1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * The USB Monitor, inspired by Dave Harding's USBMon. 4 * 5 * This is a text format reader. 6 */ 7 8 #include <linux/kernel.h> 9 #include <linux/list.h> 10 #include <linux/usb.h> 11 #include <linux/slab.h> 12 #include <linux/sched/signal.h> 13 #include <linux/time.h> 14 #include <linux/ktime.h> 15 #include <linux/export.h> 16 #include <linux/mutex.h> 17 #include <linux/debugfs.h> 18 #include <linux/scatterlist.h> 19 #include <linux/uaccess.h> 20 21 #include "usb_mon.h" 22 23 /* 24 * No, we do not want arbitrarily long data strings. 25 * Use the binary interface if you want to capture bulk data! 26 */ 27 #define DATA_MAX 32 28 29 /* 30 * Defined by USB 2.0 clause 9.3, table 9.2. 31 */ 32 #define SETUP_MAX 8 33 34 /* 35 * This limit exists to prevent OOMs when the user process stops reading. 36 * If usbmon were available to unprivileged processes, it might be open 37 * to a local DoS. But we have to keep to root in order to prevent 38 * password sniffing from HID devices. 39 */ 40 #define EVENT_MAX (4*PAGE_SIZE / sizeof(struct mon_event_text)) 41 42 /* 43 * Potentially unlimited number; we limit it for similar allocations. 44 * The usbfs limits this to 128, but we're not quite as generous. 45 */ 46 #define ISODESC_MAX 5 47 48 #define PRINTF_DFL 250 /* with 5 ISOs segs */ 49 50 struct mon_iso_desc { 51 int status; 52 unsigned int offset; 53 unsigned int length; /* Unsigned here, signed in URB. Historic. */ 54 }; 55 56 struct mon_event_text { 57 struct list_head e_link; 58 int type; /* submit, complete, etc. */ 59 unsigned long id; /* From pointer, most of the time */ 60 unsigned int tstamp; 61 int busnum; 62 char devnum; 63 char epnum; 64 char is_in; 65 char xfertype; 66 int length; /* Depends on type: xfer length or act length */ 67 int status; 68 int interval; 69 int start_frame; 70 int error_count; 71 char setup_flag; 72 char data_flag; 73 int numdesc; /* Full number */ 74 struct mon_iso_desc isodesc[ISODESC_MAX]; 75 unsigned char setup[SETUP_MAX]; 76 unsigned char data[DATA_MAX]; 77 }; 78 79 #define SLAB_NAME_SZ 30 80 struct mon_reader_text { 81 struct kmem_cache *e_slab; 82 int nevents; 83 struct list_head e_list; 84 struct mon_reader r; /* In C, parent class can be placed anywhere */ 85 86 wait_queue_head_t wait; 87 int printf_size; 88 size_t printf_offset; 89 size_t printf_togo; 90 char *printf_buf; 91 struct mutex printf_lock; 92 93 char slab_name[SLAB_NAME_SZ]; 94 }; 95 96 static struct dentry *mon_dir; /* Usually /sys/kernel/debug/usbmon */ 97 98 static void mon_text_ctor(void *); 99 100 struct mon_text_ptr { 101 int cnt, limit; 102 char *pbuf; 103 }; 104 105 static struct mon_event_text * 106 mon_text_read_wait(struct mon_reader_text *rp, struct file *file); 107 static void mon_text_read_head_t(struct mon_reader_text *rp, 108 struct mon_text_ptr *p, const struct mon_event_text *ep); 109 static void mon_text_read_head_u(struct mon_reader_text *rp, 110 struct mon_text_ptr *p, const struct mon_event_text *ep); 111 static void mon_text_read_statset(struct mon_reader_text *rp, 112 struct mon_text_ptr *p, const struct mon_event_text *ep); 113 static void mon_text_read_intstat(struct mon_reader_text *rp, 114 struct mon_text_ptr *p, const struct mon_event_text *ep); 115 static void mon_text_read_isostat(struct mon_reader_text *rp, 116 struct mon_text_ptr *p, const struct mon_event_text *ep); 117 static void mon_text_read_isodesc(struct mon_reader_text *rp, 118 struct mon_text_ptr *p, const struct mon_event_text *ep); 119 static void mon_text_read_data(struct mon_reader_text *rp, 120 struct mon_text_ptr *p, const struct mon_event_text *ep); 121 122 /* 123 * mon_text_submit 124 * mon_text_complete 125 * 126 * May be called from an interrupt. 127 * 128 * This is called with the whole mon_bus locked, so no additional lock. 129 */ 130 131 static inline char mon_text_get_setup(struct mon_event_text *ep, 132 struct urb *urb, char ev_type, struct mon_bus *mbus) 133 { 134 135 if (ep->xfertype != USB_ENDPOINT_XFER_CONTROL || ev_type != 'S') 136 return '-'; 137 138 if (urb->setup_packet == NULL) 139 return 'Z'; /* '0' would be not as pretty. */ 140 141 memcpy(ep->setup, urb->setup_packet, SETUP_MAX); 142 return 0; 143 } 144 145 static inline char mon_text_get_data(struct mon_event_text *ep, struct urb *urb, 146 int len, char ev_type, struct mon_bus *mbus) 147 { 148 void *src; 149 150 if (len <= 0) 151 return 'L'; 152 if (len >= DATA_MAX) 153 len = DATA_MAX; 154 155 if (ep->is_in) { 156 if (ev_type != 'C') 157 return '<'; 158 } else { 159 if (ev_type != 'S') 160 return '>'; 161 } 162 163 if (urb->num_sgs == 0) { 164 src = urb->transfer_buffer; 165 if (src == NULL) 166 return 'Z'; /* '0' would be not as pretty. */ 167 } else { 168 struct scatterlist *sg = urb->sg; 169 170 if (PageHighMem(sg_page(sg))) 171 return 'D'; 172 173 /* For the text interface we copy only the first sg buffer */ 174 len = min_t(int, sg->length, len); 175 src = sg_virt(sg); 176 } 177 178 memcpy(ep->data, src, len); 179 return 0; 180 } 181 182 static inline unsigned int mon_get_timestamp(void) 183 { 184 struct timespec64 now; 185 unsigned int stamp; 186 187 ktime_get_ts64(&now); 188 stamp = now.tv_sec & 0xFFF; /* 2^32 = 4294967296. Limit to 4096s. */ 189 stamp = stamp * USEC_PER_SEC + now.tv_nsec / NSEC_PER_USEC; 190 return stamp; 191 } 192 193 static void mon_text_event(struct mon_reader_text *rp, struct urb *urb, 194 char ev_type, int status) 195 { 196 struct mon_event_text *ep; 197 unsigned int stamp; 198 struct usb_iso_packet_descriptor *fp; 199 struct mon_iso_desc *dp; 200 int i, ndesc; 201 202 stamp = mon_get_timestamp(); 203 204 if (rp->nevents >= EVENT_MAX || 205 (ep = kmem_cache_alloc(rp->e_slab, GFP_ATOMIC)) == NULL) { 206 rp->r.m_bus->cnt_text_lost++; 207 return; 208 } 209 210 ep->type = ev_type; 211 ep->id = (unsigned long) urb; 212 ep->busnum = urb->dev->bus->busnum; 213 ep->devnum = urb->dev->devnum; 214 ep->epnum = usb_endpoint_num(&urb->ep->desc); 215 ep->xfertype = usb_endpoint_type(&urb->ep->desc); 216 ep->is_in = usb_urb_dir_in(urb); 217 ep->tstamp = stamp; 218 ep->length = (ev_type == 'S') ? 