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/slab.h> 11 #include <linux/time.h> 12 #include <linux/mutex.h> 13 #include <linux/debugfs.h> 14 #include <linux/scatterlist.h> 15 #include <asm/uaccess.h> 16 17 #include "usb_mon.h" 18 19 /* 20 * No, we do not want arbitrarily long data strings. 21 * Use the binary interface if you want to capture bulk data! 22 */ 23 #define DATA_MAX 32 24 25 /* 26 * Defined by USB 2.0 clause 9.3, table 9.2. 27 */ 28 #define SETUP_MAX 8 29 30 /* 31 * This limit exists to prevent OOMs when the user process stops reading. 32 * If usbmon were available to unprivileged processes, it might be open 33 * to a local DoS. But we have to keep to root in order to prevent 34 * password sniffing from HID devices. 35 */ 36 #define EVENT_MAX (4*PAGE_SIZE / sizeof(struct mon_event_text)) 37 38 /* 39 * Potentially unlimited number; we limit it for similar allocations. 40 * The usbfs limits this to 128, but we're not quite as generous. 41 */ 42 #define ISODESC_MAX 5 43 44 #define PRINTF_DFL 250 /* with 5 ISOs segs */ 45 46 struct mon_iso_desc { 47 int status; 48 unsigned int offset; 49 unsigned int length; /* Unsigned here, signed in URB. Historic. */ 50 }; 51 52 struct mon_event_text { 53 struct list_head e_link; 54 int type; /* submit, complete, etc. */ 55 unsigned long id; /* From pointer, most of the time */ 56 unsigned int tstamp; 57 int busnum; 58 char devnum; 59 char epnum; 60 char is_in; 61 char xfertype; 62 int length; /* Depends on type: xfer length or act length */ 63 int status; 64 int interval; 65 int start_frame; 66 int error_count; 67 char setup_flag; 68 char data_flag; 69 int numdesc; /* Full number */ 70 struct mon_iso_desc isodesc[ISODESC_MAX]; 71 unsigned char setup[SETUP_MAX]; 72 unsigned char data[DATA_MAX]; 73 }; 74 75 #define SLAB_NAME_SZ 30 76 struct mon_reader_text { 77 struct kmem_cache *e_slab; 78 int nevents; 79 struct list_head e_list; 80 struct mon_reader r; /* In C, parent class can be placed anywhere */ 81 82 wait_queue_head_t wait; 83 int printf_size; 84 char *printf_buf; 85 struct mutex printf_lock; 86 87 char slab_name[SLAB_NAME_SZ]; 88 }; 89 90 static struct dentry *mon_dir; /* Usually /sys/kernel/debug/usbmon */ 91 92 static void mon_text_ctor(void *); 93 94 struct mon_text_ptr { 95 int cnt, limit; 96 char *pbuf; 97 }; 98 99 static struct mon_event_text * 100 mon_text_read_wait(struct mon_reader_text *rp, struct file *file); 101 static void mon_text_read_head_t(struct mon_reader_text *rp, 102 struct mon_text_ptr *p, const struct mon_event_text *ep); 103 static void mon_text_read_head_u(struct mon_reader_text *rp, 104 struct mon_text_ptr *p, const struct mon_event_text *ep); 105 static void mon_text_read_statset(struct mon_reader_text *rp, 106 struct mon_text_ptr *p, const struct mon_event_text *ep); 107 static void mon_text_read_intstat(struct mon_reader_text *rp, 108 struct mon_text_ptr *p, const struct mon_event_text *ep); 109 static void mon_text_read_isostat(struct mon_reader_text *rp, 110 struct mon_text_ptr *p, const struct mon_event_text *ep); 111 static void mon_text_read_isodesc(struct mon_reader_text *rp, 112 struct mon_text_ptr *p, const struct mon_event_text *ep); 113 static void mon_text_read_data(struct mon_reader_text *rp, 114 struct mon_text_ptr *p, const struct mon_event_text *ep); 115 116 /* 117 * mon_text_submit 118 * mon_text_complete 119 * 120 * May be called from an interrupt. 