Greg Kroah-Hartman | b244131 | 2017-11-01 15:07:57 +0100 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Jakub Kicinski | b645941 | 2021-12-28 16:49:13 -0800 | [diff] [blame] | 18 | #include <linux/compat.h> |
Milind Arun Choudhary | 022a169 | 2007-05-08 00:29:02 -0700 | [diff] [blame] | 19 | #include <linux/kernel.h> |
Ingo Molnar | 3f07c01 | 2017-02-08 18:51:30 +0100 | [diff] [blame] | 20 | #include <linux/sched/signal.h> |
| 21 | #include <linux/sched/rt.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | #include <linux/syscalls.h> |
Paul Gortmaker | 630d9c4 | 2011-11-16 23:57:37 -0500 | [diff] [blame] | 23 | #include <linux/export.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | #include <linux/slab.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | #include <linux/poll.h> |
| 26 | #include <linux/personality.h> /* for STICKY_TIMEOUTS */ |
| 27 | #include <linux/file.h> |
Al Viro | 9f3acc3 | 2008-04-24 07:44:08 -0400 | [diff] [blame] | 28 | #include <linux/fdtable.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | #include <linux/fs.h> |
Dipankar Sarma | b835996 | 2005-09-09 13:04:14 -0700 | [diff] [blame] | 30 | #include <linux/rcupdate.h> |
Arjan van de Ven | 8ff3e8e | 2008-08-31 08:26:40 -0700 | [diff] [blame] | 31 | #include <linux/hrtimer.h> |
Colin Cross | 9745cdb | 2013-05-06 23:50:17 +0000 | [diff] [blame] | 32 | #include <linux/freezer.h> |
Eliezer Tamir | 076bb0c | 2013-07-10 17:13:17 +0300 | [diff] [blame] | 33 | #include <net/busy_poll.h> |
Vlastimil Babka | 2d19309 | 2016-10-11 13:51:14 -0700 | [diff] [blame] | 34 | #include <linux/vmalloc.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | |
Linus Torvalds | 7c0f6ba | 2016-12-24 11:46:01 -0800 | [diff] [blame] | 36 | #include <linux/uaccess.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | |
Arjan van de Ven | 90d6e24 | 2008-09-01 15:55:35 -0700 | [diff] [blame] | 38 | |
| 39 | /* |
| 40 | * Estimate expected accuracy in ns from a timeval. |
| 41 | * |
| 42 | * After quite a bit of churning around, we've settled on |
| 43 | * a simple thing of taking 0.1% of the timeout as the |
| 44 | * slack, with a cap of 100 msec. |
| 45 | * "nice" tasks get a 0.5% slack instead. |
| 46 | * |
| 47 | * Consider this comment an open invitation to come up with even |
| 48 | * better solutions.. |
| 49 | */ |
| 50 | |
Guillaume Knispel | 5ae87e7 | 2009-09-22 16:43:30 -0700 | [diff] [blame] | 51 | #define MAX_SLACK (100 * NSEC_PER_MSEC) |
| 52 | |
Deepa Dinamani | 766b9f9 | 2016-05-19 17:09:05 -0700 | [diff] [blame] | 53 | static long __estimate_accuracy(struct timespec64 *tv) |
Arjan van de Ven | 90d6e24 | 2008-09-01 15:55:35 -0700 | [diff] [blame] | 54 | { |
Arjan van de Ven | 96d2ab4 | 2008-09-07 16:08:55 -0700 | [diff] [blame] | 55 | long slack; |
Arjan van de Ven | 90d6e24 | 2008-09-01 15:55:35 -0700 | [diff] [blame] | 56 | int divfactor = 1000; |
| 57 | |
Guillaume Knispel | 5ae87e7 | 2009-09-22 16:43:30 -0700 | [diff] [blame] | 58 | if (tv->tv_sec < 0) |
| 59 | return 0; |
| 60 | |
Arjan van de Ven | 4ce105d | 2008-09-07 15:31:39 -0700 | [diff] [blame] | 61 | if (task_nice(current) > 0) |
Arjan van de Ven | 90d6e24 | 2008-09-01 15:55:35 -0700 | [diff] [blame] | 62 | divfactor = divfactor / 5; |
| 63 | |
Guillaume Knispel | 5ae87e7 | 2009-09-22 16:43:30 -0700 | [diff] [blame] | 64 | if (tv->tv_sec > MAX_SLACK / (NSEC_PER_SEC/divfactor)) |
| 65 | return MAX_SLACK; |
| 66 | |
Arjan van de Ven | 90d6e24 | 2008-09-01 15:55:35 -0700 | [diff] [blame] | 67 | slack = tv->tv_nsec / divfactor; |
| 68 | slack += tv->tv_sec * (NSEC_PER_SEC/divfactor); |
| 69 | |
Guillaume Knispel | 5ae87e7 | 2009-09-22 16:43:30 -0700 | [diff] [blame] | 70 | if (slack > MAX_SLACK) |
| 71 | return MAX_SLACK; |
Arjan van de Ven | 96d2ab4 | 2008-09-07 16:08:55 -0700 | [diff] [blame] | 72 | |
Arjan van de Ven | 90d6e24 | 2008-09-01 15:55:35 -0700 | [diff] [blame] | 73 | return slack; |
| 74 | } |
| 75 | |
Deepa Dinamani | 766b9f9 | 2016-05-19 17:09:05 -0700 | [diff] [blame] | 76 | u64 select_estimate_accuracy(struct timespec64 *tv) |
Arjan van de Ven | 90d6e24 | 2008-09-01 15:55:35 -0700 | [diff] [blame] | 77 | { |
John Stultz | da8b44d | 2016-03-17 14:20:51 -0700 | [diff] [blame] | 78 | u64 ret; |
Deepa Dinamani | 766b9f9 | 2016-05-19 17:09:05 -0700 | [diff] [blame] | 79 | struct timespec64 now; |
Arjan van de Ven | 90d6e24 | 2008-09-01 15:55:35 -0700 | [diff] [blame] | 80 | |
| 81 | /* |
| 82 | * Realtime tasks get a slack of 0 for obvious reasons. |
| 83 | */ |
| 84 | |
Arjan van de Ven | 4ce105d | 2008-09-07 15:31:39 -0700 | [diff] [blame] | 85 | if (rt_task(current)) |
Arjan van de Ven | 90d6e24 | 2008-09-01 15:55:35 -0700 | [diff] [blame] | 86 | return 0; |
| 87 | |
Deepa Dinamani | 766b9f9 | 2016-05-19 17:09:05 -0700 | [diff] [blame] | 88 | ktime_get_ts64(&now); |
| 89 | now = timespec64_sub(*tv, now); |
Arjan van de Ven | 90d6e24 | 2008-09-01 15:55:35 -0700 | [diff] [blame] | 90 | ret = __estimate_accuracy(&now); |
| 91 | if (ret < current->timer_slack_ns) |
| 92 | return current->timer_slack_ns; |
| 93 | return ret; |
| 94 | } |
| 95 | |
| 96 | |
| 97 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 98 | struct poll_table_page { |
| 99 | struct poll_table_page * next; |
| 100 | struct poll_table_entry * entry; |
Gustavo A. R. Silva | 5e01fdf | 2020-08-31 08:25:42 -0500 | [diff] [blame] | 101 | struct poll_table_entry entries[]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | }; |
| 103 | |
| 104 | #define POLL_TABLE_FULL(table) \ |
| 105 | ((unsigned long)((table)->entry+1) > PAGE_SIZE + (unsigned long)(table)) |
| 106 | |
| 107 | /* |
| 108 | * Ok, Peter made a complicated, but straightforward multiple_wait() function. |
| 109 | * I have rewritten this, taking some shortcuts: This code may not be easy to |
| 110 | * follow, but it should be free of race-conditions, and it's practical. If you |
| 111 | * understand what I'm doing here, then you understand how the linux |
| 112 | * sleep/wakeup mechanism works. |
| 113 | * |
| 114 | * Two very simple procedures, poll_wait() and poll_freewait() make all the |
| 115 | * work. poll_wait() is an inline-function defined in <linux/poll.h>, |
| 116 | * as all select/poll functions have to call it to add an entry to the |
| 117 | * poll table. |
| 118 | */ |
Adrian Bunk | 75c96f8 | 2005-05-05 16:16:09 -0700 | [diff] [blame] | 119 | static void __pollwait(struct file *filp, wait_queue_head_t *wait_address, |
| 120 | poll_table *p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 121 | |
| 122 | void poll_initwait(struct poll_wqueues *pwq) |
| 123 | { |
| 124 | init_poll_funcptr(&pwq->pt, __pollwait); |
Tejun Heo | 5f820f6 | 2009-01-06 14:40:59 -0800 | [diff] [blame] | 125 | pwq->polling_task = current; |
Guillaume Knispel | b2add73 | 2009-08-15 19:30:24 +0200 | [diff] [blame] | 126 | pwq->triggered = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 127 | pwq->error = 0; |
| 128 | pwq->table = NULL; |
Andi Kleen | 70674f9 | 2006-03-28 01:56:33 -0800 | [diff] [blame] | 129 | pwq->inline_index = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 130 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 131 | EXPORT_SYMBOL(poll_initwait); |
| 132 | |
Andi Kleen | 70674f9 | 2006-03-28 01:56:33 -0800 | [diff] [blame] | 133 | static void free_poll_entry(struct poll_table_entry *entry) |
| 134 | { |
WANG Cong | ccf6780 | 2007-05-09 07:10:02 +0200 | [diff] [blame] | 135 | remove_wait_queue(entry->wait_address, &entry->wait); |
Andi Kleen | 70674f9 | 2006-03-28 01:56:33 -0800 | [diff] [blame] | 136 | fput(entry->filp); |
| 137 | } |
| 138 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 139 | void poll_freewait(struct poll_wqueues *pwq) |
| 140 | { |
| 141 | struct poll_table_page * p = pwq->table; |
Andi Kleen | 70674f9 | 2006-03-28 01:56:33 -0800 | [diff] [blame] | 142 | int i; |
| 143 | for (i = 0; i < pwq->inline_index; i++) |
| 144 | free_poll_entry(pwq->inline_entries + i); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 145 | while (p) { |
| 146 | struct poll_table_entry * entry; |
| 147 | struct poll_table_page *old; |
| 148 | |
| 149 | entry = p->entry; |
| 150 | do { |
| 151 | entry--; |
Andi Kleen | 70674f9 | 2006-03-28 01:56:33 -0800 | [diff] [blame] | 152 | free_poll_entry(entry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 153 | } while (entry > p->entries); |
| 154 | old = p; |
| 155 | p = p->next; |
| 156 | free_page((unsigned long) old); |
| 157 | } |
| 158 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 159 | EXPORT_SYMBOL(poll_freewait); |
| 160 | |
Tejun Heo | 5f820f6 | 2009-01-06 14:40:59 -0800 | [diff] [blame] | 161 | static struct poll_table_entry *poll_get_entry(struct poll_wqueues *p) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 162 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 163 | struct poll_table_page *table = p->table; |
| 164 | |
Andi Kleen | 70674f9 | 2006-03-28 01:56:33 -0800 | [diff] [blame] | 165 | if (p->inline_index < N_INLINE_POLL_ENTRIES) |
| 166 | return p->inline_entries + p->inline_index++; |
| 167 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 168 | if (!table || POLL_TABLE_FULL(table)) { |
| 169 | struct poll_table_page *new_table; |
| 170 | |
| 171 | new_table = (struct poll_table_page *) __get_free_page(GFP_KERNEL); |
| 172 | if (!new_table) { |
| 173 | p->error = -ENOMEM; |
Andi Kleen | 70674f9 | 2006-03-28 01:56:33 -0800 | [diff] [blame] | 174 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 175 | } |
| 176 | new_table->entry = new_table->entries; |
| 177 | new_table->next = table; |
| 178 | p->table = new_table; |
| 179 | table = new_table; |
| 180 | } |
| 181 | |
Andi Kleen | 70674f9 | 2006-03-28 01:56:33 -0800 | [diff] [blame] | 182 | return table->entry++; |
| 183 | } |
| 184 | |
Ingo Molnar | ac6424b | 2017-06-20 12:06:13 +0200 | [diff] [blame] | 185 | static int __pollwake(wait_queue_entry_t *wait, unsigned mode, int sync, void *key) |
Tejun Heo | 5f820f6 | 2009-01-06 14:40:59 -0800 | [diff] [blame] | 186 | { |
| 187 | struct poll_wqueues *pwq = wait->private; |
| 188 | DECLARE_WAITQUEUE(dummy_wait, pwq->polling_task); |
| 189 | |
| 190 | /* |