219 urb->transfer_buffer_length : urb->actual_length; 220 /* Collecting status makes debugging sense for submits, too */ 221 ep->status = status; 222 223 if (ep->xfertype == USB_ENDPOINT_XFER_INT) { 224 ep->interval = urb->interval; 225 } else if (ep->xfertype == USB_ENDPOINT_XFER_ISOC) { 226 ep->interval = urb->interval; 227 ep->start_frame = urb->start_frame; 228 ep->error_count = urb->error_count; 229 } 230 ep->numdesc = urb->number_of_packets; 231 if (ep->xfertype == USB_ENDPOINT_XFER_ISOC && 232 urb->number_of_packets > 0) { 233 if ((ndesc = urb->number_of_packets) > ISODESC_MAX) 234 ndesc = ISODESC_MAX; 235 fp = urb->iso_frame_desc; 236 dp = ep->isodesc; 237 for (i = 0; i < ndesc; i++) { 238 dp->status = fp->status; 239 dp->offset = fp->offset; 240 dp->length = (ev_type == 'S') ? 241 fp->length : fp->actual_length; 242 fp++; 243 dp++; 244 } 245 /* Wasteful, but simple to understand: ISO 'C' is sparse. */ 246 if (ev_type == 'C') 247 ep->length = urb->transfer_buffer_length; 248 } 249 250 ep->setup_flag = mon_text_get_setup(ep, urb, ev_type, rp->r.m_bus); 251 ep->data_flag = mon_text_get_data(ep, urb, ep->length, ev_type, 252 rp->r.m_bus); 253 254 rp->nevents++; 255 list_add_tail(&ep->e_link, &rp->e_list); 256 wake_up(&rp->wait); 257 } 258 259 static void mon_text_submit(void *data, struct urb *urb) 260 { 261 struct mon_reader_text *rp = data; 262 mon_text_event(rp, urb, 'S', -EINPROGRESS); 263 } 264 265 static void mon_text_complete(void *data, struct urb *urb, int status) 266 { 267 struct mon_reader_text *rp = data; 268 mon_text_event(rp, urb, 'C', status); 269 } 270 271 static void mon_text_error(void *data, struct urb *urb, int error) 272 { 273 struct mon_reader_text *rp = data; 274 struct mon_event_text *ep; 275 276 if (rp->nevents >= EVENT_MAX || 277 (ep = kmem_cache_alloc(rp->e_slab, GFP_ATOMIC)) == NULL) { 278 rp->r.m_bus->cnt_text_lost++; 279 return; 280 } 281 282 ep->type = 'E'; 283 ep->id = (unsigned long) urb; 284 ep->busnum = urb->dev->bus->busnum; 285 ep->devnum = urb->dev->devnum; 286 ep->epnum = usb_endpoint_num(&urb->ep->desc); 287 ep->xfertype = usb_endpoint_type(&urb->ep->desc); 288 ep->is_in = usb_urb_dir_in(urb); 289 ep->tstamp = mon_get_timestamp(); 290 ep->length = 0; 291 ep->status = error; 292 293 ep->setup_flag = '-'; 294 ep->data_flag = 'E'; 295 296 rp->nevents++; 297 list_add_tail(&ep->e_link, &rp->e_list); 298 wake_up(&rp->wait); 299 } 300 301 /* 302 * Fetch next event from the circular buffer. 303 */ 304 static struct mon_event_text *mon_text_fetch(struct mon_reader_text *rp, 305 struct mon_bus *mbus) 306 { 307 struct list_head *p; 308 unsigned long flags; 309 310 spin_lock_irqsave(&mbus->lock, flags); 311 if (list_empty(&rp->e_list)) { 312 spin_unlock_irqrestore(&mbus->lock, flags); 313 return NULL; 314 } 315 p = rp->e_list.next; 316 list_del(p); 317 --rp->nevents; 318 spin_unlock_irqrestore(&mbus->lock, flags); 319 return list_entry(p, struct mon_event_text, e_link); 320 } 321 322 /* 323 */ 324 static int mon_text_open(struct inode *inode, struct file *file) 325 { 326 struct mon_bus *mbus; 327 struct mon_reader_text *rp; 328 int rc; 329 330 mutex_lock(&mon_lock); 331 mbus = inode->i_private; 332 