1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2016-2018, Matthew Macy <mmacy@freebsd.org> 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 * 27 */ 28 29 #include <sys/param.h> 30 #include <sys/systm.h> 31 #include <sys/queue.h> 32 #include <sys/blist.h> 33 #include <sys/conf.h> 34 #include <sys/exec.h> 35 #include <sys/filedesc.h> 36 #include <sys/kernel.h> 37 #include <sys/linker.h> 38 #include <sys/malloc.h> 39 #include <sys/mount.h> 40 #include <sys/mutex.h> 41 #include <sys/proc.h> 42 #include <sys/resourcevar.h> 43 #include <sys/sbuf.h> 44 #include <sys/smp.h> 45 #include <sys/socket.h> 46 #include <sys/vnode.h> 47 #include <sys/bus.h> 48 #include <sys/pciio.h> 49 50 #include <dev/pci/pcivar.h> 51 #include <dev/pci/pcireg.h> 52 53 #include <net/if.h> 54 55 #include <vm/vm.h> 56 #include <vm/pmap.h> 57 #include <vm/vm_map.h> 58 #include <vm/vm_param.h> 59 #include <vm/vm_object.h> 60 #include <vm/swap_pager.h> 61 62 #include <machine/bus.h> 63 64 #include <compat/linux/linux_ioctl.h> 65 #include <compat/linux/linux_mib.h> 66 #include <compat/linux/linux_util.h> 67 #include <fs/pseudofs/pseudofs.h> 68 69 #include <asm/atomic.h> 70 #include <linux/compat.h> 71 #include <linux/debugfs.h> 72 #include <linux/fs.h> 73 74 MALLOC_DEFINE(M_DFSINT, "debugfsint", "Linux debugfs internal"); 75 76 static struct pfs_node *debugfs_root; 77 78 #define DM_SYMLINK 0x1 79 #define DM_DIR 0x2 80 #define DM_FILE 0x3 81 82 struct dentry_meta { 83 struct dentry dm_dnode; 84 const struct file_operations *dm_fops; 85 void *dm_data; 86 umode_t dm_mode; 87 int dm_type; 88 }; 89 90 static int 91 debugfs_attr(PFS_ATTR_ARGS) 92 { 93 struct dentry_meta *dm; 94 95 dm = pn->pn_data; 96 97 vap->va_mode = dm->dm_mode; 98 return (0); 99 } 100 101 static int 102 debugfs_destroy(PFS_DESTROY_ARGS) 103 { 104 struct dentry_meta *dm; 105 106 dm = pn->pn_data; 107 if (dm != NULL && dm->dm_type == DM_SYMLINK) 108 free(dm->dm_data, M_DFSINT); 109 110 free(dm, M_DFSINT); 111 return (0); 112 } 113 114 static int 115 debugfs_fill(PFS_FILL_ARGS) 116 { 117 struct dentry_meta *d; 118 struct linux_file lf = {}; 119 struct vnode vn; 120 char *buf; 121 int rc; 122 off_t off = 0; 123 124 if ((rc = linux_set_current_flags(curthread, M_NOWAIT))) 125 return (rc); 126 127 d = pn->pn_data; 128 vn.v_data = d->dm_data; 129 130 rc = d->dm_fops->open(&vn, &lf); 131 if (rc < 0) { 132 #ifdef INVARIANTS 133 printf("%s:%d open failed with %d\n", __func__, __LINE__, rc); 134 #endif 135 return (-rc); 136 } 137 138 rc = -ENODEV; 139 switch (uio->uio_rw) { 140 case UIO_READ: 141 if (d->dm_fops->read != NULL) { 142 rc = -ENOMEM; 143 buf = malloc(sb->s_size, M_DFSINT, M_ZERO | M_NOWAIT); 144 if (buf != NULL) { 145 rc = d->dm_fops->read(&lf, buf, sb->s_size, 146 &off); 147 if (rc > 0) 148 sbuf_bcpy(sb, buf, strlen(buf)); 149 150 free(buf, M_DFSINT); 151 } 152 } 153 break; 154 case UIO_WRITE: 155 if (d->dm_fops->write != NULL) { 156 sbuf_finish(sb); 157 rc = d->dm_fops->write(&lf, sbuf_data(sb), sbuf_len(sb), 158 &off); 159 } 160 break; 161 } 162 163 if (d->dm_fops->release) 164 d->dm_fops->release(&vn, &lf); 165 166 if (rc < 0) { 167 #ifdef INVARIANTS 168 printf("%s:%d read/write failed with %d\n", __func__, __LINE__, rc); 169 #endif 170 return (-rc); 171 } 172 return (0); 173 } 174 175 static int 176 