something, stop busy polling */
 922                                        busy_flag = 0;
 923                                        can_busy_loop = false;
 924                                }
 925                        }
 926                }
 927                /*
 928                 * All waiters have already been registered, so don't provide
 929                 * a poll_table->_qproc to them on the next loop iteration.
 930                 */
 931                pt->_qproc = NULL;
 932                if (!count) {
 933                        count = wait->error;
 934                        if (signal_pending(current))
 935                                count = -ERESTARTNOHAND;
 936                }
 937                if (count || timed_out)
 938                        break;
 939
 940                /* only if found POLL_BUSY_LOOP sockets && not out of time */
 941                if (can_busy_loop && !need_resched()) {
 942                        if (!busy_start) {
 943                                busy_start = busy_loop_current_time();
 944                                continue;
 945                        }
 946                        if (!busy_loop_timeout(busy_start))
 947                                continue;
 948                }
 949                busy_flag = 0;
 950
 951                /*
 952                 * If this is the first loop and we have a timeout
 953                 * given, then we convert to ktime_t and set the to
 954                 * pointer to the expiry value.
 955                 */
 956                if (end_time && !to) {
 957                        expire = timespec64_to_ktime(*end_time);
 958                        to = &expire;
 959                }
 960
 961                if (!poll_schedule_timeout(wait, TASK_INTERRUPTIBLE, to, slack))
 962                        timed_out = 1;
 963        }
 964        return count;
 965}
 966
 967#define N_STACK_PPS ((sizeof(stack_pps) - sizeof(struct poll_list))  / \
 968                        sizeof(struct pollfd))
 969
 970static int do_sys_poll(struct pollfd __user *ufds, unsigned int nfds,
 971                struct timespec64 *end_time)
 972{
 973        struct poll_wqueues table;
 974        int err = -EFAULT, fdcount, len;
 975        /* Allocate small arguments on the stack to save memory and be
 976           faster - use long to make sure the buffer is aligned properly
 977           on 64 bit archs to avoid unaligned access */
 978        long stack_pps[POLL_STACK_ALLOC/sizeof(long)];
 979        struct poll_list *const head = (struct poll_list *)stack_pps;
 980        struct poll_list *walk = head;
 981        unsigned long todo = nfds;
 982
 983        if (nfds > rlimit(RLIMIT_NOFILE))
 984                return -EINVAL;
 985
 986        len = min_t(unsigned int, nfds, N_STACK_PPS);
 987        for (;;) {
 988                walk->next = NULL;
 989                walk->len = len;
 990                if (!len)
 991                        break;
 992
 993                if (copy_from_user(walk->entries, ufds + nfds-todo,
 994                                        sizeof(struct pollfd) * walk->len))
 995                        goto out_fds;
 996
 997                todo -= walk->len;
 998                if (!todo)
 999                        break;
1000
1001                len = min(todo, POLLFD_PER_PAGE);
1002                walk = walk->next = kmalloc(struct_size(walk, entries, len),
1003                                            GFP_KERNEL);
1004                if (!walk) {
1005                        err = -ENOMEM;
1006                        goto out_fds;
1007                }
1008        }
1009
1010        poll_initwait(&table);
1011        fdcount = do_poll(head, &table, end_time);
1012        poll_freewait(&table);
1013
1014        if (!user_write_access_begin(ufds, nfds * sizeof(*ufds)))
1015                goto out_fds;
1016
1017        for (walk = head; walk; walk = walk->next) {
1018                struct pollfd *fds = walk->entries;
1019                int j;
1020
1021                for (j = walk->len; j; fds++, ufds++, j--)
1022                        unsafe_put_user(fds->revents, &ufds->revents, Efault);
1023        }
1024        user_write_access_end();
1025
1026        err = fdcount;
1027out_fds:
