Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/fs/pipe.c |
| 3 | * |
| 4 | * Copyright (C) 1991, 1992, 1999 Linus Torvalds |
| 5 | */ |
| 6 | |
| 7 | #include <linux/mm.h> |
| 8 | #include <linux/file.h> |
| 9 | #include <linux/poll.h> |
| 10 | #include <linux/slab.h> |
| 11 | #include <linux/module.h> |
| 12 | #include <linux/init.h> |
| 13 | #include <linux/fs.h> |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 14 | #include <linux/log2.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | #include <linux/mount.h> |
Muthu Kumar | b502bd1 | 2012-03-23 15:01:50 -0700 | [diff] [blame] | 16 | #include <linux/magic.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | #include <linux/pipe_fs_i.h> |
| 18 | #include <linux/uio.h> |
| 19 | #include <linux/highmem.h> |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 20 | #include <linux/pagemap.h> |
Al Viro | db34950 | 2007-02-07 01:48:00 -0500 | [diff] [blame] | 21 | #include <linux/audit.h> |
Ulrich Drepper | ba719ba | 2008-05-06 20:42:38 -0700 | [diff] [blame] | 22 | #include <linux/syscalls.h> |
Jens Axboe | b492e95 | 2010-05-19 21:03:16 +0200 | [diff] [blame] | 23 | #include <linux/fcntl.h> |
Vladimir Davydov | d86133b | 2016-07-26 15:24:33 -0700 | [diff] [blame] | 24 | #include <linux/memcontrol.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | |
| 26 | #include <asm/uaccess.h> |
| 27 | #include <asm/ioctls.h> |
| 28 | |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 29 | #include "internal.h" |
| 30 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 31 | /* |
Jens Axboe | b492e95 | 2010-05-19 21:03:16 +0200 | [diff] [blame] | 32 | * The max size that a non-root user is allowed to grow the pipe. Can |
Jens Axboe | ff9da69 | 2010-06-03 14:54:39 +0200 | [diff] [blame] | 33 | * be set by root in /proc/sys/fs/pipe-max-size |
Jens Axboe | b492e95 | 2010-05-19 21:03:16 +0200 | [diff] [blame] | 34 | */ |
Jens Axboe | ff9da69 | 2010-06-03 14:54:39 +0200 | [diff] [blame] | 35 | unsigned int pipe_max_size = 1048576; |
| 36 | |
| 37 | /* |
| 38 | * Minimum pipe size, as required by POSIX |
| 39 | */ |
| 40 | unsigned int pipe_min_size = PAGE_SIZE; |
Jens Axboe | b492e95 | 2010-05-19 21:03:16 +0200 | [diff] [blame] | 41 | |
Willy Tarreau | 759c011 | 2016-01-18 16:36:09 +0100 | [diff] [blame] | 42 | /* Maximum allocatable pages per user. Hard limit is unset by default, soft |
| 43 | * matches default values. |
| 44 | */ |
| 45 | unsigned long pipe_user_pages_hard; |
| 46 | unsigned long pipe_user_pages_soft = PIPE_DEF_BUFFERS * INR_OPEN_CUR; |
| 47 | |
Jens Axboe | b492e95 | 2010-05-19 21:03:16 +0200 | [diff] [blame] | 48 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | * We use a start+len construction, which provides full use of the |
| 50 | * allocated memory. |
| 51 | * -- Florian Coosmann (FGC) |
| 52 | * |
| 53 | * Reads with count = 0 should always return 0. |
| 54 | * -- Julian Bradfield 1999-06-07. |
| 55 | * |
| 56 | * FIFOs and Pipes now generate SIGIO for both readers and writers. |
| 57 | * -- Jeremy Elson <jelson@circlemud.org> 2001-08-16 |
| 58 | * |
| 59 | * pipe_read & write cleanup |
| 60 | * -- Manfred Spraul <manfred@colorfullife.com> 2002-05-09 |
| 61 | */ |
| 62 | |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 63 | static void pipe_lock_nested(struct pipe_inode_info *pipe, int subclass) |
| 64 | { |
Al Viro | 6447a3c | 2013-03-21 11:01:38 -0400 | [diff] [blame] | 65 | if (pipe->files) |
Al Viro | 72b0d9a | 2013-03-21 02:32:24 -0400 | [diff] [blame] | 66 | mutex_lock_nested(&pipe->mutex, subclass); |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 67 | } |
| 68 | |
| 69 | void pipe_lock(struct pipe_inode_info *pipe) |
| 70 | { |
| 71 | /* |
| 72 | * pipe_lock() nests non-pipe inode locks (for writing to a file) |
| 73 | */ |
| 74 | pipe_lock_nested(pipe, I_MUTEX_PARENT); |
| 75 | } |
| 76 | EXPORT_SYMBOL(pipe_lock); |
| 77 | |
| 78 | void pipe_unlock(struct pipe_inode_info *pipe) |
| 79 | { |
Al Viro | 6447a3c | 2013-03-21 11:01:38 -0400 | [diff] [blame] | 80 | if (pipe->files) |
Al Viro | 72b0d9a | 2013-03-21 02:32:24 -0400 | [diff] [blame] | 81 | mutex_unlock(&pipe->mutex); |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 82 | } |
| 83 | EXPORT_SYMBOL(pipe_unlock); |
| 84 | |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 85 | static inline void __pipe_lock(struct pipe_inode_info *pipe) |
| 86 | { |
| 87 | mutex_lock_nested(&pipe->mutex, I_MUTEX_PARENT); |
| 88 | } |
| 89 | |
| 90 | static inline void __pipe_unlock(struct pipe_inode_info *pipe) |
| 91 | { |
| 92 | mutex_unlock(&pipe->mutex); |
| 93 | } |
| 94 | |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 95 | void pipe_double_lock(struct pipe_inode_info *pipe1, |
| 96 | struct pipe_inode_info *pipe2) |
| 97 | { |
| 98 | BUG_ON(pipe1 == pipe2); |
| 99 | |
| 100 | if (pipe1 < pipe2) { |
| 101 | pipe_lock_nested(pipe1, I_MUTEX_PARENT); |
| 102 | pipe_lock_nested(pipe2, I_MUTEX_CHILD); |
| 103 | } else { |
Peter Zijlstra | 023d43c | 2009-07-21 10:09:23 +0200 | [diff] [blame] | 104 | pipe_lock_nested(pipe2, I_MUTEX_PARENT); |
| 105 | pipe_lock_nested(pipe1, I_MUTEX_CHILD); |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 106 | } |
| 107 | } |
| 108 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 109 | /* Drop the inode semaphore and wait for a pipe event, atomically */ |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 110 | void pipe_wait(struct pipe_inode_info *pipe) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 111 | { |
| 112 | DEFINE_WAIT(wait); |
| 113 | |
Ingo Molnar | d79fc0f | 2005-09-10 00:26:12 -0700 | [diff] [blame] | 114 | /* |
| 115 | * Pipes are system-local resources, so sleeping on them |
| 116 | * is considered a noninteractive wait: |
| 117 | */ |
Mike Galbraith | af92723 | 2007-10-15 17:00:13 +0200 | [diff] [blame] | 118 | prepare_to_wait(&pipe->wait, &wait, TASK_INTERRUPTIBLE); |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 119 | pipe_unlock(pipe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 120 | schedule(); |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 121 | finish_wait(&pipe->wait, &wait); |
Miklos Szeredi | 61e0d47 | 2009-04-14 19:48:41 +0200 | [diff] [blame] | 122 | pipe_lock(pipe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 123 | } |
| 124 | |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 125 | static void anon_pipe_buf_release(struct pipe_inode_info *pipe, |
| 126 | struct pipe_buffer *buf) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 127 | { |
| 128 | struct page *page = buf->page; |
| 129 | |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 130 | /* |
| 131 | * If nobody else uses this page, and we don't already have a |
| 132 | * temporary page, let's keep track of it as a one-deep |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 133 | * allocation cache. (Otherwise just release our reference to it) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 134 | */ |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 135 | if (page_count(page) == 1 && !pipe->tmp_page) |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 136 | pipe->tmp_page = page; |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 137 | else |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 138 | put_page(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 139 | } |
| 140 | |
Vladimir Davydov | d86133b | 2016-07-26 15:24:33 -0700 | [diff] [blame] | 141 | static int anon_pipe_buf_steal(struct pipe_inode_info *pipe, |
| 142 | struct pipe_buffer *buf) |
| 143 | { |
| 144 | struct page *page = buf->page; |
| 145 | |
| 146 | if (page_count(page) == 1) { |
Vladimir Davydov | c4159a7 | 2016-08-08 23:03:12 +0300 | [diff] [blame] | 147 | if (memcg_kmem_enabled()) |
Vladimir Davydov | d86133b | 2016-07-26 15:24:33 -0700 | [diff] [blame] | 148 | memcg_kmem_uncharge(page, 0); |
Vladimir Davydov | d86133b | 2016-07-26 15:24:33 -0700 | [diff] [blame] | 149 | __SetPageLocked(page); |
| 150 | return 0; |
| 151 | } |
| 152 | return 1; |
| 153 | } |
| 154 | |
Jens Axboe | 0845718 | 2007-06-12 20:51:32 +0200 | [diff] [blame] | 155 | /** |
Randy Dunlap | b51d63c | 2008-02-13 15:03:22 -0800 | [diff] [blame] | 156 | * generic_pipe_buf_steal - attempt to take ownership of a &pipe_buffer |
Jens Axboe | 0845718 | 2007-06-12 20:51:32 +0200 | [diff] [blame] | 157 | * @pipe: the pipe that the buffer belongs to |
| 158 | * @buf: the buffer to attempt to steal |
| 159 | * |
| 160 | * Description: |
Randy Dunlap | b51d63c | 2008-02-13 15:03:22 -0800 | [diff] [blame] | 161 | * This function attempts to steal the &struct page attached to |
Jens Axboe | 0845718 | 2007-06-12 20:51:32 +0200 | [diff] [blame] | 162 | * @buf. If successful, this function returns 0 and returns with |
| 163 | * the page locked. The caller may then reuse the page for whatever |
Randy Dunlap | b51d63c | 2008-02-13 15:03:22 -0800 | [diff] [blame] | 164 | * he wishes; the typical use is insertion into a different file |
Jens Axboe | 0845718 | 2007-06-12 20:51:32 +0200 | [diff] [blame] | 165 | * page cache. |
| 166 | */ |