121 * 122 * This is called with the whole mon_bus locked, so no additional lock. 123 */ 124 125 static inline char mon_text_get_setup(struct mon_event_text *ep, 126 struct urb *urb, char ev_type, struct mon_bus *mbus) 127 { 128 129 if (ep->xfertype != USB_ENDPOINT_XFER_CONTROL || ev_type != 'S') 130 return '-'; 131 132 if (urb->setup_packet == NULL) 133 return 'Z'; /* '0' would be not as pretty. */ 134 135 memcpy(ep->setup, urb->setup_packet, SETUP_MAX); 136 return 0; 137 } 138 139 static inline char mon_text_get_data(struct mon_event_text *ep, struct urb *urb, 140 int len, char ev_type, struct mon_bus *mbus) 141 { 142 void *src; 143 144 if (len <= 0) 145 return 'L'; 146 if (len >= DATA_MAX) 147 len = DATA_MAX; 148 149 if (ep->is_in) { 150 if (ev_type != 'C') 151 return '<'; 152 } else { 153 if (ev_type != 'S') 154 return '>'; 155 } 156 157 if (urb->num_sgs == 0) { 158 src = urb->transfer_buffer; 159 if (src == NULL) 160 return 'Z'; /* '0' would be not as pretty. */ 161 } else { 162 struct scatterlist *sg = urb->sg->sg; 163 164 /* If IOMMU coalescing occurred, we cannot trust sg_page */ 165 if (urb->sg->nents != urb->num_sgs || 166 PageHighMem(sg_page(sg))) 167 return 'D'; 168 169 /* For the text interface we copy only the first sg buffer */ 170 len = min_t(int, sg->length, len); 171 src = sg_virt(sg); 172 } 173 174 memcpy(ep->data, src, len); 175 return 0; 176 } 177 178 static inline unsigned int mon_get_timestamp(void) 179 { 180 struct timeval tval; 181 unsigned int stamp; 182 183 do_gettimeofday(&tval); 184 stamp = tval.tv_sec & 0xFFF; /* 2^32 = 4294967296. Limit to 4096s. */ 185 stamp = stamp * 1000000 + tval.tv_usec; 186 return stamp; 187 } 188 189 static void mon_text_event(struct mon_reader_text *rp, struct urb *urb, 190 char ev_type, int status) 191 { 192 struct mon_event_text *ep; 193 unsigned int stamp; 194 struct usb_iso_packet_descriptor *fp; 195 struct mon_iso_desc *dp; 196 int i, ndesc; 197 198 stamp = mon_get_timestamp(); 199 200 if (rp->nevents >= EVENT_MAX || 201 (ep = kmem_cache_alloc(rp->e_slab, GFP_ATOMIC)) == NULL) { 202 rp->r.m_bus->cnt_text_lost++; 203 return; 204 } 205 206 ep->type = ev_type; 207 ep->id = (unsigned long) urb; 208 ep->busnum = urb->dev->bus->busnum; 209 ep->devnum = urb->dev->devnum; 210 ep->epnum = usb_endpoint_num(&urb->ep->desc); 211 ep->xfertype = usb_endpoint_type(&urb->ep->desc); 212 ep->is_in = usb_urb_dir_in(urb); 213 ep->tstamp = stamp; 214 ep->length = (ev_type == 'S') ? 215 urb->transfer_buffer_length : urb->actual_length; 216 /* Collecting status makes debugging sense for submits, too */ 217 ep->status = status; 218 219 if (ep->xfertype == USB_ENDPOINT_XFER_INT) { 220 ep->interval = urb->interval; 221 } else if (ep->xfertype == USB_ENDPOINT_XFER_ISOC) { 222 ep->interval = urb->interval; 223 ep->start_frame = urb->start_frame; 224 ep->error_count = urb->error_count; 225 } 226 ep->numdesc = urb->number_of_packets; 227 if (ep->xfertype == USB_ENDPOINT_XFER_ISOC && 228 urb->number_of_packets > 0) { 229 if ((ndesc = urb->number_of_packets) > ISODESC_MAX) 230 ndesc = ISODESC_MAX; 231 fp = urb->iso_frame_desc; 232 dp = ep->isodesc; 233 for (i = 0; i < ndesc; i++) { 234 dp->status = fp->status; 235 dp->offset = fp->offset; 236 dp->length = (ev_type == 'S') ? 