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/ktime.h> 13 #include <linux/export.h> 14 #include <linux/mutex.h> 15 #include <linux/debugfs.h> 16 #include <linux/scatterlist.h> 17 #include <asm/uaccess.h> 18 19 #include "usb_mon.h" 20 21 /* 22 * No, we do not want arbitrarily long data strings. 23 * Use the binary interface if you want to capture bulk data! 24 */ 25 #define DATA_MAX 32 26 27 /* 28 * Defined by USB 2.0 clause 9.3, table 9.2. 29 */ 30 #define SETUP_MAX 8 31 32 /* 33 * This limit exists to prevent OOMs when the user process stops reading. 34 * If usbmon were available to unprivileged processes, it might be open 35 * to a local DoS. But we have to keep to root in order to prevent 36 * password sniffing from HID devices. 37 */ 38 #define EVENT_MAX (4*PAGE_SIZE / sizeof(struct mon_event_text)) 39 40 /* 41 * Potentially unlimited number; we limit it for similar allocations. 42 * The usbfs limits this to 128, but we're not quite as generous. 43 */ 44 #define ISODESC_MAX 5 45 46 #define PRINTF_DFL 250 /* with 5 ISOs segs */ 47 48 struct mon_iso_desc { 49 int status; 50 unsigned int offset; 51 unsigned int length; /* Unsigned here, signed in URB. Historic. */ 52 }; 53 54 struct mon_event_text { 55 struct list_head e_link; 56 int type; /* submit, complete, etc. */ 57 unsigned long id; /* From pointer, most of the time */ 58 unsigned int tstamp; 59 int busnum; 60 char devnum; 61 char epnum; 62 char is_in; 63 char xfertype; 64 int length; /* Depends on type: xfer length or act length */ 65 int status; 66 int interval; 67 int start_frame; 68 int error_count; 69 char setup_flag; 70 char data_flag; 71 int numdesc; /* Full number */ 72 struct mon_iso_desc isodesc[ISODESC_MAX]; 73 unsigned char setup[SETUP_MAX]; 74 unsigned char data[DATA_MAX]; 75 }; 76 77 #define SLAB_NAME_SZ 30 78 struct mon_reader_text { 79 struct kmem_cache *e_slab; 80 int nevents; 81 struct list_head e_list; 82 struct mon_reader r; /* In C, parent class can be placed anywhere */ 83 84 wait_queue_head_t wait; 85 int printf_size; 86 char *printf_buf; 87 struct mutex printf_lock; 88 89 char slab_name[SLAB_NAME_SZ]; 90 }; 91 92 static struct dentry *mon_dir; /* Usually /sys/kernel/debug/usbmon */ 93 94 static void mon_text_ctor(void *); 95 96 struct mon_text_ptr { 97 int cnt, limit; 98 char *pbuf; 99 }; 100 101 static struct mon_event_text * 102 mon_text_read_wait(struct mon_reader_text *rp, struct file *file); 103 static void mon_text_read_head_t(struct mon_reader_text *rp, 104 struct mon_text_ptr *p, const struct mon_event_text *ep); 105 static void mon_text_read_head_u(struct mon_reader_text *rp, 106 struct mon_text_ptr *p, const struct mon_event_text *ep); 107 static void mon_text_read_statset(struct mon_reader_text *rp, 108 struct mon_text_ptr *p, const struct mon_event_text *ep); 109 static void mon_text_read_intstat(struct mon_reader_text *rp, 110 struct mon_text_ptr *p, const struct mon_event_text *ep); 111 static void mon_text_read_isostat(struct mon_reader_text *rp, 112 struct mon_text_ptr *p, const struct mon_event_text *ep); 113 static void mon_text_read_isodesc(struct mon_reader_text *rp, 114 struct mon_text_ptr *p, const struct mon_event_text *ep); 115 static void mon_text_read_data(struct mon_reader_text *rp, 116 struct mon_text_ptr *p, const struct mon_event_text *ep); 117 118 /* 119 * mon_text_submit 120 * mon_text_complete 121 * 122 * May be called from an interrupt. 