Re: [PATCH v12 6/6] usb: gadget: f_ecm: Add suspend/resume and remote wakeup support

From: Dan Carpenter
Date: Tue Mar 21 2023 - 04:12:36 EST

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In reply to: Thinh Nguyen: "Re: [PATCH v12 6/6] usb: gadget: f_ecm: Add suspend/resume and remote wakeup support"
Next in thread: Elson Roy Serrao: "[PATCH v12 2/6] usb: dwc3: Add remote wakeup handling"
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Hi Elson,

https://git-scm.com/docs/git-format-patch#_base_tree_information]

url: https://github.com/intel-lab-lkp/linux/commits/Elson-Roy-Serrao/usb-gadget-Properly-configure-the-device-for-remote-wakeup/20230317-074030
base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
patch link: https://lore.kernel.org/r/1679009888-8239-7-git-send-email-quic_eserrao%40quicinc.com
patch subject: [PATCH v12 6/6] usb: gadget: f_ecm: Add suspend/resume and remote wakeup support
config: riscv-randconfig-m031-20230319 (https://download.01.org/0day-ci/archive/20230321/202303211515.XaO8YKCz-lkp@xxxxxxxxx/config)
compiler: riscv32-linux-gcc (GCC) 12.1.0

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Reported-by: Dan Carpenter <error27@xxxxxxxxx>
| Link: https://lore.kernel.org/r/202303211515.XaO8YKCz-lkp@xxxxxxxxx/

New smatch warnings:
drivers/usb/gadget/function/u_ether.c:474 eth_start_xmit() error: we previously assumed 'dev->port_usb' could be null (see line 466)
drivers/usb/gadget/function/u_ether.c:539 eth_start_xmit() warn: variable dereferenced before check 'dev->port_usb' (see line 474)

Old smatch warnings:
drivers/usb/gadget/function/u_ether.c:553 eth_start_xmit() error: we previously assumed 'skb' could be null (see line 491)

vim +474 drivers/usb/gadget/function/u_ether.c

25a79c41ce0ce8 drivers/usb/gadget/u_ether.c Stephen Hemminger 2009-08-31 454 static netdev_tx_t eth_start_xmit(struct sk_buff *skb,
25a79c41ce0ce8 drivers/usb/gadget/u_ether.c Stephen Hemminger 2009-08-31 455 struct net_device *net)
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 456 {
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 457 struct eth_dev *dev = netdev_priv(net);
6d3865f9d41f15 drivers/usb/gadget/u_ether.c Jim Baxter 2014-07-07 458 int length = 0;
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 459 int retval;
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 460 struct usb_request *req = NULL;
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 461 unsigned long flags;
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 462 struct usb_ep *in;
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 463 u16 cdc_filter;
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 464
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 465 spin_lock_irqsave(&dev->lock, flags);
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 @466 if (dev->port_usb) {
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 467 in = dev->port_usb->in_ep;
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 468 cdc_filter = dev->port_usb->cdc_filter;
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 469 } else {
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 470 in = NULL;
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 471 cdc_filter = 0;

NULL on this path.

2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 472 }
11f254fc796c87 drivers/usb/gadget/function/u_ether.c Elson Roy Serrao 2023-03-16 473
11f254fc796c87 drivers/usb/gadget/function/u_ether.c Elson Roy Serrao 2023-03-16 @474 if (dev->port_usb->is_suspend) {
^^^^^^^^^^^^^^^
Dead. (Both ->port_usb warnings are caused by this dereference).

