1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * file.c - part of debugfs, a tiny little debug file system 4 * 5 * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com> 6 * Copyright (C) 2004 IBM Inc. 7 * 8 * debugfs is for people to use instead of /proc or /sys. 9 * See Documentation/filesystems/ for more details. 10 */ 11 12 #include <linux/module.h> 13 #include <linux/fs.h> 14 #include <linux/seq_file.h> 15 #include <linux/pagemap.h> 16 #include <linux/debugfs.h> 17 #include <linux/io.h> 18 #include <linux/slab.h> 19 #include <linux/atomic.h> 20 #include <linux/device.h> 21 #include <linux/pm_runtime.h> 22 #include <linux/poll.h> 23 #include <linux/security.h> 24 25 #include "internal.h" 26 27 struct poll_table_struct; 28 29 static ssize_t default_read_file(struct file *file, char __user *buf, 30 size_t count, loff_t *ppos) 31 { 32 return 0; 33 } 34 35 static ssize_t default_write_file(struct file *file, const char __user *buf, 36 size_t count, loff_t *ppos) 37 { 38 return count; 39 } 40 41 const struct file_operations debugfs_noop_file_operations = { 42 .read = default_read_file, 43 .write = default_write_file, 44 .open = simple_open, 45 .llseek = noop_llseek, 46 }; 47 48 #define F_DENTRY(filp) ((filp)->f_path.dentry) 49 50 const struct file_operations *debugfs_real_fops(const struct file *filp) 51 { 52 struct debugfs_fsdata *fsd = F_DENTRY(filp)->d_fsdata; 53 54 if ((unsigned long)fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT) { 55 /* 56 * Urgh, we've been called w/o a protecting 57 * debugfs_file_get(). 58 */ 59 WARN_ON(1); 60 return NULL; 61 } 62 63 return fsd->real_fops; 64 } 65 EXPORT_SYMBOL_GPL(debugfs_real_fops); 66 67 /** 68 * debugfs_file_get - mark the beginning of file data access 69 * @dentry: the dentry object whose data is being accessed. 70 * 71 * Up to a matching call to debugfs_file_put(), any successive call 72 * into the file removing functions debugfs_remove() and 73 * debugfs_remove_recursive() will block. Since associated private 74 * file data may only get freed after a successful return of any of 75 * the removal functions, you may safely access it after a successful 76 * call to debugfs_file_get() without worrying about lifetime issues. 77 * 78 * If -%EIO is returned, the file has already been removed and thus, 79 * it is not safe to access any of its data. If, on the other hand, 80 * it is allowed to access the file data, zero is returned. 81 */ 82 int debugfs_file_get(struct dentry *dentry) 83 { 84 struct debugfs_fsdata *fsd; 85 void *d_fsd; 86 87 /* 88 * This could only happen if some debugfs user erroneously calls 89 * debugfs_file_get() on a dentry that isn't even a file, let 90 * them know about it. 91 */ 92 if (WARN_ON(!d_is_reg(dentry))) 93 return -EINVAL; 94 95 d_fsd = READ_ONCE(dentry->d_fsdata); 96 if (!((unsigned long)d_fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT)) { 97 fsd = d_fsd; 98 } else { 99 fsd = kmalloc(sizeof(*fsd), GFP_KERNEL); 100 if (!fsd) 101 return -ENOMEM; 102 103 if ((unsigned long)d_fsd & DEBUGFS_FSDATA_IS_SHORT_FOPS_BIT) { 104 fsd->real_fops = NULL; 105 fsd->short_fops = (void *)((unsigned long)d_fsd & 106 ~(DEBUGFS_FSDATA_IS_REAL_FOPS_BIT | 107 DEBUGFS_FSDATA_IS_SHORT_FOPS_BIT)); 108 } else { 109 fsd->real_fops = (void *)((unsigned long)d_fsd & 110 ~DEBUGFS_FSDATA_IS_REAL_FOPS_BIT); 111 fsd->short_fops = NULL; 112 } 113 refcount_set(&fsd->active_users, 1); 114 init_completion(&fsd->active_users_drained); 115 INIT_LIST_HEAD(&fsd->cancellations); 116 mutex_init(&fsd->cancellations_mtx); 117 118 if (cmpxchg(&dentry->d_fsdata, d_fsd, fsd) != d_fsd) { 119 mutex_destroy(&fsd->cancellations_mtx); 120 kfree(fsd); 121 fsd = READ_ONCE(dentry->d_fsdata); 122 } 123 } 124 125 /* 126 * In case of a successful cmpxchg() above, this check is 127 * strictly necessary and must follow it, see the comment in 128 * __debugfs_remove_file(). 129 * OTOH, if the cmpxchg() hasn't been executed or wasn't 130 * successful, this serves the purpose of not starving 131 * removers. 132 */ 133 if (d_unlinked(dentry)) 134 return -EIO; 135 136 if (!refcount_inc_not_zero(&fsd->active_users)) 137 return -EIO; 138 139 return 0; 140 } 141 EXPORT_SYMBOL_GPL(debugfs_file_get); 142 143 /** 144 * debugfs_file_put - mark the end of file data access 145 * @dentry: the dentry object formerly passed to 146 * debugfs_file_get(). 147 * 148 * Allow any ongoing concurrent call into debugfs_remove() or 149 * debugfs_remove_recursive() blocked by a former call to 150 * debugfs_file_get() to proceed and return to its caller. 151 */ 152 void debugfs_file_put(struct dentry *dentry) 153 { 154 struct debugfs_fsdata *fsd = READ_ONCE(dentry->d_fsdata); 155 156 if (refcount_dec_and_test(&fsd->active_users)) 157 complete(&fsd->active_users_drained); 158 } 159 EXPORT_SYMBOL_GPL(debugfs_file_put); 160 161 /** 162 * debugfs_enter_cancellation - enter a debugfs cancellation 163 * @file: the file being accessed 164 * @cancellation: the cancellation object, the cancel callback 165 * inside of it must be initialized 166 * 167 * When a debugfs file is removed it needs to wait for all active 168 * operations to complete. However, the operation itself may need 169 * to wait for hardware or completion of some asynchronous process 170 * or similar. As such, it may need to be cancelled to avoid long 171 * waits or even deadlocks. 172 * 173 * This function can be used inside a debugfs handler that may 174 * need to be cancelled. As soon as this function is called, the 175 * cancellation's 'cancel' callback may be called, at which point 176 * the caller should proceed to call debugfs_leave_cancellation() 177 * and leave the debugfs handler function as soon as possible. 178 * Note that the 'cancel' callback is only ever called in the 179 * context of some kind of debugfs_remove(). 180 * 181 * This function must be paired with debugfs_leave_cancellation(). 