On Tue, Oct 22, 2019 at 12:28:39PM +0300, Dan Carpenter wrote: > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master > head: 7d194c2100ad2a6dded545887d02754948ca5241 > commit: ea44d190764b4422af4d1c29eaeb9e69e353b406 usbip: Implement SG support to vhci-hcd and stub driver > date: 7 weeks ago > > If you fix the issue, kindly add following tag > Reported-by: kbuild test robot <lkp@xxxxxxxxx> > Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> > > New smatch warnings: > drivers/usb/usbip/stub_rx.c:505 stub_recv_cmd_submit() error: uninitialized symbol 'nents'. > > Old smatch warnings: > drivers/usb/usbip/stub_rx.c:450 stub_recv_xbuff() error: uninitialized symbol 'ret'. > > # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ea44d190764b4422af4d1c29eaeb9e69e353b406 > git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git > git remote update linus > git checkout ea44d190764b4422af4d1c29eaeb9e69e353b406 > vim +/nents +505 drivers/usb/usbip/stub_rx.c > > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09 453 static void stub_recv_cmd_submit(struct stub_device *sdev, > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09 454 struct usbip_header *pdu) > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09 455 { > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09 456 struct stub_priv *priv; > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09 457 struct usbip_device *ud = &sdev->ud; > 2d8f4595d1f275 drivers/staging/usbip/stub_rx.c Max Vozeler 2011-01-12 458 struct usb_device *udev = sdev->udev; > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 459 struct scatterlist *sgl = NULL, *sg; > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 460 void *buffer = NULL; > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 461 unsigned long long buf_len; > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 462 int nents; > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 463 int num_urbs = 1; > c6688ef9f29762 drivers/usb/usbip/stub_rx.c Shuah Khan 2017-12-07 464 int pipe = get_pipe(sdev, pdu); > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 465 int use_sg = pdu->u.cmd_submit.transfer_flags & URB_DMA_MAP_SG; > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 466 int support_sg = 1; > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 467 int np = 0; > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 468 int ret, i; > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09 469 > 635f545a7e8be7 drivers/usb/usbip/stub_rx.c Shuah Khan 2017-12-07 470 if (pipe == -1) > 635f545a7e8be7 drivers/usb/usbip/stub_rx.c Shuah Khan 2017-12-07 471 return; > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09 472 > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09 473 priv = stub_priv_alloc(sdev, pdu); > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09 474 if (!priv) > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09 475 return; > 4d7b5c7f8ad49b drivers/staging/usbip/stub_rx.c Takahiro Hirofuchi 2008-07-09 476 > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 477 buf_len = (unsigned long long)pdu->u.cmd_submit.transfer_buffer_length; > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 478 > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 479 /* allocate urb transfer buffer, if needed */ > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 480 if (buf_len) { > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 481 if (use_sg) { > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 482 sgl = sgl_alloc(buf_len, GFP_KERNEL, &nents); > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 483 if (!sgl) > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 484 goto err_malloc; > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 485 } else { > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 486 buffer = kzalloc(buf_len, GFP_KERNEL); > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 487 if (!buffer) > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 488 goto err_malloc; > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 489 } > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 490 } > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 491 > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 492 /* Check if the server's HCD supports SG */ > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 493 if (use_sg && !udev->bus->sg_tablesize) { > > Smatch thinks "use_sg" can be true when "buf_len" is zero. It's hard > to tell if Smatch is right or wrong without more context... This is a bit strange. The meaning of "use_sg" is that client will use scatter-gather and client's urb->num_sgs is not zero. And buffer length should not be zero. usb_sg and buf_len are both client-dependent variables, so I think if they have wrong value in the server side, the client must have sent use_sg and buf_len with incorrect values. Did this error occur when compiling? If then, Did Smatch also consider vhci tx side? Regards Suwan Kim > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 494 /* > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 495 * If the server's HCD doesn't support SG, break a single SG > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 496 * request into several URBs and map each SG list entry to > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 497 * corresponding URB buffer. The previously allocated SG > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 498 * list is stored in priv->sgl (If the server's HCD support SG, > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 499 * SG list is stored only in urb->sg) and it is used as an > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 500 * indicator that the server split single SG request into > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 501 * several URBs. Later, priv->sgl is used by stub_complete() and > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 502 * stub_send_ret_submit() to reassemble the divied URBs. > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 503 */ > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 504 support_sg = 0; > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 @505 num_urbs = nents; > ^^^^^^^^^^^^^^^^ > > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 506 priv->completed_urbs = 0; > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 507 pdu->u.cmd_submit.transfer_flags &= ~URB_DMA_MAP_SG; > ea44d190764b44 drivers/usb/usbip/stub_rx.c Suwan Kim 2019-08-28 508 } > > --- > 0-DAY kernel test infrastructure Open Source Technology Center > https://lists.01.org/pipermail/kbuild-all Intel Corporation