123 * 124 * This is called with the whole mon_bus locked, so no additional lock. 125 */ 126 127 static inline char mon_text_get_setup(struct mon_event_text *ep, 128 struct urb *urb, char ev_type, struct mon_bus *mbus) 129 { 130 131 if (ep->xfertype != USB_ENDPOINT_XFER_CONTROL || ev_type != 'S') 132 return '-'; 133 134 if (urb->setup_packet == NULL) 135 return 'Z'; /* '0' would be not as pretty. */ 136 137 memcpy(ep->setup, urb->setup_packet, SETUP_MAX); 138 return 0; 139 } 140 141 static inline char mon_text_get_data(struct mon_event_text *ep, struct urb *urb, 142 int len, char ev_type, struct mon_bus *mbus) 143 { 144 void *src; 145 146 if (len <= 0) 147 return 'L'; 148 if (len >= DATA_MAX) 149 len = DATA_MAX; 150 151 if (ep->is_in) { 152 if (ev_type != 'C') 153 return '<'; 154 } else { 155 if (ev_type != 'S') 156 return '>'; 157 } 158 159 if (urb->num_sgs == 0) { 160 src = urb->transfer_buffer; 161 if (src == NULL) 162 return 'Z'; /* '0' would be not as pretty. */ 163 } else { 164 struct scatterlist *sg = urb->sg; 165 166 if (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 timespec64 now; 181 unsigned int stamp; 182 183 ktime_get_ts64(&now); 184 stamp = now.tv_sec & 0xFFF; /* 2^32 = 4294967296. Limit to 4096s. */ 185 stamp = stamp * USEC_PER_SEC + now.tv_nsec / NSEC_PER_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 /* Wasteful, but simple to understand: ISO 'C' is sparse. */ 242 if (ev_type == 'C') 243 ep->length = urb->transfer_buffer_length; 244 } 245 246 ep->setup_flag = mon_text_get_setup(ep, urb, ev_type, rp->r.m_bus); 247 ep->data_flag = mon_text_get_data(ep, urb, ep->length, ev_type, 248 rp->r.m_bus); 249 250 rp->nevents++; 251 list_add_tail(&ep->e_link, &rp->e_list); 252 wake_up(&rp->wait); 253 } 254 255 static void mon_text_submit(void *data, struct urb *urb) 256 { 257 struct mon_reader_text *rp = data; 258 mon_text_event(rp, urb, 'S', -EINPROGRESS); 259 } 260 261 static void mon_text_complete(void *data, struct urb *urb, int status) 262 { 263 struct mon_reader_text *rp = data; 264 mon_text_event(rp, urb, 'C', status); 265 } 266 267 static void mon_text_error(void *data, struct urb *urb, int error) 268 { 269 struct mon_reader_text *rp = data; 270 struct mon_event_text *ep; 271 272 if (rp->nevents >= EVENT_MAX || 273 (ep = kmem_cache_alloc(rp->e_slab, GFP_ATOMIC)) == NULL) { 274 rp->r.m_bus->cnt_text_lost++; 275 return; 276 } 277 278 ep->type = 'E'; 279 ep->id = (unsigned long) urb; 280 ep->busnum = urb->dev->bus->busnum; 281 ep->devnum = urb->dev->devnum; 282 ep->epnum = usb_endpoint_num(&urb->ep->desc); 283 ep->xfertype = usb_endpoint_type(&urb->ep->desc); 284 ep->is_in = usb_urb_dir_in(urb); 285 ep->tstamp = mon_get_timestamp(); 286 ep->length = 0; 287 ep->status = error; 288 289 ep->setup_flag = '-'; 290 ep->data_flag = 'E'; 291 292 rp->nevents++; 293 list_add_tail(&ep->e_link, &rp->e_list); 294 wake_up(&rp->wait); 295 } 296 297 /* 298 * Fetch next event from the circular buffer. 