182 */ 183 void debugfs_enter_cancellation(struct file *file, 184 struct debugfs_cancellation *cancellation) 185 { 186 struct debugfs_fsdata *fsd; 187 struct dentry *dentry = F_DENTRY(file); 188 189 INIT_LIST_HEAD(&cancellation->list); 190 191 if (WARN_ON(!d_is_reg(dentry))) 192 return; 193 194 if (WARN_ON(!cancellation->cancel)) 195 return; 196 197 fsd = READ_ONCE(dentry->d_fsdata); 198 if (WARN_ON(!fsd || 199 ((unsigned long)fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT))) 200 return; 201 202 mutex_lock(&fsd->cancellations_mtx); 203 list_add(&cancellation->list, &fsd->cancellations); 204 mutex_unlock(&fsd->cancellations_mtx); 205 206 /* if we're already removing wake it up to cancel */ 207 if (d_unlinked(dentry)) 208 complete(&fsd->active_users_drained); 209 } 210 EXPORT_SYMBOL_GPL(debugfs_enter_cancellation); 211 212 /** 213 * debugfs_leave_cancellation - leave cancellation section 214 * @file: the file being accessed 215 * @cancellation: the cancellation previously registered with 216 * debugfs_enter_cancellation() 217 * 218 * See the documentation of debugfs_enter_cancellation(). 219 */ 220 void debugfs_leave_cancellation(struct file *file, 221 struct debugfs_cancellation *cancellation) 222 { 223 struct debugfs_fsdata *fsd; 224 struct dentry *dentry = F_DENTRY(file); 225 226 if (WARN_ON(!d_is_reg(dentry))) 227 return; 228 229 fsd = READ_ONCE(dentry->d_fsdata); 230 if (WARN_ON(!fsd || 231 ((unsigned long)fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT))) 232 return; 233 234 mutex_lock(&fsd->cancellations_mtx); 235 if (!list_empty(&cancellation->list)) 236 list_del(&cancellation->list); 237 mutex_unlock(&fsd->cancellations_mtx); 238 } 239 EXPORT_SYMBOL_GPL(debugfs_leave_cancellation); 240 241 /* 242 * Only permit access to world-readable files when the kernel is locked down. 243 * We also need to exclude any file that has ways to write or alter it as root 244 * can bypass the permissions check. 245 */ 246 static int debugfs_locked_down(struct inode *inode, 247 struct file *filp, 248 const struct file_operations *real_fops) 249 { 250 if ((inode->i_mode & 07777 & ~0444) == 0 && 251 !(filp->f_mode & FMODE_WRITE) && 252 (!real_fops || 253 (!real_fops->unlocked_ioctl && 254 !real_fops->compat_ioctl && 255 !real_fops->mmap))) 256 return 0; 257 258 if (security_locked_down(LOCKDOWN_DEBUGFS)) 259 return -EPERM; 260 261 return 0; 262 } 263 264 static int open_proxy_open(struct inode *inode, struct file *filp) 265 { 266 struct dentry *dentry = F_DENTRY(filp); 267 const struct file_operations *real_fops = NULL; 268 int r; 269 270 r = debugfs_file_get(dentry); 271 if (r) 272 return r == -EIO ? -ENOENT : r; 273 274 real_fops = debugfs_real_fops(filp); 275 276 r = debugfs_locked_down(inode, filp, real_fops); 277 if (r) 278 goto out; 279 280 if (!fops_get(real_fops)) { 281 #ifdef CONFIG_MODULES 282 if (real_fops->owner && 283 real_fops->owner->state == MODULE_STATE_GOING) { 284 r = -ENXIO; 285 goto out; 286 } 287 #endif 288 289 /* Huh? Module did not clean up after itself at exit? */ 290 WARN(1, "debugfs file owner did not clean up at exit: %pd", 291 dentry); 292 r = -ENXIO; 293 goto out; 294 } 295 replace_fops(filp, real_fops); 296 297 if (real_fops->open) 298 r = real_fops->open(inode, filp); 299 300 out: 301 debugfs_file_put(dentry); 302 return r; 303 } 304 305 const struct file_operations debugfs_open_proxy_file_operations = { 306 .open = open_proxy_open, 307 }; 308 309 #define PROTO(args...) args 310 #define ARGS(args...) args 311 312 #define FULL_PROXY_FUNC(name, ret_type, filp, proto, args) \ 313 static ret_type full_proxy_ ## name(proto) \ 314 { \ 315 struct dentry *dentry = F_DENTRY(filp); \ 316 const struct file_operations *real_fops; \ 317 ret_type r; \ 318 \ 319 r = debugfs_file_get(dentry); \ 320 if (unlikely(r)) \ 321 return r; \ 322 real_fops = debugfs_real_fops(filp); \ 323 r = real_fops->name(args); \ 324 debugfs_file_put(dentry); \ 325 return r; \ 326 } 327 328 #define FULL_PROXY_FUNC_BOTH(name, ret_type, filp, proto, args) \ 329 static ret_type full_proxy_ ## name(proto) \ 330 { \ 331 struct dentry *dentry = F_DENTRY(filp); \ 332 struct debugfs_fsdata *fsd; \ 333 ret_type r; \ 334 \ 335 r = debugfs_file_get(dentry); \ 336 if (unlikely(r)) \ 337 return r; \ 338 fsd = dentry->d_fsdata; \ 339 if (fsd->real_fops) \ 340 r = fsd->real_fops->name(args); \ 341 else \ 342 r = fsd->short_fops->name(args); \ 343 debugfs_file_put(dentry); \ 344 return r; \ 345 } 346 347 FULL_PROXY_FUNC_BOTH(llseek, loff_t, filp, 348 PROTO(struct file *filp, loff_t offset, int whence), 349 ARGS(filp, offset, whence)); 350 351 FULL_PROXY_FUNC_BOTH(read, ssize_t, filp, 352 PROTO(struct file *filp, char __user *buf, size_t size, 353 loff_t *ppos), 354 ARGS(filp, buf, size, ppos)); 355 356 FULL_PROXY_FUNC_BOTH(write, ssize_t, filp, 357 PROTO(struct file *filp, const char __user *buf, 358 size_t size, loff_t *ppos), 359 ARGS(filp, buf, size, ppos)); 360 361 FULL_PROXY_FUNC(unlocked_ioctl, long, filp, 362 PROTO(struct file *filp, unsigned int cmd, unsigned long arg), 363 ARGS(filp, cmd, arg)); 364 365 static __poll_t full_proxy_poll(struct file *filp, 366 struct poll_table_struct *wait) 367 { 368 struct dentry *dentry = F_DENTRY(filp); 369 __poll_t r = 0; 370 const struct file_operations *real_fops; 371 372 if (debugfs_file_get(dentry)) 373 return EPOLLHUP; 374 375 real_fops = debugfs_real_fops(filp); 376 r = real_fops->poll(filp, wait); 377 debugfs_file_put(dentry); 378 return r; 379 } 380 381 static int full_proxy_release(struct inode *inode, struct file *filp) 382 { 383 const struct dentry *dentry = F_DENTRY(filp); 384 const struct file_operations *real_fops = debugfs_real_fops(filp); 385 const struct file_operations *proxy_fops = filp->f_op; 386 int r = 0; 387 388 /* 389 * We must not protect this against removal races here: the 390 * original releaser should be called unconditionally in order 391 * not to leak any resources. Releasers must not assume that 392 * ->i_private is still being meaningful