Jens Axboe | 330ab71 | 2006-05-02 15:29:57 +0200 | [diff] [blame] | 167 | int generic_pipe_buf_steal(struct pipe_inode_info *pipe, |
| 168 | struct pipe_buffer *buf) |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 169 | { |
Jens Axboe | 46e678c | 2006-04-30 16:36:32 +0200 | [diff] [blame] | 170 | struct page *page = buf->page; |
| 171 | |
Jens Axboe | 0845718 | 2007-06-12 20:51:32 +0200 | [diff] [blame] | 172 | /* |
| 173 | * A reference of one is golden, that means that the owner of this |
| 174 | * page is the only one holding a reference to it. lock the page |
| 175 | * and return OK. |
| 176 | */ |
Jens Axboe | 46e678c | 2006-04-30 16:36:32 +0200 | [diff] [blame] | 177 | if (page_count(page) == 1) { |
Jens Axboe | 46e678c | 2006-04-30 16:36:32 +0200 | [diff] [blame] | 178 | lock_page(page); |
| 179 | return 0; |
| 180 | } |
| 181 | |
| 182 | return 1; |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 183 | } |
Miklos Szeredi | 51921cb | 2010-05-26 08:44:22 +0200 | [diff] [blame] | 184 | EXPORT_SYMBOL(generic_pipe_buf_steal); |
Jens Axboe | 5abc97a | 2006-03-30 15:16:46 +0200 | [diff] [blame] | 185 | |
Jens Axboe | 0845718 | 2007-06-12 20:51:32 +0200 | [diff] [blame] | 186 | /** |
Randy Dunlap | b51d63c | 2008-02-13 15:03:22 -0800 | [diff] [blame] | 187 | * generic_pipe_buf_get - get a reference to a &struct pipe_buffer |
Jens Axboe | 0845718 | 2007-06-12 20:51:32 +0200 | [diff] [blame] | 188 | * @pipe: the pipe that the buffer belongs to |
| 189 | * @buf: the buffer to get a reference to |
| 190 | * |
| 191 | * Description: |
| 192 | * This function grabs an extra reference to @buf. It's used in |
| 193 | * in the tee() system call, when we duplicate the buffers in one |
| 194 | * pipe into another. |
| 195 | */ |
Matthew Wilcox | 9557090 | 2019-04-05 14:02:10 -0700 | [diff] [blame] | 196 | bool generic_pipe_buf_get(struct pipe_inode_info *pipe, struct pipe_buffer *buf) |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 197 | { |
Matthew Wilcox | 9557090 | 2019-04-05 14:02:10 -0700 | [diff] [blame] | 198 | return try_get_page(buf->page); |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 199 | } |
Miklos Szeredi | 51921cb | 2010-05-26 08:44:22 +0200 | [diff] [blame] | 200 | EXPORT_SYMBOL(generic_pipe_buf_get); |
Jens Axboe | 7052449 | 2006-04-11 15:51:17 +0200 | [diff] [blame] | 201 | |
Jens Axboe | 0845718 | 2007-06-12 20:51:32 +0200 | [diff] [blame] | 202 | /** |
| 203 | * generic_pipe_buf_confirm - verify contents of the pipe buffer |
Randy Dunlap | 79685b8 | 2007-07-27 08:08:51 +0200 | [diff] [blame] | 204 | * @info: the pipe that the buffer belongs to |
Jens Axboe | 0845718 | 2007-06-12 20:51:32 +0200 | [diff] [blame] | 205 | * @buf: the buffer to confirm |
| 206 | * |
| 207 | * Description: |
| 208 | * This function does nothing, because the generic pipe code uses |
| 209 | * pages that are always good when inserted into the pipe. |
| 210 | */ |
Jens Axboe | cac36bb0 | 2007-06-14 13:10:48 +0200 | [diff] [blame] | 211 | int generic_pipe_buf_confirm(struct pipe_inode_info *info, |
| 212 | struct pipe_buffer *buf) |
Jens Axboe | f84d751 | 2006-05-01 19:59:03 +0200 | [diff] [blame] | 213 | { |
| 214 | return 0; |
| 215 | } |
Miklos Szeredi | 51921cb | 2010-05-26 08:44:22 +0200 | [diff] [blame] | 216 | EXPORT_SYMBOL(generic_pipe_buf_confirm); |
Jens Axboe | f84d751 | 2006-05-01 19:59:03 +0200 | [diff] [blame] | 217 | |
Miklos Szeredi | 6818173 | 2009-05-07 15:37:36 +0200 | [diff] [blame] | 218 | /** |
| 219 | * generic_pipe_buf_release - put a reference to a &struct pipe_buffer |
| 220 | * @pipe: the pipe that the buffer belongs to |
| 221 | * @buf: the buffer to put a reference to |
| 222 | * |
| 223 | * Description: |
| 224 | * This function releases a reference to @buf. |
| 225 | */ |
| 226 | void generic_pipe_buf_release(struct pipe_inode_info *pipe, |
| 227 | struct pipe_buffer *buf) |
| 228 | { |
Kirill A. Shutemov | 09cbfea | 2016-04-01 15:29:47 +0300 | [diff] [blame] | 229 | put_page(buf->page); |
Miklos Szeredi | 6818173 | 2009-05-07 15:37:36 +0200 | [diff] [blame] | 230 | } |
Miklos Szeredi | 51921cb | 2010-05-26 08:44:22 +0200 | [diff] [blame] | 231 | EXPORT_SYMBOL(generic_pipe_buf_release); |
Miklos Szeredi | 6818173 | 2009-05-07 15:37:36 +0200 | [diff] [blame] | 232 | |
Eric Dumazet | d4c3cca | 2006-12-13 00:34:04 -0800 | [diff] [blame] | 233 | static const struct pipe_buf_operations anon_pipe_buf_ops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 234 | .can_merge = 1, |
Jens Axboe | cac36bb0 | 2007-06-14 13:10:48 +0200 | [diff] [blame] | 235 | .confirm = generic_pipe_buf_confirm, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 236 | .release = anon_pipe_buf_release, |
Vladimir Davydov | d86133b | 2016-07-26 15:24:33 -0700 | [diff] [blame] | 237 | .steal = anon_pipe_buf_steal, |
Jens Axboe | f84d751 | 2006-05-01 19:59:03 +0200 | [diff] [blame] | 238 | .get = generic_pipe_buf_get, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 239 | }; |
| 240 | |
Jann Horn | 943ebf4 | 2019-01-23 15:19:17 +0100 | [diff] [blame] | 241 | static const struct pipe_buf_operations anon_pipe_buf_nomerge_ops = { |
| 242 | .can_merge = 0, |
| 243 | .confirm = generic_pipe_buf_confirm, |
| 244 | .release = anon_pipe_buf_release, |
| 245 | .steal = anon_pipe_buf_steal, |
| 246 | .get = generic_pipe_buf_get, |
| 247 | }; |
| 248 | |
Linus Torvalds | 9883035 | 2012-04-29 13:12:42 -0700 | [diff] [blame] | 249 | static const struct pipe_buf_operations packet_pipe_buf_ops = { |
| 250 | .can_merge = 0, |
Linus Torvalds | 9883035 | 2012-04-29 13:12:42 -0700 | [diff] [blame] | 251 | .confirm = generic_pipe_buf_confirm, |
| 252 | .release = anon_pipe_buf_release, |
Vladimir Davydov | d86133b | 2016-07-26 15:24:33 -0700 | [diff] [blame] | 253 | .steal = anon_pipe_buf_steal, |
Linus Torvalds | 9883035 | 2012-04-29 13:12:42 -0700 | [diff] [blame] | 254 | .get = generic_pipe_buf_get, |
| 255 | }; |
| 256 | |
Jann Horn | 943ebf4 | 2019-01-23 15:19:17 +0100 | [diff] [blame] | 257 | void pipe_buf_mark_unmergeable(struct pipe_buffer *buf) |
| 258 | { |
| 259 | if (buf->ops == &anon_pipe_buf_ops) |
| 260 | buf->ops = &anon_pipe_buf_nomerge_ops; |
| 261 | } |
| 262 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 263 | static ssize_t |
Al Viro | fb9096a | 2014-04-02 19:56:54 -0400 | [diff] [blame] | 264 | pipe_read(struct kiocb *iocb, struct iov_iter *to) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 265 | { |
Al Viro | fb9096a | 2014-04-02 19:56:54 -0400 | [diff] [blame] | 266 | size_t total_len = iov_iter_count(to); |
Badari Pulavarty | ee0b3e6 | 2006-09-30 23:28:47 -0700 | [diff] [blame] | 267 | struct file *filp = iocb->ki_filp; |
Al Viro | de32ec4 | 2013-03-21 11:16:56 -0400 | [diff] [blame] | 268 | struct pipe_inode_info *pipe = filp->private_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 269 | int do_wakeup; |
| 270 | ssize_t ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 271 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 272 | /* Null read succeeds. */ |
| 273 | if (unlikely(total_len == 0)) |
| 274 | return 0; |
| 275 | |
| 276 | do_wakeup = 0; |
| 277 | ret = 0; |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 278 | __pipe_lock(pipe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 279 | for (;;) { |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 280 | int bufs = pipe->nrbufs; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 281 | if (bufs) { |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 282 | int curbuf = pipe->curbuf; |
| 283 | struct pipe_buffer *buf = pipe->bufs + curbuf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 284 | size_t chars = buf->len; |
Al Viro | 637b58c | 2014-02-03 19:11:42 -0500 | [diff] [blame] | 285 | size_t written; |
| 286 | int error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 287 | |
| 288 | if (chars > total_len) |
| 289 | chars = total_len; |
| 290 | |
Miklos Szeredi | fba597d | 2016-09-27 10:45:12 +0200 | [diff] [blame] | 291 | error = pipe_buf_confirm(pipe, buf); |
Jens Axboe | f84d751 | 2006-05-01 19:59:03 +0200 | [diff] [blame] | 292 | if (error) { |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 293 | if (!ret) |
Nicolas Kaiser | e5953cb | 2010-10-21 14:56:00 +0200 | [diff] [blame] | 294 | ret = error; |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 295 | break; |
| 296 | } |
Jens Axboe | f84d751 | 2006-05-01 19:59:03 +0200 | [diff] [blame] | 297 | |
Al Viro | fb9096a | 2014-04-02 19:56:54 -0400 | [diff] [blame] | 298 | written = copy_page_to_iter(buf->page, buf->offset, chars, to); |
Al Viro | 637b58c | 2014-02-03 19:11:42 -0500 | [diff] [blame] | 299 | if (unlikely(written < chars)) { |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 300 | if (!ret) |
Al Viro | 637b58c | 2014-02-03 19:11:42 -0500 | [diff] [blame] | 301 | ret = -EFAULT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 302 | break; |
| 303 | } |
| 304 | ret += chars; |
| 305 | buf->offset += chars; |
| 306 | buf->len -= chars; |
Linus Torvalds | 9883035 | 2012-04-29 13:12:42 -0700 | [diff] [blame] | 307 | |
| 308 | /* Was it a packet buffer? Clean up and exit */ |
| 309 | if (buf->flags & PIPE_BUF_FLAG_PACKET) { |
