1 /* 2 * The USB Monitor, inspired by Dave Harding's USBMon. 3 * 4 * This is a text format reader. 5 */ 6 7 #include <linux/kernel.h> 8 #include <linux/list.h> 9 #include <linux/usb.h> 10 #include <linux/time.h> 11 #include <linux/mutex.h> 12 #include <linux/debugfs.h> 13 #include <asm/uaccess.h> 14 15 #include "usb_mon.h" 16 17 /* 18 * No, we do not want arbitrarily long data strings. 19 * Use the binary interface if you want to capture bulk data! 20 */ 21 #define DATA_MAX 32 22 23 /* 24 * Defined by USB 2.0 clause 9.3, table 9.2. 25 */ 26 #define SETUP_MAX 8 27 28 /* 29 * This limit exists to prevent OOMs when the user process stops reading. 30 * If usbmon were available to unprivileged processes, it might be open 31 * to a local DoS. But we have to keep to root in order to prevent 32 * password sniffing from HID devices. 33 */ 34 #define EVENT_MAX (4*PAGE_SIZE / sizeof(struct mon_event_text)) 35 36 /* 37 * Potentially unlimited number; we limit it for similar allocations. 38 * The usbfs limits this to 128, but we're not quite as generous. 39 */ 40 #define ISODESC_MAX 5 41 42 #define PRINTF_DFL 250 /* with 5 ISOs segs */ 43 44 struct mon_iso_desc { 45 int status; 46 unsigned int offset; 47 unsigned int length; /* Unsigned here, signed in URB. Historic. */ 48 }; 49 50 struct mon_event_text { 51 struct list_head e_link; 52 int type; /* submit, complete, etc. */ 53 unsigned long id; /* From pointer, most of the time */ 54 unsigned int tstamp; 55 int busnum; 56 char devnum; 57 char epnum; 58 char is_in; 59 char xfertype; 60 int length; /* Depends on type: xfer length or act length */ 61 int status; 62 int interval; 63 int start_frame; 64 int error_count; 65 char setup_flag; 66 char data_flag; 67 int numdesc; /* Full number */ 68 struct mon_iso_desc isodesc[ISODESC_MAX]; 69 unsigned char setup[SETUP_MAX]; 70 unsigned char data[DATA_MAX]; 71 }; 72 73 #define SLAB_NAME_SZ 30 74 struct mon_reader_text { 75 struct kmem_cache *e_slab; 76 int nevents; 77 struct list_head e_list; 78 struct mon_reader r; /* In C, parent class can be placed anywhere */ 79 80 wait_queue_head_t wait; 81 int printf_size; 82 char *printf_buf; 83 struct mutex printf_lock; 84 85 char slab_name[SLAB_NAME_SZ]; 86 }; 87 88 static struct dentry *mon_dir; /* Usually /sys/kernel/debug/usbmon */ 89 90 static void mon_text_ctor(void *); 91 92 struct mon_text_ptr { 93 int cnt, limit; 94 char *pbuf; 95 }; 96 97 static struct mon_event_text * 98 mon_text_read_wait(struct mon_reader_text *rp, struct file *file); 99 static void mon_text_read_head_t(struct mon_reader_text *rp, 100 struct mon_text_ptr *p, const struct mon_event_text *ep); 101 static void mon_text_read_head_u(struct mon_reader_text *rp, 102 struct mon_text_ptr *p, const struct mon_event_text *ep); 103 static void mon_text_read_statset(struct mon_reader_text *rp, 104 struct mon_text_ptr *p, const struct mon_event_text *ep); 105 static void mon_text_read_intstat(struct mon_reader_text *rp, 106 struct mon_text_ptr *p, const