1028        walk = head->next;
1029        while (walk) {
1030                struct poll_list *pos = walk;
1031                walk = walk->next;
1032                kfree(pos);
1033        }
1034
1035        return err;
1036
1037Efault:
1038        user_write_access_end();
1039        err = -EFAULT;
1040        goto out_fds;
1041}
1042
1043static long do_restart_poll(struct restart_block *restart_block)
1044{
1045        struct pollfd __user *ufds = restart_block->poll.ufds;
1046        int nfds = restart_block->poll.nfds;
1047        struct timespec64 *to = NULL, end_time;
1048        int ret;
1049
1050        if (restart_block->poll.has_timeout) {
1051                end_time.tv_sec = restart_block->poll.tv_sec;
1052                end_time.tv_nsec = restart_block->poll.tv_nsec;
1053                to = &end_time;
1054        }
1055
1056        ret = do_sys_poll(ufds, nfds, to);
1057
1058        if (ret == -ERESTARTNOHAND)
1059                ret = set_restart_fn(restart_block, do_restart_poll);
1060
1061        return ret;
1062}
1063
1064SYSCALL_DEFINE3(poll, struct pollfd __user *, ufds, unsigned int, nfds,
1065                int, timeout_msecs)
1066{
1067        struct timespec64 end_time, *to = NULL;
1068        int ret;
1069
1070        if (timeout_msecs >= 0) {
1071                to = &end_time;
1072                poll_select_set_timeout(to, timeout_msecs / MSEC_PER_SEC,
1073                        NSEC_PER_MSEC * (timeout_msecs % MSEC_PER_SEC));
1074        }
1075
1076        ret = do_sys_poll(ufds, nfds, to);
1077
1078        if (ret == -ERESTARTNOHAND) {
1079                struct restart_block *restart_block;
1080
1081                restart_block = &current->restart_block;
1082                restart_block->poll.ufds = ufds;
1083                restart_block->poll.nfds = nfds;
1084
1085                if (timeout_msecs >= 0) {
1086                        restart_block->poll.tv_sec = end_time.tv_sec;
1087                        restart_block->poll.tv_nsec = end_time.tv_nsec;
1088                        restart_block->poll.has_timeout = 1;
1089                } else
1090                        restart_block->poll.has_timeout = 0;
1091
1092                ret = set_restart_fn(restart_block, do_restart_poll);
1093        }
1094        return ret;
1095}
1096
1097SYSCALL_DEFINE5(ppoll, struct pollfd __user *, ufds, unsigned int, nfds,
1098                struct __kernel_timespec __user *, tsp, const sigset_t __user *, sigmask,
1099                size_t, sigsetsize)
1100{
1101        struct timespec64 ts, end_time, *to = NULL;
1102        int ret;
1103
1104        if (tsp) {
1105                if (get_timespec64(&ts, tsp))
1106                        return -EFAULT;
1107
1108                to = &end_time;
1109                if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec))
1110                        return -EINVAL;
1111        }
1112
1113        ret = set_user_sigmask(sigmask, sigsetsize);
1114        if (ret)
1115                return ret;
1116
1117        ret = do_sys_poll(ufds, nfds, to);
1118        return poll_select_finish(&end_time, tsp, PT_TIMESPEC, ret);
1119}
1120
1121#if defined(CONFIG_COMPAT_32BIT_TIME) && !defined(CONFIG_64BIT)
1122
1123SYSCALL_DEFINE5(ppoll_time32, struct pollfd __user *, ufds, unsigned int, nfds,
1124                struct old_timespec32 __user *, tsp, const sigset_t __user *, sigmask,
1125                size_t, sigsetsize)
1126{
1127        struct timespec64 ts, end_time, *to = NULL;
1128        int ret;
1129
1130        if (tsp) {
1131                if (get_old_timespec32(&ts, tsp))
1132                        return -EFAULT;
1133
1134                to = &end_time;
1135                if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec))
1136                        return -EINVAL;
1137        }
1138
1139        ret = set_user_sigmask(sigmask, sigsetsize);
1140        if (ret)
1141                return ret;
1142
1143        ret = do_sys_poll(ufds, nfds, to);
1144        return poll_select_finish(&end_time, tsp, PT_OLD_TIMESPEC, ret);
1145}
1146#endif
1147
1148#ifdef CONFIG_COMPAT
1149#define __COMPAT_NFDBITS       (8 * sizeof(compat_ulong_t))
1150
1151/*
1152 * Ooo, nasty.  We need here to frob 32-bit unsigned longs to
1153 * 64-bit unsigned longs.