here. 393 */ 394 if (real_fops && real_fops->release) 395 r = real_fops->release(inode, filp); 396 397 replace_fops(filp, d_inode(dentry)->i_fop); 398 kfree(proxy_fops); 399 fops_put(real_fops); 400 return r; 401 } 402 403 static void __full_proxy_fops_init(struct file_operations *proxy_fops, 404 struct debugfs_fsdata *fsd) 405 { 406 proxy_fops->release = full_proxy_release; 407 408 if ((fsd->real_fops && fsd->real_fops->llseek) || 409 (fsd->short_fops && fsd->short_fops->llseek)) 410 proxy_fops->llseek = full_proxy_llseek; 411 412 if ((fsd->real_fops && fsd->real_fops->read) || 413 (fsd->short_fops && fsd->short_fops->read)) 414 proxy_fops->read = full_proxy_read; 415 416 if ((fsd->real_fops && fsd->real_fops->write) || 417 (fsd->short_fops && fsd->short_fops->write)) 418 proxy_fops->write = full_proxy_write; 419 420 if (fsd->real_fops && fsd->real_fops->poll) 421 proxy_fops->poll = full_proxy_poll; 422 423 if (fsd->real_fops && fsd->real_fops->unlocked_ioctl) 424 proxy_fops->unlocked_ioctl = full_proxy_unlocked_ioctl; 425 } 426 427 static int full_proxy_open(struct inode *inode, struct file *filp) 428 { 429 struct dentry *dentry = F_DENTRY(filp); 430 const struct file_operations *real_fops; 431 struct file_operations *proxy_fops = NULL; 432 struct debugfs_fsdata *fsd; 433 int r; 434 435 r = debugfs_file_get(dentry); 436 if (r) 437 return r == -EIO ? -ENOENT : r; 438 439 fsd = dentry->d_fsdata; 440 real_fops = fsd->real_fops; 441 r = debugfs_locked_down(inode, filp, real_fops); 442 if (r) 443 goto out; 444 445 if (real_fops && !fops_get(real_fops)) { 446 #ifdef CONFIG_MODULES 447 if (real_fops->owner && 448 real_fops->owner->state == MODULE_STATE_GOING) { 449 r = -ENXIO; 450 goto out; 451 } 452 #endif 453 454 /* Huh? Module did not cleanup after itself at exit? */ 455 WARN(1, "debugfs file owner did not clean up at exit: %pd", 456 dentry); 457 r = -ENXIO; 458 goto out; 459 } 460 461 proxy_fops = kzalloc(sizeof(*proxy_fops), GFP_KERNEL); 462 if (!proxy_fops) { 463 r = -ENOMEM; 464 goto free_proxy; 465 } 466 __full_proxy_fops_init(proxy_fops, fsd); 467 replace_fops(filp, proxy_fops); 468 469 if (!real_fops || real_fops->open) { 470 if (real_fops) 471 r = real_fops->open(inode, filp); 472 else 473 r = simple_open(inode, filp); 474 if (r) { 475 replace_fops(filp, d_inode(dentry)->i_fop); 476 goto free_proxy; 477 } else if (filp->f_op != proxy_fops) { 478 /* No protection against file removal anymore. */ 479 WARN(1, "debugfs file owner replaced proxy fops: %pd", 480 dentry); 481 goto free_proxy; 482 } 483 } 484 485 goto out; 486 free_proxy: 487 kfree(proxy_fops); 488 fops_put(real_fops); 489 out: 490 debugfs_file_put(dentry); 491 return r; 492 } 493 494 const struct file_operations debugfs_full_proxy_file_operations = { 495 .open = full_proxy_open, 496 }; 497 498 ssize_t debugfs_attr_read(struct file *file, char __user *buf, 499 size_t len, loff_t *ppos) 500 { 501 struct dentry *dentry = F_DENTRY(file); 502 ssize_t ret; 503 504 ret = debugfs_file_get(dentry); 505 if (unlikely(ret)) 506 return ret; 507 ret = simple_attr_read(file, buf, len, ppos); 508 debugfs_file_put(dentry); 509 return ret; 510 } 511 EXPORT_SYMBOL_GPL(debugfs_attr_read); 512 513 static ssize_t debugfs_attr_write_xsigned(struct file *file, const char __user *buf, 514 size_t len, loff_t *ppos, bool is_signed) 515 { 516 struct dentry *dentry = F_DENTRY(file); 517 ssize_t ret; 518 519 ret = debugfs_file_get(dentry); 520 if (unlikely(ret)) 521 return ret; 522 if (is_signed) 523 ret = simple_attr_write_signed(file, buf, len, ppos); 524 else 525 ret = simple_attr_write(file, buf, len, ppos); 526 debugfs_file_put(dentry); 527 return ret; 528 } 529 530 ssize_t debugfs_attr_write(struct file *file, const char __user *buf, 531 size_t len, loff_t *ppos) 532 { 533 return debugfs_attr_write_xsigned(file, buf, len, ppos, false); 534 } 535 EXPORT_SYMBOL_GPL(debugfs_attr_write); 536 537 ssize_t debugfs_attr_write_signed(struct file *file, const char __user *buf, 538 size_t len, loff_t *ppos) 539 { 540 return debugfs_attr_write_xsigned(file, buf, len, ppos, true); 541 } 542 EXPORT_SYMBOL_GPL(debugfs_attr_write_signed); 543 544 static struct dentry *debugfs_create_mode_unsafe(const char *name, umode_t mode, 545 struct dentry *parent, void *value, 546 const struct file_operations *fops, 547 const struct file_operations *fops_ro, 548 const struct file_operations *fops_wo) 549 { 550 /* if there are no write bits set, make read only */ 551 if (!(mode & S_IWUGO)) 552 return debugfs_create_file_unsafe(name, mode, parent, value, 553 fops_ro); 554 /* if there are no read bits set, make write only */ 555 if (!(mode & S_IRUGO)) 556 return debugfs_create_file_unsafe(name, mode, parent, value, 557 fops_wo); 558 559 return debugfs_create_file_unsafe(name, mode, parent, value, fops); 560 } 561 562 static int debugfs_u8_set(void *data, u64 val) 563 { 564 *(u8 *)data = val; 565 return 0; 566 } 567 static int debugfs_u8_get(void *data, u64 *val) 568 { 569 *val = *(u8 *)data; 570 return 0; 571 } 572 DEFINE_DEBUGFS_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%llu\n"); 573 DEFINE_DEBUGFS_ATTRIBUTE(fops_u8_ro, debugfs_u8_get, NULL, "%llu\n"); 574 DEFINE_DEBUGFS_ATTRIBUTE(fops_u8_wo, NULL, debugfs_u8_set, "%llu\n"); 575 576 /** 577 * debugfs_create_u8 - create a debugfs file that is used to read and write an unsigned 8-bit value 578 * @name: a pointer to a string containing the name of the file to create. 579 * @mode: the permission that the file should have 580 * @parent: a pointer to the parent dentry for this file. This should be a 581 * directory dentry if set. If this parameter is %NULL, then the 582 * file will be created in the root of the debugfs filesystem. 