struct mon_event_text *ep); 107 static void mon_text_read_isostat(struct mon_reader_text *rp, 108 struct mon_text_ptr *p, const struct mon_event_text *ep); 109 static void mon_text_read_isodesc(struct mon_reader_text *rp, 110 struct mon_text_ptr *p, const struct mon_event_text *ep); 111 static void mon_text_read_data(struct mon_reader_text *rp, 112 struct mon_text_ptr *p, const struct mon_event_text *ep); 113 114 /* 115 * mon_text_submit 116 * mon_text_complete 117 * 118 * May be called from an interrupt. 119 * 120 * This is called with the whole mon_bus locked, so no additional lock. 121 */ 122 123 static inline char mon_text_get_setup(struct mon_event_text *ep, 124 struct urb *urb, char ev_type, struct mon_bus *mbus) 125 { 126 127 if (ep->xfertype != USB_ENDPOINT_XFER_CONTROL || ev_type != 'S') 128 return '-'; 129 130 if (urb->setup_packet == NULL) 131 return 'Z'; /* '0' would be not as pretty. */ 132 133 memcpy(ep->setup, urb->setup_packet, SETUP_MAX); 134 return 0; 135 } 136 137 static inline char mon_text_get_data(struct mon_event_text *ep, struct urb *urb, 138 int len, char ev_type, struct mon_bus *mbus) 139 { 140 if (len <= 0) 141 return 'L'; 142 if (len >= DATA_MAX) 143 len = DATA_MAX; 144 145 if (ep->is_in) { 146 if (ev_type != 'C') 147 return '<'; 148 } else { 149 if (ev_type != 'S') 150 return '>'; 151 } 152 153 if (urb->transfer_buffer == NULL) 154 return 'Z'; /* '0' would be not as pretty. */ 155 156 memcpy(ep->data, urb->transfer_buffer, len); 157 return 0; 158 } 159 160 static inline unsigned int mon_get_timestamp(void) 161 { 162 struct timeval tval; 163 unsigned int stamp; 164 165 do_gettimeofday(&tval); 166 stamp = tval.tv_sec & 0xFFFF; /* 2^32 = 4294967296. Limit to 4096s. */ 167 stamp = stamp * 1000000 + tval.tv_usec; 168 return stamp; 169 } 170 171 static void mon_text_event(struct mon_reader_text *rp, struct urb *urb, 172 char ev_type, int status) 173 { 174 struct mon_event_text *ep; 175 unsigned int stamp; 176 struct usb_iso_packet_descriptor *fp; 177 struct mon_iso_desc *dp; 178 int i, ndesc; 179 180 stamp = mon_get_timestamp(); 181 182 if (rp->nevents >= EVENT_MAX || 183 (ep = kmem_cache_alloc(rp->e_slab, GFP_ATOMIC)) == NULL) { 184 rp->r.m_bus->cnt_text_lost++; 185 return; 186 } 187 188 ep->type = ev_type; 189 ep->id = (unsigned long) urb; 190 ep->busnum = urb->dev->bus->busnum; 191 ep->devnum = urb->dev->devnum; 192 ep->epnum = usb_endpoint_num(&urb->ep->desc); 193 ep->xfertype = usb_endpoint_type(&urb->ep->desc); 194 ep->is_in = usb_urb_dir_in(urb); 195 ep->tstamp = stamp; 196 ep->length = (ev_type == 'S') ? 197 urb->transfer_buffer_length : urb->actual_length; 198 /* Collecting status makes debugging sense for submits, too */ 199 ep->status = status; 200 201 if (ep->xfertype == USB_ENDPOINT_XFER_INT) { 202 ep->interval = urb->interval; 203 } else if (ep->xfertype == USB_ENDPOINT_XFER_ISOC) { 204 ep->interval = urb->interval; 205 ep->start_frame = urb->start_frame; 206 ep->error_count = urb->error_count; 207 } 208 ep->numdesc = urb->number_of_packets; 209 if (ep->xfertype == USB_ENDPOINT_XFER_ISOC && 210 urb->number_of_packets > 0) { 211 if ((ndesc = urb->number_of_packets) > ISODESC_MAX) 212 ndesc = ISODESC_MAX; 213 fp = urb->iso_frame_desc; 214 dp = ep->isodesc; 215 for (i = 0; i < ndesc; i++) { 216 dp->status = fp->status; 217 dp->offset = fp->offset; 218 dp->length = (ev_type == 'S') ? 