| 191 | * Although this function is called under waitqueue lock, LOCK |
| 192 | * doesn't imply write barrier and the users expect write |
| 193 | * barrier semantics on wakeup functions. The following |
| 194 | * smp_wmb() is equivalent to smp_wmb() in try_to_wake_up() |
Peter Zijlstra | b92b8b3 | 2015-05-12 10:51:55 +0200 | [diff] [blame] | 195 | * and is paired with smp_store_mb() in poll_schedule_timeout. |
Tejun Heo | 5f820f6 | 2009-01-06 14:40:59 -0800 | [diff] [blame] | 196 | */ |
| 197 | smp_wmb(); |
| 198 | pwq->triggered = 1; |
| 199 | |
| 200 | /* |
| 201 | * Perform the default wake up operation using a dummy |
| 202 | * waitqueue. |
| 203 | * |
| 204 | * TODO: This is hacky but there currently is no interface to |
| 205 | * pass in @sync. @sync is scheduled to be removed and once |
| 206 | * that happens, wake_up_process() can be used directly. |
| 207 | */ |
| 208 | return default_wake_function(&dummy_wait, mode, sync, key); |
| 209 | } |
| 210 | |
Ingo Molnar | ac6424b | 2017-06-20 12:06:13 +0200 | [diff] [blame] | 211 | static int pollwake(wait_queue_entry_t *wait, unsigned mode, int sync, void *key) |
Eric Dumazet | 4938d7e | 2009-06-16 15:33:36 -0700 | [diff] [blame] | 212 | { |
| 213 | struct poll_table_entry *entry; |
| 214 | |
| 215 | entry = container_of(wait, struct poll_table_entry, wait); |
Al Viro | 3ad6f93 | 2017-07-03 20:14:56 -0400 | [diff] [blame] | 216 | if (key && !(key_to_poll(key) & entry->key)) |
Eric Dumazet | 4938d7e | 2009-06-16 15:33:36 -0700 | [diff] [blame] | 217 | return 0; |
| 218 | return __pollwake(wait, mode, sync, key); |
| 219 | } |
| 220 | |
Andi Kleen | 70674f9 | 2006-03-28 01:56:33 -0800 | [diff] [blame] | 221 | /* Add a new entry */ |
| 222 | static void __pollwait(struct file *filp, wait_queue_head_t *wait_address, |
| 223 | poll_table *p) |
| 224 | { |
Tejun Heo | 5f820f6 | 2009-01-06 14:40:59 -0800 | [diff] [blame] | 225 | struct poll_wqueues *pwq = container_of(p, struct poll_wqueues, pt); |
| 226 | struct poll_table_entry *entry = poll_get_entry(pwq); |
Andi Kleen | 70674f9 | 2006-03-28 01:56:33 -0800 | [diff] [blame] | 227 | if (!entry) |
| 228 | return; |
Al Viro | cb0942b | 2012-08-27 14:48:26 -0400 | [diff] [blame] | 229 | entry->filp = get_file(filp); |
Andi Kleen | 70674f9 | 2006-03-28 01:56:33 -0800 | [diff] [blame] | 230 | entry->wait_address = wait_address; |
Hans Verkuil | 626cf23 | 2012-03-23 15:02:27 -0700 | [diff] [blame] | 231 | entry->key = p->_key; |
Tejun Heo | 5f820f6 | 2009-01-06 14:40:59 -0800 | [diff] [blame] | 232 | init_waitqueue_func_entry(&entry->wait, pollwake); |
| 233 | entry->wait.private = pwq; |
WANG Cong | ccf6780 | 2007-05-09 07:10:02 +0200 | [diff] [blame] | 234 | add_wait_queue(wait_address, &entry->wait); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 235 | } |
| 236 | |
Christoph Hellwig | 8f546ae | 2018-01-11 12:23:05 +0100 | [diff] [blame] | 237 | static int poll_schedule_timeout(struct poll_wqueues *pwq, int state, |
Tejun Heo | 5f820f6 | 2009-01-06 14:40:59 -0800 | [diff] [blame] | 238 | ktime_t *expires, unsigned long slack) |
| 239 | { |
| 240 | int rc = -EINTR; |
| 241 | |
| 242 | set_current_state(state); |
| 243 | if (!pwq->triggered) |
Rafael J. Wysocki | 59612d1 | 2013-10-29 23:43:08 +0100 | [diff] [blame] | 244 | rc = schedule_hrtimeout_range(expires, slack, HRTIMER_MODE_ABS); |
Tejun Heo | 5f820f6 | 2009-01-06 14:40:59 -0800 | [diff] [blame] | 245 | __set_current_state(TASK_RUNNING); |
| 246 | |
| 247 | /* |
| 248 | * Prepare for the next iteration. |
| 249 | * |
Peter Zijlstra | b92b8b3 | 2015-05-12 10:51:55 +0200 | [diff] [blame] | 250 | * The following smp_store_mb() serves two purposes. First, it's |
Tejun Heo | 5f820f6 | 2009-01-06 14:40:59 -0800 | [diff] [blame] | 251 | * the counterpart rmb of the wmb in pollwake() such that data |
| 252 | * written before wake up is always visible after wake up. |
| 253 | * Second, the full barrier guarantees that triggered clearing |
| 254 | * doesn't pass event check of the next iteration. Note that |
| 255 | * this problem doesn't exist for the first iteration as |
| 256 | * add_wait_queue() has full barrier semantics. |
| 257 | */ |
Peter Zijlstra | b92b8b3 | 2015-05-12 10:51:55 +0200 | [diff] [blame] | 258 | smp_store_mb(pwq->triggered, 0); |
Tejun Heo | 5f820f6 | 2009-01-06 14:40:59 -0800 | [diff] [blame] | 259 | |
| 260 | return rc; |
| 261 | } |
Tejun Heo | 5f820f6 | 2009-01-06 14:40:59 -0800 | [diff] [blame] | 262 | |
Thomas Gleixner | b773ad4 | 2008-08-31 08:16:57 -0700 | [diff] [blame] | 263 | /** |
| 264 | * poll_select_set_timeout - helper function to setup the timeout value |
Deepa Dinamani | 766b9f9 | 2016-05-19 17:09:05 -0700 | [diff] [blame] | 265 | * @to: pointer to timespec64 variable for the final timeout |
Thomas Gleixner | b773ad4 | 2008-08-31 08:16:57 -0700 | [diff] [blame] | 266 | * @sec: seconds (from user space) |
| 267 | * @nsec: nanoseconds (from user space) |
| 268 | * |
| 269 | * Note, we do not use a timespec for the user space value here, That |
| 270 | * way we can use the function for timeval and compat interfaces as well. |
| 271 | * |
| 272 | * Returns -EINVAL if sec/nsec are not normalized. Otherwise 0. |
| 273 | */ |
Deepa Dinamani | 766b9f9 | 2016-05-19 17:09:05 -0700 | [diff] [blame] | 274 | int poll_select_set_timeout(struct timespec64 *to, time64_t sec, long nsec) |
Thomas Gleixner | b773ad4 | 2008-08-31 08:16:57 -0700 | [diff] [blame] | 275 | { |
Deepa Dinamani | 766b9f9 | 2016-05-19 17:09:05 -0700 | [diff] [blame] | 276 | struct timespec64 ts = {.tv_sec = sec, .tv_nsec = nsec}; |
Thomas Gleixner | b773ad4 | 2008-08-31 08:16:57 -0700 | [diff] [blame] | 277 | |
Deepa Dinamani | 766b9f9 | 2016-05-19 17:09:05 -0700 | [diff] [blame] | 278 | if (!timespec64_valid(&ts)) |
Thomas Gleixner | b773ad4 | 2008-08-31 08:16:57 -0700 | [diff] [blame] | 279 | return -EINVAL; |
| 280 | |
| 281 | /* Optimize for the zero timeout value here */ |
| 282 | if (!sec && !nsec) { |
| 283 | to->tv_sec = to->tv_nsec = 0; |
| 284 | } else { |
Deepa Dinamani | 766b9f9 | 2016-05-19 17:09:05 -0700 | [diff] [blame] | 285 | ktime_get_ts64(to); |
| 286 | *to = timespec64_add_safe(*to, ts); |
Thomas Gleixner | b773ad4 | 2008-08-31 08:16:57 -0700 | [diff] [blame] | 287 | } |
| 288 | return 0; |
| 289 | } |
| 290 | |
Deepa Dinamani | 8bd27a3 | 2018-09-19 21:41:06 -0700 | [diff] [blame] | 291 | enum poll_time_type { |
| 292 | PT_TIMEVAL = 0, |
| 293 | PT_OLD_TIMEVAL = 1, |
| 294 | PT_TIMESPEC = 2, |
| 295 | PT_OLD_TIMESPEC = 3, |
| 296 | }; |
| 297 | |
Oleg Nesterov | ac30102 | 2019-07-16 16:29:59 -0700 | [diff] [blame] | 298 | static int poll_select_finish(struct timespec64 *end_time, |
| 299 | void __user *p, |
| 300 | enum poll_time_type pt_type, int ret) |
Thomas Gleixner | b773ad4 | 2008-08-31 08:16:57 -0700 | [diff] [blame] | 301 | { |
Deepa Dinamani | 36819ad | 2017-08-04 21:12:31 -0700 | [diff] [blame] | 302 | struct timespec64 rts; |
Thomas Gleixner | b773ad4 | 2008-08-31 08:16:57 -0700 | [diff] [blame] | 303 | |
Oleg Nesterov | ac30102 | 2019-07-16 16:29:59 -0700 | [diff] [blame] | 304 | restore_saved_sigmask_unless(ret == -ERESTARTNOHAND); |
| 305 | |
Thomas Gleixner | b773ad4 | 2008-08-31 08:16:57 -0700 | [diff] [blame] | 306 | if (!p) |
| 307 | return ret; |
| 308 | |
| 309 | if (current->personality & STICKY_TIMEOUTS) |
| 310 | goto sticky; |
| 311 | |
| 312 | /* No update for zero timeout */ |
| 313 | if (!end_time->tv_sec && !end_time->tv_nsec) |
| 314 | return ret; |
| 315 | |
Deepa Dinamani | 36819ad | 2017-08-04 21:12:31 -0700 | [diff] [blame] | 316 | ktime_get_ts64(&rts); |
| 317 | rts = timespec64_sub(*end_time, rts); |
| 318 | if (rts.tv_sec < 0) |
| 319 | rts.tv_sec = rts.tv_nsec = 0; |
Deepa Dinamani | 766b9f9 | 2016-05-19 17:09:05 -0700 | [diff] [blame] | 320 | |
Thomas Gleixner | b773ad4 | 2008-08-31 08:16:57 -0700 | [diff] [blame] | 321 | |
Deepa Dinamani | 8bd27a3 | 2018-09-19 21:41:06 -0700 | [diff] [blame] | 322 | switch (pt_type) { |
| 323 | case PT_TIMEVAL: |
| 324 | { |
Arnd Bergmann | 75d319c | 2019-10-25 22:56:17 +0200 | [diff] [blame] | 325 | struct __kernel_old_timeval rtv; |
Thomas Gleixner | b773ad4 | 2008-08-31 08:16:57 -0700 | [diff] [blame] | 326 | |
Deepa Dinamani | 8bd27a3 | 2018-09-19 21:41:06 -0700 | [diff] [blame] | 327 | if (sizeof(rtv) > sizeof(rtv.tv_sec) + sizeof(rtv.tv_usec)) |
| 328 | memset(&rtv, 0, sizeof(rtv)); |
| 329 | rtv.tv_sec = rts.tv_sec; |
| 330 | rtv.tv_usec = rts.tv_nsec / NSEC_PER_USEC; |
| 331 | if (!copy_to_user(p, &rtv, sizeof(rtv))) |
| 332 | return ret; |
| 333 | } |
| 334 | break; |
| 335 | case PT_OLD_TIMEVAL: |
| 336 | { |
| 337 | struct old_timeval32 rtv; |
| 338 | |
| 339 | rtv.tv_sec = rts.tv_sec; |
| 340 | rtv.tv_usec = rts.tv_nsec / NSEC_PER_USEC; |
| 341 | if (!copy_to_user(p, &rtv, sizeof(rtv))) |
| 342 | return ret; |
| 343 | } |
| 344 | break; |
| 345 | case PT_TIMESPEC: |
| 346 | if (!put_timespec64(&rts, p)) |
Thomas Gleixner | b773ad4 | 2008-08-31 08:16:57 -0700 | [diff] [blame] | 347 | return ret; |
Deepa Dinamani | 8bd27a3 | 2018-09-19 21:41:06 -0700 | [diff] [blame] | 348 | break; |
| 349 | case PT_OLD_TIMESPEC: |
| 350 | if (!put_old_timespec32(&rts, p)) |
| 351 | return ret; |
| 352 | break; |
| 353 | default: |
| 354 | BUG(); |
| 355 | } |
Thomas Gleixner | b773ad4 | 2008-08-31 08:16:57 -0700 | [diff] [blame] | 356 | /* |
| 357 | * If an application puts its timeval in read-only memory, we |
| 358 | * don't want the Linux-specific update to the timeval to |
| 359 | * cause a fault after the select has completed |
| 360 | * successfully. However, because we're not updating the |
| 361 | * timeval, we can't restart the system call. |
| 362 | */ |
| 363 | |
| 364 | sticky: |
| 365 | if (ret == -ERESTARTNOHAND) |
| 366 | ret = -EINTR; |
| 367 | return ret; |
| 368 | } |
| 369 | |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 370 | /* |
| 371 | * Scalable version of the fd_set. |
| 372 | */ |
| 373 | |
| 374 | typedef struct { |
| 375 | unsigned long *in, *out, *ex; |
| 376 | unsigned long *res_in, *res_out, *res_ex; |
| 377 | } fd_set_bits; |
| 378 | |
| 379 | /* |
| 380 | * How many longwords for "nr" bits? |