1154 */
1155static
1156int compat_get_fd_set(unsigned long nr, compat_ulong_t __user *ufdset,
1157                        unsigned long *fdset)
1158{
1159        if (ufdset) {
1160                return compat_get_bitmap(fdset, ufdset, nr);
1161        } else {
1162                zero_fd_set(nr, fdset);
1163                return 0;
1164        }
1165}
1166
1167static
1168int compat_set_fd_set(unsigned long nr, compat_ulong_t __user *ufdset,
1169                      unsigned long *fdset)
1170{
1171        if (!ufdset)
1172                return 0;
1173        return compat_put_bitmap(ufdset, fdset, nr);
1174}
1175
1176
1177/*
1178 * This is a virtual copy of sys_select from fs/select.c and probably
1179 * should be compared to it from time to time
1180 */
1181
1182/*
1183 * We can actually return ERESTARTSYS instead of EINTR, but I'd
1184 * like to be certain this leads to no problems. So I return
1185 * EINTR just for safety.
1186 *
1187 * Update: ERESTARTSYS breaks at least the xview clock binary, so
1188 * I'm trying ERESTARTNOHAND which restart only when you want to.
1189 */
1190static int compat_core_sys_select(int n, compat_ulong_t __user *inp,
1191        compat_ulong_t __user *outp, compat_ulong_t __user *exp,
1192        struct timespec64 *end_time)
1193{
1194        fd_set_bits fds;
1195        void *bits;
1196        int size, max_fds, ret = -EINVAL;
1197        struct fdtable *fdt;
1198        long stack_fds[SELECT_STACK_ALLOC/sizeof(long)];
1199
1200        if (n < 0)
1201                goto out_nofds;
1202
1203        /* max_fds can increase, so grab it once to avoid race */
1204        rcu_read_lock();
1205        fdt = files_fdtable(current->files);
1206        max_fds = fdt->max_fds;
1207        rcu_read_unlock();
1208        if (n > max_fds)
1209                n = max_fds;
1210
1211        /*
1212         * We need 6 bitmaps (in/out/ex for both incoming and outgoing),
1213         * since we used fdset we need to allocate memory in units of
1214         * long-words.
1215         */
1216        size = FDS_BYTES(n);
1217        bits = stack_fds;
1218        if (size > sizeof(stack_fds) / 6) {
1219                bits = kmalloc_array(6, size, GFP_KERNEL);
1220                ret = -ENOMEM;
1221                if (!bits)
1222                        goto out_nofds;
1223        }
1224        fds.in      = (unsigned long *)  bits;
1225        fds.out     = (unsigned long *) (bits +   size);
1226        fds.ex      = (unsigned long *) (bits + 2*size);
1227        fds.res_in  = (unsigned long *) (bits + 3*size);
1228        fds.res_out = (unsigned long *) (bits + 4*size);
1229        fds.res_ex  = (unsigned long *) (bits + 5*size);
1230
1231        if ((ret = compat_get_fd_set(n, inp, fds.in)) ||
1232            (ret = compat_get_fd_set(n, outp, fds.out)) ||
1233            (ret = compat_get_fd_set(n, exp, fds.ex)))
1234                goto out;
1235        zero_fd_set(n, fds.res_in);
1236        zero_fd_set(n, fds.res_out);
1237        zero_fd_set(n, fds.res_ex);
1238
1239        ret = do_select(n, &fds, end_time);
1240
1241        if (ret < 0)
1242                goto out;
1243        if (!ret) {
1244                ret = -ERESTARTNOHAND;
1245                if (signal_pending(current))
1246                        goto out;
1247                ret = 0;
1248        }
1249
1250        if (compat_set_fd_set(n, inp, fds.res_in) ||
1251            compat_set_fd_set(n, outp, fds.res_out) ||
1252            compat_set_fd_set(n, exp, fds.res_ex))