| 310 | total_len = chars; |
| 311 | buf->len = 0; |
| 312 | } |
| 313 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 314 | if (!buf->len) { |
Miklos Szeredi | a779638 | 2016-09-27 10:45:12 +0200 | [diff] [blame] | 315 | pipe_buf_release(pipe, buf); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 316 | curbuf = (curbuf + 1) & (pipe->buffers - 1); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 317 | pipe->curbuf = curbuf; |
| 318 | pipe->nrbufs = --bufs; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 319 | do_wakeup = 1; |
| 320 | } |
| 321 | total_len -= chars; |
| 322 | if (!total_len) |
| 323 | break; /* common path: read succeeded */ |
| 324 | } |
| 325 | if (bufs) /* More to do? */ |
| 326 | continue; |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 327 | if (!pipe->writers) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 328 | break; |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 329 | if (!pipe->waiting_writers) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 330 | /* syscall merging: Usually we must not sleep |
| 331 | * if O_NONBLOCK is set, or if we got some data. |
| 332 | * But if a writer sleeps in kernel space, then |
| 333 | * we can wait for that data without violating POSIX. |
| 334 | */ |
| 335 | if (ret) |
| 336 | break; |
| 337 | if (filp->f_flags & O_NONBLOCK) { |
| 338 | ret = -EAGAIN; |
| 339 | break; |
| 340 | } |
| 341 | } |
| 342 | if (signal_pending(current)) { |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 343 | if (!ret) |
| 344 | ret = -ERESTARTSYS; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 345 | break; |
| 346 | } |
| 347 | if (do_wakeup) { |
Linus Torvalds | 28e58ee | 2011-01-20 16:21:59 -0800 | [diff] [blame] | 348 | wake_up_interruptible_sync_poll(&pipe->wait, POLLOUT | POLLWRNORM); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 349 | kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 350 | } |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 351 | pipe_wait(pipe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 352 | } |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 353 | __pipe_unlock(pipe); |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 354 | |
| 355 | /* Signal writers asynchronously that there is more room. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 356 | if (do_wakeup) { |
Linus Torvalds | 28e58ee | 2011-01-20 16:21:59 -0800 | [diff] [blame] | 357 | wake_up_interruptible_sync_poll(&pipe->wait, POLLOUT | POLLWRNORM); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 358 | kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 359 | } |
| 360 | if (ret > 0) |
| 361 | file_accessed(filp); |
| 362 | return ret; |
| 363 | } |
| 364 | |
Linus Torvalds | 9883035 | 2012-04-29 13:12:42 -0700 | [diff] [blame] | 365 | static inline int is_packetized(struct file *file) |
| 366 | { |
| 367 | return (file->f_flags & O_DIRECT) != 0; |
| 368 | } |
| 369 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 370 | static ssize_t |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 371 | pipe_write(struct kiocb *iocb, struct iov_iter *from) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 372 | { |
Badari Pulavarty | ee0b3e6 | 2006-09-30 23:28:47 -0700 | [diff] [blame] | 373 | struct file *filp = iocb->ki_filp; |
Al Viro | de32ec4 | 2013-03-21 11:16:56 -0400 | [diff] [blame] | 374 | struct pipe_inode_info *pipe = filp->private_data; |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 375 | ssize_t ret = 0; |
| 376 | int do_wakeup = 0; |
| 377 | size_t total_len = iov_iter_count(from); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 378 | ssize_t chars; |
| 379 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 380 | /* Null write succeeds. */ |
| 381 | if (unlikely(total_len == 0)) |
| 382 | return 0; |
| 383 | |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 384 | __pipe_lock(pipe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 385 | |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 386 | if (!pipe->readers) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 387 | send_sig(SIGPIPE, current, 0); |
| 388 | ret = -EPIPE; |
| 389 | goto out; |
| 390 | } |
| 391 | |
| 392 | /* We try to merge small writes */ |
| 393 | chars = total_len & (PAGE_SIZE-1); /* size of the last buffer */ |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 394 | if (pipe->nrbufs && chars != 0) { |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 395 | int lastbuf = (pipe->curbuf + pipe->nrbufs - 1) & |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 396 | (pipe->buffers - 1); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 397 | struct pipe_buffer *buf = pipe->bufs + lastbuf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 398 | int offset = buf->offset + buf->len; |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 399 | |
Miklos Szeredi | fba597d | 2016-09-27 10:45:12 +0200 | [diff] [blame] | 400 | if (buf->ops->can_merge && offset + chars <= PAGE_SIZE) { |
| 401 | ret = pipe_buf_confirm(pipe, buf); |
Eric Biggers | 6ae0806 | 2015-10-17 16:26:09 -0500 | [diff] [blame] | 402 | if (ret) |
Jens Axboe | 5274f05 | 2006-03-30 15:15:30 +0200 | [diff] [blame] | 403 | goto out; |
Jens Axboe | f84d751 | 2006-05-01 19:59:03 +0200 | [diff] [blame] | 404 | |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 405 | ret = copy_page_from_iter(buf->page, offset, chars, from); |
| 406 | if (unlikely(ret < chars)) { |
Eric Biggers | 6ae0806 | 2015-10-17 16:26:09 -0500 | [diff] [blame] | 407 | ret = -EFAULT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 408 | goto out; |
Jens Axboe | f6762b7 | 2006-05-01 20:02:05 +0200 | [diff] [blame] | 409 | } |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 410 | do_wakeup = 1; |
Eric Biggers | 6ae0806 | 2015-10-17 16:26:09 -0500 | [diff] [blame] | 411 | buf->len += ret; |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 412 | if (!iov_iter_count(from)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 413 | goto out; |
| 414 | } |
| 415 | } |
| 416 | |
| 417 | for (;;) { |
| 418 | int bufs; |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 419 | |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 420 | if (!pipe->readers) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 421 | send_sig(SIGPIPE, current, 0); |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 422 | if (!ret) |
| 423 | ret = -EPIPE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 424 | break; |
| 425 | } |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 426 | bufs = pipe->nrbufs; |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 427 | if (bufs < pipe->buffers) { |
| 428 | int newbuf = (pipe->curbuf + bufs) & (pipe->buffers-1); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 429 | struct pipe_buffer *buf = pipe->bufs + newbuf; |
| 430 | struct page *page = pipe->tmp_page; |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 431 | int copied; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 432 | |
| 433 | if (!page) { |
Vladimir Davydov | d86133b | 2016-07-26 15:24:33 -0700 | [diff] [blame] | 434 | page = alloc_page(GFP_HIGHUSER | __GFP_ACCOUNT); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 435 | if (unlikely(!page)) { |
| 436 | ret = ret ? : -ENOMEM; |
| 437 | break; |
| 438 | } |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 439 | pipe->tmp_page = page; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 440 | } |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 441 | /* Always wake up, even if the copy fails. Otherwise |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 442 | * we lock up (O_NONBLOCK-)readers that sleep due to |
| 443 | * syscall merging. |
| 444 | * FIXME! Is this really true? |
| 445 | */ |
| 446 | do_wakeup = 1; |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 447 | copied = copy_page_from_iter(page, 0, PAGE_SIZE, from); |
| 448 | if (unlikely(copied < PAGE_SIZE && iov_iter_count(from))) { |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 449 | if (!ret) |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 450 | ret = -EFAULT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 451 | break; |
| 452 | } |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 453 | ret += copied; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 454 | |
| 455 | /* Insert it into the buffer array */ |
| 456 | buf->page = page; |
| 457 | buf->ops = &anon_pipe_buf_ops; |
| 458 | buf->offset = 0; |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 459 | buf->len = copied; |
Linus Torvalds | 9883035 | 2012-04-29 13:12:42 -0700 | [diff] [blame] | 460 | buf->flags = 0; |
| 461 | if (is_packetized(filp)) { |
| 462 | buf->ops = &packet_pipe_buf_ops; |
| 463 | buf->flags = PIPE_BUF_FLAG_PACKET; |
| 464 | } |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 465 | pipe->nrbufs = ++bufs; |
| 466 | pipe->tmp_page = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 467 | |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 468 | if (!iov_iter_count(from)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 469 | break; |