| 381 | */ |
| 382 | #define FDS_BITPERLONG (8*sizeof(long)) |
| 383 | #define FDS_LONGS(nr) (((nr)+FDS_BITPERLONG-1)/FDS_BITPERLONG) |
| 384 | #define FDS_BYTES(nr) (FDS_LONGS(nr)*sizeof(long)) |
| 385 | |
| 386 | /* |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 387 | * Use "unsigned long" accesses to let user-mode fd_set's be long-aligned. |
| 388 | */ |
| 389 | static inline |
| 390 | int get_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset) |
| 391 | { |
| 392 | nr = FDS_BYTES(nr); |
| 393 | if (ufdset) |
| 394 | return copy_from_user(fdset, ufdset, nr) ? -EFAULT : 0; |
| 395 | |
| 396 | memset(fdset, 0, nr); |
| 397 | return 0; |
| 398 | } |
| 399 | |
| 400 | static inline unsigned long __must_check |
| 401 | set_fd_set(unsigned long nr, void __user *ufdset, unsigned long *fdset) |
| 402 | { |
| 403 | if (ufdset) |
| 404 | return __copy_to_user(ufdset, fdset, FDS_BYTES(nr)); |
| 405 | return 0; |
| 406 | } |
| 407 | |
| 408 | static inline |
| 409 | void zero_fd_set(unsigned long nr, unsigned long *fdset) |
| 410 | { |
| 411 | memset(fdset, 0, FDS_BYTES(nr)); |
| 412 | } |
| 413 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 414 | #define FDS_IN(fds, n) (fds->in + n) |
| 415 | #define FDS_OUT(fds, n) (fds->out + n) |
| 416 | #define FDS_EX(fds, n) (fds->ex + n) |
| 417 | |
| 418 | #define BITS(fds, n) (*FDS_IN(fds, n)|*FDS_OUT(fds, n)|*FDS_EX(fds, n)) |
| 419 | |
| 420 | static int max_select_fd(unsigned long n, fd_set_bits *fds) |
| 421 | { |
| 422 | unsigned long *open_fds; |
| 423 | unsigned long set; |
| 424 | int max; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 425 | struct fdtable *fdt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 426 | |
| 427 | /* handle last in-complete long-word first */ |
Josh Boyer | 8ded2bb | 2012-07-25 10:40:34 -0400 | [diff] [blame] | 428 | set = ~(~0UL << (n & (BITS_PER_LONG-1))); |
| 429 | n /= BITS_PER_LONG; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 430 | fdt = files_fdtable(current->files); |
David Howells | 1fd36ad | 2012-02-16 17:49:54 +0000 | [diff] [blame] | 431 | open_fds = fdt->open_fds + n; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 432 | max = 0; |
| 433 | if (set) { |
| 434 | set &= BITS(fds, n); |
| 435 | if (set) { |
| 436 | if (!(set & ~*open_fds)) |
| 437 | goto get_max; |
| 438 | return -EBADF; |
| 439 | } |
| 440 | } |
| 441 | while (n) { |
| 442 | open_fds--; |
| 443 | n--; |
| 444 | set = BITS(fds, n); |
| 445 | if (!set) |
| 446 | continue; |
| 447 | if (set & ~*open_fds) |
| 448 | return -EBADF; |
| 449 | if (max) |
| 450 | continue; |
| 451 | get_max: |
| 452 | do { |
| 453 | max++; |
| 454 | set >>= 1; |
| 455 | } while (set); |
Josh Boyer | 8ded2bb | 2012-07-25 10:40:34 -0400 | [diff] [blame] | 456 | max += n * BITS_PER_LONG; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 457 | } |
| 458 | |
| 459 | return max; |
| 460 | } |
| 461 | |
Jan Kara | 68514da | 2022-01-10 19:19:23 +0100 | [diff] [blame] | 462 | #define POLLIN_SET (EPOLLRDNORM | EPOLLRDBAND | EPOLLIN | EPOLLHUP | EPOLLERR |\ |
| 463 | EPOLLNVAL) |
| 464 | #define POLLOUT_SET (EPOLLWRBAND | EPOLLWRNORM | EPOLLOUT | EPOLLERR |\ |
| 465 | EPOLLNVAL) |
| 466 | #define POLLEX_SET (EPOLLPRI | EPOLLNVAL) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 467 | |
Eric Dumazet | 4938d7e | 2009-06-16 15:33:36 -0700 | [diff] [blame] | 468 | static inline void wait_key_set(poll_table *wait, unsigned long in, |
Eliezer Tamir | 2d48d67 | 2013-06-24 10:28:03 +0300 | [diff] [blame] | 469 | unsigned long out, unsigned long bit, |
Al Viro | 0169943 | 2017-07-03 03:14:15 -0400 | [diff] [blame] | 470 | __poll_t ll_flag) |
Eric Dumazet | 4938d7e | 2009-06-16 15:33:36 -0700 | [diff] [blame] | 471 | { |
Eliezer Tamir | 2d48d67 | 2013-06-24 10:28:03 +0300 | [diff] [blame] | 472 | wait->_key = POLLEX_SET | ll_flag; |
Hans Verkuil | 626cf23 | 2012-03-23 15:02:27 -0700 | [diff] [blame] | 473 | if (in & bit) |
| 474 | wait->_key |= POLLIN_SET; |
| 475 | if (out & bit) |
| 476 | wait->_key |= POLLOUT_SET; |
Eric Dumazet | 4938d7e | 2009-06-16 15:33:36 -0700 | [diff] [blame] | 477 | } |
| 478 | |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 479 | static int do_select(int n, fd_set_bits *fds, struct timespec64 *end_time) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 480 | { |
Arjan van de Ven | 8ff3e8e | 2008-08-31 08:26:40 -0700 | [diff] [blame] | 481 | ktime_t expire, *to = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 482 | struct poll_wqueues table; |
| 483 | poll_table *wait; |
Arjan van de Ven | 8ff3e8e | 2008-08-31 08:26:40 -0700 | [diff] [blame] | 484 | int retval, i, timed_out = 0; |
John Stultz | da8b44d | 2016-03-17 14:20:51 -0700 | [diff] [blame] | 485 | u64 slack = 0; |
Al Viro | 0169943 | 2017-07-03 03:14:15 -0400 | [diff] [blame] | 486 | __poll_t busy_flag = net_busy_loop_on() ? POLL_BUSY_LOOP : 0; |
Alexander Duyck | 3705671 | 2017-03-24 10:08:18 -0700 | [diff] [blame] | 487 | unsigned long busy_start = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 488 | |
Dipankar Sarma | b835996 | 2005-09-09 13:04:14 -0700 | [diff] [blame] | 489 | rcu_read_lock(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 490 | retval = max_select_fd(n, fds); |
Dipankar Sarma | b835996 | 2005-09-09 13:04:14 -0700 | [diff] [blame] | 491 | rcu_read_unlock(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 492 | |
| 493 | if (retval < 0) |
| 494 | return retval; |
| 495 | n = retval; |
| 496 | |
| 497 | poll_initwait(&table); |
| 498 | wait = &table.pt; |
Arjan van de Ven | 8ff3e8e | 2008-08-31 08:26:40 -0700 | [diff] [blame] | 499 | if (end_time && !end_time->tv_sec && !end_time->tv_nsec) { |
Hans Verkuil | 626cf23 | 2012-03-23 15:02:27 -0700 | [diff] [blame] | 500 | wait->_qproc = NULL; |
Arjan van de Ven | 8ff3e8e | 2008-08-31 08:26:40 -0700 | [diff] [blame] | 501 | timed_out = 1; |
| 502 | } |
| 503 | |
Arjan van de Ven | 96d2ab4 | 2008-09-07 16:08:55 -0700 | [diff] [blame] | 504 | if (end_time && !timed_out) |
Andrew Morton | 231f3d3 | 2010-10-27 15:34:53 -0700 | [diff] [blame] | 505 | slack = select_estimate_accuracy(end_time); |
Arjan van de Ven | 90d6e24 | 2008-09-01 15:55:35 -0700 | [diff] [blame] | 506 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 507 | retval = 0; |
| 508 | for (;;) { |
| 509 | unsigned long *rinp, *routp, *rexp, *inp, *outp, *exp; |
Eliezer Tamir | cbf5500 | 2013-07-08 16:20:34 +0300 | [diff] [blame] | 510 | bool can_busy_loop = false; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 511 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 512 | inp = fds->in; outp = fds->out; exp = fds->ex; |
| 513 | rinp = fds->res_in; routp = fds->res_out; rexp = fds->res_ex; |
| 514 | |
| 515 | for (i = 0; i < n; ++rinp, ++routp, ++rexp) { |
Al Viro | e6c8adc | 2017-07-03 22:25:56 -0400 | [diff] [blame] | 516 | unsigned long in, out, ex, all_bits, bit = 1, j; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 517 | unsigned long res_in = 0, res_out = 0, res_ex = 0; |
Al Viro | e6c8adc | 2017-07-03 22:25:56 -0400 | [diff] [blame] | 518 | __poll_t mask; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 519 | |
| 520 | in = *inp++; out = *outp++; ex = *exp++; |
| 521 | all_bits = in | out | ex; |
| 522 | if (all_bits == 0) { |
Josh Boyer | 8ded2bb | 2012-07-25 10:40:34 -0400 | [diff] [blame] | 523 | i += BITS_PER_LONG; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 524 | continue; |
| 525 | } |
| 526 | |
Josh Boyer | 8ded2bb | 2012-07-25 10:40:34 -0400 | [diff] [blame] | 527 | for (j = 0; j < BITS_PER_LONG; ++j, ++i, bit <<= 1) { |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 528 | struct fd f; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 529 | if (i >= n) |
| 530 | break; |
| 531 | if (!(bit & all_bits)) |
| 532 | continue; |
Jan Kara | 68514da | 2022-01-10 19:19:23 +0100 | [diff] [blame] | 533 | mask = EPOLLNVAL; |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 534 | f = fdget(i); |
| 535 | if (f.file) { |
Christoph Hellwig | 9965ed17 | 2018-03-05 07:26:05 -0800 | [diff] [blame] | 536 | wait_key_set(wait, in, out, bit, |
| 537 | busy_flag); |
| 538 | mask = vfs_poll(f.file, wait); |
| 539 | |
Al Viro | 2903ff0 | 2012-08-28 12:52:22 -0400 | [diff] [blame] | 540 | fdput(f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 541 | } |
Jan Kara | 68514da | 2022-01-10 19:19:23 +0100 | [diff] [blame] | 542 | if ((mask & POLLIN_SET) && (in & bit)) { |
| 543 | res_in |= bit; |
| 544 | retval++; |
| 545 | wait->_qproc = NULL; |
| 546 | } |
| 547 | if ((mask & POLLOUT_SET) && (out & bit)) { |
| 548 | res_out |= bit; |
| 549 | retval++; |
| 550 | wait->_qproc = NULL; |
| 551 | } |
| 552 | if ((mask & POLLEX_SET) && (ex & bit)) { |
| 553 | res_ex |= bit; |
| 554 | retval++; |
| 555 | wait->_qproc = NULL; |
| 556 | } |
| 557 | /* got something, stop busy polling */ |
| 558 | if (retval) { |
| 559 | can_busy_loop = false; |
| 560 | busy_flag = 0; |
| 561 | |
| 562 | /* |
| 563 | * only remember a returned |
| 564 | * POLL_BUSY_LOOP if we asked for it |
| 565 | */ |
| 566 | } else if (busy_flag & mask) |
| 567 | can_busy_loop = true; |
| 568 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 569 | } |
| 570 | if (res_in) |
| 571 | *rinp = res_in; |
| 572 | if (res_out) |
| 573 | *routp = res_out; |
| 574 | if (res_ex) |
| 575 | *rexp = res_ex; |
Linus Torvalds | 55d8538 | 2008-06-22 12:23:15 -0700 | [diff] [blame] | 576 | cond_resched(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 577 | } |
Hans Verkuil | 626cf23 | 2012-03-23 15:02:27 -0700 | [diff] [blame] | 578 | wait->_qproc = NULL; |
Arjan van de Ven | 8ff3e8e | 2008-08-31 08:26:40 -0700 | [diff] [blame] | 579 | if (retval || timed_out || signal_pending(current)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 580 | break; |
Pavel Machek | f526448 | 2008-04-21 22:15:06 +0000 | [diff] [blame] | 581 | if (table.error) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 582 | retval = table.error; |
| 583 | break; |
| 584 | } |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 585 | |
Eliezer Tamir | cbf5500 | 2013-07-08 16:20:34 +0300 | [diff] [blame] | 586 | /* only if found POLL_BUSY_LOOP sockets && not out of time */ |