1253                ret = -EFAULT;
1254out:
1255        if (bits != stack_fds)
1256                kfree(bits);
1257out_nofds:
1258        return ret;
1259}
1260
1261static int do_compat_select(int n, compat_ulong_t __user *inp,
1262        compat_ulong_t __user *outp, compat_ulong_t __user *exp,
1263        struct old_timeval32 __user *tvp)
1264{
1265        struct timespec64 end_time, *to = NULL;
1266        struct old_timeval32 tv;
1267        int ret;
1268
1269        if (tvp) {
1270                if (copy_from_user(&tv, tvp, sizeof(tv)))
1271                        return -EFAULT;
1272
1273                to = &end_time;
1274                if (poll_select_set_timeout(to,
1275                                tv.tv_sec + (tv.tv_usec / USEC_PER_SEC),
1276                                (tv.tv_usec % USEC_PER_SEC) * NSEC_PER_USEC))
1277                        return -EINVAL;
1278        }
1279
1280        ret = compat_core_sys_select(n, inp, outp, exp, to);
1281        return poll_select_finish(&end_time, tvp, PT_OLD_TIMEVAL, ret);
1282}
1283
1284COMPAT_SYSCALL_DEFINE5(select, int, n, compat_ulong_t __user *, inp,
1285        compat_ulong_t __user *, outp, compat_ulong_t __user *, exp,
1286        struct old_timeval32 __user *, tvp)
1287{
1288        return do_compat_select(n, inp, outp, exp, tvp);
1289}
1290
1291struct compat_sel_arg_struct {
1292        compat_ulong_t n;
1293        compat_uptr_t inp;
1294        compat_uptr_t outp;
1295        compat_uptr_t exp;
1296        compat_uptr_t tvp;
1297};
1298
1299COMPAT_SYSCALL_DEFINE1(old_select, struct compat_sel_arg_struct __user *, arg)
1300{
1301        struct compat_sel_arg_struct a;
1302
1303        if (copy_from_user(&a, arg, sizeof(a)))
1304                return -EFAULT;
1305        return do_compat_select(a.n, compat_ptr(a.inp), compat_ptr(a.outp),
1306                                compat_ptr(a.exp), compat_ptr(a.tvp));
1307}
1308
1309static long do_compat_pselect(int n, compat_ulong_t __user *inp,
1310        compat_ulong_t __user *outp, compat_ulong_t __user *exp,
1311        void __user *tsp, compat_sigset_t __user *sigmask,
1312        compat_size_t sigsetsize, enum poll_time_type type)
1313{
1314        struct timespec64 ts, end_time, *to = NULL;
1315        int ret;
1316
1317        if (tsp) {
1318                switch (type) {
1319                case PT_OLD_TIMESPEC:
1320                        if (get_old_timespec32(&ts, tsp))
1321                                return -EFAULT;
1322                        break;
1323                case PT_TIMESPEC:
1324                        if (get_timespec64(&ts, tsp))
1325                                return -EFAULT;
1326                        break;
1327                default:
1328                        BUG();
1329                }
1330
1331                to = &end_time;
1332                if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec))
1333                        return -EINVAL;
1334        }
1335
1336        ret = set_compat_user_sigmask(sigmask, sigsetsize);
1337        if (ret)
1338                return ret;
1339
1340        ret = compat_core_sys_select(n, inp, outp, exp, to);
1341        return poll_select_finish(&end_time, tsp, type, ret);
1342}
1343
1344struct compat_sigset_argpack {
1345        compat_uptr_t p;
1346        compat_size_t size;
1347};
1348static inline int get_compat_sigset_argpack(struct compat_sigset_argpack *to,
1349                                            struct compat_sigset_argpack __user *from)