237 fp->length : fp->actual_length; 238 fp++; 239 dp++; 240 } 241 } 242 243 ep->setup_flag = mon_text_get_setup(ep, urb, ev_type, rp->r.m_bus); 244 ep->data_flag = mon_text_get_data(ep, urb, ep->length, ev_type, 245 rp->r.m_bus); 246 247 rp->nevents++; 248 list_add_tail(&ep->e_link, &rp->e_list); 249 wake_up(&rp->wait); 250 } 251 252 static void mon_text_submit(void *data, struct urb *urb) 253 { 254 struct mon_reader_text *rp = data; 255 mon_text_event(rp, urb, 'S', -EINPROGRESS); 256 } 257 258 static void mon_text_complete(void *data, struct urb *urb, int status) 259 { 260 struct mon_reader_text *rp = data; 261 mon_text_event(rp, urb, 'C', status); 262 } 263 264 static void mon_text_error(void *data, struct urb *urb, int error) 265 { 266 struct mon_reader_text *rp = data; 267 struct mon_event_text *ep; 268 269 if (rp->nevents >= EVENT_MAX || 270 (ep = kmem_cache_alloc(rp->e_slab, GFP_ATOMIC)) == NULL) { 271 rp->r.m_bus->cnt_text_lost++; 272 return; 273 } 274 275 ep->type = 'E'; 276 ep->id = (unsigned long) urb; 277 ep->busnum = urb->dev->bus->busnum; 278 ep->devnum = urb->dev->devnum; 279 ep->epnum = usb_endpoint_num(&urb->ep->desc); 280 ep->xfertype = usb_endpoint_type(&urb->ep->desc); 281 ep->is_in = usb_urb_dir_in(urb); 282 ep->tstamp = mon_get_timestamp(); 283 ep->length = 0; 284 ep->status = error; 285 286 ep->setup_flag = '-'; 287 ep->data_flag = 'E'; 288 289 rp->nevents++; 290 list_add_tail(&ep->e_link, &rp->e_list); 291 wake_up(&rp->wait); 292 } 293 294 /* 295 * Fetch next event from the circular buffer. 296 */ 297 static struct mon_event_text *mon_text_fetch(struct mon_reader_text *rp, 298 struct mon_bus *mbus) 299 { 300 struct list_head *p; 301 unsigned long flags; 302 303 spin_lock_irqsave(&mbus->lock, flags); 304 if (list_empty(&rp->e_list)) { 305 spin_unlock_irqrestore(&mbus->lock, flags); 306 return NULL; 307 } 308 p = rp->e_list.next; 309 list_del(p); 310 --rp->nevents; 311 spin_unlock_irqrestore(&mbus->lock, flags); 312 return list_entry(p, struct mon_event_text, e_link); 313 } 314 315 /* 316 */ 317 static int mon_text_open(struct inode *inode, struct file *file) 318 { 319 struct mon_bus *mbus; 320 struct mon_reader_text *rp; 321 int rc; 322 323 mutex_lock(&mon_lock); 324 mbus = inode->i_private; 325 326 rp = kzalloc(sizeof(struct mon_reader_text), GFP_KERNEL); 327 if (rp == NULL) { 328 rc = -ENOMEM; 329 goto err_alloc; 330 } 331 INIT_LIST_HEAD(&rp->e_list); 332 init_waitqueue_head(&rp->wait); 333 mutex_init(&rp->printf_lock); 334 335 rp->printf_size = PRINTF_DFL; 336 rp->printf_buf = kmalloc(rp->printf_size, GFP_KERNEL); 337 if (rp->printf_buf == NULL) { 338 rc = -ENOMEM; 339 goto err_alloc_pr; 340 } 341 342 rp->r.m_bus = mbus; 343 rp->r.r_data = rp; 344 rp->r.rnf_submit = mon_text_submit; 345 rp->r.rnf_error = mon_text_error; 346 rp->r.rnf_complete = mon_text_complete; 347 348 snprintf(rp->slab_name, SLAB_NAME_SZ, "mon_text_%p", rp); 349 rp->e_slab = kmem_cache_create(rp->slab_name, 350 sizeof(struct mon_event_text), sizeof(long), 0, 351 mon_text_ctor); 352 if (rp->e_slab == NULL) { 353 rc = -ENOMEM; 354 goto err_slab; 355 } 356 357 mon_reader_add(mbus, &rp->r); 358 359 file->private_data = rp; 360 mutex_unlock(&mon_lock); 361 return 0; 362 363 // err_busy: 364 // kmem_cache_destroy(rp->e_slab); 365 err_slab: 366 kfree(rp->printf_buf); 367 err_alloc_pr: 368 kfree(rp); 369 err_alloc: 370 mutex_unlock(&mon_lock); 371 return rc; 372 } 373 374 /* 375 * For simplicity, we read one record in one system call and throw out 376 * what does not fit. This means that the following does not work: 377 * dd if=/dbg/usbmon/0t bs=10 378 * Also, we do not allow seeks and do not bother advancing the offset. 