Eliezer Tamir | 76b1e9b | 2013-07-09 13:09:21 +0300 | [diff] [blame] | 587 | if (can_busy_loop && !need_resched()) { |
Alexander Duyck | 3705671 | 2017-03-24 10:08:18 -0700 | [diff] [blame] | 588 | if (!busy_start) { |
| 589 | busy_start = busy_loop_current_time(); |
Eliezer Tamir | 76b1e9b | 2013-07-09 13:09:21 +0300 | [diff] [blame] | 590 | continue; |
| 591 | } |
Alexander Duyck | 3705671 | 2017-03-24 10:08:18 -0700 | [diff] [blame] | 592 | if (!busy_loop_timeout(busy_start)) |
Eliezer Tamir | 76b1e9b | 2013-07-09 13:09:21 +0300 | [diff] [blame] | 593 | continue; |
| 594 | } |
| 595 | busy_flag = 0; |
Eliezer Tamir | 2d48d67 | 2013-06-24 10:28:03 +0300 | [diff] [blame] | 596 | |
Arjan van de Ven | 8ff3e8e | 2008-08-31 08:26:40 -0700 | [diff] [blame] | 597 | /* |
| 598 | * If this is the first loop and we have a timeout |
| 599 | * given, then we convert to ktime_t and set the to |
| 600 | * pointer to the expiry value. |
| 601 | */ |
| 602 | if (end_time && !to) { |
Deepa Dinamani | 766b9f9 | 2016-05-19 17:09:05 -0700 | [diff] [blame] | 603 | expire = timespec64_to_ktime(*end_time); |
Arjan van de Ven | 8ff3e8e | 2008-08-31 08:26:40 -0700 | [diff] [blame] | 604 | to = &expire; |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 605 | } |
Arjan van de Ven | 8ff3e8e | 2008-08-31 08:26:40 -0700 | [diff] [blame] | 606 | |
Tejun Heo | 5f820f6 | 2009-01-06 14:40:59 -0800 | [diff] [blame] | 607 | if (!poll_schedule_timeout(&table, TASK_INTERRUPTIBLE, |
| 608 | to, slack)) |
Arjan van de Ven | 8ff3e8e | 2008-08-31 08:26:40 -0700 | [diff] [blame] | 609 | timed_out = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 610 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 611 | |
| 612 | poll_freewait(&table); |
| 613 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 614 | return retval; |
| 615 | } |
| 616 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 617 | /* |
| 618 | * We can actually return ERESTARTSYS instead of EINTR, but I'd |
| 619 | * like to be certain this leads to no problems. So I return |
| 620 | * EINTR just for safety. |
| 621 | * |
| 622 | * Update: ERESTARTSYS breaks at least the xview clock binary, so |
| 623 | * I'm trying ERESTARTNOHAND which restart only when you want to. |
| 624 | */ |
Al Viro | a2dcb44 | 2008-04-23 14:05:15 -0400 | [diff] [blame] | 625 | int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp, |
Deepa Dinamani | 766b9f9 | 2016-05-19 17:09:05 -0700 | [diff] [blame] | 626 | fd_set __user *exp, struct timespec64 *end_time) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 627 | { |
| 628 | fd_set_bits fds; |
Andrew Morton | 29ff2db | 2006-04-10 22:52:46 -0700 | [diff] [blame] | 629 | void *bits; |
Vadim Lobanov | bbea9f6 | 2006-12-10 02:21:12 -0800 | [diff] [blame] | 630 | int ret, max_fds; |
Vlastimil Babka | 2d19309 | 2016-10-11 13:51:14 -0700 | [diff] [blame] | 631 | size_t size, alloc_size; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 632 | struct fdtable *fdt; |
Andi Kleen | 70674f9 | 2006-03-28 01:56:33 -0800 | [diff] [blame] | 633 | /* Allocate small arguments on the stack to save memory and be faster */ |
Jes Sorensen | 30c14e4 | 2006-03-31 11:18:57 -0500 | [diff] [blame] | 634 | long stack_fds[SELECT_STACK_ALLOC/sizeof(long)]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 635 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 636 | ret = -EINVAL; |
| 637 | if (n < 0) |
| 638 | goto out_nofds; |
| 639 | |
Vadim Lobanov | bbea9f6 | 2006-12-10 02:21:12 -0800 | [diff] [blame] | 640 | /* max_fds can increase, so grab it once to avoid race */ |
Dipankar Sarma | b835996 | 2005-09-09 13:04:14 -0700 | [diff] [blame] | 641 | rcu_read_lock(); |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 642 | fdt = files_fdtable(current->files); |
Vadim Lobanov | bbea9f6 | 2006-12-10 02:21:12 -0800 | [diff] [blame] | 643 | max_fds = fdt->max_fds; |
Dipankar Sarma | b835996 | 2005-09-09 13:04:14 -0700 | [diff] [blame] | 644 | rcu_read_unlock(); |
Vadim Lobanov | bbea9f6 | 2006-12-10 02:21:12 -0800 | [diff] [blame] | 645 | if (n > max_fds) |
| 646 | n = max_fds; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 647 | |
| 648 | /* |
| 649 | * We need 6 bitmaps (in/out/ex for both incoming and outgoing), |
| 650 | * since we used fdset we need to allocate memory in units of |
| 651 | * long-words. |
| 652 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 653 | size = FDS_BYTES(n); |
Mitchell Blank Jr | b04eb6a | 2006-04-10 22:54:08 -0700 | [diff] [blame] | 654 | bits = stack_fds; |
| 655 | if (size > sizeof(stack_fds) / 6) { |
| 656 | /* Not enough space in on-stack array; must use kmalloc */ |
| 657 | ret = -ENOMEM; |
Vlastimil Babka | 2d19309 | 2016-10-11 13:51:14 -0700 | [diff] [blame] | 658 | if (size > (SIZE_MAX / 6)) |
| 659 | goto out_nofds; |
| 660 | |
| 661 | alloc_size = 6 * size; |
Linus Torvalds | 0bcfe68 | 2021-09-07 11:26:23 -0700 | [diff] [blame] | 662 | bits = kvmalloc(alloc_size, GFP_KERNEL); |
Mitchell Blank Jr | b04eb6a | 2006-04-10 22:54:08 -0700 | [diff] [blame] | 663 | if (!bits) |
| 664 | goto out_nofds; |
| 665 | } |
Andrew Morton | 29ff2db | 2006-04-10 22:52:46 -0700 | [diff] [blame] | 666 | fds.in = bits; |
| 667 | fds.out = bits + size; |
| 668 | fds.ex = bits + 2*size; |
| 669 | fds.res_in = bits + 3*size; |
| 670 | fds.res_out = bits + 4*size; |
| 671 | fds.res_ex = bits + 5*size; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 672 | |
| 673 | if ((ret = get_fd_set(n, inp, fds.in)) || |
| 674 | (ret = get_fd_set(n, outp, fds.out)) || |
| 675 | (ret = get_fd_set(n, exp, fds.ex))) |
| 676 | goto out; |
| 677 | zero_fd_set(n, fds.res_in); |
| 678 | zero_fd_set(n, fds.res_out); |
| 679 | zero_fd_set(n, fds.res_ex); |
| 680 | |
Arjan van de Ven | 8ff3e8e | 2008-08-31 08:26:40 -0700 | [diff] [blame] | 681 | ret = do_select(n, &fds, end_time); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 682 | |
| 683 | if (ret < 0) |
| 684 | goto out; |
| 685 | if (!ret) { |
| 686 | ret = -ERESTARTNOHAND; |
| 687 | if (signal_pending(current)) |
| 688 | goto out; |
| 689 | ret = 0; |
| 690 | } |
| 691 | |
| 692 | if (set_fd_set(n, inp, fds.res_in) || |
| 693 | set_fd_set(n, outp, fds.res_out) || |
| 694 | set_fd_set(n, exp, fds.res_ex)) |
| 695 | ret = -EFAULT; |
| 696 | |
| 697 | out: |
Andi Kleen | 70674f9 | 2006-03-28 01:56:33 -0800 | [diff] [blame] | 698 | if (bits != stack_fds) |
Vlastimil Babka | 2d19309 | 2016-10-11 13:51:14 -0700 | [diff] [blame] | 699 | kvfree(bits); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 700 | out_nofds: |
| 701 | return ret; |
| 702 | } |
| 703 | |
Dominik Brodowski | 4bdb9ac | 2018-03-18 07:53:04 +0100 | [diff] [blame] | 704 | static int kern_select(int n, fd_set __user *inp, fd_set __user *outp, |
Arnd Bergmann | 75d319c | 2019-10-25 22:56:17 +0200 | [diff] [blame] | 705 | fd_set __user *exp, struct __kernel_old_timeval __user *tvp) |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 706 | { |
Deepa Dinamani | 766b9f9 | 2016-05-19 17:09:05 -0700 | [diff] [blame] | 707 | struct timespec64 end_time, *to = NULL; |
Arnd Bergmann | 75d319c | 2019-10-25 22:56:17 +0200 | [diff] [blame] | 708 | struct __kernel_old_timeval tv; |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 709 | int ret; |
| 710 | |
| 711 | if (tvp) { |
| 712 | if (copy_from_user(&tv, tvp, sizeof(tv))) |
| 713 | return -EFAULT; |
| 714 | |
Arjan van de Ven | 8ff3e8e | 2008-08-31 08:26:40 -0700 | [diff] [blame] | 715 | to = &end_time; |
Arjan van de Ven | 4d36a9e | 2008-10-25 12:41:41 -0700 | [diff] [blame] | 716 | if (poll_select_set_timeout(to, |
| 717 | tv.tv_sec + (tv.tv_usec / USEC_PER_SEC), |
| 718 | (tv.tv_usec % USEC_PER_SEC) * NSEC_PER_USEC)) |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 719 | return -EINVAL; |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 720 | } |
| 721 | |
Arjan van de Ven | 8ff3e8e | 2008-08-31 08:26:40 -0700 | [diff] [blame] | 722 | ret = core_sys_select(n, inp, outp, exp, to); |
Oleg Nesterov | ac30102 | 2019-07-16 16:29:59 -0700 | [diff] [blame] | 723 | return poll_select_finish(&end_time, tvp, PT_TIMEVAL, ret); |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 724 | } |
| 725 | |
Dominik Brodowski | 4bdb9ac | 2018-03-18 07:53:04 +0100 | [diff] [blame] | 726 | SYSCALL_DEFINE5(select, int, n, fd_set __user *, inp, fd_set __user *, outp, |
Arnd Bergmann | 75d319c | 2019-10-25 22:56:17 +0200 | [diff] [blame] | 727 | fd_set __user *, exp, struct __kernel_old_timeval __user *, tvp) |
Dominik Brodowski | 4bdb9ac | 2018-03-18 07:53:04 +0100 | [diff] [blame] | 728 | { |
| 729 | return kern_select(n, inp, outp, exp, tvp); |
| 730 | } |
| 731 | |
Heiko Carstens | c9da9f2 | 2009-01-14 14:13:57 +0100 | [diff] [blame] | 732 | static long do_pselect(int n, fd_set __user *inp, fd_set __user *outp, |
Deepa Dinamani | e024707 | 2018-09-19 21:41:07 -0700 | [diff] [blame] | 733 | fd_set __user *exp, void __user *tsp, |
| 734 | const sigset_t __user *sigmask, size_t sigsetsize, |
| 735 | enum poll_time_type type) |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 736 | { |
Deepa Dinamani | 36819ad | 2017-08-04 21:12:31 -0700 | [diff] [blame] | 737 | struct timespec64 ts, end_time, *to = NULL; |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 738 | int ret; |
| 739 | |
| 740 | if (tsp) { |
Deepa Dinamani | e024707 | 2018-09-19 21:41:07 -0700 | [diff] [blame] | 741 | switch (type) { |
| 742 | case PT_TIMESPEC: |
| 743 | if (get_timespec64(&ts, tsp)) |
| 744 | return -EFAULT; |
| 745 | break; |
| 746 | case PT_OLD_TIMESPEC: |
| 747 | if (get_old_timespec32(&ts, tsp)) |
| 748 | return -EFAULT; |
| 749 | break; |
| 750 | default: |
| 751 | BUG(); |
| 752 | } |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 753 | |
Arjan van de Ven | 8ff3e8e | 2008-08-31 08:26:40 -0700 | [diff] [blame] | 754 | to = &end_time; |
Deepa Dinamani | 36819ad | 2017-08-04 21:12:31 -0700 | [diff] [blame] | 755 | if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec)) |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 756 | return -EINVAL; |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 757 | } |