583 * @value: a pointer to the variable that the file should read to and write 584 * from. 585 * 586 * This function creates a file in debugfs with the given name that 587 * contains the value of the variable @value. If the @mode variable is so 588 * set, it can be read from, and written to. 589 */ 590 void debugfs_create_u8(const char *name, umode_t mode, struct dentry *parent, 591 u8 *value) 592 { 593 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u8, 594 &fops_u8_ro, &fops_u8_wo); 595 } 596 EXPORT_SYMBOL_GPL(debugfs_create_u8); 597 598 static int debugfs_u16_set(void *data, u64 val) 599 { 600 *(u16 *)data = val; 601 return 0; 602 } 603 static int debugfs_u16_get(void *data, u64 *val) 604 { 605 *val = *(u16 *)data; 606 return 0; 607 } 608 DEFINE_DEBUGFS_ATTRIBUTE(fops_u16, debugfs_u16_get, debugfs_u16_set, "%llu\n"); 609 DEFINE_DEBUGFS_ATTRIBUTE(fops_u16_ro, debugfs_u16_get, NULL, "%llu\n"); 610 DEFINE_DEBUGFS_ATTRIBUTE(fops_u16_wo, NULL, debugfs_u16_set, "%llu\n"); 611 612 /** 613 * debugfs_create_u16 - create a debugfs file that is used to read and write an unsigned 16-bit value 614 * @name: a pointer to a string containing the name of the file to create. 615 * @mode: the permission that the file should have 616 * @parent: a pointer to the parent dentry for this file. This should be a 617 * directory dentry if set. If this parameter is %NULL, then the 618 * file will be created in the root of the debugfs filesystem. 619 * @value: a pointer to the variable that the file should read to and write 620 * from. 621 * 622 * This function creates a file in debugfs with the given name that 623 * contains the value of the variable @value. If the @mode variable is so 624 * set, it can be read from, and written to. 625 */ 626 void debugfs_create_u16(const char *name, umode_t mode, struct dentry *parent, 627 u16 *value) 628 { 629 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u16, 630 &fops_u16_ro, &fops_u16_wo); 631 } 632 EXPORT_SYMBOL_GPL(debugfs_create_u16); 633 634 static int debugfs_u32_set(void *data, u64 val) 635 { 636 *(u32 *)data = val; 637 return 0; 638 } 639 static int debugfs_u32_get(void *data, u64 *val) 640 { 641 *val = *(u32 *)data; 642 return 0; 643 } 644 DEFINE_DEBUGFS_ATTRIBUTE(fops_u32, debugfs_u32_get, debugfs_u32_set, "%llu\n"); 645 DEFINE_DEBUGFS_ATTRIBUTE(fops_u32_ro, debugfs_u32_get, NULL, "%llu\n"); 646 DEFINE_DEBUGFS_ATTRIBUTE(fops_u32_wo, NULL, debugfs_u32_set, "%llu\n"); 647 648 /** 649 * debugfs_create_u32 - create a debugfs file that is used to read and write an unsigned 32-bit value 650 * @name: a pointer to a string containing the name of the file to create. 651 * @mode: the permission that the file should have 652 * @parent: a pointer to the parent dentry for this file. This should be a 653 * directory dentry if set. If this parameter is %NULL, then the 654 * file will be created in the root of the debugfs filesystem. 655 * @value: a pointer to the variable that the file should read to and write 656 * from. 657 * 658 * This function creates a file in debugfs with the given name that 659 * contains the value of the variable @value. If the @mode variable is so 660 * set, it can be read from, and written to. 661 */ 662 void debugfs_create_u32(const char *name, umode_t mode, struct dentry *parent, 663 u32 *value) 664 { 665 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u32, 666 &fops_u32_ro, &fops_u32_wo); 667 } 668 EXPORT_SYMBOL_GPL(debugfs_create_u32); 669 670 static int debugfs_u64_set(void *data, u64 val) 671 { 672 *(u64 *)data = val; 673 return 0; 674 } 675 676 static int debugfs_u64_get(void *data, u64 *val) 677 { 678 *val = *(u64 *)data; 679 return 0; 680 } 681 DEFINE_DEBUGFS_ATTRIBUTE(fops_u64, debugfs_u64_get, debugfs_u64_set, "%llu\n"); 682 DEFINE_DEBUGFS_ATTRIBUTE(fops_u64_ro, debugfs_u64_get, NULL, "%llu\n"); 683 DEFINE_DEBUGFS_ATTRIBUTE(fops_u64_wo, NULL, debugfs_u64_set, "%llu\n"); 684 685 /** 686 * debugfs_create_u64 - create a debugfs file that is used to read and write an unsigned 64-bit value 687 * @name: a pointer to a string containing the name of the file to create. 688 * @mode: the permission that the file should have 689 * @parent: a pointer to the parent dentry for this file. This should be a 690 * directory dentry if set. If this parameter is %NULL, then the 691 * file will be created in the root of the debugfs filesystem. 692 * @value: a pointer to the variable that the file should read to and write 693 * from. 694 * 695 * This function creates a file in debugfs with the given name that 696 * contains the value of the variable @value. If the @mode variable is so 697 * set, it can be read from, and written to. 698 */ 699 void debugfs_create_u64(const char *name, umode_t mode, struct dentry *parent, 700 u64 *value) 701 { 702 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u64, 703 &fops_u64_ro, &fops_u64_wo); 704 } 705 EXPORT_SYMBOL_GPL(debugfs_create_u64); 706 707 static int debugfs_ulong_set(void *data, u64 val) 708 { 709 *(unsigned long *)data = val; 710 return 0; 711 } 712 713 static int debugfs_ulong_get(void *data, u64 *val) 714 { 715 *val = *(unsigned long *)data; 716 return 0; 717 } 718 DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong, debugfs_ulong_get, debugfs_ulong_set, 719 "%llu\n"); 720 DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong_ro, debugfs_ulong_get, NULL, "%llu\n"); 721 DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong_wo, NULL, debugfs_ulong_set, "%llu\n"); 722 723 /** 724 * debugfs_create_ulong - create a debugfs file that is used to read and write 725 * an unsigned long value. 726 * @name: a pointer to a string containing the name of the file to create. 727 * @mode: the permission that the file should have 728 * @parent: a pointer to the parent dentry for this file. This should be a 729 * directory dentry if set. If this parameter is %NULL, then the 730 * file will be created in the root of the debugfs filesystem. 