| 470 | } |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 471 | if (bufs < pipe->buffers) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 472 | continue; |
| 473 | if (filp->f_flags & O_NONBLOCK) { |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 474 | if (!ret) |
| 475 | ret = -EAGAIN; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 476 | break; |
| 477 | } |
| 478 | if (signal_pending(current)) { |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 479 | if (!ret) |
| 480 | ret = -ERESTARTSYS; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 481 | break; |
| 482 | } |
| 483 | if (do_wakeup) { |
Linus Torvalds | 28e58ee | 2011-01-20 16:21:59 -0800 | [diff] [blame] | 484 | wake_up_interruptible_sync_poll(&pipe->wait, POLLIN | POLLRDNORM); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 485 | kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 486 | do_wakeup = 0; |
| 487 | } |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 488 | pipe->waiting_writers++; |
| 489 | pipe_wait(pipe); |
| 490 | pipe->waiting_writers--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 491 | } |
| 492 | out: |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 493 | __pipe_unlock(pipe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 494 | if (do_wakeup) { |
Linus Torvalds | 28e58ee | 2011-01-20 16:21:59 -0800 | [diff] [blame] | 495 | wake_up_interruptible_sync_poll(&pipe->wait, POLLIN | POLLRDNORM); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 496 | kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 497 | } |
Dmitry Monakhov | 7e775f4 | 2014-01-23 15:55:21 -0800 | [diff] [blame] | 498 | if (ret > 0 && sb_start_write_trylock(file_inode(filp)->i_sb)) { |
Josef Bacik | c3b2da3 | 2012-03-26 09:59:21 -0400 | [diff] [blame] | 499 | int err = file_update_time(filp); |
| 500 | if (err) |
| 501 | ret = err; |
Dmitry Monakhov | 7e775f4 | 2014-01-23 15:55:21 -0800 | [diff] [blame] | 502 | sb_end_write(file_inode(filp)->i_sb); |
Josef Bacik | c3b2da3 | 2012-03-26 09:59:21 -0400 | [diff] [blame] | 503 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 504 | return ret; |
| 505 | } |
| 506 | |
Andi Kleen | d59d0b1 | 2008-02-08 04:21:23 -0800 | [diff] [blame] | 507 | static long pipe_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 508 | { |
Al Viro | de32ec4 | 2013-03-21 11:16:56 -0400 | [diff] [blame] | 509 | struct pipe_inode_info *pipe = filp->private_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 510 | int count, buf, nrbufs; |
| 511 | |
| 512 | switch (cmd) { |
| 513 | case FIONREAD: |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 514 | __pipe_lock(pipe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 515 | count = 0; |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 516 | buf = pipe->curbuf; |
| 517 | nrbufs = pipe->nrbufs; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 518 | while (--nrbufs >= 0) { |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 519 | count += pipe->bufs[buf].len; |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 520 | buf = (buf+1) & (pipe->buffers - 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 521 | } |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 522 | __pipe_unlock(pipe); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 523 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 524 | return put_user(count, (int __user *)arg); |
| 525 | default: |
Will Deacon | 46ce341 | 2012-05-25 11:39:13 +0100 | [diff] [blame] | 526 | return -ENOIOCTLCMD; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 527 | } |
| 528 | } |
| 529 | |
| 530 | /* No kernel lock held - fine */ |
| 531 | static unsigned int |
| 532 | pipe_poll(struct file *filp, poll_table *wait) |
| 533 | { |
| 534 | unsigned int mask; |
Al Viro | de32ec4 | 2013-03-21 11:16:56 -0400 | [diff] [blame] | 535 | struct pipe_inode_info *pipe = filp->private_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 536 | int nrbufs; |
| 537 | |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 538 | poll_wait(filp, &pipe->wait, wait); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 539 | |
| 540 | /* Reading only -- no need for acquiring the semaphore. */ |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 541 | nrbufs = pipe->nrbufs; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 542 | mask = 0; |
| 543 | if (filp->f_mode & FMODE_READ) { |
| 544 | mask = (nrbufs > 0) ? POLLIN | POLLRDNORM : 0; |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 545 | if (!pipe->writers && filp->f_version != pipe->w_counter) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 546 | mask |= POLLHUP; |
| 547 | } |
| 548 | |
| 549 | if (filp->f_mode & FMODE_WRITE) { |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 550 | mask |= (nrbufs < pipe->buffers) ? POLLOUT | POLLWRNORM : 0; |
Pekka Enberg | 5e5d7a2 | 2005-09-06 15:17:48 -0700 | [diff] [blame] | 551 | /* |
| 552 | * Most Unices do not set POLLERR for FIFOs but on Linux they |
| 553 | * behave exactly like pipes for poll(). |
| 554 | */ |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 555 | if (!pipe->readers) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 556 | mask |= POLLERR; |
| 557 | } |
| 558 | |
| 559 | return mask; |
| 560 | } |
| 561 | |
Linus Torvalds | b0d8d22 | 2013-12-02 09:44:51 -0800 | [diff] [blame] | 562 | static void put_pipe_info(struct inode *inode, struct pipe_inode_info *pipe) |
| 563 | { |
| 564 | int kill = 0; |
| 565 | |
| 566 | spin_lock(&inode->i_lock); |
| 567 | if (!--pipe->files) { |
| 568 | inode->i_pipe = NULL; |
| 569 | kill = 1; |
| 570 | } |
| 571 | spin_unlock(&inode->i_lock); |
| 572 | |
| 573 | if (kill) |
| 574 | free_pipe_info(pipe); |
| 575 | } |
| 576 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 577 | static int |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 578 | pipe_release(struct inode *inode, struct file *file) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 579 | { |
Linus Torvalds | b0d8d22 | 2013-12-02 09:44:51 -0800 | [diff] [blame] | 580 | struct pipe_inode_info *pipe = file->private_data; |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 581 | |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 582 | __pipe_lock(pipe); |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 583 | if (file->f_mode & FMODE_READ) |
| 584 | pipe->readers--; |
| 585 | if (file->f_mode & FMODE_WRITE) |
| 586 | pipe->writers--; |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 587 | |
Al Viro | ba5bb14 | 2013-03-21 02:21:19 -0400 | [diff] [blame] | 588 | if (pipe->readers || pipe->writers) { |
Linus Torvalds | 28e58ee | 2011-01-20 16:21:59 -0800 | [diff] [blame] | 589 | wake_up_interruptible_sync_poll(&pipe->wait, POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM | POLLERR | POLLHUP); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 590 | kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); |
| 591 | kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 592 | } |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 593 | __pipe_unlock(pipe); |
Al Viro | ba5bb14 | 2013-03-21 02:21:19 -0400 | [diff] [blame] | 594 | |
Linus Torvalds | b0d8d22 | 2013-12-02 09:44:51 -0800 | [diff] [blame] | 595 | put_pipe_info(inode, pipe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 596 | return 0; |
| 597 | } |
| 598 | |
| 599 | static int |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 600 | pipe_fasync(int fd, struct file *filp, int on) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 601 | { |
Al Viro | de32ec4 | 2013-03-21 11:16:56 -0400 | [diff] [blame] | 602 | struct pipe_inode_info *pipe = filp->private_data; |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 603 | int retval = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 604 | |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 605 | __pipe_lock(pipe); |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 606 | if (filp->f_mode & FMODE_READ) |
| 607 | retval = fasync_helper(fd, filp, on, &pipe->fasync_readers); |
| 608 | if ((filp->f_mode & FMODE_WRITE) && retval >= 0) { |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 609 | retval = fasync_helper(fd, filp, on, &pipe->fasync_writers); |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 610 | if (retval < 0 && (filp->f_mode & FMODE_READ)) |
| 611 | /* this can happen only if on == T */ |
Oleg Nesterov | e5bc49b | 2009-03-12 14:31:28 -0700 | [diff] [blame] | 612 | fasync_helper(-1, filp, 0, &pipe->fasync_readers); |
| 613 | } |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 614 | __pipe_unlock(pipe); |
Jonathan Corbet | 60aa492 | 2009-02-01 14:52:56 -0700 | [diff] [blame] | 615 | return retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 616 | } |
| 617 | |
Michael Kerrisk (man-pages) | 9c87bcf | 2016-10-11 13:53:40 -0700 | [diff] [blame] | 618 | static unsigned long account_pipe_buffers(struct user_struct *user, |
Willy Tarreau | 759c011 | 2016-01-18 16:36:09 +0100 | [diff] [blame] | 619 | unsigned long old, unsigned long new) |
| 620 | { |
Michael Kerrisk (man-pages) | 9c87bcf | 2016-10-11 13:53:40 -0700 | [diff] [blame] | 621 | return atomic_long_add_return(new - old, &user->pipe_bufs); |