333 rp = kzalloc(sizeof(struct mon_reader_text), GFP_KERNEL); 334 if (rp == NULL) { 335 rc = -ENOMEM; 336 goto err_alloc; 337 } 338 INIT_LIST_HEAD(&rp->e_list); 339 init_waitqueue_head(&rp->wait); 340 mutex_init(&rp->printf_lock); 341 342 rp->printf_size = PRINTF_DFL; 343 rp->printf_buf = kmalloc(rp->printf_size, GFP_KERNEL); 344 if (rp->printf_buf == NULL) { 345 rc = -ENOMEM; 346 goto err_alloc_pr; 347 } 348 349 rp->r.m_bus = mbus; 350 rp->r.r_data = rp; 351 rp->r.rnf_submit = mon_text_submit; 352 rp->r.rnf_error = mon_text_error; 353 rp->r.rnf_complete = mon_text_complete; 354 355 snprintf(rp->slab_name, SLAB_NAME_SZ, "mon_text_%p", rp); 356 rp->e_slab = kmem_cache_create(rp->slab_name, 357 sizeof(struct mon_event_text), sizeof(long), 0, 358 mon_text_ctor); 359 if (rp->e_slab == NULL) { 360 rc = -ENOMEM; 361 goto err_slab; 362 } 363 364 mon_reader_add(mbus, &rp->r); 365 366 file->private_data = rp; 367 mutex_unlock(&mon_lock); 368 return 0; 369 370 // err_busy: 371 // kmem_cache_destroy(rp->e_slab); 372 err_slab: 373 kfree(rp->printf_buf); 374 err_alloc_pr: 375 kfree(rp); 376 err_alloc: 377 mutex_unlock(&mon_lock); 378 return rc; 379 } 380 381 static ssize_t mon_text_copy_to_user(struct mon_reader_text *rp, 382 char __user * const buf, const size_t nbytes) 383 { 384 const size_t togo = min(nbytes, rp->printf_togo); 385 386 if (copy_to_user(buf, &rp->printf_buf[rp->printf_offset], togo)) 387 return -EFAULT; 388 rp->printf_togo -= togo; 389 rp->printf_offset += togo; 390 return togo; 391 } 392 393 /* ppos is not advanced since the llseek operation is not permitted. */ 394 static ssize_t mon_text_read_t(struct file *file, char __user *buf, 395 size_t nbytes, loff_t *ppos) 396 { 397 struct mon_reader_text *rp = file->private_data; 398 struct mon_event_text *ep; 399 struct mon_text_ptr ptr; 400 ssize_t ret; 401 402 mutex_lock(&rp->printf_lock); 403 404 if (rp->printf_togo == 0) { 405 406 ep = mon_text_read_wait(rp, file); 407 if (IS_ERR(ep)) { 408 mutex_unlock(&rp->printf_lock); 409 return PTR_ERR(ep); 410 } 411 ptr.cnt = 0; 412 ptr.pbuf = rp->printf_buf; 413 ptr.limit = rp->printf_size; 414 415 mon_text_read_head_t(rp, &ptr, ep); 416 mon_text_read_statset(rp, &ptr, ep); 417 ptr.cnt += scnprintf(ptr.pbuf + ptr.cnt, ptr.limit - ptr.cnt, 418 " %d", ep->length); 419 mon_text_read_data(rp, &ptr, ep); 420 421 rp->printf_togo = ptr.cnt; 422 rp->printf_offset = 0; 423 424 kmem_cache_free(rp->e_slab, ep); 425 } 426 427 ret = mon_text_copy_to_user(rp, buf, nbytes); 428 mutex_unlock(&rp->printf_lock); 429 return ret; 430 } 431 432 /* ppos is not advanced since the llseek operation is not permitted. */ 433 static ssize_t mon_text_read_u(struct file *file, char __user *buf, 434 size_t nbytes, loff_t *ppos) 435 { 436 struct mon_reader_text *rp = file->private_data; 437 struct mon_event_text *ep; 438 struct mon_text_ptr ptr; 439 ssize_t ret; 440 441 mutex_lock(&rp->printf_lock); 442 443 if (rp->printf_togo == 0) { 444 445 ep = mon_text_read_wait(rp, file); 446 if (IS_ERR(ep)) { 447 mutex_unlock(&rp->printf_lock); 448 return PTR_ERR(ep); 449 } 450 ptr.cnt = 0; 451 ptr.pbuf = rp->printf_buf; 452 ptr.limit = rp->printf_size; 453 454 mon_text_read_head_u(rp, &ptr, ep); 455 if (ep->type == 'E') { 456 mon_text_read_statset(rp, &ptr, ep); 457 } else if (ep->xfertype == USB_ENDPOINT_XFER_ISOC) { 458 mon_text_read_isostat(rp, &ptr, ep); 459 mon_text_read_isodesc(rp, &ptr, ep); 460 } else if (ep->xfertype == USB_ENDPOINT_XFER_INT) { 461 mon_text_read_intstat(rp, &ptr, ep); 462 } else { 463 mon_text_read_statset(rp, &ptr, ep); 464 } 465 ptr.cnt += scnprintf(ptr.pbuf + ptr.cnt, ptr.limit - ptr.cnt, 466 " %d", ep->length); 467 mon_text_read_data(rp, &ptr, ep); 468 469 rp->printf_togo = ptr.cnt; 470 rp->printf_offset = 0; 471 472 kmem_cache_free(rp->e_slab, ep); 473 } 474 475 ret = mon_text_copy_to_user(rp, buf, nbytes); 476 mutex_unlock(&rp->printf_lock); 477 return ret; 478 } 479 480 static struct mon_event_text *mon_text_read_wait(struct mon_reader_text *rp, 481 struct file *file) 482 { 483 struct mon_bus *mbus = rp->r.m_bus; 484 DECLARE_WAITQUEUE(waita, current); 485 struct mon_event_text *ep; 486 487 add_wait_queue(&rp->wait, &waita); 488 set_current_state(TASK_INTERRUPTIBLE); 489 while ((ep = mon_text_fetch(rp, mbus)) == NULL) { 490 if (file->f_flags & O_NONBLOCK) { 491 set_current_state(TASK_RUNNING); 492 remove_wait_queue(&rp->wait, &waita); 493 return ERR_PTR(-EWOULDBLOCK); 494 } 495 /* 496 * We do not count nwaiters, because ->release is supposed 497 * to be called when all openers are gone only. 498 */ 499 schedule(); 500 if (signal_pending(current)) { 501 remove_wait_queue(&rp->wait, &waita); 502 return ERR_PTR(-EINTR); 503 } 504 set_current_state(TASK_INTERRUPTIBLE); 505 } 506 set_current_state(TASK_RUNNING); 507 remove_wait_queue(&rp->wait, &waita); 508 return ep; 509 } 510 511 static void mon_text_read_head_t(struct mon_reader_text *rp, 512 struct mon_text_ptr *p, const struct mon_event_text *ep) 513 { 514 char udir, utype; 515 516 udir = (ep->is_in ? 'i' : 'o'); 517 switch (ep->xfertype) { 518 case USB_ENDPOINT_XFER_ISOC: utype = 'Z'; break; 519 case USB_ENDPOINT_XFER_INT: utype = 'I'; break; 520 case USB_ENDPOINT_XFER_CONTROL: utype = 'C'; break; 521 default: /* PIPE_BULK */ utype = 'B'; 522 } 523 p->cnt += scnprintf(p->pbuf + p->cnt, p->limit - p->cnt, 524 "%lx %u %c %c%c:%03u:%02u", 525 ep->id, ep->tstamp, ep->type, 526 utype, udir, ep->devnum, ep->epnum); 527 } 528 529 static void mon_text_read_head_u(struct mon_reader_text *rp, 530 struct mon_text_ptr *p, const struct mon_event_text *ep) 531 { 532 char udir, utype; 533 534 udir = (ep->is_in ? 'i' : 'o'); 535 switch (ep->xfertype) { 536 case USB_ENDPOINT_XFER_ISOC: utype = 'Z'; break; 537 case USB_ENDPOINT_XFER_INT: utype = 'I'; break; 538 case USB_ENDPOINT_XFER_CONTROL: utype = 'C'; break; 539 default: /* PIPE_BULK */ utype = 'B'; 540 } 541 p->cnt += scnprintf(p->pbuf + p->cnt, p->limit - p->cnt, 542 "%lx %u %c %c%c:%d:%03u:%u", 543 ep->id, ep->tstamp, ep->type, 544 utype, udir, ep->busnum, ep->devnum, ep->epnum); 545 } 546 547 static void mon_text_read_statset(struct mon_reader_text *rp, 548 struct mon_text_ptr *p, const struct mon_event_text *ep) 549 { 550 551 