| 758 | |
Oleg Nesterov | b772434 | 2019-07-16 16:29:53 -0700 | [diff] [blame] | 759 | ret = set_user_sigmask(sigmask, sigsetsize); |
Deepa Dinamani | ded653c | 2018-09-19 21:41:04 -0700 | [diff] [blame] | 760 | if (ret) |
| 761 | return ret; |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 762 | |
Bernd Schmidt | 6256851 | 2009-01-13 22:14:48 +0100 | [diff] [blame] | 763 | ret = core_sys_select(n, inp, outp, exp, to); |
Oleg Nesterov | ac30102 | 2019-07-16 16:29:59 -0700 | [diff] [blame] | 764 | return poll_select_finish(&end_time, tsp, type, ret); |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 765 | } |
| 766 | |
| 767 | /* |
| 768 | * Most architectures can't handle 7-argument syscalls. So we provide a |
| 769 | * 6-argument version where the sixth argument is a pointer to a structure |
| 770 | * which has a pointer to the sigset_t itself followed by a size_t containing |
| 771 | * the sigset size. |
| 772 | */ |
Al Viro | 7e71609 | 2020-02-19 09:54:24 -0500 | [diff] [blame] | 773 | struct sigset_argpack { |
| 774 | sigset_t __user *p; |
| 775 | size_t size; |
| 776 | }; |
| 777 | |
| 778 | static inline int get_sigset_argpack(struct sigset_argpack *to, |
| 779 | struct sigset_argpack __user *from) |
| 780 | { |
| 781 | // the path is hot enough for overhead of copy_from_user() to matter |
| 782 | if (from) { |
| 783 | if (!user_read_access_begin(from, sizeof(*from))) |
| 784 | return -EFAULT; |
| 785 | unsafe_get_user(to->p, &from->p, Efault); |
| 786 | unsafe_get_user(to->size, &from->size, Efault); |
| 787 | user_read_access_end(); |
| 788 | } |
| 789 | return 0; |
| 790 | Efault: |
| 791 | user_access_end(); |
| 792 | return -EFAULT; |
| 793 | } |
| 794 | |
Heiko Carstens | d4e8204 | 2009-01-14 14:14:34 +0100 | [diff] [blame] | 795 | SYSCALL_DEFINE6(pselect6, int, n, fd_set __user *, inp, fd_set __user *, outp, |
Deepa Dinamani | e024707 | 2018-09-19 21:41:07 -0700 | [diff] [blame] | 796 | fd_set __user *, exp, struct __kernel_timespec __user *, tsp, |
Heiko Carstens | d4e8204 | 2009-01-14 14:14:34 +0100 | [diff] [blame] | 797 | void __user *, sig) |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 798 | { |
Al Viro | 7e71609 | 2020-02-19 09:54:24 -0500 | [diff] [blame] | 799 | struct sigset_argpack x = {NULL, 0}; |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 800 | |
Al Viro | 7e71609 | 2020-02-19 09:54:24 -0500 | [diff] [blame] | 801 | if (get_sigset_argpack(&x, sig)) |
| 802 | return -EFAULT; |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 803 | |
Al Viro | 7e71609 | 2020-02-19 09:54:24 -0500 | [diff] [blame] | 804 | return do_pselect(n, inp, outp, exp, tsp, x.p, x.size, PT_TIMESPEC); |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 805 | } |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 806 | |
Deepa Dinamani | e024707 | 2018-09-19 21:41:07 -0700 | [diff] [blame] | 807 | #if defined(CONFIG_COMPAT_32BIT_TIME) && !defined(CONFIG_64BIT) |
| 808 | |
| 809 | SYSCALL_DEFINE6(pselect6_time32, int, n, fd_set __user *, inp, fd_set __user *, outp, |
| 810 | fd_set __user *, exp, struct old_timespec32 __user *, tsp, |
| 811 | void __user *, sig) |
| 812 | { |
Al Viro | 7e71609 | 2020-02-19 09:54:24 -0500 | [diff] [blame] | 813 | struct sigset_argpack x = {NULL, 0}; |
Deepa Dinamani | e024707 | 2018-09-19 21:41:07 -0700 | [diff] [blame] | 814 | |
Al Viro | 7e71609 | 2020-02-19 09:54:24 -0500 | [diff] [blame] | 815 | if (get_sigset_argpack(&x, sig)) |
| 816 | return -EFAULT; |
Deepa Dinamani | e024707 | 2018-09-19 21:41:07 -0700 | [diff] [blame] | 817 | |
Al Viro | 7e71609 | 2020-02-19 09:54:24 -0500 | [diff] [blame] | 818 | return do_pselect(n, inp, outp, exp, tsp, x.p, x.size, PT_OLD_TIMESPEC); |
Deepa Dinamani | e024707 | 2018-09-19 21:41:07 -0700 | [diff] [blame] | 819 | } |
| 820 | |
| 821 | #endif |
| 822 | |
Christoph Hellwig | 5d0e528 | 2010-03-10 15:21:13 -0800 | [diff] [blame] | 823 | #ifdef __ARCH_WANT_SYS_OLD_SELECT |
| 824 | struct sel_arg_struct { |
| 825 | unsigned long n; |
| 826 | fd_set __user *inp, *outp, *exp; |
Arnd Bergmann | 75d319c | 2019-10-25 22:56:17 +0200 | [diff] [blame] | 827 | struct __kernel_old_timeval __user *tvp; |
Christoph Hellwig | 5d0e528 | 2010-03-10 15:21:13 -0800 | [diff] [blame] | 828 | }; |
| 829 | |
| 830 | SYSCALL_DEFINE1(old_select, struct sel_arg_struct __user *, arg) |
| 831 | { |
| 832 | struct sel_arg_struct a; |
| 833 | |
| 834 | if (copy_from_user(&a, arg, sizeof(a))) |
| 835 | return -EFAULT; |
Dominik Brodowski | 4bdb9ac | 2018-03-18 07:53:04 +0100 | [diff] [blame] | 836 | return kern_select(a.n, a.inp, a.outp, a.exp, a.tvp); |
Christoph Hellwig | 5d0e528 | 2010-03-10 15:21:13 -0800 | [diff] [blame] | 837 | } |
| 838 | #endif |
| 839 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 840 | struct poll_list { |
| 841 | struct poll_list *next; |
| 842 | int len; |
Gustavo A. R. Silva | 5e01fdf | 2020-08-31 08:25:42 -0500 | [diff] [blame] | 843 | struct pollfd entries[]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 844 | }; |
| 845 | |
| 846 | #define POLLFD_PER_PAGE ((PAGE_SIZE-sizeof(struct poll_list)) / sizeof(struct pollfd)) |
| 847 | |
Vadim Lobanov | 4a4b69f | 2006-06-23 02:05:16 -0700 | [diff] [blame] | 848 | /* |
| 849 | * Fish for pollable events on the pollfd->fd file descriptor. We're only |
| 850 | * interested in events matching the pollfd->events mask, and the result |
| 851 | * matching that mask is both recorded in pollfd->revents and returned. The |
| 852 | * pwait poll_table will be used by the fd-provided poll handler for waiting, |
Hans Verkuil | 626cf23 | 2012-03-23 15:02:27 -0700 | [diff] [blame] | 853 | * if pwait->_qproc is non-NULL. |
Vadim Lobanov | 4a4b69f | 2006-06-23 02:05:16 -0700 | [diff] [blame] | 854 | */ |
Al Viro | fb36793 | 2017-07-16 23:51:03 -0400 | [diff] [blame] | 855 | static inline __poll_t do_pollfd(struct pollfd *pollfd, poll_table *pwait, |
Eliezer Tamir | cbf5500 | 2013-07-08 16:20:34 +0300 | [diff] [blame] | 856 | bool *can_busy_poll, |
Al Viro | fb36793 | 2017-07-16 23:51:03 -0400 | [diff] [blame] | 857 | __poll_t busy_flag) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 858 | { |
Christoph Hellwig | a0f8dcf | 2018-03-05 07:15:25 -0800 | [diff] [blame] | 859 | int fd = pollfd->fd; |
| 860 | __poll_t mask = 0, filter; |
| 861 | struct fd f; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 862 | |
Christoph Hellwig | a0f8dcf | 2018-03-05 07:15:25 -0800 | [diff] [blame] | 863 | if (fd < 0) |
| 864 | goto out; |
| 865 | mask = EPOLLNVAL; |
| 866 | f = fdget(fd); |
| 867 | if (!f.file) |
| 868 | goto out; |
| 869 | |
| 870 | /* userland u16 ->events contains POLL... bitmap */ |
| 871 | filter = demangle_poll(pollfd->events) | EPOLLERR | EPOLLHUP; |
Christoph Hellwig | 9965ed17 | 2018-03-05 07:26:05 -0800 | [diff] [blame] | 872 | pwait->_key = filter | busy_flag; |
| 873 | mask = vfs_poll(f.file, pwait); |
| 874 | if (mask & busy_flag) |
| 875 | *can_busy_poll = true; |
Christoph Hellwig | a0f8dcf | 2018-03-05 07:15:25 -0800 | [diff] [blame] | 876 | mask &= filter; /* Mask out unneeded events. */ |
| 877 | fdput(f); |
| 878 | |
| 879 | out: |
Al Viro | fb36793 | 2017-07-16 23:51:03 -0400 | [diff] [blame] | 880 | /* ... and so does ->revents */ |
Al Viro | c71d227 | 2017-11-29 19:00:41 -0500 | [diff] [blame] | 881 | pollfd->revents = mangle_poll(mask); |
Vadim Lobanov | 4a4b69f | 2006-06-23 02:05:16 -0700 | [diff] [blame] | 882 | return mask; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 883 | } |
| 884 | |
Mateusz Guzik | ccec5ee | 2016-01-06 06:41:53 +0100 | [diff] [blame] | 885 | static int do_poll(struct poll_list *list, struct poll_wqueues *wait, |
Deepa Dinamani | 766b9f9 | 2016-05-19 17:09:05 -0700 | [diff] [blame] | 886 | struct timespec64 *end_time) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 887 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 888 | poll_table* pt = &wait->pt; |
Arjan van de Ven | 8ff3e8e | 2008-08-31 08:26:40 -0700 | [diff] [blame] | 889 | ktime_t expire, *to = NULL; |
| 890 | int timed_out = 0, count = 0; |
John Stultz | da8b44d | 2016-03-17 14:20:51 -0700 | [diff] [blame] | 891 | u64 slack = 0; |
Al Viro | fb36793 | 2017-07-16 23:51:03 -0400 | [diff] [blame] | 892 | __poll_t busy_flag = net_busy_loop_on() ? POLL_BUSY_LOOP : 0; |
Alexander Duyck | 3705671 | 2017-03-24 10:08:18 -0700 | [diff] [blame] | 893 | unsigned long busy_start = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 894 | |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 895 | /* Optimise the no-wait case */ |
Arjan van de Ven | 8ff3e8e | 2008-08-31 08:26:40 -0700 | [diff] [blame] | 896 | if (end_time && !end_time->tv_sec && !end_time->tv_nsec) { |
Hans Verkuil | 626cf23 | 2012-03-23 15:02:27 -0700 | [diff] [blame] | 897 | pt->_qproc = NULL; |
Arjan van de Ven | 8ff3e8e | 2008-08-31 08:26:40 -0700 | [diff] [blame] | 898 | timed_out = 1; |
| 899 | } |
Oleg Nesterov | 9bf084f | 2007-10-16 23:26:18 -0700 | [diff] [blame] | 900 | |
Arjan van de Ven | 96d2ab4 | 2008-09-07 16:08:55 -0700 | [diff] [blame] | 901 | if (end_time && !timed_out) |
Andrew Morton | 231f3d3 | 2010-10-27 15:34:53 -0700 | [diff] [blame] | 902 | slack = select_estimate_accuracy(end_time); |
Arjan van de Ven | 90d6e24 | 2008-09-01 15:55:35 -0700 | [diff] [blame] | 903 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 904 | for (;;) { |
| 905 | struct poll_list *walk; |
Eliezer Tamir | cbf5500 | 2013-07-08 16:20:34 +0300 | [diff] [blame] | 906 | bool can_busy_loop = false; |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 907 | |
Vadim Lobanov | 4a4b69f | 2006-06-23 02:05:16 -0700 | [diff] [blame] | 908 | for (walk = list; walk != NULL; walk = walk->next) { |
| 909 | struct pollfd * pfd, * pfd_end; |
| 910 | |
| 911 | pfd = walk->entries; |
| 912 | pfd_end = pfd + walk->len; |
| 913 | for (; pfd != pfd_end; pfd++) { |
| 914 | /* |
| 915 | * Fish for events. If we found one, record it |
Hans Verkuil | 626cf23 | 2012-03-23 15:02:27 -0700 | [diff] [blame] | 916 | * and kill poll_table->_qproc, so we don't |
Vadim Lobanov | 4a4b69f | 2006-06-23 02:05:16 -0700 | [diff] [blame] | 917 | * needlessly register any other waiters after |