379 */ 380 static ssize_t mon_text_read_t(struct file *file, char __user *buf, 381 size_t nbytes, loff_t *ppos) 382 { 383 struct mon_reader_text *rp = file->private_data; 384 struct mon_event_text *ep; 385 struct mon_text_ptr ptr; 386 387 if (IS_ERR(ep = mon_text_read_wait(rp, file))) 388 return PTR_ERR(ep); 389 mutex_lock(&rp->printf_lock); 390 ptr.cnt = 0; 391 ptr.pbuf = rp->printf_buf; 392 ptr.limit = rp->printf_size; 393 394 mon_text_read_head_t(rp, &ptr, ep); 395 mon_text_read_statset(rp, &ptr, ep); 396 ptr.cnt += snprintf(ptr.pbuf + ptr.cnt, ptr.limit - ptr.cnt, 397 " %d", ep->length); 398 mon_text_read_data(rp, &ptr, ep); 399 400 if (copy_to_user(buf, rp->printf_buf, ptr.cnt)) 401 ptr.cnt = -EFAULT; 402 mutex_unlock(&rp->printf_lock); 403 kmem_cache_free(rp->e_slab, ep); 404 return ptr.cnt; 405 } 406 407 static ssize_t mon_text_read_u(struct file *file, char __user *buf, 408 size_t nbytes, loff_t *ppos) 409 { 410 struct mon_reader_text *rp = file->private_data; 411 struct mon_event_text *ep; 412 struct mon_text_ptr ptr; 413 414 if (IS_ERR(ep = mon_text_read_wait(rp, file))) 415 return PTR_ERR(ep); 416 mutex_lock(&rp->printf_lock); 417 ptr.cnt = 0; 418 ptr.pbuf = rp->printf_buf; 419 ptr.limit = rp->printf_size; 420 421 mon_text_read_head_u(rp, &ptr, ep); 422 if (ep->type == 'E') { 423 mon_text_read_statset(rp, &ptr, ep); 424 } else if (ep->xfertype == USB_ENDPOINT_XFER_ISOC) { 425 mon_text_read_isostat(rp, &ptr, ep); 426 mon_text_read_isodesc(rp, &ptr, ep); 427 } else if (ep->xfertype == USB_ENDPOINT_XFER_INT) { 428 mon_text_read_intstat(rp, &ptr, ep); 429 } else { 430 mon_text_read_statset(rp, &ptr, ep); 431 } 432 ptr.cnt += snprintf(ptr.pbuf + ptr.cnt, ptr.limit - ptr.cnt, 433 " %d", ep->length); 434 mon_text_read_data(rp, &ptr, ep); 435 436 if (copy_to_user(buf, rp->printf_buf, ptr.cnt)) 437 ptr.cnt = -EFAULT; 438 mutex_unlock(&rp->printf_lock); 439 kmem_cache_free(rp->e_slab, ep); 440 return ptr.cnt; 441 } 442 443 static struct mon_event_text *mon_text_read_wait(struct mon_reader_text *rp, 444 struct file *file) 445 { 446 struct mon_bus *mbus = rp->r.m_bus; 447 DECLARE_WAITQUEUE(waita, current); 448 struct mon_event_text *ep; 449 450 add_wait_queue(&rp->wait, &waita); 451 set_current_state(TASK_INTERRUPTIBLE); 452 while ((ep = mon_text_fetch(rp, mbus)) == NULL) { 453 if (file->f_flags & O_NONBLOCK) { 454 set_current_state(TASK_RUNNING); 455 remove_wait_queue(&rp->wait, &waita); 456 return ERR_PTR(-EWOULDBLOCK); 457 } 458 /* 459 * We do not count nwaiters, because ->release is supposed 460 * to be called when all openers are gone only. 461 */ 462 schedule(); 463 if (signal_pending(current)) { 464 remove_wait_queue(&rp->wait, &waita); 465 return ERR_PTR(-EINTR); 466 } 467 set_current_state(TASK_INTERRUPTIBLE); 468 } 469 set_current_state(TASK_RUNNING); 470 remove_wait_queue(&rp->wait, &waita); 471 return ep; 472 } 473 474 static void mon_text_read_head_t(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:%03u:%02u", 488 ep->id, ep->tstamp, ep->type, 489 utype, udir, ep->devnum, ep->epnum); 490 } 491 492 static void mon_text_read_head_u(struct mon_reader_text *rp, 493 struct mon_text_ptr *p, const struct mon_event_text *ep) 494 { 495 char udir, utype; 496 497 udir = (ep->is_in ? 