Messages in this thread | | | Subject | Re: drivers/usb/usbip/stub_rx.c:505 stub_recv_cmd_submit() error: uninitialized symbol 'nents'. | From | shuah <> | Date | Tue, 29 Oct 2019 05:07:58 -0600 |
| |
On 10/25/19 9:40 PM, Suwan Kim wrote: > On Thu, Oct 24, 2019 at 04:52:52PM -0600, shuah wrote: >> On 10/24/19 1:45 PM, Dan Carpenter wrote: >>> On Wed, Oct 23, 2019 at 04:11:20PM +0900, Suwan Kim wrote: >>>> 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@intel.com> >>>>> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> >>>>> >>>>> 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? >>> >>> Smatch is doing static analysis, yes. >>> >>>> If then, Did Smatch also consider vhci tx side? >>> >>> I'm not really sure... I can't reproduce the warning because on my >>> system Smatch doesn't parse usbip_recv() correctly so it ends up >>> silencing that warning. :/ >>> >> >> Hi Suwan, >> >> This is a problem that needs fixing. nents >> >> /* allocate urb transfer buffer, if needed */ >> if (buf_len) { >> if (use_sg) { >> sgl = sgl_alloc(buf_len, GFP_KERNEL, &nents); >> >> nents gets initialized here by sgl_alloc() >> >> if (!sgl) >> goto err_malloc; >> } else { >> buffer = kzalloc(buf_len, GFP_KERNEL); >> if (!buffer) >> goto err_malloc; >> } >> } >> >> /* Check if the server's HCD supports SG */ >> if (use_sg && !udev->bus->sg_tablesize) { >> /* >> * If the server's HCD doesn't support SG, break a single SG >> * request into several URBs and map each SG list entry to >> * corresponding URB buffer. The previously allocated SG >> * list is stored in priv->sgl (If the server's HCD support >> SG, >> * SG list is stored only in urb->sg) and it is used as an >> * indicator that the server split single SG request into >> * several URBs. Later, priv->sgl is used by stub_complete() >> and >> * stub_send_ret_submit() to reassemble the divied URBs. >> */ >> support_sg = 0; >> num_urbs = nents; >> >> I think nents will be valid here. Is there need for this additional >> check here? You can fold this into the previous use_sg check, right >> after the sg_alloc() success, I would think. > > Or Is it your intention to check as follows? > I think this looks good. > > ... > int nents = 0 > > ... > > /* allocate urb transfer buffer, if needed */ > if (buf_len) { > if (use_sg) { > sgl = sgl_alloc(buf_len, GFP_KERNEL, &nents); > if (!sgl) > goto err_malloc;
Why can't we move the > /* Check if the server's HCD supports SG */ > if (use_sg && !udev->bus->sg_tablesize) { >
under this check?
> } else { > buffer = kzalloc(buf_len, GFP_KERNEL); > if (!buffer) > goto err_malloc; > } > } > > /* Additional check here */ > if (use_sg && !nents) { > err_message; > goto err_urbs; > } > > /* Check if the server's HCD supports SG */ > if (use_sg && !udev->bus->sg_tablesize) { >
thanks, -- Shuah
| |