Willy Tarreau | 759c011 | 2016-01-18 16:36:09 +0100 | [diff] [blame] | 622 | } |
| 623 | |
Michael Kerrisk (man-pages) | 9c87bcf | 2016-10-11 13:53:40 -0700 | [diff] [blame] | 624 | static bool too_many_pipe_buffers_soft(unsigned long user_bufs) |
Willy Tarreau | 759c011 | 2016-01-18 16:36:09 +0100 | [diff] [blame] | 625 | { |
Eric Biggers | 71baf27 | 2018-02-06 15:41:56 -0800 | [diff] [blame] | 626 | return pipe_user_pages_soft && user_bufs > pipe_user_pages_soft; |
Willy Tarreau | 759c011 | 2016-01-18 16:36:09 +0100 | [diff] [blame] | 627 | } |
| 628 | |
Michael Kerrisk (man-pages) | 9c87bcf | 2016-10-11 13:53:40 -0700 | [diff] [blame] | 629 | static bool too_many_pipe_buffers_hard(unsigned long user_bufs) |
Willy Tarreau | 759c011 | 2016-01-18 16:36:09 +0100 | [diff] [blame] | 630 | { |
Eric Biggers | 71baf27 | 2018-02-06 15:41:56 -0800 | [diff] [blame] | 631 | return pipe_user_pages_hard && user_bufs > pipe_user_pages_hard; |
Willy Tarreau | 759c011 | 2016-01-18 16:36:09 +0100 | [diff] [blame] | 632 | } |
| 633 | |
Eric Biggers | a705c24 | 2018-02-06 15:41:53 -0800 | [diff] [blame] | 634 | static bool is_unprivileged_user(void) |
| 635 | { |
| 636 | return !capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN); |
| 637 | } |
| 638 | |
Al Viro | 7bee130 | 2013-03-21 11:04:15 -0400 | [diff] [blame] | 639 | struct pipe_inode_info *alloc_pipe_info(void) |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 640 | { |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 641 | struct pipe_inode_info *pipe; |
Michael Kerrisk (man-pages) | 09b4d19 | 2016-10-11 13:53:34 -0700 | [diff] [blame] | 642 | unsigned long pipe_bufs = PIPE_DEF_BUFFERS; |
| 643 | struct user_struct *user = get_current_user(); |
Michael Kerrisk (man-pages) | 9c87bcf | 2016-10-11 13:53:40 -0700 | [diff] [blame] | 644 | unsigned long user_bufs; |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 645 | |
Vladimir Davydov | d86133b | 2016-07-26 15:24:33 -0700 | [diff] [blame] | 646 | pipe = kzalloc(sizeof(struct pipe_inode_info), GFP_KERNEL_ACCOUNT); |
Michael Kerrisk (man-pages) | 09b4d19 | 2016-10-11 13:53:34 -0700 | [diff] [blame] | 647 | if (pipe == NULL) |
| 648 | goto out_free_uid; |
Willy Tarreau | 759c011 | 2016-01-18 16:36:09 +0100 | [diff] [blame] | 649 | |
Michael Kerrisk (man-pages) | 086e774 | 2016-10-11 13:53:43 -0700 | [diff] [blame] | 650 | if (pipe_bufs * PAGE_SIZE > pipe_max_size && !capable(CAP_SYS_RESOURCE)) |
| 651 | pipe_bufs = pipe_max_size >> PAGE_SHIFT; |
| 652 | |
Michael Kerrisk (man-pages) | 9c87bcf | 2016-10-11 13:53:40 -0700 | [diff] [blame] | 653 | user_bufs = account_pipe_buffers(user, 0, pipe_bufs); |
Michael Kerrisk (man-pages) | a005ca0 | 2016-10-11 13:53:37 -0700 | [diff] [blame] | 654 | |
Eric Biggers | a705c24 | 2018-02-06 15:41:53 -0800 | [diff] [blame] | 655 | if (too_many_pipe_buffers_soft(user_bufs) && is_unprivileged_user()) { |
Michael Kerrisk (man-pages) | 9c87bcf | 2016-10-11 13:53:40 -0700 | [diff] [blame] | 656 | user_bufs = account_pipe_buffers(user, pipe_bufs, 1); |
Michael Kerrisk (man-pages) | a005ca0 | 2016-10-11 13:53:37 -0700 | [diff] [blame] | 657 | pipe_bufs = 1; |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 658 | } |
| 659 | |
Eric Biggers | a705c24 | 2018-02-06 15:41:53 -0800 | [diff] [blame] | 660 | if (too_many_pipe_buffers_hard(user_bufs) && is_unprivileged_user()) |
Michael Kerrisk (man-pages) | a005ca0 | 2016-10-11 13:53:37 -0700 | [diff] [blame] | 661 | goto out_revert_acct; |
| 662 | |
| 663 | pipe->bufs = kcalloc(pipe_bufs, sizeof(struct pipe_buffer), |
| 664 | GFP_KERNEL_ACCOUNT); |
| 665 | |
Michael Kerrisk (man-pages) | 09b4d19 | 2016-10-11 13:53:34 -0700 | [diff] [blame] | 666 | if (pipe->bufs) { |
| 667 | init_waitqueue_head(&pipe->wait); |
| 668 | pipe->r_counter = pipe->w_counter = 1; |
| 669 | pipe->buffers = pipe_bufs; |
| 670 | pipe->user = user; |
Michael Kerrisk (man-pages) | 09b4d19 | 2016-10-11 13:53:34 -0700 | [diff] [blame] | 671 | mutex_init(&pipe->mutex); |
| 672 | return pipe; |
| 673 | } |
| 674 | |
Michael Kerrisk (man-pages) | a005ca0 | 2016-10-11 13:53:37 -0700 | [diff] [blame] | 675 | out_revert_acct: |
Michael Kerrisk (man-pages) | 9c87bcf | 2016-10-11 13:53:40 -0700 | [diff] [blame] | 676 | (void) account_pipe_buffers(user, pipe_bufs, 0); |
Michael Kerrisk (man-pages) | 09b4d19 | 2016-10-11 13:53:34 -0700 | [diff] [blame] | 677 | kfree(pipe); |
| 678 | out_free_uid: |
| 679 | free_uid(user); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 680 | return NULL; |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 681 | } |
| 682 | |
Al Viro | 4b8a8f1 | 2013-03-21 11:06:46 -0400 | [diff] [blame] | 683 | void free_pipe_info(struct pipe_inode_info *pipe) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 684 | { |
| 685 | int i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 686 | |
Michael Kerrisk (man-pages) | 9c87bcf | 2016-10-11 13:53:40 -0700 | [diff] [blame] | 687 | (void) account_pipe_buffers(pipe->user, pipe->buffers, 0); |
Willy Tarreau | 759c011 | 2016-01-18 16:36:09 +0100 | [diff] [blame] | 688 | free_uid(pipe->user); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 689 | for (i = 0; i < pipe->buffers; i++) { |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 690 | struct pipe_buffer *buf = pipe->bufs + i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 691 | if (buf->ops) |
Miklos Szeredi | a779638 | 2016-09-27 10:45:12 +0200 | [diff] [blame] | 692 | pipe_buf_release(pipe, buf); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 693 | } |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 694 | if (pipe->tmp_page) |
| 695 | __free_page(pipe->tmp_page); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 696 | kfree(pipe->bufs); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 697 | kfree(pipe); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 698 | } |
| 699 | |
Eric Dumazet | fa3536c | 2006-03-26 01:37:24 -0800 | [diff] [blame] | 700 | static struct vfsmount *pipe_mnt __read_mostly; |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 701 | |
Eric Dumazet | c23fbb6 | 2007-05-08 00:26:18 -0700 | [diff] [blame] | 702 | /* |
| 703 | * pipefs_dname() is called from d_path(). |
| 704 | */ |
| 705 | static char *pipefs_dname(struct dentry *dentry, char *buffer, int buflen) |
| 706 | { |
| 707 | return dynamic_dname(dentry, buffer, buflen, "pipe:[%lu]", |
David Howells | 75c3cfa | 2015-03-17 22:26:12 +0000 | [diff] [blame] | 708 | d_inode(dentry)->i_ino); |
Eric Dumazet | c23fbb6 | 2007-05-08 00:26:18 -0700 | [diff] [blame] | 709 | } |
| 710 | |
Al Viro | 3ba13d1 | 2009-02-20 06:02:22 +0000 | [diff] [blame] | 711 | static const struct dentry_operations pipefs_dentry_operations = { |
Eric Dumazet | c23fbb6 | 2007-05-08 00:26:18 -0700 | [diff] [blame] | 712 | .d_dname = pipefs_dname, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 713 | }; |
| 714 | |
| 715 | static struct inode * get_pipe_inode(void) |
| 716 | { |
Eric Dumazet | a209dfc | 2011-07-26 11:36:34 +0200 | [diff] [blame] | 717 | struct inode *inode = new_inode_pseudo(pipe_mnt->mnt_sb); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 718 | struct pipe_inode_info *pipe; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 719 | |
| 720 | if (!inode) |
| 721 | goto fail_inode; |
| 722 | |
Christoph Hellwig | 85fe402 | 2010-10-23 11:19:54 -0400 | [diff] [blame] | 723 | inode->i_ino = get_next_ino(); |
| 724 | |
Al Viro | 7bee130 | 2013-03-21 11:04:15 -0400 | [diff] [blame] | 725 | pipe = alloc_pipe_info(); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 726 | if (!pipe) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 727 | goto fail_iput; |
Ingo Molnar | 3a326a2 | 2006-04-10 15:18:35 +0200 | [diff] [blame] | 728 | |
Al Viro | ba5bb14 | 2013-03-21 02:21:19 -0400 | [diff] [blame] | 729 | inode->i_pipe = pipe; |
| 730 | pipe->files = 2; |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 731 | pipe->readers = pipe->writers = 1; |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 732 | inode->i_fop = &pipefifo_fops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 733 | |
| 734 | /* |
| 735 | * Mark the inode dirty from the very beginning, |
| 736 | * that way it will never be moved to the dirty |
| 737 | * list because "mark_inode_dirty()" will think |
| 738 | * that it already _is_ on the dirty list. |
| 739 | */ |
| 740 | inode->i_state = I_DIRTY; |
| 741 | inode->i_mode = S_IFIFO | S_IRUSR | S_IWUSR; |
David Howells | da9592e | 2008-11-14 10:39:05 +1100 | [diff] [blame] | 742 | inode->i_uid = current_fsuid(); |
| 743 | inode->i_gid = current_fsgid(); |
Deepa Dinamani | 078cd82 | 2016-09-14 07:48:04 -0700 | [diff] [blame] | 744 | inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode); |
Ingo Molnar | 923f4f2 | 2006-04-11 13:53:33 +0200 | [diff] [blame] | 745 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 746 | return inode; |
| 747 | |
| 748 | fail_iput: |
| 749 | iput(inode); |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 750 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 751 | fail_inode: |
| 752 | return NULL; |