731 * @value: a pointer to the variable that the file should read to and write 732 * from. 733 * 734 * This function creates a file in debugfs with the given name that 735 * contains the value of the variable @value. If the @mode variable is so 736 * set, it can be read from, and written to. 737 */ 738 void debugfs_create_ulong(const char *name, umode_t mode, struct dentry *parent, 739 unsigned long *value) 740 { 741 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_ulong, 742 &fops_ulong_ro, &fops_ulong_wo); 743 } 744 EXPORT_SYMBOL_GPL(debugfs_create_ulong); 745 746 DEFINE_DEBUGFS_ATTRIBUTE(fops_x8, debugfs_u8_get, debugfs_u8_set, "0x%02llx\n"); 747 DEFINE_DEBUGFS_ATTRIBUTE(fops_x8_ro, debugfs_u8_get, NULL, "0x%02llx\n"); 748 DEFINE_DEBUGFS_ATTRIBUTE(fops_x8_wo, NULL, debugfs_u8_set, "0x%02llx\n"); 749 750 DEFINE_DEBUGFS_ATTRIBUTE(fops_x16, debugfs_u16_get, debugfs_u16_set, 751 "0x%04llx\n"); 752 DEFINE_DEBUGFS_ATTRIBUTE(fops_x16_ro, debugfs_u16_get, NULL, "0x%04llx\n"); 753 DEFINE_DEBUGFS_ATTRIBUTE(fops_x16_wo, NULL, debugfs_u16_set, "0x%04llx\n"); 754 755 DEFINE_DEBUGFS_ATTRIBUTE(fops_x32, debugfs_u32_get, debugfs_u32_set, 756 "0x%08llx\n"); 757 DEFINE_DEBUGFS_ATTRIBUTE(fops_x32_ro, debugfs_u32_get, NULL, "0x%08llx\n"); 758 DEFINE_DEBUGFS_ATTRIBUTE(fops_x32_wo, NULL, debugfs_u32_set, "0x%08llx\n"); 759 760 DEFINE_DEBUGFS_ATTRIBUTE(fops_x64, debugfs_u64_get, debugfs_u64_set, 761 "0x%016llx\n"); 762 DEFINE_DEBUGFS_ATTRIBUTE(fops_x64_ro, debugfs_u64_get, NULL, "0x%016llx\n"); 763 DEFINE_DEBUGFS_ATTRIBUTE(fops_x64_wo, NULL, debugfs_u64_set, "0x%016llx\n"); 764 765 /* 766 * debugfs_create_x{8,16,32,64} - create a debugfs file that is used to read and write an unsigned {8,16,32,64}-bit value 767 * 768 * These functions are exactly the same as the above functions (but use a hex 769 * output for the decimal challenged). For details look at the above unsigned 770 * decimal functions. 771 */ 772 773 /** 774 * debugfs_create_x8 - create a debugfs file that is used to read and write an unsigned 8-bit value 775 * @name: a pointer to a string containing the name of the file to create. 776 * @mode: the permission that the file should have 777 * @parent: a pointer to the parent dentry for this file. This should be a 778 * directory dentry if set. If this parameter is %NULL, then the 779 * file will be created in the root of the debugfs filesystem. 780 * @value: a pointer to the variable that the file should read to and write 781 * from. 782 */ 783 void debugfs_create_x8(const char *name, umode_t mode, struct dentry *parent, 784 u8 *value) 785 { 786 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x8, 787 &fops_x8_ro, &fops_x8_wo); 788 } 789 EXPORT_SYMBOL_GPL(debugfs_create_x8); 790 791 /** 792 * debugfs_create_x16 - create a debugfs file that is used to read and write an unsigned 16-bit value 793 * @name: a pointer to a string containing the name of the file to create. 794 * @mode: the permission that the file should have 795 * @parent: a pointer to the parent dentry for this file. This should be a 796 * directory dentry if set. If this parameter is %NULL, then the 797 * file will be created in the root of the debugfs filesystem. 798 * @value: a pointer to the variable that the file should read to and write 799 * from. 800 */ 801 void debugfs_create_x16(const char *name, umode_t mode, struct dentry *parent, 802 u16 *value) 803 { 804 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x16, 805 &fops_x16_ro, &fops_x16_wo); 806 } 807 EXPORT_SYMBOL_GPL(debugfs_create_x16); 808 809 /** 810 * debugfs_create_x32 - create a debugfs file that is used to read and write an unsigned 32-bit value 811 * @name: a pointer to a string containing the name of the file to create. 812 * @mode: the permission that the file should have 813 * @parent: a pointer to the parent dentry for this file. This should be a 814 * directory dentry if set. If this parameter is %NULL, then the 815 * file will be created in the root of the debugfs filesystem. 816 * @value: a pointer to the variable that the file should read to and write 817 * from. 818 */ 819 void debugfs_create_x32(const char *name, umode_t mode, struct dentry *parent, 820 u32 *value) 821 { 822 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x32, 823 &fops_x32_ro, &fops_x32_wo); 824 } 825 EXPORT_SYMBOL_GPL(debugfs_create_x32); 826 827 /** 828 * debugfs_create_x64 - create a debugfs file that is used to read and write an unsigned 64-bit value 829 * @name: a pointer to a string containing the name of the file to create. 830 * @mode: the permission that the file should have 831 * @parent: a pointer to the parent dentry for this file. This should be a 832 * directory dentry if set. If this parameter is %NULL, then the 833 * file will be created in the root of the debugfs filesystem. 834 * @value: a pointer to the variable that the file should read to and write 835 * from. 836 */ 837 void debugfs_create_x64(const char *name, umode_t mode, struct dentry *parent, 838 u64 *value) 839 { 840 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x64, 841 &fops_x64_ro, &fops_x64_wo); 842 } 843 EXPORT_SYMBOL_GPL(debugfs_create_x64); 844 845 846 static int debugfs_size_t_set(void *data, u64 val) 847 { 848 *(size_t *)data = val; 849 return 0; 850 } 851 static int debugfs_size_t_get(void *data, u64 *val) 852 { 853 *val = *(size_t *)data; 854 return 0; 855 } 856 DEFINE_DEBUGFS_ATTRIBUTE(fops_size_t, debugfs_size_t_get, debugfs_size_t_set, 857 "%llu\n"); /* %llu and %zu are more or less the same */ 858 DEFINE_DEBUGFS_ATTRIBUTE(fops_size_t_ro, debugfs_size_t_get, NULL, "%llu\n"); 859 DEFINE_DEBUGFS_ATTRIBUTE(fops_size_t_wo, NULL, debugfs_size_t_set, "%llu\n"); 860 861 /** 862 * debugfs_create_size_t - create a debugfs file that is used to read and write an size_t value 863 * @name: a pointer to a string containing the name of the file to create. 864 * @mode: the permission that the file should have 865 * @parent: a pointer to the parent dentry for this file. This should be a 866 * directory dentry if set. If this parameter is %NULL, then the 867 * file will be created in the root of the debugfs filesystem. 