From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2696ECA9EC3 for ; Tue, 29 Oct 2019 11:08:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DED8920874 for ; Tue, 29 Oct 2019 11:08:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572347314; bh=2XPeSQrgKYbg9jIXdV8wF43Dck1ti9xTT7Hwb1CUYHw=; h=Subject:To:Cc:References:From:Date:In-Reply-To:List-ID:From; b=QNO+eNZKvL+k4XZo+ZK6CwMVbMTp/a+McSDxaueTc+WRqX/aVGRkXeq7UNo0uaixd BME5v5Ru2leX3i+Q9cdXYTaHN7PjZ0FOs6UA4xUf+WvKr+b6lS+HflbMg7ajMZb/2f yXRHL2Lmf+5pzTnjK6UoJJuK6a51o2QXnXJQbM+4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732060AbfJ2LIa (ORCPT ); Tue, 29 Oct 2019 07:08:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:51856 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728370AbfJ2LIa (ORCPT ); Tue, 29 Oct 2019 07:08:30 -0400 Received: from [172.20.52.151] (unknown [91.217.168.176]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 755A920874; Tue, 29 Oct 2019 11:08:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572347308; bh=2XPeSQrgKYbg9jIXdV8wF43Dck1ti9xTT7Hwb1CUYHw=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=SEHzfGucReCNYw1N7/y/rIK11ODdZCHSjaCIIifUi6FoKsvTUQ0lwsUnONPMm44Zf 87wvPY9NDg6yqYaJso16BfkFUQRGH7kVbrOuyhYX5kx7xe0B/qzDSa1YQLHuBWRFWc A19rp5vo9Zq1O4VcPjeaptOdj0pB0J6M8YAAKmVE= Subject: Re: drivers/usb/usbip/stub_rx.c:505 stub_recv_cmd_submit() error: uninitialized symbol 'nents'. To: Suwan Kim Cc: Dan Carpenter , kbuild@lists.01.org, kbuild-all@lists.01.org, linux-kernel@vger.kernel.org, Greg Kroah-Hartman , linux-usb@vger.kernel.org, shuah References: <20191022092839.GD10833@kadam> <20191023071120.GA3061@localhost.localdomain> <20191024194500.GD23523@kadam> <20191026034010.GA6411@localhost.localdomain> From: shuah Message-ID: Date: Tue, 29 Oct 2019 05:07:58 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20191026034010.GA6411@localhost.localdomain> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org 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 >>>>> Reported-by: Dan Carpenter >>>>> >>>>> 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