| 753 | } |
| 754 | |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 755 | int create_pipe_files(struct file **res, int flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 756 | { |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 757 | int err; |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 758 | struct inode *inode = get_pipe_inode(); |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 759 | struct file *f; |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 760 | struct path path; |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 761 | static struct qstr name = { .name = "" }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 762 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 763 | if (!inode) |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 764 | return -ENFILE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 765 | |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 766 | err = -ENOMEM; |
Nick Piggin | 4b93688 | 2011-01-07 17:50:07 +1100 | [diff] [blame] | 767 | path.dentry = d_alloc_pseudo(pipe_mnt->mnt_sb, &name); |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 768 | if (!path.dentry) |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 769 | goto err_inode; |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 770 | path.mnt = mntget(pipe_mnt); |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 771 | |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 772 | d_instantiate(path.dentry, inode); |
Dave Hansen | 430e285 | 2008-02-15 14:37:26 -0800 | [diff] [blame] | 773 | |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 774 | f = alloc_file(&path, FMODE_WRITE, &pipefifo_fops); |
Eric Biggers | e9bb1f9 | 2015-10-17 16:26:08 -0500 | [diff] [blame] | 775 | if (IS_ERR(f)) { |
| 776 | err = PTR_ERR(f); |
Dave Hansen | 430e285 | 2008-02-15 14:37:26 -0800 | [diff] [blame] | 777 | goto err_dentry; |
Eric Biggers | e9bb1f9 | 2015-10-17 16:26:08 -0500 | [diff] [blame] | 778 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 779 | |
Linus Torvalds | 9883035 | 2012-04-29 13:12:42 -0700 | [diff] [blame] | 780 | f->f_flags = O_WRONLY | (flags & (O_NONBLOCK | O_DIRECT)); |
Al Viro | de32ec4 | 2013-03-21 11:16:56 -0400 | [diff] [blame] | 781 | f->private_data = inode->i_pipe; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 782 | |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 783 | res[0] = alloc_file(&path, FMODE_READ, &pipefifo_fops); |
Eric Biggers | e9bb1f9 | 2015-10-17 16:26:08 -0500 | [diff] [blame] | 784 | if (IS_ERR(res[0])) { |
| 785 | err = PTR_ERR(res[0]); |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 786 | goto err_file; |
Eric Biggers | e9bb1f9 | 2015-10-17 16:26:08 -0500 | [diff] [blame] | 787 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 788 | |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 789 | path_get(&path); |
Al Viro | de32ec4 | 2013-03-21 11:16:56 -0400 | [diff] [blame] | 790 | res[0]->private_data = inode->i_pipe; |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 791 | res[0]->f_flags = O_RDONLY | (flags & O_NONBLOCK); |
| 792 | res[1] = f; |
| 793 | return 0; |
| 794 | |
| 795 | err_file: |
| 796 | put_filp(f); |
| 797 | err_dentry: |
Al Viro | 4b8a8f1 | 2013-03-21 11:06:46 -0400 | [diff] [blame] | 798 | free_pipe_info(inode->i_pipe); |
Al Viro | 2c48b9c | 2009-08-09 00:52:35 +0400 | [diff] [blame] | 799 | path_put(&path); |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 800 | return err; |
Al Viro | ed15243 | 2008-04-22 19:51:27 -0400 | [diff] [blame] | 801 | |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 802 | err_inode: |
Al Viro | 4b8a8f1 | 2013-03-21 11:06:46 -0400 | [diff] [blame] | 803 | free_pipe_info(inode->i_pipe); |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 804 | iput(inode); |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 805 | return err; |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 806 | } |
| 807 | |
Al Viro | 5b249b1 | 2012-08-19 12:17:29 -0400 | [diff] [blame] | 808 | static int __do_pipe_flags(int *fd, struct file **files, int flags) |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 809 | { |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 810 | int error; |
| 811 | int fdw, fdr; |
| 812 | |
Linus Torvalds | 9883035 | 2012-04-29 13:12:42 -0700 | [diff] [blame] | 813 | if (flags & ~(O_CLOEXEC | O_NONBLOCK | O_DIRECT)) |
Ulrich Drepper | ed8cae8 | 2008-07-23 21:29:30 -0700 | [diff] [blame] | 814 | return -EINVAL; |
| 815 | |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 816 | error = create_pipe_files(files, flags); |
| 817 | if (error) |
| 818 | return error; |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 819 | |
Ulrich Drepper | ed8cae8 | 2008-07-23 21:29:30 -0700 | [diff] [blame] | 820 | error = get_unused_fd_flags(flags); |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 821 | if (error < 0) |
| 822 | goto err_read_pipe; |
| 823 | fdr = error; |
| 824 | |
Ulrich Drepper | ed8cae8 | 2008-07-23 21:29:30 -0700 | [diff] [blame] | 825 | error = get_unused_fd_flags(flags); |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 826 | if (error < 0) |
| 827 | goto err_fdr; |
| 828 | fdw = error; |
| 829 | |
Al Viro | 157cf64 | 2008-12-14 04:57:47 -0500 | [diff] [blame] | 830 | audit_fd_pair(fdr, fdw); |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 831 | fd[0] = fdr; |
| 832 | fd[1] = fdw; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 833 | return 0; |
| 834 | |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 835 | err_fdr: |
| 836 | put_unused_fd(fdr); |
| 837 | err_read_pipe: |
Al Viro | e4fad8e | 2012-07-21 15:33:25 +0400 | [diff] [blame] | 838 | fput(files[0]); |
| 839 | fput(files[1]); |
Andi Kleen | d6cbd28 | 2006-09-30 23:29:26 -0700 | [diff] [blame] | 840 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 841 | } |
| 842 | |
Al Viro | 5b249b1 | 2012-08-19 12:17:29 -0400 | [diff] [blame] | 843 | int do_pipe_flags(int *fd, int flags) |
| 844 | { |
| 845 | struct file *files[2]; |
| 846 | int error = __do_pipe_flags(fd, files, flags); |
| 847 | if (!error) { |
| 848 | fd_install(fd[0], files[0]); |
| 849 | fd_install(fd[1], files[1]); |
| 850 | } |
| 851 | return error; |
| 852 | } |
| 853 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 854 | /* |
Ulrich Drepper | d35c7b0 | 2008-05-03 15:10:37 -0400 | [diff] [blame] | 855 | * sys_pipe() is the normal C calling standard for creating |
| 856 | * a pipe. It's not the way Unix traditionally does this, though. |
| 857 | */ |
Heiko Carstens | d4e8204 | 2009-01-14 14:14:34 +0100 | [diff] [blame] | 858 | SYSCALL_DEFINE2(pipe2, int __user *, fildes, int, flags) |
Ulrich Drepper | d35c7b0 | 2008-05-03 15:10:37 -0400 | [diff] [blame] | 859 | { |
Al Viro | 5b249b1 | 2012-08-19 12:17:29 -0400 | [diff] [blame] | 860 | struct file *files[2]; |
Ulrich Drepper | d35c7b0 | 2008-05-03 15:10:37 -0400 | [diff] [blame] | 861 | int fd[2]; |
| 862 | int error; |
| 863 | |
Al Viro | 5b249b1 | 2012-08-19 12:17:29 -0400 | [diff] [blame] | 864 | error = __do_pipe_flags(fd, files, flags); |
Ulrich Drepper | d35c7b0 | 2008-05-03 15:10:37 -0400 | [diff] [blame] | 865 | if (!error) { |
Al Viro | 5b249b1 | 2012-08-19 12:17:29 -0400 | [diff] [blame] | 866 | if (unlikely(copy_to_user(fildes, fd, sizeof(fd)))) { |
| 867 | fput(files[0]); |
| 868 | fput(files[1]); |
| 869 | put_unused_fd(fd[0]); |
| 870 | put_unused_fd(fd[1]); |
Ulrich Drepper | d35c7b0 | 2008-05-03 15:10:37 -0400 | [diff] [blame] | 871 | error = -EFAULT; |
Al Viro | 5b249b1 | 2012-08-19 12:17:29 -0400 | [diff] [blame] | 872 | } else { |
| 873 | fd_install(fd[0], files[0]); |
| 874 | fd_install(fd[1], files[1]); |
Ulrich Drepper | ba719ba | 2008-05-06 20:42:38 -0700 | [diff] [blame] | 875 | } |
Ulrich Drepper | d35c7b0 | 2008-05-03 15:10:37 -0400 | [diff] [blame] | 876 | } |
| 877 | return error; |
| 878 | } |
| 879 | |
Heiko Carstens | 2b66421 | 2009-01-14 14:14:35 +0100 | [diff] [blame] | 880 | SYSCALL_DEFINE1(pipe, int __user *, fildes) |
Ulrich Drepper | ed8cae8 | 2008-07-23 21:29:30 -0700 | [diff] [blame] | 881 | { |
| 882 | return sys_pipe2(fildes, 0); |
| 883 | } |
| 884 | |
Al Viro | fc7478a | 2013-03-21 02:07:59 -0400 | [diff] [blame] | 885 | static int wait_for_partner(struct pipe_inode_info *pipe, unsigned int *cnt) |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 886 | { |
| 887 | int cur = *cnt; |
| 888 | |
| 889 | while (cur == *cnt) { |
Al Viro | fc7478a | 2013-03-21 02:07:59 -0400 | [diff] [blame] | 890 | pipe_wait(pipe); |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 891 | if (signal_pending(current)) |
| 892 | break; |
| 893 | } |
| 894 | return cur == *cnt ? -ERESTARTSYS : 0; |
| 895 | } |
| 896 | |
Al Viro | fc7478a | 2013-03-21 02:07:59 -0400 | [diff] [blame] | 897 | static void wake_up_partner(struct pipe_inode_info *pipe) |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 898 | { |
Al Viro | fc7478a | 2013-03-21 02:07:59 -0400 | [diff] [blame] | 899 | wake_up_interruptible(&pipe->wait); |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 900 | } |
| 901 | |
| 902 | static int fifo_open(struct inode *inode, struct file *filp) |