| 918 | * this. They'll get immediately deregistered |
| 919 | * when we break out and return. |
| 920 | */ |
Eliezer Tamir | cbf5500 | 2013-07-08 16:20:34 +0300 | [diff] [blame] | 921 | if (do_pollfd(pfd, pt, &can_busy_loop, |
| 922 | busy_flag)) { |
Vadim Lobanov | 4a4b69f | 2006-06-23 02:05:16 -0700 | [diff] [blame] | 923 | count++; |
Hans Verkuil | 626cf23 | 2012-03-23 15:02:27 -0700 | [diff] [blame] | 924 | pt->_qproc = NULL; |
Eliezer Tamir | cbf5500 | 2013-07-08 16:20:34 +0300 | [diff] [blame] | 925 | /* found something, stop busy polling */ |
| 926 | busy_flag = 0; |
| 927 | can_busy_loop = false; |
Vadim Lobanov | 4a4b69f | 2006-06-23 02:05:16 -0700 | [diff] [blame] | 928 | } |
| 929 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 930 | } |
Vadim Lobanov | 4a4b69f | 2006-06-23 02:05:16 -0700 | [diff] [blame] | 931 | /* |
| 932 | * All waiters have already been registered, so don't provide |
Hans Verkuil | 626cf23 | 2012-03-23 15:02:27 -0700 | [diff] [blame] | 933 | * a poll_table->_qproc to them on the next loop iteration. |
Vadim Lobanov | 4a4b69f | 2006-06-23 02:05:16 -0700 | [diff] [blame] | 934 | */ |
Hans Verkuil | 626cf23 | 2012-03-23 15:02:27 -0700 | [diff] [blame] | 935 | pt->_qproc = NULL; |
Oleg Nesterov | 9bf084f | 2007-10-16 23:26:18 -0700 | [diff] [blame] | 936 | if (!count) { |
| 937 | count = wait->error; |
| 938 | if (signal_pending(current)) |
Oleg Nesterov | 8cf8b55 | 2019-07-16 16:29:56 -0700 | [diff] [blame] | 939 | count = -ERESTARTNOHAND; |
Oleg Nesterov | 9bf084f | 2007-10-16 23:26:18 -0700 | [diff] [blame] | 940 | } |
Arjan van de Ven | 8ff3e8e | 2008-08-31 08:26:40 -0700 | [diff] [blame] | 941 | if (count || timed_out) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 942 | break; |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 943 | |
Eliezer Tamir | cbf5500 | 2013-07-08 16:20:34 +0300 | [diff] [blame] | 944 | /* only if found POLL_BUSY_LOOP sockets && not out of time */ |
Eliezer Tamir | 76b1e9b | 2013-07-09 13:09:21 +0300 | [diff] [blame] | 945 | if (can_busy_loop && !need_resched()) { |
Alexander Duyck | 3705671 | 2017-03-24 10:08:18 -0700 | [diff] [blame] | 946 | if (!busy_start) { |
| 947 | busy_start = busy_loop_current_time(); |
Eliezer Tamir | 76b1e9b | 2013-07-09 13:09:21 +0300 | [diff] [blame] | 948 | continue; |
| 949 | } |
Alexander Duyck | 3705671 | 2017-03-24 10:08:18 -0700 | [diff] [blame] | 950 | if (!busy_loop_timeout(busy_start)) |
Eliezer Tamir | 76b1e9b | 2013-07-09 13:09:21 +0300 | [diff] [blame] | 951 | continue; |
| 952 | } |
| 953 | busy_flag = 0; |
Eliezer Tamir | 91e2fd33 | 2013-06-28 15:59:35 +0300 | [diff] [blame] | 954 | |
Arjan van de Ven | 8ff3e8e | 2008-08-31 08:26:40 -0700 | [diff] [blame] | 955 | /* |
| 956 | * If this is the first loop and we have a timeout |
| 957 | * given, then we convert to ktime_t and set the to |
| 958 | * pointer to the expiry value. |
| 959 | */ |
| 960 | if (end_time && !to) { |
Deepa Dinamani | 766b9f9 | 2016-05-19 17:09:05 -0700 | [diff] [blame] | 961 | expire = timespec64_to_ktime(*end_time); |
Arjan van de Ven | 8ff3e8e | 2008-08-31 08:26:40 -0700 | [diff] [blame] | 962 | to = &expire; |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 963 | } |
| 964 | |
Tejun Heo | 5f820f6 | 2009-01-06 14:40:59 -0800 | [diff] [blame] | 965 | if (!poll_schedule_timeout(wait, TASK_INTERRUPTIBLE, to, slack)) |
Arjan van de Ven | 8ff3e8e | 2008-08-31 08:26:40 -0700 | [diff] [blame] | 966 | timed_out = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 967 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 968 | return count; |
| 969 | } |
| 970 | |
Andi Kleen | 70674f9 | 2006-03-28 01:56:33 -0800 | [diff] [blame] | 971 | #define N_STACK_PPS ((sizeof(stack_pps) - sizeof(struct poll_list)) / \ |
| 972 | sizeof(struct pollfd)) |
| 973 | |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 974 | static int do_sys_poll(struct pollfd __user *ufds, unsigned int nfds, |
Deepa Dinamani | 766b9f9 | 2016-05-19 17:09:05 -0700 | [diff] [blame] | 975 | struct timespec64 *end_time) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 976 | { |
| 977 | struct poll_wqueues table; |
Gustavo A. R. Silva | 43e11fa | 2019-07-16 16:30:58 -0700 | [diff] [blame] | 978 | int err = -EFAULT, fdcount, len; |
Jes Sorensen | 30c14e4 | 2006-03-31 11:18:57 -0500 | [diff] [blame] | 979 | /* Allocate small arguments on the stack to save memory and be |
| 980 | faster - use long to make sure the buffer is aligned properly |
| 981 | on 64 bit archs to avoid unaligned access */ |
| 982 | long stack_pps[POLL_STACK_ALLOC/sizeof(long)]; |
Oleg Nesterov | 252e572 | 2007-10-16 23:26:17 -0700 | [diff] [blame] | 983 | struct poll_list *const head = (struct poll_list *)stack_pps; |
| 984 | struct poll_list *walk = head; |
| 985 | unsigned long todo = nfds; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 986 | |
Jiri Slaby | d554ed89 | 2010-03-05 13:42:42 -0800 | [diff] [blame] | 987 | if (nfds > rlimit(RLIMIT_NOFILE)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 988 | return -EINVAL; |
| 989 | |
Oleg Nesterov | 252e572 | 2007-10-16 23:26:17 -0700 | [diff] [blame] | 990 | len = min_t(unsigned int, nfds, N_STACK_PPS); |
| 991 | for (;;) { |
| 992 | walk->next = NULL; |
| 993 | walk->len = len; |
| 994 | if (!len) |
| 995 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 996 | |
Oleg Nesterov | 252e572 | 2007-10-16 23:26:17 -0700 | [diff] [blame] | 997 | if (copy_from_user(walk->entries, ufds + nfds-todo, |
| 998 | sizeof(struct pollfd) * walk->len)) |
| 999 | goto out_fds; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1000 | |
Oleg Nesterov | 252e572 | 2007-10-16 23:26:17 -0700 | [diff] [blame] | 1001 | todo -= walk->len; |
| 1002 | if (!todo) |
| 1003 | break; |
| 1004 | |
| 1005 | len = min(todo, POLLFD_PER_PAGE); |
Gustavo A. R. Silva | 43e11fa | 2019-07-16 16:30:58 -0700 | [diff] [blame] | 1006 | walk = walk->next = kmalloc(struct_size(walk, entries, len), |
Linus Torvalds | 0bcfe68 | 2021-09-07 11:26:23 -0700 | [diff] [blame] | 1007 | GFP_KERNEL); |
Oleg Nesterov | 252e572 | 2007-10-16 23:26:17 -0700 | [diff] [blame] | 1008 | if (!walk) { |
| 1009 | err = -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1010 | goto out_fds; |
| 1011 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1012 | } |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 1013 | |
Oleg Nesterov | 252e572 | 2007-10-16 23:26:17 -0700 | [diff] [blame] | 1014 | poll_initwait(&table); |
Mateusz Guzik | ccec5ee | 2016-01-06 06:41:53 +0100 | [diff] [blame] | 1015 | fdcount = do_poll(head, &table, end_time); |
Oleg Nesterov | 252e572 | 2007-10-16 23:26:17 -0700 | [diff] [blame] | 1016 | poll_freewait(&table); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1017 | |
Linus Torvalds | ef0ba05 | 2021-01-07 09:43:54 -0800 | [diff] [blame] | 1018 | if (!user_write_access_begin(ufds, nfds * sizeof(*ufds))) |
| 1019 | goto out_fds; |
| 1020 | |
Oleg Nesterov | 252e572 | 2007-10-16 23:26:17 -0700 | [diff] [blame] | 1021 | for (walk = head; walk; walk = walk->next) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1022 | struct pollfd *fds = walk->entries; |
| 1023 | int j; |
| 1024 | |
Linus Torvalds | ef0ba05 | 2021-01-07 09:43:54 -0800 | [diff] [blame] | 1025 | for (j = walk->len; j; fds++, ufds++, j--) |
| 1026 | unsafe_put_user(fds->revents, &ufds->revents, Efault); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1027 | } |
Linus Torvalds | ef0ba05 | 2021-01-07 09:43:54 -0800 | [diff] [blame] | 1028 | user_write_access_end(); |
Oleg Nesterov | 252e572 | 2007-10-16 23:26:17 -0700 | [diff] [blame] | 1029 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1030 | err = fdcount; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1031 | out_fds: |
Oleg Nesterov | 252e572 | 2007-10-16 23:26:17 -0700 | [diff] [blame] | 1032 | walk = head->next; |
| 1033 | while (walk) { |
| 1034 | struct poll_list *pos = walk; |
| 1035 | walk = walk->next; |
| 1036 | kfree(pos); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1037 | } |
Oleg Nesterov | 252e572 | 2007-10-16 23:26:17 -0700 | [diff] [blame] | 1038 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1039 | return err; |
Linus Torvalds | ef0ba05 | 2021-01-07 09:43:54 -0800 | [diff] [blame] | 1040 | |
| 1041 | Efault: |
| 1042 | user_write_access_end(); |
| 1043 | err = -EFAULT; |
| 1044 | goto out_fds; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1045 | } |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 1046 | |
Chris Wright | 3075d9d | 2007-10-16 23:27:18 -0700 | [diff] [blame] | 1047 | static long do_restart_poll(struct restart_block *restart_block) |
| 1048 | { |
Arjan van de Ven | 8ff3e8e | 2008-08-31 08:26:40 -0700 | [diff] [blame] | 1049 | struct pollfd __user *ufds = restart_block->poll.ufds; |
| 1050 | int nfds = restart_block->poll.nfds; |
Deepa Dinamani | 766b9f9 | 2016-05-19 17:09:05 -0700 | [diff] [blame] | 1051 | struct timespec64 *to = NULL, end_time; |
Chris Wright | 3075d9d | 2007-10-16 23:27:18 -0700 | [diff] [blame] | 1052 | int ret; |
| 1053 | |
Arjan van de Ven | 8ff3e8e | 2008-08-31 08:26:40 -0700 | [diff] [blame] | 1054 | if (restart_block->poll.has_timeout) { |
| 1055 | end_time.tv_sec = restart_block->poll.tv_sec; |
| 1056 | end_time.tv_nsec = restart_block->poll.tv_nsec; |
| 1057 | to = &end_time; |
| 1058 | } |
| 1059 | |
| 1060 | ret = do_sys_poll(ufds, nfds, to); |
| 1061 | |
Oleg Nesterov | 5abbe51 | 2021-02-01 18:46:41 +0100 | [diff] [blame] | 1062 | if (ret == -ERESTARTNOHAND) |
| 1063 | ret = set_restart_fn(restart_block, do_restart_poll); |
| 1064 | |
Chris Wright | 3075d9d | 2007-10-16 23:27:18 -0700 | [diff] [blame] | 1065 | return ret; |
| 1066 | } |
| 1067 | |
Heiko Carstens | 5a8a82b | 2009-01-14 14:14:25 +0100 | [diff] [blame] | 1068 | SYSCALL_DEFINE3(poll, struct pollfd __user *, ufds, unsigned int, nfds, |
Linus Torvalds | faf3090 | 2012-02-21 17:24:20 -0800 | [diff] [blame] | 1069 | int, timeout_msecs) |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 1070 | { |
Deepa Dinamani | 766b9f9 | 2016-05-19 17:09:05 -0700 | [diff] [blame] | 1071 | struct timespec64 end_time, *to = NULL; |