219 fp->length : fp->actual_length; 220 fp++; 221 dp++; 222 } 223 } 224 225 ep->setup_flag = mon_text_get_setup(ep, urb, ev_type, rp->r.m_bus); 226 ep->data_flag = mon_text_get_data(ep, urb, ep->length, ev_type, 227 rp->r.m_bus); 228 229 rp->nevents++; 230 list_add_tail(&ep->e_link, &rp->e_list); 231 wake_up(&rp->wait); 232 } 233 234 static void mon_text_submit(void *data, struct urb *urb) 235 { 236 struct mon_reader_text *rp = data; 237 mon_text_event(rp, urb, 'S', -EINPROGRESS); 238 } 239 240 static void mon_text_complete(void *data, struct urb *urb, int status) 241 { 242 struct mon_reader_text *rp = data; 243 mon_text_event(rp, urb, 'C', status); 244 } 245 246 static void mon_text_error(void *data, struct urb *urb, int error) 247 { 248 struct mon_reader_text *rp = data; 249 struct mon_event_text *ep; 250 251 if (rp->nevents >= EVENT_MAX || 252 (ep = kmem_cache_alloc(rp->e_slab, GFP_ATOMIC)) == NULL) { 253 rp->r.m_bus->cnt_text_lost++; 254 return; 255 } 256 257 ep->type = 'E'; 258 ep->id = (unsigned long) urb; 259 ep->busnum = 0; 260 ep->devnum = urb->dev->devnum; 261 ep->epnum = usb_endpoint_num(&urb->ep->desc); 262 ep->xfertype = usb_endpoint_type(&urb->ep->desc); 263 ep->is_in = usb_urb_dir_in(urb); 264 ep->tstamp = 0; 265 ep->length = 0; 266 ep->status = error; 267 268 ep->setup_flag = '-'; 269 ep->data_flag = 'E'; 270 271 rp->nevents++; 272 list_add_tail(&ep->e_link, &rp->e_list); 273 wake_up(&rp->wait); 274 } 275 276 /* 277 * Fetch next event from the circular buffer. 278 */ 279 static struct mon_event_text *mon_text_fetch(struct mon_reader_text *rp, 280 struct mon_bus *mbus) 281 { 282 struct list_head *p; 283 unsigned long flags; 284 285 spin_lock_irqsave(&mbus->lock, flags); 286 if (list_empty(&rp->e_list)) { 287 spin_unlock_irqrestore(&mbus->lock, flags); 288 return NULL; 289 } 290 p = rp->e_list.next; 291 list_del(p); 292 --rp->nevents; 293 spin_unlock_irqrestore(&mbus->lock, flags); 294 return list_entry(p, struct mon_event_text, e_link); 295 } 296 297 /* 298 */ 299 static int mon_text_open(struct inode *inode, struct file *file) 300 { 301 struct mon_bus *mbus; 302 struct mon_reader_text *rp; 303 int rc; 304 305 mutex_lock(&mon_lock); 306 mbus = inode->i_private; 307 308 rp = kzalloc(sizeof(struct mon_reader_text), GFP_KERNEL); 309 if (rp == NULL) { 310 rc = -ENOMEM; 311 goto err_alloc; 312 } 313 INIT_LIST_HEAD(&rp->e_list); 314 init_waitqueue_head(&rp->wait); 315 mutex_init(&rp->printf_lock); 316 317 rp->printf_size = PRINTF_DFL; 318 rp->printf_buf = kmalloc(rp->printf_size, GFP_KERNEL); 319 if (rp->printf_buf == NULL) { 320 rc = -ENOMEM; 