1350{
1351        if (from) {
1352                if (!user_read_access_begin(from, sizeof(*from)))
1353                        return -EFAULT;
1354                unsafe_get_user(to->p, &from->p, Efault);
1355                unsafe_get_user(to->size, &from->size, Efault);
1356                user_read_access_end();
1357        }
1358        return 0;
1359Efault:
1360        user_access_end();
1361        return -EFAULT;
1362}
1363
1364COMPAT_SYSCALL_DEFINE6(pselect6_time64, int, n, compat_ulong_t __user *, inp,
1365        compat_ulong_t __user *, outp, compat_ulong_t __user *, exp,
1366        struct __kernel_timespec __user *, tsp, void __user *, sig)
1367{
1368        struct compat_sigset_argpack x = {0, 0};
1369
1370        if (get_compat_sigset_argpack(&x, sig))
1371                return -EFAULT;
1372
1373        return do_compat_pselect(n, inp, outp, exp, tsp, compat_ptr(x.p),
1374                                 x.size, PT_TIMESPEC);
1375}
1376
1377#if defined(CONFIG_COMPAT_32BIT_TIME)
1378
1379COMPAT_SYSCALL_DEFINE6(pselect6_time32, int, n, compat_ulong_t __user *, inp,
1380        compat_ulong_t __user *, outp, compat_ulong_t __user *, exp,
1381        struct old_timespec32 __user *, tsp, void __user *, sig)
1382{
1383        struct compat_sigset_argpack x = {0, 0};
1384
1385        if (get_compat_sigset_argpack(&x, sig))
1386                return -EFAULT;
1387
1388        return do_compat_pselect(n, inp, outp, exp, tsp, compat_ptr(x.p),
1389                                 x.size, PT_OLD_TIMESPEC);
1390}
1391
1392#endif
1393
1394#if defined(CONFIG_COMPAT_32BIT_TIME)
1395COMPAT_SYSCALL_DEFINE5(ppoll_time32, struct pollfd __user *, ufds,
1396        unsigned int,  nfds, struct old_timespec32 __user *, tsp,
1397        const compat_sigset_t __user *, sigmask, compat_size_t, sigsetsize)
1398{
1399        struct timespec64 ts, end_time, *to = NULL;
1400        int ret;
1401
1402        if (tsp) {
1403                if (get_old_timespec32(&ts, tsp))
1404                        return -EFAULT;
1405
1406                to = &end_time;
1407                if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec))
1408                        return -EINVAL;
1409        }
1410
1411        ret = set_compat_user_sigmask(sigmask, sigsetsize);
1412        if (ret)
1413                return ret;
1414
1415        ret = do_sys_poll(ufds, nfds, to);
1416        return poll_select_finish(&end_time, tsp, PT_OLD_TIMESPEC, ret);
1417}
1418#endif
1419
1420/* New compat syscall for 64 bit time_t*/
1421COMPAT_SYSCALL_DEFINE5(ppoll_time64, struct pollfd __user *, ufds,
1422        unsigned int,  nfds, struct __kernel_timespec __user *, tsp,
1423        const compat_sigset_t __user *, sigmask, compat_size_t, sigsetsize)
1424{
1425        struct timespec64 ts, end_time, *to = NULL;
1426        int ret;
1427
1428        if (tsp) {
1429                if (get_timespec64(&ts, tsp))
1430                        return -EFAULT;
1431
1432                to = &end_time;
1433                if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec))
1434                        return -EINVAL;
1435        }
1436
1437        ret = set_compat_user_sigmask(sigmask, sigsetsize);
1438        if (ret)
1439                return ret;
1440
1441        ret = do_sys_poll(ufds, nfds, to);
1442        return poll_select_finish(&end_time, tsp, PT_TIMESPEC, ret);
1443}
1444
1445#endif
1446
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