299 */ 300 static struct mon_event_text *mon_text_fetch(struct mon_reader_text *rp, 301 struct mon_bus *mbus) 302 { 303 struct list_head *p; 304 unsigned long flags; 305 306 spin_lock_irqsave(&mbus->lock, flags); 307 if (list_empty(&rp->e_list)) { 308 spin_unlock_irqrestore(&mbus->lock, flags); 309 return NULL; 310 } 311 p = rp->e_list.next; 312 list_del(p); 313 --rp->nevents; 314 spin_unlock_irqrestore(&mbus->lock, flags); 315 return list_entry(p, struct mon_event_text, e_link); 316 } 317 318 /* 319 */ 320 static int mon_text_open(struct inode *inode, struct file *file) 321 { 322 struct mon_bus *mbus; 323 struct mon_reader_text *rp; 324 int rc; 325 326 mutex_lock(&mon_lock); 327 mbus = inode->i_private; 328 329 rp = kzalloc(sizeof(struct mon_reader_text), GFP_KERNEL); 330 if (rp == NULL) { 331 rc = -ENOMEM; 332 goto err_alloc; 333 } 334 INIT_LIST_HEAD(&rp->e_list); 335 init_waitqueue_head(&rp->wait); 336 mutex_init(&rp->printf_lock); 337 338 rp->printf_size = PRINTF_DFL; 339 rp->printf_buf = kmalloc(rp->printf_size, GFP_KERNEL); 340 if (rp->printf_buf == NULL) { 341 rc = -ENOMEM; 342 goto err_alloc_pr; 343 } 344 345 rp->r.m_bus = mbus; 346 rp->r.r_data = rp; 347 rp->r.rnf_submit = mon_text_submit; 348 rp->r.rnf_error = mon_text_error; 349 rp->r.rnf_complete = mon_text_complete; 350 351 snprintf(rp->slab_name, SLAB_NAME_SZ, "mon_text_%p", rp); 352 rp->e_slab = kmem_cache_create(rp->slab_name, 353 sizeof(struct mon_event_text), sizeof(long), 0, 354 mon_text_ctor); 355 if (rp->e_slab == NULL) { 356 rc = -ENOMEM; 357 goto err_slab; 358 } 359 360 mon_reader_add(mbus, &rp->r); 361 362 file->private_data = rp; 363 mutex_unlock(&mon_lock); 364 return 0; 365 366 // err_busy: 367 // kmem_cache_destroy(rp->e_slab); 368 err_slab: 369 kfree(rp->printf_buf); 370 err_alloc_pr: 371 kfree(rp); 372 err_alloc: 373 mutex_unlock(&mon_lock); 374 return rc; 375 } 376 377 /* 378 * For simplicity, we read one record in one system call and throw out 379 * what does not fit. This means that the following does not work: 380 * dd if=/dbg/usbmon/0t bs=10 381 * Also, we do not allow seeks and do not bother advancing the offset. 382 */ 383 static ssize_t mon_text_read_t(struct file *file, char __user *buf, 384 size_t nbytes, loff_t *ppos) 385 { 386 struct mon_reader_text *rp = file->private_data; 387 struct mon_event_text *ep; 388 struct mon_text_ptr ptr; 389 390 ep = mon_text_read_wait(rp, file); 391 if (IS_ERR(ep)) 392 return PTR_ERR(ep); 393 mutex_lock(&rp->printf_lock); 394 ptr.cnt = 0; 395 ptr.pbuf = rp->printf_buf; 396 ptr.limit = rp->printf_size; 397 398 mon_text_read_head_t(rp, &ptr, ep); 399 mon_text_read_statset(rp, &ptr, ep); 400 ptr.cnt += snprintf(ptr.pbuf + ptr.cnt, ptr.limit - ptr.cnt, 401 " %d", ep->length); 402 mon_text_read_data(rp, &ptr, ep); 403 404 if (copy_to_user(buf, rp->printf_buf, ptr.cnt)) 405 ptr.cnt = -EFAULT; 406 mutex_unlock(&rp->printf_lock); 407 kmem_cache_free(rp->e_slab, ep); 408 return ptr.cnt; 409 } 410 411 static ssize_t mon_text_read_u(struct file *file, char __user *buf, 412 size_t nbytes, loff_t *ppos) 413 { 414 struct mon_reader_text *rp = file->private_data; 415 struct mon_event_text *ep; 416 struct mon_text_ptr ptr; 417 418 ep = mon_text_read_wait(rp, file); 419 if (IS_ERR(ep)) 420 return PTR_ERR(ep); 421 mutex_lock(&rp->printf_lock); 422 ptr.cnt = 0; 423 ptr.pbuf = rp->printf_buf; 424 ptr.limit = rp->printf_size; 425 426 mon_text_read_head_u(rp, &ptr, ep); 427 if (ep->type == 'E') { 428 mon_text_read_statset(rp, &ptr, ep); 429 } else if (ep->xfertype == USB_ENDPOINT_XFER_ISOC) { 430 mon_text_read_isostat(rp, &ptr, ep); 431 mon_text_read_isodesc(rp, &ptr, ep); 432 } else if (ep->xfertype == USB_ENDPOINT_XFER_INT) { 433 mon_text_read_intstat(rp, &ptr, ep); 434 } else { 435 mon_text_read_statset(rp, &ptr, ep); 436 } 437 ptr.cnt += snprintf(ptr.pbuf + ptr.cnt, ptr.limit - ptr.cnt, 438 " %d", ep->length); 439 mon_text_read_data(rp, &ptr, ep); 440 441 if (copy_to_user(buf, rp->printf_buf, ptr.cnt)) 442 ptr.cnt = -EFAULT; 443 mutex_unlock(&rp->printf_lock); 444 kmem_cache_free(rp->e_slab, ep); 445 return ptr.cnt; 446 } 447 448 static struct mon_event_text *mon_text_read_wait(struct mon_reader_text *rp, 449 struct file *file) 450 { 451 struct mon_bus *mbus = rp->r.m_bus; 452 DECLARE_WAITQUEUE(waita, current); 453 struct mon_event_text *ep; 454 455 add_wait_queue(&rp->wait, &waita); 456 set_current_state(TASK_INTERRUPTIBLE); 457 while ((ep = mon_text_fetch(rp, mbus)) == NULL) { 458 if (file->f_flags & O_NONBLOCK) { 459 set_current_state(TASK_RUNNING); 460 remove_wait_queue(&rp->wait, &waita); 461 return ERR_PTR(-EWOULDBLOCK); 462 } 463 /* 464 * We do not count nwaiters, because ->release is supposed 465 * to be called when all openers are gone only. 466 */ 467 schedule(); 468 if (signal_pending(current)) { 469 remove_wait_queue(&rp->wait, &waita); 470 return ERR_PTR(-EINTR); 471 } 472 set_current_state(TASK_INTERRUPTIBLE); 473 } 474 set_current_state(TASK_RUNNING); 475 remove_wait_queue(&rp->wait, &waita); 476 return ep; 477 } 478 479 static void mon_text_read_head_t(struct mon_reader_text *rp, 480 struct mon_text_ptr *p, const struct mon_event_text *ep) 481 { 482 char udir, utype; 483 484 udir = (ep->is_in ? 'i' : 'o'); 485 switch (ep->xfertype) { 486 case USB_ENDPOINT_XFER_ISOC: utype = 'Z'; break; 487 case USB_ENDPOINT_XFER_INT: utype = 'I'; break; 488 case USB_ENDPOINT_XFER_CONTROL: utype = 'C'; break; 489 default: /* PIPE_BULK */ utype = 'B'; 490 } 491 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 492 "%lx %u %c %c%c:%03u:%02u", 493 ep->id, ep->tstamp, ep->type, 494 utype, udir, ep->devnum, ep->epnum); 495 } 496 497 static void mon_text_read_head_u(struct mon_reader_text *rp, 498 struct mon_text_ptr *p, const struct mon_event_text *ep) 499 { 500 char udir, utype; 501 502 udir = (ep->is_in ? 'i' : 'o'); 503 switch (ep->xfertype) { 504 case USB_ENDPOINT_XFER_ISOC: utype = 'Z'; break; 505 case USB_ENDPOINT_XFER_INT: utype = 'I'; break; 506 case USB_ENDPOINT_XFER_CONTROL: utype = 'C'; break; 507 default: /* PIPE_BULK */ utype = 'B'; 508 } 509 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 510 "%lx %u %c %c%c:%d:%03u:%u", 511 ep->id, ep->tstamp, ep->type, 512 utype, udir, ep->busnum, ep->devnum, ep->epnum); 513 } 514 515 static void mon_text_read_statset(struct mon_reader_text *rp, 516 struct mon_text_ptr *p, const struct mon_event_text *ep) 517 { 518 519 if (ep->setup_flag == 0) { /* Setup packet is present and captured */ 520 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 521 " s %02x %02x %04x %04x %04x", 522 ep->setup[0], 523 ep->setup[1], 524 (ep->setup[3] << 