321 goto err_alloc_pr; 322 } 323 324 rp->r.m_bus = mbus; 325 rp->r.r_data = rp; 326 rp->r.rnf_submit = mon_text_submit; 327 rp->r.rnf_error = mon_text_error; 328 rp->r.rnf_complete = mon_text_complete; 329 330 snprintf(rp->slab_name, SLAB_NAME_SZ, "mon_text_%p", rp); 331 rp->e_slab = kmem_cache_create(rp->slab_name, 332 sizeof(struct mon_event_text), sizeof(long), 0, 333 mon_text_ctor); 334 if (rp->e_slab == NULL) { 335 rc = -ENOMEM; 336 goto err_slab; 337 } 338 339 mon_reader_add(mbus, &rp->r); 340 341 file->private_data = rp; 342 mutex_unlock(&mon_lock); 343 return 0; 344 345 // err_busy: 346 // kmem_cache_destroy(rp->e_slab); 347 err_slab: 348 kfree(rp->printf_buf); 349 err_alloc_pr: 350 kfree(rp); 351 err_alloc: 352 mutex_unlock(&mon_lock); 353 return rc; 354 } 355 356 /* 357 * For simplicity, we read one record in one system call and throw out 358 * what does not fit. This means that the following does not work: 359 * dd if=/dbg/usbmon/0t bs=10 360 * Also, we do not allow seeks and do not bother advancing the offset. 361 */ 362 static ssize_t mon_text_read_t(struct file *file, char __user *buf, 363 size_t nbytes, loff_t *ppos) 364 { 365 struct mon_reader_text *rp = file->private_data; 366 struct mon_event_text *ep; 367 struct mon_text_ptr ptr; 368 369 if (IS_ERR(ep = mon_text_read_wait(rp, file))) 370 return PTR_ERR(ep); 371 mutex_lock(&rp->printf_lock); 372 ptr.cnt = 0; 373 ptr.pbuf = rp->printf_buf; 374 ptr.limit = rp->printf_size; 375 376 mon_text_read_head_t(rp, &ptr, ep); 377 mon_text_read_statset(rp, &ptr, ep); 378 ptr.cnt += snprintf(ptr.pbuf + ptr.cnt, ptr.limit - ptr.cnt, 379 " %d", ep->length); 380 mon_text_read_data(rp, &ptr, ep); 381 382 if (copy_to_user(buf, rp->printf_buf, ptr.cnt)) 383 ptr.cnt = -EFAULT; 384 mutex_unlock(&rp->printf_lock); 385 kmem_cache_free(rp->e_slab, ep); 386 return ptr.cnt; 387 } 388 389 static ssize_t mon_text_read_u(struct file *file, char __user *buf, 390 size_t nbytes, loff_t *ppos) 391 { 392 struct mon_reader_text *rp = file->private_data; 393 struct mon_event_text *ep; 394 struct mon_text_ptr ptr; 395 396 if (IS_ERR(ep = mon_text_read_wait(rp, file))) 397 return PTR_ERR(ep); 398 mutex_lock(&rp->printf_lock); 399 ptr.cnt = 0; 400 ptr.pbuf = rp->printf_buf; 401 ptr.limit = rp->printf_size; 402 403 mon_text_read_head_u(rp, &ptr, ep); 404 if (ep->type == 'E') { 405 mon_text_read_statset(rp, &ptr, ep); 406 } else if (ep->xfertype == USB_ENDPOINT_XFER_ISOC) { 407 mon_text_read_isostat(rp, &ptr, ep); 408 mon_text_read_isodesc(rp, &ptr, ep); 409 } else if (ep->xfertype == USB_ENDPOINT_XFER_INT) { 410 mon_text_read_intstat(rp, &ptr, ep); 411 } else { 412 mon_text_read_statset(rp, &ptr, ep); 413 } 414 ptr.cnt += snprintf(ptr.pbuf + ptr.cnt, ptr.limit - ptr.cnt, 415 " %d", ep->length); 416 mon_text_read_data(rp, &ptr, ep); 417 418 if (copy_to_user(buf, rp->printf_buf, ptr.cnt)) 419 ptr.cnt = -EFAULT; 420 mutex_unlock(&rp->printf_lock); 421 kmem_cache_free(rp->e_slab, ep); 422 return ptr.cnt; 423 } 424 