868 * @value: a pointer to the variable that the file should read to and write 869 * from. 870 */ 871 void debugfs_create_size_t(const char *name, umode_t mode, 872 struct dentry *parent, size_t *value) 873 { 874 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_size_t, 875 &fops_size_t_ro, &fops_size_t_wo); 876 } 877 EXPORT_SYMBOL_GPL(debugfs_create_size_t); 878 879 static int debugfs_atomic_t_set(void *data, u64 val) 880 { 881 atomic_set((atomic_t *)data, val); 882 return 0; 883 } 884 static int debugfs_atomic_t_get(void *data, u64 *val) 885 { 886 *val = atomic_read((atomic_t *)data); 887 return 0; 888 } 889 DEFINE_DEBUGFS_ATTRIBUTE_SIGNED(fops_atomic_t, debugfs_atomic_t_get, 890 debugfs_atomic_t_set, "%lld\n"); 891 DEFINE_DEBUGFS_ATTRIBUTE_SIGNED(fops_atomic_t_ro, debugfs_atomic_t_get, NULL, 892 "%lld\n"); 893 DEFINE_DEBUGFS_ATTRIBUTE_SIGNED(fops_atomic_t_wo, NULL, debugfs_atomic_t_set, 894 "%lld\n"); 895 896 /** 897 * debugfs_create_atomic_t - create a debugfs file that is used to read and 898 * write an atomic_t value 899 * @name: a pointer to a string containing the name of the file to create. 900 * @mode: the permission that the file should have 901 * @parent: a pointer to the parent dentry for this file. This should be a 902 * directory dentry if set. If this parameter is %NULL, then the 903 * file will be created in the root of the debugfs filesystem. 904 * @value: a pointer to the variable that the file should read to and write 905 * from. 906 */ 907 void debugfs_create_atomic_t(const char *name, umode_t mode, 908 struct dentry *parent, atomic_t *value) 909 { 910 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_atomic_t, 911 &fops_atomic_t_ro, &fops_atomic_t_wo); 912 } 913 EXPORT_SYMBOL_GPL(debugfs_create_atomic_t); 914 915 ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf, 916 size_t count, loff_t *ppos) 917 { 918 char buf[2]; 919 bool val; 920 int r; 921 struct dentry *dentry = F_DENTRY(file); 922 923 r = debugfs_file_get(dentry); 924 if (unlikely(r)) 925 return r; 926 val = *(bool *)file->private_data; 927 debugfs_file_put(dentry); 928 929 if (val) 930 buf[0] = 'Y'; 931 else 932 buf[0] = 'N'; 933 buf[1] = '\n'; 934 return simple_read_from_buffer(user_buf, count, ppos, buf, 2); 935 } 936 EXPORT_SYMBOL_GPL(debugfs_read_file_bool); 937 938 ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf, 939 size_t count, loff_t *ppos) 940 { 941 bool bv; 942 int r; 943 bool *val = file->private_data; 944 struct dentry *dentry = F_DENTRY(file); 945 946 r = kstrtobool_from_user(user_buf, count, &bv); 947 if (!r) { 948 r = debugfs_file_get(dentry); 949 if (unlikely(r)) 950 return r; 951 *val = bv; 952 debugfs_file_put(dentry); 953 } 954 955 return count; 956 } 957 EXPORT_SYMBOL_GPL(debugfs_write_file_bool); 958 959 static const struct file_operations fops_bool = { 960 .read = debugfs_read_file_bool, 961 .write = debugfs_write_file_bool, 962 .open = simple_open, 963 .llseek = default_llseek, 964 }; 965 966 static const struct file_operations fops_bool_ro = { 967 .read = debugfs_read_file_bool, 968 .open = simple_open, 969 .llseek = default_llseek, 970 }; 971 972 static const struct file_operations fops_bool_wo = { 973 .write = debugfs_write_file_bool, 974 .open = simple_open, 975 .llseek = default_llseek, 976 }; 977 978 /** 979 * debugfs_create_bool - create a debugfs file that is used to read and write a boolean value 980 * @name: a pointer to a string containing the name of the file to create. 981 * @mode: the permission that the file should have 982 * @parent: a pointer to the parent dentry for this file. This should be a 983 * directory dentry if set. If this parameter is %NULL, then the 984 * file will be created in the root of the debugfs filesystem. 985 * @value: a pointer to the variable that the file should read to and write 986 * from. 987 * 988 * This function creates a file in debugfs with the given name that 989 * contains the value of the variable @value. If the @mode variable is so 990 * set, it can be read from, and written to. 991 */ 992 void debugfs_create_bool(const char *name, umode_t mode, struct dentry *parent, 993 bool *value) 994 { 995 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_bool, 996 &fops_bool_ro, &fops_bool_wo); 997 } 998 EXPORT_SYMBOL_GPL(debugfs_create_bool); 999 1000 ssize_t debugfs_read_file_str(struct file *file, char __user *user_buf, 1001 size_t count, loff_t *ppos) 1002 { 1003 struct dentry *dentry = F_DENTRY(file); 1004 char *str, *copy = NULL; 1005 int copy_len, len; 1006 ssize_t ret; 1007 1008 ret = debugfs_file_get(dentry); 1009 if (unlikely(ret)) 1010 return ret; 1011 1012 str = *(char **)file->private_data; 1013 len = strlen(str) + 1; 1014 copy = kmalloc(len, GFP_KERNEL); 1015 if (!copy) { 1016 debugfs_file_put(dentry); 1017 return -ENOMEM; 1018 } 1019 1020 copy_len = strscpy(copy, str, len); 1021 debugfs_file_put(dentry); 1022 if (copy_len < 0) { 1023 kfree(copy); 1024 return copy_len; 1025 } 1026 1027 copy[copy_len] = '\n'; 1028 1029 ret = simple_read_from_buffer(user_buf, count, ppos, copy, len); 1030 kfree(copy); 1031 1032 return ret; 1033 } 1034 EXPORT_SYMBOL_GPL(debugfs_create_str); 1035 1036 static ssize_t debugfs_write_file_str(struct file *file, const char __user *user_buf, 1037 size_t count, loff_t *ppos) 1038 { 1039 struct dentry *dentry = F_DENTRY(file); 1040 char *old, *new = NULL; 1041 int pos = *ppos; 1042 int r; 1043 1044 r = debugfs_file_get(dentry); 1045 if (unlikely(r)) 1046 return r; 1047 1048 old = *(char **)file->private_data; 1049 1050 /* only allow strict concatenation */ 1051 r = -EINVAL; 1052 if (pos && pos != strlen(old)) 1053 goto error; 1054 1055 r = -E2BIG; 1056 if (pos + count + 1 > PAGE_SIZE) 1057 goto error; 1058 1059 r = -ENOMEM; 1060 new = kmalloc(pos + count + 1, GFP_KERNEL); 1061 if (!new) 1062 goto error; 1063 1064 if (pos) 1065 memcpy(new, old, pos); 1066 1067 r = -EFAULT; 1068 if (copy_from_user(new + pos, user_buf, count)) 1069 goto error; 1070 1071 new[pos + count] = '\0'; 1072 