8) | ep->setup[2], 525 (ep->setup[5] << 8) | ep->setup[4], 526 (ep->setup[7] << 8) | ep->setup[6]); 527 } else if (ep->setup_flag != '-') { /* Unable to capture setup packet */ 528 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 529 " %c __ __ ____ ____ ____", ep->setup_flag); 530 } else { /* No setup for this kind of URB */ 531 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 532 " %d", ep->status); 533 } 534 } 535 536 static void mon_text_read_intstat(struct mon_reader_text *rp, 537 struct mon_text_ptr *p, const struct mon_event_text *ep) 538 { 539 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 540 " %d:%d", ep->status, ep->interval); 541 } 542 543 static void mon_text_read_isostat(struct mon_reader_text *rp, 544 struct mon_text_ptr *p, const struct mon_event_text *ep) 545 { 546 if (ep->type == 'S') { 547 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 548 " %d:%d:%d", ep->status, ep->interval, ep->start_frame); 549 } else { 550 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 551 " %d:%d:%d:%d", 552 ep->status, ep->interval, ep->start_frame, ep->error_count); 553 } 554 } 555 556 static void mon_text_read_isodesc(struct mon_reader_text *rp, 557 struct mon_text_ptr *p, const struct mon_event_text *ep) 558 { 559 int ndesc; /* Display this many */ 560 int i; 561 const struct mon_iso_desc *dp; 562 563 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 564 " %d", ep->numdesc); 565 ndesc = ep->numdesc; 566 if (ndesc > ISODESC_MAX) 567 ndesc = ISODESC_MAX; 568 if (ndesc < 0) 569 ndesc = 0; 570 dp = ep->isodesc; 571 for (i = 0; i < ndesc; i++) { 572 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 573 " %d:%u:%u", dp->status, dp->offset, dp->length); 574 dp++; 575 } 576 } 577 578 static void mon_text_read_data(struct mon_reader_text *rp, 579 struct mon_text_ptr *p, const struct mon_event_text *ep) 580 { 581 int data_len, i; 582 583 if ((data_len = ep->length) > 0) { 584 if (ep->data_flag == 0) { 585 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 586 " ="); 587 if (data_len >= DATA_MAX) 588 data_len = DATA_MAX; 589 for (i = 0; i < data_len; i++) { 590 if (i % 4 == 0) { 591 p->cnt += snprintf(p->pbuf + p->cnt, 592 p->limit - p->cnt, 593 " "); 594 } 595 p->cnt += snprintf(p->pbuf + p->cnt, 596 p->limit - p->cnt, 597 "%02x", ep->data[i]); 598 } 599 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 600 "\n"); 601 } else { 602 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, 603 " %c\n", ep->data_flag); 604 } 605 } else { 606 p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, "\n"); 607 } 608 } 609 610 static int mon_text_release(struct inode *inode, struct file *file) 611 { 612 struct mon_reader_text *rp = file->private_data; 613 struct mon_bus *mbus; 614 /* unsigned long flags; */ 615 struct list_head *p; 616 struct mon_event_text *ep; 617 618 mutex_lock(&mon_lock); 619 mbus = inode->i_private; 620 621 if (mbus->nreaders <= 0) { 622 printk(KERN_ERR TAG ": consistency error on close\n"); 623 mutex_unlock(&mon_lock); 624 return 0; 625 } 626 mon_reader_del(mbus, &rp->r); 627 628 /* 629 * In theory, e_list is protected by mbus->lock. However, 630 * after mon_reader_del has finished, the following is the case: 631 * - we are not on reader list anymore, so new events won't be added; 632 * - whole mbus may be dropped if it was orphaned. 