425 static struct mon_event_text *mon_text_read_wait(struct mon_reader_text *rp, 426 struct file *file) 427 { 428 struct mon_bus *mbus = rp->r.m_bus; 429 DECLARE_WAITQUEUE(waita, current); 430 struct mon_event_text *ep; 431 432 add_wait_queue(&rp->wait, &waita); 433 set_current_state(TASK_INTERRUPTIBLE); 434 while ((ep = mon_text_fetch(rp, mbus)) == NULL) { 435 if (file->f_flags & O_NONBLOCK) { 436 set_current_state(TASK_RUNNING); 437 remove_wait_queue(&rp->wait, &waita); 438 return ERR_PTR(-EWOULDBLOCK); 439 } 440 /* 441 * We do not count nwaiters, because ->release is supposed 442 * to be called when all openers are gone only. 443 */ 444 schedule(); 445 if (signal_pending(current)) { 446 remove_wait_queue(&rp->wait, &waita); 447 return ERR_PTR(-EINTR); 448 } 449 set_current_state(TASK_INTERRUPTIBLE); 450 } 451 set_current_state(TASK_RUNNING); 452 remove_wait_queue(&rp->wait, &waita); 453 return ep; 454 } 455 456 static void mon_text_read_head_t(struct mon_reader_text *rp, 457 struct mon_text_ptr *p, const struct mon_event_text *ep) 458 { 459 char udir, utype; 460 461 udir = (ep->is_in ? 'i' : 'o'); 462 switch (ep->xfertype) { 463 case USB_ENDPOINT_XFER_ISOC: utype = 'Z'; break; 464 case USB_ENDPOINT_XFER_INT: utype = 'I'; break; 465 case USB_ENDPOINT_XFER_CONTROL: utype = 'C'; break; 466 default: /* PIPE_BULK */ utype = 'B'; 467 } 468 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 469 "%lx %u %c %c%c:%03u:%02u", 470 ep->id, ep->tstamp, ep->type, 471 utype, udir, ep->devnum, ep->epnum); 472 } 473 474 static void mon_text_read_head_u(struct mon_reader_text *rp, 475 struct mon_text_ptr *p, const struct mon_event_text *ep) 476 { 477 char udir, utype; 478 479 udir = (ep->is_in ? 'i' : 'o'); 480 switch (ep->xfertype) { 481 case USB_ENDPOINT_XFER_ISOC: utype = 'Z'; break; 482 case USB_ENDPOINT_XFER_INT: utype = 'I'; break; 483 case USB_ENDPOINT_XFER_CONTROL: utype = 'C'; break; 484 default: /* PIPE_BULK */ utype = 'B'; 485 } 486 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 487 "%lx %u %c %c%c:%d:%03u:%u", 488 ep->id, ep->tstamp, ep->type, 489 utype, udir, ep->busnum, ep->devnum, ep->epnum); 490 } 491 492 static void mon_text_read_statset(struct mon_reader_text *rp, 493 struct mon_text_ptr *p, const struct mon_event_text *ep) 494 { 495 496 if (ep->setup_flag == 0) { /* Setup packet is present and captured */ 497 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 498 " s %02x %02x %04x %04x %04x", 499 ep->setup[0], 500 ep->setup[1], 501 (ep->setup[3] << 8) | ep->setup[2], 502 (ep->setup[5] << 8) | ep->setup[4], 503 (ep->setup[7] << 8) | ep->setup[6]); 504 } else if (ep->setup_flag != '-') { /* Unable to capture setup packet */ 505 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 506 " %c __ __ ____ ____ ____", ep->setup_flag); 507 } else { /* No setup for this kind of URB */ 508 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 509 " %d", ep->status); 510 } 511 } 512 513 static void mon_text_read_intstat(struct