if (ep->setup_flag == 0) { /* Setup packet is present and captured */ 552 p->cnt += scnprintf(p->pbuf + p->cnt, p->limit - p->cnt, 553 " s %02x %02x %04x %04x %04x", 554 ep->setup[0], 555 ep->setup[1], 556 (ep->setup[3] << 8) | ep->setup[2], 557 (ep->setup[5] << 8) | ep->setup[4], 558 (ep->setup[7] << 8) | ep->setup[6]); 559 } else if (ep->setup_flag != '-') { /* Unable to capture setup packet */ 560 p->cnt += scnprintf(p->pbuf + p->cnt, p->limit - p->cnt, 561 " %c __ __ ____ ____ ____", ep->setup_flag); 562 } else { /* No setup for this kind of URB */ 563 p->cnt += scnprintf(p->pbuf + p->cnt, p->limit - p->cnt, 564 " %d", ep->status); 565 } 566 } 567 568 static void mon_text_read_intstat(struct mon_reader_text *rp, 569 struct mon_text_ptr *p, const struct mon_event_text *ep) 570 { 571 p->cnt += scnprintf(p->pbuf + p->cnt, p->limit - p->cnt, 572 " %d:%d", ep->status, ep->interval); 573 } 574 575 static void mon_text_read_isostat(struct mon_reader_text *rp, 576 struct mon_text_ptr *p, const struct mon_event_text *ep) 577 { 578 if (ep->type == 'S') { 579 p->cnt += scnprintf(p->pbuf + p->cnt, p->limit - p->cnt, 580 " %d:%d:%d", ep->status, ep->interval, ep->start_frame); 581 } else { 582 p->cnt += scnprintf(p->pbuf + p->cnt, p->limit - p->cnt, 583 " %d:%d:%d:%d", 584 ep->status, ep->interval, ep->start_frame, ep->error_count); 585 } 586 } 587 588 static void mon_text_read_isodesc(struct mon_reader_text *rp, 589 struct mon_text_ptr *p, const struct mon_event_text *ep) 590 { 591 int ndesc; /* Display this many */ 592 int i; 593 const struct mon_iso_desc *dp; 594 595 p->cnt += scnprintf(p->pbuf + p->cnt, p->limit - p->cnt, 596 " %d", ep->numdesc); 597 ndesc = ep->numdesc; 598 if (ndesc > ISODESC_MAX) 599 ndesc = ISODESC_MAX; 600 if (ndesc < 0) 601 ndesc = 0; 602 dp = ep->isodesc; 603 for (i = 0; i < ndesc; i++) { 604 p->cnt += scnprintf(p->pbuf + p->cnt, p->limit - p->cnt, 605 " %d:%u:%u", dp->status, dp->offset, dp->length); 606 dp++; 607 } 608 } 609 610 static void mon_text_read_data(struct mon_reader_text *rp, 611 struct mon_text_ptr *p, const struct mon_event_text *ep) 612 { 613 int data_len, i; 614 615 if ((data_len = ep->length) > 0) { 616 if (ep->data_flag == 0) { 617 p->cnt += scnprintf(p->pbuf + p->cnt, p->limit - p->cnt, 618 " ="); 619 if (data_len >= DATA_MAX) 620 data_len = DATA_MAX; 621 for (i = 0; i < data_len; i++) { 622 if (i % 4 == 0) { 623 p->cnt += scnprintf(p->pbuf + p->cnt, 624 p->limit - p->cnt, 625 " "); 626 } 627 p->cnt += scnprintf(p->pbuf + p->cnt, 628 p->limit - p->cnt, 629 "%02x", ep->data[i]); 630 } 631 p->cnt += scnprintf(p->pbuf + p->cnt, p->limit - p->cnt, 632 "\n"); 633 } else { 634 p->cnt += scnprintf(p->pbuf + p->cnt, p->limit - p->cnt, 635 " %c\n", ep->data_flag); 636 } 637 } else { 638 p->cnt += scnprintf(p->pbuf + p->cnt, p->limit - p->cnt, "\n"); 639 } 640 } 641 642 static int mon_text_release(struct inode *inode, struct file *file) 643 { 644 struct mon_reader_text *rp = file->private_data; 645 struct mon_bus *mbus; 646 /* unsigned long flags; */ 647 struct list_head *p; 648 struct mon_event_text *ep; 649 650 