'i' : 'o'); 498 switch (ep->xfertype) { 499 case USB_ENDPOINT_XFER_ISOC: utype = 'Z'; break; 500 case USB_ENDPOINT_XFER_INT: utype = 'I'; break; 501 case USB_ENDPOINT_XFER_CONTROL: utype = 'C'; break; 502 default: /* PIPE_BULK */ utype = 'B'; 503 } 504 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 505 "%lx %u %c %c%c:%d:%03u:%u", 506 ep->id, ep->tstamp, ep->type, 507 utype, udir, ep->busnum, ep->devnum, ep->epnum); 508 } 509 510 static void mon_text_read_statset(struct mon_reader_text *rp, 511 struct mon_text_ptr *p, const struct mon_event_text *ep) 512 { 513 514 if (ep->setup_flag == 0) { /* Setup packet is present and captured */ 515 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 516 " s %02x %02x %04x %04x %04x", 517 ep->setup[0], 518 ep->setup[1], 519 (ep->setup[3] << 8) | ep->setup[2], 520 (ep->setup[5] << 8) | ep->setup[4], 521 (ep->setup[7] << 8) | ep->setup[6]); 522 } else if (ep->setup_flag != '-') { /* Unable to capture setup packet */ 523 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 524 " %c __ __ ____ ____ ____", ep->setup_flag); 525 } else { /* No setup for this kind of URB */ 526 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 527 " %d", ep->status); 528 } 529 } 530 531 static void mon_text_read_intstat(struct mon_reader_text *rp, 532 struct mon_text_ptr *p, const struct mon_event_text *ep) 533 { 534 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 535 " %d:%d", ep->status, ep->interval); 536 } 537 538 static void mon_text_read_isostat(struct mon_reader_text *rp, 539 struct mon_text_ptr *p, const struct mon_event_text *ep) 540 { 541 if (ep->type == 'S') { 542 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 543 " %d:%d:%d", ep->status, ep->interval, ep->start_frame); 544 } else { 545 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 546 " %d:%d:%d:%d", 547 ep->status, ep->interval, ep->start_frame, ep->error_count); 548 } 549 } 550 551 static void mon_text_read_isodesc(struct mon_reader_text *rp, 552 struct mon_text_ptr *p, const struct mon_event_text *ep) 553 { 554 int ndesc; /* Display this many */ 555 int i; 556 const struct mon_iso_desc *dp; 557 558 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 559 " %d", ep->numdesc); 560 ndesc = ep->numdesc; 561 if (ndesc > ISODESC_MAX) 562 ndesc = ISODESC_MAX; 563 if (ndesc < 0) 564 ndesc = 0; 565 dp = ep->isodesc; 566 for (i = 0; i < ndesc; i++) { 567 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 568 " %d:%u:%u", dp->status, dp->offset, dp->length); 569 dp++; 570 } 571 } 572 573 static void mon_text_read_data(struct mon_reader_text *rp, 574 struct mon_text_ptr *p, const struct mon_event_text *ep) 575 { 576 int data_len, i; 577 578 if ((data_len = ep->length) > 0) { 579 if (ep->data_flag == 0) { 580 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 581 " ="); 582 if (data_len >= DATA_MAX) 583 data_len = DATA_MAX; 584 for (i = 0; i < data_len; i++) { 585 if (i % 4 == 0) { 586 p->cnt += snprintf(p->pbuf + p->cnt, 587 p->limit - p->cnt, 588 " "); 589 } 590 p->cnt += snprintf(p->pbuf + p->cnt, 591 p->limit - p->cnt, 592 "%02x", ep->data[i]); 593 } 594 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 595 "\n"); 596 } else { 597 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 598 " %c\n", ep->data_flag); 599 } 600 } else { 601 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, "\n"); 602 } 603 } 604 605 static int mon_text_release(struct inode *inode, struct file *file) 606 { 607 struct mon_reader_text *rp = file->private_data; 608 struct mon_bus *mbus; 609 /* unsigned long flags; */ 610 struct list_head *p; 611 struct mon_event_text *ep; 612 613 mutex_lock(&mon_lock); 614 mbus = inode->i_private; 615 616 if (mbus->nreaders <= 0) { 617 printk(KERN_ERR TAG ": consistency error on close\n"); 618 mutex_unlock(&mon_lock); 619 return 0; 620 } 621 mon_reader_del(mbus, &rp->r); 622 623 /* 624 * In theory, e_list is protected by mbus->lock. However, 625 * after mon_reader_del has finished, the following is the case: 626 * - we are not on reader list anymore, so new events won't be added; 627 * - whole mbus may be dropped if it was orphaned. 