mon_reader_text *rp, 514 struct mon_text_ptr *p, const struct mon_event_text *ep) 515 { 516 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 517 " %d:%d", ep->status, ep->interval); 518 } 519 520 static void mon_text_read_isostat(struct mon_reader_text *rp, 521 struct mon_text_ptr *p, const struct mon_event_text *ep) 522 { 523 if (ep->type == 'S') { 524 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 525 " %d:%d:%d", ep->status, ep->interval, ep->start_frame); 526 } else { 527 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 528 " %d:%d:%d:%d", 529 ep->status, ep->interval, ep->start_frame, ep->error_count); 530 } 531 } 532 533 static void mon_text_read_isodesc(struct mon_reader_text *rp, 534 struct mon_text_ptr *p, const struct mon_event_text *ep) 535 { 536 int ndesc; /* Display this many */ 537 int i; 538 const struct mon_iso_desc *dp; 539 540 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 541 " %d", ep->numdesc); 542 ndesc = ep->numdesc; 543 if (ndesc > ISODESC_MAX) 544 ndesc = ISODESC_MAX; 545 if (ndesc < 0) 546 ndesc = 0; 547 dp = ep->isodesc; 548 for (i = 0; i < ndesc; i++) { 549 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 550 " %d:%u:%u", dp->status, dp->offset, dp->length); 551 dp++; 552 } 553 } 554 555 static void mon_text_read_data(struct mon_reader_text *rp, 556 struct mon_text_ptr *p, const struct mon_event_text *ep) 557 { 558 int data_len, i; 559 560 if ((data_len = ep->length) > 0) { 561 if (ep->data_flag == 0) { 562 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 563 " ="); 564 if (data_len >= DATA_MAX) 565 data_len = DATA_MAX; 566 for (i = 0; i < data_len; i++) { 567 if (i % 4 == 0) { 568 p->cnt += snprintf(p->pbuf + p->cnt, 569 p->limit - p->cnt, 570 " "); 571 } 572 p->cnt += snprintf(p->pbuf + p->cnt, 573 p->limit - p->cnt, 574 "%02x", ep->data[i]); 575 } 576 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 577 "\n"); 578 } else { 579 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 580 " %c\n", ep->data_flag); 581 } 582 } else { 583 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, "\n"); 584 } 585 } 586 587 static int mon_text_release(struct inode *inode, struct file *file) 588 { 589 struct mon_reader_text *rp = file->private_data; 590 struct mon_bus *mbus; 591 /* unsigned long flags; */ 592 struct list_head *p; 593 struct mon_event_text *ep; 594 595 mutex_lock(&mon_lock); 596 mbus = inode->i_private; 597 598 if (mbus->nreaders <= 0) { 599 printk(KERN_ERR TAG ": consistency error on close\n"); 600 mutex_unlock(&mon_lock); 601 return 0; 602 } 603 mon_reader_del(mbus, &rp->r); 604 605 /* 606 * In theory, e_list is protected by mbus->lock. However, 607 * after mon_reader_del has finished, the following is the case: 608 * - we are not on reader list anymore, so new events won't be added; 609 * - whole mbus may be dropped if it was orphaned. 