strim(new); 1073 1074 rcu_assign_pointer(*(char __rcu **)file->private_data, new); 1075 synchronize_rcu(); 1076 kfree(old); 1077 1078 debugfs_file_put(dentry); 1079 return count; 1080 1081 error: 1082 kfree(new); 1083 debugfs_file_put(dentry); 1084 return r; 1085 } 1086 1087 static const struct file_operations fops_str = { 1088 .read = debugfs_read_file_str, 1089 .write = debugfs_write_file_str, 1090 .open = simple_open, 1091 .llseek = default_llseek, 1092 }; 1093 1094 static const struct file_operations fops_str_ro = { 1095 .read = debugfs_read_file_str, 1096 .open = simple_open, 1097 .llseek = default_llseek, 1098 }; 1099 1100 static const struct file_operations fops_str_wo = { 1101 .write = debugfs_write_file_str, 1102 .open = simple_open, 1103 .llseek = default_llseek, 1104 }; 1105 1106 /** 1107 * debugfs_create_str - create a debugfs file that is used to read and write a string value 1108 * @name: a pointer to a string containing the name of the file to create. 1109 * @mode: the permission that the file should have 1110 * @parent: a pointer to the parent dentry for this file. This should be a 1111 * directory dentry if set. If this parameter is %NULL, then the 1112 * file will be created in the root of the debugfs filesystem. 1113 * @value: a pointer to the variable that the file should read to and write 1114 * from. 1115 * 1116 * This function creates a file in debugfs with the given name that 1117 * contains the value of the variable @value. If the @mode variable is so 1118 * set, it can be read from, and written to. 1119 */ 1120 void debugfs_create_str(const char *name, umode_t mode, 1121 struct dentry *parent, char **value) 1122 { 1123 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_str, 1124 &fops_str_ro, &fops_str_wo); 1125 } 1126 1127 static ssize_t read_file_blob(struct file *file, char __user *user_buf, 1128 size_t count, loff_t *ppos) 1129 { 1130 struct debugfs_blob_wrapper *blob = file->private_data; 1131 struct dentry *dentry = F_DENTRY(file); 1132 ssize_t r; 1133 1134 r = debugfs_file_get(dentry); 1135 if (unlikely(r)) 1136 return r; 1137 r = simple_read_from_buffer(user_buf, count, ppos, blob->data, 1138 blob->size); 1139 debugfs_file_put(dentry); 1140 return r; 1141 } 1142 1143 static ssize_t write_file_blob(struct file *file, const char __user *user_buf, 1144 size_t count, loff_t *ppos) 1145 { 1146 struct debugfs_blob_wrapper *blob = file->private_data; 1147 struct dentry *dentry = F_DENTRY(file); 1148 ssize_t r; 1149 1150 r = debugfs_file_get(dentry); 1151 if (unlikely(r)) 1152 return r; 1153 r = simple_write_to_buffer(blob->data, blob->size, ppos, user_buf, 1154 count); 1155 1156 debugfs_file_put(dentry); 1157 return r; 1158 } 1159 1160 static const struct file_operations fops_blob = { 1161 .read = read_file_blob, 1162 .write = write_file_blob, 1163 .open = simple_open, 1164 .llseek = default_llseek, 1165 }; 1166 1167 /** 1168 * debugfs_create_blob - create a debugfs file that is used to read and write 1169 * a binary blob 1170 * @name: a pointer to a string containing the name of the file to create. 1171 * @mode: the permission that the file should have 1172 * @parent: a pointer to the parent dentry for this file. This should be a 1173 * directory dentry if set. If this parameter is %NULL, then the 1174 * file will be created in the root of the debugfs filesystem. 1175 * @blob: a pointer to a struct debugfs_blob_wrapper which contains a pointer 1176 * to the blob data and the size of the data. 1177 * 1178 * This function creates a file in debugfs with the given name that exports 1179 * @blob->data as a binary blob. If the @mode variable is so set it can be 1180 * read from and written to. 1181 * 1182 * This function will return a pointer to a dentry if it succeeds. This 1183 * pointer must be passed to the debugfs_remove() function when the file is 1184 * to be removed (no automatic cleanup happens if your module is unloaded, 1185 * you are responsible here.) If an error occurs, ERR_PTR(-ERROR) will be 1186 * returned. 1187 * 1188 * If debugfs is not enabled in the kernel, the value ERR_PTR(-ENODEV) will 1189 * be returned. 1190 */ 1191 struct dentry *debugfs_create_blob(const char *name, umode_t mode, 1192 struct dentry *parent, 1193 struct debugfs_blob_wrapper *blob) 1194 { 1195 return debugfs_create_file_unsafe(name, mode & 0644, parent, blob, &fops_blob); 1196 } 1197 EXPORT_SYMBOL_GPL(debugfs_create_blob); 1198 1199 static size_t u32_format_array(char *buf, size_t bufsize, 1200 u32 *array, int array_size) 1201 { 1202 size_t ret = 0; 1203 1204 while (--array_size >= 0) { 1205 size_t len; 1206 char term = array_size ? ' ' : '\n'; 1207 1208 len = snprintf(buf, bufsize, "%u%c", *array++, term); 1209 ret += len; 1210 1211 buf += len; 1212 bufsize -= len; 1213 } 1214 return ret; 1215 } 1216 1217 static int u32_array_open(struct inode *inode, struct file *file) 1218 { 1219 struct debugfs_u32_array *data = inode->i_private; 1220 int size, elements = data->n_elements; 1221 char *buf; 1222 1223 /* 1224 * Max size: 1225 * - 10 digits + ' '/'\n' = 11 bytes per number 1226 * - terminating NUL character 1227 */ 1228 size = elements*11; 1229 buf = kmalloc(size+1, GFP_KERNEL); 1230 if (!buf) 1231 return -ENOMEM; 1232 buf[size] = 0; 1233 1234 file->private_data = buf; 1235 u32_format_array(buf, size, data->array, data->n_elements); 1236 1237 return nonseekable_open(inode, file); 1238 } 1239 1240 static ssize_t u32_array_read(struct file *file, char __user *buf, size_t len, 1241 loff_t *ppos) 1242 { 1243 size_t size = strlen(file->private_data); 1244 1245 return simple_read_from_buffer(buf, len, ppos, 1246 file->private_data, size); 1247 } 1248 1249 static int u32_array_release(struct inode *inode, struct file *file) 1250 { 1251 kfree(file->private_data); 1252 1253 return 0; 1254 } 1255 1256 static const struct file_operations u32_array_fops = { 1257 .owner = THIS_MODULE, 1258 .open = u32_array_open, 1259 .release = u32_array_release, 1260 .read = u32_array_read, 1261 }; 1262 1263 /** 1264 * debugfs_create_u32_array - create a debugfs file that is used to read u32 1265 * array. 