debugfs_fill_data(PFS_FILL_ARGS) 177 { 178 struct dentry_meta *dm; 179 180 dm = pn->pn_data; 181 sbuf_printf(sb, "%s", (char *)dm->dm_data); 182 return (0); 183 } 184 185 struct dentry * 186 debugfs_create_file(const char *name, umode_t mode, 187 struct dentry *parent, void *data, 188 const struct file_operations *fops) 189 { 190 struct dentry_meta *dm; 191 struct dentry *dnode; 192 struct pfs_node *pnode; 193 int flags; 194 195 dm = malloc(sizeof(*dm), M_DFSINT, M_NOWAIT | M_ZERO); 196 if (dm == NULL) 197 return (NULL); 198 dnode = &dm->dm_dnode; 199 dm->dm_fops = fops; 200 dm->dm_data = data; 201 dm->dm_mode = mode; 202 dm->dm_type = DM_FILE; 203 if (parent != NULL) 204 pnode = parent->d_pfs_node; 205 else 206 pnode = debugfs_root; 207 208 flags = fops->write ? PFS_RDWR : PFS_RD; 209 pfs_create_file(pnode, &dnode->d_pfs_node, name, debugfs_fill, 210 debugfs_attr, NULL, debugfs_destroy, flags | PFS_NOWAIT); 211 if (dnode->d_pfs_node == NULL) { 212 free(dm, M_DFSINT); 213 return (NULL); 214 } 215 dnode->d_pfs_node->pn_data = dm; 216 217 return (dnode); 218 } 219 220 struct dentry * 221 debugfs_create_file_size(const char *name, umode_t mode, 222 struct dentry *parent, void *data, 223 const struct file_operations *fops, 224 loff_t file_size __unused) 225 { 226 227 return debugfs_create_file(name, mode, parent, data, fops); 228 } 229 230 /* 231 * NOTE: Files created with the _unsafe moniker will not be protected from 232 * debugfs core file removals. It is the responsibility of @fops to protect 233 * its file using debugfs_file_get() and debugfs_file_put(). 234 * 235 * FreeBSD's LinuxKPI lindebugfs does not perform file removals at the time 236 * of writing. Therefore there is no difference between functions with _unsafe 237 * and functions without _unsafe when using lindebugfs. Functions with _unsafe 238 * exist only for Linux compatibility. 239 */ 240 struct dentry * 241 debugfs_create_file_unsafe(const char *name, umode_t mode, 242 struct dentry *parent, void *data, 243 const struct file_operations *fops) 244 { 245 246 return (debugfs_create_file(name, mode, parent, data, fops)); 247 } 248 249 struct dentry * 250 debugfs_create_mode_unsafe(const char *name, umode_t mode, 251 struct dentry *parent, void *data, 252 const struct file_operations *fops, 253 const struct file_operations *fops_ro, 254 const struct file_operations *fops_wo) 255 { 256 umode_t read = mode & S_IRUGO; 257 umode_t write = mode & S_IWUGO; 258 259 if (read && !write) 260 return (debugfs_create_file_unsafe(name, mode, parent, data, fops_ro)); 261 262 if (write && !read) 263 return (debugfs_create_file_unsafe(name, mode, parent, data, fops_wo)); 264 265 return (debugfs_create_file_unsafe(name, mode, parent, data, fops)); 266 } 267 268 struct dentry * 269 debugfs_create_dir(const char *name, struct dentry *parent) 270 { 271 struct dentry_meta *dm; 272 struct dentry *dnode; 273 struct pfs_node *pnode; 274 275 dm = malloc(sizeof(*dm), M_DFSINT, M_NOWAIT | M_ZERO); 276 if (dm == NULL) 277 return (NULL); 278 dnode = &dm->dm_dnode; 279 dm->dm_mode = 0700; 280 dm->dm_type = DM_DIR; 281 if (parent != NULL) 282 pnode = parent->d_pfs_node; 283 else 284 pnode = debugfs_root; 285 286 pfs_create_dir(pnode, &dnode->d_pfs_node, name, debugfs_attr, NULL, 287 debugfs_destroy, PFS_RD | PFS_NOWAIT); 288 if (dnode->d_pfs_node == NULL) { 289 free(dm, M_DFSINT); 290 return (NULL); 291 } 292 dnode->d_pfs_node->pn_data = dm; 293 return (dnode); 294 } 295 296 struct dentry * 297 debugfs_create_symlink(const char *name, struct dentry *parent, 298 const char *dest) 299 { 300 struct dentry_meta *dm; 301 struct dentry *dnode; 302 struct pfs_node *pnode; 303 void *data; 304 305 data = strdup_flags(dest, M_DFSINT, M_NOWAIT); 306 if (data == NULL) 307 return (NULL); 308 dm = malloc(sizeof(*dm), M_DFSINT, M_NOWAIT | M_ZERO); 309 if (dm == NULL) 310 goto fail1; 311 dnode = &dm->dm_dnode; 312 dm->dm_mode = 0700; 313 dm->dm_type = DM_SYMLINK; 314 dm->dm_data = data; 315 if (parent != NULL) 316 pnode = parent->d_pfs_node; 317 else 318 pnode = debugfs_root; 319 320 pfs_create_link(pnode, &dnode->d_pfs_node, name, &debugfs_fill_data, 321 NULL, NULL, NULL, PFS_NOWAIT); 322 if (dnode->d_pfs_node == NULL) 323 goto fail; 324 dnode->d_pfs_node->pn_data = dm; 325 return (dnode); 326 fail: 327 free(dm, M_DFSINT); 328 fail1: 329 free(data, M_DFSINT); 330 return (NULL); 331 } 332 333 struct dentry * 334 debugfs_lookup(const char *name, struct dentry *parent) 335 { 336 struct dentry_meta *dm; 337 struct dentry *dnode; 338 struct pfs_node *pnode; 339 340 pnode = pfs_find_node(parent->d_pfs_node, name); 341 if (pnode == NULL) 342 return (NULL); 343 344 dm = (struct dentry_meta *)pnode->pn_data; 345 dnode = &dm->dm_dnode; 346 347 return (dnode); 348 } 349 350 void 351 debugfs_remove(struct dentry *dnode) 352 { 353 if (dnode == NULL) 354 return; 355 356 pfs_destroy(dnode->d_pfs_node); 357 } 358 359 void 360 debugfs_remove_recursive(struct dentry *dnode) 361 { 362 if (dnode == NULL) 363 return; 364 365 pfs_destroy(dnode->d_pfs_node); 366 } 367 368 static int 369 debugfs_bool_get(void *data, uint64_t *ullval) 370 { 371 bool *bval = data; 372 373 if (*bval) 374 *ullval = 1; 375 else 376 *ullval = 0; 377 378 return (0); 379 } 380 381 static int 382 debugfs_bool_set(void *data, uint64_t ullval) 383 { 384 bool *bval = data; 385 386 if (ullval) 387 *bval = 1; 388 else 389 *bval = 0; 390 391 return (0); 392 } 393 394 DEFINE_DEBUGFS_ATTRIBUTE(fops_bool, debugfs_bool_get, debugfs_bool_set, "%llu\n"); 395 DEFINE_DEBUGFS_ATTRIBUTE(fops_bool_ro, debugfs_bool_get, NULL, "%llu\n"); 396 DEFINE_DEBUGFS_ATTRIBUTE(fops_bool_wo, NULL, debugfs_bool_set, "%llu\n"); 397 398 void 399 debugfs_create_bool(const char *name, umode_t mode, struct dentry *parent, bool *value) 400 { 401 402 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_bool, 403 &fops_bool_ro, &fops_bool_wo); 404 } 405 406 407 static int 408 debugfs_u8_get(void *data, uint64_t *value) 409 { 410 uint8_t *u8data = data; 411 *value = *u8data; 412 return (0); 413 } 414 415 static int 416 debugfs_u8_set(void *data, uint64_t value) 417 { 418 uint8_t *u8data = data; 419 *u8data = (uint8_t)value; 420 return (0); 421 } 422 423 DEFINE_DEBUGFS_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%u\n"); 424 DEFINE_DEBUGFS_ATTRIBUTE(fops_u8_ro, debugfs_u8_get, NULL, "%u\n"); 425 DEFINE_DEBUGFS_ATTRIBUTE(fops_u8_wo, NULL, debugfs_u8_set, "%u\n"); 426 427 void 428 debugfs_create_u8(const char *name, umode_t mode, struct dentry *parent, uint8_t *value) 429 { 430 431 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u8, 432 &fops_u8_ro, &fops_u8_wo); 433 } 434 435 