Chris Wright | 3075d9d | 2007-10-16 23:27:18 -0700 | [diff] [blame] | 1072 | int ret; |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 1073 | |
Arjan van de Ven | 8ff3e8e | 2008-08-31 08:26:40 -0700 | [diff] [blame] | 1074 | if (timeout_msecs >= 0) { |
| 1075 | to = &end_time; |
| 1076 | poll_select_set_timeout(to, timeout_msecs / MSEC_PER_SEC, |
| 1077 | NSEC_PER_MSEC * (timeout_msecs % MSEC_PER_SEC)); |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 1078 | } |
| 1079 | |
Arjan van de Ven | 8ff3e8e | 2008-08-31 08:26:40 -0700 | [diff] [blame] | 1080 | ret = do_sys_poll(ufds, nfds, to); |
| 1081 | |
Oleg Nesterov | 8cf8b55 | 2019-07-16 16:29:56 -0700 | [diff] [blame] | 1082 | if (ret == -ERESTARTNOHAND) { |
Chris Wright | 3075d9d | 2007-10-16 23:27:18 -0700 | [diff] [blame] | 1083 | struct restart_block *restart_block; |
Arjan van de Ven | 8ff3e8e | 2008-08-31 08:26:40 -0700 | [diff] [blame] | 1084 | |
Andy Lutomirski | f56141e | 2015-02-12 15:01:14 -0800 | [diff] [blame] | 1085 | restart_block = ¤t->restart_block; |
Arjan van de Ven | 8ff3e8e | 2008-08-31 08:26:40 -0700 | [diff] [blame] | 1086 | restart_block->poll.ufds = ufds; |
| 1087 | restart_block->poll.nfds = nfds; |
| 1088 | |
| 1089 | if (timeout_msecs >= 0) { |
| 1090 | restart_block->poll.tv_sec = end_time.tv_sec; |
| 1091 | restart_block->poll.tv_nsec = end_time.tv_nsec; |
| 1092 | restart_block->poll.has_timeout = 1; |
| 1093 | } else |
| 1094 | restart_block->poll.has_timeout = 0; |
| 1095 | |
Oleg Nesterov | 5abbe51 | 2021-02-01 18:46:41 +0100 | [diff] [blame] | 1096 | ret = set_restart_fn(restart_block, do_restart_poll); |
Chris Wright | 3075d9d | 2007-10-16 23:27:18 -0700 | [diff] [blame] | 1097 | } |
| 1098 | return ret; |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 1099 | } |
| 1100 | |
Heiko Carstens | d4e8204 | 2009-01-14 14:14:34 +0100 | [diff] [blame] | 1101 | SYSCALL_DEFINE5(ppoll, struct pollfd __user *, ufds, unsigned int, nfds, |
Deepa Dinamani | 8bd27a3 | 2018-09-19 21:41:06 -0700 | [diff] [blame] | 1102 | struct __kernel_timespec __user *, tsp, const sigset_t __user *, sigmask, |
Heiko Carstens | d4e8204 | 2009-01-14 14:14:34 +0100 | [diff] [blame] | 1103 | size_t, sigsetsize) |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 1104 | { |
Deepa Dinamani | 36819ad | 2017-08-04 21:12:31 -0700 | [diff] [blame] | 1105 | struct timespec64 ts, end_time, *to = NULL; |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 1106 | int ret; |
| 1107 | |
| 1108 | if (tsp) { |
Deepa Dinamani | 36819ad | 2017-08-04 21:12:31 -0700 | [diff] [blame] | 1109 | if (get_timespec64(&ts, tsp)) |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 1110 | return -EFAULT; |
| 1111 | |
Arjan van de Ven | 8ff3e8e | 2008-08-31 08:26:40 -0700 | [diff] [blame] | 1112 | to = &end_time; |
| 1113 | if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec)) |
| 1114 | return -EINVAL; |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 1115 | } |
| 1116 | |
Oleg Nesterov | b772434 | 2019-07-16 16:29:53 -0700 | [diff] [blame] | 1117 | ret = set_user_sigmask(sigmask, sigsetsize); |
Deepa Dinamani | ded653c | 2018-09-19 21:41:04 -0700 | [diff] [blame] | 1118 | if (ret) |
| 1119 | return ret; |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 1120 | |
Arjan van de Ven | 8ff3e8e | 2008-08-31 08:26:40 -0700 | [diff] [blame] | 1121 | ret = do_sys_poll(ufds, nfds, to); |
Oleg Nesterov | ac30102 | 2019-07-16 16:29:59 -0700 | [diff] [blame] | 1122 | return poll_select_finish(&end_time, tsp, PT_TIMESPEC, ret); |
David Woodhouse | 9f72949 | 2006-01-18 17:44:05 -0800 | [diff] [blame] | 1123 | } |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 1124 | |
Deepa Dinamani | 8bd27a3 | 2018-09-19 21:41:06 -0700 | [diff] [blame] | 1125 | #if defined(CONFIG_COMPAT_32BIT_TIME) && !defined(CONFIG_64BIT) |
| 1126 | |
| 1127 | SYSCALL_DEFINE5(ppoll_time32, struct pollfd __user *, ufds, unsigned int, nfds, |
| 1128 | struct old_timespec32 __user *, tsp, const sigset_t __user *, sigmask, |
| 1129 | size_t, sigsetsize) |
| 1130 | { |
Deepa Dinamani | 8bd27a3 | 2018-09-19 21:41:06 -0700 | [diff] [blame] | 1131 | struct timespec64 ts, end_time, *to = NULL; |
| 1132 | int ret; |
| 1133 | |
| 1134 | if (tsp) { |
| 1135 | if (get_old_timespec32(&ts, tsp)) |
| 1136 | return -EFAULT; |
| 1137 | |
| 1138 | to = &end_time; |
| 1139 | if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec)) |
| 1140 | return -EINVAL; |
| 1141 | } |
| 1142 | |
Oleg Nesterov | b772434 | 2019-07-16 16:29:53 -0700 | [diff] [blame] | 1143 | ret = set_user_sigmask(sigmask, sigsetsize); |
Deepa Dinamani | 8bd27a3 | 2018-09-19 21:41:06 -0700 | [diff] [blame] | 1144 | if (ret) |
| 1145 | return ret; |
| 1146 | |
| 1147 | ret = do_sys_poll(ufds, nfds, to); |
Oleg Nesterov | ac30102 | 2019-07-16 16:29:59 -0700 | [diff] [blame] | 1148 | return poll_select_finish(&end_time, tsp, PT_OLD_TIMESPEC, ret); |
Deepa Dinamani | 8bd27a3 | 2018-09-19 21:41:06 -0700 | [diff] [blame] | 1149 | } |
| 1150 | #endif |
| 1151 | |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 1152 | #ifdef CONFIG_COMPAT |
| 1153 | #define __COMPAT_NFDBITS (8 * sizeof(compat_ulong_t)) |
| 1154 | |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 1155 | /* |
| 1156 | * Ooo, nasty. We need here to frob 32-bit unsigned longs to |
| 1157 | * 64-bit unsigned longs. |
| 1158 | */ |
| 1159 | static |
| 1160 | int compat_get_fd_set(unsigned long nr, compat_ulong_t __user *ufdset, |
| 1161 | unsigned long *fdset) |
| 1162 | { |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 1163 | if (ufdset) { |
Al Viro | 464d624 | 2017-06-04 03:24:26 -0400 | [diff] [blame] | 1164 | return compat_get_bitmap(fdset, ufdset, nr); |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 1165 | } else { |
Helge Deller | 79de3cb | 2017-08-23 22:37:00 +0200 | [diff] [blame] | 1166 | zero_fd_set(nr, fdset); |
Al Viro | 464d624 | 2017-06-04 03:24:26 -0400 | [diff] [blame] | 1167 | return 0; |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 1168 | } |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 1169 | } |
| 1170 | |
| 1171 | static |
| 1172 | int compat_set_fd_set(unsigned long nr, compat_ulong_t __user *ufdset, |
| 1173 | unsigned long *fdset) |
| 1174 | { |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 1175 | if (!ufdset) |
| 1176 | return 0; |
Al Viro | 464d624 | 2017-06-04 03:24:26 -0400 | [diff] [blame] | 1177 | return compat_put_bitmap(ufdset, fdset, nr); |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 1178 | } |
| 1179 | |
| 1180 | |
| 1181 | /* |
| 1182 | * This is a virtual copy of sys_select from fs/select.c and probably |
| 1183 | * should be compared to it from time to time |
| 1184 | */ |
| 1185 | |
| 1186 | /* |
| 1187 | * We can actually return ERESTARTSYS instead of EINTR, but I'd |
| 1188 | * like to be certain this leads to no problems. So I return |
| 1189 | * EINTR just for safety. |
| 1190 | * |
| 1191 | * Update: ERESTARTSYS breaks at least the xview clock binary, so |
| 1192 | * I'm trying ERESTARTNOHAND which restart only when you want to. |
| 1193 | */ |
| 1194 | static int compat_core_sys_select(int n, compat_ulong_t __user *inp, |
| 1195 | compat_ulong_t __user *outp, compat_ulong_t __user *exp, |
Deepa Dinamani | 36819ad | 2017-08-04 21:12:31 -0700 | [diff] [blame] | 1196 | struct timespec64 *end_time) |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 1197 | { |
| 1198 | fd_set_bits fds; |
| 1199 | void *bits; |
| 1200 | int size, max_fds, ret = -EINVAL; |
| 1201 | struct fdtable *fdt; |
| 1202 | long stack_fds[SELECT_STACK_ALLOC/sizeof(long)]; |
| 1203 | |
| 1204 | if (n < 0) |
| 1205 | goto out_nofds; |
| 1206 | |
| 1207 | /* max_fds can increase, so grab it once to avoid race */ |
| 1208 | rcu_read_lock(); |
| 1209 | fdt = files_fdtable(current->files); |
| 1210 | max_fds = fdt->max_fds; |
| 1211 | rcu_read_unlock(); |
| 1212 | if (n > max_fds) |
| 1213 | n = max_fds; |
| 1214 | |
| 1215 | /* |
| 1216 | * We need 6 bitmaps (in/out/ex for both incoming and outgoing), |
| 1217 | * since we used fdset we need to allocate memory in units of |
| 1218 | * long-words. |
| 1219 | */ |
| 1220 | size = FDS_BYTES(n); |
| 1221 | bits = stack_fds; |
| 1222 | if (size > sizeof(stack_fds) / 6) { |
Kees Cook | 6da2ec5 | 2018-06-12 13:55:00 -0700 | [diff] [blame] | 1223 | bits = kmalloc_array(6, size, GFP_KERNEL); |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 1224 | ret = -ENOMEM; |
| 1225 | if (!bits) |
| 1226 | goto out_nofds; |
| 1227 | } |
| 1228 | fds.in = (unsigned long *) bits; |
| 1229 | fds.out = (unsigned long *) (bits + size); |
| 1230 | fds.ex = (unsigned long *) (bits + 2*size); |
| 1231 | fds.res_in = (unsigned long *) (bits + 3*size); |
| 1232 | fds.res_out = (unsigned long *) (bits + 4*size); |
| 1233 | fds.res_ex = (unsigned long *) (bits + 5*size); |
| 1234 | |
| 1235 | if ((ret = compat_get_fd_set(n, inp, fds.in)) || |
| 1236 | (ret = compat_get_fd_set(n, outp, fds.out)) || |
| 1237 | (ret = compat_get_fd_set(n, exp, fds.ex))) |
| 1238 | goto out; |
| 1239 | zero_fd_set(n, fds.res_in); |
| 1240 | zero_fd_set(n, fds.res_out); |
| 1241 | zero_fd_set(n, fds.res_ex); |
| 1242 | |
| 1243 | ret = do_select(n, &fds, end_time); |
| 1244 | |
| 1245 | if (ret < 0) |
| 1246 | goto out; |
| 1247 | if (!ret) { |
| 1248 | ret = -ERESTARTNOHAND; |
| 1249 | if (signal_pending(current)) |
| 1250 | goto out; |
| 1251 | ret = 0; |
| 1252 | } |
| 1253 | |
| 1254 | if (compat_set_fd_set(n, inp, fds.res_in) || |
| 1255 | compat_set_fd_set(n, outp, fds.res_out) || |
| 1256 | compat_set_fd_set(n, exp, fds.res_ex)) |
| 1257 | ret = -EFAULT; |
| 1258 | out: |
| 1259 | if (bits != stack_fds) |
| 1260 | kfree(bits); |
| 1261 | out_nofds: |
| 1262 | return ret; |
| 1263 | } |
| 1264 | |
Dominik Brodowski | 05585e4 | 2018-03-20 19:33:48 +0100 | [diff] [blame] | 1265 | static int do_compat_select(int n, compat_ulong_t __user *inp, |
| 1266 | compat_ulong_t __user *outp, compat_ulong_t __user *exp, |
Arnd Bergmann | 9afc5ee | 2018-07-13 12:52:28 +0200 | [diff] [blame] | 1267 | struct old_timeval32 __user *tvp) |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 1268 | { |