11f254fc796c87 drivers/usb/gadget/function/u_ether.c Elson Roy Serrao 2023-03-16 475 DBG(dev, "Port suspended. Triggering wakeup\n");
11f254fc796c87 drivers/usb/gadget/function/u_ether.c Elson Roy Serrao 2023-03-16 476 netif_stop_queue(net);
11f254fc796c87 drivers/usb/gadget/function/u_ether.c Elson Roy Serrao 2023-03-16 477 spin_unlock_irqrestore(&dev->lock, flags);
11f254fc796c87 drivers/usb/gadget/function/u_ether.c Elson Roy Serrao 2023-03-16 478 ether_wakeup_host(dev->port_usb);
11f254fc796c87 drivers/usb/gadget/function/u_ether.c Elson Roy Serrao 2023-03-16 479 return NETDEV_TX_BUSY;
11f254fc796c87 drivers/usb/gadget/function/u_ether.c Elson Roy Serrao 2023-03-16 480 }
11f254fc796c87 drivers/usb/gadget/function/u_ether.c Elson Roy Serrao 2023-03-16 481
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 482 spin_unlock_irqrestore(&dev->lock, flags);
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 483
8ae01239609b29 drivers/usb/gadget/function/u_ether.c Maciej Żenczykowski 2021-07-01 484 if (!in) {
8ae01239609b29 drivers/usb/gadget/function/u_ether.c Maciej Żenczykowski 2021-07-01 485 if (skb)
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 486 dev_kfree_skb_any(skb);
6ed106549d1747 drivers/usb/gadget/u_ether.c Patrick McHardy 2009-06-23 487 return NETDEV_TX_OK;
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 488 }
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 489
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 490 /* apply outgoing CDC or RNDIS filters */
6d3865f9d41f15 drivers/usb/gadget/u_ether.c Jim Baxter 2014-07-07 491 if (skb && !is_promisc(cdc_filter)) {
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 492 u8 *dest = skb->data;
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 493
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 494 if (is_multicast_ether_addr(dest)) {
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 495 u16 type;
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 496
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 497 /* ignores USB_CDC_PACKET_TYPE_MULTICAST and host
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 498 * SET_ETHERNET_MULTICAST_FILTERS requests
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 499 */
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 500 if (is_broadcast_ether_addr(dest))
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 501 type = USB_CDC_PACKET_TYPE_BROADCAST;
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 502 else
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 503 type = USB_CDC_PACKET_TYPE_ALL_MULTICAST;
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 504 if (!(cdc_filter & type)) {
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 505 dev_kfree_skb_any(skb);
6ed106549d1747 drivers/usb/gadget/u_ether.c Patrick McHardy 2009-06-23 506 return NETDEV_TX_OK;
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 507 }
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 508 }
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 509 /* ignores USB_CDC_PACKET_TYPE_DIRECTED */
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 510 }
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 511
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 512 spin_lock_irqsave(&dev->req_lock, flags);
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 513 /*
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 514 * this freelist can be empty if an interrupt triggered disconnect()
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 515 * and reconfigured the gadget (shutting down this queue) after the
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 516 * network stack decided to xmit but before we got the spinlock.
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 517 */
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 518 if (list_empty(&dev->tx_reqs)) {
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 519 spin_unlock_irqrestore(&dev->req_lock, flags);
5b548140225c6b drivers/usb/gadget/u_ether.c Patrick McHardy 2009-06-12 520 return NETDEV_TX_BUSY;
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 521 }
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 522
fea14e68ff5e11 drivers/usb/gadget/function/u_ether.c Felipe Balbi 2017-03-22 523 req = list_first_entry(&dev->tx_reqs, struct usb_request, list);
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 524 list_del(&req->list);
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 525
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 526 /* temporarily stop TX queue when the freelist empties */
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 527 if (list_empty(&dev->tx_reqs))
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 528 netif_stop_queue(net);
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 529 spin_unlock_irqrestore(&dev->req_lock, flags);
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 530
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 531 /* no buffer copies needed, unless the network stack did it
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 532 * or the hardware can't use skb buffers.
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 533 * or there's not enough space for extra headers we need
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 534 */
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 535 if (dev->wrap) {
9b39e9ddedeef4 drivers/usb/gadget/u_ether.c Brian Niebuhr 2009-08-14 536 unsigned long flags;
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 537
9b39e9ddedeef4 drivers/usb/gadget/u_ether.c Brian Niebuhr 2009-08-14 538 spin_lock_irqsave(&dev->lock, flags);
9b39e9ddedeef4 drivers/usb/gadget/u_ether.c Brian Niebuhr 2009-08-14 @539 if (dev->port_usb)