DEFINE_DEBUGFS_ATTRIBUTE(fops_x8, debugfs_u8_get, debugfs_u8_set, "0x%016llx\n"); 436 DEFINE_DEBUGFS_ATTRIBUTE(fops_x8_ro, debugfs_u8_get, NULL, "0x%016llx\n"); 437 DEFINE_DEBUGFS_ATTRIBUTE(fops_x8_wo, NULL, debugfs_u8_set, "0x%016llx\n"); 438 439 void 440 debugfs_create_x8(const char *name, umode_t mode, struct dentry *parent, uint8_t *value) 441 { 442 443 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x8, 444 &fops_x8_ro, &fops_x8_wo); 445 } 446 447 448 static int 449 debugfs_u16_get(void *data, uint64_t *value) 450 { 451 uint16_t *u16data = data; 452 *value = *u16data; 453 return (0); 454 } 455 456 static int 457 debugfs_u16_set(void *data, uint64_t value) 458 { 459 uint16_t *u16data = data; 460 *u16data = (uint16_t)value; 461 return (0); 462 } 463 464 DEFINE_DEBUGFS_ATTRIBUTE(fops_u16, debugfs_u16_get, debugfs_u16_set, "%u\n"); 465 DEFINE_DEBUGFS_ATTRIBUTE(fops_u16_ro, debugfs_u16_get, NULL, "%u\n"); 466 DEFINE_DEBUGFS_ATTRIBUTE(fops_u16_wo, NULL, debugfs_u16_set, "%u\n"); 467 468 void 469 debugfs_create_u16(const char *name, umode_t mode, struct dentry *parent, uint16_t *value) 470 { 471 472 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u16, 473 &fops_u16_ro, &fops_u16_wo); 474 } 475 476 DEFINE_DEBUGFS_ATTRIBUTE(fops_x16, debugfs_u16_get, debugfs_u16_set, "0x%016llx\n"); 477 DEFINE_DEBUGFS_ATTRIBUTE(fops_x16_ro, debugfs_u16_get, NULL, "0x%016llx\n"); 478 DEFINE_DEBUGFS_ATTRIBUTE(fops_x16_wo, NULL, debugfs_u16_set, "0x%016llx\n"); 479 480 void 481 debugfs_create_x16(const char *name, umode_t mode, struct dentry *parent, uint16_t *value) 482 { 483 484 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x16, 485 &fops_x16_ro, &fops_x16_wo); 486 } 487 488 489 static int 490 debugfs_u32_get(void *data, uint64_t *value) 491 { 492 uint32_t *u32data = data; 493 *value = *u32data; 494 return (0); 495 } 496 497 static int 498 debugfs_u32_set(void *data, uint64_t value) 499 { 500 uint32_t *u32data = data; 501 *u32data = (uint32_t)value; 502 return (0); 503 } 504 505 DEFINE_DEBUGFS_ATTRIBUTE(fops_u32, debugfs_u32_get, debugfs_u32_set, "%u\n"); 506 DEFINE_DEBUGFS_ATTRIBUTE(fops_u32_ro, debugfs_u32_get, NULL, "%u\n"); 507 DEFINE_DEBUGFS_ATTRIBUTE(fops_u32_wo, NULL, debugfs_u32_set, "%u\n"); 508 509 void 510 debugfs_create_u32(const char *name, umode_t mode, struct dentry *parent, uint32_t *value) 511 { 512 513 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u32, 514 &fops_u32_ro, &fops_u32_wo); 515 } 516 517 DEFINE_DEBUGFS_ATTRIBUTE(fops_x32, debugfs_u32_get, debugfs_u32_set, "0x%016llx\n"); 518 DEFINE_DEBUGFS_ATTRIBUTE(fops_x32_ro, debugfs_u32_get, NULL, "0x%016llx\n"); 519 DEFINE_DEBUGFS_ATTRIBUTE(fops_x32_wo, NULL, debugfs_u32_set, "0x%016llx\n"); 520 521 void 522 debugfs_create_x32(const char *name, umode_t mode, struct dentry *parent, uint32_t *value) 523 { 524 525 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x32, 526 &fops_x32_ro, &fops_x32_wo); 527 } 528 529 530 static int 531 debugfs_u64_get(void *data, uint64_t *value) 532 { 533 uint64_t *u64data = data; 534 *value = *u64data; 535 return (0); 536 } 537 538 static int 539 debugfs_u64_set(void *data, uint64_t value) 540 { 541 uint64_t *u64data = data; 542 *u64data = (uint64_t)value; 543 return (0); 544 } 545 546 DEFINE_DEBUGFS_ATTRIBUTE(fops_u64, debugfs_u64_get, debugfs_u64_set, "%u\n"); 