633 * So, we better not touch mbus. 634 */ 635 /* spin_lock_irqsave(&mbus->lock, flags); */ 636 while (!list_empty(&rp->e_list)) { 637 p = rp->e_list.next; 638 ep = list_entry(p, struct mon_event_text, e_link); 639 list_del(p); 640 --rp->nevents; 641 kmem_cache_free(rp->e_slab, ep); 642 } 643 /* spin_unlock_irqrestore(&mbus->lock, flags); */ 644 645 kmem_cache_destroy(rp->e_slab); 646 kfree(rp->printf_buf); 647 kfree(rp); 648 649 mutex_unlock(&mon_lock); 650 return 0; 651 } 652 653 static const struct file_operations mon_fops_text_t = { 654 .owner = THIS_MODULE, 655 .open = mon_text_open, 656 .llseek = no_llseek, 657 .read = mon_text_read_t, 658 .release = mon_text_release, 659 }; 660 661 static const struct file_operations mon_fops_text_u = { 662 .owner = THIS_MODULE, 663 .open = mon_text_open, 664 .llseek = no_llseek, 665 .read = mon_text_read_u, 666 .release = mon_text_release, 667 }; 668 669 int mon_text_add(struct mon_bus *mbus, const struct usb_bus *ubus) 670 { 671 struct dentry *d; 672 enum { NAMESZ = 10 }; 673 char name[NAMESZ]; 674 int busnum = ubus? ubus->busnum: 0; 675 int rc; 676 677 if (mon_dir == NULL) 678 return 0; 679 680 if (ubus != NULL) { 681 rc = snprintf(name, NAMESZ, "%dt", busnum); 682 if (rc <= 0 || rc >= NAMESZ) 683 goto err_print_t; 684 d = debugfs_create_file(name, 0600, mon_dir, mbus, 685 &mon_fops_text_t); 686 if (d == NULL) 687 goto err_create_t; 688 mbus->dent_t = d; 689 } 690 691 rc = snprintf(name, NAMESZ, "%du", busnum); 692 if (rc <= 0 || rc >= NAMESZ) 693 goto err_print_u; 694 d = debugfs_create_file(name, 0600, mon_dir, mbus, &mon_fops_text_u); 695 if (d == NULL) 696 goto err_create_u; 697 mbus->dent_u = d; 698 699 rc = snprintf(name, NAMESZ, "%ds", busnum); 700 if (rc <= 0 || rc >= NAMESZ) 701 goto err_print_s; 702 d = debugfs_create_file(name, 0600, mon_dir, mbus, &mon_fops_stat); 703 if (d == NULL) 704 goto err_create_s; 705 mbus->dent_s = d; 706 707 return 1; 708 709 err_create_s: 710 err_print_s: 711 debugfs_remove(mbus->dent_u); 712 mbus->dent_u = NULL; 713 err_create_u: 714 err_print_u: 715 if (ubus != NULL) { 716 debugfs_remove(mbus->dent_t); 717 mbus->dent_t = NULL; 718 } 719 err_create_t: 720 err_print_t: 721 return 0; 722 } 723 724 void mon_text_del(struct mon_bus *mbus) 725 { 726 debugfs_remove(mbus->dent_u); 727 if (mbus->dent_t != NULL) 728 debugfs_remove(mbus->dent_t); 729 debugfs_remove(mbus->dent_s); 730 } 731 732 /* 733 * Slab interface: constructor. 734 */ 735 static void mon_text_ctor(void *mem) 736 { 737 /* 738 * Nothing to initialize. No, really! 739 * So, we fill it with garbage to emulate a reused object. 740 */ 741 memset(mem, 0xe5, sizeof(struct mon_event_text)); 742 } 743 744 int __init mon_text_init(void) 745 { 746 struct dentry *mondir; 747 748 mondir = debugfs_create_dir("usbmon", usb_debug_root); 749 if (IS_ERR(mondir)) { 750 /* debugfs not available, but we can use usbmon without it */ 751 return 0; 752 } 753 if (mondir == NULL) { 754 printk(KERN_NOTICE TAG ": unable to create usbmon directory\n"); 755 return -ENOMEM; 756 } 757 mon_dir = mondir; 758 return 0; 759 } 760 761 void mon_text_exit(void) 762 { 763 debugfs_remove(mon_dir); 764 } 765