628 * So, we better not touch mbus. 629 */ 630 /* spin_lock_irqsave(&mbus->lock, flags); */ 631 while (!list_empty(&rp->e_list)) { 632 p = rp->e_list.next; 633 ep = list_entry(p, struct mon_event_text, e_link); 634 list_del(p); 635 --rp->nevents; 636 kmem_cache_free(rp->e_slab, ep); 637 } 638 /* spin_unlock_irqrestore(&mbus->lock, flags); */ 639 640 kmem_cache_destroy(rp->e_slab); 641 kfree(rp->printf_buf); 642 kfree(rp); 643 644 mutex_unlock(&mon_lock); 645 return 0; 646 } 647 648 static const struct file_operations mon_fops_text_t = { 649 .owner = THIS_MODULE, 650 .open = mon_text_open, 651 .llseek = no_llseek, 652 .read = mon_text_read_t, 653 .release = mon_text_release, 654 }; 655 656 static const struct file_operations mon_fops_text_u = { 657 .owner = THIS_MODULE, 658 .open = mon_text_open, 659 .llseek = no_llseek, 660 .read = mon_text_read_u, 661 .release = mon_text_release, 662 }; 663 664 int mon_text_add(struct mon_bus *mbus, const struct usb_bus *ubus) 665 { 666 struct dentry *d; 667 enum { NAMESZ = 10 }; 668 char name[NAMESZ]; 669 int busnum = ubus? ubus->busnum: 0; 670 int rc; 671 672 if (ubus != NULL) { 673 rc = snprintf(name, NAMESZ, "%dt", busnum); 674 if (rc <= 0 || rc >= NAMESZ) 675 goto err_print_t; 676 d = debugfs_create_file(name, 0600, mon_dir, mbus, 677 &mon_fops_text_t); 678 if (d == NULL) 679 goto err_create_t; 680 mbus->dent_t = d; 681 } 682 683 rc = snprintf(name, NAMESZ, "%du", busnum); 684 if (rc <= 0 || rc >= NAMESZ) 685 goto err_print_u; 686 d = debugfs_create_file(name, 0600, mon_dir, mbus, &mon_fops_text_u); 687 if (d == NULL) 688 goto err_create_u; 689 mbus->dent_u = d; 690 691 rc = snprintf(name, NAMESZ, "%ds", busnum); 692 if (rc <= 0 || rc >= NAMESZ) 693 goto err_print_s; 694 d = debugfs_create_file(name, 0600, mon_dir, mbus, &mon_fops_stat); 695 if (d == NULL) 696 goto err_create_s; 697 mbus->dent_s = d; 698 699 return 1; 700 701 err_create_s: 702 err_print_s: 703 debugfs_remove(mbus->dent_u); 704 mbus->dent_u = NULL; 705 err_create_u: 706 err_print_u: 707 if (ubus != NULL) { 708 debugfs_remove(mbus->dent_t); 709 mbus->dent_t = NULL; 710 } 711 err_create_t: 712 err_print_t: 713 return 0; 714 } 715 716 void mon_text_del(struct mon_bus *mbus) 717 { 718 debugfs_remove(mbus->dent_u); 719 if (mbus->dent_t != NULL) 720 debugfs_remove(mbus->dent_t); 721 debugfs_remove(mbus->dent_s); 722 } 723 724 /* 725 * Slab interface: constructor. 726 */ 727 static void mon_text_ctor(void *mem) 728 { 729 /* 730 * Nothing to initialize. No, really! 731 * So, we fill it with garbage to emulate a reused object. 732 */ 733 memset(mem, 0xe5, sizeof(struct mon_event_text)); 734 } 735 736 int __init mon_text_init(void) 737 { 738 struct dentry *mondir; 739 740 mondir = debugfs_create_dir("usbmon", usb_debug_root); 741 if (IS_ERR(mondir)) { 742 printk(KERN_NOTICE TAG ": debugfs is not available\n"); 743 return -ENODEV; 744 } 745 if (mondir == NULL) { 746 printk(KERN_NOTICE TAG ": unable to create usbmon directory\n"); 747 return -ENODEV; 748 } 749 mon_dir = mondir; 750 return 0; 751 } 752 753 void mon_text_exit(void) 754 { 755 debugfs_remove(mon_dir); 756 } 757