610 * So, we better not touch mbus. 611 */ 612 /* spin_lock_irqsave(&mbus->lock, flags); */ 613 while (!list_empty(&rp->e_list)) { 614 p = rp->e_list.next; 615 ep = list_entry(p, struct mon_event_text, e_link); 616 list_del(p); 617 --rp->nevents; 618 kmem_cache_free(rp->e_slab, ep); 619 } 620 /* spin_unlock_irqrestore(&mbus->lock, flags); */ 621 622 kmem_cache_destroy(rp->e_slab); 623 kfree(rp->printf_buf); 624 kfree(rp); 625 626 mutex_unlock(&mon_lock); 627 return 0; 628 } 629 630 static const struct file_operations mon_fops_text_t = { 631 .owner = THIS_MODULE, 632 .open = mon_text_open, 633 .llseek = no_llseek, 634 .read = mon_text_read_t, 635 .release = mon_text_release, 636 }; 637 638 static const struct file_operations mon_fops_text_u = { 639 .owner = THIS_MODULE, 640 .open = mon_text_open, 641 .llseek = no_llseek, 642 .read = mon_text_read_u, 643 .release = mon_text_release, 644 }; 645 646 int mon_text_add(struct mon_bus *mbus, const struct usb_bus *ubus) 647 { 648 struct dentry *d; 649 enum { NAMESZ = 10 }; 650 char name[NAMESZ]; 651 int busnum = ubus? ubus->busnum: 0; 652 int rc; 653 654 if (ubus != NULL) { 655 rc = snprintf(name, NAMESZ, "%dt", busnum); 656 if (rc <= 0 || rc >= NAMESZ) 657 goto err_print_t; 658 d = debugfs_create_file(name, 0600, mon_dir, mbus, 659 &mon_fops_text_t); 660 if (d == NULL) 661 goto err_create_t; 662 mbus->dent_t = d; 663 } 664 665 rc = snprintf(name, NAMESZ, "%du", busnum); 666 if (rc <= 0 || rc >= NAMESZ) 667 goto err_print_u; 668 d = debugfs_create_file(name, 0600, mon_dir, mbus, &mon_fops_text_u); 669 if (d == NULL) 670 goto err_create_u; 671 mbus->dent_u = d; 672 673 rc = snprintf(name, NAMESZ, "%ds", busnum); 674 if (rc <= 0 || rc >= NAMESZ) 675 goto err_print_s; 676 d = debugfs_create_file(name, 0600, mon_dir, mbus, &mon_fops_stat); 677 if (d == NULL) 678 goto err_create_s; 679 mbus->dent_s = d; 680 681 return 1; 682 683 err_create_s: 684 err_print_s: 685 debugfs_remove(mbus->dent_u); 686 mbus->dent_u = NULL; 687 err_create_u: 688 err_print_u: 689 if (ubus != NULL) { 690 debugfs_remove(mbus->dent_t); 691 mbus->dent_t = NULL; 692 } 693 err_create_t: 694 err_print_t: 695 return 0; 696 } 697 698 void mon_text_del(struct mon_bus *mbus) 699 { 700 debugfs_remove(mbus->dent_u); 701 if (mbus->dent_t != NULL) 702 debugfs_remove(mbus->dent_t); 703 debugfs_remove(mbus->dent_s); 704 } 705 706 /* 707 * Slab interface: constructor. 708 */ 709 static void mon_text_ctor(void *mem) 710 { 711 /* 712 * Nothing to initialize. No, really! 713 * So, we fill it with garbage to emulate a reused object. 714 */ 715 memset(mem, 0xe5, sizeof(struct mon_event_text)); 716 } 717 718 int __init mon_text_init(void) 719 { 720 struct dentry *mondir; 721 722 mondir = debugfs_create_dir("usbmon", usb_debug_root); 723 if (IS_ERR(mondir)) { 724 printk(KERN_NOTICE TAG ": debugfs is not available\n"); 725 return -ENODEV; 726 } 727 if (mondir == NULL) { 728 printk(KERN_NOTICE TAG ": unable to create usbmon directory\n"); 729 return -ENODEV; 730 } 731 mon_dir = mondir; 732 return 0; 733 } 734 735 void mon_text_exit(void) 736 { 737 debugfs_remove(mon_dir); 738 } 739