mutex_lock(&mon_lock); 651 mbus = inode->i_private; 652 653 if (mbus->nreaders <= 0) { 654 printk(KERN_ERR TAG ": consistency error on close\n"); 655 mutex_unlock(&mon_lock); 656 return 0; 657 } 658 mon_reader_del(mbus, &rp->r); 659 660 /* 661 * In theory, e_list is protected by mbus->lock. However, 662 * after mon_reader_del has finished, the following is the case: 663 * - we are not on reader list anymore, so new events won't be added; 664 * - whole mbus may be dropped if it was orphaned. 665 * So, we better not touch mbus. 666 */ 667 /* spin_lock_irqsave(&mbus->lock, flags); */ 668 while (!list_empty(&rp->e_list)) { 669 p = rp->e_list.next; 670 ep = list_entry(p, struct mon_event_text, e_link); 671 list_del(p); 672 --rp->nevents; 673 kmem_cache_free(rp->e_slab, ep); 674 } 675 /* spin_unlock_irqrestore(&mbus->lock, flags); */ 676 677 kmem_cache_destroy(rp->e_slab); 678 kfree(rp->printf_buf); 679 kfree(rp); 680 681 mutex_unlock(&mon_lock); 682 return 0; 683 } 684 685 static const struct file_operations mon_fops_text_t = { 686 .owner = THIS_MODULE, 687 .open = mon_text_open, 688 .llseek = no_llseek, 689 .read = mon_text_read_t, 690 .release = mon_text_release, 691 }; 692 693 static const struct file_operations mon_fops_text_u = { 694 .owner = THIS_MODULE, 695 .open = mon_text_open, 696 .llseek = no_llseek, 697 .read = mon_text_read_u, 698 .release = mon_text_release, 699 }; 700 701 int mon_text_add(struct mon_bus *mbus, const struct usb_bus *ubus) 702 { 703 enum { NAMESZ = 10 }; 704 char name[NAMESZ]; 705 int busnum = ubus? ubus->busnum: 0; 706 int rc; 707 708 if (mon_dir == NULL) 709 return 0; 710 711 if (ubus != NULL) { 712 rc = snprintf(name, NAMESZ, "%dt", busnum); 713 if (rc <= 0 || rc >= NAMESZ) 714 goto err_print_t; 715 mbus->dent_t = debugfs_create_file(name, 0600, mon_dir, mbus, 716 &mon_fops_text_t); 717 } 718 719 rc = snprintf(name, NAMESZ, "%du", busnum); 720 if (rc <= 0 || rc >= NAMESZ) 721 goto err_print_u; 722 mbus->dent_u = debugfs_create_file(name, 0600, mon_dir, mbus, 723 &mon_fops_text_u); 724 725 rc = snprintf(name, NAMESZ, "%ds", busnum); 726 if (rc <= 0 || rc >= NAMESZ) 727 goto err_print_s; 728 mbus->dent_s = debugfs_create_file(name, 0600, mon_dir, mbus, 729 &mon_fops_stat); 730 731 return 1; 732 733 err_print_s: 734 debugfs_remove(mbus->dent_u); 735 mbus->dent_u = NULL; 736 err_print_u: 737 if (ubus != NULL) { 738 debugfs_remove(mbus->dent_t); 739 mbus->dent_t = NULL; 740 } 741 err_print_t: 742 return 0; 743 } 744 745 void mon_text_del(struct mon_bus *mbus) 746 { 747 debugfs_remove(mbus->dent_u); 748 debugfs_remove(mbus->dent_t); 749 debugfs_remove(mbus->dent_s); 750 } 751 752 /* 753 * Slab interface: constructor. 754 */ 755 static void mon_text_ctor(void *mem) 756 { 757 /* 758 * Nothing to initialize. No, really! 759 * So, we fill it with garbage to emulate a reused object. 760 */ 761 memset(mem, 0xe5, sizeof(struct mon_event_text)); 762 } 763 764 int __init mon_text_init(void) 765 { 766 mon_dir = debugfs_create_dir("usbmon", usb_debug_root); 767 return 0; 768 } 769 770 void mon_text_exit(void) 771 { 772 debugfs_remove(mon_dir); 773 } 774