1266 * @name: a pointer to a string containing the name of the file to create. 1267 * @mode: the permission that the file should have. 1268 * @parent: a pointer to the parent dentry for this file. This should be a 1269 * directory dentry if set. If this parameter is %NULL, then the 1270 * file will be created in the root of the debugfs filesystem. 1271 * @array: wrapper struct containing data pointer and size of the array. 1272 * 1273 * This function creates a file in debugfs with the given name that exports 1274 * @array as data. If the @mode variable is so set it can be read from. 1275 * Writing is not supported. Seek within the file is also not supported. 1276 * Once array is created its size can not be changed. 1277 */ 1278 void debugfs_create_u32_array(const char *name, umode_t mode, 1279 struct dentry *parent, 1280 struct debugfs_u32_array *array) 1281 { 1282 debugfs_create_file_unsafe(name, mode, parent, array, &u32_array_fops); 1283 } 1284 EXPORT_SYMBOL_GPL(debugfs_create_u32_array); 1285 1286 #ifdef CONFIG_HAS_IOMEM 1287 1288 /* 1289 * The regset32 stuff is used to print 32-bit registers using the 1290 * seq_file utilities. We offer printing a register set in an already-opened 1291 * sequential file or create a debugfs file that only prints a regset32. 1292 */ 1293 1294 /** 1295 * debugfs_print_regs32 - use seq_print to describe a set of registers 1296 * @s: the seq_file structure being used to generate output 1297 * @regs: an array if struct debugfs_reg32 structures 1298 * @nregs: the length of the above array 1299 * @base: the base address to be used in reading the registers 1300 * @prefix: a string to be prefixed to every output line 1301 * 1302 * This function outputs a text block describing the current values of 1303 * some 32-bit hardware registers. It is meant to be used within debugfs 1304 * files based on seq_file that need to show registers, intermixed with other 1305 * information. The prefix argument may be used to specify a leading string, 1306 * because some peripherals have several blocks of identical registers, 1307 * for example configuration of dma channels 1308 */ 1309 void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, 1310 int nregs, void __iomem *base, char *prefix) 1311 { 1312 int i; 1313 1314 for (i = 0; i < nregs; i++, regs++) { 1315 if (prefix) 1316 seq_printf(s, "%s", prefix); 1317 seq_printf(s, "%s = 0x%08x\n", regs->name, 1318 readl(base + regs->offset)); 1319 if (seq_has_overflowed(s)) 1320 break; 1321 } 1322 } 1323 EXPORT_SYMBOL_GPL(debugfs_print_regs32); 1324 1325 static int debugfs_regset32_show(struct seq_file *s, void *data) 1326 { 1327 struct debugfs_regset32 *regset = s->private; 1328 1329 if (regset->dev) 1330 pm_runtime_get_sync(regset->dev); 1331 1332 debugfs_print_regs32(s, regset->regs, regset->nregs, regset->base, ""); 1333 1334 if (regset->dev) 1335 pm_runtime_put(regset->dev); 1336 1337 return 0; 1338 } 1339 1340 DEFINE_SHOW_ATTRIBUTE(debugfs_regset32); 1341 1342 /** 1343 * debugfs_create_regset32 - create a debugfs file that returns register values 1344 * @name: a pointer to a string containing the name of the file to create. 1345 * @mode: the permission that the file should have 1346 * @parent: a pointer to the parent dentry for this file. This should be a 1347 * directory dentry if set. If this parameter is %NULL, then the 1348 * file will be created in the root of the debugfs filesystem. 1349 * @regset: a pointer to a struct debugfs_regset32, which contains a pointer 1350 * to an array of register definitions, the array size and the base 1351 * address where the register bank is to be found. 1352 * 1353 * This function creates a file in debugfs with the given name that reports 1354 * the names and values of a set of 32-bit registers. If the @mode variable 1355 * is so set it can be read from. Writing is not supported. 1356 */ 1357 void debugfs_create_regset32(const char *name, umode_t mode, 1358 struct dentry *parent, 1359 struct debugfs_regset32 *regset) 1360 { 1361 debugfs_create_file(name, mode, parent, regset, &debugfs_regset32_fops); 1362 } 1363 EXPORT_SYMBOL_GPL(debugfs_create_regset32); 1364 1365 #endif /* CONFIG_HAS_IOMEM */ 1366 1367 struct debugfs_devm_entry { 1368 int (*read)(struct seq_file *seq, void *data); 1369 struct device *dev; 1370 }; 1371 1372 static int debugfs_devm_entry_open(struct inode *inode, struct file *f) 1373 { 1374 struct debugfs_devm_entry *entry = inode->i_private; 1375 1376 return single_open(f, entry->read, entry->dev); 1377 } 1378 1379 static const struct file_operations debugfs_devm_entry_ops = { 1380 .owner = THIS_MODULE, 1381 .open = debugfs_devm_entry_open, 1382 .release = single_release, 1383 .read = seq_read, 1384 .llseek = seq_lseek 1385 }; 1386 1387 /** 1388 * debugfs_create_devm_seqfile - create a debugfs file that is bound to device. 1389 * 1390 * @dev: device related to this debugfs file. 1391 * @name: name of the debugfs file. 1392 * @parent: a pointer to the parent dentry for this file. This should be a 1393 * directory dentry if set. If this parameter is %NULL, then the 1394 * file will be created in the root of the debugfs filesystem. 1395 * @read_fn: function pointer called to print the seq_file content. 1396 */ 1397 void debugfs_create_devm_seqfile(struct device *dev, const char *name, 1398 struct dentry *parent, 1399 int (*read_fn)(struct seq_file *s, void *data)) 1400 { 1401 struct debugfs_devm_entry *entry; 1402 1403 if (IS_ERR(parent)) 1404 return; 1405 1406 entry = devm_kzalloc(dev, sizeof(*entry), GFP_KERNEL); 1407 if (!entry) 1408 return; 1409 1410 entry->read = read_fn; 1411 entry->dev = dev; 1412 1413 debugfs_create_file(name, S_IRUGO, parent, entry, 1414 &debugfs_devm_entry_ops); 1415 } 1416 EXPORT_SYMBOL_GPL(debugfs_create_devm_seqfile); 1417