547 DEFINE_DEBUGFS_ATTRIBUTE(fops_u64_ro, debugfs_u64_get, NULL, "%u\n"); 548 DEFINE_DEBUGFS_ATTRIBUTE(fops_u64_wo, NULL, debugfs_u64_set, "%u\n"); 549 550 void 551 debugfs_create_u64(const char *name, umode_t mode, struct dentry *parent, uint64_t *value) 552 { 553 554 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u64, 555 &fops_u64_ro, &fops_u64_wo); 556 } 557 558 DEFINE_DEBUGFS_ATTRIBUTE(fops_x64, debugfs_u64_get, debugfs_u64_set, "0x%016llx\n"); 559 DEFINE_DEBUGFS_ATTRIBUTE(fops_x64_ro, debugfs_u64_get, NULL, "0x%016llx\n"); 560 DEFINE_DEBUGFS_ATTRIBUTE(fops_x64_wo, NULL, debugfs_u64_set, "0x%016llx\n"); 561 562 void 563 debugfs_create_x64(const char *name, umode_t mode, struct dentry *parent, uint64_t *value) 564 { 565 566 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x64, 567 &fops_x64_ro, &fops_x64_wo); 568 } 569 570 571 static int 572 debugfs_ulong_get(void *data, uint64_t *value) 573 { 574 uint64_t *uldata = data; 575 *value = *uldata; 576 return (0); 577 } 578 579 static int 580 debugfs_ulong_set(void *data, uint64_t value) 581 { 582 uint64_t *uldata = data; 583 *uldata = value; 584 return (0); 585 } 586 587 DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong, debugfs_ulong_get, debugfs_ulong_set, "%llu\n"); 588 DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong_ro, debugfs_ulong_get, NULL, "%llu\n"); 589 DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong_wo, NULL, debugfs_ulong_set, "%llu\n"); 590 591 void 592 debugfs_create_ulong(const char *name, umode_t mode, struct dentry *parent, unsigned long *value) 593 { 594 595 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_ulong, 596 &fops_ulong_ro, &fops_ulong_wo); 597 } 598 599 600 static int 601 debugfs_atomic_t_get(void *data, uint64_t *value) 602 { 603 atomic_t *atomic_data = data; 604 *value = atomic_read(atomic_data); 605 return (0); 606 } 607 608 static int 609 debugfs_atomic_t_set(void *data, uint64_t value) 610 { 611 atomic_t *atomic_data = data; 612 atomic_set(atomic_data, (int)value); 613 return (0); 614 } 615 616 DEFINE_DEBUGFS_ATTRIBUTE(fops_atomic_t, debugfs_atomic_t_get, debugfs_atomic_t_set, "%d\n"); 617 DEFINE_DEBUGFS_ATTRIBUTE(fops_atomic_t_ro, debugfs_atomic_t_get, NULL, "%d\n"); 618 DEFINE_DEBUGFS_ATTRIBUTE(fops_atomic_t_wo, NULL, debugfs_atomic_t_set, "%d\n"); 619 620 void 621 debugfs_create_atomic_t(const char *name, umode_t mode, struct dentry *parent, atomic_t *value) 622 { 623 624 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_atomic_t, 625 &fops_atomic_t_ro, &fops_atomic_t_wo); 626 } 627 628 629 static int 630 fops_str_open(struct inode *inode, struct file *filp) 631 { 632 633 return (simple_open(inode, filp)); 634 } 635 636 static ssize_t 637 fops_str_read(struct file *filp, char __user *ubuf, size_t read_size, 638 loff_t *ppos) 639 { 640 ssize_t ret; 641 char *str, *str_with_newline; 642 size_t str_len, str_with_newline_len; 643 644 if (filp->private_data == NULL) 645 return (-EINVAL); 646 647 str = *(char **)filp->private_data; 648 str_len = strlen(str); 649 650 /* 651 * `str_with_newline` is terminated with a newline, but is not 652 * NUL-terminated. 