| 903 | { |
| 904 | struct pipe_inode_info *pipe; |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 905 | bool is_pipe = inode->i_sb->s_magic == PIPEFS_MAGIC; |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 906 | int ret; |
| 907 | |
Al Viro | ba5bb14 | 2013-03-21 02:21:19 -0400 | [diff] [blame] | 908 | filp->f_version = 0; |
| 909 | |
| 910 | spin_lock(&inode->i_lock); |
| 911 | if (inode->i_pipe) { |
| 912 | pipe = inode->i_pipe; |
| 913 | pipe->files++; |
| 914 | spin_unlock(&inode->i_lock); |
| 915 | } else { |
| 916 | spin_unlock(&inode->i_lock); |
Al Viro | 7bee130 | 2013-03-21 11:04:15 -0400 | [diff] [blame] | 917 | pipe = alloc_pipe_info(); |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 918 | if (!pipe) |
Al Viro | ba5bb14 | 2013-03-21 02:21:19 -0400 | [diff] [blame] | 919 | return -ENOMEM; |
| 920 | pipe->files = 1; |
| 921 | spin_lock(&inode->i_lock); |
| 922 | if (unlikely(inode->i_pipe)) { |
| 923 | inode->i_pipe->files++; |
| 924 | spin_unlock(&inode->i_lock); |
Al Viro | 4b8a8f1 | 2013-03-21 11:06:46 -0400 | [diff] [blame] | 925 | free_pipe_info(pipe); |
Al Viro | ba5bb14 | 2013-03-21 02:21:19 -0400 | [diff] [blame] | 926 | pipe = inode->i_pipe; |
| 927 | } else { |
| 928 | inode->i_pipe = pipe; |
| 929 | spin_unlock(&inode->i_lock); |
| 930 | } |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 931 | } |
Al Viro | de32ec4 | 2013-03-21 11:16:56 -0400 | [diff] [blame] | 932 | filp->private_data = pipe; |
Al Viro | ba5bb14 | 2013-03-21 02:21:19 -0400 | [diff] [blame] | 933 | /* OK, we have a pipe and it's pinned down */ |
| 934 | |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 935 | __pipe_lock(pipe); |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 936 | |
| 937 | /* We can only do regular read/write on fifos */ |
| 938 | filp->f_mode &= (FMODE_READ | FMODE_WRITE); |
| 939 | |
| 940 | switch (filp->f_mode) { |
| 941 | case FMODE_READ: |
| 942 | /* |
| 943 | * O_RDONLY |
| 944 | * POSIX.1 says that O_NONBLOCK means return with the FIFO |
| 945 | * opened, even when there is no process writing the FIFO. |
| 946 | */ |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 947 | pipe->r_counter++; |
| 948 | if (pipe->readers++ == 0) |
Al Viro | fc7478a | 2013-03-21 02:07:59 -0400 | [diff] [blame] | 949 | wake_up_partner(pipe); |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 950 | |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 951 | if (!is_pipe && !pipe->writers) { |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 952 | if ((filp->f_flags & O_NONBLOCK)) { |
| 953 | /* suppress POLLHUP until we have |
| 954 | * seen a writer */ |
| 955 | filp->f_version = pipe->w_counter; |
| 956 | } else { |
Al Viro | fc7478a | 2013-03-21 02:07:59 -0400 | [diff] [blame] | 957 | if (wait_for_partner(pipe, &pipe->w_counter)) |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 958 | goto err_rd; |
| 959 | } |
| 960 | } |
| 961 | break; |
| 962 | |
| 963 | case FMODE_WRITE: |
| 964 | /* |
| 965 | * O_WRONLY |
| 966 | * POSIX.1 says that O_NONBLOCK means return -1 with |
| 967 | * errno=ENXIO when there is no process reading the FIFO. |
| 968 | */ |
| 969 | ret = -ENXIO; |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 970 | if (!is_pipe && (filp->f_flags & O_NONBLOCK) && !pipe->readers) |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 971 | goto err; |
| 972 | |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 973 | pipe->w_counter++; |
| 974 | if (!pipe->writers++) |
Al Viro | fc7478a | 2013-03-21 02:07:59 -0400 | [diff] [blame] | 975 | wake_up_partner(pipe); |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 976 | |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 977 | if (!is_pipe && !pipe->readers) { |
Al Viro | fc7478a | 2013-03-21 02:07:59 -0400 | [diff] [blame] | 978 | if (wait_for_partner(pipe, &pipe->r_counter)) |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 979 | goto err_wr; |
| 980 | } |
| 981 | break; |
| 982 | |
| 983 | case FMODE_READ | FMODE_WRITE: |
| 984 | /* |
| 985 | * O_RDWR |
| 986 | * POSIX.1 leaves this case "undefined" when O_NONBLOCK is set. |
| 987 | * This implementation will NEVER block on a O_RDWR open, since |
| 988 | * the process can at least talk to itself. |
| 989 | */ |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 990 | |
| 991 | pipe->readers++; |
| 992 | pipe->writers++; |
| 993 | pipe->r_counter++; |
| 994 | pipe->w_counter++; |
| 995 | if (pipe->readers == 1 || pipe->writers == 1) |
Al Viro | fc7478a | 2013-03-21 02:07:59 -0400 | [diff] [blame] | 996 | wake_up_partner(pipe); |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 997 | break; |
| 998 | |
| 999 | default: |
| 1000 | ret = -EINVAL; |
| 1001 | goto err; |
| 1002 | } |
| 1003 | |
| 1004 | /* Ok! */ |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 1005 | __pipe_unlock(pipe); |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 1006 | return 0; |
| 1007 | |
| 1008 | err_rd: |
| 1009 | if (!--pipe->readers) |
| 1010 | wake_up_interruptible(&pipe->wait); |
| 1011 | ret = -ERESTARTSYS; |
| 1012 | goto err; |
| 1013 | |
| 1014 | err_wr: |
| 1015 | if (!--pipe->writers) |
| 1016 | wake_up_interruptible(&pipe->wait); |
| 1017 | ret = -ERESTARTSYS; |
| 1018 | goto err; |
| 1019 | |
| 1020 | err: |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 1021 | __pipe_unlock(pipe); |
Linus Torvalds | b0d8d22 | 2013-12-02 09:44:51 -0800 | [diff] [blame] | 1022 | |
| 1023 | put_pipe_info(inode, pipe); |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 1024 | return ret; |
| 1025 | } |
| 1026 | |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 1027 | const struct file_operations pipefifo_fops = { |
| 1028 | .open = fifo_open, |
| 1029 | .llseek = no_llseek, |
Al Viro | fb9096a | 2014-04-02 19:56:54 -0400 | [diff] [blame] | 1030 | .read_iter = pipe_read, |
Al Viro | f0d1bec | 2014-04-03 15:05:18 -0400 | [diff] [blame] | 1031 | .write_iter = pipe_write, |
Al Viro | 599a0ac | 2013-03-12 09:58:10 -0400 | [diff] [blame] | 1032 | .poll = pipe_poll, |
| 1033 | .unlocked_ioctl = pipe_ioctl, |
| 1034 | .release = pipe_release, |
| 1035 | .fasync = pipe_fasync, |
Al Viro | f776c73 | 2013-03-12 09:46:27 -0400 | [diff] [blame] | 1036 | }; |
| 1037 | |
Ulrich Drepper | d35c7b0 | 2008-05-03 15:10:37 -0400 | [diff] [blame] | 1038 | /* |
Michael Kerrisk (man-pages) | f491bd7 | 2016-10-11 13:53:22 -0700 | [diff] [blame] | 1039 | * Currently we rely on the pipe array holding a power-of-2 number |
Joe Lawrence | 5b13f59 | 2017-11-17 15:29:21 -0800 | [diff] [blame] | 1040 | * of pages. Returns 0 on error. |
Michael Kerrisk (man-pages) | f491bd7 | 2016-10-11 13:53:22 -0700 | [diff] [blame] | 1041 | */ |
| 1042 | static inline unsigned int round_pipe_size(unsigned int size) |
| 1043 | { |
| 1044 | unsigned long nr_pages; |
| 1045 | |
Joe Lawrence | 5b13f59 | 2017-11-17 15:29:21 -0800 | [diff] [blame] | 1046 | if (size < pipe_min_size) |
| 1047 | size = pipe_min_size; |
| 1048 | |
Michael Kerrisk (man-pages) | f491bd7 | 2016-10-11 13:53:22 -0700 | [diff] [blame] | 1049 | nr_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; |
Joe Lawrence | 5b13f59 | 2017-11-17 15:29:21 -0800 | [diff] [blame] | 1050 | if (nr_pages == 0) |
| 1051 | return 0; |
| 1052 | |
Michael Kerrisk (man-pages) | f491bd7 | 2016-10-11 13:53:22 -0700 | [diff] [blame] | 1053 | return roundup_pow_of_two(nr_pages) << PAGE_SHIFT; |
| 1054 | } |
| 1055 | |
| 1056 | /* |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1057 | * Allocate a new array of pipe buffers and copy the info over. Returns the |
| 1058 | * pipe size if successful, or return -ERROR on error. |
| 1059 | */ |
Michael Kerrisk (man-pages) | d37d416 | 2016-10-11 13:53:25 -0700 | [diff] [blame] | 1060 | static long pipe_set_size(struct pipe_inode_info *pipe, unsigned long arg) |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1061 | { |
| 1062 | struct pipe_buffer *bufs; |
Michael Kerrisk (man-pages) | d37d416 | 2016-10-11 13:53:25 -0700 | [diff] [blame] | 1063 | unsigned int size, nr_pages; |
Michael Kerrisk (man-pages) | 9c87bcf | 2016-10-11 13:53:40 -0700 | [diff] [blame] | 1064 | unsigned long user_bufs; |
Michael Kerrisk (man-pages) | b0b91d1 | 2016-10-11 13:53:31 -0700 | [diff] [blame] | 1065 | long ret = 0; |
Michael Kerrisk (man-pages) | d37d416 | 2016-10-11 13:53:25 -0700 | [diff] [blame] | 1066 | |
| 1067 | size = round_pipe_size(arg); |
Joe Lawrence | 5b13f59 | 2017-11-17 15:29:21 -0800 | [diff] [blame] | 1068 | if (size == 0) |
| 1069 | return -EINVAL; |
Michael Kerrisk (man-pages) | d37d416 | 2016-10-11 13:53:25 -0700 | [diff] [blame] | 1070 | nr_pages = size >> PAGE_SHIFT; |
| 1071 | |
| 1072 | if (!nr_pages) |
| 1073 | return -EINVAL; |
| 1074 | |
Michael Kerrisk (man-pages) | b0b91d1 | 2016-10-11 13:53:31 -0700 | [diff] [blame] | 1075 | /* |
| 1076 | * If trying to increase the pipe capacity, check that an |
| 1077 | * unprivileged user is not trying to exceed various limits |
| 1078 | * (soft limit check here, hard limit check just below). |
| 1079 | * Decreasing the pipe capacity is always permitted, even |
| 1080 | * if the user is currently over a limit. |