Deepa Dinamani | 36819ad | 2017-08-04 21:12:31 -0700 | [diff] [blame] | 1269 | struct timespec64 end_time, *to = NULL; |
Arnd Bergmann | 9afc5ee | 2018-07-13 12:52:28 +0200 | [diff] [blame] | 1270 | struct old_timeval32 tv; |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 1271 | int ret; |
| 1272 | |
| 1273 | if (tvp) { |
| 1274 | if (copy_from_user(&tv, tvp, sizeof(tv))) |
| 1275 | return -EFAULT; |
| 1276 | |
| 1277 | to = &end_time; |
| 1278 | if (poll_select_set_timeout(to, |
| 1279 | tv.tv_sec + (tv.tv_usec / USEC_PER_SEC), |
| 1280 | (tv.tv_usec % USEC_PER_SEC) * NSEC_PER_USEC)) |
| 1281 | return -EINVAL; |
| 1282 | } |
| 1283 | |
| 1284 | ret = compat_core_sys_select(n, inp, outp, exp, to); |
Oleg Nesterov | ac30102 | 2019-07-16 16:29:59 -0700 | [diff] [blame] | 1285 | return poll_select_finish(&end_time, tvp, PT_OLD_TIMEVAL, ret); |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 1286 | } |
| 1287 | |
Dominik Brodowski | 05585e4 | 2018-03-20 19:33:48 +0100 | [diff] [blame] | 1288 | COMPAT_SYSCALL_DEFINE5(select, int, n, compat_ulong_t __user *, inp, |
| 1289 | compat_ulong_t __user *, outp, compat_ulong_t __user *, exp, |
Arnd Bergmann | 9afc5ee | 2018-07-13 12:52:28 +0200 | [diff] [blame] | 1290 | struct old_timeval32 __user *, tvp) |
Dominik Brodowski | 05585e4 | 2018-03-20 19:33:48 +0100 | [diff] [blame] | 1291 | { |
| 1292 | return do_compat_select(n, inp, outp, exp, tvp); |
| 1293 | } |
| 1294 | |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 1295 | struct compat_sel_arg_struct { |
| 1296 | compat_ulong_t n; |
| 1297 | compat_uptr_t inp; |
| 1298 | compat_uptr_t outp; |
| 1299 | compat_uptr_t exp; |
| 1300 | compat_uptr_t tvp; |
| 1301 | }; |
| 1302 | |
| 1303 | COMPAT_SYSCALL_DEFINE1(old_select, struct compat_sel_arg_struct __user *, arg) |
| 1304 | { |
| 1305 | struct compat_sel_arg_struct a; |
| 1306 | |
| 1307 | if (copy_from_user(&a, arg, sizeof(a))) |
| 1308 | return -EFAULT; |
Dominik Brodowski | 05585e4 | 2018-03-20 19:33:48 +0100 | [diff] [blame] | 1309 | return do_compat_select(a.n, compat_ptr(a.inp), compat_ptr(a.outp), |
| 1310 | compat_ptr(a.exp), compat_ptr(a.tvp)); |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 1311 | } |
| 1312 | |
| 1313 | static long do_compat_pselect(int n, compat_ulong_t __user *inp, |
| 1314 | compat_ulong_t __user *outp, compat_ulong_t __user *exp, |
Deepa Dinamani | e024707 | 2018-09-19 21:41:07 -0700 | [diff] [blame] | 1315 | void __user *tsp, compat_sigset_t __user *sigmask, |
| 1316 | compat_size_t sigsetsize, enum poll_time_type type) |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 1317 | { |
Deepa Dinamani | 36819ad | 2017-08-04 21:12:31 -0700 | [diff] [blame] | 1318 | struct timespec64 ts, end_time, *to = NULL; |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 1319 | int ret; |
| 1320 | |
| 1321 | if (tsp) { |
Deepa Dinamani | e024707 | 2018-09-19 21:41:07 -0700 | [diff] [blame] | 1322 | switch (type) { |
| 1323 | case PT_OLD_TIMESPEC: |
| 1324 | if (get_old_timespec32(&ts, tsp)) |
| 1325 | return -EFAULT; |
| 1326 | break; |
| 1327 | case PT_TIMESPEC: |
| 1328 | if (get_timespec64(&ts, tsp)) |
| 1329 | return -EFAULT; |
| 1330 | break; |
| 1331 | default: |
| 1332 | BUG(); |
| 1333 | } |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 1334 | |
| 1335 | to = &end_time; |
| 1336 | if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec)) |
| 1337 | return -EINVAL; |
| 1338 | } |
| 1339 | |
Oleg Nesterov | b772434 | 2019-07-16 16:29:53 -0700 | [diff] [blame] | 1340 | ret = set_compat_user_sigmask(sigmask, sigsetsize); |
Deepa Dinamani | ded653c | 2018-09-19 21:41:04 -0700 | [diff] [blame] | 1341 | if (ret) |
| 1342 | return ret; |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 1343 | |
| 1344 | ret = compat_core_sys_select(n, inp, outp, exp, to); |
Oleg Nesterov | ac30102 | 2019-07-16 16:29:59 -0700 | [diff] [blame] | 1345 | return poll_select_finish(&end_time, tsp, type, ret); |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 1346 | } |
| 1347 | |
Al Viro | 7e71609 | 2020-02-19 09:54:24 -0500 | [diff] [blame] | 1348 | struct compat_sigset_argpack { |
| 1349 | compat_uptr_t p; |
| 1350 | compat_size_t size; |
| 1351 | }; |
| 1352 | static inline int get_compat_sigset_argpack(struct compat_sigset_argpack *to, |
| 1353 | struct compat_sigset_argpack __user *from) |
| 1354 | { |
| 1355 | if (from) { |
| 1356 | if (!user_read_access_begin(from, sizeof(*from))) |
| 1357 | return -EFAULT; |
| 1358 | unsafe_get_user(to->p, &from->p, Efault); |
| 1359 | unsafe_get_user(to->size, &from->size, Efault); |
| 1360 | user_read_access_end(); |
| 1361 | } |
| 1362 | return 0; |
| 1363 | Efault: |
| 1364 | user_access_end(); |
| 1365 | return -EFAULT; |
| 1366 | } |
| 1367 | |
Deepa Dinamani | e024707 | 2018-09-19 21:41:07 -0700 | [diff] [blame] | 1368 | COMPAT_SYSCALL_DEFINE6(pselect6_time64, int, n, compat_ulong_t __user *, inp, |
| 1369 | compat_ulong_t __user *, outp, compat_ulong_t __user *, exp, |
| 1370 | struct __kernel_timespec __user *, tsp, void __user *, sig) |
| 1371 | { |
Al Viro | 7e71609 | 2020-02-19 09:54:24 -0500 | [diff] [blame] | 1372 | struct compat_sigset_argpack x = {0, 0}; |
Deepa Dinamani | e024707 | 2018-09-19 21:41:07 -0700 | [diff] [blame] | 1373 | |
Al Viro | 7e71609 | 2020-02-19 09:54:24 -0500 | [diff] [blame] | 1374 | if (get_compat_sigset_argpack(&x, sig)) |
| 1375 | return -EFAULT; |
Deepa Dinamani | e024707 | 2018-09-19 21:41:07 -0700 | [diff] [blame] | 1376 | |
Al Viro | 7e71609 | 2020-02-19 09:54:24 -0500 | [diff] [blame] | 1377 | return do_compat_pselect(n, inp, outp, exp, tsp, compat_ptr(x.p), |
| 1378 | x.size, PT_TIMESPEC); |
Deepa Dinamani | e024707 | 2018-09-19 21:41:07 -0700 | [diff] [blame] | 1379 | } |
| 1380 | |
| 1381 | #if defined(CONFIG_COMPAT_32BIT_TIME) |
| 1382 | |
Arnd Bergmann | 8dabe72 | 2019-01-07 00:33:08 +0100 | [diff] [blame] | 1383 | COMPAT_SYSCALL_DEFINE6(pselect6_time32, int, n, compat_ulong_t __user *, inp, |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 1384 | compat_ulong_t __user *, outp, compat_ulong_t __user *, exp, |
Arnd Bergmann | 9afc5ee | 2018-07-13 12:52:28 +0200 | [diff] [blame] | 1385 | struct old_timespec32 __user *, tsp, void __user *, sig) |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 1386 | { |
Al Viro | 7e71609 | 2020-02-19 09:54:24 -0500 | [diff] [blame] | 1387 | struct compat_sigset_argpack x = {0, 0}; |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 1388 | |
Al Viro | 7e71609 | 2020-02-19 09:54:24 -0500 | [diff] [blame] | 1389 | if (get_compat_sigset_argpack(&x, sig)) |
| 1390 | return -EFAULT; |
Deepa Dinamani | e024707 | 2018-09-19 21:41:07 -0700 | [diff] [blame] | 1391 | |
Al Viro | 7e71609 | 2020-02-19 09:54:24 -0500 | [diff] [blame] | 1392 | return do_compat_pselect(n, inp, outp, exp, tsp, compat_ptr(x.p), |
| 1393 | x.size, PT_OLD_TIMESPEC); |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 1394 | } |
| 1395 | |
Deepa Dinamani | e024707 | 2018-09-19 21:41:07 -0700 | [diff] [blame] | 1396 | #endif |
| 1397 | |
Deepa Dinamani | 8bd27a3 | 2018-09-19 21:41:06 -0700 | [diff] [blame] | 1398 | #if defined(CONFIG_COMPAT_32BIT_TIME) |
Arnd Bergmann | 8dabe72 | 2019-01-07 00:33:08 +0100 | [diff] [blame] | 1399 | COMPAT_SYSCALL_DEFINE5(ppoll_time32, struct pollfd __user *, ufds, |
Arnd Bergmann | 9afc5ee | 2018-07-13 12:52:28 +0200 | [diff] [blame] | 1400 | unsigned int, nfds, struct old_timespec32 __user *, tsp, |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 1401 | const compat_sigset_t __user *, sigmask, compat_size_t, sigsetsize) |
| 1402 | { |
Deepa Dinamani | 36819ad | 2017-08-04 21:12:31 -0700 | [diff] [blame] | 1403 | struct timespec64 ts, end_time, *to = NULL; |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 1404 | int ret; |
| 1405 | |
| 1406 | if (tsp) { |
Arnd Bergmann | 9afc5ee | 2018-07-13 12:52:28 +0200 | [diff] [blame] | 1407 | if (get_old_timespec32(&ts, tsp)) |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 1408 | return -EFAULT; |
| 1409 | |
| 1410 | to = &end_time; |
| 1411 | if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec)) |
| 1412 | return -EINVAL; |
| 1413 | } |
| 1414 | |
Oleg Nesterov | b772434 | 2019-07-16 16:29:53 -0700 | [diff] [blame] | 1415 | ret = set_compat_user_sigmask(sigmask, sigsetsize); |
Deepa Dinamani | ded653c | 2018-09-19 21:41:04 -0700 | [diff] [blame] | 1416 | if (ret) |
| 1417 | return ret; |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 1418 | |
| 1419 | ret = do_sys_poll(ufds, nfds, to); |
Oleg Nesterov | ac30102 | 2019-07-16 16:29:59 -0700 | [diff] [blame] | 1420 | return poll_select_finish(&end_time, tsp, PT_OLD_TIMESPEC, ret); |
Al Viro | e99ca56 | 2017-04-08 16:50:24 -0400 | [diff] [blame] | 1421 | } |
| 1422 | #endif |
Deepa Dinamani | 8bd27a3 | 2018-09-19 21:41:06 -0700 | [diff] [blame] | 1423 | |
| 1424 | /* New compat syscall for 64 bit time_t*/ |
| 1425 | COMPAT_SYSCALL_DEFINE5(ppoll_time64, struct pollfd __user *, ufds, |
| 1426 | unsigned int, nfds, struct __kernel_timespec __user *, tsp, |
| 1427 | const compat_sigset_t __user *, sigmask, compat_size_t, sigsetsize) |
| 1428 | { |
Deepa Dinamani | 8bd27a3 | 2018-09-19 21:41:06 -0700 | [diff] [blame] | 1429 | struct timespec64 ts, end_time, *to = NULL; |
| 1430 | int ret; |
| 1431 | |
| 1432 | if (tsp) { |
| 1433 | if (get_timespec64(&ts, tsp)) |
| 1434 | return -EFAULT; |
| 1435 | |
| 1436 | to = &end_time; |
| 1437 | if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec)) |
| 1438 | return -EINVAL; |
| 1439 | } |
| 1440 | |
Oleg Nesterov | b772434 | 2019-07-16 16:29:53 -0700 | [diff] [blame] | 1441 | ret = set_compat_user_sigmask(sigmask, sigsetsize); |
Deepa Dinamani | 8bd27a3 | 2018-09-19 21:41:06 -0700 | [diff] [blame] | 1442 | if (ret) |
| 1443 | return ret; |
| 1444 | |
| 1445 | ret = do_sys_poll(ufds, nfds, to); |
Oleg Nesterov | ac30102 | 2019-07-16 16:29:59 -0700 | [diff] [blame] | 1446 | return poll_select_finish(&end_time, tsp, PT_TIMESPEC, ret); |
Deepa Dinamani | 8bd27a3 | 2018-09-19 21:41:06 -0700 | [diff] [blame] | 1447 | } |
| 1448 | |
| 1449 | #endif |