653 */ 654 str_with_newline_len = str_len + 1; 655 str_with_newline = kmalloc(str_with_newline_len, GFP_KERNEL); 656 if (str_with_newline == NULL) 657 return (-ENOMEM); 658 659 strncpy(str_with_newline, str, str_len); 660 str_with_newline[str_len] = '\n'; 661 662 ret = simple_read_from_buffer(ubuf, read_size, ppos, 663 str_with_newline, str_with_newline_len); 664 665 kfree(str_with_newline); 666 667 return (ret); 668 } 669 670 static ssize_t 671 fops_str_write(struct file *filp, const char *buf, size_t write_size, 672 loff_t *ppos) 673 { 674 char *old, *new; 675 size_t old_len, new_len; 676 677 if (filp->private_data == NULL) 678 return (-EINVAL); 679 680 old = *(char **)filp->private_data; 681 new = NULL; 682 683 /* 684 * We enforce concatenation of the newly written value to the existing 685 * value. 686 */ 687 old_len = strlen(old); 688 if (*ppos && *ppos != old_len) 689 return (-EINVAL); 690 691 new_len = old_len + write_size; 692 if (new_len + 1 > PAGE_SIZE) 693 return (-E2BIG); 694 695 new = kmalloc(new_len + 1, GFP_KERNEL); 696 if (new == NULL) 697 return (-ENOMEM); 698 699 memcpy(new, old, old_len); 700 if (copy_from_user(new + old_len, buf, write_size) != 0) { 701 kfree(new); 702 return (-EFAULT); 703 } 704 705 new[new_len] = '\0'; 706 strim(new); 707 708 filp->private_data = &new; 709 710 kfree(old); 711 712 return (write_size); 713 } 714 715 static const struct file_operations fops_str = { 716 .owner = THIS_MODULE, 717 .open = fops_str_open, 718 .read = fops_str_read, 719 .write = fops_str_write, 720 .llseek = no_llseek 721 }; 722 static const struct file_operations fops_str_ro = { 723 .owner = THIS_MODULE, 724 .open = fops_str_open, 725 .read = fops_str_read, 726 .llseek = no_llseek 727 }; 728 static const struct file_operations fops_str_wo = { 729 .owner = THIS_MODULE, 730 .open = fops_str_open, 731 .write = fops_str_write, 732 .llseek = no_llseek 733 }; 734 735 void 736 debugfs_create_str(const char *name, umode_t mode, struct dentry *parent, 737 char **value) 738 { 739 debugfs_create_mode_unsafe(name, mode, parent, value, 740 &fops_str, &fops_str_ro, &fops_str_wo); 741 } 742 743 744 static ssize_t 745 fops_blob_read(struct file *filp, char __user *ubuf, size_t read_size, loff_t *ppos) 746 { 747 struct debugfs_blob_wrapper *blob; 748 749 blob = filp->private_data; 750 if (blob == NULL) 751 return (-EINVAL); 752 if (blob->size == 0 || blob->data == NULL) 753 return (-EINVAL); 754 755 return (simple_read_from_buffer(ubuf, read_size, ppos, blob->data, blob->size)); 756 } 757 758 static int 759 fops_blob_open(struct inode *inode, struct file *filp) 760 { 761 762 return (simple_open(inode, filp)); 763 } 764 765 static const struct file_operations __fops_blob_ro = { 766 .owner = THIS_MODULE, 767 .open = fops_blob_open, 768 .read = fops_blob_read, 769 .llseek = no_llseek 770 }; 771 772 struct dentry * 773 debugfs_create_blob(const char *name, umode_t mode, struct dentry *parent, 774 struct debugfs_blob_wrapper *value) 775 { 776 /* Blobs are read-only. */ 777 return (debugfs_create_file(name, mode & 0444, parent, value, &__fops_blob_ro)); 778 } 779 780 781 static int 782 lindebugfs_init(PFS_INIT_ARGS) 783 { 784 785 debugfs_root = pi->pi_root; 786 787 (void)debugfs_create_symlink("kcov", NULL, "/dev/kcov"); 788 789 return (0); 790 } 791 792 static int 793 lindebugfs_uninit(PFS_INIT_ARGS) 794 { 795 796 return (0); 797 } 798 799 PSEUDOFS(lindebugfs, 1, VFCF_JAIL); 800 MODULE_DEPEND(lindebugfs, linuxkpi, 1, 1, 1); 801