9b39e9ddedeef4 drivers/usb/gadget/u_ether.c Brian Niebuhr 2009-08-14 540 skb = dev->wrap(dev->port_usb, skb);
3a383cc0b8cc33 drivers/usb/gadget/function/u_ether.c Greg Kroah-Hartman 2016-09-19 541 spin_unlock_irqrestore(&dev->lock, flags);
6d3865f9d41f15 drivers/usb/gadget/u_ether.c Jim Baxter 2014-07-07 542 if (!skb) {
6d3865f9d41f15 drivers/usb/gadget/u_ether.c Jim Baxter 2014-07-07 543 /* Multi frame CDC protocols may store the frame for
6d3865f9d41f15 drivers/usb/gadget/u_ether.c Jim Baxter 2014-07-07 544 * later which is not a dropped frame.
6d3865f9d41f15 drivers/usb/gadget/u_ether.c Jim Baxter 2014-07-07 545 */
88c09eacf560c3 drivers/usb/gadget/function/u_ether.c Peter Chen 2016-07-01 546 if (dev->port_usb &&
3a383cc0b8cc33 drivers/usb/gadget/function/u_ether.c Greg Kroah-Hartman 2016-09-19 547 dev->port_usb->supports_multi_frame)
6d3865f9d41f15 drivers/usb/gadget/u_ether.c Jim Baxter 2014-07-07 548 goto multiframe;
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 549 goto drop;
6d3865f9d41f15 drivers/usb/gadget/u_ether.c Jim Baxter 2014-07-07 550 }
6d3865f9d41f15 drivers/usb/gadget/u_ether.c Jim Baxter 2014-07-07 551 }
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 552
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 553 length = skb->len;
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 554 req->buf = skb->data;
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 555 req->context = skb;
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 556 req->complete = tx_complete;
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 557
5c1168dbc50828 drivers/usb/gadget/u_ether.c Yauheni Kaliuta 2010-12-08 558 /* NCM requires no zlp if transfer is dwNtbInMaxSize */
79775f44183840 drivers/usb/gadget/function/u_ether.c Harish Jenny K N 2016-09-09 559 if (dev->port_usb &&
79775f44183840 drivers/usb/gadget/function/u_ether.c Harish Jenny K N 2016-09-09 560 dev->port_usb->is_fixed &&
5c1168dbc50828 drivers/usb/gadget/u_ether.c Yauheni Kaliuta 2010-12-08 561 length == dev->port_usb->fixed_in_len &&
5c1168dbc50828 drivers/usb/gadget/u_ether.c Yauheni Kaliuta 2010-12-08 562 (length % in->maxpacket) == 0)
5c1168dbc50828 drivers/usb/gadget/u_ether.c Yauheni Kaliuta 2010-12-08 563 req->zero = 0;
5c1168dbc50828 drivers/usb/gadget/u_ether.c Yauheni Kaliuta 2010-12-08 564 else
5c1168dbc50828 drivers/usb/gadget/u_ether.c Yauheni Kaliuta 2010-12-08 565 req->zero = 1;
5c1168dbc50828 drivers/usb/gadget/u_ether.c Yauheni Kaliuta 2010-12-08 566
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 567 /* use zlp framing on tx for strict CDC-Ether conformance,
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 568 * though any robust network rx path ignores extra padding.
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 569 * and some hardware doesn't like to write zlps.
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 570 */
5c1168dbc50828 drivers/usb/gadget/u_ether.c Yauheni Kaliuta 2010-12-08 571 if (req->zero && !dev->zlp && (length % in->maxpacket) == 0)
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 572 length++;
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 573
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 574 req->length = length;
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 575
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 576 retval = usb_ep_queue(in, req, GFP_ATOMIC);
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 577 switch (retval) {
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 578 default:
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 579 DBG(dev, "tx queue err %d\n", retval);
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 580 break;
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 581 case 0:
860e9538a9482b drivers/usb/gadget/function/u_ether.c Florian Westphal 2016-05-03 582 netif_trans_update(net);
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 583 atomic_inc(&dev->tx_qlen);
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 584 }
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 585
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 586 if (retval) {
9b39e9ddedeef4 drivers/usb/gadget/u_ether.c Brian Niebuhr 2009-08-14 587 dev_kfree_skb_any(skb);
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 588 drop:
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 589 dev->net->stats.tx_dropped++;
6d3865f9d41f15 drivers/usb/gadget/u_ether.c Jim Baxter 2014-07-07 590 multiframe:
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 591 spin_lock_irqsave(&dev->req_lock, flags);
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 592 if (list_empty(&dev->tx_reqs))
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 593 netif_start_queue(net);
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 594 list_add(&req->list, &dev->tx_reqs);
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 595 spin_unlock_irqrestore(&dev->req_lock, flags);
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 596 }
6ed106549d1747 drivers/usb/gadget/u_ether.c Patrick McHardy 2009-06-23 597 return NETDEV_TX_OK;
2b3d942c487808 drivers/usb/gadget/u_ether.c David Brownell 2008-06-19 598 }

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests

Next message: Faicker Mo: "Re:Re: [PATCH] net/net_failover: fix queue exceeding warning"
Previous message: John Paul Adrian Glaubitz: "Re: [PATCH 6/7 v5] sh: fix Kconfig entry for NUMA => SMP"
In reply to: Thinh Nguyen: "Re: [PATCH v12 6/6] usb: gadget: f_ecm: Add suspend/resume and remote wakeup support"
Next in thread: Elson Roy Serrao: "[PATCH v12 2/6] usb: dwc3: Add remote wakeup handling"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]