| 1081 | */ |
| 1082 | if (nr_pages > pipe->buffers && |
| 1083 | size > pipe_max_size && !capable(CAP_SYS_RESOURCE)) |
Michael Kerrisk (man-pages) | d37d416 | 2016-10-11 13:53:25 -0700 | [diff] [blame] | 1084 | return -EPERM; |
| 1085 | |
Michael Kerrisk (man-pages) | 9c87bcf | 2016-10-11 13:53:40 -0700 | [diff] [blame] | 1086 | user_bufs = account_pipe_buffers(pipe->user, pipe->buffers, nr_pages); |
Michael Kerrisk (man-pages) | b0b91d1 | 2016-10-11 13:53:31 -0700 | [diff] [blame] | 1087 | |
| 1088 | if (nr_pages > pipe->buffers && |
Michael Kerrisk (man-pages) | 9c87bcf | 2016-10-11 13:53:40 -0700 | [diff] [blame] | 1089 | (too_many_pipe_buffers_hard(user_bufs) || |
| 1090 | too_many_pipe_buffers_soft(user_bufs)) && |
Eric Biggers | a705c24 | 2018-02-06 15:41:53 -0800 | [diff] [blame] | 1091 | is_unprivileged_user()) { |
Michael Kerrisk (man-pages) | b0b91d1 | 2016-10-11 13:53:31 -0700 | [diff] [blame] | 1092 | ret = -EPERM; |
| 1093 | goto out_revert_acct; |
| 1094 | } |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1095 | |
| 1096 | /* |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1097 | * We can shrink the pipe, if arg >= pipe->nrbufs. Since we don't |
| 1098 | * expect a lot of shrink+grow operations, just free and allocate |
| 1099 | * again like we would do for growing. If the pipe currently |
| 1100 | * contains more buffers than arg, then return busy. |
| 1101 | */ |
Michael Kerrisk (man-pages) | b0b91d1 | 2016-10-11 13:53:31 -0700 | [diff] [blame] | 1102 | if (nr_pages < pipe->nrbufs) { |
| 1103 | ret = -EBUSY; |
| 1104 | goto out_revert_acct; |
| 1105 | } |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1106 | |
Vladimir Davydov | d86133b | 2016-07-26 15:24:33 -0700 | [diff] [blame] | 1107 | bufs = kcalloc(nr_pages, sizeof(*bufs), |
| 1108 | GFP_KERNEL_ACCOUNT | __GFP_NOWARN); |
Michael Kerrisk (man-pages) | b0b91d1 | 2016-10-11 13:53:31 -0700 | [diff] [blame] | 1109 | if (unlikely(!bufs)) { |
| 1110 | ret = -ENOMEM; |
| 1111 | goto out_revert_acct; |
| 1112 | } |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1113 | |
| 1114 | /* |
| 1115 | * The pipe array wraps around, so just start the new one at zero |
| 1116 | * and adjust the indexes. |
| 1117 | */ |
| 1118 | if (pipe->nrbufs) { |
Miklos Szeredi | 1d862f4 | 2010-06-08 16:28:45 +0200 | [diff] [blame] | 1119 | unsigned int tail; |
| 1120 | unsigned int head; |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1121 | |
Miklos Szeredi | 1d862f4 | 2010-06-08 16:28:45 +0200 | [diff] [blame] | 1122 | tail = pipe->curbuf + pipe->nrbufs; |
| 1123 | if (tail < pipe->buffers) |
| 1124 | tail = 0; |
| 1125 | else |
| 1126 | tail &= (pipe->buffers - 1); |
| 1127 | |
| 1128 | head = pipe->nrbufs - tail; |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1129 | if (head) |
| 1130 | memcpy(bufs, pipe->bufs + pipe->curbuf, head * sizeof(struct pipe_buffer)); |
| 1131 | if (tail) |
Miklos Szeredi | 1d862f4 | 2010-06-08 16:28:45 +0200 | [diff] [blame] | 1132 | memcpy(bufs + head, pipe->bufs, tail * sizeof(struct pipe_buffer)); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1133 | } |
| 1134 | |
| 1135 | pipe->curbuf = 0; |
| 1136 | kfree(pipe->bufs); |
| 1137 | pipe->bufs = bufs; |
Jens Axboe | b9598db | 2010-05-24 19:34:43 +0200 | [diff] [blame] | 1138 | pipe->buffers = nr_pages; |
| 1139 | return nr_pages * PAGE_SIZE; |
Michael Kerrisk (man-pages) | b0b91d1 | 2016-10-11 13:53:31 -0700 | [diff] [blame] | 1140 | |
| 1141 | out_revert_acct: |
Michael Kerrisk (man-pages) | 9c87bcf | 2016-10-11 13:53:40 -0700 | [diff] [blame] | 1142 | (void) account_pipe_buffers(pipe->user, nr_pages, pipe->buffers); |
Michael Kerrisk (man-pages) | b0b91d1 | 2016-10-11 13:53:31 -0700 | [diff] [blame] | 1143 | return ret; |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1144 | } |
| 1145 | |
Jens Axboe | ff9da69 | 2010-06-03 14:54:39 +0200 | [diff] [blame] | 1146 | /* |
Jens Axboe | ff9da69 | 2010-06-03 14:54:39 +0200 | [diff] [blame] | 1147 | * This should work even if CONFIG_PROC_FS isn't set, as proc_dointvec_minmax |
| 1148 | * will return an error. |
| 1149 | */ |
| 1150 | int pipe_proc_fn(struct ctl_table *table, int write, void __user *buf, |
| 1151 | size_t *lenp, loff_t *ppos) |
| 1152 | { |
Joe Lawrence | 5b13f59 | 2017-11-17 15:29:21 -0800 | [diff] [blame] | 1153 | unsigned int rounded_pipe_max_size; |
Jens Axboe | ff9da69 | 2010-06-03 14:54:39 +0200 | [diff] [blame] | 1154 | int ret; |
| 1155 | |
| 1156 | ret = proc_dointvec_minmax(table, write, buf, lenp, ppos); |
| 1157 | if (ret < 0 || !write) |
| 1158 | return ret; |
| 1159 | |
Joe Lawrence | 5b13f59 | 2017-11-17 15:29:21 -0800 | [diff] [blame] | 1160 | rounded_pipe_max_size = round_pipe_size(pipe_max_size); |
| 1161 | if (rounded_pipe_max_size == 0) |
| 1162 | return -EINVAL; |
| 1163 | |
| 1164 | pipe_max_size = rounded_pipe_max_size; |
Jens Axboe | ff9da69 | 2010-06-03 14:54:39 +0200 | [diff] [blame] | 1165 | return ret; |
| 1166 | } |
| 1167 | |
Linus Torvalds | 7208364 | 2010-11-28 16:27:19 -0800 | [diff] [blame] | 1168 | /* |
| 1169 | * After the inode slimming patch, i_pipe/i_bdev/i_cdev share the same |
| 1170 | * location, so checking ->i_pipe is not enough to verify that this is a |
| 1171 | * pipe. |
| 1172 | */ |
| 1173 | struct pipe_inode_info *get_pipe_info(struct file *file) |
| 1174 | { |
Al Viro | de32ec4 | 2013-03-21 11:16:56 -0400 | [diff] [blame] | 1175 | return file->f_op == &pipefifo_fops ? file->private_data : NULL; |
Linus Torvalds | 7208364 | 2010-11-28 16:27:19 -0800 | [diff] [blame] | 1176 | } |
| 1177 | |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1178 | long pipe_fcntl(struct file *file, unsigned int cmd, unsigned long arg) |
| 1179 | { |
| 1180 | struct pipe_inode_info *pipe; |
| 1181 | long ret; |
| 1182 | |
Linus Torvalds | c66fb34 | 2010-11-28 14:09:57 -0800 | [diff] [blame] | 1183 | pipe = get_pipe_info(file); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1184 | if (!pipe) |
| 1185 | return -EBADF; |
| 1186 | |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 1187 | __pipe_lock(pipe); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1188 | |
| 1189 | switch (cmd) { |
Michael Kerrisk (man-pages) | d37d416 | 2016-10-11 13:53:25 -0700 | [diff] [blame] | 1190 | case F_SETPIPE_SZ: |
| 1191 | ret = pipe_set_size(pipe, arg); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1192 | break; |
| 1193 | case F_GETPIPE_SZ: |
Jens Axboe | b9598db | 2010-05-24 19:34:43 +0200 | [diff] [blame] | 1194 | ret = pipe->buffers * PAGE_SIZE; |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1195 | break; |
| 1196 | default: |
| 1197 | ret = -EINVAL; |
| 1198 | break; |
| 1199 | } |
| 1200 | |
Al Viro | ebec73f | 2013-03-21 12:24:01 -0400 | [diff] [blame] | 1201 | __pipe_unlock(pipe); |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1202 | return ret; |
| 1203 | } |
| 1204 | |
Nick Piggin | ff0c7d1 | 2011-01-07 17:49:50 +1100 | [diff] [blame] | 1205 | static const struct super_operations pipefs_ops = { |
| 1206 | .destroy_inode = free_inode_nonrcu, |
Pavel Emelyanov | d70ef97 | 2011-10-31 17:10:04 -0700 | [diff] [blame] | 1207 | .statfs = simple_statfs, |
Nick Piggin | ff0c7d1 | 2011-01-07 17:49:50 +1100 | [diff] [blame] | 1208 | }; |
| 1209 | |
Jens Axboe | 35f3d14 | 2010-05-20 10:43:18 +0200 | [diff] [blame] | 1210 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1211 | * pipefs should _never_ be mounted by userland - too much of security hassle, |
| 1212 | * no real gain from having the whole whorehouse mounted. So we don't need |
| 1213 | * any operations on the root directory. However, we need a non-trivial |
| 1214 | * d_name - pipe: will go nicely and kill the special-casing in procfs. |
| 1215 | */ |
Al Viro | 51139ad | 2010-07-25 23:47:46 +0400 | [diff] [blame] | 1216 | static struct dentry *pipefs_mount(struct file_system_type *fs_type, |
| 1217 | int flags, const char *dev_name, void *data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1218 | { |
Al Viro | c74a1cb | 2011-01-12 16:59:34 -0500 | [diff] [blame] | 1219 | return mount_pseudo(fs_type, "pipe:", &pipefs_ops, |
| 1220 | &pipefs_dentry_operations, PIPEFS_MAGIC); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1221 | } |
| 1222 | |
| 1223 | static struct file_system_type pipe_fs_type = { |
| 1224 | .name = "pipefs", |
Al Viro | 51139ad | 2010-07-25 23:47:46 +0400 | [diff] [blame] | 1225 | .mount = pipefs_mount, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1226 | .kill_sb = kill_anon_super, |
| 1227 | }; |
| 1228 | |
| 1229 | static int __init init_pipe_fs(void) |
| 1230 | { |
| 1231 | int err = register_filesystem(&pipe_fs_type); |
Ingo Molnar | 341b446 | 2006-04-11 13:57:45 +0200 | [diff] [blame] | 1232 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1233 | if (!err) { |
| 1234 | pipe_mnt = kern_mount(&pipe_fs_type); |
| 1235 | if (IS_ERR(pipe_mnt)) { |
| 1236 | err = PTR_ERR(pipe_mnt); |
| 1237 | unregister_filesystem(&pipe_fs_type); |
| 1238 | } |
| 1239 | } |
| 1240 | return err; |
| 1241 | } |
| 1242 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1243 | fs_initcall(init_pipe_fs); |